The licensed PNNL technology can help stabilize the electrical grid by continuously monitoring the grid’s alternating current (AC) frequency and varying the vehicle charging rate in response. Additionally, in the event of a rapid drop in grid frequency, the charging system stops charging, providing a grid “shock absorber.”
Such rapid frequency drops, while small in overall magnitude, indicate that a fault condition has occurred somewhere on the grid and that there is an imbalance between load and electricity generation. By reducing load the system can be rebalanced.
As renewable generation sources such as wind and solar grow in overall share, the overall frequency-responsive generation capability provided by conventional power plants is gradually decreasing. AeroVironment and PNNL’s frequency-responsive technology brings this same grid frequency support capability to PEV charging stations.
With millions of plug-in electric vehicles charging at any given time, modulating the aggregate charging rate of PEVs can help control grid frequency and support the integration of variable renewable generation sources, such as wind and solar.
“Vehicle charging infrastructure is important for the market adoption of electric vehicles and plug-in hybrid electric vehicles,” said Dan Ton, DOE’s program manager of Smart Grid Research and Development.
“We need charging stations and we need them to be intelligent in order to work with smart vehicles and smart grid infrastructure to avoid potential strain on the grid and to provide flexible billing transactions for energy and grid services,” Ton added.