Method and power transmitter for controlling power transmission

A power transmitter for controlling power transmission, the power transmitter comprising:

• a resonator;
• a power supply;
• a wireless communication unit configured to receive, from each of a plurality of power receivers, voltage information including a minimum voltage, a maximum voltage, and a first voltage, and to receive, from each of the plurality of power receivers, a respective report about a power reception condition while transmitting power, wherein each respective report includes a measured voltage at a corresponding power receiver of the plurality of power receivers;
• and
• a controller configured to:
• control the power supply to transmit the power to the plurality of power receivers through the resonator;
• select a power receiver from among the plurality of power receivers based on the received reports;
• and
• adjust an amount of the power by reducing a difference between a first voltage of the selected power receiver and a measured voltage of the selected power receiver.