JPH04336718A - Submarine branching device - Google Patents

Abstract

PURPOSE:To attain power feeding between two normal remaining branches even when a fault takes place on any branch in a submarine branching device where three terminal stations are connected in a star form. CONSTITUTION:In an optical communication system where a submarine branching point, 1st land station 11-3rd land station 13 on land are connected in a star form via a submarine cable including a feeder and an optical fiber, branches of the 1st station 11 and the 2nd station 12 have a relay point and the branch of the 3rd station 13 has no relay point, the submarine branching device 40 is provided with a relay contact section 42 provided in the branch of the 2nd station 12 and connecting selectively the 2nd station 12 to a branching point 41 or one of a submarine earth electrode 38 and with a driving section 43 provided in the branch of the 3rd station 13 and driving the contact section 42 so as to connect the 2nd station 12 to the submarine earth electrode 38 when a current flows between the 1st station 11 and the 3rd station 13 and connect in other cases the 2nd station 12 to the branching point 41.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater branching device in an optical communication system using a submarine cable relay system.

0002

[Prior Art] In an optical communication system using a submarine cable relay method, terminal stations on land are connected by communication optical fibers in a submarine cable laid on the ocean floor. Three or more terminal stations are connected by an underwater branching device. There is also a system in which the optical fibers are connected in a star shape and the optical fibers are branched at this underwater branching device so that one terminal station can communicate with two or more terminal stations, or the terminal stations that can communicate with each other can be switched.

By the way, in an optical communication system using a submarine cable relay system, a submarine repeater becomes necessary as the distance between terminal stations increases. This submarine repeater is supplied with DC power, usually a constant DC current, from a power supply device at a terminal station on land via a communication optical fiber and a power supply line provided in the submarine cable. For multiple submarine repeaters on one power line, two-end power supply is available, in which a power supply device with different polarity is connected to both ends of the power line, and a power supply device is connected only at one end of the power line, and the other end is grounded. Both single-end power supply and single-end power supply are possible. However, in the case of a system that has an underwater branching device like the one mentioned above, the power supply line is branched within the underwater branching device, so it is necessary to devise ways to supply constant DC current to all submarine repeaters. .

FIG. 6 is an explanatory diagram showing the configuration of an optical communication system including a conventional underwater branching device. In this system, three terminal stations, a first station 11, a second station 12, and a third station 13, are connected in a star shape by a submarine cable and an underwater branching device 30. The first
Between station 11 and second station 12, and between first station 11 and third station 1
3 are connected by communication optical fibers 14 and 15 in submarine cables, respectively. In addition, one end is connected to the power supply devices 21, 22, 23 of each terminal station 11, 12, 13, and the other end of the power supply lines 16, 17, 18, which are provided in the submarine cable together with the communication optical fiber, It is connected to terminals 31A, 31B, and 31C of branching device 30.

Optical submarine repeaters 24 and 25 are interposed in the submarine cable between the first station 11 and the underwater branching device 30 and the submarine cable between the second station 12 and the underwater branching device 30, respectively. . A non-repeater line is provided between the third station 13 and the underwater branching device 30.

[0006] Inside the underwater branching device 30, an optical fiber 14 is installed.
, 15 are inserted. Furthermore, a first relay and a second relay are provided in the underwater branching device 30. The movable contact 32c of the contact part 32 of the first relay is the terminal 31
The movable contact 33c of the contact portion 33 of the second relay is connected to the feeder line 17 via the terminal 31C.
8 is connected. The fixed contact 32a of the contact section 32 of the first relay is connected to the terminal 3 via the drive section 36 of the second relay.
1A, and the fixed contact 33a of the contact section 33 of the second relay is connected to the terminal 31A via the drive section 34 of the first relay.
and both are connected to the power supply line 16 via this terminal 31A. Note that each of the drive sections 34 and 36 has a coil, and when current flows through this coil, the contact sections 32 and 33 are driven. Further, the fixed contact 32b of the contact portion 32 of the first relay and the contact portion 3 of the second relay
The fixed contact 33b of No. 3 is connected to the underwater earth electrode 38 via the terminal 31D. In addition, the drive section 3 of each relay
Diodes 35 and 37 are connected in parallel to 4 and 36, respectively. The diodes 35 and 37 serve as current bypasses so that the relay drive units 34 and 36 do not operate against reverse current.

