JP2012217323A - Wireless power transmission system, power transmission apparatus and rectenna base station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless power transmission system, a power transmission apparatus and a rectenna base station that more efficiently match a phase when a microwave transmitted from each power transmission apparatus is received by the rectenna base station without causing an increase in circuit scale, and suppress a reduction in power transmission efficiency in the event of an anomaly in each power transmission apparatus.SOLUTION: Not only a calculation is performed by a REV method using a radio field strength of a microwave received by a monitor antenna 25 of a rectenna base station 4 to adjust the phase of a power transmission apparatus 1, but also a measurement result by the REV method is used for anomaly detection in the power transmission apparatus 1 to suppress an increase in circuit scale, and power supply to the failed power transmission apparatus 1 is stopped by a distribution section 32 to avoid a reduction in efficiency of the overall system.

Description

  The present invention relates to a wireless power transmission system that receives sunlight and performs photoelectric conversion, transmits microwaves generated based on the obtained power from a plurality of transmitting devices, and receives the received power by receiving devices to generate power. The present invention relates to a power transmission apparatus and a rectenna base station used for this.

For example, Patent Document 1 describes a conventional wireless power transmission system that performs microwave power transmission from a power generation satellite arranged on an orbit in outer space to a rectenna base station that is a ground receiving device. Yes.
In this conventional wireless power transmission system, a pilot signal transmitted from a rectenna base station is received by a power generation satellite, and a pilot reply signal is transmitted to the rectenna base station. The pilot signal is subjected to spread spectrum modulation, and the pilot signal is identified for each satellite to extract the reference phase.
On the other hand, spread spectrum modulation is also applied to the pilot reply signal, and the rectenna base station extracts the phase information of each pilot reply signal to obtain the phase delay of each power generation satellite. By forming a feedback system that reflects the above, the phases of the microwaves from the power generation satellites are aligned to obtain a larger amount of power.

JP 2005-319853 A

  According to the conventional wireless power transmission system described in Patent Document 1, the terrestrial rectenna base station performs spread modulation on a pilot signal to be transmitted and performs despread demodulation on a received pilot reply signal, and despreading Therefore, it is necessary to provide a circuit for comparing the phases of the pilot reply signals of the satellites obtained by the above and feeding them back so as to make them coincide with each other.

In addition, each satellite in orbit requires a circuit for despreading and demodulating the pilot signal and spreading and modulating the pilot reply signal, which increases the circuit scale and drives these circuits. Therefore, a part of the electric power generated by the photoelectric conversion is consumed by a circuit related to the pilot signal, and there is a problem that the entire transmission efficiency is lowered.
Furthermore, even if the phases of the microwaves from the satellites can be made uniform by transmitting and receiving pilot signals, there is a problem in that an abnormality occurring on the satellite side is detected and the transmission efficiency decreases accordingly.

  The present invention has been made to solve the above-described problems, and more efficiently receives microwaves transmitted from each power transmission apparatus at a rectenna base station without causing an increase in circuit scale. An object of the present invention is to obtain a wireless power transmission system, a power transmission device, and a rectenna base station that align the phases when the power transmission is performed and suppress a decrease in power transmission efficiency when an abnormality occurs in each power transmission device.

A wireless power transmission system according to the present invention receives sunlight, performs photoelectric conversion, transmits microwaves to a rectenna base station from a plurality of power transmission devices that generate microwaves based on the obtained power, and In a wireless power transmission system that receives at a base station and converts it to DC power,
The rectenna base station includes a rectenna that receives the microwave, a monitor antenna that is provided in the vicinity of the rectenna and receives the microwave, and a pilot signal transmission antenna that transmits a pilot signal to the plurality of power transmission devices. The phase of the microwaves in the plurality of power transmission devices is changed so that the radio wave intensity of the microwaves received by the monitor antenna or the DC power converted by the rectenna is maximized by the calculation based on the measurement of the REV method And a phase monitoring control unit that determines abnormality of the plurality of power transmission devices from the measurement result of the REV method, and each of the plurality of power transmission devices transmits the microwave to the rectenna base. A plurality of transmitting antenna elements for transmitting to the station and a pilot signal receiving for receiving the pilot signal An antenna, a tracking receiver that detects the arrival direction of the pilot signal received by the pilot signal receiving antenna, and a microwave that is transmitted from the plurality of transmitting antenna elements in the arrival direction of the pilot signal detected by the tracking receiver. A beam drive control unit that adjusts the phase to direct, a phase control unit that changes the phase of the microwave based on the command signal from the phase monitoring control unit, and power converted from the sunlight. A plurality of amplifiers that are used to amplify the microwave and a power distribution unit that controls power supply to the amplifiers are provided.

