Improved Discrete-Time Resonant Extended State Observer Based Robust DPCC of Winding-Discontinuous-Segmented PMLSM

For a permanent magnet linear synchronous motor with discontinuous-segmented windings, when the secondary is partly coupled with segmented primaries, multi-harmonic-type no-load back electromotive force (EMF) disturbances degrade the tracking accuracy of deadbeat predictive current control (DPCC). Therefore, this article proposes a robust DPCC based on an improved discrete-time resonant extended state observer (IDRESO) to achieve static-errorless tracking accuracy while maintaining high tracking dynamics for commands. The structure of IDRESO is established based on pole placement, the z-transform of step and harmonic signals, and the internal model principle. The phase correction angle of the embedded resonator is parameterized based on the frequency response of the equivalent model of the disturbance estimator. The tuning rule of resonators’ integral gains is formulated based on the phase margin of the equivalent model and the selective filtering bandwidth of the expected equivalent proportional resonant controller. Additionally, the influence of using observer-predicted current for DPCC on the performance of the active disturbance rejection control (ADRC) based current inner loop is explored. Experimental validation confirms the effectiveness of the proposed robust DPCC method.