Research On Permanent Magnet Synchronous Motor Vector Control System Based On Improved Sliding Mode Observer

Permanent magnet synchronous motor(PMSM)has been widely used in automobile,industrial control,aerospace,household electrical appliances and other fields,because its low price and high performance.The PMSM control needs the rotor position information provided by mechanical position sensor that installed in the motor shaft.But in some applications,mechanical position sensor is not suitable for the installation of mechanical position sensor because its cost is High and its low reliability.Therefore,the research on sensorless vector control system for PMSM based on sliding mode observer(SMO)is carried out to obtain the rotor information.This paper introduces the structure and coordinate transformation of PMSM,and the mathematical model of PMSM is deduced.The vector control theory is introduced in detail and thei_d(28)0control strategy is selected for the studied PMSM.In SIMULINK,the speed and current double closed loop models of PMSM are built and simulated under different working conditions.It provides a basic model for the following sensorless control technology.This paper analyzes the problems of chattering,inaccurate velocityestimation and high harmonic of counter electromotive existing in traditional SMO,and studies the optimization of traditional SMO algorithm.This paper presents an improved algorithm based on improved SMO technology combined with fuzzy PID to acquire rotor information.The improved sliding mode observer uses continuous function instead of switching function to suppress chattering,and uses fuzzy PID control instead of traditional speed loop PID regulator.Finally,the PMSM vector control model based on the improved SMO system is established on the SIMULINK platform,which proves the feasibility and correctness of the improved sliding mode observation system.On the basis of theoretical research,the experimental platform of PMSM control system with DSP chip as the core control chip is built,and the debugging of software and hardware is completed.Finally,some experiments are carried out on the basis of the experimental platform to verify the feasibility and effectiveness of the algorithm.