Abstract
Electric vehicles (EVs) are expected to play a leading role in the changeover from fossil fuels to clean energy. However, EVs are currently not very popular. This is because of their short cruising distance and long charging time. Wireless power transfer from infrastructure to running EVs is expected to be the solution to these problems. Electric Vehicle on Electrified Roadway (EVER) has been proposed as a wireless power transfer system to EVs in motion. Via-wheel power transfer (V-WPT) is expected to be a wireless power transfer scheme for EVER. We designed and prototyped a 1/32 scaled model of a V-WPT system that comprises an RF inverter, an electrified roadway, a rectifier, and DC-motor EV. The output power of the prototype RF inverter is 5.9W, and the DC-RF conversion efficiency is 36.6%. LC matching circuits for the V-WPT are designed with two-port conjugate matching because the S11 of the V-WPT was intrinsically -0.06dB. After matching, the S11 value is reduced to -21.5dB. The power transmission efficiency of the V-WPT system is 75%. The RF-DC conversion efficiency of the rectifier is 62%. The total efficiency of EVER system is 24.2%.
