The Dynamic And Economic Analysis Of Pure Electric Vehicle

As a symbol of modern civilization， auto has brought great convenience tohuman beings. Recently, due to the increasing scarcity of oil resources andheavier air pollution, traditional internal combustion engine vehicles are badlyunable to meet the requirements of the times. Pure electric vehicle, with itsadvantages of zero pollution, low noise, diversification of energy sources andthe capability to employ the trough power, is becoming more and more popular.Major automobile plants invest a lot of money in pure electric field.The dynamic and economic indexes of pure electric vehicle: maximum speed,acceleration time, maximum climbable gradient and the driving range arestandards of measuring the performance of pure electric vehicles. This papermainly focuses on the dynamic and economic indexes of pure electric vehicle.The first is to match the driving system, to determine the drive motor bydynamic indexes, to determine the power battery on the basis of the economicindexes and the relationship among the drive motor, the power battery’s voltageand its maximum power, proposing a way to retain the torsional damper andremove the clutch. Then this paper is trying to analyze the feasibility of asingle-speed gearbox, and to determine the speed ratio of the two-speed gearbox,then doing simulation on ADVISOR platform. Before simulation, for theinsignificance of the control strategy and according to the request of the car andthe motor efficiency map, shift point is re-determined. Because in the defaultregenerative braking control strategy, the regenerative braking proportion onlychanges with the vehicle speed while not consider the battery SOC, re-establishing the regenerative braking control strateg y is needed. Finally, newmodel has been generated in ADVISOR, in which the corresp onding dynamicand economic results have been got. It can verify that the second-speed gearboxis more advantageous to the single-speed gearbox and the new control strategyis more advantageous to the default control strategy in the driving range andenergy recovery.The simulation results can’t fully meet the designing requirements. Byadjusting the speed ratio, we can make pure electric vehicle maximum possiblyworking in high efficient area. At the same time, the dynamics of pure electricvehicle is related to the speed ratio as well. Thus the author here try to establish the optimazing fitness function with the dynamic and economic performanceobjectives by using ratio optimization. so that the dynamic and economicperformances are optimized, which can meet the designed requirements. Finally,through the simulation, the new speed ratio on the pure electric vehicle’sdynamic and economic performances have enhanced greatly. And it will satisfythe design requirements.Subjecting to the bottleneck of current battery technology, this paperprovides another method on the study of the dynamic and economicperformances of pure electric vehicle, especially for the study of the drivingrange.