Below figure shows a single line diagram of a portion of a radial distribution system. The PS of Relay 3 (R3) is 75% of CT Secondary and time setting multiplier is given 0.1. The CT ratio is given with each relay and fault current of each in bus bar is given in figure. PS for R1 and R2 is set at 100%. Determine the operating time of each relay. Consider 0.25 sec for time coordination time interval. R3= 0.297 R2 = .475 R1 = .654 A B C |D 1000/1 B R₁ 10,000 A 800/1 800/1 शि R₂ R₁ 8000 A 6000 A 5000 A

Below figure shows a single line diagram of a portion of a radial distribution system. The PS of Relay 3 (R3) is 75% of CT Secondary and time setting multiplier is given 0.1. The CT ratio is given with each relay and fault current of each in bus bar is given in figure. PS for R1 and R2 is set at 100%. Determine the operating time of each relay. Consider 0.25 sec for time coordination time interval. R3= 0.297 R2 = .475 R1 = .654 A B C |D 1000/1 B R₁ 10,000 A 800/1 800/1 शि R₂ R₁ 8000 A 6000 A 5000 A

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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For the following single line diagram of a three-phase system, a three-phase fault occurs at point P and just before the fault the line voltage is 18 kV at P. Find out the transient fault current in pu and original value at point P. Take, the given kVA and kV of the G1 as the new base. [hint: the transient and sub-transient reactances of the synchronous generators are assumed to be same. But for the motors, assume that the transient one is 1.7 times of the sub-transient reactance.] 20,000 KV A 6.9KV 5メ G1 7000 KVA 5 KV 14% Tz 11/33KV 33/6.9 kV lond 5tj8 2 G2 load 20000K VA 15000 KVA 10% 12% 25,000 KVA 6.9KV 8/% as orebtransient [AH the mpedances are given per-unit valeues)
44
If the fault current is 100A at the secondary side of CT having a ratio of 400:5, for an IDMT relay with plug setting of 125% and time of operation is 5 sec for PSM = 12, 4 sec for PSM = 16, 3 sec for PSM = 20, Where, PSM is plug setting multiplier If the actual time of operation is 0.4 sec, then the value of Time Multiplier Setting is.
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