Current deviation decoupling control based on sliding mode active disturbance rejection for PMLSM

Current deviation decoupling control based on sliding mode active disturbance rejection (SADRC-CDDC) was designed for permanent magnet linear synchronous motors (PMLSMs), which were affected by current decoupling and parameter variation. The d-q axis cross-coupled branch was introduced at the difference point between the reference and actual currents. The current deviation decoupling controller (CDDC) was then designed by establishing the current control dynamics with the coupling term and calculating the coupling term for system compensation, which weakened the influence of the d-q axis current coupling. However, the decoupling value cannot be eliminated when the value of inductance varies. Therefore, the sliding mode active disturbance rejection controller (SADRC) was used to solve the disturbance caused by the parameter variation and to compensate for the system; thus, the system can realize approximately complete decoupling. From the theoretical analysis, the controller satisfied asymptotic stability, and the robustness of the system was verified. The effectiveness of the designed SADRC-CDDC scheme was proved by the system experiment result. Compared with CDDC, SADRC-CDDC can achieve a more robust performance as the maximum oscillation amplitude of the d-axis current is reduced by 34.88%-54.76%, and the maximum oscillation amplitude of the q-axis current is reduced by 47.83%-71.43% when the system is affected by current coupling and parameter variation. © 2022, Science Press. All right reserved.