Next, the operation of the conventional underwater branching device 30 configured as described above will be explained. The state of the relay contact portion in FIG. 6 indicates a non-power-supplied state. Here, the first station 1
When both-end power feeding is performed between the power feeding device 21 of the first station 11 and the power feeding device 23 of the third station 13, the current sent from the power feeding device 21 of the first station 11 is transmitted to the optical submarine repeater 24 and the underwater branching device 3.
The power passes through the relay drive unit 34 and relay contact unit 33 in the third station 13 and reaches the power supply device 23 of the third station 13. Relay drive section 34
When a current flows through, the relay contact section 32 driven by the relay drive section 34 is switched so that the movable contact 32c and the fixed contact 32b are connected. When one-end power supply is executed from the second station 12 in this state, the power supply current flows from the underwater earth electrode 38 attached to the underwater branching device 30, passes through the relay contact part 32 and the optical submarine repeater 25,
The power supply device 22 of the second station 12 is reached. In other words, one-end power supply can be performed using the underwater earth as the return path. As a result of the above, power supply has been completed to both the optical submarine repeaters 24 and 25, and the optical fiber 14,
15 between the first station 11 and the second station 12 and between the first station 11 and the third station 13.

By the same procedure, power is supplied at both ends between the power supply device 21 of the first station 11 and the power supply device 22 of the second station 12, the relay drive section 36 is operated, and the relay contact section 33
Accordingly, it is also possible to connect the power supply path of the power supply device 23 of the third station 13 to the underwater earth electrode 38 to enable one-end power supply from the third station 13 side. However, in this case, the third terminal 1
Since the section from 3 to the underwater branching device 30 is a non-repeater line, it does not have much meaning.

[0009]

[Problem to be solved by the invention] By the way, the first station 11
If a failure occurs in the section from 1 to 30, there is a desire to ensure communication between the remaining second station 12 and third station 13. As shown in FIG. 6, if there is a non-repeater line between the third station 13 and the underwater branching device 30, the current flowing in the non-repeater line may flow in either direction. Therefore, when the above-mentioned failure occurs, either the polarity of the power supply device 23 of the third station 13 is changed from negative to positive and power is supplied from both ends between the third station 13 and the second station 12, or the third station It is conceivable that the 13 side is grounded and one-end power is supplied from the second station side. However, in the conventional underwater branching device 30, if the polarity of the power supply device 23 of the third station 13 is changed from negative to positive and power is supplied at both ends between the third station 13 and the second station 12, the relay is driven. section 36 operates, the relay contact section 33 switches so that the movable contact 33c and the fixed contact 33b are connected, and the power supply path between the third station 13 and the second station 12 is cut off. Such power supply cannot be implemented. Therefore, it is not possible to provide a communication path using an optical fiber between the second station 12 and the third station 13. This also applies when there is a ground fault on the third station 13 side.

[0010] Therefore, an object of the present invention is to enable, in an underwater branching device that connects three terminal stations in a star shape, even if a fault occurs in any branch, power can be supplied between the two remaining normal branches. An object of the present invention is to provide an underwater branching device that can maintain communication between these two branching branches.

[0011]

[Means for Solving the Problems] An underwater branching device according to the invention described in claim 1 provides for connecting one branch on the seabed via a submarine cable having a power supply line and a communication optical fiber for supplying DC power to a submarine repeater. The point and the first to third terminal stations on land are connected in a star shape, and the branch connecting the first terminal station and the branch point and the branch branch connecting the second terminal station and the branch point are relayed, A power feed line between the second terminal station and the branch point that connects each branch branch in a submarine cable relay type optical communication system in which the branch branch connecting the third terminal station and the branch point is non-repeater. A switch section that is installed only in the line of the feeder line between the third terminal station and the branch point, and a switch section that selectively connects the second terminal station to one of the branch point and the underwater earth. When a current is flowing in a predetermined direction between the first terminal station and the third terminal station, the second terminal station is connected to the underwater earth; otherwise, the second terminal station is connected to the underwater earth. and a driving means for driving the switch section so as to connect it to the branch point.

[0012] This underwater branching device has a first terminal station and a third terminal station.
When the two-end power supply is carried out between the terminal station and the second terminal station, the driving means is operated and the second terminal station is connected to the underwater earth, allowing one-end electric power feeding between the second terminal station and the underwater earth. If a failure occurs in the branch connecting the second terminal station and the branch point, power can be supplied at both ends between the first terminal station and the third terminal station, as in the case described above. If a failure occurs in the branch that connects the third terminal station and the branch point, no current will flow between the first terminal station and the third terminal station, so the current will not flow between the first terminal station and the third terminal station. station and second
is connected to the terminal station, and power can be supplied at both ends between the two. In addition, if a fault occurs in the branch connecting the first terminal station and the branch point, changing the polarity of the power supply device of the third terminal station changes the direction of the current flowing through the drive unit, which connects the branch point to the branch point. The second terminal station and the third terminal station are connected through the terminal station, and power can be supplied from both ends between the second terminal station and the third terminal station.

[0013] In the underwater branching device according to the invention set forth in claim 2, in the invention set forth in claim 2, the driving means connects the switch section to connect the second terminal station to the underwater ground when current is flowing. The device includes a drive section that drives the drive section, and a diode that is connected in parallel to the drive section and bypasses current in one direction.

