Wireless power feeding system and method and wireless power transmission system

Abstract

To provide a wireless power feeding system and method and a wireless power transmission system, in which a decrease in power transmission efficiency is reduced even when an impedance of a load-side circuit varies. A wireless power feeding system 1 that transmits and receives power using magnetism includes a power transmission device 3 that includes a power transmission-side resonance circuit 36 including a power transmission coil 32 and a power feeding coil 31 that is provided to be capable of magnetic field coupling to the power transmission coil 32 and transmits power to be fed from its input end IE to the power transmission coil 32, and a power reception device 4 that includes a power reception-side resonance circuit 43 including a power reception coil 41 and feeds power received by the power reception coil 41 to a load 8, and an impedance matching mechanism 9 that performs impedance matching processing for alleviating a difference between a load-side impedance as an impedance of a circuit on a load 8 side from the input end IE of the power transmission device 3 and an input-side impedance as an impedance of a circuit on an AC power supply 5 side from the input end IE of the power transmission device 3 by changing a coupling strength in magnetic-field coupling between the power feeding coil 31 and the power transmission coil 32.

Dependencies are inferred from the claim text.