Torque Ripple Suppression in the Full Torque Operation Range for Dual Three-Phase PMSM Under Single-Phase Open-Circuit Fault

Better fault-tolerant operation performance of dual three-phase permanent magnet synchronous motor (DTPMSM) has always been pursued by both academia and industry. Torque output capability, torque ripple and copper losses are of the three most concerned performance metrics. Optimizing the torque output capability and copper losses of drive in the postfault operation is usually considered simultaneously and have been well addressed, whereas the suppression of torque ripple has not been well studied. In addition, there is a lack of methods that can take into account all three metrics at the same time. Aiming to fill these gaps, this article reveals the cause of torque ripple generated under single-phase open-circuit fault (OCF) and proposes a torque ripple suppression (TRS) scheme without the need of additional controller. Furthermore, this article also reveals the feasibility of improving these metrics at the same time. The proposed TRS scheme is combined with an existing full-range minimum copper loss scheme using a multireference frame harmonic subspace controller, which allows for taking care of all the three metrics mentioned above. The proposed scheme has the same control structure as in normal operation, so it is highlighted with the features of minimum reconfiguration and easy implementation. The effectiveness of the proposed strategy is verified by a large number of experimental results.