400kV Rajpura TPPS - Nakodar Line (Main 1) RELAY TYPE : MiCOM P444 DETAILS OF PROTECTED LINE : (RAJPURA TPPS - NAKODAR) Length of protected line 139 Positive Sequence Resistance per KM 0.02897 Positive Sequence Reactance per KM 0.30720 Positive sequence impedance per KM 0.30856 Zero Sequence Resistance per KM 0.25697 Zero Sequence Reactance per KM 1.02230 Zero Sequence Impedance per KM 1.05410 Positive Sequence Resistance for Protected line 4.02683 Positive Sequence Reactance for Protected line 42.70080 Positive Sequence Impedence for Protected line 42.89025 Positive sequence Impedence angle 84.58 Zero Sequence Resistance for Protected line 35.71883 Zero Sequence Reactance for Protected line 142.0997 Zero Sequence Impedence for Protected line 146.5202 Zero Sequence Impedence Angle 75.86 DETAILS OF ADJACENT LINE : (NAKODAR - MAKHU) Length of the adjacent line 53 Pos.Seq. Resistance of Adj. Line per KM 0.02897 Pos.Seq. Reactance of Adj. Line per KM 0.30720 Pos.Seq. Impedence of Adj. Line per KM 0.30856 Positive Sequence Resistance for adj.line 1.53541 Positive Sequence Reactance for adj.line 16.28160 Positive Sequence Impedence for adj.line 16.35384 Positive sequence Impedence angle 84.58 ICT DETAILS ICT impedance 12.5% ICT rating 315
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NO. OF ICT Circuits Voltage rating
KM Ohms Ohms Ohms Ohms Ohms Ohms Ohm Ohm Ohm Degree Ohm Ohm Ohm Degree KM Ohm Ohm Ohm Ohm Ohm Ohm Degree
MVA
2 400
KV
Impedance when one ICT is connected in the circuit((KV)^2)/(1*MVA ) x Percentage impedance
63.49
Ohm
Impedance when 2 ICT's are connected in the circuit((KV)^2)/(2*MVA ) x Percentage impedance
31.75
Ohm
2000 1 400
Amp Amp Kilo Volt
CT & PT Details CT Primary CT Secondary PT Primary 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.
PT Secondary 110 CT/PT Ratio 0.55 GROUND FACTOR Grounding Factor kg = (Z0/Z1)/(3*Z1) Magnitude of grounding factor Kg =(SQRT((X0-XL)*(X0-XL))+((R00.811 RL)*(R0-RL)))/ (3*(SQRT(RL*RL)+(XL*XL))) Angle of Grounding factor Kg = (arc Tan((X0-XL/(R0-RL)))-(arc -12.292 Tan(XL/RL))*180*7/22 KZ1,KZ2,KZ3…..PS1 0.811 Angle Kg -12.292 ZONE SETTINGS DIST Z1 80% DIST Z2 (100 of Protected line + 25% DIST Z3 (100 of Protected line + 100% DIST Z4 10% ZONE SETTING CALCULATIONS VALUES ZONE 1 80% of Protected line (recommended) 18.872 VALUES ZONE 2 100% of protected line + 50% of Adjacent line 28.087 27.955 100% of protected line + 25% of Transformer On comparing the above values, the recommended value is the smallest of all values VALUES ZONE 3 100% of protected line + 100 % of longest line 32.584 100% of protected line + 50% of Transformer 32.320 On comparing the above values, the recommended value is the smallest of all values ZONE 4 10% of Zone 1 Impedence 1.887 RESISTIVE REACH SETTING: Primary full load current, CTR considered as Full load 2000
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Resistance at this current=(0.8*(PT Primary * 10^3) / (1.732) / (1.2*Primary full load current) 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) DIST R1,PG(Quad) (80% of RL) DIST R2,PG(Quad) (80% of RL) DIST R3 & R4,PG(Quad) (80% of RL) OPERATING TIME DELAY
For 2x700MW Rajpura Thermal Power Plant 400kV Line Protection. Rev:0
Volt
Degree
Degree of protected line of parallel ICT Impedance of parallel ICT Impedance of zone 1 impedence
Ohm Ohm Ohm
Ohm Ohm
Ohm Amp
76.982
Ohm
42.340 25.404 25.404 25.404 33.872 33.872 33.872
Ohm Ohm Ohm Ohm Ohm Ohm Ohm
M/s. Alstom T&D India Limited, 19/1, GST Road, Pallavaram, Chennai - 600043.
