JP2016019241A - Remote meter reading system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an installation cost and running cost of a system by widening one master unit modem's range of covering slave unit modems.SOLUTION: A remote meter reading system 1A comprises: low voltage power distribution lines 6A, 6B, 6C as first to third systems; and a plurality of power meters 7 connected to the low voltage power distribution lines 6A, 6B, 6C. The low voltage power distribution lines 6A, 6B, 6C are single-phase three-wire distribution lines, each of which includes a ground line 6b, a first non-ground line 6a, and a second non-ground line 6c. The low voltage power distribution lines 6A, 6B, 6C have branch lines, of which power lines in the same phase are connected with each other through a bypass signal line 15. Each of the plurality of power meters 7 includes a power line modem 8 for transferring meter reading data. Only one of a plurality of power line modems 8 is a master unit modem 8A; all of the other power line modems 8 are a slave unit modem 8B. A slave unit modem 8B provided in a power system in which the master unit modem 8A is not provided performs power line communication with the master unit modem 8A through the bypass signal line 15.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a remote meter-reading system for power consumption using power line communication.

  In recent years, the introduction of a remote meter-reading system that collects power usage from a remote location has been promoted. When a remote meter reading system is introduced in an apartment house such as a condominium, a next-generation power meter called a smart meter is installed in each house of the apartment house, and metering of power consumption is performed, for example, every 30 minutes. The meter reading data is transferred to the server of the power company by the communication function of the power meter.

  In a remote meter reading system using PLC (Power Line Communication), a power line modem is built in (or externally attached to) a power meter, and meter reading data is collected via the power line. Each power meter is provided with a power line modem slave unit (slave unit modem), and meter-reading data from a large number of power meters is sent from the slave unit modem to the power line modem master unit (master modem). It is transferred to the server via a WAN (Wide Area Network). In this system, a power line to which a power meter is connected is used as a communication path, so there is no need to newly lay a communication line, which is very advantageous in terms of introduction cost.

  In order to improve the communication quality between the main unit modem and the sub unit modem, for example, Patent Document 1 discloses a main unit modem connected to a neutral line (ground line) of a low-voltage distribution line by an inductive coupling method, and two A power line communication system is disclosed that includes a handset modem connected to both one of the non-ground lines and the ground line by a capacitive coupling method. Patent Document 2 discloses a power line communication system having a configuration in which signal lines for bypassing them are provided in consideration of large signal loss in a transformer, a distribution board, and a power meter.

JP 2013-118593 A Japanese Patent No. 434189

  Many apartment buildings have substation facilities on the premises, and high-voltage distribution lines are drawn into the electrical room that houses the substation facilities, converted to commercial voltage in the electrical room, and then distributed to each house in the building . Here, when the number of houses in the apartment house increases, a plurality of transformers are provided in accordance with the number of houses, which may divide the power system in the apartment house into a plurality. In this case, since each power system forms an independent power line network, a master modem must be prepared for each power system. However, when a plurality of master modems are prepared, there is a problem that the line cost for connecting each master modem to the WAN increases. In addition, the master modem is expensive because it has multiple functions, and there is a problem that the equipment cost increases due to the increase in the number of installed master modems.

  Accordingly, an object of the present invention is to reduce the installation cost and the running cost of the system by expanding the range of the slave modem covered by one master phone modem even when the power system in the apartment house is divided into a plurality of parts. An object of the present invention is to provide a remote meter-reading system.

  In order to solve the above problems, a remote meter reading system according to the present invention includes a first transformer and a second transformer that step down the voltage of a high-voltage distribution line and convert it into commercial power, and a secondary side of the first transformer. Connected to the first system low voltage distribution line, the second system low voltage distribution line extending from the secondary side of the second transformer, and the first system low voltage distribution line or the second system low voltage distribution line. A plurality of power meters, a bypass signal line for connecting the first system low-voltage distribution line and the second system low-voltage distribution line by an inductive coupling method, and the first system and the second system low-voltage distribution line. Each of the distribution lines has a plurality of branch lines branched from the main line connected to the first or second transformer, and the bypass signal line is a plurality of branch lines of the low-voltage distribution line of the first system At least one branch line selected from the above and the low-voltage distribution of the second system And at least one branch line selected from the plurality of branch lines is connected by the inductive coupling method, and each of the plurality of power meters includes a power line modem for transferring meter-reading data, and the first system or The power line modem in the power meter connected to the second low-voltage distribution line performs power line communication via the bypass signal line.

  According to the present invention, since the low-voltage distribution lines of different systems are connected via the bypass signal line, the power line communication between the power line modem on the first system side and the power line modem on the second system side is ensured. be able to. Therefore, for example, it is possible to expand the range of the slave unit modem covered by one master unit modem installed in any one of the power systems, thereby reducing the system installation cost and the running cost. Moreover, since the bypass signal line is connected to the branch line branched from the main line of the low-voltage distribution line, the bypass signal line can be easily connected to the low-voltage distribution line.

