Series-connected thyristors: the capacitor value in a dynamic equalizing (voltage-sharing) network is primarily selected based on which device characteristic?

Introduction / Context:
When SCRs are placed in series for high-voltage applications, differences in device dynamics during turn-off can cause unequal voltage sharing. Dynamic equalizing RC networks mitigate this problem; choosing C correctly is critical.

Given Data / Assumptions:

• Multiple SCRs in series across a high voltage.
• Each device exhibits slightly different reverse-recovery charge and tail current.
• Equalizing network: typically a capacitor (with or without a resistor) across each SCR.

Concept / Approach:
During commutation or reverse recovery, some devices cease conduction earlier and start blocking sooner, momentarily taking higher voltage. The capacitor provides a transient current path so that device voltages share more evenly. Therefore, C is chosen based on worst-case reverse-recovery behavior (charge, time, di/dt) and expected dv/dt across devices, not on steady forward characteristics.

Step-by-Step Solution:

Verification / Alternative check:

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