Phase-Lifting Extended State Observer-Based Switching Quasiresonant Control Design for PMSMs With Periodic and Aperiodic Disturbances

Achieving robust and precise speed regulation in permanent magnet synchronous motor (PMSM) drive systems remains a significant challenge, particularly under disturbances comprising both periodic and aperiodic components. For aperiodic disturbances, disturbance observers are commonly employed; however, conventional designs often exhibit slow convergence and phase lag, limiting their effectiveness. To address the issue of slow convergence, we first develop a modified supertwisting extended state observer (MSESO), which guarantees finite-time convergence while avoiding the discontinuities inherent in traditional sliding mode observers. Building upon the MSESO, a phase-lifting extended state observer (PLESO) is further designed to mitigate phase lag and enhance the dynamic performance of disturbance estimation. Its phase-lifting characteristics are quantitatively validated via frequency-domain analysis. To suppress periodic disturbances, a switching quasi-resonant (SQR) controller is developed, which demonstrates superior harmonic rejection capability. In contrast to conventional quasi-resonant controllers that may degrade system dynamics, the proposed SQR controller employs a smooth switching mechanism to activate resonant compensation only when needed, thereby preserving transient performance. Extensive experimental results under both aperiodic and periodic disturbance conditions demonstrate that the proposed control scheme achieves robust disturbance rejection and high steady-state speed accuracy in PMSMs.