JP5327059B2 - Wireless power transmission system and rectenna base station - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless power transmission system, along with a power transmission apparatus and rectenna base station, capable of aligning a phase when microwaves transmitted from each power transmission apparatus are received at the rectenna base station more effectively without increasing a circuit scale. <P>SOLUTION: The rectenna base station receives microwaves transmitted by the power transmission apparatus via a receiving antenna for REV, generates a command signal for adjusting a phase so that a radio field intensity becomes the maximum, and transmits it to the power transmission apparatus. The power transmission apparatus receives a pilot signal by a pilot signal receiving antenna 10, performs phase control on a phase-shifter 15 so that the microwaves irradiated are directed to the incoming direction of the pilot signal received by a tracking receiver 18, regenerates the command signal superposed on the pilot signal by a demodulator 20, and performs phase control based on the command signal by a phase-control unit 23. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

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. And a rectenna base station used therefor .

  For example, Patent Literature 1 describes a conventional wireless power transmission system that performs microwave power transmission from a power generation satellite disposed on an orbit in outer space to a ground receiving device. In this conventional wireless power transmission system, a power generation satellite receives a pilot signal transmitted from a rectenna base station, and transmits a pilot reply signal 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 return signals for the respective 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 the circuit related to the pilot signal, and the whole power generation efficiency is lowered.

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 and a rectenna base station capable of aligning the phases when being performed.

A wireless power transmission system according to the invention of claim 1 is a wireless power transmission system in which each microwave is transmitted from a plurality of power transmission devices to a rectenna base station, and received by the rectenna base station to generate power. The rectenna base station is provided in the vicinity of the rectenna that receives the microwaves transmitted from the plurality of power transmission devices, and the microwaves transmitted from the plurality of power transmission devices. Each of the plurality of power transmission apparatuses receives a REV receiving antenna, a pilot signal transmission antenna that transmits a pilot signal to the plurality of power transmission apparatuses, and an intensity of radio waves received by the REV reception antenna. A phase monitoring control unit for generating each command signal for instructing a change in the phase of each microwave. Each of the plurality of power transmission devices includes a microwave transmission antenna that transmits the microwave to the rectenna base station, a pilot signal reception antenna that receives the pilot signal, and a pilot signal. Each tracking receiver for detecting the arrival direction of the pilot signal received by the receiving antenna, and each of the microwaves transmitted from each of the microwave transmission antennas in the arrival direction of the pilot signal detected by each of the tracking receivers. and each beam drive control unit for controlling the direction of transmitting to face the direction of the waves, based on the respective command signal from the phase monitor and control unit, each of the distance variation of the plurality of power transmission apparatus due to, each phase system for correcting the phase shift of the micro waves transmitted from each of the power transmission apparatus It is obtained by and a part.

The rectenna base station according to the invention of claim 2 is transmitted from the plurality of power transmission devices in the rectenna base station that receives and combines the microwaves transmitted from the plurality of power transmission devices to generate power. A rectenna that receives each of the microwaves, a REV receiving antenna that is provided in the vicinity of the rectenna and receives each of the microwaves transmitted from the plurality of power transmission devices, and the plurality of power transmission devices Each of the plurality of power transmission devices is instructed to change the phase of each of the microwaves so that the radio wave intensity received by the pilot signal transmitting antenna for transmitting the pilot signal and the REV receiving antenna is increased. And a phase monitoring control unit for generating a command signal.

A wireless power transmission system according to a third aspect of the invention is the wireless power transmission system according to the first aspect of the invention, wherein each of the microwave transmission antennas includes a plurality of transmission antenna elements, and each of the beam drive control units is The direction of transmitting each microwave is controlled by controlling the phase of each of the plurality of transmission antenna elements .

A wireless power transmission system according to a fourth aspect of the present invention is the wireless power transmission system according to the first or third aspect of the present invention, wherein the rectenna base station further superimposes each of the command signals on the pilot signal. Each of the plurality of power transmission devices further includes a demodulator that reproduces each command signal from a pilot signal received by each tracking receiver.

A rectenna base station according to a fifth aspect of the present invention is the rectenna base station according to the second aspect of the present invention, further comprising a modulator for superimposing each of the command signals on the pilot signal .

According to the present invention, the rectenna base station generates the command signal for changing the phase of the power transmission device so that the radio wave intensity of the microwave received by the REV receiving antenna increases, and the power transmission device The phase of the microwaves transmitted from each of the power transmission devices due to the distance change of each of the plurality of power transmission devices is suppressed while suppressing an increase in circuit scale. The shift can be corrected, and the phase shift between the microwaves transmitted from the respective power transmission apparatuses is corrected, so that larger power can be obtained in the rectenna base station.

