JP2017220729A - Coupler for power line carrier communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coupler for a power line carrier communication, capable of making magnetic saturation unlikely to occur in a core while miniaturizing the core.SOLUTION: A coupler for a power line carrier communication 10 is used for a power line carrier communication in which a communication signal S1 transferred between a plurality of communication devices to an AC power supplied from a power supply through an electric power line 3 is multiplied. The coupler for the power line carrier communication 10 comprises: a core 1; and a flux reduction part 2. The core 1 includes a penetration hole 11 to which the electric power line 3 and a signal line 302 connected to the plurality of communication devices are penetrated. The flux reduction part 2 includes a coil 21 mounted to the core 1, and generates, by the coil 21 to the core 1, a flux φ2 in a reverse direction of a direction of a flux φ1 occurred in the core 1 due to the flow of a supply current I1 from the power supply to the electric line 3.SELECTED DRAWING: Figure 1

Description

  The present invention generally relates to a coupler for power line carrier communication, and more specifically, for power line carrier communication used for power line carrier communication in which a communication signal transmitted between a plurality of communication devices is superimposed on AC power supplied through the power line. Concerning couplers.

  Conventionally, a power line carrier signal processing apparatus including a ferrite core has been provided (see, for example, Patent Document 1). The power line carrier signal processing device described in Patent Document 1 includes a toroidal ferrite core, a first conductor, and a second conductor. The ferrite core has a hollow portion through which the power line passes. Each of the first conductor and the second conductor is wound around the ferrite core with a predetermined number of turns.

  In the power line carrier signal processing device described in Patent Document 1, current flows through the first conductor and the second conductor by a magnetic field generated when the power line carrier signal flowing through the power line passes through the hollow portion of the ferrite core. . The current flowing through the first conducting wire and the current flowing through the second conducting wire flow in directions that cancel each other, whereby the power line carrier signal processing device functions as a blocking filter.

International Publication No. 2007/023527

  Incidentally, in the configuration described in Patent Document 1, there is a possibility that magnetic saturation may occur in the ferrite core depending on the magnitude of the alternating current flowing through the power line. Further, in order to prevent magnetic saturation from occurring in the ferrite core, it is necessary to increase the cross-sectional area of the ferrite core, and as a result, the ferrite core may be increased in size.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a power line carrier communication coupler capable of reducing magnetic saturation at the core while reducing the size of the core.

  A power line carrier communication coupler according to an aspect of the present invention is used for power line carrier communication in which a communication signal transmitted between a plurality of communication devices is superimposed on AC power supplied from a power source through a power line. The power line carrier communication coupler includes a core and a magnetic flux reduction unit. The core has a through hole through which the power line and a signal line connected to each of the plurality of communication devices pass. The magnetic flux reduction unit includes a coil attached to the core, and a magnetic flux in a direction opposite to the direction of the magnetic flux generated in the core when a feeding current from the power source flows through the power line is applied to the core by the coil. generate.

  The present invention has an effect that magnetic saturation at the core can be made difficult to occur while the core is downsized.

FIG. 1 is a perspective view showing a configuration of a power line carrier communication coupler according to Embodiment 1 of the present invention. FIG. 2 is a block diagram of a communication system using the above power line carrier communication coupler. FIG. 3 is a perspective view showing a configuration of a power line carrier communication coupler according to Embodiment 2 of the present invention. FIG. 4 is a plan view showing a configuration of a power line carrier communication coupler according to Embodiment 3 of the present invention. 5A and 5B are plan views showing magnetic fluxes generated in the core of the above power line carrier communication coupler. FIG. 6 is an explanatory diagram for explaining the operation of the power line carrier communication coupler according to the comparative example of the third embodiment of the present invention. FIG. 7 is a plan view showing the configuration of a power line carrier communication coupler according to Embodiment 4 of the present invention. FIG. 8 is a plan view showing a configuration of a power line carrier communication coupler according to a modification of the fourth embodiment of the present invention.

  Hereinafter, a power line carrier communication coupler according to an embodiment of the present invention will be specifically described with reference to the drawings. However, the configuration described below is merely an example of the present invention, and the present invention is not limited to the following first to fourth embodiments. Therefore, various modifications can be made in accordance with the design and the like, as long as the embodiments are not within the scope of the technical idea of the present invention, except for Embodiments 1 to 4.

