JPH07118669B2 - Power supply path switching circuit for undersea branching device and power supply method for undersea cable communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] A power feeding path switching circuit of an undersea branching device in an undersea cable communication system for branching a submarine cable in the sea to perform communication between three or more landing stations, and this power feeding path switching circuit. Regarding a power supply method using a power supply line switching circuit capable of performing a DC insulation resistance test by insulating the power supply lines of all submarine cables from seawater when there is no power supply, and a power supply method using the same. And having a first, second, and third connection terminal connected to the power supply path of the submarine cable, and forming a first power supply path for supplying power at both ends between the first and second connection terminals, A second power feeding path is formed between the third connection terminal and the ground for single-end power feeding, and the first power feeding path and the second power feeding path are always insulated from each other. And the drive section is connected to the first power supply line, The switch section is arranged in the second power supply path, and the switch section is provided with the third connection terminal that is disconnected from the ground when the relay is deenergized and that is installed when the relay is energized.

[Field of Industrial Application] The present invention relates to a power feeding path switching circuit of an undersea branching device in an undersea cable communication system for branching a submarine cable in the sea to perform communication between three or more landing stations, and this power feeding path switching circuit. The present invention relates to a power feeding 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 repeater is fed with a constant DC current through a feeding path in the submarine cable. When laying a submarine cable, it is necessary to confirm whether or not the above-mentioned submarine cable power supply line is normally laid during or after the laying, and a DC insulation resistance test is used for this. Therefore, a power supply path switching circuit for an undersea 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 undersea branching device. As shown in the figure, the submarine branching device BU mainly comprises an optical fiber circuit 1 and a power feeding circuit 2, the optical fiber circuit 1 is coupled to an optical fiber transmission line 3 in the optical submarine cable, and the feeding circuit 2 is in the optical submarine cable. Is connected to the power feeding path 4. This submarine branching device BU accommodates three optical submarine cables,
This makes it possible to branch to three landing stations A, B, and C.

As the optical fiber circuit 1, as shown in FIG.
Optical fiber branch circuit, optical repeater circuit + optical fiber branch circuit, optical fiber branch / switch circuit, optical repeater circuit + optical fiber branch / switch circuit, optical repeater circuit + multiplex conversion circuit, optical repeater circuit + multiplex conversion circuit + optical fiber Combinations such as switching circuits are possible.

As a method of feeding power to a repeater of an optical submarine cable using such an underwater branching device, a single-end feeding method in which power is fed only from one landing station and a both-end feeding method in which power is fed between two landing stations There is. The single-end feeding method is a method in which the submarine cable feed line from the landing station is grounded in the sea in the feed circuit of the undersea branching device, and an independent feeding line is formed between the landing station and the underwater branching device to feed power. On the other hand, in the double-end feeding method, the feeding lines of the submarine cables from the two landing stations are connected by the feeding circuit of the undersea branching device without being grounded in the sea, and independent feeding lines are formed between the two landing stations. This is a method of supplying power.

FIG. 14 shows a conventional example of a power feeding method in a submarine cable communication system. In this power supply system, each landing station A,
All submarine cable feeders from B and C are submerged
BU is grounded in the sea, and independent power feed lines are formed between each landing station A, B, C and submarine branching device BU, and each landing station A, B, C independently feeds one end. .

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

[Problems to be Solved by the Invention] In a submarine cable communication system, when laying a submarine cable, it is necessary to inspect whether or not the feeder line of the submarine cable is normally laid during or after the laying. For this inspection, a DC insulation resistance test of the power supply line of the submarine cable should be performed to check whether the submarine cable has a ground fault in the middle. If one end of the above is grounded in the sea, there is a problem that the above DC insulation resistance test cannot be performed. Therefore, as a power supply circuit for the submarine branching device,
When there is no power supply, it is necessary to be able to insulate the power supply paths of all submarine cables from seawater.

