纯电动汽车动力系统速比优化设计

综合考虑纯电动汽车的动力性、续驶里程以及能耗需求,在某款固定速比纯电动汽车作为研究样本的基础上,为了使驱动电机工作点落在高效率区域范围,提出了两挡电控机械式自动变纯电动车模型和动力系统优化数学模型,基于Isight集成Cruise,构建两挡AMT纯电动汽车联合优化仿真流程及平台。以100 km/h加速时间和整车NEDC工况100 km能量消耗为优化目标,将动力性、能量消耗以及变速器速比约束等指标作为约束条件,对动力系统速比进行优化;将优化后的设计变量在Cruise仿真平台进行动力性与经济性仿真分析,并制订以车速、负荷率为参考的双参数经济性换挡策略。结果表明,NEDC循环工况能量消耗降低0. 52 kWh/100km,经济性改善率3. 78%,100 km/h加速时间缩短了2. 23%。

Optimization Design of Pure Electric Vehicle Power System Speed Ratio

Comprehensive consideration of the dynamic performance,driving range and energy consumption requirements of pure electric vehicles,on the basis of a fixed speed ratio pure electric vehicle as the research sample,in order to make the driving motor work point on the high efficiency area,two-speed Automatic Manual Transmission(AMT) drive scheme is put forward. The mathematical model of two gears AMT pure electric vehicle model and power system optimization model are established on Cruise simulation platform. Based on the Isight integration Cruise,the co-simulation process and platform of AMT pure electric vehicles are constructed. With 100 km/h acceleration time and the NEDC working condition per 100 km energy consumption as the optimization objectives,the maximum speed,the maximum climbable gradient and speed ratio constraint are used as constraints,the speed ratio of the powertrain are optimized,after optimization of the design variables,the reference two-parameter shift strategy in speed and load degree are established,in the meanwhile,a simulation research is conducted on the dynamic and economic performance of the vehicle with Cruise. The results show that,the NEDC consumption has reduced by 0.52 kWh/100 km,the economic improvement rate is 3.78%,and the 100 km/h acceleration time has shortened by 2.23%.