JP2007174547A - Power line communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve communication quality in a power line communication. <P>SOLUTION: The power line communication method is performed by using an indoor wiring in which a plurality of branch lines 14 are connected to a lead-in line 13 of a single phase three-line system via branch points. Further, a termination circuit 30 for matching the impedance of a communication path connecting the first communication apparatus 31 configured by the lead-in line 13 and the branch lines 14(1), 14(2) to the second communication apparatus 41 is provided only in outlets 51(1), (2), (7), (8), provided on the first branch line 14(1) or the second branch line 14(2), and a filter circuit 17 is provided including an inductor formed by winding two conductor wires around a circular core and a capacitor to be connected between the two conductor wires near each of the branch points of the branch lines 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power line communication method, and more particularly to a technique for improving the communication quality of power line communication by efficiently installing a termination circuit at an appropriate place.

  2. Description of the Related Art Power line communication (PLC) that performs communication using a power line (electric light line) wired indoors is known. FIG. 7 shows an example of an indoor power distribution facility in which power line communication is performed. In the figure, a distribution board 11 accommodates a single-phase three-wire lead-in wire 13 whose one end is connected to a pole transformer 12. A branch line 14 is connected to the lead-in line 13 for supplying power to outlets, lamps and the like provided in various places in the room. Further, the distribution board 11 accommodates a main breaker 15 that turns on and off the power supplied through the lead-in line 13 and a branch breaker 16 provided for each branch line 14. Communication devices 31 and 41 such as personal computers that perform power line communication are connected to an outlet 51 provided on the branch line 14 via the PLC modem 21 and communicate using the branch line 14 and the lead-in line 13 as a communication path.

Here, the outlet 51 existing in the communication path constitutes an open end in the communication path, which causes reflection and attenuation of the communication signal, thereby reducing the communication quality of the power line communication. For this reason, for example, Patent Document 1 discloses a termination circuit in which an impedance composed of a series circuit of a termination resistor and a capacitance equivalent to a characteristic impedance between indoor power lines in a use frequency band of power line carrier communication is accommodated in a case. A technique for matching impedance by plugging into an outlet of an indoor power line is disclosed.
JP 2003-264486 A

  By the way, there are many outlets indoors where power line communication is performed, and it is not always realistic from the viewpoint of economy and convenience to connect termination circuits to all outlets to which no electrical product is connected.

  The single-phase three-wire lead wire has a live line L1 (hereinafter, red phase L1), a live line L2 (hereinafter, black phase L2), and a neutral line N (hereinafter, white phase N). As shown in FIG. 8A, when the communication devices 31 and 41 are connected to the branch line 14 connected to the same phase line among the three lines constituting the lead-in line 13 in the communication path (hereinafter referred to as “A”). 8B, each communication device 31 and 41 is connected to a line of a different phase (adjacent phase) among the three lines constituting the lead-in wire 13 (hereinafter, referred to as “in-phase connection”). When it is intended to improve the communication quality of power line communication, it is necessary to consider such a difference in the form of the communication path.

  In addition, when communication is performed using a certain branch line 14, noise mixed from other branch lines 14 coupled via the lead-in line 13 or noise generated by the electrical equipment connected to these branch lines 14 Impact becomes a problem. Further, the impedance of the communication path becomes unstable by being influenced by the difference between the other branch lines 14 coupled in the distribution board 11 and the types and operating states of the electric devices connected to these branch lines 14. Furthermore, transmission loss due to propagation of the transmission signal to the branch line 14 other than the communication path is also a problem.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a power line communication method capable of improving the communication quality of power line communication by efficiently installing a termination circuit at an appropriate place.

  In order to achieve the above object, the invention according to the first aspect of the present invention is carried out using an indoor wiring in which a plurality of branch lines are connected to a single-phase three-wire service line through branch points. A first communication device is connected to the first branch line, and the second branch line is connected to the lead-in line in phase with the first branch line. A termination circuit for connecting a communication device and matching the impedance of a communication path connecting the first communication device and the second communication device is provided on the first branch line or the second branch line. Provided only at the outlet, and at least one of the branch lines in the vicinity of the branch point, an inductor formed by canceling two conductors on an annular core and connected between the two conductors It is assumed that a filter circuit including a capacitor to be connected is provided. .

