JP2018121417A - Power supply system and power supply method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply system and power supply method for supplying stable power in a simple configuration using an electric supply line.SOLUTION: The power supply system includes: an electric supply line 1 formed into a loop shape, and contactlessly supplying power to a power reception device 200; and a progressive wave generator 2s having a plurality of high frequency power supplies 22a and 22b for generating a progressive wave for supplying power to the electric supply line. The positions of the plurality of high frequency power supplies 22a and 22b are determined such that the phases of high frequency waves outputted from the high frequency power supplies 22a and 22b synchronize with each other.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a power feeding system and a power feeding method.

  In recent years, development of a non-contact power transmission system that transmits power from a power transmission device to a power reception device in a contactless manner has been advanced. Some non-contact power transmission systems use a power supply line as a power transmission device and transmit power from the power supply line to the power reception device in a contactless manner (see, for example, Patent Documents 1 and 2 and Non-Patent Document 1 below). ).

  In such a non-contact power transmission system, if the impedance at the end of the feeder line does not match the impedance of the feeder line, a reflected wave is generated at the end of the feeder line. When a reflected wave is generated, a standing wave is generated in the feed line due to the reflected wave and the traveling wave toward the end of the feed line. In the standing wave, the waveform does not move, and the antinodes and nodes of the wave are fixed. Therefore, it is impossible to supply power at a portion near the node of the standing wave. As a technique for improving such a situation, for example, there are techniques disclosed in Patent Documents 1 and 2 and Non-Patent Document 1.

  Patent Document 1 discloses a technique for suppressing the occurrence of a standing wave by matching the impedance on the terminal end side of the power supply line with the impedance on the power supply line side. In Patent Document 2, the standing wave generated in the feeder line includes two kinds of standing waves, that is, a standing wave caused by an electric field and a standing wave caused by a magnetic field. It is disclosed that a standing wave due to a magnetic field becomes antinode at a position where the standing wave becomes a node, and a standing wave due to a magnetic field becomes a node at a position where the standing wave due to an electric field becomes antinode. This Patent Document 2 discloses a technique for receiving power by selecting the higher one of the electric field level and the magnetic field level using such a relationship.

  Non-Patent Document 1 prepares two systems of feeder lines, and two systems of feeder lines so that an antinode of a standing wave that appears in the other feeder line appears at the position of the node of the standing wave that occurs in one feeder line. And a technique for mitigating power fluctuations due to standing waves by combining power received from both feeders.

JP 2013-162625 A JP-A-2005-45326

Takuya Maekawa, “Stabilization of Received Power in Parallel Two-Wire Wireless Power Supply”, Master's Thesis, NAIST-IS-MT1451094, Nara Institute of Science and Technology, February 4, 2016

  However, in the technique described in Patent Document 1, it is necessary to provide a power regeneration device at the end of the power supply line. In the technique described in Patent Document 2, two types of couplings, that is, an electric field coupler and a magnetic field coupler are provided for each transport vehicle. It is necessary to provide a device, and the technique described in Non-Patent Document 1 requires two power supply lines. Therefore, the configuration is complicated with any of the techniques, and the cost increases.

  Then, an object of this invention is to provide the electric power feeding system and electric power feeding method which can supply the stable electric power with a simple structure using an electric power feeding line.

  A power supply system according to an aspect of the present invention is formed in a loop shape, and includes a power supply line that supplies power to a power receiving device in a contactless manner, and a plurality of high-frequency power sources that generate a traveling wave for supplying power to the power supply line A traveling wave generating device.

  According to this aspect, by forming the feed line in a loop shape, it is possible to generate a traveling wave for supplying power to the feed line with a plurality of high-frequency power sources while suppressing the occurrence of standing waves due to reflected waves. Therefore, it is possible to supply power uniformly along the feeder line.

  In the above aspect, the positions of the plurality of high frequency power supplies may be determined so that the phases of the high frequencies output from the respective high frequency power supplies are synchronized.

