A power feed system includes a power feed mat. The power feed mat includes a plurality of power transmission coils. The power feed mat is configured to feed power to at least one movable body on the power feed mat by using at least one of the plurality of power transmission coils. The power feed system further includes a computer. When the computer restricts power feed to at least one movable body among a plurality of movable bodies on the power feed mat, the computer selects the at least one movable body power feed to which is to be restricted, based on a priority of each of the plurality of movable bodies.

This application provides a foreign object detection method and apparatus, and a wireless charging system. The foreign object detection apparatus includes a coil array and a foreign object detection circuit. The coil array includes at least one coil group, and each coil group includes four detection coils whose locations are symmetrical to each other. The foreign object detection circuit determine an abnormal-value threshold of each coil group based on induction signals of each coil group and that are obtained in a first time period, and detect, based on the abnormal-value threshold and the induction signals of each coil group, whether there is a foreign object; when it is determined that there is no foreign object, detect, based on the signal threshold of each coil group and induction signals that are of each coil group and that are obtained in a second time period, whether there is a foreign object.

This application provides a foreign object detection method and apparatus, and a wireless charging system. The foreign object detection apparatus includes a coil array and a foreign object detection circuit. The coil array includes at least one coil group, and each coil group includes four detection coils whose locations are symmetrical to each other. The foreign object detection circuit determine an abnormal-value threshold of each coil group based on induction signals of each coil group and that are obtained in a first time period, and detect, based on the abnormal-value threshold and the induction signals of each coil group, whether there is a foreign object; when it is determined that there is no foreign object, detect, based on the signal threshold of each coil group and induction signals that are of each coil group and that are obtained in a second time period, whether there is a foreign object.

A power transfer system includes: a compact mobility; a ground unit disposed on a second lane which is a driving lane for the compact mobility, the ground unit being capable of wireless power transfer; and a controller that controls the ground unit. The compact mobility has an amount of electric power that can be stored less than a predetermined amount, and travels at a speed dependent on electric power wirelessly received from the ground unit. When a pedestrian is sensed in the second lane, the controller forces the compact mobility to decelerate by reducing transmission power from the ground unit to the compact mobility, as compared to when the pedestrian is not sensed in the second lane.

A power transfer system includes: a compact mobility; a ground unit disposed on a second lane which is a driving lane for the compact mobility, the ground unit being capable of wireless power transfer; and a controller that controls the ground unit. The compact mobility has an amount of electric power that can be stored less than a predetermined amount, and travels at a speed dependent on electric power wirelessly received from the ground unit. When a pedestrian is sensed in the second lane, the controller forces the compact mobility to decelerate by reducing transmission power from the ground unit to the compact mobility, as compared to when the pedestrian is not sensed in the second lane.

A vehicle for receiving power by noncontact from a power transmission apparatus of a ground power supplying apparatus, has: a power reception apparatus for receiving power from the power transmission apparatus; a vehicle side communication device for transmitting a signal including identification information of the vehicle to the ground power supplying apparatus by short range wireless communication; a lateral deviation detection device for detecting a deviation in a relative position of the power reception apparatus with respect to the power transmission apparatus; and a vehicle side control device for controlling the vehicle side communication device. The vehicle side control device controls the vehicle side communication device so that power is not transmitted from the ground power supplying apparatus when the deviation is detected.

A vehicle enabling confirmation of an end of power transfer from a ground power supplying apparatus at the vehicle side, that is, a vehicle receiving power from a ground power supplying apparatus by noncontact, provided with a power reception apparatus for receiving power from the ground power supplying apparatus and a control device configured to judge an end of power transfer from the ground power supplying apparatus based on a change along with time of received power received by the power reception apparatus.

A noncontact power supplying system transfers power by noncontact between a ground power supplying apparatus and a vehicle. The vehicle includes a power reception side resonance circuit for receiving power, and a signal emitting device for emitting an alternating magnetic field or electric wave for transmitting vehicle identification information of the vehicle to the ground power supplying apparatus. The ground power supplying apparatus includes a power transmission side resonance circuit for transmitting power to the power reception side resonance circuit, and a signal reception device for receiving an alternating magnetic field or electric wave emitted from the signal emitting device. The ground power supplying apparatus detects a relative positional relationship between the power transmission side resonance circuit and the power reception side resonance circuit, based on the strength of the alternating magnetic field or electric wave which the signal reception device receives.

A noncontact power supplying system transfers power by noncontact between a ground power supplying apparatus and a vehicle. The vehicle includes a power reception side resonance circuit for receiving power, and a signal emitting device for emitting an alternating magnetic field or electric wave for transmitting vehicle identification information of the vehicle to the ground power supplying apparatus. The ground power supplying apparatus includes a power transmission side resonance circuit for transmitting power to the power reception side resonance circuit, and a signal reception device for receiving an alternating magnetic field or electric wave emitted from the signal emitting device. The ground power supplying apparatus detects a relative positional relationship between the power transmission side resonance circuit and the power reception side resonance circuit, based on the strength of the alternating magnetic field or electric wave which the signal reception device receives.

An electric vehicle includes a power receiver and a controller. The power receiver is configured to wirelessly receive electric power from power transmission equipment disposed outside the vehicle. The controller is configured to control power transmission from the power transmission equipment to the power receiver. The controller includes a determination processor and a frequency control unit. The determination processor is configured to make a determination, in a case where the power transmission is stopped due to a foreign object present between the power transmission equipment and the vehicle, as to whether the power transmission is restartable with a predetermined frequency after the power transmission is stopped. The frequency control unit is configured to change the frequency with which the determination processor makes the determination.