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

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)

Please solve quickly.

what is bus impedance matrix ? how it is useful in symmetrical fault analysis?