  When the first branch line to which the first communication device is connected and the second branch line to which the second communication device is connected have the same phase relationship, the termination circuit is connected to the first branch as described later. The communication quality of power line communication can be improved only by providing it only at an outlet provided on the line or the second branch line. For example, when one branch line is assigned to each room as in the case of indoor wiring for general households, communication quality can be improved by providing a termination circuit only at the outlet of the room where the communication equipment is placed. Can be improved.

  Further, by providing the filter circuit having the above structure in the vicinity of the branch point of the branch line, both the differential signal component and the in-phase signal component which become obstacles in power line communication can be effectively removed. Further, the impedance of the communication path can be maintained at a flat value over the entire frequency band of the transmission signal of the power line communication by the action of the capacitor. In addition, a filter circuit that can effectively remove both the differential signal component and the in-phase signal component can be configured by an inductor configured using one core, so that it is possible to reduce the size, and in a narrow space such as a distribution board. A filter circuit that can be installed can be easily realized. In particular, in the case where the lead-in wire is a single-phase three-wire system, both of the differential signal component and the in-phase signal component become a problem when communication is performed using a branch line having an adjacent phase connection relationship. By providing the filter circuit consisting of, both the differential signal component and the in-phase signal component can be removed.

  In addition, according to the present invention, it is possible to prevent the influence of noise and impedance due to other branch lines other than the branch lines used for power line communication, and electrical devices connected to these other branch lines. Furthermore, the filter circuit can prevent a communication signal in power line communication from propagating to a branch line other than the branch line used for the communication, and transmission loss of the transmission signal can be reduced.

  Further, as will be described later, the provision of a filter circuit does not affect the communication speed between communication devices connected in the same phase. Therefore, according to the present invention, it is possible to ensure the communication quality of both the in-phase connection and the adjacent phase connection.

The invention according to a second aspect of the present invention is the power line communication method according to the first aspect, wherein the termination circuit is provided in the first branch line and the second branch line. It will be installed in all outlets.
As described above, by providing the termination circuits in all the outlets provided in the first branch line and the second branch line, it is possible to reliably improve the communication quality.

The invention according to a third aspect of the present invention is the power line communication method according to the first aspect, wherein the termination circuit is connected to either the first branch line or the second branch line. It shall be provided only at the outlet provided on one side.
As described above, the communication quality can be reliably improved by providing the termination circuit only in the outlet provided in one of the first branch line and the second branch line.

According to a fourth aspect of the present invention, in the power line communication method according to the first aspect, the termination circuit is connected to the first communication device of the first branch line. It should be installed only at the outlet provided closest to the outlet.
As described above, the communication quality of the power line communication can be improved also by providing the termination circuit only at the outlet provided at the position closest to the outlet to which the first communication device of the first branch line is connected. Can do. This situation is the same even when a termination circuit is provided only at an outlet provided closest to the outlet to which the second communication device of the second branch line is connected.

The invention according to a fifth aspect of the present invention is the power line communication method according to any one of the first to fourth aspects, wherein the termination circuit has two terminals connected to the outlet. A resistance element connected in series between two terminals and a capacitor connected in series to the resistance element are included.
By setting the termination circuit in such a configuration, a termination circuit having a desired impedance can be configured. Moreover, AC100V (60 Hz) of the commercial power supply can be surely cut off by the capacitor connected in series with the resistance element.

According to a sixth aspect of the present invention, the power line communication method according to any one of the first to fifth aspects is provided, wherein the termination circuit is connected to the communication path in a frequency band used for power line communication. It has an impedance equal to the characteristic impedance of.
As described above, by providing the termination circuit with an impedance equal to the characteristic impedance of the communication path in the frequency band used for power line communication, reflection and attenuation of the communication signal can be reliably suppressed.

