Abstract: In a dynamic wireless power transfer system, a power transmission coil is provided in a road. A power transmission circuit supplies electric power to the power transmission coil. A power reception coil is provided in a vehicle. A power reception circuit is connected to the power reception coil. A relay circuit is provided in a tire of the vehicle. The relay circuit includes at least two relay coils that are connected in series. The relay circuit transfers electric power from the power transmission coil to the power reception coil by one relay coil of the two relay coils opposing the power transmission coil and the other relay coil opposing the power reception coil. A resonance frequency of the relay circuit is a frequency that is within a fixed range that is centered on an applied frequency of an alternating-current voltage that is applied to the power transmission coil.

Abstract: A dynamic wireless power transfer system includes a power transmission coil, a power transmission circuit, a power reception coil, a power reception circuit, and a relay circuit. The power transmission coil is provided in a road. The power transmission circuit supplies electric power to the power transmission coil. The power reception coil is provided in a vehicle. The power reception circuit is connected to the power reception coil. The relay circuit transfers electric power between the power transmission coil and the power reception coil in a contactless manner.

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: 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: 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 contactless power supply device that supplies electric power to a vehicle in a contactless manner, includes: a power transmission resonance circuit; a power source circuit supplying direct-current power; and a power transmission circuit converting the direct-current power of the power source circuit into alternating-current power and supplying alternating-current power to the power transmission resonance circuit. The power transmission circuit includes: an inverter circuit converting the direct-current power of the power source circuit into alternating-current power; and a power transmission-side immittance conversion circuit adjusting the alternating-current power of the inverter circuit and supplies the adjusted alternating-current power to the power transmission resonance circuit.

Abstract: A system for power feeding during traveling includes a coil for power transmission, a power supply unit which supplies power to the coils, at least one shielding member which shields an electromagnetic field of the coil, and a hole provided to the shielding members.

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: A power receiving device installable to a vehicle and included in a contactless power supply system for supplying power in a contactless manner between the power receiving device and a power transmission device installable on a road includes: polyphase receiver coils having at least three phases; an iron core that provides magnetic flux coupling between the receiver coils for the respective phases; and receiver capacitors connected on a one-to-one basis to the receiver coils for the respective phases. The receiver coils for the respective phases are arranged to have inter-coil distances between the receiver coils, with at least one of the inter-coil distances different from the other inter-coil distances. The receiver capacitors have capacitances set based on the inter-coil distances.

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 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 power inversion apparatus includes a smoothing capacitor, first and second primary coils, a secondary coil, first to fourth switches of bridge circuit switches, a clamp capacitor, and a switch controller. The switch controller calculates a lower-arm duty ratio of each of the first and second switches using a map or a mathematical expression by feed-forward control based on an input voltage. The switch controller outputs a fixed value that is equal to or greater than a maximum value of the lower-arm duty ratio within a variation range of the input voltage as an upper-arm duty ratio of each of the third and fourth switches. The switch controller generates a pulse width modulation signal based on the calculated lower-arm duty ratio and the fixed value of the upper-arm duty ratio, and outputs the pulse width modulation signal to the bridge circuit switches.

Abstract: A power inversion apparatus includes a smoothing capacitor, first and second primary coils, a secondary coil, first to fourth switches of bridge circuit switches, a clamp capacitor, and a switch controller. The switch controller calculates a lower-arm duty ratio of each of the first and second switches using a map or a mathematical expression by feed-forward control based on an input voltage. The switch controller outputs a fixed value that is equal to or greater than a maximum value of the lower-arm duty ratio within a variation range of the input voltage as an upper-arm duty ratio of each of the third and fourth switches. The switch controller generates a pulse width modulation signal based on the calculated lower-arm duty ratio and the fixed value of the upper-arm duty ratio, and outputs the pulse width modulation signal to the bridge circuit switches.