  In the present invention, each of the low-voltage distribution lines of the first system and the second system has a first phase current flowing through a ground line, a first non-ground line, and a current that flows in the first non-ground line. A single-phase, three-wire distribution line having two ungrounded wires, and the bypass signal line connects in-phase power lines of the first system low-voltage distribution line and the second system low-voltage distribution line It is preferable.

  In the present invention, the bypass signal line connects the first ungrounded line of the first system low-voltage distribution line and the first ungrounded line of the second system low-voltage distribution line by an inductive coupling method. In addition, the plurality of power line modems are configured to connect the second ungrounded line of the first system low-voltage distribution line and the second ungrounded line of the second system low-voltage distribution line by an inductive coupling method. Are preferably connected to both the first non-ground line and the second non-ground line.

  In the present invention, the bypass signal line connects the ground line of the low-voltage distribution line of the first system and the ground line of the low-voltage distribution line of the second system by an inductive coupling method, and the plurality of power line modems Each is preferably connected to the ground line.

  In the present invention, the bypass signal line connects all branch lines branched from the trunk line of the first system low-voltage distribution line and all branch lines branched from the trunk line of the second system low-voltage distribution line. Preferably it is.

  In the present invention, the first and second branch lines in the same system are connected to each other by the bypass signal line, and the connection polarity of the bypass signal line with respect to the first branch line is the second branch line. The connection polarity of the bypass signal line with respect to the line is preferably different.

  When the sum of the first and second branch lines in the same system is an even number, it is preferable that the sum of the first branch lines and the sum of the second branch lines are the same. In addition, when the sum of the first and second branch lines in the same system is an odd number, it is preferable that the sum of the second branch lines is one more than the sum of the first branch lines. In this way, when there are a large number of branch lines, the number of branch lines whose bypass signal line connection polarity is “positive” and the number of branch lines “reverse” are almost equal to each other, so that the PLC based on the feedback signal can be used. Signal degradation can be reliably suppressed, and the quality of power line communication can be improved.

  In the present invention, a power line modem provided in one of the plurality of power meters is a master modem, and the remaining power meters except for the power meter provided with the master modem among the plurality of power meters. The power line modem provided in all the power meters is preferably a slave modem.

  In the present invention, it is preferable that all power line modems provided in each of the plurality of power meters are slave modems, and the slave modems perform power line communication with a master modem connected to the bypass signal line. .

  In the present invention, the base modem includes a power line communication interface unit that communicates with the handset modem via a power line network constituted by the low-voltage distribution lines of the first system and the second system, and a wide-area communication network. A power line communication interface unit that communicates with the handset modem via a power line network configured by the first system and the second system low-voltage distribution lines. It is preferable to have.

  According to the present invention, even when the power system is divided into a plurality of remote meters, it is possible to expand the range of the slave unit modem covered by one master unit modem and reduce the system installation cost and the running cost. A system can be provided.

FIG. 1 is a configuration diagram of a remote meter reading system 1A according to the first embodiment of the present invention. 2 is a block diagram showing in detail a part of the configuration of the remote meter reading system 1A. FIG. 2A shows the configuration of the S1 portion of FIG. 1, and FIG. 2B shows the configuration of the S2 portion of FIG. . FIG. 3 is a functional block diagram showing the configuration of the power line modem 8, wherein (a) shows the master modem 8A and (b) shows the slave modem 8B. FIG. 4 is a diagram showing a connection form of bypass signal lines in the remote meter reading system 1A. FIG. 5 is a configuration diagram of a remote meter reading system 1B according to the second embodiment of the present invention. FIG. 6 is a configuration diagram of a remote meter reading system 1C according to the third embodiment of the present invention. FIG. 7 is a block diagram of a remote meter reading system 1D according to the fourth embodiment of the present invention. FIG. 8 is a configuration diagram of a remote meter reading system 1E according to the fifth embodiment of the present invention. FIG. 9 is a diagram showing a connection form of the bypass signal line of the present invention, where (a) is a diagram showing parallel connection, (b) is a diagram showing series connection, and (c) is a diagram showing parallel connection and series connection. It is a graph showing the comparison of signal quality.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a configuration diagram of a remote meter reading system 1A according to the first embodiment of the present invention.

  As shown in FIG. 1, this remote meter reading system 1A includes three transformers 5A, 5B, 5C provided in an electric room 4 of an apartment house 3 such as an apartment, and a first system extending from the first transformer 5A. Low voltage distribution line 6A, a second low voltage distribution line 6B extending from the second transformer 5B, a third low voltage distribution line 6C extending from the third transformer 5C, and the low voltage distribution lines 6A, 6B, 6C, and a plurality of power meters 7 for measuring the amount of power used by the customer's house 10. The three-digit number of the customer's house 10 indicates the room number of the apartment house.

