380kv ct-vt calculation_c4_rev_d 17.12.09

137
CERT'D NO. B C D BY:- BY:- DATE:- BY DATE:- BY:- DATE:- BY:- DATE:- DATE INDEX PLANT REV NO. DMS (CROSS BAY C#4) SEC-ERB CAD-E (2002/03) EXCEL 01 OF 50 D 3-083300.01 DWG.CONT.SHT. EE-086950 THIS DRAWING IS NOT TO BE USED FOR CONSTRUCTION OF FOR ORDERING MATERIALS UNTIL CERTIFIED AND DATED DRAWING TITLE DRAWING NO. SHEET NO. 380kV CT SIZING CALCULATION A T201 EE-086959 ABU-HADRIYAH 380/115kV BSP KHURSANIYAH ENG'G. DEPT. CERTIFIED. AS BUILT BY CHECKED JA 22.12.08 OPRG. DEPT URD DATE 03.04.2009 CHK'D RJP BY PG DRAWN RJP DATE:- 20.12.08 REVISIONS DESCRIPTION REVISED AS PER BASE DESIGN REVIEW MEETING DATED 16.03.09 & 17.03.09 REVISED AS PER SEC COMMENTS DATED 03.06.2009 ON REVISED CT CALCULATION. REVISED AS PER SEC COMMENTS DATED 06.12.2009 ON REVISED CT CALCULATION. PG لكهرباء الشركة السعودية لة الشرقية فرع المنطقTHIS DRAWING AND THE INFORMATION CONTAINED HEREIN ARE THE SOLE PROPERTY OF SAUDI ELECTRICITY CO. NO REPRODUCTION IN FULL OR IN PART SHALL BE OBTAINED FROM THIS DOCUMENT WITHOUT THE WRITTEN CONSENT OF ITS OWNER. SAUDI ARABIA JOB ORDER NO. RJP RJP 380kV CT/VT SIZING CALCULATION 25.06.2009 17.12.2009 APPR'D JA JA JA Saudi Electricity Company Eastern Region Branch

Upload: siva2001eee

Post on 02-Apr-2015

2.415 views

Category:

Documents


25 download

TRANSCRIPT

Page 1: 380kV CT-VT calculation_C4_Rev_D 17.12.09

CE

RT

'DN

O.

B C D

BY:-

BY:-

DATE:-

BY

DATE:-

BY:-

DATE:-

BY:-

DATE:- DATE

INDEX PLANT REV NO.

DMS

(CROSS BAY C#4)

SEC-ERB CAD-E (2002/03)

EXCEL

01 OF 50 D

3-083300.01 DWG.CONT.SHT. EE-086950

THIS DRAWING IS NOT

TO BE USED FOR

CONSTRUCTION OF

FOR ORDERING

MATERIALS UNTIL

CERTIFIED AND

DATED

DRAWING TITLE DRAWING NO. SHEET NO.

380kV CT SIZING CALCULATIONA T201 EE-086959

ABU-HADRIYAH 380/115kV BSP

KHURSANIYAH

ENG'G. DEPT.

CERTIFIED.

AS BUILT BY

CHECKED

JA

22.12.08

OPRG. DEPT

UR

D

DA

TE

03.0

4.2

009

CH

K'D

RJP

BY

PG

DRAWN

RJP

DATE:- 20.12.08

REVISIONS

DE

SC

RIP

TIO

N

RE

VIS

ED

AS

PE

R B

AS

E D

ES

IGN

RE

VIE

W M

EE

TIN

G D

AT

ED

16.0

3.0

9 &

17.0

3.0

9

RE

VIS

ED

AS

PE

R S

EC

CO

MM

EN

TS

DA

TE

D 0

3.0

6.2

009 O

N R

EV

ISE

D C

T C

ALC

ULA

TIO

N.

RE

VIS

ED

AS

PE

R S

EC

CO

MM

EN

TS

DA

TE

D 0

6.1

2.2

009 O

N R

EV

ISE

D C

T C

ALC

ULA

TIO

N.

PG

الشركة السعودية للكهرباءفرع المنطقة الشرقية

TH

IS D

RA

WIN

G A

ND

TH

E IN

FO

RM

AT

ION

CO

NT

AIN

ED

HE

RE

IN A

RE

TH

E S

OL

E P

RO

PE

RT

Y O

F S

AU

DI E

LE

CT

RIC

ITY

CO

. N

O R

EP

RO

DU

CT

ION

IN

FU

LL

OR

IN

PA

RT

SH

AL

L B

E O

BT

AIN

ED

FR

OM

TH

IS D

OC

UM

EN

T W

ITH

OU

T T

HE

WR

ITT

EN

CO

NS

EN

T O

F IT

S O

WN

ER

.

SAUDI ARABIA JOB ORDER NO.

RJP

RJP

380kV CT/VT SIZING CALCULATION

25.0

6.2

009

17.1

2.2

009

AP

PR

'D

JA

JA

JA

Saudi Electricity CompanyEastern Region Branch

Page 2: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH

380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

INDEX

SR. NO. SHEET NO.

1.0 1

1.1 1

1.2 11.3

1.3 2

2.0 3

2.1 3

2.2 5

2.3 1216

2.4 14

2.5 15

2.6 16

2.7 20

2.8 24

2.9 25

2.10 31

2.11 34

2.12 35

2.13 35

2.14 36

2.15 36

2.16 37

2.17 38

2.18 39

2.19 40

2.20 40

2.21 41

2.22 41

CT: 810 B1.C3 :- OHL FEEDER SET-2 PROTECTION (7SA522)

CT: 810 B1.C4 :- METERING

CT: 810 F.C2 :- BUS-BAR PROTECTION MAIN-2 (MFAC14)

CT: 810 F.C1 :- BUS-BAR PROTECTION MAIN-1 (MCAG 14)

CT: 811 B2.C4 :- METERING

CT: 811 B1.C1 :- BF PROTECTION (RAICA)

CT: 811 B1.C2 :- OHL FEEDER SET-1 PROTECTION (RED 670)

CT: 811 B1.C3 :- OHL FEEDER SET-2 PROTECTION (MiCOM P546)

CT: 811 B1.C4 :- METERING

CT: 810 F.C3 :- SPARE

DESCRIPTION

GENERAL DESIGN CRITERIA FOR CT CALCULATION

SYSTEM DESIGN DATA

CT: 811 B2.C3 :- OHL FEEDER SET-2 PROTECTION (7SA522)

DESIGN BASIS AND REFERENCES FOR CT CALCULATION

CT LEAD RESISTANCE CALCULATION

CT CALCULATION FOR THE FOLLOWING CT's.

CT: 810 B1.C1 :- BF PROTECTION (RAICA)

CT: 810 B1.C2 :- OHL FEEDER SET-1 PROTECTION (REL 531)

CT: 812 B2.C1 :- BF PROTECTION

CT: 811 B2.C2 :-OHL FEEDER SET-1 PROTECTION (REL 531)

CT: 811 B2.C1 :- SPARE

CT: 812 F.C1 :- BUS-BAR PROTECTION MAIN-1 (MCAG 14)

CT: 812 F.C2 :- BUS-BAR PROTECTION MAIN-2 (MFAC14)

CT: 812 F.C3 :- SPARE

CT: 812 B2.C4 :- METERING

CT: 812 B2.C3 :- OHL FEEDER SET-2 PROTECTION (7SA522)

CT: 812 B2.C2 :- OHL FEEDER SET-1 PROTECTION (REL 531)

BAY NUMBER: CROSS BAY C4

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 3: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH

380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

3.00 42

47

49

LINE VT SIZING CALCULATION

BUS-1 VT SIZING CALCULATION

ATTACHMENTS:

ANNEXURE-1 CT REQUIREMENT OF RELAY

ANNEXURE-2 VA REQUIREMENT OF RELAY

BUS-2 VT SIZING CALCULATION

ANNEXURE-4A 380kV GIS DATA SCHEDULE FROM AREVA

ANNEXURE-5 MANIFA SUBSTATION ELECTRICAL LAYOUT

ANNEXURE-6 380kV RELAYING & METERING ONE LINE DIAGRAM

ANNEXURE-9 M&I METROSIL CATALOGUE

ANNEXURE-3 SAUDI CABLE CATALOGUE

ANNEXURE-4 380kV GIS CT DATA FROM AREVA

ANNEXURE-7 LINE PARAMETER

ANNEXURE-8 380kV CVT DATA SCHEDULE

BAY NUMBER: CROSS BAY C4

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 4: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

1.0 GENERAL DESIGN CRITERIA FOR CT SIZING CALCULATION

1.1 System Design Data:

1.1.1 380kV

1.1.2 > 17 (As per 32-TMSS-02, sh. No. 31 of 53, Annexure-4A)

1.1.3 63000 Amps

1.1.4 63000 Amps

1.1.5 63kA (As per 32-TMSS-02, sh. No. 31 of 53, Annexure-4A)

1.2 DESIGN BASIS AND REFERENCES FOR CT CALCULATION :

1.2.1 CT secondary excitation limiting emf and other parameters of CT's are calculated

at adopted tap setting, as shown in relaying & metering one line diagram.

1.2.2 Lead length considered is 500 meters including safety margin.

Refer to the attached Abuhadriyah substation electrical layout (dwg. No. EA-009912).

Refer Annexure 5 sheet 2.

Thus we have ensured that assumed 500m length is not exceeded by any actual length.

500m is also used as basis for any future modifications for normal S/S life time of 35years.

1.2.3 Safety margin of 20% is considered for protection class CT and 25% for metering class CT in the formulae

for CT calculation as a general and where-ever applicable relay manufacturer's recommendation is followed.

1.2.4 CT specification is considered as per PTS 07EN307 part'F', Appendix-VII and GIS vendor data.

1.2.5 Zs (source Impedance) is calculated based on CB Interrupting capacity. The Line Impedance value will be added

to Zs to derive the fault current (PF & EF) at zone1 end for CT excitation limiting EMF calculation. Only one way

is considered for PF zone1 Ual calculation and 2 way CT lead length is considered for EF zone1 Ual calculation.

CT Calculation for close in fault is done for 3 phase fault level 63kA.

We also have assumed 3km long line in view of any future modifications in the 380kV system,

1.2.6 Annexure-1: CT requirement of relay

Annexure-2: VA burden requirement of relay

Annexure-3: Saudi cable catalogue for CT lead resistance calculation

Annexure-4: CT data from 380kV GIS vendor (TOSHIBA)

Annexure-4A: Data Schedule for 380kV GIS

Annexure-5: Abu-hadriyah substation electrical Layout drawing for CT/VT cable route length (dwg. No. EA-009912)

Annexure-6: 380kV Relaying & Metering one line diagram for cross bay C4.

Annexure-7: Line parameters

Annexure-8: 380kV GIS Data schedule-CCVT

Annexure-9: M&I Metrosil catalogue

Design Fault level (CB Interr. capacity)

System Voltage in kV

380kV system X/R Ratio

380kV Maximum 3 pahse fault level

380kV Maximum P-E fault level :

BAY NUMBER:

CROSS BAY C4

Sheet No.

1 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 5: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

1.3 CT LEAD RESISTANCE CALCULATION :

CT secondary lead size considered is 6 sq.mm.

6 sq.mm copper cable resistance at 200C is 3.08 ohms/km.i.e Rdc at 20

0C = 3.08 ohm/km (Refer Annexure-3)

Rdc at 75ºC = R20(1+α20(T2-T1)); α at 20ºC = 0.004,Where α= temperature co-efficient of resistance.

Hence, Rdc at 75ºC = 3.08(1+0.004(75-20));

= 3.76 ohm/km

Consider a distance from 380kV GIS CT to relay panel as per layout attached with considerable

(Refer Annexure-5) safe margin = 500 meter, Lead resistance calculated is,

= 3.76 x 0.5

= 1.88 ohms for 500 meters

BAY NUMBER:

CROSS BAY C4

Sheet No.

