Improved Terminal SMC with Model Predictive Current Control for LIM in Urban Rail Transit

This paper introduces a finite state-model predictive current control (FS-MPCC) strategy combined with terminal sliding mode control (TSMC) to improve the dynamic response of linear induction machines (LIM) across the entire speed range. First, TSMC is developed for the speed loop to ensure superior tracking performance and faster transient responses. Second, to address the challenges of balancing coefficient tuning complexity and computational effort in conventional finite state-model predictive thrust control (FS-MPTC), the control objective is redefined in terms of the primary current using the FS-MPCC approach. The design, implementation, and stability of the proposed TSMC-MPCC are explored in depth. Finally, a 3 kW arc induction machine underwent detailed simulations and experimental tests, with comparisons to conventional method under various speeds and loads, demonstrating the effectiveness and practicality of the proposed method.