Comparative Study On Key Performance Of Battery Electric Vehicles Under Different Drive Configurations

At present,limited by motor power density and power battery specific energy,multi-speed drive,multi-motor drive and winding switchable motor of battery electric vehicle have become a research hotspot to improve the power and economy of battery electric vehicles,Therefore,based on the same vehicle parameters and the experimental data of variable winding permanent magnet synchronous motor provided by a company,this paper conducts relevant research on the single-speed drive system,two-speed AMT drive system and variable winding permanent magnet synchronous motor drive system of battery electric vehicles.Firstly,according to the configuration parameters of a 4.5-ton battery electric light truck,the peak power,rated power and total energy of the power battery are determined,and the submodels required for the drive system are constructed,including driver model,motor model,power battery model,gearbox,main reducer model and vehicle longitudinal dynamics.Secondly,in order to meet the requirements of vehicle dynamics and the matching of the maximum vehicle speed and the maximum speed of the motor,the speed ratio of the singlespeed and two-speed AMT drive system is designed and optimized based on the elite genetic algorithm and dynamic programming theory.Considering that the two-speed AMT drive system has a gear shift process,the vehicle dynamic gear shifting law is designed with the goal of always having the best acceleration performance before and after gear shifting.With the goal of the lowest energy consumption and the highest residual SOC before and after gear shifting,the vehicle economic shifting law is designed.Then,in order to construct the winding switchable permanent magnet synchronous motor drive system,the elite genetic algorithm and dynamic programming theory are used to design and optimize the system speed ratio,and the dynamic and economic design of the winding switching process of winding switchable permanent magnet synchronous motor is carried out.In addition,the winding switchable permanent magnet synchronous motor control strategy is designed,including full-speed domain MTPA control and dq axis current decoupling control,so that the motor can accurately output torque according to the winding switching requirements.Finally,the simulation model of single-speed drive,two-speed AMT drive and winding switchable permanent magnet synchronous motor drive system of battery electric vehicle is constructed in MATLAB/Simulink,and the influence of the above three drive systems on the performance of battery electric vehicles is compared and analyzed from the perspective of power and economy.The simulation results show that in terms of dynamics,the acceleration performance of the two-speed AMT drive system is the best,and the acceleration performance of the winding switchable permanent magnet synchronous motor drive system is the second.In terms of economy,the winding switchable permanent magnet synchronous motor drive system has the smallest energy consumption per 100 km,followed by the 100 km energy consumption of the two-speed AMT drive system,and the power and economy of the single-speed drive system are the least satisfactory.