Analysis of Characteristics for Direct-drive Uneven-tooth Dual-winding Permanent Magnet Vernier Motor in UAVs

To address the issues of insufficient low-speed torque density, large torque ripple, and weak fault tolerance in traditional UAV rotor motors, as well as to meet the power demands of industrial UAVs in complex scenarios, an uneven-tooth dual-winding permanent magnet vernier motor(UD-PMVM) is proposed. Firstly, the basic structure of the motor is designed based on the magnetic field modulation principle. An outer rotor structure is adopted to eliminate mechanical transmission devices, an uneven-tooth structure is used to optimize magnetic field distribution, and a dual-winding structure is employed to improve fault tolerance performance. Secondly, a motor model is established using finite element software, and its characteristics are analyzed under no-load, load, and winding inter-turn short-circuit fault conditions. Finally, an experimental platform based on the UD-PMVM is built, and experimental verification is conducted on the motor. The results show that the main harmonics of the air-gap magnetic flux density of the motor conform to the modulation law, the electromagnetic torque ripple is small under load conditions, and the motor has strong fault-tolerant capability, which can meet the direct-drive requirements of the UAV rotor motors.