JP7369844B1 - Wireless power transmission system, power transmission system, power receiving system, power transmitting device, power receiving device, and space solar power generation satellite - Google Patents

Abstract

The present invention provides a system that enables stable wireless power transmission from a power transmitting device located at a high altitude to a power receiving device. The system is mounted on a floating body 10 located at a predetermined altitude, and includes a plurality of power transmission devices 100 that transmit transmission signals for wireless power transmission via electromagnetic waves of a predetermined frequency; The power receiving device 20 includes one or more power receiving devices 20 that output power by phase-combining a plurality of received signals that have received a plurality of transmitted signals. The frequency of the electromagnetic waves may be 300 [GHz] or less, and the electromagnetic waves may be microwaves. The electromagnetic wave may be a beam-shaped electromagnetic wave formed to have directivity from the power transmitting device to the power receiving device. The floating object may be a HAPS, a balloon or a drone located in the stratosphere. The power receiving device may be located on the ground, the sea, or a lake, or may be located in a space at a lower altitude than the power transmitting device. [Selection diagram] Figure 1

Description

The present invention relates to wireless power transfer (WPT).

Conventionally, systems that transmit power using electromagnetic waves are known. For example, Patent Document 1 describes a power transmission system (power transmission device) in space that transmits electrical energy as a microwave beam, a power reception system (power reception device) on the ground that receives the microwave beam transmitted from the power transmission system, A power supply system is disclosed.

Japanese Patent Application Publication No. 2008-259392

In conventional systems that transmit power using electromagnetic waves, the challenge is to realize stable wireless power transmission from a power transmitting device located at high altitude to a power receiving device located on the ground, at sea, on a lake, or in a low-altitude space. There is.

A system according to a first aspect of the present invention is a system that performs wireless power transmission. This system is mounted on a floating body located at a predetermined altitude, and includes a plurality of power transmission devices that transmit transmission signals for wireless power transmission via electromagnetic waves of a predetermined frequency, and a plurality of power transmission devices that transmit transmission signals from the plurality of power transmission devices. The power receiving device includes one or more power receiving devices that receive the transmitted signals, combine the phases of a plurality of received signals, and output power.

In the system according to the first aspect, the power receiving device transmits a pilot signal to the plurality of power transmitting devices, and the plurality of power transmitting devices are time-synchronized with each other, and the plurality of wireless power transmitted from the plurality of power transmitting devices are synchronized with each other. The transmission timing of the transmission signal for wireless power transmission may be determined based on the reception result of the pilot signal received from the power reception device so that the transmission signal for transmission reaches the power reception device in the same phase. .

In the system according to the first aspect, the frequency of the electromagnetic wave may be 300 [GHz] or less.

In the system according to the first aspect, the electromagnetic wave may be a microwave.

In the system according to the first aspect, the electromagnetic wave may be a beam-shaped electromagnetic wave formed to have directivity from the power transmitting device toward the power receiving device.

In the system according to the first aspect, the floating object may be a HAPS, a balloon or a drone located in the stratosphere.

In the system according to the first aspect, the power receiving device may be located on the ground, on the sea, or on a lake, or may be located in a space at a low altitude lower than the power transmitting device.

A power transmission device according to a first aspect of the present invention is a power transmission device for wireless power transmission. This power transmission device is mounted on a floating body located at a predetermined altitude, and includes a transmitter that transmits a transmission signal for wireless power transmission via electromagnetic waves of a predetermined frequency.

The power transmission device according to the first aspect includes a synchronization processing unit that performs time synchronization with another power transmission device that has a common power transmission target, and the transmission unit includes a plurality of wireless power transmitted from the plurality of power transmission devices. The transmission timing of the transmission signal for wireless power transmission may be determined based on a reception result of a pilot signal received from the power reception device so that the transmission signal for transmission reaches the power reception device in the same phase.

A power transmission system according to a first aspect of the present invention includes a plurality of the power transmission devices.

A power receiving device according to a first aspect of the present invention is a power receiving device for wireless power transmission. This power receiving device includes a receiving section that receives transmission signals for wireless power transmission via electromagnetic waves of a predetermined frequency from a plurality of power transmission devices each mounted on a floating body located at a predetermined altitude, and a receiver that receives the plurality of transmission signals via electromagnetic waves of a predetermined frequency. A combining unit that combines the plurality of received signals in the same phase.

The power receiving device according to the first aspect may include a transmitting unit that transmits a pilot signal to the plurality of power transmitting devices.

A system according to a second aspect of the present invention is a system that performs wireless power transmission. This system is mounted on a floating body located at a predetermined altitude, receives a transmission signal for wireless power transmission from an external device via electromagnetic waves of a first frequency, and changes the frequency of the transmission signal for wireless power transmission to the first frequency. a power transmission device that converts the transmission signal to a second frequency lower than the first frequency and transmits the transmission signal for wireless power transmission via electromagnetic waves of the second frequency; and a power transmission device that receives the transmission signal transmitted from the power transmission device. A power receiving device that outputs electric power.

In the system according to the second aspect, the first frequency electromagnetic wave may be a millimeter wave, a terahertz wave, or a light wave, and the second frequency electromagnetic wave may be a microwave.

In the system according to the second aspect, the electromagnetic wave of the first frequency is a beam-shaped electromagnetic wave formed to have directivity from an external device toward the power transmission device, and the electromagnetic wave of the second frequency is It may be a beam-shaped electromagnetic wave formed to have directivity from the device to the power receiving device.

In the system according to the second aspect, the external device may be a space solar power generation satellite located in a space outside the atmosphere, and the floating body may be a HAPS, a balloon, or a drone located in the stratosphere.

