Relay Setting Chart _ CRP Panel_Shambhu_REVB

(1)

Revision-A

Date : 02.01.2007

GRASIM CEMENTS - GRINDING UNIT AT PANIPAT

RECOMMENDED RELAY SETTING CHART

33/6.6 kV, 12/16 MVA

Prepared by : ABB

(2)

1 Differential

Protection

(Restrained)

ABB - RET

670 87T>

Stage 1

(T2D1 )

2 Differential

Protection

(Unrestrained)

,Stage 2

ABB - RET

670 87T>>

3 Restricted

Earth fault

Protection

ABB - RET

670 64R LV

( Low

impedance

RECOMMENDED RELAY SETTING CHART FOR 132/11.5kV, 20/25 MVA TRANSFORMER

SI. No.

Type of

Protection

Relay Make

/ No.

PROTECTION ANSI

CODE

(3)

64R HV

Restricted

Earth fault

Protection

ABB - RET

670 64R LV

(High

Impedence

64R HV

4 Stand -by

Earth fault

Protection

(HV Side)

ABB - RET

670 51s-EFR HV

( 4th-Stage- OFF)

RET-670 , TIME CO-ORDINATED SETTINGS OF

Stan-by-EFR ( HV & LV )

(4)

Stand -by Earth fault

Protection (LV Side)

ABB - RET

670 51s-EFR LV

I_base

I1>

t1>

I2>

t2>

I3>

t3>

I4>

t4>

Stand -by Earth fault

Protection (HV Side)

ABB - RET

670 51s-EFR HV

I_base

I1>

t1>

I2>

t2>

I3>

t3>

I4>

t4>

STAGE-3

STAGE-4

STAGE-1

STAGE-3

STAGE-4

600/1A (132KV side)

150/1A (132KV side)

STAGE-1

STAGE-2

(5)

Parameter

Description

150/1A (132KV side)

Operation

on

2000/1A (11 kV Side)

IdMin

Setting of minimum

differential operating current

%Z = 12.5% ( TAKE

FROM Name plate of

trafo. )

End section 1

Cross-Over point b/w slope1

& Slope-2

Vector group = YNyn0

Slope section 2

Setting of slope 2

stabilisation, (Slope 1 has

fixed stabilization)

End section 2

Cross-Over point b/w slope2

& Slope-3

Slope section 3

Setting of slope 3

stabilisation,

150/1A (132KV side)

2000/1A (11 kV Side)

Idunre

Differential current, High set

(Unrestrained)

Cross blocking logic

OpCrossBlock

= on

I

d2f

/ I

d1f

> (%)

2nd Harmonic restraint

I

_d5f

/ I

_d1f

> (%)

5th Harmonic restraint

Set the operation of

Negative sequence

differential protection

OpNegSeqDiff =

= on

IMinNegSeq =

Setting of minimum negative

sequence differential current

level

NegSeqROA

Relay operate angle

2000/1A (11 kV Side)

Idmin (%)

ROA

Relay operate angle

RECOMMENDED RELAY SETTING CHART FOR 132/11.5kV, 20/25 MVA TRANSFORMER

CT Ratio / PT Ratio/

OTHER

Relay Setting

(6)

150/1A (132KV side)

Idmin (%)

ROA

Relay operate angle

2000/1A (11 kV Side)

U alarm

Operate voltage

t Alarm

Operate time

U trip

Operate voltage

t trip

Operate time

Rs

Series Resistor

150/1A (132KV side)

U alarm

Operate voltage

t Alarm

Operate time

U trip

Operate voltage

t trip

Operate time

Rs

Series Resistor

150/1A (132KV side)

I

N1

>/ Ib

Base Current Setting

Dir mode

Ibase

1st-stage

t11>

DT setting

NA

k11>

TMS

I

N2

>/ Ib

Base Current Setting

Dir mode

2nd-stage

t1 2>

DT setting

NA

k1 2>

TMS

I

N3

>/ Ib

Base Current Setting

Dir mode

3rd-stage

t1 3>

DT setting

NA

k1 3>

TMS

(7)

100%

80%

80% of Ibase

0.96 sec

0.0 sec

50% of Ibase

1.2 sec

0.40 sec

40% of Ibase

1.4sec

0.80 sec

30% of Ibase

1.6sec

1.20 sec

100%

80%

80% of Ibase

1.26 sec

0.3 sec

100% of Ibase

1.46 sec

0.15 sec

off

OFF

off

OFF

t= 0.96 sec. is the

Normal-EFR ( in incomer of

11KV-rex-521 ) Relay's time

setting. So, the same has

been maintained as trip-

time to SB-EFR-LV.

Assuming a time

descripation of 0.3 sec.

b/w 11KV & 132KV -trip

time , t1= 0.96 + 0.3sec. =

1.26 SEC.

600/1A (132KV side)

150/1A (132KV side)

(8)

Available range

PSM

TMS/DMT (sec)

----

----0.10-0.60

0.25 * Ibase.

Inst

0.2 - 1.5

1.25 * Ibase.

10.0 -50.0 %

40 * Ibias

1.0 -10

3 * Ibase.

30.0 -100.0 %

80 * Ibias

100- 5000 % of

Ibase

10 * Ibase.

