southern regional power committee (srpc) bangalore

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Southern Regional Power Committee (SRPC) Bangalore

Minutes of the 75th Meeting of the Operation Coordination Sub-Committee (OCC) of SRPC held at Thiruvananthapuram, Kerala on

13th September, 2012

1. Introduction

1.1 The 75th meeting of the Operation Coordination Sub-Committee was held at

Thiruvananthapuram, Kerala on 13th September, 2012. This meeting was hosted by

NTPC. The list of Participants is given at Annexure - I.

Shri B.R.Tatineni, AGM (OS), SRHQ, NTPC extended a warm welcome to Member

Secretary, SRPC, the Members of OCC forum and other participants to the Meeting.

He recalled that the 50th OCC had earlier been hosted by NTPC at Visakhapatnam.

He stated that it was a matter of pride for NTPC to host the 75th OCC in

Thiruvananthapuram, Kerala. Shri S. Chandramouli, AGM i/c (OS), NTPC also

welcomed the gathering and placed on record appreciation of SRPC Secretariat for

the initiatives taken in resolution of various issues. He also thanked KSEB, SRLDC

and SRPC for the efforts in scheduling RGCCPP, Kayamkulam plant. He also

thanked MS, SRPC for having given an opportunity to host the 75th OCC at

Thiruvananthapuram.

Shri S.R. Bhat, Member Secretary i/c, SRPC welcomed the Members & other

distinguished delegates of the OCC forum to the 75th OCC Meeting. He thanked Shri

S. Chandramouli, AGM i/c (OS), NTPC for having kindly consented for organizing

the OCC meeting at Thiruvananthapuram. He added that Mr. Chandramouli had

provided good leadership to the team of NTPC officers enabling excellent conduct of

the meeting. On behalf of OCC forum, on the eve of his superannuation from

NTPC, he wished Shri S. Chandramouli a happy and peaceful retired life. He also

appreciated the dedicated efforts of the NTPC officers in making arrangements for

smooth conduct of the Meeting.

Minutes of the 75th OCC Meeting of SRPC held at Thiruvananthapuram, Kerala on 13.09.2012

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MS i/c said that as the Members were already aware, the Enquiry Committee

headed by Chairperson, CEA which had gone into the disturbances in the NEW grid

on 30th and 31st July, 2012 had submitted the Report to MoP. A number of measures

to be adopted in the Regional Grids in a time-bound manner had been

recommended. He requested the constituents to implement the recommended

measures, within the time-frame and also submit details of implementation to the

OCC forum. He also said that a Meeting had been conducted in CEA, New Delhi to

discuss issues relating to delay in extension of start-up power after the grid

disturbance in NEW grid. He also said that issues relating to ICT opening as part of

physical Regulation measures had been brought to the OCC forum by Kerala and

Tamil Nadu. He further informed that issues relating to URS power, high and low

voltage, overdrawal at lower frequency, coal stock issues, mock drill exercise for

extending start up power to NTPC Ramagundam, and frequent blocking of

Bhadrawathi HVDC poles would be discussed in the meeting. He congratulated

KPTCL for commissioning of the 400 KV line from UPCL to 400 KV Hassan,

enabling evacuation from both the units of UPCL. Karnataka had also continued its

tradition of high degree of grid discipline, which too needed appreciation. TS I Expn

had achieved availability of 99 % during August 2012, which was commendable...

1.2 MS i/c requested Shri Anil Thomas, Executive Engineer to take up the Agenda for

discussion and accordingly the same was taken up.

2. Confirmation of the Minutes of the 74th Meeting of OCC of SRPC held on 13th August, 2012

The Minutes of the 74th OCC Meeting were confirmed with the following addition:

TN stated that on 31st July 2012, after the grid disturbance in NEW Grid due to which Talcher generation had been affected, relief through UF relays had been obtained only in Tamil Nadu and Karnataka systems.

………………………………………..

3. Major Issues

3.1 Frequent Tripping of HVDC Bhadravathi

The following had been noted in the earlier Meetings:

a) The issue was discussed from 64th to 74th OCC meetings, special meetings and also in the WRPC Meeting held on 18th May 2012.


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b) In the 69th OCC meeting, SRLDC had informed that they had sought high resolution data in respect of all the units of Ramagundam to analyze the hunting phenomenon when the power flow on HVDC Bhadrawathi is increased from 900 MW to 1000 MW.

c) In the 70th OCC meeting, SRLDC had informed that they were in receipt of data from NTPC. As inter-regional control area oscillations were involved, the data needed to be sent to other RLDCs for analysis. SRLDC further informed that it did not have the necessary expertise for analysis of this data. It had suggested that the System Study Sub Committee or Subject Experts could decode and interpret the data for further progress.

d) In the 73rd OCC meeting, MS i/c had informed that the related issue had been discussed in the 20th WRPC meeting held on 18th May 2012. It had been decided in the WRPC meeting that WRLDC shall share the data of oscillations observed by them with MSETCL and POWERGRID and actions of the controllers at that time shall also be studied before deciding further course of action. MSETCL had assured that whatever appropriate action required on the HVDC Chandrapur – Padghe shall be taken. It would therefore be prudent to await the outcome of the above mentioned studies.

e) In the 74th meeting it was noted that the outcome of the studies of oscillation data by WRLDC was awaited. It was also noted that SRLDC had addressed a letter dated 07th August 2012 to WRTS, POWERGRID bringing to attention the frequent blocking of HVDC Bhadravathi poles.

f) It was also noted that General Manager (O&M), WRTS -I vide letter dated 10th August 2012 had requested GM, SRLDC/WRLDC to schedule the power transfer through HVDC Bhadravathi below 800 MW. Analyzing the power transfer through HVDC Bhadravathi Link(from West to South) during the New Grid Disturbances which had occurred on 30th and 31st July, it was opined that HVDC link could provide good relief during emergency if enough power margin was left to meet emergency requirement. It was pointed out that when SR frequency had dipped to 48.82 Hz, the frequency controller of HVDC Bhadravathi had acted and enhanced the power transfer from 830 MW to 1097 MW. (West to South).

g) In the Meeting, it was noted that SRLDC vide letter dated 28th August 2012 had stressed the requirement for oscillation damping features in all the HVDC installations to be kept in service.

3.2 SPS for 400 KV Hiriyur – Nelamangala D/C Line The proposal for SPS on 400 kV Hiriyur- Nelamangala and also the progress of

implementation were discussed in detail in the various forums of SRPC.

a) In the 69th OCC meeting, Karnataka had informed that the second unit of BTPS was likely to come up by 2nd or 3rd week of March-2012. SRLDC reiterated that without SPS in place for the 400 KV Hiriyur – Nelamangala line, the COD of the new unit would not be possible. SRLDC had said that all new generating units must be with RGMO features. It was suggested by the forum that a check list of the requirements could be prepared by SRLDC and circulated to the Generators.


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b) It had been noted in the 72nd OCC meeting that the SPS scheme was under active implementation by KPTCL. It was informed that the remaining pending works would be completed in about one month time. The SPS will be implemented soon after the commissioning of 400 KV BTPS – Hiriyur line.

c) In the 74th meeting, KPTCL was requested to complete the pending works at an early date, so that the SPS could be made operational. KPTCL had informed that the SPS Schemes in their system would be made operational by 15th of August 2012.

d) It was noted that in the First Meeting of the Core Committee which had been held on 31.08.2012, KPTCL had informed that the SPS works had been completed on 23.07.2012

3.3 SPS for 400 KV Vijayawada – Nellore Line Issues relating to the requirement of SPS for 400 KV Vijayawada-Nellore DC

lines and also immediate implementation of the same were deliberated in

earlier OCC meetings, PCC meetings and Special Meetings.

a) After discussions in 69th OCC Meeting, it was resolved that the SPS scheme on 400 KV Vijayawada – Nellore lines would be implemented by 15th April 2012.

b) In the 71st OCC meeting, APTRANSCO informed that due to less gas availability the generation had reduced considerably. OCC however noted that the flow on the 400 KV Vijayawada- Nellore line continued to be high. One unit of SEPL had already been declared on COD. COD of Unit 2 of Simhadri II was also expected in the coming months. It was noted that the commissioning of 400 KV Vijayawada – Malkaram line of AP as well as Narsraopet 400 KV S/S had been getting delayed, thus adding to the congestion on the Vijayawada – Nellore corridor. After deliberations, it was decided to discuss the matter further in the forthcoming TCC/SRPC meetings, wherein this issue figures as an Agenda Item.

c) After discussions in the 19th SRPC meeting held on 1st June 2012 it had been decided that a Sub Group consisting of members from constituents would be formed to deliberate on the scheme and suggest any review, in the changed scenario. The deliberations of this Sub Group would be put up to Special TCC for consideration.

d) In the meeting conducted on 5th July 2012 it had been decided in that APTRANSCO would take up with IPPS for immediate implementation of the SPS scheme in the present form which would be an interim measure till identification of new generators and implementation of any modified scheme.

e) In the Special Meeting held on 18th July 2012 to discuss SPS for 400 KV Vijayawada- Nellore, it was agreed that the implementation would be taken up through persuasion of IPPs by SLDC / APTRANSCO.

f) In the Special TCC meeting held on 10-08-2012 in SRPC POWERGRID had informed that the SPS Scheme for 400 kV Vijayawada - Nellore line would be commissioned in the next three months.


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g) In the Meeting it was noted that POWERGRID vide letter dated 30th August 2012 had informed that administrative approval for the scheme had been obtained and tendering was under progress. The time period for implementation of the scheme would be around three months as earlier informed.

3.4 Physical, Cyber Security in power supply

3.4.1 The following was noted in the earlier Meetings:

a) In the 63rd OCC Meeting, it was noted that a meeting was taken by Member (GO&D), CEA on 9th August 2011 regarding Physical, Cyber Security in power supply. After detailed deliberations, it had been agreed that the activity of monitoring of Crisis Management Plan for countering the cyber-attacks and its implementation including the Mock Drills, audits etc. by all the Power Utilities on a regular basis would be monitored by the Regional Power Committees. In the OCC Meeting, it was decided that all the constituents including RLDC/SLDC would furnish the status of measures taken to counter the cyber-attacks in their system along with mock drills, audit etc.

b) In the 69th OCC meeting, MS i/c had informed that CEA had recently addressed letter dated 01st February 2012 stating that India Smart Grid Task Force (ISGTF) had requested to furnish the status in this regard. CEA had sought the action taken and the present status of preparation of Crisis Management Plan (CMP). Accordingly, the Constituents were requested to speed up the cyber security measures for their system.

c) It was noted that AP, TN, KSEB, KPCL and SRLDC had initiated certain cyber security measures and submitted the details to the forum.

d) In the 74th Meeting, KTPCL had been requested to expedite the efforts to fulfill the cyber security requirements

3.4.2 It was noted that the Enquiry Committee which had gone into the recent

disturbances in NEW grid in its report submitted to MoP had emphasized the

need for improved telecom infra-structure for cyber security. It was also stated

that for smooth operation of grid systems, it was absolutely important that all the

power generating and distributing stations are connected on a very reliable

telecom network. The recommendations suggested are given below:

i) A proper network may be built up preferably using MPLS (Multi-Protocol Label Switching) which is simple, cost effective and reliable. In remote places where connectivity is a problem, the stations can be use dedicated fibre cable from the nearest node.

ii) Since POWERGRID has its own fibre optic cables, practically covering all major nodes and power stations. A proper communication/IT network may be built using dedicated fibres to avoid any cyber-attack on the power system. CTUs and STUs had been requested to complete the process within a time frame of one year.