In the system according to the second aspect, the power receiving device may be located on the ground, on the sea, or on a lake, or may be located in a space at a low altitude lower than the power transmitting device.

A power transmission device according to a second aspect of the present invention is a power transmission device for wireless power transmission. This power transmission device is mounted on a floating body located at a predetermined altitude, and includes a receiving unit that receives a transmission signal for wireless power transmission via electromagnetic waves of a first frequency, and a reception unit that receives a transmission signal for wireless power transmission using a first frequency. It includes a converter that converts the first frequency to a second frequency lower than the first frequency, and a transmitter that transmits the transmission signal for wireless power transmission via electromagnetic waves of the second frequency.

A system according to a third aspect of the present invention is a system that performs wireless power transmission. This system consists of a space solar power generation satellite that is located at a higher altitude than the atmosphere and transmits multi-beam transmission signals for multiple wireless power transmissions via electromagnetic waves of a predetermined frequency; A plurality of power receiving devices are mounted on each of a plurality of floating bodies located at a predetermined altitude lower than and.

In the system according to the third aspect, the electromagnetic wave may be a millimeter wave, a terahertz wave, or a light wave.

In the system according to the third aspect, the floating object may be a HAPS, a balloon or a drone located in the stratosphere.

A space solar power generation satellite according to a third aspect of the present invention includes a plurality of floating bodies mounted on each of a plurality of floating bodies located at an altitude higher than the atmosphere and at a predetermined altitude lower than the space solar power generation satellite. The power receiving device includes a transmitter that transmits a plurality of transmission signals for wireless power transmission in a multi-beam manner via electromagnetic waves of a predetermined frequency.

A power receiving device according to a third aspect of the present invention is a power receiving device for wireless power transmission. This power receiving device is mounted on each of a plurality of floating bodies located at a predetermined altitude lower than the space solar power generation satellite, and is used for wireless power transmission transmitted from the space solar power generation satellite via electromagnetic waves of a predetermined frequency. It includes a receiving section that receives the transmission signal.

A power receiving system for wireless power transmission according to a third aspect of the present invention includes a plurality of the power receiving devices.

According to the present invention, stable wireless power transmission from a power transmitting device located at a high altitude to a power receiving device is possible.

1 is an explanatory diagram showing an example of a schematic configuration of a system according to a first embodiment. FIG. 1 is a block diagram illustrating an example of the main configurations of a HAPS and a base station that constitute the wireless power transfer (WPT) system of Embodiment 1. FIG. (a) is a graph showing a composite signal when the phases of reception signals of a base station due to respective transmission signals from a plurality of HAPS are not matched. (b) is a graph showing a composite signal when the phases of the received signals of the base station are matched (when the phases are combined) between the respective transmission signals from a plurality of HAPS. FIG. 3 is an explanatory diagram illustrating an example of a method for performing phase synthesis so that the phases of a plurality of received signals match. FIG. 2 is an explanatory diagram showing an example of a schematic configuration of a system according to a second embodiment. FIG. 2 is a block diagram illustrating an example of the main configurations of a HAPS and a base station that constitute a wireless power transfer (WPT) system according to a second embodiment. FIG. 7 is an explanatory diagram showing an example of a schematic configuration of a system according to Embodiment 3. FIG. FIG. 3 is a block diagram illustrating an example of the main configuration of HAPS that constitutes the wireless power transfer (WPT) system of Embodiment 3;

Embodiments of the present invention will be described below with reference to the drawings.

[Embodiment 1]
A wireless power transfer (WPT) system according to an embodiment described in this document transmits power from multiple power transmission devices mounted on multiple floating bodies (e.g., HAPS, balloons, drones) distributed in the upper stratosphere, etc. This is a large-space distributed power supply system that can stably supply power to power receiving devices located on the ground, at sea, on lakes, etc., and to power receiving devices mounted on drones and other devices located at low altitudes.

FIG. 1 is an explanatory diagram showing an example of a schematic configuration of a system according to the first embodiment.
The system of Embodiment 1 is a system that performs wireless power transmission (WPT), and includes a plurality of power transmitting devices and one or more power receiving devices, each of which is mounted on a floating body located at a predetermined altitude. Each of the plurality of power transmission devices transmits a transmission signal for wireless power transmission via electromagnetic waves of a predetermined frequency. Further, one or more power receiving devices receive a plurality of transmission signals transmitted from a plurality of power transmission devices mounted on each floating body, phase synthesize the plurality of reception signals, and output power.

Floating objects are, for example, HAPS, balloons or drones. This embodiment is an example in which a HAPS (also referred to as a "high altitude pseudosatellite") 10, which is a high altitude platform station, is used as a floating object. The HAPS 10 is equipped with a communication relay device, is located in an airspace at a predetermined altitude, and forms a three-dimensional cell (three-dimensional area) in a cell formation target airspace at a predetermined altitude. The airspace where the HAPS 10 is located is, for example, a stratospheric airspace with an altitude of 11 [km] or more and 50 [km] or less. This airspace may be an airspace at an altitude of 15 [km] or more and 25 [km] or less where weather conditions are relatively stable, and particularly may be an airspace at an altitude of approximately 20 [km]. The cell formation target airspace may be over an ocean, river or lake.

The relay communication device of the HAPS 10 forms a beam toward the ground for wireless communication with a terminal device, which is a mobile station. The terminal device may be a communication terminal module built into a drone, which is an aircraft such as a small helicopter that can be remotely controlled, or a user device used by a user in an airplane (aircraft).

Further, the relay communication device of the HAPS 10 is connected to the core network of the mobile communication network via a feeder station that is a relay station located on land, on the sea, or on a lake. Communication between the HAPS 10 and the feeder station may be performed by wireless communication using radio waves such as microwaves, or by optical communication using laser light or the like.

