JP2004356917A - Signal impressing and extracting device for power line carrier communication, and power line carrier communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a signal injecting and extracting device capable of impressing a high-frequency communication signal into a power line where a commercial current of commercial frequency is caused to flow at a stable level or extracting the high-frequency signal from the power line at a stable level. <P>SOLUTION: Provided are an annular ferromagnetic material core arranged surrounding one set of a plurality of power lines for feeding a multi-phase AC current or a plurality of annular ferromagnetic material cores 21, 22 and 23 arranged surrounding a plurality of power lines 110, 120 and 130, and high-frequency communication signals are impressed and extracted through signal impression/extraction coils 31, 32 and 33 arranged on the outer peripheral surface of the annular ferromagnetic material core and magnetic flux saturation in the cores due to a commercial current is suppressed by a method of providing coils 51, 52 and 53 for cancellation and so on. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a signal injection and extraction device used for power line carrier communication, and more specifically, a high frequency signal for injecting a high frequency signal into a conductor of a power line in a non-contact state or extracting a high frequency signal from a power line in a non-contact state. The present invention relates to a signal injection extraction device.
[0002]
[Prior art]
Conventionally, in order to inject an electric signal such as an alternating current into a power line in a non-contact state or to extract an electric signal from the power line, an apparatus having a transformer structure using a ferromagnetic core has been used. FIG. 8 is a perspective view conceptually showing a configuration of a conventional signal injection / extraction apparatus described in Patent Document 1. As shown in FIG. 8, the signal injection / extraction apparatus 100 includes a ferromagnetic core 102 arranged so as to surround a power line 101. In order to inject or extract a high-frequency signal, a ferrite core having high magnetic permeability and exhibiting low-loss characteristics in a high-frequency region is often used as the ferromagnetic core 102. The annular ferromagnetic core 102 does not have to be an integral structure such as a half-split structure to facilitate attachment and detachment to and from a power line. A signal injection / extraction winding 103 is arranged around the outer peripheral surface of the ferromagnetic core 102.
[0003]
[Patent Document 1]
JP 2001-319815 A
[0004]
When a high-frequency signal is injected into the power line 101 using the signal injection / extraction device 100, a high-frequency current is supplied to the winding 103 as a signal to be injected. A magnetic flux is generated inside the ferromagnetic core 102 by the high-frequency current flowing through the winding 103, and a high-frequency current is induced in the power line 101 according to the magnetic flux and the magnetic permeability of the ferromagnetic core 102. Is injected.
[0005]
When a high-frequency current flowing through the power line 101, that is, a high-frequency signal is extracted by using the device 100 shown in FIG. 8, a magnetic flux is generated in the ferromagnetic core 102 by the high-frequency current flowing through the power line 101. A high-frequency current, that is, a high-frequency signal induced in the winding 103 according to the magnetic permeability of the magnetic core 102 is extracted.
[0006]
A power line carrier communication system (hereinafter referred to as a PLC) is provided with a high frequency signal as a communication signal (several kHz to several tens MHz or higher) on a power line through which a commercial current of a commercial frequency (generally 50 Hz or 60 Hz) flows. ) Is superimposed for communication. Such a PLC is a system capable of transmitting and receiving a large amount of data using an existing power line (also referred to as a distribution line or a power line) drawn into each house or the like without using a dedicated communication line. Attention has been paid.
[0007]
In a PLC, it is necessary to inject a high-frequency signal into an existing power line through which a commercial current flows, and to extract only a high-frequency signal as a communication signal from a power line on which the high-frequency signal and the commercial current are superimposed. In this case, for the signal injection and extraction device, the commercial current acts as a commercial frequency signal in the same manner as a high frequency signal. That is, for example, a signal extracted in signal extraction is a signal in which a commercial frequency component and a high frequency component are superimposed, although there is a difference in magnitude due to the frequency characteristics of the core and the winding.
[0008]
When a signal injection / extraction device using a ferromagnetic core and a winding as described above is applied to the injection and extraction of a high-frequency signal in a PLC, the magnitude of the commercial current flowing through the power line and the high-frequency signal current flowing through the power line are superimposed. Problems arise because the sizes differ by orders of magnitude.
