JP6952254B2 - Coupler for power line carrier communication - Google Patents

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. Regarding couplers.

Conventionally, a power line carrier signal processing device 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 type ferrite core, a first conductor wire, and a second conductor wire. The ferrite core has a hollow portion through which the power line penetrates. The first conductor and the second conductor are each wound around a ferrite core in a predetermined number of turns.

In the power line carrier signal processing device described in Patent Document 1, a current flows through the first lead wire and the second lead wire by the 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 conductor and the current flowing through the second conductor cancel each other out, whereby the power line carrier signal processing device functions as a blocking filter.

International Publication No. 2007/023527

By the way, in the configuration described in Patent Document 1, magnetic saturation may occur in the ferrite core depending on the magnitude of the alternating current flowing in 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 become large 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 the size of the core and making it difficult for magnetic saturation to occur in the core.

The power line carrier communication coupler according to one 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. This power line carrier communication coupler includes a core and a magnetic flux reducing unit. The core has a through hole through which the power line and the signal line connected to each of the plurality of communication devices penetrate. The magnetic flux reducing unit includes one coil mounted on the core, and the coil causes the magnetic flux in the direction opposite to the direction of the magnetic flux generated in the core when a power supply current from the power source flows through the power line. Generate in the core. The coil has a function of detecting a current induced by a magnetic flux generated in the core and a function of generating a magnetic flux in the core in the direction opposite to the direction of the magnetic flux generated in the core. The coil is mounted over the entire circumference of the through hole in the core.

The present invention has an effect that magnetic saturation in the core can be made less likely to occur while reducing the size of the core.

FIG. 1 is a perspective view showing a configuration of a power line carrier communication coupler according to a first embodiment of the present invention. FIG. 2 is a configuration diagram of a communication system using the same power line carrier communication coupler. FIG. 3 is a perspective view showing the configuration of the power line carrier communication coupler according to the second embodiment of the present invention. FIG. 4 is a plan view showing the configuration of the power line carrier communication coupler according to the third embodiment of the present invention. 5A and 5B are plan views showing the magnetic flux generated in the core of the power line carrier communication coupler of the same. FIG. 6 is an explanatory diagram illustrating 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 the power line carrier communication coupler according to the fourth embodiment of the present invention. FIG. 8 is a plan view showing a configuration of a power line carrier communication coupler according to a modified example of the fourth embodiment of the present invention.

Hereinafter, the power line carrier communication coupler according to the 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 embodiments 1 to 4. Therefore, even if the embodiments are other than those of the first to fourth embodiments, various changes can be made according to the design and the like as long as the technical idea of the present invention is not deviated.

(Embodiment 1)
The power line carrier communication coupler 10 (hereinafter referred to as the coupler 10) of the present embodiment will be specifically described with reference to FIGS. 1 and 2. As shown in FIG. 2, the coupler 10 is used for power line carrier communication in which a communication signal S1 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 board 30 and the switchboard 40. The communication system 100 is applied to consumer facilities such as commercial facilities, factories, office buildings, and hospitals that require a large amount of electric power, for example. The case where the consumer facility is an office building will be described below.

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

The cubicle 20 includes a transformer 201, which transforms (steps down) 6600 volt AC power supplied from a power plant via a substation to 200 volt (or 100 volt) AC power. Then, the cubicle 20 supplies the AC power transformed by the transformer 201 to the power receiving board 30 via the pair of power lines 3. One of the pair of power lines 3 (left side in FIG. 2) is electrically connected to one output (L1 phase) of the cubicle 20, and the other power line 3 (right side in FIG. 2) is the other 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 electric room.

The power receiving board 30 includes at least a main shutoff device. The main cutoff device is used as a power receiving cutoff device for the cubicle 20, and automatically cuts off the electric circuit when an overload current, a short circuit current, or the like occurs in the electric circuit on the secondary side of the main cutoff device. Further, in the present embodiment, the power receiving board 30 further includes a pair of couplers 10 and a communication device 301. The power receiving board 30 is installed in, for example, a management room of an office building.