  The transformers 5A, 5B, and 5C are for stepping down a high voltage of 6600 V supplied from the high-voltage distribution line 11 to a commercial voltage (100 V or 200 V), and in this embodiment, a plurality of transformers are used. The power system in the apartment house 3 is also divided into a plurality of systems. Each of the low-voltage distribution lines 6A, 6B, 6C of the first to third systems is a single phase composed of a ground line (white phase), a first non-ground line (red phase), and a second non-ground line (black phase). This is a three-wire distribution line. The power lines 6a and 6c (red phase and black phase) connected to one end and the other end of the secondary side of the transformers 5A, 5B and 5C are ungrounded lines, and the secondary side of the transformers 5A, 5B and 5C. The power line 6b (white phase) connected to the middle point is a ground line (neutral line). The voltage between the power lines 6a and 6c is 200V, and the voltage between the power lines 6a and 6b and between the power lines 6c and 6b is 100V.

Trunk of the first system of low-voltage distribution line 6A extending from the first transformer 5A is 3 branched by the distributor device 12A, and the branch line 6A ₁ 1-1 system, 1-2 system branch line 6A ₂ 1 to ₃ branch lines 6A3. Each of the branch lines 6A ₁ , 6A ₂ , 6A ₃ is further branched and drawn into the plurality of customer houses 10. In FIG. 1, the branch lines 6A ₁ , 6A ₂ , 6A ₃ of the 1-1 system to the 1-3 system each cover eight customer houses 10 and are at the positions where the branch lines are drawn into the customer houses 10. A power meter 7 is provided.

Similarly to the first system low-voltage distribution line 6A, the trunk line of the second system low-voltage distribution line 6B extending from the second transformer 5B is also branched into three by the distribution device 12B, and the 2-1 system branch line 6B ₁ If, 2-2 a branch line 6B ₂ strains, is divided into a branch line 6B ₃ 2-3 lines. The number of branches may not be the same as that of the low voltage distribution line 6A. Each of the branch lines 6B ₁ , 6B ₂ , 6B ₃ is further branched and drawn into the plurality of customer houses 10. In FIG. 1, the branch lines 6B ₁ , 6B ₂ , and 6B ₃ of the 2-1 system to the 2-3 system each cover eight customer houses 10, and the branch lines are drawn into the customer houses 10. A power meter 7 is provided.

Similarly to the first and second system low-voltage distribution lines 6A and 6B, the trunk line of the third system low-voltage distribution line 6C extending from the third transformer 5C is also branched into three by the distribution device 12C. a branch line 6C _1, 3-2 and the branch line 6C ₂ strains, 3-3 is divided into a branch line 6C ₃ strains. The number of branches may not be the same as that of the low-voltage distribution lines 6A and 6B. Each of the branch lines 6C ₁ , 6C ₂ , 6C ₃ is further branched and drawn into the plurality of customer homes 10. In FIG. 1, the branch lines 6C ₁ , 6C ₂ , and 6C ₃ of the 3-1 system to the 3-3 system each cover eight customer houses 10, and the branch lines are drawn into the respective customer houses 10. A power meter 7 is provided.

  Although details will be described later, each power meter 7 has a built-in power line modem, and the meter reading data of the customer's house 10 is sent to a server (not shown) of the power company via the power line modem. There are two types of power line modems: a master modem and a slave modem. The master modem is mounted on only one power meter 7 selected from all the power meters 7 and all the remaining power meters. All the power line modems installed in 7 are slave modems. Hereinafter, a case where the master modem is built in the power meter 7 of the customer's house 10 in the 109th room will be described.

  FIG. 2 is a block diagram showing in detail the configuration of the S1 portion of the remote meter reading system 1A.

As shown in FIG. 2, the branch line 6B ₂ of low-voltage distribution lines 6B is connected to the distribution board 13 for each customer house 10, home appliances in the home wiring 14 extending from the distribution panel 13 device (not shown) Is connected. A power meter 7 is provided in front of the distribution board 13. The power meter 7 is a so-called smart meter, and includes a power line modem 8 that is a communication function for transferring meter reading data, and a measuring unit 9 that actually measures the amount of power used. All the power line modems 8 are connected to a low-voltage distribution line (power line) as a communication path (power line network). In particular, in this embodiment, the power line modems 8 are connected to both the red phase power line 6a and the black phase power line 6c. . The connection form between the power line modem 8 and the power lines 6a and 6c is not particularly limited, and may be an inductive coupling method or a capacitive coupling method.

  In the present embodiment, the master modem 8A is built in only one of the power meters 7 (the power meter 7 in the 109th room) connected to the second low-voltage distribution line 6B, and the other power line modems 8A. Are all handset modems 8B. That is, there is only one power meter 7 incorporating the base modem 8A in common with the first to third system low-voltage distribution lines 6A, 6B, 6C. The master modem 8A and the plurality of slave modems 8B are connected via a power line to constitute a power line communication system. The meter reading data of the power meter 7 is sent from the slave unit modem 8B to the master unit modem 8A, and the master unit modem 8A transfers this to the server via the WAN (not shown).

