REACTOR PROTECTIONPREPARED BY

GOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

gk_aptransco@yahoo.co.in, Mobile:9440336984

MAIN-1 & MAIN-2PROTECTION FORSHUNT REACTOR

ADOPTED IN ONE AND HALF

CIRCUIT BREAKER SCHEME

PREPARED BYGOPALA KRISHNA PALEPU

ADE/MRT(PROTECTION)

BASICS OF SHUNT REACTOR1. TYPES OF REACTORS :

A. BASED ON REACTOR CONNECTIONi. SHUNT REACTOR. ii. SERIES REACTOR.B. BASED ON REACTOR LOCATIONi. BUS REACTOR ii. LINE REACTORC. BASED ON CONTROLi. 3-PH OIL IMMERSED REACTOR WITH GAPPED IRON CORE. ii. THYRISTOR CONTROLLED REACTOR (STATIC VAR COMPENSATOR)(APTRANSCO UTILISING SHUNT REACTORS FOR BUS & LINE IN 400KV NETWORK)

2. NEED OF SHUNT REACTOR:A. LINE REACTORSHUNT REACTORS ARE USED IN ORDER TO COMPENSATE FOR THE CAPACITIVE SHUNT REACTANCE OF TRANSMISSION LINES. THE REACTOR IS CONNECTED PARALLEL TO THE LINE. THE LOCATION OF REACTOR IS OUT GOING SIDE OF LINE i.e AFTER CIRCUIT BREAKER. LENGTH OF LINE IS MORE THERE MAY BE VOLTAGE IS RAISING DUE TO FARANTI EFFECT(CAPACITANCE) DURING CHARGING. IN CASE OF ZONE-2 (OPEN JUMPER) FAULT, THE FAULT CLEARED BY REMOTE END IS FAST, BUT THIS END IT WILL TAKE TIME DELAY DUE TO ZONE-2. DURING THIS TIME, VOLTAGE MAY RAISING. SO, LINE REACTOR IS USED FOR CONTROLLING THE SWITCHING OVER VOLTAGES AND SAFEGUARD THE OPERATING EQUIPMENT. NORMALLY IT IS ALWAYS IN SERVICE. NORMALLY BOTH ENDS LINE REACTORS ARE PROVIDED. THE ELECTRICAL INTERLOCK IS PROVIDED THAT IF REACTOR ISOLATOR CLOSSED POSITION ONLY WILL GIVE PERMIT TO CLOSE THE LINE ISOLATOR. SIMILARLY FOR OPENING REACTOR ISOLATOR THE LINE ISOLATOR SHOULD BE IN OPEN POSITION. NEUTRAL REACTOR CONNECTED BETWEEN THE STAR POINT OF EHV SHUNT REACTOR AND THE GROUND, LIMITS THE SECONDARY ARC CURRENT TO A LOW VALUE OF AROUND 10 AMPS TYPICALLY FOR 400KV SYSTEM TO ENSURE COMPLETE DE-IONISATION OF ARC PATH WHEN EHV SYSTEM DEVELOPS A SINGLE LINE TO GROUND FAULT. ARC EXTINCTION DURING LINE SINGLE-PHASE AUTORECLOSE DEAD TIME IS ASSISTED BY THIS NEUTRAL REACTOR.

B. BUS REACTORTHE REACTOR IS CONNECTED PARALLEL TO THE BUS i.e LIKE A FEEDER/LINE. DURING LIGHTLY LOADED CONDITIONS THERE MAY BE POSSIBULITY OF RAISING BUS VOLTAGES. FOR SAFEGUARD THE OPERATING EQUIPMENT BUS REACTORSARE UTILISING. NORMALLY IT IS NOT IN SERVICE. WHENEVER THE VOLTAGE RAISES TO 4%TO 5% MORE THAN THE RATED VOLTAGE THIS MAY BE KEPT IN SERVICE AND 2% TO 3% LESS THAN THE RATED VOLTAGE THIS MAY BE KEPT OUT OF SERVICE.

