Fault-Tolerant Control of Open-Circuit Faults in Standard PMSM Drives Considering Torque Ripple and Copper Loss

Although many auxiliary circuits based fault-tolerant solutions have been developed for three-phase motor drives, the standard three-phase motor drive without any auxiliary circuits still dominates the market. It is important to improve the fault-tolerant capability of standard motor drive. In this paper, a predictive current control based fault-tolerant control scheme is proposed to optimize the fault-tolerant performance of standard PMSM drives under open-phase fault and open-switch fault. In the proposed scheme for open-phase fault, the fault-tolerant current references considering reluctance torque and overcurrent endurance of motor drive are derived. On this basis, the fault-tolerant current references are further optimized to reduce the copper loss without increasing the torque ripple. Besides, a fundamental period based speed calculation method is proposed to eliminate the negative impact of speed fluctuation. In the proposed scheme for open-switch fault, a two-mode current control based fault-tolerant control is designed to reduce the copper loss and torque ripple by fully utilizing the remaining healthy switch in the faulty inverter leg. The validity of the proposed scheme is verified by experiments.