A wireless power transmitter configured to transfer power to a wireless power receiver, including a coil assembly comprising first and second bottom coils placed adjacent to each other in a line and each consisting of a single layer of 11 turns and a top coil stacked on the first and second bottom coils and consisting of a single layer of 12 turns; and a full-bridge inverter. The first and second bottom coils and the top coil have a substantially rectangular frame structure with a through hole in the center, wherein the top coil lies on a plane surface in the middle between the first and second bottom coils, a distance from the center of the first and second bottom coils to the center of the top coil is set to a range of 21 mm to 25 mm, the first and second bottom coils have a height of 48 mm to 50 mm and a width of 43 mm to 45 mm, and the through hole in the first and second bottom coils has a height of 25 mm to 27 mm and a width of 21 mm to 23 mm, the top coil has a height of 45 mm to 47 mm and a width of 48.5 mm to 50.5 mm, and the through hole in the top coil has a height of 20 mm to 22 mm and a width of 24.5 mm to 26.5 mm, the first and second bottom coils and the top coil have a thickness of 0.9 mm to 1.3 mm, the wireless power transmitter uses an input voltage of the full-bridge inverter to control an amount of power which is transferred, the input voltage has a range of 1 V to 18 V, wherein an operating frequency to control the amount of the power is within a range of 140 kHz to 150 kHz, and the first and second bottom coils and the top coil have a inductance value within a range of 10.6 μH to 12.0 μH.

A wireless power transmission device for a vehicle and a method are provided. The wireless power transmission device for a vehicle may transmit a signal for detection of a wireless power reception device by using a lower frequency band that is different from an operating frequency band used to control the vehicle. The wireless power transmission device may receive a response signal for the transmitted signal and a power control signal from the wireless power reception device. The wireless power transmission device may control an operating frequency or a voltage (or both) in the wireless power transmission device for the vehicle according to the power control signal. The wireless power transmission device may transmit wireless power to the wireless power reception device.

A wireless power transmission device for a vehicle and a method are provided. The wireless power transmission device for a vehicle may transmit a signal for detection of a wireless power reception device by using a lower frequency band that is different from an operating frequency band used to control the vehicle. The wireless power transmission device may receive a response signal for the transmitted signal and a power control signal from the wireless power reception device. The wireless power transmission device may control an operating frequency or a voltage (or both) in the wireless power transmission device for the vehicle according to the power control signal. The wireless power transmission device may transmit wireless power to the wireless power reception device.

A power transmission device wirelessly transmits electric power to a power reception device. A power transmission coil is configured by winding a conductive wire. A foreign object detection device detects a foreign object. Sensor coils are placed to cover the power transmission coil. A detector executes determination processing of determining existence of the foreign object on each of the sensor coils, based on a comparison result between a comparison target value based on output voltage output from one sensor coil of the sensor coils and a threshold value set to the one sensor coil. The detector executes threshold value change processing of changing the threshold value set to the one sensor coil on each of the sensor coils, based on induced voltage induced in the one sensor coil by magnetic flux generated by the power transmission coil.

A power transmission device wirelessly transmits electric power to a power reception device. A power transmission coil is configured by winding a conductive wire. A foreign object detection device detects a foreign object. Sensor coils are placed to cover the power transmission coil. A detector executes determination processing of determining existence of the foreign object on each of the sensor coils, based on a comparison result between a comparison target value based on output voltage output from one sensor coil of the sensor coils and a threshold value set to the one sensor coil. The detector executes threshold value change processing of changing the threshold value set to the one sensor coil on each of the sensor coils, based on induced voltage induced in the one sensor coil by magnetic flux generated by the power transmission coil.

A wireless power-supply system (1) performing a wireless power supply between a vehicle (10) and a stop station (20), wherein the wireless power-supply system includes a heat-transfer device (30). The heat-transfer device (30) transfers heat generated due to the wireless power supply to the stop station (20) having high heat capacity from the vehicle (10) having low heat capacity. The heat-transfer device (30) includes a flexible heat-transfer member (32), in which the flexible heat-transfer member has tiltability in a moving direction of the vehicle (10).

A detection device includes a detection mat having a plurality of detection coils, and at least one pair of groups of detection coils, the pair of groups of detection coils includes first and second groups of detection coils. The first and second group of detection coils comprises first and second first and second impedance values. The detection device includes one or more drive sub-systems and a comparison sub-system. The drive sub-systems are operatively coupled to the detection mat and configured to excite at least one pair of groups of detection coils. The comparison sub-system is operatively coupled to the detection mat and configured to receive a differential current signal from the pair of groups of detection coils, the comparison subsystem is configured to generate a control signal based on the differential current signal.

A detection device includes a detection mat having a plurality of detection coils, and at least one pair of groups of detection coils, the pair of groups of detection coils includes first and second groups of detection coils. The first and second group of detection coils comprises first and second first and second impedance values. The detection device includes one or more drive sub-systems and a comparison sub-system. The drive sub-systems are operatively coupled to the detection mat and configured to excite at least one pair of groups of detection coils. The comparison sub-system is operatively coupled to the detection mat and configured to receive a differential current signal from the pair of groups of detection coils, the comparison subsystem is configured to generate a control signal based on the differential current signal.

An assembly and method are provided for detecting an object within a wireless charging region of an electric vehicle. The method includes applying by a controller, a voltage to the wireless charging region to generate a capacitance value and measuring by the controller, the capacitance value of an electromagnetic shield disposed on the underside of the vehicle. Further, the controller monitors the capacitance value of the electromagnetic shield; and the controller detects a change in the capacitance value when the object enters the wireless charging region.

A wireless electric vehicle charging system comprises base-side equipment for generating a magnetic field and vehicle-side equipment for receiving energy via the magnetic field to supply power to a vehicle-driving battery. Monitoring circuitry monitors one or more of voltage, current, or phase associated with the base-side equipment and halts generation of the magnetic field in response to a change in the voltage, current, or phase associated with the operation of the base-side equipment that indicates a fault condition at the vehicle-side equipment, which may include a loss of power or disconnection of a battery. Based on detection of the change, the monitoring circuitry can halt generation of the magnetic field to prevent damage at the vehicle-side equipment.