Armature MMF Reconfiguration Method of Six-Phase Integral-Slot PMSMs for Zero-Order Vibration Reduction Under Open-Circuit Faults

It is well known that the vibration performance of the permanent magnet synchronous machines (PMSMs) will deteriorate under the open-circuit fault operation. However, the cause of the vibration deterioration and corresponding methods to reduce the vibration is still unclear. This article reveals the reason of the zero-order vibration deterioration for integral-slot six-phase PMSMs open-circuit fault operation. Furthermore, a magnetomotive force (MMF) reconfiguration method is proposed to suppress the fault-resulted zero-order vibration. The key is to eliminate the fundamental backward-rotating MMF, which contributes to the fault-resulted zero-order radial force under the open-circuit fault operation. With the aid of the response surface method, the analytical expressions of the optimal reconfigured current are derived considering all four open-circuit fault types. Compared with the conventional method, the fault-resulted zero-order radial force is greatly weakened by adopting the proposed method. Finally, the prototype of a six-phase 72-slot/12-pole PMSM is manufactured. The current and vibration tests are carried out to validate the theoretical analysis.