The invention according to claim 7 of the present invention is the power distribution facility according to claim 1, wherein only the branch line to which no communication device for power line communication is connected is connected among the branch lines. The filter circuit is provided.
In this way, by providing a filter circuit only on a branch line that is not connected to a communication device that performs power line communication, it can be connected to other branch lines other than the branch line used for power line communication, or to these other branch lines. It is possible to prevent the influence of noise and impedance due to existing electrical equipment, and to improve the communication quality of the communication path connecting the communications equipment.

According to an eighth aspect of the present invention, the branch line connected to the first communication device and the branch line connected to the second communication device are connected in adjacent phases. Suppose that
In the case where the lead-in wire is a single-phase three-wire system, when communication is performed using a branch line having an adjacent phase connection relationship, both the differential signal component and the in-phase signal component become a problem. By providing such a filter circuit, both the differential signal component and the in-phase signal component can be removed.

  According to the power line communication method of the present invention, the termination circuit can be efficiently installed at an appropriate place to improve the communication quality of the power line communication.

  Hereinafter, embodiments of the present invention will be described in detail. In order to evaluate the communication quality of the power line communication performed using the indoor power distribution facility 1 by providing the termination circuit, the present inventors perform the first communication for each of the forms shown in FIGS. 1A to 1F. The communication speed between the device 31 and the second communication device 41 was measured. 1A to 1F, the specific configurations of the distribution board 11, the columnar transformer 12, the lead-in line 13, the branch line 14, the main breaker 15, the branch breaker 16, the outlet 51, and the communication devices 31, 41 are as follows. Since it is the same as that of FIG. 5, description is abbreviate | omitted here.

  1A shows a case where the first communication device 31 is connected to the outlet 51 (3) and the second communication device 41 is connected to the outlet 51 (9). As shown in the figure, the branch line 14 (1) provided with the outlet 51 (3) is connected to the black phase L2 and the white phase N, and the branch line provided with the outlet 51 (9). 14 (3) is also connected to the black phase L2 and the white phase N. Therefore, the branch line 14 (1) and the branch line 14 (3) are in the same phase connection relationship. 1A shows a case where the termination circuit 30 is connected only to the outlets 51 (1), (2), (7), and (8) provided in the branch line 14 (1) and the branch line 14 (3). The outlet circuit 51 (1) has a termination circuit 30 (1), the outlet 51 (2) has a termination circuit 30 (2), the outlet 51 (7) has a termination circuit 30 (3), and the outlet 51 The termination circuit 30 (4) is connected to (8).

  FIG. 1B shows a case where the first communication device 31 is connected to the outlet 51 (3) and the second communication device 41 is connected to the outlet 51 (6). As shown in the figure, the branch line 14 (1) provided with the outlet 51 (3) is connected to the black phase L2 and the white phase N, and the branch line provided with the outlet 51 (6). 14 (2) is connected to the red phase L1 and the white phase N. Therefore, the branch line 14 (1) and the branch line 14 (2) are in an adjacent phase connection relationship. In FIG. 1B, the termination circuit 30 is connected only to the outlets 51 (1), (2), (4), and (5) provided in the branch line 14 (1) and the branch line 14 (2). The termination circuit 30 (1) is connected to the outlet 51 (1), the termination circuit 30 (2) is connected to the outlet 51 (2), and the termination circuit 30 (3) is connected to the outlet 51 (4). A termination circuit 30 (4) is connected to each of 51 (5).

  FIG. 1C shows that the first communication device 31 and the second communication device 41 are connected to the branch line 14 (1) and the branch line (3), respectively, which are in the in-phase connection relationship, and any outlets in the room. This is a case where the termination circuit 30 is not connected to 51.

  In FIG. 1D, the first communication device 31 and the second communication device 41 are connected to the branch line 14 (1) and the branch line (2), respectively, which are in an adjacent phase connection relationship. This is a case where the termination circuit 30 is not connected to the outlet 51 as well.

  In FIG. 1E, the first communication device 31 and the second communication device 41 are connected to the branch line 14 (1) and the branch line (3), respectively, which are in the in-phase connection relationship. This is a case where the termination circuit 30 is connected to all the indoor outlets 51 that are not connected.

