San Antonio-based Southwest Research Institute (SWRI) has deployed the first electric vehicle aggregation system that supplements energy supply at an Army base in Colorado. It uses the new Society of Automotive Engineers 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, controls five DC fast-charge stations at the Fort Carson Army Base in Colorado Springs, Colo. Last month, the system passed integration and acceptance testing, successfully aggregating electric vehicles from two vehicle manufacturers equipped with SAE-compliant bidirectional charging interfaces.
SWRI says its system manages a fleet of electric vehicles, controlling vehicle charging and microgrid needs, supporting vehicle schedules as well as supplementing the base’s energy supply. 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.
The systems’ cyber security components meet military requirements, and variable charge and discharge controls precisely manage EV energy consumption or generation in real time, says SWRI.
According to a program manager at the institute, aggregating a fleet of vehicles using software control algorithms allows the microgrid to see the electric vehicles as a single energy resource. ‘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 is part of a team that last year was awarded a $7 million contract from the US Army Corps of Engineers to demonstrate integration of electric vehicles, generators and solar arrays to supply emergency power for Fort Carson. The team, led by Burns and McDonnell Engineering, built a microgrid out of existing electrical infrastructure at the Army post, integrating a 2-MW PV array, diesel generator sets and electric vehicles.