  According to this aspect, since the phase of the high frequency output from each high frequency power supply can be synchronized in the loop-shaped power supply line, it is possible to more reliably suppress the occurrence of standing waves.

  In the above aspect, the positions of the plurality of high frequency power supplies are determined such that the phase of the high frequency output from each high frequency power supply is synchronized with one of the two waves traveling in opposite directions on the feeder line. It is good to be.

  According to this aspect, the phase of the high frequency output from each high frequency power supply can be synchronized with one of the two waves traveling in the opposite directions on the feeder line, and the traveling wave is generated in a desired direction. It becomes possible.

  In the above aspect, when the plurality of high-frequency power sources are a plurality of voltage sources or a plurality of current sources, the adjacent high-frequency power sources have a positional relationship with an interval of ¼ wavelength of the high frequency in the feeder line, or It is good also as connecting to a feeder line so that it may become the positional relationship which left the space | interval for the length which added the 1/4 wavelength of the high frequency to the positive integer multiple of this wavelength.

  According to this aspect, since the apportioning ratio of each magnetic field generated by each high-frequency power supply can be changed seamlessly, a magnetic field can always be generated at all locations on the feeder line, and a standing wave can be generated. Can be suppressed more reliably.

  In the above aspect, when the plurality of high-frequency power sources are one voltage source and one current source, the voltage source and the current source may be connected to the same portion of the feeder line.

  According to this aspect, since the apportioning ratio of each magnetic field generated by each high-frequency power supply can be changed seamlessly, a magnetic field can always be generated at all locations on the feeder line, and a standing wave can be generated. Can be suppressed more reliably.

  In the above aspect, the length of the portion of the feeder line formed in a loop shape may be a positive integer multiple of the wavelength of the high frequency output from the high frequency power supply.

  According to this aspect, the phase of the high frequency output from the high frequency power supply and the phase of the high frequency that circulates around the power supply line can be more reliably matched and can be seamlessly connected. Generation of standing waves can be suppressed.

  In the above aspect, the traveling wave generator may further include a control unit that controls at least the phase of the high frequency output from the high frequency power supply.

  According to this aspect, the high-frequency phases output from the plurality of high-frequency power sources can be integrated and controlled by a command from the control unit.

  In the above aspect, the power supply line may be a parallel two-wire transmission line.

  According to this aspect, electric power can be supplied in a non-contact manner using a parallel two-wire transmission line. By adopting a parallel two-wire transmission line, for example, it becomes possible to easily extend the feeder line, which is effective when it is necessary to provide the feeder line over a wide range or a long distance.

  A power supply method according to another aspect of the present invention is a power supply method that supplies power to a power receiving device in a contactless manner using a power supply line, and a plurality of power supply methods connected to a power supply line formed in a loop shape. And a step of generating a traveling wave for supplying power to the power supply line using a high frequency power source.

  According to this aspect, by forming the feed line in a loop shape, it is possible to generate a traveling wave for supplying power to the feed line with a plurality of high-frequency power sources while suppressing the occurrence of standing waves due to reflected waves. Therefore, it is possible to supply power uniformly along the feeder line.

  ADVANTAGE OF THE INVENTION According to this invention, the electric power feeding system and electric power feeding method which can supply the stable electric power with a simple structure using an electric power feeding line can be provided.

It is the block diagram which showed typically the structure of the electric power feeding system in 1st Embodiment. It is the figure which showed typically the mode of the electric field which generate | occur | produces in a feeder line when using a single voltage source as a high frequency power supply. It is the figure which showed typically the mode of the electric field which generate | occur | produces in a feeder line when using a single current source as a high frequency power supply. 4 is a graph for explaining spatial and temporal changes in a magnetic field generated by the voltage source of FIG. 2 and the current source of FIG. 3. It is the block diagram which showed typically the structure of the electric power feeding system in 2nd Embodiment. FIG. 6 is a diagram schematically illustrating traveling waves generated by the two voltage sources in FIG. 5. It is the figure which showed typically the mode of the electric field which generate | occur | produces in a feeder line when the two voltage sources of FIG. 5 are used. It is the figure which showed typically the traveling wave which generate | occur | produces by the three voltage sources in the modification 3.