  The reason why the master modem 8A is installed in the power meter 7 in the 109th room is to make the master modem 8A as close as possible to all the slave modems 8B. That is, when the master modem 8A is installed on the second system low-voltage distribution line 6B, it is preferably provided in the power meter 7 arranged closest to the transformer 5B. According to this configuration, the distance between the master modem 8A and the plurality of slave modems 8B on the first system low-voltage distribution line 6A can be shortened, and further, the master modem 8A and the third system low-voltage distribution line can be shortened. The distance from the plurality of slave modems 8B on 6C can be shortened.

  FIG. 3 is a functional block diagram showing the configuration of the power line modem 8, wherein (a) shows the master modem 8A and (b) shows the slave modem 8B.

  As shown in FIG. 3A, the base modem 8A includes a control unit 21, a meter interface unit 22 connected to the measuring unit 9 of the power meter 7, and a PLC interface connected to the power lines constituting the power line network. Unit 23 and a WAN interface unit 24 connected to the WAN.

  The control unit 21 is a power line communication control function for performing power line network control and power line communication control through the PLC interface unit 23, a function of collecting meter reading data from the slave modem, a function of transmitting the collected meter reading data to the server of the power company, It has a metering control function for performing meter communication control through the meter interface unit 22 and a WAN control function through the WAN interface unit 24, and controls the entire modem in an integrated manner. Although not particularly limited, the WAN is preferably a public wireless communication line network including a mobile phone line such as 3G or LTE, and a public wireless LAN.

  As shown in FIG. 3B, the handset modem 8B includes a control unit 21, a meter interface unit 22 connected to the measuring unit 9 of the power meter 7, and a PLC interface connected to the power lines constituting the power line network. Part 23. That is, it differs from the main unit modem 8A in that the function of collecting meter reading data from the slave unit modem, the function of transmitting the collected meter reading data to the server of the power company, and the WAN interface unit 24 are omitted. The configuration is substantially the same as the master modem 8A.

  As described above, in the present embodiment, since the base unit modem 8A includes the meter interface unit 22, the meter data can be transferred by being built in the power meter 7 similarly to the handset modem 8B. In this case, the meter reading data input through the meter interface unit 22 is transferred to the server side through the WAN interface unit 24. This is different from the operation of the handset modem 8B in which the meter reading data input through the meter interface unit 22 is transmitted from the PLC interface unit 23 onto the power line.

As shown in FIG. 1, the 1-2 branch line 6A _{2 of} the first low-voltage distribution line 6A, the 2-2 branch line 6B _{2 of the second} low-voltage distribution line 6B, and the third line branch line 6C ₂ 3-2 systems of low-voltage distribution line 6C are connected by inductive coupling method via a bypass signal line 15. That is, the bypass signal line 15 connects one branch line selected from a plurality of branch lines of each power system. As a result, power line communication is possible between the plurality of handset modems 8B connected to the first and third system low-voltage distribution lines 6A and 6C and the base unit modem 8A connected to the second system low-voltage distribution line 6B. Become.

  FIG. 4 is a diagram illustrating an example of a connection form of the bypass signal line 15 in the remote meter reading system 1A.

As shown in FIG. 4, each power line modem 8 (master modem 8A, slave modem 8B) is connected to both the red phase power line 6a and the black phase power line 6c, and is connected to the power line of the power line modem 8 According to the configuration, the 1-2 branch line 6A ₂ , the 2-2 branch line 6B ₂ , and the red power line 6a of the 3-2 branch line 6C ₂ are connected to each other via the bypass signal line 15. The black-phase power line 6c of the 1-2 branch line 6A ₂ , the 2-2 branch line 6B ₂ , and the 3-2 branch line 6C ₂ is also connected via the bypass signal line 15. Connected.

  In the present embodiment, a connection between a plurality of systems of red phase power lines 6 a and a connection between black phase power lines 6 c are realized by parallel connection of loop-shaped bypass signal lines 15. Clamp type couplers 16 (inductive couplers) are respectively installed on the first to third system red phase power lines 6a and the first to third system black phase power lines 6c, and each loop bypass signal line 15 is clamped. By inserting the coupler 16 in the correct orientation, the red phase and the black phase can be connected simultaneously.

  For example, when the red phase power lines 6a and 6a or the black phase power lines 6c and 6c are directly connected by the bypass signal line 15 without using the clamp coupler 16, the AC 200V is insulated on the bypass signal line 15. It is necessary to insert an insulating circuit, and the configuration becomes complicated. Moreover, since it is dangerous to carry out the connection work of the bypass signal line 15 in a live line state, it is necessary to take measures such as a power failure, and the connection work is greatly restricted. However, in the present embodiment, an inductive coupling method is adopted for connection between the bypass signal line 15 and the power line, and the power lines of different systems are bypassed in a non-contact manner, so the configuration is very simple and for connection work. No measures such as power outages are required. Therefore, the construction period can be shortened and the safety of workers can be ensured.

