Researchers at Oak Ridge National Laboratory demonstrated a 20-kilowatt bi-directional wireless charging system on a UPS plug-in hybrid electric delivery truck, advancing the technology to a larger class of vehicles and enabling a new energy storage method for fleet owners and their facilities.
The demo was the first of its kind to achieve high power transfer across an 11-inch air gap between the truck and a charging pad. Specially designed electromagnetic coils and power electronic converters transferred electricity from the grid to the vehicle battery terminals at more than 92% efficiency.
At a 20-kilowatt level, it would take about three hours to charge the vehicle’s battery packs; conventional wired charging takes between five and six hours. With its bi-directional design, the system supports use of the vehicle’s batteries for energy storage.
“The system expands the possibilities for fleets that want convenient, efficient electric vehicle charging as well as electricity storage solutions,” said ORNL’s Omer Onar.