2 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 6: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.0 CT CALCULATION AS PER RELAY/INSTRUMENT MANUFACTURER'S RECOMMENDATION

2.1 CT: 810 B1.C1

Protection : BF protection (50BF)

Core : CT: 810 B1.C1

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 3.1 Ohms at 2000A tap.

Knee point voltage, Vk Vk > 3700 V at 2000A tap

CT excitation current at 2000A tap in mA Ie < 75

Thermal rating factor 200%

Application : CB Fail Protection (50BF)

Relay Type / Make: "RAICA", ABB,(50BF)

CT CALCULATION:

2.1.1 CT Vk requirement:

For 2000 A

Vk Knee point voltage

I P = Nominal ( rated) CT primary Current = 2000 amps

T = Turn ratio = 1/2000

I s = Nominal ( rated) CT secondary Current = 1 amps

I F = Maximum short circuit current = 63000 amps

IF sec = CT Secondary short circuit current in Amps. = 31.5 amps

RCT = Internal CT secondary resistance = 3.1 ohms

RL = Lead Resistance =2 L x Rpkm / 1000 = 1.88 ohms

RL = Lead resistance of cable. = 1.88 Ohms

=For 6 sq.mm copper cable, RL= 0.00308 ohm/meter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1)) RL = 1.88 ohms.

Consider length of cable = 500 meters.

RRAICA= Relay Burden (Refer Annexure-2, Sh. No. 6) = 0.15 VA

RRAICA= Relay resistance = RB / Is 2

= (0.15/12) = 0.15 ohms

BAY NUMBER:

CROSS BAY C4

Sheet No.

3 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 7: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Note:

Maximum Relay burdens occur for 1ph-G fault when both phase & ground BFP O/C relay units are in series.

2x BFP Relay Fault Detectors = 0.30 Ohms

Total= 0.30 ohms Ground o/c relay [1ph-G loop]

0.15 ohms phase o/c relay [3ph]

BFP fault detectors come once main protection operates & initiate BFP. Worst case relay operation (fatest)

is ½ cycle & hence @ maximum peak during fully offset.

CT Requirement considering 20% margin.

General formulae:

Vkrequired > 1.2xOffset for DC x Ifsecondaryx (Connected burden)

Vkrequired > 1.2x2xIf x ( RCT + 2RL + 2x(RRAICA ))

> 1.2x2x31.5 x ( 3.1 + 3.76 + 2x(0.15))

> 541.296 Volts

Since CT rated knee point voltage is 3700V which is greater than 541.3 volts, CT is adequate.

BAY NUMBER:

CROSS BAY C4

Sheet No.

4 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 8: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.2 CT: 810 B1.C2

Protection : OHL feeder protection Set-1 (87L-1,21-1)

Core : CT: 810 B1.C2

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 3.1 Ohms at 2000A tap.

Knee point voltage, Vk Vk > 3700 V at 2000A tap

CT excitation current at 2000A tap in mA Ie < 75

Thermal rating factor 200%

Application : OHL feeder protection Set-1 (87L-1,21-1)

Relay Type / Make: "REL 531", ABB

2.2.1 Line Data: (Refer Annexure-7 attached)

Line length as per annexure attached = 44.485 km (Annexure-7)

Line parameter for Abu-hadriyah Al-fadhili line. Refer Annexure-7 for Line parameters.

Z1 = 0.00054+j 0.0098 p.u Base MVA = 100

Z0 = 0.00645+j 0.03112 p.u Base kV = 380

Base Impedance calculated = (BasekV2) = 1444 ohms

Base MVA

Base Current calculated = (Base MVA) = 151.9 amps

√3 x Base kV

Zline in ohms calculated; R1= 0.794 ohms

(Base Impedance x p.u Impedance) X1= 14.15 ohms

R0= 9.314 ohms

X0= 44.94 ohms

X/R = 17 Phase volt.= 219393.1 Volts

sin(tan-1(X/R)) = 0.998 Phase Curr.=63000 Amperes

cos(tan-1(X/R)) = 0.059

BAY NUMBER:

CROSS BAY C4

Sheet No.

5 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 9: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.2.2 Source impedance:

Xs = (Ph vol/Ph cu)xsin(tan-1

(X/R)) Rs = (Ph vol/Ph cu)xcos(tan-1

(X/R))

= 380000 x sin(tan-1

(X/R)) = 380000 x cos(tan-1

(X/R))

Sqrt.(3)x63000 Sqrt.(3)x63000

= 3.48 ohms = 0.20 ohms

Z s = 0.2 + j 3.48 ohms

2.2.3 Line impedance:

X1 full Line: Line length x Reactance value/km X0 full Line: Line length x Reactance value/km

= 14.1512 ohms = 44.93728 ohms

R1 full Line: Line length x Resistance value/km R0 full Line: Line length x Resistance value/km

= 0.7942 ohms = 9.3138 ohms

Z1 line = 0.7942 + j 14.15 ohms Z0 line = 9.3 + j 44.94 ohms

2.2.4 THREE PHASE FAULT CONDITION

Close in Fault

Fault current = 63 kA

X/R = 17

Source Imp. Z1=Z2=Z0 =0.2 + j 3.48 ohms

Through fault current at the end of the line:

For 44.485 Km line

Impedance calculated : (Rs + R1) + j(Xs+X1)

(Positive sequence) = (0.2+0.794) + j (3.48+14.15)

= 0.994+j17.63 ohms

ZT1 = 17.66 ohms

Phase fault current = Ph. Volt / Ph. Imp.

= 380000

Sqrt.(3)x17.63

= 12424.57 Amps

Phase fault X/R = 17.63

0.994

= 17.74

BAY NUMBER:

CROSS BAY C4

Sheet No.

6 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 10: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Fault current calculation at the end of zone1 fault i.e 80% of line length:

For 44.485 Km line

Impedance calculated : (Rs+0.8R1) + j(Xs+0.8X1)

(Positive sequence) = (0.2+0.635) + j (3.48+11.32)

= 0.84+j14.8

ZT1 = 14.82 ohms

Phase fault current = Ph. Volt / Ph. Imp.

= 380000

Sqrt.(3)x14.82

= 14800.04 Amps

Phase fault X/R = 14.82

0.835

= 17.75

2.2.5 SINGLE PHASE-GROUND FAULT CONDITION:

Through fault current at the end of the line:

For 44.485 Km line

Impedance calculated : (3Rs+2R1+R0) +

(Loop Impedance) j(3Xs+2X1+X0)

= 11.5+j83.79 ohms

ZT1 = 84.39 ohms

Earth fault current = Ph. Volt / Ph. Imp.

= 380000

Sqrt.(3)x84.39

I0 = 2599.62 Amps

Earth fault X/R = 83.79

11.5

= 7.29

3I0 = 7798.87 Amps

BAY NUMBER:

CROSS BAY C4

Sheet No.

7 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 11: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Fault current calculation at the end of zone1 fault i.e 80% of line length:

For 44.485 Km line

Impedance calculated : (3Rs+0.8x2R1+R0) +

(Loop Impedance) j(3Xs+0.8x2X1+X0)

= 9.32+j69.12 ohms

ZT1 = 69.75 ohms

Earth fault current = Ph. Volt / Ph. Imp.

= 380000

Sqrt.(3)x69.75

= 3145.62 Amps

Earth fault X/R = 69.12

9.32

= 7.42

3I0= = 9436.869326 Amps

2.2.6 CT Requirement : ( As per Annexure-1, Sh. No.20,21)

Eal > Ealreq = {I kmax x I sn} / Ipn x 0.5 x (RCT + RL + SR / Ir 2

) Equation-1

Eal > Ealreq = 2 x {Ikmax x I sn} / Ipn x (RCT + RL + SR / Ir 2 ) Equation-2

Eal > Ealreq = 0.12 x f x Isn x(RCT + RL + SR / Ir 2 ) Equation-3

Eal > Ealreq = (Imin sat x CT factor x Ir) / 100 x (RCT + RL + SR / Ir 2

) Equation-4

Where,

Ikmax = Maximum Primary fundamental frequency fault current for internal close-in faults (A)

Itfdb = Maximum Primary fundamental frequency fault current for external faults (A) that

passes through two CT's (A).

Here for one and half breaker scheme Ikmax is equal to Itfdb.

Ipn = The rated primary CT current (A)

Isn = The rated secondary CT current (A)

Ir = The rated current of the protection IED (A)

SR = The burden of IED 670 a current input channel (VA). SR = 0.25 VA/channel.

f = system frequeny in Hz.

Imin sat= Saturation detector min current ( 100 - 1000% Of Ir) and set at 500%

CT factor = set current scalling factor (0.4 - 1.0)

Where, For 2000 amps

Ealreq=

Eal = = 3700 volts

I K max = Maximum short circuit current-Three phase = 63000 amps

Required secondary e.m.f.

Rated equivalent secondary e.m.f.= Vk

BAY NUMBER:

CROSS BAY C4

Sheet No.

8 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 12: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Itfdb = Maximum Primary fault current for external faults (A) = 63000 amps

I pn = Nominal ( rated) CT primary Current = 2000 amps

I sn = Nominal ( rated) CT secondary Current = 1 amps

RCT = CT secondary winding resistance = 3.1 ohms

RB = = 0.25 ohms

RL = Lead resistance of cable.

=For 6 sq.mm copper cable, RL= 3.08 ohm/kmeter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1)) RL 1.88

Consider length of cable = 500 meters. 2RL = 3.76 ohms

I r = = 1 amps

f = = 60 Hz

Imin Sat=

X/R = = 17

Tp = Primary time constant, (L/R)

L/R = (X/(2x 3.14x f )/R

.= ( 17 / 2x 3.14x 60) x 1000 = 45.09 msec

RTFR = Burden value for TFR (Refer Annexure-2,Sh. No.7) = 0.01 VA

Hence, total VA burden including TFR. = 0.26 VA

Voltage developed across CT as per ABB relay catalogue.

At 2000/1 A tap

Considering 20% margin

Eal > Ealreq = {I kmax x I sn} / Ipn x 0.5 x (RCT + RL + SR / Ir 2

) Equation-1

As per REL 531 relay requirement, the factor 0.5( for Tc less than 120ms) is replaced with 0.53 & 0.54

for primary time constant of 200ms and 300ms respectively.

Ealreq = 63000 x 1 x 0.5 x ( 3.1+ 1.88 + 0.27/1^2 ) = 82.5 volts

2000

With 20% extra margin Ealreq = 99.0 volts

Sat saturation detector min current

Burden of relay

Protection terminal rated Current

System ratio

System Frequency

BAY NUMBER:

CROSS BAY C4

Sheet No.

9 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 13: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Eal > Ealreq = 2 x {Ikmax x I sn} / Ipn x (RCT + RL + SR / Ir 2

) Equation-2

As per REL 531 relay requirement, the factor 2 ( for Tc less than 120ms) is replaced with 2.32 & 2.5

for primary time constant of 200ms and 300ms respectively.

Ealreq = 63000 x 1 x 2 x ( 3.1+ 1.88 + 0.27/1^2 ) = 330.1 volts

2000

With 20% extra margin Ealreq = 396.1 volts

Eal > Ealreq = 0.12 x f x Isn x (RCT + RL + SR / Ir 2

) Equation-3

Ealreq = 0.12 x 50 x 1x(3.1+ 1.88 +0.27/12

) = 31.4 volts

With 20% extra margin Ealreq = 37.7 volts

Eal > Ealreq = (Imin sat x CT factor x Ir) / 100 x (RCT + RL + SR / Ir 2 ) Equation-4

Ealreq = 500 x 1 x 1x(3.1+ 1.88 +0.27/12

) = 26.2 volts

100

With 20% extra margin Ealreq = 31.4 volts

Since CT rated knee point voltage is 3700V which is greater than the required value,

the proposed CT is adequate.

The Voltage developed across the CT secondary for distance protection (21L) feature as per

ABB catalogue. (Refer Annexure-1 Sh. No. 22 )

Requirement -1

At 2000/1 A tap

Eal > Ealreq = {I kmax x I sn} / Ipn x a x (RCT + RL + SR / Ir 2

) Equation-5

a' = 2 for primary time constant less than 50msec.

