A Fast Diagnosis Method for Power Switch Faults in Inverter Based on DC Voltage Waveform

A fast diagnosis method for power switch open-circuit faults of half-bridge inverters with different topologies is proposed in this research. To begin with, the inverter dc voltage models of inverters are established based on the consideration of dc side inductance parameters. Next, the current paths of inverter under different switching states are analyzed, and the characteristics of dc voltage waveform during circuit commutation are studied. Then, the effect of the switch open-circuit fault on the voltage waveform characteristics of the inverter is analyzed. Subsequently, a fast diagnosis method for the open-circuit fault of the inverter switch tube is proposed, the method can accurately locate the fault within several switching cycles by comparing the temporal position relationship between the characteristics waveform of dc voltage and the changes of switching control signal. Finally, the feasibility and accuracy of the method are verified by experiments.