  FIG. 1F shows that the first communication device 31 and the second communication device 41 are connected to the branch line 14 (1) and the branch line (2), respectively, which are in an adjacent phase connection relationship, and all the outlets 51 in the room are connected. This is a case where the termination circuit 30 is connected to.

  In the measurement of the communication speed for each form shown in FIGS. 1A to 1F described above, the communication speed is measured for each case where the measurement location, the connection position of the communication devices 31 and 41, and the model of the PLC modem 21 are changed. The average value was obtained as a measurement result. In addition, in order to see the influence of the presence / absence of connection of the electric device and the on / off state of the power supply of the electric device, the measurement was performed for each case where the presence / absence of the connection of the electric device and the on / off state of the power supply of the electric device were changed. The PLC modem 21 uses a modulation method of OFDM (Orthogonal Frequency Division Multiplexing), a use frequency band of 2 to 30 MHz, a maximum communication speed of 200 Mbps, a maximum output of 85 dBμV / 10 kHz, and a LAN interface standard of 100/10 BASE. It was. As the first communication device 31 and the second communication device 41, a personal computer having a CPU, a memory, and a hard disk was used.

  FIG. 2 shows a circuit diagram of the termination circuit 30 used for the measurement of the communication speed. The termination circuit 30 shown in FIG. 2 is connected in series between two terminals 181 (1) and 181 (2) connected to the outlet 51 and these two terminals 181 (1) and 181 (2). , Two capacitors 182 (1) and 182 (2) for cutting off AC 100V (60Hz) of the commercial power source, and a resistance element connected in series between the two capacitors 182 (1) and 182 (2) 183 and a case 184 that accommodates a part of the termination circuit 30.

  In the termination circuit 30 shown in FIG. 2, capacitors 182 (1) and 182 (2) having a capacitance of 0.1 μF were used. Further, in order to match the impedance of the termination circuit 30 with the characteristic impedance of the communication path in the frequency band (2 MHz to 30 MHz) used for power line communication, a resistor element 183 having a resistance value of 50 to 100Ω was used.

== Measurement result ==
First, Table 1 shows the measurement results of the communication speed when no electrical device is connected to any outlet 51 (no load). In Table 1, the unit of communication speed is Mbps. In Table 1 and each table shown below, the first case is a case where the termination circuit 30 is not connected to any indoor outlet (corresponding to FIGS. 1C and 1D). When the termination circuit 30 is connected only to the outlet 51 provided on the branch line 14 that constitutes the communication path between the first communication device 31 and the second communication device 41 (corresponding to FIGS. 1A and 1B) The third case is when the termination circuit 30 is connected to all indoor outlets 51 (excluding outlets to which communication devices and electrical products are connected) (corresponding to FIGS. 1E and 1F). is there.

  As shown in Table 1, in the case of in-phase connection, the termination circuit 30 is only connected to the outlet 51 provided on the branch line 14 constituting the communication path (second case), and the communication speed Is up about 1.5 times. Further, the improvement effect is almost the same as when the termination circuit 30 is connected to all the outlets 51 in the room (third case). On the other hand, for the adjacent phase connection, the communication speed is not improved even if the termination circuit 30 is connected.

Table 2 shows the measurement results when an electrical device is connected to a predetermined outlet and the power source of the connected electrical device is turned on.

  As shown in Table 2, in the case of in-phase connection, only the termination circuit 30 is connected to the outlet 51 provided on the branch line constituting the communication path (second case), and the communication speed is about It is up 1.6 times. Further, the improvement effect is almost the same as when the termination circuit 30 is connected to all the outlets 51 in the room (third case). On the other hand, for the adjacent phase connection, the communication speed is not improved even if the termination circuit 30 is connected.

Table 3 shows the measurement results when an electrical device is connected to the predetermined outlet 51 and the power source of the electrical device is turned off.

  As shown in Table 3, in the case of in-phase connection, only the termination circuit 30 is connected to the outlet 51 provided on the branch line 14 constituting the communication path (second case), and the communication speed Is up about 1.7 times. Further, the improvement effect is almost the same as when the termination circuit 30 is connected to all the outlets 51 in the room (third case). On the other hand, for the adjacent phase connection, the communication speed is not improved even if the termination circuit 30 is connected.