With 20% extra margin

Ealreq = 63000 x 1.2 x 2 x ( 3.1+ 1.88 + 0.27/1^2 ) = 538.3 volts

2000

BAY NUMBER:

CROSS BAY C4

Sheet No.

10 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 14: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Requirement -2

Eal > Ealreq = Ikzone1x 7 x (Isn / Ipn) x (RCT + RL + SR / Ir 2

) Equation-6

k' = 7 for primary time constant greater than 30 msec.

Ikzone1= Maximum primary fundamental fault current at the end of zone 1 reach.

Considering 80% of actual line length = 14800.04 Amps

(Refer above fault current calculation at the end of zone1 reach considering actual line length)

At 2000/1 A tap and with 20% extra margin

Ealreq = 14800 x 1.2 x 7 x ( 3.1+ 1.88 +0.27/12

) = 442.58038 volts

2000

Since CT rated knee point voltage is 3700V which is greater than the required value,

the proposed CT is adequate.

BAY NUMBER:

CROSS BAY C4

Sheet No.

11 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 15: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.3 CT: 810 B1.C3

Protection : OHL feeder protn. -Set-2 (87L-2,21-2)

Core : CT: 810 B1.C3

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 3.1 Ohms at 2000A tap.

Knee point voltage, Vk Vk > 3700 V at 2000A tap

CT excitation current at 2000A tap in mA Ie < 75

Thermal rating factor 200%

Application : OHL feeder protection - Set-2 (87L-2,21-2)

Relay Type/make : ''7SA522 ", Siemens.

2.3.1 CT Calculation

Where For 2000 amps

Vk = Knee point voltage of CT 3700 Volts

RB = Resistance of relay 7SA522 = 0.05 ohms

Rr = Relay resistance

RCT = CT secondary winding resistance = 3.1 ohms

RL = Lead resistance of cable.

For 6 sq.mm copper cable, RL= 3.08 ohm/kmeter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1)) RL = 1.88 ohms

Consider length of cable = 500 meters. 2RL= 3.76 ohms

I P = Nominal ( rated) CT primary Current = 2000 amps

I S = Nominal ( rated) CT secondary Current = 1 amps

ISCC max = Maximum short circuit current-Three phase = 63000 amps

VK CT knee point voltage specified = 3700 volts

X/R = System ratio = 17

I f = Maximum value of through fault current for

stability ( multiple of Is) = I SCC max / IP = 31.50

( I f )x( X/R) = 535.5

Tp = Primary time constant, (L/R)

L/R = (X/(2x 3.14x f )/R

.= ( 17 / 2x 3.14x 60) x 1000 = 45.09 msec

BAY NUMBER:

CROSS BAY C4

Sheet No.

12 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 16: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

The CT should meet the following Vk requirement as per Siemens publication.

( Refer Annexure-1 Sh. No. 24 )

Vk 1 > {Ktd(a)xIssc max(close-in fault)/1.3xIpn} x Isn x (RB + RCT +RL) For close-in fault

Vk 2 > {Ktd(b)xIssc max(zone-1 end fault)/1.3xIpn} x Isn x (RB + RCT +RL) For zone-1 end fault

Ktd(a) = 2' for primary time constants less than 50ms

Ktd(b) = 5' for primary time constants less than 50ms

Vk1 = Accuracy limiting voltage for close in fault in volts

Vk2 = Accuracy limiting voltage for end of zone 1 line fault in volts

IFZ1 = Maximum secondary fault current for end of zone 1 fault in amps.

Considering actual line length as a worst case, primary fault current (A) calculated is equal 14800.04

Amps. Hence, CT secondary fault current = 14800.04

2000

= 7.40 Amps.

RB = Relay burden

CT requirement for close-in fault condition:

Vk 1 > {Ktd(a)xIssc max(close-in fault)/1.3xIpn} x Isn x (RB + RCT +RL)

= {2 x 63000/1.3x2000} x (0.05 + 3.1 + 1.88) = 244 volts

Vk 2 with 20 % margin = 293 volts

Peak voltage = 413.7 Vpeak

CT requirement for zone1 fault condition:

Vk 2 > {Ktd(b)xIssc max(zone-1 end fault)/1.3xIpn} x Isn x (RB + RCT +RL)

= {5 x 14800/1.3x2000} x (0.05 + 3.1 + 1.88) = 143 volts

Vk 2 with 20 % margin = 172 volts

Peak voltage = 243.0 Vpeak

Since CT rated knee point voltage is 3700V which is greater than the required value,

the proposed CT is adequate.

BAY NUMBER:

CROSS BAY C4

Sheet No.

13 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 17: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.4 CT: 810 B1.C4

Protection : Metering

Core : CT: 810 B1.C4

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : 0.2

VA Burden 50 VA

Thermal rating factor 200%

Application : Metering

Burden Calculation (Refer Annexure-2)

a LCP

Ammeter 0.5 VA (Assumed)

b Revenue metering panel

ABB, ALPHA A3R 1E-04 VA ( Refer Annexure-1 Sh. No. 18 )

c Mosaic panel

Watt transducer, , AREVA, ISTAT300 1 VA ( Refer Annexure-1 Sh. No. 13 )

Var transducer, AREVA, ISTAT300 1 VA ( Refer Annexure-1 Sh. No. 13 )

Watt meter, PML ION6200 0.5 VA (Assumed)

Var meter PML ION6200 0.5 VA (Assumed)

d DSM 0.1 VA (Assumed)

Cabling loop (500 meters)

For 4 sq.mm copper cable, RL= 0.00461 ohm/meter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1));

Consider length of wire = 500 meters. RL = 2.812 Ohms

2RL = 5.624 VA

Total connected burden, PBC = 9.224 VA

Considering 25% safe margin, connected VA equals to= 11.53 VA

CT Rated burden = 50VA

The total connected burden is less than the CT rated burden i.e 50VA. Hence the CT is adequate.

BAY NUMBER:

CROSS BAY C4

Sheet No.

14 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 18: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.5 CT: 810 F.C3

Protection : Spare

Core : CT: 810 F.C3

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 4.65 Ohms at 3000A tap.

Knee point voltage, Vk Vk > 5550 V at 3000A tap

CT excitation current at 3000A tap in mA Ie < 50

Thermal rating factor 200%

Application : Spare

BAY NUMBER:

CROSS BAY C4

Sheet No.

15 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 19: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.6 CT: 810 F.C2

Protection : Bus-bar protection (87M2)

Core : CT: 810 F.C2

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 4.65 Ohms at 3000A tap.

Knee point voltage, Vk Vk > 5550 V at 3000A tap

CT excitation current at 3000A tap in mA Ie < 50

Thermal rating factor 200%

NOTE:

Typical bus-bar protection CT's core detail for adjacent cross bay's(3 nos. including future bays)

are shown below.

Protection : Bus-bar protection (87M2)

Core : Core 2

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 4.65 Ohms at 3000A tap.

Knee point voltage, Vk Vk > 5550 V at 3000A tap

CT excitation current at 3000A tap in mA Ie < 50

Thermal rating factor 200%

Application : Bus-Bar Protection-Main-2 (87M2)

Relay Type / Make: "MFAC14", AREVA (Setting range: 25V-325V)

2.6.1 CT Calculation

The setting voltage is determined by the following relationship. (Refer Annexure-1, Sh. No.11)

Vs > 1.2 x If x ( RCT + 2 x RL ) (20% additional margin is taken)

Where For 3000

I P = Nominal ( rated) CT primary Current 3000 amps

I S = Nominal ( rated) CT secondary Current 1 amps

IF = Maximum Fault Current = 63000 amps

If = CT secondary fault current = 21 amps

RCT = Internal CT secondary resistance 4.65 ohms

BAY NUMBER:

CROSS BAY C4

Sheet No.

16 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 20: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

RL = Lead resistance of cable. = 1.88 Ohms

=For 6 sq.mm copper cable, RL= 0.00308 ohm/meter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1)) RL = 1.88 ohms.

Consider length of cable = 500 meters.

Vk = Specified knee point voltage = 5550 Volts

Calculation of relay setting voltage:

Vs > 1.2 x If x ( RCT + 2 x RL )

Vs > 1.2 x 21 x (4.65 + 3.76 )

Vs > 211.932

Hence select Vs = 275 Vrms

Peak voltage = 388.91 Vpeak

Hence, select a metrosil with setting range 25V- 325V and set at 275 volts.

2.6.2 Metrosil requirement

For this relay Metrosil proposed by the manufacturer has the following parameters.

C = 900

β = 0.25

The current drawn by metrosil at relay setting voltage is given by formulae below.

Irms drawn = 0.52((√2xV')/C))1/β

where V' = voltage in (RMS Sine)

Metrosil recommended for 25-325V relay range @ 2kVrms

Irms drawn = 0.52x((√2x2000)/900)1/0.25

= 50.72 A rms

At voltage setting Vs = 275V, Metrosil draws about 18mA

%Error = (0.018 / Ifs ) x 100

= (0.018 / 21 ) x 100

= 0.086%

Error introduce by metrosil at voltage setting Vs = 275V is 0.086% only.

BAY NUMBER:

CROSS BAY C4

Sheet No.

17 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 21: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Metrosil selection: (Refer Annexure-8)

To limit voltage to 2kVrms, select metrosil same as recommended by MFAC 14 for Vs = 275V

C = 900

β = 0.25

As per M&I materials catalogue attached, for the above 'C' and 'β' characteristics, the recommended

metrosil type is 600A/S1/S1088.

We recommend standard metrosil as per AREVA recommandation only as the relay & scheme is by AREVA.

CT secondary fault current calculated as above = 21 Amps.

Hence, Metrosil withstanding capability is greater than CT secondary current.

2.6.3 Determination of primary fault current setting:

At 3000/1 A tap

Taking Primary fault currrent setting as 1% of maximum fault current i.e 63000 Amps.

1% of bus-bar fault current = 630 amps

Primary Fault current setting Calculation

The primary operating current or fault setting calculated as Ip= { n Im+ Ir +IM+IV}xT

Ip = Primary fault setting

n = number of CTs in parallel including 3 future bays = 8.0

Im = exciting current of each CT at the relay circuit setting voltage 0.005 Amps

RMVTP31 = Resistance of CT supervision relay MVTP 31(Assumed) 90000.0 ohms

IV = Current in MVTP11 relay, (Vs/RMVTP31) 0.003 Amps

IM = current in metrosil at the relay circuit setting voltage 0.018 Amps

Ir = Relay operating current as per MFAC manual for setting range 25-325V 0.03 Amps

Where relay setting voltage is low then current in non linear resistor is ignored.

Primary fault setting (Ip) = {n Im+ Ir +IM+IV}xT

= 273.167

This current is too small as compared to 63kA i.e 0.43% of 63kA.

It is observed that the primary operating current is less than 630A.

Hence, an external shunt resistor (Rsh) needs to be connected inorder to get a primary operating current 630A.

Select shunt resistor to get primary operating current of say 742 Amps.

Ip = { nIe+ Ir +IM+(Vs/Rsh)+IV}xT

742 = {8x0.005+0.03+0.018+(275/Rsh)+0.003} x3000 0.156

The value of external shunt resistor required is calculated as Rsh = 1759.7 ohms

As per AREVA MCAG14 catalogue attached Annexure-2 sheet no. 4

Select a resistor 2700 ohms and set at 1760 ohms with the short time current rating (1 seconds) of 1.3 Amps.

BAY NUMBER:

CROSS BAY C4

Sheet No.

18 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 22: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.6.4 Shunt resistor Wattage calculation:

Current in shunt resistor at setting voltage Vs =275 Volts;= 275 = 0.16 Amps.

Shunt resistor Wattage = 0.16x0.16x1760 Watts. 1759.7

45.06 Watts.

Hence, select a shunt resistor of 50 watts.

Hence, Primary operating current calculated =

Primary fault setting (Ip) = {n Im+ Ir +IM+IV+IRsh}T

= 742.0 Amps.

BAY NUMBER:

CROSS BAY C4

Sheet No.

