Design and analysis of a new partitioned stator flux‐modulation motor for direct drive applications

Abstract

In this study, in order to improve the torque density of the conventional permanent magnet (PM) motor, a flux‐modulation (FM) motor employing the magnetic gear effect is proposed. However, the FM motor has space conflict in the finite stator area, which limits the further improvement of torque density. Therefore, a new partitioned stator flux‐modulation (PSFM) motor with separated PM excitation and armature windings is artfully proposed. The main design parameters influence on the average electromagnetic torque in the proposed PSFM motor is investigated, together with the proposed FM motor. Furthermore, based on the optimal designs for the highest average electromagnetic torque in this study, the electromagnetic performances of the three motors, including back‐electromotive force performances, torque characteristics and several other performances with respect to speed are analysed by finite‐element method. Additionally in the PSFM motor, torque generation mechanism and the reduction method of torque ripple are theoretically analysed. Results show that the proposed PSFM motor exhibits 29.1% higher torque density than the FM motor and 87.6% higher than the conventional PM motor with reduced torque ripple and superior loss performance. Finally, the proposed PSFM motor is prototyped for verification.

In Search of the Proper Dimensions of the Optimum In-Wheel Permanent Magnet Synchronous Motor Design

“…This kind of system does not contain a large number of mechanical parts and does not cause a decrease in efficiency, output power and speed. Therefore, the probability of malfunctions is lower than in other drive systems due to their simpler structure [11].…”