380kV CT-VT Calculation C4 Rev D 17.12.09

7/24/2019 380kV CT-VT Calculation C4 Rev D 17.12.09

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380kV CT/VT SIZING CALCULATION

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PROJ ECT:

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 1

1.3 2

2.0 3

2.1 3

2.2 5

2.3 12

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 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: 810 F.C3 :- SPARE

DESCRIPTION

GENERAL DESIGN CRITERIA FOR CT CALCULATION

SYSTEM DESIGN DATA


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

BAY NUMBER: CROSS BAY C4

ABU-HADRIYAH CONTRACT No.

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ABU-HADRIYAH

380/115 kV BSP

DOCUMENT TITLE:


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

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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

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

Hence, Rdc at 75C = 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

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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 75C, RCTohms < 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

IFsec = 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 20C.

at 20C = 0.004, RL at 75C = RL(1+20(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/ Is2

= (0.15/12) = 0.15 ohms

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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 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.

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2.2 CT: 810 B1.C2

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


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






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

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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

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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)


= 0.84+j14.8

ZT1 = 14.82 ohms


= 380000

Sqrt.(3)x14.82

= 14800.04 Amps


0.835

= 17.75

2.2.5 SINGLE PHASE-GROUND FAULT CONDITION:


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

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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 20C.

at 20C = 0.004, RL at 75C = RL(1+20(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 kmaxx 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

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Eal > Ealreq = 2 x {Ikmaxx I sn} / Ipn x (RCT + RL + SR / Ir2

) 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


Eal > Ealreq = 0.12 x f x Isn x (RCT + RL + SR / Ir2

) Equation-3

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

) = 31.4 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


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 kmaxx I sn} / Ipn x a x (RCT + RL + SR / Ir2

) 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

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Requirement -2

Eal > Ealreq = Ikzone1x 7 x (Isn / Ipn) x (RCT + RL + SR / Ir2

) 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



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2.3 CT: 810 B1.C3

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


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






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




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

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


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


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

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

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

( Refer Annexure-1 Sh. No. 24 )

Vk1 > {Ktd(a)xIssc max(close-in fault)/1.3xIpn} x Isn x (RB + RCT +RL) For close-in fault

Vk2 > {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:

Vk1 > {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 2with 20 % margin = 293 volts

Peak voltage = 413.7 Vpeak

CT requirement for zone1 fault condition:

Vk2 > {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





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2.4 CT: 810 B1.C4

Protection : Metering


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

Class of Accuracy : 0.2

VA Burden 50 VA


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)


at 20C = 0.004, RL at 75C = RL(1+20(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.

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2.5 CT: 810 F.C3

Protection : Spare

Core : CT: 810 F.C3

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






Application : Spare

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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






NOTE:

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

are shown below.


Core : Core 2

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






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

IP = 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

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


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


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

= 0.25

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

Irms dra = 0.52((2xV')/C))1/

where V' = voltage in (RMS Sine)

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

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

= 50.72 A rms

At voltage settingVs = 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.

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Metrosil selection: (Refer Annexure-8)

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

C = 900

= 0.25

As per M&I materials catalogue attached, for the above 'C' and '' 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.

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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.

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2.7 CT: 810 F.C1


Core : CT: 810 F.C1

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




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


NOTE:


are shown below.


Core : Core 1

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







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


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

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RCT = Internal CT secondary resistance = 4.65 ohms



at 20C = 0.004, RLat 75C = RL(1+20(T2-T1)) RL = 1.88 ohms.


RB-MCAG Relay Burden = 1.00 VA

RRMCAG= Relay resistance = RB/ Is2 = 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


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.

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Metrosil requirement

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

C = 900

= 0.25

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

Irms dra = 0.52((2xV')/C))1/

where V' = voltage in (RMS Sine)

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

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

= 50.72 A rms

At voltage settingVs = 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

= 0.25

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

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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.

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2.8 CT: 811 B1.C1

Protection : CB fail protection


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








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

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2.9 CT: 811 B1.C2



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







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

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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


1) For 50 Km line

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


= 0.994+j19.08 ohms

ZT1 = 19.11 ohms


= 380000

Sqrt.(3)x19.11

= 11483.02 Amps


0.994

= 19.20

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1) For 50 Km line

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


= 0.84+j16

ZT1 = 16.02 ohms


= 380000

Sqrt.(3)x16.02

= 13693.21 Amps


0.835

= 19.14

2.9.5 SINGLE PHASE-GROUND FAULT CONDITION:


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


= 380000

Sqrt.(3)x88.69

I0 = 2473.58 Amps


10.08

= 8.74

3I0 = 7420.73 Amps

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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


= 380000

Sqrt.(3)x72.96

= 3007.03 Amps


8.18

= 8.86

3I0= = 9021.097278 Amps

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

Eal > Ealreq = {I kmaxx I sn} / Ipn x (RCT + RL + SR / Ir2

) Equation-1

Eal > Ealreq = 2 x {I tmaxx I sn} / Ipn x (RCT + RL + SR / Ir2) Equation-2

Eal > Ealreq = Itfdb x (Isn / Ipn) x (RCT + RL + SR / Ir2

) 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

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


RB = = 0.25 ohms



at 20C = 0.004, RL at 75C = RL(1+20(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