  As can be seen from Tables 1 to 3, in the case of in-phase connection, only the termination circuit 30 is connected to the outlet 51 provided on the branch line 14 constituting the communication path (second circuit). In this case, it can be seen that the communication quality can be improved in the same manner as when the termination circuit 30 is connected to all the outlets 51 in the room.

  From the above, it has been found that the communication speed is improved only by connecting the termination circuit 30 only to the outlet 51 provided in the branch line 14 constituting the communication path. In order to investigate, next, simulation was performed for a plurality of cases where the positions where the termination circuits 30 are provided were changed, and the impedance of the communication path was obtained. The results of the simulation are shown in FIGS. 3A to 3F. 3A shows a case where the termination circuit 30 is not provided in any of the indoor outlets. FIG. 3B shows a case where the termination circuits 30 are provided in all the indoor outlets 51. FIG. 3C shows a communication path. When the termination circuit 30 is provided only in the outlet 51 of the branch line 14 that is connected, FIG. 3D shows the one on the branch line 14 to which one of the two communication apparatuses 31 and 41 is connected. This is a case where the termination circuit 30 is provided in all the outlets 51 and the termination circuit 30 is not provided in the outlets 51 on the branch line 14 to which the other communication devices 31 and 41 are connected. 3E shows a case where the termination circuit 30 is provided only in the outlet 51 located closest to the communication device on the branch line to which one of the two communication devices is connected. The termination circuit 30 is only connected to the outlet 51 that is the second closest to the communication device 31, 41 on the branch line 14 to which one of the two communication devices 31, 41 is connected. Is provided.

  Comparing FIG. 3A and FIG. 3B, by providing the termination circuit 30 in all indoor outlets 51, the impedance hump (bounce) is higher than that in FIG. 3A in the frequency band (0 to 30 MHz) used for communication. It turns out that it is decreasing. 3C and 3D also show that the impedance hump is reduced compared to FIG. 3A, as in FIG. 3B. Further, in FIG. 3E, the impedance hump is increased as compared with FIG. 3D, but it is understood that the hump is decreased as compared with FIG. 3A. In addition, although the same simulation as the above was performed by changing the outlet 51 which connects the communication apparatuses 31 and 41, it became a result almost the same as FIG. 3A-FIG. 3F.

  As a result of the above simulation, even if the termination circuit 30 is provided only at the outlet 51 closest to the communication device on the branch line 14 to which one of the two communication devices 31 and 41 is connected. It was found that the communication speed can be improved.

== Filter circuit ==
By the way, the branch lines 14 (1) to (4) are coupled via the lead-in line 13 in the distribution board 11. For this reason, in power line communication, noise derived from electrical equipment connected to the branch line 14 not involved in communication or the branch line 14 not involved in communication, and the change in impedance of the communication path are not a little, and the communication quality is affected. Effect. Further, when communication is performed between the communication devices 31 and 41 connected in adjacent phases, there is the following problem.

  FIG. 4 is a diagram for explaining a problem in the case where communication is performed between the communication devices 31 and 41 connected in adjacent phases. In FIG. 4, the first communication device 31 is connected to the branch line 14 (1) connected to the red phase L1 and the white phase N, while the second communication device 41 is connected to the black phase L2 and the white phase N. It is connected to the branch line 14 (2) to be connected. Here, when the communication signal S1 is transmitted from the first communication device 31 to the second communication device 41, the communication signal S1 reaches the second communication device 41 via the white phase N. The return communication signal S2 from the second communication device 41 for the communication signal S1 is output to the black phase L2, and the communication signal S2 is red via the stray capacitance C1 between the red phase L1 and the black phase L2. Transmitted to phase L1.

