Question

What is the expression for the value of the capacitor in the voltage commutation circuit? Let tc be the circuit turn off time and Io be the constant load current.

(a) Io x (dv/dt)

(b) Vs/Io

(c) (tc x Io)/Vs

(d) none of the mentioned

The question was posed to me in an internship interview.

The above asked question is from Thyristor Chopper Circuits in division Choppers of Power Electronics

Answer 1

Right option is (c) (tc x Io)/Vs

For explanation I would say: Capacitor current = C dv/dt

For constant load current Io, the above expression can be

Io = C x (Vs/tc) or C = (tc x Io)/Vs.