Research On The Sensorless Rotor Position Estimation Of PMSM

In recent years,with the rapid development of power electronic technology, new electric control theory permanent magnet materials and the gradual promotion of permanent magnet synchronous motor, the applications of permanent magnet synchronous motor were gradually diversified.The permanent magnet synchronous motor had advantages including micro volume,low cost and high efficiency,but as a kind of synchronous motor,it also has the character of Easily lost steps, so this dissertation made a detailed analysis and research in response to these advantages and problems.This dissertation on the basis of the theory of the permanent magnet synchronous motor proposed the detection technology of rotor position which was the sensorless drive based on PMSM,and its implementation of the approach. Firstly, the working principle of high frequency injection method had been introduced and analyzed detailedly, and researched for the rotor position estimation, come to the defects of high frequency rotating injection method under the high speed which was based on the analysis,then lead to the sliding mode observer method, and extracted the rotor position through sliding mode observer, the estimation method had been improved in the original on the sliding mode observer to make it more accurate. For both methods which could not be estimated in the full speed range, this dissertation presented a composite detection,and made use of weighted algorithm in the transition zone of the two methods, combined the two methods effectively,then simulated the high frequency injection method and the rotor position detection of sliding mode observer method by means of MATLAB/Simulink.The estimation method of the rotor position in this study could be guaranteed accurately estimate the position of the rotor, at the same to insure the motor that run continuously and stably. The estimate of this study improved the shortcomings of the speed regulation than ever before, and to make the permanent magnet synchronous motor run without slip. The proposed approach in this dissertation of the the sensorless drives’ control based on permanent magnet synchronous motor had advantages of high stability, good dynamic performance, wide speed range and could be widely used in practical engineering.