Question

A three-phase half-wave controlled converter is fed from a 3-phase, 400 V source and is connected to a load which takes a constant current of 36 A. Find,the value of average output voltage and average current rating of SCR for a firing angle of 30°.

(a) 234 V, 36 A

(b) 234 V, 12 A

(c) 135 V, 36 A

(d) 135 V, 12 A

This question was addressed to me during an online exam.

Origin of the question is Three Phase Converters-1 in chapter Converters of Power Electronics

Answer 1

The correct answer is (b) 234 V, 12 A

The explanation: Vo = (3√3/2π) x Vmp x cosα = 233.874 V.

Ia = Io/3 = 12 A.