Each HAPS 10 may autonomously control its own flight movement and processing at a relay communication station by having a control unit configured with an internal computer or the like execute a control program. For example, the HAPS 10 stores its own current location information (e.g., GPS (Global Positioning System) location information), pre-stored position control information (e.g., flight schedule information), location information of other HAPSs located in the vicinity, etc. The flight movement and the processing at the relay communication device may be autonomously controlled based on the acquired information.

Further, the flight movement in the HAPS 10 and the processing in the relay communication device may be controlled by a remote control device as a management device provided at a communication center of a mobile communication network. Communication between the HAPS 10 and the remote control device is performed by a HAPS control communication station, which is a facility on land or on the sea. The HAPS control communication station preferably uses an omnidirectional antenna so that it can support a plurality of HAPSs 10, but a directional antenna may also be used. As such a HAPS control communication station, a GCS (Ground Control System) can be used.

The wireless communication between the HAPS 10 and the HAPS control communication station includes communication for controlling flight movement and cell optimization of the HAPS 10, and therefore requires high reliability and low delay. Therefore, for wireless communication between the HAPS 10 and the HAPS control communication station, a frequency band lower than the frequency band used for wireless communication via the feeder link of mobile communication performed between the HAPS 10 and the feeder station is used. is preferred. For example, when using a gigahertz (GHz) frequency band for wireless communication between the HAPS 10 and a feeder station, a megahertz (MHz) frequency band is used for wireless communication between the HAPS 10 and a HAPS control communication station. Use.

In addition, when controlled by a remote control device, the HAPS 10 is equipped with a control communication terminal device (for example, a mobile communication module) so that it can receive control information from the remote control device, and the terminal is configured so that it can be identified from the remote control device. Identification information (eg, IP address, telephone number, etc.) may be assigned. The MAC address of the communication interface may be used to identify the control communication terminal device. In addition, the HAPS 10 is configured to transmit information such as information regarding the flight movement of itself or surrounding HAPS, processing at relay communication devices, and observation data acquired by various sensors to a predetermined destination such as a remote control device. It's okay.

The power receiving device is a target to which power is supplied by wireless power transmission (WPT) from the power transmitting device on the HAPS 10, and is not particularly limited. In this embodiment, for example, a power receiving device (for example, a mobile communication base station, a mobile station, or other equipment) located on the ground, the sea, or a lake, or a power receiving device located in a space at a low altitude lower than the position of the HAPS 10 is used. A power receiving device (eg, another HAPS, balloon, drone, airplane, or other floating object). This embodiment is an example in which a mobile communication base station 20 installed on the ground is used as a power receiving device.

The base station 20 is equipped with, for example, a plurality of array antennas 210 having a large number of antenna elements, and is capable of communicating with a plurality of terminal devices (for example, a mobile communication UE (mobile station) or an IoT device; hereinafter also referred to as "UE 20"). Massive MIMO (hereinafter also referred to as "mMIMO") transmission method communication can be performed between the two. mMIMO is a wireless transmission technology that achieves high-capacity, high-speed communication by transmitting and receiving data using the array antenna 210. Further, communication can be performed using an MU (Multi User)-MIMO transmission method in which beamforming is performed to form beams for each of the plurality of UEs 20 in time division or simultaneously. By performing MU-MIMO transmission using a multi-element array antenna, it is possible to direct and communicate an appropriate beam to each UE 20 according to the communication environment of each UE 20, thereby improving the communication quality of the entire cell. Moreover, since communication with a plurality of UEs 20 can be performed using the same radio resource (time/frequency resource), system capacity can be expanded.

FIG. 2 is a block diagram showing an example of the main configurations of the HAPS 10 and the base station 20 that constitute the wireless power transfer (WPT) system of the first embodiment.
HAPS 10 includes a communication relay device 100 as a power transmission device and an antenna 110. Antenna 110 is, for example, an array antenna having a large number of antenna elements. The antenna 110 may be singular or plural. For example, a plurality of antennas 110 may be arranged corresponding to a plurality of sector cells.

The communication relay device 100 includes a communication signal processing section 120, a wireless processing section 130, a power transfer control section 140, and a NW communication section 150. The communication signal processing unit 120 processes signals such as control information transmitted and received with the base station 20. The wireless processing unit 130 transmits the transmission signal generated by the communication signal processing unit 120 from the antenna 110 to the base station 20, and outputs the reception signal received from the base station 20 via the antenna 110 to the communication signal processing unit 120. or

The power transmission control unit 140 sends control information from the base station 20 to the communication signal processing unit 120, and generates a control signal (BF) for wireless power transmission beamforming (WPT beamforming) of the array antenna 110 based on the control information. control signal) and sends it to the wireless processing unit 130. Communication signal processing section 120 generates a downlink (DL) transmission signal including a WPT signal based on the control information received from power transfer control section 140 and sends it to radio processing section 130 .

The power transfer control unit 140 transfers the information received from the base station 20 to the NW communication unit 150, receives control information generated by the external platform 55 based on the information from the NW communication unit 150, and transmits the control information. Based on this, a downlink (DL) transmission signal including a WPT signal and a BF control signal may be generated.

The NW communication unit 150 is connected to the communication network 50 via a wireless communication line, and can communicate with a cloud system, a server, etc. of an external platform 55. The NW communication unit 150 can also transmit communication data or information received from the base station 20 to the communication network 50 side, or receive communication data or information to be transmitted to the base station 20 from the communication network 50 side. The NW communication unit 150 is, for example, a communication unit that communicates with a feeder station located on the ground.

