JPH0470129A - Power feeding path switching circuit for underwater branching device and feeding method for submarine cable communication system - Google Patents

Abstract

PURPOSE:To execute a direct current insulated resistance test for the feeding path of the submarine cable communication system by insulating the feeding path in the underwater branching device from sea water in the state of no feeding. CONSTITUTION:First - third connecting terminals 101-103 are provided to be connected to the feeding paths of submarine cables, a first feeding path 104 is formed between the first and second connecting terminals 101 and 102 to execute feeding between both terminals, and a second feeding path 105 is formed between the third connecting terminal 103 and the ground to execute feeding at one terminal. The driving part 106L of a first relay 106 is arranged at the first feeding path 104, and a switching part 106C is arranged at the second feeding path 105. In the case of de-energizing the relay, the switch part 106C disconnects the third connecting terminal 103 from the ground and in energizing the relay, the terminal is grounded. In such a manner, all the feeding paths in the feeding path switching circuit are insulated from sea water. Thus, in the case of no feeding, the direct current insulated resistance test can be executed for the feeding path of the submarine cable.

Description

[Detailed Description of the Invention] [Summary] A power supply path switching circuit for an underwater branching device in a submarine cable communication system that branches a submarine cable underwater and communicates between three or more landing stations, and this power supply path switching circuit. The purpose of this invention is to provide a power supply line switching circuit that can insulate all submarine cable power supply lines from seawater and conduct DC insulation resistance tests when no power is being supplied, and a power supply method using the same. and having first, second, and third connection terminals connected to a power supply path of the submarine cable, forming a first power supply path for supplying power at both ends between the first and second connection terminals, A second power supply path for performing one-end power supply is formed between the third connection terminal and the ground, and the first
The relay is arranged such that its drive part is disposed in the first power supply path and its switch part is arranged in the second power supply path, and the switch part disconnects the third connection terminal from the ground when the relay is deenergized;
It is equipped with something that is grounded when the relay is energized.

[Industrial Application Field] The present invention relates to a power supply line switching circuit for an underwater branching device in a submarine cable communication system in which a submarine cable is branched underwater and communication is performed between three or more landing stations, and this power supply line switching circuit. The present invention relates to a power supply method using .

In a submarine cable communication system using an optical submarine cable or the like, repeaters are attached to the submarine cable at intervals, and the repeaters are supplied with DC constant current power via a power supply line in the submarine cable. When laying a submarine cable, it is necessary to confirm whether the above-mentioned submarine cable power supply path is properly laid during or after the installation, and a DC insulation resistance test is used for this purpose. Therefore, a feed line switching circuit for an underwater branching device used in a submarine cable communication system is required to have a configuration suitable for this DC insulation resistance test.

[Prior Art] FIG. 12 shows a schematic configuration of an underwater branching device. As shown in the figure, the underwater branching device BU mainly consists of an optical fiber circuit 1 and a power supply circuit 2. The optical fiber circuit 1 is coupled to an optical fiber transmission line 3 in an optical submarine cable, and the power supply circuit 2 is connected to an optical fiber transmission line 3 in an optical submarine cable. It is connected to the power supply path 4. This underwater branching device BU accommodates three optical submarine cables, thereby making it possible to branch to three landing stations A, B, and C.

As shown in Fig. 13, optical fiber circuits include: ■Optical fiber branch circuit, ■Optical repeater circuit + optical fiber branch circuit, ■Optical fiber branch/switch circuit, ■Optical repeater circuit +
Combinations such as optical fiber branching/switching circuits, (1) optical repeater circuits + multiplex conversion circuits, (2) optical repeater circuits + multiplex conversion circuits + optical fiber switching circuits are possible.

There are two methods of supplying power to optical submarine cable repeaters using such underwater branching equipment: a single-end power supply method in which power is supplied from only one landing station, and a double-end power supply method in which power is supplied between two landing stations. There is. The single-end power supply method is a method in which the submarine cable power supply path from the landing station is grounded underwater at the power supply circuit of the underwater branching device, and an independent power feeding path is formed between the landing station and the underwater branching device to supply power. On the other hand, the double-end power supply method connects the power supply lines of submarine cables from two landing stations using the power supply circuit of the underwater branching device without being grounded underwater, and forms an independent power supply line between the two landing stations. This is a method of supplying power.

