Apparatus and method for wireless power reception, apparatus and method for wireless power transmission, and wireless power transmission system

An apparatus for receiving power wirelessly, the apparatus comprising:

• a target resonator configured to receive power wirelessly from a source resonator;
• a power converter configured to convert the received power into a form and a level that corresponds to a load;
• and
• a matching unit configured to connect a passive device to the power converter in series or in parallel to match an input impedance of the power converter and an output impedance of the target resonator,
• wherein the passive device is configured to control a connection between the passive device and the power converter to be in parallel or to be in series in response to a passive device of a wireless power transmitter connected to a power supply unit of the wireless power transmitter in parallel or series, and
• wherein the passive device of the wireless power transmitter is configured to connect to the power supply unit of the wireless power transmitter in parallel or in series according to an output impedance of the power supply unit, which changes based on a change in load impedance and a number of the target resonator.

A method of transmitting power wirelessly, the method comprising:

• supplying power from a power supply unit to a source resonator;
• connecting a passive device to the power supply unit in series or in parallel to match an output impedance of the power supply unit and an input impedance of the source resonator;
• and
• transmitting power wirelessly to a target resonator through a mutual resonance between the source resonator and the target resonator,
• wherein the passive device is configured to control a connection between the passive device and the power supply unit to be in series or to be in parallel according to the output impedance which changes based on a change in load impedance and a number of the target resonator, and
• wherein the input impedance changes to match the changed output impedance.

A method of receiving power wirelessly, the method comprising:

• connecting a passive device to a power converter in series or in parallel to match an input impedance of the power converter and an output impedance of a target resonator;
• receiving power wirelessly from a source resonator through a mutual resonance between the target resonator and the source resonator;
• and
• converting the received power into a form and a level that corresponds to a load,
• wherein the passive device is configured to control a connection between the passive device and the power converter to be in parallel or to be in series in response to a passive device of a wireless power transmitter connected to a power supply unit of the wireless power transmitter in parallel or series, and
• wherein whether the passive device of the wireless power transmitter is to be connected to the power supply unit of the wireless power transmitter in parallel or series according to an output impedance of the power supply unit, which changes based on a change in load impedance and a number of the target resonator.