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3.5 Coal Stock Position and DC declaration of Talcher

3.5.1 Coal stock position published by CEA

It was noted that as per CEA norms, coal stock position is termed as critical (<

7 days) or super critical (< 4 days) of coal stock. Daily Coal stock position

report as on 12th September, 2012 as downloaded from CEA website is

furnished at Annexure - II. It was noted that the coal stock position in the

following Thermal Stations was less than that for 7 days generation:

STATE STATION DAYS(< 7) REASONS

AP Dr. N.Tata Rao 3 Less receipt - MCL Kothagudam 5 Coal Sup. for Ext U-1 yet

to be commenced. Rayalaseema 1 Less Receipt Ramagundam 6 Less Receipt - CCL Simhadri 2 Coal support for U-4 yet to

commence. KA Bellary 4 Less receipt. for U-2 TN Ennore 5 Less receipt. Orissa Talcher STPS 1 Less import

3.5.2 Coal stock position: Submission by constituents:

In the 75th OCC meeting the following was noted:

i) KPCL informed that to supplement the coal stock, agreement had been executed for supply of 15 Lakh MT of imported coal.

ii) TANTRANSCO informed that as per the FSA signed by TANGEDCO with MCL & ECL, 9.88 LT (per month) of indigenous coal had to be supplied to TANGEDCO during July 2012 to Sep 2012. Against this 9.34 LT and 7.67 LT of indigenous coal had been received at the load ports during July 2012 & August 2012 respectively. The present coal stock in the three load ports was 1.09 LT. ECL had supplied 82% of FSA quantity and MCL had supplied only 77 % of the FSA quantity due to heavy rain in Talcher mines during the period 12.08.2012 to 20.08.2012 and due to the receipt of oversized coal from Talcher mines (sidings 7 & 8) during August 2012. Overall 78 % of FSA quantity had been realized. All efforts were being taken for increasing the realization of indigenous coal from mines to TANGEDCO in the ensuing months. Purchase orders had been issued to M/s MMTC and M/s MSTC for supply of 14 and 7 LT of imported coal to Ennore port and Tuticorin port respectively for the period from April 2012 to September 2012. Against the above purchase orders, the receipt of imported coal (Apr 2012 to August 2012) from M/s. MSTC and M/S. MMTC are 7.14 LT and 5.85 LT respectively. Further a tender had been invited to procure 17.50 LT


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and 7.50 LT of imported coal for Ennore/Karaikal port and VOC port/Tuticorin respectively upto May 2013.

iii) SRLDC suggested that KPTCL may arrange Coal Stock Position reports from UPCL and Jindal also. KPTCL assured to take-up the matter with UPCL and Jindal for the needful action.

iii) OCC had expressed concern over NTPC not furnishing the requisite information in the format though all the generators of Southern Region were furnishing this information. OCC again requested NTPC to furnish the information in the format given below:

Coal Stock Position

Generating Company: Month: ...................

Name of the station

Statutory Requirement

Minimum coal stock in the month

Coal stock as on last day of the month Steps taken

to supple-ment stock

Time by which position likely to

improve In lakh T

In no. of days

In lakh T

In no. of days In lakh T In no. of

days

Signature: .......................

Designation: …………… Contact Tel. No:

iv) In the 74th Meeting SRPC had stated that generators needed to maintain coal stock position as per norms to avoid any loss of generation. OCC had expressed serious concern over the low coal stock being maintained by the generating units. It was felt that higher forum needed to be again apprised of the situation to identify appropriate remedial action. In the Meeting, during discussions about the DC declaration of Talcher St II, issues regarding coal quality and supply problem had come into focus. NTPC had reiterated that since it was unable to predict the coal quality in advance, it was not possible to predict the exact DC. OCC Forum had requested CEA to use its good offices and please take up coal supply related issues since it was affecting ISGS generation. Mr. Ghansyam Prasad, Director, OPM, CEA, had suggested that utilities could address their constraints in this regard to CEA/Ministry of Power for better appreciation and solution of the issues. SRLDC had stated that Talcher St II must maintain the generation as per the schedule. Reduction of the Talcher II generation was causing over loading of Talcher – Rourkela lines in ER. Hence NEW Grid frequency notwithstanding, Talcher II should adhere to the schedule, since line loading issues were also involved. Hence already approved STOA transactions may get curtailed, thus affecting the power availability in SR which was already facing a crisis due to weak monsoon.

v) In the Meeting KSEB informed that during July 2012, the actual energy scheduled from CGS was less than the anticipated generation by about 26.5 %. In certain cases, the transmission corridor which was released due to mismatch of original DC and actual schedule could not be utilized to import power from other regions. Non availability from CGS affects the State with heavy unscheduled load shedding and in event of


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unforeseen outages, the situation gets aggravated with reduction in ATC due to transmission constrain in ER.

vi) MS, SRPC informed the Members that the issue regarding less availability and poor quality of coal had been raised in the Inter Ministerial subgroup meeting under the agies of JS(LA), Ministry of Coal on 29th August 2012. JS (LA), Ministry of Coal had agreed to discuss the issue with SR Constituents in the next subcommittee meeting scheduled on 12th September 2012. However this meeting had been postponed. OCC would be kept informed of the developments in this regard.

3.6 Facilitation of Inter-State/Inter-Regional transfer of power & utilization of IPPs Operation of Talcher – Kolar HVDC Link

3.6.1 The following had been noted in the earlier Meetings:

a) The constituents were being requested to furnish details of any requirement/surplus (quantum, period, time of day, tentative rates, etc.) along with details of contact person to enable SRPC to post this information on its website, to enable faster buyer/seller interaction.

b) In the 69th OCC meeting, Constituents had desired that extended-mode (i.e. 10 hours @ 2500 MW) of HVDC Talcher – Kolar link may additionally cover time required for ramping up and ramping down also. PGCIL had expressed its inability in this regard and stated that the outer limit for extended mode operation was 10 hrs. which included ramping up and ramping down time also. SRLDC had informed that due to this requirement for ramping up and down, certain other transactions may get curtailed for few time blocks during the extended mode of HVDC Talcher-Kolar link. SRLDC had also said that that extended mode operation of 2500 MW for 10 hours on a daily basis was recently committed by POWERGRID before Hon’ble CERC without any time limits. After discussions, it had been agreed that this issue would be put up for deliberations in the ensuing TCC/SRPC Meetings.

c) This issue had been deliberated in the TCC and SRPC meetings held on 31st May and 1st June 2012 respectively. After discussions, the SRPC Committee had approved the Recommendations as follows.

i) Operation of Talcher - Kolar HVDC link from 1300 Hrs to 1700 Hrs would be at a level of 1800 MW upto 31st July 2012.

ii) For all other time slots already agreed, the existing level of operation would continue.

iii) Monthly OCC would review the quantum for succeeding month of operation. First review would be in July 2012 OCC for the month of August 2012.

d) In the Special TCC Meeting held on 25th July 2012, it had been agreed by POWERGRID that due to improvement in the ambient temperature in Talcher, the link could be operated at the level of 2000 MW with immediate effect. However operation at 2000/2500 MW was also subject to temperature and other limiting factors in real time operation.


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3.6.2 Bilateral energy exchanges

a) On a review of the bilateral exchanges made by the constituents and also by the embedded IPPs during August -2012, the following was noted:

i) Imports (inter-regional) were carried out by: Andhra Pradesh, Karnataka, Kerala, TN, and Karnataka & Tamil Nadu IPPs

ii) Imports (intra-regional) were carried out by: Andhra Pradesh, Kerala, Tamil Nadu IPPs & Andhra Pradesh IPPs.

iii) Exports (inter-regional: NIL

iv) Exports (intra-regional) were carried out by Andhra Pradesh, Karnataka IPPs, Lanco & Simhapuri.

b) Details of Energy interchanges between the constituent systems and exchanges with the other regions are given at Annexure – III (as per PSP).

c) It was also noted that Andhra Pradesh, Karnataka, Kerala & Tamil Nadu had furnished the relevant details regarding energy exchanges through Power Exchanges (Annexure - IV).

3.7 Generation Schemes scheduled for 2012 -13 a) Progress of generation schemes scheduled to be commissioned during

2012-13 was reviewed. The updated information as furnished by the constituents is given at Annexure - V.

b) SRLDC presented the list of important generating schemes, transmission lines and generation evacuation lines under construction (Annexure - VI).

c) SRLDC again requested the constituents to furnish updated information in respect of these important elements/stations in the OCC Meeting. They said that this matter was being discussed in the OCC Meetings so that the states could identify and monitor all lines (i.e. ATS – Associated Transmission System) which are to be necessarily available during unit commissioning to avoid evacuation bottlenecks at a later stage.

d) In the meeting it was informed that the 400 KV VTPS -Malkaram line was likely to be ready by October 2012.

3.8 Pump mode operation of Kadamparai and Srisailam It was noted that Kadamparai machines had consumed about 67.103 MU in pump

mode during August-2012. SRLDC suggested that the possibility of running for two to

three blocks of Kadamparai and Srisailam machines in pump mode needed to be explored.

3.9 Minimum to Maximum demand ratio 3.9.1 The following was noted in the earlier Meetings:

a) It was requested that the constituents initiate all possible measures to ensure appropriate Demand Side Management and Energy Efficiency Programmes considering that there were sizeable energy and demand


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shortages in the States with capacity addition generally not matching with demand growth in addition to also limitations in possible import of power. The constituents were requested to come out with specific details of proposed new approaches to Demand Side Management so that these recommendations could be put up to TCC/SRPC. KPTCL had informed that ESCOMS had shifted a portion of the load from peak hours to off peak hours.

b) It was noted that Members were aware that the matter regarding wide variation between maximum demand and minimum demand was being regularly taken up with the constituents in the OCC Meetings.

3.9.2 The details of percentage variation between maximum and minimum demand for

the month of August - 2012 are given below:

State Maximum to Minimum Demand Variation % Highest Lowest Average

Andhra Pradesh 31.56 24th (Fri)

8.75 7th (Tue) 13.62

Karnataka 34.19 13th (Mon)

18.19 22nd h (Wed) 24.95

Kerala 48.78 31th (Fri)

36.66 5th (Sun) 41.91

Tamil Nadu 30.10 23rd (Thursday)

12.21 7th (Tue) 18.80

Puducherry 34.01 29th (Wed)

12.31 5th (Sun) 22.72

Southern Region 21.03 24th (Fri)

8.68 22nd(Wed) 13.98

Note: Highest and lowest have been computed from daily values over the month.