3. SELECTION OF REACTORA. LINE REACTORNORMALLY LINE REACTORS ARE PROVIDED IF THE LINE IS MORE OR EQUAL TO 250KM. IN APTRANSCO NETWORK MAXIMUM LENTH OF LINE IS 350KM. AS PER SYSTEM STUDIES RECOMANDATIONS IF LINE LENGTH IS 250KM TO 300KM 50MVAR REACTOR IS TO BE USED. IF MORE THAN 300KM 63MVAR REACTOR IS TO BE USED.B. BUS REACTOR NORMALLY BUS REACTORS ARE PROVIDED IF THE SUBSTATION BUS VOLTAGE IS RAISING 5% MORE THAN THE RATED VOLTAGE DURING LIGHTLY LOADED CONDITION. BASED ON THE SYSTEM STUDIES RECOMANDATIONS BUS REACTORS ARE TO BE PROVIDED. CALCULATIONS ARE REQUIRED FOR PROVIDING BUS REACTOR. IN THIS THERE IS NO STANDARDISATION.

4. LOCATION OF REACTORS WITH CAPACITY IN APTRANSCOA. LINE REACTOR1. 400KV KALAPAKA-KHAMMAM 1 AT BOTH ENDS – 63MVAR 2. 400KV KALAPAKA-KHAMMAM 2 AT BOTH ENDS – 63MVARB. BUS REACTOR1. 400KV KALAPAKA SS – 2 X 50 MVAR2. 400KV NUNNA SS(PGCIL BAYS) – 1 x 63 MVAR

5. PURPOSE OF SHUNT REACTOR PROTECTIONTHE PURPOSE OF THE PROTECTION RELAYING IS TO DISCONNECT THE REACTOR AND LIMIT DAMAGE IN CASE OF INTERNAL SHORT CIRCUITS, EARTH FAULTS, INTERTURN FAULTS AND OVER VOLTAGE OR OVER LOAD.THE REACTOR FORMS CERTAIN IMPEDENCE FOR RATED FREQUENCY, AND AS IT IS SHUNT CONNECTED, AS OVER LOAD MAY BE CAUSED BY OVER VOLTAGE OR HARMONICS IN VOLTAGE AND CURRENT.

6. PROTECTION DEVICES INBUILT OR MOUNTED ON REACTORA. OIL IMMERSED REACTOR USUALLY HAVE A GAS DETECTOR AND OIL SURGE. DETECTOR (BUCHHOLZ ALARAM & TRIP DEVICES), WHICH ARE EXCELLENT FOR DETECTING INTERNAL FAULTS.B. TEMPARATURE MONITORS FOR OIL & WINDING PROVIDE GOOD OVER LOAD PROTECTION.C. PRESSURE RELIEF DEVICE IS PROVIDED TO SAFE GUARD THE REACTOR FROM HIGH PRESURES.

7. REACTOR DIFFERENTIAL PROTECTIONIT IS WIDELY USED AS INSTANTANEOUS PROTECTION FOR SHORT CIRCUIT FAULTS WITH IN THE DIFFERENTIAL ZONE. THIS IS TREATED AS MAIN-1 PROT FOR REACTOR.IT CAN BE OF HIGH IMPEDENCE TYPE OR OF A SENSITIVE CURRENT STABILISED TYPE. HIGH IMPEDENCE DIFFERENTIAL PROTECTION RELAYS REQUIRE AN EQUAL CT TURNS RATIO ON THE PHASE AND NEUTRAL SIDE. SENSITIVITY IS 5% OF NOMINAL REACTOR CT CURRENT.

8. BACK-UP PROTECTIONA VARIETY OF RELAYS ARE AVAILABLE.A. OVER CURRENT & EARTH FAULT PROTECTION. ( 50, 50N, 51, 51N, 67, 67N - ANY COMBINATION OF THESE)B. UNDER IMPEDENCE / DISTANCE ( Z<)(21R).C. NEUTRAL DISPLACEMENT PROTECTION (Un>).

9. RESTRICTED EARTH FAULT PROTECTIONIF, FOR SOME REASON, A SENSITIVE DIFFERENTIAL PROTECTION NOT CHOOSEN A RESTRICTED EARTH FAULT PROTECTION CAN BE UTILISED.

SHUNT REACTOR (BUS & LINE) (ONE AND HALF CIRCUIT BREAKER SYSTEM )

LINE 1

1-89

1-89A

1-52CB

1-CT3

3

3-89

3-89A

3-52CB

3-CT3

2-52CB

2-CT

2-89A 2-89B

1-89L

BUS-1 BUS-2

P1

P1

P1

P2 P2

P2

U UU

LINESHUNT

REACTOR

1-89R

U UU

BUSSHUNT

REACTOR

.3-89R

U UUU

.

IL

INTER LOCK FACILITY:WHEN 1-89R CLOSES ONLY

PERMIT TO CLOSE 1-89L AND1-89L OPENS ONLY

PERMIT TO OPEN 1-89R.

