A Diagnosis Method for Open-Switch Faults in Open-Winding Sinusoidal Doubly Salient Electromagnetic Machine Drive System

Sinusoidal Doubly Salient Electromagnetic Machine (SDSEM) has simple structure, high reliability, high temperature and high speed operation ability. It has good application prospects in aerospace, rail transit, electric vehicles and other fields. Compared with the single inverter drive system, the open-winding SDSEM drive system has better operation performance and stronger fault-tolerant operation ability. However, the redundant operation characteristics of the open-winding topology make the fault diagnosis of the switch more difficult. To address the issues of slow diagnosis speed, high diagnosis cost, and complex fault localization in existing diagnosis methods for open-switch faults in the common-bus open-winding motor drive system, this paper proposes a diagnosis method based on diagnostic pulse self-injection. Firstly, the mathematical model of SDSEM and the common-bus open-winding motor drive system are introduced. Secondly, the phase current characteristics of the open-winding SDSEM drive system after the open-switch faults are analyzed. Then, according to the current characteristics of SDSEM in normal operation and fault state, the fault detection is carried out, and the response current is generated on the phase winding by the back electromotive force (EMF) of the motor to realize the self-injection of the diagnostic pulse, so as to locate the fault switch. Finally, the correctness and feasibility of the proposed method are verified by simulations.