(Embodiment 1)
A power line carrier communication coupler 10 (hereinafter referred to as a coupler 10) according to the present embodiment will be specifically described with reference to FIGS. As shown in FIG. 2, the coupler 10 is used for power line carrier communication in which a communication signal S <b> 1 transmitted between a plurality of communication devices 301 and 401 is superimposed on AC power supplied through a pair of power lines 3. In other words, the coupler 10 is used in the communication system 100 including the power receiving panel 30 and the switchboard 40. The communication system 100 is applied to a customer facility such as a commercial facility, a factory, an office building, or a hospital that requires a large amount of power. Below, the case where a consumer facility is an office building is demonstrated.

  As shown in FIG. 2, the communication system 100 includes a power receiving board 30 and a power distribution board 40. AC power output from a cubicle (high voltage power receiving facility) 20 as a power source is supplied to the power receiving panel 30 via a pair of power lines 3. AC power output from the power receiving panel 30 is supplied to the distribution board 40 via the pair of power lines 3.

  The cubicle 20 includes a transformer (transformer) 201, and transforms (steps down) 6600 volt AC power supplied from a power plant via a substation to 200 volt (or 100 volt) AC power. The cubicle 20 supplies the AC power transformed by the transformer 201 to the power receiving panel 30 via the pair of power lines 3. One (left side in FIG. 2) of the pair of power lines 3 is electrically connected to one output (L1 phase) of the cubicle 20, and the other (right side in FIG. 2) is connected to the other power line 3 of the cubicle 20. It is electrically connected to the output (L2 phase). The cubicle 20 is installed, for example, on the roof of an office building or in an electrical room.

  The power receiving panel 30 includes at least a main shut-off device. The main circuit breaker is used as a power receiving circuit breaker for the cubicle 20, and automatically shuts off the electric circuit when an overload current, a short circuit current, or the like occurs in the secondary circuit of the main circuit breaker. In the present embodiment, the power receiving panel 30 further includes a pair of couplers 10 and a communication device 301. The power receiving panel 30 is installed in a management room of an office building, for example.

  One of the pair of couplers 10 (the left side in FIG. 2) is attached to the power receiving panel 30 with the L1-phase power line 3 passed through a through hole 11 of the core 1 described later. Also, the other coupler 10 (the right side in FIG. 2) of the pair of couplers 10 is attached to the power receiving panel 30 with the L2-phase power line 3 passed through the through hole 11.

  The communication device 301 is a modem that enables, for example, high-speed power line communication (HD-PLC: High Definition Power Line Communication). A signal line 302 is electrically connected to the communication device 301, and the communication device 301 and the signal line 302 constitute a closed circuit. One end side of the signal line 302 is electrically connected to the communication device 301 in a state of being passed through the through hole 11 of one of the couplers 10 (left side in FIG. 2). Further, the other end side of the signal line 302 is electrically connected to the communication device 301 in a state of being passed through the through hole 11 of the other coupler 10 (right side in FIG. 2). For example, the communication device 301 outputs a communication signal S1 having a frequency of 2 [MHz] to 30 [MHz] to the signal line 302.

  The switchboard 40 includes a main breaker, a plurality of branch breakers, and the like. The main breaker is, for example, an earth leakage breaker, and is configured to be able to switch between a state of supplying AC power from the power receiving panel 30 and a state of stopping supply to a plurality of branch breakers. Each of the plurality of branch breakers is, for example, an overcurrent circuit breaker, and is switched between a state in which AC power is supplied to a load 50 electrically connected via a pair of power lines 3 and a state in which supply is stopped. It is configured as follows. In this embodiment, the switchboard 40 further includes a pair of couplers 10 and a communication device 401.

  Here, although only one switchboard 40 is shown in FIG. 2, a plurality of switchboards 40 are actually connected to the power receiving board 30. And each of the some switchboard 40 is installed in each floor (each floor) of an office building, for example. The pair of couplers 10 is the same as that of the power receiving panel 30 and will not be described in detail here.

