One-kilowatt capacitive Power Transfer via wheels of a compact Electric Vehicle

This paper demonstrates 1 kW power transfer to an Electric Vehicle on Electrified Roadway prototype. To gain a sufficient efficiency to drive the motor onboard, we create a high-kQ capacitive coupling scheme of Via-Wheel Power Transfer. To enhance kQ, newly developed wheel uprights play the pivotal role in effective electrical insulation of the wheels from the vehicle frame. We also develop 1 kW impedance matching circuits based on the simultaneous two-port conjugate matching theory. As a result, the measured power transfer efficiency exceeds 80 %. The driving wheels successfully ran at a speed of up to 10 km/h on roller stands.