· transient nature; hence provision of auto-reclosure certainly helps not only in preventing...

Agenda for the 76th

Meeting of PCSC scheduled to be held on 26th

July, 2018 Page 1

SOUTHERN REGIONAL POWER COMMITTEE BENGALURU

Agenda for the 76th Meeting of Protection Coordination Sub-Committee of SRPC to be held on 26th July, 2018

1. Introduction

2. Confirmation of Minutes of last PCSC meeting

Confirmation of minutes of 75th Protection Coordination Sub-Committee meeting held on 28.06.2018.

3. Grid Occurrences

3.1 Grid Disturbances (GD), Grid Incidences (GI), and trippings due to failure of Auto-

reclosing (A/R), and mal-operation of PLCC equipment that occurred during the period June, 2018 given at Annexure-I would be discussed in the PCSC meeting.

Constituents are requested to furnish the following information in respect of the above grid occurrences to have fruitful discussions.

(a) Single line diagram of the station with switching devices, CT, PT and relay details. (b) Cause of the tripping & Remedial Action taken (c) Relay setting details

Constituents are requested to bring/ furnish full particulars of the tripping events pertaining to their system.

3.2 In compliance of Regulations 5.2 (r) of IEGC, the Constituents are required to furnish

the following information in respect of Grid Occurrences within 24 hrs of occurrence of the same to SRLDC/ SRPC: (a) First Information Report (FIR) (b) Event Logger (EL) output (c) Disturbance Recorder (DR) output (d) Trip event analysis report (with pre and post fault system conditions) Non-furnishing of tripping details (FIR/DR/EL/TR) for the period 01.06.2018 – 30.06.2018 had been brought to Constituents’ notice vide letters (i) No. SRPC/ SE-III/ PCSC/ 2018/ 3937 - 46 dated 20.06.2018, (ii) No. SRPC/ SE-III/ PCSC/ 2018/ 4536- 54 dated 13.07.2018. Non-compliance in this regard would be discussed in the meeting.

4. Submission of Reports/ Compliance by Constituents

4.1 Status of implementation of pending Protection Coordination

Sub-Committee (PCSC) Recommendations

The status of implementation of pending PCSC recommendations (up to 74th PCSC meeting) is given at Annexure-II. The latest status on the same may please be sent latest by 20.07.2018.

Agenda for the 76th


July, 2018 Page 2

4.2 Remedial measures for "Transmission Elements under Forced Outage"

The Constituents are requested to furnish the remedial measures/ action taken by them for the tripping events as circulated vide our emails. (Annexure-III)

The tripping events are based on the daily reports at SRLDC website http://srldc.in/Reports.aspx under the menu: Reports->Daily-> "TL under Forced Outage")

4.3 Certificate for Healthiness of Batteries

As per the MoP direction given in pursuant to recommendations of the Enquiry Committee (NEW grid disturbance on 30th & 31st July, 2012), RPC’s are required to obtain from their respective Constituents the monthly certificate for healthiness of batteries, installed at 220 KV and above voltage level Substations (for power supply to Relays, RTUs and PLCC equipment) and furnish the same to CEA/ MoP.

With reference to above, the Constituents have been requested to submit the certificate on healthiness of batteries on monthly basis (i.e. status for a month shall be sent by the 7th day of the following month) to SRPC Secretariat.

The sought status for the months of June, 2018 is awaited from the following SR-Constituents:

KPTCL, TANGEDCO, TANTRANSCO, Puducherry ED, PGCIL (SR-I) & NTPC (Ramagundam)

5. Review of Compliance of Recommendations given in the Special Meeting on HVDC

Gajuwaka Pole Trippings held on 02.04.2018

A Special Meeting was held on 02nd April, 2018 at RHQ POWERGRID (SRTS-I), Hyderabad to deliberate on all outstanding issues involved in the recent HVDC Gajuwaka Pole trippings. The minutes of the meeting were issued vide SRPC letter no: SRPC/ SE-III/ SPM/ 2018/ 2015-19 dated 11.04.2018. Since it is proposed to review the status of implementation of the recommendations given in the meeting (present status enclosed at Annexure-IV), PGCIL (SR-I) is requested to furnish the updated status latest by 20.07.2018 for discussion during the meeting.

6. Auto-Reclosure Implementation (with Carrier Communication) on all 220 kV &

above Transmission Lines of Southern Region

It is common knowledge that majority of the faults that occur on transmission lines are of transient nature; hence provision of Auto-Reclosure certainly helps not only in preventing forced outage of the subject transmission line, but also in averting cascade trippings, in some cases, of adjacent transmission lines due to consequent over-loading. Further, the provision for Auto-Reclosure is also mandated by Regulation 43 (4) (c) of CEA Technical Standards for Construction of Electrical Plants and Electric Lines, 2010, which has force of law. Therefore, it is in the interest of grid security that all Constituents implement auto-reclosure feature on all 220 kV & above transmission lines in their respective control areas. Any exceptions to this needed to be properly justified. In this connection, the status furnished by SR-Constituents w.r.t. implementation status of A/R on their 220 kV & above transmission lines in SR-grid and the action plan furnished for

http://srldc.in/Reports.aspx

Agenda for the 76th


July, 2018 Page 3

implementing A/R where it is presently not in service is enclosed at Annexure-V for kind reference. The latest status of A/R implementation by SR-Constituents on their 220 kV & above transmission lines in SR-grid and the action plan proposed for implementing A/R where it is presently not in service (present status) is proposed to be reviewed in the meeting. Since it is proposed to review A/R implementation in SR in the meeting, all concerned Constituents [APGENCO (Hydro), APGENCO (Thermal), APTRANSCO, TSGENCO (Thermal), TSGENCO (Hydro), TSTRANSCO, KPCL, KPTCL, KSEBL, TANGEDCO, TANTRANSCO, NPCIL (KKNPP), NPCIL (MAPS), NLCIL, UPCL & JSWEL] are requested to furnish (i) latest status of A/R implementation on their lines, and (ii) revised timelines, if any, latest by 20.07.2018 for discussion during the meeting. It may also be noted that the same status would be put up for discussion during the forthcoming TCC – 33 & SRPC-34 meetings.

7. Review of Compliance Status of New Protection Audit Recommendations

As part of GSC (Task-II) under Package-A, protection audit check of 15 stations was carried out byM/s Tractebel Engineering (TE) in the southern region during the period, December, 2015– July, 2016, when certain recommendations were also given for each of these stations for compliance. Subsequently, protection audit of various stations in SR has also been regularly conducted by SRPC teams in line with CERC Order dated 27.04.2015 in respect of APTRANSCO Petition No.95/MP/2015 dated 09.04.2015. So far, protection audit of 11 stations was carried out during the period December, 2016 – July, 2018, when certain recommendations were also given for each of these stations for compliance. The list of Stations audited & compliance % of the recommendations given is given below for kind reference:

Sl. No. Name of the Station Period of Protection Audit Compliance %

APTRANSCO 30.65

1 400/ 220 kV Narnoor SS 16–18 February, 2016 61.29

2 400/ 220 kV Uravakonda SS 5-6 April, 2018 0.00

TSGENCO (Thermal) 58.50

1 (i) 220 kV KTPS (O&M) 14-16 March, 2016 50.00

1 (ii) 220 kV KTPS (Stage-V) 14-16 March, 2016 40.90

1 (iii) 220 kV KTPS (Stage-VI) 14-16 March, 2016 84.67

TSTRANSCO 72.72

1 400/ 220 kV Shankarapally SS 20-21 March, 2017 72.72

KPCL 30.34

1 400 kV & 220 kV Raichur TPS 8-10 June, 2016 36.58

2 220 kV Nagjheri PH 14-16 July, 2016 41.93

3 220kV Sharavathy GS 30-31 October, 2017 12.50

KPTCL 51.13

1 400/ 220 kV Guttur SS 4-6 May, 2016 65.12

2 400/ 220 kV Nelamangala SS 8–10 February, 2016 37.14

KSEBL 27.91

1 220 kV Edamon SS 18-20 January, 2016 27.91

TANTRANSCO 17.07

Agenda for the 76th


July, 2018 Page 4

1 400/ 230 kV Alamathy SS 4-6 January, 2016 38.71

2 230 kV Alundur SS 17 December, 2016 12.50

3 400/ 230 – 110 kV Palavadi SS 14-15 May, 2018 0.00

Puducherry ED 10.10

1 230/ 110 kV Villianur SS 10 July, 2017 9.67

2 230/ 110 kV Bahour SS 11 July, 2017 10.52

PGCIL (SR-I) 40.00

1 400 kV & HVDC Gazuwaka SS 28-30 December, 2015 50.00

2 400/ 220 kV Gooty SS 12th,13th and 15th February, 2016 50.00

3 765/ 400 kV Nellore PS 19-20 June, 2017 60.00

4 765/ 400 kV Maheshwaram SS 8-9 February, 2018 0.00

PGCIL (SR-II) 43.75

1 400 kVHosur SS of PGCIL (SR-II) 9-11 December, 2015 25.00

2 400 kV Tirunelveli SS 8th, ,9th and 11th January, 2016 50.00

3 400 kV Alundur SS 16 December, 2016 100.00

4 400/ 220 kV Kozhikode SS 21-22 December, 2017 0.00

NTPC 85.00

1 400 kV Ramagundam STPS 18-20 February, 2016 85.00

NPCIL 33.33

1 220 kV Kaiga GS 4-6 April, 2016 33.33

NLCIL 50.00

1 400 kV NLC TPS-II Station 8–10 February, 2016 50.00

The status of compliance of recommendations given for the above stations is circulated vide SRPC mail dated 12.06.2018 (Copy enclosed at Annexure-V). Since it is proposed to review compliance of these new protection audit recommendations in the meeting, all concerned Constituents [APTRANSCO, TSGENCO, TSTRANSCO, KPCL, KPTCL, KSEBL, TANTRANSCO, Puducherry ED, NTPC (RSTPS), NPCIL (KGS), NLCIL, PGCIL (SR-I) & PGCIL (SR-II)] are requested to furnish latest status in this regard to us latest by 20.07.2018 for discussion during the meeting. It may also be noted that the same status would be put up for discussion during the forthcoming TCC – 33 & SRPC-34 meetings.

8. Other Protection Issues, if any, with the permission of the Chair

9. Sending Agenda items for the PCSC meetings

As per the Guidelines of CEA/MOP, it has been decided to conduct the PCSC meetings on monthly basis. It is requested that Agenda Items for the PCSC meetings, if any, may please be sent latest by 5th working day of the month to SRPC Secretariat to compile and circulate the same so as to have fruitful discussions in the PCSC meetings.

10. Date of next PCSC meeting

It is informed that the 77th meeting of PCSC will be held on 21st August, 2018 (Tuesday) from 10:30 hrs onwards in the Conference Hall of SRPC Secretariat, Bengaluru.

*****

Grid Occurrences to be discussed in the 76th Meeting of PCSC scheduled to be held on 26th July, 2018 1/4

Grid Occurrences - 76

For all tripping events involving failure of substation equipment, Constituents are requested to kindly furnish the SLD or equivalent pictorial representation showing (i) Location of the fault, and (ii) Bus-bar arrangement/ Configuration of feeders and other connected equipment with proper CB positions (OPEN/ CLOSE) at the time of occurrence of the fault.

I. Details of Grid Disturbances:

Sl. No.

Details of Event Date &Time Reason Remarks Category

1 Complete outage of 230kV Villianur station

15-06-2018 at 7:29 hrs

Triggering incident was failure of B-phase 230KV Current Transformer of HV-I Breaker of 230/110KV 100MVA Auto Transformer-I. Fault was cleared by tripping of source feeders i.e. 230KV Neyveli-Villianur Line breaker at NLC TS-II and 230KV Pondy-Villianur Line Breaker at 400KV Pondy S/S. Fault cleared in 350 ms as observed from PMU data plot.

Load loss - 102 MW

GD-1

2 Complete outage of 220kV Sedam Station

19-06-2018 at 1:41 hrs

Triggering incident was B-phase to ground fault in 220kV Sedam – RTPS line-1. Bus bar protection operated and all connected lines tripped resulting in complete outage of Sedam station.

Load loss - 25 MW

GD-1

II. Details of Grid Incidents:

Sl. No. Details of Event Date &Time Reason Category

1 Tripping of 400/ 220 kV ICT-1 at BTPS

01-06-18 at 00:01 hrs

As per FIR ICT-1 got tripped on operation of backup over-current protection (high set) during R-N fault in 220kV BTPS-LINGAPUR line

GI-2

27-06-18 at 4:17 hrs

ICT-1 at BTPS got tripped during fault in 220KV BTPS-ALLIPUR LINE. Back up O/C & E/F relay at 220KV side of ICT got operated

GI-2

2 Tripping of 400 kV Trichy – Karaikudy line

02-06-18 at 1:33 hrs, Line tripped on operation of over-voltage

stg-1 protection at Karaikudi and direct trip received at Trichy. At Karaikudi, R-phase voltage was higher when compared with Y & B phases

GI-2 04-06-18 at 21:38 hrs,

05-06-18 at 21:01 hrs,

06-06-18 at

Annexure-I


22:50 hrs,

14-06-18 at 4:33 hrs,

19-06-18 at 20:59 hrs

3 Tripping of 400 kV Ghani – Narnoor line- 2

02-Jun-2018 at 05:35 hrs

Line tripped tripped on mal-operation of TIE LBB at Narnoor end and DT receive was received at Ghani.

GI-2

4 Tripping of 400 kV Guttur – Hiriyur line-2

04-06-2018 at 01:31 hrs

Line tripped on operation of over-voltage stg-1 protection at Hiryur and direct trip was received at Guttur end. B-phase voltage is comparatively higher when compared to R & Y phase at Hiryur

GI-2 05-06-2018 at 02:02 hrs

06-06-2018 at 2:00 hrs

5 Tripping of 400 kV Kurnool – Srisailam line

04-06-2018 at 17:03 hrs

Line tripped on operation of over-voltage stg-1 protection at Srisailam and direct trip was received at Kurnool. Voltages difference observed between R, Y & B phase at recorded in Srisailam end

GI-2

21-06-2018 at 23:56 hrs

6 Tripping of 400 kV Gooty-Kurnool (AP)

07-06-18 at 1:37 hrs

Line tripped on operation of over-voltage stg-1 protection at Kurnool(AP) and direct trip was received at Gooty. The Y phase Voltage was higher when compared to R & B phase at Kurnool(AP)

GI-2 14-06-18 at 1:39 hrs

15-06-18 at 00:28 hrs

15-06-18 at 23:46 hrs

28-06-18 at 01:59 hrs

7 Tripping of 400 kV Salem - Udumalpet line-1

08-06-2018 at 08:48 hrs

Line tripped on operation of instantaneous over-voltage during fault in adjacent K.R Thoppur S/S (ICT Rph bushing failure). Line was in service from Udumalpet end.

GI-2

8 Tripping of 765kV Kurnool – Nellore PS line-1

10-06-2018 at 15:53hrs

765kV KURNOOL - NPS line-1 tripped at NPS end only during LA failure in 765kV Kurnool-Thiruvelam line-2.

GI-2

9 Tripping of 230 kV Thiruvelam-Chitoor line

13-06-2018 at 18:55hrs

Y-phase to earth fault occurred in line. At 230KV Tiruvelam end, breaker was under lockout leading to operation of LBB

GI-1

10 400/220 kV ICT-2 at Raichur

17-06-2018 at 03:54 hrs

ICT-2 got tripped on operation of 220KV side over-flux protection.

GI-1

Annexure-I


11 Complete outage of 220kV Hoody SS

17-06-2018 at 3:53 hrs

Triggering incident was R-phase HV side CT flashover of 220/110kV, 100MVA transformer-3 and snapping of R phase jumper of CT connected to 220/110kV transformer-4 at Hoody. 400/220kV, 500MVA ICT-1 and 3 also tripped on operation of earth fault protection.

GI-1

12 Tripping of HVDC Talcher-Kolar pole- 1 and 2

18-Jun-2018 at 17:42 hrs

Trip command was generated from the DC station control system at Talcher end due to tripping of AC filters. ESOF was received at Kolar

13 Tripping of 400kV Veltoor - Uravakonda-1

20-06-2018 at 08:07 hrs

Line tripped on operation of over-voltage protection at Uruvakonda and direct trip was received at Veltoor. DR of Uruvakonda substaiton was not furnished to validate the operation of over-voltage protection

GI-2

14 Tripping of 400 kV Kurnool – Srisailam line

20-06-2018 at 18:52 hrs

Line tripped at Srisailam end and was holding from Kurool. At 20:02 hrs, direct trip was received at Kurnool end.

GI-2

15

400 kV Tiruvelam-Kalivandapattu line-2

21-06-2018 at 04:29 hrs

Line tripped on operation of over-voltage stg-1 protection at Thiruvelam end and DT was received at kalivandapattu. At Thiruvelam end, Y-phase voltage was high when compared to R and B phase.

GI-2

16

Tripping of 400kV Madurai-Tirunelveli-2 & 400kV Kudankulam-Tirunelveli-1

21-06-2018 at 17:37 hrs

400kV Kudankulam-Tirunelveli line-1 got tripped from Tirunelveli end only and line was holding from Kudankulam during R-phase Main bay CT failure occurred in 400kV Madurai-Tirunelveli line-2

GI-2

17

Tripping of 400/110kV PALAVADI-ICT-3 and 400 kV THIRUVALEM - PALAVADI-1

25-Jun-2018 at 17:14 hrs

Triggering incident was failure of B-phase CT of 400/110kV PALAVADI-ICT-3. Bus1 BBP operated. 400 kV THIRUVALEM - PALAVADI-1 tripped at Palavadi end only on actuation of over flux relay.

GI-2

18 Tripping of HVDC Bhadrawati Pole-1&2

25-Jun-2018 at 19:33 hrs

HVDC Pole-1&2 went into standby mode due to tripping of AC filters which in-turn tripped on operation of resistor thermal overload & IDMT earth Fault protection.

19 Tripping of 400kV 400kV JSW-BPS-2 & 400kV YTPS-BPS line-1

27-Jun-2018 at 17:24 hrs

400kV JSW TORANAGALLU BPS-2 tripped at BPS end on direct trip receive. 400kV YTPS-BPS line-1 tripped at YTPS end only. This happened during R- phase to earth fault occurred in 400kV YTPS-BPS-2 line

GI-2

Annexure-I


III. Details of Trippings due to Failure or Non-operation of Auto-Reclose:

Sl. No. Element Date & Time Reason

1 Tripping of 400 kV Khammam – Mamidapally line-1

01-Jun-2018 at 17:57 hrs

Y-phase to earth fault occurred in line. Auto-reclose was successful at Mamidapalli end. At Khammam end Main & Tie breaker got tripped due to operation of DEF.

2

Tripping of 400KV-SURYAPET-K.V.KOTA-1

01-Jun-2018 at 19:17 hrs

R-phase to earth fault occurred in line. Auto-reclose was successful at Suryapet and breakers got tripped at K.V.Kota

3 Tripping of 400kV Yelahanka Neelamangala

02-06-2018 at 19:53 hrs

R-phase to earth fault occurred in line. Auto-reclose was successful at Yelahanka end and breakers got tripped at Nelamnagala.

4 Tripping of 400kV YTPS-BPS line-1

03-Jun-2018 16:03

B-phase to earth fault occurred in 400kV YTPS-BPS line-1. Line did not auto-reclose from both ends.

5 Tripping of 400 kV Warangal – Boopalapalli line-1

21-Jun-2018 21:51:00

R-phase to earth fault occurred in line. Auto-reclose was successful at Kakatiya TPS end. At Warangal end there was Zone-2 trip due to non-receipt of Carrier signal.

IV. Details of Trippings due to PLCC mal-operation:

Sl. No. Element Date & Time Reason

1 Tripping of 400kV JSW-BPS line-1

03-Jun-2018 16:03hrs

B-phase to earth fault occurred in 400kV YTPS-BPS line-1. 400kV JSW-BPS line-1 got tripped due to spurious DT send from JSW end.

2 Tripping of 400 kV Warangal – Boopalapalli line- 2

14-Jun-2018 11:31hrs

Line tripped at Warangal end on DT receive and line was holding from KTPP end.

*****

Annexure-I

Meeting

No /

Index

Details of Event Date & Time Reason PCSC Recommendations Utility

responsible for

Implementation

Status of Implementation of PCSC Recommendations Remarks

34/I/6 400/220 kV ICT-1 & 2 at

Munirabad

As reported directional over current relay of ICT’s

operated due to snapping of line jumper in 220kV

Lingapur line.

1. Bus bar protection shall be provided by asset owner ( i.e

KPTCL).

2. Settings for main distance protection & Overcurrent

protection shall be examined and reviewed.

3. Time synchronization of the Substation shall be ensured.

KPTCL/

PGCIL (SR-I)

Pending

(with KPTCL)

Status of Pending Implementation of PCSC Recommendations as on 13.07.2018 (up to 74th Meeting)

KPTCL Mail dated 27-05-2015:

1. KPTCL has taken action to provide bus bar protection to 220kV buses. --- Pending

2. Over current relay Settings of ICTs to be reviewed by PGCIL.

--- Pending

3. --- Pending

KPTCL Mail dated 29-07-2015:

1. Initial Tendering stage. --- Pending

2. --- Pending

3. --- Pending

KPTCL Mail dated on 23-01-2016:

1. Detailed estimate prepared for taking up the work. CEE, Transmission Zone, Gulbarga will take

up necessary procurement and further execution. --- Pending

2. --- Pending with PGCIL (SR-I).

3. --- Pending

PGCIL (SR-I) Mail dated 14.07.2016:

2. Relay settings of all the stations in SRTS-1 were derived as per Ramakrishna Commettee

recomendations and implemented" --- Completed.

KPTCL Mail dated 16.12.2017:

1) & 3). DPR is approved. Tender is to be called by CEE,TZ Kalaburgi --- Pending

Review Meeting dated 19.12.2017:

1. KPTCL informed that Tenders for providing BBP would be called in Jan-Feb, 2018; Supply of the

same is targeted by September, 2018; Erection & Commissioning is targeted by January, 2019

--- Pending

3. PGCIL (SR-I) informed that time-synchronization of 220 kV side is in place. --- Completed.

16-07-2014

Multi-Utilities

Annexure-II

Page 1 of 47

PGCIL (SR-I) mail dated 20.06.2018:

PGCI(SR1) procuring LDP relays for retrofitting of Main-1&2 distance relays. Tenders are invited

from bidders & tender floated. Technical bid opening in this week.

Pending

[with

PGCIL (SR-I)]

APGENCO/

PGCIL (SR-I)

1. APGENCO to furnish to PCSC forum (i) A3-size Single Line

Diagram of SDSTPS, and (ii) the sequence of events with time

stamp showing the protection that opened Tie-CB (405) at

SDSTPS.

2. APGENCO to review STUB/TEED protection in all dias at

SDSTPS and ensure that they are configured for instantaneous

operation.

3. APGENCO to properly configure the STATE of the tripping

events so that they get recorded appropriately like TRIP/

OPERATED in their corresponding Event Loggers.

4. APGENCO to ensure time sync of all DR’s and EL’s at

SDSTPS.

5. PGCIL (SR-I) to provide line differential protection for 400

kV NPS –Nellore-PG lines 1 & 2.

As per FIR submitted, CT damage observed in Chitoor-

Main bay (404). Main breakers connected to bus-1 (401,

404, 407, 410) got tripped on operation of bus bar

protection. Unit-1 tripped on operation of MFT. Unit-2

was not in service

Complete outage of

Krishnapatnam TPS

08-09-2015

at 18:20 hrs

47/I/2 APGENCO letter dated 18.03.2016:

1.SOE and SLD are attached. The DR of 405 CB is not generated during the incident. Now the

problem is identified and rectified.

--------- Completed

2.All the 3 lines i.e CHTR-2, MNBL-I & II tripped in zone

protection. The fault was in Blind zone i.e P2 side of CT, where it was covered under Bus fault by

the time fault moved on to P1 side when the fault comes under STUB/TEED zone after 330msec

all the feeders expect CHTR-1 tripped in Zone-II and total fault persisted for 500msec before the

405 TIE CB opens and clear the fault. As a remedial the STUB protection operation also checked

and found OK.------- Completed

3.The Time Sync was missed on the day and found there was problem with LAN Timer same was

rectified. Now found OK.

-----------Completed

4.Now the DR Time scale changed to 1 sec for Pre fault and 3 sec for Post fault and STATE of

events are corrected wherever found wrong/or misguiding during analysis.---------Completed.

PGCIL-SR1 RVMD 27-04-2016:

5. Procurement of differential protection for 400kV NPS-NLR D/C and 400kV RCR-RTPS-D/C is

under tendering.

PGCIL-SR1 RVMD 14-07-2016:

5. The proposal for procurement of Line differential Protections for 400kV Raichur - RTPS-1 & 2

and 400kV Nellore - NPS - 1 & 2 lines has been approved and tender is under technical

evaluation


PGCIL: On 23.11.2017 LDP relays commissioned in place of Main-1 distance relay in 400kV NPS-

Nellore line-2 & In line-1 installation of LDP relay is planned in Dec-2017/Jan-2018.


5. PGCIL (SR-I) informed that LDP commissioning on both lines would be completed by February,

2018. In this regard, PCSC made it clear that the recommendation pertains to providing LDP as

both Main-I & Main-II on both the lines, and asked PGCIL (SR-I) to ensure & comply with the

same.

Annexure-II

Page 2 of 47

PGCIL (SR-I) mail received on 27-04-2016:

1. The firmware of REL670 is being upgraded. ------- Completed.

2. The recording of events in msec interval is being taken up with OEM. Henceforth, for analysis

purpose, we will provide larm list which has msec time stamp. -------- Completed.

3. End to end testing of PLCC code transmision and tuning of channels carried out. -------

Completed.

4. Procurement of differential protection for 400kV NPS-NLR D/C and 400kV RCR-RTPS-D/C is

under tendering. The legends modified in Event/alarm list. Provision of diff. relay for all short

lines emanating from NPS is being taken up with our corporate.

----- Pending.

PGCIL(SR-I) RVMD 14-07-2016:

4. The proposal for procurement of Line differential Protections for 400kV Raichur - RTPS-1 & 2

and 400kV Nellore - NPS - 1 & 2 lines has been approved and tender is under technical

evaluation --- Pending


4. LDP relays procurement is under process. Procurement will be completed by Feb-2018. TPCIL

has to give written confirmation for LDP relay procurement. For want of written confirmation

from TPCIL, PGCIL approving authority has withheld the LDP proposal.


4. PGCIL (SR-I) informed that they are waiting for written confirmation from TPCIL to complete

procurement of LDP relays. To this, PCSC forum asked TPCIL to submit written confirmation to

PGCIL (SR-I) by 29.12.2017. PGCIL (SR-I) assured that with receipt of above confirmation from

TPCIL by Dec, 2017, they would be able to complete the work by FEbruary, 2018.

APTRANSCO informed that they would be able to implement LDP from their & APGENCO side by

April, 2018.

In this regard, PCSC forum made it clear that the recommendation is about providing LDP as

both Main-I & Main-II relays on all stated lines in Nellore Complex, ans asked all stakeholders to

ensure & comply with the same.

Pending

Tripping of 220 kV Kadra-Karwar

lines - 1&2 and 220kV Kaiga-

Kadra line

50/I/2 Complete outage of TPCIL power

station

30-12-2015 at

06:02hrs

Running units at Thermal Powertech power Station

tripped due to tripping of 400kV Nellore pooling station

(NPS)-TPCIL line and 400kV Nellore pooling station (NPS)-

NCC line

47/II/7 KPTCL Mail recieved on 25-05-2016:

1. Availability of week end infeed with eco feature to be confirmed by SEE,RTC,Hubli ---

Pending.

NPCIL (KGA) Mail recieved on 03-12-2016:

2. The 200 ms Definite time DEFR element in both Kaiga Kadra and Kaiga Kodasally lines were

disabled. IDMT DEFR is retained. The 200 ms Definite time back up o/c element in both Kaiga

Kadra and Kaiga Kodasally lines were disabled. IDMT is retained. --- Completed.

Status received vide KPCL mail dated 14.06.2017 & 29.11.2017:

1. Since PT blasted (B phase) at Karwar end, resistive over reach occurred. hence Backup

protecion operated at Kadra end (zone-2 not sensed) --- Pending.

2. ---- Completed

3.Newly commissioned micom P444 relay time synchronised with GPS ------ Completed.


1. Week end infeed logic will be enabled in the new numerical relays supplied to Karwar under

R&U during retrofitting works.

--- Pending


1. KPTCL informed that since the line is a double circuit, there may not be need for implementing

Weak Infeed logic with Echo feature at Karwar end. However, the same would be looked into

w.r.t. the newly commissioned NR's at Karwar, and final action taken would be informed by

March, 2018.

Pending

[with KPTCL]

31-07-2015 at

11:44 hrs

KPTCL/ KPCL/

NPCIL (KGS)

1. KPTCL/ KPCL to see the possibility of implementing Weak

Infeed logic with Echo feature enabled by Under

Voltage (27) element on Kadra-Karwar lines 1 &2, and

implement the same if feasible.

2. NPCIL to time-coordinate Kaiga’s DEFR settings with (i)

Zone-2 settings at Kaiga, and (ii) primary protections of the

lines emanating from Kadra and Kodasalli.

3. KPCL to ensure time-sync of EL’s, and healthiness of the

Fault Locators at Kadra.

220kV Kadra-Karwar lines-1&2 tripped

on earth fault in B-phase in zone-2.

Kaiga-Kadra line tripped at Kaiga end

only on operation of directional eath

fault protection.

1.PGCIL (SR-I) to furnish Action Taken Report on the findings

of OEM on relay mal-operation at NPS end on 400 kV NPS –

NCC line to PCSC forum.

2. PGCIL (SR-I) to appropriately configure Station Event Logger

at NPS to record events at msec interval.

3. PGCIL (SR-I) to carry out PLCC end-to-end testing in

coordination with TPCIL for 400 kV NPS –TPCIL line.

4.PGCIL (SR-I), MEPL, SEL, TPCIL & NCC to take steps to

provide line differential protection at their respective ends on

all 400 kV lines (except Gooty line) emanating from Nellore

Pooling Station, and furnish an action plan to implement the

same.

PGCIL (SR-I),

MEPL, SEL, TPCIL,

NCC

Annexure-II

Page 3 of 47




Pending50/I/2 Complete outage of TPCIL power

station

30-12-2015 at

06:02hrs

Running units at Thermal Powertech power Station

tripped due to tripping of 400kV Nellore pooling station

(NPS)-TPCIL line and 400kV Nellore pooling station (NPS)-

NCC line

1.PGCIL (SR-I) to furnish Action Taken Report on the findings

of OEM on relay mal-operation at NPS end on 400 kV NPS –

NCC line to PCSC forum.

2. PGCIL (SR-I) to appropriately configure Station Event Logger

at NPS to record events at msec interval.

3. PGCIL (SR-I) to carry out PLCC end-to-end testing in

coordination with TPCIL for 400 kV NPS –TPCIL line.

4.PGCIL (SR-I), MEPL, SEL, TPCIL & NCC to take steps to

provide line differential protection at their respective ends on

all 400 kV lines (except Gooty line) emanating from Nellore

Pooling Station, and furnish an action plan to implement the

same.

PGCIL (SR-I),

MEPL, SEL, TPCIL,

NCC

Annexure-II

Page 4 of 47

PGCIL mail received on 27-04-2016:

Being pursued with APTRANSCO

APTRANSCO mail dated on 22-06-2016:

AS maintenance being carrired out by PGCIL(SR-1), the required relay replacement

(wiring/programming) may also be carried out by PGCIL(SR-1).

PGCIL RVMD 14.07.2016:

1. The CB problem has been attended by POWERGRID by using OEM M/s BHEL services &

POWERGRID's O&M spares.

------ Completed.

2. Being pursued with APTRANSCO to replace the faulty Event Logger at Vijayawada (Nunna) SS. -

--- Pending

APTRANSCO mail dated on 31-08-2016 & 04.03.2017 & 24.05.2017:

As maintenance being carrired out by PGCIL(SR-1), the required relay replacement

(wiring/programming) may also be carried out by PGCIL(SR-1).

APTRANSCO mail dated 20.10.2017:

May be coordinated with PGCIL


PGCIL may be requested to take necessary action


2. EL procured and drawn. Configuration to be done by Alstorm company engineer. Will be

configured in four weeks.

---Pending


2. APTRANSCO is to replace the faulty/outdated relays & POWERGRID has to maintain the relays

after retrofitting.


2. APTRANSCO informed that the recommended works would be completed in one-month

period.

APTRANSCO Mail dated 30.01.2018 & 24.05.2018 & 26.06.2018

As per the requirement of PGCIL.Event logger(BCU) with data base is configured and handed

over to PGCIL/Nunna on 27 th dec 17.PGCIL is requested to take action for taking event logger

(BCU) into service.


PGCIL(SR1): New event logger was given by APTRANSCO to be installed & commissioned by

APTRANSCO.

As asset belongs to APTRANSCO & they have to commission the same.

56/I/2 Complete outage of 220kV

Sedam Substation of KPTCL.

19-06-2016 at

15:27hrs

220kV Sedam-Humnabad-2 tripped at Sedam on

Distance protection, Zone-2. Sedam-RTPS-1 &2 lines

tripped at RTPS end only. 220kV Tandoor inter-state line

was hand tripped due to incoming supply failure

KPTCL and TSTRANSCO to take steps to provide A/R feature

on 220 kV Sedam – Tandur inter-state line at their respective

ends at the earliest.

KPTCL/

TSTRANSCO


Carrier protection is to be restored. B/U OC and EF relay is to be replaced by M-II distance

relay. Required materials like wave trap, M-II distance relay are already supplied. The work will

be taken up on top priority through GE Ltd. --- Pending


TSTRANSCO informed that they have kept A/R in service from Tandur end. KPTCL informed that

the works relating to put A/R in service are going on at their Sedam SS, and assured that it would

be put into service by February, 2018.

Pending

[with KPTCL]

Pending

[with PGCIL (SR-I)]

1. PGCIL (SR-I), in co-ordination with APTRANSCO, to address

the problem with CB at the earliest opportune time.

2. APTRANSCO to take steps to replace the faulty Event

Logger at Vijayawada (Nunna) SS.

Line tripped due to operation of over voltage protection

at Vijayawada end and Direct Trip was received at

Sattenapalli end

Tripping of 400kV Sattenapalli-

Vijayawada line

PGCIL (SR-I)/

APTRANSCO

25-12-2015 at 3:01

hrs

51/II/6

Annexure-II

Page 5 of 47


To avoid the unwanted malopeartions due to the external LBB trip initiation from PGCIL, Vide

letter Dt: 04-08-2016, APTRANSCO has requsted the PGCIL to arrange the Master trip relay and

breaker contacts of ICT-1 &2 LV side to enable the internal LBB feature in the Busbar protection

scheme at 220kV Gooty Switching station. Waiting for the PGCIL response.


To avoid the unwanted maloperations due to the external LBB trip initiation from PGCIL, vide

letter Dt: 04-08-2016, ARTRANSCO has requested the PGCIL to arrange the Master trip relay and

breaker contacts of ICT-1&2 LV side to enable the internal LBB feature in the Busbar protection

scheme at 220kV Gooty Switching station. Waiting for the PGCIL response.


Waiting for the PGCIL response.

APTRANSCO mail dated 04.03.2017 & 24.05.2017.

SRPC is requested to coordinate with PGCIL in takind necessary action.

APTRANSCO mail dated 20.09.2017 & 22.11.2017

PGCIL may be requested to take necessary action

APTRANSCO maild ated 15.12.2017:

1. Cable healthiness checked and found ok. But it is proposed to replace the cable with armored

cable. --Completed

2. After replacing the cable contactors will be removed so as to avoid unwarrented delays in

transmitting trigging signal to the central unit . ---Pending


APTRANSCO informed that replacement of the existing cable with armoured cable and

subsequent removal of cable contactors would be completed by 31.12.2017. In this regard,

PGCIL (SR-I) also assured that they would render all required help from their side to complete

the stated works in time.

APTRANSCO Mail Dated 30.01.2018:

New armoured cable is laid from 220 kv Gooty (AP) to 400/220 kv Gooty (PGCIL) for replacing

the existing cable connected to ICT-2.PGCIL is requested to provide spare contacts from trip

relays of 315 mva LV-1 and LV-2 for providing internal CB failure in busbar protection scheme.

APTRANSCO Mail Dated 24.04.2018 & 24.05.2018:

As requested by PGCIL the busbar drawings Were submitted for providing spare contacts from

trip relays of 315 mva LV-1 and LV-2 for providing LBB in busbar protection scheme.


220kV CB LBB protection (Stand alone protection) available at PGCIL end is to protect ICT in case

of non tripping of CB. It is opined that stand alone protection is better than new LBB logic

proposed by APTRANSCO in Busbar schme. The reason for mal-operation of 220kV Bus on

24.06.2016 is mainly due to cable issue. The problem shall be solved once we replace, this

suspected cable betweem POWERGRID & APTRANSCO.

24-06-2016 at 16:04

hrs

LBB protection got operated for 400/220kV ICT-2 breaker

which had resulted in tripping of 220kV Bus-2 at 220kV

Gooty Substation

Tripping at 220 kV Gooty

Substation of APTRANSCO

56/II/13 1.APTRANSCO to check the healthiness of the connecting

cable between Gooty (PGCIL) and Gooty (APTRANSCO), and

replace it, if required.

2.APTRANSCO to ensure that the distributed architecture

employed in implementing busbar protection at their Gooty

220 kV SS does not introduce any unwarranted delays in

transmitting the triggering signals to the Central Unit.

Pending [ with

PGCIL (SR-I) ]

APTRANSCO/

PGCIL (SR-I)

Annexure-II

Page 6 of 47

56/III/4 Tripping of 220 kV Sedam-Tandur

line

03-06-2016

at 21:52 hrs

Line tripped on B-phase to earth fault. Auto-reclose is

not enabled for line.

KPTCL and TSTRANSCO to fast-track providing A/R on 220 kV

Sedam – Tandur line, and furnish an action plan of providing

the same by next PCSC meeting (PCSC-57).

KPTCL/

TSTRANSCO




be taken up on top priority through GE Ltd.


TSTRANSCO informed that they have kept A/R in service from Tandur end. KPTCL informed that

the works relating to put A/R in service are gonig on at their Sedam SS, and assured that it would

be put into service by February, 2018.

TSTRANSCO MAIL DATED 20.01.2018:

As discussed in the review meeting on 19-12-2017, A/R is kept in service from

Tandur(TSTRANSCO) end.---Pending


Issue is not pending from TSTRANSCO side.

Pending

(With KPTCL)

57/I/1 Complete outage of 220 kV

Karwar Substation of KPTCL

12-07-2017

at 11:36 hrs

Triggering incident was failure of R phase PT in Bus-1 at

220kV Karwar substation. 220kV Kaiga-Kodasalli tripped

during the incident. Also bus shut down occurred at

Kadra and Kodasally stations.

1.NPCIL (KAPS) to disable DefiniteTime O/C relay, and put in

its place by IDMT O/C relay for backup protection on both 220

kV Kaiga – Kadra line and 220 kV Kaiga – Kodasalli line at

Kaiga end.

2.KPTCL to put bus bar protection in service at their 220 kV

Karwar SS at the earliest.

3.KPCL/ KPTCL to implement Weak In-feed Logic with Echo

feature enabled by Under Voltage (27) element on Kadra –

Karwar lines 1 & 2.

4.KPTCL to furnish equipment failure report of the current

incident to PSE&TD Division of CEA with a copy marked to

SRPC.

KPTCL/ KPCL/

NPCIL (KGS)

NPCIL(KGS) mail dated on 03-12-2016 & 29.11.2017:

1.The 200 ms Definite time DEFR element in both Kaiga Kadra and Kaiga Kodasally lines were

disabled. IDMT DEFR is retained. --- Completed

2. --- Pending

3. --- Pending

4. --- Pending


2) Bus-bar protection panel is supplied under R&U. Replacement work will be taken up after

priority Sub stations.

--- Pending

3] Weak end Infeed logic available in new relays supplied; Will be enabled During R&U works. ---

Pending

4] Equipement failure reports are being sent to CEA regularly.

--- Completed


2. KPTCL informed that the works relating to providing BBP are targeted to be completed by

March, 2018.

3. KPTCL informed that since the line is a double circuit, there may not be need for implementing

Weak Infeed logic with Echo feature at Karwar end. However, the same would be looked into

w.r.t. the newly commissioned NR's at Karwar, and final action taken would be informed by

March, 2018.

Pending

[with KPCL &

KPTCL]

Annexure-II

Page 7 of 47


ABB make LDP relays inspection is completed. SNEIDER make LDP relays inspection yet to be

completed. Delivery of relays expected in the 1st weak of May-2018.


SNEIDER make LDP relays inspection yet to be completed.Delivery of relays expected in the

month of june 2018.





ABB make LDP relays are delivered. Schneider make LDP relays inspection to be offered by the

company.


Issue was addressed to the concerned for necessary action.


Meeting was conducted and the relays procurement for all the loctions is under progress.

APTRANSCO mail dated on 20-10-2017 & 22.11.2017:

Relays procurement for all the locations is under progress.

APTRANSCO Mail dated 15.12.2017:

Technical bids opened. PQ evaluation under progress . Price bids expected to open in next

week.


LDP relays procurement is under process. Procurement will be completed by Feb-2018. TPCIL

has to give written confirmation for LDP relay procurement. For want of written confirmation

from TPCIL, PGCIL approving authority has withheld the LDP proposal.


PGCIL (SR-I) informed that they are waiting for written confirmation from TPCIL to complete



TPCIL by Dec, 2017, they would be able to complete the work by FEbruary, 2018.


April, 2018.




APTRANSCO MAIL DATED 30.01.2018

Technical & financial bids are opened. Tenders will be awarded shortly.

PGCIL (SR-I), TPCIL, MEPL, SEL, SGPL, APTRANSCO, APGENCO

and SDSTPS to implement line differential protection on all

400 kV transmission lines (of length less than 50 km)

emanating from Nellore PS, Nellore (PG) SS, and Nellore (AP)

SS. [It may be noted here that the cut-off length of 50 km has

been specified with a view to exclude only long transmission

lines].

APGENCO/

PGCIL(SR-I)/

TPCIL/MEPL/SEL/

SGPL/ APTRANSCO

Pending57/II/9 Tripping of 400 kV Nellore (PG) -

NPS line-1, 400 kV

Krishnapatnam-Nellore (AP) lines

-1&2 and 400kV NPS - MEPL line

18-07-2016

at 19:05 hrs

Triggering incident was snapping of Y phase conductor in

400kV Nellore (PG) - NPS line-1. Distance relay at

Krishnapatnam end over-reached in Zone-1, and resulted

in tripping of 400kV Krishnapatnam – Nellore (AP) lines -

1&2 from Krishnapatnam end. Distance relay at MEPL

over-reached and resulted in tripping of MEPL-NPS line

from MEPL end.

Annexure-II

Page 8 of 47

63/II/9 Tripping of 400 kV YTPS-BTPS

line and 400 kV BTPS-JSWEL line

14-03-2017 at 19:11

hrs

R-phase to earth had occurred in 400kV BTPS-JSWEL line

and protection issued a 3 phase trip

1. JSWEL to follow file naming terminology provided by

SRPC for various tripping files uploaded in SRLDC’s TMS

portal.

2.JSWEL to furnish reasons for AR-BLOCK observed

during the instant tripping and remedial action taken

by them to keep A/R in service.

3. KPCL to configure DR & EL properly to record OVR

Stage-I & Stage-II protections at their BTPS station.

KPCL/ JSWEL Status received vide mail dated 14.12.2017:

1. JSWEL will follow the file naming terminology provided by SRPC during future uploads -----

Completed

2. Auto-reclosure is in service for JSW BTPS line. The reason for AR-Block was due to carrier fail

signal which was after the fault clearance. As per the attached event list, the fault occurred at

7:11:21:550 PM & the AR block appeared around 7:11:21:586 PM, after the clearance of the

fault at around 7:11:21:583 PM (3PH-TRIP) -----Completed

3. --- Pending with KPCL


3. KPCL informed that DR's & EL's had been configured for OVR (Stage-I & Stage-II) protections at

their BTPS sttaion, and the exact date of completion of the same would be intimated soon.

JSWEL Status received vide mail dated 01.03.2018:

1. JSWEL will follow the file naming terminology provided by SRPC during future uploads.

2. Auto-reclosure is in service for JSW BTPS line. The reason for AR-Block was due to carrier fail

signal which was after the fault clearance. As per the attached event list, the fault occurred at

7:11:21:550 PM & the AR block appeared around 7:11:21:586 PM, after the clearance of the

fault at around 7:11:21:583 PM (3PH-TRIP)

Pending

Annexure-II

Page 9 of 47

64/I/1 Complete outage of North

Chennai TPS STG-2

24-04-2017

at 21:02hrs

Tripping of evacuating lines due to fault led to tripping of

Units


Chennai TPS STG-2

25-04-2017

at 18:27hrs


Unit


Chennai TPS STG-2

26-03-2017

at 21:09 hrs


running Unit at NCTPS Stg-2

TANTRANSCO MAIL DATED 22.05.2018:

Existing Porcelain insulators of all other 400kV feeders are being replaced with Polymer

insulators in a phased manner. Timeline: Sep-2018. Detailed plan of action will be submitted.




TANTRANSCO/

PGCIL(SR-II)

TANTRANSCO and PGCIL (SR-II) to take steps to complete

insulator replacement works on the 400 kV lines owned by

them in Chennai area within 3 months.

Pending

[with

TANTRANSCO]

Status received vide TANTRANSCO mail dated 15-06-2017 & 04.08.2017 & 18.09.2017 & 12-12-

2017:

1. All the Porcelain insulators of 400kV NCTPS-II - Vallur feeders-1&2 were replaced with

Polymer insulators by 20.05.2017. -----Completed

2. Existing Porcelain insulators of all other 400kV feeders are being replaced with Polymer

insulators in a phased manner.

--- Pending

PGCIL (SR-II) Mail dated 11-12-2017:

Pertaining to POWERGRID all the porceleing insulators in the polluted streches has been

completed. - Completed.


TANTRANSCO informed that a total of 597 insulators ahd alreeady been replaced, and the total

replacement would take another 9-month period.

In this regard, TANTRANSCO was asked to furnish detailed plan of action regarding replacement

of insulators on all 400 kV lines owned by them in Chennai area.




