Open-Phase Fault-Tolerant Control Strategy for Open-Winding Permanent Magnet Synchronous Motors with Torque Ripple Suppression

Maintenance of postfault operational capabilities is significant to improving the reliability of electric drive systems. This paper proposes a novel fault-tolerant operation scheme based on deadbeat predictive current control (DPCC) for the single phase open-circuit fault in common-bus type open-winding permanent magnet synchronous motor (OW-PMSM), with q -axis current injection and extended state observer (ESO) to suppress the torque ripples. Firstly, the relationship between zero-sequence current (ZSC) and residual phases current under postfault condition is analyzed. The fault-tolerant strategy based on providing ZSC and zero-sequence voltage (ZSV) is proposed. To offset the torque ripples generated by ZSC, the q -axis current is injected in to the armature circuit. Meanwhile, ESO is established to observe the DPCC model disturbances caused by the dq 0 axes parameters perturbation, and the estimated errors are added to the target voltages as feedforward compensation. Finally, experimental tests are conducted to verify the effectiveness of the proposed method, in which the deviation of the postfault phase current amplitude from the theoretical value is within 0.7%, the error of the average torque from the reference is within 1%, and the statistical mean value of torque deviation has an average reduction of around 30% compared with the conventional method.