19 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 23: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.7 CT: 810 F.C1

Protection : Bus-bar protection (87M1)

Core : CT: 810 F.C1

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 4.65 Ohms at 3000A tap.

Knee point voltage, Vk Vk > 5550 V at 3000A tap

CT excitation current at 3000A tap in mA Iex < 50

Thermal rating factor 200%

NOTE:

Typical bus-bar protection CT's core detail for adjacent cross bay's(3 nos. including future bays)

are shown below.

Protection : Bus-bar protection (87M1)

Core : Core 1

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 4.65 Ohms at 3000A tap.

Knee point voltage, Vk Vk > 5550 V at 3000A tap

CT excitation current at 3000A tap in mA Ie < 50

Thermal rating factor 200%

Application : Bus-Bar Protection-Main-1 (87M1)

Relay Type / Make: "MCAG 14", AREVA (Setting range: 20%-80% of 1A)

2.7.1 CT Requirement

Where For 3000 A

Vk Knee point voltage = 5550 volts

Vs Setting Voltage

I P = Nominal ( rated) CT primary Current = 3000 amps

T = Turn ratio = 1/3000

I s = Nominal ( rated) CT secondary Current = 1 amps

I F = Maximum short circuit current = 63000 amps

If = CT secondary fault current in amps. = 21 amps

BAY NUMBER:

CROSS BAY C4

Sheet No.

20 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 24: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

RCT = Internal CT secondary resistance = 4.65 ohms

RL = Lead resistance of cable. = 1.88 Ohms

=For 6 sq.mm copper cable, RL= 0.00308 ohm/meter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1)) RL = 1.88 ohms.

Consider length of cable = 500 meters.

RB-MCAG =Relay Burden = 1.00 VA

RRMCAG = Relay resistance = RB / Is 2 = 1.00 ohms

The setting voltage Vs shall be calculated in order to ensure the stability of the protection in

regard with the maximum through fault current If . The setting voltage is determined by the following eqn.

Vs > 1.2 x If x ( RCT + 2 x RL ) (Refer Annexure-1, Sh.No.8)

Vs > 1.2 x 21 x (4.65 + 3.76 )

Vs > 211.932

Hence, select Vs same as Main-2 protection = 275 Vrms

Peak voltage = 388.91 Vpeak

2.7.2 Voltage Llimiting Resistor- Metrosiles: (Refer MCAG 14 sheet attached)

To establish the requirement for a Metrosil the peak voltage needs to exceed 3kV.

Hence V rms needs to be exceeded is equal to (Vpk/ root2) = 2.12 kV

VPK = ( 2 VK ( V f -VK)) 1/2

Where VPK = Peak voltage of the voltage wave form.

Vf = If x Tx(RCT+2RL+Rsr+RRMCAG)

Where

V f = Maximum voltage in absence of saturation = 28547.6 volts

VPK = ( 2x5550x (28547.6- 5550))1/2 = 15977.28 volts

= 15.98 kVolts

VPK is 15.98kV which is more than 3kV hence Metrosiles are required.

Therefore select metrosil to limit the secondary voltage to 3kV peak.

BAY NUMBER:

CROSS BAY C4

Sheet No.

21 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 25: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Metrosil requirement

For this relay Metrosil proposed by the manufacturer has the following parameters.

C = 900

β = 0.25

The current drawn by metrosil at relay setting voltage is given by formulae below.

Irms drawn = 0.52((√2xV')/C))1/β

where V' = voltage in (RMS Sine)

Metrosil recommended for 25-325V relay range @ 2kVrms

Irms drawn = 0.52x((√2x2000)/900)1/0.25

= 50.72 A rms

At voltage setting Vs = 275V, Metrosil draws about 18mA

%Error = (0.018 / Ifs ) x 100

= (0.018 / 21 ) x 100

= 0.387%

Error introduce by metrosil at voltage setting Vs = 275V is 0.086% only.

Metrosil selection: (Refer Annexure-9)

To limit voltage to 2kVrms, select metrosil same as recommended by MCAG14 for Vs = 275V

C = 900

β = 0.25

As per M&I materials catalogue attached, for the above 'C' and 'β' characteristics, the recommended

metrosil type is 600A/S1/S1088.

We recommend standard metrosil as per AREVA recommandation only as the relay & scheme is by AREVA.

CT secondary fault current calculated as above = 21 Amps.

Hence, Metrosil withstanding capability is greater than CT secondary current.

2.7.3 Determination of primary fault current setting:

Taking Primary fault currrent setting as 1% of maximum fault current i.e 63000 Amps.

1% of bus-bar fault current = 630 amps

Primary Fault current setting Calculation

The primary operating current or fault setting calculated as Ip= { n Im+ Ir +IM+IV}xT

Ip = Primary fault setting

n = number of CTs in parallel including 3 future bays = 8.0

Im = exciting current of each CT at the relay circuit setting voltage 0.005 Amps

RMVTP31 = Resistance of CT supervision relay MVTP 31(Assumed) 90000.0 ohms

BAY NUMBER:

CROSS BAY C4

Sheet No.

22 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 26: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

IV = Current in MVTP11 relay, (Vs/RMVTP31) 0.003 Amps

IM = current in metrosil at the relay circuit setting voltage (Assumed) '= 0.018 Amps

Ir = Relay setting current 0.20 Amps

Where relay setting voltage is low then current in non linear resistor is ignored.

=

Primary fault setting (Ip) = { n Im+ Ir +IM+IV}xT

{(8x0.005)+0.2+0.018+0.003}x3000

= 783.2 Amps.

2.7.4 Determination of stabilising resistor Rsr: (Refer MCAG 14 Manual attached, Annex-1, Sh. No.10)

Relay circuit Voltage Vs = 275.00 Volts

Relay setting current, Is = 0.20 Amps

Relay burden at 275V setting is considered as 1VA,

Stabilising resistor required, Rsr = (Vs/Ir) - (Relay burden)/(Ir^2) =Rs= 1350.00 ohms

Select a resistor of range (0 -1500 ohms),0.31A continous,1.36A/3sec,1.8A/1sec as per MCAG 14 Manual.

BAY NUMBER:

CROSS BAY C4

Sheet No.

23 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 27: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.8 CT: 811 B1.C1

Protection : CB fail protection

Core : CT: 811 B1.C1

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 3.1 Ohms at 2000A tap.

Knee point voltage, Vk Vk > 3700 V at 2000A tap

CT excitation current at 2000A tap in mA Ie < 75

Thermal rating factor 200%

Application : CB Fail Protection (50BF)

Relay Type / Make: "RAICA", ABB,(50BF)

CT calculation same as CT: 810 B1.C1. Refer above CT: 810 B1.C1 for detailed calculation.

BAY NUMBER:

CROSS BAY C4

Sheet No.

24 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 28: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.9 CT: 811 B1.C2

Protection : OHL feeder protn. -Set-1 (87L-1,21-1)

Core : CT: 811 B1.C2

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 3.1 Ohms at 2000A tap.

Knee point voltage, Vk Vk > 3700 V at 2000A tap

CT excitation current at 2000A tap in mA Ie < 75

Thermal rating factor 200%

Application : OHL feeder protection Set-1 (87L-1,21-1)

Relay Type / Make: "RED 670", ABB

2.9.1 Line Data: (Refer Annexure-7 attached)

Line length as per annexure attached = 50 km

Z1 = 0.00055+j 0.0108 p.u Base MVA = 100

Z0 = 0.00545+j 0.0322 p.u Base kV = 380

Base Impedance calculated = (BasekV2) = 1444 ohms

Base MVA

Base Current calculated = (Base MVA) = 151.9 amps

√3 x Base kV

Zline in ohms calculated; R1= 0.794 ohms

(Base Impedance x p.u Impedance) X1= 15.6 ohms

R0= 7.87 ohms

X0= 46.5 ohms

X/R = 17 Phase volt.= 219393.1 Volts

sin(tan-1(X/R)) = 0.998 Phase Curr.=63000 Amperes

cos(tan-1(X/R)) = 0.059

2.9.2 Source impedance:

Xs = (Ph vol/Ph cu)xsin(tan-1

(X/R)) Rs = (Ph vol/Ph cu)xcos(tan-1

(X/R))

= 380000 x sin(tan-1

(X/R)) = 380000 x cos(tan-1

(X/R))

Sqrt.(3)x63000 Sqrt.(3)x63000

= 3.48 ohms = 0.20 ohms

Z s = 0.2 + j 3.48 ohms

BAY NUMBER:

CROSS BAY C4

Sheet No.

25 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 29: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.9.3 Line impedance:

X1 full Line: Line length x Reactance value/km X0 full Line: Line length x Reactance value/km

= 15.5952 ohms = 46.4968 ohms

R1 full Line: Line length x Resistance value/km R0 full Line: Line length x Resistance value/km

= 0.7942 ohms = 7.8698 ohms

Z1 line = 0.7942 + j 15.6 ohms Z0 line = 7.8698 + j 46.5 ohms

2.9.4 THREE PHASE FAULT CONDITION

Close in Fault

Fault current = 63 kA

X/R = 17

Source Imp. Z1=Z2=Z0 =0.2 + j 3.48 ohms

Through fault current at the end of the line:

1) For 50 Km line

Impedance calculated : (Rs + R1) + j(Xs+X1)

(Positive sequence) = (0.2+0.794) + j (3.48+15.6)

= 0.994+j19.08 ohms

ZT1 = 19.11 ohms

Phase fault current = Ph. Volt / Ph. Imp.

= 380000

Sqrt.(3)x19.11

= 11483.02 Amps

Phase fault X/R = 19.08

0.994

= 19.20

BAY NUMBER:

CROSS BAY C4

Sheet No.

26 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 30: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Fault current calculation at the end of zone1 fault i.e 80% of line length:

1) For 50 Km line

Impedance calculated : (Rs+0.8R1) + j(Xs+0.8X1)

(Positive sequence) = (0.2+0.635) + j (3.48+12.5)

= 0.84+j16

ZT1 = 16.02 ohms

Phase fault current = Ph. Volt / Ph. Imp.

= 380000

Sqrt.(3)x16.02

= 13693.21 Amps

Phase fault X/R = 15.98

0.835

= 19.14

2.9.5 SINGLE PHASE-GROUND FAULT CONDITION:

Through fault current at the end of the line:

1) For 50 Km line

Impedance calculated : (3Rs+2R1+R0) +

(Loop Impedance) j(3Xs+2X1+X0)

= 10.08+j88.12 ohms

ZT1 = 88.69 ohms

Earth fault current = Ph. Volt / Ph. Imp.

= 380000

Sqrt.(3)x88.69

I0 = 2473.58 Amps

Earth fault X/R = 88.12

10.08

= 8.74

3I0 = 7420.73 Amps

BAY NUMBER:

CROSS BAY C4

Sheet No.

27 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 31: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Fault current calculation at the end of zone1 fault i.e 80% of line length:

1) For 50 Km line

Impedance calculated : (3Rs+0.8x2R1+R0) +

(Loop Impedance) j(3Xs+0.8x2X1+X0)

= 8.18+j72.5 ohms

ZT1 = 72.96 ohms

Earth fault current = Ph. Volt / Ph. Imp.

= 380000

Sqrt.(3)x72.96

= 3007.03 Amps

Earth fault X/R = 72.50

8.18

= 8.86

3I0= = 9021.097278 Amps

2.9.6 CT Requirement : ( As per Annexure-1, Sh. No.2)

Eal > Ealreq = {I kmax x I sn} / Ipn x (RCT + RL + SR / Ir 2

) Equation-1

Eal > Ealreq = 2 x {I tmax x I sn} / Ipn x (RCT + RL + SR / Ir 2 ) Equation-2

Eal > Ealreq = Itfdb x (Isn / Ipn) x (RCT + RL + SR / Ir 2

) Equation-3

Where,

Ikmax = Maximum Primary fundamental frequency fault current for internal close-in faults (A)

Itfdb = Maximum Primary fundamental frequency fault current for external faults (A) that

passes through two CT's (A).

