In a thyristor, dv/dt protection is achieved through the use of

In a thyristor, dv/dt protection is achieved through the use of

Right Answer is:

RC across thyristor


Thyristor protection or SCR Protection 

The transient overvoltages can switch on the thyristor. In some cases, the thyristor can be damaged due to these transient voltages. These transient voltages are very common when the converter is having inductive loads.

Snubber circuit: The thyristors can be protected against transient voltages by an RC network This RC network is connected in parallel across the thyristor. It is called a snubber circuit.

Fig. shows a snubber(RC) circuit. The resistance has a value of a few hundred ohms. Whenever there is a large spike or voltage transient across the thyristor, it is absorbed by the RC circuit. The RC circuit (snubber) acts as a lowpass filter for this voltage transient. A low-pass filter (LPF) is a filter that passes signals with a frequency lower than a certain cutoff frequency and attenuates signals with frequencies higher than the cutoff frequency.

The resistance has a normally low value so that the transient is absorbed by the capacitor quickly. Thus the thyristor is protected against voltage transients. The RC snubber circuit is very commonly used for the protection of thyristors against transient voltage High-frequency voltage spikes).

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