An ESO-Based Repetitive Controller Design for PMLSM

For rejecting aperiodic disturbances at the moment of loading, following the periodic velocity reference signals better, and realizing the precise velocity tracking control in Permanent Magnet Synchronous Linear Motors (PMLSMs), an extended state observer based repetitive control strategy (ESO-RC) is proposed in this paper. First, a repetitive controller is used to track periodic signal, and suppress the periodic disturbances caused by slot effect. Then, low pass filter, dynamic compensator, and time-delay compensation are added to the repetitive controller to enhance the tracking ability and dynamic ability. Second, an ESO method is taken to improve the velocity tracking ability and anti-disturbance performance, because it can compensate the aperiodic disturbances, and alleviate the velocity drop amplitude especially at the moment of loading. Last, the performance of the ESO-RC strategy is verified. The velocity tracking curves and thrust force curves at different velocity are figured out and analyzed in Matlab.