Power feeding system and vehicle

A power feeding system, comprising:

• a power feeding installation;
• and
• a power receiving unit to which the power feeding installation feeds power;
• wherein:
• the power feeding installation has:
• a power supply device that produces power having a predetermined frequency a power transmission resonator that receives the power produced by the power supply device and generates an electromagnetic field via which the power is wirelessly transmitted to the power receiving unit, and
• a first communication device that sends power information on power at the power feeding installation to the power receiving unit;
• and
• the power receiving unit has:
• a power receiving resonator that wirelessly receives the power from the power transmission resonator by resonating with the power transmission resonator via the electromagnetic field,
• an impedance matching device that includes a variable impedance circuit so as to be capable of adjusting an impedance at a resonance system that is constituted of the power transmission resonator and the power receiving resonator,
• a second communication device that receives the power information sent from the first communication device, and
• a controller that controls the impedance matching device based on the power information received by the second communication device, said controller being capable of adjusting an impedance at the variable impedance circuit so that an input impedance at the resonance system is matched to an impedance at a section including the power supply device and adjacent to the resonance system.