  A preferred embodiment of the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is a block diagram schematically showing the configuration of the power feeding system in the first embodiment. As shown in the figure, the power supply system 100 includes a power supply line 1 and a traveling wave generator 2. The traveling wave generator 2 includes a control unit 21, and a voltage source 22 and a current source 23 that are high-frequency power sources. Among the components shown in the figure, the components excluding the power receiving device 200 constitute the power feeding system 100.

  The power feeding system 100 transmits, for example, high-frequency power of several kHz to several hundreds of MHz generated by a high-frequency power source to the power receiving device 200 through the power supply line 1 in a non-contact manner, thereby connecting to the power receiving device 200 (the power receiving device). (Including the load).

  For example, the feed line 1 is laid along a production line such as a factory, and the power receiving apparatus 200 is an automatic guided vehicle (hereinafter referred to as “AGV”) that automatically travels using electromagnetic induction by the feed line 1. It is also mounted.) The power receiving device 200 includes a power receiving coil that generates a voltage by being coupled with a magnetic field generated in the vicinity of the feeder line 1 and a resonance capacitor. Thereby, the power receiving device 200 can receive power from the power supply line 1 in a contactless manner.

  The feeder 1 is, for example, a parallel two-wire transmission line and is constituted by two conductive wires. The feed line 1 is formed in a loop shape so that traveling waves are generated. By forming the feed line 1 in a loop shape, it is possible to avoid the generation of a reflected wave generated at the end, and thus it is possible to suppress the occurrence of a standing wave due to the reflected wave.

  The length of the portion forming the loop shape in the feeder line 1 is set to a positive integer multiple of the wavelength of the high frequency output from the voltage source 22 and the current source 23 which are high frequency power supplies. As a result, when the high frequency output from the high frequency power source circulates around the feeder line 1 and returns to the same location, the returned high frequency phase and the high frequency phase output from the high frequency power source more reliably match. (Synchronization is possible), and high frequencies can be seamlessly connected.

  The voltage source 22 and the current source 23 of the traveling wave generating device 2 generate a traveling wave for supplying power to the power receiving device 200 in the power supply line 1. The voltage source 22 and the current source 23 are connected to the same place P of the loop-shaped power supply line 1. Illustratively, the voltage source 22 can be connected between two conductors constituting the feeder 1. On the other hand, the current source 23 can be connected in series with the loop-shaped power supply line 1 by, for example, transformer coupling using an annular ferrite core. With such a configuration, each high frequency output from the voltage source 22 and the current source 23 starts from the connection point P with the loop-shaped power supply line 1, and each has two directions, clockwise and counterclockwise. proceed.

  The control unit 21 of the traveling wave generator 2 performs control so that the phases of the high frequencies output from the voltage source 22 and the current source 23 are synchronized. This makes it possible to more reliably suppress the occurrence of standing waves. The control part 21 should just be able to control so that it may synchronize with either one of the two waves which advance in the reverse direction in the feeder 1, when controlling so that each phase may synchronize. Thereby, the phase of the high frequency output from each high frequency power supply can be synchronized with one of the two waves traveling in the opposite directions, and the traveling wave can be generated in a desired direction.

  By configuring the power feeding system 100 in this manner, traveling waves that circulate around the loop-shaped power feeding line 1 can be generated. Thereby, power can be supplied uniformly along the feeder line 1. In the present embodiment, the high frequency that travels through the feeder line 1 by controlling the high frequency generated in both directions of the loop-shaped feeder line 1 using a plurality of high frequency power sources is referred to as a traveling wave.