[0009]
An example will be described in which a signal is extracted from a power line. A magnetic field is generated in the ferromagnetic core by a magnetic field generated around the power line by a current flowing through the power line. When a current is induced in the winding in such a direction as to cancel the magnetic flux, the same signal as the current flowing through the power line is extracted from the winding. Here, the magnitude of the extracted signal differs depending on the configuration of the winding. Since a large commercial current signal and a weak high-frequency signal are superimposed and flowing on the power line, if the frequency characteristic determined by the ferromagnetic core and the winding is the same sensitivity characteristic for both signals, it is extracted. The signals are detected as superimposed signals of the same ratio. Because we want to extract only high-frequency signals for communication, the signal injection and extraction device is provided with a filter to provide frequency characteristics to cut low-frequency commercial frequency signals and pass only high-frequency signals. Is used.
[0010]
However, in this configuration, the saturation characteristic of the ferromagnetic core becomes a problem. The ferromagnetic core has a saturation characteristic. When a magnetic flux of a certain level or more is generated in the core, magnetic saturation occurs in which no more magnetic flux is induced. As described above, since there is a large level difference between the commercial current signal and the high-frequency signal, when magnetic saturation occurs due to the commercial current signal, a magnetic flux corresponding to the high-frequency signal cannot be additionally generated in the core. As a result, there is a problem that a high-frequency signal is not extracted to the winding.
[0011]
For this reason, a method of making a cut (also referred to as a core with a gap) in a closed annular ferromagnetic core, or a magnetic field canceling winding devised by the inventors of the present application is used as a device for making magnetic saturation less likely to occur. A method (Patent Document 1) and the like have been proposed.
[0012]
[Problems to be solved by the invention]
However, these methods have the effect of suppressing magnetic flux saturation due to the commercial current signal and the disadvantage of increasing the loss of necessary high-frequency signals. That is, the effect of reducing the magnetic flux also occurs for the high-frequency signal, and the magnitude of the signal to be injected and extracted is reduced (in other words, the coupling loss for the high-frequency signal is large). In addition, there is a problem that the level of the high-frequency signal to be injected and extracted fluctuates because magnetic flux saturation occurs or does not occur depending on the presence or magnitude of the commercial current.
[0013]
In order to solve such a problem, the present invention provides a signal injection / extraction apparatus which suppresses magnetic saturation of a ferromagnetic core and has small coupling loss of a high-frequency signal.
[0014]
[Means for Solving the Problems]
The present invention is directed to injecting and extracting a high-frequency signal into a power line through which a multi-phase AC current flows, and a ring-shaped ferromagnetic ferromagnetic member arranged to surround a set of a plurality of power lines for supplying the multi-phase AC current. The signal injection / extraction device includes a body core and a signal injection / extraction winding disposed on the outer peripheral surface of the annular ferromagnetic core so as to penetrate the center hole of the annular ferromagnetic core. (Claim 1)
[0015]
The multi-phase alternating current is an alternating current in which n-phase (n is a natural number of 2 or more) phase currents is a set, and a single-phase alternating current (two phases) is generally used. Or three-phase alternating current. The number of power lines corresponding to the number of phases is configured as a set, and a current having a phase difference of 180 degrees flows through each power line, and a current having a phase difference of 120 degrees flows through each power line in the case of three phases. If a core surrounding the power line is provided so that these one set of power lines pass through the center hole, the magnetic flux induced in the core by the magnetic field generated by the current flowing through each power line will be caused by the currents having different phases from each other. Since the magnetic flux cancels each other and ideally becomes zero, there is an effect that the problem that injection and extraction of a high-frequency signal cannot be performed due to magnetic saturation does not occur.
[0016]
The high-frequency signal is injected and extracted as an in-phase signal to each of a set of power lines via a signal injection and extraction winding provided in the core.
