Fault Diagnosis of Full-Bridge Power Converter for SRMs Based on Modified Current Detection

This article proposes a fault diagnosis method for power transistors of full-bridge power converter (FBPC) in switched reluctance motors (SRMs) based on a modified current detection strategy. First, the circuit status is analyzed for fault operation. A novel current measurement scheme based on cross-bridge current is then provided to obtain the enough current information, and two current variables are given and dealt with based on sensor currents. On the basis of driving signal and the corresponding currents, a characteristic variable is proposed to highlight the fault type and locate faulty power transistor. Different fault situations are simulated on a three-phase SRM and followed by the experiments. A good agreement between the analysis and the measured results validates the proposed fault diagnosis method.