Masahiro Kusunoki

Reduce of electric ner-field intensity by a shield box in wireless power transfer via field resinance coupling

Wireless Power transfer using electric field can realize highly efficient electrical power transmission and the transmission units are thin and light. However, the transmission system produces large electric field intensity and the electric field noise can make other electronic devices malfunction. A shield box is greatly effective to reduce the electric intensity 60dB without a decline of transmission efficiency. The distance between the shield box and the transmission unit should be a half of the transmission distance between a transmitter and a receiver. The shield box can attenuate the intensity behind the box less than 100V/m in case of 1kW transmission.

Wireless Power Transfer via Electric Field Resonance Coupling

Wireless power transfer systems using electric fields have been investigated mainly for power transfer over extremely close regions. Using an electromagnetic field simulator, we have made a prototype of an LC series type resonance coupler made from a coil and electrode. When the distance between the transmission and reception couplers was varied, it was found that a transfer efficiency of 90% or more was achieved at a distance of 180 mm. Also a large power transfer test was carried out in which it was found that it was possible to transfer 838 W of power.