  According to the present invention, since the phase of the power transmission device is adjusted so that the phases of the microwaves transmitted from the plurality of power transmission devices to the rectenna base station are aligned, an increase in circuit scale can be suppressed. Furthermore, by determining the abnormality of the power transmission device and stopping the power supply to the power transmission device in which the abnormality has occurred, it is possible to avoid a decrease in power transmission efficiency when an abnormality has occurred.

It is a block diagram which shows the structure of the wireless power transmission system which concerns on Embodiment 1 of this invention. 6 is a schematic diagram illustrating an example of a change in position and posture of the power transmission device according to Embodiment 1. FIG. FIG. 3 is an external view showing an external shape of a transmission panel of the power transmission device according to Embodiment 1. 3 is a functional block diagram illustrating a configuration of a power transmission device according to Embodiment 1. FIG. 3 is a functional block diagram showing a configuration of a rectenna base station in Embodiment 1. FIG. 3 is a flowchart illustrating an operation flow of the wireless power transmission system according to the first embodiment. It is a block diagram which shows the structure of the wireless power transmission system which concerns on Embodiment 2 of this invention. 6 is a functional block diagram illustrating a configuration of a power transmission device according to Embodiment 2. FIG. 6 is a functional block diagram illustrating a configuration of a rectenna base station in Embodiment 2. FIG. 6 is a flowchart illustrating an operation flow of the wireless power transmission system according to the second embodiment.

Embodiment 1 FIG.
A wireless power transmission system, a rectenna base station, and a power transmission apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of a wireless power transmission system according to Embodiment 1 of the present invention. FIG. 1A shows a case where microwave transmission is performed from discretely arranged power transmission apparatuses. Represents a case where microwaves are transmitted from a plurality of mechanically coupled power transmission devices. Note that the transmission side device including the power transmission device in FIGS. 1A and 1B may be a device arranged in outer space, a device arranged on the earth, the stratosphere, or the like.
In FIG. 1A, reference numeral 1 denotes a power transmission device that receives sunlight to perform photoelectric conversion to generate electric power, and transmits power by microwaves. Reference numeral 2 denotes a source control device that controls the source signal of the reference signal of each power transmission device 1, and reference numeral 3 denotes a receiving antenna that receives the reference signal from the source control device 2. Transmission / reception of the reference signal to / from each power transmission device 1 may be wireless transmission or wired transmission. Reference numeral 4 denotes a rectenna base station that receives microwaves from the power transmission device 2 and generates power. Reference numeral 5 denotes a rectenna including a plurality of microwave reception antennas and rectifier circuits. The rectenna base station 4 has a pilot signal transmission antenna, which will be described later, and transmits a pilot signal to the power transmission device 1. The rectenna 5 and the pilot signal transmitting antenna form part of the rectenna base station 4.
In FIG. 1B, reference numeral 6 denotes a mechanical structure that couples a plurality of power transmission apparatuses 1, and the reference signal transmission / reception between the source oscillation control apparatus 2 and each power transmission apparatus 1 is described above. It is as follows.

Each power transmission device 1 transmits microwaves to the rectenna base station 4, and the microwaves are received and synthesized by the rectenna 5 in the rectenna base station 4. If it deviates, the electric power produced | generated in the rectenna base station 4 will fall. Such a phase shift occurs due to a phase shift of a reference signal serving as a reference of a microwave generated by each power transmission device 1 or a change in position or posture of each power transmission device 1.
FIG. 2 shows an example of the change in position and posture of the microwave transmission antenna 7 for power transmission provided in the power transmission device 1, and the change in posture occurring in each microwave transmission antenna 7 is measured in the azimuth direction. An angle change θ _AZ and an angle change θ _EL in the elevation angle direction are represented, and a position change is represented by a distance ΔL from one virtual plane S. When the posture changes (θ _AZ , θ _EL ) occur, the direction of the microwaves transmitted from each power transmission device 1 is deviated from the direction of the rectenna 5, and thus a pilot signal is used to correct this. That is, each power transmission device 1 receives the pilot signal, obtains the arrival direction, and is controlled so that the transmission direction of the microwave is directed to the arrival direction of the pilot signal. Further, when the position change ΔL occurs, the microwave transmitted from each power transmission device 1 causes a phase shift corresponding to the change ΔL for each device. It is necessary to examine the device configuration for correcting the phase shift caused by the position change ΔL.

Next, configurations of the power transmission apparatus and the rectenna base station according to Embodiment 1 of the present invention will be described with reference to FIGS.
FIG. 3 is an external view showing the external shape of the transmission panel of the microwave transmission antenna 7 provided in the power transmission device 1, wherein 8 is a substrate, 9 is an array arranged on the surface of the substrate 8, and a plurality of microwaves are transmitted. The transmitting antenna element 10 is a pilot signal receiving antenna that receives a pilot signal. The transmitting antenna elements 9 are arranged in an array on the surface of the substrate 8 and are microwave-fed by a feed line provided on the substrate 8.