  Similar to the communication device 301, the communication device 401 is a modem that enables high-speed power line communication, for example. A signal line 402 is electrically connected to the communication device 401, and the communication device 401 and the signal line 402 constitute a closed circuit. One end side of the signal line 402 is electrically connected to the communication device 401 while being passed through the through hole 11 of one of the couplers 10 (left side in FIG. 2). Further, the other end side of the signal line 402 is electrically connected to the communication device 401 while being passed through the through hole 11 of the other coupler 10 (the right side in FIG. 2). For example, the communication apparatus 401 outputs a communication signal S1 having a frequency of 2 [MHz] to 30 [MHz] to the signal line 402.

  Next, the coupler 10 of this embodiment will be described with reference to FIG. The coupler 10 according to the present embodiment includes a core 1 and a magnetic flux reduction unit 2.

  The core 1 is formed in an annular shape from a magnetic material such as ferrite. The core 1 has a circular through hole 11 in the center, and is installed in a state where the power line 3 and the signal line 302 (or 402) are passed through the through hole 11.

  As shown in FIG. 1, the magnetic flux reduction unit 2 includes a coil 21 and a low-pass filter 22. The coil 21 is attached to the core 1. Here, the coil 21 being attached to the core 1 means that the coil 21 is formed by winding a conductive wire around the core 1. In the present embodiment, the coil 21 is attached to a part of the core 1 in the circumferential direction of the through hole 11 (see FIG. 1). The low-pass filter 22 is an inductor, for example. The cut-off frequency of the low-pass filter 22 is a frequency between the frequency of the feeding current I1 flowing through the power line 3 and the frequency of the communication signal S1 output from the communication device 301 (or 401), as will be described later. Is preferred. The operation of the magnetic flux reduction unit 2 will be described later.

  In this coupler 10, when a feeding current I1 flows through the power line 3, a magnetic flux φ1 is generated in the core 1 by the feeding current I1. In the coupler 10, when the communication signal S1 from the communication device 301 (or 401) is applied to the signal line 302 (or 402), the communication signal S1 generates a magnetic flux φ3 in the core 1. Here, since the feeding current I1 is an alternating current and the communication signal S1 is an alternating signal, the direction of the feeding current I1 and the communication signal S1 illustrated in FIG. 1 is an example. The directions of the magnetic fluxes φ1 and φ3 generated in the core 1 by the feeding current I1 and the communication signal S1 are also an example.

  Next, a case where communication is performed between the communication device 301 of the power receiving panel 30 and the communication device 401 of the switchboard 40 will be described. Here, the case where the communication signal S1 is transmitted from the communication device 301 to the communication device 401 will be described, but the same applies to the case where the communication signal S1 is transmitted from the communication device 401 to the communication device 301.

  When the communication device 301 outputs the communication signal S1 to the signal line 302, a magnetic flux φ3 (see FIG. 1) is generated in each core 1 when the communication signal S1 passes through each core 1 of the pair of couplers 10. Then, the communication signal S1 is superimposed on the feeding current I1 flowing in each power line 3 by the magnetic flux φ3 generated in each core 1. The communication signal S1 superimposed on the feeding current I1 is transmitted to the switchboard 40 through the power line 3.

  In the distribution board 40, when the communication signal S1 superimposed on the feeding current I1 passes through each core 1 of the pair of couplers 10, a magnetic flux φ3 is generated in each core 1. Then, the communication signal S1 is applied to the signal line 402 by the magnetic flux φ3 generated in each core 1, and the communication device 401 receives the communication signal S1.

  By the way, in a customer facility that requires a large amount of power, such as an office building, the power supply current I1 flowing through the power line 3 is also large (for example, about 300 A). When the feeding current I1 increases, the magnetic flux φ1 generated in the core 1 by the feeding current I1 also increases, and as a result, there is a possibility that magnetic saturation occurs in the core 1. On the other hand, it may be possible to prevent the occurrence of magnetic saturation by increasing the cross-sectional area of the core 1, but in this case, the core 1 is increased in size and the workability is reduced. There is a problem. In the coupler 10 of the present embodiment, the magnetic flux reduction unit 2 is provided in order to reduce the magnetic flux saturation in the core 1 while reducing the size of the core 1. Hereinafter, the operation of the magnetic flux reduction unit 2 will be described.

