Satoshi Shimokawa

Bio: Satoshi Shimokawa is an academic researcher from Fujitsu. The author has contributed to research in topics: Electromagnetic coil & Power transmission. The author has an hindex of 13, co-authored 70 publications receiving 846 citations.

Wireless power supply system and wireless power supply method

Abstract: A wireless power supply apparatus includes: a transmitting coil configured to transmit power in the form of magnetic field energy using magnetic resonance; and a power transmitter configured to supply power at a resonant frequency that produces magnetic resonance between the transmitting coil and a receiving coil; wherein the power transmitter includes a detector configured to detect current flowing into the transmitting coil, a controller configured to control the frequency of the power supplied to the transmitting coil, and a determining unit configured to determine the coupling strength between the transmitting coil and the receiving coil on the basis of the frequency of the current detected by the detector as well as the frequency of the supplied power.

Wireless power apparatus and wireless power-receiving method

Abstract: A wireless power apparatus includes: a power receiver coil which receives power, as magnetic field energy, from a power transmitter coil by magnetic field resonance produced between the power transmitter coil and the power receiver coil; a power pickup coil which derives power from the power receiver coil by electromagnetic induction; a detector which detects current flowing through the power pickup coil; and a controller which controls a coupling strength between the power pickup coil and the power receiver coil based on the current detected by the detector.

Wireless power supply system

Abstract: A wireless power supply system has a power sending resonance coil, a power receiving resonance coil, and a relay resonance coil. The power sending resonance coil has a predetermined resonance frequency characteristic, and transmits power wirelessly. The power receiving resonance coil has the same resonance frequency characteristic as the power sending resonance coil, and receives power wirelessly with a magnetic field resonance mode generated by synchronization of the resonance frequency. The relay resonance coil has the same resonance frequency characteristic as the power sending resonance coil and the power receiving resonance coil, and relay power from the power sending resonance coil to the power receiving resonance coil wirelessly with the magnetic field resonance mode generated by synchronization of the resonance frequency with them.

Power transmission apparatus

Abstract: A power transmission apparatus includes a cover part attached to one of a power transmitter and an electronic apparatus, the power transmitter including a primary-side coil connected to an alternating-current power supply and a primary-side resonant coil configured to receive power from the primary-side coil by electromagnetic induction, the electronic apparatus including a secondary-side coil; and a secondary-side resonant coil disposed in the cover part, and configured to transmit to the secondary-side coil the power received from the primary-side resonant coil by magnetic field resonance generated between the primary-side resonant coil and the secondary-side resonant coil

Resonance frequency control method, power transmission device, and power reception device for magnetic-resonant-coupling type power transmission system

Abstract: Provided is a magnetic-resonant-coupling type power transmission system, wherein power is transmitted from a power-transmission side coil to a power-reception side coil utilizing magnetic resonant coupling, and wherein the resonance frequencies of the coils can be adjusted at high speed, with accuracy, and in real time. In this magnetic-resonant-coupling type power transmission system, the phase of the voltage supplied to the power-transmission side coil, and the phase of the current flowing through the power-transmission side coil or the power-reception side coil are detected, and the resonance frequencies of the power-transmission side coil or the power-reception side coil are varied so that the difference between the phases will become a target value. The power-transmission side coil comprises a power supplying coil to which an AC power supply is to be connected, and a power-transmission resonance coil electromagnetically coupled closely with the power supplying coil. The power-reception side coil comprises a power-reception resonance coil, and a power extraction coil electromagnetically coupled closely with the power-reception resonance coil. The phase difference between the phase of the voltage of the AC power supply and the phase of the current flowing through the power-transmission resonance coil is controlled to become a target value (β), and the phase difference between the phase of the voltage of the AC power supply and the phase of the current flowing through the power-reception resonance coil is controlled to become a target value (β - π/2).

Wireless energy transfer systems

Abstract: Described herein are improved capabilities for a source resonator having a Q-factor Q 1 >100 and a characteristic size x 1 coupled to an energy source, and a second resonator having a Q-factor Q 2 >100 and a characteristic size x 2 coupled to an energy drain located a distance D from the source resonator, where the source resonator and the second resonator are coupled to exchange energy wirelessly among the source resonator and the second resonator.

Wireless energy transfer converters

Abstract: Described herein are improved configurations for a wireless power converter that includes at least one receiving magnetic resonator configured to capture electrical energy received wirelessly through a first oscillating magnetic field characterized by a first plurality of parameters, and at least one transferring magnetic resonator configured to generate a second oscillating magnetic field characterized by a second plurality of parameters different from the first plurality of parameters, wherein the electrical energy from the at least one receiving magnetic resonator is used to energize the at least one transferring magnetic resonator to generate the second oscillating magnetic field.

Wireless energy transfer, including interference enhancement

Abstract: Disclosed is an apparatus for use in wireless energy transfer, which includes a first resonator structure configured for energy transfer with a second resonator structure over a distance D larger than characteristic sizes, [insert formula] and [insert formula], of the first and second resonator structures. A power generator is coupled to the first structure and configured to drive the first resonator structure or the second resonator structure at an angular frequency away from the resonance angular frequencies and shifted towards a frequency corresponding to an odd normal mode for the resonator structures to reduce radiation from the resonator structures by destructive far-field interference.

Wireless energy transfer using variable size resonators and system monitoring

Abstract: A variable type magnetic resonator includes an array of resonators each having one of at least two substantially different magnetic dipole moment orientations and at least one power and control circuit configured to selectively connect to and energize at least one of the array of resonators.

Wireless energy transfer using repeater resonators

Abstract: Described herein are improved configurations for a device for wireless power transfer that includes a conductor forming at least one loop of a high-Q resonator, a capacitive part electrically coupled to the conductor, and a power and control circuit electrically coupled to the conductor, the power and control circuit providing two or more modes of operation and the power and control circuit selecting how the high-Q resonator receives and generates an oscillating magnetic field.