[0014] In this underwater branching device, the first terminal station and the third
When power is supplied from both ends to the terminal station of In this case, if the polarity of the power supply device of the third terminal station is changed, the current flows through the diode, the drive section does not operate, and the second terminal station and the third terminal station are connected via the branch point. Ru.

[0015]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 5 relate to one embodiment of the present invention.

FIG. 1 is an explanatory diagram showing the configuration of an optical communication system including an underwater branching device of this embodiment. In this optical communication system, three terminal stations, a first station 11, a second station 12, and a third station 13, are connected in a star shape by a submarine cable and an underwater branching device 40. Via this underwater branching device 40, submarine cables are connected between the first station 11 and the second station 12, between the first station 11 and the third station 13, and between the second station 12 and the third station 13. Communication optical fibers 51, 52, 5 within
Connected by 3. In addition, one end is each terminal station 11,
The other ends of the power supply lines 16, 17, 18 connected to the power supply devices 21, 22, 23 of 12, 13 and provided in the submarine cable together with the communication optical fiber are connected to the underwater branching device 4, respectively.
0 terminals 31A, 31B, and 31C.

Optical submarine repeaters 24 and 25 are interposed in the submarine cable between the first station 11 and the underwater branching device 40 and the submarine cable between the second station 12 and the underwater branching device 40, respectively. . A non-repeater line is provided between the third station 13 and the underwater branching device 40.

[0018] Inside the underwater branching device 40, an optical fiber 51 is installed.
, 52 and 53 are inserted, and this underwater branching device 4
Two optical fibers are extended from zero to each terminal station. Moreover, one relay contact section 42 and one relay drive section 43 that drives this contact section 42 are provided in the underwater branching device 40. Movable contact 42 of contact part 42
c is connected to the feeder line 17 via the terminal 31B, and the fixed contact 42a is connected to the branch point 41 of the feeder line, and the fixed contact 42a is connected to the branch point 41 of the feeder line.
2b is connected to an underwater earth electrode 38 attached to the underwater branching device 40 via a terminal 31D. The aforementioned branch point 41 is connected to the power supply line 16 via the terminal 31A. Further, the relay drive section 43 is interposed between the branch point 41 and the terminal 31C. This drive section 43 has a coil, and when current flows through this coil, it drives the contact section 42 to connect the movable contact 42c and the fixed contact 42b, and when no current flows through the coil, the movable contact 42 of the contact section 42
c and the fixed contact 42a are connected. Further, a diode 44 is connected in parallel to the drive section 43. This diode 44 has an anode connected to the terminal 31.
C side, the cathode is connected to the branch point 41 side, and plays the role of a current bypass so that the drive unit 43 does not operate with respect to the current flowing from the third station 13 toward the branch point 41. .

Note that in normal times, as shown in FIG.
The power supply device 21 of the station 11 has a positive pole, and the power supply device 22 of the second station 12 and the power supply device 23 of the third station 13 have a negative pole.

Next, the operation of this embodiment will be explained with reference to FIGS. 2 to 5. 2 to 5 are explanatory diagrams each showing the power supply method in this embodiment.

In FIG. 1, the power supply device 21 of the first station 11
When power is supplied at both ends between the branch point 41 and the power supply device 23 of the third station 13, the relay drive unit 43 disposed on the power supply path in the underwater branch device 40 of the non-relay branch connecting the branch point 41 and the third station 13 operates, and the relay contact section 42 driven by this relay drive section 43 has a movable contact 42c and a fixed contact 42.
b is switched so that it is connected. Therefore, the second station 1
One end of the power supply path on the underwater branching device 40 side of the branch including the optical submarine repeater 25 connecting the underwater branching device 2 and the underwater branching device 40 is connected to the underwater ground electrode 38 . As a result, power can be supplied at both ends between the first station 11 and the third station 13, and power can be supplied at one end between the second station 11 and the underwater earth electrode 38. In this way, when the optical submarine repeaters 24 and 25 are activated by power supply, the optical fibers 51, 52, 53 interconnecting the first station 11, second station 12, and third station 13 are , all become communicable. FIG. 2 shows the state of the relay contact portion 42 and the power supply current at this time. In this figure, I1 is the power supply current between the first station 11 and the third station 13, and I2 is the power supply current between the second station 11 and the third station 13.
2 and the underwater earth electrode 38.

Next, in the optical communication system of this embodiment, when a fault occurs in each branch and the power supply current cannot flow to the faulty branch, the remaining non-faulty branch A power supply current is passed between two branch branches,
A method for securing a communication path within the branch will be explained.