  Here, the principle that a traveling wave is generated in the loop-shaped power supply line 1 by connecting the voltage source 22 and the current source 23 to the same portion of the power supply line 1 will be described below.

  First, FIG. 2 illustrates a state of an electric field generated in the feeder line 1 when a single voltage source 22 is used as a high-frequency power source. In the figure, the darker the color, the higher the electric field strength. In the figure, for convenience of explanation, the length of the feeder line 1 is set to three times the high frequency wavelength. In this case, the high frequency output from the voltage source 22 proceeds separately from the connection point P with the power supply line 1 and returns to the connection point P again. Since the length of the feeder line 1 is set to an integral multiple of the high frequency wavelength, the high frequency phase returning to the connection point P and the high frequency phase output from the voltage source 22 coincide with each other. Waves traveling from the connection point P to the left and right are seamlessly connected.

  In other words, the high-frequency wave that rotates clockwise and the high-frequency wave that rotates counterclockwise are two opposite waves having the same wavelength, period, and amplitude, and the two opposite waves overlap each other. A standing wave occurs. The standing wave maximizes the electric field at the connection point P of the feeder line 1 and at each point away from the connection point P by a positive integer multiple of ½ wavelength, while the magnetic field at these points is 0. Become.

  Next, FIG. 3 illustrates a state of an electric field generated in the feeder line 1 when a single current source 23 is used as a high-frequency power source. As in FIG. 2, the darker the color, the greater the electric field strength, and the length of the feeder line 1 is three times the high frequency wavelength. In this case, the high frequency output from the current source 23 proceeds separately from the connection point P with the power supply line 1 and returns to the connection point P again. Since the length of the feeder line 1 is set to an integral multiple of the wavelength of the high frequency, the phase of the high frequency returned to the connection point P and the phase of the high frequency output from the current source 23 are the same. Waves traveling from the connection point P to the left and right are seamlessly connected.

  In other words, the high-frequency wave that rotates clockwise and the high-frequency wave that rotates counterclockwise are two opposite waves having the same wavelength, period, and amplitude, and the two opposite waves overlap each other. A standing wave occurs. By this standing wave, the electric field at the connection point P of the feeder line 1 and at each point away from the connection point P by a positive integer multiple of ½ wavelength becomes zero, while the magnetic field at those points is maximum. Become.

  FIG. 4 illustrates a graph for explaining the spatial and temporal changes of the magnetic field generated by the voltage source 22 of FIG. 2 and the current source 23 of FIG. In the figure, x indicates the distance from the connection point P, and t indicates time. As shown in the figure, the magnetic field 23H due to the current source 23 exists at the connection point P, while the magnetic field 22H due to the voltage source 22 does not exist. The magnetic field 23H and the magnetic field 22H are spatially shifted by a quarter wavelength in the length direction of the feeder line 1, and are temporally shifted in phase by a quarter period (90 degrees). There is a relationship.

  As shown in the figure, when moving from the connection point P, the magnetic fields 22H and 23H generated by the voltage source 22 and the current source 23 change. The respective magnetic fields 22H and 23H can be expressed as magnetic field components represented by the following formulas (1) and (2) with respect to H which is a combined magnetic field. H in each equation is a combined magnetic field generated by the voltage source 22 and the current source 23, x is a distance from the connection point P, and λ is a high frequency wavelength on the feeder line 1.

Magnetic field 22H by voltage source 22: H × sin (2πx / λ) (1)
Magnetic field 23H by current source 23: H × cos (2πx / λ) (2)

  Since the magnetic field 22H and the magnetic field 23H are in the relationship of the equations (1) and (2), when the voltage source 22 and the current source 23 are connected to the same portion of the feeder line 1, With the movement, the proration ratio between the magnetic field 22H and the magnetic field 23H changes seamlessly. As an event at this time, when the voltage source 22 bears power, current flows from the voltage source 22 (current does not flow from the voltage source 22 when there is no load), and when the current source 23 bears power, the current source A voltage is generated at the output terminal 23 (when there is no load, the feeder line viewed from the current source 23 is short-circuited and no voltage is generated). That is, since a magnetic field is always generated at all locations on the feed line 1, only a traveling wave is generated without generating a standing wave on the feed line 1.