ZONE 1 OPERATING TIME(t1) ZONE 2 OPERATING TIME(t2) ZONE 3 OPERATING TIME(t3) ZONE 4 OPERATING TIME(t4) POWER SWING SETTING: ΔR & ΔX ΔR = 10 to 30% of Z3 R3,PP ΔR = 10 to 30% of Z3 R3, PP ΔX = 10 to 30% of Z3 R3, PP ΔX = 10 to 30% of Z3 R3, PP UNBLOCKING CURRENT THRESHOLDS: Unblocking stages using to trip if any fault when relay blocked on PSB
0.00 0.30 0.75 1.00
Sec Sec SEC SEC
20 5.081 20 5.081
% of R3 Ohm % of R3 Ohm
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. IN> 40% I2> 30 % Value of Imax line = 3 Inom NOTE: PSB Block – Zone 2, Zone 3 & Zone 4 PSB Allowed to trip – Zone 1 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 Standard Mode PUR Permissive under reach scheme Disabled Z1Ext Fail Trip mode 1 pole Z1 , CR Received SWITCH ON TO FAULT Switch on to fault logic is pre-set in MiCOM P444 I>3 Current Set 3.00A I>3 Time delay 3sec I>4 Status Disabled 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.
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BACK UP OVER CURRENT: Enable I>1 Current setting tI>1 Time delay EARTHFAULT OVERCURRENT PROTECTION IN>1 Function
For 2x700MW Rajpura Thermal Power Plant 400kV Line Protection. Rev:0
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Yes 3A 1.2 sec IDMT M/s. Alstom T&D India Limited, 19/1, GST Road, Pallavaram, Chennai - 600043.
IN>1 Directional IN>1 VTS Block IN>1 Current set IN>1 Time Delay IN>1 Time VTS IN>2 status BROKEN CONDUCTOR PROTECTION I2/I1 ratio Time Set VT SUPERVISION VTS Time Delay VTS I2> & I0> Inhibit Detect 3P Threshold 3P U< Delta I> OVER VOLTAGE PROTECTION: V> V>1 Function V>1 Voltage Set V>1 Time Delay V>2 Status V>2 Voltage Set V>2 Time Delay UNDER VOLTAGE PROTECTION: V< Mode V< Operation V<1 Function V<1 Voltage Set (80% of Nominal Voltage) V<1 Time Delay V<1 Pole Dead Inh V<2 Status V<2 Voltage Set (70% of Nominal Voltage) V<2 Time Delay Stub Bus Protection (50STB) Relay Type CT Primary in Amps CT Secondary in Amps Settings: Stub Bus Pickup for Stub Bus in secondary
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For 2x700MW Rajpura Thermal Power Plant 400kV Line Protection. Rev:0
Directional Forward Non Directional 0.2 A 1.2 sec 1.2 sec Disabled 0.20. 60 Sec. 5.000 s (alarm indication time ) 50 mA Enabled 10 Volts 100 mA
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Measurement Mode Ph-Ph DT 121 V (110%) 2 sec Enabled 154 V (140%) 1 sec Phase-Phase Any Phase DT 88 V (80%) 2 sec Enabled Enabled 77 V (80%) 0.5 sec P444 2000 1 Enabled 4.0 A M/s. Alstom T&D India Limited, 19/1, GST Road, Pallavaram, Chennai - 600043.
Frequency Protection: Relay type used P141 Under Frequency Protection F<1 Status Enabled F<1 Setting in Hz 48.5 F<1 Time delay in sec 2 F<2 Status Enabled F<2 Setting in Hz 48 F<2 Time delay in sec 0.5 Over Frequency Protection F>1 Status Enabled F>1 Setting in Hz 51.0 F>1 Time delay in sec 1.5 F>2 Status Enabled F>2 Setting in Hz 50.5 F>2 Time delay in sec 0.5 DF/DT Protection df/dt>1 Status Enabled df/dt>1 Setting in Hz 0.250 df/dt>1 Time in sec 0.200 df/dt>1 Dir'n Both df/dt>2 Status Enabled df/dt>2 Setting in Hz 0.300 df/dt>2 Time in sec 0.200 df/dt>2 Dir'n Both Note: These settings of Frequency & DF/DT Protection are recommended based on general practice. These settings shall be adjusted if required as per the site conditions. These settings are applicable only if the protections are enabled in P442.
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For 2x700MW Rajpura Thermal Power Plant 400kV Line Protection. Rev:0
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M/s. Alstom T&D India Limited, 19/1, GST Road, Pallavaram, Chennai - 600043.
