Denso Corporation

Toyota Jidosha Kabushiki Kaisha

The University of Tokyo

Denso Corpora Tion

Oita University

National University Corporation Oita University

Masaya Takahashi

Nobuhisa Yamaguchi

Eisuke Takahashi

Mitsuru Shibanuma

Masaki Kanesaki

Hayato Sumiya

Takuya Kiguchi

Kazuhiro Uda

Kazuyoshi Obayashi

Yusei Nakayashiki

Yuusei Nakayashiki

Shoichi Takemoto

Tomoyuki Fujikawa

Osamu Shimizu

Naoki Katayama

Hiroshi Fujimoto

Koji Takahata

Kimihiro Nishijima

Shimpei Takita

Koji Mazaki

Shinpei Takita

Tomoyoshi Ueki

Kouji Mazaki

Kazuyuki Kato

Hiroe Takenaka

Mariko Sumi

Mika Okubo

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.

Contactless power transmission apparatus and adjustment method thereof

A power supply system includes: a power transmission circuit provided on the ground side; a high frequency generation circuit that supplies high-frequency electric power to the power transmission circuit; a measurement unit that measures a physical quantity corresponding to the degree of coupling between the power transmission circuit and a power reception circuit provided in a vehicle; and a control unit. When the degree of coupling is determined, based on the measured physical quantity, to be lower than a predetermined degree, the control unit sets the impedance of the power transmission circuit to a first impedance and thereby sets the power transmission circuit to a non-resonant state. In contrast, when the degree of coupling is determined to be not lower than the predetermined degree, the control unit sets the impedance of the power transmission circuit to a second impedance and thereby sets the power transmission circuit to a resonant state.

Power supply system

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.

Wireless power transmission system

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.

Contactless power supply system and coil unit thereof

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.

Contactless power supply system and contactless power supply apparatus

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.

Dynamic wireless power transfer system

A contactless power supply system includes: a power transmitter including a first capacitor and a power transmission coil, and having a first resonant frequency; a power receiver including a second capacitor and a power reception coil, and having a second resonant frequency; and a repeater that transmits, to the power reception coil, AC power received from the power transmission coil. The repeater may include: a relay power reception coil unit that receives AC power and includes at least one coil that defines a first stray capacitance for forming a first self-resonant frequency having a frequency identical to the first resonant frequency; and a relay power transmission coil unit that transmits AC power and includes at least one coil that defines a second stray capacitance for forming a second self-resonant frequency having a frequency identical to the second resonant frequency.

Contactless power supply system

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. The abnormality determination unit shares the electrical characteristics between a subject segment subjected to abnormality determination and at least one of a previous segment previous to the subject segment and a subsequent segment subsequent to the subject segment, and compares the electrical characteristics in the subject segment with at least either the electrical characteristics in the previous segment or the electrical characteristics in the subsequent segment to determine whether the electrical characteristics in the subject segment are abnormal.

In-motion power supply system, and abnormality determination method for electrical characteristics in said system

A power supply system for moving body includes a first power source, a first current path, a second power source, a second current path. The first power source supplies electric power to a redundant load. The first current path connects the first power source and the redundant load. The second power source supplies electric power to the redundant load. The second current path connects the second power source and the redundant load.

Power supply system for moving body

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.

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.

Power feeding system during travelling

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.

Moving-object power supply system

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. The ratio of a characteristic impedance of the power transmission-side immittance conversion circuit to an impedance backward on the power transmission resonance circuit side from the power transmission-side immittance conversion circuit is adjusted such that harmonic components in the alternating-current power of the inverter circuit becomes lessened.

Contactless power supply device, contactless power reception device, and contactless power supply system

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.

Power conversion apparatus

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.

Growing community of inventors

Kariya, Japan

Masaya Takahashi