The single neutral point winding configuration in dual three-phase permanent magnet synchronous motors (PMSMs) offers superior fault-tolerant capability. However

back electromotive force (EMF) harmonics introduce significant torque ripple. To address this issue

this paper proposes a fault-tolerant control strategy based on harmonic current injection for torque ripple suppression. First

the advantages of the single neutral point configuration in fault-tolerant operation under both single-phase and two-phase open-circuit faults are analyzed. Then

a detailed investigation of torque ripple under open-circuit faults is conducted

confirming that the single neutral point configuration results in greater torque ripple compared to the isolated neutral point configuration. Based on the torque composition of the motor under open-circuit faults

analytical expressions for the harmonic current injected into the q-axis are derived to generate a compensatory torque component with a phase opposite to that induced by back-EMF harmonics. This effectively suppresses torque ripple during fault-tolerant operation. The proposed method is applicable to fault-tolerant control strategies that modify the harmonic current reference and can be extended to both single-phase and two-phase open-circuit fault scenarios. Finally

experimental results validate the effectiveness of the proposed method in suppressing torque ripple.