  The clamp coupler 16 for connecting the bypass signal line 15 by the inductive coupling method is connected to a branch line branched from the main line of the low-voltage distribution line. In many cases, a bus bar (metal plate wiring) is connected to the secondary side terminals of the transformers 5A to 5C that handle large currents, and the transformers 5A to 5C are connected to the distribution devices 12A to 12C via the bus bars. Alternatively, it is difficult to install the clamp type coupler 16 on the trunk line connecting the transformers 5A to 5C and the distribution devices 12A to 12C because they are connected to the distribution devices 12A to 12C via bus bars and short distribution lines. . However, by installing the clamp coupler 16 on the branch line branched from the main line, the connection of the bypass signal line 15 to the low voltage distribution lines 6A, 6B, 6C can be facilitated.

  As described above, the bypass signal line 15 connects one branch line selected from a plurality of branch lines of each power system. Since the bypass signal line 15 is connected to the branch line of the low-voltage distribution line, the connection position of the bypass signal line 15 is separated from the transformers 5A to 5C to some extent. Since the transformers 5A to 5C have a low impedance, there is a problem that the amount of signal attenuation increases. Although measures such as providing a relay amplifier for amplifying the attenuated signal can be taken, there is a problem that the structure of the relay amplifier becomes complicated and the cost is high because power line communication uses the same band. However, by adopting an inductive coupling method for connecting the bypass signal line 15 and the power line, the above problem can be avoided and different power systems can be easily connected.

With the above configuration, the master unit modem 8A provided on the second system low-voltage distribution line 6B is not only the second system slave unit modem 8B, but also the first system or third system unit modem 8B. Power line communication is possible. The PLC signal transmitted from the master modem 8A is transmitted to the first system low-voltage distribution line 6A and the third system low-voltage distribution line 6C through the bypass signal line 15, and is transmitted to the target slave modem 8B. On the other hand, the PLC signal transmitted from the slave modem 8B connected to the first system low-voltage distribution line 6A is transmitted to the second system low-voltage distribution line 6B through the bypass signal line 15 and sent to the master modem 8A. It is done. For example, the connected handset modem 8B to the branch line 6A ₂ 1-2 lines can be accessed master unit modem 8A via the branch line 6A _2, the bypass signal line 15 and the branch line 6B _2. Also, 1-1 lines connected handset modem 8B branch line 6A ₁ of the branch line 6A _1, the dispensing device 12A, the branch line 6A _2, the bypass signal line 15 and the base unit via the branch line 6B ₂ The modem 8A can be accessed. Therefore, the meter reading data of all the power meters 7 on the first and third systems is sent to the master modem 8A through the slave modem 8B, and the master modem 8A transfers it to the server via the WAN (not shown). Can do.

  As described above, in the remote meter reading system 1A according to the present embodiment, the master modem 8A connected to the second low-voltage distribution line 6B is not only the slave modem 8B in the same system but also the first and third systems. Since communication is performed with the slave modem 8B connected to the low-voltage distribution lines 6A and 6C of the system, it is not necessary to prepare the master modem 8A for each power system. The master modem 8A has a higher function than the slave modem 8B, but the device unit price is also high. Therefore, it is better that the number of slave modems 8B covered by one master modem 8A is as large as possible. Furthermore, in order to transfer the meter reading data to the server, it is sufficient that one master modem 8A can be connected to the WAN, and the range of the slave modem 8B covered by the single master modem 8A is expanded, so Running cost can be reduced. Further, when a public wireless communication network is used as a WAN, the installation location is not limited to an electrical room or the like, and can be installed in an arbitrary location.

  FIG. 5 is a configuration diagram of a remote meter reading system 1B according to the second embodiment of the present invention.

As shown in FIG. 5, this remote meter reading system 1B includes a 1-2 branch line 6A ₂ , a 2-2 branch line 6B ₂ , and a white phase power line 6b of a 3-2 branch line 6C _2. It is characterized by being connected via a bypass signal line 15. At this time, each power line modem 8 (master modem 8A, slave modem 8B) has a red phase power line 6a and white phase power line 6b, a white phase power line 6b and black phase power line 6c, or a red phase power line 6a and white phase power line 6b. The power line 6b and the black-phase power line 6c are connected by any of the methods, and other basic configurations are the same as those in the first embodiment.

As in the first embodiment, since the base unit modem 8A is connected to the branch line 6B ₂ 2-2 lines, the master unit without handset modem 8B of the second system is passing through the bypass signal line 15 Power line communication can be performed with the modem 8A. On the other hand, the slave modem 8B in the first system or the third system can access the master modem 8A via the bypass signal line 15. For example, the connected handset modem 8B to the branch line 6A ₂ 1-2 lines can be accessed master unit modem 8A via the branch line 6A _2, the bypass signal line 15 and the branch line 6B _2. Also, 1-1 lines connected handset modem 8B branch line 6A ₁ of the branch line 6A _1, the dispensing device 12A, the branch line 6A _2, the bypass signal line 15 and the base unit via the branch line 6B ₂ The modem 8A can be accessed.