FIG. 3 shows a case where a fault has occurred in the branch between the underwater branch device 40 and the power supply device 22 of the second station 12, and reference numeral F in the figure indicates the fault point. In this case, as in normal times, both-end power feeding may be performed between the power feeding device 21 of the first station 11 and the power feeding device 23 of the third station 13. This enables communication between the first station 11 and the third station 13 via the optical fiber 52. At this time, the relay drive section 43 operates, the relay contact section 42 switches so that the movable contact 42c and the fixed contact 42b are connected, and the branch branch connected to the power supply device 23 of the third station 13 is placed underwater. Although the earth electrode 38 is grounded under the sea, it has no meaning in terms of securing a communication path between the first station 11 and the third station 13.

FIG. 4 shows a case where a failure occurs in the branch between the underwater branch device 40 and the power supply device 23 of the third station 13. In this case, since no current flows through the relay drive unit 43, it is sufficient to carry out both-end power feeding between the first station 11 and the second station 12 without considering the relay operation. This enables communication between the first station 11 and the second station 12 via the optical fiber 51. In addition, in this figure, I3
indicates the power supply current between the first station 11 and the second station 12.

FIG. 5 shows a case where a fault occurs in the branch between the underwater branch device 40 and the power supply device 21 of the first station 11. In this case, the polarity of the power feeding device 23 of the third station 13 may be changed from negative to positive, and power may be fed from both ends between the third station 13 and the second station 12. At this time, the feeding current I4 flows through the diode 44 provided in parallel to the coil of the relay drive section 43, so the relay drive section 43 does not operate. Therefore, in the relay contact section 42, the movable contact 42c remains connected to the fixed contact 42a without switching to the fixed contact 42b side, and the third station 13 and the second station 1
The power supply path between 2 and 2 is not interrupted. This enables communication between the third station 13 and the second station 12 via the optical fiber 53. Note that since there is a non-repeater line between the third station 13 and the underwater branching device 40, there is no problem even if the direction of the current flowing in this non-repeater line changes.

As described above, according to this embodiment, even if a fault occurs in any branch, power can be supplied at both ends between the remaining two normal branches. Moreover, the configuration of the underwater branching device 40 is simplified. Note that if a fault occurs in the branch between the underwater branch device 40 and the power supply device 21 of the first station 11, instead of changing the polarity of the power supply device 23 of the third station 13, It is also possible to perform one-end power supply from the second station 12 side with a ground fault.

[0027]

[Effects of the Invention] As explained above, according to the present invention, among the three branch branches connected in a star shape to the underwater branch device,
Even if a fault occurs in any branch, power can be supplied between the two remaining normal branches, and communication between these two branches can be maintained.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the configuration of an optical communication system including an underwater branching device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the state of the relay contact section and power supply current of the underwater branching device of FIG. 1 when there is no fault;

[Figure 3] Figure 1 when a failure occurs in the branch on the second station side
FIG. 2 is an explanatory diagram showing the state of the relay contact part and the power supply current of the underwater branching device.

[Figure 4] Figure 1 when a failure occurs in the branch on the third station side
FIG. 2 is an explanatory diagram showing the state of the relay contact part and the power supply current of the underwater branching device.

[Figure 5] Figure 1 when a failure occurs in the branch on the first station side
FIG. 2 is an explanatory diagram showing the state of the relay contact part and the power supply current of the underwater branching device.

FIG. 6 is an explanatory diagram showing the configuration of an optical communication system including a conventional underwater branching device.

[Explanation of symbols]

11 1st station 12 Second station 13 3rd station 21, 22, 23 Power supply device 24, 25 Optical submarine repeater 38 Undersea earth electrode 40 Undersea branching device 41 Turning point 42 Relay contact part 43 Relay drive part 44 Diode

Claims (2)

[Claims] Claim 1: A submarine cable is connected between one branch point on the ocean floor and the first to third terminal stations on land via a submarine cable that has a feeder line that supplies DC power to a submarine repeater and an optical fiber for communication. The branch branch that connects the first terminal station and the branch point and the branch branch that connects the second terminal station and the branch point are connected in the form of a relay,
An underwater branching device that connects each branch in a submarine cable relay type optical communication system in which a branch connecting a third terminal station and a branch point is non-repeater, A switch part that is provided only in the line of the feeder line between the branch point and selectively connects the second terminal station to one of the branch point and the underwater earth, and a switch part of the feed line between the third terminal station and the branch point. It is installed only within the line, and when a current in a predetermined direction is flowing between the first terminal station and the third terminal station, the second terminal station is connected to the underwater earth, and at other times, the second terminal station is connected to the underwater earth. and a driving means for driving the switch section so as to connect the terminal station to the branch point. 2. The drive means is connected in parallel to the drive unit and a drive unit that drives the switch unit so as to connect the second terminal station to underwater earth when current is flowing. 2. The underwater branching device according to claim 1, further comprising a diode for bypassing current in the direction.