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

The communication device 301 is, for example, a modem that enables high-speed power line communication (HD-PLC). A signal line 302 is electrically connected to the communication device 301, and the communication device 301 and the signal line 302 form 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 the coupler 10 on one side (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 coupler 10 on the other side (right side in FIG. 2). The communication device 301 outputs a communication signal S1 having a frequency of, for example, 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 circuit breaker is, for example, an earth leakage breaker, and is configured to switch between a state of supplying AC power from the power receiving board 30 and a state of stopping the supply to a plurality of branch breakers. Each of the plurality of branch breakers is, for example, an overcurrent circuit breaker, and can switch between a state of supplying AC power to a load 50 electrically connected via a pair of power lines 3 and a state of stopping the supply. It is configured as follows. Further, in the present 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, in reality, a plurality of switchboards 40 are connected to the power receiving board 30. Each of the plurality of switchboards 40 is installed, for example, on each floor (each floor) of an office building. The pair of couplers 10 are the same as those of the power receiving board 30, and detailed description thereof will be omitted here.

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

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

The core 1 is formed in an annular shape by 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 reducing unit 2 has a coil 21 and a low-pass filter 22. The coil 21 is mounted on the core 1. Here, the fact that the coil 21 is mounted on the core 1 means that the coil 21 is formed by winding a conducting wire around the core 1. In the present embodiment, the coil 21 is mounted on a part of the core 1 in the circumferential direction of the through hole 11 (see FIG. 1). The low-pass filter 22 is, for example, an inductor. The cutoff 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 preferable. The operation of the magnetic flux reducing unit 2 will be described later.

In the coupler 10, when the power supply current I1 flows through the power line 3, the magnetic flux φ1 is generated in the core 1 by the power supply current I1. Further, 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 current, the directions of the feeding current I1 and the communication signal S1 shown in FIG. 1 are examples. Further, 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 examples.

Next, a case where communication is performed between the communication device 301 of the power receiving board 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 feed current I1 flowing through each power line 3 by the magnetic flux φ3 generated in each core 1. The communication signal S1 superimposed on the power supply current I1 is transmitted to the switchboard 40 through the power line 3.

In the switchboard 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 consumer facility that requires a large amount of electric power, such as an office building, the power supply current I1 flowing through the power line 3 also becomes large (for example, about 300 A). When the feeding current I1 becomes large, the magnetic flux φ1 generated in the core 1 by the feeding current I1 also becomes large, and as a result, magnetic saturation may occur in the core 1. On the other hand, it is conceivable to prevent the occurrence of magnetic saturation by increasing the cross-sectional area of the core 1, but in this case, the increase in size of the core 1 increases the cost and reduces the workability. There is a problem. In the coupler 10 of the present embodiment, the magnetic flux reducing unit 2 is provided in order to make it difficult for the magnetic flux saturation in the core 1 to occur while reducing the size of the core 1. Hereinafter, the operation of the magnetic flux reducing unit 2 will be described.

The frequency of the power supply current I1 flowing through the power line 3 is a commercial power supply frequency, which 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 cutoff frequency of the low-pass filter 22 described above is preferably a frequency between the frequency of the feeding current I1 and the frequency of the communication signal S1 (for example, 100 [Hz]). That is, according to this 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 the coil 21 is generated when the magnetic flux φ1 is generated in the core 1 by the feeding current I1. Pass the current flowing through.

When the power supply 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 magnetic fluxes φ1 and φ3 are generated in the core 1, an induced current is generated in the coil 21, but since low-pass filters 22 are connected to both ends of the coil, only the low-frequency current corresponding to the magnetic flux φ1 is generated among the induced currents. It flows through the coil 21. 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 have the same magnitude, the magnetic flux φ1 can be canceled. Then, by reducing the magnetic flux φ1, it is possible to make it difficult for magnetic saturation in the core 1 to occur. Further, since the magnetic flux reducing unit 2 makes it difficult for magnetic saturation in the core 1 to occur, the core 1 can be miniaturized.