Abstract: In a discharge generator, a switch is connected to a DC power source, and a transformer includes a primary coil connected to the switch, and a secondary coil magnetically coupled to the primary coil and connected to a discharge load. A power measuring unit measures input power supplied from the direct-current power source. A control unit controls on-off switching operations of the switch to thereby convert an input direct-current voltage to an alternating-current voltage. The control unit changes a switching frequency of the on switching operations of the switch while performing an analysis of a frequency characteristic of the input power based on change of the switching frequency. The control unit determines whether the discharge load is a normal state or at least one of predetermined failure modes has occurred in the discharge load in accordance with a result of the analysis of the frequency characteristic of the input power.

Abstract: A pulse power source apparatus that supplies a drive power to a pulse load circuit that periodically generates pulse current constituted of one or more consecutive pulses from the drive power. The pulse power source apparatus includes a DC voltage generation unit generating DC output voltage supplied to the pulse load circuit, and a pulse load drive signal generation unit generating a drive signal that drives the pulse load circuit to generate the pulse current. The DC output voltage which has dropped due to output of the pulse current is controlled such that a timing at which the DC output voltage reaches a reference potential corresponds to a timing at which a subsequent pulse current is generated, the reference potential being a potential capable of generating the pulse.

Abstract: In a power conversion apparatus, a controller calculates a duty ratio being a ratio of an on-duration of each of bridge-circuit switches configured by first to fourth switches to a switching period, and outputs a gate signal to each of the bridge-circuit switches. The controller adjusts the duty ratio of each of the bridge-circuit switches such that a switch-current difference becomes closer to a value obtained by multiplying an input-current difference by the predetermined target ratio that is a value greater than 0 and less than 1. The switch-current difference is a difference between a first switch current and a second switch current or a difference between a third switch current and a fourth switch current detected by a switch-current sensor at predetermined timings in the switching period. The input-current difference is a difference between input currents detected by an input-current sensor simultaneously with detection timings of switch currents.

Abstract: In a power conversion apparatus, a controller calculates a duty ratio being a ratio of an on-duration of each of bridge-circuit switches configured by first to fourth switches to a switching period, and outputs a gate signal to each of the bridge-circuit switches. The controller adjusts the duty ratio of each of the bridge-circuit switches such that a switch-current difference becomes closer to a value obtained by multiplying an input-current difference by the predetermined target ratio that is a value greater than 0 and less than 1. The switch-current difference is a difference between a first switch current and a second switch current or a difference between a third switch current and a fourth switch current detected by a switch-current sensor at predetermined timings in the switching period. The input-current difference is a difference between input currents detected by an input-current sensor simultaneously with detection timings of switch currents.

Abstract: In a power converter, switch-off of the synchronous rectification switch while the auxiliary switch is on causes the first capacitance of the main switch and the second capacitance of the synchronous rectification switch to resonate with the inductance of the second magnetic component. A parameter obtainer detects a voltage across a selected one of the main switch and the synchronous rectification switch, and obtains a parameter indicative of a corresponding one of rising and falling waveforms of the voltage across the selected switch while the selected switch is switched. A controller controls a switching control signal for the auxiliary switch to adjust switch-on timing of the auxiliary switch as a function of the parameter obtained by the parameter obtainer.

Abstract: An AC line filter is connected to an enclosure serving as a ground. A power transmission unit is configured to transmit electric power to a power reception device in a contactless manner. An inverter is provided between the AC line filter and the power transmission unit. A common mode filter is provided between the inverter and the power transmission unit. A Y capacitor of the common mode filter is not connected to the enclosure, but is connected to a power line between the AC line filter and the inverter.

Abstract: A contactless power supply system for transferring power without contact between a primary side coil and a secondary side coil is provided. In the contactless power supply system, a manipulation unit manipulates a secondary side converter so that power outputted to a load is controlled to be a command value. The manipulation unit manipulates an input voltage of a primary side resonance circuit so that a current flowing in the primary side resonance circuit equals a product of a current flowing in the secondary side resonance circuit and a current coefficient. The current coefficient is defined as a square root of a specific value and the specific value is an equivalent resistance of the secondary side resonance circuit divided by an equivalent resistance of the primary side resonance circuit.