  The frequency of the feeding current I1 flowing through the power line 3 is a commercial power supply frequency and is 50 [Hz] or 60 [Hz]. On the other hand, the frequency of the communication signal S1 is 2 [MHz] to 30 [MHz] as described above. Therefore, the cut-off frequency of the low-pass filter 22 described above is preferably a frequency (for example, 100 [Hz]) between the frequency of the feeding current I1 and the frequency of the communication signal S1. That is, according to the low-pass filter 22, the current flowing through the coil 21 when the magnetic flux φ3 is generated in the core 1 by the communication signal S1 is cut off, and when the magnetic flux φ1 is generated in the core 1 by the feeding current I1, the coil 21 is blocked. The current flowing through is passed.

  When a feeding current I1 flows through the power line 3, a magnetic flux φ1 is generated in the core 1. Further, when the communication signal S1 is applied to the signal line 302 (or 402), a magnetic flux φ3 is generated in the core 1. When the magnetic fluxes φ1 and φ3 are generated in the core 1, an induced current is generated in the coil 21, but since a low-pass filter 22 is connected to both ends of the coil, only a low-frequency current corresponding to the magnetic flux φ1 is included in the induced current. The coil 21 flows. As a result, a magnetic flux φ2 in a direction that cancels the magnetic flux φ1 is generated in the core 1, whereby the magnetic flux φ1 can be reduced. In particular, when the magnetic flux φ1 and the magnetic flux φ2 are the same size, the magnetic flux φ1 can be canceled out. Then, by reducing the magnetic flux φ1, magnetic saturation in the core 1 can be made difficult to occur. Moreover, since the magnetic flux reduction part 2 can make it hard to produce the magnetic saturation in the core 1, the core 1 can be reduced in size.

  By the way, in the conventional power line carrier communication, an electrostatic coupling method using a capacitor is generally used as a coupler method, but in this case, an operation of connecting a capacitor to the power line 3 is necessary, and time is required for the construction. It was necessary. On the other hand, in the inductive coupling method using the core 1, it is only necessary to pass the power line 3 and the signal line 302 (or 402) through the through hole 11 of the core 1, and the construction time can be shortened. In particular, when the core 1 is a split-type core, the core can be attached without passing the power line 3 and the signal line 302 (or 402) through the through hole, so that it is not necessary to cause a power failure during construction. There is also an advantage.

  As described above, in the power line carrier communication coupler 10 of the present embodiment, the communication signal S1 transmitted between the plurality of communication devices 301 and 401 is superimposed on the AC power supplied from the power source (cubic 20) through the power line 3. Used for power line carrier communication. The power line carrier communication coupler 10 includes a core 1 and a magnetic flux reduction unit 2. The core 1 has a through hole 11 through which the power line 3 and the signal line 302 (or 402) connected to each of the plurality of communication devices 301 and 401 pass. The magnetic flux reduction unit 2 includes a coil 21 attached to the core 1, and the coil 21 generates a magnetic flux φ 2 in a direction opposite to the direction of the magnetic flux φ 1 generated in the core 1 when the power supply current I 1 from the power source flows through the power line 3. It is generated in the core 1. According to this configuration, the magnetic flux φ1 generated in the core 1 by the feeding current I1 flowing through the power line 3 can be reduced by the reverse magnetic flux φ2, thereby making it difficult to cause magnetic saturation in the core 1. Further, since the magnetic flux φ1 generated in the core 1 due to the feeding current I1 is reduced to make it difficult for magnetic saturation to occur in the core 1, the cross-sectional area of the core 1 does not need to be increased, and the core 1 can be downsized. Can be achieved. In other words, according to the power line carrier communication coupler 10 of the present embodiment, magnetic saturation in the core 1 can be made difficult to occur while the core 1 is reduced in size. Furthermore, compared to the case where a gap is provided in the core 1 to prevent magnetic saturation, only the magnetic flux φ1 generated in the core 1 by the feeding current I1 can be reduced, so that the power line 3 and the signal line 302 for the communication signal S1. The degree of coupling with (or 402) can be increased.