Inst

---

---5-100 % of fn

15%

5-100 % of fn

25%

---

---(0.01 - 0.10 )* Iopr.

0.04 * Iopr.

60 - 90 Degrees

60 °

4.0 -100.0

30%

Inst

60 - 90 Degrees

60 °

see ANNEXURE-01

This settings may not be

applicable - while we have

adopted High -Impedence

based REFR-Protection.

RECOMMENDED RELAY SETTING CHART FOR 132/11.5kV, 20/25 MVA TRANSFORMER

Relay Setting

Remarks

(9)

4.0 -100.0

30%

Inst

60 - 90 Degrees

60 °

( 2 -500 ) V

N / A

0 - 60 sec

N / A

5.0 sec.

( 5 -900 ) V

109.5 V

---

----

Inst

10 -20000 Ohms.

396 ohms.

( 2 -500 ) V

N / A

0 - 60 sec

N / A

5.0 sec.

( 5 -900 ) V

63 V

---

----

Inst

10 -20000 Ohms.

250 ohms.

1.0 -2500.0 %

Ibase

**20% * Ibase**

---

Non directional

0 - 60 Secs

----

1.0 sec.

0.05 - 999

0.15 Secs

NI 0.15 Secs

1.0 -2500.0 %

Ibase

15% * Ibase

---

Non directional

0 - 60 Secs

----

1.5 sec.

0.05 - 999

0.15 Secs

NI 0.15 Secs

1.0 -2500.0 %

Ibase

**10% * Ibase**

---

Non directional

0 - 60 Secs

----

2.0 sec.

0.05 - 999

0.15 Secs

NI 0.15 Secs

This settings may not be

applicable - while we have

adopted High -Impedence

based REFR-Protection.

see ANNEXURE-01

(10)

PACP

Recomended Relay Settings

Parameter

Description

Available range

PSM

TMS/DMT

(sec)

1 Differential Protection

(Restrained)

ABB - RET

670 87T>

150/1A (132KV side)

Operation

on

----

Stage 1

(T2D1 )

2000/1A (11 kV Side)

IdMin

Setting of minimum

differential operating

current

0.10-0.60

0.25 * Ibase.

Inst

%Z = 12.5% ( TAKE

FROM Name plate of

trafo. )

End section 1

Cross-Over point b/w

slope1 & Slope-2

0.2 - 1.5

1.25 * Ibase.

Vector group = YNyn0

Slope section 2

Setting of slope 2

stabilisation, (Slope 1

has fixed stabilization)

10.0 -50.0 %

40 * Ibias

End section 2

Cross-Over point b/w

slope2 & Slope-3

1.0 -10

3 * Ibase.

Slope section 3

Setting of slope 3

stabilisation,

30.0 -100.0 %

80 * Ibias

2 Differential Protection

(Unrestrained) ,Stage 2

ABB - RET

670 87T>>

150/1A (132KV side)

2000/1A (11 kV Side)

Idunre

Differential current,

High set (Unrestrained)

100- 5000 % of

Ibase

10 * Ibase.

Inst

Cross blocking logic

OpCrossBlock

= on

---

---I

d2f

/ I

d1f

> (%)

2nd Harmonic restraint

5-100 % of fn

15%

I

d5f

/ I

d1f

> (%)

5th Harmonic restraint

5-100 % of fn

25%

Set the operation of

Negative sequence

differential protection

OpNegSeqDiff =

= on

---

---IMinNegSeq =

Setting of minimum

negative sequence

differential current level

(0.01 - 0.10 )* Iopr.

0.04 * Iopr.

NegSeqROA

Relay operate angle

60 - 90 Degrees

60 °

3 Restricted Earth fault

Protection

ABB - RET

670 64R LV

2000/1A (11 kV Side)

Idmin (%)

4.0 -100.0

30%

Inst

( Low impedance bsed.)

ROA

Relay operate angle

60 - 90 Degrees

60 °

64R HV

150/1A (132KV side)

Idmin (%)

4.0 -100.0

30%

Inst

ROA

Relay operate angle

60 - 90 Degrees

60 °

Restricted Earth fault

Protection

ABB - RET

670 64R LV

2000/1A (11 kV Side)

U alarm

Operate voltage

( 2 -500 ) V

N / A

(High Impedence based.)

t Alarm

Operate time

0 - 60 sec

N / A

5.0 sec.

U trip

Operate voltage

( 5 -900 ) V

109.5 V

t trip

Operate time

---

----

Inst

Rs

Series Resistor

10 -20000 Ohms.

396 ohms.

64R HV

150/1A (132KV side)

U alarm

Operate voltage

( 2 -500 ) V

N / A

t Alarm

Operate time

0 - 60 sec

N / A

5.0 sec.

U trip

Operate voltage

( 5 -900 ) V

63 V

t trip

Operate time

---

----

Inst

Rs

Series Resistor

10 -20000 Ohms.

250 ohms.

see ANNEXURE-01

CT Ratio / PT Ratio/

OTHER

Relay Setting

This settings may not

be applicable - while

we have adopted High

-Impedence based

REFR-Protection.

see ANNEXURE-01

Available setting range

see ANNEXURE-01

RECOMMENDED RELAY SETTING CHART FOR 132/11.5kV, 20/25 MVA TRANSFORMER

Recommended setting

Remarks

SI.

