Research On Position Sensorless Control Technology Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor has the advantages of high power factor,large starting torque,simple structure and good speed regulation.It is widely used in transportation,home appliances,aerospace,manufacturing and other fields.Precise control of permanent magnet synchronous motors requires accurate rotor speed and position information.It is usually obtained by adding a mechanical sensor such as an encoder or a resolver on the permanent magnet synchronous motor,but the addition of the sensor increases the cost and space of the motor.Especially in some special work environment,the detection accuracy is reduced,and in serious cases,it directly affects the normal operation of the motor.Based on a large number of literature research and related theoretical research,the related research on the position sensorless control method of permanent magnet synchronous motor under low speed and medium speed is carried out.The main work is as follows:(1)Research on low-speed position sensorless control technology of permanent magnet synchronous motor based on high frequency signal injection method.The permanent magnet synchronous motor runs at low speed and uses high frequency signal injection method to obtain the rotor position and velocity information.For the traditional pulse vibration high frequency voltage signal injection method,the problem of extracting the rotor error angle is complicated,and a linear sine tracking algorithm based on linear sinusoidal tracking algorithm is proposed.The pulsed high-frequency voltage signal is injected into the position sensorless control method,and the stability of the algorithm is proved.For the pulse high-frequency voltage signal injection method,the filter is used to limit the system bandwidth and affect the dynamic performance of the system.The high-frequency square wave voltage signal injection method is used to achieve the position sensorless control.The high-frequency square wave voltage signal injection method only needs First-order smoothing and difference operations can be extract high-frequency signals and fundamental signals,simplifying the system structure and improving the dynamic performance of the system.Two kinds of high-frequency signal injection method for permanent magnet synchronous motor position sensorless control model are built on Simulink platform,and two kinds of position sensorless control methods are simulated.(2)Research on high-speed position sensorless control technology in permanent magnet synchronous motor based on nonlinear filtering algorithm.In the case of medium and high speed,the extended kalman filter algorithm is usually used to achieve motor position sensorless control,but large filter error occurs when dealing with strong nonlinear systems.Therefore,the cubatuer kalman filter algorithm is applied to motor position sensorless control.The mathematical transformation of the volume conversion principle and filtering process of the algorithm is carried out,and the position sensorless control model of permanent magnet synchronous motor based on cubatuer kalman filter algorithm is built.The simulation results and comparative analysis of the two nonlinear filtering algorithms in the position sensorless control method are carried out on Simulink platform.The experimental results show that the cubatuer kalman filter method has higher estimation accuracy.