Document Text Contents
Page 1
FO
R R
EFE
REN
CE
ON
LY
139 KM
0.02897 Ohms
0.30720 Ohms
0.30856 Ohms
0.25697 Ohms
1.02230 Ohms
1.05410 Ohms
4.02683 Ohm
42.70080 Ohm
42.89025 Ohm
84.58 Degree
35.71883 Ohm
142.0997 Ohm
146.5202 Ohm
75.86 Degree
Zero Sequence Impedence for Protected line
Zero Sequence Impedence Angle
Positive sequence impedance per KM
Zero Sequence Resistance per KM
Zero Sequence Reactance per KM
Zero Sequence Impedance per KM
Positive Sequence Impedence for Protected line
Positive sequence Impedence angle
Positive Sequence Resistance for Protected line
Positive Sequence Reactance for Protected line
Zero Sequence Resistance for Protected line
Zero Sequence Reactance for Protected line
DETAILS OF ADJACENT LINE : (NAKODAR - MAKHU)
400kV Rajpura TPPS - Nakodar Line (Main 1)
RELAY TYPE : MiCOM P444
DETAILS OF PROTECTED LINE : (RAJPURA TPPS - NAKODAR)
Length of protected line
Positive Sequence Resistance per KM
Positive Sequence Reactance per KM
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
53 KM
0.02897 Ohm
0.30720 Ohm
0.30856 Ohm
1.53541 Ohm
16.28160 Ohm
16.35384 Ohm
84.58 Degree
12.5%
315 MVA
2
400 KV
63.49 Ohm
31.75 Ohm
2000 Amp
1 Amp
400 Kilo Volt
CT & PT Details
CT Primary
CT Secondary
PT Primary
NO. OF ICT Circuits
Voltage rating
Impedance when 2 ICT's are connected in the circuit((KV)^2)/(2*MVA
) x Percentage impedance
Pos.Seq. Resistance of Adj. Line per KM
Pos.Seq. Reactance of Adj. Line per KM
Impedance when one ICT is connected in the circuit((KV)^2)/(1*MVA
) x Percentage impedance
ICT DETAILS
ICT impedance
ICT rating
Positive Sequence Impedence for adj.line
Positive sequence Impedence angle
Length of the adjacent line
Pos.Seq. Impedence of Adj. Line per KM
Positive Sequence Resistance for adj.line
Positive Sequence Reactance for adj.line
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
Page 2
FO
R R
EFE
REN
CE
ON
LY
110 Volt
0.55
0.811
-12.292 Degree
0.811
-12.292 Degree
80% of protected line
25% of parallel ICT Impedance
100% of parallel ICT Impedance
10% of zone 1 impedence
VALUES
18.872 Ohm
VALUES
Grounding Factor kg = (Z0/Z1)/(3*Z1)
ZONE SETTING CALCULATIONS
ZONE 1
80% of Protected line (recommended)
ZONE 2
DIST Z4
PT Secondary
CT/PT Ratio
GROUND FACTOR
DIST Z3 (100 of Protected line +
KZ1,KZ2,KZ3…..PS1
Angle Kg
ZONE SETTINGS
DIST Z1
DIST Z2 (100 of Protected line +
Magnitude of grounding factor Kg =(SQRT((X0-XL)*(X0-XL))+((R0-
RL)*(R0-RL)))/ (3*(SQRT(RL*RL)+(XL*XL)))
Angle of Grounding factor Kg = (arc Tan((X0-XL/(R0-RL)))-(arc
Tan(XL/RL))*180*7/22
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
28.087 Ohm
27.955 Ohm
VALUES
32.584 Ohm
32.320 Ohm
1.887 Ohm
2000 Amp
76.982 Ohm
42.340 Ohm
25.404 Ohm
25.404 Ohm
25.404 Ohm
33.872 Ohm
33.872 Ohm
33.872 Ohm
DIST R1,PG(Quad) (80% of RL)
DIST R3 & R4,PG(Quad) (80% of RL)
OPERATING TIME DELAY
DIST R2,PG(Quad) (80% of RL)
Load Resistance (RL) in Secondary
DIST R1,PP(Quad) (60% of RL)
DIST R2,PP(Quad) (60% of RL)
DIST R3 & R4,PP(Quad) (60% of RL)
100% of protected line + 50% of Transformer
On comparing the above values, the recommended value is the smallest of all values
10% of Zone 1 Impedence
RESISTIVE REACH SETTING:
100% of protected line + 50% of Adjacent line
Primary full load current, CTR considered as Full load
Resistance at this current=(0.8*(PT Primary * 10^3) / (1.732) /
(1.2*Primary full load current)
ZONE 3
100% of protected line + 100 % of longest line
ZONE 4
100% of protected line + 25% of Transformer
On comparing the above values, the recommended value is the smallest of all values
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
Page 3
FO
R R
EFE
REN
CE
ON
LY
0.00 Sec
0.30 Sec
0.75 SEC
1.00 SEC
20 % of R3
5.081 Ohm
20 % of R3
5.081 Ohm
POWER SWING SETTING:
�dR & �dX
�dR = 10 to 30% of Z3 R3,PP
�dR = 10 to 30% of Z3 R3, PP
UNBLOCKING CURRENT THRESHOLDS:
Unblocking stages using to trip if any fault when relay blocked on PSB
�dX = 10 to 30% of Z3 R3, PP
�dX = 10 to 30% of Z3 R3, PP
The three unblocking current thresholds namely, IN>, I2> and Imax should be set above the maximum expected residual
current unbalance, the maximum negative sequence unbalance and the maximum expected power swing current.