No.

Type of Protection

Relay Make /

No.

PROTECTION

ANSI CODE

(11)

PACP

Recomended Relay Settings

Parameter

Description

Available range

PSM

TMS/DMT

(sec)

CT Ratio / PT Ratio/

OTHER

Relay Setting

Available setting range

see ANNEXURE-01

RECOMMENDED RELAY SETTING CHART FOR 132/11.5kV, 20/25 MVA TRANSFORMER

Recommended setting

Remarks

SI.

No.

Type of Protection

Relay Make /

No.

PROTECTION

ANSI CODE

4 Stand -by Earth fault

Protection (HV Side)

ABB - RET

670 51s-EFR HV

150/1A (132KV side)

I

N1

>/ Ib

Base Current Setting

1.0 -2500.0 % Ibase

**20% * Ibase**

( 4th-Stage-

OFF)

Dir mode

---

Non directional

1st-stage

t11>

DT setting

0 - 60 Secs

----

1.0 sec.

NA

k11>

TMS

0.05 - 999

0.15 Secs

NI 0.15 Secs

I

_N2

>/ Ib

Base Current Setting

1.0 -2500.0 % Ibase

15% * Ibase

Dir mode

---

Non directional

2nd-stage

t1 2>

DT setting

0 - 60 Secs

----

1.5 sec.

NA

k1 2>

TMS

0.05 - 999

0.15 Secs

NI 0.15 Secs

I

_N3

>/ Ib

Base Current Setting

1.0 -2500.0 % Ibase

**10% * Ibase**

Dir mode

---

Non directional

3rd-stage

t1 3>

DT setting

0 - 60 Secs

----

2.0 sec.

NA

k1 3>

TMS

0.05 - 999

0.15 Secs

NI 0.15 Secs

see ANNEXURE-01 ---

(12)

PACP

Recomended Relay Settings

Parameter

Description

Available range

PSM

TMS/DMT

(sec)

CT Ratio / PT Ratio/

OTHER

Relay Setting

Available setting range

see ANNEXURE-01

RECOMMENDED RELAY SETTING CHART FOR 132/11.5kV, 20/25 MVA TRANSFORMER

Recommended setting

Remarks

SI.

No.

Type of Protection

Relay Make /

No.

PROTECTION

ANSI CODE

5 Stand -by Earth fault

Protection (LV Side)

ABB - RET

670 51s-EFR LV

600/1A ( in NGR )

I

N1

>/ Ib

Base Current Setting

1.0 -2500.0 % Ibase

**15% * Ibase**

( 4th-Stage-

OFF)

Dir mode

---

Non directional

1st-stage

t11>

DT setting

0 - 60 Secs

----

2.0 sec.

NA

k11>

TMS

0.05 - 999

0.15 Secs

NI 0.15 Secs

I

N2

>/ Ib

Base Current Setting

1.0 -2500.0 % Ibase

**25% * Ibase**

Dir mode

---

Non directional

2nd-stage

t1 2>

DT setting

0 - 60 Secs

----

1.5 sec.

NA

k1 2>

TMS

0.05 - 999

0.15 Secs

NI 0.15 Secs

I

N3

>/ Ib

Base Current Setting

1.0 -2500.0 % Ibase

**30% * Ibase**

Dir mode

---

Non directional

3rd-stage

t1 3>

DT setting

0 - 60 Secs

----

1.0 sec.

NA

k1 3>

TMS

0.05 - 999

0.15 Secs

NI 0.15 Secs

6 Under Frequency .

Protection.

ABB - RET

670 81.U

132KV / 110 Volts.

Operation mode

on /Off

on.

Ubase (KV)

Base voltage setting

0.05 - 2000 volts.

132 KV

f <

Start Freq.

Freq setting / start

value.

35 -75 Hz.

48.8 Hz.

Int_Bloc_Level

Internal_Blocking

_Level in % Of Ubase

0 -100 % Of UB

50%

Time delay operate

0 -60 sec.

0.2 sec.

Time delay Reset

0 -60 sec.

0.0 sec.

Time delay Restore

0 -60 sec.

0.0 sec.

Restore freq.

45 - 65 Hz.

50.10 Hz.

Timer Operation

DT/ Voltage based

DT

----Unom

50 -150 % Ub

100 N / A

Umin

50 -150 % Ub

90 N / A

Exponent .

0.0 - 5.0

1 N / A

Tmax.

0.01 -60 sec.

1 N / A

Tmin

0.01 -60 sec.

1 N / A

6 Over Frequency . Protection.

ABB - RET

670 81.O

132KV / 110 Volts.

Operation mode

on /Off

off

Ubase (KV)

Base voltage setting

0.05 - 2000 volts.

132 KV

f >

Start Freq.

Freq setting / start

value.

35 -75 Hz.

51.20 Hz.

Int_Bloc_Level

Internal_Blocking

_Level in % Of Ubase

0 -100 % Of UB

50%

Time delay operate

0 -60 sec.

0.0 sec.

Time delay Reset

0 -60 sec.