Annexure-II

Page 10 of 47

1. --- Pending with TSGENCO

PGCIL (SR-I) Mail dated 15-12-2017:

2). TOR feature in MiCOM P444 relay enabled for 400kV KMM-KTPS lines at Khammam end. DT

send on TOR trip is not as per protection philosopy. However if SRPC/SRLDC gives separate

instructions exclusively for this line, the same shall be imoplemented after getting our CC

approval. --- Pending

3). At Khammam SS all DR & ELs are time synched. --- Completed.

4). --- Pending

TSGENCO Mail dated 18.12.2017:

1). If the auto reclose function dead time kept same at both ends as 1 sec uniformly. In case of

persistent fault, it leads to feed the fault from both ends and cause the generator breaker

switching on to high fault current and chances of pole slip. To avoid this time differentiated A/R

scheme to be implemented. In KTPS 400KV Line –I & II at KTPS end dead time is 1.2sec and at

KMM end it is 1sec.

In our relay 7SA522 does not have the adaptive dead time function A/R. Hence, it is requested to

send DT in case of on 3-phase trip and A/R unsuccessful at KMM end to avoid reclose attempt

from KTPS end after dead time (1.2Sec) for persistent faults.

We communicated to M/s Siemens to upgrade the firmware version regarding adaptive dead

time.

Hence, it is requested to review these settings to reduce the stress on Generating Station ---

Completed


2. It was made clear to PGCIL (SR-I) that this is a specific case of those 400 kV lines where one

one of the ends is a generating station, and the other end is grid-connected substation having

TOR feature in line protection relays. The said recommendation of enabling TOR along with

sending DT to the other end is basically to ensure safety of Generating Units at the other end.

Accordingly, PGCIL (SR-I) was asked to take steps to ensure the same. --- Pending

4. PGCIL (SR-I) informed that shutdown was availed by TSGENCO on 14.12.2017, and all issues

relating to PLCC including end-to-end testing were carried out. --- Completed


2. Please mention clearly which feature to be enaled at KMM end(DT send feature on TOR or DT

send feature while 3-ph trip). SRPC may advise TS TRANSCO for arrangieing OEM (MiCOM p444

relay) service engineer for configuration & implementation of DT send for TOR trip, as the

feature is no where implemented in POWERGRID-SR1.--- Pending

4. 400kV KMM-KTPS-1 line PLCC system checked & End to end code transmission checked on

19.01.2018 & found ok. ---Completed

TSGENCO/

PGCIL (SR-I)

1. TSGENCO to keep uniform A/R dead-time of 1 sec on the

lines emanating from their KPTS station.

2. PGCIL (SR-I) to enable Trip-on-Reclose (TOR) functionality

for Zone-2 faults for Khammam – KTPS lines at Khammam

end, if such a feature is available in the concerned relay, and

to configure it for sending Direct Trip (DT) Command to KTPS

end.

3. PGCIL (SR-I) to set right time-sync issues w.r.t. Khammam

end Event Loggers on Khammam – KTPS lines.

4. For 400 kV Khammam – KTPS line-1, PGCIL (SR-I), in

coordination with TSGENCO, shall carry out the following:

(i) End-to-end communication for DT/ permissive & other

signals may be ensured by testing at both the ends.

(ii) Healthiness of PLCC system components (hardware and

software) at both ends shall be checked and faulty

components shall be repaired/ replaced.

66/ II/ 8 Tripping of 400 kV Khammam –

KTPS lines – 1 & 2

08-06-2017 at 18:32

hrs

Lines – 1 & 2 tripped on B-phase to earth faults Pending

[with

PGCIL (SR-I)]

Annexure-II

Page 11 of 47

66/ II/ 10 Tripping of 400/ 220 kV ICT’s – 3

& 4 at Ramagundam STPS

11-06-2017

at 19:46hrs

Triggering incident was failure of 220 kV

B-phase LA in ICT-3 LV extension feeder (220KV line-2)

at Malayalapalli substation

1. NTPC to disable high-set of DEFR on the 220 kV lines

emanating from their Ramagundam STPS.

2. NTPC/ TSTRANSCO to provide Line Differential Protection

(with or without pilot) on 220 kV Ramagundam –

Malayalapalli lines – 1 & 2 & 3.

NTPC-

Ramagundam/

TSTRANSCO

NTPC mail dated 07.12.2017:

1. High set DEFR on 220 KV lines is disabled ----Completed

2. ---- Pending


TSTRANSCO informed that the works are under progress, and are targeted to be completed in 3

months time.


Line Differential Protection will be provided within 3 months i.e., by end of March, 2018.


Line Differential Protection relays are under procurement and will be provided by end of May,

2018.


Line Differential relays will be supplied to site by manufacturer by end of May, 2018 and

erection will be completed by end of June, 2018.

Pending

1. --- Pending

2. --- Pending

3. --- Pending

Status received vide NPCIL mail dated 29-11-2017:

4. The event logger(ESCADA) has inherent time resolution of 10 millisecond for digital inputs. In

future higesht resultion event logger history will be extratced for submission to grid authorities..-

-NPCIL-KAIGA ----Completed


1). Kadra-kaiga 220KV line tripped on both end in Zone-1 distance protection. Fault distance is

0.9KM from kadra end. Kodasalli-Kadra 220KV tripped at Kodasalli end only in Zone-1 fault.

Reason for tripping is the both Kadra-kodasalli, kadra-Kaiga line are in same tower, hence same

fault reflected adjuscent line. Because of no Bus source, Kadra end relay stopped to detect,

hence Kadra end breaker was intact.

---- Completed

2). Issue relating to downloading of DRs & Els at Kadra PH rectified. --- Completed

3). KPCL informed that they have planned to take up providing double-bus operation at their 220

kV Kadra PH, 220 kV Gersoppa PH, and 220 kV Raichur TPS through PSDF funding, and DPR for

the same is under preparation. After obtaining approval of the same from their management,

other activities inluding tenders floating, approaching PSDF would be taken up. All these

activites are targeted to be completed within 2 years.

--- Pending

Complete outage of 220 kV

Kadra Power Station of KPCL.

68/I/2 KPCL/ NPCIL (KGS)1. KPCL to investigate the reasons for non-tripping of 220 kV

Kadra – Kodasalli line from Kadra end by any of the Main

protection relays, and opening of only B-ph pole at Kodasalli

end, and furnish an action taken report on the same.

2.KPCL to sort out issues relating to downloading of DR’s &

EL’s at Kadra PH at the earliest.

3. KPCL to use both the 220 kV buses as main buses under

normal operation, and to go for single bus operation only

during emergencies at their Kadra PH.

4. NPCIL (KGS) to configure time resolution of Event Loggers

to milli seconds at their Kaiga GS.

Triggering incident was tripping of 220 kV Kadra-

Kodasalli and 220 kV Kadra-Kaiga line. There was no

generation at Kadra in antecedent condition.

25-09-2017

at 11:41hrs

Pending

[with KPCL]

Annexure-II

Page 12 of 47

69/I/2 Complete outage of 400kV TPCIL

station

30-10-2017 at 21:37

hrs

400kV TPCIL - Nellore line-1 got tripped at TPCIL end

during failure of LA of Station Transformer-2 at TPCIL.

Running Units at TPCIL got tripped due to loss of

evacuating line. 400kV TPCIL - Nellore PS line-2 was

under emergency shutdown

1. TPCIL to configure DEF protection such that it remains in

blocked condition as long as Distance Protection is active, and

becomes active only when distance protection does not

pickup.

2.PGCIL (SR-I) to ensure healthiness of Carrier

communication, and the set PUP mode of carrier aided

scheme operates reliably on TPCIL lines 1 & 2.

TPCIL/

PGCIL (SR-I)


PGCIL (SR-I) informed that they are waiting for written confirmation from TPCIL to complete



TPCIL by Dec, 2017, they would be able to complete the work by February, 2018.


April, 2018.







Pending

69/III/3 Tripping of 400 kV Kurnool(PG) –

Kurnool(AP) line-2

02-10-2017 at 02:03

hrs

Line tripped on B-ph to ground fault. A/R was

unsuccessful at both Kurnool (AP) and Kurnool (PG) ends.

1) PGCIL (SR-I) and APTRANSCO to provide for Line

Differential Protection as both the Main protections on 400 kV

Kurnool (AP) – Kurnool (PG) lines 1 & 2 lines.

2) APTRANSCO to furnish an action taken report w.r.t.

resolving A/R non-operation at Kurnool-AP end for the subject

trippings and configure EL for capturing PDR operation at

their 400 kV Kurnool-AP SS.

APTRANSCO/

PGCIL (SR-I)


1. Pending...

2.A/R scheme on 400kV Kurnool (PGCIL) feeder-2 will be checked after getting LC.

APTRANSCO maild ated 24.04.2018 & 24.05.2018 & 26.06.2018:

1. Pending...

2. B Ph auxilary trip relay is found defective. The same is to be replaced by M/S PGCIL. Ii) PD

relay event is configured in the EL as per the recommendation.


1. ---Pending

2. PGCIl(SR-1): B-Ph auxiliary relay problem rectified at Narnoor end by replacing relay contact. ---

Completed

Pending

69/III/7 Tripping of 220 kV Ragulapadu –

Alipura line

12-10-2017 at 01:30

hrs

Line tripped on B-Ph to earth fault. A/R was successful at

Regulapadu and breakers at Alipura end got tripped.

KPTCL and APTRANSCO to sort out issues relating to

incongruence in denoting R, Y, B phases of the electric supply

on their respective sides.

APTRANSCO/

KPTCL


APTRANSCO would extend support and requirements if any ,for the rectification proposed by

KPTCL.


It was noted that the original Gooty - Lingapur line got LILOed at BTPS, Alipura, and Ragulapadu.

It was also noted that Phase Discrepancy is being observed in Ragulapadu - Alipira section only.

When enquired about the same, KPTCL informed that they would examine the issue in detail,

and would inform the action lan proposed by next PCSC-71 meeting. On this, APTRANSCO was

also asked to render all help required from their side to KPTCL.

APTRANSCO maild dated 30.01.2018:

APTransco world extend required support .

APTRANSCO maild dated 24.04.2018 & 24.05.2018 & 26.06.2018:

AP Transco would extend required support for attending, phase discrepancy issue in ragulapadu-

Alipura line by KPTCL.

Pending [ with

KPTCL ]

Annexure-II

Page 13 of 47

72/II/4 Tripping of 400/ 220 kV Hoody

ICT-3 and 400 kV Kolar-Hoody

line-2

14-01-2014 at 17:42

hrs

Triggering incident was failure of Y-phase lightning

arrestor of 400kV Hoody-Kolar line-2 at Hoody end due

to which 400 kV Kolar – Hoody line-2 tripped on

operation of distance protection. At the same time

400/220 kV, 500 MVA ICT-3 at Hoody also tripped on

earth fault protection.

For the Hoody – Kolar line-2, the following shall be carried out

by KPTCL, in coordination with

PGCIL (SR-II):






KPTCL to keep A/R in service on Hoody – Kolar line-2 after

verifying the healthiness of PLCC communication.

KPTCL / PGCIL (SR-

II)

Yet to be informed Pending

73/II/7 Multiple trippings at 400 kV

Guttur Substation.

17-03-2018 at 08:25

hrs

400 kV Guttur-Kaiga-1 Breaker was in lock-out condition.

It was intended to take Kaiga line-1 on tie CB. While

carrying out this operation bus bar protection operated

at Guttur resulting in tripping of all connected elements.

1) NPCIL (KGS) to take steps to disable sending of DT to

remote ends upon 86X operation for any line protection

operation at its 400 kV KGS.

2) KPTCL to resolve PLCC issues on 400 kV Guttur –Kaiga lines

at the earliest.

KPTCL/

NPCIL [KGS]

KPTCL Mail dated

It is observed that the loop wire(i.e from BCU to CB closing coil)missed for A/R close operation to

CB remote close and it was given on 21.04.2018 in the presence of PGCIL authorities.

NPCIL (KGS) mail dated 25.06.2018:

1) KGS agreed to disable sending of DT to remote ends upon 86X operations for any line

protection operation at its 400kV KGS within one month.

2) KPTCL agreed to resolve the PLCC issues at Guttur SS at the earliest.

Pending

73/IV/3 Tripping of 400 kV Pondicherry-

S.V.Chatram line.

10-03-2018 at 17:58

hrs

Line tripped at SVChatram end only and was holding

from Puducherry. No fault was observed from DR of

S.V.Chatram. Suspected PLCC mal-operation.

For the line under consideration, the following shall be carried

out by PGCIL (SR-II), in coordination with TSTRANSCO:






TANTRANSCO/

PGCIL (SR-II)

TANTRANSCO Mail dated 22.05.2018 & 08.06.2018:

PLCC LINK will be checked on availing LC

Pending

27-03-2018 at 17:17

hrs (Line-1)

73/IV/7 Line-1&2 got tripped on Direct Trip receive at Karamadai

end and the line was in service from Arasur end.

Suspected PLCC mal-operation.


out by PGCIL (SR-II), in coordination with TANTRANSCO:






TANTRANSCO/

PGCIL(SR-II)


Protection coupler NSD 570 “input ON Time delay” introduced as 10 msec at Karamadai end

during commissioning Subsequently Arasur end time delay introduced.

Pending

Annexure-II

Page 14 of 47

27-03-2018 at 18:11

hrs (Line-2)


Sedam Substation

01-04-2018 at

19:56hrs

Triggering incident was fault in 220 kV Sedam-Tandur

line. 220 kV Sedam-Shahapur, 220 kV Sedam-RTPS lines -

1&2 and 220 kV Sedam-Tandoor line tripped from RTPS,

Shahpur and Tandoor. Tripping of incoming lines to

Sedam caused shut down at Sedam Sub Station resulting

in complete outage of the station.

KPTCL and TSTRANSCO to establish PLCC link on 220 kV

Sedam – Tandur line, and implement A/R using PLCC carrier

communication.

KPTCL/TSTRANSCO TSTRANSCO mail dated 20.06.2018:

Will coordinate with KPTCL and arrange for procurement of PLCC panel at Tandur end.

pending

52/I/2

(GD)


Yerraguntla substation and

tripping of running Units at

Rayalaseema TPS

21-02-2016 at 10:39

hrs

HV B-Ph Current transformer of 100MVA Power

Transformer -1 failed resulting into a bus fault on 220KV

Bus-1. Unit-1 and Unit-5 at RYTPS tripped during the

fault at Yerraguntla substation

1. APGENCO to check associated logic for lube oil pump for

correct operation under transient low voltage conditions at

Rayalaseema TPS, Unit-1.

2. APGENCO to keep appropriate time delay/ fault ride

through delay (typically 2 sec) in VFD speed sensor relay at all

its generating Units including Rayalaseema TPS Units.

APGENCO Mail received on 27-07-2016:

1.The drop out relays of reducer oil pumps time setting was increased for all mills.So there will

not be any trip under transient low voltage condition.----Complied

2.The recommendation regarding 2 sec time delay will be implemented during unit shut down

and will be intimated immediately after implementation.------Pending


It was noted that no APGENCO representative had come to attend the meeting.

Pending

73/IV/7 Line-1&2 got tripped on Direct Trip receive at Karamadai

end and the line was in service from Arasur end.

Suspected PLCC mal-operation.


out by PGCIL (SR-II), in coordination with TANTRANSCO:






TANTRANSCO/

PGCIL(SR-II)


Protection coupler NSD 570 “input ON Time delay” introduced as 10 msec at Karamadai end

during commissioning Subsequently Arasur end time delay introduced.

Pending

Andhra Pradesh

Annexure-II

Page 15 of 47

57/II/9 Tripping of 400 kV Nellore (PG) -

NPS line-1, 400 kV

Krishnapatnam-Nellore (AP) lines

-1&2 and 400kV NPS - MEPL line

18-07-2016

at 19:05 hrs

Triggering incident was snapping of Y phase conductor in

400kV Nellore (PG) - NPS line-1. Distance relay at

Krishnapatnam end over-reached in Zone-1, and resulted

in tripping of 400kV Krishnapatnam – Nellore (AP) lines -

1&2 from Krishnapatnam end. Distance relay at MEPL

over-reached and resulted in tripping of MEPL-NPS line

from MEPL end.

APGENCO to furnish a report on the remedial action

implemented w.r.t. overreaching of Krishnapatnam end

distance relays during the tripping of 400 kV Nellore (PG) -

NPS line-1

APGENCO Review Meeting dated 19.12.2017:

It was noted that no APGENCO representative had come to attend the meeting.

APGENCO Mail dated 19.12.2017:

Procurement of relays is under progress

Pending

69/II/1 Multiple trippings at Tripping at

220 kV Srisailam Right Bank

power station

09-10-2017 at 14:39

hrs

220kV Srisailam RB – Markapuram S/C line and 220 kV

Srisailam – Podili S/C line tripped on operation of

distance protection. Srisailam Units - 3, 4, 6 and 7 got

tripped during the incident.

1.APGENCO to furnish compliance report on the

recommendations given by PSAG-9 team that had visited

Srisailam RB PH on 14-15 October, 2014.

2.APGENCO to carry out the following:

(i)Removal of DC earth leakage in station switchyard on

priority basis (latest by 10.12.2017)

(ii)Integration of Station earth-mat and Switchyard earth-

mat.

3. APGENCO to provide for numerical relays (as both Main-I &

Main-II) on all 220 kV feeders emanating from Srisailam RB

PH.

4.APGENCO to put A/R into service on all 220 kV feeders

emanating from Srisailam RB PH.

5.APGENCO to provide for Time Synchronization equipment

at their Srisailam RB PH to synchronize all protection relays

with GPS.

APGENCO APGENCO Mail dated 06.03.2018:

1. Complainance report on PSAG -9 recommendations is enclosed in next sheet.

--Completed

2. i ) Attended and removed the earth leakage. --Completed

2 ii) Procurement of material is under progress. --Pending

3. Material received at site. Work will be completed by April 2018. --Pending

4. Will be provided at the time of commissioning of new protection panels. --Pending

5. i) Time synchronization for Unit-4 both MAin- I & II relays was provided through SNTP.

--Completed

ii) Time synchronization for Unit-1,2 ,3,5,6, & 7 RET- 670 Main -II Relays was provided through

SNTP. --Completed

iii) Time synchronization for Unit -1,2,3,5,6, & 7 REG- 670 Main - I & II Relays was provided

through PPM. --Completed

APGENCO Mail dated 25.06.2018:

2 ii) Procurement of material is under progress.

3. New numerical Relay panels erection nad commissioning work is under progress. It will be

completed within two months for all feeders.

4. Work is under progress and it will be completed within two months for all feeders -Pending

Pending


Kalikiri station

25-04-2018 at 16:55

hrs

Triggering incident was Y-phase to ground fault in 400kV

Kalikiri - RYTPP line-2. 400kV Kalikiri- Chittoor lines - 1&2

got tripped from Chittoor end. This resulted in complete

outage of 400kV Kalikiri station.

APGENCO to furnish tripping files (FIR/DR/EL/TR) of an event

involving their system within 24-hrs of occurrence of the

same to SRLDC and SRPC in line with IEGC Regulation 5.2 (r).

APGENCO Yet to be informed Pending

Annexure-II

Page 16 of 47

74/II/5 Tripping of 400 kV Nellore-AP -

VTPS-IV

04-04-2018 at 15:49

hrs

Spurious trip signal from PRD of NGR of Nellore line

Reactor at VTPS end resulted in Direct Trip send to

Nellore (AP)

APGENCO to take steps to remove the observed DC leakage

at their VTPS-IV switchyard at the earliest.


74/II/21 Tripping of 400 KV Kalikiri –

RYTPP line-2

29-04-2018 at 19:29

hrs

Line tripped on operation of over-voltage protection at

RYTPP and Direct Trip receipt at Kalikiri. The correct

operation of over-voltage tripping could not be validated

as FIR, DR and EL of RYTPP and DR and EL of Kalikiri were

not furnished.

1). APGENCO to furnish detailed report on the reasons for the

tripping of the line including remedial measures taken.

2). APGENCO to ensure that the OVR-settings implemented at

Rayalaseema TPP are as per the SRPC provided settings issued

vide letter dated 01.05.2018, and confirm the same.


69/II/7 Tripping of 400 kV Uravakonda –

Jamalamadugu line-1

06-10-2017 at 10:22

hrs

Line tripped on overvoltage at Uravakonda end and

Direct Trip received at Jamalamadugu end. DR & EL of

Uravakonda end not furnished.

APTRANSCO to complete configuration of DR’s & EL’s for all

protections relays at their 400 kV Uravakonda SS, and render

them suitable for extraction/downloading of relevant tripping

records/ events within a month’s time.

APTRANSCO APTRANSCO Mail dated 15.12.2017 & Review Meeting dated 19.12.2017:

Instructions were issued for taking necessary action.


Configuration of DR & EL’s in the relays completed configuration of DR & EL at SAS is to be

verified.


Informed to M/S .Siemens for rectification.

Pending


Uravakonda Substation of

APTRANSCO

20-01-2018 at 4:48

hrs

400kV Uravakonda- Jammalmadugu line-1 tripped at

4:48hrs due to Y-phase to ground fault at both the ends.

400kV Uravakonda Jammalmadugu line-2,

Mahabubnagar line-1 and 2 were in open condition due

to high voltage. After tripping of 400kV UV Konda-

Jammalmadugu line-1, 400/220kV ICT #1,2,3 and 4 at

400kV UV Konda were hand tripped due to loss of

evacuating lines.

APTRANSCO to get checked Auto-Reclosure scheme

provided on 400 kV & 220 kV lines for correctness of

functionality & healthiness of the logic employed by April,

2018.

APTRANSCO APTRANSCO maild ated 24.05.2018:

Informed to M/S .Siemens for rectification.

Pending

Annexure-II

Page 17 of 47

73/I/7 Complete outage of 220 kV Vizag

(Gazuwaka) switching station

27-03-2018 at 16:14

hrs

Triggering incident was R-ph CT failure Bus-Coupler. This

resulted in tripping of all the connected elements due to

operation of bus bar protection.

1) APTRANSCO to furnish equipment failure report of the

current incident (CT blast) to PSE&TD Division of CEA with a

copy marked to SRPC.

2) APTRANSCO to take steps to provide one more thermo-

vision camera to Vizag division for use exclusively on 400 kV &

220 & 132 kV transmission lines emanating from Kalpaka,

Gajuwaka, VSS, Pendurti and other adjoining substations of

APTRANSCO.

APTRANSCO APTRANSCO Mail Dated 26.06.2018:

i) Vide Lr.No.CE/Tr/SE/Tr/DE/SS/ADE-4/F.No.1/D.No.138/18Dt:20.06.18. Equipment & failure

report communicated to CE(STED),CE/(IC),CEA.

---Complied.

ii) Indent is being processed.---Pending.

Pending

74/II/19 Tripping of 400 kV Maradam -

Kalpaka line-1&2

24-04-2018 at

11:53hrs

400kV Maradam-Kalpaka line-2 - B-phase to earth fault

had occurred in line. Auto-reclose was un-successful due

to persistent fault.

400kV Maradam-Kalpaka line-1 - Line tripped at

Maradam end only on B-N, zone-1. Suspected over-reach

of distance protection from Maradam end.

APTRANSCO to address and correct the A/R issues at

Maradam end on 400 kV Mardam – Kalpaka lines – 1 & 2, and

put the corrected A/R functionality into service.

APTRANSCO Yet to be informed Pending

Annexure-II

Page 18 of 47

61/III/5 Tripping of 400 kV Khammam -

KTPS line-2

24-12-2016 at 10:52

hrs

Line tripped on B-phase to earth fault. First fault was

persistent for 380 ms. Auto-reclose was successful at

Khammam end during 1st fault. 2nd fault occurred

during re-claim time of breaker hence Khammam end

breakers also got tripped.

1. TSGENCO to implement the SRPC agreed philosophy for

Power Swing Blocking in all distance relays on the feeders

emanating from KTPS.

2. For the line under consideration, TSGENCO to consult relays

OEM to migrate to new versions of Firmware (from 4.68.03 to

4.72.01) and Pset (from 4.63.04 to 4.70.02).

TSGENCO TSGENCO mail dated 30.03.2017:

1. According to SRPC phylosphy power swing block settings are changed to ALL ZONES BLOCK

EXCEPT ZONE1.

---------- Completed

2. M/s. Siemens is requested to depute the service Engineer to update the firm ware of existing

SIPROTEC relays in 400KV switch yard. This work will be completed on or before 15.04.2017.

----------- Pending

TSGENCO mail dated 08.12.2017:

1. --- Completed

2. As this KTPS line-II is being LILOed at KTPS, Stage-VII, those relays would be replaced with line

diff relays. --- Pending


As recommeded, TSGENCO was asked to migrate to new versions of firmware in consultation

with relays OEM.

------- Pending

Pending

07-11-2017 at 23:02

hrs

09-11-2017 at 21:57

hrs

12-11-2017 at 20:54

hrs

17-11-2017 at 21:19

hrs

11-11-2017 at 22:02

hrs

12-11-2017 at 23:09

hrs

24-11-2017 at 18:46

hrs

11-12-2017 at 18:49

hrs

TSGENCO

TSGENCOTSGENCO to adopt stipulated OVR, Stage-I gradings for the

400 kV lines emanating from their 400 kV Srisailam LB RH, and

furnish an action taken report w.r.t. mitigating observed

voltage difference among R & Y & B phases

Line tripped on operation of Over-Voltage protection at

Srisailam and Direct Trip was received at Kurnool.

Considerable voltage difference was observed between

R, Y & B phases.

Yet to be informed TSGENCO to adopt stipulated OVR, Stage-I gradings for the

400 kV lines emanating from their 400 kV Srisailam LB RH, and

furnish an action taken report w.r.t. mitigating observed

voltage difference among R & Y & B phases.

70/II/2

Tripping of 400 kV Satenapalli-

Srisailam line-1

Yet to be informed Pending

Tripping of 400 kV Narnoor –

Srisailam LB line


at Srisailam LB end. Considerable phase difference was

observed between phases at Srisailam end

Tripping of 400kV Kurnool-

Srisailam line

1. TSGENCO to take steps to replace the existing faulty CVT’s

at Srisalam end on 400 kV Srisailam – Narnoor line at the

earliest.

2. TSGENCO to adopt stipulated OVR, Stage-I gradings on all

400 kV transmission lines emanating from Srisaliam LB.

TSGENCO Yet to be informed

Line tripped on operation of over-voltage protection at

Srisailam and Direct Trip was received at Sattenapalli.

Considerable voltage difference was observed between

R, Y & B phases at Srisailam end.

71/II/7

70/II/3

Telangana

Pending

Pending

Annexure-II

Page 19 of 47

18-12-2017 at 19:10

hrs

74/II/2 Tripping of 400 kV Kurnool-

Srisailam line

01-04-2018 at 18:03

hrs

Line tripped on operation of Over Voltage Stg-1

protection at Srisailam and Direct Trip was received at

Kurnool. Considerable difference between Phase

voltages was observed in Srisailam end DR. (Vr-257kV, Vy-

246kV, Vb-239kV)

1). TSGENCO was asked to double—check the faulty CVT’s and

replace them at the earliest.

2). TSGENCO was also asked to implement new OVR gradings

issued vide SRPC letter dated 01.05.2018.

TSGENCO Yet to be informed Pending

74/II/4 Tripping of 400 kV Gajwel -

Shankarapally line-1 and 400kV

Gajwel-Hyderabad line

03-04-2018 at 14:13

hrs

400 kV Gajwel-Shankarapally line-1 tripped due to B-

phase to earth fault (persistent fault). At this instant, 400

kV Gajwel-Hyderabad line also tripped on operation of

over-voltage protection at Gajwel and Direct Trip was

received at Hyderabad.

TSTRANSCO to expedite commissioning of new numerical

relays (with voltage drop-off to pick-up ratio better than 0.97)

on all 400 kV lines at their Gajwel SS and implement OVR

(Stage-I & Stage-II) functionality from the numerical relays.

TSTRANSCO TSTRANSCO mail dated 20.06.2018:

New relays are available at site and will be commissioned by 2nd week of August-2018. Over

Voltage settings will be implemented in the new relays.

Pending

74/II/8 Tripping of 400/220 kV ICT-2 at

Gajwel

11-04-2018 at 5:50

hrs

400/220 kV ICT-2 at Gajwel tripped on mal-operation of

Buchholtz relay.

1). TSTRANSCO was asked to keep the ICT and its mechanical

protections under observation for detecting any slippages.

2). TSTRANSCO was also asked to configure capturing of

mechanical protections of ICT’s in the respective relay’s/

station’s event logger.

TSTRANSCO TSTRANSCO mail dated 20.06.2018:

1. Mechanical protections of ICTs is under observation.

2.New relays are available at site and will be commissioned by 2nd week of August-2018. The

mechanical protection of ICTs will be configured in the new relays.

Pending

The issue was discussed in PCSC-58 meeting held on 18.10.2016, when PCSC forum agreed to de-

link the implementation of the Item from the scope of Protection Audit Recommendations

(PAR), and pursue it as part of PCSC Recommendations.

TSGENCO mail dated 30-05-2017

Procurement of Differential Protection relays is under process and the work will be completed

by the end of November 2017.


Procurement of Line Differential Protection Relays is under process and the work will be

completed by the end of January 2018.


TSGENCO informed that they are in constant touch with TSTRANSCO in this regard, and hope to

implement LDP by February, 2018.

TSTRANSCO informed that procurement of LDP relays is under progress, and assured that LDP

would be implemented in 3-months time.

TSTRANSCO MAIL DATED ON 20-01-2018:

The matter is being coordinated with TSGENCO.


As a part of implementation of line differential relays for short distance (Jurala PH to Jurala SS)

feeders, procurement of Line Differential Protection Relays are in process and the work will be

completed by the end of June 2018

Tripping of 400 kV Narnoor –

Srisailam LB line


at Srisailam LB end. Considerable phase difference was

observed between phases at Srisailam end

PAR/

PCSC-58

Provision of line differential protection for Jurala line 1 & 2 (line length-1.45 KM) feeders at 220 kV Jurala HPS

[Carry-Over from Protection Audit Recommendations]

TSGENCO/

TSTRANSCO

Pending

1. TSGENCO to take steps to replace the existing faulty CVT’s

at Srisalam end on 400 kV Srisailam – Narnoor line at the

earliest.

2. TSGENCO to adopt stipulated OVR, Stage-I gradings on all

400 kV transmission lines emanating from Srisaliam LB.

TSGENCO Yet to be informed71/II/7 Pending

Annexure-II

Page 20 of 47

74/II/18 Tripping of 400 kV Srisailam-

Dindi line-2

24-04-2018 at 17:05

hrs

Line tripped at Srisailam end on operation of distance

protection B-E, Zone-1. There was no tripping at Dindi

end and line was holding from Dindi. B-phase to earth

fault occurred in 400 kV Mamidapally-Dindi line-2 at the

same time.

1) It was noted that tripping of 400 kV Srisailam – Dindi line-2

from Srisailam end for a fault on 400 kV Dindi – Mamidipally

line-2 was a typical case of Zone-1 Over-reach. Accordingly

TSGENCO was asked to review DPR, Zone settings of the

subject line along with checking mutual compensation factor.

TSGENCO was also asked to keep the line under observation

so as to determine the integrity and operation of the distance

protection relay under similar conditions.

2) W.r.t. OVR operation on 400 kV Dindi – Mamidipally line-2

at Dindi end, TSTRANSCO was asked to ensure that they kept

required time delay of 100 msec for OVR, Stage-II operation.

TSGENCO/

TSTRANSCO

TSTRANSCO mail dated 20.06.2018:

1. ---Pending.

2. Stage-2 Over Voltage setting time delay is 100msec on 400 kV Dindi – Mamidipally line-2 at

Dindi end. --- Completed

Pending

[with TSGENCO]

41/I/1 GD-1 at 220kV Kadra power

Station of KPCL

16-02-2015 at 12:56

hrs

Triggering incident was B-phase to earth fault had

occurred in 220kV Kadra-Kodasalli line. Line tripped from

Kodasalli end only. 220kV Kaiga-Kadra tripped in Zone-3

from Kaiga end. Tripping of evacuating lines caused bus

shut down at Kadra hydro station.

1. KPCL to make functional the Main2 (EPAC) relay with the

help of KPTCL at the earliest.

2. KPCL to investigate the reason for DC fuse fail during

transient fault in 220kV Kadra-Kodasalli line including the

testing/ checking of DC supply cables, breaker control cables,

and trip coils.

3. KPCL to ensure supply for Main-1& Main-2 protections,

Trip Coils (TC1, TC2) from separate battery banks.

KPCL Mail received on 28-05-2015:

1. Main-2 relays already installed and commissioned.

2. DC fuses are intact. Till date no such incidence occurred.

3. Possibility of DC-1 & DC-2 arrangement and splitting of DC will be reviewed.

Mail received on 07-07-2015 , 21-10-2015 and 23-11-2015:

1. --- Completed.

2. --- Completed.

3. Possibility of DC-1 & DC-2 arrangement and splitting of DC will be reviewed --- Pending

Status received vide KPCL mail dated 14.06.2017:

3. Providing 2 separate DC sources is under process --- Pending


3. Work under implementation stage --- Pending


3. KPCL informed that for providing 2 separate DC sources with new battery charger, LOA &

Work order were placed on M/s Eltek Power system. The works would be completed in March,

2018. --- Pending

Pending





Procurement of Differential Protection relays is under process and the work will be completed

by the end of November 2017.


Procurement of Line Differential Protection Relays is under process and the work will be

completed by the end of January 2018.


TSGENCO informed that they are in constant touch with TSTRANSCO in this regard, and hope to

implement LDP by February, 2018.

TSTRANSCO informed that procurement of LDP relays is under progress, and assured that LDP

would be implemented in 3-months time.


The matter is being coordinated with TSGENCO.


As a part of implementation of line differential relays for short distance (Jurala PH to Jurala SS)

feeders, procurement of Line Differential Protection Relays are in process and the work will be

completed by the end of June 2018

Karnataka

PAR/

PCSC-58

Provision of line differential protection for Jurala line 1 & 2 (line length-1.45 KM) feeders at 220 kV Jurala HPS

[Carry-Over from Protection Audit Recommendations]

TSGENCO/

TSTRANSCO

Pending

Annexure-II

Page 21 of 47

Mail received on 21-10-2015:

1) Anti-pumping contactors of all the nine 220KV Lines are in circuit and tested periodically

during AOH works of lines along with other protections.

2) Completed.

3) Possibility to use both the 220kV buses as main bus under normal operation is under review.

Mail recieved on 23-11-2015:

1) Completed

3) Two bus operation for 220kV buses : In place of existing CT switching relays, High speed

manual heavy duty change over switch of sufficient current capacity will be retrofitted to all

feeders at 220kV station and same will be operated manually during changeover of feeder by

one bus to the other and this arrangement may facilitate to put both buses in service. Time

required for this retrofit is around 90days . However, this work will be taken up only after

retrofitting of electromagnetic relays with numerical relays for Main-2 protection of all 220kV

lines, for which work is in progress.

Status received vide mail dated 10-07-2017:

1) --- Completed.

2) --- Completed. Status received vide KPCL mail dated 14.12.2017:

3) DPR for implementation of Two Bus operation for 220kV bus system has been prepared and

proposal is placed for funds from PSDF. After the approval of the DPR, the work is proposed to

be taken up.


3) KPCL informed that DPR for implementation of Two Bus operation for 220kV bus system has

been prepared and proposal is placed for funds from PSDF. After the approval of the DPR, the

work is proposed to be taken up. Time frame requested for is 2 yrs.

54/II/4 Tripping of 400 kV Raichur TPS-

Mahboobnagar line

05-04-2016 at 10:23

hrs

Line tripped on operation of Backup impedance

protection of line reactor. Direct trip was received at

Mahboobnagar end.

KPCL to keep the functioning of the concerned electro-

mechanical back-up impedance protection relay under

observation, and replace it with a spare at the earliest.

KPCL Status received vide KPCL mail dated 10.07.2017:

The electro-mechanical back-up impedance protection relay is in service. However, Budgetary

offer obtained for the retrofitting of Line reactor protection with Numerical relay and is under

process


Tendering under process


KPCL informed that the new numerical relay for backup impedance protection of Line Reactor

would be provided by June, 2018.

KPCL Mail dated 19.01.2018:

E-tender for the retrofitting work of Line Reactor protections will be invited shortly.

Pending


1. (ii) Hot line water washing stopped and off line water washing is carried out whenever the 400

KV Unit or line is under tripped condition / Shutdown condition. --- Completed

1. (iii) Silicon coating for Unit#8 main & tie breakers carried out in Sep'16 and same is under

observation. Till today in order and good condition. For remaining breakers, since it is big order,

approval for the same is under process. --- Pending

2. Static / Electromechanical relays are existing in all 1 to 7 units. Breaker flash over protection

feature will be enabled (if available) in the numerical relays which will be retrofitted in phased

manner during R&M works.


1.(i) --- Pending

Tripping of 400kV Raichur TPS

Bus-2

13-04-2016 at 21:12

hrs

1.KPCL to undertake the following remedial measures to

avoid breaker flashovers:

(i) Replacing all porcelain insulators with composite insulators

(ii) Carrying out hot-line water washing of all insulators on

regular basis.

(iii) Applying Room Temperature Vulcanizing (RTV) Silicone

high voltage insulator coatings to all bus-connected ceramic

insulators of equipment like CT, PT, CB, Isolators etc.

2.KPCL to take steps to provide dedicated breaker flashover

protection to all breakers at Raichur TPS at the earliest.

Y-ph Pole of Tie-breaker of Unit-4 at RTPS failed. Unit-4

got tripped on operation of Generator Differential,

Reverse power & LBB protection. Operation of LBB

protection led to tripping of BUS-2 at RTPS

46/II/21

54/II/9

Pending

Pending

07-06-2015 at 01:35

hrs

KPCL

KPCL1. KPCL to check the operation of anti-pumping relay on 220

kV side and keep it in healthy condition.

2. KPCL to provide manual reset to the 220 kV side master trip

relay.

3. KPCL to use both the 220 kV buses as main buses under

normal operation, and should go for single bus operation only

during emergencies.

Trippings at 220kV Raichur TPS

Annexure-II

Page 22 of 47


1 (iii) As upgradation of 400kV switchyard equip's to be taken under PSDF funds, Silicon rubber

coating for breakers is deffered till then. --- Pending

2. Replacement by Num relay for Units - 5,6 & 7 completed in the month of Oct-2017. Main-I is

Seimens make and Main-II is ABB make. --- Pending

KPCL mail dated 19.01.2018:

2. Replacement of Numerical relays for Units-5, 6 & 7 have been completed. Referred to OEM for

providing the Breaker flashover protection for all the breakers.

54/II/13 Tripping of Units at 220 kV

Raichur TPS

15-04-2016 at 15:36

hrs

During testing of retrofitted distance protection in 400kV

Raichur-2 feeder, LBB protection trip DC got extended to

Bus trip. This resulted in tripping of 220kV bus at RTPS

and all connected 220 kV elements. Unit-4 which is

connected to 400 kV Bus got tripped due to tripping of

Station Utility Transformer that is connected 220 kV bus

In view of the availability of two buses along with healthy bus-

coupler at 220 kV RTPS, KPCL is recommended to put in

service the double-bus operation at 220 kV RTPS by suitably

distributing loads within 15 days.

KPCL Status received vide KPCL mail dated 10.07.2017 & 14.12.2017:

Two Bus operation for 220kV bus is being carried out whenever required. However scheme for

tripping of one bus during LBB/fault and maintaining the other bus intact by tripping B/C breaker

will be taken up in R&M works.


3) KPCL informed that DPR for implementation of Two Bus operation for 220kV bus system has

been prepared and proposal is placed for funds from PSDF. After the approval of the DPR, the

work is proposed to be taken up. Time frame requested is 2 yrs.

Pending

Tripping of 400kV Raichur TPS

Bus-2

13-04-2016 at 21:12

hrs

1.KPCL to undertake the following remedial measures to

avoid breaker flashovers:

(i) Replacing all porcelain insulators with composite insulators

(ii) Carrying out hot-line water washing of all insulators on

regular basis.

(iii) Applying Room Temperature Vulcanizing (RTV) Silicone

high voltage insulator coatings to all bus-connected ceramic

insulators of equipment like CT, PT, CB, Isolators etc.

2.KPCL to take steps to provide dedicated breaker flashover

protection to all breakers at Raichur TPS at the earliest.

Y-ph Pole of Tie-breaker of Unit-4 at RTPS failed. Unit-4

got tripped on operation of Generator Differential,

Reverse power & LBB protection. Operation of LBB

protection led to tripping of BUS-2 at RTPS

54/II/9 PendingKPCL

Annexure-II

Page 23 of 47

58/I/3

(GD)


Kadra power station of KPCL

06-09-2016

at 14:40 hrs

LBB of 220kV Kodasalli breaker at Kadra end got

operated which resulted in tripping of Bus at Kadra and

in turn led to tripping of all elements

1) KPCL to check settings of LBB protection in all relays from

which it was implemented, and ensure that their

configuration, logic, and timing are in order at their 220 kV

Kadra PH.

2) KPCL to furnish details regarding the existing LT auxiliary

supply arrangement at their 220 kV Kadra PH, and take steps

to provide a suitable Auto-Main-Fail (AMF) panel for DG set to

effect its auto-starting in case of failure of LT supply.

3) KPCL to ensure time-sync of all relays (DR’s & EL’s) with GPS

at their 220 kV Kadra PH.

4) KPCL to provide stand-alone Event Logger at their 220 kV

Nagjheri PH.

KPCL Status received vide KPCL mail dated 14.06.2017:

1. All logics checked and found normal. LBB timing checked and found 200msec as per KPTCL

MRT recommendation. - Completed

2. Work Under Progress ---- Pending

3. New GPS System commissioned along with new numerical and synchronised with GPS system -

Complied

4. Work Under Progress ---- Pending

Status received vide mail dated 14.12.2017:

1),3),4) Completed

2. Auto Start of DG set is taken up --- Pending


2. KPCL informed that for AMF of DG, Scheme prepared & material procurement under process.

The AMF scheme will be implemented in January 2018. --- Pending

3. The GPS system commissioned on Nov 2016 & all the numarical relay time synchronised with

GPS ---- Completed

Pending


Nagjheri substation of KPCL

21-01-2017

at 00:38 hrs

Triggering event was the fault on 220 kV Nagjheri

–Kodasalli line-2. Both buses of 220 kV Nagjeri power

station of KPCL got

de-energized.

1. KPCL to adopt the following VT fuse-fail logic for all 220 kV

lines emanating from NPH:

“Under VT fuse fail condition, distance protection shall

normally be kept blocked. However, upon detection of a fault

(sensed by negative sequence component), blocking of

distance protection shall give rise to operation of its inherent

Over-Current protection set with a definite time delay of 500

msec”.

2. KPTCL/ KPCL to revise Zone-2, Zone-3 and Zone-4 (reverse)

timings of DPR of all 220 kV lines emanating from Nagjheri PH

in line with Ramakrishna Committee guidelines.

KPCL Status received vide mail dated 14.06.2017:

1. Already settings are discussed with EE(RT), Hubli and soon relays will be tested for VT fuse fail

condition.

2. Timings of Zones were set as per the recommendations of CE(RT) & R&D, KPTCL, Bangalore &

EE(RT), KPTCL, Hubli.Regarding revision of timings will be carried out in coordination with

EE(RT), KPTCL, Hubli.


1. As per the recommendations of SRPC and SRLDC, in the event of VT fuse fail, non directional

over current and earth fault feature is enabled in the distance relay with a definite time lag of

600msec on pick up and the same is tested by KPTCL Hubli(RT) and KPCL jointly on 18.05.2017.

--- Completed

2. --- Pending


2. KPCL informed that Zone settings of distance relays of all 220 kV lines emanating from

Magjheri SS had been revised in line with Ramakrishna Committee guidelines.. --- Completed.

Pending

69/II/8 Tripping of 220 kV Kaiga- Kadra

line-1

06-10-2017 at 22:22

hrs

While de-synchronising of Unit-2, B-phase pole of GCB

did not open and pole descrepancy relay operated.

Hence all 220KV lines CB hand tripped.

KPCL to take steps to replace the existing static protection

relays for Generator Units and Generating Transformers

(GT’s) with suitable Numerical relays at their 220 kV Kadra PH.

KPCL Yet to be informed Pending


Sedam, Shahapur, Shahabad,

Kapanoor, Humnabad and

Halabarga Stations of KPTCL

01-02-2018

at 17:46 hrs

High resistance fault occurred in 110kV Sedam-Chittapur

line near Sedam end. Line DEF operated and backup OC

protection of 100MVA transformer operated at Sedam

end. But line breaker and transformer HV breaker didn’t

open due to problem in trip circuit. This resulted in

cascade tripping of upstream feeders and power supply

was lost to six 220kV stations of KPTCL.

KPCL to disable GFC protection on all lines emanating from

their generating stations.


Annexure-II

Page 24 of 47


Varahi power station

15-03-2018 at 22:36

hrs

There was Y-phase to ground fault on 220 kV Varahi -

Shimoga line-2. Consequent to persisting fault in ‘Y’

phase, the breaker failure protection operated resulting

in operation of 220KV bus bar protection at Varahi,

tripping all the connected lines and Varahi running units.

KPCL to take steps to put double-bus operation into service at

their 220 kV Varahi PH.


73/II/6 Multiple trippings at 220 kV

Sharavathy Power station.

15-03-2018

at 22:05 hrs

The incident happened during shifting of Unit-8 from 220

kV North West bus to 220 kV South West Bus. The 220 kV

buses got tied together without synchronizing which

resulted in operation of bus bar protection.

KPCL to take steps to using full-fledged Double Main-Bus

system with four sections instead of the present Single Main-

Bus with two sections at their 220 kV Sharavathy GS.



1. In view of operating 220kV Ambewadi SS in split bus mode, action is being taken up by KPTCL.

Problem in the 220kV bus coupler breaker is attended and isolator overhauling work is under

progress. Spilt bus operation at Ambewadi will be made possible at the earliest. --- Pending

2. ICT Protection system at Ambewadi and trippings occured at Supa GS during the instance is

checked up and remedial measures already furnished in this regard.

---- Completed


1. Action is being taken by KPTCL for operating Ambewadi in split bus mode. Problem in bus

coupler breaker is attended.Isolator overhaulling work is completed.PTs are already provided to

220kV Bus-II. After commissioning of Bus-II PTs, Ambewadi can be operated in split bus mode.

Pending works will be completed within a months time.KPTCL Mail dated 16.12.2017 & Review Meeting dated 19.12.2017:

1. Recommended works at Ambewadi have not been taken up due to various problems faced

due to poor response from the turn key agency M/s ERL. A site meeting is planned during this

month to discuss about further plan of action for attending SRPC recommendations pertaining to

the Sub station.

