Application Of ADRC In PMSM Speed Regulating System

Permanent magnet synchronous motors(PMSMs)have been widely used in the field of AC speed regulation in recent years due to their high power density,simple structure,and high reliability.For PMSM speed regulating system,there are two as-pects worth studying:the sensorless control technology and the control algorithm.For the sensorless control technology,the extended state observer(ESO)in the active dis-turbance rejection control(ADRC)technique is used to estimate the back electromo-tive force(back-EMF),and then the rotor position and speed information can be solved from the back-EMF,which provides a new speed estimation algorithm for the PMSM.As for the control algorithm,this thesis uses the characteristic of strong robustness of the ADRC controller to model uncertainty and disturbance,and designs four kinds of ADRC algorithms for PMSM,which improves the robustness of the speed regulating system.First of all,in order to facilitate the following study of sensorless control and con-trol strategies,this thesis presents the mathematical model of PMSM under three types of coordinate systems(including ABC natural coordinate system,?-? stationary co-ordinate system and d-q synchronous rotation coordinate system),analyzes the basic principle and frame structure of id = 0 vector control,and describes the composition and implementation details of the ADRC technique.Secondly,for the sensorless control of PMSM,this thesis designs a rotor position and speed estimation algorithm based on ESO,and compares it with the commonly used sliding mode observer(SMO)method.The current equation of PMSM under the ?-?stationary coordinate system is taken as a reference,and the back-EMF term in PMSM is expanded into a new state,which can be estimated in real time by ESO.A phase-lock loop(PLL)is designed,which is used to solve the rotor position and speed information from the estimated back-EMF.The simulation results show that the ESO method has better estimation performance and higher estimation accuracy for the back-EMF,rotor position and speed compared with the SMO method,and can provide better support for the sensorless control of PMSM.In addition,considering that the traditional PI regulator is difficult to meet the high steady-state control accuracy and strong robustness to the load change for PMSM,this thesis designs four kinds of ADRC controller.For the speed loop of vector control,a speed loop ADRC controller is designed to replace the PI speed regulator.In order to further improve the robustness of ADRC controller,a Kalman observer is introduced,and a Kalman observer based speed loop ADRC controlle is designed.For the current loop of vector control,the current loop ADRC controller is proposed to replace the PIcurrent regulator so that the current loop can follow the command current more accu-rately and quickly.The speed loop and the current loop are combined into one loop,and a second-order ADRC controller is obtained.The simulation results show that compared with the traditional PI regulator,the speed regulating system using the ADRC controller achieves higher control accuracy and stronger robustness to load changes.Finally,in order to verify the performance of various algorithms proposed in this thesis,a PMSM experimental platform has been built.It's verified through experiments that the ADRC technology has great application value for PMSM speed regulating sys-tem in both of the sensorless control technology and the control algorithm.