Research On Application Of Magnetized Permanent Magnet Stepless Speed Regulating Device In Pure Electric Vehicle

In the context of energy saving and emission reduction,the development of new energy vehicles is the trend of the automotive industry,in which pure electric vehicles play an important role.At present,pure electric vehicles mostly adopt single-stage reducer drive scheme,which has simple structure and low cost.However,it has the problem that the drive motor works in the low efficiency range,and can not give attention to both power and economy.In order to solve this problem,a new type of magnetized permanent magnet stepless speed regulation device based on permanent magnet transmission is proposed in this thesis.To this end,the following research has been done:Firstly,based on the structure characteristics of magnetized permanent magnet stepless speed regulation device,the working principle of the device was analyzed and its mathematical model was deduced by electromagnetic theory.The structure of different driving device of electric vehicle was analyzed,and different installation methods were designed.According to the relevant parameters and performance requirements of a certain vehicle on the market,reasonable parameters of drive motor and magnetized permanent magnet stepless speed regulation device were designed.Used Ansys Maxwell finite element software to analyze the different working states of magnetized permanent magnet stepless speed regulation device,and built functional test platform to verify its working characteristics.Secondly,according to the working characteristics of magnetized permanent magnet stepless speed regulation device,the optimal control strategy for the whole vehicle was developed,and the required torque was compensated by fuzzy control.The linear motor was controlled by PID controller and the magnetized permanent magnet stepless speed regulation device was controlled.The model of pure electric vehicle with magnetized permanent magnet stepless device was built.The performance tests under different working conditions was carried out by MATLAB / Simulink and AVL CRUISE software,and the superiority of the device was verified.Finally,the simulation results showed that the frequency of driving motor working point in high efficiency region increased by comparing with the pure electric vehicle with single-stage reducer.In the aspect of power,acceleration time,maximum climb and maximum speed were all improved;In terms of economy,it reduced the electricity consumption of 100 kilometers and increased the mileage of the car.To sum up,magnetized permanent magnet stepless speed regulation device has a certain significance for engineering application.