Sensorless Control Of Permanent Magnet Synchronous Motor Based On Vector Control

Permanent Magnet Synchronous Motor is widely used in electric vehicles,rail transit,intelligent elevators,intelligent household appliances and so due to its advantages of simple structure,high power factor,low noise,low energy consumption and high reliability.In the traditional closed-loop control of Permanent Magnet Synchronous Motor,position sensors such as resolver and photoelectric encoder are usually used to obtain the speed and position information of the motor.However,the position sensors have many problems such as high cost,large volume and poor anti-interference ability,which lead to the Permanent Magnet Synchronous Motor cannot be applied in a wider range.Therefore,the study of sensorless control technology has important practical significance.Firstly,the research background and current status of sensorless control technology for Permanent Magnet Synchronous Motor are analyzed in this paper.The simulation model of vector control system of Permanent Magnet Synchronous Motor is built and analyzed by studying the physical model,mathematical model,coordinate transformation theory,basic theory of vector control and space vector modulation principle.Secondly,in order to solve the poor dynamic performance of traditional pulse high frequency voltage injection method,the Internal Permanent Magnet Synchronous Motor is taken as the research object,a novel rotor position estimation scheme is proposed which based on the second-order generalized integrators.By analyzing the feasibility of extracting high frequency current response signals from the second-order generalized integrators,a new position observer is designed.Compared with the position observer based on low-pass filter,the parameters of the designed position observer are easier to adjust.In the dynamic process of the system,the signal processing delay is smaller,and the high frequency current response signal can be extracted more accurately,which effectively reduces the dynamic estimation error of the rotor position;At the same time,in order to solve the chattering and phase delay of traditional sliding mode observer,the Surface-mounted Permanent Magnet Synchronous Motor is taken as the research object,a sensorless control method for Permanent Magnet Synchronous Motor which based on fuzzy control and Kalman filter is proposed.A sliding mode observer is designed by using Sigmoid function,a kind of fuzzy controller is designed to adjust the sliding mode gain dynamically inreal time by combining the estimated current error and its error rate,the chattering phenomenon of the sliding mode observer is effectively weakened,and the stability and dynamic performance of the system are improved.A Kalman filter is designed to eliminate high frequency components and the system measurement noises in the back EMF,which can avoid the problem of phase delay and improve the observation precision of the system.Finally,on the basis of theoretical deduction,the corresponding simulation model is built and analyzed by using MATLAB/Simulink software.The simulation results verify the reliability of the proposed method.