Abstract: A power transmission apparatus supplies power to a power reception apparatus without contact therebetween. The power transmission apparatus includes: a power conversion unit that outputs an alternating-current voltage of a predetermined frequency; a power transmission unit that has a power transmission coil and a capacitor that is connected to the power transmission coil; a transmission line that connects the power conversion unit and the power transmission unit; and a compensator that is disposed between the power conversion unit and the transmission line. The compensator includes: an inductive reactance element that has an inductive reactance that is greater than an inductive reactance of the transmission line; and a capacitor that reduces an inductive reactance that is a sum of an inductive reactance of the transmission line and an inductive reactance of the inductive reactance element. The inductive reactance element and the capacitor are connected.

Abstract: A power receiving device performs a power supply control including repeatedly performing: first rectification mode in which in response to detection of an energization of a first bridge circuit, a first high-side and a second low-side switches are turned on and a first low-side and a second high-side switches are turned off; and second rectification mode in which in response to detection of an energization of a second bridge circuit, the first low-side and the second high-side switches are turned on and the first high-side and the second low-side switches are turned off, and a power adjustment control including: first commutation mode in which the first high-side switch is turned off and the first low-side switch is turned on during the first rectification mode; and second commutation mode in which the second high-side switch is turned off and the second low-side switch is turned on during the second rectification mode.

Abstract: A contactless power feeding apparatus includes a plurality of primary coils mounted on a road and a power feed controller which uses a portion of the primary coils as a power transmitting coil to achieve delivery of electrical power from the power transmitting coil to a secondary coil mounted in a vehicle. The power feed controller uses a selected primary coil that is one of the primary coils other than the power transmitting coil to decrease a leakage of magnetic flux arising from excitation of the power transmitting coil. Instead of the selected primary coil, the secondary coil may be used to reduce the leakage of magnetic flux.

Abstract: A first power supply unit rectifies, to first DC power, external AC power that is wirelessly received by a power receiving coil using magnetic coupling. The first power supply unit supplies the converted first DC power to one or more loads as main power. A second power supply unit is connected to an input stage of the first power supply unit, and outputs second DC power used for control of the first power supply unit. This makes it possible to stably ensure the second DC power used for control of the first power supply unit even if the one or more loads are configured to receive power from the first power supply unit.

Abstract: A power output circuit includes a plurality of circuit blocks that are provided in power wirings to which power is inputted and connected to each other side by side. Each of the plurality of circuit blocks includes at least a filter in a last post-stage. Each of the plurality of filters includes a reactor and a capacitor connected to the reactor at a node differing from an output node. Either of the reactor and the capacitor provided in each of the plurality of filters is connected to the power wirings in series so as to connect with the output node. A connection line between the reactor and the capacitor in one filter is connected to a connection line between the reactor and the capacitor in the remaining other filter.

Abstract: A wireless power transfer system comprises: a power conversion unit generating power to be transmitted to a power reception coil; a power transmission unit group constituted by two or more power transmission units, each power transmission unit having a power transmission circuit including a power transmission coil; a control unit controlling supply of power from the power conversion unit to the power transmission unit group; and a position detection unit detecting a position of a mobile body. The control unit, based on position information, supplies power from the power conversion unit to a power transmission unit group that satisfies a power transmission condition including that a distance of the power transmission coil relative to the power reception coil of the mobile body is less than or equal to a predetermined threshold, and does not supply power to a power transmission unit group that does not satisfy the power transmission condition.

Abstract: A wireless power supply apparatus that supplies power to a reception apparatus in a wireless manner, the wireless power supply apparatus including: a power source apparatus that outputs an AC power, a transmission coil electrically connected to the power source apparatus; and a setting circuit interposed between the power source apparatus and the transmission coil, setting the transmission coil to be in either a power feeding state or a standby state, wherein the setting circuit is provided separately from the power source apparatus.

Abstract: A wireless power transmission system is provided which wirelessly transfer electric power from a power transmitter to a power receiver. The wireless power transmission system works to set a capacitance of a primary capacitor of a primary resonant circuit to undergo resonance with a self-inductance of a primary coil at an angular frequency that is an operating frequency. A tertiary capacitor of a tertiary resonant circuit has a capacitance set to undergo resonance with a self-inductance of a tertiary coil. A secondary capacitor of a secondary resonant circuit has a capacitance set to reduce a reactive component of ac power arising from self-inductances and mutual inductances of the primary coil, the secondary coil, and the tertiary coil.

Abstract: A period for performing pre-power-supply check prior to main power supply from a power supply device to a power reception device is provided and, a power-receiving-side controller is configured to: check a supplied electric power supplied from the power supply device to the power reception device, in a state where an effective value of an output voltage of a inverter circuit is fixed to a predetermined first voltage by the power-supply-side controller and an input voltage of the DC-DC converter is fixed to a predetermined second voltage by the power-receiving-side controller, in the pre-power-supply check, and cause, in response to the supplied electric power being equal to a predetermined electric power or more, the power supply device to start the main power supply.

Abstract: A coil unit for a contactless power supply system includes a plurality of coils for electric power transfer, and a magnetic flux reduction structure. The plurality of coils include a first coil and a second coil adjacent to the first coil in a predetermined direction. The magnetic flux reduction structure reduces, during electric power transfer using the first coil, magnetic flux by which the first coil causes an induced voltage or induced current to be generated in the second coil.

