Advanced science.  Applied technology.


SwRI deploys novel vehicle-to-grid aggregation system

For immediate release

San Antonio — Sept. 9, 2013 — Southwest Research Institute (SwRI) has deployed the first electric vehicle (EV) aggregation system using the new Society of Automotive Engineers (SAE) standard for bidirectional power using direct current (DC) fast charging. The system, part of the Smart Power Infrastructure Demonstration for Energy Reliability and Security (SPIDERS) Phase II program, is controlling five DC fast-charge stations at the Fort Carson Army Post in Colorado Springs, Colo. In August, the system passed integration and acceptance testing, successfully aggregating electric vehicles from two vehicle manufacturers equipped with SAE-compliant bidirectional charging interfaces.

"The SwRI aggregation system manages a fleet of electric vehicles, controlling both vehicle charging and microgrid needs and supporting vehicle schedules as well as supplementing the base's energy supply," said Sean Mitchem, project manager and a principal analyst in SwRI's Automation and Data Systems Division.

"SPIDERS is pioneering a new way of managing energy," said Yaxi Liu, a research analyst also in the Automation and Data Systems Division. "The batteries in electric vehicles are used as cushions against fluctuations in the grid, creating more stability and resiliency while improving its ability to accommodate renewable energy. This helps satisfy goals of reducing dependence on fossil fuels and the impact of emissions."

The aggregation system features a distributed architecture with a dynamic capacity for self-recovery to ensure maximum reliability and redundancy in the military environment. Cyber security components meet military requirements, and variable charge and discharge controls precisely manage EV energy consumption or generation in real time.

"Aggregating the fleet of vehicles using software control algorithms allows the microgrid to see the electric vehicles as a single energy resource," said Mitchem. "Reactive power management allows chargers to absorb or inject power to better manage energy resources, particularly variable energy produced by a solar energy array at the base. Using this new technology, electric vehicles can use or store this green energy more efficiently than previously was possible."

The aggregation system is an important component of the SPIDERS Secure Microgrid project because it allows EVs to participate in vehicle-to-grid (V2G) services, such as peak shaving, demand charge mitigation, and frequency regulation. These V2G services allow the base to save on energy costs with the potential to generate income by participating as an ancillary service in energy markets.

SwRI's electric vehicle aggregation system is an integrated component of the SPIDERS Secure Microgrid. The SPIDERS project is led by Burns and McDonnell Engineering Company, Inc. Working with SwRI on the electric vehicle system are Intelligent Power and Energy Research Corporation (IPERC) as the microgrid control developer, Coritech Services Inc. for the electric vehicle charging systems, and Boulder Electric Vehicles and Smith Electric Vehicles as the electric vehicle suppliers.

For more information, contact Deb Schmid at (210) 522-2254, Communications Department, 6220 Culebra Road, San Antonio, TX 78238-5166.