The issue was discussed in the review meeting. Considering the importance of the substation

and delay in executing the works, it was decided to escalate all pending issues relating to

Ambewadi SS to KPTCL top Management for early completion.

GD-1 at 220kV Ambewadi Station

of KPTCL

Triggering incident was B-phase to earth fault in 220kV

Ambewadi- Nagzari line-1. B-pole of breaker did not

open at Ambewadi end. LBB protection not available at

Ambewadi end. All elements tripped on Zone-2 from

remote ends.

22-12-2014 at 21:22

hrs

1. Till the completion of R&M works for bus bar and LBB

protection, KPTCL shall explore the possibility of having split

bus operation at Ambewadi and submit the details of the

same to PCSC forum.

2. KPTCL shall provide the details of the tripping of Supa hydro

station connected downstream from 110 kV bus.

PendingKPTCL40/I/1

Annexure-II

Page 25 of 47


Procurement of Bus bar and LBB protection is in the final tendering stage. 2. Action is being

taken to restore the carrier protection for 220kV Sedam-Tandoor line. AR will be enabled.


1. Procurement of Bus bar and LBB protection is in the final tendering stage.

2. Action is being taken to restore the carrier protection for 220kV Sedam-Tandoor line. AR will

be enabled after restoration of PLCC.

KPTCL mail received on 23-01-2016:

1. Bus bar protection panels pocured and erected at Sedam. Wiring , testing ,commissioning is

being taken up.Planned to complete by April 2016.

2. Action is being taken to restore the carrier protection for 220kV Sedam-Tandoor line. AR will KPTCL Mail dated 16.12.2017:

1 & 2) Replacement of Bus Bar Protection is included under R&U project. Awarded to M/s GE Ltd.

Panels have alredy been supplied by the Agency. The work will be taken up on top priority.


KPTCL informed that the works relating to put A/R in service are going on at their Sedam SS, and

assured that it would be put into service by February, 2018.

KPTCLKPTCL was requested to explore the possibility of providing

A/R feature to this line and submit the remedial measures to

the PCSC forum.

Complete outage at 220kV

Sedam Substation of KPTCL (GD-

1)

KPTCL 1. KPTCL to provide Bus bar and LBB protections for 220 kV

bus at Sedam S/s.

2. KPTCL to implement A/R feature on 220 kV Sedam-Tandur

inter-state line.

R-Phase to ground fault occurred on 220kV Sedam-

Shahpur line. Fault not cleared from Sedam end due to

stuck-breaker condition. While the Sedam- Sahapur line

tripped from Shahapur end in Zone-1, the other 220 kv

lines from Sedam tripped at remote ends in Zone-2. This

caused complete outage of 220kV Sedam substation.

27-01-2015 at 8.00

hrs

220kV Sedam-

Tandur line


Carrier protection is being restored for 220kV Sedam-Tandoor line at Sedam end. After restoring

the carrier protection , AR will be enabled.

KPTCL mail recieved on 23-01-2016:

Carrier protection is being restored for 220kV Sedam-Tandoor line at Sedam end. After restoring

the carrier protection , AR will be enabled.


SEE,SCADA to update the latest status


Action is being taken to restore carrier protection.AR will be enabled once carrier signal is

restored.

KPTCL Mail Recieved dated 22-11-2017:

The Wave traps required are supplied under R&U project and the same is to be commisioned at

Sedam end for restoration of PLCC. Also,M-II distance relays have already been supplied by GE

Ltd.




be taken up on top priority through GE Ltd.




40/IV/1 20-12-2014

at 22:20 hrs

Line tripped on Yphase to earth fault from both the ends Pending

Pending41/I/4

Annexure-II

Page 26 of 47


Sedam substation of KPTCL

15-02-2015

at 14:24 hrs

Fault occurred in 220kV Sedam-Shahpur line 1. KPTCL to provide Bus Bar protection and LBB protection at

Sedam S/s and furnish the status of their implementation to

PCSC forum.

2. KPTCL to implement A/R feature on 220 kV Sedam-Tandur

inter-state line.

KPTCL Mail received on 27-05-2015:

1. Bus Bar protection will be provded under R&U.

2. A/R yet to be enabled.






Bus Bar Protection panel and required Wave traps are supplied under R&U. Wave trap to be

commisioned in Tandoor line and PLCC to be restored.Once PLCC is restored AR will be enabled.


1. Replacement of Bus Bar Protection is included under R&U project. Awarded to M/s GE Ltd.

Panels have alredy been supplied by the Agency. The work will be taken up on top priority.

2. AR feature will be enabled during retrofitting of Main-2 relays.


1 & 2) KPTCL informed that the works are under progress and are targeted to be completed by

February, 2018.

Pending

42/I/2

(GD)


Ambewadi substation of KPTCL

12-03-2015 at 7:51

hrs

Fault in 220kV Ambewadi-Nagjheri line-2 1. KPTCL shall provide A/R feature on Ambewadi – Ponda 220

kV D/C inter-state line.

2. Till the completion of R&M works for bus bar and LBB

protection, KPTCL shall explore the possibility of having split

bus operation at Ambewadi and submit the details of the

same to PCSC forum.

KPTCL Mail received on 29-07-2015:




KPTCL Mail Recieved dated 22-11-2017 & 16.12.2017:

1.Enabling the AR feature was discussed during PCSC meetings and since Ambewadi-Ponda and

Ambewadi-Xeldom lines are radial lines, it was decided that enabling AR is not required. To clear

the faults in the abovelines early, the timings of the Zone 2 was reduced to 150mS and the Back

Up EFR timings have been reducedto 150mS. --- Completed

2.The planned works as per R&M could not be taken up due to the problem with the vendor and

could not be taken up under R&U project due to administrative reasons. ---- Pending


2. The issue was discussed. Considering the importance of the substation and delay in executing

the works, it was decided to escalate all pending issues relating to Ambewadi SS to KPTCL top

Management for early completion.

Pending

Annexure-II

Page 27 of 47


Peenya Substation in Karnataka

27-09-2015

at 4:23:17 hrs

All connected 220kV lines and transformers were taken

on 220kV North bus as South bus was under shut down

for conversion of strung bus to rigid bus and isolator

replacement under R&M works. Failure of HV side Y

phase CT of 150MVA Transformer-3 occurred at Peenya

Substation which resulted in operation of Differential

and HV REF protection. The failure of CT also resulted in

a 220kV bus fault in North Bus.

KPTCL to revise distance relay settings at Nelamangala end

for 220 kV Nelamangala – Hebbal - Peenya line – 1 for the

effective line length of 17 km. These new settings can be

appropriately reviewed as and when the tie-arrangement at

Hebbal is done away with.

KPTCL KPTCL mail received on 25-05-2016:

Presentl 220kV Nelamangala -Hoody (i.e. nelamangala-Peenya-Hebbal -Hoody line is made LIILO

at Yelahanka sub station and breaker at Peenya is kept open, necessary modification in distance

relay settings adopted for new configuration.


Since usage of this line as an Incoming line at Peenya is required for emrgency purposes, the

settings of this line at Nelamangala end will be reduced to 17KMs and as a special case, to cover

the rest of the length of the line, Zone 2 timing will be reduced to 150 ms.


The revised settings to be adpopted for this line considering reduced protected line length(

17KMs) is issued as a special case which will be implemened and tested during scheduled

outage.


KPTCL informed that the revised setting would be implemented by December, 2017.


Attended . Revised settings adopted at Nelamangala and connectted sub stations.

Pending

Annexure-II

Page 28 of 47

48/I/3 Outage of 220kV Ambewadi

station in Karnataka

30-09-2015 at 10:41

hrs

220kV Ambewadi-Nagjheri line-2 tripped on B-phase to

earth fault. This resulted in loss of supply to 220kV

Ambewadi bus. 220kV Ambewadi-Ponda line-1&2 were

hand tripped after deenergization of bus at Ambewadi.

KPTCL to fast-track providing A/R on all 220 kV lines

emanating from Ambewadi SS to prevent Station shut-down

on temporary faults.

KPTCL KPTCL mail received on 23-01-2016:

Will be complied in a months time.


Enabling the AR feature was discussed during PCSC meetings and since Ambewadi-Ponda and



Up EFR timings have been reducedto 150mS.


Enabling the AR feature was discussed during PCSC meetings and since Ambewadi-Ponda and



Up EFR timings have been reduced to 150mS. In view of the above, it is requested to drop the

issue from this list.


KPTCL informed that AR would be enabled at Ambewadi end for lines other than Ponda and

Xeldom lines during retrofitting of Back Up protection by Distance protection relay at Ambewadi.

Considering the importance of the substation and delay in executing various works, it was

decided to escalate all pending issues relating to Ambewadi SS to KPTCL top Management for

early completion.

Pending

KPTCL Mail received dated 25-05-2016:

SEE, RTC, Bangalore to update the status


Providing numerical bus bar protection to 400kV buses and GPS time synchronising equipment

at Guttur is considered under R&U. Work is awarded to M/s Alstom, execution will be taken up

shortly.


GPS and accessories will be supplied during May 2017, expected to complete the work within a

month after supply of materials.


1). The work of replacing static type 400kV Bus Bar Protection scheme by numerical BBP is

under progress at Guttur.

--- Pending

2). GPS time syncronising device is expected to be supplied before end of December 2017 ---

Pending


1) & 2) KPTCL informed that the works are under progress, and are targeted to br completed by

February, 2018.


GPS time synchronisaionis provided for protection relays under R&U project. Replacement of

400kV BBP by numerical BBP is envisaged under R&U works. Additional quantity of controls

cables required to take up the BBP replacement work. Supply of control cables awaited.

Multiple tripping at 400kV Guttur

SS

1. KPTCL to configure all DR’s and EL’s at 400 kV Guttur SS so

that they will also get triggered for BBP operation.

2. KPTCL to ensure time-synchronization of all DR’s and EL’s

with GPS at their 400 kV Guttur SS.

51/II/21 Failure of Lightning Arrestor of Y-phase Line Reactor of

400kV Guttur-Hiriyur line-1 and line tripped on distance

protection Zone-1. Bus-bar protection of 400kV Bus-2 at

Guttur substation also got operated during the event

sensing this through fault. 400/220 kV ICT-1 & 2 at

Guttur, 400kV Kaiga-Guttur-2, 400kV

Guttur-Narendra-2, 400kV Guttur-Hiriyur-2 and 400kV

Guttur-Munirabad which are on 400kV Bus-2 got tripped

during the incident. 400kV Guttur-Narendra-1 which was

on Bus-1 also tripped at the same time.

17-01-2016 at 18:53

hrs

PendingKPTCL

Annexure-II

Page 29 of 47


Shimoga substation

22-02-2016 at 15:03

hrs

220kV Bus Bar protection operated during failure of R

phase CT in DVG-2 line bay.

KPTCL to operate 220 kV Shimoga on multi-bus operation

under normal conditions, and put it on single-bus operation

only under emergency conditions.

KPTCL KPTCL Mail received dated 25-04-2017:

Replacement of existing BBP by new BBP with 4 zone protection is being taken up under R&U.


GE Ltd has already supplied the necessary Bus Bar protection panels for replacement of the

existing static type BBP by new numerical BBP with 4 zone protection under R&U project. The

work of commissioning the same will be taken up shortly.


Due to operational constraints two/ multi bus operation is not being implemented.


It was noted that Shimoga SS is having required configuration for providing double-bus

operation. However, due to large no. of feeders (15 in no) with variable gneration at certain

remote ends like Varahi, the flows on these lines are bound to vary. As such it is necessary to

zero in on appropriate arrangement of feeders on different buses so that bus-isolators of the

feeders are not overloaded.

The issue was discussed. KPTCL was asked to try out multi-bus operation on trial basis to arrive

at suitable arrangement of feeders.

Pending


Peenya Substation of KPTCL

16-03-2016 at 11:39

Hrs

220kV Peenya-Nelamangala-3 tripped on B-E fault at

both ends. At the same time, 220kV Peenya-

Nelamangala-4 tripped on R-Y fault only at Nelamangala

end, and was in service from Peenya end. Due to tripping

of these two lines, 220kV Peenya-Nelamangala-2 tripped

on overcurrent protection.

KPTCL to furnish a report on the tripping of 220 kV Peenya-

Nelamangala line-4 Nelamangala detailing the remedial

measures taken including the settings adopted for Z1B (Zone

extension) and Power Swing Block.

KPTCL KPTCL Mail received dated 25-05-2016:

SEE, RTC, Bangalore to update the status


Since usage of this line as an Incoming line at Peenya is required for emrgency purposes, the

settings of this line at Nelamangala end will be reduced to 17KMs and as a special case, to cover

the rest of the length of the line, Zone 2 timing will be reduced to 150 ms.


Considering it as special case, revised settings to be adpopted for this line considering reduced

protected line length( 17KMs) is issued which will be implemened and tested during next

scheduled outage.


KPTCL informed that the revised settings would be implemented by December, 2017.

Pending

57/II/1 Tripping of 220 kV Chikkodi-

Mudshingi and 220 kV Chikkodi-

Talandage lines

01-07-2016 at 03:03

hrs

Triggering incident was failure of B-ph PT of 220kV Bus-2

(western bus) at 220KV Chikkodi substation. 220KV

Chikodi- Belgaum-I line tripped on DEFR (Inst), 220KV

Chikkodi-Kudachi line tripped on Distance protection and

also 100MVA transformer-2 tripped on E/F protection.

1.KPTCL to take steps to provide busbar protection at their

220 kV Chikkodi inter-regional substation, and furnish a time-

line for the same.

2.KPTCL to review distance protection settings for 220 kV

Chikkodi – Kudachi line.

3.KPTCL to furnish equipment failure report of the current

incident to PSE&TD Division of CEA with a copy marked to

SRPC.

KPTCL KPTCL Mail Recieved dated 22-11-2017:

1. The necessary Bus Bar protection panels are already supplied to Chikkodi under R&U project.

Presently R&U works at sub stations subjected to audit are taken up. After completion of PAR

works, the baove works are planned.

--- Pending

2. --- Pending

3. --- Pending

KPTCL mail dated 16.12.2017:

1.The necessary Bus Bar protection panels are already supplied to Chikkodi under R&U project.

Control cables have to be supplied. Presently R&U works at sub stations subjected to audit are

taken up. After completion of PAR works at 26 Sub stations, remaining works will be taken up

through M/s GE.

--- Pending.

2. --- Pending

3. --- Pending


1. KPTCL informed that BBP would be provided by April, 2018.

---- Pending

2. KPTCL informed that DPR settings had been reviewed.

---- Completed

3. EFR on failure of B-ph PT of 220 kV Bus-2 had been furnished to CEA. ---- Completed

Pending

Annexure-II

Page 30 of 47

62/II/3 Tripping of 220 kV Bus 2 and

connected elements (220kV HAL

#1 and 2, 400/220 kV ICT- 1, 2

and 220/66 kV ICT-2) at 400/220

kV Hoody substation of KPTCL

(Load loss : 590 MW)

09-01-2017

at 23:06 hrs

Failure of R-phase CT of 220/ 66 kV transformer-2 at

220kV Hoody end resulted in a bus fault in 220kV Bus-2.

Fault was cleared by backup protection of ICT's (220kV

lines were being radially operated) due to absence of

busbar protection

1. KPTCL to provide Busbar protection at their 220 kV Hoody

SS at the earliest.

2. KPTCL to furnish an Equipment Failure Report on CT failure

to CEA with a copy marked to SRPC.

KPTCL KPTCL mail received dated 25.04.2017:

Numerical BBP is being provided under R&M works.


1. Numerical Bus Bar protection panels have already been supplied as a part of R&M works

awarded to GE Ltd. Due to issue regarding the sectionaliser CTs, the work had stopped. Now the

same is resolved and the the above work will be taken up after supply of sectionaliser CTs. ---

Pending

2. --- Pending


1. Numerical Bus Bar protection panels have already been supplied as a part of R&M works

awarded to GE Ltd. Due to issue regarding the sectionaliser CTs, the work had stopped. Now the

same is resolved and the the above work will be taken up after supply of sectionaliser CTs. ---

Pending

2. --- Pending


1. KPTCL informed that BBP at 220 kV Hoody would be provided by March, 2018.

---- Pending

2. EFR on failure of R-ph CT of 220/ 66 kV Transformer-2 had been furnished to CEA. ----

Completed

Pending

62/II/5 Tripping of 220 kV South Bus and

connected elements (220kV HSR,

220kV Nagnathpura, 220 kV

Harohalli, 220 kV

Subramanyapura, 220 kV

Tataguni, 220 kV Mallur and

400/220kV ICT-2 and 3) at

400/220kV Somanhalli

substation of KPTCL

(Load loss: 850 MW)

20-01-2017 at 14:34

hrs

Triggering incident was fault in 66 kV Somanahalli -

Bannerghatta line and fault was cleared by operation of

Back-up OCR at Somanahalli end.

KPTCL to provide numerical Busbar Protection at their 220 kV

Somanahalli SS at the earliest.

KPTCL KPTCL mail received dated 25.04.2017:

Numerical BBP is being provided under R&M works


Tesing & Commissioning of numerical BBP at Somanahalli is under progress. There was some

technical issue wth BBP scheme supplied to Somanahally which is being finalised in consultation

with OEM SIFANG. Numerical BBP will be commissioned at Somanahally within a month's time.


Numerical Bus Bar protection Scheme will be commissioned at Somanahally before end of

December 2017

Pending

69/III/5 Tripping of 220 kV Sedam-Tandur

line

10-10-2017 at 00:50

hrs &

10-10-2017 at 17:27

hrs

Tripped on Y-Phase to ground fault due to distance

protection operation. Auto reclosure could not be

validated from the submitted DR/EL.

KPTCL to enable and put A/R into service from Sedam end on

220 kV Sedam – Tandur S/C line.

KPTCL Review Meeting dated 19.12.2017:



Pending

72/I/3 Complete outage of 220kV TK

Halli, Kadakola,

Chamarajanagara and

Maduvinahally substation of

KPTCL

27-01-2018

at 12:41 hrs

Snapping of B-phase Jumper in 220 kV Bastipura -

Kadakola line-1 resulted in tripping of the line. 220kV

Bastipura-Kadakola line-2 also got tripped during fault in

line-1. Due to tripping of above lines bus shutdown

occurred at TK Halli, Madhuvanahally, Chamarajanagara

and Kadakola stations due to overloading of connected

lines.

1. KPTCL to provide the detailed logics of SPS proposed in

Hotagally – Bastipura – Kadakola area, and take steps to

implement the same at the earliest.

2. KPTCL to take steps to put A/R into service on 220 kV

Bastipura – Kadakola lines at the earliest.

KPTCL KPTCL Mail dated 26.06.2018:

1. ---Pending.

2. Auto Reclosure enabled for 220kV Bastipura Lines at Kadakola end. Power Grid has been

requested to enable AR for Kadakola lines at Bastipura Sub Station. ---Completed.

Pending

Annexure-II

Page 31 of 47


Sedam Substation

01-04-2018 at

19:56hrs

Triggering incident was fault in 220 kV Sedam-Tandur

line. 220 kV Sedam-Shahapur, 220 kV Sedam-RTPS lines -

1&2 and 220 kV Sedam-Tandoor line tripped from RTPS,

Shahpur and Tandoor. Tripping of incoming lines to

Sedam caused shut down at Sedam Sub Station resulting

in complete outage of the station.

KPTCL to adopt the following VT fuse-fail logic for all 220 kV

lines emanating from Sedam:

“Under VT fuse fail condition, distance protection shall

normally be kept blocked. However, upon detection of a fault

(sensed by negative sequence component), blocking of

distance protection shall give rise to operation of its inherent

Over-Current protection set with a definite time delay of say,

500 msec”.

KPTCL KPTCL Mail dated 26.06.2018:

Attended in all 220kV bays at Sedam.

Pending


Ambewadi station

02-04-2018 at

13:46hrs

Loss of supply occurred to 220 kV Ambewadi station due

to tripping of 220kV Nagzhari-Ambewadi line-2 (Source)

from Nagzhari power station. After bus dead, Ambewadi-

Ponda lines – 1 & 2 were hand-tripped. In antecedent

conditions, 220kV Ambewadi - Nagjheri ckt-1, 220kV

Ambewadi-Narendra Ckt-1 &2 were out of service.

1). KPTCL to review operation of SPS at NPH for proper

functionality and changed network conditions (reduction of

generation with tripping of evacuating lines) and put it into

service at the earliest.

2). KPTCL to furnish equipment failure report of the current

incident (R-phase CT in Nagjheri – 1 bay at Ambewadi SS) to

PSE&TD Division of CEA with a copy marked to SRPC.

KPTCL Yet to be informed Pending

74/II15 Multiple Trippings at 400/220kV

Guttur station

21-04-2018 at 12:50

hrs

Triggering incident was fault in 220 kV Davanagare -

Shimoga line. Bus bar protection operated at Guttur

resulting in tripping of all the connected elements. 220

kV Guttur was on single bus operation due to CVT

problem in Bus-2.

KPTCL to put double-bus operation at their 220 kV Guttur

substations by attending to Bus-2 CVT problem.

KPTCL Yet to be informed Pending

21-04-2018 at 12:55

hrs

21-04-2018 at 13:33

hrs

yet to be informed PendingTripping of 400 kV Nelamangala-

Bidadi line-1&2 and 400/220 kV

ICT-3 at Nelamangala

Mal-functioning of LBB relay provided on the 400 kV side

of ICT-3 resulted in Bus-B tripping at Nelamangala

KPTCL to furnish a detailed action taken report for the subject

trippings including remedial measures taken.

KPTCL74/II/16

Annexure-II

Page 32 of 47


Ambewadi Substation of KPTCL

29.10.2015 at 14:34

hrs

220kV Nagjheri-Ambewadi line-1 tripped at 13:33 hrs

due to B phase to earth fault. Ambewadi was radially fed

from Nagjheri power station through 220kV Nagjheri-

Ambewadi line-2. Tripping of this line caused 220kV Bus

shut down at Ambewadi and remaining lines and

transformers were hand tripped

1. KPCL to provide A/R on all 220 kV lines emanating from

Nagjheri PH.

2. KPTCL to provide A/R on all 220 kV lines emanating from

Ambewadi SS.

KPCL/ KPTCL KPTCL Mail Recieved dated 22-11-2017:

1. coordination of KPCL has been requested for enabling AR lines terminated to Nagajari.

2. AR will be enabled at Ambewadi end for lines other than Ponda and Xeldom lines during

retrofitting of Back Up protection by Distance protection relay at Ambewadi.

KPTCL Mail dadted 16.12.2017 & Review Meeting dated 19.12.2017:

1. KPTCL informed that Coordination of KPCL has been requested for enabling AR lines

terminated to Nagajari.

--- Pending

2. KPTCL informed that AR would be enabled at Ambewadi end for lines other than Ponda and

Xeldom lines during retrofitting of Back Up protection by Distance protection relay at Ambewadi.

-- Pending

Pending

Status informed during Special Meeting held on 03.06.2016:

1. KPTCL informed that the matter had been taken up with concerned Line Operation and

Maintenance wing to carry out corridor clearance and maintenance as per schedule to avoid

frequent line faults in this corridor. A letter had also been addressed to Chief Engineer,

Bhagalkot zone, to ensure lines in & around Kali complex are maintained in healthy condition. ---

Completed

2. KPTCL assurd that the final modified SPS would be implemented at Nagjheri PH at the earliest.

------ Pending

3. KPCL informed that Nagjhari- Kodasalli Lines 1 & 2 had been kept in service since 23.05.2016

@ 08.06hrs.

--- Completed

KPTCL Mail received dated 28-06-2016:KPTCL Mail dated 16.12.2017:

1) & 3). --- Completed.

2). Proposed revision in existing SPS scheme is already submitted to SRLDC/SRPC., yet to be

discussed and approved by the SRPC forum --- Pending


2. The SPS proposed by KPTCL was discussed and the PCSC forum suggested certain changes for

suitable incorporation. KPTCL agreed to look into the same and assured that the modified SPS

would be furnished by January, 2018.


Nagjheri power station and 220

kV Ambewadi substation of

KPTCL

Pending 1. To avoid tripping of transmission lines on transient faults,

KPCL/ KPTCL is recommended to carry out periodic patrolling

of lines, and ensure their proper maintenance by carrying out

jungle/ bushing clearance and trimming of tree branches

within the RoW of transmission lines as per the SRPC

transmission line patrolling guidelines (available under the

menu item "All Uploads/ Operation/ Miscellaneous/

Transmission Line Patrolling Protocol / Guidelines for

Southern Region" on SRPC website).

2. KPCL/ KPTCL to review operation of SPS at NPH for

functionality (reduction of generation with tripping of

evacuating lines) and healthiness.

3. KPCL to put 220 kV Kodasalli - Nagjheri D/C lines into

service if more than 200 MW generation from Kali Complex

(with Nagheri Contribution not less than 50 MW) is ensured

on sustained basis.

51/I/3 220kV lines from Nagjheri power house started tripping

from 11:00 hrs due to fault in lines. The sequence of

tripping is shown in SOE list. At 12:33 hrs, 220kV

Narendra-Ambewadi lines-1&2 got tripped which

resulted in loss of evacuation path to Nagjheri station

resulting in tripping of running Units and complete

outage at Nagjhheri power station. 220kV Ambewadi

station also got de-energized due to tripping of source

feeders i.e. 220kV Narendra-Ambewadi-1&2 and 220kV

Nagjheri-Ambewadi-1&2.

22-02-2016 at 12:36

hrs

KPCL/ KPTCL

Annexure-II

Page 33 of 47

Ambewadi Narendra line-2 tripped on fault and 220kV

ambewadi Narendra line-1 tripped due to over-loading.

Running Units at Nagjheri also tripped during the event

due to tripping of evacuating lines

1. KPCL to furnish a report on the reasons for Unit-6 tripping

at Nagjheri PH.

2. KPCL/ KPTCL to modify suitably the SPS at Nagjheri Power

House such that it would also factor in the over loading of

Ambewadi-Narendra lines.

3. KPCL to put 220 kV Kodasalli - Nagjheri D/C lines into

service if more than 200 MW generation from Kali Complex

(with Nagheri Contribution not less than 50 MW) is ensured

on sustained basis.

TANGEDCO mail dated 15.04.2017:

1) New Relay is tested and ready for replacement.Now all 5 units are in service.The relay will be

replaced when lesser units are in service. --- Pending

2.a)Steps are taken to renovate & mordernization of all the control panel into Numerical based

control panels. --- Pending

2.b) Since 230 KV indoor switchyard has no spare space providing dual CT`s is not fessible. --

Completed

3) Procurement of EL & DR is under progress. --- Pending


1) Check zone New Relay is replaced on 17.04.2017 -- Completed.

2. --- Pending

3. --- Pending


2).P & C wing gives clearance to TTPS to procure the Bus bar protection relays and protection

relays and SER / DR system vide Lr.CE/P&C/SE/D/EEPC4/AEE3/F.TECH/D.27/17 Dated:

05.10.2017. To get administrative approval budgetary offer has bar protection relay from various

companies ----Pending

3). SRPC vide Lr: SRPC/SE- III/CEA/2017/6450/DT:27.10.2017 gives features of SER/DR.

Budgetary offer will be called for SER / DR having above features. ---Penidng


2) & 3) The issue was discussed and TANGEDCO was asked to provide time-line for implementing

the recommendations.

Mail dated 29.01.2018:

Procurement work is under progress and will be completed by December 2018.

PendingKPCL/ KPTCL18-03-2016 at 14:40

hrs

Failure of Bus Section-I Y-ph CT resulted in operation of

bus-bar protection for Bus Sections -I & II. Running

Units#1, 4 and 5, 230 kV Kayathar, 230kV Kudankulam,

230kV Sterlite, Station Transformer-1, 2 & 3 got tripped

during the incident. Unit – 2 & 3 were not in service.

TANGEDCO1. TANGEDCO to replace existing Check-Zone relay with a new

one possessing required performance.

2. TANGEDCO to take steps to provide numerical busbar

protection at their 220 kV Tuticorin TPS. TANGEDCO may also

explore providing dual CT’s (on either side) for all B/S

breaakers at the time of commissioning of numerical BBP, if

there were no space constraints.

3. TANGEDCO to take steps to provide for standalone Event

Logger (EL) and standalone Disturbance Recorder (DR) with

automatic downloading facility to a centralized server.

Tamil Nadu

25-01-2017 at 22:36

hrs

Tripping of running Units &

230kV feeders at Tuticorin TPS of

TANGEDCO

(Gen Loss: 640 MW)

53/I/3

62/II/7


Modifications to be carried in Nagzari SPS logic is submitted to SRLDC/SRPC for verification and

approval


1. Tripped since there was evacuation problem and there were only two lines NA-1 and NA-2 ----

Completed

2. Will be reviewed in consultation with EE(RT), KPTCL, Hubli. --- Pending

3. Both the lines are in charged condition. --- Completed.


2. Proposed revision in existing SPS scheme is already submitted to SRLDC/SRPC., yet to be

discussed and approved by the SRPC forum. --- Pending


Pending

Complete outage of 220kV

Ambewadi station of KPTCL and

220kV Nagjheri of KPCL

Annexure-II

Page 34 of 47

TANTRANSCO MAIL DATED 22.05.2018 & 08.06.2018:

230kV Othakalmandapam - Myvadi feeder replacement of kundha conductor with Zebra and

tower replacement work has been sanctioned. Work will be taken up. Timeline: June-2018.

TANTRANSCO Mail received on 19-02-2016 and 24-03-2016:

Revision of Bus Bar Protection setting was carried out. The stabilizing voltage setting was raised

from 410 to 450 volts. After completing the necessary test, the bus bar protection put in to

service on 29.12.2015.

Mail Received on 27-04-2016 ,16-06-2016,25-07-2016 & 24-09-2016:

Revision of Bus Bar Protection setting was carried out. After completing the necessary test, the

bus bar protection put in to service on 29.12.2015.

Mail received on 10-11-2016 & 20.12.2016:

Provision of Bus Coupler bay arrangement was included in the Upgradation works proposed and

the same was sanctioned by MoP through PSDF.

Numerical relay allotted and being commissioned.


Numerical BBP relay was commissioned on 02.02.2017

Status received vide mail dated 12.04.2017 & 01.06.2017 & 15-06-2017:

Numerical BBP relay was commissioned on 02.02.2017.

Provision of Bus Coupler bay arrangement was included in the Upgradation works proposed and

the same was sanctioned by MoP through PSDF.


05-09-2015 at 14:04

hrs

Complete outage of 230kV Palladam, 230 kV

Othakalmandapam S/s, 230 kV Coimbatore S/s, 230 kV

Thudialur and 230 kV Sadayapalayam S/s

TANTRANSCO to take suitable measures like installing more

stub-towers along 230 kV OK Mandapam – Myvady line to

avoid excessive sag due to over-loading.

Busbar protection got operated for a fault in 230kV

Mywadi-Anaikadavu line

TANTRANSCO Mail received on 19-02-2016, 24-03-2016 and 27-04-2016:

230kV Othakalmandapam - Myvadi feeder will be made LILO at Kongal Nagar. Line restringing

will be carried out along with the above proposal.

Mail Received on 20-05-2016 ,16-06-2016,25-07-2016 & 24-09-2016:



Status received vide mails received on 10-11-2016 & 20.12.2016 & 12.04.2017 & 01.06.2017 &

15-06-2017 & 04.08.2017:



TANTRANSCO mail dated 18-09-2017 & 31-10-2017:

Othakalmandapam - Myvadi feeder will be made LILO at Kongal Nagar. Line restringing will be

carried out along with the above proposal.

Status received vid email dated 12-12-2017:

Othakalmandapam - Myvadi feeder replacement of kundha conductor with Zebra and tower

replacement work has been sanctioned. Work will be taken up.


TANTRANSCO informed that 230 kV OK Mandapam - Myvady feeer was LILOed at Anaikadavu on

06.11.2017. Further replacement of the existing Kundah condductor with Zebra has also been

taken up, and is targeted to be completed by June, 2018.

TANTRANSCO mail dated 25-01-2018:

230kV Othakalmandapam - Myvadi feeder replacement of kundha conductor with Zebra and

tower replacement work has been sanctioned. Work will be taken up. Timeline: June-2018.

TANTRANSCO PendingTANTRANSCO to examine the feasibility of providing two

main-zone operation for bus bar protection by exploring

various alternatives like replacing existing bus-coupler CB

with a hybrid bus-coupler CB that comes with inbuilt CT,

replacing existing BBP relay with another suitable relay that

supports two main-zone operation, and implement the same.


Mywadi station of TANTRANSCO

48/I/1 PendingDisturbance in 220kV Tamilnadu

system

TANTRANSCO

21-12-2015 at 6:28

hrs

50/I/3

Annexure-II

Page 35 of 47

Status received vide mail dated 18-09-2017 & 31-20-2017:

Numerical BBP relay was commissioned on 02.02.2017. Provision of CT in Bus Coupler bay is

arranged and zone segregation will be provided.


Numerical BBP relay was commissioned on 02.02.2017. Provision of CT in Bus Coupler bay has

been allotted. Zone segregation will be provided after commissioning of CT.


TANTRANSCO informed that the recommendation would be complied with by March, 2018.

TANTRANSCO Mail received on 25-01-2018:

Provision of CT in Bus Coupler bay is arranged and zone segregation will be provided. Timeline:

March-2018.


Bus coupler bay equipments allotted will be commissioned by Aug 2018

Busbar protection got operated for a fault in 230kV

Mywadi-Anaikadavu line

TANTRANSCO PendingTANTRANSCO to examine the feasibility of providing two

main-zone operation for bus bar protection by exploring

various alternatives like replacing existing bus-coupler CB

with a hybrid bus-coupler CB that comes with inbuilt CT,

replacing existing BBP relay with another suitable relay that

supports two main-zone operation, and implement the same.


Mywadi station of TANTRANSCO

21-12-2015 at 6:28

hrs

50/I/3

Annexure-II

Page 36 of 47

TANTRANSCO mail received on 25-01-2018:

1) Commissioning of Bus Coupler CT, Extended Bus with Additional Bus Coupler is under

progress. Timeline: June-2018.

2) Numerical BBP commissioned on 29.08.2017 to enable Bus seggregation.

3) Providing Re-Trip feature for LBB will be studied.


Providing new Bus coupler bay involes bay shifting work.work awarded and under progress.

Time line. Dec2018.

Mail recieved on 25-07-2016 & 24-09-2016:

TANTRANSCO: Auto Transformer-2 HV side Bus isolator 'C'-phase support insulator of 230kV

Southern Bus was replaced and Bus Bar Protection scheme was restored on 12.05.2016.

Status received vide mails received on 10-11-2016 & 20.12.2016 & 12.04.2017 & 01.06.2017 &

15-06-2017 & 04.08.2017 & 18.09.2017:

CT is not available in the Bus Coupler bay for zone segregation. CT latch relay is to be provided

for all bays for zone segregation.

Status received vide mails received on 31-10-2017 & 12-12-2017:

Numerical Bus bar protection panel allotted and will be commissioned with zone segregation..


TANTRANSCO informed that Numerical BBP would be commissioned by March, 2018.


Commissioning of Numerical Bus bar protection is under progress. Zone segregation will be

ensured. Timeline: March-2018.


CMR relay for extending LBB protection was released and LBB extended from Distance

Protection relay directly. CT is not available in the Bus Coupler bay for zone segregation.

However, during commissioning of third ICT, Bus section Breaker will be provided for zone

segregation. Numerical BBP relay will be provided.

Status received vide mails recieved on 27-04-2016 and 20-05-2016 ,16-06-2016, 25-07-2016, 24-

09-2016,10-11-2016 & 20.12.2016 & 12.04.2017 & 01.06.2017 & 15-06-2017:

1 & 2) CT is not available in the Bus Coupler bay for zone segregation. However, during

commissioning of third ICT, Bus section Breaker will be provided for zone segregation. Numerical

BBP relay will be provided.


1 & 2) Contract awarded for providing third ICT & Bus modification works to accomodate bus

coupler bay. Numerical BBP relay has been provided and tesing under progress.



coupler bay. Numerical BBP relay has been provided and tesing under progress.



coupler bay.

55/I/1

(GD)


Gummidipoondi Station of

TANTRANSCO

12-05-2016 at 12:15

hrs

Flashover of Auto Transformer- 2 HV

B-phase Isolator supporting insulator of 230kV Southern

Bus occurred at Gummidipoondi station. At the time of

fault, Bus bar protection relay was not in service for pre-

commissioning testing of Auto Transformer-2. All

feeders got tripped due to operation of zone-2

protection from remote ends.

TANTRANSCO to take steps to provide double-bus operation

at their 230 kV Gummidipoondi SS.

TANTRANSCO Pending

51/I/1

(GD)

PendingTANTRANSCO 1. TANTRANSCO to provide split-bus operation with bus

sectionalizer CB for their 230 kV Madurai (Chekanurani) SS.

2. TANTRANSCO to provide two main-zone operation for the

numerical BBP that is being commissioned.

3. TANTRANSCO to examine the feasibility of providing Re-

Trip feature for the LBB protection, and accordingly take steps

for implementing the same.

Fault had occurred in 230kV Madurai-Sembatty line. Trip

from distance relay was not extended to breaker due to

protection DC fail. LBB protection got operated resulting

in a busbar trip at 230kV Madurai substation. All

elements got tripped as there is a single bus operation at

230kV Madurai S/s

19-01-2016

at 11:56 hrs


Madurai S/s (Chekanaurani) of

TANTRANSCO

Annexure-II

Page 37 of 47


Numerical Busbar protection relay commissioned on 14.05.2018

55/I/1

(GD)


Gummidipoondi Station of

TANTRANSCO

12-05-2016 at 12:15

hrs

Flashover of Auto Transformer- 2 HV

B-phase Isolator supporting insulator of 230kV Southern

Bus occurred at Gummidipoondi station. At the time of

fault, Bus bar protection relay was not in service for pre-

commissioning testing of Auto Transformer-2. All

feeders got tripped due to operation of zone-2

protection from remote ends.

TANTRANSCO to take steps to provide double-bus operation

at their 230 kV Gummidipoondi SS.

TANTRANSCO Pending

Annexure-II

Page 38 of 47




Status received vide mails dated 10.01.2017 & 12.04.2017 & 01.06.2017 &15-06-2017 &

04.08.2017 & 18.09.2017 & 31-10-2017& 12-12-2017:

Different make Relays will be provided for Main-I & II relays at Sunguvarchatram end in a phased

manner.


TANTRANSCO informed that the recommended works of providing different make Relays for

Main-I & Main-II are targeted to be completed by September, 2018.


Different make Relays will be provided for Main-I & II relays at Sunguvarchatram end in a phased

manner. Timeline: September-2018.


TANTRANSCO informed that the recommended works of providing different make Relays for

Main-I & Main-II are targeted to be completed by September, 2018.


provision of Different make Relays for Main-I & Main-II will be completed by September, 2018.

14-09-2016 at

11:13Hrs

Bus Bar Protection (Zone-2) of 230 kV Bus-B got operated

at Alamathy Station during fault in 230 kV Alamathy-

Korattur feeder.

15-09-2016 at 22:14

hrs

Bus Bar Protection (Zone1) of 230kV Bus-A got operated

at Alamathy Station during fault in 230 kV Alamathy-OPG-

1 feeder.

58/II/17 Multiple tripping at 230 kV

Alamathy Station

1. TANTRANSCO to check the healthiness of BBP relay by

conducting stability test, and take appropriate remedial

action like increasing voltage settings, ensuring the

healthiness of CT’s, using CT’s with similar characteristics

(equal saturation effects & equal winding resistances) etc. at

their 230 kV Alamathy SS.

2. TANTRANSCO to replace the existing high-impedance BBP

relay with its low-impedance/ numerical variant so as to

accommodate variation in CT characteristics at their 230 kV

Alamathy SS.

Mail received on 10-11-2016 & 20.12.2016:

1. The Bus Bar Protection scheme will be tested for healthiness including the CT circuits.

2. High impedance BBP relay will be replaced by Numerical relay.

Status received vide mails dated 10.01.2017 & 12.04.2017 & 01.06.2017 & 15-06-2017:

1. The Bus Bar Protection scheme was tested for healthiness including the CT circuits. AREVA

make CTs in Alamathy SS are having different kneepoint voltage for the cores. CT cores of higher

knee point voltage has been choosen for BBP in 230kV Korattur, 230kV OPG-1 & 230kV OPG-2

feeders on 29.11.2016. ---- Completed.

2. High impedance BBP relay will be replaced by Numerical relay. --- Pending,

Status received vide mails dated 04.08.2017 & 18.09.2017 & 31-10-2017 & 12-12-2017.

1. ---- Completed

2. High impedance BBP relay will be replaced by Numerical relay. --- Pending


2) TANTRANSCO informed that Numerical BBP would be provided by April, 2018 --- Pending


1. --- Complied.

2. High impedance BBP relay will be replaced by Numerical relay. Timeline: April-2018.


2.Numerical BBP relay will be provided. Timeline: Sep-2018.

TANTRANSCO Pending

58 Different type and Make of distance protection relays to be provided for Main-I & Main-II protection for 230kV feeders at 400 kV Sunguvarchathiram & 230 kV

Sunguvarchathiram Substation [Carry-Over from Protection Audit Recommendations]

TANTRANSCO Pending

Annexure-II

Page 39 of 47

64/1/4 Complete outage of North

Chennai TPS STG-1

26-03-2017

at 23:14hrs


running Unit at NCTPS Stg-1

1. TANTRANSCO to take steps to complete insulator

replacement works on the 230 kV lines owned by them in

NCTPS area within 6 months.

2. TANTRANSCO to take steps to implement A/R on all 230 kV

lines emanating from NCTPS-I at the earliest.

TANTRANSCO Status received vide mails dated 04.08.2017 & 18.09.2017 & 31-10-2017:

1. All the Porcelain insulators were replaced with Polymer insulators in 230kV NCTPS-I -

Tondiarpet feeders - 1 & 2.

---- Completed

2. AR will be implemented on all 230kV lines emanating from NCTPS-I. --- Pending


1. Completed

2. The scheme needs modification to enable AR, since AR was not envisaged for this station

during commissioning. AR will be implemented on all 230kV lines emanating from NCTPS-I

within six months. --- Pending


2) TANTRANSCO informed that A/R would be implemented on all 230 kV lines emanating from

NCTPS-I by June, 2018.


1. Complied.



within six months. Timeline:June-2018.

Pending




Timeline:Sep -2018.


1. Complied.



Timeline:Sep -2018.


Sriperumbudur station

24-03-2018 at 18:01

hrs

There was HV side Y-phase CT failure of 400/ 230 kV ICT-

2 at Sriperumbudur. This resulted in tripping of all

connected feeders and ICTs.

1) TANTRANSCO to ensure healthiness of 400 kV side CB of

ICT-3 (CB-1752) and integrity of its LBB protection.

2) TANTRANSCO to furnish equipment failure report of the

current incident (CT blast) to PSE&TD Division of CEA with a

copy marked to SRPC.

3) TANTRANSCO to refer the instant case of PRV operation of

ICT-1 to its OEM, and take appropriate action based on their

advice.

TANTRANSCO TANTRANSCO MAIL DATED 22.05.2018 & 08-06-2018:

1. 96 relay operation checked and scheme operation ensured.

----Complied

2. Failure Report will be sent to CEA

----Pending

3.Issue will be refered with OEM and appropriate action will be taken

----Pending

Pending

Annexure-II

Page 40 of 47

Kerala

Annexure-II

Page 41 of 47

KSEB Mail received vide dated 17.01.2017:

1. 110 kV bus bar protection progressing ----Pending

2. Connection of 220kV earth mat and 110 kV plate earthing system completed.---- Completed

3. Redundancy of 110V DC system in progress. Complete independent redundancy is not

practical for the time being. 48 V DC redundancy was already there. ----Pending

4. Instead of stand alone event logger, SCADA system of 110 kV feeder is expected to be

completed by the end of 2017. SCADA system of 220kV side will be taken up after that ----

Pending

KSEB Mail received vide dated 18.09.2017:Status received vide mail dated 12-12-2017:

1. Detailed engineering of the scheme has been completed. Material procurement is in progress.

---Pending

2.,3. ---- Completed

68/II/12 Tripping of 400 kV NPS – Nellore-

PG D/C line

08-10-2017

at 18:58 hrs

Lines tripped during a fault on 400 kV Nellore-PG –

Vijayawada line-2

1. For the 400 kV Nellore-PG – Vijayawada line, PGCIL (SR-I) to

investigate the reasons for 3-ph tripping of Main-CB upon

detection of the fault without trying for A/R and operation of

Stub/ Tee protection at the time of Tie-CB A/R attempt at

Vijayawada end during instant trippings, and furnish remedial

measures taken to address the issues involved.

2. PGCIL (SR-I) to test the recently commissioned CSD’s at

their 400 kV Nellore-PG SS at the earliest and ensure their

correct operation.

3. PGCIL (SR-I) to configure DR’s and EL’s of Distance

Protection Relays at Nellore-PG with suitable LEGENDs for

indicating operation of type of protections (like Zone-1, Zone-

2, Zone-3, DEFR, OVR-I, OVR-II, etc.).

PGCIL (SR-I) PGCIL-SR1 Mail dated 15.12.2017 & Review Meeting dated 19.12.2017:

1. --- Pending.

2. Due to CSD contractor problem CB Y-pole reclosed & defective contactors replaced & wiring

problem in CSD rectified on next day --- Completed.

3. NPS end DR & EL configured as suggested. --- Completed.


1. Line A/R scheme checked at VJA end during the S/D on and A/R scheme is operating correctly

for both Main & Tie CBs, A/R sucessful at both ends during the trippings on 03.05.2018. At VJA

end Stub protection checked & found relay faulty & the same was replaced with spare relay on

22.03.2018 during line S/D.

Pending

74/III/4Tripping of 400 kV

Maheshwaram - Narnoor line

03-04-2018 at 12:28

hrs

B-phase to earth fault occurred in line. Auto-reclose was

successful at Maheshwaram and Auto reclose was not

attempted at Kurnool (AP).

PGCIL (SR-I) to furnish a detailed report on the reasons for

the tripping of the line including remedial measures taken. PGCIL (SR-I)


The protection operation at Maheshwaram (POWERGRID) end is in order. Ony permissive PLCC

code was transmitted from POWERGRID end.

At Narnoor (APTRANSCO) en, NO DT signal receive was recorded in DR (from DR & Eluploaded by

AP in SRLDC trip portal. The EL list uploaded by AP is BCU internal events. The BCU was recently

commissioned by APTRANSCO under SAS upgradation. The spurious DT signal high in BCU might

be wrong wiring/configuration of BCU.

