Research On Sensorless Control Of Permanent Magnet Synchronous Motor For Electric Vehicle Air Conditioner

The permanent magnet synchronous motor is the core part of the air-conditioning compressor of electric vehicles.As an extremely important component of the air-conditioning compressor,its operating performance directly affects the cooling effect and temperature adjustment ability of the air-conditioning compressor.Permanent magnet synchronous motors need to identify rotor position information to achieve precise control.The traditional identification method is through mechanical sensors,but the volume of the system will increase and the reliability will decrease.Therefore,the sensorless speed regulation control of the permanent magnet synchronous motor becomes an urgent need.In this paper,the permanent magnet synchronous motor,the core driving component of the electric vehicle air conditioner,is the research object,and the position sensorless vector control fault-tolerant system of the permanent magnet synchronous motor is studied.The main content of this article is as follows:In view of the defect that the sensor relied on in the speed regulation control of the air conditioning drive motor of electric vehicle will reduce the measurement accuracy under bad working conditions such as corrosion,high temperature and chattering,a sensorless algorithm based on vector transformation technology is proposed,and the sliding mode observer is used to replace the mechanical sensor to ensure the efficient and stable operation of the air conditioning drive motor.Aiming at the situation that the traditional sliding mode observer estimates the rotor position accuracy at low speeds,an improved sliding mode observer algorithm based on anti-disturbance PID is proposed and applied to the speed control of electric vehicle air-conditioning drive motors.Through the method of numerical simulation and experimental bench,the target speed following situation,anti-disturbance performance and transient response of the drive motor during operation are tested.Simulation and experimental results show that within the test range,the improved sliding mode observer algorithm based on anti-disturbance PID can accurately estimate the position and speed signal of the drive motor rotor,thereby effectively completing the drive motor’s position sensorless operation at medium and low speeds.The closed-loop precise control can meet the actual working conditions of electric vehicle air-conditioning compressors,laying a solid foundation for further matching of the whole machine,and has good engineering practical value.