The present invention has been made in view of the above points, and an object thereof is to provide a power supply path switching circuit of an undersea branching device capable of insulating the power supply paths of all submarine cables from seawater when there is no power supply, and the circuit. It is to provide a power feeding method using the.

[Means for Solving the Problems] FIG. 1 is a diagram illustrating the principle of the present invention.

As a first form, a power feeding path switching circuit for an undersea branching device according to the present invention has first, second, and third connection terminals 101, 102, 103 that are connected to a power feeding path of a submarine cable. And the second
Forming a first feeding path 104 for feeding both ends between the connecting terminals 101 and 102, and forming a second feeding path 105 for feeding one end between the third connecting terminal 103 and the ground; The first power feeding path 104 and the second power feeding path 105 are always insulated from each other, and the first relay 106 has a driving unit 106L connected to the first power feeding path 104 and a switch unit 106C. Is provided in the second power feeding unit 105, and the switch unit 106C is provided with a unit that disconnects the third connection terminal 103 from the ground when the relay is deenergized and grounds when the relay is energized.

Further, the power feeding path switching circuit of the underwater branching device according to the present invention is, as a second mode, further a second relay 107 and its driving unit 107L in addition to the power feeding path switching circuit of the first mode.
Is arranged in the ground electric path between the third connection terminal 103 and the ground, and its switch portion 107C is connected in parallel with the switch portion 106C of the first relay 106 to form a self-holding circuit of the ground electric path. Be prepared.

Further, the power feeding method of the submarine cable communication system according to the present invention is the above-mentioned first or first power feeding path switching circuit in a submarine cable communication system in which three or more landing stations are connected by branching a submarine cable with an undersea branching device. The second type is used, and at the time of operation, both ends are fed between the landing stations respectively connected to the first and second connection terminals 101 and 102 of the feed line switching circuit, and then the third connection terminal 103 is used. The landing station connected to the power supply terminal forms a power supply path by supplying power from one end.

In another embodiment, the power feeding method for a submarine cable communication system according to the present invention is a power feeding path switching circuit in a submarine cable communication system in which a submarine cable is branched by a plurality of submarine branching devices to connect four or more landing stations. As above mentioned first
Alternatively, the second mode is used, and the first power feeding path 104 of the power feeding path switching circuits of a plurality of submarine branching devices is connected in series via a submarine cable to form a main power feeding path, and both ends of this main power feeding path are connected. After feeding both ends between the landing stations, one-end feeding is performed from each landing station connected to the third connection terminal 103 of each feeding path switching circuit to form a feeding line.

Further, the power feeding method for a submarine cable communication system according to the present invention is, in yet another form, a submarine cable communication system in which four or more landing stations are connected by branching a submarine cable with a plurality of submarine branching devices to switch the power feeding path. As the circuit, a circuit having the above-described first or second form and a circuit having another circuit configuration other than that are used in combination.

[Operation] In the power supply path switching circuits of the first and second modes described above, the third connection terminal 103 is the switch portion of the first relay 106 when no power is supplied.
It is separated from the undersea ground by 106C, so that all the power supply lines in the power supply line switching circuit are insulated from seawater. Therefore, in a submarine cable communication system using this power feeding path switching circuit, it is possible to perform a DC insulation resistance test of the submarine cable power feeding path when there is no power feeding.

As a basic power feeding method using the power feeding path switching circuit according to the present invention, in the submarine cable communication system in which three or more landing stations are connected by branching an undersea cable with an undersea branching device, the power feeding path is used during operation. Both ends are fed between the landing stations respectively connected to the first and second connection terminals 101 and 102 of the switching circuit, thereby energizing the first relay 106 and making a third connection by the switch section 106C. Ground terminal 103 in the sea. After that, the landing station connected to the third connection terminal 103 performs one-end power feeding to form a power feeding path.

