Wireless power transmission device and power transmission system to aerial moving body

Patent metadata

Field	Value
Publication number	US-10962579-B2
Application number	US-202016938076-A
Country	US
Kind code	B2
Filing date	Jul 24, 2020
Priority date	May 29, 2017
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

A wireless power transmission device includes: a power transmission antenna; a radiation direction determiner; an orientation direction changer; and a transmission signal generator. The power transmission antenna is a phased array antenna including: a plurality of element antennas to radiate radio waves; and a plurality of element modules, each of the plurality of element modules including a phase shifter to change a phase of a transmission signal and an amplifier to amplify the transmission signal from the power transmission antenna. A phase offset value for the phase shifter included in each of the plurality of element modules is calculated by performing a REV (rotating element electric field vector) method using an aerial moving body hovering over the power transmission antenna and mounting a measurement antenna to receive a radio wave and a radio wave measurer to measure received radio wave data including an amplitude of the radio wave received by the measurement antenna.

First claim

The invention claimed is:

1. A wireless power transmission device comprising:
a power transmission antenna to transmit power by radiating a radio wave and being capable of changing an orientation direction;
a radiation direction determiner to determine a radiation direction, the radiation direction being a direction in which an aerial moving body exists, the aerial moving body being a target to transmit the power;
an orientation direction changer to direct the orientation direction of the power transmission antenna toward the radiation direction; and
a transmission signal generator to generate a transmission signal transmitted as the radio wave from the power transmission antenna, wherein
the power transmission antenna is a phased array antenna including:
a plurality of element antennas to radiate the radio wave; and
a plurality of element modules, each of the plurality of element modules including a phase shifter to change a phase of the transmission signal and an amplifier to amplify the transmission signal,

the orientation direction changer controls a phase shift amount of the phase shifter, and
a phase offset value for the phase shifter included in each of the plurality of element modules is calculated by performing a REV (rotating element electric field vector) method using an aerial moving body hovering over the power transmission antenna and mounting a measurement antenna to receive the radio wave and a radio wave measurer to measure received radio wave data including an amplitude of the radio wave received by the measurement antenna.

2. The wireless power transmission device according to claim 1 , wherein
the aerial moving body mounting the measurement antenna and the radio wave measurer further mounts a mobile time device to output time data synchronized with a ground time device installed on a ground and a received radio wave data time adder to generate time-added received radio wave data by adding, to the received radio wave data, the time data outputted from the mobile time device at a point of time when the received radio wave data is measured, and
the phase offset value is calculated based on REV method performing time radio wave data being the time-added received radio wave data measured by the radio wave measurer while performing the REV method in which the radio wave is radiated, a phase of the radio wave being varied by a part of the phase shifters according to the time data outputted from the ground time device.

3. The wireless power transmission device according to claim 1 , wherein
the power transmission antenna includes a plurality of power transmitters, each of the plurality of power transmitters includes a plurality of element antennas, a plurality of second-stage modules, each of the plurality of second-stage modules being the element module provided in each predetermined number of the element antennas, and a first-stage module being the element module changing the phases of the transmission signals uniformly, each of the transmission signals being inputted to each of the plurality of element antennas,
the phase offset value for the phase shifter included in each of the plurality of second-stage modules is determined so that the element antenna corresponding to the second-stage module radiate the radio wave having the same phase when the same phase command value is given to each of the plurality of second-stage modules, and
the phase offset value for the phase shifter included in the first-stage module is determined based on a phase difference measured among the radio waves, each of the radio waves being radiated by each of the plurality of power transmitters.

4. A power transmission system to an aerial moving body, the power transmission system comprising:
a wireless power transmission device including:
a power transmission antenna to transmit power by radiating a radio wave and being capable of changing an orientation direction;
a radiation direction determiner to determine a radiation direction, the radiation direction being a direction in which an aerial moving body exists, the aerial moving body being a target to transmit the power;
an orientation direction changer to direct the orientation direction of the power transmission antenna toward the radiation direction; and
a transmission signal generator to generate a transmission signal transmitted as the radio wave from the power transmission antenna, wherein
the power transmission antenna is a phased array antenna including:
a plurality of element antennas to radiate the radio wave; and
a plurality of element modules provided in each predetermined number of the element antennas, each of the plurality of element modules including a phase shifter to change a phase of the transmission signal and an amplifier to amplify the transmission signal, and

the orientation direction changer controls a phase shift amount of the phase shifter;

a power transmission control device to control the wireless power transmission device;
a ground time device installed on a ground and to output time data;
an aerial moving body mounting a measurement antenna, a radio wave measurer, a mobile time device, a received radio wave data time adder, and a mobile communicator,
the measurement antenna to receive the radio wave radiated by the wireless power transmission device,
the radio wave measurer to measure received radio wave data including electric field strength that is an amplitude of the radio wave received by the measurement antenna,
the mobile time device to output time data synchronized with the ground time device,
the received radio wave data time adder to generate time-added received radio wave data by adding, to the received radio wave data, the time data outputted from the mobile time device at a point of time when the received radio wave data is measured,
the mobile communicator to communicate with the power transmission control device; and
a REV method analyzer to obtain an element electric field phase in each of the plurality of element modules based on a REV scenario and REV method performing time radio wave data, the element electric field phase being a phase of an element electric field vector generated at a position of the measurement antenna by the radio wave radiated by the element antenna being supplied with the transmission signal outputted from one element module, the REV method scenario defining a phase operation pattern in which a phase shift amount of at least one operation phase shifter that is a part of the phase shifters is changed repeatedly with at least a part of the element antennas radiating the radio wave to perform a REV (rotating element electric field vector) method for obtaining the element electric field phase, the REV method performing time radio wave data being the time-added received radio wave data measured by the radio wave measurer while performing the REV method scenario, wherein
the power transmission control device includes a power transmission control communicator to communicate with the mobile communicator and REV method performing circuitry to control the wireless power transmission device based on the REV method scenario, and
the orientation direction changer directs the orientation direction toward the radiation direction, under a condition in which each of the plurality of element modules has a phase reference matched based on the element electric field phase of each of the plurality of element modules.

5. The power transmission system to the aerial moving body according to claim 4 , further comprising:
a power reception antenna mounted on the aerial moving body mounting the measurement antenna and to receive the radio wave radiated by the wireless power transmission device.

6. The power transmission system to the aerial moving body according to claim 4

Assignees

• Mitsubishi Electric Corp

Inventors

• HOMMA Yukihiro
• Sato Maho
• Sawa Manabu

Classifications

• B64U50/34

  In-flight charging (photovoltaics B64U50/31) · CPC title

• G01R29/10 Primary

  Radiation diagrams of antennas · CPC title

• G01R29/0871 Primary

  Complete apparatus or systems; circuits, e.g. receivers or amplifiers (G01R29/0878, G01R29/0892 take precedence; dosimeters, warning devices G01R29/0857) · CPC title

• H02J50/80

  involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices · CPC title

• H02J50/402

  the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas · CPC title