Research on Speed Fluctuation Suppression of a Dual-Sided Permanent Magnet In-Wheel Motor

The direct-drive hub motor stands as the central power unit in distributed electric vehicles, shaping the vehicle's power traits through its performance. With a direct linkage between the motor and the wheel, the challenge of motor speed fluctuation emerges as a crucial factor shaping the drive performance of the system. The paper, based on the requirements of vehicle hub direct drive applications, focuses on the study of a dual-sided permanent magnet hub motor with excellent “low-speed high-torque” capabilities. It specifically analyzes cogging torque, a significant factor causing motor torque fluctuations, and identifies the associated dominant harmonic orders. Confronting the intricate operational and challenging road conditions in hub direct drive scenarios, there arises a need to incorporate the “remarkable disturbance rejection capability” offered by Active Disturbance Rejection Control (ADRC) technology. The proposal involves the targeted introduction of a suppression component for the dominant harmonic of motor cogging torque within the error feedback control law of the ADRC. This introduces a quasi-resonant form error feedback control law, effectively mitigating the motor's speed fluctuations. Simulation results provide confirmation of the study's rationale.