Purdue University researchers have demonstrated a high-power wireless charging system capable of delivering significantly more energy to electric vehicles than previously tested systems in the U.S. During testing on a roadway segment in West Lafayette, Indiana, the system transferred 190 kilowatts to a Class 8 battery-electric truck traveling at 65 mph.
“To put that in perspective, 200 kilowatts is roughly the power demand of about 100 homes,” said Steve Pekarek, professor of electrical and computer engineering at Purdue.
High-Power Wireless Charging Focused On Trucks
The system was designed to meet the power requirements of heavy-duty trucks first, with the ability to support lower-power vehicles as well.
“This design supports everything from the heaviest trucks to passenger vehicles,” said Aaron Brovont, research assistant professor in Purdue’s Elmore Family School of Electrical and Computer Engineering.
Because trucking contributes more to U.S. gross domestic product than other freight modes, researchers say reducing operating costs for electric trucks could help accelerate investment in electrified highways. If trucks can charge while driving, battery sizes could be reduced, allowing for higher payload capacity and lower vehicle costs.
A Class 8 electric truck travels over a wireless charging test lane while receiving power during on-road testing in Indiana.
Electrified highways could also enable smaller battery packs for passenger vehicles, addressing range anxiety and vehicle cost concerns.
“Battery size drives much of the cost in electric vehicles,” said John Haddock, professor in Purdue’s Lyles School of Civil and Construction Engineering. “Charging while driving would reduce the need for large battery packs.”
System Design And On-Road Testing
The Purdue system uses embedded transmitter coils installed in dedicated highway lanes. These coils send power wirelessly to receiver coils mounted underneath the vehicle, similar in concept to smartphone wireless charging but at much higher power levels.
“Wireless power transfer at these distances is challenging, especially for heavy-duty vehicles operating at very high power,” said Dionysios Aliprantis, professor of electrical and computer engineering at Purdue.
Transmitter coils installed beneath concrete pavement deliver wireless power to electric vehicles through magnetic fields as they drive over the roadway.
Cummins collaborated with Purdue to adapt a prototype Class 8 battery-electric truck for the on-road testing.
“The testing demonstrated strong performance and collaboration,” said John Kresse, chief technology engineer at Cummins. “The power levels and cost structure show potential for on-highway commercial transportation.”
Unlike other systems that require multiple low-power receiver coils, the Purdue design uses a single receiver assembly mounted under the tractor, simplifying system integration.
Infrastructure Integration And Industry Collaboration
The Indiana Department of Transportation embedded the transmitter coils into concrete pavement, which carries the heaviest traffic despite representing only about 20% of the interstate system.
Most U.S. wireless charging roadway projects are led by members of Aspire, a national consortium focused on electrified transportation. Purdue is a founding member of Aspire, which is headquartered at Utah State University and includes 10 partner universities and more than 70 industry, government, and nonprofit organizations.
A test segment of highway near Purdue University was modified to support dynamic wireless charging for electric trucks traveling at highway speeds.
“This work shows how collaboration across public agencies, industry, and academia can advance electrified transportation,” said Don Linford, director of industry and ecosystem engagement for ASPIRE.
Toward Industry Standards For Electrified Highways
The system is also being used to support the development of industry standards for dynamic wireless power transfer. Researchers say standardized designs would be critical for departments of transportation considering roadway-based charging infrastructure.
Future demonstrations are planned for additional vehicle classes, including light-duty vehicles.
In April, the Purdue team received the Technology Innovation Award at the IEEE PES Energy and Policy Forum Innovation Showcase.
“This project shows how research can move from the lab to real-world infrastructure,” said Gkritza.
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