[0017]
Further, a plurality of annular ferromagnetic cores arranged to surround the periphery of each power line of a set of a plurality of power lines for supplying a multi-phase AC current, and at least one of the plurality of annular ferromagnetic cores A signal injection / extraction wire winding disposed on the outer peripheral surface of one annular ferromagnetic core so as to penetrate the center hole of one annular ferromagnetic core; and at least two annular ferromagnetic materials of the plurality of annular ferromagnetic cores The signal injection extraction device may include a canceling winding that forms a closed curve passing through the center hole of the core. (Claim 2)
[0018]
According to this configuration, the magnetic flux generated in the annular ferromagnetic core (hereinafter, simply referred to as “core”) is canceled out by each other, so that the occurrence of magnetic saturation is suppressed. This has the effect that the problem of being unable to do so is less likely to occur. In this case, two or three cores are required as compared with the case where a core is provided in a plurality of phases collectively, but there is an advantage that each core can be made smaller. In addition, it is particularly effective when it is difficult to provide a core so as to penetrate all at once, for example, because the power lines are arranged at intervals from each other, in terms of the grounding location and the size of the core. .
[0019]
The canceling winding is provided so as to penetrate the center holes of two cores adjacent to each other, and the direction of the penetration is arranged such that the directions of currents induced by magnetic fluxes generated in the respective cores are opposite to each other. Is effective. (Claim 3)
[0020]
The phase currents are currents of the same frequency having different phases, and currents having different phases are superposed and induced on the canceling windings penetrated by the adjacent cores. When the currents of all phases are superimposed on each other, the magnitudes ideally become zero by canceling each other out, so that the magnetic flux generated by the alternating current to the core is canceled out. As a result, magnetic saturation does not occur.
[0021]
Even if the signal injection / extraction windings are individually provided for each core, they are arranged on the outer peripheral surface so that one signal injection / extraction winding passes through the center holes of a plurality of cores so as to form one curve. May be performed. In any case, the signal injection and extraction winding needs to be arranged in a direction in which the high-frequency signal is injected and extracted in the same phase on the power line of each phase. (Claim 4)
[0022]
This is because, for example, in the case of signal injection, the magnetic flux generated in each core by the high-frequency signal current flowing through the signal injection and extraction winding is in phase, and the high-frequency current induced in the canceling winding by the magnetic flux is This means that high-frequency currents induced by magnetic fluxes generated in other cores penetrating the same cancellation winding cancel each other out. Therefore, for high-frequency current, the canceling winding does not hinder the injection and extraction.
[0023]
The signal injection / extraction winding may be provided only on the core of any one phase. Also in this case, as a result of the suppression of the magnetic saturation, the effect that the high-frequency signal injected or extracted by the signal injection / extraction line is not affected by the alternating current of the commercial frequency can be similarly obtained. There is a disadvantage that the canceling winding acts on the high-frequency signal current in a direction that hinders the injection and extraction, but because the canceling winding is provided in a form that penetrates other cores as well. However, the impedance to the high-frequency signal becomes relatively high, and the degree of hindering the injection and extraction of the high-frequency signal is not large. This configuration is preferable when importance is attached to the merit that the overall device configuration can be relatively simplified.
[0024]
Using a signal injection / extraction device as described above, if a PLC uses at least one power line as a transmission line among a set of power lines for supplying a multi-phase AC current, the commercial current flowing through the power line can be reduced. It is possible to provide a power line carrier communication system in which the influence on the communication quality due to the size is reduced, and the injection and extraction loss of the communication signal is reduced. (Claim 5)
[0025]
Embodiment
(Embodiment 1)
The AC current for power distribution is generally a single-phase or three-phase multi-phase AC current, and the distribution line is composed of a set of power lines for flowing each phase current. Hereinafter, three-phase alternating current will be described as an example, but it is possible to generalize the case of n-phase.
[0026]
FIG. 1 is a cross-sectional view of a configuration in which a core is provided so that a set of power lines for supplying three-phase alternating current passes therethrough, in a cross-sectional direction perpendicular to the extending direction of the power lines. The three power lines 110, 120, and 130 for supplying three-phase alternating current are general power lines each including a conductor and an insulator as main components. An annular ferromagnetic core 20 is provided so that three power lines pass therethrough. A signal injection / extraction winding 30 is provided on the outer peripheral surface of the core, and is connected to the communication device 40. Here, providing the winding on the outer peripheral surface of the core means that a wire is arranged so as to penetrate the center hole of the annular core at least once, and the number of turns, that is, the number of times of passing through the center hole of the core is determined by signal injection extraction. Can be designed according to the desired sensitivity. The core has a depth in the direction along the power line (perpendicular to the plane of the drawing), but the length can be arbitrarily designed. Each cross-sectional dimension can be designed according to the size of the power line to be applied. The material of the core is ferrite or iron, but is not particularly limited as long as the material is generally called a ferromagnetic material.
