Fault‐tolerant control of DSBLDC motor drive under open‐circuit faults

Doubly salient brushless dc (DSBLDC) motor drive system has attracted increasing attention due to the rugged rotor structure, brushless operation and low cost. The switch open‐circuit (OC) fault increases the torque ripple and decreases the maximal output power of DSBLDC motor drive system. A fault‐tolerance control strategy for switch OC circuit is proposed in this study. The back electromotive force (BEMF) current would occur in a pulse‐width modulation (PWM) pattern. It severely degrades the proposed method's fault‐tolerant performance. So the cause of the BEMF current is analysed and BEMF current is suppressed by specific PWM pattern. Finally, the fault‐tolerance control strategy is verified by experiment results and the selection PWM pattern is proved to be correct and practical.