Composite Speed Control of Linear Induction Machine Based on Model Predictive Flux Control with Sliding Mode Disturbance Observer for Linear Metro

A novel sliding mode control (SMC) based model predictive flux control (MPFC), integrated with a sliding mode disturbance observer (SMDO), is proposed to enhance the speed control performance of a linear induction machine (LIM) under disturbances. Firstly, a finite set model predictive flux control (FS-MPFC) is established to mitigate the drawbacks associated with the traditional model predictive thrust control (MPTC), primarily in reducing the tedious tuning of weighting factor. Secondly, a speed control loop is designed to improve the speed transient response and tracking performance, and meanwhile reduce thrust ripple. Thirdly, the SMDO is developed to estimate the overall disturbances of the LIM drive system. Moreover, the estimated disturbance is used for feed-forward compensation approach to increase the disturbance rejection capacity of the whole system. Finally, extensive simulation and experiments have fully demonstrated that the proposed method has fast speed response, improved steady state performance and robustness against load disturbance compared to MPFC-SMC and MPFC-PI.