Fault Diagnosis Method for Power switch in Dual-winding PM Motor System

The dual-winding permanent magnet (PM) motor system has the advantages of high power density, high efficiency and strong fault tolerance. Compared with the short-circuit fault of power switch, the open-circuit fault of power switch usually does not cause the system to terminate operation immediately. However, if not dealt with in time, it will lead to overheating, insulation damage, torque reduction and other problems, and even damage the whole system. The existing literature only studies the open-circuit fault of the winding in dual-winding PM motor drive system. There are still many problems in the diagnosis of the open-circuit fault of power switch, such as false alarm in the traditional open-circuit fault diagnosis method. Therefore, this paper proposes and researches a high reliability open-circuit fault diagnosis method based on high frequency current signal injection, which can effectively avoid false alarm, detect and locate the open-circuit fault of power switch in real time and accurately.