Research on Fault Diagnosis and Fault tolerant Control of Bridge Converter for Doubly Salient Electro-magnetic Motor

Power converter is the weakest link in doubly salient electro-magnetic motor (DSEM) drives, which is the key factor affecting the reliability of DSEM drives. This paper focuses on DSEM driven by bridge converter, analyzes the working characteristics of motor before and after fault. Based on this, a simple fault diagnosis method is proposed without adding additional hardware. Firstly, the fault is detected according to the relationship between the phase current and the driving signal; then, by changing the working state of the motor, the fault position is located by using the phase current of the motor working in three-phase six-state. Finally, in order to make up for the torque loss after the fault, a fault tolerant control method of asymmetric three-phase three-state is proposed. The experimental results show that the proposed fault diagnosis and fault tolerant control method is effective and helpful to improve the reliability of DSEM drives.