Research On Direct Torque Control Of Permanent Magnet Synchronous Motor Based On Super-twisting Sliding Mode Active Disturbance Rejection Control

The permanent magnet synchronous motor(PMSM)has a simple structure,low production,low maintenance costs,high reliability,and a high power factor.It can reduce grid losses and improve energy utilization.With the development of industrial automation,the demand for high-precision control of PMSMs is increasing.Therefore,improving the control performance of PMSMs is crucial.Direct torque control(DTC)has been widely used in PMSM control due to its low dependence on motor parameters and fast torque dynamic response.However,it suffers from large magnetic flux and torque ripples,non-constant inverter switching frequency,and poor robustness of the speed loop,making it difficult to meet the high-performance control requirements of PMSM systems.In order to improve the DTC performance of PMSM,this paper mainly conducts the following research:(1)Analyzing the structure and characteristics of PMSMs,establishing mathematical models in natural coordinate system,stationary coordinate system,and synchronous rotating coordinate system,introducing the control theory and working principle of DTC,and conducting a detailed analysis of the problems of traditional DTC and simulation verification.(2)To address the problem of excessive torque and flux ripples and unstable inverter switching frequency in DTC,the SVM-DTC strategy is used to improve the control performance of traditional DTC method through SVPWM algorithm and PI controller.To solve the problem of poor robustness of the speed and torque loops in SVM-DTC,a super-twisting sliding mode speed and torque controller based on unsaturated functions is designed.In addition,simulation results verify that this strategy can effectively improve the robustness of the system and reduce speed overshoot.(3)In order to further reduce the speed overshoot of the super-twisting sliding mode speed controller and improve the robustness of the system,the active disturbance rejection control(ADRC)algorithm is introduced.However,the conventional ADRC has many adjustable parameters,while the linear ADRC with fewer adjustable parameters has a slower response speed.To solve this problem,a super-twisting sliding mode active disturbance rejection controller(STSM-ADRC)is designed,which reduces the number of adjustable parameters of traditional ADRC and improves the response speed and robustness of the system.Through comparative simulations,this strategy improves its rapidity,achieves speed loop non-overshoot,and has good robustness under sudden load disturbances.(4)The super-twisting sliding mode active disturbance rejection speed controller is experimentally verified by building a hardware-in-the-loop experimental platform.The experimental results show that the super-twisting sliding mode active disturbance rejection speed controller has stronger dynamic response and robustness than linear active disturbance rejection controller,sliding mode controller and PI controller.