0.0 sec.

see ANNEXURE-01

(13)

PACP

Recomended Relay Settings

Parameter

Description

Available range

PSM

TMS/DMT

(sec)

CT Ratio / PT Ratio/

OTHER

Relay Setting

Available setting range

see ANNEXURE-01

RECOMMENDED RELAY SETTING CHART FOR 132/11.5kV, 20/25 MVA TRANSFORMER

Recommended setting

Remarks

SI.

No.

Type of Protection

Relay Make /

No.

PROTECTION

ANSI CODE

6 Rate of change of

Frequency . Protection.

ABB - RET

670 Df /dt

132KV / 110 Volts.

Operation mode

on /Off

off

Ubase (KV)

Base voltage setting

0.05 - 2000 volts.

132 KV

f >

Start Freq. Gradient.

Freq .Gradient.

-10 - 10 Hz/sec..

0.5 Hz /sec.

Int_Bloc_Level

Internal_Blocking

_Level in % Of Ubase

0 -100 % Of UB

50%

Operate Time ( tTrip )

0 -60 sec.

0.2 sec.

Time delay Reset

0 -60 sec.

0.0 sec.

Time delay Restore

0 -60 sec.

0.0 sec.

Restore freq.

45 - 65 Hz.

49.90 Hz.

6 Over Fluxing (Over

excitation)

ABB - RET

670 99 (24)

220KV / 110 Volts.

V/Hz>

Voltage / Freq.

100 - 180% x U/f

110% x U/f

t alarm

oprtng. Time

0-9000 sec.

----

5sec.

T-alarm_level

Alarm operate level

50 -120%

100%

V/Hz>>

Voltage / Freq.

100 - 200% x U/f

140% x U/f

tmax.

max. trip delay for I

-curves

0 - 9000 sec.

1500

1800

tmin

min. trip delay for I

-curves

0 - 60 secs

4 sec

7 tr-pulse

length of Pulse for trip

0 - 60 secs

0.1

0.1 X-leakage

Leaakage reactance of

trafo. Winding.

0.00-200 ohms.

0 t-cooling

cooling time constant

for Trao.

0.1 -9000 sec

1200

1200 sec.

CurveType

curve selection.

INVERSE/ IEEE /

TAILOR MADE.

IEEE

see ANNEXURE-01

(14)

PACP

Recomended Relay Settings

Parameter

Description

Available range

PSM

TMS/DMT

(sec)

CT Ratio / PT Ratio/

OTHER

Relay Setting

Available setting range

see ANNEXURE-01

RECOMMENDED RELAY SETTING CHART FOR 132/11.5kV, 20/25 MVA TRANSFORMER

Recommended setting

Remarks

SI.

No.

Type of Protection

Relay Make /

No.

PROTECTION

ANSI CODE

7 Local Breaker Back-up

ABB - RET

670 50 LBB

150 / 1A

(132KV side)

Operating mode

backup trip mode

1 out of 4/ 2 out of 4

/ 1 out of 3

1 out of 3

Retrip-mode

re-trip -Off

IP >

Operate Ph. Current in

% of Ibase

5-200%

10%

IN >

Operate Residual.

Current in % of Ibase

2-200%

10%

t1 >

time delay of re-trip

0-60sec.

0 sec.

8 Residual -Over voltage

Voltage Protection Protn.

ABB - RET

670 59N

132KV/√3 / 110V/√3

Operation Mode

----

0n , STAGE-1

UB =

Open-delta Voltage

CurveType

DT/C-A/C-B/C-C

DT

U1 >

START VOLTAGE

1- 200 % UB

30 % UB

t1 >

Definite Time Delay

0 - 6000 sec.

5 sec.

t1 min >

Operating Time for I

-curves

0 - 60 sec.

5 sec.

NA

k1 >

TMS

0.05 - 1.10

0.05 NA

HystAbs1

Absolute Hysteresis

in% of Ubase.

0 -100 % UB

0.5 % UB

Operation Mode

----

0n , STAGE-2

CurveType

DT/C-A/C-B/C-C

DT

U2 >

START VOLTAGE

1- 100 % UB

45 % UB

t2 >

Definite Time Delay

0 - 6000 sec.

5 sec.

t2 min >

Operating Time for I

-curves

0 - 60 sec.

5 sec.

NA

k2 >

TMS

0.05 - 1.10

0.05 NA

HystAbs2

Absolute Hysteresis

in% of Ubase.

0 -100 % UB

0.5 % UB

9 Back-up Overcurrent/ Earth

fualt protection ( Non-dir /

Dir )

REX 521

51 / 50 / 51N / 67

/ 67N

150/1A (132KV side)

Operation Mode

Not in use / DT/ NI/VI /

c-2 ETC. ( 1 to 15 )

DT =01

31>

H-02

NOC3Low (51)

31>

Current setting (I/ In)

0.10 - 5.00 xIn.

0.7 Operate time ( in DT)

0.05 - 300 Secs

0.05 time Multiplier ' K '( in

IDMT -mode )

0.05 - 1.00

0.05 IDMT

IEEE- time DAIL in

IDMT -mode

0.5 - 15

0.5 NOC3High ( 50 / 51 )

Operation Mode

Not in use / DT / inst..

Inst. = 02

31>>

Current setting (I/ In)

0.10 - 40 xIn.

