Wireless power transmission system for optimal power transmission, and method for controlling optimal resonance frequency of same system

A wireless power transfer system for optimal power transfer using magnetic resonant coupling in which a metal object is provided near a transmitter, the wireless power transfer system comprising:

• the transmitter configured to transmit power by including an AC/DC conversion circuit, a DC/RF conversion circuit, a matching circuit, a transmitting coil, a control circuit, and a communication circuit;
• and
• a receiver configured to receive power by including a receiving coil, a matching circuit, a rectifier circuit, a stabilization circuit, a DC/DC conversion circuit, a control circuit, and a communication circuit, wherein:
• the system is configured to control reception power of the receiver by controlling a frequency of transmission power from the transmitter, and
• a resonance unit of the receiver including the receiving coil and the matching circuit of the receiver is designed so that a Q (quality factor)-value of the resonance unit defined by Mathematical Formula 1 is less than a preset value:
• =
• f
• resonance
• ⁢
• frequency
• f
• 2
• -
• f
• 1
• [
• Mathematical
• ⁢
• Formula
• ⁢
• 1
• ]
• where the Q-value is a full width at half maximum (FWHM), and is defined as a value obtained by dividing a resonance frequency by a frequency (f2, f1) width at half a maximum power transmission/reception performance value shown at the resonance frequency.