Model Free Current Harmonic Suppression in PMLSM Drives Based on Linear Extended State Observer

With the increasing precision requirements in industrial processing, Permanent magnet synchronous linear motor (PMLSM) are widely used in high-end manufacturing due to its high thrust and precision characteristics. However, the effectiveness of traditional control methods is influenced by the precise model of the PMLSM. In this paper, a model free control (MFC) strategy based on linear extended state observer (LESO) is studied. Under this control strategy, the parameter changes of PMLSM and other external disturbances of the system are considered as total disturbances. The total disturbance is observed by LESO and compensated in the current loop of the system, thus achieving the goal of improving the robustness and anti-interference ability of PMLSM. To further improve the current loop control performance, a quasi resonant controller (QRC) to suppress current harmonics is adopted in this paper. Considering that harmonic frequencies are not fixed, a frequency adaptive quasi-resonant controller is adopted. Finally, verified by simulation, this control strategy can effectively improve the dynamic response ability and anti-interference ability of the PMLSM.