  Further, like the power line carrier communication coupler 10 of the present embodiment, the magnetic flux reduction unit 2 preferably has a low-pass filter 22 that is electrically connected between both ends of the coil 21. In this case, the frequency of the communication signal S1 is higher than the frequency of the feeding current I1. The cut-off frequency of the low-pass filter 22 is a frequency between the frequency of the feeding current I1 and the frequency of the communication signal S1. According to this configuration, only the current flowing through the coil 21 due to the magnetic flux φ1 is passed by the low-pass filter 22, so that only the magnetic flux φ1 is reduced without affecting the magnetic flux φ3 generated in the core 1 by the communication signal S1. Can do. That is, in this case as well, it is possible to reduce the magnetic saturation in the core 1 while reducing the size of the core 1. Moreover, according to this structure, the magnetic flux reduction part 2 can be implement | achieved only by the coil 21 and the low-pass filter 22, and cost reduction can be achieved. However, this configuration is not an essential configuration of the power line carrier communication coupler 10, and the magnetic flux reduction unit 2 may be configured other than the low-pass filter 22.

  Hereinafter, modifications of the first embodiment will be described.

  The application target of the above-described communication system 100 is not limited to a large-scale consumer facility such as a commercial facility, a factory, an office building, or a hospital, and may be, for example, a single-family house or an apartment house. Further, the number of communication devices is not limited to two, and may be three or more.

  In the first embodiment, the non-divided core 1 has been described as an example. However, a split core may be used. Moreover, the shape of the core 1 is an example, for example, the core 1 may be formed in the shape of a rectangular tube.

  Furthermore, in the above-described first embodiment, the case where the low-pass filter 22 is an inductor has been described as an example. However, the low-pass filter 22 is not limited to an inductor, and may be, for example, an RC circuit or an operational amplifier. Good.

(Embodiment 2)
The power line carrier communication coupler 10A of the second embodiment will be specifically described with reference to FIG. However, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The power line carrier communication coupler 10A (hereinafter referred to as coupler 10A) of the present embodiment includes a core 1 and a magnetic flux reduction unit 2A as shown in FIG.

  The magnetic flux reduction unit 2 </ b> A includes a detection unit 25, a separation unit 26, and a reverse magnetic flux generation unit 27. The detection unit 25 includes a detection coil 23 and a detection circuit 24.

  The detection coil 23 is attached to a part of the core 1 in the circumferential direction of the through hole 11. That is, the detection coil 23 is formed by winding a conducting wire around the core 1. Both ends of the detection coil 23 are electrically connected to the detection circuit 24.

  The detection circuit 24 detects the electrical signal S2. The electric signal S2 includes a magnetic flux φ11 generated in the core 1 when the feeding current I1 flows through the power line 3, and a magnetic flux φ13 generated in the core 1 when the communication signal S1 is applied to the signal line 302 (or 402). It corresponds to the magnetic flux containing. In the present embodiment, the detection circuit 24 has a resistor, and the detection circuit 24 detects a voltage generated between both ends of the resistor as an electric signal S2 by an induced current that generates a magnetic flux in a direction to cancel the magnetic flux. That is, in the present embodiment, the electric signal S2 is a voltage signal.

  The separation unit 26 is, for example, a low pass filter. This low-pass filter is preferably an inductor as in the first embodiment. The cut-off frequency of this low-pass filter is preferably a frequency between the frequency of the feed current I1 and the frequency of the communication signal S1. The separation unit 26 separates the component corresponding to the magnetic flux φ11 generated in the core 1 by the feeding current I1 flowing through the power line 3 from the electric signal S2 detected by the detection unit 25, and the separated component is supplied to the reverse magnetic flux generation unit 27. Output.

  The reverse magnetic flux generator 27 includes a coil 28 and a reverse magnetic flux generator 29. The coil 28 corresponds to the coil 21 of the first embodiment and is attached to the core 1. That is, the coil 28 is formed by winding a conducting wire around the core 1. The reverse magnetic flux generation circuit 29 causes the coil 1 to generate a magnetic flux in the direction opposite to the magnetic flux φ11 based on the component corresponding to the magnetic flux φ11 separated by the separation unit 26. In the present embodiment, the reverse magnetic flux generation circuit 29 generates the magnetic flux φ12 by causing the current I2 to flow through the coil 28.

