Sensorless Control Research For Permanent Magnet Synchronous Motor Of Hybrid Electric Vehicle

With the rising oil prices and increasingly prominent environmental issues, it is of great importance for us to improve the negative effects by internal combustion engine vehicle. As the most effective way to solve these problems at present, the research of Hybrid Electric Vehicle (HEV) is the key point and future development direction throughout the world. As one of the key technology of HEV, the control mode of HEV drive motor directly reflects the vehicle fuel economy, security and exhaust emission index etc.The common control method of motor control system is vector control. The principle is to control motor stator current space vector phase by rotor position information. For this reason, in order to realize motor vector control effectively, the rotor position must be detected accurately. The usual way of angle detection is to put a position sensor in the motor system. However, there is some hidden trouble during the detecting process by position sensor. And there are also control mistakes because of measurement error. These may make the motor noisy and unstable. Consequently, it is necessary to study a method of motor sensorless vector control thought as motor auxiliary measure.Based on Permanent Magnet Synchronous Motor (PMSM), the paper makes several aspects of the research as follows:Firstly, the paper analyses frequently used motor sensorless control methods at home and abroad. According to the characteristics of the vehicle drive motor, sensorless vector control method brought up in the paper which is adequate for PMSM.Secondly, through the analysis of the principle of coordinate transformation and motor vector control mathematical model in different coordinate system, the motor vector control basic principle is studied in the paper.Thirdly, PMSM sensorless vector control basic principle is brought up which is suit for HEV. According to the theory motor speed and rotor magnetic field position are analyzed and studied. Besides, simulation model is set up by means of Matlab/Simulink to prove the correctness and feasibility.Fourthly, after the research of the PMSM control system, the paper improves the control system hardware circuit, software design and PC monitor interface. Finally, in order to make sure that it is regular and safe, the whole system of software and hardware is tested in the experimental platform. After the bench test, the paper estimates the motor speed and rotor magnetic field position according to the sensorless vector control method. And the compared experiment is brought up between sensor control and sensorless control. Then the paper performs the mode switch experiment between these two methods under the stable state. The bench test shows that these are simplification, good maneuverability, and high fault-tolerant ability in the controlling process. It can be considered as an auxiliary control method to realize multi-mode control in motor control of HEV.