Research On Control Of Permanent Magnet Synchronous Motor With High Frequency Pulsating Voltage Injection

Compared with other motors,permanent magnet synchronous motor can reduce the volume,increase the power factor,and then reduce the cost.At the same time,with the rise of the third generation rare earth permanent magnet material NdFeB,the application of permanent magnet synchronous motor is more and more extensive.Initially,the mechanical position sensor used in permanent magnet synchronous motors could not be used in some harsh environments because of its large size and high failure rate.Therefore,the sensorless technology was proposed.Sensorless technology mainly includes various observer methods used in medium and high speed situations and high frequency signal injection methods used in low speed situationsThis thesis focuses on the control of permanent magnet synchronous motor at low speed.At low speed,high-frequency rotating signal injection method and high-frequency pulse signal injection method are commonly used in Position-free control method.Through the analysis and comparison of two traditional high frequency signal injection methods,it can be concluded that the high frequency rotating signal injection method causes serious signal lag due to the use of synchronous shaft high-pass filters and more filters;The injection method of high frequency pulse signal may diverge at start-up.In order to avoid the above shortcomings,a PMSM control method for injecting high frequency pulse signals into the stationary coordinate system is adopted.This method injects high-frequency pulse voltage into the static alpha-beta coordinate system,derives high-frequency response current from the high-frequency excitation model of the motor,filters the high-frequency response current,extracts the DC component and so on,and finally obtains the position information through the rotor position observer.In order to reduce overshoot and speed up speed regulation time,an improved high frequency injection method using fuzzy adaptive PID instead of traditional PID is proposed,which can realize on-line adjustment of PID parameters and improve the dynamic performance of the whole vector control.Combining with theoretical analysis,this paper simulates based on MATLAB/Simulink,and verifies the correctness of theoretical analysis.Finally,the actual simulation platform is built through the design of hardware circuit and software programming.Through the control analysis of the actual motor,it can be proved that this method can estimate the rotor positionmore accurately than the traditional high frequency signal injection method,and has good speed following performance,which has practical application value.