Global adaptive sliding mode control for PMLSM based on third-order super-twisting disturbance observer

Aiming at the problem that the position tracking accuracy of permanent magnet linear synchronous motor is easily affected by uncertain factors such as external disturbance and parameter change, a compound control strategy combining global adaptive sliding mode controller and three-order super-twisting disturbance observer was proposed. Firstly, in order to solve the chattering problem of global sliding mode control, the global adaptive sliding mode controller was designed according to the adaptive reaching law. The adaptive approach law can adjust the switching gain in real time according to the changing process of the system state variables, so as to improve the response speed of the system and reduce chattering. Then, in order to improve the tracking accuracy and anti-interference ability of the system, a three-order super-twisting disturbance observer was designed to observe the disturbance and uncertainty that cannot be accurately measured in the system and realize the feedforward compensation of the system. Finally, simulation and experimental verification were carried out. The simulation and experimental results show that compared with global sliding mode control, the proposed method can effectively improve the response speed and tracking accuracy of the system, and make the system have good steady-state and dynamic performance. © 2024 Editorial Department of Electric Machines and Control. All rights reserved.