  According to this embodiment, the same effect as that of the first embodiment can be obtained. That is, the base unit modem 8A connected to the second system low-voltage distribution line 6B is connected not only to the slave unit modem 8B in the same system but also to the first system and the third system low-voltage distribution lines 6A and 6C. Since communication is performed with the modem 8B, there is no need to prepare a master modem 8A for each power system. In addition, the range of the slave modem 8B covered by one master modem 8A can be expanded to reduce the system running cost such as the line cost.

  FIG. 6 is a configuration diagram of a remote meter reading system 1C according to the third embodiment of the present invention.

  As shown in FIG. 6, this remote meter reading system 1 </ b> C is that the bypass signal line 15 is connected to all branch lines branched from the trunk lines of the first to third system low-voltage distribution lines 6 </ b> A, 6 </ b> B, 6 </ b> C. is there. Other basic configurations are the same as those in the first embodiment.

The low-voltage distribution line 6A of the first system is divided into branch lines 6A ₁ , 6A ₂ , 6A ₃ of the 1-1 system to 1-3 systems, and the low-voltage distribution line 6B of the second system is 2-1 systems to 2- 3 branch lines _6B 1 _strains, divided into 6B 2, 6B _3, low-voltage distribution line 6C of the third line is divided into 3-1 system ～3-3 system branch line _{6C 1,} 6C 2, 6C ₃ Yes. The bypass signal line 15 connects these branch lines 6A ₁ , 6A ₂ , 6A ₃ , 6B ₁ , 6B ₂ , 6B ₃ , 6C ₁ , 6C ₂ , 6C ₃ .

The clamp type coupler 16 includes the red phase of each branch line 6A ₁ , 6A ₂ , 6A ₃ , 6B ₁ , 6B ₂ , 6B ₃ , 6C ₁ , 6C ₂ , 6C ₃ of the first to third system low-voltage distribution lines. The bypass signal line 15 is connected to all the branch lines via these clamp-type couplers 16 and is installed in both of the black phase power lines 6a and 6c.

Here, the insertion direction (connection direction) of the bypass signal line 15 to the clamp-type coupler alternately repeats the forward direction and the reverse direction along the connection order to the plurality of branch lines. When the flow signal shown by the arrow X, next to 1-1 lines of the branch line 6A ₁ is a signal shown by the arrow D1 direction (positive), 1-2 lines of branch lines 6A ₂ signals the direction (opposite of the arrow D2 ), and the branch line 6A ₃ 1-3 lines is the direction of the signal shown by the arrow D3 (positive). That is, the connection polarity of the bypass signal line 15 with respect to the branch lines 6A ₁ , 6A ₂ , 6A ₃ of the 1-1 system to the 1-3 system is “normal”, “reverse”, and “normal”.

Similarly, the branch lines 6B ₁ , 6B ₂ , 6B _{3 of the} 2-1 system, the 2-2 system, and the 2-3 system become “normal”, “reverse”, and “normal”, and the 3-1 system and the 3-2 system. Similarly, the branch lines 6C ₁ , 6C ₂ , 6C ₃ of the 3-3 system are also “normal”, “reverse”, and “normal”. In this way, the bypass signal for the branch line is alternately repeated in the order of connection polarity of the bypass signal line with respect to the branch line (the insertion direction of the signal line with respect to the clamp coupler) in the order of connection to the plurality of branch lines. The number of positive pole connections and the number of reverse pole connections of the line are almost the same. The reason for such a configuration is as follows.

For example, 1-1 part of the PLC signal transmitted from the slave unit modem 8B on branch lines 6A ₁ strains, through to 1-2 systems of dispensing device 12A branch line 6A ₂ and 1-3 systems of wrap the branch line 6A _3, via a bypass signal line 15 is fed back to the branch line 6A ₁ side of the 1-1 system, the feedback signal is a factor that degrades the quality of the PLC signal. As the number of branch lines in the first system 6A increases, the deterioration of the quality of the PLC signal due to the influence of the feedback signal increases. However, it is possible to suppress the deterioration of the PLC signal due to the feedback signal by alternately changing the connection polarity of the bypass signal line with respect to the branch line for each branch line so that the positive polarity connection and the reverse polarity connection are approximately the same number. And the quality of power line communication can be improved.

  When the total number of the plurality of branch lines in the same system is an even number, it is preferable that the total number of branch lines connected to the bypass signal line with the positive polarity is equal to the total number of branch lines connected with the reverse polarity. In addition, when the total number of branch lines in the same system is an odd number, the total number of branch lines connected with the reverse polarity is one more than the total number of branch lines to which the bypass signal lines are connected with positive polarity. Or one less. In this way, when there are a lot of branch lines, the number of “forward” and “reverse” lines is almost the same, so that deterioration of the PLC signal due to the feedback signal can be reliably suppressed, and the quality of the power line communication is improved. be able to.