3.10 LGBR forecasted figures vs. Actual Figures

It was noted that variations between actual and forecasted availability and

requirement LGBR figures were more than 10% in respect of the following States

during the month of August 2012: Forecasted Actual Deviation

from Actual %

Variation Reason

a b c=b-a d=c/a Karnataka Demand Availability (MW) 6,976 7,689 713 10

Purchases. Demand Requirement (MW) 7710 8950 1240 16

Due to delay in onset of rains. Energy Availability(MU) 5149 4506 -643 -12

Kerala Energy Availability (MU) 1,345 1,675 330 25 Higher hydro utilization

and purchases Demand Availability (MW) 2,547 3,235 688 27 Purchases

Tamil Nadu

Energy Availability (MU) 6006 6763 757 13 Increased use of Hydro sources and power purchases.

Demand Availability (MW) 8958 10,566 1608 18


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3.11 MoP Gross generation: Targets vs. Actual Details showing more than 10% shortfall in gross generation with respect to MoP

target figures for the month of August - 2012 are tabulated below:

August-

2012 (%)

Cumulative (%)

Reasons for shortfall (>10% in MU) in gross generation

Andhra Pradesh

Hydro -85 -69 Decreased inflow into reservoirs.

Private sector -34 -17 Less gas availability

Karnataka

Hydro -32 -24 Decreased inflow into reservoirs.

Diesel -34 -41 LSHS shortage; Merit order constraints.

Private sector -41 -15

Kerala

Hydro -34 -16

Kayamkulam -13 Merit order considerations.

Tamil Nadu

Hydro -68 -44 Decreased inflow into reservoirs

Gas -42 -31 Outage of units

ISGS Talcher STPS II NTPC -10 Coal Shortage

MAPS, Kalpakkam -23 -11

KGS -15

3.12 Forced outages of thermal units

3.12.1 The following was noted in the earlier meetings:

a) MS I/c, SRPC said that, the Generators were always apprised of the concerns raised by the SR constituents, CEA, MoP etc. over the high quantum of forced outages.

b) OCC recommended that the planned/preventive maintenance be carried out as per the schedule to reduce the instances of forced outages.

3.12.2 OCC was apprised of the forced thermal outages of more than 24 hours duration

during the month of August-2012 (Annexure - VII). It was noted that the forced

outages of thermal units had varied between 3.32 – 6.90 % during the month of

August -2012.

3.13 Prolonged outages

3.13.1 MS i/c, SRPC pointed out that Hon’ble Commission was monitoring the

instances of prolonged outages and hence requested the constituents to furnish

the required information regularly to SRPC/SRLDC for further needful.


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3.13.2 In the 75th OCC meeting, the following was noted:

i) ETPS Units 3, 4 and 5 were under forced outage. EE/TNEB informed that it is due to aging of units.

ii) Valathur Unit Stage II which was out from 30.06.2012 to 07.08.2012 due to failure of Electronic Control unit for its Inlet guide vane was recommissioned on 08.08.2012.

iii) Valathur Unit Stage I which was out from 26.06.2012 due to turbine blade damages was expected by 15.09.2012.

iv) Thirunelveli- Kudankulam lines 1, 2 & 3 were out from 23rd Aug 2012, 29th June 2012and 15th Aug 2012 respectively.

v) 400 kV Kaiga - Guttur line which was out from 23rd July 2012 had been charged on 30th August 2012.

3.13.3 OCC was apprised of the prolonged outages in Southern Region during the

month of August -2012 (Annexure - VIII).

3.14 Generation levels at NPCIL Units

It was noted that this issue was deliberated in the earlier SRPC meetings wherein

NPCIL had informed that the generation level of SR NPCIL Units would be

maintained at around 65 - 70% due to fuel constraints. In the 19th SRPC meeting

held on 1st June 2012, NPCIL had informed that they could maintain a generation

level of around 70-75 % depending on fuel availability.

3.15 IPP Utilization OCC was also apprised of the PLFs of the IPPs operating in Southern Region

during the month of August-2012 (Annexure - IX).

3.16 Generation targets for the year 2012 - 13 3.16.1 Ministry of Power had approved Annual Generation Targets for the year 2012-

13. All the constituents had been requested to make all efforts to achieve the

targets as set for their organizations. The details had already been circulated in

this regard.

3.16.2 Electricity Generation Review during the period April to June 2012. a) CEA has been monitoring the performance of all generating stations in

the country with a view to improve the availability of power in the country. During the Periodic Review undertaken in CEA, it had been observed that the following thermal stations of SR had not performed as per the target fixed for them during the period April to June 2012.

Neyveli TPS I (NLC)

Kothagudem TPS & RayalseemaTPS (Andhra Pradesh)

Ennore TPS & Mettur TPS (Tamil Nadu).


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The letters received from CEA in this regard are enclosed at (Annexure - X).

b) It was requested the concerned may examine the matter and furnish specific reasons which had caused shortfall in generation to OPM Division CEA. It was also requested that strategy/action plan decided to increase generation so that the loss of generation suffered during the period April to June 2012 be made up during the remaining period of the year 2012-13.

c) NLC TS I had submitted the details and the same is at Annexure – XI.

MS i/c, SRPC requested APTRANSCO and TNEB to look into this matter and

revert back at the earliest. TN said that aging of Ennore units was one reason

for the decreased generation.

.4. Low Frequency Grid Operation

4.1 Low frequency operation in the last month MS i/c, SRPC said that the frequency of operation of the Southern Regional Grid

had been less than 49.5 Hz for about 3.17 % of the time during August -2012.

Mutual support/cooperation was the need of the hour to operate the grid in a safe

and secure manner. He said that concerted efforts were required by the constituents

to operate the grid within IEGC parameters. SRLDC also stressed on proper

management of load generation balance in real time. They highlighted the remedial

measures to be pursued for low frequency. They suggested that harnessing all

unutilized generation within the region such as Kayamkulam, BSES, BDPP,

GMRBRG, KDPP, Kuttalam and Valathur stage I & II.

Grid Code violation messages 4.1.1 Details of caution/violation Type A, B & C messages issued by SRLDC to the

constituents during the month of August -2012 are given at Annexure - XII.

4.1.2 SRLDC said that 12% violation messages pertaining to Over Drawal / Under

Injection while the frequency was below 49.7 Hz over a time block were on the

higher side as given below: Number of 12% violation messages

Regional Entity August-2012 September-2012 (Up to 10th)

Andhra Pradesh 398 66

Karnataka 7 0

Kerala 197 37


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Tamil Nadu 239 39

Puducherry 6 2

LANCO 8 16

Simhapuri 156 59

Total 1011 219

SRLDC added that the States needed to put more efforts to curtail the instances

of overdrawals. As informed in earlier meetings, the details in this regard were

being regularly communicated to Hon’ble CERC. Further there should be strict

compliance action for SRLDC messages (Type – A, B, C) and reporting the

details of compliance through a reply message

4.1.3 In the 74th meeting, SRLDC had presented the revised methodology for the

issuance of violation messages which would be in force from 16-08-2012 as

agreed in the Special TCC Meeting On a query from TN regarding certain

inconsistency in the issuance of message, SRLDC clarified that there was no such

inconsistency. It had been decided that any such specific instance have to be

brought to the attention of SRLDC in advance, enabling them to clarify the same.

4.2 Measures by constituents to improve the frequency

4.2.1 APTRANSCO informed that even with purchases and resource management,

the State had to face demand & energy shortages. Load shedding upto 4880

MW amounting to about 1648 MU had been carried out during August-2012.

Details of Load relief imposed during the month of August-2012 are given at Annexure - XIII. It was appreciated by the forum that AP had not been issued

any Type C Message during August 2012 despite the severe load management

measures implemented by them. AP also informed that there was no immediate

proposal to utilize RLNG to enhance the generation levels affected due to gas

shortage.

4.2.2 KPTCL informed that load shedding in the State upto 2700 MW amounting to

about 824 MU for the month had been carried out. Strict grid discipline was

maintained during August -2012. CE (LD), KPTCL also placed on record the

appreciation of the generators who had maintained generation levels despite

various issues with coal supply etc. Efforts were also on to conserve the hydro

storage in the reservoirs for the ensuing summer demand.


15

4.2.3 KSEB informed that with purchases they were able to maintain load generation

balance in their system. Need based load shedding up to 500 MW amounting to

about 19 MU had been carried out during August-2012. Measures taken by

KSEB to maintain grid discipline include cyclic load restrictions and switching off

of identified radial feeders as directed by SRLDC.

4.2.4 TANTRANSCO said that load shedding up to 3815 MW amounting to about

1011 MU was carried out during the month. They briefed about the load

restriction measures in their system for August-2012 which is given below:

40% in respect of HT Industrial and Commercial consumers

1 hour Load Shedding for Chennai (between 0800 to 1800 hrs.)

3 hour Load Shedding for urban and rural Areas (between 0600 to 1800 hrs.)

Agriculture was being fed 6 hours of three phase supply in day time and 3 hours of three phase supply in night time.

4.2.5 In the Special TCC meeting held on 25.07.2012, SRLDC had informed that

contingency arrangements by Tamil Nadu were highly necessary to address

wind generation variations. Since UFR relay operation for wind generation

fluctuations were not desirable SRLDC had suggested that TN may implement

automatic load reduction measures to care about the wind generation

fluctuation. In the Special TCC meeting held on 10.08.2012, it had been

informed by TANTRANSCO that the variability issue had been addressed to a

great extent. It had been suggested to TN that they may approach Hon’ble

CERC to apprise them of the progress. In the meeting, SRLDC stated that

Status review of Contingency arrangements by TN to address wind variations

4.2.6 It was noted that SRLDC had addressed a letter dated 31st July 2012 to the

utilities bringing to attention the contents of MOP letter dated 30th July 2012 and

again stressing the need to maintain grid discipline.

4.3 Arranging of interruptible loads in four groups

4.3.1 In the earlier OCC meetings, it was noted that as per IEGC, to maintain the

frequency within stipulated band and also to ensure network security, the

interruptible loads were to be arranged in four groups of loads. This was for the

purpose of scheduled power cuts/load shedding, loads for unscheduled load

shedding, loads to be shed through UF relays, df/dt relays and loads to be shed


16

under any SPS Scheme. These loads were to be grouped in such a manner

that there was no overlapping between different groups of loads.

4.3.2 It was noted that Andhra Pradesh, Kerala, Tamil Nadu & Puducherry had

completed this exercise. It was informed by KPTCL that they had already

implemented the grouping of loads as per IEGC provisions.

4.3.3 SRLDC stated that Demand side Management as per the Grouping of Loads

details furnished by SR constituents should be effected. Automatic disconnection

of identified loads through PLC logic scheme needs to be implemented by all the

Constituents. Also, the effectiveness of Demand Side Management needs to be

monitored.

4.4 Automatic Demand Management Schemes

4.4.1 Automatic Demand Management Scheme in line with clause 5.4.2 (d) of the

IEGC was to be provided by all the constituents by 01.01.2011.

