Investigation of Partitioned-Stator PM Machines Equipped with Open-Winding Inverter

This paper comparatively investigates the electromagnetic performances of the partitioned-stator field modulated permanent magnet machines (PS-PMMs) having different inner PM-stator configurations when the open-winding is utilized. With the open-winding inverter, the sinusoidal phase current with DC-bias, i.e., the hybrid excitation concept, can be applied into the phase winding. As such, the additional DC current component can be effective for the torque density and field-regulation capability improvement for the investigated four PS-PMMs. The results show that there is an optimum DC current ratio (k) for achieving the maximum torque when the RMS value of the phase current is fixed. Besides, due to flux-concentrating phenomenon, the PS-Spoke machine features higher torque than others while the PS-I machine exhibits higher torque adjustment ratio, i.e., excellent flux-regulation capability, albeit with the lowest torque capability among these machines.