Research On The Multi-Speed Of Pure Electric Vehicle Drive System Impact On The Performance Of The Vehicle

With the advent of energy crisis and the increase of the environmental pollution, the global energy conservation and emissions reduction becomes increasingly urgent. In automobile industry, many famous auto companies began to invest huge energy research and promotion of electric vehicles, governments have also introduced a variety of related policies and regulations to promote the development of electric vehicles. PEV are basically adopted fixed speed reducer on the current market, but this transmission mode requests the matched motor to provide larger reserve capacity and have lower drive efficiency at the same time. Some key technologies of pure electric vehicles (PEV) were not break through effectively by now such as power battery and motor control, so those fundamental problems like Limited driving range, poor safety and higher cost also could not be solved effectively. So in the present circumstances, the study on the PEV transmission system is an important way to improve the driving range of the PEV.This paper study on the Multi-gear transmission system of the PEV, and analysis the difference of the PEV’s performance which were equipped with different gear transmission. The main research contents and innovation points as follows:(1)Make use of the Matlab/Simulink platform and the method combined bench test with theory analysis, the facing-forward simulation models of the PEVs were constructed. What’s more, the power battery charge and discharge test and resistance test were made to provide data for the modeling of the power battery. The battery test improve the precision of the model and provides the ways and means for the research of pure electric vehicles in this paper.(2) The power battery and drive motor parameters were selected and matched according to a PEV parameters and performance requirements, meanwhile, three types of transmission system plan (fixed ratio gear reducer, two speed AMT, three speed AMT) were determined. Take advantage of the facing-forward simulation models of the PEVs, the vehicle performance (acceleration time, maximum speed and driving range) of each PEV equipped with different transmission system (motor and transmission) were simulated and analyzed respectively.The results of the simulation shows that the PEV that equipped with two speed AMT transmission system has performance better than other schemes in all aspects. Meanwhile, the results shows that the multi-speed of pure electric vehicle drive system allows to adopt lower torque motor to meet the requirements of the vehicle performance, which can provide reference for the optimal design of the PEV transmission system.