Research On Position Sensorless Control System Of Permanent Magnet Synchronous Motor Based On MRAS

With the development of high-performance permanent magnet materials,permanent magnet synchronous motors(PMSM)have been widely used in industry and daily life.In order to improve the performance of the permanent magnet synchronous motor vector control system,it is necessary to monitor the position and speed of the motor rotor in real time.In the traditional control scheme,the rotor position and speed need to be obtained through the sensor.The sensor is susceptible to the influence of the surrounding working environment,which leads to the performance of the control system and The accuracy decreases,and the presence of sensors increases the volume and cost of the permanent magnet synchronous motor.Therefore,sensorless control has become a research hotspot today.This dissertation takes the surface-mounted permanent magnet synchronous motor as the research object,and adopts the Model Reference Adaptive System(MRAS)sensorless control method to realize the detection of the rotor position of the motor.Permanent magnet synchronous motor parameters will change under the influence of the external environment.Aiming at the problem of error in estimation results caused by motor parameter changes,combined with the characteristics of surface-mounted permanent magnet synchronous motors,the motor parameters are identified through a model reference adaptive system.The identification results are sent to the observer to correct the adjustable model,thereby reducing the estimation error of the speed and rotor position.The derivation of the adjustable model and the adaptive law is carried out,and the stability of the nonlinear feedback system is verified according to the Popov superstability theory.In order to enhance the robustness of the system,the speed loop of the double closed-loop vector control system adopts a combination of sliding mode variable structure and PI control.The sliding mode control has fast dynamic response and strong anti-interference ability.The composite controller has overcome the traditional sliding mode The problem of controlling high-frequency jitter improves the steady-state performance of the control system.The system simulation model was built in the MATLAB/Simulink environment to verify the effectiveness of the control system under multiple operating conditions.With the main control chip TMS320F28335 as the core,a permanent magnet synchronous motor sensorless control system is designed,including power supply circuit,drive isolation circuit,current detection circuit,overcurrent protection circuit and software program control flow chart.The experiment proves that the position sensorless control system of permanent magnet synchronous motor based on MRAS can accurately obtain the speed and rotor position.