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 kmaxx I sn} / Ipn x (RCT + RL + SR / Ir2

) Equation-1

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

2000


Eal > Ealreq = 2 x {I tmaxx I sn} / Ipn x (RCT + RL + SR / Ir2

) Equation-2

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

2000


System Frequency

Sat saturation detector min current

System ratio

Burden of relay

Protection terminal rated Current

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At 2000/1 A tap

Eal > Ealreq = Itfdb x (Isn / Ipn) x (RCT + RL + SR / Ir2

) Equation-3

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

) = 224.3 volts

2000




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 kmaxx I sn} / Ipn x a x (RCT + RL + SR / Ir2

) 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 / Ir2

) 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



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2.10 CT: 811 B1.C3



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







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

2.10.1CT Calculation

Where For 2000 amps

Vk = Knee point voltage of CT 3700 Volts

RB = Resistance of relay P543 = 0.04 ohms

Rr = Relay resistance




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

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


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

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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

Vk2 > KRPAxIFZ1x (1+X/R)x(RB + RCT +RL+Rr) (equation -2) for zone1 fault condition

Vk3 > Kmax x IFmaxx (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

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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


CT requirement for zone1 fault condition:

Vk2 > KRPAxIFZ1x (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



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



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

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2.11 CT: 811 B1.C4



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


VA Burden 50 VA



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)


at 20C = 0.004, RL at 75C = RL(1+20(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.

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2.12 CT: 811 B2.C4



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


VA Burden 50 VA




2.13 CT: 811 B2.C3



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







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


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2.14 CT: 811 B2.C2

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


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







Relay Type / Make: "REL 531", ABB


2.15 CT: 811 B2.C1

Protection : spare


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






Application : spare

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2.16 CT: 812 F.C1


Core : CT: 812 F.C1

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






NOTE:


are shown below.


Core : Core 1

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







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.

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2.17 CT: 812 F.C2


Core : CT: 812 F.C2

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






NOTE:


are shown below.


Core : Core 2

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







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.

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2.18 CT: 812 F.C3

Protection : Spare

Core : CT: 812 F.C3

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






Application: Spare

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2.19 CT: 812 B2.C4



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


VA Burden 50 VA




2.20 CT: 812 B2.C3



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







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


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2.21 CT: 812 B2.C2

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


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


CT Secondary resistance at 75C, RCTohms ) < 3.1 Ohms at 2000A tap.





Relay Type / Make: "RED 670", ABB


2.22 CT: 812 B2.C1

Protection : BF protection (50BF)


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









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

Hence, Rdc at 75C = 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.


at 20C = 0.004, RLat 75C = RL(1+20(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

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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)

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Core-2:


(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





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)



Wattmeter, PML

VARmeter, PML

Energy meter


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

Assumed

Assumed

Voltmeter, PML

Assumed

FFR (98) (Meas.) for revenue meter




Assumed

(Annexure-2 Sh. No.9)


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


25MC/A811

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



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

(27L2), Under voltage relay

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

CCVT Details :

Core-1 Core-2


Class : 0.2/3P 0.2/3P

VA Burden : 100 100













RB=(2 x 2.81 x 0.1954 x 0.1954)

Core-1 :


(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



.= (VA Connected + VA Lead)

The Burden calculated consider ing 25% safety margin = 15.8 VA


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)





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

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Core-2:


(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


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



.= (VA Connected + VA Lead)

The Burden calculated consider ing 25% safety margin = 44.5 VA


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)




Voltmeter Assumed

Wattmeter Assumed


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

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

VT Details :

Core-1 Core-2


Class : 0.2/3P 0.2/3P

VA Burden : 100 100













RB=(2 x 2.81 x 0.0945 x 0.0945)

Core-1 :


(VA)

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

Total VA = 6 VA per phase



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



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


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


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Core-2:


(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


PML 1 0.5 0.5

LCC

PML 1 0.5 0.5










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


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

98B1-25AR/810

DSM Assumed


25AR / A810


Voltmeter

AssumedVoltmeter




Assumed

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3.5 380kV BUS2-VT

VT Details : (Refer Annexure-4A)

Core-1 Core-2


Class : 0.2/3P 0.2/3P

VA Burden : 100 100













RB=(2 x 2.81 x 0.0945 x 0.0945)

Core-1 :


(VA)

RXBA 4 1 2 2

RXBA 4 1 2 2

RXBA 4 1 2 2

Total VA = 6 VA per phase









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

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Core-2:


(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


PML 1 0.5 0.5

LCC

PML 1 0.5 0.5







25MC/A806

Voltmeter Assumed


DSM Assumed


Voltmeter Assumed







98B2-25MC/812




Transient Fault Recorder

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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


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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


12 Transducer AREVA ISTAT300 13


14 Line differential protection main-2 SIEMENS 7SA522 16

15 Synchro check relay ABB RASC 17

16 Revenue Meter ELSTER A3 ALPHA 18


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7/24/2019 380kV CT-VT Calculation C4 Rev D 1

Documents

380kV CT-VT Calculation C4 Rev D 17.12.09