Pending

74/III/11Tripping of Ramagundam -

Hyderabad line-4

08-04-2018 at

05:16hrs

Y-phase to earth fault. Auto-reclose was successful at

Ghanapur end. Ramagundam end did not attempt auto-

reclose as there was operation of distance protection

Zone-2 leading to tripping of breaker.

For the line under consideration, the following shall be

carried out by NTPC-Ramagundam, in coordination with PGCIL

(SR-I):






PGCIL (SR-I)


PLCC end to end testing, Relay testing completed & verified and found ok- on 21.02.2018 during

line S/D. However same will be checked during the next shutdown.

Pending

73/II/8 Tripping of 400 kV Pavagada-

Tumkur line-1, 400/ 220 kV ICT-

1&2 at 400 kV Pavagada SS

16-03-2018 at 14:18

Hrs

Multiple trippings occurred during charging of 400 kV

Pavagada-Tumkur line-2.

1) PGCIL (SR-II) to review SOTF settings at Tumkur end on

Tumkur – Pavagada lines considering the least expected fault

current levels.

PGCIL (SR-II) Yet to be Informed Pending

PendingKSEB to take steps to provide the following at their 220/ 110

kV Kalamassery SS:

1. Busbar protection at 110 kV level

2. Connecting 220 kV and 110 kV sides on to a common

earthmat

3. Redundant DC supply for both protection (220 V) and

communication (48 V) applications

4. Stand-alone Event Logger

23-08-2016

at 11:20 hrs

KSEBComplete outage of 220 kV

Kalamassery Substation

58/I/1

(GD)

Triggering incident was conductor snapping in 110 kV

Kalamassery- Kaloor feeder

PGCIL (SR-I) & PGCIL (SR-II)

Annexure-II

Page 42 of 47

73/II/9 Tripping of HVDC Talcher-Kolar

Pole-1.

17-03-2018 at 15:12

hrs

Talcher – Kolar Pole-1 tripped due to mal operation of

DC protection system at Talcher end and Emergency

Switch OFF (ESOF) signal received at Kolar end.

PGCIL (SR-II) to furnish a detailed report on the instant

tripping explaining clearly the reasons for repeated voltage

recovery sequences, reasons for Pole-2 going into ground

return mode while attempting Pole-1 de-block around 20:28

hrs, and non-operation of SPS

(i) at around 15:12 hrs when the Pole-1 was blocked, and

(ii) at around 20:28 hrs when Pole-2 went into ground return

mode.


73/III/4 Tripping of 400 kV ILFS-

Nagapattinam PS line-1.

28-03-2018 at 10:32

Hrs

R-phase to earth fault had occurred in line. Auto-reclose

attempt could not be validated with submitted DR of

Nagapattinam end.

PGCIL (SR-II) to furnish a report on the reasons for A/R non-

operation, and the remedial action taken to rectify the same.


74/II/20 Tripping of 400/ 220 kV ICT-2 at

Somanahalli

25-04-2018 at

15:23hrs

ICT-2 got tripped due to mal-operation of Buchholtz’s

relay.

1). PGCIL (SR-II) to take steps to replace the faulty PNRV’s of

the ICT’s with the proposed reverse flow blocking devices at

the earliest at their Bidadi, Somanahalli, and Pavagada

stations.

2). PGCIL (SR-II) to configure Event Loggers (EL’s) to capture

events msec level at their Somanahalli SS.


Annexure-II

Page 43 of 47

Others

PendingNPCIL (MAPS)B-phase CT failure occurred in 230 kV S.P.Koil - MAPS

line-1. Busbar protection got operated at SP.Koil station.

All elements except 230kV Oragadam and 230kV

Kalivandapattu got tripped at 230kV S.P.Koil station. ‘Y’

phase CT and support insulators also got damaged.

1.MAPS to furnish a detailed report on the tripping of SP Koil

– MAPS lines 1 & 2 at MAPS end with focus on the correctness

of the settings of Main-I & Main-II relays (for primary & back-

up protections) on both the lines.

2.MAPS to take steps to provide down-loading facility for DR

& EL from Main-I & Main-II relays on all 230 kV lines

emanating from MAPS.

3.MAPS, in co-ordination with SP Koil, to carry out PLCC end-

to-end testing, on SP Koil – MAPS lines 1 & 2, and ensure

healthiness of PLCC communication & carrier-aided

protection.

4.MAPS to put in service Auto-Reclosure feature on all four

230 kV lines emanating from MAPS by June, 2016.

54/I/1 02-04-2016 at 17:08

hrs

Status revided vide MAPS mail dated 06.12.2016;

1. The settings given by M/s TANTRANSCO were adopted for Main –I & Main- II relays for both

the lines. The same settings were verified to be same. Subsequently calibrated was done and

no drift was observed. --- Completed

2. From May 2016 onwards, the DR, EL and trip report are being sent by mail to SRLDC,

Bengaluru by MAPS. --- Completed

3. Monthly maintenance of PLCC equipments is being done by M/s TANTRANSCO. At present

PLCC telephone is not working, it is being followed up. --- Completed

4. CVTs are planned to be procured from M/s TANTRANSCO by the end of February 2017 and

A/R will be implemented for all the lines emanating from MAPS by July-2017 as discussed in the

current SRPC meeting on 25/11/2016. --- Pending

Status received vide MAPS mail dated 06.12.2016 & Review Meeting dated 19.12.2017;

The CVTs procurement is in progress and the scheme (A/R) would be implemented before 31-03-

2018.


S.P.Koil Station of TANTRANSCO

Annexure-II

Page 44 of 47

62/III/2 Tripping of 400 kV Kaiga-Guttur

line-1

06-02-2017

at 05:01 hrs

B-phase to earth fault. Line did not auto-reclose at Kaiga

end.

1. KGS to properly configure all relays DR’s time scale for a

post-triggering period of 2 sec to capture events such as

complete A/R operation.

2. KGS to ensure time-synchronization of all protection relays

with GPS in their 400 kV switchyard.

NPCIL (KGS) Status received vide mail dated 29.11.2017 & Review Meeting dated 19.12.2017:

1. All 400kv transmisisonlines relays DR time scale for a post-triggering period of 2 sec is

implemented. ----Completed

2.Time-synchronization for all lines protection relays (M1 &M2) with GPS in their 400 kV

switchyard is being implemeneted. Scheme design is in process. ECD-April-2018 ---- Pending

NPCIL (KGS) Reply during Special Meeting at Kaiga dated 22.06.2018:

2. KGS agreed to ensure time-synchronization of all protection relays with GPS in their 400kV

swithcyard by Dec 2018. --- Pending

Pending

68/II/11 Tripping of 400 kV

K V KOTA - HNPCL lines – 1 & 2

29-09-2017 at 22:36

hrs

Line-1 tripped on R-E Zone-1 fault, and the Line-2 tripped

on Direct Trip receipt at KV Kota end

1. HNPCL to ensure time sync of all of their protection relays

with GPS, and to configure corresponding DR’s for post

triggering time of 2 sec.HNPCL to configure DEF operation

only when Distance relay does not sense the fault.

2.HNPCL to ensure healthiness of A/R scheme implemented

on all 400 kV lines at their station.

3.HNPCL to provide priority A/R scheme for 400 kV Tie-CB’s

with s suitable dead-time of say 2 sec.

4.HNPCL to revise PDR timing as 1.5 sec till implementation of

A/R for Tie-CB’s after which it shall be further revised to 2.5

sec.

5.HNPCL to implement following OVR-I gradings for the 400

kV lines emanating from their station:

Kalpaka Line-1 7.35 A 111%, 10 sec

Kalpaka Line-2 7.35 D 110%, 8 sec

KV Kota Line-1 246 B 111%, 9 sec

HNPCL HNPCL Mail dated 11.01.2018:

1. Time synchronization of protection relays and BCU's with GPS completed. As per APTRANSCO

recommendations DEF has been switched off in line protection relays.

--- Pending

2. --- Pending

3. Line Tie CBs Priority closing has been implemented for all the lines. --- Pending

4. --- Pending

5. --- Completed

HNPCL Mail dated 12.05.2018:

CB close interlock gone to “self-check Fault” state during the AR cycle. Due to that AR gone to

lockout state. Breaker open state CB close interlock should be satisfied condition.Accordingly

the logic has been modiified.

Pending

69/I/1 Complete outage of 400kV TPCIL

station

25-10-2017 at 19:33

hrs

400 kV TPCIL-Nellore PS line-1 got tripped from TPCIL

end during fault in 400kV Nellore-Nellore PS line-2.

Running units at TPCIL got tripped due to loss of

evacuating line. 400kV Nellore PG - Nellore PS line-2 and

400kV TPCIL - Nellore PS line-1 were under shutdown.

TPCIL to configure DEF protection such that it remains in



pickup.

TPCIL Yet to be informed Pending

Annexure-II

Page 45 of 47

NLCIL Mail dated 18.01.2018:

1. Shut down was taken on 400kV Neyveli TS-II to Pugalur feeder on 18-01-18 to check the end-

to-end communication for DT/ permissive & other signals by testing at both the ends and to

check the healthiness of the PLCC system components.

The system was thoroughly checked and the missing loops in the relay circuit (Carrier send in

Main1 relay and Carrier receive in Main2 relay) were provided.NLCIL Mail dated 24.04.2018:

1. Completed.

2. The tripping of Pugalur feeder on 10-10-2017 at 23:54 hrs as per PCSC recommendation, the

Defective relay P437 was replaced with spare P437 relay and the settings were checked.The

spare relay replacement work carried out on 26& 27th March at the time shut down of Pugalur

feeder.

71/III/1 Tripping of 400 kV HNPCL- KV

Kota line-2

26-12-2017 at 12:34

hrs

R-phase to earth fault had occurred in line. Breakers at

HNPCL got tripped due to auto-reclose lockout and auto-

reclose was successful at KV Kota end.

HNPCL to furnish a report detailing the reasons for A/R non-

operation in the instant tripping, and remedial measures

taken to set right them.

HNPCL HNPCL Mail dated 12.05.2018:

CB close interlock gone to “self-check Fault” state during the AR cycle. Due to that AR gone to



Pending

72/III/5 Tripping of 400 kV HNPCL - K.V.

Kota line

02-02-2018 at 11:46

hrs

Tripped due to R-phase to ground fault. Line did not

reclose at HNPCL.

1. HNPCL to configure DEF protection such that it remains in



pickup.

2. HNPCL to ensure healthiness of A/R scheme implemented

on all 400 kV lines at their station.

HNPCL APTRANSCO maild ated 24.04.2018 & 24.05.2018:

To be attended by HNPCL

HNPCL maild ated 12.05.2018:

1....Pending

2.CB close interlock gone to “self-check Fault” state during the AR cycle. Due to that AR gone to



Pending

73/I/3 Complete outage of following

220kV stations of KPTCL

Narendra (KPTCL), Bidnal, SRS

Hubballi, Ambewadi Haveri,

Karwar, Belgaum, Chikkodi,

Soudatti, ML Pura, Athani,

Kudachi, Ghataprabha, MK Hubli,

NPH, Kodasalli and Kadra

08-03-2018 at 10:01

hrs

220kV Kaiga-kadra and 220kV Kadra-Kodasalli lines

tripped on backup over-rcurrent protection. 400/220kV

Narendra ICT tripped on over load protection. Running

units at Nagjhari and Kodasalli tripped due to non-

availability of evacuation lines. Cascaded tripping

occurred due to overloading of 220 kV network and

there was complete outage of several stations of KPTCL.

1). NPCIL (KGS) to use stipulated formats for furnishing FIR

and TR.

2). NPCIL (KGS) to configure DR’s & EL’s of all protection

relays at their 400 kV & 220 kV Kaiga GS for recording all

mandated protections.

NPCIL (KGS) NPCIL(KGS) Reply during Special Meeting at Kaiga dated 22.06.2018:

1.KGS agreed to use stipulated formats for furnishing FIR and TR

---- Completed

2.KGS agreed to include line backup protections in Main-I & Main-II within 2 months and

configure DR's and EL's of Main -I & II for recording all mandated protections --- Pending

Pending


Kemar, MSEZ Bajpe, Kavoor,

Netlamandur (Puttur) and 400/

220 kV ICT-2 at UPCL

14-03-2018 at 18:45

hrs

Fault in 220 kV Kemar – Bajpe line-2 led to tripping of

220kV UPCL-Kemar Line-2 due to faulty LBB operation.

Subsequently, lnie faults on 220 kV Varahi – Kemar lines

and UPCL – Kemar line-1 led to complete outage of

220kV Kemar, MSEZ Bajpe, Kavoor, Netlamandur

(Puttur).

UPCL to provide re-trip feature for LBB protection of all

breakers at their 220 kV Udupi power plant.

UPCL Yet to be informed Pending

69/II/9 Tripping of 400 kV Neyvelli TS2 –

Pugalur and 400 kV Neyvelli TS2

(exp) – Pugalur line

10-10-2017 at 23:54

hrs

Protection at NLCTS-2 & NLCTS-2 Exp has sensed as R-Y-E

fault and given a 3 phase trip. At Pugalur end protection

has sensed fault as Y-N and B-N fault in 400kV Neyveli

TS2-Pugalur line & 400kV Neyveli TS2 EXP-Pugalur line

respectively. Breaker at Pugalur got tripped due to Direct

Trip receipt.

1.For the tripping of 400 kV NLC TS2 – Pugalur line, NLCIL to

investigate the reasons for sending of DT to Pugalur end, and

furnish an action taken report including remedial action taken

and setting right various LEGEND issues in DR & EL of

protection relays to PCSC forum.

2. For the tripping of 400 kV NLC TS2Exp – Pugalur line, NLCIL

to investigate the reasons for 3-ph tripping (detection of the

fault as Y-B-E) of the line from NLC TS2Exp end including

verifying pertinent settings of P437 relay (reference may be

made to explanation given by TPCIL in GD - I.1/ GD - I.2), and

furnish an action taken report including remedial action taken

and setting right various LEGEND issues in DR & EL of

protection relays to PCSC forum.

NLCIL Pending

Annexure-II

Page 46 of 47

73/III/3 Tripping of 400kV Kaiga-

Narendra line-2

18-03-2018 at 13:25

hrs

Narendra end auto reclose could not be attempted due

to direct trip receive from Kaiga. From EL of Kaiga, R-

phase Zone-1 trip and A/R lock out were observed.

NPCIL (KGS) to take steps to disable sending of DT to remote

ends upon 86X operation for any line protection operation at

its 400 kV KGS.

NPCIL (KGS) NPCIL (KGS) Reply during Special Meeting at Kaiga dated 22.06.2018:

KGS agreed to disable sending of DT to remote ends upon 86X operations for any line protection

operation at its 400kV KGS within one month. --- Pending

Pending

74/II/12 Tripping of 400 kV Bellary PS -

JSWEL line

16-04-2018 at 16:16

hrs

Main#2 (ABB REL 670) relay’s SOTF protection mal-

operated at JSWEL. DT sent to BTPS

1). It was noted from DR that there was an R-E fault at the

time of occurrence of above tripping, which might have

(wrongly) led to SOTF initiation; hence logic employed for

SOTF protection operation needed to be checked.

2). JSWEL was asked to check whether interlock with CB OPEN

status has been properly incorporated in SOTF logic.

JSWEL Yet to be Informed Pending

74/II/17 Tripping of 400 kV

Kalavindapattu - Vallur line- 1

23-04-2018 at 10:22

hrs

At Vallur station, tracking was observed in stack of CVT

while carrying out hot-line water washing of CVT in B

phase. This was suspected to have caused Over-voltage

in CVT secondary circuit. Direct trip was sent to

Kalavindapattu end.

• In this regard, NTECL-Vallur was asked to ensure that they

have kept time setting for OVR operation as 100 msec.

NTECL

(Vallur)

Yet to be Informed Pending

Annexure-II

Page 47 of 47

Sl.No. Element Name Outage date/time Revival date/time Reason for outage Sender/ Receiver Remedial Measures/ Actions taken

1 400KV-NARNOOR-SRISAILAM_LEFT_BANK-1 20-03-2018/17:53:00 20-03-2018/20:31:00

Ground Time Over

Current operated at

Srisailam

APTRANSCO/TSGENCO

TSGENCO:

Direct trip send wiring was done for the

ground time over current faults

APTRANSCO:

Feeder not tripped at Narnoor End.

2 400KV/220KV KOZHIKODE-ICT-3 01-04-2018/10:46:00 01-04-2018/14:18:00DIFFERENTIAL

PROTECTION ACTEDPGCIL (SR-II)

PGCIL (SR-II):

3 220KV-YERRAANDAHALLI-HOSUR_TN-1 19-04-2018/12:45:00 19-04-2018/12:57:00TRIPPED DUE TO B-N

LINE FAULTKPTCL/ TANTRASNCO

TANTRANSCO:

No visible fault

KPTCL:

4 220KV-AMBEWADI-XELDEM 21-04-2018/14:15:00 21-04-2018/17:43:00B PHASE TO GROUND

FAULTKPTCL/ GED

KPTCL:

5 220KV-YERRAANDAHALLI-HOSUR_TN-1 24-04-2018/13:10:00 24-04-2018/13:25:00tripped at hosur end

onlyKPTCL/ TANTRANSCO

TANTRANSCO:

No visible fault

KPTCL:

Radially fed from Hosur

6 400KV-HINDUJA-KV_KOTA-1 01-05-2018/10:12:00 01-05-2018/11:24:00 TRIPPED ON B-N FAULT HNPCL/ APTRANSCO

APTRANSCO:

Patrolling was done.No visible fault found.

Tree cutting done.

HNPCL:

7 400KV-JINDAL-BPS-2 03-05-2018/19:56:00 03-05-2018/21:53:00 BREAKER AIR LOCK OUT JSWEL/ KPCL

JSWEL:

KPCL:

8 400KV-NARNOOR-JAMMALAMADUGU-1 03-05-2018/17:29:00LINE TO GROUND

FAULTAPTRANSCO

APTRANSCO:

Feeder tripped at both ends. At that time

Heavy rain ,wind and thunders were

reported.

9 400KV-RTPS-BTPS-1 04-05-2018/14:14:00 04-05-2018/19:26:00 TRIPPED ON B-N FAULT KPCLKPCL:

10 400KV-RTPS-BTPS-1 05-05-2018/12:54:00 05-05-2018/17:57:00TRIPPED DUE TO B-N

LINE FAULTKPCL

KPCL:

Pending Remedial Measures/ Actions taken

for the Critical Tripping Incidents (as on 12.07.2018)

Annexure-III

Page 1 of 8

11 220KV-YERRAANDAHALLI-HOSUR_TN-1 10-05-2018/11:50:00 10-05-2018/12:18:00 C-N fault KPTCL/ TANTRANSCOTANTRANSCO:

Passing fault

12 220KV-UDUMALPET_TN-IDDUKKI-1 11-05-2018/15:44:00 11-05-2018/16:58:00 TRIPPED ON R-N FAULT TANTRANSCO/ KSEBL

TANTRANSCO:

Passing fault

KSEBL:

Tripped on Ph to Ph fault in Z1, Carrier send,

A/R Lock out

13 400KV-UPCL-HASSAN-1 11-05-2018/20:41:00 Tripped on Y-B Fault UPCL/ PGCIL (SR-II)KPTCL:

Stood OK after test charging.

14 400KV-NARENDRA-GUTTUR-1 14-05-2018/23:39:00H /T TO CONTAIN OVER

VOLTAGRKPTCL

KPTCL:

15 400KV-NEYVELI_TS_II-SALEM-1 14-05-2018/12:37:00 14-05-2018/17:28:00LINE TO GROUND

FAULTNLCIL/ PGCIL (SR-II)

NLCIL :

The feeder got tripped on line to ground

fault . The feeder got auto reclosed at

Neyveli TS2 end but it again got tripped on

sustained fault. The feeder was charged

from Salem end but it got tripped again .

Requested to PGCIL for patrolling of the

line.

PGCIL (SR-II):

16 400KV-PAVAGADA-TUMKUR-3 14-05-2018/23:43:00H /T TO CONTAIN OVER

VOLTAGRPGCIL (SR-II)

PGCIL (SR-II):

17 400KV-NEYVELI_TS_II-SALEM-1 15-05-2018/11:16:00 15-05-2018/20:59:00TRIPPED ON Y PHASE

FAULTNLCIL/ PGCIL (SR-II)

NLCIL :

The feeder got tripped on line to ground

fault . The feeder got auto reclosed at

Neyveli TS2 end but it again got tripped on

sustained fault. The feeder was charged

from Salem end but it got tripped again .

Requested to PGCIL for patrolling of the

line.

PGCIL (SR-II):

18 400KV-KUDGI_PG-KHOLAPUR_PG-1 17-05-2018/16:27:00 17-05-2018/16:59:00 TRIPPED ON R-N FAULT PGCIL (SR-II)PGCIL (SR-II):

19 400KV-RTPS-BTPS-1 21-05-2018/21:15:00 21-05-2018/22:17:00 DISTANCE PROTECTION KPCL/ KPTCL

KPCL:

KPTCL:

20 400KV-BTPS-HIRIYUR-2 21-05-2018/20:48:00 R-Y FAULT KPCL/ PGCIL (SR-II)

KPCL:

PGCIL (SR-II):

Annexure-III

Page 2 of 8

21 400KV-TUMKUR-KUDGI_PG-2 23-05-2018/18:52:00 23-05-2018/20:03:00 TRIPPED ON R-N FAULT PGCIL (SR-II)PGCIL (SR-II):

22 400KV-MYSORE-KOZHIKODE-2 23-05-2018/15:07:00 23-05-2018/15:16:00 TRIPPED ON B-N FAULT PGCIL (SR-II)PGCIL (SR-II):

23 400KV-BTPS-HIRIYUR-2 24-05-2018/10:36:00 24-05-2018/15:29:00 Triiped on R-B Fault KPCL/ PGCIL (SR-II)

KPCL:

PGCIL (SR-II):

24 400KV-TUMKUR-KUDGI_PG-2 24-05-2018/22:24:00 TRIPPED ON Y-N FAULT PGCIL (SR-II)PGCIL (SR-II):

25 400KV/230KV UDUMALPET-ICT-1 27-05-2018/16:10:00 27-05-2018/17:18:00 MAL-OPERATION PGCIL (SR-II)

PGCIL (SR-II):

26 400KV-NAGAPATTNAM_PS-NEYVELI_TS_II 28-05-2018/13:17:00 28-05-2018/13:48:00TRIPPED ON SINGLE

PHASE TO GND FAULTPGCIL (SR-II)/ NLCIL

NLCIL :

The feeder got tripped on Zone 2 distance

protection due to a fault in NPS- ILFS feeder.

PGCIL (SR-II):

27 400KV-MEPL-NPS-1 29-05-2018/12:33:00 R-Y FAULT MEPL/ PGCIL (SR-I)

PGCIL(SR1): Line tripped on R-Y fault. At

NPS: Main-I: Dist. 22.53km, FC: 13.11kA,

Main-II: Dist: 22.80km, FC: 13.10kA.

Fault jurisdiction comes into MEPL section.

MEPL:

28 230KV-PUDUCHERRY-VILLIANUR-1 30-05-2018/08:40:00R-pH CT BLAST at

VILIANURPED

PED:

29 400KV-GUTTUR-HIRIYUR-2 01-06-2018/15:38:00B phase light arrester

flashoverKPTCL/ PGCIL (SR-II)

To-be-discussed

30 400KV/220KV GUTTUR-ICT-1 01-06-2018/19:01:00 01-06-2018/19:34:00 RELAY MALOPERATION KPTCLTo-be-discussed

Annexure-III

Page 3 of 8

31 400KV-KTPS_VII-KHAMMAM-1 01-06-2018/21:25:00BUS BAR PROTECTION

OPERATEDTSGENCO/ PGCIL (SR-I)

PGCIL(SR1):

Khammam-KTPS-1 line tripped on R-N fault

in 1st attempt & Y-B persisting fault. It is

reported that CT blasted at KTPS end.

TSGENCO:

At 21:25 hrs R ph CT blasted in TIE-1(b/w

KTPS-VI to KTPS-VII line and KTPS-VI to

KHAMMAM PGCL line). At that time Line

Khammam-KTPS-1 line tripped on R-N fault

in 1st attempt & Y-B persisting fault.

32 400KV-MAMIDAPALLI-KHAMMAM-1 01-06-2018/17:57:00 01-06-2018/18:10:00 RELAY MALOPERATION TSTRANSCO/ PGCIL (SR-I)

PGCIL (SR-I):

Khammam-Mamidipally-1 line tripped at

KMM end only. At Mpally end A/R sucessful

but Khammam end A/R not attempted due

to operation of DEF protection at KMM.

From DR & EL it is clearly observed that fault

is directional & persisted long time which

caused the operation of DEF protection.

Relay operation is in order.

TSTRANSCO:

A/R operated and successful at Suryapet

end.

33 400KV-GUTTUR-HIRIYUR-1 01-06-2018/13:10:00 DT RECEIVED KPTCL/ PGCIL (SR-II)To-be-discussed

34 400KV-SURYAPET-KV_KOTA-1 01-06-2018/19:17:00 01-06-2018/19:44:00 TRIPPED ON R-N FAULT TSTRANSCO

TSTRANSCO:

A/R operated and successful at Suryapet

end.

35 400KV/220KV BTPS-ICT-1 01-06-2018/00:01:00 01-06-2018/01:10:00R-pH OVER CURRENT

RELAY OPERATEDKPCL

To-be-discussed

36 400KV-KTPS_VI-KTPS_VII-1 01-06-2018/21:25:00BUS BAR PROTECTION

OPERATEDTSGENCO

TSGENCO:

At 21:25 hrs R ph CT blasted in TIE-1(b/w

KTPS-VI to KTPS-VII line and KTPS-VI to

KHAMMAM PGCL line). At that time Line

tripped on R-ph differential trip at both

ends.

Annexure-III

Page 4 of 8

37 400KV-NELLORE_PG-THIRUVALAM-1 02-06-2018/19:24:00 02-06-2018/19:35:00 TRIPPED ON Y-N FAULT PGCIL (SR-I)/ PGCIL (SR-II)

PGCIL (SR1):

Line tripped on Y-N fault. A/R attempted

sucessfully and line tripped on persisitng Y-

N fault. From NLR distance: M1:138.3 kms,

FC: 3.5kA & M2: distance 139.3kms,

FC:3.1kA. From TVLM end distance M1

distance 46.5 kms, FC: 7.5kA & M2 distance

46.2 kms, FC: 7.45 kA.

Fault distance comes under SR-2 TLM

Jurisdiction.

PGCIL (SR-II):

38 400KV-YELHANKA-NELAMANGALA-1 02-06-2018/19:53:00 02-06-2018/20:00:00 TRIPPED ON R-N FAULT PGCIL (SR-II)/ KPTCLTo-be-discussed

39 400KV-JINDAL-BPS-1 03-06-2018/16:04:00 03-06-2018/19:05:00 DISTANCE PROTECTION JSWEL/ KPTCLTo-be-discussed

40 400KV-BPS-YTPS-1 03-06-2018/16:03:00 03-06-2018/18:52:00 DISTANCE PROTECTION KPTCL/ KPCLTo-be-discussed

41 400KV-SALEM-UDUMALPET-1 08-06-2018/08:48:00 08-06-2018/09:10:00

TRIPPED DUE TO R -

PHASE WINDING OF ICT

4 BURNOUT AT

SALEM(TN)

PGCIL (SR-II)

To-be-discussed

42 220KV-AMBEWADI-PONDA-1 10-06-2018/09:29:00 10-06-2018/09:50:00 TRIPPED ON B-N FAULT KPTCLTo-be-discussed

43 400KV-HINDUJA-KV_KOTA-2 10-06-2018/12:01:00 TRIPPED ON Y-N FAULT HNPCL/ APTRANSCO

APTRANSCO:

A/R successful at K.kota end but again

tripped on DT Receive pulse from HNPCL

end.

HNPCL:

44 400KV/220KV GOOTY-ICT-2 14-06-2018/17:04:00 14-06-2018/21:17:00 RELAY MALOPERATION PGCIL (SR-I)To-be-discussed

45 400KV-BHOOPALAPALLY-WARANGAL-2 14-06-2018/11:31:00 14-06-2018/17:36:00 PLCC MAL OPERATION TSGENCO/ PGCIL (SR-I)To-be-discussed

46 230KV-PUDUCHERRY-VILLIANUR-1 15-06-2018/07:29:00 15-06-2018/09:12:00

Burst of B phase CT HV

side of Auto

Transformer - I

PUDUCHERRY ED/ PGCIL

(SR-II)

To-be-discussed

47 400KV-HOODY-NELAMANGALA-1 15-06-2018/12:12:00 15-06-2018/13:03:00 PLCC MAL OPERATION KPTCLTo-be-discussed

48 400KV-BIDADI-TUMKUR-2 15-06-2018/16:20:00 15-06-2018/17:03:00R Phase distance

protection operatedPGCIL (SR-II)

To-be-discussed

49 400KV-VIJAYAWADA-NELLORE_AP-2 15-06-2018/18:08:00 15-06-2018/18:20:00TRIPPED ON B PHASE

FAULTPGCIL (SR-I)/ APTRANSCO

APTRANSO:

Line belongs to PGCIL.

Annexure-III

Page 5 of 8

50 765KV-KURNOOL_PG-THIRUVALAM-2 15-06-2018/22:10:00 15-06-2018/23:51:00 TRIPPED ON Y-N FAULT PGCIL (SR-I)/PGCIL (SR-II)To-be-discussed

51 230KV-NEYVELI_TS_II-VILLIANUR-1 15-06-2018/07:29:00 15-06-2018/08:45:00

Burst of B phase CT HV

side of Auto

Transformer - I

NLCIL/ PUDUCHERRY ED

To-be-discussed

52 400KV/220KV HOODY-ICT-3 17-06-2018/03:53:00CT FLASH OVER at 220

kV SIDEKPTCL

To-be-discussed

53 400KV/220KV HOODY-ICT-1 17-06-2018/03:53:00TRIPPED ON OCR

OPERATEDKPTCL

To-be-discussed

54 400KV/220KV RAICHUR_KA-ICT-2 17-06-2018/03:54:00

OVER FLUX

PROTECTION RELAY

OPERATED

KPCL

To-be-discussed

55 HVDC 500KV KOLAR_DC Pole 1 18-06-2018/17:42:00 18-06-2018/18:02:00esof received from

talcherPGCIL (SR-II)

To-be-discussed

56 HVDC 500KV KOLAR_DC Pole 2 18-06-2018/17:42:00 18-06-2018/18:03:00esof received from


To-be-discussed

57 HVDC500KV-TALCHER-KOLAR_DC-2 18-06-2018/17:42:00 18-06-2018/18:03:00esof received from


To-be-discussed

58 HVDC500KV-TALCHER-KOLAR_DC-1 18-06-2018/17:42:00 18-06-2018/18:02:00esof received from


To-be-discussed

59 220KV-SEDAM-TANDUR-1 19-06-2018/01:44:00 19-06-2018/03:10:00

BUSBAR PROTECTION

OPERATED AT SADEM

END

KPTCL/ TSTRANSCO

TSTRANSCO:

The fault was high resistance fault and Earth

fault protection operated at Tandur end.

60 400KV-NARNOOR-SRISAILAM_LEFT_BANK-1 20-06-2018/18:51:00DT RECEIVED AT

SRISAILAMAPTRANSCO/ TSGENCO

APTRNSCO:

Feeder not tripped at Narnoor end.

61 400KV-URAVAKONDA-MEHBOOBNAGAR-1 20-06-2018/08:07:00 20-06-2018/08:26:00 DT RECEIVED APTRANSCO/ TSTRANSCO

APTRANSCO: Feeder tripped on over

voltage at Uravakonda end.

TSTRANSCO:

Tripped on Direct Trip received indications

at Veltoor end.

62 400KV-NARNOOR-SRISAILAM_LEFT_BANK-1 21-06-2018/23:56:00 DISTANCE PROTECTION APTRANSCO/ TSGENCOTo-be-discussed

63 400KV-BHOOPALAPALLY-WARANGAL-1 21-06-2018/21:51:00 21-06-2018/22:26:00 TRIPPED ON Y-N FAULT TSGENCO/ PGCIL (SR-I)To-be-discussed

64 400KV-KUDANKULAM-TIRUNELVELI-1 21-06-2018/17:37:00 21-06-2018/18:11:00 CT FAILEDNPCIL (KKNPP)/ PGCIL (SR-

II)

To-be-discussed

65 400KV-MADURAI-TIRUNELVELI-1 21-06-2018/17:37:00 21-06-2018/18:55:00 CT FAILED PGCIL (SR-II) To-be-discussed

66 400KV-HINDUJA-KV_KOTA-2 22-06-2018/22:18:00 22-06-2018/22:40:00 TRIPPED ON R-N FAULT HNPCL/ APTRANSCOTo-be-discussed

67 400KV-GUTTUR-JINDAL-1 22-06-2018/06:05:00 TRIPPED ON R-N FAULT KPTCL/ JSWELTo-be-discussed

68 400KV/220KV DINDI-ICT-1 22-06-2018/06:29:00 22-06-2018/18:33:00 RELAY MALOPERATION TSTRANSCOTo-be-discussed

Annexure-III

Page 6 of 8

69 400KV-BHADRAVATHI-RAMAGUNDAM-1 25-06-2018/20:34:00 25-06-2018/21:08:00DT RECEIVED FROM

BHADRAVATHIPGCIL (SR-I)/ NTPC

To-be-discussed

70 400KV/110KV PALAVADI-ICT-3 25-06-2018/17:14:00ICT-3 B-Ph CT blast at

PalvadiTANTRANSCO

To-be-discussed

71 400KV-PALAVADI-TIRUVALAM_TN-1 25-06-2018/17:14:00ICT-3 B-Ph CT blast at

PalvadiTANTRANSCO

To-be-discussed

72 400KV-BHADRAVATHI-RAMAGUNDAM-2 25-06-2018/19:20:00 25-06-2018/21:12:00To take line reactor into

servicePGCIL (SR-I)/ NTPC

To-be-discussed

73 400KV/220KV BTPS-ICT-1 26-06-2018/04:17:00 Evacuation of Feeders KPCLTo-be-discussed

74 400KV-BPS-YTPS-2 27-06-2018/17:24:00 27-06-2018/18:41:00 TRIPPED ON R-N FAULT KPTCL/ KPCLTo-be-discussed

75 220KV-AMBEWADI-PONDA-2 28-06-2018/00:56:00 DISTANCE PROTECTION KPTCL/ GEDTo-be-discussed

76 400KV-HASSAN-MYSORE-1 28-06-2018/01:44:00H /T TO CONTAIN OVER

VOLTAGRPGCIL (SR-II)

To-be-discussed

77 400KV-KUDGI_PG-NARENDRA-2 28-06-2018/02:12:00H /T TO CONTAIN OVER

VOLTAGRPGCIL (SR-II)/ KPTCL

To-be-discussed

78 400KV/110KV SALEM_TN-ICT-3 29-06-2018/20:07:00TRIPPED ON BUCCHOLZ

RELAY OPERATIONTANTRANSCO

To-be-discussed

79 400KV-RASIPALYAM-ANAIKADAVU-2 29-06-2018/07:30:00 R-Y FAULT TANTRANSCO To-be-discussed

80 220KV-AMBEWADI-PONDA-1 01-07-2018/10:57:00 01-07-2018/12:01:00 DISTANCE PROTECTION KPTCL/ GEDTo-be-discussed

81 400KV/110KV SUNGAVARACHATRAM-ICT-3 02-07-2018/19:53:00 02-07-2018/23:15:00Tripped on LV side Y-Ph

LA blastTANTRANSCO

To-be-discussed

82 400KV-KTPS_VI-KHAMMAM-1 02-07-2018/13:38:00 02-07-2018/17:31:00 TRIPPED ON B-N FAULT TSGENCO/ PGCIL (SR-I)To-be-discussed

83 400KV-CEPL-TUTICORIN_PS-2 02-07-2018/16:38:00 02-07-2018/17:28:00 TRIPPED ON R-N FAULT CEPL/ PGCIL (SR-II)To-be-discussed

84 400KV/230KV KAMUDHI-ICT-1 03-07-2018/13:40:00 03-07-2018/20:25:00TRIPPED ON BUCCHOLZ

RELAY OPERATIONTANTRANSCO

To-be-discussed

85 400KV-GHANAPUR-RAMAGUNDAM-3 06-07-2018/14:40:00 07-07-2018/03:04:00 TRIPPED ON Y-N FAULT PGCIL (SR-I)/ NTPCTo-be-discussed

86 400KV-BPS-YTPS-1 06-07-2018/19:12:00 TRIPPED ON LA BLAST KPTCL/ KPCLTo-be-discussed

87 220KV-UDUMALPET_TN-IDDUKKI-1 08-07-2018/16:01:00 TRIPPED ON B-N FAULT TANTRANSCO/ KSEBTo-be-discussed

88 400KV-JINDAL-BPS-4 08-07-2018/20:10:00 08-07-2018/20:56:00DT RECEIVED AT JINDAL

ENDJSWL/ KPTCL

To-be-discussed

89 400KV-KARAIKUDI-KAYATHAR-2 08-07-2018/09:48:00 08-07-2018/10:10:00DT RECEIVED AT

KARIKUDI ENDPGCIL (SR-II)/ TANTRANSCO

To-be-discussed

90 400KV-PAVAGADA-TUMKUR-3 08-07-2018/20:10:00TRIPPED ON Y PHASE

FAULTPGCIL (SR-II)

To-be-discussed

91 400KV-CUDDAPAH-CHITTOOR-1 10-07-2018/17:15:00 10-07-2018/17:25:00 DT RECEIVED PGCIL (SR-I)/ APTRANSCOTo-be-discussed

Annexure-III

Page 7 of 8

92 400KV-HINDUJA-KV_KOTA-1 10-07-2018/11:29:00 TRIPPED ON R-N FAULT HNPCL/ APTRANSCOTo-be-discussed

93 400KV-HINDUJA-KV_KOTA-2 10-07-2018/11:29:00 DT RECEIVED HNPCL/ APTRANSCO To-be-discussed

94 400KV/230KV SHOLINGANALLUR-ICT-1 11-07-2018/19:04:00OLTC Surge Relay

operatedTANTRANSCO

To-be-discussed

95 220KV-AMBEWADI-PONDA-1 11-07-2018/06:15:00 11-07-2018/17:14:00LINE TO GROUND

FAULTKPTCL

To-be-discussed

Annexure-III

Page 8 of 8

Compliance Status of the Recommendations given in the Special Meeting on HVDC Gajuwaka Pole Trippings held on 02.04.2018

Sl. No. Recommendation given Status of Implementation Remarks

1 POWERGRID to see the feasibility of providing suitable Circuit Breaker on the tertiary (33 kV) side of ICT-2, and implement the same, if feasible.

Status furnished vide PGCIL (SR-I) mail dated 23.05.2018: 33kV CBs are available for both Tertiaries of ICT-1 & 2 in downstreams at Pole-1 & Pole-2.

Pending

2 It was agreed to keep LT side (415 V bus connected) CB’s and fuses under observation to ascertain whether they operate with required time discrimination.

Status furnished vide PGCIL (SR-I) mail dated 23.05.2018: Fuse discrimination available in 415V LT side

Complied

3 POWERGRID to look into the correctness of the settings employed on the 220 kV side of ICT-1 and revise them if necessary and provide a copy the settings employed to SRPC Secretariat.

Status furnished vide PGCIL (SR-I) mail dated 23.05.2018: The settings are as per POWERGRID standard settings. The copy of settings shared with SRPC.

Pending

4 Arrangement for ensuring full-fledged redundancy for Pole-1 (ICT-1 tertiary + ICT-2 tertiary + its DG), replacement of LT side Circuit Breakers and commissioning of PLC based AMF panel forPole-1 would be completed well before 28.04.2019.

Status furnished vide PGCIL (SR-I) mail dated 23.05.2018: All LT CB's pertaining to Pole -1 have been replaced on shutdown on dated 28.04.2018 and 29.04.2018. The new PLC has also been installed and commissioned.

Complied

5 (i) Verification of various logics in effecting AC supply auto-changeover from ICT-1 tertiary to ICT-2 tertiary to DG set for Pole-1 would be tested and completed by availing shut down on 28th & 29th April, 2018. During this period, mock-exercise would also be conducted for verification of proper functioning / sequence of operation of new PLC. POWERGRID would give the procedure & detailed schedule of testing in the OCC meeting of April, 2018.

Status furnished vide PGCIL (SR-I) mail dated 23.05.2018: The same has been checked during installation and commissioning of PLC on shutdown on dated 28.04.2018 and 29.04.2018.

Complied

6 As a short-term measure for avoiding pole trippings under ferro-resonance conditions, immediate disconnection of FSC would be effected by ensuring fool-proof communication of the ferro-resonance carrier signal from Gajuwaka to Jeypore. To achieve this, it was agreed that the existing PLCC based carrier communication would be replaced by fibre-

Status furnished vide PGCIL (SR-I) mail dated 23.05.2018: The station level checks of the code transmission path was carried out at both Vizag and Jeypore ends. The FSC detection code transmission was successful in both instances of detection of

Pending

Annexure-IV

Page 1 of 2

optic communication by installing Digital Tele-Protection Couplers (DTPCs) at both ends within 2 months (i.e., by May, 2018). It was also agreed that dual communication channels would be provided to ensure reliable bypassing of FSCs.

ferro-resonance on 04.04.2018 and 17.04.2018 and there was no Pole 2 tripping. The New DTPC's are expected to receive by June 2018. The same shall be commissioned by availing shgutdown of 400kV Jeypore-Gajuwaka - 1 & 2 lines (one by one) in Jul/Aug'2018.

7 As a medium-term measure for avoiding pole trippings under ferro-resonance conditions, it was agreed that POWERGRID would expedite commissioning of the proposed STATCOM at Jeypore end to improve general voltage profile under disturbance/ fault conditions.

Status furnished vide PGCIL (SR-I) mail dated 23.05.2018: Under progress in Odisha Projects

Pending

8 It was also agreed to study the effect of the proposed STATCOM on improving the voltage profile under transient conditions, to establish its efficacy in arresting ferro-resonance kind of phenomena, and based on the study results to devise a scheme to effect auto-bypassing of FSC for low power order (say 400 MW) in Jeypore – Gajuwaka lines.

Status furnished vide PGCIL (SR-I) mail dated 23.05.2018: Shall be done after commissioning of STATCOM at Jeypore end

Pending

9 As a long-term measure for avoiding pole trippings under ferro-resonance conditions, it was agreed that POWERGRID would carry out necessary refurbishment works of controller protections at Jeypore end for detecting ferro-resonance locally at FSC location (Jeypore end) and effect automatic by-passing of FSCs by putting necessary infrastructure in place at Jeypore end. POWERGRID was requested to furnish a concrete proposal with suitable time-lines in this regard.

Status furnished vide PGCIL (SR-I) mail dated 23.05.2018: To be decided/approved in SRPC / Standing committee meetings

Pending

Annexure-IV

Page 2 of 2

Auto-Reclosure Implementation on all 220 kV & above transmission lines of Southern

Region

The status of implementation of A/R (excluding Tie-lines & Radial feeders & Cables) as

furnished by SR-Constituents is as follows:

Sl.

No. Name of the Constituent

220 kV

400 kV 765 kV

Total no. of lines

No. of lines where A/R is in service

Total no. of lines


Total no. of lines


1 APGENCO (Hydro)

19

(Tie-lines: 8)

Nil --- --- --- ---

2 APGENCO (Thermal)

25 Nil 6 6 --- ---

3 APTRANSCO 215 63 54 54 --- ---

4 TSGENCO (Hydro)

15 Nil 5 Nil --- ---

For the 5 no. of 400 kV lines, A/R has been kept disabled since they are of composite type (consist of Cable of length 1 km).

5 TSGENCO (Thermal)

15

(Tie lines:4)

Nil 6 6 --- ---

6 TSTRANSCO 241 10 50 50 --- ---

7 KPCL 44

(Tie-lines: 8)

8 11

(Tie-lines: 4)

7 --- ---

8 KPTCL 241 9 29 29 --- ---

9 TANGEDCO & TANTRANSCO

215

139 32 32 --- ---

10 KSEB 61 56 --- --- --- ---

11 PED 6 6 --- --- --- ---

12 PGCIL (SR-I) --- --- 68 68 14 14

13 PGCIL (SR-II) 15 15 92 92 2 2

14 NTPC

NTPC-Simhadri --- --- 8 8 --- ---

NTPC-Kudgi --- --- 4 4 --- ---

NTPC-

Ramagundam

4 Nil 10 10 --- ---

On 220 kV lines, A/R has not been provided as they are of very short length (1 km).

NTPC-

Kayamkulam

6 6 --- --- --- ---

15 NPCIL

MAPS 4 Nil --- --- --- ---

Annexure-V

Page 1 of 10

KGS 2 Nil 4 4 --- ---

A/R on 220 kV lines has not been provided since they are between two generating stations

KKNPP 2 Nil 4 4 --- ---

16 BHAVINI 4 Nil --- --- --- ---

17 NLCIL 10

(Tie-lines: 3)

2 9

(Tie-lines: 2)

7 --- ---

18 JSWEL 2 Nil 2 2 --- ---

19 UPCL 2 Nil 2 2 --- ---

20 NTECL-Vallur --- --- 6

(Tie-lines: 2)

4 --- ---

21 TPCIL --- --- 2 2 --- ---

22 CEPL --- --- 2 2 --- ---

23 HNPCL --- --- 2 2 --- ---

24 IL&FS --- --- 2 2 --- ---

25 Lanco KPL 2 Nil 2 2 --- ---

For the 220 kV lines, since the distance between Kondapally and VTPS Stage IV is only one

span (350 mtrs), A/R has been kept blocked from both the ends.

26 NTPL --- --- 2 2 --- ---

27 MEPL --- --- 2 (Tie-line: 1)

1 --- ---

28 SEL --- --- 2 2 --- ---

Annexure-V

Page 2 of 10

Action plan furnished by SR-Constituents for implementing A/R on the 220 kV & above

transmission lines, where it is presently not in service:

Sl. No.

Constituent Action plan for implementing A/R

1 APGENCO (Hydro)

At 220 kV level, there are total 19 feeders, out of which 8 lines are tie-lines. Action plan for the remaining 11 lines is as given below:

Sl. No.

Name of the Station

Name of the Feeder Action plan for implementing of Auto-reclosure

1

Srisailam Right Bank Power House

SSLM- Dindi- I

Auto-reclosure scheme for all 220kV is available but not commissioned since inception

A/R scheme will be implemented while commissioning of new protection panels, whose inspection is complete and about to dispatch. Protection Couplers are commissionedfor all the feeders except Dindi – I & II and Nagarjunasagar feeders. Expected to be completed by March, 2018.

