Influence of Magnetic Pole Stepping Combined with Auxiliary Stator Slots on the Stability of Dual-Rotor Disc Motors

Abstract

With the growing utilization of disc motors, the enhancement of their operational stability has become a critical research area. The existing studies usually focus on improving the pole structure of the rotor or the stator structure to optimize one performance of the motor and less on optimizing multiple performances. This paper simultaneously improves the rotor pole structure and stator tooth structure of the motor in order to optimize the sinusoidal waveform of the no-load back electromotive force and the cogging torque at the same time to achieve the goal of reducing the vibration and noise of the permanent-magnet synchronous dual-rotor statorless magnetically coupled disc motor and improve its operational stability. A finite element simulation model of a 20-pole, 24-slot permanent-magnet synchronous dual-rotor statorless magnetically coupled disc motor is established to analyze the influence of various factors, including the number of magnetic pole steps, the opening position, depth, and width of the stator auxiliary slot, on the motor performance. The results show that this stator–rotor combination improvement method effectively reduces the total harmonic distortion (THD) and attenuates multiple harmonics, and the peak cogging torque pulsation is significantly improved while other properties of the motor meet the technical requirements, and the motor performance is improved.

Keywords

• disc permanent-magnet synchronous motor
• stator auxiliary slot
• stepped magnetic pole
• cogging torque
• no-load harmonic