Sensorless Control System Of PMSM Based On Sliding Mode Observer

Permanent magnet synchronous motor(PMSM)is a kind of electric motor that is widely used in the development of modern electrical appliances and has higher performance.In the past research of permanent magnet synchronous motor,researchers used the sensor to detect the position of the rotor,which is indeed more accurate,but it also brings a lot of negative shortcomings and deficiencies.For this reason,the emergence of the positionless sensor solves the problem of correlation.The position sensor not only saves the economic cost of the motor control system,but also can reduce the occupied volume of the motor and becomes a high-level development of the permanent magnet synchronous motor.This greatly broadens the application scope of the permanent magnet synchronous motor.Some control technologies that can be applied to PMSM without position control system become the research focus.In this dissertation,the vector control system of PMSM is taken as the research object,and the operation of the motor based on the sliding mode observer(SMO)control method is realized.The application and development of the sensorless technology in the PMSM control system are verified.Firstly,based on the sliding mode control theory,a sliding mode observer is designed to estimate the position information of the motor rotor,which is applied to the position sensorless vector control system of permanent magnet synchronous motor and has good robustness,anti-interference and control algorithm is simple,easy to implement in the project.Secondly,based on the analysis of the mathematical model and vector control scheme of PMSM,the system model of the sensorless vector control system based on sliding mode observer is established,which provides the theory for the simulation and experimental research on vector control of sensorless PMSM.Based on this,the hardware circuit design and software programming of PMSM vector control system based on sliding mode observer are completed.Finally,the simulation and experimental study of SMO-based sensorless PMSM vector control system is carried out.Using MATLAB/Simulink software,the simulation research of the PMSM vector control system without position and simulation wave forms are obtained,which proves the feasibility of this method.Based on DSPF2812 as the core to build the experimental platform,the software program is designed and the hardware D/A conversion circuit is designed when outputting the angle information.The controlled digital quantity is converted into analog quantity for output.The conversion chip MX7847 and 12-bit digital signal are used,through the two simultaneous acquisition of d,q axis current,while the output rotor position information,the experimental results and simulation results are consistent to meet the design requirements.