2 SSLM- Dindi-II

3 SSLM-Tallapalli-l

4 SSLM- Tallapalli-II

5 SSLM- Podili

6 SSLM- Markapuram

7 SSLM- Mydukur

8 SSLM- BilakalaGuduru

9 SSLM-Somayajulapalli

10 SSLM-Nagarjunasagar

Between Generating Stations (Optional)

Not willing to provide being feeder between two generating stations

11

Lower Sileru Power House (LS)

L - Bommuru

Auto-reclosure scheme is available but not commissioned since inception

A/R scheme will be implemented while commissioning of new protection panels for which tender evaluation is in progress. Protection Coupler was commissioned and work is expected to be completed by August 2018.

12 LS-Donkarayi Between Generating Stations (Optional)

Not willing to provide being feeders between two generating stations

13 LS-Kothagudem- I

14 I.S-Kothagude rn-Il

15

Upper Sileru Power House (US)

US - Pendurthy Auto-reclosure scheme is available but not commissioned since inception

A/R scheme will be implemented while commissioning of new protection panels for which tender evaluation is in progress. Protection Coupler was commissioned and work is expected to be completed by August 2018.

16 US-Donkarayi Between Generating Stations (Optional)

Not willing to provide being feeders between two generating stations 17 US-Balimela

18 Donakari Canal Power House DCPH

DCPH-Upper Sileru Between Generating Stations (Optional)

Not willing to provide being feeders between two generating stations

19 DCPH- Lower Sileru

Annexure-V

Page 3 of 10

2 APGENCO (Thermal)

W.r.t. existing 400 kV lines, A/R is in service on all 6 lines.

At 220 kV level, there are two plants under APGENCO (Thermal) viz. Dr. NTTPS (VTPS) and Rayalaseema TPP (RyTPP). The action plan furnished for implementing A/R is as follows:

VTPS: A/R scheme is available for 9 feeders out of the total 15 feeders, but not commissioned since inception. For remaining 6 feeders, Static relays have to be replaced with Numerical relays to facilitate Auto-Reclose. An action plan for replacement of existing static relays of the feeders with numerical relays under PSDF funds was initiated. The time-line proposed for implementing on all 15 feeders is as follows:

Sl. No.

Name of 220 kV feeder

Whether A/R Enabled

Action plan

1. VTS-PODILI No Implemented by 16.03.2018

2. VTS-Gunadala No Implemented by 16.03.2018

3. VTS-Nunna No Implemented by 16.03.2018

4. VTS-K'Kota No Implemented by 16.03.2018

5. VTS-Tadikonda·1 No Implemented by 16.03.2018

6. VTS-Tadikonda·2 No Implemented by 16.03.2018

7. VTS-Tallapalli No Implemented by 16.03.2018

8. VTS-Tallapalli-3 No Implemented by 16.03.2018

9. VTS-Tallapalli·4 No Implemented by 16.03.2018

10. VTS-Narasa Rao Pet No Implemented by 16.09.2018

11. VTS-Chillakallu- l No Implementation of A/R for these feeders deferred, since they are of composite type (consist of Cable of length 1.5 km above the ground) implemented by 16.09.2018

12. VTS-Chillakallu-2 No

13. VTS-Konadapalli -l No

14. VTS-Konadapalli -2 No

15. VTS-Renatachintala No Implemented by 16.09.2018

As per above schedule, the implementation of A/R scheme will be completed at NTTPS by 16.09.2018.

RyTPP: Action plan for implementing A/R scheme includes procurement of necessary auxiliary relays, scheme checking/modification, testing and commissioning for the following 10 no. of 220 kV Transmission lines:

Sl. No. Name of 220kV Feeder Date of Completion of A/R scheme

1 RTPP – Chinakampalli -1 17.09.2018




5 RTPP – Yerraguntla -1 22.09.2018

6 RTPP – Yerraguntla -2 24.09.2018

7 RTPP – Pulivendula -1 25.09.2018

8 RTPP – Pulivendula -2 27.09.2018

9 RTPP – Thimmapuram -1 29.09.2018

10 RTPP – Thimmapuram -2 30.09.2018

As per above schedule, the implementation of A/R scheme will be completed at RyTPP by 30.09.2018.

Annexure-V

Page 4 of 10

3 APTRANSCO A/R scheme is implemented in all 400 kV network, and will be implemented for the latest & upcoming future 220 kV & above lines in APTRANSCO.

W.r.t. existing 400 kV lines, A/R has been proposed for 54 lines out of the total 59 lines, and is in service on all 54 lines.

W.r.t. existing 220 kV lines, A/R has been proposed for 215 lines out of the total 258 lines. Of these 215 lines, A/R is in service on 63 lines. For the remaining 186 lines, action plan for implementing A/R is as follows:

Category of feeders

No. of 220 kV Feeders

Time-line for A/R Implementation

Remarks

Feeders on which A/R is proposed to be implemented in Phase-I

19 3 months from July, 2017

Completed

Feeders on which A/R is proposed to be implemented in Phase-II


A/R implemented on 11 lines

Feeders on which A/R is proposed to be implemented in Phase-III


---

Feeders on which A/R is proposed to be implemented in Phase-IV


---

4 TSGENCO (Hydro) At 400 kV level, there are total 5 no. of lines. However, A/R has been kept disabled on them since they are of composite type (consist of Cables of length 1 km).

The action plan for the existing 15 no. of 220 kV lines is as follows:

Sl. No.

Name of the Plant

Total no. of 220 kV lines

Action Plan

NSHES (220 kV) 5 Will be implemented by 30.04.2018

PJHEP (220 kV) 4 Will be implemented by 31.05.2018

LJHEP (220 kV) 4 Will be implemented by 31.05.2018

PCHES (220 kV) 2 Will be implemented by 30.06.2018

5 TSGENCO (Thermal) Out of the existing 15 no. of 220 kV lines, 4 are tie-lines. Action plan for the remaining 11 lines is given below:

Annexure-V

Page 5 of 10

Sl. No.

Name of the Plant

No. of Feeders

Action plan for implementing A/R

1 KPTS/ O&M 6 (i) Miryalaguda (ii) Shapurnagar (iii)Lower Sileru-I (iv)Nunna (v) Manuguru-I (vi) Manuguru-II

A/R feature for all 220 kV feeders will be completed by June, 2018as the material procurement is under progress

2 KTPS/ Stage-V 3 (i) Budidampadu-I (ii) Budidampadu-II (iii) Lower Sileru-II

For these feeders, A/R scheme is configured and ready to be enabled. Once the other end substations complete the implementation process, A/R can be put into service. Presently, negotiations are on with the OEM's of Relays suppliers for testing of the scheme.

3 KTPS/ Stage-V 2 Sitaramapuram – I & II As per SRPC recommendation, it is decided to implement Line Differential Protection Scheme on these Lines (having Line length less than 10 kms). For this, the existing distance Relays would be replaced with Differential Relays. Presently, procurement of LDP relays is in progress. A/R would be implemented in the new LDP relays. In the existing distance Relays, A/R has been configured, and ready to be enabled. However, the same would be put into service after implementation of the same from the remote end station.

4 KTPS/ O&M 2 Tie Lines I & II As these lines are connecting between generating stations, it is decided to not implement A/R scheme on these lines as per reference minutes of the 62nd meeting of PCSC held on 15.03.2017.

5 KPTS/ Stage-V 2 Tie Lines I & II

6 TSTRANSCO For all the upcoming 220 kV & above feeders, the concerned wings have been requested to ensure A/R function and its implementation in the field.

W.r.t. existing 400 kV lines, A/R has been proposed for 50 lines out of the total 52 lines, and is in service on all 50 lines.

W.r.t. existing 220 kV lines, A/R has been proposed for 241 lines out of the total 269 lines. Of these 241 lines, A/R is in service on 10 lines. For the remaining 231 lines, action plan for implementing A/R is as follows:

Annexure-V

Page 6 of 10

Category of feeders

No. of 220 kV

Feeders Time-line for A/R Implementation

Feeders on which A/R is proposed to be implemented in Phase-I (immediately)

171 31.08.2018

Feeders on which A/R is proposed to be implemented in Phase-II (with minor modifications)

32 31.12.2018

Feeders on which A/R is proposed to be implemented in Phase-III (with major modifications)

28 30.06.2019

5 KPCL Out of the total 44 no. of 220 kV lines, there are 8 no. of tie-lines. Out of the remaining 36 lines, A/R is in service on 8 no. of lines. Action plan for implementing A/R on the remaining 28 no. of lines is as follows:

On 9 no. of lines emanating from RTPS, A/R function is Ready at RTPS end. M/s. KPTCL informed that A/R function will be enabled only after R&M works of Numerical Protection system and R&M works are under progress.

On 9 no. of lines emanating from Sharavathy GS, A/R function will be kept 'ON' only after completion of Earth Mat augmentation works, which will be completed by March – 2018.

On 2 no. of lines emanating from Gerusoppa PH, 220kV Line Breakers are having problems. Proposed for replacement under PSDF. After replacement of Breakers Auto reclosure feature will be enabled - Time required 24-30 Months approximately.

On 2 no. feeders emanating from Kadra, settings for Auto reclosure feature completed at Kadra. Clearance from M/s. KPTCL is awaited.

On 6 no. of feeders emanating from Nagjheri, Auto-reclose scheme is ready at NPH end and will be enabled in all the six lines (Nagjhari - Hubli-1, Nagjhari - Hubli-2, Nagjhari - Hubli-3, Nagjhari -Bidnal, Nagjhari - Ambewadi-1, Nagjhari -Ambewadi-2) once clearance from respective receiving end is obtained.

6 KPTCL W.r.t. existing 400 kV lines, A/R is in service on all 29 lines.

W.r.t. existing 220 kV lines, A/R has been proposed on 241 lines out of the total 279 lines. Of these 241 lines, A/R is in service on 9 lines. Action plan for the remaining lines is given below: AR scheme tested and it is ready to be enabled at Sharavathy &

STRP lines (10 in no.) at 220kV Substations Shimoga,Talaguppa, Shiralakoppa and BTPS. It is communicated to KPCL to confirm regarding readiness at their end.

Retrofitting of Main-2 distance scheme in place of back up OC and EF relays of 220kV lines is being carried out under R&U project awarded to M/s GE T&D India Limited. Works at 26 No.s of audited sub stations are taken up on priority and M-II retrofitting work is completed at many sub stations. Along with M-II retrofitting works, AR Scheme testing is also completed at one end of the line for about 25 no.s of 220kV lines. Other end belongs to KPCL/Power Grid/ KPTCL where M-II retrofitting is yet to be taken up. Readiness from our end is already communicated to KPCL

Annexure-V

Page 7 of 10

regarding 220kV lines emanating from Talaguppa, Shimoga and Shiralakopa and Lingapur connecting to Sharavathy, STRP, and BTPS Genarating Stations. Confirmation awaited from their end. Also, AR scheme is ready for enabing for 220 kV PGCIL connected lines at Kadakola, Tubinkere and Gowribidanur Sub Stations. Communication will be sent to Power Grid shortly.

Providing auto reclosure for 220kV lines connected to Generating stations, POWERGRID stations and ISTS is planned to be completed by end of March 2018. Remaining lines will be taken up along with commissioning of M-II scheme and will be completed before end of December 2018.

7 TANGEDCO &

TANTRANSCO

W.r.t. existing 400 kV lines, A/R is in service on all the existing 32 no. of feeders.

W.r.t. existing 230 kV lines, A/R has been proposed for 215 lines out of the total 239 lines. Of these 215 lines, A/R is in service on 139 lines. Action plan for the remaining 76 lines is given below:

Category of feeders

No. of Feeders

Time-line for A/R Implementation

Generation connected feeders (excluding tie-lines)

66 CVT supplied. AR will be enabled by June-2018

Communication network to be provided

8 Communication network established for 6 feeders. Control cable to be provided for AR implementation. Timeline requested: March-2018.

Breaker problem 1 Procurement of Breaker is under progress by availing PSDF. AR will be enabled by June-2018.

Inter-State feeder 1 AR to be provided at Chittoor end in 230kV Thiruvalam-Chittoor feeder

8

KSEB Details of 220 kV feeders where A/R was not implemented are as follows:

Sl. No.

Feeder Name Status of A/R facility

Remarks

1 220 kV Kozhikode-PG – Areacode line-1 Short lines; Current Differential Protection provided; so A/R not provided. 2 220 kV Kozhikode-PG – Areacode line-2

3 220 kV Kozhikode-PG – Areacode line-3

4 220 kV Shornur – Areakode NIL Optical fibre link work is Completed, SDH equipment work is awarded, Protection coupler is under tendering process. Expected to be commissioned during June, 2018.

5 220 kV New Pallom – Pallom line Very short line; Pilot wire protection implemented; auto-reclosing facility not provided.

Annexure-V

Page 8 of 10

10 NPCIL (Kudankulam NPP)

A/R has not been kept in service on the TTPS bound 230 kV line as TTPS is a generating station.

A/R on SR Pudur bound 230 kV line is proposed to be put in service by April, 2018.

11 NPCIL (MAPS) A/R on all four 230 kV lines would be put into service by September, 2018. P.O. was placed on M/s Crompton Greaves limited for CVTs on 22.12.2017. The expected delivery period is six months i.e. on or before 20-06-2018. Implementation would take about another three months. Thus, A/R implementation would be completed by 30.09.2018.

12

NLCIL There are total 10 no. of 220 kV lines. Out of these, 3 are tie-lines, and A/R is in service on 2 no. of lines (Villianur & Bahour). For the remaining 5 lines, action plan for implementing is as follows: For the 3 no. of lines emanating from NLC TS-I, the issue of

implementing A/R was discussed in PCSC-71 meeting held on 31.01.2018. The time-line for implementing A/R has been fixed as June, 2018.

For the 2 no. of lines emanating from NLC TS-II (Kadalangudi, Ulundurpet), the issue of implementing A/R was discussed in PCSC-71 meeting held on 31.01.2018. The time-line for implementing A/R has been fixed as June, 2018.

13 UPCL The A/R in 220 kV lines at UPCL end has already been configured and scheme is ready.

On completion of A/R readiness at opposite end (Kemar) the A/R can be put in service.

14 JSWEL A/R logic being uploaded in both the line relays. Trial would be taken after getting confirmation from 220 kV Lingasugur (KPTCL) end. Planned to be completed by 15.02.2018.

In this regard, the time-line committed by various SR-Constituents for implementing A/R on their 220 kV & above transmission lines is given below:

Sl. No.

Name of the Constituent

Time-frame for implementing A/R on 220 kV lines

Time-frame for implementing A/R on 400 kV

lines

Time-frame for

implementing A/R on 765

kV lines

1 APGENCO (Hydro) August, 2018 N/A ---

2 APGENCO (Thermal) September, 2018 Implemented ---

3 APTRANSCO October, 2017 – October, 2018 Implemented ---

4 TSGENCO (Hydro) June, 2018 N/A ---

5 TSGENCO (Thermal) June, 2018 Implemented ---

6 TSTRANSCO August, 2018 – June, 2019 Implemented ---

7 KPCL March, 2018 – June, 2020 Implemented ---

Annexure-V

Page 9 of 10

8 KPTCL March, 2018 – December, 2018 Implemented ---

9 TANGEDCO & TANTRANSCO

June, 2018 Implemented ---

10 KSEB June, 2018 N/A ---

11 PED Implemented N/A ---

12 PGCIL (SR-I) N/A Implemented Implemented

13 PGCIL (SR-II) Implemented Implemented Implemented

14 NTPC

NTPC-Simhadri N/A Implemented ---

NTPC-Kudgi N/A Implemented ---

NTPC-Ramagundam N/A Implemented ---

NTPC-Kayamkulam Implemented N/A ---

15 NPCIL

MAPS September, 2018 N/A ---

KGS N/A Implemented ---

KKNPP April, 2018 Implemented ---

16 BHAVINI Not furnished N/A ---

17 NLCIL June, 2018 Implemented ---

18 JSWEL February, 2018 Implemented ---

19 UPCL Not furnished Implemented ---

20 NTECL-Vallur N/A Implemented ---

21 TPCIL N/A Implemented ---

22 CEPL N/A Implemented ---

23 HNPCL N/A Implemented ---

24 IL&FS N/A Implemented ---

25 Lanco KPL N/A Implemented ---

26 NTPL N/A Implemented ---

27 MEPL N/A Implemented ---

28 SEL N/A Implemented ---

*****

Annexure-V

Page 10 of 10

Sl. No. Bay name/Bus Voltage Protection/Element/

Equipment/ System

auditated

Remarks/Deficiences/Nonconformity observed Status of Implementation of Protection Audit

Recommendations

Remarks Latest Status (To be filled up by the

Constituent)

1 Control and

Protection Panels

For 400 KV Busbar protection, one number of main Bus bar protection

scheme is available for each bus; Check Zone protection is available as

inbuilt feature to main relay (Distributed system).Commissioning of new

busbar protection panels with nemerical relay is under progress.


New Busbar protection panels with numerical relay

commissioned on 17.12.2016.

Complied

2 On 220 kV side, Only Single Bus bar protection scheme is available (ABB

RADSS) for each of the two buses . No redundant main 2 or Check zone

protection available. CT supervision relays are not provided. Redundant

Bus bar protection or Check zone shall be considerd.


New 220KV Busbar protection panel will be commissioned by

May 2018.

Pending

3 Auto-reclose feature is not enabled for 220kV lines. Mail dated 14.02.2018:

Completed. Auto-reclosure feature enabled for all 220KV lines.

Complied

4 Over current protection has been kept enabled on alll 400 kV feeders. Mail dated 14.02.2018:

Normal Over current function is not enabled in MICOM P444

relay. Over current function with SOTF is enabled. During dead

line charging condition it acts as SOTF function and remaining

time it acts as definite time over current function. However

considerable time delay 3 seconds and 200% pick up is adopted.

Pending

5 For all 220 kV feeders [except S.Palli-1 Main-2 feeder (ABBREL670)] all

relays are of static relays.


All the static relays were replaced with numerical relays during

retrofitting works. Completed for all 220KV feeders.

Complied

6 400kV Ghanapur line Main -1 is of POTT (SEL 421) scheme and Main-2 is

of PUTT scheme.


Main-1 SEL 421 relay which was with POTT was replaced with

7SA522 with PUTT during retrofitting works. 400KV Ghanapur

(now Maheswaram) line Main-1 and Main-2 kept in PUTT

scheme.

Complied

7 Relay Setting Pole discrepency relay time :

- 2.5s for 400kV Power grid transmission line main and tie breakers.

- 1.25s for 400kV AP TRANSCO (Srisailam) transmission line main and

1.5s for tie breakers.

- 0.5s for 220kV transmission lines.

- 0.5s for ICT-1 and Bus Reactor.

- 2.5s for ICT-2.


Pole discrepancy relay time provided as per standard. (Line main

breaker:1.5s, Tie breaker:2.5s, Transformer and Reactor

breakers:0.5s) And for all 220KV transmission lines 1.5s

provided.

Complied

Status of Implementation of New Protection Audit Recommendations (as on 12.06.2018)

APTRANSCO

1) 400/ 220 kV Narnoor SS [16–18 February, 2016]

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Annexure-VI

Page 1 of 70

8 PSB was kept blocked for all zones with unblock time delay of 2 sec on

400 kV Srisailam feeder. For all 400 kV PGCIL feeders, PSB was kept

blocked for all zones except zone-1 with unblock time delay of 2 sec.


APTRANSCO views on power swing protection philosophy

communicated to SRPC vide

Lr.No.CPS/SP/121/SRPC/D.No.510/15, Dt.14.12.2015. As per

setting provided.

Pending

9 400kV Stub protection current set and time delay set as I> 150% and

100ms against the recommendeed setting of I>250% and time delay of

50ms by M/S Tractebel. APTRANSCO to take action as appropriate.


As per APTRANSCO practise Stub protection pick up current

setting 200% and time delay 0 ms is adopted.

Pending

10 Zone resistive reach setting & time setting for all 400kV and 220kV

distance protection are found to be different from the recommanded

setting given by Tractebel based on Ramakrishna committee

recommendations (Task force committee guidelines). APTRANSCO to

take action as appropriate.


The existing resistive reach settings are found to be OK for

distance protection resistive reaches.

Complied

11 DEF is enabled in main-1 and disabled in main-2 distance relay in 400kV

srisailam line . Due to this, DEF will not be available in the event of

outage of Main-1 distance relay. DEFR timing on 400 kV feeders was

found to be kept at different settings (308 msec, 470 msec.)


DEF is enabled in Main-1 and Main-2 distance relay in 400KV

Srisailam line. (New relays for Main-2 provided with 7SA522.)

Complied

12 SOTF funtion disabled in all 220 kV feeders except Somayajulapalli line-1

(main-2) and Brahmanakotkur line (Main-1 & 2).


SOTF function enabled for all 220KV feeders.

Complied

13 The distance protection for all 200 kV feeders was configured for three

(forward) zones only. There was no reverse-zone available for the

distance protection provided on 220 kV feeders. In 220kV B. Kotkur

feeder, distance protection was configured with 5 zones (forward - zone -

1 to 4); however, zone-5 was kept off.


The distance protection for all 220KV feeders configured for four

(forward) and one (reverse) zone.

Complied

14 Over current and directional earth fault protections are not provided on

any of the 220kV lines.


In old realys these functions are not available.Over current and

directional earth fault protections provided for all 220KV lines

during retrofitting works (Numerical relays).

Complied

15 High set unit was not provided for over flux protection of ICT’s. Mail dated 14.02.2018:

Inverse charactaristic is selected for over flux protection.

Complied

16 GPS is not available. Mail dated 14.02.2018:

GPS provided.

Complied

17 Stand alone DR with automatic downlaoding facility to centralized PC is

not availble. Stand-alone EL though available, is not in working condition.

APTRANSCO informed that manual downloading from relay specific DR's

and EL's is being done as and when fault occurred for 400kV lines.


Centralised EWS is provided for downloading EL and DR

automatically.

Complied

18 DR is not available for 400kV/220kV bus bar protection and for all 220kV

lines .


1. Completed for 400KV Busbar protection DR can be download.

2. Completed for 220KV lines DR can be downloaded.

3. Pending for 220KV Busbar protection panel; will be

commissioned by May 2018.

Pending

2/70

Annexure-VI

Page 2 of 70

19 AC Distribution Auto Changeover is not available in ACDB for 415V Auxiliary supply 1 & 2

and DG set. Auto Main FAilure (AMF) panel in DG set is not in service.

Supply Change over operation is carried out manually.


Auto changeover operation is not possible in ACDB for 415V

Auxilary supply 1&2 and DG set as with the existing older

version of LT AC scheme, where the necessary protection

scheme for changeover operation is not available and hence the

supply change over operation is being carried out manually.

Pending

20 For ACDB, there is only one AC source from 33kV/11kV Narnoor SS;

however, the same is being fed to various switchyard auxiliaries through

two parallel transformers.


It was requested the APSPDCL authorities for the alternate 11KV

supply source and the same will be completed by May 2018.

Pending

21 DC Distribution For 220kV and 400kV bus bar protection panel, 2 DC sources are

available with selector switch only. Automatic changeover is not provided.


Completed:-For 400KV busbar protection panel (new panel

commissioned), 2 DC sources are available and automatic

changeover provided. Pending:-

220KV Busbar protection panels will be commissioned by May

2018.

Pending

22 Communication

system

In Communication panels (except Ghanapur, Gooty and AP Carbides 1 &

2 feeders as per shceme), each panel has been supplied with dual DC

source.


There is no provision of dual DC source for PLCC equipments.

Complied

23 The communication with the only numerical relay (ABB REL670) available

on S.Palli line-1 (Main-2) feeder, was found to be unhealthy.


The communication with the only numerical relay (ABB REL670)

available on S.Palli line-1 (Main-2) feeder is rectified and found

healthy. Main-1 also provided with numerical relay.

Complied

24 Walkie-talkie system for communicating with Control room personnel is

not provided.


Walkie takie will be provided by May 2018.

Pending

25 400kV/

220kV

Switchyard Field

Equipments

Even though the designed 220 kV busbar arrangement has bus-1 & bus-2

& transfer bus, the transfer bus was kept out of service, and the transfer

bus coupler is being used as line-CB. With this arrangement, breaker

maintenance cannot be undertaken without availing line shutdown


The rectification/modification works will be attended in the due

course duly entrusting the works either in the existing contacts (

if any) or in forth coming tenders/orders.

Pending

26 Lightning protection (LA's) Earthing is not done as per standards/ NFPA

in the most of 220kV and 400kV bays. LA's (system) earthing is

connected to earth electrodes directly as well as through equipment

earthing.


Attended & Rectified as per the directions given by the

protection audit team by isolating the surge counters from the

erected structures of 220KV and 400KV lightening arrestors with

insulating media.

Complied

27 400kV Bus reactor has not been equipped with cooling fans. Mail dated 14.02.2018:

Attended & Rectified by arranging cooling fans to 63MVAR

400KV Bus reactor.

Complied

28 Door earthing not done for some of marshalling boxes iin 400kV and

220kV bays; PVC conduits for cable entries to the marshalling boxes

found to be kept unsealed in some of the 400kV and 220kV bays.


Attended & Rectified by arranging door earthing to all the

marshalling boxes in the 400KV and 220KV bays as well as seal

the PVC conduits to the marshalling boxes.

Complied

3/70

Annexure-VI

Page 3 of 70

29 220 V Battery Units and Battery chargers were housed in the same room

along with other relay panels. 48 V Battery Units and Battery chargers

were housed in the same room along with other PLCC panels


The 220V Battery units and Battery chargers were housed in the

same room along with other relay panels and 48V Battery units

and Battery chargers were housed in the same room along with

other PLCC panels at the time of commissioning of the Sub-

station by the Construction wing as per the approved plan &

design.

Pending

30 General It is observed that the existing test-kits are of obsolete models and not in

working condition. The following test kits shall be generally required for

proper maintenance of 400 kV Narnoor SS:

1. Digital Earth resistance Tester

2. 12 kV Capacitance and Tan Delta Kit

3. Digital Multi Meter Model:287

4. Digital Low Range Tong Tester

5. Energey Meter Testing Kit

6. Dynamic Contact Resistance Measurement Test Kit

7. Transformer Winding Resistance Measurement Test Kit

8. Transformer Turns Ratio Kit

9. Insulation Resistance test-kit with induction compensator


Items Nos 2 & 7 are provided. The remaining kits will be

arranged by July 2018.

Pending

31 It is observed that no Laptop with latest features for downloading the

disturbance data and relay settings is available.


Received laptop during retrofitting works.

Complied

Sl. No. Status of Implementation of Protection Audit

Recommendations


Constituent)

1 Yet to be informed







2) 400/ 220 kV Uravakonda SS [5–6 April, 2018]

Deficiences/Nonconformity observed

Substation is well maintained.

The following have been found to be satisfactory:

(i) Operation of various electrical & mechanical interlocks

(ii) Remote operation of Isolators from work-station

(iii) Earth-mat resistance is around mandated limits (Measured value - 0.51 ohms)

Protection Philosophy being followed by APTRANSCO for various transmission elements (Lines/ ICT's/ Reactors/ Busbar/ etc.) shall

be furnished.

In 400 kV lines, distance protection timings for Zone-2, Zone-3, Zone-4 and Zone-5 (reverse) shall be reviewed in line with

Ramakrishna Committee guidelines.

The existing Power Swing Philosophy (with all Zones blocked for unblocked time delay) for 220 kV & 400 kV transmission lines to

be reviewed to adopt either of the following two approaches:

(i) Zone-1 --> Trip; Highers Zones --> Block for a delay of unblocking time delay (2 sec) & then Trip.

(ii) Block all Zones with Out-of-Step tripping enabled at electrical zero locations by carrying out required system studies.

In view of the short length of the 220 Amidyala lines 1 & 2 (9. 45 km), Line Differential Protection may be provided in place of the

existing distance protection.

Auto-Reclosure feature provided on 400 kV & 220 kV lines may be got checked for correctness of functionality & healthiness of the

logic employed.

4/70

Annexure-VI

Page 4 of 70
















23 Yet to be informedAC Supply Changeover Scheme for the Substation may be provided

Door-to-Panel earthing may be provided in various control & marshalling boxes

Visual display indicating bay-element names may be suitably provided for all 400 kV & 220 kV bays.

Cable trenches in the switchyard should be covered properly. Control Cables & Power Cables may be properly segregated in

different trays provided in the cable trenches.

It is observed that Substation is not having Internet connectivity. Steps may be taken to provide the same to enable substation

personnel to discharge their official duties effectively.

It is observed that some of the relays not communicating with SAS Work Station, which may be rectified.

Walkie-talkie system for yard communication is not available, which may be provided.

It is observed that earth-resistance for various identified Points of station earth-mat have been measured in 2016. It is

recommedned to measure these earth resistances on yearly basis, and maintain relevant records with suitable earth lay-out

diagrams.

It is obsereved that metal spreading has not been provided in HV & LV side bays of ICT-3 and ICT-4. Since these bays have

already been kept in operation, it is recommended to take up this job on priority basis so as to ensure safety for the working

personnel by maintaining touch & step potentials within limits.

Smoke detection systems have been found to be either not installed or not in working condition in 220 kV kiosks. It is recommeded

to rectify the same, and put them into operation at the earliest.

It is observed that Pole Discrepancy time delay has not been set uniformly. It is recommended to keep PDR gtime delays as

follows:

(i) For all line Main-CB's and Tie-CB's where Aut-Reclosure with priority has been employed with dead-times of 1 sec & 2 se

respectively, PDR time delay shall be kept as 1.5 sec and 2.5 sec respectively.

(ii) For all other elements, PDR time delay shall be kept as the minimum avaiable in the relay, but not less than 100 msec. This

may be preferably kept as 0.5 sec.

For the 400/ 220 kV ICT's, O/C & E/F protections high-set operation may be provided with time delay of 50 msec.

O/C Protection (high-set & IDMT) may be provided on 220 kV sides of the 400/ 220 kV ICT's.

Group-A Protections and Group-B Protections for 400/ 220 kV ICT's shall be arranged to be fed from different DC Supplies.

Re-Trip feature time delay for the circuit breakers shall be revised from the existing 200 msec to 100 msec.

Automatic supply changeover from AC auxiliary supply to DG set may be provided. Also remote starting of DG set may be provided

from control room SCADA

5/70

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Page 5 of 70


Equipment/ System

auditated


Recommendations


Constituent)

1 Control and

Protection Panels

Main 1 & Main 2 distance relay are of same make, Type & model in

Miryalaguda and Shapoornagar feeders .


Main –I & Main-II different make/model of Miryalaguda and

Shapoornagar feeders relays were procured and it will be

replaced whenever LC is available by deputing the service

engineer

Pending

2 DC supervision relays are not availble for all feeders. Mail dated 30.01.2018

DC supervision relays for all the feeders were commissioned.

Complied

3 For 220 KV Busbar protection,one number of main distributed Bus bar

protection scheme and inbuilt Check Zone protection is available. CT

supervision relays are not seperately provided.

Mail dated 30.01.2018

220 KV Bus bar Protection Scheme through differential current

Alarm CT supervision was provided.

Complied

4 220 kV Tie line-2 main-1 relays is of static relays (ABB RADSL). Mail dated 30.01.2018

220 kV Tie line-2 main- I relays were replaced with new RED-

670 relays

Complied

5 For 220kV Main 1& Main 2 distance protection same CT core is used. Mail dated 30.01.2018

Due to Phasing out of the Units in 2019, it will not be possible to

procure the new CTs with two protection cores.

Pending

6 Remote indication of WTI and OTI of IBT-3&4 not provided in control

room.


As per the existing OT&WT gauges it is not possible to provide

the remote indication at control room

Pending

7 Smoke detection system is not available in control room building. Mail dated 30.01.2018

Due to Phasing out of the Units in 2019 it will not possible to

implement smoke detection system

Pending

8 Relay Setting Auto-reclose feature is not enabled for 220kV lines. Mail dated 30.01.2018

Auto-reclose feature for all 220kV lines will be enabled soon.

Pending

9 Zone time setting & Resistive reach setting for distance protection are

found to be different from the recommanded setting given by Tractebel

based on Ramakrishna committee recommendations (Task force

committee guidelines).


All the feeder settings were followed by as per the CE/

PowerSystems/TSTransco Recommendations only.

Pending

10 PSB was kept blocked for all zones. Mail dated 30.01.2018

Followed as per the CE/PowerSystems /TSTransco

Recommendations

Pending

11 All distance protection zones are set as forward Direction and Reverse

zone is not provided in distance relay (Main-1 & Main-2) for

Nunna,Manuguru-1&2,Tie line-1&2 feeders.


followed as per the CE/PowerSystems /TSTransco

Recommendations

Pending

TSGENCO

1 (i) 220 kV KTPS (O&M) [14-16 March, 2016]

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Page 6 of 70

12 For 220kV Tie line-1&2, STUB function is in activated condition in Main-2

distance relay (REL-100)


Tie line 1&2 REL-100 relays were replaced with RED-670 &

MICOM P442 relays.

Pending

13 Carrier aided protection is available only in Nunna feeder and is not

provided for any of the 220kV feeder due to non-availability of PLCC/

Wave trap.


Carrier aided protection for all Feeders panels were

commissioned and relay mapping will be done by deputing

service Engineer.

Pending

14 AC Distribution Auto Changeover is not available in ACDB for 415V Auxiliary supply 1 & 2. Mail dated 30.01.2018

As per the existing scheme AC change over was not available

Pending

15 DG set is not available to cater to substation loads.TSGENCO informed

that procurement of DG is under progress.


From the existing DG set one source was connected to

emergency loads of 220 KV switch Yard.

Pending

16 DC Distribution One source of 110V DC supply only available for substation loads and one

DC source only used for Trip coil 1 & 2.,


As per the existing scheme only one 110 V DC source was

available.

Pending

17 Earth leakage is observed in KTPS(O&M)-A station.The measured values

at battery is as below:

P-N:114.6V ; P-E:110V ;N-E:1.3V;


Earth leakage of KTPS –‘A’ station was identified in 220KV Bus

coupler Bay and it was isolated.

Complied

18 Acid leakageand bulging of batteries is observed in KTPS(O&M)-C station

220V batteries.


Failed batteries in KTPS(O&M)-C station were replaced with new

batteries.

Complied

19 Communication

system

Common PC with auto downloading facility for relays DRs is not available. Mail dated 30.01.2018

As per the existing scheme it was not provided.

Pending

20 GPS is not available. Mail dated 30.01.2018

GPS was commissioned and it was time synchronized with the

numerical relays.

Complied

21 Stand alone EL is not availble. Mail dated 30.01.2018

EL was not available in the existing scheme.

Pending

22 DR is not available for 220kV Tie line ckt-1 & 2. Mail dated 30.01.2018

220 KV Tie-1&2 old RADSL relays were replaced with new RED-

670 & Micom P442 relays and now they are provided with DR.

Complied

23 Redundancy not maintained in Fibre optic termination equipment. Mail dated 30.01.2018

Fiber optic termination equipment redundancy was provided.

Complied

24 PLCC protection couplers are not availbale for 220kV lines except Nunna

feeder.


For all 220KV feeders PLCC protection Couplers were provided.

Complied

25 220kV Switchyard Field

Equipments

Wave trap is available only in Nunna feeder. Mail dated 30.01.2018

Wave traps are available for all the feeders except Miryalaguda

feeder.

Pending

7/70

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Page 7 of 70

26 Lightning Arrestor Earthing is not done as per standards/ NFPA in the

most of 220kV bays. LA's (system) earthing is connected to earth

electrodes directly as well as through equipment earthing. Healthiness

checking (leakage current measurement) of Lightrning Arrestor is not

being done.


As per the standards LA Earthing is provided directly.

Complied

27 In most of the 220kV bays, LA surge counters and monitors (Nunna,IBT3

& 4,Tie line,Miryalaguda) are not in working condition.


LA surge counters and monitors were replaced with new ones.

Complied

28 In 220kV Nunna line Y phase CVT is not available. Mail dated 30.01.2018

220 KV Nunna line Y-Phase CVT will be replaced

soon.

Pending

29 In 220kV Bus Coupler-II Y phase CT is not available. Mail dated 30.01.2018

220 KV Bus Coupler-II Y-Phase CT will be replaced soon.

Pending

30 Walkie-talkie system for yard communication is not avalable. Mail dated 30.01.2018

Walkie-talkie system for yard communication was provided.

Complied

31 Lot of Grasses and other weeds are found over the Gravels in the 220kV

KTPS-A & C yard.


Grasses and other weeds were removed over the grounds in 220

KV KTPS-A & C yards.

Complied

32 Air pressure low alarm checking was done for Buscoupler bay breaker. CB

trouble/ air pressure low alarm did not get activated in controlroom.


CB trouble/Air pressure low alarm card was replaced with new

one and it is found OK.

Complied

33 It is observed that line CVT structures corroded in Miryalayaguda bay.

Action may be taken to rectify the same.


Line CVT corroded structures were cleaned and painted.

Complied

34 For few 220kV bays, it is observed that the Marshalling box and indication

window of circuit breakers are not visible.


Marshalling Box and Indication window of circuit breakers were

provided.

Complied

35 Bay identification codes/name and phase identification are not visible. Mail dated 30.01.2018

Bay identification codes/names and phase identification were

provided

Complied

36 Oil leakage was observed in 220kV IBT 3 & 4 bushing turrets and oil inlet

pipes.


Oil leakage was arrested for IBT-3&4 and also IBT-3 transformer

was replaced with 100MVA transformer from TSTRANSCO.

Complied


Equipment/ System

auditated


Recommendations


Constituent)

1 (ii) 220 kV KTPS (Stage-V) [14-16 March, 2016]

8/70

Annexure-VI

Page 8 of 70

1 Control and

Protection Panels

On 220 kV side, Only Single Bus bar protection scheme is available (High

impedance Static type - ABB RADSS) for each of the two buses . No

redundant main 2 or Check zone protection available. CT supervision

provided as inbuilt feature. No DR is available.


Planning to replace total 220kv bus bar protection panels in the

upcoming R&M at KTPS-V 220 KV switchyard.

Pending

2 Relay Setting Auto-reclose feature is not enabled for 220kV lines. Mail dated 30.01.2018

Tie Lines-I&II: As these lines are connecting between

generating sub stations, we are not implementing Auto

Reclosure scheme on these lines as per reference minutes of the

62nd meeting of PCSC held on 15.03.2017.

Budidampadu-I&II and Lower Sileru-II: For these lines the

Auto Reclosure scheme is configured and ready to enable in our

substation. Once the other end substations complete the

implementation process we can enable the scheme on our side.

We are also in ther process of negotiation with the OEM's of

Relays for testing of the scheme.

Sitarampatnam-I&II: As per SRPC recommendation it is

decided to implement Line Differential Protection Scheme on

these Lines (having Line length less than 10 KMs). For this we

need to replace the existing distance Relays with Differential

Relays. We are in the process of procuring the Differentioal

Relays. We will implement the A/R scheme in the new

Differential relays. In the existing distance Relays we are

configured A/R feature and to enable in our substation once

other end S/S complete the implementation process.

Pending

3 PSB was kept blocked for all zones. Mail dated 30.01.2018

It is enabled for all zones in our latest Numerical Relays of

220KV feeders in KTPS-V switchyard.

Pending

4 Zone time setting & Resistive reach setting for distance protection are

found to be different from the recommended setting given by Tractebel

based on Ramakrishna committee recommendations


The settings provided by TSTRANSCO were configured in all our

latest Numerical Relays of 220kv feeders in KTPS-V switchyard.

Pending

5 The distance protection for all 200 kV feeders (except for REL670) was

configured with 3 zones (forward) zones only. There was no reverse-zone

available for the distance protection provided on 220 kV feeders.


Four forward and one reverse Zones were configured in our

latest Numerical relays of 220KV feeders in KTPS-V switchyard ,

which are provided by TSTRANSCO.

Complied

6 For Budidampadu line-1 and Lower sileru line-2 , STUB function is in

activated condition in Main-1 distance relay (REL-100) and binary output

is not configured.


In KTPS-V 220KV swichyard , Budidampadu line-1 and lower

sileru line-2 STUB function is in deactivated condition in Main-1

distance relay which are replaced with REL-670 Numerical

relays.

Complied

7 Carrier aided protection is available only in Budidampadu feeder-2 and is

not provided for any of the 220kV feeder due to non-availabilyi of PLCC/

Wave trap.


New PLCC panels for all 7 No.220KV feeders at KTPS-V stage

swichyard were installed, But commissioning is under progress

and it is in scope of TSTRANSCO.

Pending

8 DEF protection not available in Budidampadu-1 feeder. Mail dated 30.01.2018:

It is configured in latest Numerical relays of all 7 No.220KV

feeders at KTPS-V stage swichyard.

Complied

9/70

Annexure-VI

Page 9 of 70

9 Main-2 distance relay (Make ABB, Type - REZOA) is of static type in 220

kV Sitaramapatnam-1&2, Budidampadu-1&2 and Lower sileru-2 feeders.

Relay does not have DR feature, cannot be time synchronized with GPS

and there is no provision for additional features in these relays


In 220KV feeders of KTPS-V SWITCHYARD, Main-2 distance

relay (Make ALSTOM make MICOM P442) is in service for

Sitaramapatnam-1&2, Budidampadu-1&2 and Lower sileru-2

feeders which has DR feature and can be time synchronised

with GPS and there is provisions for additional features in these

relays.

Complied

10 AC Distribution DG set not available to cater substation loads.TSGENCO informed that

entension of supply from generating station DG will be planned shortly.


Indent for DG set is raised at KTPS-V 220KV swichyardand it is

in procurement stage.

Pending

11 DC Distribution One source of 48V DC system is available.TSGENCO informer that

commisioning of second source of 48V DC system is under progress.


In KTPS-V 220KV stage swichyard Second 48V battery bank also

available with same charger. Second charger procurement is

under process.

Pending

12 Communication

system

Common PC with auto downloading facility for relays DRs is not available. Mail dated 30.01.2018:

For all KTPS-V stage swichyard, Separate Laptop is maintaining

for Relay configuration,retreiving DRs and Els

Pending

13 GPS is not available. Mail dated 30.01.2018:

For KTPS-V 220KV swichyard, Indent is raised and it is in

procurement stage.

Pending

14 Stand alone EL is not availble. Mail dated 30.01.2018:

For all 220KV feeders of KTPS-V swichyard, Stand alone EL is

available with latest Numerical Relays.

Complied

15 The communication with the only numerical relay (ABB REL670/RED670)

is available. Interfacing cables for relay setting and DR extraction is not

availble for REL 511 relays.


In KTPS-V Switchyard, 220KV Feeder REL511 Relays were

retrofitted with ALSTOM make MiCOM P442 Numerical Relays.

Complied

16 Redundancy not maintained in Fibre optic termination equipment. Mail dated 30.01.2018:

In KTPS-V Switchyard, new PLCC equipment installed for all

220KV Feeders which are having redundancy in fibre optic

termination equipment.

Complied

17 PLCC protection couplers are not availbale for 220kV lines except

Budhidampadu feeders.


In KTPS-V Switchyard, new PLCC equipment installed for all

220KV feeders it is under commissioning stage and it is in scope

of TSTRANSCO.

Pending


Equipments

Wave trap available in Sitaramapatnam-1&2 (inter circuit coupling and in

Budidampadu feeder-2. Wave trap is not available in other 220kV

feeders.


In KTPS-V 220 KV Switchyard, Wave traps are available for

BDPD-I & II, SRPM-II, LSR-II feeders(SRPM-II has 2 wave

traps), only SRPM-I feeder doesn't have wave-trap.

Pending

19 Even though the designed 220 kV busbar arrangement has bus-1 & bus-2

& transfer bus, the transfer bus was kept out of service due to the low

SF6 pressure in transfer bus circuit breaker.


In KTPS-V 220KV Switchyard, the Transfer Bus is in healthy

conditions (all its interlocks also checked). Now breaker is filled

with required SF6 gas pressure.

Complied

10/70

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20 Lightning Arrestor Earthing is not done as per standards/ NFPA in the

most of 220kV bays. LA's (system) earthing is connected to earth

electrodes directly as well as through equipment earthing. Healthiness

checking (leakage current measurement) of Lightrning Arrestor is not

being done.


In KTPS-V 220KV Switchyard, earthing for LA's were provided as

per the standards and leakage current monitoring is recording

every quarterly.

Complied

21 In most of the 220kV bays, LA surge counters and monitors are not in

working condition.


In KTPS-V 220KV Switchyard, Indent is raised for LA's surge

counters and monitors and it is in procurement stage.

Pending


not provided.


In KTPS-V 220KV Switchyard, Walkie-Talkie system will be

procured shortly, presently dedicated Mobile phones are

available location-wise (MCR, UCB)

Pending


Equipment/ System

auditated


Recommendations


Constituent)

1 Relay Setting Stub protection current set and time delay set as I> 150% and 100ms. Mail dated 30.01.2018:

stub protection current set value and time delay value are

I>150% and 0 ms

Pending

2 Main-1 relays all five zones are looking forward direction.No reverse zone

provided.

In Main-2 relays four zones are kept in forward direction and Zone-5 is of

reverse direction.


Reverse Zone protection for main-I provided

Complied

3 AC Distribution DG set is not available to feed substation loads.TSGENCO informed that

extension of supply from generating station DG will be planned shortly.


Supply extended from Generating Station DG

Complied

4 DC Distribution 2nos, 220 V DC system each with one Battery chargers , one no of

Battery bank and one DCDB with Bus couplers are available. Each set

will feed Trip circuit 1 and Trip circuit 2 separately. In the event of failure

of one set , Buscoupler will be closed manually to extend supply to the

affected section.


Presently existing system with buscoupler will be closed

manually to the affected section.

Complied

5 Communication

system

Common PC with auto downloading facility for relays DRs is not available.

TSGENCO informed that dedicated PC is available but not in working

condition at present.


Auto downloding yet to be configured, presently it is manual

download

Pending

6 GPS is not available. TSGENCO informed that PST feeder protection

relays are time synchronised with Generating station GPS.Other feeder

relays are not time synchronised and procurement of GPS is under

progress.


GPS Commissioned. All relays are synchronized.

Complied


Equipments

Lightning protection (LA's) Earthing is not done as per standards/ NFPA

in the most of 400kV bays. LA's (system) earthing is connected to earth

electrodes directly as well as through equipment earthing.


LA's Earthing is provided with Earth mats seperately and these

mats are connected to system earth.

Complied

8 Emulsifier system for fire fighting of Phase Shifting Transformer is not in

healthy condition and Local indication are not available.


Rectified Emulsifier System.

