POWER SUPPLY APPARATUS

A power supply system includes a first power supply apparatus and a second power supply apparatus. The second power supply apparatus includes a power transmission controller and a receiver. The power transmission controller transmits a power transmission signal for power supply. The receiver receives information on a wireless system to which neither the first power supply apparatus nor the second power supply apparatus belongs from the first power supply apparatus. The power transmission controller determines at least one of a transmission time at which the power transmission signal is transmitted, a transmission direction in which the power transmission signal is transmitted, a power level of the power transmission signal, or a frequency of the power transmission signal, using the information on the wireless system, and transmits the power transmission signal based on this determination.