4.4.2 It was noted that Andhra Pradesh, Kerala, Tamil Nadu and Puducherry had

implemented the scheme.

4.4.3 KPTCL informed that all ESCOMS had taken following measures for

implementation of Automatic Demand Management scheme.

i) Provided rostering of 11 kV rural feeders & it will be operated during peak hours for controlling the agricultural demand.

ii) Replacing conventional incandescent bulbs by CFL bulbs provided by BESCOM at concessional rates to consumers and it is in vague.

iii) As per directives of KERC, ESCOMs are implementing the scheme of providing TOD meters to EHT & HT consumers and differential tariffs are imposed to control the demand during the peak hours. At present CESC & MESCOM have already implemented.

iv) All the distribution companies are implementing the NIRANTRA JYOTHI Scheme for bifurcating the agricultural loads of 11 kV rural feeders.

4.4.4 It was suggested that constituents could identify other Demand Management

Schemes other than Automatic Load Shedding Schemes.

4.4.5 SRLDC informed that the scheme had been not effective fully to take care of fall

in frequency.


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4.5 Automatic Load Disconnection Schemes for overdrawing constituents

4.5.1 It was noted that SRPC in its 14th meeting held on 27th August 2010 had agreed

to implement Automatic Load Disconnection Scheme for overdrawing

constituents with the following relief:

Sl.No. Constituents Load Relief 1 APTRANSCO 450 MW 2 KPTCL 350 MW 3 KSEB 125 MW 4 TNEB 650 MW 5 Puducherry 25 MW

4.5.2 APTRANSCO, KSEB, TNEB and Puducherry had implemented the scheme.

4.5.3 KPTCL informed in the Meeting that 350 MW of load relief through remote

tripping of loads during crisis period has been implemented and is

operationalized from SLDC. Letter in this regard was being addressed to

Secretary, CERC.

4.5.4 It was noted that the Automatic Load Disconnection Scheme was part of

Automatic Demand Management Scheme which had been discussed above.

4.6 On Line Demand Estimation

In the earlier OCC meetings, it was noted that all the states were furnishing the

15 Minute requirements. The constituents were apprised that the forecasting

tool should take into account weather inputs as well.

5. Grid Operation

Different aspects of grid operation were reviewed and the following grid events were

noted. Grid operation data for August -2012 is enclosed as Appendix - A. 5.1 Grid events

5.1.1 Frequency profile during August - 2012: a) Frequency remained within IEGC range (49.5 - 50.2 Hz):

i) During August-2012: 95.57% of time

ii) Previous month (July-2012): 92.19% of time

iii) Same month last year (August -2011): 96.24% of time

b) Frequency remained below 49.5 Hz for 3.17% of time c) Frequency remained above 50.2 Hz for 1.27% of time

d) Average frequency was 49.75 Hz.


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5.1.2 Activities: a) SRLDC successfully completed Black Start Restoration Procedure

workshops during August and September 2012 with cooperation of the utilities.

b) UPCIL Unit 2 (600 MW) declared commercial operation on 19.08.2012.

c) 400 kV UPCIL-Hassan Circuit I & II were synchronized.

d) 400 kV Gooty- Somanahalli S/C made through on 08.08.2012.

e) 400 kV Udumalpet-Trichur Ckt-I made LILO at Palakkad.

f) Bus Reactor at Kurnool was synchronized on 21.08.2012.

g) NPCIL – KKNPP migrated from UI mechanism of PGCIL to HT consumer of TANGEDCO LTD for drawing commissioning power for KKNPP from 09.08.2012.

5.2 Generation capacity added The following were the additions to Installed Capacity to SR Grid during the month:

State Sector Type Station Capacity (MW)

Date of commissioning

Tamil Nadu Private Wind Mill Wind Mill 27.5 August 2012

Karnataka Private Coal UPCL 600 COD on 19.08.2012

5.3 Transmission lines added during August 2012

State Line Name Voltage (kV)

Length in ckt

kM Date

AP 220 kV DC line from Thimmapuram to Kondapuram 220 19.21 13.08.2012

5.4 Substations added during August 2012 Following Sub-stations were commissioned during the month:

State Station Name MVA KV Ratio Date

AP 220/11 kV Gudemdoddi SS 220/11 01.08.2012

AP 220/11 kV Kondapuram SS 220/132 200 13.08.2012

Sub-stations augmented during the month:

State Station Name MVA KV Ratio Date

AP 220/132/33 kV at Brandix

(1x16+1x100+1x50) to (1x16+2x100+1x50)

220/132 01.08.2012


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5.5 Maximum demand met & Average daily consumption 5.5.1 The Table below furnishes the details of actual Maximum Demand met (MW) &

Average Energy Consumption per day (MU) in respect of the SR constituents

for August-2012 vis-à-vis August-2011. The maximum daily consumption by the

respective constituents during August -2012 is also included.

System

State

Actual Maximum Demand (MW)

Average Consumption/day (MU)

Max. Daily Consumption

during Aug 2012 (MU)

Aug 2012

Aug 2011

%-age variation

Aug 2012

Aug 2011

%-age variation

a b c=(a-b)/b d e f=(d-e)/e Andhra Pradesh 10319 11738 ‐12.09 218.38 238.71 ‐8.52 225.97

Karnataka 7849 7234 8.50 148.65 139.86 6.28 159.46

Kerala 3250 2898 12.14 53.42 48.90 9.26 58.12

Tamil Nadu 10751 10430 3.08 220.56 236.34 ‐6.68 249.13

Puducherry 300 310 ‐3.26 6.25 6.08 2.70 6.51

Southern Region 29695 30236 ‐1.79 647.26 669.90 ‐3.38 687.05

5.5.2 It could be seen from above that the Peak Demand of all the states in August-

2012 recorded percentage variation between -12 to 12% compared to Aug -

2011 figures. Southern Region as a whole had met a maximum demand of

29,695 MW in August-2012, which was 541 MW less than last year’s same

month figure of 30,236 MW. In respect of average daily energy consumption,

the constituents had registered a percentage variation between -9 and 9 %. The

average daily energy consumption of Southern Region was about 3% less than

during last year.

5.6 Load duration curve & Daily consumption patterns It was observed from the SR Load Duration Curve for August-2012 (Annexure -

XIV) that the maximum demand was less than that of July 2012 and about 70 % of

the time less than that of August 2011. State-wise daily consumption patterns were

also presented (Annexure – XV).

5.7 Hydel Availability 5.7.1 The energy availability in major hydel reservoirs at the end of August-2012 vis-à-

vis that for August-2011 was reviewed, which is given below:


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(Figures in MU)

System State

Energy at FRL Storage as on Inflows in August 2012

31.08.2012 31.8.2011 Anticipated Actual ANDHRA PRADESH

Jalaput 495 161.58 461 191 191 (828.17)* (836.37*) Srisailam 269.8* 0 1130 1367 195 (MDDL:243.8m) (242.19)* (269.29)* Nagarjunasagar 179.8* 13.56 699 (MDDL:149.3m)

(155.8)1* (172.03)*

KARNATAKA Linganamakki 4547 3099 3760 1632 2040 Supa 3152 1616 553 932 915 KERALA Idukki 2190 554 1729 463 290 Kakki 916 307 686 255 183 Total 4131 1446 3308 1232 894TAMIL NADU Nilgiris 1504 580 1142 406 313 Total (excluding Mettur)

2183 827 1593 742 428

* Level in meters

5.7.2 SRLDC stated that energy storage in the hydro reservoirs showed around 44%

deficit (5254 MU) as on 31st August-2012 compared to the same day last year

and about 32% (3140 MU) deficit in monthly (i.e. August) average compared to

last 10 years’ corresponding monthly average. They stressed on appropriate

R&C measures during the coming months on account of the poorer hydro

position resulting from inadequate monsoon.

5.7.3 It was requested to continue the optimum utilization of hydro, keeping in view the

energy storage position vis-à-vis management of demand/energy requirements

from the overall view of maintaining system parameters within IEGC limits and to

optimize the load generation balance.

5.8 System Frequency 5.8.1 The following was noted in the earlier Meetings:

a) The recommendations finalized in the 60th OCC are reproduced for implementation please:

Karnataka & Tamil Nadu to finish their changeover during 1730 – 1800 hrs with proper staggering (evenly spread over).


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Andhra Pradesh to finish their changeover during 1800-1830 hrs with proper staggering (evenly spread over).

Andhra Pradesh to decrease it’s under drawal during changeover period.

Improved coordination with Discoms required.

Each state to balance its load removal with matching generation reduction.

No loads should be taken out at frequency > 50.0 Hz.

Loads removal should preferably be frequency dependent rather than time dependent.

SLDCs may consider tripping of some of the feeders from their control room using SCADA.

States could plan automation of load changeover with reference to frequency.

All the units should participate in RGMO which would help moderate the impact of the changeover.

Proper training and awareness should be imparted to the officials handling the substations.

Generating stations including ISG stations should not inject excess power into the grid above 50.2 Hz.

It was noted that there were other frequency excursions during other changeovers and the recommendations needed to be implemented in respect of those periods also. All the constituents were requested to adhere to above recommendations to avoid excursion in frequency during changeover.

b) KPTCL had said that as informed earlier they had taken all precautionary measures by backing down hydro generation to the maximum possible extent without under drawing from CGS during high frequency conditions. They were monitoring the situation on a daily basis and the change over time had been staggered by 15-20 minutes either by postponing & proponing. However at times due to line loading issues, Karnataka was forced to under draw.

c) After detailed deliberations, AP had been requested to postpone the load changeover by 10 minutes from the existing schedule both during the morning and evening peak hours on 12th and 13th March 2012. Accordingly AP had shifted timing of load changeover on 13th March and submitted the data to SRLDC.

d) TN had been requested to do the load change over exercise by LDCs with a gap of five minutes amongst them on 20th and 21st April, 2012 and TNEB carried out the exercise and submitted the required information to SRLDC.


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e) The issue was discussed in 75th OCC meeting and it was decided that SRLDC would monitor frequency behavior during load change over and analyze any wide variation in UI to also understand whether the excursions were due to simultaneous load changeover in AP & TN.

5.8.2 Frequency within IEGC band: 49.5 – 50.2 Hz

a) It was noted that the SR frequency during the month of August-2012 was within IEGC range for about 95.57% of the time, as compared to 96.24% of IEGC range during August-2011.

b) OCC observed that grid operation below 49.5 Hz and above 50.2 Hz should have been avoided since it violated the provisions of IEGC and also caused threat to grid security. Operational control needed to be streamlined so that uneconomic operation of the grid above 50.2 Hz is avoided.