FIG. 4 is a functional block diagram showing the configuration of the power transmission device 1.
In FIG. 4, 11 is an input terminal for a reference signal input from the source oscillation control device 2, 12 is a multiplier for multiplying the reference signal and outputting a microwave, 13 is a phase shifter for adjusting the phase of the microwave, 14 Is a distributor that distributes the microwaves to each transmitting antenna element 9, 15 is a phase shifter that adjusts the phase of the distributed microwaves, and 16 is an amplifier that amplifies the microwaves. 17 is a photoelectric conversion unit, and 32 is a power distribution unit that switches ON / OFF of the power supplied to the amplifier 16 based on a command from the command discriminator 21, and the power generated by the photoelectric conversion unit 17 passes through the power distribution unit 32. Then, a microwave having a predetermined power level is generated by being input to the amplifier 16, and is radiated from the transmitting antenna element 9 connected to the amplifier 16 to the space. The connection between the amplifier 16 and the transmission antenna element 9 may be one-to-one, or a plurality of transmission antenna elements 9 are connected to one amplifier 16 as in one-to-four. But it ’s okay. Reference numeral 18 denotes a tracking receiver that obtains the arrival direction (θ _AZ , θ _EL ) of the pilot signal based on the sum signal and the difference signal obtained from the pilot signal receiving antenna 10, and 19 denotes the arrival direction (θ _AZ , θ _{EL of the} pilot signal). ) Is a beam drive control unit for obtaining the phase shift amount of each phase shifter 15 so that the microwave transmitted from the transmission antenna element 9 is directed. 20 is a demodulator that demodulates the command signal from the sum signal of the pilot signals received by the tracking receiver 18, and 21 is an identification code attached to the power transmission device 1 (this identification code is stored as its own identification code) ) And an identification code included in the control signal demodulated and detected by the demodulator 20, and when the codes match, a command discriminator that outputs a command included in the control signal, 22 is a REV control unit that performs phase adjustment control related to the REV method (element electric field vector rotation method: REV is an abbreviation for Rotating Element Electric Field Vector) based on a command from the command discriminator 21, and 23 is a phase shifter 13. And a phase control unit for setting a phase with respect to the phase shifter 15.

FIG. 5 is a functional block diagram showing the configuration of the rectenna base station. In FIG. 5, 24 is a rectifying and synthesizing unit that rectifies and synthesizes the microwaves received by the rectenna 5 to generate power, 25 is a monitor antenna that receives the microwaves transmitted from the power transmission device 1, and 26 is This is a receiver that detects the radio wave intensity of the microwave received by the monitor antenna 25. Here, both the rectenna 5 and the monitor antenna 25 receive microwaves transmitted from the plurality of transmission antenna elements 9 of the power transmission device 1, and the monitor antenna 25 is disposed in the vicinity of the rectenna 5. The monitor antenna 25 is preferably provided at the approximate center on the opening surface of the rectenna 5.
Reference numeral 27 denotes a phase monitoring control unit that monitors the radio wave intensity P and controls the phase of each power transmission device 1. Reference numeral 28 denotes a pilot signal transmitter that generates and outputs a pilot signal. In the pilot signal transmitter 28, 29 is a pilot based on a command signal (including an identification code of the power transmission device 1 to be controlled) output from the phase monitoring controller 27. A modulator 30 that modulates a carrier wave of the signal is a transmitter 30 that amplifies the pilot signal and outputs the pilot signal to the pilot signal transmitting antenna 31.

Next, the operation will be described. The pilot signal transmitted from the pilot signal transmission antenna 31 of the rectenna base station 4 is received by the pilot signal reception antenna 10 of the power transmission device 1. FIG. 3 shows an example of the configuration of the pilot signal receiving antenna 10. In this example, the pilot signal receiving antenna 10 includes five antenna elements provided in the center on the surface of the substrate 8.
The tracking receiver 18 synthesizes signals received by the pilot signal receiving antenna 10 and generates a sum signal and a difference signal in the AZ direction and a sum signal and a difference signal in the EL direction. The tracking receiver 18 utilizes the property that the values of the sum signal and the difference signal change when the AZ direction and the EL direction of the pilot signal change, so that θ _AZ and θ _EL which are the arrival directions of the pilot signal are used. And output.
The beam drive control unit 19 calculates a phase amount to be set in each phase shifter 15 and outputs the phase amount to the phase control unit 23 in order to perform microwave transmission in the direction of arrival of the pilot signal (θ _AZ , θ _EL ). The phase control unit 23 sets the phase of each phase shifter 15 according to the input phase amount.
Such an operation corrects a deviation between the direction of the rectenna 5 of the rectenna base station 4 and the directivity direction of the microwave transmitted from the power transmission device 1 among the changes in position and posture shown in FIG. The Note that the configuration and arrangement of the pilot signal receiving antenna 10 are not limited to those shown in FIG. 3, and the values of the sum signal and the difference signal corresponding to the two-dimensional change in the pilot signal arrival direction as described above. As long as it changes.