  In the coupler 10A of the present embodiment, as described above, the magnetic flux φ12 opposite to the magnetic flux φ11 is applied to the core 1 based on the component corresponding to the magnetic flux φ11 generated in the core 1 when the feeding current I1 flows through the power line 3. Is generated. Therefore, the magnetic flux φ12 having substantially the same size as the magnetic flux φ11 can be generated in the core 1, and the magnetic flux φ11 can be canceled out. In other words, according to the coupler 10A of the present embodiment, it is possible to generate the magnetic flux φ12 having such a magnitude that the magnetic flux φ11 generated in the core 1 can be canceled by the feeding current I1 flowing through the power line 3. Further, since the magnetic flux φ11 can be canceled by the magnetic flux φ12, the core 1 can be further downsized.

  As described above, in the power line carrier communication coupler 10A of the present embodiment, the magnetic flux reduction unit 2A includes the detection unit 25 (the detection coil 23 and the detection circuit 24), the separation unit 26, and the reverse magnetic flux generation unit 27 ( A coil 28 and a reverse magnetic flux generating circuit 29). The detection unit 25 detects an electric signal S2 corresponding to the magnetic flux φ11 and the magnetic flux φ13 generated in the core 1. The separation unit 26 separates a component corresponding to the magnetic flux φ11 generated in the core 1 by the feeding current I1 from the electric signal S2 detected by the detection unit 25. The reverse magnetic flux generator 27 includes a coil 28, and causes the core 1 to generate a magnetic flux φ 12 opposite to the magnetic flux φ 11 based on the components separated by the separator 26. According to this configuration, the magnitude of the reverse magnetic flux φ12 generated in the reverse magnetic flux generator 27 by the detector 25 and the separator 26 is made closer to the magnitude of the magnetic flux φ11 generated in the core 1 by the feeding current I1. Can do. As a result, it is possible to generate a magnetic flux φ12 having such a magnitude that the magnetic flux φ11 generated in the core 1 can be canceled by the feeding current I1. Further, since the magnetic flux φ11 can be canceled by the magnetic flux φ12, the core 1 can be further downsized.

  In addition, like the power line carrier communication coupler 10 </ b> A of the present embodiment, the detection unit 25 preferably includes a detection coil 23 attached to the core 1. According to this configuration, since the magnetic fluxes φ11 and φ13 generated in the core 1 are detected using the detection coil 23, the cost can be reduced compared to the case where the magnetic fluxes φ11 and φ13 are detected using a current sensor. Can be achieved. However, this configuration is not an essential configuration of the power line carrier communication coupler 10A, and the detection coil 23 may not be included in the detection unit 25.

  Further, like the power line carrier communication coupler 10A of the present embodiment, the separation unit 26 is preferably a low-pass filter. In this case, the frequency of the communication signal S1 is higher than the frequency of the feeding current I1. The cut-off frequency of the low-pass filter is a frequency between the frequency of the feeding current I1 and the frequency of the communication signal S1. According to this configuration, since only the current flowing in the detection coil 23 is passed by the magnetic flux φ11 generated in the core 1 by the feeding current I1, the magnetic flux φ13 generated in the core 1 by the communication signal S1 is not affected. Only the magnetic flux φ11 can be reduced. Further, according to this configuration, the separation unit 26 can be realized only by the low-pass filter, and the cost can be reduced. However, this configuration is not an essential configuration of the power line carrier communication coupler 10A, and the separation unit 26 may be configured other than the low-pass filter.

  Furthermore, the configuration described in the above-described second embodiment can be applied in appropriate combination with the modification described in the first embodiment.

(Embodiment 3)
The power line carrier communication coupler 10B of the third embodiment will be specifically described with reference to FIGS. However, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The power line carrier communication coupler 10B (hereinafter referred to as coupler 10B) of the present embodiment includes a core 1 and a magnetic flux reduction unit 2B as shown in FIG. The magnetic flux reduction unit 2 </ b> B includes a coil 21 and a low-pass filter 22. Here, in Embodiment 1 described above, the coil 21 is mounted only on a part of the circumferential direction of the through hole 11 in the core 1, but in this embodiment, the coil 21 is entirely around the through hole 11 in the core 1. (See FIG. 4). In other words, the coil 21 is formed by winding a conducting wire over the entire circumference of the through hole 11 in the core 1. Here, the entire circumference of the through hole 11 in the core 1 refers to a range in which the coil 21 is mounted to such an extent that local magnetic saturation does not occur in the core 1, for example, an area of 90% or more of the core 1 It is sufficient that the coil 21 is attached to the.

