Utility Factor Definitions for Plug-In Hybrid Electric Vehicles Using Travel Survey Data
The total fuel and energy consumption rates of a Plug-In Hybrid Electric Vehicle (PHEV) vary depending upon the distance driven. For PHEVs, the assumption is that operation starts in battery charge-depleting mode and eventually changes to battery charge-sustaining mode. Total distance between charge events determines how much of the driving is performed in each of the two fundamental modes. An equation describing the portion of driving in each mode is defined. Driving statistics from the National Highway Transportation Survey are used as inputs to the equation to provide an aggregate "Utility Factor" (UF) applied to the charge-depleting mode results.
Rationale: This document has been reviewed by the technical committee and determined to be current with no need for immediate revision. If/when new data compatible with the original analysis becomes available, the document can undergo a revision.
Describing the fuel and electrical energy usage of plug-in hybrid electric vehicles (PHEVs) is very challenging for the reason that these values vary greatly depending upon the distance traveled between charging. Detailed test procedures recommended for PHEVs are found within SAE J1711, this document serves to supply appropriate curves for the equations in that document that weigh the charge-depleting mode operation with the charge-sustaining operation as a function of the charge-depleting range found from testing. The original issue of J2841 introduced the “Utility Factor” curves based on US DOT National Household Transportation Survey data. The second issue of J2841 added more options to the Utility Factor calculations by analyzing another data set from a Georgia Tech called the ―Commute Atlanta in order to find a vehicle-weighted analysis.