Enhancing robustness and precision in PMSM speed regulation via fractional-order integral sliding mode control with improved super twisting algorithm

Aiming at the permanent magnet synchronous motor’s speed regulation system that is highly sensitive to load disturbances and parameter variations, this paper proposes a fractional-order integral sliding mode control strategy based on an improved super twisting algorithm (FOISMC). First, by integrating the fractional-order integral theory with sliding mode variable structure control, a fractional-order integral sliding mode surface is constructed to enhance the system’s robustness. Second, an improved super twisting algorithm is designed to replace the conventional exponential reaching law, which significantly suppresses the sliding mode chattering phenomenon and improves the system’s control accuracy. Finally, comparative simulations with sliding mode control with exponential reaching law (ERL), FOISMC-ERL, and FOISMC-super twisting algorithm (STA) are conducted to verify the effectiveness of the proposed strategy.