Analysis of the Relay Multiple-Receiver WPT System

The magnetic coupling resonant Wireless Power Transfer (WPT) for multiple-receiver has a wide application prospect. In this paper the relay method is applied to multiple-receiver wireless power transfer systems. In order to analyze the energy efficiency of the multiple-receiver WPT system with relay coil, an equivalent method is proposed, in which the multiple-receiver system is equivalent to a single receiver model. It is proved that the multiple-receiver WPT with relay coil is more efficient than the general multiple-receiver system when the coupling coefficient between the transmitting coil and the relay coil is sufficiently large. It is pointed out that the multiple-receiver WPT system with relay coil is more suitable for long distance, small size, high load and so on. The conclusion is proved by numerical simulation.