5.8.3 Frequency below 49.5 Hz: It was also noted that the frequency of grid operation was in the lower range of

IEGC and had operated below 49.5 Hz for 3.17 % of the time during the month

of August-2012. It was also noted that the frequency on certain days was less

than 49.5 Hz for more than 5% of the time duration as shown below:

Date (%) Percentage of time of frequency

Less than 48.5 Hz

48.5 Hz & < 49.0 Hz

49.0 Hz & < 49.2 Hz

Less than 49.5 Hz

14‐08‐2012 0 0 0 5.9 17‐08‐2012 0 0 0 6.39 20‐08‐2012 0 0 0 5.35 22‐08‐2012 0 0.21 0.21 13.41 23‐08‐2012 0 0 0 7.08 24‐08‐2012 0 0 0.07 9.45

5.8.4 Frequency above 50.0 Hz:

It was also noted that the Regional Grid had operated above 50.2 Hz for 0.87%

of the time, during the month. It was also noted that the frequency on some of

the days was more than 50.0 Hz for some 5% and above period of time as given

below:

Date % of time of frequency:

50.0 Hz & < 50.2 Hz

More than 50.2 Hz

04-08-2012 6.18 1.25 05-08-2012 14.72 1.32 06-08-2012 15.35 0.9 07-08-2012 7.01 0.69


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08-08-2012 5.76 0.21 09-08-2012 7.85 0.35 10-08-2012 15.42 2.64 11-08-2012 23.89 5.07 12-08-2012 13.68 3.75 13-08-2012 5.07 0 15-08-2012 5.35 0.83 16-08-2012 4.93 2.5 18-08-2012 8.89 1.81 19-08-2012 5.63 1.53 26-08-2012 13.68 2.43 27-08-2012 8.26 1.18 28-08-2012 9.1 2.29 29-08-2012 9.58 2.08 30-08-2012 18.75 3.82 31-08-2012 12.5 1.11

5.8.5 Frequency histogram & Frequency duration curve: SRLDC said that RGMO/ FGMO (characteristics of RGMO with manual

intervention) implementation in all the units would also help in easing the

situation. SRLDC also presented the Frequency Histogram & Frequency

Duration Curve (Annexure - XVI) for August-2012. They said that the regional

entities were being requested to furnish details to SRLDC to analyze and

ascertain effectiveness of RGMO/FGMO participation of individual major thermal

units in the region with respect to specific instances. Further there needed to be

planned and advance intimation for surrendering of ISGS to contain the high

frequency.

5.9 Under Frequency Relay

5.9.1 The following was noted in the earlier meetings:

a) It had been emphasized that the UFRs were meant for protection of the grid. As stressed earlier, set points should not be changed in any manner. It had also been stressed at higher levels that the UF Relays be made fully effective by all the utilities so as to give the designated relief at specified frequency levels.

b) Tripping details like name of the feeder, load affected, date and time of the tripping, frequency at the time of tripping and restoration time needed to be furnished to SRLDC/SRPC regularly and in a timely manner. Constituents agreed to furnish the details in a timely manner. It was also noted that the IEGC stipulates that SLDC shall furnish a monthly report of UFR & df/dt relay operation to the RPC.


24

c) MS i/c, SRPC had said that reasons for tripping at undesired settings needed to be examined. Corrective action such as calibration is required to be taken to avoid such incidents in future.

d) As discussed in the 70th OCC meeting, for the year 2012 -13, additional Load relief (303MW) was to be implemented by constituents through AUFR. APTRANSCO, KSEB and Puducherry had submitted the identified feeder wise details and quantum of load relief expected. The details as furnished by KSEB are at Annexure – XVII. Karnataka had stated that additional load relief envisaged was under implementation. KPTCL and TNEB were requested to furnish the feeders identified and quantum of relief expected at the earliest.

5.9.2 There was NIL UFR trippings during August -2012.

5.10 df/dt Protection System

5.10.1 There was NIL df/dt trippings during August -2012.

5.10.2 It was noted that an additional df/dt quantum (2000 MW) was to be implemented

by the constituents as reviewed and accepted in the Protection Sub Committee

meeting held in March 2012. Kerala and Puducherry had furnished the required

information about the implementation. KPTCL informed that additional load relief

as envisaged by SRPC was under implementation. APTRANSCO informed that

they had identified the feeders and sent to the concerned Sub Stations to

implement the same and after implementation they would revert back the Status. KPTCL and TNEB were requested to furnish the feeders identified and quantum

of relief expected at the earliest.

5.11 Inter-trip Scheme

5.11.1 HVDC Talcher – Kolar link

a) SRLDC had suggested modification of SPS for operation of HVDC Talcher-Kolar bipole at 2500 MW level and also for load relief during the instances of tripping of all units at Talcher Stage-II making zero flow in HVDC Talcher-Kolar bipole.

b) It was noted that in the PCC held on 18th July 2012, PGCIL informed that Trip signal III would be ready by August 2012...

c) There was nil inter- trip trippings reported in SR during August 2012.

d) Kerala had given the details of identified feeders for the additional load relief for Talcher-Kolar Signal III. They informed that implementation of the same is under progress. The details furnished by them are at Annexure - XVIII.

e) It was noted that a Meeting with POWERGRID had been held on 10th August 2012. After discussions, it had been decided to have an additional logic to cover instances as occurred on 31st July 12. It was


25

therefore decided that in case the fall in power level (dp/dt) exceeded 50 MW/sec and persisted for more than 1 sec, then signal 1or 2 would be sent based on initial Power Level of HVDC (or set point). It was also agreed that on account of limitations, the dp/dt signal would be generated externally. Based on the operational experience acquired, further changes, if any, could be contemplated at a later date.

f) It was later informed by POWERGRID that as discussed in Meeting on 10.08.12 in SRPC, they were to implement the new logic of DP/DT (Rate of Change of Power ) for SPS at Kolar HVDC Station for Tal-Kolar HVDC Power flow by using a transducer externally (without loading the existing PLC ). POWERGRID had tried to procure the same through various channels, but the same was not available in the market. Another alternative, the PMU was also checked for the feature of DP/DT but not available as of now. Hence POWERGRID had explored the possibility of using the present PLC used for the SPS. Accordingly, on 04.09.2012, outage of SPS scheme was availed for about 2 Hrs from 15:30 hrs for checking the PLC of Special Protection Scheme. The trip signals were isolated at the PLC to avoid any mal-operation. The PLC was taken out of service and the memory was checked. It is observed that the memory card capacity was not sufficient for adding any additional logic.

5.11.2 The tripping details as furnished by the constituents are at Annexure - XIX.

6. Anticipated Availability and Consumption for the months of September- 2012 & October- 2012 6.1 OCC noted the information regarding anticipated availability & requirement for the

months of September and October 2012 as furnished by the Constituents and the

same is furnished at Annexure - XX.

6.2 All the constituents agreed to initiate requisite measures to maintain appropriate

load generation balance in their systems, and adhere to the IEGC provisions.

6.3 Review of the availability during August-2012

The Table below gives the anticipated availability as furnished in the 73rd OCC

against the actual availability for the month of August -2012: (Figures in MU)

State Anticipated

availability as given in 74th OCC

Actual availability (ex-bus)

Deviation

a b c = b - a Andhra Pradesh 245.53 209.84 ‐35.69 Karnataka 146.13 145.42 ‐0.71 Kerala 47.00 53.24 6.24 Tamil Nadu 214.00 215.88 1.88


26

APTRANSCO informed that large variation in the actual and anticipated availability

was mainly due to depleted hydro position of their reservoirs.

6.4 It was noted that the average load shedding per day in the states were: Andhra

Pradesh – 53 MU, Karnataka - 27 MU, Kerala – 0.6 MU, Tamil Nadu – 33 MU and

Puducherry – 0.22 MU.

6.5 SRLDC stated that the loss of generation due to coal shortage/technical problems

was to be furnished by 10:00 hrs for onward transmission to NLDC.

7. Restricted Governor Mode of Operation (RGMO)

7.1 The following was noted in the earlier Meetings:

a) RGMO operation was highly critical during load changeover. As informed earlier, NLDC had been submitting the status report of RGMO in various regions to Hon’ble CERC on a monthly basis. He pointed out that as per CERC Order on Petition No.237/2010, the units were required to be put on FGMO, in case RGMO operation was not possible. Either RGMO or FGMO should be in place for all the units as mandated under IEGC. If under FGMO, with manual intervention the units should be operated for the desired characteristics of RGMO.

b) MS i/c, SRPC had said that maximum number of units needed to be put in RGMO in the interest of the security of the grid. For any constraints for implementation of RGMO on particular units, exemption from CERC could be obtained. SRLDC informed that NLC TS I Expansion Units are not in RGMO. SRLDC informed that declaration of RGMO compliance of Simhadri Stg.II Unit III, KTPP Unit-XI, Kakatiya Unit I were yet to be received.

c) SRLDC stated in all instances Idukki, Varahi, Nagjheri, Lower Sileru, Sharavathi, Kundah –I, II, III are responding for immediate increase and decrease. (Units already in FGMO) However there was inadequate response from thermal generating units. Mostly hydro generating units had responded (which is under FGMO)

7.2 SRLDC presented the RGMO Analysis Summary (details in Annexure - XXI).

8. Voltage Profile

8.1 High Voltage

8.1.1 It was noted by SRLDC that Nagarjunsagar (433 kV), Vijayawada (436 kV),

Hyderabad (437 kV), Hiriyur (434 kV), Vemagiri (432 kV), Srisailam (430 kV),

Gooty (434 kV) and Kurnool (435 kV) were facing high voltage situation. There

were 86 trippings due to over voltage of the 400 kV lines during the month. It

was noted that Jeypore - Gazuwaka I, Vijayawada-Vemagiri I & II, Talaguppa-


27

Nelamangala, Srisailam- Mamidippally I & II lines, Tirunelveli-Kudankulam I,

Vemagiri-Simhadri I and VTPS IV – Srisailam II lines were kept open for more

than 3 days due to over voltages.

8.1.2 In the meeting, SRLDC presented the high voltage graph for the nodes at Gooty,

Hyderabad, Kurnool, Nagarjunsagar, Salem, Vijayawada, for August - 2012

when high voltage conditions had prevailed (Annexure - XXII).

8.1.3 SRLDC had earlier stated that simultaneous critically High Voltages at some

locations and low voltages at some locations of the grid posed the threat of

power swing. They had added that for containing High voltages all other

measures needed to be resorted and then only lines would be opened if

required. Chief Engineer, KPTCL had brought to attention the high voltage

situation prevailing at Kaiga and added that remedial action needed to be taken.

8.1.4 Deputy General Manager (OS & S) via letter dated 05.09.2012 (Annexure -

XXIII) had informed that bus voltages at most of the sub stations in SR I were

more than 425 kV throughout the day. It was also observed that the voltages

were more than 430 kV during night times. It was also brought to the notice that

many feeders were either being taken out for voltage regulation or tripping on

operation of over voltage protection. Temporary and permanent measures to

avoid over voltage situation at the above sub stations were sought for the safety

and security of the grid.

8.1.5 TNEB stated that 400 KV Almathy-Nellore line 1 had tripped on 16th and 17th of

August 2012 on account of over voltage and desired to know the reasons. There

was another tripping of this line on 22nd August 2012.

8.1.6 SRLDC said that the possibility of synchronous condenser mode of operation of

the generators should be explored. (Yelahanka, Kadra and Kodasalli)

APTRANSCO informed that Nagarjunsagar and Srisailam Left Bank Units were

operating in synchronous condenser mode as and when system warranted.