In a submarine cable communication system in which a submarine cable is branched by a plurality of submarine branching devices to connect four or more landing stations, the power feeding path switching circuit of the present invention is used to feed electric power. The first feed line 104 of the switching circuit is connected in series via a submarine cable to form a main feed line, and both ends are fed between landing stations at both ends of the main feed line to make the first feed line of each feed line switching circuit. Energize the relay 106 of the switch section 1
The third connecting terminal 103 is grounded by 06C, and thereafter, one end is fed from each landing station connected to the third connecting terminal 103 of each feeding path switching circuit to form a feeding path.

Further, in a submarine cable communication system in which a submarine cable is branched by a plurality of submarine branching devices to connect four or more landing stations, in addition to the above-mentioned first or second form as a power feeding path switching circuit, other than that It can also be used in combination with the one having the circuit configuration of.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

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

In FIG. 2, BU is an undersea branching device, which has three connection terminals T1, T2, T3, and each connection terminal T1, T2, T3 is respectively connected to the landing station A via the power supply line of the optical submarine cable. , B, C
The power supply device of is connected.

In the underwater branching device BU, the connection terminals T1 and T2 are connected by a power feeding path I, which is insulated from the underwater ground. The drive coil of the relay RL1 is inserted in the power supply line I, and the connection terminal T3 is grounded in the sea by the power supply line II via the make contact rl1 of the relay RL1. A high voltage relay such as a vacuum relay is used as the relay RL1.

Here, both ends are fed between two stations connected to the above-mentioned connection terminals T1 and T2 (that is, between landing stations A and B), and one landing station is connected to the landing station C connected to the remaining connection terminal T3. To do so.

In this embodiment circuit, the make contact rl1 of the relay RL1 is open as shown in FIG. 2 when no power is supplied, so that the power feeding path of each submarine cable is insulated from seawater in the undersea branching device. Therefore, the DC insulation resistance test can be carried out.

Each landing station A, B, using the feed line switching circuit of this embodiment,
The method of feeding power from C to the optical submarine cable is described below with reference to FIG.

When starting operation, first landing station A and landing station B
Power supply at both ends is started in between. This energizes the relay RL1 in the power supply line I, closes the relay contact rl1 and connects the connection terminal T3 (thus the power supply line of the optical submarine cable from the landing station C).
Is grounded in the sea. After this, one-sided power feeding is performed from the landing station C using the underwater ground of the underwater branching device BU. In the power supply stopping procedure, the power supply at one end of the landing station C is stopped, and then the power supply at both ends of the landing station A and the landing station B is stopped.

A feed line switching circuit as another embodiment of the present invention is shown in FIG. The feed line switching circuit of the above-described embodiment is used when the feed line between the landing stations A and B, which is in operation, has an open fault, or when the feed stop procedure is incorrect and the landing station C is landed before the feed is stopped. When the power supply between stations A and B is stopped, the relay RL1 is deenergized and its make contact rl1 is opened, so that the submarine cable power supply line on the operating landing station C side is under constant current power supply. It will be released. When the power supply path is released during constant current power supply, a high voltage is generated in the power supply path, which may cause damage to the optical repeater and other devices. The embodiment of FIG. 4 solves this problem.

The circuit of FIG. 4 differs from the circuit of FIG. 2 in that
The drive coil of the relay RL2 is inserted in the power supply path II on the side of the landing station C, and its break contact rl2 is connected in parallel to the relay RL1 make contact rl1. The break contact rl2 has a function of forming a self-holding circuit of the relay RL2.

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

As shown in FIG. 5, the power supply start procedure of this embodiment circuit starts by supplying power to both ends between the landing stations A and B. As a result, the relay RL1 is energized and the relay contact rl1 is closed, and as a result, the optical submarine cable power supply line from the landing station C is grounded in the sea, and power can be supplied from the landing station C. There is.

After this, as shown in FIG. 6, the landing station C starts single-end power feeding. This energizes relay RL2 and closes its break contact rl2. As a result, the grounding path II that grounds the power supply line on the landing station C side at the underwater branching device
Is as long as the feeding current is flowing in the feeding line on the landing station C side,
It is self-held by the relay RL2 regardless of the on / off state of the make contact rl1 of the relay RL1.