  Here, if there is an open end on the branch line 14 (2) to which the second communication device 41 is connected, the communication signal S1 output from the first communication device 31 to the white phase N is the red phase L1. There is a path that returns to the red phase L1 via the stray capacitance C2 between the white phase N, and a differential signal component is generated between the red phase L1 and the white phase N. The communication signal S2 output to the black phase L2 of the second communication device 41 is returned to the red phase L1 of the first communication device 31 via the stray capacitance C3 between the red phase L1 and the black phase L2. There is a path coming in, and an in-phase signal component is generated between the white phase N and the black phase L2. Thus, when communication is performed between the two communication devices 31 and 41 connected to the two branch lines 14 connected in adjacent phases, the differential signal component and the in-phase signal component Both are problematic.

  This problem can be improved by providing a filter circuit having the configuration shown in FIGS. 5A and 5B in the vicinity of the connection point (branch point) of the branch line 14 to which the communication devices 31 and 41 are not connected to the lead-in line 13. Can do. 5A is a circuit diagram of the filter circuit, and FIG. 5B is an external view of the filter circuit (only the inductor portion). This filter circuit has an annular core 21 (toroidal core) made of ferrite or the like between an inductor 23 formed by canceling two conductive wires 22 such as an enameled wire and a copper wire, and the two conductive wires 22. And a capacitor 24 to be connected. The conducting wire 22 is wound around the core 21 so that the magnetic fluxes in the core 21 cancel each other with respect to the differential signal component. In addition, since the winding method of the conducting wire 22 to the core 21 is a conventional transformer, there exists a leakage inductance, and this filter circuit can also remove a differential signal component. Further, since the magnetic flux is canceled out, it is not necessary to consider the influence of magnetic saturation. The conducting wire 22 is wound around the core 21 so that the magnetic fluxes in the core 21 strengthen each other with respect to the in-phase signal component. For the in-phase signal component, this filter circuit serves as a common mode filter. Function. The capacitor 24 acts to flatten the impedance of the communication path between the first communication device 31 and the second communication device 41 over the entire frequency band of the transmission signal of power line communication.

  6A and 6B are examples of power distribution equipment 1 provided with a filter circuit having the configuration shown in FIGS. 5A and 5B. FIG. 6A shows a case of in-phase connection, and FIG. 6B shows a case of adjacent phase connection. In the power distribution facility 1 shown in FIG. 6A, outlets provided on the branch line 14 (1) to which the first communication device 31 is connected and the branch line 14 (3) to which the second communication device 41 is connected. The filter circuit 17 is connected in the vicinity of the connection point of the branch line 14 (2) and the branch line 14 (4) where the termination circuit 30 is connected only to 51 and the branch line 14 (2) and the branch line 14 (4) are not connected. Provided. Moreover, in the power distribution equipment 1 shown to FIG. 6B, it is provided in the branch line 14 (1) to which the 1st communication apparatus 31 is connected, and the branch line 14 (2) to which the 2nd communication apparatus 41 is connected. The termination circuit 30 is connected only to the outlet 51, and the filter circuit 17 is provided in the vicinity of the connection point between the branch line 14 (3) and the branch line 14 (4), which are not connected to the communication devices 31 and 41, and the lead-in line 13. Is provided.

Table 4 shows the measurement result of the communication speed when the electrical device is connected and the power source of the connected electrical device is turned on. In Table 4, “second case + filter circuit” means the branch line 14 (1) to which the first communication device 31 is connected and the branch line 14 (2) to which the second communication device 41 is connected. ) Only, and the filter circuit 17 is connected in the vicinity of the connection point of the branch line 14 (3) and the branch line 14 (4) where the communication devices 31 and 41 are not connected to the respective lead-in lines 13. This is the case. In Table 4, the contents other than “second case + filter circuit” are the same as those in Table 2.

  As shown in Table 4, by providing the filter circuit 17 (fourth case), it can be seen that the communication speed in the case of adjacent phase connection is increased by about 1.5 times compared to the second case. . It can also be seen that the provision of the filter circuit 17 hardly affects the communication speed between communication devices connected in phase.

Table 5 shows the measurement results when the electrical equipment is connected and the power of the connected electrical equipment is turned off. In Table 5, the contents other than the fourth case are the same as those in Table 3.

