The Control Of Sensorless PMSM Based On High Frequency Signal Injection

Permanent Magnet Synchronous Motor(PMSM)has been widely used in the field of industrial production,daily life,new energy vehicles and so on due to its small volume,high efficiency,high energy density,etc.In general,common control strategy for PMSM needs realtime rotor position,which is usually obtained by rotor position sensor.Meanwhile,control system with position sensor should offer additional interface electric circuit,and the stability and cost of position sensor should be taken into consideration.In addition,position sensor could not be installed in harsh situation.In consideration of these reasons,sensorless control system for PMSM need to be proposed.This paper aims at this issue and studies strategy of sensorless control on PMSM based on high frequency signal injection.This paper analyzes the basic structure and mathematic model of PMSM,and introduces the theory of Space Vector Pulse Width Modulation(SVPWM).Based on SVPWM,vector control system of PMSM is introduced,which decouples excitation and torque variable using coordinates transform,so two variables could be controlled alone.Basic principle of high frequency signal injection is introduced based on the frame of vector control.Sinusoidal signal is injected into motor basic voltage,whose amplitude is far below dc bus voltage and frequency is far higher than rotor electrical frequency.After sampling stator current which is generated by high frequency injection,high frequency signal with rotor position information could be obtained by filter.Rotor position could be solved with mathematic operation by high frequency signal.Based on these theoretical analysis,MATLAB/Simulink model of rotating high frequency signal injection and fluctuating high signal frequency injection are built,which have superior performance on rotor position trace.At last,a sensorless PMSM control system experiment platform is designed,which uses the MKV46F256VLH16 chip as the core component,and experiment of high frequency signal injection is operated on graphic uppercomputer FreeMASTER,and detailed experimental waveforms and data are obtained.Finally,this paper draw a conclusion based on simulation and experiment.