Discrete Terminal Integral Sliding-Mode Backstepping Speed Control of SMPMSM Drives Based on Ultra-Local Mode

In this paper, a novel discrete terminal integral sliding-mode backstepping control (DTISM-BSC) is proposed for the surface-mounted permanent magnet synchronous motor (SMPMSM) drive system, which improves the speed tracking performance and robustness of the system. In this control scheme, the discrete ultra-local model (ULM) of the SMPMSM drives, which employs the algebraic parameter identification technology to handle the unknown disturbance and parametric uncertainties, is first set up. Then, the terminal integral sliding-mode surface is proposed for its advantages of finite-time convergence to achieve speed rapid tracking, in which the control performance of backstepping control is improved. Thirdly, the equivalent control law is combined with the designed switching law to construct the speed controller based on the ULM. In this case, the bounded function is adopted to improve chattering problem. Meanwhile, the asymptotic stability and rapid convergence is verified. Finally, the experimental comparisons between the proposed method and the non-singular terminal sliding mode backstepping control (NTSM-BSC) are developed to validate the effectiveness of the proposed DTISM-BSC.