  As shown in Table 5, in this case as well, by providing the filter circuit 17 (fourth case), the communication speed in the case of adjacent phase connection is increased by about 1.5 times compared to the second case. You can see that It can also be seen that the provision of the filter circuit 17 hardly affects the communication speed in the case of the in-phase connection.

  As described above, both the differential signal component and the in-phase signal component can be removed by the filter circuit 17 shown in FIGS. 5A and 5B. Therefore, by providing the filter circuit 17, the above-described differential which becomes a problem when communication is performed between the two communication devices 31 and 41 connected to the two branch lines 14 in the adjacent phase connection relationship, respectively. Both signal components and in-phase signal components can be removed. Also, the capacitor 24 keeps the impedance constant over the entire frequency range used for communication. Even when the filter circuit 17 is provided, the filter circuit 17 can be used together with the termination circuit 30 because the communication speed in the case of the in-phase connection is hardly affected. Therefore, the communication quality of both the in-phase connection and the adjacent phase connection can be used. Can be improved. Furthermore, since the filter circuit 17 shown in FIGS. 5A and 5B can be configured using only one toroidal core, it can be downsized and installed in a narrow space such as the distribution board 11. A filter circuit can be easily realized.

  As mentioned above, although one Embodiment of this invention was described in detail, description of the above Embodiment is for making an understanding of this invention easy, and does not limit this invention. It goes without saying that the present invention can be changed and improved without departing from the gist thereof, and that the present invention includes equivalents thereof.

It is a figure which shows the indoor power distribution equipment 1 used for power line communication demonstrated as one Embodiment of this invention, and is 1st to each of branch line 14 (1) and branch line 14 (3) in the relationship of in-phase connection The communication device 31 and the second communication device 41 are connected to the outlets 51 (1), (2), (7), (8) provided on the branch line 14 (1) and the branch line 14 (3). FIG. 4 is a diagram showing a case where a termination circuit 30 is connected only. It is a figure which shows the indoor power distribution equipment 1 used for power line communication demonstrated as one Embodiment of this invention, and is 1st to each of branch line 14 (1) and branch line 14 (2) in the relationship of adjacent phase connection. The communication device 31 and the second communication device 41 are connected, and the outlets 51 (1), (2), (4), (5) provided on the branch line 14 (1) and the branch line 14 (2). It is a figure which shows the case where the termination | terminus circuit 30 is connected only to. It is a figure which shows the indoor power distribution equipment 1 used for power line communication demonstrated as one Embodiment of this invention, and is 1st communication to each of branch line 14 (1) and branch line (3) which are in the relationship of in-phase connection It is a figure which shows the case where the apparatus 31 and the 2nd communication apparatus 41 are connected, respectively, and the termination | terminus circuit 30 is not connected to any indoor outlet 51. It is a figure which shows the indoor power distribution equipment 1 used for power line communication demonstrated as one Embodiment of this invention, and is 1st to each of branch line 14 (1) and branch line (2) in the relationship of adjacent phase connection It is a figure which shows the case where the communication apparatus 31 and the 2nd communication apparatus 41 are connected, and the termination circuit 30 is not connected to any indoor outlet 51. It is a figure which shows the indoor power distribution equipment 1 used for power line communication demonstrated as one Embodiment of this invention, and is 1st communication to each of branch line 14 (1) and branch line (3) which are in the relationship of in-phase connection It is a figure which shows the case where the termination | terminus circuit 30 is connected to all the indoor outlets 51 which connected the apparatus 31 and the 2nd communication apparatus 41, and nothing is connected to a communication apparatus or an electric equipment. It is a figure which shows the indoor power distribution equipment 1 used for power line communication demonstrated as one Embodiment of this invention, and each of branch line 14 (1) and branch line (2) in the relationship of adjacent phase connection is 1st. It is a figure which shows the case where the communication device 31 and the 2nd communication device 41 are connected, and the termination | terminus circuit 30 is connected to all the outlets 51 indoors. It is a figure which shows the termination circuit 30 demonstrated as one Embodiment of this invention. It is the result of simulating the impedance of a communication path when no termination circuit 30 is provided in any indoor outlet, which is described as an embodiment of the present invention. It is the result of having simulated the impedance of the communication path in the case where termination circuit 30 is provided in all the indoor outlets explained as one embodiment of the present invention. It is the result of simulating the impedance of the communication path when the termination circuit 30 is provided only in the outlet 51 of the branch line 14 constituting the communication path, which will be described as an embodiment of the present invention. The termination circuit 30 is provided in all the outlets 51 provided in the branch line 14 to which one of the two communication devices 31 and 41, which is described as one embodiment of the present invention, is connected. This is a result of simulating the impedance of the communication path when the termination circuit 30 is not provided in the outlet 51 on the branch line 14 to which one communication device is connected. An outlet 51 that is provided in a branch line 14 connected to one of the two communication devices 31 and 41 and that is closest to the communication device will be described as an embodiment of the present invention. This is a result of simulating the impedance of the communication path when only the termination circuit 30 is provided. Terminating only the outlet 51 located closest to the second communication device on the branch line 14 to which one of the two communication devices 31, 41 is connected, which is described as an embodiment of the present invention. It is the result of simulating the impedance of the communication path when the circuit 30 is provided. It is a figure explaining the problem in the case of communicating between the communication apparatuses 31 and 41 connected by adjacent phase. It is a circuit diagram of the filter circuit 17 by one Embodiment of this invention. It is a partial external view of the filter circuit 17 by one Embodiment of this invention. It is an example of the power distribution equipment 1 which provided the filter circuit 17 which consists of a structure shown to FIG. 5A and FIG. 5B in the case of in-phase connection by one Embodiment of this invention. It is an example of the power distribution equipment 1 which provided the filter circuit 17 which consists of a structure shown to FIG. 5A and FIG. 5B in the case of adjacent phase connection by one Embodiment of this invention. It is a figure which shows an example of the indoor power distribution equipment in which power line communication is performed. It is a figure explaining the case where two branch lines have the relationship of in-phase connection. It is a figure explaining the case where two branch lines have the relation of adjacent phase connection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Indoor wiring installation 11 Distribution board 12 Columnar transformer 13 Service line L1 Red phase N White phase L2 Black phase 14 Branch line 15 Master breaker 16 Branch breaker 17 Filter circuit 21 PLC modem 30 Termination circuit 31 1st communication equipment 41 2nd Communication equipment 51 outlet