  In particular, an adjustment method of the phase shifter 15 using the REV method can be used for phase adjustment of each transmission antenna element 9 in the initial and regular maintenance of the power transmission device 1. The phase setting value is output from the REV control unit 22 shown in FIG. 4 based on the REV method, and the phase control unit 23 sets the phase shift of the phase shifter 15 based on the phase setting value input from the REV control unit 22. . In the REV method, the phase of one phase shifter among a plurality of phase shifters 15 is rotated, and the radio wave intensity of the combined wave at that time is measured, and this is performed for all the phase shifters 15 and measured. Based on the received radio wave intensity, the phase setting value of each phase shifter 15 at which the radiated radio wave in the front direction of the substrate surface is maximized is obtained. The measurement of the radio wave intensity includes a measurement method in which a probe antenna is provided on or near the surface of the substrate 8 and a measurement method using the monitor antenna 25 of the rectenna base station 4. In the initial and regular maintenance of the power transmission device 1, in the phase adjustment performed for each power transmission device 1 alone, the power transmission device 1 to be adjusted transmits microwaves, and the microwaves of the other power transmission devices 1 Stop sending. The phase monitoring control unit 27 performs an operation for calculating the phase adjustment amount by the REV method based on the radio wave intensity (or radio wave intensity and phase) measured by the receiver 26 by rotating the phase of each phase shifter 15. The phase adjustment amount stored in the command signal is superimposed on the pilot signal and transmitted to the power transmission device 1. In the power transmission device 1, the command discriminator 21 reproduces the command from the received pilot signal, and the phase adjustment amount stored by the REV control unit 22 is output to the phase control unit 23.

Further, the REV control unit 22 of the power transmission device 1 can perform the calculation for obtaining the phase adjustment amount by the REV method. In this case, the phase of each phase shifter 15 is rotated, and the radio wave intensity (or radio wave intensity and phase) data measured by the receiver 26 is stored in the command by the phase monitoring controller 21 and superimposed on the pilot signal. Transmit to the power transmission device 1. The REV control unit 22 performs a calculation for obtaining the phase adjustment amount by the REV method based on the reproduced radio wave intensity data, and outputs the phase adjustment amount to the phase control unit 23.
The calculation for obtaining the phase adjustment amount by the REV method is, for example, “Electronic Communication Society Papers '82 / 5. Vol. J65-B No.5 pages 555-560” It is widely known as shown in “Vector method”.

Next, an example of processing for correcting a phase shift between the power transmission apparatuses 1 caused by the position change ΔL illustrated in FIG. 2 will be described. The phase monitoring control unit 27 of the rectenna base station 4 first designates the power transmission device 1 by its identification code, and instructs the phase shifter 13 of the power transmission device 1 to change the phase (designated signal). (Including an identification code) is superimposed on the pilot signal from the rectenna base station 4 and transmitted. The power transmission device 1 with the matching identification code changes the transfer amount of the phase shifter 13 by a predetermined amount based on the command signal. Due to this change, the radio wave intensity P of the microwave received by the monitor antenna 25 of the rectenna base station 4 changes and is detected by the receiver 26 of the rectenna base station 4. This phase shift amount change instruction to the phase shifter 13 and detection by the receiver 26 are repeated several times for all the phase shift states of the phase shifter 13, and the next phase shift amount change instruction to the power transmission device 1 is given. Move.
By repeating this for each power transmission device 1 in order, the radio wave intensity P of the microwave is obtained, and the phase of the entire transmission panel of each power transmission device 1 is uniformly determined by calculation based on the REV method. The phase adjustment amount to be changed to (the phase adjustment amount of the phase shifter 13) can be obtained. Note that the REV method described here may use the magnitude of the DC power output from the rectifying and synthesizing unit 24 instead of the microwave radio wave intensity P detected by the receiver 26.

In addition, not only the radio wave intensity P but also the phase change of the microwave is measured, and a phase adjustment amount (phase shift) for uniformly changing the phase of the entire transmission panel of each power transmission device 1 by calculation based on the REV method. The phase adjustment amount of the device 13 may be obtained.
According to the modified REV method described in detail in Japanese Patent Laid-Open No. 2001-201526, the radio wave intensity and phase of a microwave are measured, and based on these measurement results, the REV method is targeted. It is also possible to perform highly accurate phase adjustment in consideration of the amplitude error and the phase error according to the total phase shift state of the phase shifter.
As shown in FIG. 5, a receiver 26 is connected to the monitor antenna 25 of the rectenna base station 4, and by this receiver 26, the radio wave intensity and phase of the combined wave of the microwaves transmitted from the power transmission device 1 are changed. Therefore, the phase shifter 15 can be accurately adjusted for each power transmission device 1 by using the above-described modified REV method.

