Improved adaptive sliding mode active disturbance rejection control for PMLSM based on model-free theory

In order to study and improve the dynamic response and anti-interference performance of the active disturbance rejection control of permanent magnet linear synchronous motor (PMLSM), and enhance the overall control performance of the system, an improved sliding mode active disturbance rejection control strategy (ISM-ADRC) based on model-free control was proposed. Firstly, the extended state observer (ESO) and nonlinear state error feedback (NLSEF) in the ADRC were optimized by the sliding mode variable structure principle and model-free control theory. By establishing the ultra-local model and using nonsingular fast terminal sliding mode control to replace the traditional NLSEF, the corresponding sliding mode surface was designed to combine with the ESO. The dynamic response performance and anti-interference ability of the controller were enhanced by improving the observation accuracy of the observer to the disturbance factors. Then, based on this, an improved exponential reaching law was designed, and the controller can adjust itself by introducing system state variables, to further improve the control performance of the PMLSM system. The stability of the control strategy was proved by Lyapunov theory. Through simulation and experiment, it is confirmed that this control strategy has advantages over traditional ADRC. © 2024 Editorial Department of Electric Machines and Control. All rights reserved.