WIRELESS POWER TRANSMISSION SYSTEM FOR WIRELESSLY TRANSMITTING POWER TO PREVENT POWER SHORTAGE IN LOAD DEVICE OF WIRELESS POWER RECEIVING APPARATUS

A wireless power transmitting apparatus is provided with: a power transmitting circuit for transmitting power for a load device to a wireless power receiving apparatus; a signal transmitting circuit for transmitting a control signal for the load device to the wireless power receiving apparatus; a signal receiving circuit for obtaining an estimated received power level indicating a level of the power transmitted from the wireless power transmitting apparatus and received by the wireless power receiving apparatus; and a control circuit. The control circuit periodically allocates time slots to wireless power receiving apparatuses for wireless power transmission. When the received power level is smaller than a threshold in a first time slot allocated to one wireless power receiving apparatus, the control circuit extends a second time slot allocated to the one wireless power receiving apparatus, the second time slot preceding or following the first time slot.