Question

Find the circuit turn-off time (Tc) for the below given semi-converter configuration. Take α = 30° and Vs = 230√2 sin100t

(a) 20π radians

(b) 5π/6 radians

(c) π/120 radians

(d) 3/π radians

I have been asked this question in final exam.

This key question is from Single Phase Semi-Converters-2 in chapter Converters of Power Electronics

Answer 1

The correct choice is (c) π/120 radians

To explain I would say: For the given circuit, ωt = π-α. tc = π – α/ω

α = π/6 and ω = 100 … (given)

tc = (π – π/6)/100.