A Thrust Ripple Suppression Strategy of PMLSM Based on Resonant Disturbance Observer with Optimal Gain and Phase Compensation

A thrust ripple suppression strategy of PMLSM is proposed based on a multi-resonant disturbance observer. To avoid anomalous gain peaks, a tuning method for resonant gain and compensation phase is designed through the loop shaping for disturbance estimation error sensitivity. The optimal stability margin is achieved. The disturbance and measurement noise sensitivity function of the velocity closed-loop system is analyzed to verify the superiority of the proposed parameter tuning methods for multiple harmonic disturbance suppression. Effective experiment and simulation results are included.