2 Operate time ( in DT -

Mode)

0.05 - 300 Secs

0.05 DT- 0.05

SECS.

see ANNEXURE-01

see ANNEXURE-02

Page 14 of 21

(15)

PACP

Recomended Relay Settings

Parameter

Description

Available range

PSM

TMS/DMT

(sec)

CT Ratio / PT Ratio/

OTHER

Relay Setting

Available setting range

see ANNEXURE-01

RECOMMENDED RELAY SETTING CHART FOR 132/11.5kV, 20/25 MVA TRANSFORMER

Recommended setting

Remarks

SI.

No.

Type of Protection

Relay Make /

No.

PROTECTION

ANSI CODE

REX 521

DEF2Low ( 67N / 51N )

Operation Mode

Not in use / DT/ NI/VI /

c-2 ETC.

DT =01

Io >->

Operation Criteria

67N,51N etc.., (1 to 05)

4 = Non-directional

Io>

---Operation direction

forward / Reverse

forward=0

N/A

Operation

Charecteristics.

IoSin(phi) / IoCos(phi)

( 0,1)

0 N/A

Basic Angle

-90 deg to 60 deg.

-90 deg

N/A

Io >

Current setting (Io/ In)

0.01 - 5.00 xIn.

0.075 Uo>

Start voltage

2.0 - 100 % of Un.

75%

N/A

Operate time ( in DT)

0.10 - 300 Secs

0.1 REX 521

DEF2High ( 67N )

Operation Mode

Not in use / DT/ NI/VI /

c-2 ETC.

DT =01

Io >>->

Operation Criteria

67N, etc.., (1 to 05)

0 = Basic angle &

Uo

---Operation direction

forward / Reverse

forward=0

---Operation

Charecteristics.

IoSin(phi) / IoCos(phi)

( 0,1)

**0=Io*sin(phi)**

----Basic Angle

-90 deg to 60 deg.

-90 deg

---Io >

Current setting (Io/ In)

0.01 - 5.00 xIn.

0.075 Uo>

Start voltage

2.0 - 100 % of Un.

5%

Operate time ( in DT)

0.1 - 300 Secs

0.1 intermittent EFR

Active / Not-active (0,1)

0 ---REX 521

DOC6Low ( 67 )

Operation Mode

Not in use / DT/ NI/VI /

c-2 ETC.

DT =01

3I >_>

3I >>_>

Operation direction

forward / Reverse

forward=0

---Operation

Charecteristics.

IoSin(phi) / IoCos(phi)

( 0,1)

**0=Io*sin(phi)**

---Basic Angle

0 deg to 90 deg.

60 deg

---Io >

Current setting (Io/ In)

0.05 - 40 xIn.

0.75 time Multiplier ' K '( in

IDMT -mode )

0.05 - 1.00

0.05 IDMT

Operate time ( in DT)

0.05 - 300 Secs

0.05 see ANNEXURE-02

(16)

PACP

Recomended Relay Settings

Parameter

Description

Available range

PSM

TMS/DMT

(sec)

CT Ratio / PT Ratio/

OTHER

Relay Setting

Available setting range

see ANNEXURE-01

RECOMMENDED RELAY SETTING CHART FOR 132/11.5kV, 20/25 MVA TRANSFORMER

Recommended setting

Remarks

SI.

No.

Type of Protection

Relay Make /

No.

PROTECTION

ANSI CODE

intermittent EFR

-protection

Disabled / Enabled(0,1)

0 ---REX 521

DOC6High ( 67 )

Operation Mode

Not in use / DT/ Inst.

Inst. = 02

3I >>_>

Operation direction

forward / Reverse

forward=0

---Operation

Charecteristics.

IoSin(phi) / IoCos(phi)

( 0,1)

**0=Io*sin(phi)**

---Basic Angle

0 deg to 90 deg.

60 deg

---Io >

Current setting (Io/ In)

0.05 - 40 xIn.

0.05 Non directional

Operation

when the dir. Cannot be

determined ( 0, 1 )

0 ----Operate time ( in DT)

0.05 - 300 Secs

0.05 intermittent EFR

-protection

Disabled / Enabled(0,1)

0 ---10

Under-Voltage Relay.

RXEG 21

27 132000V/√3 / 110V/√3

Operation Mode

DT -ALARM / trip

stage

U<

-U< Alarm

Under voltage setting.

40 -120 V

85 volts.

t > alarm

time setting.(DT)

0 - 99 hrs.

3.0 sec.

U< Trip

Under voltage setting.

40 -120 V

77 volts.

t > Trip

time setting.(DT)

0 - 99 hrs.

1.0 sec.

11 Over-Voltage Relay.

RXEG 21

59 132000V/√3 / 110V/√3

Operation Mode

DT -ALARM / TRIP

stage

U>

-U> Alarm

Under voltage setting.

60 -160 V

115 volts.

t > alarm

time setting.(DT)

0 - 99 hrs.

3.0 sec.

U> Trip

Under voltage setting.

40 -120 V

121 volts.

t > Trip

time setting.(DT)

0 - 99 hrs.