IL

1-PH NEUTRAL GROUNDING REACTOR

REACTOR BUSHING CT INFORMATIONCAPACITY OF 400KV REACTORS : 50, 63, 80, 125 MVAR

NGRSHUNT REACTORITEMSr

NOEARTH SIDELINE SIDESTAR / NEUTRAL SIDE400KV / LINE SIDE

CORE-2CORE-1CORE-4CORE -3CORE-2CORE-1CORE-5CORE-4CORE-3CORE -2CORE-1

200/1200/1200/1200/1WTI200/12000-1000-500/1

2000-1000-500/1

200/1200/1200/1RATIO1

NEUTRAN BUSHING CT : CORE-1 : BEFORE STAR FORMATION IN RYB PHASES

64 RREF1/2

64 RREF2

64 RREF1

87 RDIFFMET

FOR 21L1 /TEED-2 /

BBC

FOR 21L2 /TEED-1 /

BBM21 R IMP

64 R REF1

87 RDIFFPURPOSE5

PSPSPSPSPSPSPSPSPSCLASS OF ACURACY4

1 OHM1 OHM1 OHM1 OHM10 – 5 – 2.5 OHM

10 – 5 –2.5

OHM1 OHM1 OHM1 OHMRCT IN OHMS3

200V200V200V200V

Parameters of WTI CT for each winding shall be provided by the contractor

1.0 CLAND

BURDEN 10 VA

1000-500-250V

1000-500-250V

200V200V200VVKNEE FOR PS

& VA FOR MET

2

SHUNT REACTOR PROTECTION

400KV SIDE

21R – 3Ph, REACTOR BACKUP IMPEDANCE RELAY OF SUITABLY SHAPED CHARECRESTICS EITHER SINGLE /

DOUBLE ZONE TYPE.CORE-3

87 BBC/BB-221L2(M_CT+T_CT – R_CT)

87 TEED-2(M_CT, T_CT, R_CT)

21L2(M_CT+T_CT–R_CT)

CORE-4

87 BBM/BB-121L1(M_CT+T_CT – R_CT)

87 TEED-1(M_CT, T_CT, R_CT)

21L1(M_CT+T_CT–R_CT)

CORE-5

64R - REACTOR RESTRICTED EARTH FAULT PROTECTION OF1-POLE HIGH IMPEDANCE TYPE.(REF1)CORE-2

87R – 3Ph, 2Wdg REACTOR DIFFERENTIAL RELAY EITHER LOW or HIGH IMPEDANCE TYPE.CORE-1

BUSLINEBUSLINE

DOUBLE BUS & TRANSFER BUS SYSTEM

ONE & HALF BREAKER SYSTEMCORES

M_CT: Main CT, T_CT: Tie CT, R_CT: Reactor CT

SHUNT REACTOR PROTECTION

NEUTRAL GROUNDING REACTOR SIDE- -64 REF2- -64 REF1CORE-1

STAR / NEUTRAL SIDE

87R – 3Ph, 2Wdg REACTOR DIFFERENTIAL RELAY EITHER LOW / HIGH IMPEDANCE TYPE.CORE-3

64R - REACTOR RESTRICTED EARTH FAULT PROTECTION OF1-POLE HIGH IMPEDANCE TYPE .(REF1)CORE-4

- -64 REF 1 / 2- -64 REF1CORE-2

WINDING TEMPARETURE OF REACTORCORE-2METERING OF REACTORCORE-1

BUSLINEBUSLINE

DOUBLE BUS & TRANSFER BUS SYSTEM

ONE & HALF BREAKER SYSTEMCORES

U UU

LINESHUNT

REACTOR

.1-PH NEUTRAL

GROUNDING REACTOR

3

3

3

3

3

3

3

3

U UU

3

3

3

3

3

3

3

3

3

U UU

3

3

3

3

3

3

3

3

U UU

3

3CORE -1

CORE -2

CORE -3

CORE -4

CORE -5

CORE -1

CORE -2

CORE -3

CORE -4

CORE -1

CORE -2

REA

CTO

R B

USH

ING

CT

INFO

RM

ATI

ON

U UU

BUSSHUNT

REACTOR

.