Complied

1 (iii) 400 kV KTPS (Stage-VI) [14-16 March, 2016]

11/70

Annexure-VI

Page 11 of 70

9 Oil leakage is observed in PST shunt and series transformer inlet pipelines

to tank.


Attended and Rectified

Complied

10 Drainage system in switchyard is not properly maintained.Water logging

in cable trenches has been observed and submerged drain pump also not

in working condition.


Pumps are working found Normal

Complied

11 PST-Shunt HV side WTI meter is not calibrated. Mail dated 30.01.2018:

Calibrated

Complied

12 Bay identification codes/name and phase identification are not visible. Mail dated 30.01.2018:

Name plate Boards are fixed with new one.

Complied


not provided.


Provided Walkie-Talkies

Complied


Recommendations


Constituent)

1 Mail dated 19.03.2018:

Implemented

Complied

2 Mail dated 19.03.2018:

Revised

Complied

3 Mail dated 19.03.2018:

Already ensured.

Complied

4 Mail dated 19.03.2018:

As per ramakrishna committee recommendations, revised to All

zones blocking except zone-1.

Complied 1

5 Mail dated 19.03.2018:

Already ensured.s

Complied

6 Mail dated 19.03.2018:

AR feature implemented for all 220KV Feeders, except 220KV

Pargi-1 &2 . The work is under progress, will be implemented by

Pending

7 Mail dated 19.03.2018:

Auto Change over is provided.

Complied

8 Mail dated 19.03.2018:

Only one BUS Bar C.U. is enough as per the existing philosophy

Complied

9 Mail dated 19.03.2018:

Will be implemented in 15days.

Pending

10 Mail dated 19.03.2018:

Under progress. Will be implemented in coordination with

remote end substations within 2 months.s

Pending

11 Mail dated 19.03.2018:

Already ensured

Complied .

Remarks/Deficiences/Nonconformity observed

KPCL

The existing Power Swing Philosophy (with all Zones blocked for unblocked time delay) to be reviewed to adopt either of the

following two approaches:

(i) Zone-1 --> Trip; Highers Zones --> Block for a delay of unblocking time delay (2 sec) & then Trip

(ii) Block all Zones with Out-of-Step tripping enabled at electrical zero locations by carrying out required system studies.

Load Encroachment feature, though explicitly not available in P444, has been taken care of by maintaining sufficient marign

beween Zone-4 resitive reach and expected load resistance.

Auto-Reclosure feature in 220 kV lines may be provided as decided in SRPC meetings

Provision of auto supply changeover to BBP may be explored

Bus Bar protection at each ovoltage level (220 kV/ 400 kV) for all Zones has been provided in P741 relay

VT Fuse File operation to be made independent of Over Current (67) functionality in Main-I & Main-II relays of all 400 kV & 220 kV

feeders. Case my be referred to OEM, if required.

VT Fuse fail time delay, which has been presently kept at 0.8 sec, may be suitably revised to say 0.5 sec

Drop-Off to Pick-up ratio of Over-Voltage functionality of Main-I & Main-II relays to be ensured at > 0.97.

Provsision for auto-starting of DG set shall be provided

In 400 kV lines, distance protection timings for Zone-2, Zone-3, Zone-4 and Zone-5(reverse) may be reviewed in line with

Ramakrishna Committee guidelines

High-set operation of ICT's may be checked to ensure their non-operation for downstream/ upstream faults

1) 400/220 kV Shankarapally SS [20 - 21 March, 2017]

TSTRANSCO

12/70

Annexure-VI

Page 12 of 70


Equipment/ System

auditated

Deficiences/Nonconformity observed Status of Implementation of Protection Audit

Recommendations


Constituent)

1 Main-1 &

Main-2 Bus

220KV Protection Single Bus operation is being done for 220kV Switchyard. Two main

Buses (1 Working + 1 Standby) to be provided in the 220KV.


Time frame is requested for 2 yrs. To carry out 220Kv double

bus operation using Num relay under PSDF funds

Pending

2 All Line Feeders 220KV Protection Carrier Protection was kept off in all 220KV feeders. PLCC provided in

220KV feeders. KPCL informed that retrofitting of new 48V DC system is

under progress.


The retrofitting of new 48V DC system was completed during

July-2016. PLCC system in RTPS is monitored and maintained by

KPTCL. At present KPTCL staff are working on the PLCC system.

Pending

3 ICT-2 220KV Earthmat Resistance Earth resistance values of earth pit of lines were observed to be higher. Mail dated 14.02.2018:

M/s CPRI was awarded the work of earth mat adequecy study at

220/400KV switchyard. Their conclusion is as follows. "A detailed

study of earth resistance measurment, checking the adequacy of

existing earthing system and step and touch potential

measurment was made at RTPS. from the measurment results,

the interconnected earth resistance is found to be 0.05ohm

which is less than the standard value of 0.5ohm for a large

earthing system. soil resistiviy at the side near the switchyard is

found to be homogenous with an average value 30.02ohm-m.

step and touch potential were made found ti be within the

tolerable value. Adequacy checks have been made at all the

locations of RTPS"

Complied

4 Lingasugear -3,

Sadam-1&2

220KV Equipment Wave Trap is not available Mail dated 14.02.2018:

Wave traps are normally provided and commissioned by M/s

KPTCL. However the same is being processed by CEED/CETD

under PSD fund.


Wave traps are normally provided and commissioned by M/s

KPTCL. However the same is being processed under PSD fund.

Time frame is requested for 2 yrs.

Pending

5 General 400KV &

220KV

Control room Fire alarm/detection system is not working in 400KV & 220KV control

room. KPCL informed that retrofitting is under progress.

Mail dated 14.02.2018 & 21.02.2018:

Action has been taken for retrofitting works.

Pending

6 SHAHAPUR-1&2 220KV Protection Its observed that the Only one Main relay is used in the 220KV Shahapur-

1&2 (ABB REL100 in Shahapur-2 line feeder and ENGLISH ELECTRIC -

QUADRAM40 in Shahapur-1 line feeder). These relays are very old one

and static type. There is no reverse Zone selection in these relays and

Only one DC source is being used


The old Distance Protection relays of Shahapur 1&2 lines were

retrofitted with Numerical relays during July-Aug 2016. ABB

REL511 for Main-I and Alstom MiCOM P444 for Main-II distance

protection.

Complied

7 Raichur-1&2,

Lingasuguar-1&2

220KV Protection In Raichur-1&2 and Lingasuguar-1&2 220KV line feeder DEF provided

only in the Main-2 relay.


ABB REL511 and MiCOM P444 relays are in service for Raichur-

1&2 and Lingasuguar-1&2 lines as Main-I & Main-II Dist. Protn.

respectively. DEF is provided in the Main-2 relay and the same

will be enabled in the Main-I relay after retrofitting old REL511

relays with latest version numerical relays under PSDF funds.


Pending

1) 400 Raichur TPS & 220 kV Raichur TPS [8-10 June, 2016]

13/70

Annexure-VI

Page 13 of 70

8 Lingasuguar-3,

Sadam-1&2

220KV Protection DEF not enabled in Main1&2 relay in the Lingasuguar-3, Sadam-1&2 line

feeder. Separate Earth Fault relay (static type) provided.


DEF is enabled in MiCOM P444 (Main-II Dist. Protn.) relay and

also separate ABB make E/F relay RAPDK is existing.

Complied

9 Line Feeders 220KV Protection Auto-reclose feature is not enabled for 220kV lines. Mail dated 21.02.2018:

Auto-reclose function is configured and tested for all the nine

lines in Main-II numerical relays. At present, as per the

requirement of KPTCL, Auto-reclose function is disabled.

Pending

10 General 400KV &

220KV

Equipment It was observed that stand alone Disturbance Recorder with automatic

downloading facility to centralized PC not provided for static relays.

Mail dated 14.02.2018 & 21.02.2018:

Tender has been invited for retrofitting work of balance static

relays with Numerical protection relays and will be completed by

June-2018. Budgetary offer obtained for Retrofitting of stand

alone Disturbance recorder and is under process.

Pending

11 General 220KV Equipment No time Synchronisation in the 220KV system, GPS not avilable. Mail dated 21.02.2018:

GPS system was installed during Aug-2016

Complied

12 Bus Bar 400KV Equipment Two Main zones are available for busbar protection of 400kV Bus-1 and

Bus-2. No check zone is available.

Mail dated 14.02.2018 & 21.02.2018:

Action has been taken for Retrofitting of Numerical Bus bar

protection relays and the same will be reviewed and will be

completed by December 2018.


Pending

13 Raichur PG-1 &2 400KV Protection Resisitive reach is set at a higher value in 400KV Raichur PG-1 & 2

feeder, Load encroachment is not available.


As per PGCIL directions, Revised settings for resistive reach and

load encroachment have been uploaded on 24-06-2016.

Complied

14 Raichur PG-1 &2 400KV PLCC Its observed that the channel failure alarm indication in Raichure PG-2

line Chennel-1 & Raichure PG-1 line Channel-1&2.


Same has been set-right and both the channels of Raichur PG-1

& 2 are healthy.

Complied

15 ICT Protection Backup over current and earth fault protection of ICT's is kept non-

directional.


Settings will be revised in co-ordination with KPTCL & OEM.


Settings will be revised in co-ordination with KPTCL & OEM

during annual shut down of respective equipments.

Pending

16 All Line Feeders 400KV Protection Stub protection Kept off in 400KV lines Main-1&2 relays. But Separate

relay (Static type) provided for the same. Stub protection set value as

0.2A and time delay is instantaneous.

Mail dated 14.02.2018 & 21.02.2018:

Tender has been invited for retrofitting work of the balance

static relays with Numerical protection relays in which enabling

of stub protection is included and the will be completed by June-

2018.

Pending

17 Mehaboob nagar &

Munirabad

400KV Protection Auto reclose is not provided for Tie breaker of 400kV Munirabad &

Mehaboob Nagar lines. Pole discrepancy (PD) for Munirabad & Mehaboob

Nagar Tie-CB is kept as 0.1sec.

Mail dated 14.02.2018 & 21.02.2018:

Tender has been invited for retrofitting work of the balance

static relays with Numerical protection relays in which enabling

of Auto reclose of Tie breaker of Munirabad & Mahbubnagar line

is included and will be completed by June-2018.

Pending

14/70

Annexure-VI

Page 14 of 70

18 Distance protection adopted resistive reach setting for Zone-2 & 3 is not

matching with the recommanded setting given by Tractebel based on

Ramakrishna committee recommendations (Task force committee

guidelines).


As per PGCIL directions, revised settings for resistive reach of

Zone-2 & 3 have been uploaded on 24-06-2016 for Raichur PG-1

&2 lines--Completed

Complied

19 Zone-3 time delay is kept as 1.5 sec. Mail dated 14.02.2018:

As per PGCIL directions, revised settings for Zone-3 time delay

as 1.5 sec kept on 24-06-2016 for Raichur PG-1 &2 lines--

Completed

Complied


As per PGCIL directions, revised settings for Zone-4 time delay

as 0.5 sec kept on 24-06-2016 for Raichur PG-1 &2 lines--

Completed

Complied

21 Directionnal Earth Fault setting kept different in Main 1 & Main 2 Relay Mail dated 14.02.2018:

As per PGCIL directions, Revised settings have been uploaded

on 24-06-2016.The settingsof Directional Earth fault kept same

in Main 1 & 2 relays --Completed

Complied

22 YTPS 400KV Protection Zone-4 time delay is kept as 1.0 sec Mail dated 14.02.2018 & 21.02.2018:



Pending

23 MEHABOOB NAGAR

& MUNIRABAD

400KV Protection Zone-4 time delay is kept as 1.1 sec. Mail dated 14.02.2018 & 21.02.2018:



Pending

24 MEHABOOB

NAGAR,

MUNIRABAD, YTPS

and All 220KV Line

feeder

400KV &

220KV

Protection In distance protection the adopted resistive reach setting for Zone-1,2 &

3 is not matching with the recommanded setting given by Tractebel

based on Ramakrishna committee recommendations (Task force

committee guidelines).

Mail dated 14.02.2018 & 21.02.2018:

For 220kV lines, the settings recommended by CEERT, KPTCL is

adopted. For 400kV lines, Settings will be revised in co-

ordination with KPTCL & OEM during annual shut down of

respective equipments.

Pending

25 Zone 4 reach should be set to cover 50% of shortest line connected in

RTPC SS (existing settings are set to 20% of protected line)

Mail dated 14.02.2018 & 21.02.2018:





Pending

26 Resistive reach of reverse Zone is not Kept identical with Zone 3 resisitive

reach.

Mail dated 14.02.2018 & 21.02.2018:





Pending

27 Zone-4 (Reverse Zone) time delay not match with Zone-2 setting. Mail dated 14.02.2018 & 21.02.2018:





Pending

All Line Feeders 400KV &

220KV

Protection

Raichur-1&2 400KV Protection

15/70

Annexure-VI

Page 15 of 70

28 General - DC system In DC system +ve Earth fault was observed in 220KV switchyard. The

voltage measured values are :

DC-1

+ve to -ve = 234.6V

+ve to earth = 1.217V

-ve to earth = 233.4V

DC-2

+ve to -ve = 235.3V




Positive dead ground was partially eliminated in Oct-16. The

voltage measured values were:

+ve to -ve = 237.7V



The DC grounding problem is being attended as and when it

appears. The DC voltage measured values in Jan-18 are:

+ve to -ve = 237.7V



Pending

29 Mahaboob Nagar

Line Reactor

400KV Equipment Oil seepage was observed in the 400 kV system Line Reactor. Mail dated 14.02.2018:

Oil leakage was arrested during AOH works of M.Nagar line Dec

2016.

Complied

30 General 415V ACDB It is observed that manual Changeover arrangement only has been

provided between Incomer -1 & Incomer-2 feeder in ACDB.

Mail dated 14.02.2018 & 21.02.2018:

It has been deliberated and opined that manual changeover is

adequate.

Pending

31 General 415V DG set Generation plant emergency DG set is utlised for 400KV auxiliaries during

main source blackout. Manual changeover arrangement only has been

provided in the ACDB Main source and DG source.

Mail dated 14.02.2018 & 21.02.2018:

It has been deliberated and opined that manual changeover is

adequate.

Pending

32 General 415V DG set No dedicated DG set for 220KV switchyard auxiliaries. Emergency power

source not provided in the 220KV system ACDB during main power

supply blackout.

Mail dated 14.02.2018 & 21.02.2018:

Tender has been floated for the work of extension of AC supply

from DG-1 Bus to 220KV switchyard auxillaries.

Pending

33 General - Equipment Cables laying in 220KV Switchyard ACDB & DCDB room is observed to be

overloaded in cable trays and some of the cables laid haphazardly (not

properly laid in Cable trays)

Pending

34 General - Equipment In ACDB & DCDB, no Indication Lamps were provided. Mail dated 14.02.2018:

Fused out Indicating lamps replaced.

Complied

35 General - DC system It is observed that dedicated one no. 220V DC system provided in the

220 KV DC auxiliaries. For other DC supply, Generation plant DC source is

being used.


For protection of 220kV feeders, one dedicated 220V DC system

is provided and arrangement is ready to take either of Unit 1, 2,

3 & 4 station 220V DC as a backup.

Pending

36 General - Equipment Most of the circuit breaker cubicles in 400KV & 220KV feeders have not

been provided with panel lamp. Door switches were also not working

properly.


Panel lamps have been provided and are visible from the front

side of the panel. Failed door switches are being replaced.

Complied

37 General - Equipment It is observed that single earthing has been provided for few marshalling

boxes in switchyard. Also Door earthing was not provided for few

marshalling boxes. The dummy gland holes in few marshalling boxes

were not covered.


One more earthing has been provided to marshalling boxes

wherever they were not existing. Door earthing works

completed. Dummy gland holes are plugged with M seal and

Putty.

Complied

38 General - Equipment It was observed that most of unused cutouts in ACDB & DCDB (both 400

kV & 220 kV) in control room were not covered.


Unsed cut outs covered with dummy fuse carriers.

Complied

39 General - Equipment Drainage system in switchyard is not properly maintained.Water logging

in cable trenches has been observed and submerged drain pump not

available.


This has been brought to the notice of EEPCM2/CCET.


The problem will be attended in coordination with civil

engineers.

Pending

16/70

Annexure-VI

Page 16 of 70

40 General - Equipment It is observed that Silicon coating of 400KV bay equipments not provided. Mail dated 14.02.2018 & 21.02.2018:

Silicon coating of two breakers of Unit-8 has been completed.

Other breakers are under consideration and HO approval

awaited.

Pending

41 General Equipment It is observed that REL500 series relays are not having time

synchronisation facility.


Proposed to retrofit old REL511 relays with latest version

numerical relays under PSDF funds. Time frame is requested for

2 yrs.

Pending


Equipment/ System

auditated


Recommendations


Constituent)

1 Ambewadi-1 Line

Feeder

220KV Equipment Wave Trap is not available. Mail dated 07.02.2018:

Wave traps provided to R & B phases of all the eight lines.

Complied

2 Synchro-check protections not enabled for Line Feeders. KPCL informed

that the CVT erection & commissioning works are in progress & wiring is

completed in Relay panel & synchronizing panel. Will be commissioned at

the earliest. Synchronizing relay is available.

Mail dated 07.02.2018 & 21.02.2018:

CVT erection and commissioning works completed. Preparation

of wiring scheme is under progress.

Pending

3 CVT condition is very old and not in proper condition, only R-ph CVT is

present in all the lines except Ambewadi line#1 which is not having any

CVT. KPCL informed that the CVT replacement works are in progress. Will

be commissioned at the earliest


CVT's erected and commissioned for R,Y & B phases and wave

traps for R & B phases of all the eight lines.

Complied

4 Kodasali-1&2 Line

Feeders

220KV Protection It is observed that the ENGLISH ELECTRIC - QUADRAMHO relay is used

in the Kodasali-1&2 Line feeders Main-I. These relays are very old one

and static type. KPCL informed that the same will be replaced with in one

month.


Replaced by new Schneider make micom P444 numerical relays

in both Kodasalli lines 1 & 2.

Complied

5 All Line Feeders 220KV Protection Auto-reclose feature is not enabled for all 220kV lines. Mail dated 07.02.2018 & 21.02.2018:

Auto reclose feature is tested at Nagjhari end along with KPTCL

RT, Hubli and is clear for all the six lines (NA-1, NA-2, NH-1, NH-

2, NH-3, NB). Auto reclose function will be enabled after getting

clearance from the receiving end.

Pending

6 All Line Feeders 220KV Protection Pole discrepancy (PD) for all 220KV Line feeders CB is kept as 0.5sec. Mail dated 07.02.2018 & 21.02.2018:

Will be changed after enabling Auto reclose function to 1.7 Sec.

Pending

7 Reverse Zone Not Enabled in the Kodasali-1&2 and Ambewadi-1&2 Line

feeders.


Enabled in Kodasalli lines 1 & 2 and Ambewadi lines 1 & 2 as per

the recommended settings of CEE RT & R & D, KPTCL.

Complied

8 Zone-4 time delay is kept as 2.0 sec. Mail dated 07.02.2018 & 21.02.2018:

As per the recommendations of CEE RT & R & D, KPTCL, Zone-4

trip timing is set to 1 second.

Pending

9 Reverse Zone enabled only for alarm not for trip. Mail dated 07.02.2018:


(reverse zone) is enabled for trip also.

Complied

10 Zone-4 time delay is kept as 1.2 sec Mail dated 07.02.2018 & 21.02.2018:



Pending

Bidnal Line feeder 220KV Protection

2) 220 kV Nagjheri PH [14-16 July, 2016]

All Line Feeders 220KV Protection

Kodasali-1&2 and

Ambewadi-1&2 Line

feeders

220KV Protection

17/70

Annexure-VI

Page 17 of 70

11 Line length is confirmed as 65Kmtrs instead of 69Kmtrs. Mail dated 07.02.2018:

As per the recommendations of CEE RT & R & D, KPTCL, length

of the protected line is set to 67.6Km.

Complied

12 Hubli-1,2 & 3 Line

Feeders

220KV Protection Zone-4 time delay is kept as 1.2 sec Mail dated 07.02.2018 & 21.02.2018:



Pending

13 Distance protection's adopted resistive reach setting for Zone-1,2 & 3 is

not matching with the recommanded setting given by Tractebel based on

Ramakrishna committee recommendations (Task force committee

guidelines).


Settings in all the feeders are made as per the recommendations

of CEE RT & R & D, KPTCL.

Complied


Zone-3 time delay is set as 800msec as recommended by CEE

RT & R & D, KPTCL.

Complied

15 Zone 4 reach should be set to cover 50% of shortest line connected in

Nagjhari SS ( existing settings are set to 20% of protected line)


Settings recommended by CEE RT & R & D, KPTCL are such that

reverse zone covers 20% of the protected line or 50% of the

shortest reverse line impedence whichever is less.

Complied

16 Resistive reach of reverse Zone is not kept identical with Zone-3 resisitive

reach.

Mail dated 07.02.2018 & 21.02.2018:

Settings in all the feeders are made as per the recommendations

of CEE RT & R & D, KPTCL.

Pending

17 Bus bar Protection 220KV Protection Bus bar protection main & check relay are connected to same CT core, 4

Cores are available.

Mail dated 07.02.2018 & 21.02.2018:

Procurement of 5 core CT is under process.Time frame is

requested for 2 yrs.

Pending

18 Hubli-3 and

Kodasali-1&2 Line

Feeders

220KV Protection Carrier Protection is not working in Hubli-3 and Kodasali-1&2 Line feeder.

KPTCL informed that due to CVT & Wave Trap problem carrier protection

are not working, New CVT erection & commissioning works are in

progress & wiring is completed in PLCC panel. Will be commissioned at

the earliest.

Mail dated 07.02.2018 & 21.02.2018:

CVT's and wave traps are commissioned and the carrier

protection is working.

Pending

19 All Line Feeder 220KV PLCC There is provision for one PLCC Channel (Protection & Speech) for each

220 kV double circuit lines.


Provision available for both speech & protection for each line.

Complied

20 Bus Bar

sectionaliser

Breakers

220KV LBB Protection LBB protection is not provided for the sectionaliser breakers (Two Nos.) Mail dated 07.02.2018 & 21.02.2018:

Will be implemented in future.

Pending

21 All Line feeders

(Except Kodasali-

1&2 Line feeder)

220KV Protection Main-I & Main-II relays found to be of same type & make for all 220 KV

Line feeders except Kodasali-1&2 line feeders. KPCL informed that the

same is replaced with in one month.


Main-II distance protection relays in all the lines are replaced

with Schneider make Micom P444 numerical distance protection

relays.

Complied

22 General 220KV Control room Fire alarm/detection system is not provided in the 220KV control room. Mail dated 21.02.2018 & 21.02.2018:

Will be taken up during SCADA implimentation

Pending

23 General 220KV Equipment Time Synchronisation is not working in the 220KV line feeders, due to

GPS failure. KPCL informed that the GPS equipment will be replaced

within one month.


New GPS system is already commissioned and all the numerical

relays are time synchronized.

Complied

Bidnal Line feeder 220KV Protection

All Line Feeders 220KV Protection

18/70

Annexure-VI

Page 18 of 70

24 General - DC system It is observed that, even though two DC system is available in the

generation plant, both the sources are connected to common bus and

single DC power supply distribution to 220KV SS DC auxiliaries (Field

equipments & Relay panels). The Measured DC Voltage (V) (At farthest

point of the yard):

DC Voltage:

+ve to -ve = 253.1V



Mail dated 07.02.2018 & 21.02.2018:

OEM has been approached for providing redundancy in already

existing two separate 250 V DC sources.

Pending

25 General 415V ACDB It is observed that Only one Incoming power supply in 415V ACDB. Mail dated 21.02.2018 & 21.02.2018:

Will be taken up shortly.

Pending

26 General 415V DG set Generation plant 415 V emergency DG set is utlised for 220KV SS

emergency auxiliaries during main source blackout. DG set start in

Manual mode. Also, Manual changeover arrangement only has been

provided in the ACDB Main source and DG source.

Mail dated 07.02.2018 & 21.02.2018:

Procurement of AMF panel is under process.

Pending

27 General - 48 V DC system It is observed that even though two 48VDC sources are available in the

generation plant, both the sources are connected to common bus and

single DC power supply distribution to PLCC panel. No redundancy.

Mail dated 07.02.2018 & 21.02.2018:

OEM has been approached for providing redundancy in already

existing two separate 48 V DC sources.

Pending

28 General - Equipment Most of the circuit breaker cubicles in 220KV feeders have not been

provided with panel lamp. Door switches were also not working properly.



Pending

29 General - Equipment It is observed that single earthing has been provided for most of the

marshalling boxes and few structures in switchyard. Also Door earthing

was not provided in the most of the marshalling boxes. The dummy

gland holes in few marshalling boxes were not covered.


Double earthing provided for all MB's and structures.

Complied

30 General - Equipment The following 220KV Line feeders LA meters are not in working condition.

1.Ambewadi-2 (Y&B-Phase)

2.Hubli-1,2&3 (Y&B-Phase)

3.Ambewadi-1 (Y-Phase)

4.Bidnal (Y&B-Phase)



Pending

31 General - Equipment Due to aging some of the MBs' door gaskets are worn out and panels

rusted leading to coal dust deposition and vermin ingress in 220KV

S/S.It is advised to replace the MBs/ panels with IP 55/ IP6X panels as

soon as possible.



Pending


Recommendations


Constituent)

3) 220 kV Sharavathy GS [30 - 31 October, 2017]


19/70

Annexure-VI

Page 19 of 70

1 Mail dated 07.02.2018 & 21.02.2018:

(i) Vegetation and weeding cleaned - Jelly spreading work will

be taken up after strengthening / modification works of the

Station Earth mat at SGS.

(ii) Covering of cable trenches by checker plates/concrete blocks

is under progress. Dressing of routed cables done

(iii)Work is under progress, almost 70% of work is completed.

(iv)Door to Panel earthing made for all Marshalling boxes

(wherever not provided) - work completed

(v) Equipment labeling work is under progress.

Pending

2 Mail dated 07.02.2018 & 21.02.2018:

Work of Re-enforcement of equipment supporting (RCC)

structures is in progress.

Pending

3 Mail dated 07.02.2018:

The other bus can be used as suggested only when there is no

maintenance on the spare bus /isolators connected with it. Since

there will be maintenance work on the spare bus connected bus

/isolators the suggested scheme cannot be used for safety

reasons.

Complied

4 Mail dated 07.02.2018:

The problem was rectified.

Complied

5 Mail dated 07.02.2018 & 21.02.2018:

Letter written to EE(MRT), KPTCL vide letter No:

EE(controls)J/RT/F10. Awaiting for reply.

Pending

6 Mail dated 07.02.2018 & 21.02.2018:



Pending

7 Mail dated 07.02.2018 & 21.02.2018:



Pending

8 Mail dated 07.02.2018 & 21.02.2018:



Pending

9 Mail dated 07.02.2018 & 21.02.2018:

It has been enabled and checked at the time of

commissioning.It will be enabled immediately after completion of

station Earth Mat strengthening works.

Pending

10 Mail dated 07.02.2018 & 21.02.2018:

It has been communicated to AEE(PLCC) KPTCL,Awaiting for

reply.

Pending

11 Mail dated 07.02.2018 & 21.02.2018:

Proposal raised for replacement of exsisting D.G with new D.G

having the auto mode feature.

Pending

12 Mail dated 07.02.2018 & 21.02.2018:

Protection part has been completed at common

Auxiliary.Transformer and cabling to be done.

Pending

It is observed that some of the existing gantry & equipment supporting (RCC) structures are in dilapidated state. Steps may be

taken to reinforce them suitably.

It is noted that even though the Bus-Configuration for Sharavathy GS has been designed for a full-fledged double-bus operation

with four sections, it is mostly run on single-bus operation with two sections with both the bus-couplers in OPEN condition and the

other bus being used solely as a transfer bus. Steps may be taken to using full-fledged Double Main-Bus system with four

sections instead of the present Single Main-Bus with two sections.

DC earth leakage is observed in both 250 V DC Sources. Steps shall be taken to rectify the same at the earliest.

Time settings and Reactive & Resistive reaches of Z2, Z3, and Z4 (reverse) of distance relays are observed to be not in line with

Ramakrishna Committee guidelines, which may be reviewed appropriately in consultation with KPTCL.

(i) In PSB settings, unblocking time delay for Z2, Z3 may be revised to 2 sec from the present 3 sec.

(ii) VT fuse fail time delay, which has been presently kept as 0.2 sec, may be suitably revised to 0.5 sec.

(i) Vegetation & weeding was observed in switchyard area. Steps may be taken to provide chemically treated PCC flooring, and

then covering it with suitable blue metal spreading in switchyard area. Steps to be taken to maintain proper upkeep of station by

regularly undertaking cutting of weeds, grass & unwanted vegetation growth in the switchyard area.

(ii) Routing of cables for termination in panels in the switchyard should be done systematically employing proper raisers/ trays.

Further, cables & cable trenches in the switchyard should be covered properly.

(iii) Double-earthing to be provided for all metallic structures in switchyard area.

(iv) Door-to-Panel earthing to be provided in various marshalling boxes, whereever not provided.

(v) Equipment labeling for proper phase-sequence may be provided.

Presently, AC auxiliary supply is obtained from Station Aux.Transformers with DG set as back-up. It is also seen that works are

under progress to provide one external AC auxiliary supply (from MUSS, KPTCL, Jog). It is recommended to expedite providing

external AC aux. supply.

Re-Trip feature to be provided for Breaker Failure Protection in Feeders and GT's.

Mode of Carrier-Aided-Scheme for Talaguppa line-3 (of 20 km) may be changed to Permissive Over Reach from the existing

Permissive Under Reach.

It is observed that A/R for all 220 kV lines has been kept out of service due to pending earth-mat strengthening works. Steps shall

be taken to keep A/R in service at the earliest.

It is noted that even though two Channels per Circuit have been provided for PLCC, Card-level redundancy has not been provided

for those channels. Steps shall be taken to provide the same.

It is observed that DG-Set starting is being done manually. Steps shall be taken to provide DG-Set starting in auto-mode.

20/70

Annexure-VI

Page 20 of 70

13 Mail dated 21.02.2018:

Measures are taken to maintain records.

Pending

14 Mail dated 21.02.2018:


Pending

15 Mail dated 07.02.2018 & 21.02.2018:

Calibration, interfacing with DCS, alarm setting implementation

are in progress.

Pending

16 Mail dated 07.02.2018 & 21.02.2018:

Action is initiated to procure all equipments.

Pending


Equipment/ System

auditated


Recommendations


Constituent)

1 Zone-4 time delay is kept as 1 sec. Mail dated 30.01.2018:

Zone-4time delay setting is revised to 0.5 sec

Complied

2 VT supervision time delay is kept as 1 sec. Mail dated 30.01.2018:

VT supervision time delay kept as 5 sec.

Pending

3 Auto-Recloser was kept off. NPCIL Kaiga has raised issues for enabling

Auto-Recloser for these lines.


Auto Reclosure is enabled and it is in service

Complied

4 Narendra 1 & 2 400 kv Protection Panel

Main-I relay

STUB time delay is kept as 100 msec Mail dated 30.01.2018:

400kV Narendra-1 &2 bays at Guttur belongs to Power

Grid.Relay settings of these bays are maintained by Power Grid.

Pending

5 JSWEL 400 kV PLCC Observed that Speech panel is out of service. KPTCL is informed restored

by within two months


Speech channel is incorporated in PLCC Protection Panel

Complied

6 Protection Panel

Main-I relay

Reverse zone is not available Mail dated 30.01.2018:

ABB make static type Main-I relay is replaced by numerical

distance relay (ALSTOM make ,P442 type) under R&U

project.Reverse zone protection is provided

Complied

7 Protection Panel

Main-II relay

Carrier Protection was kept off Mail dated 30.01.2018:

Carrier protection is restored

Complied

8 Yard Found that No wave Trap is available in this line Mail dated 30.01.2018:

Wave trap is provided

Complied

9 Protection Panel

Main-II relay

DEF function was found off. Mail dated 30.01.2018:

DEF proteection is enabled

Complied

Measurement of earth-resistance values for various earth-pits shall be undertaken periodically as per relevant standards, and

records maintained properly.

In some Units, leakage current indicators of Lightning Arresters on 220KV side are found to be faulty; the same shall be replaced/

rectified.

Vibration monitoring systems of Units with alarm settings to be commissioned fully.

The following equipment shall be purchased for maintenance of various switchyard equipment:

(i) Thermo-vision imaging camera to identify hot spots in yard equipments and transmission lines.

(ii) Dynamic Contact Resistance Meter for Breaker maintenance

(iii) Winding Resistance Meter

(iv) Earth-resitance measuring kit

KPTCL

1) 400/ 220 kV Guttur SS [4-6 May, 2016]

KAIGA-1 400 kV Protection Panel

Main-I relay

Chitradurga 220 kV

Davangaere-2 220 kV

21/70

Annexure-VI

Page 21 of 70

10 Yard Found that one wave Trap is available in this line. Mail dated 30.01.2018:

Work of providing one more wavetrap is included under R&U

project.

Pending

11 Haveri-1 220 kV Isolator Isolator was not working properly the same has been bypassed.KPTCL

informed the same would be restored with in one month.


Faulty isolator has been replaced

Complied

12 Davangaree 1, 2 &

3

220 kv PLCC No separate PLCC Protection panel available for all these 3 lines and

observed that no redundant card available.


Carrier protection is availabe for Main-1 relays of all three

lines.One more PLCC panel will be provided during retrofitting of

Main-2 scheme.

Pending

13 Neelagunda 220 kV Yard Found that B phase wave trap is not connected with Line.KPTCL informed

the same would be restored with in one month.


Wave trap is connected and normaly is restored.

Complied

14 Protection panel Over Load function was not available. Mail dated 30.01.2018:

Over load protection is provided.

Complied

15 ICT Oil seepage was observed. Mail dated 30.01.2018:

Oil seepage arrested

Complied

16 Bus coupler 220 kV Isolator Found that isolator misalignment in the arcing contacts. KPTCL informed

the same would be be attended with in the one month


Misalignment of arcing contacts rectified

Complied

17 Beernahalli-1 400 kV Line reactor Observed DC Voltage (203.6 V) in Isolator marshalling Box. Mail dated 30.01.2018:

Attended. Measured DC Voltage is 218 V in Isolator marshalling

Box.

Complied

18 Bus Reactor 400 kV Protection Panel 5th Harmonic setting is kept as 35% in differential relay. Mail dated 30.01.2018:

5th Harmonic setting is changed to 25% in differential relay.

Complied

19 All 400 kV Lines Auto Reclouser enabled in both Main -1 & 2 of all 400 Kv lines (Expect

Kaiga 1 &2). KPTCL informed presently using inbuilt Auto-Reclouser in

Distance relay itself.


Auto Reclosure is enabled in all the 400kV lines. Built in auto

recloser feature is used

Complied

20 Auto Recloser reclaim time delay is kept as 20s. Mail dated 30.01.2018:

Auto Recloser reclaim time delay isrevised to 25 Sec

Complied

21 Zone 4 time delay has been is kept as 1.0 sec except Narendra-1-2 line. Mail dated 30.01.2018:

Zone-4 time delay setting is revised to 0.5 sec

Complied

22 Zone 4 reach setting should be set to cover 50% of shortest line. Mail dated 30.01.2018:

As per KPTCL practice, Zone-4 reach is set to cover 20% of

the protected line or 50% of shortest line reverse whichever is

lower. Z4 reach setting adopted at Guttur is in order

Complied

23 Overvoltage Protection Stage-2 is kept as instantaneous. Mail dated 30.01.2018:

Over voltage function stage -2 time delay set as 100ms

Complied

24 All 220 kV Lines Auto Recloser is not available in all 220 kV Lines Mail dated 30.01.2018:

AR will be enabled during retrofitting of Main-2 distance scheme

under R&U works

Pending

25 Over voltage function is enabled all 220 kV lines. Mail dated 30.01.2018:

Over voltage functionis disabled in all 220kV lines

Complied

ICT-1 & 2 400/

220 kV

Chitradurga 220 kV

22/70

Annexure-VI

Page 22 of 70

26 No redundant backup distance protection is available in all 200 kV Lines

(Except Chitrdurga and Divanagree-2)


Main2 distance protecion is being provided under R&U project.

Required relays are already supplied to the site.

Pending

27 Observed that No redundant DC supply in PLCC panel Mail dated 30.01.2018:

Two set of Batteries and Battery Chargers are available.

Complied

28 All 400 & 220 kV

Lines

All Isolator were working locally electrical and Bypassed (Removed)

electrical interlocks between Circuit Breaker and Isolator.


Action will be taken to provide electrical interlock between CB

and isolator in all bays

Pending

29 All 400 & 220 kV

Lines

Fire Fighting is not available in Control Room, Protection Panel Room &

line reactor Yard. KPTCL informed that the same would be installed within

six months.


Fire Fighting equipments are available in Control Room and

Protection Panel Room.

Complied

30 Found that redundant Auxiliary Supply is not available Mail dated 30.01.2018:

Two auxillary transformers (1 MVA each ) fed from separate

feeders from different incomers is provided at Guttur

Complied

31 No specific changeover interlock between Normal supply to Emergency

Supply (DG set)


Action will be taken to provide interlock during change over

from normal to emergency supply.

Pending

32 Auto changeover facility is not available. Mail dated 30.01.2018:

Action will be taken to provide auto change over facility.


In KPTCL system , no LT circuit breaker available for DG set

supply. Onnly switch has been provided.

Pending

33 Walkie-talkie is not available for communication between switchyard and

control room.


Dedicated mobile phones are available.

Pending

34 In some of the Marshalling boxes, single point earthing is done. Mail dated 30.01.2018:

Action will be taken to provide one more earthing.

Pending

35 CT/CVT Star grounded done in filed (Expect Kaiga 1 &2) and bus bar

protection done in relay panel.KPTCL informed earthing for Kaiga 1 & 2

to be done filed.


Attended. Iall neutral earthing is done at Switchyard.

Attended

36 Most of the BMK's, CB/Isolator MB & gland plates are very old &

corrosion, almost replace condition. Gland plate holes are open in the

most of the MB. KPTCL informed the same would be attended during

R&M


R&M scope is yet to be finalised

Pending

37 Few of the MB is door earthing was not done. Mail dated 30.01.2018:

Attended

Complied

38 GPS is not available for Time Synchronisation Mail dated 30.01.2018:

GPS time synchronisation device has been supplied under R&U,

erection and commissioning works will be taken up shortly.

Pending

23/70

Annexure-VI

Page 23 of 70

39 Ventilation is not sufficient for control & Protection and Battery rooms. Mail dated 30.01.2018:

Exhaust fans are provided in battery room. AC is being provided

to in Control Room.

Complied

40 Salt formation found in Battery Mail dated 30.01.2018:

Salt formation on the battery terminals have been removed.

Also, one battery set has been replaced by new under R&U

work. Replacement ofsecond set of battery bank is under

progess

Complied

41 Main-I & Main-II relays found to be of same type & make for some 400

kV S/S. KPTCL informed that the same would be attended during R&U .


M-II relays will be replaced by Seimens make numerical distance

relays. Required relays have been supplied by M/s GE under

R&U. Retrofitting work will be taken up shortly.

Pending

42 DC supervision relay is not available in Control Panel. Mail dated 30.01.2018:

DC supervision relay is available in the relay Panel & DC fail

annunciation has been provided in the control panel.

Complied

43 Measured DC Voltage (V):

DC-1 DC-2

+ to - : 232.2 222

+ to E : 143 132

- to E : 89.1 90


Measured DC Voltage (V):

DC-1 DC-2 +

to - : 239.5 236

+ to E : 121.3 120.2

- to E : 117.2 115.4

Complied


Equipment/ System

auditated


Recommendations


Constituent)

1 220kV

and

400kV

Control and

Protection Panels

For 400 KV Busbar protection, one main Bus bar protection scheme for

each Bus 1 & Bus 2 available and Check Zone protection is not available

because of static type relay. Redundant Bus bar protection or Check

zone shall be considerd.


The work of providing Main-1 and Main-2 Bus Bar protection for

400kV buses is included under R&U project awarded to M/s GE

T&D India Ltd.. Supply of new BBP panels is expected during

February 2018.


Main -1 and Main-2 BBP will be commissioned before end of

December 2018.

Pending

2 BFR (LBB) trips and BB protection trip are properly integrated in Trip Bus

(96).


In present conditon LBB trip is extended to BB realy thorugh trip

bus sysem

Complied

3 Main 1 & Main 2 relay make and type (Siemens 7SA522) are same in

400kV Hassan, Hiriyur-1 and Hoody-1 lines.


Main-1 and Main-2 relays of same make(Seimens) but different

of different type. Main-1 relay is 7SA522 type and main-2 is

7SA513 type.

Complied

4 In Hiriyur-1 line reactor group 2 protection relay (7SA 5101)-Backup

impedance relay is not in service.


Procurement of of New Back up Impedence realy is under

process

Pending

2) 400/ 220 kV Nelamangala SS [8–10 February, 2016]

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Annexure-VI

Page 24 of 70

5 For 400kV bus bar protection panel, 2 DC sources are available with

selector switch only. Automatic changeover is not provided. KPTCL

informed that the same will be implemented.


This observation will be implemented while commissioning of

new 400 kV Bus bar protection system

Pending

6 Auto-reclose feature is not enabled for 220kV lines. Mail dated 30.01.2018:

AR scheme testing is completed at Nelamangala end during M-II

retrofittng work. M-II retrofitting is pending with remote end sub

stations.Upon completion of M-II retrofitting work at remote

end, AR will be enabled.

Pending

7 220kV

and

400kV

Relay Setting Zone setting & Resistive reach setting for distance protection are found

to be different from the recommanded setting given by Tractebel based

on Ramakrishna committee recommendations (Task force committee

guidelines).


Zone reach & resistive reach settings are in line with the

protecion practice followed in KPTCL. Other recommendations

regarding Z4 timing, load angle,stub protection will be adopted.

Pending

8 For all 400 kV lines, stub protection current level and time delay kept as

150% IB and 300 ms against recommended settings of current level of

250% IB and time delay of 50 msec.


Stub protection settings will be revised as per the

recommendations

Pending

9 For 400 kV Hiriyur line-2 and Hoody line-2 of model 7SA513 (Main-II),

the relay has the provision to provide only 3 Zones for distance scheme.

Reverse zone is available in Main-1 and not present in Main-II.


Reverse zone setting is provided in the M-I relay.

Complied

10 400kV lines (Mysore 1&2,Bidadi 1&2 and Gooty) Zone 2 time is setting as

500ms instead of 350ms.


These bays and its relay settings are maintained by PGCIL. To

be attended by PGCIL (SR-II)

Pending

11 Load encroachment feature was not available for 400kV Neelamangala-

Talaguppa line. KPTCL informed that the resistive reach of zone-3 is

limited to less than the Minimum load resistance with a margin of 20%.

Also load encroachemnt feature will be enabled in Main-1 relay after

consultion with OEM.


Resistive reach of zone-3 is limited to less than the Minimum

load resistance with a margin of 20%.

Pending

12 DEF is available in one main distance relay in 220kV and 400kV lines. DEF

will not be available in the event of outage of Main distance relay in

which function is enabled.


Action will be taken to enable DEF protection in both M-I and M-

II relays.

Pending

13 In Mysore-1&2, Bidadi-1&2, lines over-voltage stg-1 was enabled in Main-

1 distance relay and over-voltage stage-2 was provided through a stand

alone relay. In the event of failure or non-availability of Main- distance

relay only over-voltage stage-2 protection will be available.


These bays belong to Power Grid. To be attended by PGCIL (SR-

II).

Pending

14 In 220kV feeders few trippings were observed due to power swing trip

feature provided in Siemens Distance relay (7SA522). It was also

observed that there is no provision for blocking time delay for PSB setting

in distance relay provided for 220kV lines. KPTCL informed that the same

will be taken up with OEM to ascertain the correct reason for tripping and

accordingly modify the PSB setting.


Power Swing trip has been disabled in all bays.

Pending

15 220kV

and

400kV

Field

Equipments,ICTs &

Reactors

Lot of Grasses and other weeds are found over the Gravels in the 220kV

and 400kV yard.Weed control by chemical spraying is under process.


Switchyard is kept Clean free from Weeds Periodically

Complied

16 In ICT -3 bay, cable PVC conduit are not sealed and exposed to

atmosphere .


Action taken to fill the openings of PVC pipes by Bitumen

compound

Complied

25/70

Annexure-VI

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17 Oil leakage was observed in 400 kV Hiriyur-1line reactor Y-Phase bushing

turret.


Oil leakage is arrested

Complied

18 Most of the ICT & reactor conservator tank breather silicagel was in pink

colour.Necessary moisture control action has to be done.


Silicagel is replaced.

Complied

19 SF6 leakage was frequently observed in 400kV Hassan-40752 (Nel Make)

and 220kV Nitttur-21852 (Nel make) line breakers. Necessary action has

to be taken.


Attended.

Complied

20 In some 220kV/ 400 kV bays, LA surge counters are not in working

condition.


Faulty surge counters have been replaced.

Complied

21 For 400kV Gooty line reactor, NGR is not provided. Mail dated 30.01.2018:

Bay belongs to PGCIL (SR-II). To be attended by PGCIL (SR-II).

Pending

22 Emulsifier system for fire fighting of ICT/ LR is not in healthy condition.

KPTCL informed that Nitrogen injection system will be provided.


All the ICT's and Line Reactors are provided with CTR make

Nitrogen Injection Fire Prevention System

Complied

23 Walky takie is not available for communication between switchyard and

control room.


Dedicated mobile phones are available.

Pending

24 Smoke detection system is not in heathy condition for control room

building.


Action is being taken to renovate the Smoke detection System

Pending

25 AC Distribution Auto Changeover is not available in ACDB for 415V Auxiliary supply 1 & 2

and DG set. AMF panel in DG set is not in healthy condition. Supply

Change over operation is carried out manually. Remotely switching ON

of DG is not available from ACDB


Action is being taken to provide auto change over of DG system

incase of Auxiliary supply failure

Pending

26 It was observed that one 11kV feeder is available for auxilliary supply of

station. It was informed by KPTCL that 2nd 11kV auxilliary supply will be

made available after commissioning of 66/11kV Sondekoppa substation.

It was observed that there is no automatic chaneover available for

auxilliary supply changeover.


Matter Persued with BESCOM officials and separate 11 kV UG

cable from 66kV Sondekoppa Sub station to 400 kV RS

Nelamangala is laid. 66kV Sondekoppa SS is yet to be

commissioned.

