JP3417694B2 - Low voltage distribution line transport system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low voltage distribution line carrier system used for signal transmission such as an automatic meter reading system for connecting a consumer in a building or the like and a transmission terminal in a rented room.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing the configuration of a conventional transmission terminal for low voltage distribution line transportation, which is disclosed in, for example, Japanese Patent Laid-Open No. 19033/1990. FIG. 6 is a diagram showing a low-voltage distribution line carrier metering system to which these transmission terminals are connected. In FIG. 6, reference numeral 1 is a 100 / 200V single-phase three-wire low-voltage distribution line, which is a distribution system that obtains a voltage of 200V between the distribution lines P1 and P2 and a voltage of 100V between the neutral line N and the distribution line P1 or P2. is there. This power distribution method has been adopted for most of the power distribution in buildings in Japan these days. Reference numeral 2 is a load of a customer in the building, 3 is a transaction watt hour meter (WHM) for measuring the amount of electric power used in the load, 4 is a transmission terminal device, and a transmission control unit 41, a reception unit 42, and a transmission unit 43. Etc., and each transmission terminal 4 is given an individual identification number or identification code. 5 is a distribution line P1 of a signal input / output line from the transmission terminal unit 4.
And a blocking filter inserted between the connection point of the neutral line N and the load 2. Reference numeral 6 denotes a central device, which transmits a command signal to each transmission terminal device 4 and receives a response signal from each transmission terminal device 4 to perform an aggregation process and the like. Reference numeral 7 is a transformer, the primary side receives a high-voltage power distribution line 9 of 6600V, and the secondary side constitutes a 100 / 200V single-phase three-wire low-voltage power distribution line 1. Reference numeral 8 is a second-type grounding line that grounds the neutral point on the secondary side of the transformer 7, and is connected to the neutral line N.

The conventional low voltage distribution line meter reading system is constructed as described above, and the central device 6 transmits a command signal including an identification code to each transmission terminal 4 and receives a command addressed to its own identification code. The transmission terminal 4 converts the count value of the transaction WHM 3 into a transmission signal, and transmits the transmission signal to the central unit 6 by using the distribution line P1 and the neutral line N as a transmission line. As the transmission method used at this time, the FSK method is generally used in which a signal is converted into a high frequency signal and the signal is superimposed to transmit and receive the signal. The blocking filter 5 prevents the high frequency signal from being shunted to the impedance of the load 2 in order to stabilize the transmission quality of the signal, and thus the transmission terminal 4 and the central unit 6 are connected.
It is for ensuring the signal arrival level of and.

[0004]

Since the conventional low-voltage distribution line carrier metering system is constructed as described above, the transmission signal reach distance of the transmission signal due to the change of the impedance of the load 2 due to the fluctuation of the power consumption of the customer is considered. In order to prevent the deterioration and stabilize the transmission quality, a blocking filter 5 is provided between the load 2 and the connection point of the distribution line P1 of the signal input / output line of the transmission terminal 4 and the neutral line N so that the transmission signal is not shunted to the load 2. Needed to be inserted.

Further, as shown in FIG. 7, in order to comprehensively aggregate the data in a distribution line carrier metering system having different transformer systems, the total aggregation device 10 is excluded except for the voltage difference between the distribution lines P1 of each transformer system. There is a problem that the central device 6 must be provided for each transformer system in order to connect the signal line to, and must be routed through.

The present invention has been made to solve the above-mentioned problems, and is not affected by the impedance change of the load of the low-voltage power distribution line during distribution line transportation in a building, and does not require a blocking filter for each load. A low-voltage distribution line transport system that can secure the transmission signal reach and can transmit and receive transmission signals without providing a central device for each transformer system in the distribution line transport between low-voltage distribution lines with different transformer systems. Is intended to provide.

[0007]

A low-voltage distribution line conveying system according to the present invention comprises a second-class grounding line for grounding a secondary side neutral point of a transformer constituting a low-voltage distribution line, and a secondary type of the transformer. Side neutral
And neutral of the connected low-voltage distribution line by a dotted line, the electrical equipment
High-frequency transmission near the grounding point of the ground wire for third-class grounding
Blocking filter with high impedance to signal
, And a plurality of transmission terminals including a central device for transmitting and receiving transmission signals are connected by using a ground wire and a neutral wire grounded via a blocking filter as a pair of transmission lines. is there.