In the rectenna base station 4 shown in FIG. 5, the phase monitoring control unit 27 designates the identification code of the power transmission apparatus 2 and outputs a command signal including this identification code to the modulator 29, whereby the modulator 29 performs pilot operation. A command signal is superimposed on the signal and transmitted by the transmitter 30 to execute “command to change the phase”.
The power transmission device 1 shown in FIG. 4 demodulates the sum signal received by the pilot signal receiving antenna 10 and synthesized by the tracking receiver 18, and reproduces a command signal (including an identification code) superimposed on the pilot signal. The command discriminator 21 outputs a command to the REV control unit 22 when it matches the identification code stored in advance, and the REV control unit 22 receives the command and sends it to the phase control unit 23. Instructs phase change.

As described above, the phase of each power transmission device 1 is changed one after another based on a command from the rectenna base station 4, and the radio wave intensity of the microwaves by the monitor antenna 25 and the receiver 26 provided in the rectenna base station 4. By detecting P (or radio wave intensity P and phase φ) and performing phase adjustment, the phase shift of the microwave accompanying the position change ΔL shown in FIG. 2 can be corrected and supplied to each power transmission device 1. The phase of the reference signal to be included is included and corrected by this phase adjustment, and the phase shift from each power transmission device 1 is corrected, and the rectenna base station 4 can obtain larger power. .
In addition, since it is not necessary to have a spread modulator or transmitter for transmitting a pilot reply signal to the power generation satellite as disclosed in the prior art, it is possible to suppress an increase in circuit scale and reduce weight. And the reliability of the apparatus can be improved. Also, by transmitting the command signal superimposed on the pilot signal, the command signal reception system on the power transmission device 1 side can be configured using the pilot signal reception system, and the circuit scale can be further reduced. be able to.

Next, the operation of the entire wireless power transmission system will be described with reference to FIG. FIG. 6 is a flowchart showing an operation flow of the wireless power transmission system according to Embodiment 1 of the present invention.
In step S <b> 1, the microwave transmitted from the power transmission device 1 is received by the monitor antenna 25 by the phase control monitoring unit 27 of the rectenna base station 4, and the radio wave intensity P detected by the receiver 26 is monitored. It is determined in step S2 whether or not the detected radio wave intensity P is greater than the threshold value P1. When the radio wave intensity P is larger than the threshold value P1, it is determined that the system is normal, and an instruction to start power transmission is sent to the power transmission device 1 using the pilot signal.

On the other hand, when the radio wave intensity P is smaller than the threshold value P1, it is determined that a phase shift caused by a change in position and posture of the power transmission device 1 shown in FIG. Instruct the implementation of the REV method. When the REV method measurement in step S3 is completed, the power transmission of the power transmission device 1 is temporarily stopped in step S4. Then, in step S5, the phase control monitoring unit 27 determines that all systems are based on the REV method measurement data. It is determined whether or not an abnormality has occurred. When the phase monitoring control unit 27 calculates the phase correction value for each power transmission device 1 from the measurement result of the REV method, the amplitude contribution of each power transmission device 1 is also calculated at the same time. This amplitude contribution is substantially constant in all the power transmission apparatuses 1, and it is sufficient to determine a threshold value used for determining whether an abnormality has occurred in consideration of manufacturing variation among apparatuses. When the relative amplitude obtained from the measurement result of the REV method is smaller than a preset threshold value, the monitoring control unit 27 determines that an abnormality has occurred in the power transmission device.
In addition, in the case of the highly accurate REV method using not only the radio wave intensity P but also the phase φ, it can be determined whether an abnormality has occurred in the amount of phase shift of each power transmission device 1. In this case, if the actual value of the phase shift amount can be grasped, the threshold value is determined in consideration of the range of the actual value.

  Since the power transmission device 1 is a device that transmits the power output from the photoelectric conversion unit 17 to the rectenna base station 4, it is necessary to transmit the power as efficiently as possible. Therefore, if power is supplied to the power transmission device 1 that is determined to be abnormal by the REV method, power is wasted. In order to avoid this, if it is determined in step S5 that there is an abnormality, an instruction to stop supplying power is transmitted to the power transmission apparatus 1 in which an abnormality has occurred in step 11 using a pilot signal. To do. The power transmission device 1 that has received the instruction stops the power supply to the amplifier 16 by the power distribution unit 32. Further, in step S12, when the number N of power transmission apparatuses 1 in which an abnormality has occurred exceeds a certain value N1, the operator is instructed to replace the apparatus in step S21. At this time, as the wireless power transmission system, the number of power transmission devices 1 that can realize the minimum power transmission is set in advance as N1, and the determination is made in step S12.