Pending

27 DC Distribution 2nos, 220 V DC battery banks with two Battery chargers (one is main

and another is standby). main Battery charger feeds both DCDB-1 & 2

with buscoupler closed.When Main fails standby charger will be 'ON'

manually.


M/s Caldyne Make Automatic Float and Boost Charger is

provided, with facility of keeping one in float and another in

Trickle maode. Both the Charger could not be taken on Float

simulatneaous

Pending

28 48 V DC system is also redundant similar to 220 V DC system. Mail dated 30.01.2018:

Loads on both the chargers have been bifurcated.

Complied

29 Protection DC-1&2 (220V) for 220kV and 400kV bays was observed to be

linked at DCDB through 220V bus coupler and same was being extended

to protection relays.


M/s Caldyne Make Automatic Float and Boost Charger is

provided, with facility of keeping one in float and another in

Trickle maode. Both the Charger could not be taken on Float

simulatneaous

Pending

30 48V DC-1&2 for PLCC was observed to be linked at DCDB through 48V

bus coupler and same was being extended to PLCC panels.


Loads on both the chragers have been bifurcated

Complied

26/70

Annexure-VI

Page 26 of 70

31 Communication

system

The System for Auto downloading of disturbance recorders from the

relays is not provided, however manual downloading is done as and when

fault occurred.


Remote DR/EL collection system supplied under R&U project will

be commissioned shortly.

Pending

32 SEL , ABB REL 521,EPAC 3000,Reyrolle omegha type relays of 400KV

Mysore 1 & 2, bidadi 1 & 2 lines and Busbar protection relays are not

time synchronised with GPS.


The existing CRPs of 400kV Mysore-1 &2,Bidadi-1 &2 and Gooty

bays will be replaced by new CRPs mounted in KIOSKs along

with providng 61850 based SAS & GPS time synchronisation.

The work is entrusted to M/s Shree Electricals Limited

Pending

33 Redundancy is not maintained in Fibre optic equipment. Commisioning of

second set of FOTE is under progress.


The work is entrusted to M/s Shreem Electric Limited

Pending

34 One no. PLCC protection coupler availbale for 220kV lines. Mail dated 30.01.2018:

Only One PLCC protection coupler is provided as per the

protection practice followed in KPTCL

Complied

35 General DR is not available for 400kV bus bar protection. DR of 220kV and 400kV

lines not getting triggered with operation of LBB/ Bus bar protection.

220kV bus bar relay not time synchronized with GPS. KPTCL informed

that this will be synchronized.


For 400kV Buses, Main-1 and Main-2 Numerical BBP is being

provided under R&U project wherein DR/EL will be available.

Supply of new BBP panels expected during February 2018.


Main -1 and Main-2 BBP will be commissioned before end of

December 2018.

Pending


Equipment/ System

auditated


Recommendations


Constituent)

1 Bus 220KV System Presently two buses are available with a bus coupler breaker for 220kV

switchyard. Bus bar protection is available for both the 220kV buses and

bus-bar protection is available with two main zone and one check zone.

With the present bus arrangement it is not possible to interchange

feeders between both the buses and shutdown has to be taken in the

event of any maintenance on the line breaker. Provision of additional

220kV bus (transfer bus) which is already proposed in earlier protection

audit will rectify the above issues and improve the reliability of Edamon

station. KSEB has informed that Hybrid switch gear/out door GIS is being

planned for SBEM 2&3, EMKD,EMEP and Transformer 1 & 2 Bays and bus

coupler for accommodating the additional 220kV bus. The work is

scheduled to be completed by Dec 2016.


3 Hydrid units are erected commissioned namely SBEM#2 & 3

and Transformer bay #1. Hybrid Bus coupler errected and will

be commissioned subject to line permit availability. The works

on balance namely EMEP, EMKD and Transformer #1 are under

progress and scheduled to be commisioned by March 2018.

Pending

KSEBL

1) 220 kV Edamon SS [18-20 January, 2016]

27/70

Annexure-VI

Page 27 of 70

2 Bus 220KV Protection Single CT core has been used for main and check zone is derived from

same core. KSEB had informed that the bus bar protection would be

replaced during provision of additional 220kV bus. It is proposed to use

separate cores for main and check zone and also to have a redundancy

for bus-bar protection relay for each Bus. A redundant scheme for Bus

protection to be included.


Seperate CT cores will be used for Main 1 and Main 2 relays of

newly proposed bus bar protection. Zone trip of Main 1relay +

Check zone of Main 2 relay and Zone trip of Main 2 Relay

+Check zone of Main 1 will be used for Busbar trip decision.

Hence Main and chech zone will be from different CT core

Expected date of completion= June 2018.

Pending

3 Bus 110KV Protection Bus bar protection is not available for 110kV bus at Edamon Mail dated 03.02.2018:

This is being considered. As per present standards, Busbar

protection is not mandatory for 110 kV Bus. The 110 kV Bus at

Edamon is very small.

Pending

4 Kundara and

Edappon

220KV Protection It was observed that DEF and Brocken conductor are enabled in Main-2

distance relay and not enabled in Main-1 distance protection (EPAC 3100)

of Kundra and Edappon feeder.


These feeders belongs to PGCIL and action pending with PGCIL

(SR-II).

Pending

5 Tirunelveli-1&2 220KV Protection It was observed that the load encroachment blinder was encroaching

inside zone-1 reach for these feeders which needs review.



(II).

Pending

6 Tirunelveli-1&2,

Sabarigiri-1,2&3,

Pothencode-1&2

220KV Protection Tirunelveli-1&2, Sabarigiri-1,2&3, Pothencode-1&2 feeders were having

same Make for Main-1& Main-2 relay (ABB , REL-670). It is proposed to

have different makes for Main-1 & Main-2 relays.


Pending for want of CEA's reply. In response to the draft report

of CEA's protection philosophy, KSEBL has forwarded favourable

remarks for maintaining same make Main I & II relays. Hence

this replacement work is in hold, waiting CEA's reply.

Pending

7 Tirunelveli-1&2,

Sabarigiri-1,2&3,

Pothencode-1&2

220KV Protection Reverse zone is not provided in Main-2 distance relays (ABB, REL-670) in

Tirunelveli-1&2, Sabarigiri-1,2&3 and Pothencode-1&2. The same is not

available in the terminal of the relay. The application configured by the

manufacture for three zones only.


Zone 4 has been provided for Thirunelveli 1&2 feeders .Offer

from Manufacturer for the Firmware upgradation of SBEM1,2&3

and EMPC 1&2 (to enable Zone 4) . Time synchronization of

Thirunelveli 1&2,SBEM 1,2&3 and EMPC1&2 will be taken up

without delay.


Pending

8 ICT-1 220KV /

110KV

Protection HV and LV side backup overcurrent and earth fault protection for

220/110kV ICT-1 is non-directional. It was informed that the time of

operation transformer backup earth fault and over current protection has

been co-ordinated with the 110kV and 220kV line directional earth fault

protection.


Rectified

Complied

9 Sabarigiri-1 &

Tirunelveli-1&2

220KV Protection Auto reclose function was tested for 220kv Sabarigiri-1 feeder. Same

was found to be in-order. Auto-reclose function was kept in disable

condition in Tirunelveli-1&2 feeders due to OPGW works.


Rectified

Complied

10 Sabarigiri-1,2&3 220KV System Both channel-1&2 of PLCC has been provided in a single PLCC panel for

Sabarigiri-2&3, which are fed from a single power supply module

inside the panel.


Now Two DC sources are connected to PLCC panel. Rectified.

Pending

11 Sabarigiri-1&3 220KV Protection Electrical interlock between breaker and isolator is not provided for

the 220kV bays. Manual operation of isolator and earth switch is being

done. Mechanical interlock is provided between earth switch and

isolator and same was verified.


Rectified.

Complied

28/70

Annexure-VI

Page 28 of 70

12 ICT-1 220KV /

110KV

Equipment Emulsifier and hydrant system to be provided for firefighting of

220/110kV transformers. Fire prevention wall to be provided between

transformer banks.


Form type extinguishers and Fire wall are provided now.

Rectified.

Pending

13 Sabarigiri-1,2&3 220KV Equipment It was observed that the SF6 gas pressure in Sabarigiri-1,2&3 breaker

was not uniform for all the breaker poles.


Now SBEM#2 and 3 been replaced by Hybrid switch gear and

SBEM#1 by New SF6 Breaker. Rectified.

Complied

14 ICT-2 220KV /

110KV

Equipment ICT-2 is not in working condition. It was informed that spare

transformer of 200VA will be commissioned


It is in Procurement stage.


Pending

15 ICT-1 & 2 220KV /

110KV

Equipment Oil sump pit for transformer is not available for ICT. Mail dated 03.02.2018:

Now provided. Rectified.

Complied

16 ICT-1 220KV /

110KV

Equipment Lightening arrestor is not provided on 110kV side of 220/110kV

transformer (ICT-1) . RTCC and cooler control cabinet was observed to

be not in working condition. Provided in the 110 KV Bus and it will be

relocated to transformer.


LA are now provided on 110 kV side. RTCC are now in working

condition. Rectified.

Complied

17 AC System 415V System Auxilliary supply from 11kV/0.415kV transformer-1&2 is connected to a

common incomer (breaker) in ACDB panel through a manual

changeover switch. It is suggested to implement auto bus transfer

scheme


Now incorporated in the new ACDB which will be installed by

February 2018.

Expected date of completion= February 2018.

Pending

18 DG set 415V Equipment Remote start for DG from ACDB room is not available. AMF panel is

not provided for DG set.


New ACDB panel with AMF facility has been procured and will

be retrofitted with the old panel shortly.

Expected date of completion= April 2018.

Pending

19 Sabarigiri-1,2&3 220KV Protection Direct transfer trip is not available and suggested to adopt the same for

all Sabarigiri- Edamon (SBEM) feeders.


These features are facilitated in the new protection coupler,

which will be energised in June 2018.


Pending

20 Tirunelveli-1&2,

Kundara, Edappon

220KV Protection Power swing block enabled for all zones of Kundara, Edappon and

Thirunelveli (PGCIL owned) feeders.



Pending

21 Sabarigiri-1 220KV Protection In the control & relay panel following has been observed:

a) Isolator Earthswitch open indication lamp was not working.

b) Ammeter for R&B phase not working

c) Digital Voltmeter for YB phase not working

d) Digital Frequency meter not working


Item (a) Rectified and procurement of the balance is underway.

a) done. b,c & d will be completed in June 2018.

Pending

22 Sabarigiri-2 220KV Protection In the control & relay panel Isolator Earthswitch open indication lamp

was not working.


Rectified

Complied

23 Pothencode-1&2 220KV Protection In the control & relay panel Isolator close, Earthswitch open indication

lamp was not workng.


Rectified

Complied

29/70

Annexure-VI

Page 29 of 70

24 Edappon 220KV Protection In the control & relay panel following has been observed:

a) Carrier In/out selector switch Handle is not available

b) Isolator open/close handle was broken

c) Isolator close indication lamp was not working.

d) Old name plate Kayamkulam has to be removed.

c) Annunciator not working


These feeders belongs to PGCIL(old C&R panels) and action

pending with PGCIL (SR-II).

Pending

25 Kundara 220KV Protection In the control & relay panel following has been observed:

a) Carrier In/out selector switch Handle is not available

b) Isolator open/close handle was broken

c) Isolator close indication lamp was not working.


These feeders belongs to PGCIL(old C&R panels) and

action pending with PGCIL (SR-II).

Pending

26 Tirunelveli-1&2

Kundara, Edappon,

Pothencode-1&2

220KV Protection Zone-4 (Reverse zone) setting should cover 50% of shortest line. Mail dated 03.02.2018:


(SR-II).

Pending

27 Pothencode-1&2,

Sabarigiri-1,2&3

220KV Protection Zone-4 (Reverse zone) time delay has been kept as 1.1sec- For these

feeders for reach setting 50% ( Shortest line in the local Bus) and Z3

resistive reach has been taken as per the recommendation of

Ramakrishne committee. With this setting the faults in the line with

resistive reach of Z3 may be seen by the Z4 of other relays in the bus.

Also the lines are going through forest area and frequent trippings

occured of this nature,hence a time setting which is higher than Z3 is

selected.


This matter has been already forwarded to SRPC Awaiting final

report from CEA's Protection philosophy.

Pending

28 Tirunelveli-1&2 220KV Protection Zone-4 (Reverse zone) Fault resistive reach setting not same as Zone-3

resistive reach setting



(SR-II).

Pending

29 Tirunelveli-2 220KV Protection Upolmin for Tirunelveli-2 Main-1 relay is set at 20% it should be 1% Mail dated 03.02.2018:

Rectified

Complied

30 Tirunelveli-1&2 220KV Protection t1Min and K1 for DEF is set different in Tirunelveli-1&2 Mail dated 03.02.2018:

Rectified

Complied

31 Tirunelveli-1&2,

Kundara, Edappon

220KV Protection For PSB as per PGCIL recommendation all the zones are blocked Mail dated 03.02.2018:


Pending

32 ICT-1 220KV Protection ICT differential slope setting was observed to be different Mail dated 03.02.2018:

Slope settings adopted as per differential slope equation and

relay manufacture recommendation. Expected date of

completion= June 2018.

Pending

33 ICT-1 & Bus 220KV Protection For ICT-1 single DC supply is available. Mail dated 03.02.2018:

Work in progress .control wiring almost done Will be completed

within February 2018.

Pending

34 General 220KV Protection It was observed that an intentional delay of 1.1 Sec is provided for line

Directional earth fault protection. It was proposed that the directional

earth fault protection should get enabled only in the event of distance

function not able to sense the fault and blocked in the event of pickup of

distance function. No intentional delay is desired for DEF.


Needs an edit in application configuration. correction work in

progress for KSEB feeders and for PGCIL feeder correction is

pending with PGCIL.


Pending

35 General - - Rusting was observed in lattice structure and bay equipment’s in

Pothencode-1&2 bays. It was informed that the bay will be replaced by

Hybrid switch gear system during the construction of double bus. It was

observed that dummy gland holes in marshalling boxes are not covered.


All been replaced by new ones. Rectified.

Complied

30/70

Annexure-VI

Page 30 of 70

36 General - Equipment Standby air compressor is not available for breakers with pneumatic

operating mechanism. Rusting was observed in compressor provided in

Sabarigiri-3 breaker.


Now this pneumatic system has been completely removed from

the sub station. Rectified.

Complied

37 General - - ANSI numbering system for bays is not provided. Phase identification for

bay not properly done.


This will be done on completion of Double Bus construction.


Pending

38 General - - Smoke detection system to be provided in control room Mail dated 03.02.2018:

Will be provided.

Pending

39 General - - At present there is no communication facility is available between control

room and yard. Walky-talkie system to be provided for communication

between switchyard and control room for facilitating switchyard

operations.


Will be provided.

Pending

40 General - - Auto recloser ON/OFF switch shall be provided separately for all feeders. Mail dated 03.02.2018:

At present, the station Engineer put the Auto-reclosure out of

service, through Laptop/ HMI, when ever such requirement

arises. Hence separate switch is not required in the present

condition. It is requested to drop this item.

Pending

41 General - - Considering the better operation practices the following shall be

considered

a) Operation may be done by SCADA system with remote operation

facility

b) Thermo vision survival cameras with remote viewing to be provided

c) 2 Nos BUS coupler may be provided in the proposed double bus

system


(a) This will be considered while an upgradatioin work take

place.

(b) Procurement process started. will be completed in June

2018.

(c) Expected to be completed within June 2018.

Pending

42 General - - The present C&R panels for Edappon and Kundara, Bus Coupler and Bus

Bar are observed as old. Main-1 relay (EPAC 3100) does not have

provision for collecting history of operation and DR.


These feeders belongs to PGCIL(old C&R panels) and action

pending with PGCIL (SR-II).

Pending

43 General - - As part of good safety practices the followings may be considered

a) Industrial type switches and sockets for control room

b) Fire exit to be in proper direction

c) LED lightings may be provided as the part of energy conversation


The corrective action will be taken in a phased manner.

Pending


Equipment/ System

auditated


Recommendations


Constituent)

1 Vallur 400 kV CB Pole discrepancy time delay kept as ber below

i. Line-1 main Circuit Breaker - 2.5 sec,

ii. Tie Circuit Breaker- 2.0 sec,

ii. Line-2 main Circuit Breaker-3.0 sec

Mail Dated 29.01.2018

PD Time set uniformaly as 2.5 Seconds.

Complied

1) 400/ 230 kV Alamathy SS [4-6 January, 2016]

TANTRANSCO

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2 NCTPS 1 & 2 400 kV CB Tie Breaker bay not yet commissioned Mail Dated 29.01.2018

Will be commissioned by June-2018.

Pending

3 ICT 2,3,4 & 5 400 kV ICT CB Pole discrepancy time delay kept as ber below

i. ICT-5 - 1.0 sec,

ii. ICT Tie - 1.0 sec

iii. ICT-4 - 0.1 Sec

iv. ICT-2&3 - 2.1 Sec


PD Time set uniformaly as 0.6 Seconds.

Complied

4 Thiruvalam & SVC 400 kV CB Switchyard isolator electrical interlocks were observerd to be unhealthy

for 400 & 220 kV system.


Line clearance is required for checking the isolator interlocks

which involves all bay isolator and earth switch auxillary

contacts. Will be completed by 31.03.2018.

Pending

5 NCTPS 1 & 2 400 kV Main-II It was observed in Main-2 (D60) Relay that there is provision for enabling

one stage of Over voltage protection. Hence O/V stage-2 has been

enabled in main-2 relay. In the event of outage of main-1 relay only O/V

stage-2 protection will be available.


The D 60 Relay have provision for only one element for

overvoltage Stage-I due to design limitation. Two stages of O/V

protection is adopted in Main-I (P543) Relay.

Complied

6 SVC-1&2 230 kV Main-1 & 2 It was observed in main-2 (D60) Relay that there is provision for enabling

one stage of Over voltage protection. O/V stage-1 has been enabled in

main-1 relay and O/V stage-2 in main-2 relay. In the event of outage of

any one main relay only one stage of O/V protection will be available.


Main 1 D60 relay replaced in SVC-1 & 2 feeders by P442 relay

on 23.01.2018 & 10.01.2018 respectively. The D 60 Relay have

provision for only one element for overvoltage Stage-I due to

design limitation. Two stages of O/V protection is adopted in

Main-I (P442) Relay.

Complied

7 Korattur &

Thiruverkadu

230 kV Relay panel Carrier Protection for the corresponding Lines were observered not

available. However it was informed that Digital Tele-Protection Coupler is

proposed for the corresponding feeders.


The Korattur bay name have been changed as Koyembedu

feeder. The carrier scheme will be established for Thiruverkadu

feeder by 31.01.2018. Fibre Optic link will be established for

Koyembedu feeder.

Pending

8 Manlai-1&2 230 kV Relay panel Auto recloser for the corresponding line is not available. It was informed

the frequent permanent fault prone zone due to chemical pollution at

manalai S/S. Hence ARC not enabled.


Manali 230kV AIS was upgraded to 400kV GIS Substation. Cable

portion is involved in the line. Hence, Auto Reclosure for 230kV

Manali - 1 & 2 feeders not enabled.

Complied

9 Korattur 230 kV Relay panel Trip circuit supervision for Trip Coil-1 is not in working condition. It was

informed that replacement of faulty relay is under process.


Complied.

Complied

10 General Zone-4 time delay is kept as 1.1 sec in 400 kV Line . Mail Dated 29.01.2018

The Zone 4 time is set at 1.1 sec as per approved guidelines.

Pending

11 General Auto recloser not available for the all 400 kV tie breakers. Mail Dated 29.01.2018

Auto Reclosure scheme for Tie CB enabled in SVC Bay. For Vallur

and Thiruvalam bay, the scheme will be checked during next LC.

Pending

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Constituent)

12 General STUB protection not available for 400 kV feeders. Mail Dated 29.01.2018

For enabling of STUB Protection, Line Isolator status from

swithyard is being checked for the scheme. Will be completed by

June-2018.

Pending

13 General Load encroachment is not available in 400 & 230 KV feeders. However it

was informed that the resistive reach have been suitably calculated to

take care of the same.


Suitable setting adopted to avoid load encrocachment.

Complied

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Constituent)

14 General Observed redundant power supply (48V) not available in RTU panel. Pending

15 General Observed redundant data transfer (to LDC) channel is available however

manual change over is being done in the even of failure of main channel.

Pending

16 General Stand alone Event Locker is not available for the station. Pending

17 General Disturbance recorders in 400 & 230 KV feeders are not time synchronised

with GPS.

Pending

18 General Main-1 & Main-2 relays found to be of same make in 400 kV

S.V.Chattiram Line -1&2 and 230 kV Koratur & Manali -1.


Main-1 D60 relay replaced in SVC-1 & 2 feeders by P442 relay

on 23.01.2018 & 10.01.2018 respectively.

In 230kV Manali-1 feeder & 230kV Thiruverkadu feeder, Main-2

P442 relay will be replaced with D60 relay (released from SVC-1

& 2 feeders), by February 2018.

Pending

19 General The Emulsifire fire systems are found to be not erected and commisioned

for ICT-2,4 & 5.


Estimate submitted for approval.

Pending

20 General Direct Trip not available for 230kV feeders. This may cause delayed fault

clearances from remote end in the event of operation of LBB protection.


CTs are on Bus side. Carrier inter trip scheme is available for

remote end trip.

Pending

21 General Non directional Backup Over current provided in HV/LV side of all

Transformers.


Numerical relay procurement is under progress for enabling

Directional O/C & E/F protection.

Pending

22 General Fire detection system is not healthy in control room. Mail Dated 29.01.2018

The healthiness of Fire detection system will be checked to bring

back in to service.

Pending

23 General Walkie-talkie is not available for communication between switchyard and

control room.


Walkie Talkies provided.

(Complied).

Complied

24 General Auto changeover is not available in ACDB for 0.415 kV Auxiliary supply 1

& 2. DG set was also observed to be operated in manual mode.


The feasibility for auto change over will be studied for

implemetation.

Pending

25 General CB On/Off & Spring Charged Mechanical indications in 230 kV CB are not

visible in switchyard.


Rectified. (Complied).

Complied


Will be implemented in new RTU which is under procurement

stage.


Commissioning of DR & EL collection system alongwith GPS is

under progress.

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auditated


Recommendations


Constituent)

26 General CB ON/Off and spring charged mechanical Indication functions are not

working in 230kV Manali 1 & 2 feeders circuits



Complied

27 General Name Plate details on bay Marshalling Box of 230 kV Thiruverkadu feeder

circuit is mismatching



Complied

28 General Corrosion observed in Earth mat risers and CB/Isolator operating

mechanism boxes , junction boxes and oil conservator tanks of ICTS


Estimate will be evolved soon.

Pending

29 General Rusting was observed in CB operating mechanism boxes of 230 kV OPG -

1 & 2 feeders.


Rectified.

(Complied).

Complied

30 General For 230 kV feeders for OPG-1&2 and NCTPS bypass isolator (Placed in

gantry) Moving contacts were found to be missing.

Procurement work under progress. Pending

31 General Few Indicating meters in control panel were found to be unhealthy. Mail Dated 29.01.2018

Rectified all except ICT3 & 110kV Avadi-2 feeder.

Pending


Recommendations


Constituent)

1 Mail dated 29.01.2018:

Suitable setting adopted to avoid load encrocachment.

Complied

2 Mail dated 29.01.2018:

LAS Erection and Connecting the earth pit gantry take off Tower

to Station Earth mat Works will be completed in July-2018.

Pending

3 Mail dated 29.01.2018:

Materials supplied and will be commissioned.

Pending

4 Mail dated 29.01.2018:

Proposal has been evolved.

Pending

2) 230 kV Alundur SS [4-6 January, 2016]


Load Encroachment has not been enabled as the the estimated load is much higher than Zone-3 resistive reach

Transmisssion line earthwire earthing was done at earth pit gantry take-off tower, which may be reviewed for connection to station

earth-mat

Lightning Arrestors for all 230 kV feedses are to be provided

Fire protection for 100 MVA, 230/ 110 kV Auto Transformers to be provided

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auditated


Recommendations


Constituent)

5 Mail dated 29.01.2018:

Metal Spreading will be provided for each Bay.

Pending

6 Mail dated 29.01.2018:

Will be completed by February-2018.

Pending

7 Mail dated 29.01.2018:

Will be completed by February-2018.

Pending

8 Mail dated 29.01.2018:


under progress.

Pending

9 Mail dated 29.01.2018:


under progress.

Pending

10 Mail dated 29.01.2018:

The Zone 4 time is set at 1.1 sec as per approved guidelines.

Reach settings will be revised during Relay testing.

Pending

11 Mail dated 29.01.2018:

Complied.

Complied

12 Mail dated 29.01.2018:

Will be completed by March-2018.

Pending

13 Mail dated 29.01.2018:

Will be completed by March-2018.

Pending

14 Mail dated 29.01.2018:

Programmed during April-2018.

Pending


Estimates sanctioned. Procurement of Digital type meters is

under progress and will be replaced by July-2018.


Estimate sanctioned and Procurement is under progress.


Estimate is evolved and the works will be completed in July-

2018.

15 Pending

a) All analog meters to be replaced by Digital meter

b) D.G. Set with enhancement of 75 kVA Auto/ Manual control from control room itself (remote operation)

c) Isolator position in control panels

Resistive reach settings for Zone-1, Zone-2 & Zone-3 may be reviewed in line with Ramakrishna Commitee recommendations

DR to be triggerred for LBB and BBP operations

Check-synchronizing relay to be provided in Synchronizing trolley.

Station earth mat resitance was measured to be 0.18 ohm on 07.07.2016

TANTRANSCO informed the following had been been included in the propopsed R & M works:

DC Supply selection changeover switch to be provided in BB panels

Provision for DC supply changeover by a separate coupler switch between the two DC sources may be examined for improving the

reliability.

Time synchronization of various protection relays with GPS was not available. TANTRANSCO informed that GPS facility was under

prcurement stage

Stand alone Event Logger not available. TANTRANSCO informed that GPS facility was under prcurement stage

Zone-4 settings (for reactance reach, resistivee reach and time settings) may be reviewed in line with Ramakrishna Commitee

recommendations

Swtichyard area was observed to be covered with cement flooring. Providing metal spreading may be examined for ensuring safe

touch & step potential limits

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auditated


Recommendations


Constituent)


Estimate is evolved and the Civil works will be completed.


Complied.


Estimate sanctioned. Procurement is under process and Erection

works will be completed by July-2018.

16 Mail dated 29.01.2018:

Materials supplied and will be commissioned.

Pending


Recommendations


Constituent)








f) Alarm anunciator panel in all 230 kV feeders, Auto HV - I & II, Bus coupler

15 Pending

Line CVT's to be used for feeder protection by commissioning Y-ph & B-ph CVT's in all 230 kV feeders. TANTRANSCO informed

that the related works had already been taken under PSDE funding.

d) Entire gravel filling in 230 kV & 110 kV yard

e) Extension of Battery room and Carrier room for providing panels

3) 400/ 230-110 kV Palavadi SS [16-17 May, 2018]


Substation is well maintained.

All Circuit Breakers are based on spring (Trip) - spring (Close) operating mechanism.

Time settings and Reactive & Resistive reaches of Z2, Z3, and Z4 (reverse) of distance relays for 400 kV and 230 kV feeders are

observed to be not in line with Ramakrishna Committee guidelines, which may be reviewed appropriately to bring in line with

them.

Re-Trip feature to be provided for Breaker Failure Protection for 400 kV & 230 kV circuit breakers.

Auto-reclosure dead-time may be unformly adopted across all 400 kV and 230 kV feeders as 1 sec.

It is observed that Pole Discrepancy time delay has not been set uniformly. It is recommended to keep PDR time delays as follows:

(i) For all line Main-CB's and Tie-CB's where Aut-Reclosure with priority has been employed with dead-times of 1 sec & 2 sec

respectively, PDR time delay shall be kept as 1.5 sec and 2.5 sec respectively.

(ii) For all other elements, PDR time delay shall be kept as the minimum avaiable in the relay, but not less than 100 msec. This

may be preferably kept as 0.5 sec.

It is seen that 110 kV Dharmapuri and 110 kV Pennagaram lines did not have circuit breaker at remote ends. Steps may be taken

provide them to facilitate proper discrimination of faults.

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Recommendations


Constituent)












It is found that the furnished values of earth-pit resistance (with and without grid-connected) are at variance with the values

displayed in all (400 kV & 230 kV & 110 kV) switchyards, and have not been measured after commissioning of the same in March,

2017. It is recommended to carry out measurement of earth-resistances of all earth pits (400 kV & 230 kV & 110 kV switchyards)

on yearly basis, and keep updated records with the substation along with suitable earth-mat lay-out diagrams. A copy of the same

may also be furnished to SRPC Secretariat.

It is observed that 110 kV feeders earthwire earthing has been done at respective gantry take-off towers, which may be reviewed

for connection to station earth-mat.

It is seen that REF protection has not been provided for 125 MVAR Bus-Reator, which may be provided.

Directional O/C Protection (high-set & IDMT) and Directional E/F protection (high-set & IDMT) shall be provided on both sides of

400/ 230 kV ICT's and 400/ 110 kV ICT's.

It is seen that the philosophy of Group-A & Group-B Protections has not been followed in case of ICT's. It is recommended to

adopt the same with the following model segregation of protections:

Group-A:

Differential, DOCE (HV), Overflux (HV)

Group-B:

REF, DOCE (LV), Overflux (LV)

It is also recommended to arrange supply for these two groups from two different DC supplies.

It is seen that speech channel has not been provided as part of substation communication in any of the 400 kV & 230 kV feeders.

Steps may be taken to provide the same.

It is observed that Protection Channels of Thiruvalam lines 1 & 2 have been implemented from same DTPC. Similarly Protection

channels of Mettur lines 1 & 2 have been implemented from another DTPC. Steps may be taken to implement protection channels

of each line from one/ two dedicated DTPC's.

It is seen that even though two AC auxiliary supplies are being provided from two different sources (33 kV/ 11 kV Adagapady SS,

and 33 kV/ 11 kV Paparapatty SS), since both these supplies have been derived from the same source substation, viz., 110/ 33 kV

Pennagaram SS, the independency of AC auxiliary supplies is not ensured. It is recommended to provide redundant AC auxiliary

supply from another suitable substation in addition to 110/ 33 kV Pennagaram SS.

It is seen that the provided 100 kVA DG set is insufficient for catering to mandated substation loads. It is recommneded to provide

a DG set of suitable (higher) capacity. Steps may also be taken to maintain sufficient fuel stock to take care of unforeseen

emergencies.

It is observed that DG-Set starting and Supply changeover among AC supplies & DG set are being done manually. Steps shall be

taken to provide them in auto-mode.

It is observed that earth-resistance for some of the 400 kV earth-pits (grid-connected) esp. near ICT's are found to be higher than

the mandated limit of 0.5 ohms. (measured values are found to be varying between 0.4 ohms - 20 ohms). It is recommended to

attend to them on priority basis, and take necessary steps to bring them within the mandated limit of 0.5 ohms.

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Recommendations


Constituent)







Recommendations


Constituent)

1 Mail dated 30.01.2018 & 13.03.2018:

Existing Control & Relay Panels installed with static relays are

proposed to be replaced with new control panels installed with

numerical relays under the project of Upgradation of existing

static relays and replacement of sub-station equipments at

230KV Villianur and Bahour Auto Sub-Station at the cost of

Rs.10,56,16,191/- through PSDF funding. Tendering process for

award of work on labour contract basis for the above said work

is almost over and waiting for the approval of Puducherry

Government to place order at the lowest tenderer.

Pending

Puducherry ED

1) 230/ 110 kV Villianur SS [10 - 12 July, 2017]

Directional O/C & E/F protections to be provided for 230 kV & 110 kV feeders where Main-II is not provided; Directional E/F

protection to be provided for 230 kV & 110 kV feedes where Main-I & Main-II are provided


It is observed that 110 kV switchyard has been provided with only one lighning mast to provide protection from direct lightning

strokes. It is recommended to provide sufficient no. of lightning masts to cover entire 110 kV switchyard.

The following equipment may be purchased/ provided for maintenance of various switchyard equipment:

(i) Tan delta meaurement kit.

(ii) Digital Earth-resitance measuring kit

A suitable lifting device/ aerial work platform may also be provided and maintained with the substation to carry out testing on

various equipment.

It is seen that Palavadi is a SAS station; however no CC cameras have been provided in the switchyards to exert effctive

monitoring. Steps may be taken to provide the same at suitable locations for better security.

Equipment labeling for proper phase-sequence and Bay Element labeling may be provided in all 400 kV & 230 kV & 110 kV

switchyards.

Walkie-talkie system for yard communication is not available, which may also be provided.

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Equipment/ System

auditated


Recommendations


Constituent)

2 Mail dated 30.01.2018 & 13.03.2018:

As per the recommendation of Protection Audit Team, a Detailed

Project Report at the cost of Rs.14,85,42,653.21 has been

prepared to replace the existing aged equipments and provide

additional equipments at 230KV Villianur and Bahour Auto Sub-

Station and sent to higher authority to obtain sanction under

PSDF funding. (copy enclosed)

Pending

3 Mail dated 30.01.2018 & 13.03.2018:

Existing aged Two sets of 110Volt Station Batteries have been

replaced with two sets of new 110Volt Station Batteries. Further,

in addition to the existing one set of 48Volt PLCC battery, one

more 48Volt PLCC Battery has been provided. All the above

three batteries have been commissioned in the last week of

January 2018. Wiring has to be done to segregate the existing

single circuit into two circuits.

Pending

4 Mail dated 30.01.2018 & 13.03.2018:










Pending

5 Mail dated 30.01.2018 & 13.03.2018:

Protection & Communication wing of TAN TRANSCO Limited,

Villupuram has been requested vide Lr. No.347/ED/EE-Auto

SS/AEE-M-VASS/F-4/2017-18, dated 21.09.2017 for revision of

existing relay settings as per the recommendations of Protection

Audit Team.

Pending

6 Mail dated 30.01.2018 & 13.03.2018:





Audit Team.

PendingZ2 and Z3 (reactive & resistive) reaches & time settings were observed to be not in line with Ramakrishna Committee guidelines,

which may be reviewed appropriately.

Line CVT's to be provided in all phases for all 230 kV lines.

Redundant DC suppy for protection (110 V) and communication (48 V) applications to be provided with requisite segregation in

wiring.

For 230 kV feeders, the present single-zone BB protection is to be reviewed and provided with two-zone operation & Check-zone

operation.

Z4 (reverse) is to be provided in all distance relays of 230 kV & 110 kV feeders

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auditated


Recommendations


Constituent)

7 Mail dated 30.01.2018 & 13.03.2018:





Audit Team.

Pending

8 Mail dated 30.01.2018 & 13.03.2018:





Audit Team.

Pending

9 Mail dated 30.01.2018 & 13.03.2018:





Audit Team.

Pending

10 Mail dated 30.01.2018 & 13.03.2018:





Audit Team.

Pending

11 Mail dated 30.01.2018 & 13.03.2018:








Pending

12 Mail dated 30.01.2018 & 13.03.2018:










Pending

Auto-reclosure dead-time and reclaim-time for 230 kV feeders may be revised to 1 sec and 25 sec respectively.

Power Swing Philosophy (Z1 --> Unblock; Higher Zones --> Block for 2 sec) is to be adoped unfiromly across all 230 kV feeders.

Load encroachment feature may be appropriately kept enabled in 230 kV & 110 kV feeders.

For 230 kV Pondy feeder POR may be used in place of the existing PUR.

Steps to be taken to ensure that Main-I & Main-II protections or Main & back-up protections of feeders are fed from different DC

supplies.

REF protection to be provided for 100 MVA, 230/ 110 kV ICT-1 & ICT-2.

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auditated


Recommendations


Constituent)

13 Mail dated 30.01.2018 & 13.03.2018:










Pending

14 Mail dated 30.01.2018 & 13.03.2018:










Pending

15 Mail dated 30.01.2018 & 13.03.2018:










Pending

16 Mail dated 30.01.2018 & 13.03.2018:








Pending

Overflux protection to be provided for 100 MVA, 230/ 110 kV ICT-1 & ICT-2.

Steps to be taken to ensure that Group-A & Group-B protections or Main & back-up protections of ICT's are fed from different DC

supplies.

Directionality to be provided for O/C protection of 100 MVA, 230/ 110 kV ICT-1 & ICT-2.

Directional E/F protection to be provided for 100 MVA, 230/ 110 kV ICT-1 & ICT-2.

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auditated


Recommendations


Constituent)

17 Mail dated 30.01.2018:

Various possible ways to connect the 110/22KV Villianur Sub-

Station with nearby 110/22KV Korkadu SS by 22KV feeder is

being explored.


Division-EHV of this department has been requested vide Lr.

No.714/Ed/EE-Auto SS/AEE-M-VASS/F-4/2017-18, dated

27.02.2018 (Copy enclosed) to explore the possibilities of

providing another 200KVA, 22KV/440V station transformer I

nearby 110/22KV Villianur SS that is charged by a 22KV feeder

either from 110/22KV Korkadu SS or Kurumbapet SS for

providing AC auxiliary supply to 230KV Villianur Auto SS.

Pending

18 Mail dated 30.01.2018 & 13.03.2018:










Pending

19 Mail dated 30.01.2018 & 13.03.2018:










Pending

20 Mail dated 30.01.2018 & 13.03.2018:










Pending

At present AC auxiliary supply is being provided from 440 Volt, 3phase, 50 Hz LT supply from 200 kVA, 22 kV/440 V Transformer

connected directly on the main bus of the nearby 110/22 kV Villianur SS. Since this substation is fed from 230/ 110 kV Villianur

substation, steps may be taken to provide redundant AC auxiliary supply by providing another 200 kVA, 22 kV/ 440 V transformer

in the 110/ 22 kV SS that is charged from 22 kV Korkadu feeder, and laying another 440 V cable from its secondary to thr AC

supply changeover panel at 230/ 110 kV Villianur SS.

GPS based time-synchronization equipment may be provided for synchronizing various 230 kV & 110 kV protection relays.

Steps may be to taken provide DR's with facility for automatic fault record downloading to a central PC/ server.

Standalone Event Logger may be provided.

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auditated


Recommendations


Constituent)

21 Mail dated 30.01.2018 & 13.03.2018:






PSDF funding. (copy enclosed)

Pending

22 Mail dated 30.01.2018 & 13.03.2018:






PSDF funding. (copy enclosed). In that DPR, replacement of

existing deteriorated RCC supporting structures have been

proposed to be replaced with G.I. lattice structure.

Pending

23 Mail dated 30.01.2018:






PSDF funding. (copy enclosed). In that DPR, provision has been

given to provide chemically treated PCC flooring, and then

covering it with suitable blue metal spreading in switchyard area.


Vegetation & weeds grown in the switch yard area were

manually cleared and now the switch yard is kept clean.

However, as a permanent measure, Detailed Project Report at

the cost of Rs.14,85,42,653.21 has been prepared to replace the

existing aged equipments and provide additional equipments at

230KV Villianur and Bahour Auto Sub-Station and sent to higher

authority to obtain sanction under PSDF funding. (copy

enclosed). In that DPR, provision has been given to provide

chemically treated PCC flooring, and then covering it with

suitable blue metal spreading in switchyard area.

Pending

It was observed that existing 100 MVA transformers had not been provided with fire protection. Steps may be taken to provide the

same in accordance with the relevant standards.

It was observed that supporting structures and equipment such as breakers, CT's, isolators, etc. In 110 kV switchyard had served

thier full life. Steps may be taken to refurbishing of 110 kV switchyard appropriately.

Vegetation & weeding was observed in switchyard area. Steps may be taken to provide chemically treated PCC flooring, and then


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auditated


Recommendations


Constituent)

24 Mail dated 30.01.2018 & 13.03.2018:







given to replace the existing dilapidated gantry & equipment

supporting (RCC) structures with G.I. lattice / tubular

structures.

Pending

25 Mail dated 30.01.2018 & 13.03.2018:

Action has been initiated to bring down the earth resistance

value to less than 1ohm

Pending

26 Mail dated 30.01.2018:

Action has been initiated to Equipment labeling for proper phase-

sequence


The work of Equipment labeling for proper phase-sequence was

completed on 13.03.2018.

complied

27 Mail dated 30.01.2018:

Action has been initiated for Earthing of equipment including

door-to-panel earthing.


The work of Earthing of various equipment including door-to-

panel earthing was completed on 13.03.2018.

Complied

28 Mail dated 30.01.2018 & 13.03.2018:

Suitable canopy has been fabricated and kept on hand awaiting

for shutdown to provide over Buchholz relays

Pending

29 Mail dated 30.01.2018 & 13.03.2018:

Steps have been initiated to establish Standard Testing Lab and

procurement of essential testing equipments to cater to all 230

kV substations.

Pending

Equipment labeling for proper phase-sequence may be provided.

Earthing of various equipment including door-to-panel earthing to be properly ensured.

Buccholtz relays may be provided with suitable canopy to prevent unwarranted trippings due to moisture ingress.

At present, PED is dependent on external agencies for carrying out testing of various electrical equipment & relays & protection

oriented trouble shooting. Steps may be taken to establish Standard Testing Lab and procurement of essential testing equipments

to cater to all 230 kV substations under its control.

It was observed that most of the existing gantry & equipment supporting (RCC) structures are in dilapidated state. Steps may be

taken to replace them with suitable lattice/ tubular structures.

Earth-resistance values for various earth-pits seem to be on higher side. Steps may be taken to bring it down to less than 1 ohm.

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30 Mail dated 30.01.2018:

Detailed scope of the works included in proposed R & U works

has already been furnished vide Lr.256/ED/EE-MRT&MMC/F-

SRPC/2017-18, dated 14.08.2017. (copy enclosed)




SRPC/2017-18, dated 14.08.2017. (copy enclosed

Complied

31 Mail dated 30.01.2018 & 13.03.2018:





Audit Team.

Pending


Recommendations


Constituent)

1 Mail dated 30.01.2018 & 13.03.2018:










Pending

2 Mail dated 30.01.2018 & 13.03.2018:

Control & Relay Panels installed with static relays are proposed

to be replaced with new control panels installed with numerical

relays under the project of Upgradation of existing static relays

and replacement of sub-station equipments at 230KV Villianur

and Bahour Auto Sub-Station at the cost of Rs.10,56,16,191/-

through PSDF funding. Tendering process for award of work on

labour contract basis for the above said work is almost over and

waiting for the approval of Puducherry Government to place

order at the lowest tenderer.

Pending

In view of radial operation of 110 kV feeders, Zone-1 reach may be increased to 90 % of line length, and Zone-2 time-setting may

be reduced to 150 msec.

2) 230/ 110 kV Bahour SS [10 - 12 July, 2017]


It is observed that main protections of feeders (230 kV as well as 110 kV) and trasformers are being provided from static relays.

Steps may be taken to replace the same with suitable numerical relays.

PED informed that they had already initiated steps for Renovation & Upgradation (R&U) of grid stations in Pondycherry region

(230/ 110 kV Villianur SS & 230/ 110 kV Bahour SS) under PSDF funding, covering most of the above works. In this regard, PED is

requested to furnish detailed scope of the works included in proposed R & U works.

Directional O/C & E/F protections to be provided for 230 kV & 110 kV feeders where Main-II is not provided; Directional E/F

protection to be provided for 230 kV & 110 kV feedes where Main-I & Main-II are provided

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3 Mail dated 30.01.2018 & 13.03.2018:





Audit Team.

Pending

4 Mail dated 30.01.2018 & 13.03.2018:





Audit Team.

Pending

5 Mail dated 30.01.2018 & 13.03.2018:





Audit Team.

Pending

6 Mail dated 30.01.2018 & 13.03.2018:





Audit Team.

Pending

7 Mail dated 30.01.2018 & 13.03.2018:





Audit Team.

Pending

8 Mail dated 30.01.2018 & 13-03-2018:

Co-ordination of Protection & Communication wing of TAN

TRANSCO Limited, Villupuram has been requested to bring the

230KV and 110KV Bus Bar Protection scheme into service.

Pending

Load encroachment feature may be appropriately kept enabled in 230 kV & 110 kV feeders.

It is observed that busbar protection relays have been provided for both 230 kV & 110 kV buses. However, the same have been

kept out of service since commisssioning. PED shall take steps to put these into operation.

Z4 (reverse) is to be provided in all distance relays of 230 kV & 110 kV feeders

Z2 and Z3 (reactive & resistive) reaches & time settings were observed to be not in line with Ramakrishna Committee guidelines,

which may be reviewed appropriately.

Auto-reclosure dead-time and reclaim-time for 230 kV feeders may be revised to 1 sec and 25 sec respectively. Accordingly Pole

Discreancy time-delay may be kept at 1.5 sec.

Power Swing Philosophy (Z1 --> Unblock; Higher Zones --> Block for 2 sec) is to be adoped unfiromly across all 230 kV feeders.

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9 Mail dated 30.01.2018 & 13.03.2018:





Audit Team.

Pending

10 Mail dated 30.01.2018 & 13.03.2018:

One set of existing aged 110Volt Station Battery has been

replaced with a new battery bank during the last week of

January 2018. Action has been initiated for necessary wiring to

segregate Main-I and Main-II Protection to fed from different DC

source.

Pending

11 Mail dated 30.01.2018 & 13.03.2018:










Pending

12 Mail dated 30.01.2018 & 13.03.2018:










Pending

For 230 kV Pondy feeder POR may be used in place of the existing PUR.

Steps to be taken to ensure that Main-I & Main-II protections or Main & back-up protections of feeders are fed from different DC

supplies.

REF protection to be provided for 80 MVA, 230/ 110 kV Transformers -1 & 2.

Directionality to be provided for O/C protection of 80 MVA, 230/ 110 kV Transformers -1 & 2.

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13 Mail dated 30.01.2018 & 13.03.2018:










Pending

14 Mail dated 30.01.2018 & 13.03.2018:










Pending

15 Mail dated 30.01.2018 & 13.03.2018:

One set of existing aged 110Volt Station Battery has been

replaced with a new battery bank during the last week of

January 2018. Action has been initiated for necessary wiring to

segregate Group-A and Group-B Protection of Transformer fed

from different DC source.

Pending

16 Mail dated 30.01.2018 & 13.03.2018:










Pending

Directional E/F protection to be provided for 80 MVA, 230/ 110 kV Transformers -1 & 2.

Overflux protection to be provided for 80 MVA, 230/ 110 kV Transformers -1 & 2.

Steps to be taken to ensure that Group-A & Group-B protections or Main & back-up protections of Transformers are fed from

different DC supplies.

GPS based time-synchronization equipment may be provided for time-synchronizing various 230 kV & 110 kV protection relays.