Further, a repeater for amplifying and relaying a transmission signal from a predetermined transmission terminal by changing a transmission signal form, and a transmission signal amplified and relayed by negating a direct transmission signal from the predetermined transmission terminal. Other transmission terminals are included, including a receiving central unit.

In addition, one of the input and output of the transmission terminal device, in which the neutral line and the ground line of another low-voltage distribution line formed by another transformer are connected as a pair of transmission lines, is connected to the central unit. Connect to the neutral line of the vessel.

Further, a neutral terminal of another low-voltage distribution line composed of another transformer and a ground terminal are connected as a pair of transmission lines, and a neutral terminal of the transformer connected to the central unit. A repeater having one of its input and output connected to the line is provided.

[0011]

[0012]

The operation of the low voltage distribution line conveying system according to the present invention is the second
Neutral wire connected to the neutral point of the transformer with the seed ground,
The transmission line impedance is not affected by the load impedance change of the consumer by forming the pair of transmission lines with the ground wire for performing the third type grounding on the electric equipment used . Well
Also, place a blocking filter near the grounding point of the ground wire.
By installing the transmission signal to the secondary coil of the transformer
Is suppressed and the level of the transmission signal is secured.

Further, the transmission signal in the repeater is amplified and relayed by changing the transmission signal form, thereby preventing double reception of the transmission signal which is not amplified and relayed at the receiving side.

Further, one of the input and output of the transmission terminal device, in which the neutral line and the ground line of another low-voltage distribution line constituted by another transformer are connected as a pair of transmission lines, is connected to the central unit. By connecting to the neutral line of the power supply unit, it is possible to transfer the transmission signal between the transmission terminals between the low-voltage distribution lines of different phases and with the central unit.

Further, one of the input and output of the repeater of the transmission terminal, in which the neutral line and the ground line of another low-voltage distribution line constituted by another transformer are connected as a pair of transmission lines, is connected to the central unit. By connecting to the neutral wire of the transformer
The connection between the transmission terminals between the low-voltage distribution lines of different phases and the connection between the central equipment and the transmission terminal between the low-voltage distribution lines of different phases is made only by the connection of one line of the input and output of the repeater. Allows transmission and reception of transmission signals.

[0016]

[0017]

【Example】

Example 1. FIG. 1 is a diagram showing an automatic meter-reading system using a low-voltage distribution line conveying system according to a first embodiment of the present invention. In the figure, 1 to 4 and 6 to 9 are the same as those described in the conventional example. Reference numeral 11 is a grounding wire that is grounded to connect various electric devices to the third kind, and 12 is a blocking circuit including an LC circuit provided near the third kind grounding position of the grounding wire 11. In recent years, the number of buildings and buildings in which a grounding earth wire 11 for OA equipment or the like and a single-phase three-wire low-voltage power distribution line 1 are wired in pairs has increased.

In the first embodiment, the transmission terminal 4 and the central unit 6 are connected so that the neutral wire N and the ground wire 11 form a pair of signal transmission paths. The impedance of the signal transmission line as viewed from the side of the central device 6 is mainly the sum of the secondary side grounding resistance of the transformer 7 and the third type grounding resistance of the earth line 11, and depends on the load power used by the customer. The impedance between the neutral wire N and the ground wire 11 is not affected. Further, since the neutral wire N and the ground wire 11 are hardly affected by the transmission voltage of the low-voltage distribution line 1, there is no potential difference, and the high frequency signal propagating property such as the FSK system is good, and the transmission quality is stable and the transmission distance is long. Can be extended. Further, even if the number of transmission terminals 4 is increased due to an increase in the number of customers, the existing neutral line N and the ground line 11 can be used, so that it is not necessary to lay a new transmission line.

