Fractional-order Sliding Mode Control with Disturbance Rejection for PMSM Position Tracking

In this paper, a nonlinear control method based on fractional-order sliding surface is developed for position tracking control of permanent magnet synchronous motor (PMSM). First, a fractional-order sliding mode controller (FOSMC) is designed to achieve desirable transient dynamics while avoiding the strong chattering effect of classical sliding modes. Next, a super-twisting disturbance observer (STDOB) is introduced to estimate and compensate for the adverse effects of lumped unknown disturbances in PMSM. Lyapunov functions are used to analyze stability of the proposed control strategy. Finally, the performance and robustness of the proposed composite control scheme are demonstrated by experimental results.