It is a block diagram showing the structure of the wireless power transmission system which concerns on Embodiment 1 of this invention. It is a schematic diagram showing the example of the position and attitude | position change of an electric power transmission apparatus. It is an external view which shows the external shape of the transmission panel of an electric power transmission apparatus. It is a functional block diagram which shows the structure of a power transmission device. It is a functional block diagram which shows the structure of a rectenna base station. It is a flowchart which shows the process sequence which performs phase adjustment of an electric power transmission apparatus. It is a flowchart which shows the process sequence which performs the phase adjustment of the power transmission apparatus which concerns on Embodiment 2 of this invention. It is a functional block diagram which shows the structure of the rectenna base station which concerns on Embodiment 3 of this invention. It is a functional block diagram which shows the structure of the power transmission device which concerns on Embodiment 3 of this invention.

  Embodiment 1

  A wireless power transmission system, a power transmission device, and a rectenna base station 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. Alternatively, the source oscillation control device 2 may have a wireless transmission system management (fault diagnosis, etc.) function to transmit and receive control signals between the source oscillation control device 2 and each power transmission device 1. Reference numeral 4 denotes a rectenna base station that receives microwaves from the power transmission device 2 and generates power, and 5 is a rectenna including a plurality of microwave reception antennas. 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 devices 1. Transmission and reception of reference signals between the source control device 2 and each power transmission device 1, and further control signal The transmission / reception is as described above.

  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 and a position change or posture change of each power transmission device 1 (particularly, a transmission panel portion). To do. FIG. 2 shows an example of a change in position and posture of the microwave transmission antenna 7 for power transmission provided in the power transmission device 1. FIG. 2A shows that n microwave transmission antennas 7 are almost independent. This is a case where the position and posture change due to movement, and may occur remarkably when the discrete arrangement shown in FIG. FIG. 2B shows a case where the position of the n microwave transmitting antennas 7 changes as a whole, and this may occur significantly when the mechanical structure 7 shown in FIG. 1B can be regarded as a substantially rigid body. There is. FIG. 2 (c) shows a case where n microwave transmitting antennas 7 change in position and posture in part, and the mechanical structure 7 shown in FIG. 1 (b) cannot be a rigid body and is flexible. When formed as a structure, it may occur significantly.

2 (a) to 2 (c), the change in posture occurring in each microwave transmitting antenna 7 is represented by an azimuth angle change θ _AZ and an elevation angle change θ _EL , and The 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 control device 2, 12 is a multiplier for multiplying the reference signal and outputting a carrier signal, 13 is a phase shifter for adjusting the phase of the carrier signal, 14 Is a distributor that distributes the carrier signal, 15 is a phase shifter that adjusts the phase of the distributed carrier signal, and 16 is an amplifier that amplifies the carrier signal. Reference numeral 17 denotes a photoelectric conversion unit. The power generated by the photoelectric conversion unit 17 is input to the amplifier 16 to generate a microwave having a predetermined power level, and is radiated from the transmitting antenna element 9 connected to the amplifier 16 to the space. The 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 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 element electric field vector rotation method (REV method: REV is an abbreviation of 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, reference numeral 24 denotes a rectifying / combining unit that rectifies and combines the microwaves received by the rectenna 5 to generate electric power, and 25 denotes a REV receiving antenna that receives the microwaves transmitted from the power transmission device 1. Reference numeral 26 denotes a receiver for detecting the radio wave intensity and phase of the microwave received by the REV receiving antenna. Here, both the rectenna 5 and the REV receiving antenna 25 receive microwaves transmitted from the plurality of transmitting antenna elements 9 of the power transmitting apparatus 1, and the REV receiving antenna 25 is located in the vicinity of the rectenna 5. Preferably, the REV receiving antenna 25 is 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. With such an operation, the direction of the rectenna 5 of the rectenna base station 4 caused by the attitude and the microwave transmitted from the power transmission device 1 among the changes in position and attitude shown in FIGS. 2 (a) to 2 (c). The deviation from the direction is corrected. Note that the configuration and arrangement of the pilot signal receiving antenna 10 are not limited to those shown in FIG. 3, but may be anything that can be used for tracking reception as described above.

  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 REV receiving antenna 25 of the rectenna base station 4.