Example 2. Second Embodiment FIG. 2 is a diagram of a low voltage power distribution line transport system power distribution line transport meter reading system showing a second embodiment of the present invention. 1 to 4 and 6 to 12 are the same as those described in the first embodiment. Reference numeral 13 is a transmission repeater that amplifies and retransmits midway with the transmission terminal 4a installed at a long distance from the central device 6. The transmission repeater 13 may be connected to a ground wire 11b and a neutral wire N of a system different from the ground wire 11 to which the central device 6 is connected. This makes it possible to construct a distribution line conveyance metering system in which customers scattered in different buildings to which the same ground wire 11 is not distributed are grouped.

In the distribution line meter reading system in which a plurality of buildings are in the same group, the distribution line becomes long, so the central unit 6
When there is a long distance between the transmission terminal 4a and the transmission terminal 4a, the transmission repeater 13
Is provided on the way to relay and amplify both transmission signals. Since the central device 6 and each transmission terminal device 4a specify the transmission / reception destinations with their respective individual identification codes, there is no problem if the attenuation distance between the central device 6 and the transmission terminal device 4a is such that transmission / reception is impossible. If the transmission is improved and transmission / reception is possible even slightly, for example, a transmission signal from the transmission terminal 4a to the central unit 6 is transmitted directly from the transmission terminal 4a and the transmission relay 13 at the distance where the transmission relay 13 is provided. Therefore, the transmission signal relay-amplified by will be received twice.

Therefore, in the second embodiment, the transmission signal form between the transmission terminal 4a and the transmission repeater 13 and the transmission signal form between the central unit 6 and the transmission repeater 13 are changed so that the transmission terminal 4a is directly connected to the center. By adopting a transmission signal form that cannot be directly transmitted / received by the device 6, the above-mentioned double reception can be prevented. Generally, FSK is used as a means for changing the form of transmission signal.
The means for changing the frequency of the system is used, but it is also possible to rewrite the individual identification code in the transmission repeater 13.

Example 3. Third Embodiment FIG. 3 is a diagram of a low voltage power distribution line transport system distribution line transport meter reading system according to a third embodiment of the present invention. In the figure, 1-4, 6-13 are the said Example 2
Is the same as that described in. Reference numeral 14 denotes a transformer, which is connected to the high-voltage power distribution line 9 separately from the transformer 7, and constitutes a low-voltage power distribution line 16 of 100 / 200V single-phase three-wire system on the secondary side. Reference numeral 15 is a second-type grounding wire that grounds the neutral point on the secondary side of the transformer 14, and is connected to the neutral wire N. One of the input and output of the transmission terminal 4a of the customer WHM 3a of the low voltage distribution line 16 constituted by the transformer 14 is connected to the neutral line N of the transformer 7 side to which the central device 6 is connected. There is.

In the low-voltage distribution line carrier system in which the neutral line N of the low-voltage distribution line and the ground line 11 are used as a pair of transmission lines, the neutral line N of the low-voltage distribution line 1 and the neutral line N of another low-voltage distribution line 16 are used. Since the voltage existing between them is small and the transmission signal can be directly transmitted and received by the central device 6, it is not necessary to install the central device 6 for each transformer in order to perform meter reading aggregation of the automatic meter reading system across a plurality of transformers. . Therefore, in the low-voltage distribution line conveying type automatic meter reading system configured as described above, the distribution of one group can be performed between low-voltage distribution lines composed of a plurality of different transformers without using an additional central device 6. It can be configured as an automatic meter-reading system using an electric wire transportation method.

Example 4. Fourth Embodiment FIG. 4 is a diagram of an automatic meter-reading system using a low-voltage distribution line conveying system showing a fourth embodiment of the present invention. In the figure, 1-4, 6-16 are the said Example 4
Is the same as that described in. Reference numeral 17 denotes a repeater, which has the same transmission function as the transmission repeater 13 described in the third embodiment. One end of the input / output of this relay 17 is connected to the neutral line N of another transformer 7 to which the central unit 6 is connected.

