Speed Ripple Suppression of Permanent Magnet Hub Motor Based on ADRC With Observer Error Constraints

A disturbance observation constraint term is incorporated into the expanded state observer (ESO) by using the motor state equation. Subsequently, an extended state observer based on disturbance observation error (DE-ESO) is proposed to mitigate the speed ripple in permanent magnet hub motor (PMHM) drive systems, especially under complex operating conditions. By the limitations of the disturbance observation constraint term, the DE-ESO is capable of accurately capturing and compensating for external load variations in the PMHM. Consequently, the antidisturbance properties of the entire motor drive system are significantly enhanced. Therefore, the PMHM active disturbance rejection control (ADRC) system, built upon the proposed DE-ESO, can effectively enhance the speed stability of the PMHM when operating under complex conditions. Simulation and experiments conducted under complex operating conditions have verified the feasibility and effectiveness of the proposed ESO.