Design And Optimization Of Driving System For Battery Electric Vehicle

At present,the global automobile industry is facing the transformation from traditional fuel vehicles to new energy vehicles.With the gradual decrease of fossil energy reserves and the deterioration of the global environment,governments and automobile enterprises in lots of countries are striving to promote energy conservation and emission reduction.On the one hand,the government is pushing forward the establishment of increasingly stringent emission standards and fuel consumption limit standards;on the other hand,they are striving to promote the development of new energy vehicles,and announce the ban time for sale of traditional vehicles.Most of automobile companies have announced their new energy strategy.The traditional automobile companies expect to continue the brand in this transformation,while the new automobile manufacturers hope to grasp the rare opportunity of transformation of the automobile industry and enter the automobile industry.In this paper,the battery electric vehicle in the new energy vehicle is taken as the object,researching parameters design and optimization of its driving system based on the power and economic performance.The power and economic performance of the whole vehicle is a performance of the whole vehicle hierarchy.There are many influencing factors including parameters of the whole vehicle,system and components have a direct impact on it.Because vehicle level parameters,such as windward area and wind resistance coefficient,belong to the field of aerodynamics,while tire rolling resistance belongs to the field of tire dynamics,this paper does not research vehicle parameters and tire level but research system parameters and component parameters of driving system.The parameters of power and economy of pure electric vehicle are slightly different from those of traditional fuel vehicle.This is due to the difference between the drive system of battery electric vehicle and traditional fuel engine.So this paper firstly introduces the parameters of power and economy of pure electric vehicle and the related parameters,then separately introduces the characteristics of motor? motor controller and gear box.In the process of designing and optimizing the parameters of the driving system,the power and economic performance of the whole vehicle should be taken as the requirements.Firstly,the power performance of the whole vehicle should be taken as the boundary conditions to determine the external characteristics parameters of the driving system,including peak torque/power/speed,rated torque/power/speed;secondly,the target is to optimize the efficiency of the drive system,taking peak characteristic parameters of the drive system and economic performance of the whole vehicle as constraints,taking into account the characteristics of the motor,motor controller and reducer.The simulation software is an important tool for parameter design and optimization of driving system.In this paper,AVL Cruise is used to build a simulation model of power and economic performance of a 4.5T truck.The power performance of the whole vehicle after matching the drive system is verified.Through several rounds of iteration simulation,the improvement of accelerating pedal strategy and the optimization scheme of driving system efficiency is verified.In order to verify the results of simulation calculation,the C-WTVC roller bench test of the whole vehicle is carried out.Before the roller bench test,the assembly quality of the car is ensured by coasting test to avoid other factors affecting the accuracy of the test data.Then the C-WTVC test is carried out on the roller bench.The test results are basically consistent with the simulation results.