Modeling the Impact of Increasing PHEV Loads on the Distribution Infrastructure Chris Farmer Graduate Research Assistant University of Vermont Transportation Research Center cfarmer@uvm.edu Paul Hines Assistant Professor University of Vermont School of Engineering paul.hines@uvm.edu Jonathan Dowds Graduate Research Assistant University of Vermont Transportation Research Center jdowds@uvm.edu Seth Blumsack Assistant Professor Department of Energy and Mineral Engineering Penn State Institutes of Energy & the Environment The Pennsylvania State University blumsack@psu.edu Abstract Numerous recent reports have assessed the adequacy of current generating capacity to meet the growing electricity demand from Plug-in Hybrid Electric Vehicles (PHEVs) and the potential for using these vehicles to provide grid support (Vehicle to Grid, V2G) services. However, little has been written on how these new loads will affect the medium and low-voltage distribution infrastructure. This paper briefly reviews the results of the existing PHEV studies and describes a new model: the PHEV distribution circuit impact model (PDCIM). PDCIM allows one to estimate the impact of an increasing number of PHEVs (or pure electric vehicles) on transformers and underground cables within a medium voltage distribution system. We describe the details of this model and results from its application to a distribution circuit in Vermont. 1. Introduction Volatility in petroleum prices, security concerns associated with imported oil, and anthropogenic climate change contribute to increasing interest in alternative vehicle technologies. With substantial improvements in battery technology mainstream automobile manufacturers are preparing to sell commercial versions of both Plug-in Hybrid Electric Vehicles (PHEVs) and pure Electric Vehicles (EVs). Given the potential for near-term, large-scale deployment of PHEVs it is important that policy makers and electricity industry members understand the impact these vehicles will have on national electricity infrastructures. A rapidly growing number of studies report on PHEV performance and impacts. These studies typically fall into one or more of the following categories: (1) vehicle performance studies that look at the cost of ownership and emissions impacts of vehicles; (2) supply adequacy studies that aim to assess the potential to meet growing demand with existing generation assets; (3) Vehicle to Grid (V2G) studies, that look at the value of vehicles for the provision of bi-directional grid support services; and (4) distribution system studies, which are limited in number, and which study the impact of increasing PHEVs on the medium and low voltage infrastructure. PHEV research is evolving rapidly and existing studies provide fairly comprehensive results for categories (1) through (3). However, if utilities need to invest in the distribution infrastructure to support circuits feeding increasing numbers of PHEVs, they will need good decision tools to help evaluate distibution level investment options (category 4). With this in mind, the goal of this research is to develop a model that allows distribution utilities to evaluate the impact of increasing PHEVs on medium and low voltage transformers and underground cables. The results from this tool (the expected time to failure for distribution circuit components) will allow utilities to prioritize investments given load growth projections. This paper is structured as follows. Section 2 reviews results from existing studies on the impacts of PHEVs. Section 3 describes the proposed distribution circuit/PHEV modeling method in detail. Section 4 describes the distribution circuit that we use as a test case for our model, and preliminary results from this 1 Proceedings of the 43rd Hawaii International Conference on System Sciences - 2010 978-0-7695-3869-3/10 $26.00 © 2010 IEEE