WIRELESS CHARGING DEVICE, METHOD, AND SYSTEM

A wireless power receiving device according to an embodiment of the present specification is a wireless power receiving device that receives wireless power from a wireless power transmission device. The wireless power receiving device: receives wireless power from the wireless power transmission device at an operating frequency through magnetic coupling with the wireless power transmission device; communicates with the wireless power transmission device using at least one of in-band communication using the operating frequency and out-band communication using a frequency other than the operating frequency; transmits a swap inquiry message to the wireless power transmission device through one of the in-band communication and the out-band communication; and receives a response message to the swap inquiry message from the wireless power transmission device through the other of the in-band communication and the out-band communication, and determines whether to swap the wireless power transmission device.