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17 Mail dated 30.01.2018 & 13.03.2018:










Pending

18 Mail dated 30.01.2018 & 13.03.2018:










Pending

19 Mail dated 30.01.2018 & 13.03.2018:







given to provide Line CVTs in all phases for all 230KV Lines..

Pending

20 Mail dated 30.01.2018 & 13.03.2018:







given to provide Surge Arrestors for 230KV feeders at gantry

entry point.

Pending

Steps may be to taken provide DR's with facility for automatic fault record downloading to a central PC/ server.

Stand-alone Event Logger may be provided.

Line CVT's to be provided in all phases for all 230 kV lines.

Surge Arrestors to be to be provided for 230 kV feeders at gantry entry point.

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21 Mail dated 30.01.2018 & 13.03.2018:

Budgetary offer has been called for from a reputed contractor

for arresting oil leakage observed in the Transformers. Work will

be commenced shortly on obtaining expenditure sanction from

the competent authority on the estimate prepared with the rate

offered by the contractor.

Pending

22 Mail dated 30.01.2018 & 13-03-2018:

the recommendation of Protection Audit Team, a Detailed






given to provide fire protection system to 80MVA Auto

Transformer-I&II.

Pending

23 Mail dated 30.01.2018 & 13.03.2018:

OEM M/s.Crompton Greaves Limited has been requested to offer

rate to bring back the 230KV Bus Coupler Breaker into service.







given to provide attendant CTs to make way to two-zone busbar

protection.

Pending

24 Mail dated 30.01.2018 & 13.03.2018:

Action has been initiated to segregate the wiring for extending

supply from DC1 and DC2 to trip coil of 230KV and 110KV

Breakers.

Pending

25 Mail dated 30.01.2018:

In addition to the existing 48Volt PLCC battery, one more 48Volt

PLCC Battery bank has been erected and commissioned during

the last week of January 2018. Wiring will be done to segregate

Source-1 & II.

Mail dated 30.01.2018 & 13-03-2018:

In addition to the existing 48Volt PLCC battery, one more 48Volt

PLCC Battery bank has been erected and commissioned as a

redundant DC supply for communication during the last week of

January 2018 with requisite segregation in wiring.

Complied

Oil leakage is being observed in both 80 MVA, 230/ 110 kV Tranformers. Suitable action may be taken to arrest the same.

It is observed that existing 80 MVA transformers have not been provided with fire protection. Steps may be taken to provide the

same in accordance with relevant standards.

It is observed that 230 kV & 110 kV Bus-Coupler breakers are not in working condition, and have been kept out of service. Also

they have no attendant CT's. PED may therefore take steps to replace them with attendant CT's to make way for two-zone busbar

protection.

Segregation in wiring for extending supply from DC1 and DC2 to trip coils of 230 kV & 110 kV feeders to be carried out.

Redundant DC suppy for communication (48 V) application to be provided with requisite segregation in wiring.

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26 Mail dated 30.01.2018 & 13.03.2018:

Action has been initiated to earth all gantry towers (metallic

structures) including lightning mast.

Pending

27 Mail dated 30.01.2018:

Action has been initiated to Equipment labeling for proper phase-

sequence


The work of Equipment labeling for proper phase-sequence was

completed on 13.03.2018.

complied

28 Mail dated 30.01.2018:

Action has been initiated for Earthing of equipment including

door-to-panel earthing.


The work of Door-to-panel earthing in various switchyard

marshalling panels was completed on 13.03.2018.

complied

29 Mail dated 30.01.2018 & 13.03.2018:

Suitable canopy has been fabricated and kept on hand awaiting

for shutdown to provide over Buchholz relays

Pending

30 Mail dated 30.01.2018:

Exploring all the possible ways to provide another dedicated

redundant AC auxiliary supply from nearby 110/22KV Sub-

Station which is being fed by other 230KV Sub-Stations.


Division-EHV of this department has been requested vide Lr.

No.714/Ed/EE-Auto SS/AEE-M-VASS/F-4/2017-18, dated

27.02.2018 (Copy enclosed) to explore the possibilities of

arranging an alternate 22KV supply fed from 110/22KV Sub-

Stations those are either fed from 230KV Villianur Auto SS or

230KV Thondamanatham Auto SS for the existing 22KV/440V

Distribution Transformer installed in the campus of 230KV

Bahour Auto SS, presently being fed by 22KV Pandasozhannlur

feeder from 110/22KV Bahour SS.

Pending

31 Mail dated 30.01.2018 & 13.03.2018:

DC earth leakage being observed in the battery charger will be

attended in the forthcoming total shutdown. Replacement of

existing DC Distribution Panels have been included in the DPR.

Pending

Equipment labeling for proper phase-sequence may be provided.

Door-to-panel earthing in various switchyard marshalling panels to be properly ensured.

Buccholtz relays may be provided with suitable canopy to prevent unwarranted trippings due to moisture ingress.

At present AC auxiliary supply is being obtained from 22 kV Bahour (Pandasozhanallur) feeder from nearby 110/ 22 kV Bahour SS.

Since this 110/ 22 kV SS is being fed from the present 230/ 110 kV SS, in the event of supply failure at the latter, the former will

also lose supply. PED shall take steps to provide another dedicated redundant AC auxiliary supply feeder.

DC earth leakage is being observed in both 110 V DC Sources. Also the corresponding DC Earth-fault relays in soruce end DCDB

panels are observed to be not in working-condition. Steps shall be taken to rectify the same at the earliest.

All gantry towers (metallic structures) including lightning masts to be earthed properly as per relevant standards.

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32 Mail dated 30.01.2018:







given to provide chemically treated PCC flooring, and then



Vegetation & weeds grown in the switch yard area were

manually cleared and now the switch yard is kept clean.

However, as a permanent measure, Detailed Project Report at

the cost of Rs.14,85,42,653.21 has been prepared to replace the

existing aged equipments and provide additional equipments at

230KV Villianur and Bahour Auto Sub-Station and sent to higher

authority to obtain sanction under PSDF funding. (copy

enclosed). In that DPR, provision has been given to provide

chemically treated PCC flooring, and then covering it with

suitable blue metal spreading in switchyard area.

Pending

33 Mail dated 30.01.2018 & 13.03.2018:







given to replace the existing dilapidated gantry & equipment

supporting (RCC) structures with G.I. lattice / tubular

structures.

Pending

34 Mail dated 30.01.2018 & 13.03.2018:

Actions have been initiated for Testing of various relays and

measurement of earth-resistance values for various earth-pits

periodically as per relevant standards and record them properly

Pending

35 Mail dated 30.01.2018 & 13.03.2018:

Protection and Communication wing of TAN TRANSCO Limited,

Villupuram has been requested to furnish the existing relay

settings for future reference.

Pending

Vegetation & weeding is observed in switchyard area. Steps may be taken to provide chemically treated PCC flooring, and then


It is observed that most of the existing gantry & equipment supporting structures have been of RCC. PED may take steps to

replace them with suitable lattice/ tubular structures when R & M works for the substation are propsoed.

Testing of various relays and measurement of earth-resistance values for various earth-pits should be undertaken periodically as

per relevsnt standards, and records properly maintained.

It is observed that relay settings for various protection relays have been set by TNEB at the time of commissioning. However,

records relating to the same have not been made available to PED. Steps may be taken (by PED/ TNEB) to maintain proper

records w.r.t. Implemented relay settings at Substation level.

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36 Mail dated 30.01.2018 & 13.03.2018:

Steps have been initiated to establish Standard Testing Lab and

procurement of essential testing equipments to cater to all 230

kV substations.

Pending

37 Mail dated 30.01.2018:








Complied

Mail dated 30.01.2018 & 13.03.2018:

Fault level of the station has been requested from EHV division

of this department. Details will be furnished as soon as received

from the said division.

Mail dated 30.01.2018 & 13.03.2018:

Protection and Communication wing of TAN TRANSCO Limited,

Villupuram has been requested to furnish the existing relay

settings. Relay settings will be furnished as soon as received

from the said corporation.

Mail dated 30.01.2018 & 13.03.2018:

Details are being collected from the source available at 230KV

Bahour Auto Sub-Station. Details will be furnished shortly.

Mail dated 30.01.2018 & 13.03.2018:

Action has been initiated to measure the Earth-mats and Earth-

Pits value. Measurements will be submitted shortly.

Mail dated 30.01.2018 & 13.03.2018:

Will be submitted shortly.


Details have been called for from TAN TRANSCO Limited. Will be

submitted shortly on receipt of the same.

PED informed that they had already initiated steps for Renovation & Upgradation (R&U) of grid stations in Pondycherry region

(230/ 110 kV Villianur SS & 230/ 110 kV Bahour SS) under PSDF funding, covering relay & control panel replacement works. In this

regard, PED is requested to furnish detailed scope of the works included in proposed R & U works for the 230/ 110 kV substation.

PED has not provided the following data as part of protection audit:

(i) Fault level of the Substation for 3-ph-Ground and 1-ph-Ground faults at both 230 kV and 110 kV levels

(ii) Adopted Relay Settings (given by Head Quarters/ Corporate Office and implemented in field)

(iii) Details on Periodicity of Relay Testing and latest Relay Test Reports

At present, PED is dependent on external agencies for carrying out testing of various electrical equipment & relays & protection

oriented trouble shooting. Steps may be taken to establish Standard Testing Lab and procurement of essential testing equipments

to cater to all 230 kV substations under its control.

(iv) Details of Measurement of Station Earth-Mat & Earth-Pits

(v) AC Supply Changeover Scheme

(vi) Details of 110 kV CT's Ratios and Errors

PGCIL (SR-I)

1) 400 kV & HVDC Gajuwaka SS [28-30 December, 2015]

38 Pending

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Equipment/

System auditated


Recommendations


Constituent)

1 General In pole 1 Trip Circuit Supervision relays are not available in the circuit.

However Trip Circuit Supervision is being monitored by RPC (Reactive

Power Control)

Mail Dated 05-02-2018:

Pole-1 RPC system trip circuit supervision relays are installed in

the month Dec-2017 & presently in service.

Complied

2 General HVDC pole - 1 & 2 Auxiliaries supply (33 kV) are being fed from ICT-2

(tertiary) only. In the event of failure of auxiliary supply DG set 1 & 2

respectively will feed the supply to the Auxiliaries.


Aux supply provision from ICT-1 (Second Aux supply)

comissioned. Automatic supply changeover scheme for Pole-1

has implemented. In the event of failure of auxiliary supply DG

set feed the supply to the auxiliries.

Order placed for retrofitting of LT brakers in Auxiliary system &

installation will complete by 30-April-2018.

Complied

3 General HVAC S/S Auxiliaries supply (33 kV) are being fed from APTRANSCO

feeder only. In the event of failure of auxiliary supply DG set will feed the

supply to the Auxiliaries.


Presently HVAC S/S Auxiliaries supply (33 kV) are feeding from

APTRANSCO feeder only. In the event of failure of auxiliary

supply DG set is feeding the supply to the Auxiliaries.

Pending

4 General HVAC DG set starting by manual only. Mail Dated 05-02-2018:

HVAC DG set is presently starting by manual in case of supply

failure. The same shall be changed to auto & will completed in

NTAMC sworks by October-2018.

Pending

5 General Oil leakage was observed from the line reactor of Vijayawada line Mail Dated 05-02-2018:

Oil leakages of Vijayawada L/R rectified in the month of April-

2016.

Complied

6 General Stub Protection time delay is kept as 100 ms. Mail Dated 05-02-2018:

As per POWERGRID, Corporate recommendations Stub prot

settings are adopted as 2.0 A ( Sec) if CT ratio is <=1000A & &

time delay 100 msec. For others 1.5 Amp.

Pending

7 General For 400 kV Kalpakka Line-1, Circuit Breaker Pole discrepancies kept as

1.0 s


400 kV Kalpakka Line-1, Circuit Breaker Pole discrepancies

changed to 2.5 sec from 1.0 sec in Janaury-2016.

Complied

8 General For 400kV Kalpakka line 1& line 2,

Main- 1 relay:

Reverse Zone is not available in REL-100.

Zone- 3 time delay is observed as 1.5 sec.

Stand alone Auto reclosure in off condition.

Relay is not time synchronized with GPS.

Main- 2 relay:

Reverse Zone setting time kept as 2s.

Over Current protection enabled.

DEF is not provided.

Stand alone Auto reclosure in off condition.

Relay is not time synchronized with GPS.


Informed to APTRANSCO for necessary action & 400kV

Gazuwaka-Kalpaka-1&2 line settings modified as per

Ramakrishna Committee recommendations in December-2017.

However the same relays will be retrifitted with LDP relays by

APTRANSCO. In 71st PCSC meeting APTRANSCO informed that

the LDP relay installation will complete by April-2018.

Pending

2) 400/ 220 kV Gooty SS [12th, 13th and 15th February, 2016]

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Recommendations


Constituent)

1 400kV Control and

Protection Panels

For 400 KV Busbar protection (RADSS of ABB make), one main Bus bar

protection scheme for each Bus 1 & Bus 2 available and Check Zone

protection is not available . Redundant Bus bar protection or Check zone

shall be considerd.


In place of Main & Check Zone , In ABB make RADSS B/B

protection relay Start & Differential features are available.

IN RSTPP, CTP-1 Transmission systems Bus Bar protection

scheme was envisaged as per CEA/CBIP guidelines then

existing.

Retrofitting of existing B/B schme with redundant BB

protection shall be proposed under ADD CAP.

Pending

2 DEF protection is enabled in Main-1 of 400kV Nelamangala & Kurnool AP

line. However inspite of availability of DEF protection in Main 2 (Ohmega)

Distance relays is not enabled. Powergrid informed that settings adopted

for Ohmega relay is as per CC Recommendation


We have observed mal-operation of DEF protection in Omegha

relays & hence the DEF feature disabled.

Proposal for retrofitting of Omegha relay with latest numerical

relay has been approved and is under tendering stage. The

same shall be retrofitted by October-2018.

Pending

3 Kurnool PG Line reactor and Bus reactor RWTI meters placed in control

panel are not in working condition.


Rectified & faulty meters were replaced with new meters On 05-

05-2017

Complied

4 Stub protection current set and time delay set as I> 150% and 100ms

against the recommendeed setting of I>250% and time delay of 50ms by

M/S Tractebel.Powergrid informed that settings adopted as per CC

Recommendation


As per POWERGRID, Corporate recommendations Stub prot

settings are adopted as 2.0 A ( Sec) if CT ratio is <=1000A & &

time delay 100 msec. For others 1.5 Amp.

Pending

5 AC Distribution It was observed that one 33kV feeder is available for auxilliary supply of

station. POWERGRID informed that second redundant AC supply source

from ICT-II tertiary winding is under progress.


On 29-05-2016 second redundant AC supply source from ICT-II

tertiary winding is Charged.

Complied

6 DC Distribution For 400kV bus bar protection panel, 2 DC sources are available with

selector switch only. Automatic changeover is not provided.


IN RSTPP, CTP-1 Transmission systems Bus Bar protection

scheme was envisaged as per CEA/CBIP guidelines then

existing.

Retrofitting of existing B/B schme with redundant BB

protection shall be proposed under ADD CAP.

Pending

7 Battery voltage measured on the date of audit is as below:

P-N(v) P-E(v) N-E(v)

220V Battery set 1 : 225.5 98.2 -127.0

220V Battery set 2 : 233.3 96.8 -136.0

48V Battery set 1 : 53.6 NA 51.9

48V Battery set 2 : 52.4 NA 53.0


Battery voltage measured on 03.02.2018 and is as below:

P-N(v) P-E(v) N-E(v)

220V Battery set 1 : 218.6 + 115.9 -102.5

220V Battery set 2 : 243.0 + 122.4 -120.4

48V Battery set 1 : 48.8 NA -48.5

48V Battery set 2 : 52.8 NA -52.4

Complied

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Equipments

Lightning protection ( LAs) Earthing is not done as per standards/ NFPA

for ICT-1 & 400kV Gooty-Kurnool PG Line Reactor. LAs (system ) earthing

are not connected to earth electrodes directly instead it is connected

through equipment earthing. It should be modified similar to other bays.


LA Earthing was modified during AMP S/D of GOOTY-KNL PG

L/R On dt 27.06.2017 &

During AMP S/D of ICT-1 On dt 10.06.2017

Complied


Recommendations


Constituent)

1 Letter Dated 19-AUG-2017:

The reaches/ Pickup/ Drop off of all the numerical relays are

being checked on 04 yearly basis as per powergrid preventive

maintenance procedures. However, DC logics, Trip Logics, Auto-

reclosure, O/V, Stub functions etc. are being tested/checked

during every AMPs and oppurtunity shutdowns.

Pending


Implimented as per POWERGRID philosophy and Ramakrishna

Committee recommendations.

Pending


Intentional Delay of 100 msec( with POR) provided for zone-1 of

Gooty-1 &2 feeders in view of FSC at Gooty substion.

Complied


Measurement principle of each relays (different manufacturers)

for Phase- Earth Resistive reaches are different and hence the

resistive reaches (Phase-Earth) for REL670/P444/7SA522 Relays

kept different.

Complied

5 Complied


Recommendations


Constituent)

1 Pending

2 Pending

4) 765/ 400 kV Maheshwaram (GIS) SS [8 - 9 February, 2018]


Colour coding for phase identification of breakers may be provided in 765 kV & 400 kV GIS Halls.

For 400 kV Maheshwaram (PG) - Maheshwaram (TS) lines 1 & 2, presently Line Differential Protection (LDP) and Distance

Protection (DP) have been provided as Main-I and Main-II respectively. Since they are very short lines, steps shall be taken to

provide LDP as Main-II also.

As most of the numerical relays have completed 4-years of in-service operation, comprehensive testing of the same may be

carried out.

In addition to blocking of distance protection under VT fuse-fail conditions, it shall be ensured that upon detection of a fault

(sensed by negative sequence component), blocking of distance protection gives rise to operation of its inherent Over-Current

protection with a suitable definite time delay of (say) 500 msec.

It is observed that Zone-1 time delay for Gooty lines 1 & 2 is kept as 100 msec, which may be clarified/ reviewed.

Z2, Z3 and Z4 Resistive reaches for Ph-G faults for Main-I & Main 2 have been found to be kept differently on 400 kV NCC lines 1

& 2, 400 kV Gooty lines & 765 kV Kurnool lines, which may be reviewed.

PLCC dB level (signal strength) measurements are being done on yearly basis.

3) 765/ 400 kV Nellore PS [19 - 20 June, 2017]


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3 Pending

4 Pending

In 765/ 400 kV ICTs - 1 & 2, it is noted that all Group-A protections containing the primary Differential and the secondary DOCE

(HV) have been provided from one relay. Similarly, all Group-B protections containing the primary REF and the secondary DOCE

(LV) have been provided from another relay. Since, there is no duplication of these group protections, steps shall be taken to

provide the primary and secondary protections of each group from different relays for better reliability.

Commissioning of Aux. Supply from ICT-2's Tertiary as redundant auxiliary supply may be expedited.

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5 Pending

6 Pending

7 Pending


Equipment/ System

auditated


Recommendations


Constituent)

1 General Zone 3 and reverse zone resistive reach settings are differently seted in

the relays


The Zone 3 Settings kept as 1 Sec, in case it is crossing the next

voltage level the same was kept as 1.5Sec.

Complied

2 General Zone 4 reach should be set to cover 50% of shortest line connected in

Hosur SS ( existing settings are set to 20% of protected line)


Presently kept as 20% of Protected line.


Kept as 20% of Protected line which will cater the functional

requirement as per the organizational Philosophy.

Pending

3 General PSB for 400kv is in line with guide line the same is not respected on

230kv lines ( all zone are blocked)


For 220/230kV lines all zones are blocked for PSB.


For 220/230kV lines all zones are blocked for PSB as per the

organizational Philosophy.

Pending

4 General STUB should be set to 50ms ( existing settings are 100ms) Mail dated 30.01.2018:

Under Review


Kept as 100msec of Protected line which will cater the functional

requirement as per the organizational Philosophy. In case of

inadvertant initiation, the line might trip with a delay of 50ms for

even an outzone fault. 100ms is given to let the primary

protection of the downstream line operate.

Pending

In addition to blocking of distance protection under VT fuse-fail conditions, it shall be ensured that upon detection of a fault

(sensed by negative sequence component), blocking of distance protection gives rise to operation of its inherent Over-Current

protection with a suitable definite time delay of (say) 600 msec.

Stub Protection Timing, which is presently kept as 100 msec may be suitably revised to 50 msec.

Calculation Sheet(s) showing protection settings calculation for all feeders and transformers may be furnished.

PGCIL (SR-II)

1) 400 kV Hosur SS [9-11 December, 2015]

2) 400 kV Tirunelveli SS [8th, 9th and 11th January, 2016]

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Equipment/ System

auditated


Recommendations


Constituent)


Equipment/ System

auditated


Recommendations


Constituent)

1 Zone 3 and reverse zone fault resistive reach settings are not matching

and different w.r.t. TE settings for all 400 and 230 KV feeders.



voltage level the same was kept as 1.5Sec

Complied

2 Zone3 time delay has been set as 1.5s instead of 1sec except Veeranam

line



voltage level the same was kept as 1.5Sec

Complied

3 Zone 4 reach setting should be set to cover 50% of shortest line

connected in Tirunelveli SS. The existing setting for Zone-4 is different for

all the 400kV & 220kV lines.


Presently kept as 20% of Protected line.


Kept as 20% of Protected line which will cater the functional

requirement as per the organizational Philosophy.

Pending

4 PSB: For 400kv, all zones except zone-1 are blocked. For 220kV all zones

are blocked.


For 220/230kV lines all zones are blocked for PSB.


For 220/230kV lines all zones are blocked for PSB as per the

organizational Philosophy.

Pending

5 STUB protection timing should be set to 50ms. Existing setting is 100ms

for 400kV Lines.


Under Review.







Pending

6 In 400KV Madurai line setting Zone-2 time delay is kept 0.5 sec instead of

0.35sec


The time Descremenation depends on remote end lines co

ordination. Accordingly 0.5 was kept.

Complied

7 For 220kV lines dedicated speech available for Edamon DC lines only. Not

available for all other lines pertaining to TANTRANSCO (Udayathur,

Kayathar, Veeranam, Sanganeri)


All the 220kV PLCC panels except Edamaon belongs to

TANTRANSCO.

Pending

60/70

Annexure-VI

Page 60 of 70


Equipment/ System

auditated


Recommendations


Constituent)

8 Following Protection & Data/speech channels used in 220kV Lines:

a) Edamon-1 line - 2protection+1data/speech

b) Edamon-2 line - 2protection; (Edamon 1&2 is DC Line)

c) Udayathur line - 1protection

d) Veeranam line - 1protection

e) Kayathar line - 1protection

f) Sanganeri line - 1protection


In line with Standard Philosophy for POWERGRID owned lines.

Complied


Recommendations


Constituent)

1 Mail dated 30.01.2018:

Reviewed. The Zone 3 Settings kept as 1 Sec, in case it is

crossing the next voltage level the same was kept as 1.5Sec

Complied

2 Mail dated 30.01.2018:

Reviewed and found in line with OEM recommendations

Complied

3 Mail dated 30.01.2018:

Reviewed and found correct

Complied

4 Mail dated 30.01.2018:

In Siemens relay Zone-5 kept enabled

Complied


Recommendations


Constituent)

1 Mail dated 30.01.2018:

Reviwed. The Zone 3 Settings kept as 1 Sec, in case it is

crossing the next voltage level the same was kept as 1.5Sec.


The Timer will come into picture after the CVT fuse fail delay

and is non directional. Hence maximum time delay of Zones kept

as 1.1sec which meets the functional Requirement. Reducing the

same might result in unsuccesful auto-reclosure.

PendingVT Fuse fail time delay which is presently kept as 1.1 sec may be suitably revised to say 0.5 sec

4) 400/ 220 kV Kozhikode SS [21-22 December, 2017]


3) 400 kV Alundur SS [16 December, 2016]


Zone-3 Time settings, which were presently kept at 1.5 sec to be suitably reviewed.

In Karaikudi Main-II relay, SOTF - Auto INIT, which was kept enabled, is to be reviewed

Resitive reaches for P-E faults for Zone-1 & Zone-2 of all feeders may be reviewed

Zone-5 of Main-I in Karaikudi feeders was kept enabled.

61/70

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Page 61 of 70


Equipment/ System

auditated


Recommendations


Constituent)

2 Mail dated 30.01.2018:

Under Review.







Pending

3 Mail dated 30.01.2018:

To be Provided.


As per the Recommendations, the same will be provided. The

requiered hardware is under procurement and shall be

completed by April-18 end.

Pending

4 Mail dated 30.01.2018:

Under Review.


The Scheme studied in detail and compared with other few

stations. As the trippings are meant for different areas of

protections ( 400kV side and 220kV side seperately) and Gr-A

and Gr-B relays were provided with different DC sources, the

scheme is found to be Ok, which is in line with POWERGRID

Engineering Approval.

Pending

5 Mail dated 30.01.2018:

Under Review.


The Temporary ICT is provided to Cater the immediate load

relief to KSEB as per KSEB request, where common CB and CTs

were utilized. Upon Commissioning of New ICT-3, the ICT again

shall be kept as Spare.

Pending

Stub Protection Timing, which is presently kept as 100 msec may be suitably revised to 50 msec.

DC supply selector switch may be provided in 220 kV BBP panel

Providing of DOCE (HV) protection and DOCE (LV) protections of ICT's from different DC Sources may be explored.

Presenly Differential, DOCE (HV) & DOCE (LV) protections have been provided in common to 315 MVA ICT-2 and 315 MVA ICT-3

as a temporary arrangement. However, it is noted that with the commisssioning of new 500 MVA ICT in place of the existing ICT-3

(expected in 2 months), the above protections would be made independent.

62/70

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Page 62 of 70


Equipment/ System

auditated


Recommendations


Constituent)


Equipment/ System

auditated


Recommendations


Constituent)

1 Chandrapur 2 400 kV Isolator Marshalling Box Observed that Control Supply Fuse of Isolator (389B) was in removed

condition.


Control Supply fuse placed

Complied

2 Chandrapur 1 & 2 400 kV Protection Panel Observed that Auto Recloser of Circuit Breaker is kept off Mail dated 30.01.2018:

AR kept in service

Complied

3 Chandrapur 1 & 2 400 kV Main-I relay & Main-II

relay

Zone-4 timer is kept as 1.0 sec Mail dated 30.01.2018:

Z-4 time delay made to 0.5Sec

Complied

4 Chandrapur 1 & 2 400 kV Protection panel Over Voltage stage-II time delay is kept as 0 sec. Mail dated 30.01.2018:

OV St-II Time Delay kept at 0.1Sec

Complied

5 Chandrapur 1 & 2 400 kV Protection Panel Redundant Overvoltage Stage-I protection is not available. Mail dated 30.01.2018:

OV St-I protection made available

Complied

6 Chandrapur 1 & 2 400 kV Protection Panel Observed that STUB protection is not available. Mail dated 30.01.2018:

Will be implemented.


Will be implemented by 30.06.2018.

Pending

7 Warangal 400 kV Main-I relay (ABB

RAZFE)

Reverse Zone is not available. Mail dated 30.01.2018:

Relay retroftitted with numerical relay & reverse zone

implemented

Complied

8 Warangal 400 kV Main-II relay Zone-3 time delay is kept as 1.2 s and Zone-4 time delay is kept as 1.0 s. Mail dated 30.01.2018:

Z-3 time delay changed to 1Sec & Z-4 time delay changed to

0.5Sec

Complied

9 Warangal 400 kV Protection panel Over Voltage stage-II time delay is kept as 0 sec. Mail dated 30.01.2018:


Complied

10 N.Sagar 1 & 2 400 kV Protection panel Over Voltage stage-II time delay is kept as 0 sec. Mail dated 30.01.2018:


Complied

11 N.Sagar 1 & 2 400 kV Main-II relay Observed that line Phase angle is kept as 75 degree (P-P) & 70 degree (P-

N).


Relay replaced with numerical relay & Phase angle changed to

75deg

Complied

12 N.Sagar 1 & 2 400 kV Main-I relay Observed that zone-4 time delay is kept as 1.0 s Mail dated 30.01.2018:

Z-4 time delay kept to 0.5Sec

Complied

13 N.Sagar 1 & 2 400 kV Main-II relay Observed that zone-3R time delay is kept as 1.3 s Mail dated 30.01.2018:

Z-3R (Rev zone)time delay kept to 0.5Sec

Complied

14 Gajwel 400 kv Main-1 relay Observed that zone-4 time delay is kept as 1.3 sec Mail dated 30.01.2018:


Complied

NTPC

1) 400 kV Ramagundam STPS [18-20 February, 2016]

63/70

Annexure-VI

Page 63 of 70


Equipment/ System

auditated


Recommendations


Constituent)

15 Gajwel 400 kv Main-I & II relay Observed that Zone-2 time delay is mismatching with main-I (500 ms)

and main-II(400 ms) relay.


Both Main-I&II Z-2 Time delay kept at 0.4Sec

Complied

16 Malkaram 400 kv Main-I & II relay Observed that time delay for Over Voltage Stage-II is mismatching with

numerical relay and static relay. Numerical relay time delay is 50 ms

whereas in static relay is kept 0 sec.


OV St-II Time Delay kept at 0.1Sec for both numerical & static

relays

Complied

17 Malkaram 400 kV Main-I& II relay Observed that zone-4 time delay is kept as 1.0 s Mail dated 30.01.2018:


Complied

18 Tie feeder 400 kV Control Panel Auto recloser reclaim time delay is kept as 2.5 sec and dead time delay is

kept as 0.5 sec.


AR Reclaim time kept at 25 Sec & dead time kept at 1Sec.

Complied

19 Hyderabad-3&4 400 kV Protection panel Observed that zone-4 time delay is kept as 1.0 s Mail dated 30.01.2018:


Complied

20 Hyderabad-3&4 400 kV Protection panel Observed that time delay for Over Voltage-II is mismatching with

numerical relay and static relay. Numerical relay time delay is 50 ms

whereas in static relay is kept 100 sec.


OV St-II Time Delay kept at 0.1Sec for both numerical & static

relays

Complied

21 Dichipally 400 kV Main-I relay Zone-4 time delay is kept as 1.3 s Mail dated 30.01.2018:


Complied

22 Dichipally 400 kV Main-I relay Over Voltage stage-II is not enabled. Mail dated 30.01.2018:

Relay replaced with numerical realy & OV St-II is enabled

Complied

23 Dichipally 400 kV Main-II relay Zone-4 time delay is kept as 1.3 s Mail dated 30.01.2018:


Complied

24 Dichipally 400 kV Main-II relay Over Voltage stage-I is not enabled. Mail dated 30.01.2018:

OV st-I presenlty in enabled condition

Complied

25 Dichipally 400 kV Control Panel Auto reclousre reclaim time delay is kept as 30 sec and dead time delay is

kept as 0.939 sec.


AR Reclaim time kept at 25 Sec & dead time kept at 1Sec.

Complied

26 Bus Reactor 400 kV Circuit Breaker

Marshalling Box

Circuit Breaker Pole Discreprency time delay is kept as 1.5 sec. Mail dated 30.01.2018:

PD timing set to 0.5Sec

Complied

27 Bus Reactor 400 kV Control Panel For LBB protection of Bus reactor, Current settings is at 0.05 In. Mail dated 30.01.2018:

Settings adopted are in line with our Engg recommendations.

The FL CT secondary current for reactor is 0.12A.

Complied

28 General Switchyard (ACDB) Auxiliary supply 415 V emergency feeder from DG

set is kept in test mode. The operation of changeover from normal supply

to Emergency DG supply is done manually.

Mail dated 30.01.2018 & 13.02.2018:

It is as per the scheme. Breaker presently kept in service

position.

Pending

29 General All Isolators are operated from local. Mail dated 30.01.2018:

Remote operation is available for all isolators. As per the local

practise & for extra safety local operation is being done

Complied

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Equipment/ System

auditated


Recommendations


Constituent)

30 General Auto recloser is enabled for main CB's only and disabled for all tie CBs. Mail dated 30.01.2018:

AR enabled for all Tie CB's

Complied

31 General Some of the Isolator Marshalling Boxes and CTs Junction Boxes in stage I

installations are found rusted.


Few are in rusted condition. Replacement being done in phased

manner.


The Marshalling Boxes rust has been removed & suitably painted

Complied

32 General Cable for Manual Testing Solenoid is found disconnected in emulsifier

system for Shunt Reactor1.


Completed.

Complied

33 General Pressure gauge for Emulsifier system of Shunt Reactor 2 found not

working.


Will be replaced by 31.03.2018.

Pending

34 General Electric fuses from control panel of emulsifier system of Shunt Reactor 1

and 2 are in removed condition.


Fuses placed

Complied

35 General One of the PLCC II charger (48V) is giving alarm as rectifier fuse fail Mail dated 30.01.2018:

Rectified during Battery Load Test

Complied

36 General One of the Pressure gauge for Emulsifier system for Bus Reactor found

defective.


Will be replaced by 31.03.2018.

Pending

37 General In protection chnl I & II and speech chnl panels alarm indication for -Va

is appearing


Rectified

Complied

38 General Load enchrochment is not available in 400 kV feeders. However it was

informed that the resistive reach have been suitably calculated to take

care of the same excluding the 400kV Hyderabad line-3 & 4 (Main-2).


Load Encrochment is provided in Hyderabad Line-3,4(Main-2).

Complied

39 General STUB is enabled only for 400kV Malkaram, Warangal & Hyderabad 3 & 4

as instantaneous.


Settings are as per our NTPC practice.


Exisitng is electromechanical Scheme. Will be implemented in

numerical relay by 31.10.2018.

Pending

40 General For Main-2 protection of 400kV Chandrapur line- 1 & 2 and Main-1

protection of 400kV Nagarjunasagar line-1 & 2, Zone 1 & Zone 2 is

Unblock condition for PSB.


Settings are as per our NTPC practice.

Pending

NPCIL

1) 220 kV Kaiga GS [4-6 April, 2016]

65/70

Annexure-VI

Page 65 of 70


Equipment/ System

auditated


Recommendations


Constituent)


Equipment/ System

auditated


Recommendations


Constituent)

1 Control and

Protection

Panels/Relay Setting

For ICT-1&2 Differential and REF protection is provided in the same relay

(P663).

NPCIL Reply 2016:

Ramakrishna report does not call for separate relays for DIFFL

and REF. REF protection is provided as main protection to detect

senstive earth faults. Since differential and REF belongs to main

protection single relay can be used for both protections.

NPCIL Mail dated 25.01.2018:

As per the original design Differential and REF protection for ICT-

1&2 are provided in the same relay (ALSTOM-P633). The issue is

being taken up with designer for further reviews.

NPCIL Reply during Special Meeting at Kaiga dated

22.06.2018:

Agreed to put separate relays as per reliabililty requirements.

Separate relays for ICT-1&2 Differential and REF protection will

be provided by December 2018

Pending

2 Over current protection(67 forward) has been kept enabled on all 220 kV

feeders.

NPCIL Reply 2016:

Earlier Main-II distance protection was not provided. Hence this

protection was kept as a back up.Now this protection will be

deleted from trip as Main-II is available.


All high set elements in Dir overcurrent is removed. IDMT O/C

(67 F) is only enabled as these lines are single ACSR moose with

a maximumcurrent rating of 603 amps at 75 deg C. The setting

is 800 amps with TMS0.25 onIEC-SI curve.

Complied

3 LBB time setting for lines is 0.25 sec and for ICTs - 0.2 sec. NPCIL Reply 2016:

It is being reviewed by NPCIL


It has been reviewed and decided to keep settings as 200 msec

for all. Will be completed after receiving approval letter from HQ.


22.06.2018:

Received approval letter from HQ. LBB time setting for ICTs and

lines will be set to 200ms after availing shutdown.

Pending

66/70

Annexure-VI

Page 66 of 70


Equipment/ System

auditated


Recommendations


Constituent)

4 Two sources of 48 V DC are available for PLCC communication. One

common output bus is extended to the PLCC panel.

NPCIL Reply 2016:

PLCC panels are supplied, installed and maintainind by the

owner of the 220 KV line(KPTCL).


Two separate PLCC channels are available foraigaKadra and

kaiga Kodasalli lines. They have two independent 48 V DC power

supplies which is having automatic back up at the source side.

Complied

5 Communication

system

No separate speech channel is provided. But used through PLCC MDX-50

Exchange for communication.

NPCIL Reply 2016:


owner of the 220 KV line(KPTCL).



owner of the 220 KV line(KPTCL). Hence the issue may be taken

up with KPTCL

Pending

6 Main- 1 and Main-2 Relays are not time-synchronized with GPS but

Standalone Disturbance and Event logger are time synchronized with

Station Clock which is time synchronized with GPS.

NPCIL Reply 2016:

In KGS numerical relays are not being used for event analysis.

Stand alone DR and event logger are GPS synchronised and

used for preparing trip reports. Thus unavailability of GPS

synchronisation of numerical relay does not affect the trip

analysis.


Presently Stand aalone Disturbance recorder and event logger,

which are synchronised with GPS, are used for event analysis.

GPS is being procured for synchronising MainI&II relays by June,

2018.


22.06.2018:

GPS will be procured for time synchronising of MainI&II relays

by December, 2018.

Pending


Equipment/ System

auditated


Recommendations


Constituent)

1 Bus Reactor-2 400KV Equipment Oil Leakage was observed in 400KV system Bus Reactor-2 neutral side

bottom valve.


Oil leakage attended.

Complied

2 ICT-1&2 - Equipment Oil seepage was observed in the ICT-1 & 2. Also water leakage was

found near ICT-1


Oil seepage and water leakage attended.

Complied

NLCIL

1) 400 kV NLC TS-II [8–10 February, 2016]

67/70

Annexure-VI

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Equipment/ System

auditated


Recommendations


Constituent)

3 Tie-1 (230 kV), Tie-

2 (230 kV), STCMS

(230 kV), Tie-3

(400 kV) & Tie-4

(400 kV)

400KV &

230KV

Protection Even though there are four short lines [Tie-1 (230 kV), Tie-2 (230 kV),

STCMS (230 kV), Tie-3 (400 kV) & Tie-4 (400 kV)], line differential

protection has been provided on Tie-4 only.


In 230kV Tie1 & Tie2 feeders , 2 nos of new relays with main

differential protection and backup distance protection relays

were commissioned. At present distance protection is in service.

Diferential protection will be commissioned shortly. The

possibility of introducing Differential relays in 400kV Tie3 feeder

and 230kV STCMS feeder has to be explored.

Pending

4 Nagapatnam line

bay

400KV Equipment The line CVT (Y-ph) of 400KV Nagapatnam line was not healthy, and

showing higher indication. As such, Over Voltage protection setting

(stage-I) for Nagapatnam line was set at higher value (128%)


The Y phase CVT was replaced on 20-02-2016.

Complied

5 All the line feeders 400KV &

230KV

Protection Over current protection was kept enabled on some of the 400 kV feeders

(Pugalur, Nagapattinam, Tie-4), which should be kept disabled.


Over current protections are kept disabled.

Complied


230KV

Protection DEF (Backup earth fault) protection was not provided on any of the 400

kV feeders. On some of the 400KV & 230KV feeders, it was kept non-

directional.


Backup earth fault protection (DEF) was enabled for all feeders.

Complied

7 ICT -1 & 2 400KV/23

0KV

Protection For ICT -1 & 2, REF was not provided. However, it is observed that

circulating current protection has been provided in place of REF.


Since ICT1 & 2 are single winding transformers the protection

provided is sufficient.

Pending

8 Bus Reactor 400KV Protection For Bus Reactor 1&2, Over voltage protection was kept enabled. Also no

REF has been provided to any of the bus reactors.


Over voltage protection in Reactors was disabled.Restricted

earth fault (REF) protection was not envisaged in the original

design.

Pending

9 Bahoor Line feeder 230KV Equipment For 230 kV feeders (except Bahoor feeder), Main-1 protection only has

been provided. For Bahoor feeder, even though Main-1 & Main-2 relays

were provided, it is observed that both relays are of same make & model.


A proposal has been taken up for providing Main 2 distance

protection in 230kV feeders. The equipments of Bahoor feeder

are assets of PGCIL. Any decision for replacement in Bahoor

feeder is in PGCIL scope.

Pending

10 All the line feeders 230KV Protection For 230 kV feeders, Power swing was blocked for all Zones and the

unblocking time was kept at 80 msec.


Power swing block was provided from Z2 to Z5 zones and the

unblocking time has been kept at 2.0 sec as per guidelines.

Complied

11 All the line feeders

except Bahoor

230KV Protection A/R was not provided on 230 kV feeders except Bahoor & Villianur

feeders. On Bahoor feeder, A/R, though commissioned, not put into

service. On Villianur, A/R is in service.


The Auto reclose implementation in the remaining 230kV feeders

will be taken up shortly.

Pending

12 Bus Bar Protection All 230KV feeder relays (Main-1), were provided with only one DC source.

It is observed that the second DC supply was available in relay panel.

However, no changeover arrangement for DC supply has been provided.


The Control and relay panels are more than 30 years old .As the

space available in the 230kV panels is very limited to

accommodate DC changeover scheme ,the possibility of

providing DC change over scheme will be explored.

Pending

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Annexure-VI

Page 68 of 70


Equipment/ System

auditated


Recommendations


Constituent)

13 Bus Bar Protection 400KV & 220KV Busbar protection was provided with only one DC

source. It is observed that the second DC supply was available in relay

panel. However, no changeover arrangement for DC supply has been

provided.


It has been proposed to replace the existing bus bar protection

with low impedance busbar protection The necessary Dc

changeover scheme will be introduced during the replacement

time.

Pending


230KV

Protection For all line feeders, the resistive reaches of all zones need modification.

NLC informed that the Consultant recommended settings were based on

the CVT ratio of 230 kV/ 110 V and 400 kV/ 110 V. However, as the

existing CVT ratios are 230 kV/ 115 V and 400 kV/ 115 V, the final

settings based on the existing ratios of CVT's would be implemented as

and when Consultant provides the same to them.


Resitive reach for all the zones were modified as per the

consultant recommendations.

Complied

15 All the line feeders 230KV Protection In all 230KV line feeders SOTF function were kept disabled. NLCIL Mail dated 18.01.2018:

SOTF function is kept enabled.

Complied

16 MF-1,2,3&4 230KV Protection Eventhough MF-1,2,3&4 are short lines, PUT scheme has been

implemented.


The feeders are radial. System is normal with PUT (Permissive

Under reach Transfer trip)

Pending

17 Pondy Line Bay 400KV Protection It is observed that in distance protection 5 zones are enabled. Zone-3

and Zone-4 settings were kept identically.


Zone 3 & Zone 4 settings are always kept identically.

Pending

18 General 415V ACDB It is observed that manual Changeover arrangement only has been

provided between Incomer -1 & Incomer-2 feeder in ACDB and DCDB.


Since ACDB and DCDB does not add any criticality to the system

manual change over is sufficient to take care of the situation

needs.

Pending

19 General 415V DG set No dedicated DG set for switchyard auxiliaries. Generation plant

emergency DG set power is utlised for switchyard emergency lighting

only.


Emergency supply is taken from the emergency bus of the main

plant.

Complied

20 General - Equipment Cables laying in ACDB & DCDB room is observed to be overloaded in

cable trays and some of the cables laid haphazardly (not properly laid in

Cable trays)


Cables re-arrangement is in progress.

Pending

21 General - Equipment In ACDB & DCDB and Battery Charger panel, no Indication Lamps were

provided.


Indication lamps provided.

Complied

22 General - DC system It is observed that no earthing has been provided in 220V & 48V DC

Battery room for measurement purpose. Exhaust fans are not provided in

one of the 48V Battery room


Attended

Complied

23 General - DC system Earth fault was observed in DC source-2. The voltage measured values

are : +ve to -ve = 238.3V; +ve to earth = 65.3V; -ve to earth = 172.6V


Earth fault in the system was cleared.

Complied

69/70

Annexure-VI

Page 69 of 70


Equipment/ System

auditated


Recommendations


Constituent)

24 General - Protection Pole discrepancy (PD) for all the line & tie feeder breakers are not kept

uniform. For all 400 kV feeders except tie-feeders kept as 2.4sec; For

400 kV Tie-feeders, 230 kV feeders, ICT & Reactor breaker, it was kept at

0.1 second.


For the breakers of all feeders which are provided with auto

reclose facility the Pole descrepancy is kept at 2.4 sec. For all

other breakers , pole descrepancy is kept at 100msec.

Complied

25 General - Equipment Most of the circuit breaker cubicles in 400KV & 220KV feeders have not

been provided with panel lamp. Door switches were also not working

properly.


Provided.

Complied

26 General - Equipment Star ground connection for 400KV extension feeders (viz., Tie-3, Tie-4,

Pugalur) and Bus Reactor-1 & 2's CT/CVT are done in protection panel in

control room. All other 400KV & 220KV feeders CT/ CVT star ground

connection provided in field (switchyard).


The existing arrangemnt works properly and needs no changes.

Pending

27 General - Equipment It is observed that single earthing has been provided for few marshalling

boxes in switchyard. Also Door earthing was not provided for the

marshalling boxes. NLC confirmed that marshalling box replacement

works are under progress.


A total of 62 nos of marshalling kiosks have been replaced so far

with double earthing and door earthing. Replacement of balance

marshalling kiosks will be taken up shortly.

Pending

28 General - Equipment Rusting was observed in most of the 400KV & some of the 220KV CT/CVT

Marshalling Boxes. Some of the CT/CVT Marshalling Boxes have not been

body earthed. The dummy gland holes in marshalling boxes were not

covered. NLC confirmed that marshalling box replacement works are

under progress.


A total of 62 nos of marshalling kiosks have been replaced so

far. Replacement of balance marshalling kiosks will be taken up

shortly.

Pending

29 General - Equipment CB open/close Indication Lamps were not provided in 400KV system

feeder local Circuit breaker panels.


Existing 400kV breakers which are very old are being replaced in

phased manner. Six nos of breakers have already been replaced

with proper indication lamps at local.

Pending

30 General 400KV &

230KV

Protection No MICOM relay is time synchronised with GPS system. New set of relays with GPS synchronisation is being purchased

to replace the old version MICOM P437 relays.

Pending

31 General - Equipment It was observed that standalone Event Recorder with automatic

downloading facility to centralized PC not provided.


Numerical relays provided have built in event records &DR.

Complied

32 General - Equipment It was observed that most of unused cutouts in Relay panels (both 400

kV & 230 kV) in control room were not covered.


All unused cutouts were covered.

Complied

70/70

Annexure-VI

Page 70 of 70

· transient nature; hence provision of auto-reclosure certainly helps not only in preventing...

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