Therefore, as shown in FIG. 7, each landing station A, B,
Even when the power supply is cut off due to a failure in the power supply line between the landing stations A and B during operation of C, the contact il1 of the relay RL1 opens The power supply line is not opened, and therefore there is no possibility of generating a high voltage in the power supply line.

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

An eighth embodiment of a power feeding path switching circuit as still another embodiment of the present invention
As shown in the figure. The circuit of this embodiment is one in which five optical submarine cables are accommodated in the undersea branching device, and in addition to the circuit of the embodiment of FIG. 4 described above, a feed line for feeding both ends between the connection terminals T4 and T5. I have III.

FIG. 9 shows a power feeding system in a submarine cable communication system in which four landing stations A, B, C and D are connected by using two undersea branching devices having the power feeding path switching circuit of the embodiment of FIG. Shown. In this power supply system, each submarine branching device BU
1. The feed line I of the feed line switching circuit of BU2 is connected to each other by a submarine cable, and this route is used as the feed line at both ends between the landing stations A and B. Optical submarine cables to stations C and D are branched,
These landing stations C and D respectively perform single-end power feeding.

As the power supply setting procedure in the operation of the system shown in FIG. 9, first, power is supplied to both ends between the landing stations A and B, thereby energizing the relays on the power supply lines at both ends to connect the power supply lines to the landing stations C and D. The submarine branching devices BU1 and BU2 are grounded under the sea, and then the landing stations C and D respectively feed one end.

In such a power feeding system, it is possible to branch to more landing stations by further increasing the number of submarine branching devices.

FIG. 10 shows a power supply line switching circuit of the embodiment of FIG. 4 and power supply of another configuration in a submarine cable communication system connecting four landing stations A, B, C and D by two undersea branching devices. A power supply system in which a power supply path is configured by combining with a path switching circuit is shown. In FIG. 10, the power supply path switching circuit of the undersea branching device BU1 is that of the embodiment of FIG.

On the other hand, the power supply switching circuit of the undersea branching device BU2 has a conventionally known circuit configuration, and this power supply path switching circuit is described in, for example, Japanese Unexamined Patent Publication No. 1-200832. The power supply path switching circuit of this underwater branching device BU2 is, for example, connection terminals T21 and T2.
Power is supplied between 2 (or between connection terminals T21 and T23) to energize relay RL11 (or RL22), which in turn causes relay contacts.
The rl11 (or rl22) is closed and all the power feed lines are grounded in the sea.

By combining the feed line switching circuits of different types of submarine branching devices as in the system shown in Fig. 10, the remaining submarine cables can be utilized even if a fault occurs in the feed line of the submarine cable.

The power supply system of FIG. 11 is also a combination of power supply path switching circuits of different types for the same reason as described above. In the figure, the power supply path switching circuit of the submarine branching device BU1 is that of the embodiment shown in FIG. The power supply path switching circuit of the underwater branching device BU2 has a conventionally known circuit configuration described in, for example, Japanese Patent Laid-Open No. 63-189025.

The power supply path switching circuit of the submarine branching device BU2 performs, for example, both-end power supply between the submarine cables connected to the connection terminals T21 and T22 (or between the submarine cables connected to the connection terminals T21 and T23), and thereby the relay RL11. (Or RL22) is energized and its contact point rl11 (or rl22) causes the remaining connection terminal
The submarine cable feed line connected to T23 (or T22) is grounded in the sea to feed one end. Relay RL3
3, RL44 is a self-holding relay for the single-ended power supply line.