[0027]
On the three power lines, a commercial current of an alternating current of a commercial frequency, which is different in phase by 120 degrees obtained by equally dividing 360 degrees by the number of phases of 3 and is almost equal in magnitude, flows. A magnetic field is formed around the power line by each commercial current, and a magnetic flux is induced in the core 20. Considering only the magnetic flux induced by the commercial current flowing through one power line, the magnetic flux is an AC magnetic flux that changes with time in a sine wave shape, and the magnetic flux may be saturated depending on the saturation characteristics of the core. However, since the magnetic flux due to the current flowing through the power line of the other phase is superimposed on the magnetic flux, the magnetic fluxes cancel each other out, and ideally become zero. Ideally, this means that the magnitude of the commercial current of each phase does not exactly match or the phase difference deviates strictly from 120 degrees due to factors such as the impedance characteristics of each power line. This is possible, and an ideal state may be considered in the description of the present invention.
[0028]
In this state, when a high-frequency signal from the communication device 40 is applied to the signal injection / extraction winding 30, magnetic flux is induced in the core by the high-frequency signal current, and the magnetic flux induces a high-frequency signal current in each power line. (Signal injection). Conversely, a magnetic field generated around the power line by a high-frequency signal current flowing superimposed on the power line induces a magnetic flux in the core 20, and the magnetic flux induces a high-frequency signal in the signal injection / extraction winding 30 ( Signal extraction).
[0029]
In some cases, the power line has a shield layer made of a conductor on the outer periphery of the insulator, and the shield layer is often grounded. Since the shielding layer is a layer for shielding a magnetic field generated outside due to a current flowing through the conductor, the magnetic field is extremely weak outside the shielding layer. Therefore, in the power line having the shielding layer, the portion where the core is provided in the above description is a portion where the shielding layer of each power line is removed. For example, in the vicinity of a connection portion of a power line connection box, a transformer, a switch, or the like, a shielding layer is removed or many portions can be removed. In addition, the shielding layer may be provided individually for the power lines of each phase, or may be provided so as to enclose the three conductors collectively in three phases. no problem.
[0030]
In a communication device, one end of two terminals for injecting and extracting a high-frequency signal is often connected to a shielding layer of a power line as a ground side. In that sense, the grounding 80 is shown in FIG. Therefore, the signal injected into the power line propagates between the power line and the shielding layer as if it were a coaxial cable for communication. In the case of a power line having no shielding layer, another ground wire corresponding to ground may be provided. In this case, the high-frequency signal propagates between each power line and the ground wire.
[0031]
(Embodiment 2)
FIG. 2 illustrates another embodiment of the present invention. In FIG. 2, three cores 21, 22, 23 are provided such that each of the three power lines 110, 120, 130 penetrates individually. In addition, canceling windings 51, 52, and 53 are provided, respectively, by drawing a curve through which adjacent cores penetrate. The number of canceling windings can be configured by n × (n−1) / 2 in the case of n-phase alternating current, but becomes three in the case of three-phase alternating current (n = 3). Also, signal injection / extraction windings 31, 32, 33 connected to the communication device 40 are individually provided in each core. In the figure, one end of the signal injection / extraction winding is described as being connected to the ground, but is electrically connected to the ground at the signal input / output terminal of the communication device 40, as in the case of FIG. The signal injection / extraction winding forms a closed curve via the communication device.
[0032]
A magnetic field is formed around the power line by the commercial current flowing through the power line 110, and a magnetic flux is induced in the core 21. Similarly, magnetic flux is induced in the cores 22 and 23 by the commercial current flowing through the power lines 120 and 130, respectively. The magnetic flux induced in each case is a sinusoidal AC magnetic flux, and considering this alone, the magnetic flux may be saturated depending on the saturation characteristics of the core. However, by coupling the adjacent cores with the canceling windings 51, 52, and 53, respectively, the currents induced by the magnetic fluxes having different phases act so as to cancel each other, and the magnetic flux induced by the commercial current in each core. Is less likely to saturate.