KPCL informed that they had taken up the issue with OEM as suggested by

SRLDC and M/s Man Diesel & Turbo France SAS, France the OEM, had

informed that the operation of the units in synchronous condenser mode was not

possible. Bus/Line Reactors to be commissioned.


28

8.1.7 SRLDC said that the GT tap position of all the GTs in Vemagiri Comlex,

Simhadri, VTS etc., shall be put in the Tap Position corresponding to 400kV level

so that the MVAR absorption could be at maximum permissible level during High

Voltage conditions.

8.1.8 The updated information on schedule of commissioning of reactors as originally

agreed in the Standing Committee on Power System Planning of Southern

Region is furnished at Annexure - XXIV. KPTCL had informed that work of

design, supply, erection and commissioning of new 63 MVAR bus reactors at

Guttur, Talguppa, Nelamangala and Hoody had been awarded to M/s BHEL on

turnkey basis and works were under progress. APTRANSCO informed that

Kurnool bus reactor (63 MVAR) was commissioned 0n 08.08.2012.

8.1.9 After discussions it was agreed that the matter needed to be placed before the

Standing Committee on Power System planning so that term measures could be

arrived at.

8.2 Re-commissioning of Reactor at Guttur/other Reactors

The issue regarding 50 MVAR line reactors on 400 kV Guttur-Birenahalli – I at

Guttur S/S and 400 kV Nelamangala-Hiriyur – II at Nelamangala was discussed in

the TCC meeting held on 29th April 2011 and number of OCC Meetings. KPTCL

had been requested to take up this issue with Standing Committee on Power

System Planning. Subsequently, CEE (LD), KPTCL had taken up the issue with

CEE (P&C), KPTCL vide letter dated 13th June 2011. CEE (LD), KPTCL informed

that reply dated 23rd July 2011had been received from CEE (P&C), KPTCL. In view

of the contents of the letter, the issue could be further deliberated at TCC level. In

earlier forums it had been pointed out to KPTCL to take up the issue with Standing

Committee.

8.3 Low voltage 8.3.1 In the meeting it was expressed that the utilities could examine provision of

under voltage relays as mandated in IEGC Regulations to control low voltages

at the 400 kV nodes. SRLDC informed that many 400 kV nodes touched very

low voltages such as at Thiruvananthapuram (372 kV), Trichur (374 kV),

Chennai (380 kV), Kalivanthapattu (377 kV), Alamathy (370 kV), & Trichy 372

kV.


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8.3.2 SRLDC informed that despite injection of MEPL & SEPL, the ATC could not be

enhanced due to low voltage profile downstream. In case the situation

continued, SRLDC may be constrained to reduce the ATC of S1 – S2 to

safeguard system security. They added that ensuring adequate Capacitor

Banks at LT side and also introduction of under voltage relays were essential for

ensuring system security. SRLDC stated that necessary action was therefore

highly essential to improve the voltage parameters in the above nodes. It had

been reiterated by TANTRANSCO that it was reviewing the low voltage position

continuously and taking all long term and short term measures to restrict the

MVAR drawal from the Grid. MS, SRPC informed that in a special Study

meeting held on 10th September 2012 it was noted that additional 160 MVAR

compensation was needed to be provided by TANTRANSCO near Chennai

area.

8.3.4 In the Meeting, KPTCL informed that they had commissioned 400 kV lines (I &

II) from Udupi to Shanthigram (Hassan) for evacuation of UPCL power. One line

had been commissioned on 4th September 2012 and the other one on 24th

August 2012.Both the lines were successfully evacuating Udupi power

continuously to an extent of about 1000 MW to 1150 MW for a period of 3 to 4

days. After commissioning of these lines, the low voltage situation at Mysore

and Bangalore had been eliminated and also system stability & reliability had

improved in the state. CEE Transmission zones had instructed concerned

Executive Engineers of TL and SS division under their jurisdiction to maintain all

capacitors in healthy condition and connected to the grid positively during

system low voltage conditions.

8.3.5 With respect to low voltage at Thiruvananthapuram, EE, SRPC informed that

clarifications were required regarding Thiruvananthapuram, 400 KV bus

voltages. KSEB had informed that voltage in their 220 KV system had not gone

down to the levels as stated. MS, SRPC requested POWERGRID to validate the

data and revert back at the earliest.

8.3.6 SRLDC stated that the constituents shall install Under Voltage relays at the

identified locations so that in the eventuality of critical low voltage situation could

be avoided.


30

8.4 Absorption / Injection of VARs by Generators

8.4.1 Hon’ble CERC Order dated 23.12.2009 merited attention in this regard. It was

stated in the Order that all agencies need to provide required reactive

compensation avoiding the need for exchange of reactive power to/from ISTS

and maintain ISTS voltage within specific range.

8.4.2 In the meeting, efforts of APTRANSCO in changing the Tap position of VTPS Unit

7 from 4 to 5 as suggested by SRLDC were appreciated. APTRANSCO informed

that subsequently the MVAR absorption of the unit had also increased.

8.4.3 SRLDC had addressed letter dated 25th July 2012 to APTRANSCO bringing to

attention the over voltage in Vemagiri area. Due to low gas availability the

generation in the complex was low, further adding to the problem of high voltage.

APTRANSCO was requested to urge the generators to adopt the proposed tap

settings at the earliest. APTRANSCO informed that Generators had

communicated the difficulties such as under excitation limiter alarm faced by

them when they tried to change the tap positions as suggested by SRLDC/SRPC.

The correspondences received from the Generators in the Vemagiri complex are

given at Annexure - XXV. AP stated that KTPS Unit XI, tap changing would be

attempted during the next overhaul.

8.4.4 To a query of SRLDC about the Tap position change w.r.t. Kaiga Unit 4, Kaiga

assured that they would change the Tap position during the next Shut Down

period.

8.5 SRLDC informed that MVAR absorption analysis had been carried out for BTPS Unit

I and RTPS Unit 7 on the basis of the information given by KPCL. The study report

by SRLDC is at Annexure - XXVI.

8.6 Requirement of reactor at Vemagiri Complex

It had been noted that the requirement of reactor at Vemagiri Complex was

deliberated in earlier Standing Committee Meetings and APTRANSCO was to take a

call on this issue. There had been no further developments communicated by

APTRANSCO. There were some issues with GTs in the Complex with secondary

voltage as 420 kV and the area was facing high voltage. SRLDC vide letter dated

12th June 2012 addressed to APTRANSCO had again requested that the

commissioning of bus reactor at Vemagiri needed to be expedited.


31

8.7 OCC observations

With depleting reservoir position and poor monsoon, proper planning and co-ordination of all the constituents was highly essential to be conducted.

The issues with respect to less availability and poor quality of coal were needed to be taken up appropriately.

Vijayawada, Hyderabad, Nagarjunsagar, Hiriyur, Vemagiri, Srisailam, Gooty and Kurnool voltages were above 420kV level for considerable duration.

AP has run units at Srisailam LB and Nagarjunsagar in condenser mode operation in first week of August helping contain high voltage.

Voltage around Thiruvananthapuram & Trichy had touched 372 kV while Almathi had touched 370 kV

Simultaneous critically High Voltages at some locations and low voltages at some locations of the grid poses the threat of power swing.

Ensuring adequate capacitor Banks at LT side and also possible introduction of under voltage relays are essential for ensuring system security.

9. Installation of Shunt Capacitors

The progress of installation of HT shunt capacitors was reviewed and the details are

listed below:

(Figures in MVAR) Sl. No. Description APTRANSCO KPTCL KSEB TNEB Total

1. Total Installed as on 31.03.2012 6593.4 4622.12 995 3947.5 16158.016

2. Carryover of 2011-12 55 74.16 10 101 240.16

3. Capacitors installed during August- 2012 0 0 0 2.4 2.4

4. Total Cumulative installed for 2012 -13 0 5.804 0 21.6 27.404

MS i/c, SRPC requested the constituents to go through the information furnished

above and revert back in case any discrepancy was noticed with respect to their

system.

10. Notified Power Cuts

MS i/c SRPC requested that details of Notified power cuts and load shedding be

segregated and informed to SRPC Secretariat/CEA in a timely manner by written

communication to appraise MoP/GoI appropriately.


32

11. Other Issues

11.1 Crisis Management Plan/Black Start Procedures a) The format to furnish the information regarding Crisis Management Plan

was furnished in the 44th OCC Minutes. The information is required to be sent to the following E-mail addresses:

i) [email protected] ii) [email protected] iii) [email protected]

b) In the 64th OCC meeting, MS i/c, SRPC had informed about the letter dated 27th September 2011 received from CEA wherein it was informed that the CMP was being monitored at the highest level. For this purpose, various utilities/organizations were required to submit Quarterly Reports through Regional Power Committee (RPCs) / National Load Despatch Centers (NLDC). It was also indicated that CMP be made applicable to private players of power sector.

11.1.1 AC By-pass mock drill at NTPC Ramagundam

In compliance with Clause 5.8(b) of IEGC 2010, it was planned to conduct mock

exercise for availing startup power to the auxiliary supply of NTPC Ramagundam

through HVDC Bhadrawathi as per Black Start Restoration Procedure in

Southern Region.

The matter had been discussed during earlier OCC meetings of SRPC and

SRLDC had discussions with DGM (GM), WRLDC and the exercise was

scheduled for 27.08.2012. The correspondence received in this regard from GM,

SRLDC is at Annexure - XXVII.

In the meeting it was noted that vide letter dated 26th August 2012, NTPC had

requested SRPC to postpone the same considering the power crisis in Andhra

Pradesh. The mock exercise had accordingly been rescheduled.

AGM, NTPC assured the forum that they would do all the needful for the

successful completion of the above mentioned mock exercise. MS, SRPC and

DGM, SRLDC requested the coordination from all the concerned to the

successful completion of the exercise at the earliest.


33

Workshop for Black Start Procedure 11.1.2 SRLDC thanked all the constituents and IPPS of SR for organizing black start

restoration procedure workshops at their places and making it a grant success.

11.1.3 SRLDC informed about the participation of the of the constituents in the

workshops as below:

State Date No of Participants

ANDRA PRADESH 28.08.2012 93 KARNATAKA 17.08.2012 48 KERALA 24.08.2012 61

TAMIL NADU 05.09.2012 55

11.1.4 Requirement of synchronizing facility at black start restoration critical substations

is given below:

Sl. No. Sync facility Requirement at station Status

1 Peenya station both at 220/110/66 To be provided during R&M works

2 Hubli To be provided during R&M works

3 Lingapur Yet to confirm the date

4 Ambewadi BBwadi ML Pura LingSugur Guttur 220 KV

Yet to confirm the date

5 Kayathar 110 KV Action being taken

6 Shornur Yet to provided

7 Chandrayangutta & city ring main stations Yet to provided

11.1.5 The updated status of mock drill of black start procedure furnished by SRLDC is

at Annexure – XXVIII (for 2012).

