A Model-Free Fractional-Order Composite Control Strategy for High-Precision Positioning of Permanent Magnet Synchronous Motor

This paper introduces a novel model-free fractional-order composite control methodology specifically designed for precision positioning in permanent magnet synchronous motor (PMSM) drives. The proposed framework ingeniously combines a composite control architecture, featuring a super twisting double fractional-order differential sliding mode controller (STDFDSMC) synergistically integrated with a complementary extended state observer (CESO). The STDFDSMC incorporates an innovative fractional-order double differential sliding mode surface, engineered to deliver superior robustness, enhanced flexibility, and accelerated convergence rates, while simultaneously addressing potential singularity issues. The CESO is implemented to achieve precise estimation and compensation of both intrinsic and extrinsic disturbances affecting PMSM drive systems. Through rigorous application of Lyapunov stability theory, we provide a comprehensive theoretical validation of the closed-loop system’s convergence stability under the proposed control paradigm. Extensive comparative analyses with conventional control methodologies are conducted to substantiate the efficacy of our approach. The comparative results conclusively demonstrate that the proposed control method represents a significant advancement in PMSM drive performance optimization, offering substantial improvements over existing control strategies.