POWER TRANSMISSION DEVICE AND METHOD OF CONTROLLING POWER TRANSMISSION DEVICE

A power transmission device includes a power transmission coil configured to supply electric power via a wireless connection to a power reception coil mounted on a vehicle, a cover covering at least the top surface of the power transmission coil in an axial direction, a foreign-matter detection coil provided between the power transmission coil and the cover, and an elevating mechanism configured to move the power transmission coil and the foreign-matter detection coil up and down with respect to the ground while keeping a gap between the power transmission coil and the foreign-matter detection coil. The foreign-matter detection coil is separated from the cover with a predetermined distance in the axial direction before detecting foreign matter.