Value of Imax line = 3 Inom
NOTE: PSB Block – Zone 2, Zone 3 & Zone 4
IN> 40%
I2> 30 %
ZONE 3 OPERATING TIME(t3)
ZONE 4 OPERATING TIME(t4)
ZONE 1 OPERATING TIME(t1)
ZONE 2 OPERATING TIME(t2)
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
I>1 Current setting 3A
EARTHFAULT OVERCURRENT PROTECTION
IN>1 Function IDMT
tI>1 Time delay 1.2 sec
BACK UP OVER CURRENT:
Enable Yes
I>3 Current Set 3.00A
I>3 Time delay 3sec
Disabled
Trip mode 1 pole Z1 , CR Received
SWITCH ON TO FAULT
Switch on to fault logic is pre-set in MiCOM P444
Operation on pick up of level detector method and activation of all zones is recommended.This time delay is not having role
in SOTF/TOR logic. Since not possible to block time delay, keep a higher setting as 3 Sec.
Unblocking timer:
To be set to 2s typically to un block in case of a prolonged power swing.
DISTANCE SCHEMES SETTING
Program Mode Standard Scheme
I>4 Status Disabled
Standard Mode PUR Permissive under reach scheme
Z1Ext Fail
PSB Allowed to trip – Zone 1
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
234601
Rectangle
Page 4
FO
R R
EFE
REN
CE
ON
LY
V>1 Voltage Set 121 V (110%)
Delta I> 100 mA
OVER VOLTAGE PROTECTION:
V> Measurement Mode Ph-Ph
VTS I2> & I0> Inhibit 50 mA
Detect 3P Enabled
Threshold 3P U< 10 Volts
V>1 Function DT
Disabled
BROKEN CONDUCTOR PROTECTION
I2/I1 ratio 0.20.
VT SUPERVISION
Time Set 60 Sec.
