Study on the principle of contactless electric power transfer via electromagnetic coupling

Abstract

In recent years, contactless transfer of electric power has received worldwide attention. Among many contactless electric power transmission systems, an electromagnetic resonant system showed a remarkable ability to turn on a 60 watt light bulb that was at a distances of 2 meters from a power source. Several papers that explain the principle of the system have been published, but an analytical explanation of this principle has not been provided. In this paper, the author provides an analytical explanation of the principle behind the power transfer system. The analysis can facilitate the evaluation of the characteristics of the system, such as resonant frequencies, transferable power, efficiency, coil voltages, etc., and may be useful in the synthesis of contactless power transfer systems. © 2011 The Institute of Electrical Engineers of Japan.