  When there is no abnormality in the power transmission device 1 or when the number N of the power transmission devices 1 in which the abnormality has occurred does not exceed N1, power transmission is resumed in step S6. As a result, it is possible to avoid a phase shift due to a change in position or posture of the power transmission device 1 and a waste of transmission power due to an abnormality in the power transmission device 1. Furthermore, even when the number of power transmission apparatuses 1 in which an abnormality has occurred increases and operation as a wireless power transmission system is difficult, the operator is instructed to replace the apparatus instead of repeating phase adjustment by the REV method. Thus, early recovery is possible.

Embodiment 2. FIG.
Configurations of the power transmission apparatus and the rectenna base station according to Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 7 is a configuration diagram of a wireless power transmission system according to Embodiment 2 of the present invention, and represents microwave transmission from discretely arranged power transmission apparatuses to a rectenna base station. In the second embodiment, the configuration of the rectenna base station is simplified with respect to the first embodiment, and the transmission side device and the rectenna base station including the power transmission device in FIG. 7 are installed on the ground.
In FIG. 7, the power transmission device 1 transmits power by a control command from the monitoring control device 41, and the source oscillation control device 2 controls the reference signal of each power transmission device 1. The monitor antenna 25 is installed in the vicinity of the antenna surface of the power transmission device 1, and the receiver 26 outputs the radio wave intensity of the microwave received by the monitor antenna 25 to the monitoring control device 41. The monitoring control device 41 outputs a control command to each power transmission device 1. The rectenna base station 4 receives the microwave from the power transmission device 1 by the rectenna 5 and powers it.

  Each power transmission device 1 transmits microwaves to the rectenna base station 4, and the microwaves are received and synthesized by the rectenna 5 in the rectenna base station 4. If it deviates, the electric power produced | generated in the rectenna base station 4 will fall. Such a phase shift occurs due to a phase shift of a reference signal serving as a reference of a microwave generated by each power transmission device 1 or a change in position or posture of each power transmission device 1.

FIG. 8 is a functional block diagram showing the configuration of the power transmission device 1. In FIG. 8, 11 is an input terminal of a reference signal input from the source oscillation control device 2, 12 is a multiplier that multiplies the reference signal and outputs a microwave, 13 is a phase shifter that adjusts the phase of the microwave, and 14 Is a distributor that distributes the microwaves to each transmitting antenna element 9, 15 is a phase shifter that adjusts the phase of the distributed microwaves, and 16 is an amplifier that amplifies the microwaves. Reference numeral 42 denotes a power supply device. Reference numeral 32 denotes a power distribution unit that switches ON / OFF of the power supplied to the amplifier 16 based on a command from the command discriminator 21. The power supplied from the power supply device 42 is amplified via the power distribution unit 32. A microwave having a predetermined power level is generated by being input to 16, and is radiated to the space from the transmitting antenna element 9 connected to the amplifier 16. The connection between the amplifier 16 and the transmission antenna element 9 may be one-to-one, or a plurality of transmission antenna elements 9 are connected to one amplifier 16 as in one-to-four. But it ’s okay.
The beam drive control unit 19 obtains the phase shift amount of each phase shifter 15 based on the command from the command discriminator 21 so that the microwave transmitted from the transmission antenna element 9 is directed. The command discriminator 21 compares the identification code given to the power transmission device 1 (this identification code is stored as its own identification code) with the control command from the supervisory control device 41, and the code And the REV control unit 22 performs phase adjustment control related to the REV method based on the command from the command discriminator 21. The phase control unit 23 performs phase setting for the phase shifter 13 and the phase shifter 15.

  FIG. 9 is a functional block diagram showing the configuration of the rectenna base station. The rectenna 5 receives the microwave transmitted from the power transmission device 1 and generates power. The rectifying and synthesizing unit 24 synthesizes and outputs the electric power generated by the rectenna 5.

  Next, the operation will be described. The monitoring control device 41 outputs the direction of the rectenna base station viewed from the power transmission device 1 to the power transmission device 1 as a control command. Here, the direction of the rectenna base station viewed from the power transmission device 1 is known information. The beam drive control unit 19 calculates a phase amount to be set for each phase shifter 15 based on the control command, and outputs the phase amount to the phase control unit 23. The phase control unit 23 uses the input phase amount to change the phase of each phase shifter 15. Set.

  An adjustment method of the phase shifter 15 using the REV method can be used for the phase adjustment of each transmission antenna element 9 in the initial and regular maintenance of the single power transmission device 1. A microwave is transmitted only by the power transmission device 1 to be maintained, and the calculation for obtaining the phase adjustment amount based on the REV method is monitored based on the radio wave intensity measured by the receiver 26 by rotating the phase of each phase shifter 15. This is performed by the control device 41. The obtained phase adjustment amount is stored in the REV control unit 22 as a control command. At this time, since the monitor antenna 25 is disposed in the vicinity of the antenna surface of the power transmission device 1, the phase adjustment amount is calculated so as to correct the difference from the phase adjustment amount when it is disposed sufficiently far from the antenna surface in advance. . The monitor antenna 25 may be arranged on the same plane as the antenna surface of the power transmission device 1.

