Open-Circuit Fault Diagnosis Method for Inverter in PMSM Drives Considering Closed-Loop Regulation

This article investigates the real-time diagnosis of open circuit (OC) faults in three-phase voltage source inverters. First, the faulty three-phase current distortion rule is analyzed considering the closed-loop feedback regulation of the controller. Second, the common fault characteristics under different control regulation are obtained. Then, an OC fault diagnosis method for power switches based on current bias is proposed. This method only needs the three-phase current and rotor position signals sampled by the controller and has strong generalization ability for different control parameters. In addition, the robustness of the method under different operating modes and various transient conditions has been verified through experiments. The results confirm the effectiveness of the proposed method.