VTS Time Delay 5.000 s (alarm indication time )
IN>1 VTS Block Non Directional
IN>1 Current set 0.2 A
IN>1 Time Delay 1.2 sec
IN>1 Time VTS
IN>2 status
1.2 sec
IN>1 Directional Directional Forward
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
V< Operation Any Phase
V<1 Pole Dead Inh Enabled
V<1 Voltage Set (80% of Nominal Voltage) 88 V (80%)
V<1 Function DT
V<1 Time Delay 2 sec
V>2 Time Delay 1 sec
V>2 Status Enabled
V>2 Voltage Set 154 V (140%)
V>1 Time Delay 2 sec
UNDER VOLTAGE PROTECTION:
V< Mode Phase-Phase
V<2 Status Enabled
V<2 Voltage Set (70% of Nominal Voltage) 77 V (80%)
Stub Bus Protection (50STB)
Relay Type P444
V<2 Time Delay 0.5 sec
Pickup for Stub Bus in secondary 4.0 A
CT Secondary in Amps 1
Settings:
Stub Bus Enabled
CT Primary in Amps 2000
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
FO
R R
EFE
REN
CE
ON
LY
139 KM
0.02897 Ohms
0.30720 Ohms
0.30856 Ohms
0.25697 Ohms
1.02230 Ohms
1.05410 Ohms
4.02683 Ohm
42.70080 Ohm
42.89025 Ohm
84.58 Degree
35.71883 Ohm
142.0997 Ohm
146.5202 Ohm
75.86 Degree
Zero Sequence Impedence for Protected line
Zero Sequence Impedence Angle
Positive sequence impedance per KM
Zero Sequence Resistance per KM
Zero Sequence Reactance per KM
Zero Sequence Impedance per KM
Positive Sequence Impedence for Protected line
Positive sequence Impedence angle
Positive Sequence Resistance for Protected line
Positive Sequence Reactance for Protected line
Zero Sequence Resistance for Protected line
Zero Sequence Reactance for Protected line
DETAILS OF ADJACENT LINE : (NAKODAR - MAKHU)
400kV Rajpura TPPS - Nakodar Line (Main 1)
RELAY TYPE : MiCOM P444
DETAILS OF PROTECTED LINE : (RAJPURA TPPS - NAKODAR)
Length of protected line
Positive Sequence Resistance per KM
Positive Sequence Reactance per KM
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
53 KM
0.02897 Ohm
0.30720 Ohm
0.30856 Ohm
1.53541 Ohm
16.28160 Ohm
16.35384 Ohm
84.58 Degree
12.5%
315 MVA
2
400 KV
63.49 Ohm
31.75 Ohm
2000 Amp
1 Amp
400 Kilo Volt
CT & PT Details
CT Primary
CT Secondary
PT Primary
NO. OF ICT Circuits
Voltage rating
Impedance when 2 ICT's are connected in the circuit((KV)^2)/(2*MVA
) x Percentage impedance
Pos.Seq. Resistance of Adj. Line per KM
Pos.Seq. Reactance of Adj. Line per KM
Impedance when one ICT is connected in the circuit((KV)^2)/(1*MVA
) x Percentage impedance
ICT DETAILS
ICT impedance
ICT rating
Positive Sequence Impedence for adj.line
Positive sequence Impedence angle
Length of the adjacent line
Pos.Seq. Impedence of Adj. Line per KM
Positive Sequence Resistance for adj.line
Positive Sequence Reactance for adj.line
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
Page 2
FO
R R
EFE
REN
CE
ON
LY
110 Volt
0.55
0.811
-12.292 Degree
0.811
-12.292 Degree
80% of protected line
25% of parallel ICT Impedance
100% of parallel ICT Impedance
10% of zone 1 impedence
VALUES
18.872 Ohm
VALUES
Grounding Factor kg = (Z0/Z1)/(3*Z1)
ZONE SETTING CALCULATIONS
ZONE 1
80% of Protected line (recommended)
ZONE 2
DIST Z4
PT Secondary
CT/PT Ratio
GROUND FACTOR
DIST Z3 (100 of Protected line +
KZ1,KZ2,KZ3…..PS1
Angle Kg
ZONE SETTINGS
DIST Z1
DIST Z2 (100 of Protected line +
Magnitude of grounding factor Kg =(SQRT((X0-XL)*(X0-XL))+((R0-
RL)*(R0-RL)))/ (3*(SQRT(RL*RL)+(XL*XL)))
Angle of Grounding factor Kg = (arc Tan((X0-XL/(R0-RL)))-(arc
Tan(XL/RL))*180*7/22
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
28.087 Ohm
27.955 Ohm
VALUES
32.584 Ohm
32.320 Ohm
1.887 Ohm
2000 Amp
76.982 Ohm
42.340 Ohm
25.404 Ohm
25.404 Ohm
25.404 Ohm
33.872 Ohm
33.872 Ohm
33.872 Ohm
DIST R1,PG(Quad) (80% of RL)
DIST R3 & R4,PG(Quad) (80% of RL)
OPERATING TIME DELAY
DIST R2,PG(Quad) (80% of RL)
Load Resistance (RL) in Secondary
DIST R1,PP(Quad) (60% of RL)
DIST R2,PP(Quad) (60% of RL)
DIST R3 & R4,PP(Quad) (60% of RL)
100% of protected line + 50% of Transformer
On comparing the above values, the recommended value is the smallest of all values
10% of Zone 1 Impedence
RESISTIVE REACH SETTING:
100% of protected line + 50% of Adjacent line
Primary full load current, CTR considered as Full load
Resistance at this current=(0.8*(PT Primary * 10^3) / (1.732) /
(1.2*Primary full load current)
ZONE 3
100% of protected line + 100 % of longest line
ZONE 4
100% of protected line + 25% of Transformer
On comparing the above values, the recommended value is the smallest of all values
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
Page 3
FO
R R
EFE
REN
CE
ON
LY
0.00 Sec
0.30 Sec
0.75 SEC
1.00 SEC
20 % of R3
5.081 Ohm
20 % of R3
5.081 Ohm
POWER SWING SETTING:
�dR & �dX
�dR = 10 to 30% of Z3 R3,PP
�dR = 10 to 30% of Z3 R3, PP
UNBLOCKING CURRENT THRESHOLDS:
Unblocking stages using to trip if any fault when relay blocked on PSB
�dX = 10 to 30% of Z3 R3, PP
�dX = 10 to 30% of Z3 R3, PP
The three unblocking current thresholds namely, IN>, I2> and Imax should be set above the maximum expected residual
current unbalance, the maximum negative sequence unbalance and the maximum expected power swing current.
