An Open-Circuit Fault Detection Method of PMSM Fed by Dual Inverter with High Robustness

Power semiconductor is one of the most fragile components in the drive system of electric vehicles. In order to diagnose the failure timely, this paper proposes a diagnosis method of the open-circuit fault for open-end winding permanent magnet synchronous motor (OEW-PMSM) fed by dual inverter with a single dc source. The OEW- PMSM can improve the speed range and tolerance capacity of driving systems. However, the open-circuit fault diagnosis methods for Y-connected PMSMs cannot judge the faulty switch because of the symmetry of the dual inverter structure. The first step of the proposed method is to detect the faulty switch combinations by the error of normalized average value and average value of the zero-sequence reference voltage. The next step is to judge the faulty switch from a certain fault combination. The experimental results show that the open-circuit fault can be diagnosed accurately.