11.2 Normative Vs. average actual ex-bus generation

SRLDC also presented the details of normative and average actual ex-bus

generation in respect of ISGS during the month of August-2012 which is given

below. It was noted that in respect of all the stations the actual DC was less than

the normative DC. The actual ex-bus generation was more than or almost equal to


34

DC except in the case of MAPS & Talcher St II.

Station July ’12 August ’12

Normative

DC Actual

DC Actual Ex-Bus

Normative DC

Actual DC

Actual Ex-Bus

RSTPS # 1to 6 &7 2247 2129 2138 1874 1862 1862 NLC TS-II Stg-I 395 388 391 520 504 507 NLC TS-II Stg-II 677 662 666 423 400 405 NLC TS-I (Expn) 380 377 379 380 376 378 Talcher Stg-II 1373 1262 1252 1394 1129 1128 Simhadri Stg-II 181 178 175 470 449 450 Maps 392 291 289 322 242 237 Kaiga 630 474 484 648 491 498

11.3 Utilization of inter-regional links

SRLDC also presented details of the utilization of inter-regional links for the month of

August -2012 (Annexure - XXIX).

11.4 Tripping details

11.4.1 SRLDC had expressed serious concern since the information regarding tripping

details with relay indications was awaited from nearly all the constituents. DGM

(OS), SRLDC said that the entities should furnish the preliminary report on

‘events’ in compliance of IEGC Regulation, 5.9.6(a). Detailed report along with

necessary information as mandated by IEGC should be followed. MS I/c, SRPC

had said that as stressed earlier information needed to be continuously provided

to SRLDC/SLDCs as they had to coordinate a number of activities and plan load

generation balance in real time. If concrete information was not provided it

would affect in taking optimal decisions in the interest of the grid. The issue was

being followed up both in Protection & Operation Sub-Committee meetings but

there was no noticeable improvement. Constituents should identify and

implement a methodology so that the requisite information was available to the

RLDC/RPC. SRLDC had said that as informed in the earlier meeting, they would

like to have the ownership details of bays at various stations.

11.4.2 In the meeting, SRLDC stated that Tripping details along with relay indications

for many of the Transmission Elements as per the list was yet to be received.

Tripping reports for some of the events Tripping reports for some of the events

from POWERGRID (SR-I ), APTRANSCO and KPTCL had been received


35

11.4.3 The status of pending information for the month of August-2012 is enclosed as

Annexure - XXX.

11.5 Wind Generation

SRLDC presented the day-wise Wind Generation pattern in respect of Karnataka &

Tamil Nadu for the period between 1st and 31st August-2012. With respect to SR

pattern, the generation from Kerala and Andhra Pradesh had also been included.

Wind generation in Tamil Nadu had varied from 22.883 MU (22nd August) to 80.228

MU (29th August). Wind generation in Karnataka had varied from 5.995 MU (24th

Aug.) to 30.610 MU (4th August). It could be seen from the wind graph that on

certain dates the wind generation in SR had exceeded 100 MU. Details are

furnished in Annexure - XXXI.

11.6 Drawal Extremes and Physical Regulation Measures 11.6.1 In the earlier meetings the following was noted:

a) In the 68th OCC, TN had suggested that data regarding Drawal Extremes displayed by SRLDC should also include details of frequency and schedule etc. so as to portray the correct picture. TN said that any under-drawal at high frequency was also harmful to grid stability and should be treated on similar lines of over-drawal at lower frequency. TN therefore suggested that messages could be issued for under-drawal at high frequency also. SRLDC assured that they would look into this issue.

b) MS i/c had said that at any point of time, grid discipline schedule would need to be maintained by adhering to the schedule. He also added there may be a need for issue of messages for under drawal at high frequency as discussed in earlier OCC Meetings.

11.6.2 KSEB via letter no. CESO/EELDI/AE/LD Operation/2012/1233 dated

12.09.2012 (letter at Annexure - XXXII) had informed about the

unwarranted switching off of all three ICTs at 400 kV Thiruvananthapuram

PGCIL substation at 17.54 hrs on 11.09.2012 without proper intimation and

without formal notices as contemplated by Regulations. Also vide letter No.

CESO/EE2/AEIII/LD Operation/2012-13 (letter at Annexure - XXXIII),

KSEB had brought to the notice of SRPC/SRLDC that frequent instructions

were being received from SRLDC control room operators to increase

generation even when the frequency was above 50 Hz. TNEB via letter

dated 12.09.2012 had informed that on 11.09.2012 while taking action to

reduce over drawal as requested orally by SRPC, Salem Interconnector


36

were opened without any violation messages. The correspondence

received from TNEB is at Annexure - XXXIV. These issues were

deliberated in the meeting. The constituents expressed their concern about

imposing physical regulations without proper intimation and explained how

badly it affected their system. It was stated that SRLDC was not allowing

over drawal of more than 150 MW even when frequency was above 50 Hz.

They requested that over drawal at higher frequency could be permitted as

stipulated in IEGC without endangering the security of Grid. Else the

frequency could rise further higher, thus endangering the system.

11.6.3 DGM, SRLDC quoted the clauses as per the IEGC and UI regulations and

informed that overdawal could be allowed only within the limits as stipulated

in the same. In case the over drawal quantum was higher, it would take

more time to reduce their drawal in case of contingencies which would only

drag the system to insecure operating conditions. He explained the

difficulties in controlling the system which was fragile in nature. He also

highlighted that system protection schemes like AUFR, df/dt, SPSs were

not acting to the desired level. Load Forecasting Day wise Block wise

needed to be carried out for better system operation. He iterated that the

deviation from the injection / drawal schedule shall be strictly restricted to

with in the limit specified by the relevant CERC Regulations. Even while the

frequency is above 49.8Hz, the over drawal quantum shall be such that it

will not endanger the Line loading or lead to violation of IEGC / UI

regulations in case of any contingency in the system. Constituents were

also requested to maintain their Load Generation Balance in order to

maintain SIL of Lines. He also added that NPCIL Kudankulam

representative may attend the OCC Meeting for improved

coordination.

11.6.4 After deliberations, it was agreed that SRLDC would review these incidents.

It was felt prudent that proper written intimation be given before imposing

physical regulation measures. However, the SRLDC’s endeavor for safe

and secure system operation was appreciated by the Forum. However

SRLDC was requested that any intervention including load disconnection

through implementation of physical regulation measures at ISTS drawal


37

point of states be carried out subsequent to issuance of violation messages

and non-compliance observed, if any.

11.6.5 SRLDC presented the statement of Drawal Extremes for the month of August-

2012. The details are furnished in the Table given below:

State

Extremes August -2012 Extremes till date Maximum Minimum Maximum Minimum

MW Date Time Block MW Date Time

Block MW Month MW Month

AP 33557799 3300--0088..22001122 1100 11336677 0022--0088--22001122 7755 4005 Aug-‘08 -1280 Aug-‘06 KAR 11558833 0011--0088--22001122 3333 110099 3311--0088--22001122 9966 2722 Sep-‘10 -947 Sep-‘09 KER 11773388 0066--0088--22001122 6677 559977 0011--0088--22001122 1122 22002244 Jul-‘12 -610 Oct-‘07 TN 33008811 1144--0088--22001122 2255 11221122 0011--0088--22001122 3355 4315 May-‘11 -100 Oct-‘03 PUDU 229999 0088--0088--22001122 7766 112299 2299--0088--22001122 9911 315 Jun-‘12 8 Dec-‘11

The variations (i.e. = Maximum - Minimum) were: Andhra Pradesh (2212 MW),

Karnataka (1474 MW), Kerala (1141 MW), Tamil Nadu (1869 MW) and

Pondicherry (170 MW).

11.7 Load shedding details & web based PSP system utility

It was noted in earlier OCC Meetings, that the hourly load shedding details should

be furnished online by the State SLDCs before 3 ‘O’ clock in respect of the previous

day through web. SRLDC had also requested the constituents to furnish the other

details through web based PSP system utility of SRLDC. For any assistance /

clarifications, OS department of SRLDC could be approached.

11.8 Monthly Time drift report receipt status

Constituents were requested to furnish the Time Drift Report regularly to SRLDC.

Time drift reports were not being received from the following stations:

ANDHRAPRADESH: All stations

KARNATAKA: All stations except Nelamangala and Raichur

TAMILNADU: All stations except Gummudipundi & Hosur

Puducherry : Villianur & Yanam

ISGS STATIONS: RSTPS , Vallur, Simhadri, NLC I Expn.

CTU STATIONS: Munirabad, Warangal, Kalivathapattu, Sriperumbudur, Tirunelveli, Puducherry


38

11.9 ATC / TTC computations & Load Shedding details

SRLDC had pointed out that ATC / TTC computations were to be furnished by State

utilities. LGBR for the next five months was needed to be furnished by all the

constituents before 5th of every month for the purpose of ATC computations.

11.10 Mock Exercise for implementation of RRF (Renewable Regulatory Fund)

11.10.1 It was noted that CERC had directed to start mock exercise for the

implementation of RRF w.e.f. 1st July 2011. SRLDC had taken up the issue with

beneficiaries vide letter dated 5th July 2011 requesting them to make necessary

arrangements. The actions were to be initiated by the States were also listed.

11.10.2 The issue had also been taken up at TCC/SRPC forums. SLDCs were the nodal/

focal points for collecting the information in the States. Constituent states had

been requested to furnish the relevant information to SRLDC/SRPC Secretariat.

It was noted that a Task Force had been set up by MNRE vide OM dated 28th

March 2012 to resolve various issues relating to implementation of RRF

mechanism under the Chairmanship of CEO, POSOCO. The Task Force was to

finalize and submit its recommendations within a period of three months of the

OM.

11.10.3 In the 73rd OCC meeting, SRLDC had informed that the Draft report of Task

Force on RRF had been submitted to MNRE. They had also presented the Key

Implementation Issues & Task Force Recommendations.

11.11 Weekly SEM Data Receipt Status

SRLDC informed about the delay in receipt of Weekly SEM data during August 2012

which is furnished at Annexure – XXXV.

11.12 The following was also noted in the Meeting:

a) COD of Vallur JV Unit-I: NTPC informed that COD of Vallur JV Unit I was expected to by the end of October 2012.

b) Variable cost of ISGS: In the 19th meeting of Commercial Committee held on 16.07.2012, SRLDC had requested all ISGS stations to furnish the variable cost of their generators on a monthly basis. It was also agreed by generators that previous month data could be furnished in the monthly OCC meetings.