In the above configuration, 2-1 handset modem 8B connected to branch lines 6B ₁ lineages, via a bypass signal line 15 without passing through the distributor 12B 2-2 lines of the branch line 6B ₂ above Can communicate with the master modem 8A. Also, 1-1 handset modem 8B connected to branch line 6A ₁ and 1-3 line of the branch line 6A ₃ lineages bypass signal without passing through the dispensing device 12A as in the first embodiment can communicate with the base unit modem 8A on 2-2 line of the branch line 6B ₂ via line 15. 3-1 connected handset modem 8B in the branch line 6C ₁ and 3-3 line of the branch line 6C ₃ strains also 2-2 line via a bypass signal line 15 without passing through the dispensing device 12C it can communicate with the base unit modem 8A via the branch line 6B _2. Therefore, the transmission distance of the PLC signal can be shortened, and the deterioration of communication quality due to passing through the distribution device can be suppressed.

  Also in this embodiment, the same effects as those of the first embodiment can be obtained. That is, the base unit modem 8A connected to the second system low-voltage distribution line 6B is connected not only to the slave unit modem 8B in the same system but also to the first system and the third system low-voltage distribution lines 6A and 6C. Since communication is performed with the modem 8B, there is no need to prepare a master modem 8A for each power system. In addition, the range of the slave modem 8B covered by one master modem 8A can be expanded to reduce the system running cost such as the line cost.

  FIG. 7 is a block diagram of a remote meter reading system 1D according to the fourth embodiment of the present invention.

  As shown in FIG. 7, this remote meter reading system 1D is a combination of the second embodiment and the third embodiment, and all branches branched from the main lines of each power system as shown in FIG. The bypass signal line 15 is connected to the line, and the bypass signal line 15 is connected to the white-phase power line 6b of each low-voltage distribution line. Therefore, the same effect as the third embodiment can be obtained.

  FIG. 8 is a configuration diagram of a remote meter reading system 1E according to the fifth embodiment of the present invention.

  As shown in FIG. 8, this remote meter reading system 1 </ b> E is characterized in that the master modem 8 </ b> A is provided independently from the power meter 7 without being incorporated in one of the power meters 7. Therefore, all power line modems 8 built in the power meter 7 are slave modems 8B. Other basic configurations are the same as those in the first embodiment.

Master modem 8A is directly connected to bypass signal line 15, and bypass signal line 15 connects one branch line selected from a plurality of branch lines of each power system. That is, the red power lines 6 a of the 1-2 system branch line 6 A ₂ , the 2-2 system branch line 6 B ₂ , and the 3-2 system branch line 6 C ₂ are mutually connected via the bypass signal line 15. Similarly, the black power lines 6c of the 1-2 system branch line 6A ₂ , the 2-2 system branch line 6B ₂ , and the 3-2 system branch line 6C ₂ are connected to the bypass signal line 15. Are connected to each other. Therefore, all of the slave unit modem is able to perform base unit modem 8A and power line communication through the branch line 6B ₂ bypass signal line 15 and the 2-2 lines. That is, even if a plurality of power systems are provided, it is possible to cope with one master modem 8A.

  In the embodiments of the remote meter reading systems 1A to 1E, the connection form of the clamp type coupler 16 to the bypass signal line 15 has been described as “parallel connection” as shown in FIG. 9A, but as shown in FIG. 9B. Needless to say, “series connection” is also possible. However, as shown in FIG. 9C, the quality of the received signal is influenced by the wraparound of the signal, the transmission distance, and the like, so that “parallel connection” is more efficient than “series connection”.

  9 (a) and 9 (b) illustrate an example in which the master modem 8A is connected to the bypass signal line 15 as in the remote meter reading system 1E of FIG. 8, but the remote meter reading systems 1A to 1D are illustrated. As described above, the present invention can also be applied to the case where the base unit modem 8A is built in the power meter 7.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Needless to say, it is included in the range.

  For example, in the above embodiment, three transformers 5A, 5B, and 5C are provided in the electrical room 4 of the apartment house 3, and the power system in the apartment house 3 is divided into three systems. Although the case where each of the low-voltage distribution lines 6A, 6B, 6C of the system is branched into three is given as an example, the present invention is not limited to such a case, and any number of systems can be used as long as there are two or more systems. Of course, the number of branch lines branching from the trunk line of each power system may be any number.

  Further, the fifth embodiment shown in FIG. 8 is a modification of the first embodiment, and the master modem 8A is provided independently instead of being built in the power meter 7. Although the configuration in which the main modem 8A is directly connected to the bypass signal line 15 has been described, the main modem 8A may be provided independently of the power meter 7 in the second to fourth embodiments.