FIG. 14 shows a conventional example of a power feeding system in a submarine cable communication system. In this power supply method, each landing station A
% All the power supply lines of the submarine cables from B and C are grounded underwater at the underwater branch unit BU, and independent power supply lines are formed between each landing station A, B, C and the underwater branch unit BU, and each landing station One-end power is supplied from stations A, B, and C independently.

FIG. 15 shows another conventional example of the power feeding system. In this power supply method, the power supply path of the submarine cable from landing stations A and B is connected at the underwater branch unit BU without being grounded underwater, and power is supplied at both ends between landing stations A and B. The power supply path of the submarine cable from C is connected to the underwater earth in the underwater branching device BU, and power is supplied from one end of the cable from the landing station C.

[Problem to be Solved by the Invention] In a submarine cable communication system, when laying a submarine cable, it is necessary to inspect whether the power supply line of the submarine cable is properly laid during or after laying. For this inspection, it is sufficient to perform a DC insulation resistance test on the power supply path of the submarine cable and check whether there is a ground fault in the submarine cable. There is a problem in that the above-mentioned DC insulation resistance test cannot be carried out if one end of the cable is grounded underwater. Therefore, as a power supply circuit for the underwater branch device,
It is necessary to have a system that can insulate all submarine cable power supply lines from seawater when no power is being supplied.

The present invention has been made in view of the above points, and its purpose is to provide a power supply line switching circuit for an underwater branching device that can insulate the power supply lines of all submarine cables from seawater when no power is being supplied, and the same. The purpose of the present invention is to provide a power supply method using.

[Means to solve the problem] FIG. 1 is a diagram explaining the principle of the present invention.

A power supply line switching circuit for an underwater branching device according to the present invention has, as a first form, first, second, and third connection terminals 101, 102, and 103 connected to a power supply line of a submarine cable; A first power supply path 104 for supplying power at both ends is formed between the third connection terminal 101 and the second connection terminal 102, and the third connection terminal 1
A second power supply line 10 for supplying power at one end between 03 and ground.
5, the first relay 106 has its driving part 106L disposed in the first power supply path 104, and its switch part 106C in the second power supply path 105, and the switch part 106C is disposed in the relay deenergization state. The third connection terminal 103 is disconnected from the ground when the relay is energized, and is grounded when the relay is energized.

Further, as a second form of the power supply line switching circuit for an underwater branching device according to the present invention, in addition to the power supply line switching circuit of the first form described above, a second relay 107 is further provided, and the drive unit 1 of the second relay 107 is further provided.
07L is placed in the ground electrical path between the third connection terminal 103 and the ground, and its switch portion 107C is connected to the first relay 10.
The switch section 106C is connected in parallel with the switch section 106C of No. 6 to form a self-holding circuit of a grounding electrical path.

Further, the power feeding method for a submarine cable communication system according to the present invention is a submarine cable communication system in which a submarine cable is branched by an underwater branching device to connect three or more landing stations. During operation, after carrying out both-end power feeding between the landing stations connected to the first and second connection terminals 1゜1.102 of the feed line switching circuit, the third connection is made. A power supply path is formed by supplying power at one end from a landing station connected to the terminal 103.

In addition, the power supply method for a submarine cable communication system according to the present invention provides a power supply path switching circuit in a submarine cable communication system in which a submarine cable is branched by a plurality of underwater branching devices to connect four or more landing stations. The first mentioned above as
Alternatively, a second form is used, in which the first power feed paths 104 of the power feed path switching circuits of a plurality of underwater branching devices are connected in series via submarine cables to form a main power feed path, and both ends of this main power feed path are After performing power feeding at both ends between the landing stations, a power feeding path is formed by performing power feeding at one end from each landing station connected to the third connection terminal 103 of each power feeding path switching circuit.

Furthermore, the power feeding method for a submarine cable communication system according to the present invention is a method for switching power supply paths in a submarine cable communication system in which a submarine cable is branched by a plurality of underwater branching devices to connect four or more landing stations. The circuit of the above-mentioned first or second form and one of other circuit configurations are used in combination.

[Function] In the power supply path switching circuits of the first and second embodiments described above, when no power is being supplied, the third connection terminal 103 is disconnected from the underwater earth by the switch section 106C of the first relay 106, so that the power supply is not supplied. All feed lines within the line switching circuit are insulated from seawater. Therefore, in a submarine cable communication system using this power supply line switching circuit, it is possible to perform a DC insulation resistance test of the submarine cable power supply line when no power is being supplied.

