Managing the impact on the electric distribution network of rapid of electric vehicle adoption

Chuck Roy

doi:10.3390/wevj5030748

Abstract

Many electric utilities have begun piloting Electric Vehicle (EV) charging stations with a number of manufacturers, including Siemens. As a result of working with these EV charging station manufacturers, utilities have developed a good understanding of prevailing technology. While utilities consider options like selling or recommending preferred EV charging stations to new EV owners in their service territory, a trend has emerged where new EV owners purchase charging station technology without notifying the utility based on recommendations from their EV dealers. It is important for the utilities to be aware of customers in their service territories that are installing EV charging stations in their homes and businesses in order to plan for the required distribution network upgrades to serve these stations. Siemens has worked with a number of utilities to discuss their business requirements for a software solution envisioned to manage the installation and use of EV charging stations in their networks. This paper reviews both the problem these utilities are trying to solve together with their functional and integration requirements for a comprehensive EV charging station management system which can support utility programs including critical peak pricing programs, demand response, outage management, etc.

Highlights

The US Department of Energy has forecasted that 100 million electric or hybrid cars, or 40% of domestic automobiles, will be in use by 2020
Charging stations in the utility’s service territory will trigger expensive, unplanned electric distribution network upgrades to mitigate power quality issues and power outages related to the stations
Functional requirements for the Electric Vehicle (EV) charge station management system (CSMS) include: R1: Tracking the physical and electrical address of new EV charge stations as they are added to the electric distribution network

Summary

Introduction

A typical electric utility distribution system delivers power to a residential EV charging station from a transformer which typically serves 6 customers by stepping down the utility medium voltage to dual 120Vac single phase ( called 240Vac split phase). This voltage is fed through a meter into the residential load control centre. Most electric vehicles support charging from a domestic wall socket, the benefits of using a dedicated EV charge station include faster charging times and sensing mechanisms to disconnect the power when the EV has completed charging. Residential EV charging station units are typically “dumb” chargers that don’t authenticate the user, deny access to EV car owner to prevent charging nor communicate with a host (i.e. they are not networked devices)

Challenges facing Electric Utilities

Electric Utility Requirements

Envisioned Solution

Benefits

Findings

Conclusion