JPH05327561A - Feeding path switching circuit - Google Patents

Abstract

PURPOSE:To easily confirm whether or not a newly laid and branch-connected cable is normally laid to restore a communication among the residual cables even when a fault occurs on any cable connected with a underwater diverging device, and to constitute a feeding path without any problem even when the plural diverging devices are used, in an optical underwater communication system equipped with the underwater diverging device. CONSTITUTION:A relay 1 RL1 which is operated by fed currents is provided between a cable 11 at a terminal station A side, and a cable 12 at a terminal station B side of an underwater diverging device 10, and a relay contact r11 of the relay 1 is provided between a cable 13 at a terminal station C side and a submarine ground so that the contact is closed when a feed is operated from the terminal station A to the terminal station B, and when the feed is interrupted, and so that the contact is opened when the feed is operated from the terminal station B to the terminal station A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical submarine cable communication system, and more particularly to a submarine communication system for branching an optical submarine cable in the sea using a submarine branching device to carry out communication between a plurality of landing stations. The present invention relates to a power supply path switching circuit of a branch device.

In recent years, communication systems using submarine cables have been increasing due to increasing communication demand not only internationally but also domestically. Also, not only between two points, but also communication between points exceeding three points by branching a transmission line is increasing.

However, the submarine cable has an order of magnitude higher in laying / repairing than land-based equipment, and has a fate that the repairing requires a long time. Therefore, while higher reliability is required, when a cable failure occurs, there is a demand for maximum communication in a section where no failure has occurred.

[0004]

2. Description of the Related Art An example of a conventional feed line switching circuit and a feed line switching method for an undersea branching device will be described with reference to FIGS.

FIG. 4 is a diagram showing the concept of the connection of the power feeding lines of the undersea branching device and the concept of the optical fiber cable transmission line in the underwater branching device, and FIG. 5 shows an example of the power feeding line switching circuit of the conventional underwater branching device. It is a figure. Further, FIG. 6 is an explanatory diagram of a connection state at the time of starting power feeding in a communication system having a plurality of conventional undersea branching devices, and FIG. 7 is a connection state before switching power feeding in a communication system having a plurality of conventional undersea branching devices. FIG.

[0006] The underwater branching device 10 is used to branch the communication system operating between the terminal stations A and B and connect it to the terminal station C.
4 to perform branching. However, as shown in FIG. 4 (1), when the undersea branching device 10 is inserted and the cable connection between the terminal station C and the underwater branching device 10 is completed, before power supply switching. Is
The power feeding path on the terminal C side is connected to the conventional power feeding path via a relay or the like not shown.

When power is supplied from the terminal C side, as shown in FIG.
As shown in (2), the power supply path on the terminal C side is disconnected from the conventional power supply path by opening a relay or the like (not shown) and connected to the undersea ground. Then, in this state, the terminal C feeds one end.

The optical fiber cable in the submarine branching device 10 has a terminal C as shown in the example of FIG.
From the terminal station A to the terminal station B. In the example of the power supply path switching circuit of the undersea branching device shown in FIG. 5, first, between the terminal stations A and B, a positive voltage is applied from the terminal station A and a negative voltage is applied from the terminal station B to −.
When the power is supplied with a voltage and a power supply current flows, the relay 1RL1 operates to ground the power supply path on the terminal C side to the undersea ground.

The voltage level supplied from each of the terminal stations A and B is adjusted in advance in accordance with the cable length so that the potential at the relay contact rl1 in the submarine branching device 10 will be approximately 0 V, whereby the relay contact rl1 is adjusted. A surge current is prevented from flowing when rl1 is connected to the undersea ground.

Next, since the relay contact rl1 is connected to the undersea ground, one-sided power supply from the terminal station C becomes possible, and the one-sided power supply is performed with the power supply polarity set to-. In this state, if the power supply line is disconnected on the terminal station B side due to a cable failure due to the ship's anchor, bottom net, etc., the power supply current between terminal station A and terminal station B will be cut off, and relay 1RL1 will be restored. Then
The underwater grounding of the power supply path on the terminal station C side is released, and the power supply path on the terminal station C side and the terminal station A are connected via the relay 2RL2. However, since the terminal station A detects the power supply abnormality and cuts off the power supply, the power supply route on the side of the terminal station C disappears, and normal power supply to the repeater cannot be performed.