The HAPS 10 performs beamforming (BF) control to form individual beams for each base station 20 or for each target area to which a plurality of base stations 20 belong during downlink communication to the base station 20. Wireless power transfer may be performed every 20 or target areas. BF control for each base station 20 or for each target area may be performed by digital BF control in the frequency domain in the communication signal processing section 120, or by analog BF control in the radio processing section 130.

In FIG. 2, base station 20 includes an antenna 210, a wireless processing section 220, a communication signal processing section 230, a power output section 240, and a battery 250. Antenna 210 is composed of, for example, a plurality of array antennas each having a large number of antenna elements. The wireless processing unit 220 transmits information and transmission signals generated by the communication signal processing unit 230 from the antenna 210 to the HAPS 10, and outputs a reception signal received from the HAPS 10 via the antenna 210 to the communication signal processing unit 230. .

In this embodiment, the wireless processing unit 220 receives a transmission signal for wireless power transmission transmitted from the HAPS 10. The power output unit 240 includes, for example, a rectifier, and outputs the power of the received signal that has received the transmission signal for wireless power transmission from the HAPS 10 as received power for battery charging. The battery 250 can be charged by the received power output from the power output unit 240.

The wireless processing unit 220 may have a function of measuring or acquiring information related to power reception, such as power reception beam information (for example, information on the direction and width of the power reception beam), information on the direction of arrival of WPT radio waves, and the like. The power output unit 240 may have a function of measuring received power. At least one of information regarding power reception such as power reception beam information, information on the arrival direction of WPT radio waves, information on received power, and control information can be included in the information to the HAPS 10.

The frequency of the electromagnetic wave of the transmission signal for wireless power transmission transmitted from the HAPS 10 to the base station 20 is preferably 300 [GHz] or less, and more preferably microwave. In this embodiment, since a transmission signal for wireless power transmission is transmitted from the HAPS 10 located in the stratosphere to the base station 20 on the ground, it is preferable to use electromagnetic waves, particularly microwaves, which are less susceptible to the influence of the atmosphere.

Here, when wireless power transmission (WPT) is performed from the HAPS 10 to the base station 20, it is difficult to secure sufficient received power by wireless power transmission from a single HAPS 10. Therefore, in this embodiment, the system obtains power (total power) from a composite signal obtained by combining received signals generated by the base station 20 using transmission signals for wireless power transmission from a plurality of HAPS 10.

However, if the phases of multiple received signals received from multiple HAPS 10 are not matched, power transmission efficiency decreases, making it difficult to perform highly efficient wireless power transmission (WPT). It cannot be realized. That is, if the phases of the received signals P _rIn1 and P _rIn2 of the base station 20 due to respective transmission signals from a plurality of HAPS 10 are not matched as shown in FIG. 3(a), the phases as shown in FIG. 3(b) The total power P _rInc obtained is smaller than when the power is matched (phase combined).

Therefore, in this embodiment, power is obtained by phase-combining transmission signals for wireless power transmission transmitted from a plurality of HAPS 10 so that the phases of a plurality of received signals are matched, and power is obtained with high efficiency and stability. It has realized wireless power transfer (WPT).

FIG. 4 is an explanatory diagram illustrating an example of a method for performing phase synthesis so that the phases of a plurality of received signals are matched.
As a method for phase combining so that the phases of multiple received signals match, for example, the phase of the transmission signals for wireless power transmission transmitted from multiple HAPS 10-0, 10-1, ... 10-n is used. and a method of adjusting the phases of a plurality of received signals received by the base station 20. However, with the latter phase adjustment method, it is necessary to change the equipment and settings of the existing base station 20 that is not compatible with this system, and if the phase adjustment is performed at the base station 20 on the power receiving side, the phase adjustment The former phase adjustment method is preferable in consideration of the fact that the transmission power is reduced by the amount of power consumed.

Therefore, in this embodiment, as shown in FIG. Adopt a method. In other words, the input phases Δφ1, Δφ2, ..., Δφn that compensate for the transmission signal path differences among the plurality of HAPS 10-0, 10-1, ... 10-n are set to It is added to the transmitted signals of the HAPS 10-1, . . . 10-n so that the received signals at the base station 20 are in phase.

As a specific phase adjustment method, for example, based on feedback information regarding wireless power transmission from the base station 20, the phase adjustment method for wireless power transmission transmitted from a plurality of HAPS 10-0, 10-1, ... 10-n may be used. The phase of the transmitted signal may also be adjusted. For example, the plurality of HAPS 10-0, 10-1, ... 10-n receive feedback information regarding wireless power transmission from the base station 20 via the communication UL established between each HAPS and the base station 20. Receive and obtain. The feedback information may include, for example, power receiving device information regarding power reception at the base station 20 (also referred to as "WPT power reception information", "WPT terminal information", or "WPT information"). The power receiving device information includes, for example, request information requesting wireless power transmission (WPT request), identification information that can identify the base station 20, location information of the base station 20, received power information at the base station 20, and power reception at the base station 20. At least one of beam information (for example, information on the direction and width of the power receiving beam), information on the direction of arrival of WPT radio waves at the base station 20, information on the remaining amount of battery provided in the base station 20, and approval information for approving wireless power transmission. It may also contain one piece of information.

Feedback information (FB information) from the base station 20 received by the array antenna 110 of the HAPS 10 is sent to the communication control unit 115 of the communication relay device 100. The communication control unit 115 generates control information based on feedback information from the base station 20, and based on the control information, transmits a downlink (DL) transmission signal including a wireless power transmission signal (WPT signal), A control signal (BF control signal) for wireless power transmission beamforming (WPT beamforming) of the array antenna 110 of the HAPS 10 is generated and sent to the array antenna 110. The array antenna 110 forms a wireless power transmission beam (WPT beam) in the direction of the base station 20 based on the BF control signal, and uses the WPT beam to transmit WPT through a part of the downlink (DL) radio resources. A downlink (DL) transmission signal (adjusted phased transmission signal) including the signal is transmitted.