  Moreover, in the said embodiment, although the case where transformer 5A, 5B, 5C was provided in the electrical room 4 of the apartment house 3 was mentioned as an example, this invention is not limited to such a structure, For example, transformer 5A , 5B and 5C may be pole transformers.

1A, 1B, 1C, 1D, 1E Remote meter reading system 3 Apartment house 4 Electric room 5A, 5B, 5C Transformer 6A, 6B, 6C Low voltage distribution line 6A ₁ , 6A ₂ , 6A ₃ First system branch line 6B ₁ , 6B ₂ , 6B ₃ 2nd branch line 6C ₁ , 6C ₂ , 6C ₃ 3rd branch line 6a Power line (first ungrounded line)
6b Power line (ground line)
6c Power line (second ungrounded line)
7 Power Meter 8 Power Line Modem 8A Master Modem 8B Slave Modem 9 Weighing Unit 10 Consumer Home 11 High Voltage Distribution Lines 12A, 12B, 12C Distribution Device 13 Distribution Board 14 Home Wiring 15 Bypass Signal Line 16 Clamp Type Coupler 21 Control Unit 22 Meter interface unit 23 PLC interface unit 24 WAN interface unit

Claims (11)

First and second transformers that step down the voltage of the high-voltage distribution line and convert it into commercial power;
A first system low-voltage distribution line extending from the secondary side of the first transformer;
A second low-voltage distribution line extending from the secondary side of the second transformer;
A plurality of power meters connected to the low-voltage distribution line of the first system or the low-voltage distribution line of the second system;
A bypass signal line for connecting the low-voltage distribution line of the first system and the low-voltage distribution line of the second system by an inductive coupling method;
Each of the low-voltage distribution lines of the first system and the second system has a plurality of branch lines branched from the main line connected to the first or second transformer,
The bypass signal line is at least one branch line selected from a plurality of branch lines of the first system low-voltage distribution line and at least one branch line selected from the plurality of branch lines of the second system low-voltage distribution line. The branch line is connected by the inductive coupling method,
Each of the plurality of power meters includes a power line modem for transferring meter reading data,
The remote meter-reading system characterized by the power line modem in the power meter connected to the low voltage distribution line of the 1st system or the 2nd system performing power line communication via the bypass signal line. Each of the low-voltage distribution lines of the first system and the second system has a second non-grounding current flowing in a phase opposite to a current flowing through the grounding wire, the first non-grounding wire, and the first non-grounding wire. A single-phase three-wire distribution line with wires,
2. The remote meter reading system according to claim 1, wherein the bypass signal line connects in-phase power lines of the first system low-voltage distribution line and the second system low-voltage distribution line. The bypass signal line connects the first non-grounded line of the first system low-voltage distribution line and the first non-grounded line of the second system low-voltage distribution line by inductive coupling, and Connecting the second ungrounded wire of the first system low-voltage distribution line and the second ungrounded wire of the second system low-voltage distribution line by an inductive coupling method;
The remote meter-reading system according to claim 2, wherein each of the plurality of power line modems is connected to both the first ungrounded line and the second ungrounded line. The bypass signal line connects the ground line of the low-voltage distribution line of the first system and the ground line of the low-voltage distribution line of the second system by an inductive coupling method,
The remote meter reading system according to claim 2, wherein each of the plurality of power line modems is connected to the ground line.   The bypass signal line connects all branch lines branched from a main line of the low-voltage distribution line of the first system and all branch lines branched from a main line of the low-voltage distribution line of the second system. The remote meter-reading system as described in any one of 1-4. The first and second branch lines in the same system are connected to each other by the bypass signal line,
The remote meter reading system according to claim 5, wherein a connection polarity of the bypass signal line with respect to the first branch line is different from a connection polarity of the bypass signal line with respect to the second branch line.   7. The remote meter reading according to claim 6, wherein when the sum of the first and second branch lines in the same system is an even number, the sum of the first branch lines and the sum of the second branch lines are the same. system.   7. The remote meter reading according to claim 6, wherein when the sum of the first and second branch lines in the same system is an odd number, the sum of the second branch lines is one more than the sum of the first branch lines. system. A power line modem provided in one of the plurality of power meters is a master modem,
9. The power line modem provided in all of the remaining power meters except the power meter provided with the master modem among the plurality of power meters is a slave modem. 10. The remote meter reading system described in. The power line modems provided in each of the plurality of power meters are all slave modems,
The remote meter reading system according to any one of claims 1 to 8, wherein the slave modem performs power line communication with a master modem connected to the bypass signal line. The master unit modem communicates with a power line communication interface unit that communicates with the slave unit modem via a power line network constituted by the first system and the second system low-voltage distribution lines, and communicates through a wide area communication network. A communication interface unit,
The said cordless handset modem has a power line communication interface part which communicates with the said cordless handset modem via the power line network comprised by the low voltage distribution line of the said 1st system | strain and 2nd system | strain. Remote meter reading system.