  Further, according to the modified REV method described in detail in Japanese Patent Laid-Open No. 2001-201526, the radio wave intensity and phase of the synthesized wave are measured, and based on these measurement results, the phase shifter 15 is measured. It is also possible to perform highly accurate phase adjustment in consideration of amplitude error and phase error correction according to the phase rotation on the power supply path including. As shown in FIG. 5, a receiver 26 is connected to the REV receiving antenna 25 of the rectenna base station 4, and by this receiver 26, the radio wave intensity of the combined wave of the microwaves transmitted from the power transmission device 1 is determined. Since the phase is detected, highly accurate phase adjustment of the phase shifter 15 can be performed for each power transmission device 1 by using the modified REV method.

  In the initial and regular maintenance of the power transmission device 1, in the phase adjustment performed independently for each power transmission device 1, the power transmission device 1 to be adjusted performs microwave transmission, and the microwave transmission of the other power transmission devices 1 Stop. 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 (or radio wave intensity and phase) data, and outputs the phase adjustment amount to the phase control unit 23.

  Next, an example of processing for correcting the phase shift between the power transmission devices 1 caused by the position change ΔL shown in FIGS. 2A to 2C will be described based on FIG. FIG. 6 is a flowchart showing a processing sequence for adjusting the phase of the power transmission apparatus. This processing is performed by the phase monitoring control unit 27 of the rectenna base station 4. Now, it is assumed that there are n power transmission apparatuses 1, and the phase monitoring control unit 27 in the rectenna base station 4 first sets the variable number k to 1 in step S1 and 1 corresponding to the variable number k = 1 in step S2. The power transmission device 1 is designated by its identification code. In step S <b> 3, a command signal (including a designated identification code) for instructing phase change is transmitted from the rectenna base station 4. Based on the command signal, the power transmission device 1 with the matching identification code uniformly changes the phase of the entire subordinate transmission panel by a predetermined amount. By this change, the radio wave intensity P and the phase φ of the combined wave received by the REV receiving antenna 25 of the rectenna base station 4 change, and the radio wave intensity P and the phase φ are detected in step S4. In step S5, the phase monitoring control unit 27 determines whether the number of detections for the number of phase settings has been reached, and sends a command signal for instructing repeated phase changes. As a result of the determination in step S5, the phase adjustment of the power transmission device 1 designated by k = 1 is completed, it is determined in step S6 that the variable number k is not greater than n, k is increased by 1, and the next Next, the phase adjustment of the power transmission device 1 is started. By repeating this process sequentially for each power transmission device, the data of the radio wave intensity P and the phase φ of the combined wave are obtained, and in step S8, each power transmission device is calculated by calculation based on the REV method. A phase adjustment amount (phase adjustment amount of the phase shifter 13) for uniformly changing the phase of the entire transmission panel of 1 can be obtained.

  Note that the phase monitoring control unit 27 measures and acquires only the radio wave intensity P in step S4, and changes the phase of the entire transmission panel of each power transmission device 1 uniformly by calculation based on the REV method. An adjustment amount (phase adjustment amount of the phase shifter 13) may be obtained.

  In the rectenna base station 4 shown in FIG. 5, the phase monitoring control unit 27 designates the identification code of the power transmission device 2 corresponding to the variable number k (step S <b> 2), and sends a command signal including this identification code to the modulator 29. By outputting, the command signal is superimposed on the pilot signal in the modulator 29, amplified and transmitted by the transmitter 30, thereby executing “command to change phase” in step S 3. 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 the command from the rectenna base station 4, and the composite wave is received by the REV receiving antenna 25 and the receiver 26 provided in the rectenna base station 4. By detecting the radio wave intensity P (or the radio wave intensity P and the phase φ) and adjusting the phase, correction of the phase shift of the microwave accompanying the position change ΔL shown in FIGS. 2A to 2C is performed. In addition, the phase of the reference signal supplied to each power transmission device 1 is also 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, a larger power can be obtained. 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 side can be configured using the pilot signal reception system, and the circuit scale can be further reduced. Can do.

  Embodiment 2

  A wireless power transmission system, a power transmission device, and a rectenna base station according to Embodiment 2 of the present invention will be described with reference to FIG. The power transmission apparatus and rectenna base station according to Embodiment 2 of the present invention have the same configuration and function as the configuration and function described in Embodiment 1 with reference to FIGS. Here, a processing sequence for performing phase adjustment of the power transmission apparatus, which is a different part in the second embodiment, will be described with reference to FIG.

