Novel Sliding Mode Reaching Law Based on DTC for Linear Induction Machine Applied to Linear Metro

In this article, a new sliding mode double power reaching law (DPRL) is proposed for the direct thrust control (DPRL-DTC) to enhance the dynamic response and robustness against load disturbances of the linear induction machine (LIM) drive system adopted to linear metro. Firstly, the sliding mode speed controller of the LIM drive system is developed using the DPRL-DTC method. With the DPRL-DTC technique, the sliding mode state can be brought closer to the sliding mode surface more quickly with a smaller chattering phenomenon, less tracking error, and greater robustness against load disturbances, respectively. Secondly, the DPRL-DTC method is fully studied, including its design process, implementation procedure, stability analysis, and so on. Thirdly, comprehensive simulation and experiments based on one prototyped 3 kW arc induction machine have fully demonstrated the advantages of the DPRL-DTC technique compared to other conventional methods.