Research On New Energy Vehicles Electric Air Conditioning Compressor Driver

The frequent occurrence of haze weather in our country and the problem of energy shortage make people pay more attention to new energy automobile industry which features low carbon, environmental protection and energy saving. With the rise of new energy automotive industry and the improvement of people’s living quality, people have higher requirements on reliability, comfortment and energy saving and environmental protection performance of new energy automobile, and electric air conditioning is one of the important factors determining driving comfort. In this paper, core component-compressor driver of electric automobile air conditioning system is the research object, first, the author elaborates on the present condition of development and application of electric air conditioning compressor driver of new energy automobile by domestic and foreign automobile manufacturers, and points out the shortcomings of the solution of using Brushless DC motor with position sensor, tries to use permanent magnet synchronous motor as driving motor, and develop a drive system which is based on sensorless control technology and direct torque control technology. Then the author explains basic theories related to permanent magnet synchronous motor, including structure, classification and mathematical model of PMSM, space vector and coordinate transformation, and then has a detailed discussion on the space vector pulse width modulation method that is currently used in AC motor and inverter control. After a thorough study on the traditional direct torque control, the author finds that there are shortcomings of large torque ripple and unsmooth stator flux linkage vector trajectory. And a improved direct torque control solution is proposed with combination of space vector pulse width modulation technique. Next, the development of sensorless control technology and several sensorless control methods are introduced, a sliding mode observer is used to estimate rotor position and motor speed.Under guidance of the right theory,Matlab/Simulink software is used to do simulation modeling and analysis study of location estimation results of direct torque control system and sliding mode observer. At the end, the author does corresponding hardware and software design on electric air-conditioning compressor driver and carried out the experiment, and validates the feasibility of the solution of adopting DTC control of permanent magnet synchronous motor that is based on SMO.