As a basic power supply method using the power supply line switching circuit according to the present invention, in a submarine cable communication system in which a submarine cable is branched by an underwater branching device and three or more landing stations are connected, the power supply line is Power is supplied at both ends between the landing stations respectively connected to the first and second connection terminals 101.1゜2 of the switching circuit, thereby energizing the first relay 106 and switching the switch section 106C to the third connection terminal 10
3 is grounded underwater. After that, the third connection terminal 10
A power supply path is formed by supplying power at one end from a landing station connected to 3.

In order to supply power using the power supply line switching circuit of the present invention in a submarine cable communication system in which a submarine cable is branched by a plurality of underwater branching devices to connect four or more landing stations, the power supply line of the plurality of underwater branching devices is used. The first feeder line 104 of the switching circuit is connected in series via a bottom cable to form the main feeder line, and power is fed at both ends between the landing stations at both ends of the main feeder line to connect the first feeder line 104 of each feeder line switching circuit in series. 1 relay 106 is energized and the third connection terminal 103 is grounded by the switch section 106C, and then one end power is supplied from the landing station connected to the third connection terminal 103 of each power supply path switching circuit. By doing this, a power supply path is formed.

In addition, in a submarine cable communication system in which a submarine cable is branched by a plurality of underwater branching devices to connect four or more landing stations, the power supply path switching circuit may be of the first or second form described above, or It can also be used in combination with other circuit configurations.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 shows a power supply line switching circuit for an underwater branching device as an embodiment of the present invention. This embodiment is applied to an optical submarine cable communication system, and only the power supply switching circuit excluding the optical fiber circuit is shown in the figure.

In FIG. 2, BU is an underwater branching device, and has three connection terminals T1. T2, T3, each connection terminal T1, T2
．． The t48 power equipment of landing stations A, B, and C are connected to T3 via power supply lines of optical submarine cables, respectively.

In the underwater branching device BU, the connection terminals T1 and 12 are connected by a power supply line (2), and this power supply line I is insulated from the underwater earth. This power supply path I has a relay RLI.
A drive coil is inserted therein, and the connection terminal T3 is connected to the sea earth through the power supply line (2) via the meter contact r121 of this relay RLI. As this relay RLI, a high voltage relay such as a vacuum relay is used.

Here, between the two stations connected to the connection terminals T1 and T2 mentioned above (
That is, between the landing station A and the landing station 8), power is supplied at both ends, and the landing station C, which is connected to the remaining connection terminal T3, is supplied with power at one end.

In this example circuit, when no power is being supplied, the make contact rβ1 of the relay RLI is open as shown in Figure 2, so the power supply path of each submarine cable is insulated from seawater in the underwater branch device Therefore, a DC insulation resistance test can be performed.

Each landing station A, B,
A method for supplying power from C to an optical submarine cable will be described below with reference to FIG.

To begin operation, first set up landing station A and landing station 8.
Start power supply at both ends between the two ends. This energizes the relay RLI on the power feed path (2), closes its relay contact rI21, and connects the connection terminal T3 (therefore, the power feed path of the optical submarine cable from the landing station C) to earth under the sea. After this, landing station C
From there, one-end power is supplied using the underwater ground of the underwater branch unit BU.

The power supply stop procedure is to stop power supply at one end of landing station C, and then stop power supply at both ends of landing station A and landing station B.

A feed line switching circuit as another embodiment of the present invention is shown in FIG. The power supply line switching circuit of the above-mentioned embodiment is configured to switch the power supply line between landing stations A and B during operation if a disconnection failure occurs, or if the power supply stop procedure is incorrectly performed and the power supply line is switched off before the power supply to landing station C is stopped. If power supply between stations A and B is stopped, relay RLI
is deenergized and its make contact rβ1 is released, so
The submarine cable power supply line on the landing station C side that is in operation is released during constant current power supply. If the power supply line is opened during constant current power supply in this way, a high voltage will be generated in the power supply line, which may cause damage to equipment such as optical repeaters. The embodiment shown in FIG. 4 solves this problem.

The difference between the embodiment circuit in FIG. 4 and the embodiment circuit in FIG. 2 is as follows.
The drive coil of relay RL2 is inserted into the power supply line ■ on the landing station C side, and its break contact rI22 is connected to relay RL.
This point is connected in parallel to the make contact rffl of I. This break contact ri22 functions to form a self-holding circuit for relay RL2.

