北京市区电动轻型客车制动能量回收潜力

在分析影响电动汽车制动能量回收潜力的各种主要因素的基础上，以一辆电动轻型客车为例，结合北京市区轻型客车行驶工况调查数据，统计分析了在不同车速下最大制动功率的分布特征，发现其与电动机的制动工作特性能够很好地吻合。通过对典型路段上净制动能量和可回收制动能量的统计分析，即使在行驶工况变化比较频繁的长安街上行驶，采用制动能量回收可增加的续驶里程也只有24.4%左右。最后还统计分析了制动能量相对于车速－制动减速度和电动机转速－转矩的二维分布，统计结果表明制动能量分布的密集区与所采用的电动机在制动状态下的高效率区不能很好地重合。因此从提高制动能量回收潜力的角度出发，应根据行驶工况的统计结果来指导电动汽车电驱动系统的设计，不仅要从满足驱动需求出发，还应适当兼顾制动能量回收的需求，从而更全面地提出电动汽车电驱动系统的设计要求。

EFFECTIVENESS OF REGENERATIVE BRAKING FOR ELECTRIC CAR IN BEIJING

Based on the analysis of various factors that may affect the potential of regenerative braking and an electric sedan prototype, the statistical characteristic of maximum braking power under different velocity is obtained from logged drive cycle data of a Beijing Xidan, which shows high accordance with the characteristics of electric motor. Then the net braking energy and available braking energy under typical road are analyzed, the results indicates that the maximum range improvement of regenerative braking, even in frequently stop-and-go Chang'an Street, is about 24.4%. Finally the two-dimensional distributions of braking energy to velocity-deceleration of EV(electric vehicle) and revolution-torque of electric motor are analyzed, which illustrates that the region rich in braking energy does not coincide with high regenerative braking efficiency region of electric motor. To improve the potential of regenerative braking, the design of electric drive system should consider the all-sided statistical results of drive cycle investigation, i.e., a comprehensive electric drive system design must consider not only the requirement for propulsion performance but also the potential of regenerative braking.