Control Method Of Permanent Magnet AC Servo System Based On ADRC

Active-disturbance rejection control has the advantages of not relying on an accurate model of the system and intuitive and simple design.When the traditional ADRC method is applied in permanent magnet AC servo systems,the disturbances such as back-EMF and load torque may vary greatly with the servo conditions,which limits the disturbance compensation effect.In order to improve the control accuracy and anti-disturbance capability of the permanent magnet AC servo system,a modelcompensated auto-disturbance rejection control strategy for the position and current double-closed-loop system based on the available model information of the system is proposed in this paper,which mainly includes the following aspects:First,based on the vector control theory of permanent magnet synchronous motor and the position-current double closed-loop control system model,the design process of the double closed-loop traditional ADRC controller is given,and the relationship between the total disturbance and the performance of the controller is analyzed in detail to compensate for the model.The anti-disturbance control method provides a theoretical basis.Secondly,the current loop model compensation ADRC control method is studied.Considering that there is a current filter in the actual system,the current loop mathematical model is modified,the condition of ignoring the time constant of the filter is deduced,and a compensation strategy without accurate identification of system parameters is proposed for back-EMF.Design parameter tuning method and stability proof of the controller is given.Third,the position loop model compensation ADRC control method is studied.For the load torque disturbance,a load torque observer based on direct calculation method is designed,and position loop model compensation algorithm is further designed.The model compensation parameters are converted into position open loop frequency domain model identification problems.Then model compensation method and stability proof of model-compensated ADRC controller is given.Finally,experiments are carried out on the ADRC control of permanent magnet AC servo system.Based on the identification of relevant system parameters,the proposed model-compensated ADRC control strategy is applied to the position and current double closed-loop control system.In current loop ADRC control experiment,the advantages of the modified model-compensation ADRC control compared to the traditional ADRC and PI control are demonstrated in improving response speed,reducing overshoot and smaller steady-state fluctuations,and the effectiveness of the back-EMF compensation strategy is verified.In position loop control experiment,through the constant position command tracking and changing position command tracking simulation experiments,it is verified that the proposed method can effectively improve the system's resistance to load disturbances and the robustness of the model parameter uncertainties.