[0033]
In this state, when a high-frequency signal from the communication device 40 is supplied to the signal injection / extraction windings 31, 32, and 33, a magnetic flux is induced in the core by the high-frequency signal current, and the magnetic flux causes a high-frequency signal current to flow through each power line. Is induced (signal injection). Conversely, magnetic fluxes are induced in the cores 21, 22, 23 by a magnetic field generated around the power lines due to the high-frequency signal current flowing superimposed on the power lines 110, 120, 130, and the magnetic flux induces the signal injection / extraction windings 31, 32. , 33 are guided by a high-frequency signal (signal extraction). In FIG. 2, the ground sides connected to the shielding layer are represented by ground symbols. Here, the high-frequency signal needs to be wound in a direction in which a magnetic flux is generated in the same phase with respect to each core. By winding in the same phase direction, it is prevented from being canceled by the canceling winding. This principle will be illustrated and described with a single-phase alternating current for simplicity, together with the above-described cancellation of magnetic flux by the commercial current.
[0034]
FIG. 3 is a diagram for explaining that the canceling winding does not affect the injection and extraction of the high-frequency signal. Cores 21 and 22 are provided so that two power lines 110 and 120 through which a single-phase AC flows penetrate, and a canceling winding 51 that connects the two cores is provided. The signal injection and extraction windings 31 and 32 for high frequency signals are wound around two cores so that signals can be injected and extracted in the same phase. The phrase “in phase” means that the magnetic flux induced in the core by the high-frequency signal current has the same direction as the current induced in the power line. In FIG. 3, the high-frequency signal current flowing from the communication device 40 is the current i _A And current i to winding 32 _B Divert to i _A The magnetic flux φ _A Is induced, and i _B The magnetic flux φ _B Is induced. In the figure, φ _A And φ _B Are clockwise directions, and the current induced on the power line from these magnetic fluxes is from the near side to the far side in the figure.
[0035]
The operation of the canceling winding 51 in this case will be described. Magnetic flux φ _A The cancellation winding 51 has φ _A Current I in the direction to cancel _A Is induced. Also the magnetic flux φ _B Similarly, the current I _B Is induced. Current I _A And the current I _B Is reversed as shown in the figure, and as a result, no current flows through 51. Therefore, the magnetic flux φ in the core _A And φ _B Is not generated, and the high-frequency signal current is injected into the power line without hindrance. When extracting a high-frequency current superimposed on a power line, the same concept is used, except that the relation of induction is reversed.
[0036]
Next, referring to FIG. 4, it will be described that the magnetic flux generated in the core by the commercial current is canceled and the saturation of the magnetic flux does not occur. The configurations of the power line, the core, and the canceling winding are the same as those in FIG. 3, and the communication device and the signal injection and extraction winding are not described. The single-phase alternating current flowing through the pair of power lines 110 and 120 is a sinusoidal current having a phase difference of 180 degrees. In the figure, this is indicated by the direction of the current, and the current j ₁ Is the direction from the back of the figure to the front, and the current j flowing through the power line 120 ₂ Is from the front to the back. In this case, j ₁ Magnetic flux φ in the core induced by ₁ Is counterclockwise as indicated by the arrow in the figure, and j ₂ Magnetic flux φ induced by ₂ Is clockwise as shown in the figure. The cancellation winding 51 has φ ₁ And φ ₂ The current I in the direction to cancel each ₁ And I ₂ Is induced. These induced currents I ₁ And I ₂ Are in the same direction, and consequently, I ₁ + I ₂ Will flow. Therefore, φ is generated in each of the cores 21 and 22 by the induced current. ₁ And φ ₂ Is generated, and the saturation of the magnetic flux is suppressed by canceling the magnetic flux.
[0037]
By combining the above description with FIGS. 3 and 4, the magnetic flux due to the commercial current is canceled to suppress the saturation of the magnetic flux, and the high-frequency current can be injected and extracted without canceling. Although the description has been given of a single-phase alternating current, the concept is the same even in the case of three-phase alternating current, and it is possible to obtain a canceling effect due to superposition of currents of all phases.
