面向实际交通状态的混合动力汽车能耗和CO_(2)排放模型

Energy Consumption and CO_(2) Emission Model for Hybrid Vehicles in Real Traffic Conditions

由于混合动力汽车与传统燃油车的能耗排放因子具有差异性,导致机动车交通路网能耗排放的量化评估存在不确定性。本文建立混合动力汽车在实际交通状态中的能耗和CO_(2)排放因子测算模型,基于车辆比功率VSP(Vehicle Specific Power)作为车辆行驶状态与能耗排放之间耦合关系的表征参数。通过引入内燃机转速区分内燃机开启和关闭工作状态,并计算内燃机开启状态下VSP对应的平均能耗率,同时,建立能够解析混合动力汽车能耗排放产生机理的VSP分布。通过收集典型行驶工况下车辆测试油耗数据和北京市车辆实际行驶轨迹数据,验证了模型的准确性,并应用模型测算混合动力汽车不同速度区间下的油耗和CO_(2)排放因子。研究结果表明:在城市行驶工况(UDDS)和高速行驶工况(HWY)中,模型测算能耗排放因子与真实值的平均相对误差分别为3.7%和-1.7%,与不考虑内燃机开启状态相比,测算误差减少5.6%和4.3%;在实际交通状态下,采用传统燃油车的测算方法会导致混合动力汽车行驶平均速度为高速区间时油耗和CO_(2)排放量被低估,当行驶平均速度为低速区间时油耗和CO_(2)排放量会被高估。

Due to the difference in energy consumption and emission factors between hybrid vehicles and conventional vehicles,there is uncertainty in the quantitative assessment of energy consumption and emission in automobile traffic road networks.This study establishes a model to measure the energy consumption and CO_(2) emission factors of hybrid vehicles in real traffic conditions,based on the vehicle specific power(VSP)as a parameter to characterize the coupling relationship from vehicle driving activities to energy consumption and emission.This model introduces the rotational speed of the internal combustion engine to distinguish whether it is operating or not,calculates the average energy consumption rate corresponding to the VSP in the engine operating mode,and develops the VSP distribution that can analyze the energy consumption and emission generation mechanism of hybrid vehicles.The accuracy of the model was verified by collecting fuel consumption data from hybrid vehicles test in typical driving cycles,and the model was applied to measure the fuel consumption and CO_(2) emission factors of hybrid vehicles at different average speeds using the real driving trajectory data in Beijing.The results show that the average relative errors between the model-measured energy consumption emission factors and the real values are 3.7%and-1.7%in the Urban Dynamometer Driving Schedule (UDDS) and the Highway Fuel Economy Test (HWY), respectively, which are 5.6% and 4.3% less than thoseof the original conventional model. In the real traffic condition, the measurement method of conventional vehicles willlead to the underestimation of fuel consumption and CO_(2) emissions when the average speed of hybrid vehicles is in thehigh-speed, and the overestimation of fuel consumption and CO_(2) emissions when the average speed is at a low level.