Hybrid Extended State Observer with Adaptive Switching Strategy for Overshoot-Free Speed Control and Enhanced Disturbance Rejection in PMSM Drives

Under complex operating conditions, the single-loop control structure of permanent magnet synchronous motors (PMSMs) suffers from various uncertain disturbances. Although extended state observers with high-gain designs have been widely adopted for disturbance rejection control due to their rapid convergence characteristics, they typically induce significant noise amplification and increased sensitivity to disturbances. To address this issue, this paper proposes a hybrid extended state observer-based control with adaptive switching strategy (AS-HyESO) for suppressing uncertain disturbances. In the AS-HyESO framework, matched disturbances from the control channel and unmatched disturbances from non-control channels are separately estimated using the HyESO, which are subsequently eliminated through the designed control law to ensure precise tracking of the speed reference input. Furthermore, the proposed observer incorporates an adaptive bandwidth switching mechanism that employs larger bandwidth during steady-state operation and reduced bandwidth during dynamic transients. This innovative approach achieves overshoot-free speed regulation while maintaining enhanced disturbance rejection capability, thereby effectively resolving the inherent conflict between dynamic response performance and anti-disturbance robustness. Experimental validation conducted on a 64 W PMSM dual-motor test platform demonstrates the superior effectiveness of the AS-HyESO, control strategy in practical applications.