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, it is necessary to connect a capacitor to the power line 3, and it takes time for construction. I needed it. On the other hand, in the inductively coupled 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 a power failure does not have to occur 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 supply (cubicle 20) through the power line 3. It is used for power line carrier communication. The power line carrier communication coupler 10 includes a core 1 and a magnetic flux reducing 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 penetrate. The magnetic flux reducing unit 2 includes the coil 21 mounted on the core 1, and the magnetic flux φ2 generated in the core 1 in the direction opposite to the direction of the magnetic flux φ1 generated by the power supply current I1 flowing through the power line 3 is generated by the coil 21. Generate in 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 magnetic flux φ2 in the opposite direction, which makes it difficult for magnetic saturation in the core 1 to occur. Further, since the magnetic flux φ1 generated in the core 1 by the feeding current I1 is reduced to make it difficult for magnetic saturation in the core 1 to occur, it is not necessary to increase the cross-sectional area of the core 1 and the core 1 is downsized. Can be planned. That is, according to the power line carrier communication coupler 10 of the present embodiment, it is possible to reduce the size of the core 1 while making it difficult for magnetic saturation to occur in the core 1. Further, as compared with 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 can be reduced. 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 reducing unit 2 preferably has a low-pass filter 22 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 cutoff 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, since only the current flowing through the coil 21 due to the magnetic flux φ1 is passed by the low-pass filter 22, only the magnetic flux φ1 is reduced without affecting the magnetic flux φ3 generated in the core 1 by the communication signal S1. Can be done. That is, in this case as well, it is possible to make it difficult for magnetic saturation to occur in the core 1 while reducing the size of the core 1. Further, according to this configuration, the magnetic flux reducing unit 2 can be realized only by the coil 21 and the low-pass filter 22, and the cost can be reduced. 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, a modified example of the first embodiment will be described.

The application target of the above-mentioned communication system 100 is not limited to large-scale consumer facilities such as commercial facilities, factories, office buildings, and hospitals, and may be, for example, each dwelling unit of a detached house or an apartment house. Further, the number of communication devices is not limited to two, and may be three or more.

In the above-described first embodiment, the non-divided core 1 has been described as an example, but a divided core may be used. Further, the shape of the core 1 is an example, and for example, the core 1 may be formed in a square cylinder shape.

Further, in the above-described first embodiment, the case where the low-pass filter 22 is an inductor has been described as an example, but the low-pass filter 22 is not limited to the inductor, and may be, for example, an RC circuit or may be composed of 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 reference numerals are given to the same configurations as those in the first embodiment, and detailed description thereof will be omitted.

As shown in FIG. 3, the power line carrier communication coupler 10A (hereinafter referred to as the coupler 10A) of the present embodiment includes a core 1 and a magnetic flux reducing unit 2A.

The magnetic flux reducing unit 2A includes a detecting unit 25, a separating unit 26, and a reverse magnetic flux generating unit 27. The detection unit 25 includes a detection coil 23 and a detection circuit 24.

The detection coil 23 is mounted on 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 electric signal S2. The electric signal S2 has a magnetic flux φ11 generated in the core 1 when the power supply 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 included. 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 that cancels 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. The low-pass filter is preferably an inductor as in the first embodiment. The cutoff frequency of this low-pass filter is preferably a frequency between the frequency of the feeding 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 power supply current I1 flowing from the electric signal S2 detected by the detection unit 25 to the power line 3, and transfers the separated component to the reverse magnetic flux generation unit 27. Output.

The reverse magnetic flux generating unit 27 includes a coil 28 and a reverse magnetic flux generating circuit 29. The coil 28 corresponds to the coil 21 of the above-described first embodiment and is mounted on 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 generates a magnetic flux in the direction opposite to the magnetic flux φ11 in the core 1 by the coil 28 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 passing a current I2 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 power supply current I1 flows through the power line 3. It is occurring. Therefore, a 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 a magnetic flux φ12 having a size capable of canceling the magnetic flux φ11 generated in the core 1 by the feed current I1 flowing through the power line 3. Further, since the magnetic flux φ12 can cancel the magnetic flux φ11, the core 1 can be further miniaturized.