  FIG. 7 is a flowchart showing a processing sequence for performing phase adjustment of the power transmission apparatus according to Embodiment 2 of the present invention. This processing is performed by the phase monitoring control unit 27 of the rectenna base station 4. Also in this processing flow, it is assumed that there are n power transmission apparatuses 1. The phase monitoring controller 27 in the rectenna base station 4 detects the radio wave intensity P obtained by receiving with the REV receiving antenna 25 in step S9. It is determined in step S10 whether the detected radio wave intensity P is greater than the lower threshold value P2. If the radio wave intensity P is larger than the lower threshold value P2, it is regarded as an allowable range and Steps S9 and S10 are repeated. When the detected radio wave intensity P becomes equal to or lower than the lower threshold value P2, the process proceeds to step S11 to start phase adjustment. The sequence from step S11 to step S18 is the same as the sequence from step S1 to step S8 in FIG. 6 described in the first embodiment, and a description thereof will be omitted. However, when the phase adjustment of the n power transmission apparatuses 1 is completed, step S19 is performed. , And it is determined whether or not the radio wave intensity P detected after the end of the phase adjustment is larger than the upper threshold value P1. If the power value P is greater than the upper threshold value P1, it is determined that the phase has been adjusted well, and the process returns to step S9. If the power value P is equal to or lower than the upper threshold value P1, the process returns to step S10 to perform the phase adjustment again.

  The upper threshold value P1 and the lower threshold value P2 are set to predetermined values according to the performance of the system to be constructed. The microwave power that each power transmission device 1 emits into the space takes a maximum value in consideration of the efficiency of the photoelectric conversion unit 17 and the amplifier 16 shown in FIG. 4, the loss in the transmission line, the directivity gain of the transmission panel, and the like. Further, for the radio wave intensity at which the microwave transmitted from the power transmission device 1 is received by the REV receiving antenna 25, the theoretical maximum value can be obtained by performing an appropriate analysis under conditions where the phases are uniform. With respect to this theoretical maximum value, a capability value is obtained in consideration of factors such as a phase resolution in each power transmission device 1 and a change in directivity gain of the transmission panel due to a shift in the microwave transmission direction. For example, this capability value is set as the upper threshold value P1, and the value of the radio wave intensity corresponding to the minimum power generation capability required for the system is set as the lower threshold value P2. More specifically, considering each capability value, for example, the 90% level is set as the upper threshold value P1 and the 80% level is set as the lower threshold value P2 with respect to the theoretical maximum value of the radio wave intensity of the combined wave. Such a setting may be made.

  The upper threshold value P1 and the lower threshold value P2 may be appropriately reset during operation. If the detection result of the radio wave intensity P after the actual phase adjustment is almost a specific value over a plurality of times, the value is grasped as the maximum capacity of the actual hardware. Therefore, the specific value may be set as the maximum value, and the 90% level may be set as the upper threshold value P1 and the 80% level may be set as the lower threshold value P2.

  When the power information monitored by the photoelectric conversion unit 17 is provided from the power transmission device 1 or the source oscillation control device 2 to the rectenna base station 4, the phase monitoring control unit 27 obtains the combined wave obtained at that time. The maximum value of the radio field intensity can be known, and the above-described upper threshold value P1 and lower threshold value P2 may be reset.

  Embodiment 3

A wireless power transmission system, a power transmission device, and a rectenna base station according to Embodiment 3 of the present invention will be described with reference to FIGS. The rectenna base station according to the third embodiment of the present invention transmits a command signal for instructing phase change through a communication line, and acquires power information of the power transmission device 2 through the communication line. FIG. 8 is a functional block diagram showing the configuration of the rectenna base station 4 according to Embodiment 3 of the present invention, and FIG. 9 is a functional block diagram showing the configuration of the power transmission device 1 according to Embodiment 3 of the present invention. is there. In FIG. 8, 33 is a command transmitter that transmits a command signal, 34 is a transmission / reception duplexer, 35 is a communication line transmitting / receiving antenna, 36 is a receiver that receives a communication signal from the power transmission device 1 or the source control device 2, Reference numeral 37 denotes a pilot signal transmission unit that transmits a pilot signal. 8, circuits and portions having the same reference numerals as those in FIG. 5 represent circuits and portions that are the same as or correspond to those circuits and portions in FIG. In FIG. 9, reference numeral 38 denotes an input terminal to which a command signal is input. 9, circuits and portions having the same reference numerals as those in FIG. 4 represent circuits and portions that are the same as or correspond to those circuits and portions in FIG.