In the third embodiment, each transmission terminal 4
A separate connecting line from a to the neutral line N of the low-voltage distribution line 1 of the transformer 7 is required. Further, since the low-voltage distribution line 16 of the transformer 14 and the low-voltage distribution line 1 of the transformer 7 are not necessarily close to each other, it is often difficult to install a connecting line between them. In the configuration of the fourth embodiment, by connecting only one line from the repeater 17 to the neutral line N of the low-voltage distribution line 1, one group of distribution line carriers can be transported between the low-voltage distribution lines composed of a plurality of transformers. It can be configured as an automatic meter reading system using the.

Example 5. In the conventional signal transmission line,
Regarding the impedance of the transformer 7, the secondary coil of the transformer 7 has a high impedance with respect to a high frequency signal, and the legibility of the transmission signal is maintained. However, in the signal transmission line of the present invention, the impedance on the transformer 7 side is such that the third-type ground resistance of the ground wire 11 is 100 ohms or less, and the second-type ground resistance on the secondary side of the transformer 7 is the same as that of the transformer 7. It is regulated that the ground resistance value is determined depending on the primary side voltage and the type of cut-off protection device, but the actual measurement result shows that the combined resistance value is only a few ohms to a few tens of ohms, and the transmission signal shunts and leaks. Decreases legibility.

Therefore, a blocking filter 12 is provided near the third type ground of the ground wire 11. The blocking filter 12 has a small impedance in the commercial frequency range of the distribution line, and there is no problem in passing the leakage current of the electric device connected to the distribution line. However, it has a high impedance for a high-frequency transmission signal and suppresses the leakage of the transmission signal to improve the readability of the signal.

[0028]

Since the present invention is configured as described above, it has the following effects.

In the secondary side of the transformer that constitutes the low-voltage distribution line
And neutral of the connected low-voltage distribution line sexual dotted ground point near
A block with high impedance for high-frequency transmission signals
Third class grounding for electrical equipment to which the king filter is connected
The transmission line impedance shall not be affected by the load impedance change on the consumer side by connecting the central equipment and the transmission terminal device that exchange transmission signals with the earth line to be applied as a pair of transmission lines. Grounding wire without the need for a blocking filter on the load side.
Near the grounding point of the impedance of high frequency transmission signal
By connecting a high blocking filter , the shunting of the transmission signal to the secondary coil of the transformer is suppressed and transmission is performed.
The signal level can be secured.

In addition, a repeater that amplifies and relays a transmission signal from a predetermined transmission terminal by changing the transmission signal form, and a transmission signal form in which the direct transmission signal from the predetermined transmission terminal is denied and the transmission signal form is changed. By providing the central device that receives the amplified and relayed transmission signal, it is possible to prevent double reception of the transmission signal on the receiving side due to the amplification and relay in the long distance transmission.

Further, a neutral line and a ground line of a plurality of low-voltage distribution lines formed by a plurality of transformers are used as a pair of transmission lines, and one of the input and output of the connected transmission terminals is connected to the central unit. By connecting to the neutral line of the transformer, it is possible to directly exchange the transmission signal between the transmission terminals between the low voltage distribution lines of different transformer systems and with the central device.

Further, one of the input and output of the repeater of the transmission terminal, in which a neutral line and a ground line of a plurality of low-voltage distribution lines composed of a plurality of transformers are connected as a pair of transmission lines, is a central unit. By connecting to the neutral wire of the connected transformer, it is possible to form a distribution line carrier network between low voltage distribution lines of different transformer systems.

[0033]

[Brief description of drawings]

FIG. 1 is a diagram of a low-voltage distribution line conveying system distribution line conveying meter reading system according to a first embodiment of the present invention.

FIG. 2 is a diagram of a low-voltage distribution line conveying system distribution line conveying meter reading system showing Embodiment 2 of the present invention.

FIG. 3 is a diagram of a distribution line transport meter reading system of a low voltage distribution line transport system showing a third embodiment of the present invention.

[Fig. 4] Fig. 4 is a diagram of a low voltage power distribution line transport type distribution line transport meter reading system showing Embodiment 4 of the present invention.

FIG. 5 is a configuration block diagram of a conventional transmission terminal for low voltage distribution line transportation.

FIG. 6 is a diagram of a low-voltage distribution line carrier metering system to which a conventional transmission terminal is connected.