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 (detection coil 23 and detection circuit 24), the separation unit 26, and the reverse magnetic flux generation unit 27 ( It has a coil 28 and a reverse magnetic flux generation circuit 29). The detection unit 25 detects the electric signal S2 corresponding to the magnetic flux φ11 and the magnetic flux φ13 generated in the core 1. The separation unit 26 separates the 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 generating unit 27 includes the coil 28, and generates a magnetic flux φ12 in the opposite direction to the magnetic flux φ11 in the core 1 by the coil 28 based on the above components separated by the separating unit 26. According to this configuration, the size of the reverse magnetic flux φ12 generated by the reverse magnetic flux generating unit 27 by the detecting unit 25 and the separating unit 26 is brought close to the size of the magnetic flux φ11 generated in the core 1 by the feeding current I1. Can be done. As a result, it is possible to generate a magnetic flux φ12 having a size capable of canceling the magnetic flux φ11 generated in the core 1 by the feeding current I1. Further, since the magnetic flux φ12 can cancel the magnetic flux φ11, the core 1 can be further miniaturized.

Further, like the power line carrier communication coupler 10A of the present embodiment, the detection unit 25 preferably includes a detection coil 23 mounted on the core 1. According to this configuration, since the magnetic fluxes φ11 and φ13 generated in the core 1 are detected by using the detection coil 23, the cost is reduced as compared with the case where the magnetic fluxes φ11 and φ13 are detected by using the current sensor. Can be planned. 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 cutoff 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, only the current flowing through the detection coil 23 is passed by the magnetic flux φ11 generated in the core 1 by the feeding current I1, so that 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.

Further, the configuration described in the second embodiment can be applied in combination with the modified example described in the first embodiment as appropriate.

(Embodiment 3)
The power line carrier communication coupler 10B of the third embodiment will be specifically described with reference to FIGS. 4 to 6. However, the same reference numerals are given to the same configurations as those in the first embodiment, and detailed description thereof will be omitted.

As shown in FIG. 4, 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 reducing unit 2B. Further, the magnetic flux reducing unit 2B has a coil 21 and a low-pass filter 22. Here, in the above-described first embodiment, the coil 21 is mounted only on a part of the through hole 11 in the core 1 in the circumferential direction, but in the present embodiment, the coil 21 is the entire circumference of 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 means a range in which the coil 21 is mounted to the extent that local magnetic saturation does not occur in the core 1, for example, a region of 90% or more of the core 1. It suffices if the coil 21 is attached to.

By the way, as shown in FIG. 5A, the power line 3 is preferably located at the center of the through hole 11 of the core 1. In this case, a uniform magnetic flux φ1 is generated in the core 1 by the feed current I1 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 unevenly generated. In the example shown in FIG. 5B, the magnetic flux φ1 becomes dense in the portion where the distance to the power line 3 is short in the core 1, 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 flux φ4. Become sparse.

In the coupler 10 described in the first embodiment described above, the coil 21 is mounted only on a part of the through hole 11 in the core 1 in the circumferential direction. Therefore, in the coupler 10, when the portion where the magnetic flux φ1 becomes 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, when the coil 21 is mounted only on a part of the through hole 11 in the core 1 in the circumferential direction as in the coupler 10 described in the first embodiment, the magnetic flux generated in the core 1 by the magnetic flux reducing unit 2 φ2 is as shown in FIG. That is, the magnetic flux φ2 is generated in the core 1 in the portion of the core 1 where the coil 21 is mounted, but the leakage flux φ5 is generated in the portion opposite to the portion where the coil 21 is mounted with respect to the power line 3, and the core. Local magnetic saturation may occur at 1. From the above, it is preferable that the coil 21 forming a part of the magnetic flux reducing portion 2 is 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 10B of the present 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 less likely to occur.