  Here, for example, when the frequency of the high frequency power supply is a general 13.56 MHz, the wavelength of the high frequency is about 22 m. When a standing wave is generated by this high frequency, the length between the nodes of the standing wave is about 11 m (half the wavelength of the high frequency). That is, when a standing wave is generated in the feeder 1, a node appears every 11 m, and power cannot be supplied at the place where the node appears. If there is a place where power cannot be supplied every 11 m, for example, AGV, when power is supplied to a moving body that moves at a low speed or stops in the middle, the capacity of the power storage device is increased or the power is transmitted. It is necessary to increase the peak power and the like, which causes a complicated configuration and high cost.

  Therefore, when the power receiving device 200 is mounted on a moving body that moves at a low speed such as AGV or stops in the middle, the effect obtained by not generating a standing wave in the feeder 1 is more Increase.

  As described above, according to the power supply system 100 in the first embodiment, the power supply line 1 that is formed in a loop shape and that supplies power to the power receiving apparatus 200 in a contactless manner and the traveling wave for supplying power are provided. A traveling wave generator 2 having a voltage source 22 and a current source 23 generated in the feeder 1, and the voltage source 22 and the current source 23 can be connected to the same location P of the feeder 1. Thereby, it is possible to generate a traveling wave that travels in any one direction with respect to the loop-shaped power supply line 1, and to suppress the generation of a standing wave. Therefore, power can be supplied uniformly along the feeder line 1.

  Therefore, according to the power supply system 100 in the first embodiment, it is possible to provide a power supply system that can supply stable power with a simple configuration using the power supply line 1.

[Second Embodiment]
A second embodiment of the present invention will be described. The power supply system 100s in the second embodiment shown in FIG. 5 is different from the power supply system 100 in the first embodiment shown in FIG. 1 described above. In the first embodiment, the voltage source 22 and the current source 23 are used as a high-frequency power source. In contrast, in the second embodiment, two voltage sources 22a and 22b are used as a high-frequency power source. About another structure, it is the same as that of each structure of the electric power feeding system in 1st Embodiment. Therefore, the same reference numerals are given to the respective components, and the description thereof is omitted. In the following, differences from the first embodiment will be mainly described.

  As shown in FIG. 5, the traveling wave generation device 2s includes a control unit 21s and two voltage sources 22a and 22b that are high-frequency power supplies. The two voltage sources 22a and 22b are the same type of voltage source. The control unit 21s performs control so that the voltages output from the two voltage sources 22a and 22b coincide with each other with a predetermined voltage, and the high-frequency phases output from the two voltage sources 22a and 22b are synchronized. The control unit 21s only needs to be able to control so as to synchronize with either one of the two waves traveling in the opposite directions on the feeder line 1 when performing control so that the respective phases are synchronized.

  Regarding the positional relationship between the connection point Pa of the voltage source 22a and the connection point Pb of the voltage source 22b with respect to the loop-shaped power supply line 1, the distance between the connection point Pa and the connection point Pb is output from the voltage sources 22a and 22b. The length is set to a length corresponding to a quarter wavelength of the high frequency wavelength. That is, the connection points Pa and Pb are set so that the phase between the high frequency output from the voltage source 22a and the high frequency output from the voltage source 22b is shifted by 90 degrees in time.

