eksan mongkhonkhamsao/iStock/Getty Images
Tdworld 18421 Ev Charging Eksan Mongkhonkhamsao

Architecture And Protocols for Toll-Free EV Charging

April 25, 2019
This paper proposes innovative system architecture and protocols for the deployment of a toll-free electric vehicle charging service. The architecture enables the party initiating the EV charging session to have their service request authorized by the system and paid for by a third party.

Electric vehicle (EV) charging stations are being deployed worldwide, and many utilities are stepping up to build EV charging infrastructure across the country. The California Public Utilities Commission (CPUC) has recently approved US$738 million for new EV charging infrastructure development projects which were proposed by PG&E, SCE, and SDG&E. These companies, after extensive market research, confirmed that the EV infrastructure investment would be “a prudent investment.” Utilities in Maryland proposed a US$104 million investment to create 24,000 charging stations across the state.

There are three business models for utility companies to enter the EV charging market, (a) the least involved, (b) intermediately involved, and (c) the most involved. Under model (a), a utility company will provide an incentive to private citizens, communities, and businesses to build the EV charging infrastructure. Under model (b), a utility company will make ready, that is, build and own the EV charging infrastructure from the distribution transformer all the way to the charging station, and under model (c), a utility company will fully build, own, and operate EV charging stations.

Regarding payment, EV drivers may utilize two payment models to charge their EVs. In one model, the user pays from their own account (cash, check, service subscription, credit cards, and so forth) for charging the EV, and in the other, the user may have a business, a community, or government agency pay for the charging service. Since EV charging (3–6 cents/mile) is cheaper than gasoline (12–16 cents/mile), businesses or communities may benefit from leveraging it as a marketing tool, and they may wish to a provide toll-free charging service to their patrons. Similarly, the government may leverage it as a practical tool, and provide a toll-free charging service to the first respondents or authorized government employees. The government has already started investing in the acquisition of EV fleets. Bloomberg predicts the sales of EV to increase from 1.1 million in 2017 to 11 million in 2025 and then surge to 30 million in 2030 worldwide.

The following scenarios are foreseen:

  1. Advertisers and community organizers will attract clients and communities to business and community locations by offering toll-free charging incentives.
  2. Retailers/wholesalers will include toll-free charging in the service portfolio to promote sales or services.
  3. Car rental lots/dealers will offer or package a value-added service by providing toll-free charging.
  4. Governments, for profit/nonprofit organizations, communities, and the fleet management companies, will provide toll-free charging to the first respondents, field force, and community workers, to streamline their accounting procedures. Communities may offer free charging to attract EV owners to the area of the community, which increases traffic and sales tax revenues.

A government, business, or a community may have wholesale deals with utility companies to provide toll-free charging services to their clients, employees, field force, and other community members. They may also qualify to get special rates, by providing charging schedule preferences, and, in return, allowing the utility to determine when charging occurs.

A sign-up service portal, provided by the utility company, is also proposed. This would allow the above-noted user groups to track their service usage, the cost of the service they consumed, and their billing history over the internet. The service may be enabled on mobile devices as well, as Wi-Fi and 4G networks which have become ubiquitous. The portal not only provides the real-time information about service consumption, cost, and billing history but also the convenience of paying bills around-the-clock and the ability to monitor accounts more closely for early detection of fraudulent activity and consumption trends that may cause financial damage or loss to businesses or communities.

In the realm of telephone communication, toll-free telephony has been globally successful in providing a party pay model that obviates the need for the calling party to pay for the service used. However, the concept of toll-free charging of EV, where business, government agency, or a community will pay for EV charging, has not yet been developed or proposed by any utility company. There is an opportunity in the marketplace for this model of EV charging payment. The purpose of this white paper is to provide a system, method, and architecture that enables the party initiating the EV charging to have their service request authorized and paid for by a third party including a business, government agency, or a community. In addition, the method will support conventional payment methods, in case the EV driver elects to pay for the service.

In this white paper, the EV charging station capable of providing such payment services is called the Toll-Free EV Charging Stations/EVSE (abbreviated as TEC station), the service is called toll-free service, and the number used to claim the service is called a toll-free number.

Figure 1 presents a logical system architecture for supporting a toll-free service provisioning system. It involves the following logical and functional entities. Some of them are installed in the service areas, and some in the utility companies’ network. Toll-Free EV Charging Stations/EVSE may be fully, or partly owned by the utility company, depending on the business models discussed above. However, regardless of the business model, the author, because of cyber security threats, vulnerabilities, and unforeseen factors of a new business segment, recommends that the utility own, install, maintain, and manage metering.

Toll-Free EV Charging (TEC) station

TEC-Gateway/Router (TEC-GW)

TEC-AAA (Authentication, Authorization, and Accounting) Server

Policy and Charging Rules Server (PCRS)

Subscription Profile Database (SPD) Type-1 (to support toll-free services)

Subscription Profile Database (SPD) Type-2 (to support non-toll-free services)

The Department of Electrical Engineering and Computer Science at Alabama A&M University is a T&D World media partner.

Voice your opinion!

To join the conversation, and become an exclusive member of T&D World, create an account today!