Test: SCR Commutation Techniques - Electrical Engineering (EE) MCQ

In case of class B commutation or resonant-pulse commutation with L = 5 μH and C = 20 μC with initial voltage across the capacitor (Vs) = 230 V. Find the peak value of resonant current.

 In case of class B commutation or resonant-pulse commutation with L = 5 μH and C = 20 μC with the initial voltage across the capacitor (Vs) = 230 V. Find the conduction time for auxiliary thyristor.

An SCR is connected in series with L = 5 mH and C = 20 μF. Find the resonant frequency of the circuit.

The type of commutation when the load is commutated by transferring its load current to another incoming thyristor is

The type of commutation in which the pulse to turn off the SCR is obtained by separate voltage source is

The natural reversal of ac supply voltage commutates the SCR in case of

 ___________ commutation technique is commonly employed in series inverters.

 For the circuit shown in the figure below,

C = 4 pF
L = 16 μH
Vs = 200V
The capacitor voltage after the SCR is self commutated is

 For the circuit shown below,

The maximum value of current through thyristors T1 & TA can be given by

For the circuit shown in the figure below,

C = 4 pF
L = 16 μH
Vs = 200 V
The peak thyristor current is

For the circuit shown in the figure below, ___ type of commutation would take place for the SCR (THY1)

For the circuit shown in the figure below

R1 = 50 Ω, R2 = 100 Ω, Vs = 100 V. At the time of turn-on of the SCR, initial thyristor current is

 Natural commutation of an SCR takes place when

 ___________ commutation is usually used in phase-controlled rectifiers

Parallel-capacitor commutation is

Class E commutation is a/an

Below is the circuit of a resonant-pulse commutation, the maximum voltage to which the capacitor C charges is