  By setting the connection points Pa and Pb in this way, a traveling wave W as illustrated in FIG. 6 can be generated. In the figure, for convenience of explanation, the length of the feeder line 1 is set to six times the high frequency wavelength. Vpa indicates the voltage at the connection point Pa of the voltage source 22a, and Vpb indicates the voltage at the connection point Pb of the voltage source 22b. As shown in the figure, the output voltage Vpa of the voltage source 22a and the output voltage Vpb of the voltage source 22b are respectively output from the connection points Pa and Pb set at intervals of 1/4 wavelength of the traveling wave W. ing. In addition, the output phases Vpa and Vpb are output so that the waveform phases are synchronized.

  Here, FIG. 6 shows a traveling wave W at a certain point in time, and this traveling wave W does not stop at the illustrated waveform. The traveling wave W always travels in the counterclockwise direction of FIG. The traveling direction of the traveling wave W may be clockwise in FIG.

  FIG. 7 is a diagram illustrating the state of an electric field generated in the feeder line 1 when two voltage sources 22a and 22b are used as a high-frequency power source. In the figure, the darker the color, the higher the electric field strength. In the figure, for the convenience of explanation, the length of the feeder line 1 is set to 8 times the high frequency wavelength. In this case, the magnetic field generated by the voltage source 22a and the magnetic field generated by the voltage source 22b are spatially shifted from each other by a quarter wavelength in the length direction of the feeder line 1, and the time is 1 / The four phases (90 degrees) are out of phase. That is, the relationship is similar to the relationship between the magnetic field 22H and the magnetic field 23H shown in FIG.

  Therefore, for example, when moving from the connection point Pa, the distribution ratios of the magnetic fields generated by the voltage sources 22a and 22b change seamlessly. As an event at this time, at least one of the voltage sources 22a and 22b or both of the voltage sources 22a and 22b bears power according to the proration rate, and a current that generates a traveling wave flows through the feeder line 1. It will be. That is, since a magnetic field is always generated at all locations on the feed line 1, only a traveling wave is generated without generating a standing wave on the feed line 1.

  As described above, according to the power supply system 100 s in the second embodiment, the power supply line 1 that is formed in a loop shape and supplies power to the power receiving apparatus 200 in a contactless manner, and the traveling wave for supplying power is generated. A traveling wave generator 2s having two voltage sources 22a and 22b to be generated in the feed line 1, and the two voltage sources 22a and 22b are spaced apart from each other by a quarter wavelength of the high frequency in the feed line 1 The power supply line 1 can be connected so as to have a positional relationship. Thereby, it is possible to generate a traveling wave that travels in any one direction with respect to the loop-shaped power supply line 1, and to suppress the generation of a standing wave. Therefore, power can be supplied uniformly along the feeder line 1.

  Therefore, according to the power feeding system 100 s in the second embodiment, it is possible to provide a power feeding system that can supply stable power with a simple configuration using the power feeding line 1.

[Modification]
Each embodiment described above is for facilitating understanding of the present invention, and is not intended to limit the present invention. Each element provided in each embodiment and its arrangement, material, condition, shape, size, and the like are not limited to those illustrated, and can be changed as appropriate. In addition, the structures shown in different embodiments can be partially replaced or combined.

(Modification 1)
For example, in the second embodiment described above, the distance between the connection point Pa of the voltage source 22a and the connection point Pb of the voltage source 22b is set to ¼ wavelength of the high frequency wavelength output from the voltage sources 22a and 22b. However, the present invention is not limited to this. For example, the distance between the connection point Pa and the connection point Pb may be a length obtained by adding a quarter wavelength of the high frequency to a positive integer multiple of the high frequency wavelength output from the voltage sources 22a and 22b. .

(Modification 2)
In the second embodiment described above, the case where the two voltage sources 22a and 22b are used as the high-frequency power source has been described. However, the present invention is not limited to this. For example, three or more voltage sources may be used. In this case, the adjacent voltage source has a positional relationship with an interval of a quarter wavelength of the high frequency output from each voltage source in the feeder line 1 or a positive integer of the wavelength of the high frequency output from each voltage source. It is good also as connecting to the feeder 1 so that it may become the positional relationship which left the space | interval for the length which added 1/4 wavelength of the same high frequency.

