Switch Open and Short Circuit Fault diagnosis and Fault Tolerant Operation for Push-Pull Converter

Owing to the non-maintainability and service continuity requirement of space power in earth orbit, this paper proposes a fault tolerant operation of push-pull current-fed converter under open and short circuit switch fault. Based on voltage and current time domain threshold, a fast fault detection algorithm is proposed which is essential to avoid fault propagation to the whole system. Besides, a fault tolerant topology and operation strategy are introduced. Thus, the studied converter can be reconfigured under both type of switch failures. Moreover, redundant switches are used for converter reconfiguration in post-fault operation. To confirm the validity of the proposed process, the results of Hardware-In-the-Loop (HIL) are presented and discussed, which all in excellent agreement with the good performances of the theoretical analysis.