The configuration described in the third embodiment can be applied in combination with the configuration described in the second embodiment as appropriate. That is, in the coupler 10A 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 third embodiment can be applied in combination with the modified example described in the first embodiment as appropriate.

(Embodiment 4)
The power line carrier communication couplers 10C and 10D of the fourth embodiment will be specifically described with reference to FIGS. 7 and 8. However, the same reference numerals are given to the same configurations as those in the first embodiment, and detailed description thereof will be omitted.

As shown in FIG. 7, the power line carrier communication coupler 10C (hereinafter referred to as coupler 10C) of the present embodiment includes a core 1 and a plurality of (three in FIG. 7) magnetic flux reducing units 2. In the above-described first embodiment, the coil 21 of one magnetic flux reducing unit 2 is mounted on a part of the through hole 11 in the circumferential direction in the core 1, but in the present embodiment, the coil 21 of the three magnetic flux reducing units 2 is mounted. 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 means a range in which the coil 21 is mounted to the 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 is reduced by the corresponding magnetic flux reducing unit 2 in the portion where the magnetic flux φ1 generated in the core 1 becomes dense. A magnetic flux φ2 in the opposite direction is generated according to the size of φ1. Further, in the portion where the magnetic flux φ1 generated in the core 1 is sparse, the magnetic flux φ2 in the opposite direction corresponding to the magnitude of the magnetic flux φ1 is generated in the core 1 by the corresponding magnetic flux reducing unit 2. That is, according to the coupler 10C of the present embodiment, the plurality of magnetic flux reducing portions 2 can generate the magnetic flux φ2 in the opposite direction according to the magnitude of the magnetic flux φ1 generated in the portion where the coil 21 is mounted. .. As a result, local magnetic saturation can be made less likely to occur, as in the case of the coupler 10B described in the third embodiment.

As described above, the power line carrier communication coupler 10C of the present embodiment includes a plurality of magnetic flux reducing units 2. The plurality of coils 21 in the plurality of magnetic flux reducing portions 2 are arranged along the circumferential direction of the through holes 11 in the core 1. According to this configuration, local magnetic saturation in the core 1 can be made less likely to occur.

Hereinafter, a modified example of the fourth embodiment will be described.

The number of magnetic flux reducing units 2 described in the fourth embodiment is an example. For example, as shown in FIG. 8, the power line carrier communication coupler 10D may include 12 magnetic flux reducing units 2. In this case, it is preferable that the coil 21 is mounted over the entire circumference of the through hole 11 in the core 1 by the coil 21 of the 12 magnetic flux reducing portions 2. That is, the number of the magnetic flux reducing portions 2 may be plural. In this case as well, local magnetic saturation in the core 1 can be made less likely to occur.

Further, the configuration described in the fourth embodiment can be applied in combination with the configuration described in the second embodiment as appropriate. That is, in the second embodiment, the power line carrier communication coupler 10A may include a plurality of magnetic flux reducing units 2A. In this case, the detection coils 23 and the coils 28 of the plurality of magnetic flux reducing portions 2A are set as one set, and the 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. Further, the configuration described in the above-described embodiment can be applied in combination with a modification of the first embodiment as appropriate.

1 Core 2, 2A, 2B Magnetic flux reduction unit 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 (2)

A coupler 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 from a power source through a power line.
A core having a through hole through which the power line and the signal line connected to each of the plurality of communication devices penetrate.
A magnetic flux reduction that includes one coil mounted on the core and causes the coil to generate magnetic flux in the core in the direction opposite to the direction of the magnetic flux generated in the core when the power supply current from the power supply flows through the power line. With a part
The coil
A function to detect the current induced by the magnetic flux generated in the core, and
It has a function of generating a magnetic flux in the core in the direction opposite to the direction of the magnetic flux generated in the core .
The coil is a coupler for power line carrier communication, which is mounted over the entire circumference of the through hole in the core. The magnetic flux reducing 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 feed current and the frequency of the communication signal .

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