Question

For the below given circuit configuration, the SCR is fired at angle α. For continuous current mode, find the expression for the average output voltage

(a) (Vm/2π) (1+ cosα)

(b) (Vm/2π) (2+ cosα)

(c) (Vm/2π) (3+ cosα)

(d) (3Vm/π)

I had been asked this question during an interview.

The above asked question is from Single Phase Semi-Converters-1 in chapter Converters of Power Electronics

Answer 1

The correct choice is (c) (Vm/2π) (3+ cosα)

The explanation is: The output voltage will have two parts

V1 =  [ ∫ Vm sinωt d(ωt) ] where the integration would run from α to π

V2 =  [ ∫ Vm sinωt d(ωt) ] where the integration would run from π to 2π

Vo = 1/2π x V1+V2.