In this case, since the optical submarine cable 12 between the faulty terminal station B and the submarine branching device 10 cannot be used, all the terminal stations A, B and C temporarily stop power supply. Then, when the power supply polarity is set to + from the terminal station A and the power supply polarity is set to − from the terminal station C, the relay 2RL2 operates when the power is supplied, and the relay contact rl2 of the relay 2 is connected to the terminal station B and the undersea branching device. The power supply path between 10 is opened and the terminal station B side is connected to the undersea ground.

Alternatively, a relay 3RL3 is further provided between the relay contact rl1 of the relay 1 and the undersea ground so that the power feeding path on the terminal C side can be held by itself when the power is fed from the terminal C, and the power feeding on the terminal B side is performed. There is also a method of avoiding the abrasion of the relay contact rl1 by avoiding the stop of the one-end power supply from the terminal station C due to the restoration of the relay contact rl1 of the relay 1 due to the disconnection of the path.

At present, in the optical submarine cable communication system,
In the case of performing communication between a plurality of terminal stations via the submarine branching device 10, the power feeding path of the submarine branching devices 10, 20, 30 is controlled by the terminal stations A and B serving as main lines. The power supply switching circuit is sequentially switched to set a power supply path to supply power.

Further, the power supply switching circuit which is currently put into practical use is, for example, as in the example of the undersea branching device shown in FIG. 6, the terminal stations C, D, E and the underwater branching devices 10, 20. , 3
At the initial stage after the installation of the submarine cable between 0 and before feeding power, the power feeding paths on the terminal C, terminal D, and terminal E side are connected to the undersea ground in the respective submarine branching devices 10, 20, 30. And are in an insulated state.

The cable 13 on the side of the terminal C is insulated from the undersea ground when there is no power supply. It is necessary to check whether the cable 13 is properly laid, whether there is a cable landslide, or the like. This is because the power supply between the terminal stations A and B is stopped and the power supply voltage is applied from the terminal station C.

When it is confirmed that the cable 13 is laid correctly, as shown in the example of three branches shown in FIG. 6, (1),
In the order of (2) and (3), the power feeding path is set from the undersea branching device 10.

(1) Here, the relay 1RL1 of the power feeding path switching circuit of the undersea branching device 10 is set to operate with a feeding current of, for example, 100 mA.
Adjust the power supply voltage of terminal stations A and B so that the voltage applied to 0 becomes 0V, which is the same as the undersea ground, and then supply a 100 mA power supply current between terminal stations A and B to operate relay 1RL1. Then, the terminal C side is fed with one end.

(2) Next, in the setting of the power feeding path of the undersea branching device 20, the relay 1RL1 of the undersea branching device 20 is set to operate with a feeding current of, for example, 200 mA. After adjusting the power supply voltage of both end stations so that the voltage becomes 0 V, which is the same as the undersea earth, supply a 100 mA power supply current between both end stations and relay 1RL1
Is operated to feed one end of the terminal D side.

(3) Next, in setting the power feeding path of the undersea branching device 30, the relay 1RL1 of the undersea branching device 30 is set to operate with a feeding current of, for example, 300 mA, and similarly, the underwater branching device 30 is operated. After adjusting the power supply voltage of both end stations so that the voltage applied to the same will be 0 V, which is the same as the undersea earth, feed a 300 mA power supply current between both end stations and relay 1
The RL1 is operated, and the terminal E side is supplied with one end.

It is to be noted that the power supply voltage of the undersea branching device for which the power supply path is to be set is set to 0 V, which is the same as the undersea ground, because the relay contact rl1 connecting the power supply path on each of the terminal stations B, C and D to the undersea ground is used. This is to prevent so-called hot switching, in which the voltage between the contacts is set to 0 to protect the contacts from wear.

In this way, one-end power feeding of each terminal station B, C, D is sequentially performed.

[0022]

However, in the circuit shown in FIG. 5, when a cable for branching is laid and completed as a system, it is necessary to confirm whether the laid cable is normal or not. The power supply between the terminal stations A and B is stopped, a voltage is applied from the terminal station C to the power supply path, and whether or not an abnormal current flows and whether or not there is an abnormal voltage drop are measured to determine the quality.