The communication control unit 115 of the HAPS 10 transfers the feedback information received from the base station 20 to the cloud system, server, etc. of the external platform 55, receives control information generated by the external platform 55 based on the feedback information, and controls the control information. Based on the information, a downlink (DL) transmission signal including a WPT signal and a BF control signal may be generated.

Further, the feedback information regarding wireless power transmission from the base station 20 may be control information that specifies the phase of the transmission signal for each HAPS 10. However, in this case, the base station 20 side will execute processing for determining the phase of the transmission signal transmitted from each HAPS 10.

In the phase adjustment method of this embodiment, a pilot signal is transmitted from the base station 20 to a plurality of HAPS 10-0, 10-1, ... 10-n that are time-synchronized with each other, and 10-1, . . . , 10-n transmit transmission signals based on the reception result of the pilot signal from the base station 20 so that each transmission signal for wireless power transmission reaches the base station 20 in the same phase. Determine the transmission timing.

Specifically, when a pilot signal transmitted from the base station 20 is received by the antenna 110 of each HAPS 10-0, 10-1, ... 10-n, a communication signal is transmitted from the radio processing unit 130 of each HAPS. It is sent to the power transmission control section 140 via the processing section 120. The power transmission control unit 140 functions as a synchronization processing unit that performs time synchronization with other HAPS that have a common power transmission target (base station 20), and performs time synchronization using, for example, PTP (Precision Time Protocol). Further, the power transmission control unit 140, together with the wireless processing unit 130, the antenna 110, and the like, constitutes a transmitting unit that transmits a transmission signal for wireless power transmission via electromagnetic waves of a predetermined frequency.

Since the power transmission control unit 140 can grasp the difference in transmission signal path length from the reference HAPS 10-0 based on the reception time of the pilot signal, the power transmission control unit 140 adjusts the input phases Δφ1, Δφ2, . . . to compensate for this difference. Δφn is determined, and control information for the transmission timing of the transmission signal to which the determined input phase is added is sent to the wireless processing unit 130. Thereby, the wireless processing unit 130 transmits the transmission signal for wireless power transmission (the transmission signal after phase adjustment) from the antenna 110 to the base station 20 at the transmission timing based on the control information.

As a result, as shown in FIG. 4, the transmission signals P _In e ^jφ , P _In e ^jφ−Δφ1 , . , P _In e ^jφ−Δφn have in-phase P _r e ^jφ when received by the base station 20. Therefore, as shown in FIG. 3(b), the phase-combined received signal (combined signal) _PrInc is maximized, and highly efficient and stable wireless power transmission (WPT) is realized.

[Embodiment 2]
A wireless power transfer (WPT) system according to another embodiment is configured to transmit power from a space solar power satellite (SSPS) to a plurality of floating objects (e.g., HAPS, balloons, drones) dispersedly located in the stratosphere or the like. Large-spatial distribution that enables stable power supply to power receiving devices located on the ground, on the sea, on lakes, etc., and power receiving devices mounted on drones, etc. located in low-altitude spaces, by relaying multiple power transmitting devices installed on the It is a power supply system.

In the following description, explanations that overlap with those of the first embodiment described above will be omitted as appropriate, and the explanation will focus on points that are different from the first embodiment described above.

FIG. 5 is an explanatory diagram showing an example of a schematic configuration of a system according to the second embodiment.
The system of Embodiment 2 is a system that performs wireless power transmission (WPT), and includes one or more power transmission devices mounted on a floating body located at a predetermined altitude, and receives transmission signals transmitted from the power transmission devices. and a power receiving device that outputs power. The one or more power transmission devices receive a transmission signal for wireless power transmission transmitted from an external device via electromagnetic waves of a first frequency, and set the frequency of the transmission signal for wireless power transmission to be lower than the first frequency. The transmission signal is converted to a lower second frequency, and the transmission signal for wireless power transmission is transmitted via the electromagnetic wave of the second frequency.

In the second embodiment, the floating body is also an example of the HAPS 10 located in the stratosphere, but as in the first embodiment described above, it may be a balloon, a drone, or the like. The receiving device is also an example of the base station 20 on the ground, as in the first embodiment described above. However, the transmission signal for wireless power transmission that the HAPS 10 of the second embodiment transmits to the base station 20 is a signal obtained by converting the frequency of the transmission signal for wireless power transmission transmitted from an external device to a lower frequency. This external device includes a power transmission device mounted on another floating body (for example, another HAPS), a power transmission device located on the ground, the sea, or a lake, and a power transmission device located at a higher altitude than HAPS10 (for example, a space solar power transmission device). power generation satellites, etc.).

This embodiment is an example in which the external device is a space solar power generation satellite 30 located at a higher altitude than the atmosphere. The space solar power generation satellite 30 is equipped with a solar power generation device, and transmits the power output from the solar power generation device to the HAPS 10 in the stratosphere by wireless power transmission, and from this HAPS 10 to the power receiving device on the ground by wireless power transmission. Power is transmitted to the base station 20.

FIG. 6 is a block diagram showing an example of the main configurations of the HAPS 10 and the base station 20 that constitute the wireless power transfer (WPT) system of the second embodiment.
In addition to the configuration provided in the first embodiment described above, the HAPS 10 includes an antenna 111 as a receiving unit that receives a transmission signal for wireless power transmission from the space solar power generation satellite 30 transmitted via electromagnetic waves of a first frequency; A frequency conversion unit 160 is provided as a conversion unit that converts the frequency of a transmission signal for wireless power transmission received by the antenna 111 to a lower second frequency.