Claims (8)

A power line communication method performed using indoor wiring in which a plurality of branch lines are connected to a single-phase three-wire service line via branch points,
Connecting a first communication device to the first branch line;
Connecting a second communication device to the second branch line connected to the lead-in line in phase with the first branch line;
The termination circuit for matching the impedance of the communication path connecting the first communication device and the second communication device is provided only in the outlet provided in the first branch line or the second branch line. Provided,
A filter circuit including an inductor formed by canceling two conductors around an annular core and a capacitor connected between the two conductors in the vicinity of the branch point of at least one of the branch lines; A power line communication method characterized by comprising: The power line communication method according to claim 1,
The power line communication method, wherein the termination circuit is provided in all outlets provided in the first branch line and the second branch line. The power line communication method according to claim 1,
The power line communication method, wherein the termination circuit is provided only in an outlet provided on one of the first branch line and the second branch line. The power line communication method according to claim 1,
The power line communication method, wherein the termination circuit is provided only at an outlet provided at a position closest to an outlet to which the first communication device of the first branch line is connected. A power line communication method according to any one of claims 1 to 4,
The termination circuit includes two terminals connected to the outlet, a resistance element connected in series between the two terminals, and a capacitor connected in series to the resistance element. Power line communication method. A power line communication method according to any one of claims 1 to 4,
The termination circuit has an impedance equal to a characteristic impedance of the communication path in a frequency band used for power line communication. The power line communication method according to claim 1,
The power line communication method, wherein the filter circuit is provided only in the branch line that is not connected to a communication device that performs power line communication among the branch lines. The power line communication method according to claim 2,
The branch line to which the first communication device is connected and the branch line to which the second communication device is connected are connected in adjacent phases.

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