1.0 sec.

see ANNEXURE-01

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APPM-MDP Recomended Relay Settings

1)

a) Initial setting:( Idmin) ; --- This setting covers the un-balance created in the differential operating current by the On load Tap changer. In our case the the Tap changer limits are +10% to -15% , and hence the mean tap value : [ 10 +(-15) ] / 2 = - 2.5% and so, the Hv -amps @ mean tap value =[109.35 / (1-0.0250 ] = 112.154 Amps, which corresponds to 2.56% variation in the HV-currents when mean value is considered. Also,in practice typically the initial minimum differentialpick up value for power trafos with OLTC is set between 30% - 40% . However, RET-670 is in-built with OLTC compensation factor and it is possible to set the Id(min) to more sensitive pick up value between ( 15% to 20% ) .Thus we preferred to se the Idmin = 0.25 of Ibase.

b) Endsection-1 setting: ; --- This is the most sensitive part of the charecteristic.Uncompensated OLTC currents are the reason for the existing of false diff currents in this region. so, the slope in this section is always zero.The end lit of this section is set at 1.25 after ensuring the risk of higher false differential currents relatively low.Also,this is the defualt setting set in the RET-670.

c) Slopesection-2 , End section-2 ,Slopesection-3 ; --- These settings are typically adopted to form the Differntial -curve as shown above. The curve with these setting is suitable for various applications as per the Technical -reference manual-rev-b (p-116) .Also, the basis for these settings are as descibed in the technical reference manuals.

d) Unrestrain -high set ,Idunre ; --- This setting by defualt set at 10.This setting ensures the operation instantaneously, as without any doubt this big differential current occurs only due to internal fualts. Also, this by-passes the harmonic test in its operation and so, called unstabilised operation.( Technical -reference manual-rev-b (p-115)

2)

It is a common known fact that ( compared to Low impedence based REFR protection) , High impedence based protections are highly sensitive, accurate & fast operating. Since, high impedence based protections are current / voltage based , and hence makes use of METROSIL & STABILIZING RESISTOR in it's circuit is evident due to high-impedence occurance. The settings for Metrosil and Stablising resistor are as under : CTR -HV = 150 / 1A . R nct = ( as per the field test data ) 2.0 ohms. Rct= 2.0 ohms.

RET-670 & REX-521 RELAY - DETAILED DESCRIPTION FOR SETTING BASIS.

87T -TRAFO. DIFFERENTIAL PROTECTION: The charecteristic for this protection function as adopted in the relay is as shown below.

64R-HV & 64R-LV -TRAFO.HIGH IMPEDENCE BASED RESTRICTED EARTH FUALT PROTECTION :

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Rs = Us / Ir --- 1

Rs = The resistance of the stabilizing circuit. Ir = The setting value of the Relay.. Us = The stabilizing voltage of the Relay..

Ir = The setting value of the Relay..

Us = If / CTR [ Rct + Rlead ] --- 2 If = Max. expected Through fault current. CTR = phase & nuetral common CT Ratio. Rct = Internal CT secondary resistance of the Circuit. Rl = R of Longest loop of secondary circuit.

Uk > = 2 * Us --- 3 , where Uk = Knee point voltage of the Relay. And factor 2 is used when no operate delay permitted for protection.

I prim = CTR* [ Ir + Inr + m x Ie ] --- 4

Iprim = prim. Operating Current of the relay. Ir = setting value of the Relay.

Inr = Current through the Non-Linear Resistance m = no of CT's in the circuit. / no of CT's in parallel. Ie = Excitation current of the CT @ Us.

Ie = 0.5 * I0 --- 5

Io = Excitation current of the relay @ Uk

Ir recommended > = m x Ie = m x 0.5 x Io ( as per the technical manual )

Also, as per the Relay manuals and pratice , If ( max. thro fualt current ) = 16 x IfL ---- for small Transformers. = 12 x IfL ---- for Big Transformers. = 6 x IfL ---- for Generators. IfL ---- > Full load current of the Transformer /Generator.

Also, the sensitivity requirements for the protection are jeopardize if the magnetizing current of the CT's at Vk is too high. The Iprim Vaue at which the Relay operates at certain settings can be calculated using the formula. As in the eqn --- 4.

TRANSFORMER DATA : MVA = 20 /25 ONAN /ONAF KV -Rating. : 132 /11.5 KV % Z = 12.5 P.u ON 20 MVA BASE. Vector group : YNyn.

Tap Change Limit : +10 % to -15% @ 1.25% Nct -Ratio = 150 /1A

Uk -Nct = 150 Volts. ( as phase CT's are designed for Uk> 400volts,Hence the chances getting saturated is minimum.) Excitation current for NCT < 30 mA @ Vk / 2.

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Calculations for REFR -HV :

Rnct = 2.0 ohms , Rlead = 2.0 ohms. & Rct(ph) = 4.0 ohms. ( for calculations Rct(ph) shall be taken or which ever is Higher.) Nct -Ratio = 150 /1A

Uk -Nct = 150 Volts. ( as phase CT's are designed for Uk> 400volts,Hence the chances getting saturated is minimum.) Excitation current for NCT < 30 mA @ Vk /2 ( considering the worst case ).

IfL -HV = 109.35A , CTR= 150

If = ( %Z ) x IfL = 12.5 x 109.35 = 1367 A ( Max. expected through fault current expected. )

Uk = (required) = 2 x Us. = 2 x If / CTR [ Rct + Rlead ] = 2 x (1367 / 150) [4 +2 ] = 109.36 volts.=110 V (approx.)