Here for one and half breaker scheme Ikmax is equal to Itfdb.

Ipn = The rated primary CT current (A)

Isn = The rated secondary CT current (A)

Ir = The rated current of the protection IED (A)

SR = The burden of IED 670 a current input channel (VA). SR = 0.25 VA/channel.

Where, For 2000 amps

Ealreq=

Eal = = 3700 volts

I K max = Maximum short circuit current-Three phase = 63000 amps

Itfdb = Maximum Primary fault current for external faults (A) = 63000 amps

I pn = Nominal ( rated) CT primary Current = 2000 amps

Required secondary e.m.f.

Rated equivalent secondary e.m.f.= Vk

BAY NUMBER:

CROSS BAY C4

Sheet No.

28 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 32: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

I sn = Nominal ( rated) CT secondary Current = 1 amps

RCT = CT secondary winding resistance = 3.1 ohms

RB = = 0.25 ohms

RL = Lead resistance of cable.

=For 6 sq.mm copper cable, RL= 3.08 ohm/kmeter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1)) RL 1.88

Consider length of cable = 500 meters. 2RL = 3.76 ohms

I r = = 1 amps

f = = 60 Hz

Imin Sat=

X/R = = 17

Tp = Primary time constant, (L/R)

L/R = (X/(2x 3.14x f )/R

.= ( 17 / 2x 3.14x 60) x 1000 = 45.09 msec

RTFR = Burden value for TFR (Refer Annexure-2,Sh. No.7) = 0.01 VA

Hence, total VA burden includong TFR = 0.26 VA

Voltage developed across CT as per ABB relay catalogue (Refer Annexure-1 Sh. No.2 )

At 2000/1 A tap

Considering 20% margin

Eal > Ealreq = {I kmax x I sn} / Ipn x (RCT + RL + SR / Ir 2

) Equation-1

Ealreq = 63000 x 1 x ( 3.1+ 1.88 + 0.26/1^2 ) = 224.3 volts

2000

With 20% extra margin Ealreq = 269.1 volts

Eal > Ealreq = 2 x {I tmax x I sn} / Ipn x (RCT + RL + SR / Ir 2

) Equation-2

Ealreq = 63000 x 1 x 2 x ( 3.1+ 1.88 + 0.26/1^2 ) = 448.6 volts

2000

With 20% extra margin Ealreq = 538.3 volts

System Frequency

Sat saturation detector min current

System ratio

Burden of relay

Protection terminal rated Current

BAY NUMBER:

CROSS BAY C4

Sheet No.

29 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 33: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

At 2000/1 A tap

Eal > Ealreq = Itfdb x (Isn / Ipn) x (RCT + RL + SR / Ir 2

) Equation-3

Ealreq = 63000 x 1x(3.1+ 1.88 +0.26/12

) = 224.3 volts

2000

With 20% extra margin Ealreq = 269.1 volts

Since CT rated knee point voltage is 3700V which is greater than the required value,

the proposed CT is adequate.

The Voltage developed across the CT secondary for distance protection (21L) feature as per

ABB catalogue. (Refer Annexure-1 Sh. No. 3 )

Requirement -1

At 2000/1 A tap

Eal > Ealreq = {I kmax x I sn} / Ipn x a x (RCT + RL + SR / Ir 2

) Equation-5

a' = 2 for primary time constant less than 50msec.

With 20% extra margin

Ealreq = 63000 x 1.2 x 2 x ( 3.1+ 1.88 + 0.26/1^2 ) = 538.3 volts

2000

Requirement -2

Eal > Ealreq = Ikzone1x k x (Isn / Ipn) x (RCT + RL + SR / Ir 2

) Equation-6

k' = 6 for primary time constant greater than 30 msec.

Ikzone1= Maximum primary fundamental fault current at the end of zone 1 reach.

At 2000/1 A tap and with 20% extra margin

Ealreq = 13693.21 x 1.2 x 6 x ( 3.1+ 1.88 +0.26/12

) = 350.98 volts

2000

Since CT rated knee point voltage is 3700V which is greater than the required value,

the proposed CT is adequate.

BAY NUMBER:

CROSS BAY C4

Sheet No.

30 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 34: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.10 CT: 811 B1.C3

Protection : OHL feeder protn. -Set-2 (87L-2,21-2)

Core : CT: 811 B1.C3

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 3.1 Ohms at 2000A tap.

Knee point voltage, Vk Vk > 3700 V at 2000A tap

CT excitation current at 2000A tap in mA Ie < 75

Thermal rating factor 200%

Application : OHL feeder protection - Set-2 (87L-2,21-2)

Relay Type/make : ''MiCOM P546", Areva.

2.10.1 CT Calculation

Where For 2000 amps

Vk = Knee point voltage of CT 3700 Volts

RB = Resistance of relay P543 = 0.04 ohms

Rr = Relay resistance

RCT = CT secondary winding resistance = 3.1 ohms

RL = Lead resistance of cable.

For 6 sq.mm copper cable, RL= 3.08 ohm/kmeter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1)) RL = 1.88 ohms

Consider length of cable = 500 meters. 2RL= 3.76 ohms

I P = Nominal ( rated) CT primary Current = 2000 amps

I S = Nominal ( rated) CT secondary Current = 1 amps

ISCC max = Maximum short circuit current-Three phase = 63000 amps

VK CT knee point voltage specified = 3700 volts

X/R = System ratio = 17

I f = Maximum value of through fault current for

stability ( multiple of Is) = I SCC max / IP = 31.50

( I f )x( X/R) = 535.5

BAY NUMBER:

CROSS BAY C4

Sheet No.

31 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 35: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

The CT should meet the following Vk requirement as per Areva publication.

( Refer Annexure-1 Sh. No. 5 - 6 )

Vk1 > K xI n x (RB + RCT +RL) (equation -1) for through fault condition

Vk 2 > KRPA xIFZ1 x (1+X/R)x(RB + RCT +RL+Rr) (equation -2) for zone1 fault condition

Vk3 > Kmax x IFmax x (RB + RCT +RL+Rr) (equation -3) for close-up fault

Vk1 = Accuracy limiting voltage for line through fault condition in volts

Vk2 = Accuracy limiting voltage for end of zone 1 line fault in volts

Vk2 = Accuracy limiting voltage for close in fault in volts

IFZ1 = Maximum secondary fault current for end of zone 1 fault in amps.

For 50kM line length , primary fault current (A) calculated is equal to = 13693.21

Amps. Hence, CT secondary fault current = 13693.21

2000

= 6.85 Amps.

KRPA = Fixed dimensioning factor for zone 1 fault and always = 0.6 (Refer Annex-1, Sh. No. 7)

Kmax = Fixed dimensioning factor for close in fault and always = 1.4 (Refer Annex-1, Sh. No. 7)

RB = Relay burden

Where K is dimensioning factor and depends upon the maximum value of through fault current(as a multiple of In)

and primary system X/R ratio.

For three end current differential schemes relay set at Is1=20%, Is2=2In, K1=30% and K2=100%,

K' is calculated as below. (Refer Annex-1, Sh. No. 6)

For through fault condition the fault current and X/R calculated above are

IF = 11483.02 Amps. (Primary); X/R = 19.20

CT secondary fault currect calculated = 5.74

If x X/R = 110.24

If, If x X/R < 1000xIn,

K> 40 + 0.35 x (If x X/R)

K> 40 + 0.35x(110.24)

K> 78.584

As per AREVA relay catalogue, K > 78.584

BAY NUMBER:

CROSS BAY C4

Sheet No.

32 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 36: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

CT requirement for through fault condition:

Vk = K x I n x ( RB + RCT +2RL )

.= 78.584 x 1 x ( 0.04 + 3.1 + 3.76 ) = 542 volts

Vk with 20 % margin = 651 volts

Peak voltage = 920.2 Vpeak

CT requirement for zone1 fault condition:

Vk 2 > KRPA xIFZ1 x (1+X/R)x(RB + RCT +RL+Rr)

= 0.6 x6.85 x (1+19.14) x (0.04 + 3.1 + 1.88) = 415 volts

Vk 2 with 20 % margin = 498 volts

Peak voltage = 704.8 Vpeak

CT requirement for close-up fault condition:

Vk3 > Kmax x IFmax x (RB + RCT +RL+Rr)

= 1.4 x 63000/2000 x (0.04 + 3.1 + 1.88) = 221 volts

Vk 2 with 20 % margin = 266 volts

Peak voltage = 375.7 Vpeak

Since, the CT rated knee point voltage is greater than the calculated value, the proposed CT is adequate.

BAY NUMBER:

CROSS BAY C4

Sheet No.

33 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 37: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.11 CT: 811 B1.C4

Protection : Metering

Core : CT: 811 B1.C4

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : 0.2

VA Burden 50 VA

Thermal rating factor 200%

Application : Metering

Burden Calculation (Refer Annexure-2)

a LCP

Ammeter 0.5 VA (Assumed)

b Energy metering panel

NEXUS/1262 3.2 VA (Refer Annex-2, Sh. No. 8)

c Mosaic panel

Watt transducer, , AREVA, ISTAT300 1 VA (Refer Annex-2, Sh. No. 13)

Var transducer, AREVA, ISTAT300 1 VA (Refer Annex-2, Sh. No. 13)

Watt meter, PML ION6200 0.5 VA (Assumed)

Var meter PML ION6200 0.5 VA (Assumed)

d DSM 0.1 VA (Assumed)

Cabling loop (500 meters)

For 4 sq.mm copper cable, RL= 0.00461 ohm/meter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1));

Consider length of wire = 500 meters. RL = 2.812 Ohms

2RL = 5.624 VA

Total connected burden, PBC = 12.42 VA

Considering 25% safe margin, connected VA equals to= 15.53 VA

CT Rated burden = 50VA

The total connected burden is less than the CT rated burden i.e 50VA. Hence the CT is adequate.

BAY NUMBER:

CROSS BAY C4

Sheet No.

34 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 38: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.12 CT: 811 B2.C4

Protection : Metering

Core : CT: 811 B2.C4

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : 0.2

VA Burden 50 VA

Thermal rating factor 200%

Application : Metering

CT calculation same as CT: 810 B1.C4. Refer above CT: 810 B1.C4 for detailed calculation.

2.13 CT: 811 B2.C3

Protection : OHL feeder protn. -Set-2 (87L-2,21-2)

Core : CT: 811 B2.C3

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 3.1 Ohms at 2000A tap.

Knee point voltage, Vk Vk > 3700 V at 2000A tap

CT excitation current at 2000A tap in mA Ie < 75

Thermal rating factor 200%

Application : OHL feeder protection - Set-2 (87L-2,21-2)

Relay Type/make : ''7SA522", Siemens.

CT calculation same as CT: 810 B1.C3. Refer above CT: 810 B1.C3 for detailed calculation.

BAY NUMBER:

CROSS BAY C4

Sheet No.

35 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 39: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.14 CT: 811 B2.C2

Protection : OHL feeder protn. Set-1 (87L-1,21-1)

Core : CT: 811 B2.C2

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 3.1 Ohms at 2000A tap.

Knee point voltage, Vk Vk > 3700 V at 2000A tap

CT excitation current at 2000A tap in mA Ie < 75

Thermal rating factor 200%

Application : OHL feeder protection Set-1 (87L-1,21-1)

Relay Type / Make: "REL 531", ABB

CT calculation same as CT: 810 B1.C2. Refer above CT: 810 B1.C2 for detailed calculation.

2.15 CT: 811 B2.C1

Protection : spare

Core : CT: 811 B2.C1

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 4.65 Ohms at 3000A tap.

Knee point voltage, Vk Vk > 5550 V at 3000A tap

CT excitation current at 3000A tap in mA Ie < 50

Thermal rating factor 200%

Application : spare

BAY NUMBER:

CROSS BAY C4

Sheet No.

36 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 40: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.16 CT: 812 F.C1

Protection : Bus-bar protection (87M1)

Core : CT: 812 F.C1

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 4.65 Ohms at 3000A tap.

