Fault diagnosis is one of the key technologies to improve the reliability of a doubly salient electromagnetic generator (DSEG) system with a controlled rectifier. So far

there has been no research applicable to open-circuit fault diagnosis in the DSEG system. To solve the problem

an open-circuit fault diagnosis method is proposed for switches of a controlled rectifier. First

based on the working principles of DSEG

fault detection is realized by the relationship between bus current and phase current. Then

fault location is realized in two ways: one is achieved by the relationship between bus current and phase current

and the other is achieved by the injection of a test pulse. Open-circuit faults of single switch and double switches can be diagnosed with no influence of fault angle and conduction angle

and fault diagnosis can be realized as quickly as sample periods. Finally

the effectiveness of the proposed method is verified by the experiments.