Torque Performance Improvement of Consequent-Pole PM Motors With Hybrid Rotor Configuration

Abstract

Both the consequent-pole permanent magnet (CPM) motor and the spoke-type PM motor have the potential to reduce the consumption of PMs while suffering from the high-torque pulsation. This article proposes a new hybrid rotor CPM motor, in which the hybrid rotor is composed of consequent-pole surface-mounted PM (SPM) modules and spoke-type PM rotor modules. Compared with the existed hybrid rotor CPM motor with half of spoke-type PM rotor modules, the whole of spoke-type PM rotor modules and their shifting are capable to adjust the harmonics of the rotor-MMF, which is the benefit to improvement of the torque performances. To obtain high-torque performances and low PM volume, multiobjective optimization is employed to optimize the key parameters. Afterward, the proposed motor is compared with three PM motors. The results show that, compared with the SPM motor, the proposed CPM motor offers high PM torque and PM utilization ratio, such as other CPM motors. Besides, the torque pulsation is reduced significantly compared with the traditional CPM motor. Hence, the proposed motor offers a high PM utilization ratio and low-torque pulsation simultaneously. Through the finite element method (FEM) analysis and experimental test, the merits of the proposed hybrid CPM motor are verified.