Knee point voltage, Vk Vk > 5550 V at 3000A tap

CT excitation current at 3000A tap in mA Iex < 50

Thermal rating factor 200%

NOTE:

Typical bus-bar protection CT's core detail for adjacent cross bay's(3 nos. including future bays)

are shown below.

Protection : Bus-bar protection (87M1)

Core : Core 1

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 4.65 Ohms at 3000A tap.

Knee point voltage, Vk Vk > 5550 V at 3000A tap

CT excitation current at 3000A tap in mA Ie < 50

Thermal rating factor 200%

Application : Bus-Bar Protection-Main-1 (87M1)

Relay Type / Make: "MCAG 14", AREVA (Setting range: 20%-80% of 1A)

CT calculation same as above for 87M1. Refer above CT: 810 F.C1 for detailed calculation.

BAY NUMBER:

CROSS BAY C4

Sheet No.

37 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 41: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.17 CT: 812 F.C2

Protection : Bus-bar protection (87M2)

Core : CT: 812 F.C2

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 4.65 Ohms at 3000A tap.

Knee point voltage, Vk Vk > 5550 V at 3000A tap

CT excitation current at 3000A tap in mA Iex < 50

Thermal rating factor 200%

NOTE:

Typical bus-bar protection CT's core detail for adjacent cross bay's(3 nos. including future bays)

are shown below.

Protection : Bus-bar protection (87M2)

Core : Core 2

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 4.65 Ohms at 3000A tap.

Knee point voltage, Vk Vk > 5550 V at 3000A tap

CT excitation current at 3000A tap in mA Ie < 50

Thermal rating factor 200%

Application : Bus-Bar Protection-Main-2 (87M2)

Relay Type / Make: "MFAC 14", AREVA (Setting range: 25V-325V)

CT calculation same as above CT: 810 F.C2. Refer above CT: 810 F.C2 for detailed calculation.

BAY NUMBER:

CROSS BAY C4

Sheet No.

38 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 42: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.18 CT: 812 F.C3

Protection : Spare

Core : CT: 812 F.C3

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 4.65 Ohms at 3000A tap.

Knee point voltage, Vk Vk > 5550 V at 3000A tap

CT excitation current at 3000A tap in mA Iex < 50

Thermal rating factor 200%

Application: Spare

BAY NUMBER:

CROSS BAY C4

Sheet No.

39 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 43: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.19 CT: 812 B2.C4

Protection : Metering

Core : CT: 812 B2.C4

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : 0.2

VA Burden 50 VA

Thermal rating factor 200%

Application : Metering

CT calculation same as CT: 811 B1.C4. Refer above CT: 811 B1.C4 for detailed calculation.

2.20 CT: 812 B2.C3

Protection : OHL feeder protn. -Set-2 (87L-2,21-2)

Core : CT: 812 B2.C3

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 3.1 Ohms at 2000A tap.

Knee point voltage, Vk Vk > 3700 V at 2000A tap

CT excitation current at 2000A tap in mA Ie < 75

Thermal rating factor 200%

Application : OHL feeder protection - Set-2 (87L-2,21-2)

Relay Type/make : ''MiCOM P546", Areva.

CT calculation same as CT: 811 B1.C3. Refer above CT: 811 B1.C3 for detailed calculation.

BAY NUMBER:

CROSS BAY C4

Sheet No.

40 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 44: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

2.21 CT: 812 B2.C2

Protection : OHL feeder protn. Set-1 (87L-1,21-1)

Core : CT: 812 B2.C2

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms ) < 3.1 Ohms at 2000A tap.

Knee point voltage, Vk Vk > 3700 V at 2000A tap

CT excitation current at 2000A tap in mA Ie < 75

Thermal rating factor 200%

Application : OHL feeder protection Set-1 (87L-1,21-1)

Relay Type / Make: "RED 670", ABB

CT calculation same as CT: 811 B1.C2. Refer above CT: 811 B1.C2 for detailed calculation.

2.22 CT: 812 B2.C1

Protection : BF protection (50BF)

Core : CT: 812 B2.C1

CT Ratio : 3000-2500-2000-1500-1250-1000-750 /1A

Class of Accuracy : TPS

CT Secondary resistance at 75º C, RCT ohms < 3.1 Ohms at 2000A tap.

Knee point voltage, Vk Vk > 3700 V at 2000A tap

CT excitation current at 2000A tap in mA Ie < 75

Thermal rating factor 200%

Application : CB Fail Protection (50BF)

Relay Type / Make: "RAICA", ABB,(50BF)

CT calculation same as CT: 810 B1.C1. Refer above CT: 810 B1.C1 for detailed calculation.

BAY NUMBER:

CROSS BAY C4

Sheet No.

41 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 45: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

3

3.1 VT LEAD RESISTANCE CALCULATION :

VT secondary lead size considered is 4 sq.mm.

4 sq.mm copper cable resistance at 200C is 4.61 ohms/km.i.e Rdc at 20

0C = 4.61 ohm/km

Rdc at 75ºC = R20(1+α20(T2-T1)); α at 20ºC = 0.004,Where α= temperature co-efficient of resistance.

Hence, Rdc at 75ºC = 4.61(1+0.004(75-20));

= 5.62 ohm/km

Consider a distance from 380kV GIS CT to relay panel as per layout attached with considerable

safe margin = 500 meter, Lead resistance calculated is,

= 5.62 x 0.5

= 2.81 ohms for 500 meters

380kV ABU HADRIYAH- MANIFA LINE-2

CCVT Details :

Core-1 Core-2

VT Ratio : 380kV/√3/110V/√3-110V 380kV/√3/110V/√3-110V

Class : 0.2/3P 0.2/3P

VA Burden : 100 100

Vector group : Star-Star Star-Star

Voltage Factor : 1.2 Cont., 1.2 Cont.,

1.9 for 30 sec 1.9 for 30 sec

Calculation of VT burden :

Calculation of Lead burden:

RL = Lead resistance of wire.

For 4 sq.mm copper cable, RL= 0.00461 ohm/meter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1)), RL= 2.81 ohms

Calculation of Lead current at rated burden :(IVT) = 0.1939 Amperes

Lead current is calculated considering Total VA burden.

Hence, Lead current calculated =100/63.5 = 0.19 Amperes

RB= Lead burden, 2xRLx (IVT^2) = 0.2112 VA

RB= (2 x 2.81 x 0.1939 x 0.1939)

380kV VT SIZING CALCULATION

BAY NUMBER:

CROSS BAY C4

Sheet No.

42 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 46: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Core-1 :

Relay type Quantity Unit burdenTotal burden

(VA)

RXBA 4 1 2 2

RED670 1 0.1 0.1

TR2000 1 0.01 0.01

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

1 0.2 0.2

RXBA 4 1 2 2

Total VA = 12.31 VA per phase

Hence, total required burden of VT (Meters/relays plus lead burden) = 12.52 VA

.= (VA Connected + VA Lead)

The Burden calculated considering 25% safety margin = 15.7 VA

Since, the connected burden is less than 100VA,the VT burden is adequate.

FFR (98L2) (Ref.) for 25AR (Annexure-2 Sh. No.9)

DSM Assumed

FFR (98) 25AR/A811 FOR AF-2 (Annexure-2 Sh. No.9)

Relays / Instruments

FFR (98L) A811/A812 (Annexure-2 Sh. No.9)

Line set-1 protection (Annexure-2 Sh. No.2)

Transient Fault Recorder (Annexure-2 Sh. No.7)

FFR (98) (Meas.) for set-1 protection (Annexure-2 Sh. No.9)

FFR (98) (Ref.) for set-2 protection (Annexure-2 Sh. No.9)

FFR (98) (Ref.) for Energy meter (Annexure-2 Sh. No.9)

BAY NUMBER:

CROSS BAY C4

Sheet No.

43 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 47: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Core-2:

Relay type Quantity Unit burdenTotal burden

(VA)

KVAS100 1 0.02 0.02

KVAS100 1 0.02 0.02

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

MICOMP546 1 0.02 0.02

KVAS100 1 0.02 0.02

KVAS100 1 0.02 0.02

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

KVAS100 1 0.02 0.02

RAEDA1 3 4.4 13.2

Transducer Panel

Voltage transducer for SCADA ISTAT300 1 0.1 0.1

Watt meter Watt transducer for SCADA ISTAT300 1 0.1 0.1

Var meter Var transducer for SCADA ISTAT300 1 0.1 0.1

ION6200 1 0.5 0.5

ION6200 1 0.5 0.5

ION6200 1 0.5 0.5

Energy metering panel

Nexus/1262 1 5+3.2 8.2

RAEDA1 1 4.4 4.4

RXBA 4 1 2 2

LCP

RAEDA1 1 4.4 4.4

ION6200 1 0.5 0.5

Total VA = 46.62 VA per phase

Hence, total required burden of VT (Meters/relays plus lead burden) = 46.83 VA

.= (VA Connected + VA Lead)

The Burden calculated considering 25% safety margin = 58.5 VA

Since, the connected burden is less than 100VA,the provided VT burden is adequate.

Under voltage relay

Under voltage relay

Voltmeter

FFR (98L2) (Meas.) / 25AR (Annexure-2 Sh. No.9)

FFR (98B2) (Meas.) / A812 (Annexure-2 Sh. No.9)

FFR (98) (Meas.) / A811 (Annexure-2 Sh. No.9)

(Annexure-2 Sh. No. 13)

(Annexure-2 Sh. No. 13)

(Annexure-2 Sh. No. 13)

Wattmeter, PML

VARmeter, PML

Energy meter

(Annexure-2 Sh. No. 11)

25MC/A812 (Annexure-2 Sh. No.10)

Assumed

Assumed

Voltmeter, PML

Assumed

FFR (98) (Meas.) for revenue meter

(Annexure-2 Sh. No. 8)

(Annexure-2 Sh. No. 11)

(Annexure-2 Sh. No. 11)

Assumed

(Annexure-2 Sh. No.9)

(Annexure-2 Sh. No.10)

FFR (98L) (Meas.) A811/A812 (Annexure-2 Sh. No.9)

FFR (98) (Ref.) for set-1 protection (Annexure-2 Sh. No.9)

25AR / A812 (Annexure-2 Sh. No.10)

25AR / A811

Relays / Instruments

25MC/A811

FFR (98) (Meas.) for 67N-2 (Annexure-2 Sh. No.9)

Line set-2 protection (Annexure-2 Sh. No.3)

(Annexure-2 Sh. No.10)

25AR / A811 FOR AF-2 (Annexure-2 Sh. No.10)

(27L2), Under voltage relay

BAY NUMBER:

CROSS BAY C4

Sheet No.

44 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 48: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

3.3 380kV ABU HADRIYAH- AL-FADHILI LINE-2

CCVT Details :

Core-1 Core-2

VT Ratio : 380kV/√3/110V/√3-110V 380kV/√3/110V/√3-110V

Class : 0.2/3P 0.2/3P

VA Burden : 100 100

Vector group : Star-Star Star-Star

Voltage Factor : 1.2 Cont., 1.2 Cont.,

1.9 for 30 sec 1.9 for 30 sec

Calculation of VT burden :

Calculation of Lead burden:

RL = Lead resistance of wire.

For 4 sq.mm copper cable, RL= 0.00461 ohm/meter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1)), RL= 2.81 ohms

Calculation of Lead current at rated burden :(IVT) = 0.1954 Amperes

Lead current is calculated considering Total VA burden.

Hence, Lead current calculated =100/63.5 = 0.20 Amperes

RB= Lead burden, 2xRLx (IVT^2) = 0.2147 VA

RB= (2 x 2.81 x 0.1954 x 0.1954)

Core-1 :

Relay type Quantity Unit burdenTotal burden

(VA)

RXBA 4 1 2 2

REL 531 1 0.2 0.2

TR2000 1 0.01 0.01

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

1 0.2 0.2

RXBA 4 1 2 2

Total VA = 12.41 VA per phase

Hence, total required burden of VT (Meters/relays plus lead burden) = 12.62 VA

.= (VA Connected + VA Lead)

The Burden calculated considering 25% safety margin = 15.8 VA

Since, the connected burden is less than 100VA,the VT burden is adequate.