Abstract: A contactless power supply system is provided for supplying electric power to a vehicle in a contactless manner during traveling of the vehicle. The contactless power supply system includes a plurality of primary coils installed along a traveling direction in a road and a secondary coil mounted to the vehicle. Each of the primary coils is a single-phase coil with the secondary coil being a multi-phase coil, or is a multi-phase coil with the secondary coil being a single-phase coil.

Abstract: A dynamic wireless power transfer system performs, through a plurality of primary coils installed along a traveling direction of a road and a secondary coil mounted in a vehicle, power transfer to the vehicle while the vehicle is traveling. The secondary coil is an M-phase coil including M coils, M denoting an integer which is two or higher. The M coils each include a coil end extending along a front-rear direction of the vehicle and a main coil portion extending along a width direction of the vehicle, the M coils each being configured such that a magnetic resistance of a magnetic path where a magnetic flux of the coil end passes is higher than a magnetic resistance of a magnetic path where a magnetic flux of the main coil portion passes.

Abstract: In an in-motion power supply system with a plurality of power supply segments to supply power to a vehicle, a vehicle position detection unit detects a position of the vehicle relative to each segment. An electrical characteristic acquisition unit acquires electrical characteristics in the segment involved in power transfer, and an abnormality determination unit uses the electrical characteristics to determine whether there is an abnormality in the segment involved in power transfer.

Abstract: A wireless power supply system includes a plurality of power transmission units that receives and supplies power to a power receiving unit via the power transmission coil in a resonance state, and a switching control unit that switches a state of a first power transmission unit to a resonance state when the magnitude of the magnetic flux generated in a first power transmission coil of the first power transmission unit, which is one of the plurality of power transmission units, is greater than a predetermined threshold value, and switches to a non-resonance state when the magnitude is less than the threshold value. The threshold is set as a magnitude that exceeds the magnetic flux generated in the first power transmission coil due to coupling between the first power transmission coil and a second power transmission coil of a second power transmission unit, which is adjacent to first power transmission coil.

Abstract: In a moving-object power supply system, a control unit selects, as a power transmission segment, one of segments included in at least one power transmission section. The control unit supplies, through a power supply circuit, power to the power transmission segment to thereby generate a magnetic field through a power transmission coil of the power transmission segment. The control unit determines, based on an ascertained first electrical characteristic of the power transmission segment and an ascertained second electrical characteristic of at least one power non-transmission segment, whether there is a malfunction in each of the power transmission segment and the at least one power non-transmission segment.

Abstract: A power transmission apparatus supplies power to a power reception apparatus without contact therebetween. The power transmission apparatus includes: a power conversion unit that outputs an alternating-current voltage of a predetermined frequency; a power transmission unit that has a power transmission coil and a capacitor that is connected to the power transmission coil; a transmission line that connects the power conversion unit and the power transmission unit; and a compensator that is disposed between the power conversion unit and the transmission line. The compensator includes: an inductive reactance element that has an inductive reactance that is greater than an inductive reactance of the transmission line; and a capacitor that reduces an inductive reactance that is a sum of an inductive reactance of the transmission line and an inductive reactance of the inductive reactance element. The inductive reactance element and the capacitor are connected.

Abstract: A primary-side resonant circuit of a power transmission apparatus has an impedance varying element that increases, when supply of electric power is stopped, an input impedance of the primary-side resonant circuit so as to have predetermined standby current flowing through a primary-side coil. A power reception apparatus includes a magnetic flux amplifier circuit configured to amplify magnetic flux generated by the standby current flowing through the primary-side coil of the primary-side resonant circuit. The power transmission apparatus further includes a primary-side detection circuit configured to detect a change in the voltage of the primary-side coil, a change in electric current flowing through the primary-side coil or a change in a magnetic field in the vicinity of the primary-side coil; each of the changes is caused by the magnetic flux amplified by the magnetic flux amplifier circuit.

Abstract: A wireless power transmission system is provided which wirelessly transfer electric power from a power transmitter to a power receiver. The wireless power transmission system works to set a capacitance of a primary capacitor of a primary resonant circuit to undergo resonance with a self-inductance of a primary coil at an angular frequency that is an operating frequency. A tertiary capacitor of a tertiary resonant circuit has a capacitance set to undergo resonance with a self-inductance of a tertiary coil. A secondary capacitor of a secondary resonant circuit has a capacitance set to reduce a reactive component of ac power arising from self-inductances and mutual inductances of the primary coil, the secondary coil, and the tertiary coil.

Abstract: A coil unit for a contactless power supply system includes a plurality of coils for electric power transfer, and a magnetic flux reduction structure. The plurality of coils include a first coil and a second coil adjacent to the first coil in a predetermined direction. The magnetic flux reduction structure reduces, during electric power transfer using the first coil, magnetic flux by which the first coil causes an induced voltage or induced current to be generated in the second coil.

Abstract: A vehicle power supply system is configured to supply power to a vehicle from a power supply apparatus laid on a power supply lane of a vehicle travel path, the power supply apparatus includes a plurality of power supply segments laid in a preset interval along the power supply lane, and a controller configured to control the plurality of power supply segments. The controller is configured to estimate timing of the vehicle reaching a next power supply segment that supplies power next after a present power supply segment that is supplying power, from at least a vehicle velocity derived from a change in position of the vehicle, and cause the next power supply segment to start power supply at the timing estimated.