  Next, an example of processing for correcting a phase shift between the power transmission apparatuses 1 will be described. First, the power transmission device 1 is designated by its identification code, and a control command (including the designated identification code) for instructing a phase change to the phase shifter 13 of the power transmission device 1 is transmitted from the monitoring control device 41 to the power. Transmit to the transmitter 1. While changing the identification code, the phase of the phase shifter 13 is rotated with respect to all the power transmission devices 1, and the calculation based on the REV method is performed by the monitoring control device 41 based on the radio wave intensity measured by the receiver 26. Thus, the phase adjustment amount for the phase shift between the power transmission apparatuses 1 can be obtained.

Next, the operation of the entire wireless power transmission system will be described with reference to FIG. FIG. 10 is a flowchart showing an operation flow of the wireless power transmission system according to Embodiment 2 of the present invention.
In step S1, a microwave is transmitted from the power transmission device 1, and it is determined in step 2 whether or not the time for performing regular maintenance has elapsed. When the predetermined time has elapsed, the supervisory control device 41 instructs the power transmission device 1 to execute the REV method in step 3.

  When the REV method measurement in step S3 is completed, after the power transmission of the power transmission device 1 is temporarily stopped in step S4, in step S5, the supervisory control device 41 determines all the systems based on the REV method measurement data. Judge whether any abnormality has occurred. When the monitoring control unit 41 calculates the phase correction value for each power transmission device 1 from the measurement result of the REV method, the amplitude contribution of each power transmission device 1 is also calculated at the same time. This amplitude contribution is almost constant in all the power transmission apparatuses 1, and a threshold value used for determining whether an abnormality has occurred may be determined in consideration of manufacturing variations between apparatuses. When the relative amplitude obtained from the measurement result of the REV method is smaller than a preset threshold value, the control device 41 determines that an abnormality has occurred in the power transmission device.

  Since the power transmission device 1 is a device that transmits power output from the power supply device 42 to the rectenna base station 4, it is necessary to transmit power as efficiently as possible. Therefore, if power is supplied to the power transmission device 1 that is determined to be abnormal by the REV method, power is wasted. In order to avoid this, if it is determined in step S5 that there is an abnormality, an instruction to stop the supply of power is transmitted as a control command to the power transmission device 1 in which an abnormality has occurred in step 11. The power transmission device 1 that has received the instruction stops the power supply to the amplifier 16 by the power distribution unit 32. Further, in step S12, when the number N of power transmission apparatuses 1 in which an abnormality has occurred exceeds a certain value N1, the operator is instructed to replace the apparatus in step S21. At this time, as the wireless power transmission system, the number of power transmission devices 1 that can realize the minimum power transmission is set in advance as N1, and the determination is made in step S12.

  When there is no abnormality in the power transmission device 1 or when the number N of the power transmission devices 1 in which the abnormality has occurred does not exceed N1, power transmission is resumed in step S6. As a result, it is possible to avoid the occurrence of transmission power waste due to the phase shift of the power transmission device 1 and the occurrence of an abnormality in the power transmission device 1. Furthermore, even when the number of power transmission devices 1 in which an abnormality has occurred increases and it is difficult to operate as a wireless power transmission system, early restoration is possible by instructing the operator to replace the device.

DESCRIPTION OF SYMBOLS 1 Power transmission device 2 Power source control device 3 Reference signal receiving antenna 4 Rectenna base station 5 Rectenna 7 Microwave transmission antenna 8 Substrate 9 Transmitting antenna element 10 Pilot signal receiving antenna 11 Reference signal input terminal 12 Multiplier 13 Phase shifter 14 Distributor 15 Phase shifter 16 Amplifier 17 Photoelectric conversion unit 18 Tracking receiver 19 Beam drive control unit 20 Demodulator 21 Command discriminator 22 REV control unit 23 Phase control unit 24 Rectification synthesis unit 25 Monitor antenna 26 Receiver 27 Phase monitoring control Unit 28 pilot signal transmission unit 29 modulator 30 transmitter 31 pilot signal transmission antenna 32 power distribution unit 41 monitoring control device 42 power supply unit

Claims (9)

