Improved Non-Singular Fast Terminal Sliding Mode Control for SPMSM Speed Regulation

An improved non-singular fast terminal sliding mode control (INFTSMC) is proposed in this study, to improve the dynamic speed regulation and tracking accuracy of a surface-mounted permanent magnet synchronous motor (SPMSM) system. A sliding surface that completely removes singularities from the controller input is proposed. The key characteristics of the INFTSMC are fast convergence of errors, high tracking accuracy, and robustness against disturbances. The controller designed in this study is proven to be stable, with convergence in finite time and stability based on the Lyapunov theory. The proposed INFTSMC has a fast response and better performance than conventional sliding mode control and terminal sliding mode control, as demonstrated by simulation and hardware experiments in both virtual and real-time scenarios.