As Uk is >>> than 150 V as per the Trafo. Name plate data for NCT.The operation of protection would be ensured perfectly. And is not a case dependent. Us =Uk /2 = 54.68 volts.=55 V (approx.)

Now, since the RET-670 adopts High-Impedence scheme with voltage as operand.

Hence, the Stabilizing Resistor , Rs= 250 ohms. & Us>= 63volts.

The setting to adopted is = 115% of Us> = 1.15 x 55 = 63 (Approx.) volts. Ip(prim) = (Sentivity current measured) = CTR { Ir + I_nlr + n x Ie }

Ir = Current through the Relay @ voltage Us> = 63/250 = 252 mA . Inlr = Current through the Non- Linear Resistor = (from the graph.) = 5 mA.

nxIe = no. of CT's and their average Excitation currents. = (0.0504+3x0.0252) = 126mA.(approx.) Ip(prim) = (Sentivity current measured) = CTR { Ir + I_nlr + n x Ie }= 150{ 252+5+126 } = 57.45 A. This is well below the value minimum fualt current, and only constitute 38.3 % of Rated CT current. Also,

As, per the above description , The Ir >= m x 0.5 x Io = 4 x 0.5 x ( 0.030 x 2 ) = 0.12 A so, the setting is safe.

Hence, the Stabilizing Resistor , Rs= 250 ohms. & Us>= 63volts.

Calculations for REFR -LV :

Rnct = 4.0 ohms , Rct (ph) = 10.0 ohms. & Rlead = 2.0 ohms.( for calculations Rct(ph) shall be taken or which ever is Higher. ) IfL -LV = 1255.15A , CTR= 2000/1A

Nct -Ratio = 2000 /1A

Uk -Nct = >300 Volts. ( as phase CT's are also,designed for Uk> 300volts,Hence the chances getting saturated is minimum.) Excitation current for NCT < 30 mA @ Vk / 4.

Uk = (required) = 2 x Us. = 2 x If / CTR [ Rct + Rlead ] = 2 x (15690 / 2000) [ 10 +2 ] = 188.3 volts.=189 V (approx.)

As Uk is >>> than 300 V as per the NGR. Name plate data for NCT.The operation of protection would be ensured perfectly. And is not a case dependent. Us =Uk /2 = 94.14 volts.=95 V (approx.)

Hence, the Stabilizing Resistor , Rs= Us/Ir. = 95 / 0.24 =395.83 = 396 Ohms (approx.)

Now, since the RET-670 adopts High-Impedence scheme with voltage as operand. The setting to adopted is = 115% of Us> = 1.15 x 95 = 109.5 (Approx.) volts. Calculation of Stabilizing Resistor : As per manuals of RET ,

This can be directly selected to a value Rs=396 ohms . Now , this value of resistor should satisfy the below eqn.

Ip(prim) = (Sentivity current measured) = CTR { Ir + I_nlr + n x Ie }

Ir = Current through the Relay @ voltage Us> = 109.5/396 = 276.5 mA . Inlr = Current through the Non- Linear Resistor = (from the graph.) = 5 mA.

nxIe = no. of CT's and their average Excitation currents. = (0.0544+3x0.0544) = 218mA.(approx.) Ip(prim) = (Sentivity current measured) = CTR { Ir + I_nlr + n x Ie }= 2000{ 276.5+5+218 } = 999.0 A. This is well below the value minimum fualt current, and only constitute 49.95 % of Rated CT current. Also,

Hence, the Stabilizing Resistor , Rs= 396 ohms. & Us>= 109.5 volts.

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3) 51Ns -HV & LV :

The stand by earth-fualt protection , is mainly to Protect the NGR from over heating due to Fualt current exceeding the rated current rating of the NGR. .So, the settings adopted have to be set in Definite time mode depending upon it's thermal current rating of the Transformer. The rated duty of the NGR is our case is 600A for 30 secs. And hence , the settings should be planned such that the HV - S/b EFR should trip HV-Breaker , and LV - S/b EFR should trip LV -Breaker , compeletely isolating the Transformer from the circuit. However , as discussed in the prior meeting held with Mr.B.D.Shaw,if the Lower rating -NGR that are existing in the System , then it's setting should be minimised to the value of Lower -rating NGR or 90% of that. We have attached a document on S/B EFR Protection with this for your reference. Hence, the setting should be adopted for

HV S/B EFR : CTR= 150 /1A ,

Io > setting= approx.( 15 % - considering the Lowest rating NGR ,rating = 100A ,Else 85% - considering the rated ampacity of the NGR.) Time setting: definite time , and should be with in the Rated duty of NGR i.e 3.0 secs.

LV S/B EFR : CTR= 600 /1A ,

Io > setting= approx.( 15 % - considering the Lowest rating NGR ,rating = 100A .)

4) 99 (24) : Over fluxing Protection.

Actual set limits for this protection should be in accordance with the data submitted by the ' Trafo. Manufacturer. " . However , the default settings

of as in the relay , suits for most of the applications. These default settings programmed at ABB Factory , after a detailed study of Most -common and most versatile applications. As pe the TRAFo. " Permissible Over-excitation Curve " ( attached with mail.) .

