Inverter topologies using coupled inductors Among common commutation-assisted inverter circuits, which uses magnetically coupled inductors for commutation energy transfer?

Introduction / Context:
Classic thyristor inverters often require auxiliary commutation networks. The McMurray and McMurray–Bedford families are landmark designs that use inductors and capacitors to transfer energy for turn-off, sometimes employing coupled inductors to improve commutation and reduce device stress.

Given Data / Assumptions:

• Considering historical thyristor inverter topologies.
• Focus on whether the circuit explicitly uses coupled (magnetically linked) inductors.

Concept / Approach:
The McMurray–Bedford variants introduced magnetically coupled commutation inductors to achieve efficient energy recovery and reliable device turn-off. The modified McMurray–Bedford half-bridge retains this coupled inductor concept with refinements.

Step-by-Step Solution:
Identify circuits known for coupled inductors → McMurray–Bedford half-bridge.Check modified variant → still employs coupled inductors for improved commutation.Therefore, both (b) and (c) use coupled inductors.

Verification / Alternative check:
Typical schematics show tightly coupled commutation chokes feeding capacitors to reverse-bias conducting thyristors and recover energy.

Why Other Options Are Wrong:
Option (a): The modified McMurray full bridge generally emphasizes capacitor-assisted commutation without the same hallmark coupled choke arrangement of the McMurray–Bedford variants.

Common Pitfalls:
Assuming all McMurray-type circuits use the same commutation parts. Details differ; coupled inductors are a signature of McMurray–Bedford implementations.

Final Answer:
Both (b) and (c)