Parallel inverter topology (transformer-coupled) In a classic transformer-coupled parallel inverter, how are the commutating capacitor and the load connected?

Introduction / Context:
Parallel inverters (often employing class-B type commutation) use a resonant commutating capacitor so current can naturally reverse and turn off the conducting thyristor. Transformer coupling is common to match the load and provide isolation.

Given Data / Assumptions:

• Classic parallel inverter arrangement.
• Commutating capacitor used to produce resonant reversal of current.
• Transformer provides isolation and load matching; load is typically placed on the secondary.

Concept / Approach:

In the parallel inverter, the commutation is achieved via an LC path placed on the primary side so the thyristor current can be forced through zero. The load is commonly connected on the transformer secondary, allowing the resonant action to occur primarily on the primary side where the commutating elements reside.

Step-by-Step Solution:

Verification / Alternative check:

Standard power-electronics texts depict the commutating capacitor across the primary with secondary feeding the load in typical parallel inverter schematics.

Why Other Options Are Wrong:

Placing the capacitor solely on the secondary (or in series with the load) complicates or prevents proper commutation of the primary devices. The arrangement in (a) matches the classic design intent.

Common Pitfalls:

Confusing series and parallel inverter topologies; assuming commutating elements always sit with the load rather than with the switching devices.

Final Answer:

Capacitor across the transformer primary; load connected to the secondary