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.

A foreign object detection device detects, during wireless power transfer from a power transmission unit of a power transmission device to a power reception unit of a power reception device, a foreign object on the power transmission unit, and comprises: a temperature sensitive body that is disposed at the power transmission unit and changes a color with temperature; and a detection unit that detects the foreign object by detecting a change in the color.

A foreign object detection device detects, during wireless power transfer from a power transmission unit of a power transmission device to a power reception unit of a power reception device, a foreign object on the power transmission unit, and comprises: a temperature sensitive body that is disposed at the power transmission unit and changes a color with temperature; and a detection unit that detects the foreign object by detecting a change in the color.

One aspect of the present invention pertains to a method of charging electric storage devices such as batteries. Another aspect of the present invention pertains to a system for charging electric storage devices such as batteries. Another aspect of the present invention pertains to a mobile apparatus for charging electric storage devices such as batteries.

One aspect of the present invention pertains to a method of charging electric storage devices such as batteries. Another aspect of the present invention pertains to a system for charging electric storage devices such as batteries. Another aspect of the present invention pertains to a mobile apparatus for charging electric storage devices such as batteries.

The present disclosure describes techniques for detecting foreign objects. In some aspects, an apparatus for detecting objects is provided. The apparatus includes a plurality of sense circuits, each of the plurality of sense circuits including a primary sense coil having a first terminal and a second terminal, a secondary sense coil having a first terminal and a second terminal, and a capacitor having a first terminal and a second terminal. The first terminal of the capacitor is electrically connected to the second terminals of each of the primary sense coil and the secondary sense coil. The apparatus further includes a driver circuit electrically connected to the first terminal of the primary sense coil of each of the plurality of sense circuits. The apparatus further includes a measurement circuit electrically connected to the first terminal of the secondary sense coil of each of the plurality of sense circuits.

The invention relates to a sensor arrangement (140) for a foreign object detection device which includes a current input (142) and a current output (143), a multitude of detection cells (144.1-144.9), each comprising a sense coil and a capacitive element, forming a resonant tank. The sensor arrangement (140) further has a multitude of inputs leads (148a-148c) and a multitude of output leads (150a-150c), the total number of input and output leads being equal or smaller than the number of detection cells (144.1-144.9). Each detection cell is connected between one of the input leads (148a-148c) and one of the output leads (150a-150c), in a way that each of the detection cells (144.1-144.9) is connected to a different pair of input and output leads (148a-148c, 150a-150c). An input selection circuit (152) allows to selectively establish an electrical connection between the current input (142) and one or more of the input leads (148a-148c) and an output selection circuit to (153) selectively establish an electrical connection between one or more of the output leads (150a-150c) and the current output (143). According to the invention at least one detection cell (144.1-144.9) includes a decoupling element (D1-D9) connected in series to its resonant tank. The invention further relates to foreign object detection device for a wireless power transfer system, a primary part of a wireless power transfer system, a wireless power transfer system and a method for detecting a foreign object.

The invention relates to a sensor arrangement (140) for a foreign object detection device which includes a current input (142) and a current output (143), a multitude of detection cells (144.1-144.9), each comprising a sense coil and a capacitive element, forming a resonant tank. The sensor arrangement (140) further has a multitude of inputs leads (148a-148c) and a multitude of output leads (150a-150c), the total number of input and output leads being equal or smaller than the number of detection cells (144.1-144.9). Each detection cell is connected between one of the input leads (148a-148c) and one of the output leads (150a-150c), in a way that each of the detection cells (144.1-144.9) is connected to a different pair of input and output leads (148a-148c, 150a-150c). An input selection circuit (152) allows to selectively establish an electrical connection between the current input (142) and one or more of the input leads (148a-148c) and an output selection circuit to (153) selectively establish an electrical connection between one or more of the output leads (150a-150c) and the current output (143). According to the invention at least one detection cell (144.1-144.9) includes a decoupling element (D1-D9) connected in series to its resonant tank. The invention further relates to foreign object detection device for a wireless power transfer system, a primary part of a wireless power transfer system, a wireless power transfer system and a method for detecting a foreign object.

The processing part is configured to calculate an elapsed time from an inspection date or installation date of a power transmission apparatus installed at a location of occurrence of an abnormality to a date of occurrence of an abnormality based on the inspection information and information on occurrence of an abnormality relating to the location of occurrence of an abnormality and date of occurrence of the abnormality where the power transfer efficiency from the power transmission apparatus to the power reception apparatus received from the mobile object through the communication part becomes less than a predetermined value, and is configured to judge an operating state of the power reception apparatus based on the elapsed time.

An abnormality judgment apparatus provided with a processing part, a communicating part able to communicate with a mobile object provided with a power reception apparatus receiving power wirelessly transmitted from a power transmission apparatus installed on a road, and a storage part storing power reception history information received from the mobile object. The processing part calculates a probability of occurrence of an abnormality in the power reception apparatus of the mobile object based on the power reception history information and detects a presence of an abnormality occurring location where the power transfer efficiency becomes less than a predetermined value and judges that an abnormality has occurred in the power transmission apparatus installed at the abnormality occurring location when an abnormality occurring location is detected and the probability becomes less than a predetermined judgment threshold value.