关键词: 传统滑模, 永磁同步电机, 超螺旋滑模观测器, 锁相环

Abstract: To address the issues that conventional sliding mode observers readily cause high-frequency chattering in sensorless control of permanent magnet synchronous motors,and that the rotor position estimation accuracy is restricted by the discontinuous switching characteristic of the sign function in super-twisting sliding mode observers,this paper develops a hybrid control framework that integrates an improved super-twisting sliding mode observer with an adaptive positioncompensated phase-locked loop. A sliding mode observer is constructed using the super-twisting algorithm to accomplish effective suppression of high-frequency chattering. A continuously smooth piecewise function is introduced to replace the
conventional sign function,thereby further mitigating chattering while significantly enhancing the observation precision of the extended back electromotive force. A phase-locked loop structure with an adaptive position compensation link is employed to cancel out the steady-state errors in rotor position estimation resulting from speed ramp variations during acceleration and deceleration. Theoretical analysis confirms the finite-time convergence and stability properties of the proposed observer. Simulation results show that the presented method remarkably reduces system chattering and improves the estimation precision of rotor position and speed,showing enhanced robustness particularly under dynamic conditions.

Key words: traditional sliding mode, permanent magnet synchronous motor, super-twisting sliding mode observer, phase-locked loop