Purpose of an RC snubber across a thyristor In power converters, an RC snubber network connected across a thyristor is primarily used to protect the device against what?

Introduction / Context:
Thyristors are sensitive to rapid changes in voltage (dv/dt) and overvoltage spikes that occur during switching and line disturbances. Snubber networks shape these transients to keep device stresses within safe limits.

Given Data / Assumptions:

• RC snubber placed across the device (often with a series resistor and capacitor).
• Goal: limit dv/dt, clamp overshoot, and absorb energy from stray inductances.

Concept / Approach:

The capacitor initially looks like a short to a sudden voltage step, limiting dv/dt across the thyristor; the resistor damps oscillations and dissipates energy. This combination prevents voltage spikes and steep slopes that could cause stress or inadvertent triggering.

Step-by-Step Solution:

Verification / Alternative check:

Waveform measurements with and without snubbers show reduced overshoot and ringing across the thyristor terminals.

Why Other Options Are Wrong:

While limiting dv/dt can also reduce the chance of false triggering, the primary stated purpose is protection against switching transients. Failure to turn on or commutate involves gating/commutation design, not the snubber’s main role.

Common Pitfalls:

Choosing snubber values that create excessive losses or inadequate damping; ignoring layout-induced stray inductance that can compromise snubber effectiveness.

Final Answer:

switching transients