Question

An SCR has half cycle surge current rating of 3000 A for 50 Hz. Calculate its one-cycle surge current rating

(a) 3121.32 A

(b) 2121.32 A

(c) 3131.32 A

(d) 2131.32 A

This question was posed to me in an international level competition.

My question is taken from Thyristor Ratings in portion Power Electronics Devices of Power Electronics

Answer 1

The correct option is (b) 2121.32 A

Explanation: By equating the energies involved in one cycle & subcycle

I^2.T = Isb^2.t

Isb = 3000 A

T = 1/50

t = T/2.