FIG. 7 is a diagram of a conventional distribution line carrier metering system having a different transformer system.

[Explanation of symbols]

1, 16 low-voltage distribution line, 2 customer load, 3 watt-hour meter for transaction (WHM), 4 transmission terminal, 6 central unit, 7, 14 transformer,
8, 15 Type 2 ground wire, 11 Ground wire, 1
2 blocking filter, 13, 17 repeater,
N neutral line.

─────────────────────────────────────────────────── ─── Continuation of front page (73) Patent holder 000003078 Toshiba Co., Ltd. 1-1-1, Shibaura, Minato-ku, Tokyo (73) Patent holder 000220907 Toko Electric Co., Ltd. 1-1-7 Yurakucho, Chiyoda-ku, Tokyo (73) Patent holder 000144108 Saneisha Co., Ltd. 52-1 Ebara, Shinagawa-ku, Tokyo (73) Patent holder 000002842 Takatake Manufacturing Co., Ltd. 3-7-1 Kandanishiki-cho, Chiyoda-ku, Tokyo (72) Invention Nobuo Kanno 1-3-3 Uchisaiwaicho, Chiyoda-ku, Tokyo Within TEPCO (72) Inventor Keizo Okazaki 1-8 Midoricho, Fukuyama-shi Mitsubishi Electric Corporation Fukuyama Works (72) Inventor Koji Shimizu Tokyo Hino, Tokyo Fuji Town, Fuji-shi Co., Ltd. Tokyo Factory (72) Inventor Takashi Yokoyama 2-2-7 Higashigotanda, Shinagawa-ku, Tokyo Osaki Electric Company (72) Inventor Akinori Nishi 1-1-1 Shibaura, Minato-ku, Tokyo Toshiba Corporation Head Office Office (72) Inventor Takao Kojima 1-1-7 Yurakucho, Chiyoda-ku, Tokyo Toko Electric Co., Ltd. In-house (72) Inventor Yoshio Miyahara 5-2-1 Ebara, Shinagawa-ku, Tokyo Inside Saneisha Co., Ltd. (72) Inventor Shigeyuki Yanagida 1440 Nakakuki Nakayama, Toyama Prefecture Takayama Works Oyama Plant Co., Ltd. (56) References JP 62-18837 (JP, A) JP 62-147821 (JP, A) JP 62-274831 (JP, A) JP 62-296629 (JP, A) Kai 61-237527 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04B 3/50-3/60

Claims (4)

(57) [Claims] 1. A and the low-pressure distribution line configured via a transformer in a building, and the two ground lines for grounding the secondary neutral point of the transformer, the secondary side neutral of the transformer Connected to a point
And neutral lines of the low-voltage distribution line which, for the ground wire to apply a third class grounding to the electrical equipment used in the low-voltage distribution lines, pairs connected to the high frequency transmission signal in the vicinity grounding point of the ground wire
A blocking filter with high impedance
A plurality of transmission terminal unit and the central unit exchanging a blocking filter ground wire that is grounded via the said second type via a ground line neutral line is grounded and the pair of transmission lines transmission signal is performed in A low-voltage distribution line transport system characterized by being equipped with. Wherein the repeater for amplifying and relaying by changing the transmission signal form a transmission signal from the ground line and is connected to the transmission line by the neutral conductor predetermined transmission terminal unit, direct from the predetermined transmission terminal unit It denied the transmission signal low-voltage distribution line carrier system according to claim 1, characterized in that a the central unit other transmission terminal device for receiving a transmission signal the amplifier repeater. 3. A transmission terminal device in which a neutral line and a ground line of another low-voltage distribution line configured via another transformer are connected as a pair of transmission lines, and one of the input and output of this transmission terminal device. Is connected to a neutral wire of a transformer to which a central device is connected. 4. A plurality of transmission terminal unit the neutral line and the ground line of the plurality of low-voltage distribution line configured connected to the pair of transmission lines by a transformer, relays transmit signals of the transmission terminal device and repeaters, low-voltage distribution line carrier system according to claim 3, characterized in that one of the input and output of the repeater central unit is connected to the neutral line of the connected transformers.