3

3

3

3

3

3

3

3

U UU

3

3

3

3

3

3

3

3

3

U UU

3

3

3

3

3

3

3

3

CORE -1

CORE -2

CORE -3

CORE -4

CORE -5

CORE -1

CORE -2

CORE -3

CORE -4

REA

CTO

R B

USH

ING

CT

INFO

RM

ATI

ON

ONE & HALF BREAKER LINE & BUS SHUNT REACTOR PROTECTION SCHEME87BB1

87BB2

CVT

CVT

VBB1

VBB2

79

25

79

25

79

25VBB2

BF

BFVL2 / VL1

OR VBB1

VL1 / VL2

OR VBB2

VBB1

FEEDER1 / LINE1

87L 21M2 CVT VL1

BF

VL1

BUSBAR-1

BUSBAR-2

TEED-1

TEED-2PROTECTION OF BUS REACTOR

21M1 VL1

VL1 / VBB1

VL2 / VBB2

FOR REACTOR PROTECTION & METERING VOLTAGE SELECTION RELAYS FOR BUS-1, BUS-2& LINE ARE PROVIDED .

UU U UUU

87R

64R

OR

21R

UUU

87R

64R

VL1/V

BB1/V

BB2

VBB1/

VBB2

21R

LINE/BUS REACTOR DIFFERENTIAL PROTECTION (LOW IMPEDANCE DIFFERENTIAL PROTECTION)

3 3 3

R-CT

HV BUSHING

CORE-1CTR: 200/1A

CLASS: PS

1S2 1S2 1S2

1S11S1 1S1

P2P2P2 CT MB3 3 3

R-CT

STAR BUSHING

CORE-3CTR: 200/1A

CLASS: PS

3S1 3S1 3S1

3S23S2 3S2

P2P2P2

CT MB

C

E

DISPLAY

ACTIVE START TRIP

RET 670

NORMALLYLOW / HIGH IMPEDENCE DIFFERENTIAL RELAY IS

USED FOR BUS / LINE REACTOR

DIFFERENTIAL PROTECTION

IN CASE OF REACTOR BUSHING CT P2 IS AWAY FROM REACTOR & P1 IS TOWARDS REACTOR

C

E

DISPLAY

ACTIVE START TRIP

RET 6703 3 3

3 3 3R-CT HV

BUSHING CT

CORE-1CTR: 200/1A

CLASS: PS

R-CT STAR

BUSHING CT

CORE-3CTR: 200/1A

CLASS: PS

P2P2P2

P2P2P2

P1P1P1

P1P1P1

1S21S21S2

3S23S23S2

1S11S11S1

3S13S13S1

LINE/BUS REACTOR DIFFERENTIAL PROTECTION (HIGH IMPEDANCE DIFFERENTIAL PROTECTION)

IN CASE OF REACTOR BUSHING CT P2 IS AWAY FROM REACTOR& P1 IS TOWARDS REACTOR

NORMALLYLOW / HIGH IMPEDENCE DIFFERENTIAL RELAY IS

USED FOR BUS / LINE REACTOR

DIFFERENTIAL PROTECTION

C

E

DISPLAY

ACTIVE START TRIP

RET 6703 3 3

3 3 3P2P2P2

P2P2P2

P1P1P1

P1P1P1

2S22S22S2

4S24S24S2

4S14S14S1

2S12S12S1

LINE/BUS REACTOR REF PROTECTION (NGR IS NOT AVAIALBLE)

R-CT HV

BUSHING CT

CORE-2CTR: 200/1A

CLASS: PS

R-CT STAR

BUSHING CT

CORE-4CTR: 200/1A

CLASS: PS

IN CASE OF REACTOR BUSHING CT P2 IS AWAY FROM REACTOR& P1 IS TOWARDS REACTOR

NORMALLYHIGH IMPEDENCE

VOLTAGE/CURRENT OPERATED SINGLE

POLE RELAY IS USED FOR BUS / LINE

REACTOR RESTRICTED EARTH FAULT PROTECTION.PRESENTLY NUMERICAL

DIFFERENTIAL RELAYS HAVING IN BUILT

FUNCTION OF 2 REF OR 2 SEF PROTECTIONS.

3 3 3

3 3 3P2P2P2

P2P2P2

P1P1P1

P1P1P1

2S22S22S2

2S22S22S2

2S12S12S1

2S12S12S1

LINE REACTOR REF PROTECTION (NGR IS AVAIALBLE)

R-CT HV

BUSHING CT

CORE-2CTR: 200/1A

CLASS: PS

NGR-CT EARTH

BUSHING CT

CORE-2CTR: 200/1A

CLASS: PS

IN CASE OF REACTOR BUSHING CT P2 IS AWAY FROM REACTOR& P1 IS TOWARDS REACTOR

C

E

DISPLAY

ACTIVE START TRIP

RET 670 NORMALLYHIGH IMPEDENCE

VOLTAGE/CURRENT OPERATED SINGLE

POLE RELAY IS USED FOR BUS / LINE

REACTOR RESTRICTED EARTH FAULT PROTECTION.PRESENTLY NUMERICAL

DIFFERENTIAL RELAYS HAVING IN BUILT

FUNCTION OF 2 REF OR 2 SEF PROTECTIONS.

