Research On Energy Distribution Strategy Of Distributed Drive Electric Vehicles

With the development of electric vehicle industry,distributed driven electric vehicle has become an important research field due to its high-efficient,fast-responding,compact drive system.This thesis researches the energy efficiency of different energy topological structure and energy distribution strategy aimed for better energy efficiency.Firstly,onboard energy consumptive subsystems are modeled via AMEsim and Matlab,such as HV battery,PMSM,inverter,DC/DC etc.Two different full vehicle energy topological structures compliant with distributed driven electric vehicles are established based on the models.Second,based on the topological structures,Matlab/Simulink was used for joint simulation to set drive system targets.The open loop simulation results of different rotational speed and drive/regenerate torque combinations were acquisited.The efficiency features of different types of energy flow were studied.Third,the drive energy distribution strategy of the drive system is optimized.The optimization was based on the drivetrain efficiency map from laboratory dyno test.Particle Swarm Optimization was used to calculate the most efficient distribute ratios troughout the probable target map.The optimized result was used to develop different driving strategy for simulation tests.Forth,hardware in the loop simulation is established to verify the effectiveness of the optimized distribution strategy.Different drive cycle results show that the optimized strategy reduced the energy comsuption by 4.54%,3.30%,5.35% in the NEDC,FTP75 and US06 cycle compared to the equal distribution strategy.Finally,road testings were carried out to verify the feasibility of the strategy.The results demonstrates that the energy efficiency can be effectively improved through the efficiencymap-based optimized distribution strategy.