The antenna 111 is, for example, an array antenna having a large number of antenna elements. The antenna 111 may be singular or plural. A frequency converter 160 provided in the communication relay device 100 of the HAPS 10 converts the frequency (first frequency) of a transmission signal for wireless power transmission received from the space solar power generation satellite 30 via the antenna 111 to a lower second frequency. The frequency-converted transmission signal is sent to the wireless processing section 130. The wireless processing unit 130 transmits the transmission signal for wireless power transmission sent from the frequency conversion unit 160 to the base station 20 from the antenna 110.

In this embodiment, the frequency of the electromagnetic wave of the transmission signal for wireless power transmission transmitted from the space solar power generation satellite 30 to the HAPS 10 is preferably higher than a microwave, and is preferably a millimeter wave, a terahertz wave, or a light wave. It is more preferable to have one. Because the influence of the atmosphere is small between the space solar power generation satellite 30, which is located at a higher altitude than the atmosphere, and the HAPS 10, which is located in the stratosphere, the electromagnetic waves of the transmission signal for wireless power transmission are of high frequency, especially millimeter waves. , terahertz waves, or light waves. On the other hand, the transmission signal for wireless power transmission transmitted from the HAPS 10 located in the stratosphere to the base station 20 on the ground is greatly influenced by the atmosphere. It is preferable that

In this embodiment, when wirelessly transmitting power generated by the space solar power generation satellite 30 to the base station 20 on the ground, wireless power transmission (WPT) is realized by passing the power generated by the space solar power generation satellite 30 through the HAPS 10 located in the stratosphere. There is. In other words, in wireless power transmission in areas with less atmospheric influence, the transmission signal for wireless power transmission is transmitted via higher frequency electromagnetic waves, and in wireless power transmission in areas with greater atmospheric influence, transmission signals are transmitted via higher frequency electromagnetic waves. By transmitting transmission signals for wireless power transmission via electromagnetic waves, highly efficient and stable wireless power transmission (WPT) is realized.

Furthermore, the electromagnetic wave of the transmission signal for wireless power transmission transmitted from the space solar power generation satellite 30 to the HAPS 10 is a beam-shaped electromagnetic wave formed to have directivity from the space solar power generation satellite 30 toward the HAPS 10. is preferable. This makes it possible to achieve more efficient wireless power transmission. As such electromagnetic waves, for example, electromagnetic waves whose beam shape has been shaped by beam forming technology can be used.

In particular, in this embodiment, since the space solar power generation satellite 30 transmits a transmission signal for wireless power transmission to a plurality of HAPS 10, it is necessary to transmit a plurality of transmission signals to each HAPS 10 in a multi-beam manner. Good. According to this, more efficient wireless power transmission can be realized for each HAPS 10.

Also in this embodiment, wireless power transmission is performed from a plurality of HAPS 10 to the base station 20, as in the first embodiment described above. Therefore, as in Embodiment 1 described above, it is preferable to adopt a configuration in which the phases of the plurality of reception signals that are received from the transmission signals for wireless power transmission transmitted from the plurality of HAPSs 10 are matched so that the phases thereof are matched. However, in the second embodiment, this configuration does not necessarily need to be adopted.

[Embodiment 3]
In yet another embodiment, a wireless power transfer (WPT) system stably transmits power from a space solar power satellite (SSPS) to a plurality of floating objects (e.g., HAPS, balloons, drones) dispersedly located in the stratosphere or the like. It is a large space distributed power supply system that can supply power.

In the following description, descriptions that overlap with those of the first and second embodiments described above will be omitted as appropriate, and the description will focus on points that are different from the first and second embodiments described above.

FIG. 7 is an explanatory diagram showing an example of a schematic configuration of a system according to the third embodiment.
The system of Embodiment 3 is a system that performs wireless power transmission (WPT), and includes a space solar power generation satellite 30 located at an altitude higher than the atmosphere, and a plurality of space solar power generation satellites located at a predetermined altitude lower than the space solar power generation satellite. a plurality of power receiving devices mounted on each of the floating bodies. The space solar power generation satellite 30 transmits a plurality of transmission signals for wireless power transmission in multiple beams via electromagnetic waves of a predetermined frequency. The plurality of power receiving devices receive each of the plurality of transmission signals for wireless power transmission transmitted by multi-beam from the space solar power generation satellite 30.

In the third embodiment as well, the space solar power generation satellite 30 is located at a higher altitude than the atmosphere, is equipped with a solar power generation device, and is powered by the power output from the solar power generation device. is transmitted to the HAPS 10 in the stratosphere by wireless power transmission. The receiving device of the third embodiment is the HAPS 10, which is a floating body, and the power transmission target of this system is the HAPS 10. Therefore, although the HAPS 10 of the third embodiment does not have a function (such as the power transmission control unit 140) for wirelessly transmitting power to the base station 20 on the ground, it does have a function for wirelessly transmitting power to the base station 20 on the ground. may be provided.

In Embodiment 3, the floating body on which the power receiving device to be transmitted is mounted is also an example of the HAPS 10 located in the stratosphere, but as in Embodiment 1 and Embodiment 2 described above, it may be a balloon or a drone located in the stratosphere. etc.

FIG. 8 is a block diagram showing an example of the main configuration of the HAPS 10 that constitutes the wireless power transfer (WPT) system of the third embodiment.
The HAPS 10 of the third embodiment differs from the second embodiment described above in that it does not have a function (power transfer control unit 140, frequency conversion unit 160, etc.) for wireless power transmission to the base station 20 on the ground. There is. The HAPS 10 of the third embodiment also differs from the second embodiment described above in that it includes a wireless processing section 170, a power output section 180, and a battery 190.