Value of Imax line = 3 Inom
NOTE: PSB Block – Zone 2, Zone 3 & Zone 4
IN> 40%
I2> 30 %
ZONE 3 OPERATING TIME(t3)
ZONE 4 OPERATING TIME(t4)
ZONE 1 OPERATING TIME(t1)
ZONE 2 OPERATING TIME(t2)
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
I>1 Current setting 3A
EARTHFAULT OVERCURRENT PROTECTION
IN>1 Function IDMT
tI>1 Time delay 1.2 sec
BACK UP OVER CURRENT:
Enable Yes
I>3 Current Set 3.00A
I>3 Time delay 3sec
Disabled
Trip mode 1 pole Z1 , CR Received
SWITCH ON TO FAULT
Switch on to fault logic is pre-set in MiCOM P444
Operation on pick up of level detector method and activation of all zones is recommended.This time delay is not having role
in SOTF/TOR logic. Since not possible to block time delay, keep a higher setting as 3 Sec.
Unblocking timer:
To be set to 2s typically to un block in case of a prolonged power swing.
DISTANCE SCHEMES SETTING
Program Mode Standard Scheme
I>4 Status Disabled
Standard Mode PUR Permissive under reach scheme
Z1Ext Fail
PSB Allowed to trip – Zone 1
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
234601
Rectangle
Page 4
FO
R R
EFE
REN
CE
ON
LY
V>1 Voltage Set 121 V (110%)
Delta I> 100 mA
OVER VOLTAGE PROTECTION:
V> Measurement Mode Ph-Ph
VTS I2> & I0> Inhibit 50 mA
Detect 3P Enabled
Threshold 3P U< 10 Volts
V>1 Function DT
Disabled
BROKEN CONDUCTOR PROTECTION
I2/I1 ratio 0.20.
VT SUPERVISION
Time Set 60 Sec.
VTS Time Delay 5.000 s (alarm indication time )
IN>1 VTS Block Non Directional
IN>1 Current set 0.2 A
IN>1 Time Delay 1.2 sec
IN>1 Time VTS
IN>2 status
1.2 sec
IN>1 Directional Directional Forward
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
V< Operation Any Phase
V<1 Pole Dead Inh Enabled
V<1 Voltage Set (80% of Nominal Voltage) 88 V (80%)
V<1 Function DT
V<1 Time Delay 2 sec
V>2 Time Delay 1 sec
V>2 Status Enabled
V>2 Voltage Set 154 V (140%)
V>1 Time Delay 2 sec
UNDER VOLTAGE PROTECTION:
V< Mode Phase-Phase
V<2 Status Enabled
V<2 Voltage Set (70% of Nominal Voltage) 77 V (80%)
Stub Bus Protection (50STB)
Relay Type P444
V<2 Time Delay 0.5 sec
Pickup for Stub Bus in secondary 4.0 A
CT Secondary in Amps 1
Settings:
Stub Bus Enabled
CT Primary in Amps 2000
For 2x700MW Rajpura Thermal Power Plant
400kV Line Protection.
Rev:0
M/s. Alstom T&D India Limited,
19/1, GST Road,
Pallavaram,
Chennai - 600043.