3 3 3

3 3 3P2P2P2

P2P2P2

P1P1P1

P1P1P1

2S22S22S2

4S24S24S2

4S14S14S1

2S12S12S1

LINE REACTOR 2 NOs REF PROTECTIONS (NGR IS AVAIALBLE)

R-CT HV

BUSHING CT

CORE-2CTR: 200/1A

CLASS: PS

R-CT STAR

BUSHING CT

CORE-4CTR: 200/1A

CLASS: PS

3 3 31S2 1S2 1S2

1S11S1 1S1

P1P1P1

CT MB

C

E

DISPLAY

ACTIVE START TRIP

RET 670

P2P2P2

3 3 32S1 2S1 2S1

2S22S2 2S2

P2P2P2

CT MBP1P1P1

NORMALLYHIGH IMPEDENCE

VOLTAGE/CURRENT OPERATED SINGLE POLE RELAY IS USED

FOR BUS / LINE REACTOR RESTRICTED EARTH FAULT

PROTECTION.PRESENTLY NUMERICAL

DIFFERENTIAL RELAYS HAVING IN BUILT FUNCTION OF 2 REF

OR 2 SEF PROTECTIONS.

NGR-CT BUSHING CTCORE - 1 & 2

CTR: 200/1A

CLASS: PS

C

E

DISPLAY

ACTIVE START TRIP

REL 6703 3 3

IR3 / A311IY3 / A331IB3 / A351

IN3 / A3713S2 3S2 3S2

3S13S1 3S1

P2P2P2 CT MBVR11 / E111VY11 / E131VB11 / E151VN11 / E171

LINE/BUS REACTOR B/U IMPEDANCE PROTECTION

R-CT HV

BUSHING CT

CORE-3CTR: 200/1A

CLASS: PS CVT SELECTION

BUS-1 CVT / BUS-2 CVT /

LINE CVT

CORE-1VA : 200

CLASS: 3P

LINE REACTOR PROTECTION FOR LINE (MAIN-1 PROTECTION)

C

E

DISPLAY

ACTIVE START TRIP

REL 5213 3 3

3 3 3

IR5 / A511IY5 / A531IB5 / A551

IN5 / A571

1-CT

CORE-5CTR: 2000-1000-500/1A

CLASS: PS

2-BCT

CORE-5CTR: 2000-1000-500/1A

CLASS: PS

5S4 5S4 5S4

5S25S2 5S2

P2P2P2 CT MB

P2P2P2

5S4 5S4 5S4

5S25S2 5S2

VR11 / E111VY11 / E131VB11 / E151VN11 / E171

1-CVT

CORE – 1

200VA

CLASS: 3P

3 3 3LR-CT 400KV

CORE-5CTR: 2000-1000-500/1A

CLASS: PS

P1P1P1

5S2 5S2 5S2

5S45S4 5S4

LINE REACTOR PROTECTION FOR LINE(MAIN-2 PROTECTION)

