MiCOM P442 setting example

(1)

FOR REFERENCE ONLY

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

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

(2)

FOR REFERENCE ONLY

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 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

(3)

FOR REFERENCE ONLY

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: ΔR & ΔX

ΔR = 10 to 30% of Z3 R3,PP ΔR = 10 to 30% of Z3 R3, PP

UNBLOCKING CURRENT THRESHOLDS:

Unblocking stages using to trip if any fault when relay blocked on PSB ΔX = 10 to 30% of Z3 R3, PP

ΔX = 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)

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

(4)

FOR REFERENCE ONLY

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

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

(5)

FOR REFERENCE ONLY

df/dt>1 Status

F>2 Time delay in sec Under Frequency Protection

Over Frequency Protection

DF/DT Protection df/dt>1 Setting in Hz Enabled 0.250 1.5 F>2 Status Enabled F>2 Setting in Hz Enabled F<2 Setting in Hz 48 F>1 Status Enabled F>1 Setting in Hz 51.0 0.5 F>1 Time delay in sec

F<1 Status Enabled

F<1 Setting in Hz 48.5

50.5

F<1 Time delay in sec 2

F<2 Time delay in sec 0.5

F<2 Status

Frequency Protection:

Relay type used P141

df/dt>1 Time in sec df/dt>2 Status df/dt>2 Setting in Hz df/dt>2 Dir'n 0.200 Both Enabled 0.300 Both df/dt>1 Dir'n

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.