Design and Investigation of a Low-Cogging-Torque and High-Torque-Density Double-Sided Permanent Magnet Motor

In this paper, a high-torque and low-cogging-torque double-sided permanent magnet (DS-PMFM) motor is proposed. The research focuses on adopting structure of stator split-tooth and unequal-width rotor poles, enabling the motor to have high output torque, low torque ripple, and low cogging torque. It is found that the DS-PMFM motor causes a non-negligible deterioration of cogging torque and torque ripple while increasing the output torque compared with the single-sided permanent magnet (SS-PMFM) motor. Based on this, in order to achieve the comprehensive performance improvement of a high torque density, low cogging torque, and low torque ripple for the motor, research is carried out from three perspectives: pole-slot ratio, stator modulation pole split-tooth shape design, and unequal-width rotor poles design. Ultimately, the final topology is obtained through optimization. Through comparative analysis, it was shown that the torque performance of the proposed DS-PMFM motor has been effectively improved, providing effective guidance for the design of this type of motor.