Research On Parameters Optimization And Dynamic Gearshift Schedule Of A Three-speed Pure Logistics Electric Vehicle Powertrain

Pure electric vehicles have attracted wide attention due to their advantages of zero emission,low noise and great potential for energy conservation and environmental protection,governments and automobile companies around the world have taken the industrialization of pure electric vehicles as an important development goal.In this context,it is necessary to put forward higher requirements for the power and economy of pure electric vehicles.Meanwhile,with the development of logistics industry,the pure electric logistics vehicle has been gradually applied to replace the traditional logistics vehicle,so as to reduce the transportation cost.Based on this,this paper is based on a project called “high energy efficiency transmission system of electric vehicles” of an automobile company in Chongqing,a three-speed transmission system for pure electric logistics vehicle is presented,the transmission parameters and gearshift schedule are studied to improve the dynamic performance,economic performance and adaptability to the driving conditions of pure electric logistics vehicles.Firstly,according to the characteristics and usage scenarios of the pure electric logistics vehicle,a three-speed transmission for the pure electric logistics vehicle is proposed,the original design,parts design and calculation analysis of the three-speed transmission system are carried out to obtain the overall structure of the three-speed transmission.Secondly,according to the pure electric logistics vehicle performance requirements index,the parameters of driving motor and transmission are matched preliminarily.Based on this,the optimization model is set up,which takes the parameters of driving motor and transmission as optimization variables,the vehicle acceleration time of 0-50km/h and CHTC-LT cycle specific energy consumption as the optimization objective,then the hierarchical gravity search algorithm(HGSA)is used to solve the model.Thirdly,the influence of road slope and vehicle load on gearshift is analyzed,the dynamic and economic gearshift schedule with dynamic adaptability are formulated.Then set up the comprehensive performance optimization model,which takes the vehicle acceleration time of 0-50km/h and energy consumption during the accelerated phase as the optimization objective,the HGSA is used to solve the model,the comprehensive performance gearshift schedule under different road slopes and vehicle load driving conditions are obtained.Finally,MATLAB/Simulink simulation platform is used to establish the vehicle simulation model and vehicle dynamic performance simulation model,the dynamic performance index of pure electric logistics vehicle is verified by simulation analysis,and the dynamic performance,economy and dynamic adaptability of the comprehensive performance gearshift schedule.