An Open-circuit Fault Diagnosis Method of Power Converter for Doubly Salient Electro-magnet Motor

The power converter is the weakest link in the doubly salient electro-magnet motor (DSEM) drive system. The system will be in an unbalanced working state under fault, and the entire system will not work in severe cases. Therefore, the fault diagnosis of the power converter is the key to improve the reliability of the DSEM drive system. This paper aims at the bridge converter in the DSEM drive system, under the premise of not affecting the normal operation of DSEM drive system, according to the different working characteristics of the power converter under normal and open-circuit fault, by changing the installation position of the current sensor, a new power switch open-circuit fault diagnosis scheme is proposed. Compared with the traditional phase current detection scheme, this scheme has the advantages of simple diagnosis method, no complicated calculation, and fast fault location speed. The effectiveness and rapidity of the proposed method are verified by fault simulation experiments.