Abstract

Plug-in hybrid electric vehicles (PHEVs) are an effective vehicle technology to reduce light duty vehicle greenhouse gas emissions and gasoline consumption. They combine all-electric driving capabilities of a battery electric vehicle with the engine downsizing and fuel economy improvements of a hybrid electric vehicle. Their environmental performance is predicated upon the metric utility factor (UF). It is formally defined in the Society of Automotive Engineers J2841 standard and denotes the fraction of vehicle miles traveled (VMT) on electricity (eVMT). Using year-long driving and charging data collected from 153 PHEVs in California with 11–53 miles range, this article systematically evaluates what aspects of driving and charging behavior causes observed UF to deviate from J2841 expectations. Our analyses indicated that charging behavior, distribution of daily VMT, efficiency of electrical energy consumption in the charge depleting (CD) mode, and annual VMT were the major factors contributing to the disparities between observed and expected UF. The direction and magnitude of their individual effect varied with the vehicle type and range. Approximately ±45% of deviations from J2841 UF is attributable to the observed charging behavior. Differences in daily VMT distribution were responsible for −20% to +3% of deviation. Annual VMT and effective CD range achieved on-road influenced the UF deviation by ±25% and −20% to −4%, respectively.

摘要

插电式混合动力汽车 (PHEV) 是减少轻型汽车温室气体排放和汽油消耗的有效汽车技术。它们将电池电动汽车的全电动驾驶能力与混合动力电动汽车的发动机小型化和燃油经济性改进相结合。它们的环境性能取决于公制效用因子 (UF)。它在汽车工程师协会 J2841 标准中正式定义，表示车辆行驶里程 (VMT) 的电力 (eVMT) 分数。本文使用从加利福尼亚州 153 辆 11-53 英里范围内的 153 辆 PHEV 收集的长达一年的驾驶和充电数据，系统地评估了驾驶和充电行为的哪些方面导致观察到的 UF 偏离 J2841 的预期。我们的分析表明，充电行为，每日 VMT 分布、电荷耗尽 (CD) 模式下的电能消耗效率和年 VMT 是导致观测和预期 UF 之间差异的主要因素。它们各自影响的方向和幅度因车辆类型和范围而异。与 J2841 UF 的大约 ±45% 偏差可归因于观察到的充电行为。每日 VMT 分布的差异导致偏差为 -20% 至 +3%。道路上实现的年度 VMT 和有效 CD 范围分别影响 UF 偏差 ±25% 和 -20% 至 -4%。它们各自影响的方向和幅度因车辆类型和范围而异。与 J2841 UF 的大约 ±45% 偏差可归因于观察到的充电行为。每日 VMT 分布的差异导致偏差为 -20% 至 +3%。道路上实现的年度 VMT 和有效 CD 范围分别影响 UF 偏差 ±25% 和 -20% 至 -4%。它们各自影响的方向和幅度因车辆类型和范围而异。与 J2841 UF 的大约 ±45% 偏差可归因于观察到的充电行为。每日 VMT 分布的差异导致偏差为 -20% 至 +3%。道路上实现的年度 VMT 和有效 CD 范围分别影响 UF 偏差 ±25% 和 -20% 至 -4%。