A New Hybird Excitation Motor Digital Driving System For Electric Vehicles

The motor driving system with high power density, high efficiency and better speed control characteristics is the key of electric vehicle.especially in the case of battery energy storage technology has not obtained the breakthrough.Hybird excitation motor not only inherits the advantages of permanent magnet synchronous motor, but also overcomes the difficulties that the permanent magnet motor air-gap magnetic flux is difficult to adjust.This type of motor which meets the requirements of large torque output and expand the range of speed has a great potential for the future electric vehicle driving system applications.This paper first introduces the research status of electric vehicle driving systems and hybrid excitation motor,elaborates the significance and purposes of this research.Secondly, the structural characteristics and working principle of hybird excitation motor are described in detail,and on this basis to establish the mathematical model of the control system.Thirdly.according to the electric vehicles operating requiements.this thesis puts forward the hybird excitation motor’s control strategy and analyzes the motor torque ripple.And then, the motor control system is designed based on the TI’s high-performance digital chips TMS320F2812.After that,this thesis introduces the topology structure of the main power circuit and analyzes the design principle of other hardware circuits. Finally,the system software is designed on the basis of the hardware circuitTo prove the rationality of theoretical analysis,some experiments are carried out on a6KW prototype and the related experimental data and waveforms are recorded.The results show that the hybird excitation motor driving system has a good dynamic and static performance.