As is clear from FIG. 4, in this embodiment circuit, all the power feed paths of the optical submarine cables are insulated from seawater when no power is being supplied, and therefore, a DC insulation resistance test is possible.

The power supply start procedure for this embodiment circuit is as shown in FIG. 5. First, power is supplied at both ends between landing stations A and B to start up. This energizes relay RLI and relay contact r
β1 is closed, and as a result, the optical submarine cable power supply path from the landing station C is grounded under the sea, making it possible to supply power from the landing station C.

After this, as shown in FIG. 6, one-sided power supply is started from the landing station C. This energizes relay RL2 and closes its break contact rβ2. As a result, as long as the power supply current is flowing through the power supply path on the landing station C side, the ground path Regardless of whether it is off or not, it will be self-maintained by relay RL2.

Therefore, as shown in FIG. 7, each landing station A, B,
Even if a failure occurs in the power supply path between landing stations A and B during operation of C and the power supply is cut off, contact rβ of relay RLI
Even though L is opened, the power supply line on the landing station C side will not be opened (therefore, there is no risk of high voltage occurring in the power supply line).

As the power supply stop procedure, after the power supply to the landing station C is stopped, the power supply to the landing stations A and B is stopped.

A power supply path switching circuit as still another embodiment of the present invention is provided in the eighth embodiment.
As shown in the figure. This example circuit is for a case where five optical submarine cables are housed in an underwater branching device, and in addition to the circuit shown in the example circuit shown in FIG. ■It has.

Figure 9 shows a power supply system in a submarine cable communication system that connects four landing stations A, B, C, and 0 using two underwater branching devices having the power supply line switching circuit of the embodiment in Figure 4. shown. In this power supply system, each underwater branch unit BU
The power supply lines I of the power supply line switching circuits of I and BU2 are connected by submarine cables, and this route is used as a power supply line at both ends between landing stations A and 8. Optical submarine cables to landing stations C and D are branched, and each of these landing stations C and D is supplied with power at one end.

The power supply setting procedure for operation of the system shown in Figure 9 is to first supply power at both ends between landing stations A and 8, then energize the relays on both ends of the power supply route, and connect the landing stations C and D side to the power supply side. Undersea grounding is performed at the underwater branching devices BtJl and BU2, and then power is supplied from each landing station C and D at one end.

In such a power supply system, branching to even more landing stations is possible by further increasing the number of underwater branching devices.

Fig. 10 shows the power supply path switching circuit of the embodiment shown in Fig. 4 and the power supply system of other configurations in a submarine cable communication system that connects four landing stations A, B, C, and D using two underwater branching devices. A power feeding system is shown in which a power feeding path is configured by combining a path switching circuit. In Figure 1O, the underwater branch unit BUI
The feed line switching circuit shown in FIG. 4 is that of the embodiment shown in FIG.

On the other hand, the power supply switching circuit of the underwater branching device BtJ2 has a conventionally known circuit configuration, and this power supply path switching circuit is described in, for example, Japanese Patent Laid-Open No. 1-200832.

The power supply line switching circuit of this underwater branching device BU2 is connected between, for example, connection terminals T21 and 722 (or between connection terminals T21 and 722).
3) and relay RL11 (or RL2
2), thereby closing the relay contact rβ11 (or r1222) and grounding all the power supply lines underwater.

By combining the power supply line switching circuits of different types of underwater branching devices as in the system shown in Figure 10, it becomes possible to utilize the remaining submarine cable even if a failure occurs in the power supply line of the submarine cable.

The power supply system in Figure 11 is also a combination of different types of power supply line switching circuits for the same reason as above, and in the figure, the power supply line switching circuit of the underwater branch unit BUI is that of the embodiment in Figure 4; The power supply line switching circuit of the underwater branching device BU2 has a conventionally known circuit configuration as described in, for example, Japanese Unexamined Patent Publication No. 189025/1983.

The power supply path switching circuit of this underwater branching device BU2 performs power feeding at both ends between the submarine cables connected to the connection terminals T21 and 722 (or between the submarine cables connected to the connection terminals T21 and 723), thereby relay RLII (or RL22) and its contact rI211 (or rβ22) connects the remaining connection terminal T23 (or T2
2) The submarine cable feed line connected to 2) is grounded under the sea and power is supplied at one end. In addition, relays RL33 and RL4
Reference numeral 4 denotes a self-holding relay for the one-end power supply path.

