Torque Performance Improvement of a Permanent Magnet In-Wheel Motor from Perspective of Field Modulation Permeance

This paper introduces the incorporation of flux modulation in the design of an in-wheel motor, proposing a permanent magnet in-wheel motor. The primary focus lies in the analysis of permeance modulation harmonics through the application of flux modulation. Based on this, the waveform of the permanent magnet magnetomotive force (PM-MMF) is examined after modulation, followed by a thorough investigation of the associated harmonics. The objective is to discern the impact on each harmonic on the performance of the motor. The effective improvement of the output torque of a PM-IW motor is achieved through the enhancement of positive harmonics and the suppression of negative harmonics. Additionally, this study investigates the impact of design parameters associated with the stator and rotor slot on the harmonic characteristics. Finally, the performance of motors with and without a rotor-shaped design is analyzed and compared. The results provide verification of the effectiveness of the rotor-shaped design, which takes into consideration the harmonics of permeance modulation.