Multi-phase fault-tolerant brushless DC motor drives

This paper examines the design features to be incorporated in brushless DC (BLDC) motors to enhance their fault-tolerance. Three BLDC motors with 3, 4 and 5 phases are designed with these features in order to investigate the effect of increasing the number of phases. The various faults that can occur in a motor drive are discussed, and the performance of these motors under normal conditions and open-circuit faults is compared. Possible remedial strategies following open-circuit faults are discussed. The operating mode that results in least disruption in the case of a fault and the motor with the greatest degree of fault-tolerance are identified.