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

〔The invention's effect〕

As described above, according to the present invention, in the unpowered state, the power supply path in the undersea branching device is insulated from seawater, so that the DC insulation resistance test of the power supply path of the undersea cable communication system can be performed. Like

Further, in the system using the power feeding path switching circuit of the present invention, since the both end power feeding path and the one end power feeding path are completely separated, a special current control circuit for performing power feeding polarity reversal or the like is not required in the power feeding device of the landing station. The power supply procedure is also simple.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the principle of the present invention, FIG. 2 is a diagram showing a power supply path switching circuit of an undersea branching device as one embodiment of the present invention, FIG. 3 is an operation diagram for the device of the embodiment, and FIG. FIG. 7 is a diagram showing a power supply path switching circuit of an undersea branching device as another embodiment of the present invention, FIGS. 5 to 7 are operation explanatory diagrams of the embodiment circuit of FIG. 4, and FIG. The figure which shows the electric power feeding switching circuit as another Example, FIG. 9 is a figure which shows the electric power feeding system when the electric power feeding path switching circuit of this invention is applied to the submarine cable communication system using two undersea branching devices, FIG. 10 and FIG. 11 each show a power feeding system in which the combination of the power feeding path switching circuit of the present invention and the conventionally known power feeding path switching circuit is applied to an undersea cable communication system using two undersea branching devices. Figure, Figure 12 shows the schematic configuration of the underwater branching device, and Figure 13 shows the optical fiber. Shows various configurations of the circuit, FIG. 14, FIG. 15 is a diagram for explaining a conventional power supply system, respectively. In the figure, BU, BU1, BU2 ... Submarine branching devices RL1, RL2, RL11, RL22, RL33, RL44 ... Relays T1, T2, T3 ... Connection terminals A, B, C, D, E ... Landing station REP …… Repeater

Claims (5)

[Claims] 1. A first, second, and third connection terminals (101, 102, 103) connected to a power feeding path of a submarine cable, and between the first and second connection terminals (101, 102). A first power supply path (104) for supplying power to both ends, and a second power supply path (105) for supplying power to one end between the third connection terminal (103) and the ground, The first power supply path and the second power supply path are always insulated from each other, and the first relay (106) has a drive unit (106L) connected to the first power supply path (104). , The switch section (106
C) is arranged in the second power supply path (105), and the switch section (106C) is provided with a device for disconnecting the third connection terminal (103) from ground when the relay is deenergized and grounding when the relay is energized. Power line switching circuit for undersea branching device. 2. A second relay (107), the drive section (107L) of which is arranged in a ground electric path between the third connection terminal (103) and ground, and the switch section (107C) of which is provided. The power supply path switching circuit of the undersea branching apparatus according to claim 1, further comprising: a circuit connected in parallel with the switch section of the first relay (106) to form a self-holding circuit of the ground electric path. 3. A submarine cable is branched by an undersea branching device to be 3
In the power feeding method of the submarine cable communication system for connecting the landing stations, the power feeding path switching circuit according to claim 1 or 2 is used, and the first and second connection terminals of the power feeding path switching circuit are in operation. Both ends are fed between the landing stations connected to (101, 102) respectively, and then one end is fed from the landing station connected to the third connection terminal (103) to form a feeding line. Power supply method for submarine cable communication system. 4. A power feeding method for a submarine cable communication system in which four or more landing stations are connected by branching a submarine cable with a plurality of submarine branching devices, wherein the feed line switching circuit according to claim 1 or 2 is used. The first power feeding path (104) of the power feeding path switching circuits of a plurality of submarine branching devices is connected in series via a submarine cable as a main power feeding path, and both ends of the landing station at both ends of this main power feeding path are connected. A power feeding method for a submarine cable communication system, wherein a power feeding path is formed by feeding one end from each landing station connected to the third connection terminal of each power feeding path switching circuit after feeding power. 5. A power feeding method of a submarine cable communication system in which a submarine cable is branched by a plurality of submarine branching devices to connect four or more landing stations, wherein the feed line switching circuit is the feed line switching circuit.
A power supply method for a submarine cable communication system, which is used in combination with other circuit configurations.