Research Of Sensorless Permanent Magnet Synchronous Motor Based On Hybrid Strategy Position Estimation

Permanent magnet synchronous motor has been applied in an increasing number of servo control system because of its small size, low loss and high efficiency. The traditional PMSM generally use high-precision position sensors to detect the position and velocity information of the rotor, which causes the high cost, large volume and low reliability. Sensorless permanent magnet synchronous motor (SPMSM) has a wide application value, research on sensorless control of PMSM in servo system has great significance. In this paper, a method combining the high frequency signal injection method and the Model Reference Adaptive System (MRAS) method will be introduced for SPMSM control in the whole speed range control. The main research contents include the following four parts.Firstly, according to the structure and characteristics of the PMSM, the thesis describes its mathematical model and control principle of field oriented control and the control method. This thesis gives detailed derivation of the implementation method and the space voltage vector field oriented control (SVPWM) generation algorithm.Secondly, for the sensorless control of PMSM, the key is how to accurately obtain the position of the motor rotor. The high frequency signal injection position estimation method and model reference adaptive position estimation method are analyzed and designed for rotor position estimation. To this, a hybrid control strategy is introduced to achieve the accurate position of PMSM in full speed range. And then a weighted algorithm is being used for the transition region to get a smooth transition of the two methods.Thirdly, the simulation model is built to verify the algorithm through the MATLAB simulation platform. Simulation models of the high frequency injection method and model reference adaptive method are designed. The simulation of sensorless position estimation of hybrid control strategy is designed to analyze the result compared with the high frequency injection method and model reference adaptive method.Lastly, the application of the hybrid position estimation of SPMSM will be introduced into experimental platform, including the detailed design of hardware system and software system. In the application, the field oriented control algorithm and postion estimation model will be tested and verified.