Fault-tolerant control without extra hardware for doubly salient brushless DC motor drive under open-circuit faults

摘要

Doubly salient brushless dc (DSBLDC) motors have attracted increasing attention for drive system due to the simple and rugged rotor structure, brushless operation and low cost. Open circuit (OC) faults in power converter as a common fault reduce system performance. The majority of the tolerance approaches require additional hardware which increases the cost. This paper proposes a fault-tolerant control strategy, without extra hardware, for OC tolerance in DSBLDC motor drive. Firstly, a current-based method is proposed to detect OC faults. Then fault-tolerant control strategy based on non-working bridge arm commutation is proposed and corresponding control modes are introduced for OC faults. Finally, fault switch is identified by power converter work mode. Simulation results confirm the feasibility of the proposed fault-tolerant control strategy.