Smooth super-twisting sliding mode control design with high order super-twisting observer for speed tracking control of permanent magnet synchronous motor drive system.

This paper presents a novel sliding mode control design for enhancing the reference speed tracking of permanent magnet synchronous motors under uncertain load disturbances and parametric variations. The proposed approach integrates a high-order super-twisting observer with a smooth super-twisting sliding mode control law to achieve a precise and rapid tracking performance. A smooth super-twisting sliding mode control is designed to ensure fast convergence of the speed tracking errors. Nonetheless, the incomplete state information resulting from lumped disturbances induces chattering in the system. To address this issue, a high-order super-twisting observer is devised to estimate the lumped disturbance and provide feedback compensation, thereby augmenting the robustness of the system. This study examines closed-loop finite-time stability using the Lyapunov function theory. An extensive comparison of the experimental and simulation results of the proposed control design with those of the classical sliding mode and super-twisting sliding mode shows its superiority and effectiveness. The proposed algorithm demonstrated outstanding dynamic robustness and tracking performance for managing external load disturbances and model uncertainties .