Research on Model-compensated Cascade Linear-Nonlinear Active Disturbance Rejection Control Method

In the double closed-loop control system of permanent magnet synchronous motor (PMSM), the traditional PI control is widely used due to its simple structure and easy implementation, but the PMSM suffers from poor anti-disturbance performance when it is subjected to internal and external perturbations, and the use of linear expanded state observer (LESO) can enhance the disturbance rejection capabilities, but the heavy burden of the total system perturbation estimation will lead to the degradation of the system control performance, To address these issues, this paper proposes a model-compensated cascaded linear-nonlinear active disturbance rejection control method(MCL_NLADRC). Firstly, a model-compensated linear extended state observer(MCLESO) is designed to isolate the load disturbance information from the motor equations of motion and design a reduced-order load observer to observe the load disturbance of the system, which is then compensated into the controller to reduce the burden of LESO on the estimation of the system disturbances and to improve the estimation accuracy; Secondly, MCL NLADRC is designed, combining the advantages of both linear and nonlinear mechanisms. The first stage of the controller utilizes MCLESO to ensure the system maintains performance stability under large disturbances, and the second stage uses a nonlinear expanded state observer (NLESO) to further enhance the accuracy of disturbance estimation, which effectively improves the speed tracking performance and disturbance rejection capability of the system. Subsequently, the Routh criterion is used for stability analysis of the proposed controller. Finally, the MCL-NLADRC is systematically compared through simulations with PI control, nonlinear active disturbance rejection control (NLADRC), linear active disturbance rejection control (LADRC), model compensation linear active disturbance rejection control (MCLADRC), and cascade linear-nonlinear active disturbance rejection control (CL_NLADRC) using PMSM. The comparison highlights the superiority of the proposed algorithm.