39

Energy Charges for the month of August 2012 as billed. NTPC furnished the details which are given below:

Ramagundam St I & II - 138.50 paise/kwh

Ramagundam St III - 201.70 paise/kwh

Talcher St II - 118.80 paise/kwh

Simhadri II - 153.80paise/kwh

NLC furnished the details which are given below:

NLC TS I Expn. - Rs.1.975/kWhr

NLC TS II -Rs.1.794/kWhr

c) Augmentation of Narendra ICT: The issue was discussed in earlier OCC and Commercial Sub Committee Meetings. In the Meeting, SR I gave a presentation which highlighted the requirement of the proposal. (Presentation is at Annexure - XXXVI). KPTCL confirmed about the load pattern projected by SR I. TNEB desired further study may be needed on this subject. After discussions, MS i/c, SRPC stated that the views expressed would be conveyed in the ensuing TCC/SRPC Meetings for a decision on the matter.

d) SRLDC stated that the issue regarding evacuation of wind generation after Kudankulam generation commences needed to be resolved. Further they also added that the high loading on 230 KV TNVL-Kayathar line and 400 KV ICTs at Tirunelveli & Madurai was a matter of concern. A SPS for containing overloading of 230 KV lines for wind evacuation was therefore required to be finalized.

e) Line loadings on 400 KV Nellore-Almathy, Hiriyur-Nelamangala D/C, Udumalpet-Trichur and BTPS-Jindal S/C lines were brought to the attention of the forum by SRLDC.

f) Tripping of Udumalpet-Palakkad line I causing near black out of Northern Kerala Grid: It was agreed that this matter would be discussed in the forthcoming meeting of the Protection Sub Committee.

g) Non revision of DC by Kaiga: In the Meeting, SRLDC informed that on 13th/14th August 2012, in spite of reminders from SRLDC, DC of Kaiga was not revised after the unit synchronization at 2137 hrs on 13.08.2012. With DC of 145 MW, they were injecting about 246 MW which affected the drawal schedule of the beneficiaries. NPCIL representative assured that they would look into the matter.

h) Allocation of URS Power: TANTRANSCO vide letter dated 01st September 2012 (Copy at Annexure - XXXVII) had stated that when there was surrender of about 700 MW CGS power by Karnataka, the same quantum was transferred to Andhra Pradesh by SRLDC without giving an opportunity to other constituents to avail the power as per their requirement. Hence as per request of TANTRANSCO, the manner of allocation of surrendered power was discussed in the Meeting. DGM, SRLDC denied the un-due allegations made by TANTRANSCO and requested to withdraw the same by TANRANSCO. He expressed his


40

concern and stated that SRLDC would be happy to furnish clarification on any of the observations of the Constituents and it is not appropriate to jump into any conclusion of allegation without getting clarified the issue. TANTRANSCO regretted for the communication sent. Constituents conveyed their opinion that in such situations they could be orally asked about their requirement for the surrendered power. DGM, SRLDC informed that the information regarding the URS power was being updated on the SRLDC website and hence states themselves could give the requisition. He opined that oral communication/FAX in this regard was not practical considering the constraints due to time etc as well as it will not be possible to communicate all the constituents simultaneous instant. He also informed that vide letter dated 6th September 2010, SRLDC had informed the constituents about the provision in the web based scheduling program for URS reallocation. (Copy enclosed at Annexure - XXXVIII). After discussions, it was concluded that the states could log on to the web site as explained by SRLDC and furnish their requirements.

i) OCC forum appreciated NLC TS I Expansion for good performance during the month of August 2012. It was also noted that NLC Stations (except NLC TS I) had achieved higher generation than the MoP set generation targets during April to August 2012.

j) NTPC, Ramagundam STPS Islanding Scheme:

Issue regarding requirement of unit tripping of NTPC, Ramagundam was brought to the attention of the forum by SRLDC. The total load in the island was about 1400 to 1600 MW including Hyderabad Load (1200-1300 MW), 450-500 MW (local Ramagundam). After deliberations, it was agreed that NTPC would examine the Load-Generation Balance for survival of the island and revert back on the issue regarding unit tripping.

k) Recommendations of Enquiry Committee which went into the Grid Disturbance on 30th and 31st of July 2012: 1) Extension of startup power: The Committee in its report submitted

to MoP, had mentioned that delays had occurred in lighting up the units after start up power was made available. A meeting was hence held in August 2012 at CEA to examine this issue. Summary of discussions at the meeting was circulated in the meeting and the same is at Annexure - XXXIX. MS/SRPC requested the Members to go through the same and initiate necessary actions to implement the Recommendations. This matter would be further discussed in the next Meeting of the OCC.

2) Outage Planning of Transmission Elements: The Committee had also recommended that Outage Planning of Inter State and inter regional transmission elements be carried out in a coordinated manner in RPC fora (say OCC subcommittee of RPCs in accordance with regulation 5 of Central Electricity Authority Grid Standards Regulation, 2012 and section 5.7.1. of Indian Electricity Grid Code.) The letter received from Member (GO&D), CEA in this regard was also circulated in the meeting and is furnished at Annexure - XL. MS i/c, SRPC requested the Members to furnish the outage proposals well in advance to SRPC enabling better coordination.


41

l) Declaration of availability of various protection / defence mechanism.- SRLDC informed that the declaration was yet to be submitted by Puducherry, NTPC, Talcher, NLC TS II Expansion, MAPS, Kaiga and SRTS-I.

m) SRLDC also stated that it would be issuing messages regarding under drawal to the constituents. It was expressed by the constituents that under drawal needed to be seen in unison with the frequency also. They stressed that under drawal at higher frequency range needed to be avoided.

n) POWERGRID informed that 400 KV Udumalpet – Arasur II line had tripped on two occasions due to decapping of insulators during July 2012. The reason for decapping was due to pollution and settling of fine dust due to the increased number of wind mills in the vicinity of the line. The development of wind mills was an after phenomenon after the studies for the insulator design for the line. Hence POWERGRID had taken pro active actions to avoid any further outage in this line by cleaning of the insulators. Further action to replace all the insulators with pollution resistant polymer insulators in the pollution stretches of the line had been programmed and would be completed shortly. Hence the outages were not attributable to POWERGRID since they were beyond its control. After discussions, the constituents agreed to this request of POWERGRID.

12. Maintenance Schedule of Generating Units 12.1 Reviewed & updated Outage Plan for the year 2012 -13 is available at location

(http://www.srpc.kar.nic.in/website/2012/operation/Outage%20Plan%202012-13.pdf)

on SRPC website.

12.2 Details of generating units under shut down (forced as well as planned) during

August- 2012 are enclosed as Annexure - XLI.

13. Shutdown Programme of Central Generating Stations

It had been noted in the earlier meetings that as per IEGC Provisions, RPCs are to

submit quarterly, half yearly reports to the Hon’ble Commission indicating deviations in

outages from the plan along with reasons. SRPC said that the reasons for outage

deviations also needed to be communicated to SRPC Secretariat.

14. Maintenance of Lines & ICTs completed in August - 2012

The planned maintenance of elements carried out by PGCIL/NLC during the month of

August-2012 is furnished at Annexure – XLII.


42

15. Shutdown Programme of Lines & ICTs Proposed

15.1 Planned shutdowns of 400 kV transmission elements of State Sector

In the earlier OCC meetings it had been recommended that the planned shutdowns

of 400 kV transmission elements of State Sector also needed to be approved

through OCC. State transmission utilities had been requested to furnish the planned

shutdowns of 400 kV transmission elements in their system for the year 2012-13.

15.2 The shutdowns of the ISTS system approved in the OCC meeting are given in

Annexure – XLIII.

15.3 DGM (OS), SRLDC informed that an emergency outage in 400 kV Raipur-

Chandrapur line on continuous basis was needed from 15.09.2012 to 16.09.2012.

The WR-SR Capacity would be reduced to 230 MW due to Shut down of Raipur –

Chandrapur Line and MTOA would be curtailed.

16. Capacity Addition in Southern Region

It had been decided in the SRPC meetings that the constituents would furnish the

status on upcoming Generating Schemes, since SRP Committee needed to be kept

informed of the likely capacity additions. The constituents were requested to furnish

the updated information on capacity additions including the IPPs, on a regular basis to

help apprise SRPC appropriately.

17. Review of Performance of ULDC Scheme

17.1 As the constituents were aware SRLDC had approached Hon’ble CERC through a

petition regarding establishment & maintenance of data and communication facilities

and the same had been admitted. In the 18th SRPC Meeting, all the constituents had

assured to expedite and complete the pending works.

17.2 It was noted in the 73rd OCC meeting that though unmanned stations would not use

permanent voice communications on normal operations, but in case of disaster

management situation, as the people had to man the station and communicate with

others for restoration activities, permanent communication had to be in place at all

the unmanned stations also. PGCIL said that most of the lines were with OPGW and

communication would not be a problem for data, protection and voice functions.


43

17.3 With regard to pending field inputs in respect of NTPC Talcher, it was noted that a

Meeting in this regard with participation from NTPC, POWERGRID, SRLDC and

SRPC was scheduled to be held on 17.09.2012 at Talcher. The outcome of this

meeting could be awaited.

17.4 Status of pending field inputs

17.4.1 In the Meeting, SRLDC presented the following details:

a) Standby Data Channel Status

Non-availability of standby data channels at Trivandrum, Hiriyur, Nelamangala,Talcher RCI, Kudankulam, NLY TS 2 Expansion, Kochi, Palakkadu, Bidadi, LANCO, Bhadravathi & Warangal

Voice Communication status (PUNCOM) Non-availability of voice communication at Pugalur, Kolar HVDC, Kolar HVAC, Hiriyur, Kalivathnapattu, Mysore, Narendra, Trivandrum, Talcher HVDC, Hassan, Kochi, Palakkadu, Puducherry, Munirabad, Nellore, Gazuwaka, Bhadravathy, NTPC Kayamkulam, MAPS, Kaiga, NLC ST2, NLC TS 1 Expansion & NLY TS 2 Expansion

b) Internet communication

Reliable and dedicated internet communication for system operation by SR constituents.

c) As per the Meeting held with SRTS I & SRTS II on 27.08.2012, the stand by channels and voice communication are to be provided by the end of December 2012.

d) Jindal generating station complete RTU/SAS data was not available at SRLDC. SRLDC requested KPTCL to take up this matter with concerned for rectification purpose. KPTCL informed that Jindal 400 kV data was not stable and hence they had requested to SCADA people to install new RTU for providing necessary data to SLDC/SRLDC.

e) SRLDC suggested that for validation of RTU/SAS data with SRLDC a programmer had to be made. for calibration /replacement of transducers if required.

17.4.2 SRLDC informed about the status of pending field inputs (Annexure – XLIV).

A total of about 469 field inputs needed to be attended. SRLDC informed that

details of pending inputs were also available on their web site and Members with

login details could download the same for their perusal.


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18. Vote of Thanks

MS i/c, SRPC once again thanked NTPC for the efforts taken for the smooth conduct

of the Meeting. He also thanked the Members for their active participation in the

Meeting. Shri H.S. Keshavamurthy, Chief Engineer, SLDC, KPTCL on behalf of OCC

forum also extended his thanks to the entire NTPC team and highlighted the

hospitality of coordinators of the meeting.

19. Date & Venue of the Next Meeting

The schedule for the next Meeting of OCC is as follows:

Meeting : 76th OCC of SRPC

Date : 11.10.2012 (Thursday) Time : 10:30 Hours Venue : Conference Hall, SRPC Bangalore

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southern regional power committee (srpc) bangalore

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