Research On Position Sensorless Of Permanent Magnet Synchronous Motor Based On Improved High Frequency Injection

Permanent magnet synchronous motor(PMSM)is widely used due to its high torque,high power density and high efficiency.PMSM sensorless control technology has begun to turn from theoretical research to engineering practice.This technology can effectively reduce system cost and reduce system failure rate,and can realize high performance PMSM control system with high control precision,wide speed range and strong robustness in the harsh space volume and application environment.The main work and innovation are as follows:Starting from the current PMSM control technology development status and research status of sensorless vector control technology,the progress of the research on the theory of sensorless control based on PMSM vector control and the application of these theories in the actual industrial field are described in detail.According to the application of various technologies in theory and practical engineering,this paper chooses high frequency voltage injection method applied in low speed or zero speed field as the research object.Introduce the mathematical model of PMSM under different shafting.and the principle of two traditional high frequency voltage injection methods is introduced in detail.The principle description and detailed formula deduction are made on how to extract the rotor position information in the traditional high frequency voltage injection method.Propose an improved low speed sensorless control method of PMSM,different from the traditional high frequency pulsating voltage injection method inject pulsating signal into the estimated synchronous reference axis,This method inject the high frequency pulse voltage signal into the stationary axis.By detecting the current response signal of the axis and extracting the high frequency current response component,the information containing the rotor position is obtained.At the same time,the final rotor position estimation is obtained by using a two phase phase locked loop of a simplified extended Calman filter.Compared with the traditional high frequency pulse voltage injection method,there is no problem of rotor position estimation in the start-up stage,and the anti-interference performance is better.The proposed improved high frequency voltage injection method is described in detail and theoretical deduction,the model of control system based on Matlab\Simulink is set up.The construction methods of each module in the model are introduced in detail,and the simulation of the relative dynamic and steady state characteristics is carried out.The traditional high frequency pulse voltage injection method and the improved high frequency high frequency injection method are also carried out,and verified the feasibility of the proposed method.The improved high-frequency injection method is used to extract high-frequency current response signal,electromagnetic torque ripple and sensorless control experiment.Compared with the conventional high frequency pulse voltage injection method,the experimental results show that the proposed improved high frequency injection method can get the rotor position information quickly and accurately at low speed.It has good stability and dynamic characteristics,and is better than the traditional high frequency pulse voltage injection method in the estimation accuracy.