PMSM Speed Control Based on Improved Adaptive Fractional-Order Sliding Mode Control

Addressing the problem of poor robustness and anti-interference ability in the permanent magnet synchronous motor (PMSM) speed control system, an adaptive fractional-order sliding mode controller based on a fractional-order sliding mode disturbance observer is proposed. Firstly, a mathematical model of a PMSM is established, which combines adaptive control with fractional order sliding mode control to effectively reduce the drawbacks of traditional integer order sliding mode control and improve the control accuracy of the system. At the same time, a new sliding mode approach law is used to replace the traditional exponential approach law, which reduces system buffeting and improves control performance. We use a fractional-order sliding mode observer to observe external disturbances and perform feedforward compensation on the observed disturbance values to improve the system’s anti-interference ability. By combining adaptive control with fractional-order sliding mode techniques, the system mitigates limitations of traditional integer-order approaches. It enhances symmetry preservation in system response and control accuracy under asymmetric conditions. The simulation results show that the motor system using the improved sliding mode disturbance observer and fractional order sliding mode controller can enhance system stability and anti-interference ability, and has better dynamic and steady-state performance.