Optimized Control Strategy for Dual Three-Phase IPM With Minimum Losses in Full Torque Range Under Open-Phase Fault

Fault tolerance capability is a significant advantage of multiphase drives over three-phase drives. However, previous studies have not adequately addressed fault-tolerant control (FTC) strategies for dual three-phase interior permanent magnet synchronous machines (DT-IPM) that achieve minimal copper losses and torque ripple over the full torque range while considering flux linkage saturation. This paper proposes an FTC method for DT-IPM under single open-phase faults (SOF), based on offline optimization using pre-calibrated machine parameters to incorporate saturation effects. The proposed method employs harmonic current injection to minimize copper loss, suppress torque ripple, and expand the torque range under SOF, enabling precise torque control without reconfiguration of the postfault torque regulator. By eliminating the need for complex online computations, the method enhances operational efficiency and dynamic performance. Finally, the proposed method is evaluated on a prototyped DT-IPM.