[0038]
(Embodiment 3)
Next, FIG. 5 is a diagram showing another embodiment. Only the configuration of the signal injection / extraction winding is different from that of FIG. 2, and the remaining configuration is the same. The same reference numerals as in FIG. 2 are used, and the description is omitted.
[0039]
The signal injection / extraction winding 30 is one, and is arranged so as to draw a closed curve passing through the center holes of the respective cores in order. What is important here is that the signals are arranged in such a direction as to be in phase with each core. As a result, similarly to the case described with reference to FIG. 3, the signal to be injected or extracted can be injected and extracted without being canceled by the respective canceling windings.
[0040]
There is an advantage that the configuration can be simplified as compared with a case where signal injection / extraction windings are individually provided for each core as shown in FIG.
[0041]
(Embodiment 4)
FIG. 6 is a diagram showing still another embodiment. Only the configuration of the signal injection / extraction winding is different from that of FIG. 2, and the remaining configuration is the same. The same reference numerals as in FIG. 2 are used, and the description is omitted.
[0042]
The signal injection / extraction winding 30 is one, and is arranged so as to draw a closed curve passing only through the center hole of one of the plurality of cores. Therefore, a signal can be injected and extracted from only one power line (power line 130 in the figure). In power line carrier communication, such a configuration is also possible because not all power lines need be used for signal transmission. Also in this case, communication can be performed while obtaining the effect of suppressing the saturation of the magnetic flux due to the commercial current.
[0043]
In this case, it is inevitable that the high-frequency signal currents described with reference to FIG. 3 are canceled by the canceling windings, but the magnetic field formed with the canceling windings 51, 52, 53 and the other cores 21, 22 is not eliminated. By the circuit, the impedance for the high-frequency signal is increased, so that the loss of the magnetic flux for canceling the magnetic flux corresponding to the high-frequency signal in the core 23 is increased, so that the loss received in the injection and extraction of the high-frequency signal is reduced. There is. Further, there is an advantage that the configuration can be simplified as compared with the case where each core is used for signal injection extraction as shown in FIGS.
[0044]
(Embodiment 5)
FIG. 7 is a diagram illustrating communication between two points in order to explain an example of a PLC system configuration using the above-described signal injection and extraction device. The signal injection / extraction device having the configuration described with reference to FIG. 6 is used as an example, but a signal injection / extraction device according to another embodiment may be used.
[0045]
The configuration of FIG. 7 will be described. The power lines are a set of three lines through which a three-phase AC commercial current flows. For convenience of explanation, the shielding layers 210, 220, and 230 of each cable and the portions 110, 120, and 130 that are covered by the conductors and insulators are separately illustrated. A communication device 40 and a signal injection / extraction device 90 are provided at an arbitrary point on the power line. The signal injection / extraction device 90 flows high-frequency communication signals from the cores 21, 22, 23 provided on the respective power lines, the canceling windings 51, 52, 53 provided to connect them, and the communication device 40. It comprises a signal injection / extraction winding 30. On the other hand, a communication device 41 and a signal injection / extraction device 91 are provided at other points on the power line. The description of the signal injection and extraction device 91 is omitted. One end of the signal injection / extraction winding is connected to a shielding layer 220, and the shielding layer is grounded.
[0046]
In the above configuration, a case where a signal is transmitted from the communication device 40 to the communication device 41 will be described. The communication device 40 causes a high-frequency signal current to be transmitted to flow through the signal injection / extraction winding 30. By the magnetic flux induced in the core 23 by the current flowing through the signal injection / extraction winding 30, a high-frequency signal current flows through the power line 120 by induction in such a direction as to cancel the magnetic flux. Here, since the signal injection / extraction device 90 is constituted by the three cores and the canceling windings connecting them as described above, no magnetic flux saturation occurs due to the commercial current, and the injection of the high-frequency signal is performed by the commercial current. It is not affected by the size of.
