A high-bandwidth and strong robust current control strategy for PMLSM drives

As an ideal current control method, the superiority of the predictive current control (PCC) is seriously weakened by the one-step control delay and parameter mismatch issues. To acquire the high dynamic and static characteristics, this paper studies an improved PCC scheme for the permanent magnet linear synchronous motor (PMLSM) drives. First, the discrete-time model of PMLSM considering the parameter variation is established. Second, the formation mechanisms of these two issues are analyzed in detail, respectively. Meanwhile, through replanning the timing sequence logic, the one-step control delay issue is solved. Furthermore, based on the super-twisting algorithm, the super-twisting sliding-mode observer (STSMO) is constructed to compensate for the parameter disturbance. To further improve the dynamic property and lower the chattering, a third-order STSMO is presented in comparison with the second-order STSMO. In the meantime, the estimated currents can be utilized in the solution of one-step delay issue. At last, on the PMLSM testing platform based on the aerostatic guide, the corresponding experimental results are shown to verify the effectiveness and correctness of the proposed method.