Some Important Factors / Notes for Over fluxing Protection:

1) Over excitaion occurs from the excessive applied voltage, possibly in combination with below normal Frequency. Such conditions are very often , when Transformers are directly connected to the Generators.

2) Bmax is directly proportional to the Induced voltage., as E = 4.44 x f x n x Bmax . A 3) The calculation of the relative ( M ) ,is based on the V/Hz ratio..

4) As per IEC 60076-1 , All transformers shall be capable of operating continuously at 10% above rated voltage. On that basis the setting range is 100 - 150%. & if the User does not know what exactly to be set , then th e standard IEC-60076 -1 section-4.4 suggests defualt value V/Hz > = 1.10 p.u.

5) As long as the E/f or V/F did not cross the relative value (M) set of the relay, the Trafo. Is not overexcited. The relative over excitation is thus defined as Over excitaion = M - V/Hz >

6) Operatin Time of the Overexcitation Protection :

The most famous Law ,so called IEEE Law approximates a square Law and has been choosen based on the analysis of the various transformers over excitation capability charecteristics. They can match a well a transformer core capability.

t op = 0.18 x k [ M - V/Hz>)2_{….= 0.18 x k / ( Overexcitaton ) .}

Where: M -- is the , Mean value in the interval from t=0 to t=top .

V/Hz > ---- is the Max. continously allowed voltage at no -Load and rated Frequency , in p.u . &

K --- is the time multiplier setting for the inverse time functions as usual & selects one curve frim the family of Curves.

Since , from - " Trfo. Data curves " over Excitation of beyond 110% is not allowed so, for Our setting of V/Hz > 110 % of Vr /fr is set and is same as default. Also, the Alarm setting in the relay is in-built and is 2% less than the set value , with a definite time delay of set limit - Tmin. And all other settings are as in the setting chart. We have attached a " over -Excitation Protection basis for your reference along with the Trafo. Over-Excitaion Curve.

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5) 81.O & 81.U - or df/dt Protection. : ( RET-670 )

The basis for this settings when derived from the over excitation limits ( V/Hz - ratio limits) along with the Under & Over voltage set limits , The values found to be extremely high or extremely low , such as ( f > becomes 55 Hz. & f < becomes 36 Hz.) ,Hence, these limits are set in accordance with the ELECTRICITY Regulatory Rules bound to that region. We request M/s Customer to do this setting at site.However, we maintained the same defualt settings for this application.

6) 27 & 59 - Protection. : ( REXEG-21 )

These settings are based on the common practice adopted at most of the installations. Also, the same values are acceptable to most of the Electricity Boards across India. The values adopted are --- 110% of the 110V = 121 volts. ( PT -secondary Rated-value ) --- for Over voltage Limits &

---- 70% of the 110V = 77 Volts ( PT -secondary Rated-value ) --- for Under voltage Limits

7) 50/51, 50N/51N, 67 & 67N - Protection. : ( Rex-521)

These settings are based on the relay co-ordination study , and direction is also based on the study whre in if the non-directional Overcurrent grading is set to follow relay cordination timings , then the Directional - OCR shall be graded fastly to look towards that direction where the former gives graded timing with a substantial time delay. Also, the current settings for these Relays are the full-load current of the Equipment / Feeder.So, we have achieved in this settings, whreas the setting of TMS , needs a DETAILED STUDY.

Calculations for REFR -LV :

Rnct = 4.0 ohms , Rct (ph) = 10.0 ohms. & Rlead = 2.0 ohms.( for calculations Rct(ph) shall be taken or which ever is Higher. ) IfL -LV = 15690 A , CTR= 2000/1 A

Nct -Ratio = 2000 /1A

Uk -Nct = >300 Volts. ( as phase CT's are also,designed for Uk> 300volts,Hence the chances getting saturated is minimum.) Excitation current for NCT < 30 mA @ Vk / 4.

Uk = (required) = 2 x Us. = 2 x If / CTR [ Rct + Rlead ] = 2 x (15690 / 2000) [ 10 +2 ] = 188.3 volts.=190 V (approx.)

As Uk is >>> than 300 V as per the NGR. Name plate data for NCT.The operation of protection would be ensured perfectly. And is not a case dependent. Us =Uk /2 = 95 volts.=95 V (approx.)

Now, since the RET-670 adopts High-Impedence scheme with voltage as operand. The setting to adopted is = 115% of Us> = 1.15 x 101 = 117 (Approx.) volts. Calculation of Stabilizing Resistor : As per manuals of RET ,

This can be directly selected to a value Rs=450 ohms . Now , this value of resistor should satisfy the below eqn.

Ip(prim) = (Sentivity current measured) = CTR { Ir + I_nlr + n x Ie }

Ir = Current through the Relay @ voltage Us> = 117/450 = 260 mA . Inlr = Current through the Non- Linear Resistor = (from the graph.) = 5 mA.

nxIe = no. of CT's and their average Excitation currents. = (0.0544+3x0.0544) = 218mA.(approx.) Ip(prim) = (Sentivity current measured) = CTR { Ir + I_nlr + n x Ie }= 3000{ 260+5+218 } = 1449.0 A. This is well below the value minimum fualt current, and only constitute 48.3 % of Rated CT current. Also,

Hence, the Stabilizing Resistor , Rs= 450 ohms. & Us>= 117 volts.