  Incidentally, the power line 3 is preferably located at the center of the through hole 11 of the core 1 as shown in FIG. 5A. In this case, a uniform magnetic flux φ <b> 1 is generated in the core 1 by the feeding current I <b> 1 flowing through the power line 3. On the other hand, as shown in FIG. 5B, when the power line 3 is deviated from the center of the through hole 11 of the core 1, the magnetic flux φ1 is generated in a biased manner. In the example shown in FIG. 5B, the magnetic flux φ1 is dense in the portion where the distance to the power line 3 in the core 1 is short, and the magnetic flux φ1 is generated in the portion where the distance to the power line 3 is long in the core 1 due to the leakage magnetic flux φ4. Become sparse.

  In the coupler 10 described in the first embodiment, the coil 21 is mounted only on a part of the core 1 in the circumferential direction of the through hole 11. Therefore, in the coupler 10, when the portion where the magnetic flux φ1 is dense and the portion where the coil 21 is mounted are different, the magnetic flux φ1 cannot be reduced, and local magnetic saturation occurs in the core 1. there is a possibility.

  Further, as in the coupler 10 described in the first embodiment, when the coil 21 is attached only to a part of the core 1 in the circumferential direction of the through hole 11, the magnetic flux generated in the core 1 by the magnetic flux reduction unit 2. φ2 is as shown in FIG. That is, in the portion of the core 1 where the coil 21 is mounted, the magnetic flux φ2 is generated in the core 1, but on the side opposite to the portion where the coil 21 is mounted with respect to the power line 3, the leakage flux φ5 is generated. 1 may cause local magnetic saturation. From the above, the coil 21 constituting a part of the magnetic flux reduction unit 2 is preferably mounted over the entire circumference of the through hole 11 in the core 1 as shown in FIG.

  As described above, in the power line carrier communication coupler 10 </ b> B of this embodiment, the coil 21 is mounted over the entire circumference of the through hole 11 in the core 1. According to this configuration, local magnetic saturation in the core 1 can be made difficult to occur.

  The configuration described in Embodiment 3 above can be applied in appropriate combination with the configuration described in Embodiment 2. That is, in the coupler 10 </ b> A of the second embodiment, the detection coil 23 and the coil 28 may be mounted over the entire circumference of the through hole 11 in the core 1. Further, the configuration described in the above-described third embodiment can be applied in appropriate combination with the modification described in the first embodiment.

(Embodiment 4)
The power line carrier communication couplers 10C and 10D of the fourth embodiment will be specifically described with reference to FIGS. However, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 7, the power line carrier communication coupler 10 </ b> C (hereinafter referred to as coupler 10 </ b> C) of the present embodiment includes a core 1 and a plurality (three in FIG. 7) of magnetic flux reduction units 2. In the first embodiment described above, the coil 21 of one magnetic flux reduction unit 2 is mounted on a part of the core 1 in the circumferential direction of the through hole 11, but in this embodiment, the coils 21 of the three magnetic flux reduction units 2 are mounted. Thus, the coil 21 is mounted over the entire circumference of the through hole 11 in the core 1. Also in this embodiment, the entire circumference of the through hole 11 in the core 1 refers to a range in which the coil 21 is mounted to such an extent that local magnetic saturation does not occur in the core 1.

  For example, as shown in FIG. 7, when the power line 3 is deviated from the center of the through hole 11 of the core 1, the magnetic flux φ <b> 1 generated in the core 1 becomes dense by the corresponding magnetic flux reduction unit 2 in the portion where the magnetic flux φ <b> 1 is dense. A reverse magnetic flux φ2 corresponding to the size of φ1 is generated. Further, in a portion where the magnetic flux φ1 generated in the core 1 is sparse, the corresponding magnetic flux reduction unit 2 generates a reverse magnetic flux φ2 corresponding to the magnitude of the magnetic flux φ1 in the core 1. That is, according to the coupler 10C of the present embodiment, the plurality of magnetic flux reduction units 2 can generate the reverse magnetic flux φ2 corresponding to the magnitude of the magnetic flux φ1 generated in the portion where the coil 21 is mounted. . As a result, similar to the coupler 10B described in the third embodiment, local magnetic saturation can be made difficult to occur.

