METHOD FOR TRANSMITTING WIRELESS POWER IN WIRELESS CHARGING SYSTEM INCLUDING A WIRELESS POWER TRANSMITTING UNIT AND WIRELESS POWER RECEIVING UNIT

A method for transmitting wireless power in a wireless charging system and a wireless power transmitting unit (PTU) are provided. The method for transmitting wireless power in a wireless charging system includes receiving information related to a voltage from each of a plurality of power receiving units (PRUs), identifying a voltage ratio of each of the plurality of PRUs based on the received information where the voltage ratio is a current voltage relative to a first voltage, determining a PRU among the plurality of PRUs based on the identified voltage ratio, and adjusting transmission power according to a voltage setting value of the determined PRU.