Rf5-Single Circuit Radial Line E/F Settings and Validation

     In the following figure let CTR at 132kV Bus-B is ??/1 Amp  and CTR at 132kV Bus-C is ??/1 Amp.
     At Bus-C; 3-Ph fault level is ?? MVA  and 1-ph fault levle is ?? MVA.
     Double circuit line A-B having length ?? km  while single circuit line B-C has length ?? km. For both lines conductor used is 0.2 ACSR.

     A) What shall be the PSM and TMS setting for Earth fault relay at Bus-B and Bus-C


INSIGHT:
     B) What shall be difference between time of operation for Earth Fault Relay at Bus-B and Bus-C if one of the circuit between Bus-A and Bus-B is under outage.

(NOTE: For fault MVA calculations use base MVA as 100. For 0.2 ACSR line X1 = 0.4 ohms/km and X0 = 1.2 ohms/km

Section-A: Calculations considering fault at q.

1) Bus-B Earth fault PSM =   30%    20%    15%

2) Bus-B E/F relay fault current =    Amp

3) Bus-B E/F relay current as multiple of PSM =   X

4a) Bus-B - Time of operation for O/C relay with TMS 1 =   sec
4b) Bus-B - To have time of operation as 500 ms TMS =   sec

5) Bus-C Earth fault PSM =   30%    20%    15%

6) Bus-C E/F relay fault current =    Amp

7) Bus-C E/F relay current as multiple of PSM =   X.

8a) Bus-C - Time of operation for O/C relay with TMS 1 =   sec
8b) Bus-C - To have time of operation as 500 ms TMS =   

Section-B: Calculations considering fault at p;
on the line at 20% distance from source end.

9a) +Ve sequence source reactance for Bus-C =   %

9b) Zero sequence source reactance for Bus-C =   %

Before outage on one circuit.

10a) Equivalent +Ve sequence reactance of lines from Bus-A to Bus-C =   %

10b) Equivalent Zero sequence reactance of lines from Bus-A to Bus-C =   %

11a) +Ve sequence source reactance for Bus-A =      %

11b) Zero sequence source reactance for Bus-A =&nbsp     %

After outage on one circuit.

12a) Equivalent +Ve sequence reactance of lines from Bus-A to Bus-C =   %

12b) Equivalent Zero sequence reactance of lines from Bus-A to Bus-C =   %

After outage on one circuit.

13a) +Ve sequence source reactance for Bus-C =   %

13b) Zero sequence source reactance for Bus-C =   %

14) After outage on one of circuit A-B; 1-ph short circuit MVA at Bus-C will be =   MVA

Section-C: Calculations for relay operating time.

After outage on one circuit A-B and for 1-ph fault at Bus-C

15a) Bus-B relay current =   Amp.

15b) Bus-C relay current =   Amp.

16a) Bus-B relay time of operation =   miliseconds
16b) Bus-C relay time of operation =   miliseconds

17) Operational Time Difference of RElay at Bus-B and Bus-C =   miliseconds

Topic SETOCLN Ex-5 Your score is:

000

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ABD1 ABD2 JALN PRBN NND1 NND2 LTR1 LTR2 BEED PRLI EKTN GRWL WALJ TPTN KMBH