Researchers demonstrate dielectric coupling between steel belt in tire and metal plate in roadway for EV power
Researchers at Toyohashi University of Technology (Japan) have demonstrated the transfer of electric power from wheels to power an electric car using dielectric coupling between a steel belt in a tire and a metal plate in a roadway. A paper on their work is published in IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission.
The approach exploits the steel belt usually embedded in rubber tires. The steel belt collects power excited from a pair of electrodes buried beneath the road surface. Since the steel belt is electrically insulated by the rubber tread, the researchers used a displacement current at high frequency to penetrate from underground to the steel belt.
The researchers constructed a 1/32 scale EV as a proof of concept. The car moved successfully with a power penetration efficiency exceeding 75% at 52 MHz—the first demonstration of electric power transfer via the car-wheel to the vehicle.
Y. Suzuki, T. Sugiura, N. Sakai, M.Hanazawa, and T. Ohira (2012) Dielectric Coupling from Electrified Roadway to Steel-Belt Tires Characterized for Miniature Model Car Running Demonstration. IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission, IMWS-IWPT2012, pp.35-38 doi: 10.1109/IMWS.2012.6215814