[0047]
The signal propagates through the coaxial cable constituted by the power line 120 and its shielding layer 220, and reaches the point of the signal injection / extraction device 91. In the signal injection / extraction device 91, a magnetic flux is induced in the core by a high-frequency signal flowing through the power line 120, and a high-frequency signal current is generated in the signal injection / extraction winding 31 in such a direction as to cancel the magnetic flux, so that the communication device 41 receives the high-frequency signal. You can do it. Also in this case, since the signal injection / extraction device 91 is constituted by three cores and a canceling winding connecting them, no magnetic flux saturation occurs due to the commercial current, and the injection of the high-frequency signal is affected by the magnitude of the commercial current. Never.
[0048]
【The invention's effect】
As described above, according to the present invention, the influence of the magnitude of the commercial current is suppressed by suppressing the magnetic flux saturation caused by the commercial current signal, and the coupling loss for the high-frequency signal is small. It is possible to provide a power line carrier communication system using the same.
[Brief description of the drawings]
FIG. 1 is a diagram conceptually showing a configuration of a signal injection and extraction device as an embodiment of the present invention.
FIG. 2 is a diagram conceptually showing a configuration of a signal injection and extraction device as a different embodiment of the present invention.
FIG. 3 is a diagram conceptually illustrating a relationship between a high-frequency signal current and a magnetic flux as one of the principles of the present invention.
FIG. 4 is a diagram conceptually illustrating a relationship between a commercial frequency current and a magnetic flux as one of the principles of the present invention.
FIG. 5 is a diagram conceptually showing a configuration of a signal injection and extraction device as another embodiment of the present invention.
FIG. 6 is a diagram conceptually showing a configuration of a signal injection and extraction device as still another embodiment of the present invention.
FIG. 7 is a conceptual diagram illustrating a configuration of a power line carrier communication system using the signal injection and extraction device of the present invention.
FIG. 8 is a diagram conceptually showing a conventional signal injection and extraction device.
[Explanation of symbols]
20,21,22,23 Annular ferromagnetic core
30,31,32,33 Signal injection extraction winding
40, 41 communication device
51,52,53 Winding for canceling
80 ground
90,91 signal injection and extraction device
100 signal injection extraction device
101 Power line
102 Ferromagnetic core
103 Winding for signal injection extraction
110, 120, 130 Power line
210, 220, 230 shielding layer

Claims (5)

An annular ferromagnetic core arranged to surround a set of a plurality of power lines for passing a multi-phase alternating current, and the annular ferromagnetic material penetrating a center hole of the annular ferromagnetic core A signal injection / extraction device for power line carrier communication, comprising: a signal injection / extraction winding disposed on an outer peripheral surface of a core. A plurality of ring-shaped ferromagnetic cores of a set of a plurality of power lines for passing a multi-phase alternating current, the plurality of ring-shaped ferromagnetic cores arranged so as to surround each power line; and at least one of the plurality of ring-shaped ferromagnetic cores A signal injection and extraction wire winding disposed on the outer peripheral surface of the annular ferromagnetic core so as to penetrate a center hole of the annular ferromagnetic core; A signal injection / extraction device for power line carrier communication, comprising: a canceling winding forming a closed curve passing through a center hole of a magnetic core. A set of a plurality of power lines for passing an alternating current composed of n phases (n is a natural number of 2 or more) is formed of n annular ferromagnetic cores arranged so as to surround each power line. In a combination of nx (n-1) / 2 annular ferromagnetic cores composed of two arbitrarily selected annular ferromagnetic cores, the canceling winding is formed of two annular ferromagnetic cores forming each combination. Nx (n-1) / 2 windings formed by a closed curve penetrating the center hole of the magnetic core, wherein the canceling is performed by a magnetic flux induced in the two annular ferromagnetic cores. 3. The signal injection and extraction device for power line carrier communication according to claim 2, wherein the directions of currents induced in the power windings are arranged in the same direction. The signal injection for power line carrier communication according to claim 2 or 3, wherein the signal injection and extraction winding is provided so that signals can be injected into the plurality of power lines in the same phase. Extraction device. A signal injection and extraction device according to any one of claims 1 to 4, wherein at least one power line of a set of power lines for supplying a multi-phase alternating current is used as a transmission line. A power line communication system for performing injection or extraction.

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