Model-free double fractional-order integral sliding mode control for permanent magnet synchronous motor based electric mopeds drive system

Abstract

The Electric Mopeds (EM) drive system has the characteristics of frequent startup, rapid change of load disturbance and difficulty of establishing accurate mathematical model, this study proposes a model-free double Fractional-Order integral sliding mode control (DFOISMC). Firstly, a new double Fractional-Order integral sliding mode surface is proposed to enhance the robustness and improve the dynamic response, and to improve flexibility of the conventional integral sliding mode controller (ISMC). Secondly, a super-twisting structure is chosen to suppress chattering phenomenon. Then, the model-free DFOISMC is constructed by utilizing the double Fractional-Order integral sliding mode surface, the super-twisting approach law and the ultra-local dynamic model of EM drive system. Furthermore, the stability of the closed-loop control system under the model-free DFOISMC is proved by the Lyapunov stability theorem. Finally, the digital simulation results demonstrate that the proposed control strategy is highly effective and superior.