(Modification 3)
Moreover, when setting the distance between each connection point in 2nd Embodiment and the modifications 1 and 2 mentioned above, the 1/4 wavelength of a high frequency is used, but it does not necessarily need to be a 1/4 wavelength. A plurality of voltage sources are arranged in a distributed manner, and a phase shift caused by arranging them at different positions is taken into consideration, and it is only necessary to control so that the phases of the high frequencies output from the respective voltage sources are synchronized.

  For example, as illustrated in FIG. 8, a high-frequency 1/3 wavelength (120 degrees) may be used. In the figure, adjacent voltage sources are spaced apart from each other by a length obtained by adding a 1/3 wavelength of the high frequency to the positive integer multiple of the high frequency wavelength output from each voltage source in the feeder line 1. It is connected to the feeder 1 so as to have a positional relationship.

  Specifically, the distance between the adjacent connection point Pc and the connection point Pd is a length obtained by adding 1/3 wavelength of the high frequency to twice the high frequency wavelength, and the adjacent connection point Pd and the connection point Pe. Is a length obtained by adding 1/3 wavelength of the high frequency to the high frequency wavelength, and the distance between the adjacent connection point Pe and the connection point Pc is twice as high as the high frequency wavelength. It is the length with 1/3 wavelength added.

(Modification 4)
Further, in the above-described second embodiment and each modification, the case where two voltage sources 22a and 22b or three or more voltage sources are used as the high-frequency power source has been described, but the present invention is not limited to this. For example, a current source may be used instead of the voltage source. That is, two current sources or three or more current sources may be used in the same manner as in the case of using the voltage source described above.

DESCRIPTION OF SYMBOLS 1 ... Feed line, 2, 2s ... Traveling wave production | generation apparatus, 21, 21s ... Control part, 22, 22a, 22b ... Voltage source, 23 ... Current source, 100, 100s ... Feed system, 200 ... Power receiving apparatus

Claims (9)

A power supply line that is formed in a loop shape and supplies power to the power receiving device in a contactless manner;
A traveling wave generator having a plurality of high-frequency power sources for generating a traveling wave for supplying the power to the feeder line;
A power supply system comprising: The positions of the plurality of high frequency power supplies are determined so that the phases of the high frequencies output from the respective high frequency power supplies are synchronized,
The power feeding system according to claim 1. The positions of the plurality of high-frequency power sources are determined so that the phase of the high frequency output from each high-frequency power source is synchronized with one of two waves traveling in opposite directions on the feeder line,
The power feeding system according to claim 2. When the plurality of high-frequency power sources are a plurality of voltage sources or a plurality of current sources, the adjacent high-frequency power sources are in a positional relationship with an interval of ¼ wavelength of the high frequency in the power supply line, or It is connected to the feeder line so as to have a positional relationship with an interval of a length obtained by adding a quarter wavelength of the high frequency to a positive integer multiple of the high frequency wavelength.
The power feeding system according to claim 2 or 3. When the plurality of high-frequency power sources are one voltage source and one current source, the voltage source and the current source are connected to the same portion of the feeder line,
The power feeding system according to claim 2 or 3. The length of the loop-shaped portion of the feeder line is a positive integer multiple of the wavelength of the high frequency output from the high frequency power supply.
The power feeding system according to any one of claims 1 to 5. The traveling wave generating device further includes a control unit that controls a phase of a high frequency output from at least the high frequency power source,
The power feeding system according to any one of claims 1 to 6. The feeding line is a parallel two-wire transmission line,
The power feeding system according to any one of claims 1 to 7. A power supply method for supplying power to a power receiving device in a contactless manner using a power supply line,
Using a plurality of high-frequency power supplies connected to the power supply line formed in a loop shape, and generating a traveling wave for supplying the power to the power supply line,
Power supply method including.