Receives sunlight, performs photoelectric conversion, generates microwaves based on the obtained power, transmits microwaves to the rectenna base station, receives the rectenna base station, and converts it to DC power In the wireless power transmission system
The rectenna base station includes a rectenna that receives the microwave, a monitor antenna that is provided in the vicinity of the rectenna and receives the microwave, and a pilot signal transmission antenna that transmits a pilot signal to the plurality of power transmission devices. , A command signal for changing the phase of the microwaves in the plurality of power transmission devices so that the radio wave intensity of the microwaves received by the monitor antenna or the DC power converted by the rectenna is maximized by the REV method. And a phase monitoring control unit that determines abnormality of the plurality of power transmission devices from the measurement result of the REV method,
Each of the plurality of power transmission devices includes a plurality of transmission antenna elements that transmit the microwaves to the rectenna base station, a pilot signal reception antenna that receives the pilot signal, and a pilot signal received by the pilot signal reception antenna. A tracking receiver that detects the direction of arrival, and a beam drive control unit that adjusts the phase so that the microwaves transmitted from the plurality of transmission antenna elements are directed in the direction of arrival of the pilot signal detected by the tracking receiver; Based on the command signal from the phase monitoring control unit, a phase control unit that changes the phase of the microwave, a plurality of amplifiers that amplify the microwave using the power converted from the sunlight, and A wireless power transmission system comprising a power distribution unit for controlling power supply to each amplifier.   The phase monitoring control unit determines that an abnormality has occurred in the power transmission device when the relative amplitude obtained from the measurement result of the REV method is smaller than a preset threshold value. The wireless power transmission system according to 1.   3. The wireless power transmission system according to claim 1, wherein the power transmission apparatus in which an abnormality has occurred stops power supply to the amplifier via the power distribution unit according to an instruction from the phase monitoring control unit.   The said phase monitoring control part performs the calculation by the said REV method based on the electromagnetic wave intensity and phase change of the microwave which are received with the said monitor antenna, The one of Claim 1 thru | or 3 characterized by the above-mentioned. Wireless power transmission system. In the rectenna base station that receives sunlight and converts it into DC power by receiving microwaves transmitted from a plurality of power transmission devices that generate microwaves based on photoelectric conversion obtained by photoelectric conversion,
A rectenna that receives the microwave, a monitor antenna that is provided in the vicinity of the rectenna, receives a microwave, a pilot signal transmission antenna that transmits a pilot signal to the plurality of power transmission devices, and an operation based on the REV method Generating a command signal for changing the phase of the microwaves in the plurality of power transmission devices so that the radio wave intensity of the microwaves received by the monitor antenna or the DC power converted by the rectenna is maximized; and A rectenna base station comprising a phase monitoring control unit that determines an abnormality of the plurality of power transmission devices from a measurement result of the REV method. In the power transmission device that receives the sunlight and photoelectrically converts the microwave generated based on the obtained power to the rectenna base station,
A plurality of transmitting antenna elements for transmitting the microwave to the rectenna base station, a pilot signal receiving antenna for receiving a pilot signal from the rectenna base station, and a tracking receiver for detecting an arrival direction of the received pilot signal; The beam drive control unit for adjusting the phase so that the microwaves transmitted from the plurality of transmitting antenna elements are directed in the arrival direction of the pilot signal detected by the tracking receiver, and the command signal from the rectenna base station A phase control unit that changes the phase of the microwave, a plurality of amplifiers that amplify the microwave using the power converted from the sunlight, and a power distribution unit that controls power supply to the amplifiers A power transmission device comprising: A microwave is generated based on the power supplied from the power supply device, and the microwave is transmitted to the rectenna base station from a plurality of power transmission devices that direct the microwave in the direction indicated by the monitoring and control device. The rectenna base station In the wireless power transmission system that receives and converts to DC power,
The rectenna base station includes a rectenna that receives the microwave, and a rectifying and synthesizing unit that synthesizes power generated by the rectenna.
Each of the plurality of power transmission devices has a plurality of transmission antenna elements that transmit microwaves to the rectenna base station, and a microwave that is transmitted from the plurality of transmission antenna elements is directed toward the rectenna base station. A beam drive controller that performs phase adjustment, a phase controller that changes the phase of the microwave based on a control command from the monitoring controller, and the microwave that is supplied from the power supply device. A plurality of amplifiers for amplification, and a power distribution unit for controlling power supply to each of the amplifiers,
The supervisory control device, based on the radio wave intensity of the microwave received by the monitor antenna disposed in the vicinity of the power transmission device, so that the DC power converted by the rectenna by the REV method calculation is maximized, A wireless power transmission system, comprising: generating a control command for changing a microwave phase in the plurality of power transmission devices; and determining abnormality of the plurality of power transmission devices from a measurement result of the REV method.   8. The monitoring control device according to claim 7, wherein when the relative amplitude obtained from the measurement result of the REV method is smaller than a preset threshold value, it is determined that an abnormality has occurred in the power transmission device. The wireless power transmission system described.   The wireless power transmission system according to claim 7 or 8, wherein the power transmission device in which an abnormality has occurred stops power supply to the amplifier via the power distribution unit according to an instruction from the monitoring control device.

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