  The phase monitoring control unit 27 transmits a signal instructing each power transmission device 1 to change the phase, but this may be performed by a communication line. In this case, the rectenna base station 4 has a command transmitter 33, and when a phase change command (command signal) including the identification code of the power transmission device 1 is input from the phase monitoring control unit 27 to the command transmitter 33, The command transmitter 33 superimposes this command signal on the carrier wave of the communication line, and transmits it to the power transmission device 1 or the source oscillation control device 2 via the transmission / reception duplexer 34 and the transmission / reception antenna 35. The power transmission device 1 or the source oscillation control device 2 receives this and reproduces the command signal. The reproduced command signal is input from the input terminal 38, and the identification code is compared by the command discriminator 21. If they match, the command is output to the REV control unit 22, and the REV control unit 22 receives the command and performs phase control. The unit 23 is instructed to change the phase of the phase shifter 13.

  Further, the power information monitored by the photoelectric conversion unit 17 is provided from the power transmission device 1 or the source oscillation control device 2 to the rectenna base station 4 using a communication line. The rectenna base station 4 receives the power information by the transmitting / receiving antenna 35, demodulates and reproduces it by the receiver 36 via the transmitter / receiver demultiplexer 34, and outputs it to the phase monitoring control unit 27. Based on the power information, the phase monitoring control unit 27 can know the maximum value of the radio wave intensity obtained at that time, and resets the upper threshold value P1 and the lower threshold value P2 described in the second embodiment. You may do it.

DESCRIPTION OF SYMBOLS 1 Power transmitter 4 Rectenna base station 5 Rectenna 9 Transmit antenna element 10 Pilot signal receiving antenna 13 Phase shifter 15 Phase shifter 18 Tracking receiver 19 Beam drive control part 20 Demodulator 21 Command discriminator 22 REV control part 23 Phase control Unit 24 rectifying / combining unit 25 REV receiving antenna 26 receiver 27 phase monitoring control unit 28 pilot signal transmitting unit 29 modulator 31 pilot signal transmitting antenna 33 command transmitter

Claims (5)

In a wireless power transmission system in which each microwave is transmitted from a plurality of power transmission devices to a rectenna base station, and is received by the rectenna base station to generate power, the rectenna base station transmits from the plurality of power transmission devices A rectenna that receives the microwaves, a REV receiving antenna that is provided in the vicinity of the rectenna and receives the microwaves transmitted from the plurality of power transmission devices, and the plurality of power transmissions. Instruct each of the plurality of power transmission devices to change the phase of each of the microwaves so that the radio wave intensity received by the pilot signal transmitting antenna for transmitting a pilot signal to the device and the REV receiving antenna increases. A phase monitoring control unit that generates each command signal, and each of the plurality of power transmission devices includes Each microwave transmitting antenna that transmits an electromagnetic wave to the rectenna base station, each pilot signal receiving antenna that receives the pilot signal, and the arrival direction of the pilot signal received by each pilot signal receiving antenna is detected. and each of the tracking receiver, the arrival direction of the pilot signal detected by the tracking receiver of said each said direction control to transmit to face the direction of the microwaves of the respective transmitted from each of the above microwave transmission antenna Are transmitted from each of the power transmission devices due to the distance change of each of the plurality of power transmission devices based on each of the beam drive control units that perform the above and each of the command signals from the phase monitoring control unit wireless power transmission, characterized by comprising a respective phase control unit for correcting the phase shift of the micro-waves Stem.   In the rectenna base station that receives and synthesizes the microwaves transmitted from the plurality of power transmission devices to generate power, the rectenna that receives the respective microwaves transmitted from the plurality of power transmission devices, and A REV receiving antenna that is provided in the vicinity of the rectenna and receives each of the microwaves transmitted from the plurality of power transmission devices; a pilot signal transmission antenna that transmits a pilot signal to the plurality of power transmission devices; A phase monitoring control unit that generates a command signal for instructing each of the plurality of power transmission devices to change the phase of each of the microwaves so that the radio wave intensity received by the REV receiving antenna increases; Rectena base station characterized by that.   Each of the microwave transmission antennas includes a plurality of transmission antenna elements, and each of the beam drive control units controls a direction of transmitting each of the microwaves by controlling a phase of each of the plurality of transmission antenna elements. The wireless power transmission system according to claim 1, wherein: The rectenna base station further includes a modulator that superimposes each of the command signals on the pilot signal, and each of the plurality of power transmission devices further includes a pilot signal received by each of the tracking receivers. the wireless power transmission system according to claim 1 or claim 3, characterized by comprising a respective demodulator for reproducing the command signal of the respective.   The rectenna base station according to claim 2, further comprising a modulator that superimposes each of the command signals on the pilot signal.

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