FFR (98L) (Ref.) for 25MC 810 (Annexure-2 Sh. No.9)

DSM Assumed

FFR (98) (Ref.) for 67N-2 (Annexure-2 Sh. No.9)

FFR (98) (Ref.) for Energy meter (Annexure-2 Sh. No.9)

FFR (98L2) (Ref.) for 25AR (Annexure-2 Sh. No.9)

Line set-1 protection (Annexure-2 Sh. No.15)

Transient Fault Recorder (Annexure-2 Sh. No.7)

FFR (98) (Meas.) for 67N-1 (Annexure-2 Sh. No.9)

Relays / Instruments

FFR 98-25AR/A811 FOR MAIN-2 (Annexure-2 Sh. No.9)

BAY NUMBER:

CROSS BAY C4

Sheet No.

45 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 49: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Core-2:

Relay type Quantity Unit burdenTotal burden

(VA)

RASC 1 0.25 0.25

RASC 1 0.25 0.25

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

7SA522 1 0.1 0.1

RASC 1 0.25 0.25

RASC 1 0.25 0.25

RAEDA1 3 4.4 13.2

RXBA 4 1 2 2

Transducer Panel

Voltage transducer for SCADA ISTAT300 1 0.1 0.1

Watt meter Watt transducer for SCADA ISTAT300 1 0.1 0.1

Var meter Var transducer for SCADA ISTAT300 1 0.1 0.1

PML 1 0.5 0.5

PML 1 0.5 0.5

PML 1 0.5 0.5

Revenue metering panel

ELESTER 1 0.0173 0.0173

RAEDA1 1 4.4 4.4

RXBA 4 1 2 2

LCP

FVS-U-

DC121 4.4 4.4

PML 1 0.5 0.5

Total VA = 35.42 VA per phase

Hence, total required burden of VT (Meters/relays plus lead burden) = 35.63 VA

.= (VA Connected + VA Lead)

The Burden calculated considering 25% safety margin = 44.5 VA

Since, the connected burden is less than 100VA,the provided VT burden is adequate.

FFR (98) (Meas.) for revenue meter (Annexure-2 Sh. No.9)

Under voltage relay Assumed

Voltmeter Assumed

VARmeter Assumed

Revenue meter (Annexure-2 Sh. No. 18)

Under voltage relay (Annexure-2 Sh. No. 11)

(Annexure-2 Sh. No.13)

(Annexure-2 Sh. No.13)

(Annexure-2 Sh. No.13)

Voltmeter Assumed

Wattmeter Assumed

25AR / A810 (Annexure-2 Sh. No.17)

27-L2 Under voltage relay (Annexure-2 Sh. No. 11)

FFR (98B1) (Meas.) /A810 (Annexure-2 Sh. No.9)

25AR / A811 FOR MAIN-2 (Annexure-2 Sh. No.17)

FFR (98) (Ref.) for 67N-1 (Annexure-2 Sh. No.9)

FFR (98) (Meas.) for 67N-2 (Annexure-2 Sh. No.9)

Line set-2 protection (Annexure-2 Sh. No.16)

Relays / Instruments

25MC/A811 (Annexure-2 Sh. No.17)

25MC/A810 (Annexure-2 Sh. No.17)

FFR (98L) (Meas.) A810/A811 (Annexure-2 Sh. No.9)

BAY NUMBER:

CROSS BAY C4

Sheet No.

46 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 50: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

3.4 380kV BUS1-VT (Refer Annexure-4A)

VT Details :

Core-1 Core-2

VT Ratio : 380kV/√3/110V/√3-110V 380kV/√3/110V/√3-110V

Class : 0.2/3P 0.2/3P

VA Burden : 100 100

Vector group : Star-Star Star-Star

Voltage Factor : 1.2 Cont., 1.2 Cont.,

1.9 for 30 sec 1.9 for 30 sec

Calculation of VT burden :

Calculation of Lead burden:

RL = Lead resistance of wire.

For 4 sq.mm copper cable, RL= 0.00461 ohm/meter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1)), RL= 2.81 ohms

Calculation of Lead current at rated burden :(IVT) = 0.0945 Amperes

Lead current is calculated considering Total VA burden.

Hence, Lead current calculated =100/63.5 = 0.09 Amperes

RB= Lead burden, 2xRLx (IVT^2) = 0.0502 VA

RB= (2 x 2.81 x 0.0945 x 0.0945)

Core-1 :

Relay type Quantity Unit burdenTotal burden

(VA)

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

Total VA = 6 VA per phase

Hence, total required burden of VT (Meters/relays plus lead burden) = 6.05 VA

.= (VA Connected + VA Lead)

Considering 25% safety margin for any additional FFR relay required.

The Burden calculated considering 25% safety margin = 7.6 VA

Since, the connected burden is less than 100VA,the VT burden is adequate.

FFR (98B1) (Meas.) 25AR/810 (Annexure-2 Sh. No.9)

FFR (98B1) (Meas.) 25AR/807 (Annexure-2 Sh. No.9)

FFR (98B1)-25MC/A810 (Annexure-2 Sh. No.9)

Relays / Instruments

BAY NUMBER:

CROSS BAY C4

Sheet No.

47 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 51: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Core-2:

Relay type Quantity Unit burdenTotal burden

(VA)

RASC 1 0.25 0.25

KVAS100 1 0.02 0.02

RASC 1 0.25 0.25

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

RASC 1 0.25 0.25

RASC 1 0.25 0.25

TR2000 1 0.01 0.01

1 0.2 0.2

Transducer panel

Voltage transducer for SCADA ISTAT300 1 0.1 0.1

PML 1 0.5 0.5

LCC

PML 1 0.5 0.5

Total VA = 8.33 VA per phase

Hence, total required burden of VT (Meters/relays plus lead burden) = 8.38 VA

.= (VA Connected + VA Lead)

Considering 25% safety margin for any additional FFR relay required.

The Burden calculated considering 25% safety margin = 10.5 VA

Since, the connected burden is less than 100VA,the provided VT burden is adequate.

25MC/A804 (Annexure-2 Sh. No.17)

25MC/A807 (Annexure-2 Sh. No.10)

25MC/A810 (Annexure-2 Sh. No.17)

98B1-25MC/810 (Annexure-2 Sh. No.9)

25AR / A807 (Annexure-2 Sh. No.17)

98B1-25AR/807 (Annexure-2 Sh. No.9)

98B1-25AR/810

DSM Assumed

(Annexure-2 Sh. No.9)

25AR / A810

Transient Fault Recorder (Annexure-2 Sh. No.7)

Voltmeter

AssumedVoltmeter

Relays / Instruments

(Annexure-2 Sh. No.17)

(Annexure-2 Sh. No.13)

Assumed

BAY NUMBER:

CROSS BAY C4

Sheet No.

48 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 52: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

3.5 380kV BUS2-VT

VT Details : (Refer Annexure-4A)

Core-1 Core-2

VT Ratio : 380kV/√3/110V/√3-110V 380kV/√3/110V/√3-110V

Class : 0.2/3P 0.2/3P

VA Burden : 100 100

Vector group : Star-Star Star-Star

Voltage Factor : 1.2 Cont., 1.2 Cont.,

1.9 for 30 sec 1.9 for 30 sec

Calculation of VT burden :

Calculation of Lead burden:

RL = Lead resistance of wire.

For 4 sq.mm copper cable, RL= 0.00461 ohm/meter at 20ºC.

α at 20ºC = 0.004, RL at 75ºC = RL(1+α20(T2-T1)), RL= 2.81 ohms

Calculation of Lead current at rated burden :(IVT) = 0.0945 Amperes

Lead current is calculated considering Total VA burden.

Hence, Lead current calculated =100/63.5 = 0.09 Amperes

RB= Lead burden, 2xRLx (IVT^2) = 0.0502 VA

RB= (2 x 2.81 x 0.0945 x 0.0945)

Core-1 :

Relay type Quantity Unit burdenTotal burden

(VA)

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

Total VA = 6 VA per phase

Hence, total required burden of VT (Meters/relays plus lead burden) = 6.05 VA

.= (VA Connected + VA Lead)

Considering 25% safety margin for any additional FFR relay required.

The Burden calculated considering 25% safety margin = 7.6 VA

Since, the connected burden is less than 100VA,the VT burden is adequate.

Relays / Instruments

FFR (98B2) (Meas.) 25AR/806 (Annexure-2 Sh. No.9)

FFR (98B2) (Meas.) 25AR/812 (Annexure-2 Sh. No.9)

FFR (98B2)-25MC/A812 (Annexure-2 Sh. No.9)

BAY NUMBER:

CROSS BAY C4

Sheet No.

49 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 53: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT:

ABU-HADRIYAH 380/115 kV BSP

DOCUMENT TITLE:

380 kV CT/VT SIZING CALCULATION

DOCUMENT NUMBER:

EA-086959

Core-2:

Relay type Quantity Unit burdenTotal burden

(VA)

RASC 1 0.25 0.25

RASC 1 0.25 0.25

KVAS100 1 0.02 0.02

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

RASC 1 0.25 0.25

KVAS100 1 0.02 0.02

TR2000 1 0.01 0.01

1 0.2 0.2

Transducer panel

Voltage transducer for SCADA ISTAT300 1 0.1 0.1

PML 1 0.5 0.5

LCC

PML 1 0.5 0.5

Total VA = 8.1 VA per phase

Hence, total required burden of VT (Meters/relays plus lead burden) = 8.15 VA

.= (VA Connected + VA Lead)

Considering 25% safety margin for any additional FFR relay required.

The Burden calculated considering 25% safety margin = 10.2 VA

Since, the connected burden is less than 100VA,the provided VT burden is adequate.

25MC/A806

Voltmeter Assumed

(Annexure-2 Sh. No.7)

DSM Assumed

(Annexure-2 Sh. No.13)

Voltmeter Assumed

(Annexure-2 Sh. No.17)

25MC/A809 (Annexure-2 Sh. No.17)

25MC/A812 (Annexure-2 Sh. No.10)

Relays / Instruments

(Annexure-2 Sh. No.9)

98B2-25AR/806 (Annexure-2 Sh. No.9)

98B2-25MC/812

98B2-25AR/812 (Annexure-2 Sh. No.9)

25AR / A806 (Annexure-2 Sh. No.17)

25AR / A812 (Annexure-2 Sh. No.10)

Transient Fault Recorder

BAY NUMBER:

CROSS BAY C4

Sheet No.

50 of 50

ABU-HADRIYAH CONTRACT No.

3-083300.01

Page 54: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 1

ANNEXURE-1

CT requirements of relay

Sr No. Description Make Type Page No.

1 Line differential protection main-1 ABB RED670 2

2 Line differential protection main-2 AREVA MICOMP546 5

3 Busbar differential protection AREVA MCAG14 8

4 Busbar differential protection AREVA MFAC14 11

5 CT circuit supervision relay AREVA MVTP11 15

6 Breaker failure protection relay ABB RAICA 16

7 Transient fault recorder ROCHESTER TR2000 17

8 Line differential protection main-1 ABB REL531 20

9 Line differential protection main-2 SIEMENS 7SA522 24

Page 55: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 2

Page 56: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 3

Page 57: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 4

Page 58: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 5

Page 59: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 6

Page 60: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 7

Page 61: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 8

Page 62: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 9

Page 63: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 10

Page 64: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 11

Page 65: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 12

Page 66: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 13

Page 67: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 14

Page 68: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 15

Page 69: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 16

Page 70: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 17

Page 71: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 18

Page 72: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 19

Page 73: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 20

Page 74: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 21

Page 75: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 22

Page 76: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 23

Page 77: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: CT Requirement of Relay Page 24

Page 78: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 1

ANNEXURE-2

VA burden requirements of relay

Sr No. Description Make Type Page No.

