Question

For a SCR the maximum rms on-state current is 35 A. If the SCR is used in a resistive circuit for a rectangular wave with conduction angle of 90°. Calculate the average & rms currents respectively.

(a) I/4, I/2

(b) I/2, I/√2

(c) I/4, I^2/2

(d) I/4, I/√2

The question was asked in class test.

My question is based upon Thyristor Ratings in section Power Electronics Devices of Power Electronics

Answer 1

Right answer is (a) I/4, I/2

To explain: First convert the conduction angle into N for rectangular wave.

N = 360°/Conduction angle = 4

Therefore, Iavg = I/4

Irms = I/√4 = I/2.