两挡电动汽车动力传动系统的参数设计

Parameters design of powertrain system of electric vehicle with two-speed gearbox

在一款采用固定速比减速器的电动汽车的基础上,改用两挡变速传动方案,对驱动电机进行参数匹配设计,并设计了不带离合器的两挡自动变速器。为了提高电机工作效率,对传动系统的速比进行了以整车动力性要求为约束、以ECE(欧洲城市经济)循环工况下电机能量消耗最小为目标的优化设计,制定了以电机高效运行为原则的换挡控制策略,并与采用固定速比减速器的电动汽车进行了ECE运行循环下的能耗和续驶里程的对比。结果表明,整车能耗降低了6.6%,续驶里程延长了7.1%。

A scheme of two-speed transmission is proposed based on an electric vehicle（EV） with a settled gear ratio.A new traction motor is chosen and a two-speed automatic gearbox without clutch is designed,and matching design between the motor and the two-speed gearbox is carried out.In order to improve operation efficiency of the motor,speed ratios of the two-speed gearbox are optimized aiming at lest energy consumption of the motor over the ECE drive cycle under the condition of ensuring the dynamic performance of the EV.A shifting strategy to guarantee high operation efficiency of the motor is drew up.The simulation results indicate that the energy consumption is decreased by 6.6% and the driving range is extended by 7.1% compared with the EV with a settled gear ratio.