C

E

DISPLAY

ACTIVE START TRIP

REL 3163 3 3

3 3 3

IR4 / A411IY4 / A431IB4 / A451

IN4 / A471

1-CT

CORE-4CTR: 2000-1000-500/1A

CLASS: PS

2-BCT

CORE-4CTR: 2000-1000-500/1A

CLASS: PS

4S4 4S4 4S4

4S24S2 4S2

P2P2P2 CT MB

P2P2P2

4S4 4S4 4S4

4S24S2 4S2

VR21 / E211VY21 / E231VB21 / E251VN21 / E271

1-CVT

CORE – 2

200VA

CLASS: 3P

3 3 3LR-CT 400KV

CORE-4CTR: 2000-1000-500/1A

CLASS: PS

P1P1P1

4S2 4S2 4S2

4S44S4 4S4

BUS REACTOR TEED-1 PROTECTION{BAY3&2}

C

E

DISPLAY

ACTIVE START TRIP

RET 670

3 3 3

3 3 33-CT

CORE-5CTR: 2000-1000-500/1A

CLASS: PS

BR-LCT

CORE-5CTR: 2000-1000-500/1A

CLASS: PS

P2P2P2

P1P1P1

3 3 32-CT

CORE-1CTR: 2000-1000-500/1A

CLASS: PS

P1P1P1P2P2P2

P1P1P1

P2P2P2

5S4 5S4 5S4

5S25S2 5S2

1S4 1S4 1S4

1S21S2 1S2

4S4 4S4 4S4

4S24S2 4S2 IT WORKS ON CIRCULATING CURRENT PRINCIPLE AND IT IS HIGH IMPEDENCE DIFFERENTIAL RELAY. TEED-1 PROTECTION FOR BAY 2&3 AND THE FOLLOWING CTs & CORES ARE USED 3-CT(CORE-5), 2-CT(CORE-1) & BR-CT (CORE-5) ARE STARRED AND CONNECTED TO TEED-1 PROTECTION

IR5IY5IB5

IN5

IR5IY5IB5

IN5

IR1IY1IB1

IN1

BUS REACTOR TEED-2 PROTECTION{BAY3&2}

3 3 3

3 3 3

3-CT

CORE-4CTR: 2000-1000-500/1A

CLASS: PS

BR-CT

CORE-4CTR: 2000-1000-500/1A

CLASS: PS

4S4 4S4 4S4

4S24S2 4S2

P2P2P2 CT MB

CT MBP2P2P2

4S2 4S2 4S2

4S44S4 4S4

3 3 3

2-CT

CORE-2CTR: 2000-1000-500/1A

CLASS: PS

2S2 2S2 2S2

2S42S4 2S4

P2P2P2CT MB

C

E

DISPLAY

ACTIVE START TRIP

RET 670

RA

ICA

LBB

/BFR

RA

ICA

LBB

/BFR

IT WORKS ON KIRCHOFF’S CURRENT PRINCIPLE & IT IS PERCENTAGE BIASED LOW IMPEDENCE DIFFERENTIAL RELAY. TEED-2 PROTECTION FOR BAY 2&3 IS THE FOLLOWING CTs & CORES ARE USED. 3-CT(CORE-4), 2-CT(CORE-2) & BR-CT (CORE-4) ARE CONNECTED TO TEED-2 PROTECTION.

OVER EXCITATION/FLUX RELAY{FOR LINE & BUS REACTORS}

RATUB

V/F RELAYLINE

RATUB

V/F RELAYBUS

CVT SELECTION

BUS-1 CVT /

BUS-2 CVT /

LINE CVT

CORE-1VA : 200

CLASS: 3P

VOLTAGE

SELECTION

BUS-1 PT /

BUS-2 PT

CORE-1VA : 200

CLASS: 3P

3 3 3

IR2 / D211IY2 / D231IB2 / D251

IN2 / D271

R-CT STAR

BUSHING CT

CORE-2CTR: 200/1A

CLASS: 0.2

2S2 2S2 2S2

2S12S1 2S1

P2P2P2 CT MB

VR31 / E311VY31 / E331VB31 / E351

VN31 / E371

BASED ON SELECTION

LINE CVT / BUS-1 CVT / BUS-2 CVT

CORE – 3

100VA

CLASS: 0.2

REACTOR MULTI FUNCTION PANEL METERING

CARRIER INTERTRIPPING OF LINE SHUNT REACTORLINE SHUNT REACTOR PROTECTION TRIPPINGS WILL BE USED AS DIRECT TRIPPINGS OF LINE IN ADDITION TO OTHER TRIPPINGS. BUS SHUNT REACTOR NEED NOT REQUIRE CARRIER INTER TRIPPING FACILITY.

87R REACTOR DIFFERENTIAL RELAY

21R REACTOR IMPEDENCE RELAY

64R RESTRICTED EARTH FAULT RELAY

ABBNSD 50

DC +VE FROM PANEL

G4AD V9LC 2

DC –VE FROM PANELG4AD V9LC 1

LINE PROTECTION COUPLER PANEL-1

ABBNSD 50

DC +VE FROM PANEL

G4AD V9LC 2

DC –VE FROM PANELG4AD V9LC 1

LINE PROTECTION COUPLER PANEL-2

RET 670

REL 670

RET 670REACTORS INTERNAL FAULTS

87R REACTOR DIFFERENTIAL RELAY

21R REACTOR IMPEDENCE RELAY

64R RESTRICTED EARTH FAULT RELAY

REACTORS INTERNAL FAULTS

GROUP-1/A TRIPPINGS

GROUP-2/B TRIPPINGS

RET 670

REL 670

RET 670