Design and Analysis of a New Asymmetric Consequent-Pole Flux Reversal Dual-PM Excited Machine With Trapezoidal PMs

This article proposes a new asymmetric consequent-pole flux reversal dual-permanent magnet (PM) excited machine (ACP-FRDPMM) with trapezoidal PMs (TPMs) to achieve high torque density and power factor. The ACP-FRDPMM adopts the alternately placed main teeth with PMs and auxiliary teeth, forming an asymmetric consequent-pole (CP) PM arrangement of “Fe-NFeN–Fe,” which can significantly reduce flux leakage. Meanwhile, the trapezoidal CP PMs are inset in the rotor slots to reduce the saturation effect in iron poles to enlarge the torque capability and PM utilization. Combining the stator-PMs and rotor-PMs, a dual-PM excitation structure is formed, which yields the bidirectional flux modulation effect to boost the torque density. In addition, two-slot-pitch coils are employed in ACP-FRDPMM to effectively improve the power factor. Based on a simplified magnetomotive force (MMF)-permeance model, the operation principle of ACP-FRDPMM is revealed. Then, the designs of the slot-pole combination and stator-/rotor-PM dimensions are described. To assess the merits of ACP-FRDPMM, essential electromagnetic characteristics are analyzed and compared with two existing symmetric CP-FRDPMMs (SCP-FRDPMMs). It indicates that the proposed ACP-FRDPMM exhibits superior performances in terms of torque density, power factor, and efficiency. Finally, to validate the effectiveness of analyses, a prototype of ACP-FRDPMM is manufactured and tested.