RF5:- Setting Calculations of Definite Time (Highset) O/C E/F Protection for Transformer

     Two 132/33kV transformers operating in parallel. T/F-1 Capacity is ?? MVA  and T/F-2 Capacity is ?? MVA. Consider approximate percentage reactance for both transformer as ?? %  T/F-1 HV CTR is ??/1 Amp. and LV CTR is ??/1 Amp.  T/F-2 HV CTR is ??/1 Amp. and it's LV CTR is ??/1 Amp.  As per latest fault level study 132kV Bus 3-Ph fault level is ?? MVA. and it's 1-Ph fault level is ?? MVA 

Calculate the Definite Time O/C and E/F settings for HV and LV side relays of above said transformers.

NOTES: 1) For T/F LV side relay Non-Directional HS setting shall be corresponding with fault contribution of respective T/F to 70% of LV Bus Fault. LV Non-Dircetional HS Delay shall be 350 ms.
2) For LV side relay Forward Direction HS setting shall be corresponding with fault contribution of other T/F to 70% of respective T/F LV LA fault. LV Forward Direction HS Delay shall be 50 ms.
3) For T/F HV side relay HS setting shall be corresponding with 70% of HV Bus Fault Current and for this setting HV side HS delay shall be 50 ms
4) For percentage reactance calculations consider base MVA as 100.

Section-A: Calculations for LV Bus Fault Level

1) 132kV Bus Positive Seq. Source Reactance XS1 =    %

2) 132kV Bus Zero Seq. Source Reactance XS0 =    %

3) T/F-1 Reactnace at 100 MVA base XT1 =    %

4) T/F-2 Reactnace at 100 MVA base XT2 =    %

5) Transformer Parallel Equivalent Reactance (XT1 || XT2) =    %.

6) LV Bus Positive Seq. Source Reactance (XS1 + XT1||XT2) =    %.

7) LV Bus Zero Seq. Source Reactance (XS0 + XT1||XT2) =    %.

8) LV Bus 3-Ph Short Circuit MVA =    MVA.

9) LV Bus 1-Ph Short Circuit MVA =    MVA.

10a) LV Bus 3-Ph Short Circuit current =    Amp.

10b) LV Bus 1-Ph Short Circuit current =    Amp.

Section-B: Calculations for LV Bus O/C Relay HS Settings

11a) T/F-1 Relay current for LV Bus 3-Ph Fault =    Amp.

11b) T/F-2 Relay current for LV Bus 3-Ph Fault =    Amp.

12a) T/F-1 LV Non-Directional O/C HS Setting =    Amp.

12b) T/F-2 LV Non-Directional O/C HS Setting =    Amp.

12c) HS Time Delay for LV Non-Directional O/C Relays=    ms

13a) T/F-1 LV Relay curr. for 3-Ph Fault at LV LA (Diff. Zone)=    Amp.

13b) T/F-2 LV Relay curr. for 3-Ph Fault at LV LA (Diff. Zone)=    Amp.

14a) T/F-1 LV Forward O/C HS Setting =    Amp.

14b) T/F-2 LV Forward O/C HS Setting =    Amp.

14c) HS Time Delay for LV Forward O/C Relays=    ms

Section-C: Calculations for LV Bus E/F Relay HS Settings

15a) T/F-1 Relay current for LV Bus 1-Ph Fault =    Amp.

15b) T/F-2 Relay current for LV Bus 1-Ph Fault =    Amp.

16a) T/F-1 LV Non-Directional E/F HS Setting =    Amp.

16b)T/F-2 LV Non-Directional E/F HS Setting =    Amp.

16c) HS Time Delay for LV Non-Directional E/F Relays =    ms

17a) T/F-1 LV Relay curr. for 1-Ph Fault at LV LA (Diff. Zone)=    Amp.

17b) T/F-1 LV Relay curr. for 1-Ph Fault at LV LA (Diff. Zone)=    Amp.

18a) T/F-1 LV Forward E/F HS Setting =    Amp.

18b) T/F-2 LV Forward E/F HS Setting =    Amp.

18c) HS Time Delay for LV Forward E/F Relays =    ms

Section-D: Calculations for HV Bus O/C and E/F Relay HS Settings

19a) T/F-1 HV O/C Relay Current for 3-Ph HV Terminal Fault =    Amp.

19b) T/F-2 HV O/C Relay Current for 3-Ph HV Terminal Fault =    Amp.

20a) T/F-1 HV O/C Relay HS Setting =    Amp.

20b) T/F-2 HV O/C Relay HS Setting =    Amp.

20c) HS Time Delay for HV O/C Relays =    ms

21a) T/F-1 HV E/F Relay Current for 1-Ph HV Terminal Fault =    Amp.

21b) T/F-2 HV E/F Relay Current for 1-Ph HV Terminal Fault =    Amp.

22a) T/F-1 HV E/F Relay HS Setting =    Amp.

22b) T/F-2 HV E/F Relay HS Setting =    Amp.

22c) HS Time Delay for HV E/F Relays =    ms

Topic SETOCTF Ex-4 Your score is:

000

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ABD AMT NSK PUN NGP KRD VSH

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