RESONANT FREQUENCY SEARCH DEVICE, RESONANT FREQUENCY SEARCH METHOD AND PROGRAM

PROBLEM TO BE SOLVED: To provide a resonant frequency search device that is suited to implement an extremum search through a resonant frequency in a transmitting device for power transmission from the transmitting device to a receiving device.SOLUTION: A resonant frequency search section 11 searches for a resonant frequency of a transmitting device 3 for transmitting power to a receiving device 5. A gradient computation section 15 first determines a gradient of a physical quantity measured in accordance with a perturbation signal in the transmitting device while the transmitting device 3 transmits power to the receiving device 5. A perturbation amplitude determination section 17 reduces a perturbation amplitude as the physical quantity approaches a maximum value (or minimum value). A frequency change section 19 changes the frequency of the perturbation signal on the basis of the gradient of the physical quantity.