  As described above, the power line carrier communication coupler 10 </ b> C of this embodiment includes a plurality of magnetic flux reduction units 2. The plurality of coils 21 in the plurality of magnetic flux reduction units 2 are arranged along the circumferential direction of the through hole 11 in the core 1. According to this configuration, local magnetic saturation in the core 1 can be made difficult to occur.

  Hereinafter, modifications of the fourth embodiment will be described.

  The number of the magnetic flux reduction units 2 described in the fourth embodiment is an example. For example, as illustrated in FIG. 8, the power line carrier communication coupler 10 </ b> D may include 12 magnetic flux reduction units 2. In this case, it is preferable that the coils 21 are mounted over the entire circumference of the through hole 11 in the core 1 by the coils 21 of the twelve magnetic flux reduction units 2. That is, the number of the magnetic flux reduction units 2 may be plural. In this case as well, local magnetic saturation in the core 1 can be made difficult to occur.

  In addition, the configuration described in the above-described fourth embodiment can be applied in appropriate combination with the configuration described in the second embodiment. That is, in the second embodiment, the power line carrier communication coupler 10A may include a plurality of magnetic flux reduction units 2A. In this case, the detection coils 23 and the coils 28 of the plurality of magnetic flux reduction units 2 </ b> A are taken as a set, and a plurality of sets of the detection coils 23 and the coils 28 are arranged along the circumferential direction of the through hole 11 in the core 1. preferable. Furthermore, the configuration described in the above embodiment can be applied in appropriate combination with the modification of the first embodiment.

DESCRIPTION OF SYMBOLS 1 Core 2, 2A, 2B Magnetic flux reduction part 3 Power line 10, 10A, 10B, 10C, 10D Power line carrier communication coupler 11 Through-hole 20 Cubicle (power supply)
21 Coil 22 Low-pass filter 23 Detection coil 24 Detection circuit 25 Detection unit 26 Separation unit 27 Reverse magnetic flux generation unit 28 Coil 29 Reverse magnetic flux generation circuit 301 Communication device 302 Signal line 401 Communication device 402 Signal line I1 Feed current S1 Communication signal S2 Electricity Signal φ1, φ2, φ11, φ12, φ13 Magnetic flux

Claims (7)

A power line carrier communication coupler used for power line carrier communication in which a communication signal transmitted between a plurality of communication devices is superimposed on AC power supplied from a power source through a power line,
A core having a through hole through which the power line and a signal line connected to each of the plurality of communication devices pass;
A magnetic flux reduction unit that includes a coil attached to the core, and causes the coil to generate a magnetic flux in a direction opposite to the direction of the magnetic flux generated in the core when a feeding current from the power source flows through the power line. A power line carrier communication coupler comprising: The magnetic flux reduction unit has a low-pass filter electrically connected between both ends of the coil,
The frequency of the communication signal is higher than the frequency of the feeding current,
The power line carrier communication coupler according to claim 1, wherein the cutoff frequency of the low-pass filter is a frequency between the frequency of the feeding current and the frequency of the communication signal. The magnetic flux reduction unit is
A detection unit for detecting an electrical signal corresponding to the magnetic flux generated in the core;
A separation unit that separates a component corresponding to a magnetic flux generated in the core by the feeding current from the electrical signal detected by the detection unit;
A reverse magnetic flux generation unit that includes the coil and generates a magnetic flux in the core in the direction opposite to the magnetic flux generated in the core by the feeding current based on the component separated by the separation unit. The power line carrier communication coupler according to claim 1. The power line carrier communication coupler according to claim 3, wherein the detection unit includes a detection coil attached to the core. The separation unit is a low-pass filter;
The frequency of the communication signal is higher than the frequency of the feeding current,
The power line carrier communication coupler according to claim 3 or 4, wherein the cut-off frequency of the low-pass filter is a frequency between the frequency of the feeding current and the frequency of the communication signal. The said coil is mounted over the perimeter of the said through-hole in the said core. The coupler for power line carrier communications of any one of 1-5 characterized by the above-mentioned. A plurality of the magnetic flux reduction units are provided,
6. The power line carrier communication according to claim 1, wherein the plurality of coils in the plurality of magnetic flux reduction units are arranged along a circumferential direction of the through hole in the core. Coupler.

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