POWER TRANSMISSION DEVICE AND WIRELESS POWER TRANSMISSION SYSTEM

摘要

A power transmission device includes an inverter, an oscillator, a foreign substance detector, and a power transmission control circuitry. The power transmission control circuitry causes the foreign substance detector to perform a series of multiple processes and determine whether a foreign substance is present before a transmission of first AC power starts, and then causes the inverter to start the transmission of the first AC power. After the transmission starts, a detection period in which foreign substance detecting is performed and a power transmission period in which transmission of the first AC power is performed are repeated. The series of multiple processes is divided and performed in the multiple repeated detecting periods. The foreign substance detector is caused to divide and perform the series of multiple processes using the detecting periods and determine whether a foreign substance is present.

主权项

1. A power transmission device comprising:
an inverter that generates first AC power and transmits the first AC power wirelessly to a first resonator of a power receiving device via a second resonator; an oscillator that generates second AC power which is smaller than the first AC, and transmits the second AC power to the first resonator via a third resonator; a foreign substance detector that performs a series of multiple processes thereby to determine whether or not a foreign substance is present between the first resonator and the third resonator based on a physical quantity at the third resonator, the physical quantity varying depending on the second AC power; and power transmission control circuitry operative to: cause the foreign substance detector to perform the series of multiple processes before a start of a transmission of the first AC power; cause the inverter to start the transmission of the first AC power if the foreign substance detector determines that the foreign substance is not present; repeat a foreign substance detection period and a power transmission period alternately where the foreign substance detection period is a period in which the foreign substance detector performs one of the series of multiple processes and the power transmission period is a period in which the inverter transmits the first AC power, after the start of the transmission of the first AC power; and cause the foreign substance detector to divide the series of multiple processes and determine whether or not the foreign substance is present as a result of performing all of the divided series of multiple processes.