In the above embodiment, a mechanical contact relay such as a vacuum relay was used as the relay of the underwater branching device, but the present invention is of course not limited to this, and a non-contact relay such as a solid state relay may be used. It may be something. In this case, a semiconductor switch is used instead of a switching contact or a make/break switching contact.

[Advantageous Effects of the Invention 1] As explained above, according to the present invention, the power supply line in the underwater branching device is insulated from seawater in the unpowered state, so that the DC insulation resistance test of the power supply line of the submarine cable communication system is not possible. You will be able to do this.

In addition, in a system using the feed line switching circuit of the present invention, the double-end feed line and the single-end feed line are completely separated, so there is no need for a special current control circuit for reversing the feed polarity in the landing station's power feed device. The power supply procedure is also simple.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention. FIG. 2 is a diagram showing a power supply path switching circuit of an underwater branching device as an embodiment of the present invention. 3 is an explanatory diagram of the operation of the embodiment device, FIG. 4 is a diagram showing a power supply line switching circuit of an underwater branching device as another embodiment of the present invention, and FIGS. 5 to 7 are diagrams illustrating the embodiment of FIG. 4. An explanatory diagram of the operation of the circuit. FIG. 8 is a diagram showing a power supply switching circuit as still another embodiment of the present invention, and FIG. 9 is a diagram showing a case where the power supply line switching circuit of the present invention is applied to a submarine cable communication system using two underwater branching devices. Figures 10 and 11 show a power supply system in which a combination of the power supply switching circuit of the present invention and a conventionally known power supply switching circuit is installed in a submarine cable communication system using two underwater branching devices. FIG. 12 is a diagram showing a schematic configuration of an underwater branching device. FIG. 13 is a diagram showing various configurations of an optical fiber circuit, and FIGS. 14 and 15 are diagrams each explaining a conventional power feeding system. In the figure, BU, BUI, BU2...undersea branching device RL1. R.L.
2, RLI I, RL22, RL33, RL44 - Relay TI% T2, T3... Connection terminals A, B, C, D, E... Landing station RFP... Relay

Claims (1)

[Claims] 1. First, second, third connected to the power supply line of the submarine cable
a first power supply path (104) for supplying power at both ends between the first and second connection terminals (101, 102); A second power supply path (105) for supplying power at one end is formed between the connection terminal (103) of the first relay (106) and the ground;
L) is arranged in the first power supply path (104), and its switch section (106C) is arranged in the second power supply path (105), and the switch section (106C) is arranged in the third power supply path when the relay is de-energized. A power supply path switching circuit for an underwater branch device, which is equipped with a connection terminal (103) that is disconnected from the ground and grounded when the relay is energized. 2. The second relay (107), which has a drive section (1
07L) is arranged in a grounding electrical path between the third connection terminal (103) and the ground, and its switch section (107C) is connected in parallel with the switch section (106C) of the first relay (106). A power supply path switching circuit for an underwater branching device, further comprising a circuit for forming a self-holding circuit for the grounding electrical path. 3. In a power supply method in a submarine cable communication system in which a submarine cable is branched by an underwater branching device to connect three or more landing stations, the power supply line switching circuit according to claim 1 or 2 is used, and when in operation, the The first and second connection terminals of the power supply path switching circuit (
101, 102), and then one-end power is supplied from the landing station connected to the third connection terminal (103) to form a power supply path. How to power cable communication systems. 4. In a power supply method in a submarine cable communication system in which a submarine cable is branched by a plurality of underwater branching devices to connect four or more landing stations, the power supply path switching circuit according to claim 1 or 2 is used, and a plurality of The first power supply line of the power supply line switching circuit of the underwater branching device (
104) are connected in series via a submarine cable to form the main feed line, and after performing power feeding at both ends between the landing stations at both ends of this main feed line, connect to the third connection terminal of each feed line switching circuit. A power supply method for a submarine cable communication system in which a power supply path is formed by supplying power from one end of each landing station. 5. In a power supply method in a submarine cable communication system in which a submarine cable is branched by a plurality of underwater branching devices to connect four or more landing stations, the power supply path switching circuit according to claim 1 or 2;
A power supply method for submarine cable communication systems that is used in combination with other circuit configurations.