| Permanent Magnet Synchronous Motor(PMSM)is widely used in new energy vehicles,railway operation and other fields with its simple structure,high power density and low loss.The commonly used control strategies of motors include constant voltage ratio control,field oriented control and direct torque control.It's commonly used in PMSM control system as the vector control theory is relatively perfect,can make the motor has a wide speed range,good braking performance and overload performance.Conventional PMSM control system mainly uses high precision and high resolution sensors to obtain rotor position and speed information.However,it has poor adaptability to environment and weak maintainability,which limits the operating environment of the motor.Therefore,the sensorless control system of PMSM is studied in this paper.This paper firstly introduces the development and situation of new energy vehicles,and then the basic structure,working principle and control method of PMSM are developed.On this basis,it analyzes the necessity of sensorless vector control of PMSM.Analysis of sliding mode observer and extended Kalman filter two position sensorless control methods,and its shortcomings to improve.Aiming at the problem that the traditional sliding mode observer is prone to chattering,a SMO based on the new control function is designed.The sigmoidal function is used instead of the saturation function to improve the robustness of the system at high speed and suppress the buffeting phenomenon effectively.In order to solve the problem of large amount of extended Kalman filter,the reduced order EKF is designed,and the attenuation factor is added to prevent the divergence of the system.Based on the Matlab / Simulink simulation platform,the system model is analyzed to verify the good steady-state performance and robustness of the new sliding mode sensor at high speed,the feasibility of the improved extended Kalman filter method in the full speed range,and detect the accuracy of the rotor position. |
PDF Full Text Request