1 Line differential protection main-1 ABB RED670 2

2 Line differential protection main-2 AREVA MICOMP546 3

3 Busbar differential protection AREVA MCAG4 4

4 CT circuit supervision relay AREVA MVTP11 5

5 Breaker failure protection relay ABB RAICA 6

6 Transient fault recorder ROCHESTER TR2000 7

7 Energy Meter Electro Ind. NEXUS1262 8

8 Fuse failure relay ABB RXBA4 9

9 Synchro check relay AREVA KVAS100 10

10 Undervoltage relay ABB RAEDA1 11

11 Line differential protection main-1 ABB REL531 12

12 Transducer AREVA ISTAT300 13

13 Line differential protection main-1 ABB REL531 14

14 Line differential protection main-2 SIEMENS 7SA522 16

15 Synchro check relay ABB RASC 17

16 Revenue Meter ELSTER A3 ALPHA 18

Page 79: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 2

Page 80: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 3

Page 81: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 4

Page 82: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 5

Page 83: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 6

Page 84: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 7

Page 85: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 8

Page 86: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 9

Page 87: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 10

Page 88: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 11

Page 89: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 12

Page 90: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 13

Page 91: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 14

Page 92: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 15

Page 93: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 16

Page 94: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 17

Page 95: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Annexure-: VA Requirement of Relay Page 18

Page 96: 380kV CT-VT calculation_C4_Rev_D 17.12.09

ANNEXURE-3

SAUDI CABLE CATALOGUE

Page 97: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 98: 380kV CT-VT calculation_C4_Rev_D 17.12.09

ANNEXURE-4

380kV GIS CT DATA

Page 99: 380kV CT-VT calculation_C4_Rev_D 17.12.09

Ref.No. NA40034Ref.No. NA40034Ref.No. NA40034Ref.No. NA40034----D020D020D020D020 Date : Date : Date : Date : 9999 MayMayMayMay, 2006, 2006, 2006, 2006 Rev.2 5 Aug. 2009Rev.2 5 Aug. 2009Rev.2 5 Aug. 2009Rev.2 5 Aug. 2009 Rev.3 12 Aug.,2009Rev.3 12 Aug.,2009Rev.3 12 Aug.,2009Rev.3 12 Aug.,2009 Rev.4 18 Aug.,2009Rev.4 18 Aug.,2009Rev.4 18 Aug.,2009Rev.4 18 Aug.,2009

TECHNICAL SPECIFICATION FOR CTTECHNICAL SPECIFICATION FOR CTTECHNICAL SPECIFICATION FOR CTTECHNICAL SPECIFICATION FOR CT

ProjectProjectProjectProject : New 380/115kV ABU HADRIYAH BSP: New 380/115kV ABU HADRIYAH BSP: New 380/115kV ABU HADRIYAH BSP: New 380/115kV ABU HADRIYAH BSP Contract No.Contract No.Contract No.Contract No. : : : : 30531099/0030531099/0030531099/0030531099/00 SpecificationSpecificationSpecificationSpecification : 380kV 63kA 3150/2000A GIS: 380kV 63kA 3150/2000A GIS: 380kV 63kA 3150/2000A GIS: 380kV 63kA 3150/2000A GIS

1. Applicable Standard

- IEC 60044-1, IEC 60044-6

2. Ratings

- Symmetric short circuit (Ith) : 63kA rms

- Dynamic short circuit (Idyn) : 163.8kA peak

- Continuous thermal current rating factor : 2.0

Page 100: 380kV CT-VT calculation_C4_Rev_D 17.12.09

1) GCB A810

Location Current Ratio

Specification Type

Adopted

TAP

Class Ual Rct

@75℃ Ial Burden Kssc K Rb

Bus-1

Side

1 3000-2500-2000-1500- 1250-1000-750/1A

2000/1A TPS >3700V <3.1Ω <75mA - 31.5 12.63 6.2 CT-1 50BF/A810

2 3000-2500-2000-1500- 1250-1000-750/1A

2000/1A TPS >3700V <3.1Ω <75mA - 31.5 12.63 6.2 CT-1 AL-FADHILI

LINE-2 SET-2

3 3000-2500-2000-1500- 1250-1000-750/1A

2000/1A TPS >3700V <3.1Ω <75mA - 31.5 12.63 6.2 CT-1 AL-FADHILI

LINE-2 SET-1

4 3000-2500-2000-1500- 1250-1000-750/1A

2500/1A 0.2 SF<5 - - 50VA - - - AL-FADHILI

LINE-2 MET.

Bus-2

Side

1 3000-2500-2000-1500- 1250-1000-750/1A

3000/1A TPS >5550V <4.65Ω <50mA - 21 18.95 9.3 CT-1 87B1/M1

2 3000-2500-2000-1500- 1250-1000-750/1A

3000/1A TPS >5550V <4.65Ω <50mA - 21 18.95 9.3 CT-1 87B1/M2

3 3000-2500-2000-1500- 1250-1000-750/1A

3000/1A TPS >5550V <4.65Ω <50mA - 21 18.95 9.3 CT-1 SPARE

NOTE:

1. CT-2 TYPE: Present design - 3000/1A Tap Rct<6.7ohm --- The CT is CT-2 type. If the CT will be used 2000/1A tap, Rct will be <4.65 ohm,

not <3.1ohm.

2. CT-1 TYPE: Present design - 2000/1A Tap Rct<3.1ohm --- The CT is CT-1 type. If the CT will be used 3000/1A tap, Rct will be <4.7ohm,

not <6.7ohm.

Page 101: 380kV CT-VT calculation_C4_Rev_D 17.12.09

2) GCB A811

Location Current Ratio

Specification Type

Adopted

TAP

Class Ual Rct

@75℃ Ial Burden Kssc K Rb

Bus-1

Side

1 3000-2500-2000-1500- 1250-1000-750/1A

2000/1A TPS >3700V <3.1Ω <75mA - 31.5 12.63 6.2 CT-1 50BF/A811

2 3000-2500-2000-1500- 1250-1000-750/1A

2000/1A TPS >3700V <3.1Ω <75mA - 31.5 12.63 6.2 CT-1 MANIFA

LINE-2 SET-1

3 3000-2500-2000-1500- 1250-1000-750/1A

2000/1A TPS >3700V <3.1Ω <75mA - 31.5 12.63 6.2 CT-1 MANIFA

LINE-2 SET-2

4 3000-2500-2000-1500- 1250-1000-750/1A

3000/1A 0.2 SF<5 - - 60VA - - - MANIFA

LINE-2 MET.

Bus-2

Side

1 3000-2500-2000-1500- 1250-1000-750/1A

3000/1A TPS >5550V <4.65Ω <50mA - 21 18.95 9.3 CT-1 SPARE

2 3000-2500-2000-1500- 1250-1000-750/1A

2000/1A TPS >3700V <3.1Ω <75mA - 31.5 12.63 6.2 CT-1 AL-FADHILI

LINE-2 SET-1

3 3000-2500-2000-1500- 1250-1000-750/1A

2000/1A TPS >3700V <3.1Ω <75mA - 31.5 12.63 6.2 CT-1 AL-FADHILI

LINE-2 SET-2

4 3000-2500-2000-1500- 1250-1000-750/1A

2500/1A 0.2 SF<5 - - 50VA - - - AL-FADHILI

LINE-2 MET.

NOTE:

1. CT-2 TYPE: Present design - 3000/1A Tap Rct<6.7ohm --- The CT is CT-2 type. If the CT will be used 2000/1A tap, Rct will be <4.65 ohm,

not <3.1ohm.

2. CT-1 TYPE: Present design - 2000/1A Tap Rct<3.1ohm --- The CT is CT-1 type. If the CT will be used 3000/1A tap, Rct will be <4.7ohm,

not <6.7ohm.

Page 102: 380kV CT-VT calculation_C4_Rev_D 17.12.09

3) GCB A812

Location Current Ratio

Specification Type

Adopted

TAP

Class Ual Rct

@75℃ Ial Burden Kssc K Rb

Bus-1

Side

1 3000-2500-2000-1500- 1250-1000-750/1A

3000/1A TPS >5550V <4.65Ω <50mA - 21 18.95 9.3 CT-1 87B2/M1

2 3000-2500-2000-1500- 1250-1000-750/1A

3000/1A TPS >5550V <4.65Ω <50mA - 21 18.95 9.3 CT-1 87B2/M2

3 3000-2500-2000-1500- 1250-1000-750/1A

3000/1A TPS >5550V <4.65Ω <50mA - 21 18.95 9.3 CT-1 SPARE

Bus-2

Side

1 3000-2500-2000-1500- 1250-1000-750/1A

2000/1A TPS >3700V <3.1Ω <75mA - 31.5 12.63 6.2 CT-1 50BF/A812

2 3000-2500-2000-1500- 1250-1000-750/1A

2000/1A TPS >3700V <3.1Ω <75mA - 31.5 12.63 6.2 CT-1 MANIFA

LINE-2 SET-1

3 3000-2500-2000-1500- 1250-1000-750/1A

2000/1A TPS >3700V <3.1Ω <75mA - 31.5 12.63 6.2 CT-1 MANIFA

LINE-2 SET-2

4 3000-2500-2000-1500- 1250-1000-750/1A

3000/1A 0.2 SF<5 - - 60VA - - - MANIFA

LINE-2 MET.

NOTE:

1. CT-2 TYPE: Present design - 3000/1A Tap Rct<6.7ohm --- The CT is CT-2 type. If the CT will be used 2000/1A tap, Rct will be <4.65 ohm,

not <3.1ohm.

2. CT-1 TYPE: Present design - 2000/1A Tap Rct<3.1ohm --- The CT is CT-1 type. If the CT will be used 3000/1A tap, Rct will be <4.7ohm,

not <6.7ohm.

Page 103: 380kV CT-VT calculation_C4_Rev_D 17.12.09

ANNEXURE-4A

380kV GIS DATA SCHEDULE FROM TOSHIBA

Page 104: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 105: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 106: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 107: 380kV CT-VT calculation_C4_Rev_D 17.12.09

ANNEXURE-5

SUBSTATION ELECTRICAL LAYOUT-PLAN

Page 108: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 109: 380kV CT-VT calculation_C4_Rev_D 17.12.09

PROJECT: ABU-HADRIYAH 380/115 kV BSP ABU-HADRIYAH CONTRACT No. 3-083300.01ABUHADRIYAH 380/115kV BSP

TITLE: CT LEAD ROUTE LENGTH CALCULATION

DRAWING REFERENCE: ABU-HADRIYAH SUBSTATION ELECTRICAL LAYOUT -EA-0099121.02.03.0NOTE: CT LEAD LENGTH IS CONSIDERED AS 500 METERS ON CONSIDERABLY SAFER SIDE TO ACOUNT FOR ANY CIRCUIT CHANGES IN FUTURE. HENCE, CT LEAD LENGTH IS ESTIMATED AS 500 METERS FOR ALL BAYS CT SIZING CALCULATION.299273 400350CROSS BAY C3CROSS BAY C2 RPRP 230210 LENGTH AFTER TERMINATION (WITH 30% MARGIN) IN METERS325 LENGTH SELECTED IN METERS500RPSR.NO. CROSS BAY C4 250FROM BAY NO. TO RELAY PANEL LENGTH MEASURED IN METERS

Page 110: 380kV CT-VT calculation_C4_Rev_D 17.12.09

ANNEXURE-6

RELAYING & METERING ONE LINE DIAGRAM

Page 111: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 112: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 113: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 114: 380kV CT-VT calculation_C4_Rev_D 17.12.09

ANNEXURE-7

LINE PARAMETERS

Page 115: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 116: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 117: 380kV CT-VT calculation_C4_Rev_D 17.12.09

ANNEXURE-8

M&I METROSIL CATALOGUE

Page 118: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 119: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 120: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 121: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 122: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 123: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 124: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 125: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 126: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 127: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 128: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 129: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 130: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 131: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 132: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 133: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 134: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 135: 380kV CT-VT calculation_C4_Rev_D 17.12.09

ANNEXURE-9

380kV CVT DATA SCHEDULE

Page 136: 380kV CT-VT calculation_C4_Rev_D 17.12.09
Page 137: 380kV CT-VT calculation_C4_Rev_D 17.12.09