Wireless processing section 170 receives a transmission signal for wireless power transmission transmitted from space solar power generation satellite 30 via antenna 111 and sends it to power output section 180 . The power output unit 180 includes, for example, a rectifier, and outputs the power of the received signal that has received the transmission signal for wireless power transmission from the space solar power generation satellite 30 as received power for battery charging. The battery 190 can be charged by the received power output from the power output unit 180.

In this embodiment as well, the frequency of the electromagnetic waves of the transmission signal for wireless power transmission transmitted from the space solar power generation satellite 30 to the HAPS 10 is preferably higher than that of microwaves, as in the second embodiment described above. , millimeter waves, terahertz waves, or light waves are more preferable. Because the influence of the atmosphere is small between the space solar power generation satellite 30, which is located at a higher altitude than the atmosphere, and the HAPS 10, which is located in the stratosphere, the electromagnetic waves of the transmission signal for wireless power transmission are of high frequency, especially millimeter waves. , terahertz waves or light waves.

Furthermore, in this embodiment, since the space solar power generation satellite 30 transmits a transmission signal for wireless power transmission to a plurality of HAPS 10, the plurality of transmission signals transmitted to each HAPS 10 are transmitted in a multi-beam manner. Thereby, more efficient wireless power transmission can be realized for each HAPS 10. Such multi-beams can be realized, for example, by shaping the beam shape using beam forming technology.

According to the present embodiment, a plurality of transmission signals for wireless power transmission are transmitted from the space solar power generation satellite 30 using multi-beams, and the plurality of transmission signals transmitted using the multi-beams are distributed over multiple locations such as the stratosphere. are received by the respective HAPS 10. Thereby, highly efficient and stable wireless power transmission (WPT) can be realized.

As described above, according to the first to third embodiments, stable wireless power transmission from a power transmitting device located at a high altitude to a power receiving device is possible.
In addition, the present invention can stabilize wireless power transmission from a power transmission device located at a high altitude to a power receiving device located on the ground, at sea, on a lake, or in a low-altitude space. We can contribute to achieving Goal 9 of the SDGs, ``Create a foundation for industry and technological innovation.''

Note that the processing steps and components of the wireless power transmission system, power transmission system, power receiving system, power transmitting device, power receiving device, floating body, terminal device, space solar power generation satellite, etc. described in this specification may be performed by various means. Can be implemented. For example, these steps and components may be implemented in hardware, firmware, software, or a combination thereof.

Regarding hardware implementation, in order to realize the above steps and components in entities (e.g., various transmitters, receivers, rectenna devices, wireless communication devices, Node Bs, terminals, hard disk drive devices, or optical disk drive devices) The processing units and other means used in the A programmable gate array (FPGA), processor, controller, microcontroller, microprocessor, electronic device, other electronic unit, computer, or combination thereof designed to perform the functions described herein. It may be implemented within.

Additionally, for firmware and/or software implementations, the means used to implement the components described above, such as processing units, may include programs (e.g., procedures, functions, modules, instructions) that perform the functions described herein. , etc.). In general, any computer/processor readable medium tangibly embodying firmware and/or software code, such as a processing unit, may be used to implement the above steps and components described herein. may be used for implementation. For example, the firmware and/or software code may be stored in memory and executed by a computer or processor, eg, in a controller. The memory may be implemented within the computer or processor, or external to the processor. The firmware and/or software code may also be stored in, for example, random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), programmable read-only memory (PROM), electrically erasable PROM (EEPROM), etc. ), flash memory, floppy disks, compact disks (CDs), digital versatile disks (DVDs), magnetic or optical data storage devices, etc. good. The code may be executed by one or more computers or processors and may cause the computers or processors to perform certain aspects of the functionality described herein.

Further, the medium may be a non-temporary recording medium. Further, the code of the program may be read and executed by a computer, processor, or other device or apparatus, and its format is not limited to a specific format. For example, the code of the program may be a source code, an object code, or a binary code, or may be a mixture of two or more of these codes.

The description of the embodiments disclosed herein is also provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

10:HAPS
20: Base station 30: Space solar power generation satellite 50: Communication network 55: External platform 100: Communication relay device 110, 111: Antenna 115: Communication control unit 120: Communication signal processing unit 130: Wireless processing unit 140: Power transmission control Section 150: NW communication section 160: Frequency conversion section 170: Wireless processing section 180: Power output section 190: Battery 210: Antenna 220: Wireless processing section 230: Communication signal processing section 240: Power output section 250: Battery

Claims (20)

