Sensorless DPCC of PMLSM Using SOGI-PLL-Based High-Order SMO With Cogging Force Feedforward Compensation

In order to reduce the adverse effect of the large thrust ripple of permanent magnet linear synchronous motor (PMLSM) on mover position estimation accuracy and solve the sliding mode chattering problem of the traditional sensorless algorithm based on sliding mode observer (SMO), this article proposes a systematic method to solve above issues. First, the high-order SMO method is used to suppress harmonic generation from the source of sliding mode chattering. Second, an adaptive filter based on a second-order generalized integrator (SOGI) is constructed to filter out the harmonics. Then, the normalized quadrature phase-locked loop (PLL) method is used to realize the closed-loop extraction of position information. Finally, the deadbeat predictive current control (DPCC) with the current feedforward compensation strategy is proposed to further improve the dynamic performance and mover position estimation accuracy. The simulation model and experimental platform are built. The simulation analyses and test results show that the proposed method has a better performance than conventional techniques.