Robust Fault-Tolerant Control Scheme for Open-Winding Permanent Magnet Synchronous Motors Based on Improved Predictive Control

Fault-tolerant control is crucial for ensuring reliable operation in the field of motor drives. The common-bus open-winding permanent magnet synchronous motor (OW-PMSM) topology, by involving the important role of zero-sequence loop, provides a new technical approach for fault-tolerant operation under single-phase open-circuit faults. In this article, a robust fault-tolerant control strategy based on improved predictive control for the open-phase fault of OW-PMSM is proposed, enhancing postfault torque control performance. First, the new characteristics of the postfault currents are derived, and the q-axis reference currents are redesigned accordingly, retaining the fundamental frequency component of the zero-sequence current (ZSC) to maintain constant torque output capability. The q-axis reference current is modified to mitigate high-frequency torque ripples caused by the ZSC. Then, the parameter term deviations are calculated using the error between the predicted and measured currents, and the parameter terms in the predictive model are updated to improve the accuracy of the target voltages. Experimental results validate the comprehensive performance of the innovative method for fault-tolerant control and robust torque control, both in dynamic and steady states.