Question

Figure below shows SCR having dv/dt and di/dt protection, when the switch(shown in green) is closed the current through Rl =

(a) I(1 – e^-t/τ)

(b) I(1 + e^-t/τ)

(c) I(1 – e^t/τ)

(d) I(1 + e^-t/τ)

This question was posed to me in quiz.

My enquiry is from Thyristor Protection in section Power Electronics Devices of Power Electronics

Answer 1

Correct option is (a) I(1 – e^-t/τ)

For explanation I would say: As soon as the switch is closed, C acts like a S.C & the voltage equation gives

Vs = (Rs + Rl) I + L di/dt

Solve the above D.E.