A system for wireless power transmission,
Each relay communication device is mounted on a floating body located in the stratospheric airspace and relays communication between a mobile communication terminal device and a base station, and transmits a transmission signal for wireless power transmission via electromagnetic waves of a predetermined frequency. a plurality of power transmission devices that transmit the power to the base station;
one or more power receiving devices that are provided in the base station and output power by phase-combining a plurality of received signals that have received the plurality of transmission signals transmitted from the plurality of power transmission devices;
Each of the plurality of power transmission devices includes:
receiving feedback information regarding wireless power transmission from the base station via a communication uplink established between the relay communication device and the base station;
Based on the feedback information, transmitting a downlink transmission signal including a wireless power transmission signal to the previous base station via a communication downlink constructed between the relay communication device and the base station;
A system characterized by: The system of claim 1,
The power receiving device transmits a pilot signal to the plurality of power transmitting devices,
The plurality of power transmission devices are
time synchronized with each other,
The wireless power transmission is performed based on the reception result of the pilot signal received from the power receiving device so that the plurality of transmission signals for wireless power transmission transmitted from the plurality of power transmitting devices reach the power receiving device in the same phase. determine the transmission timing of the transmission signal for
A system characterized by: The system of claim 1,
The frequency of the electromagnetic wave is 300 [GHz] or less,
A system characterized by: The system of claim 3,
The electromagnetic wave is a microwave,
A system characterized by: The system of claim 3,
The electromagnetic wave is a beam-shaped electromagnetic wave formed to have directivity from the power transmitting device to the power receiving device.
A system characterized by: The system of claim 1,
the floating object is a HAPS, a balloon or a drone located in the stratosphere;
A system characterized by: The system of claim 1,
The power receiving device is located on the ground, on the sea, or on a lake, or located in a space at a lower altitude than the power transmitting device.
A system characterized by: A power transmission device for wireless power transmission,
Installed in a relay communication device mounted on a floating body located in the stratospheric airspace and relaying communication between a mobile communication terminal device and a base station,
comprising a transmitter that transmits a transmission signal for wireless power transmission to the base station via electromagnetic waves of a predetermined frequency,
receiving feedback information regarding wireless power transmission from the base station via a communication uplink established between the relay communication device and the base station;
Based on the feedback information, transmitting a downlink transmission signal including a wireless power transmission signal to the previous base station via a communication downlink constructed between the relay communication device and the base station;
A power transmission device characterized by: The power transmission device according to claim 8,
Equipped with a synchronization processing unit that performs time synchronization with other power transmission devices that share the same power transmission target,
The transmitting unit transmits pilot signals received from the power receiving device so that the plurality of transmission signals for wireless power transmission transmitted from the plurality of power transmitting devices reach the power receiving device provided in the base station in the same phase. determining the transmission timing of the transmission signal for wireless power transmission based on the reception result of
A power transmission device characterized by: A power transmission system for wireless power transmission comprising a plurality of power transmission devices,
Each of the plurality of power transmission devices is a power transmission device according to claim 8,
A power transmission system characterized by: A power receiving device for wireless power transmission,
Installed at mobile communication base stations,
Wireless transmission is transmitted via electromagnetic waves of a predetermined frequency from multiple power transmission devices installed in relay communication devices each mounted on a floating body located in the stratospheric airspace and relaying communication between mobile communication terminal devices and base stations. a receiving unit that receives a transmission signal for power transmission;
a combining unit that combines a plurality of received signals received from the plurality of transmission signals in the same phase;
Equipped with
transmitting feedback information regarding wireless power transmission to the relay communication device via a communication uplink established between the relay communication device and the base station;
receiving a downlink transmission signal including a wireless power transmission signal transmitted from the power transmission device via a communication downlink established between the relay communication device and the base station based on the feedback information; ,
A power receiving device characterized by: The power receiving device according to claim 11,
comprising a transmitter that transmits a pilot signal to the plurality of power transmitting devices;
A power receiving device characterized by: A system for wireless power transmission,
It is installed in a relay communication device mounted on a floating body located in the airspace of the stratosphere and relays communication between a mobile communication terminal device and a base station, and is used for wireless power transmission from an external device via electromagnetic waves of the first frequency. , converting the frequency of the transmission signal for wireless power transmission to a second frequency lower than the first frequency, and transmitting the transmission signal for wireless power transmission via electromagnetic waves of the second frequency. a power transmission device that transmits to the base station;
a power receiving device provided in the base station and configured to receive the transmission signal transmitted from the power transmission device and output power;
The power transmission device includes:
receiving feedback information regarding wireless power transmission from the base station via a communication uplink established between the relay communication device and the base station;
Based on the feedback information, transmitting a downlink transmission signal including a wireless power transmission signal to the previous base station via a communication downlink constructed between the relay communication device and the base station;
A system characterized by: The system of claim 13,
The electromagnetic wave of the first frequency is a millimeter wave, a terahertz wave, or a light wave,
The electromagnetic wave of the second frequency is a microwave,
A system characterized by: The system of claim 13,
The electromagnetic wave of the first frequency is a beam-shaped electromagnetic wave formed to have directivity from an external device toward the power transmission device.
The electromagnetic wave of the second frequency is a beam-shaped electromagnetic wave formed to have directivity from the power transmitting device to the power receiving device.
A system characterized by: The system of claim 13,
The external device is a space solar power generation satellite located in space outside the atmosphere,
the floating object is a HAPS, a balloon or a drone located in the stratosphere;
A system characterized by: The system of claim 13,
The power receiving device is located on the ground, on the sea, or on a lake, or located in a space at a lower altitude than the power transmitting device.
A system characterized by: The system of claim 13,
comprising a plurality of floating bodies each carrying the relay communication device provided with the power transmission device;
A system characterized by: The system of claim 18,
The power receiving device transmits a pilot signal to the plurality of power transmitting devices,
The plurality of power transmission devices are
time synchronized with each other,
The wireless power transmission is performed based on the reception result of the pilot signal received from the power receiving device so that the plurality of transmission signals for wireless power transmission transmitted from the plurality of power transmitting devices reach the power receiving device in the same phase. determine the transmission timing of the transmission signal for
A system characterized by: A power transmission device for wireless power transmission,
Installed in a relay communication device mounted on a floating body located in the stratospheric airspace and relaying communication between a mobile communication terminal device and a base station,
a receiving unit that receives a transmission signal for wireless power transmission via electromagnetic waves of a first frequency;
a conversion unit that converts the frequency of the transmission signal for wireless power transmission to a second frequency lower than the first frequency;
a transmitter that transmits the transmission signal for wireless power transmission to the base station via the electromagnetic wave of the second frequency,
receiving feedback information regarding wireless power transmission from the base station via a communication uplink established between the relay communication device and the base station;
Based on the feedback information, transmitting a downlink transmission signal including a wireless power transmission signal to the previous base station via a communication downlink constructed between the relay communication device and the base station;
A power transmission device characterized by:

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