Further, conventionally, in the initial state of laying a cable for branching and connecting a number of submarine branching devices in a communication system to feed power, when switching the feed line from the state where each cable is insulated from the submarine ground. In order to protect the switching device and prevent the surge voltage, it was necessary to adjust the potentials of both end stations and set the potential of the submarine branching device that sets the power feeding path to 0 potential and switch in order.

Therefore, the method of switching the power feeding path becomes complicated,
In addition, there is a problem in that the number of submarine branching devices is limited to about 3 from the viewpoint of the moving current of the relay. Further, in the case of the conventional example of FIG. 5, when a failure occurs in the cable 12 on the terminal station B side, the cable on the terminal station B side is disconnected, and communication is performed by forming a power feeding path between the terminal stations A and C. Although it has been described that there is a problem, if there is a failure in the cable 11 on the terminal station A side, there is also a problem that a power feeding path cannot be formed between the terminal stations C and B.

As a method for solving such a problem, a method has been considered in which the power feeding path is connected to the underwater ground in the undersea branching device 10, but in the unlikely event that a failure occurs in another cable. In the two submarine branching devices, the power feed line must be connected to the underwater ground, making it impossible to feed power to the repeater.

Further, as shown in FIG. 7, when two or more submarine branching devices are included in the communication system, before the power feeding path is set,
When a landfall fault occurs in a cable of a communication system, the location of the fault is fixed to 0 potential. Also, the power supply switching order of the undersea branching device is that the operating currents are a, b, and
Since it is determined to be c, it is necessary to set the power feeding path while the high voltage is applied to the undersea branching device 10, and it is difficult to insert a plurality of underwater branching devices capable of switching the power feeding path in the communication system. There was a problem to say.

The present invention solves the above problems, and it is possible to easily confirm whether or not a newly laid and branch-connected cable is normally laid, and any cable connected to an undersea branching device is connected. Even if a cable failure occurs, communication can be restored between the remaining cables, and even if multiple branching devices are used in the communication system, the power feeding line can be configured without problems. An object is to provide a switching circuit.

[0028]

FIG. 1 shows a principle configuration of the present invention. In the figure, the same reference numerals as those in FIG. 5 indicate the same elements.

According to the present invention, the first and second cables 11 and 12 fed from both end stations of the terminal station A and the terminal station B, and one end of the third cable 13 toward the terminal station C are connected to the undersea ground. Then, in the submarine branching device power feeding path switching circuit that enables one-side power feeding whose polarity can be switched to the terminal station C, between the first cable 11 and the second cable 12 A relay 1RL1 that operates is provided.

Further, when power is supplied from the terminal station A to the terminal station B and when the power supply is cut off, the relay cable rl1 connects between the third cable 13 and the undersea ground, and the terminal is connected. When power is supplied from the station B to the terminal station A, the relay contact rl1 opens the connection between the third cable 13 and the undersea ground to achieve the object.

Further, in the submarine branching device, one of the optical fiber cables for transmitting an optical signal from the terminal station C to the terminal station A and the terminal station B is controlled to switch the power feeding path from the terminal station C. An optical demultiplexer 15 that extracts a signal, a switching control circuit 16 that receives the power feeding path switching control signal and drives the switches SW1 to SW5, and the terminal station A and the terminal station A are controlled by the switching control circuit 16. The power supply path between the terminal station B and the terminal station B is opened, the underwater ground of the relay contact rl1 of the relay 1 is opened, and the power supply path between the terminal station C and the terminal station A or the terminal station B is opened. You may make it provide the five switches SW1-SW5 for forming.

[0032]

According to the present invention, in the power feeding path switching circuit of the undersea branching device 10, the first cable 11 and the second cable 1 are provided.
2, a relay 1RL1 that operates by a power supply current is provided, and a relay contact rl1 of the relay 1 is provided between the third cable 13 and the undersea ground to set the terminal station A to a positive polarity voltage, When power is supplied from the terminal A to the terminal B as a negative polarity voltage to the terminal B and when the power supply is cut off, the relay contact rl1 is closed and power is supplied from the terminal B to the terminal A. Make the relay contact rl1 open. By doing so, a cable for confirming whether the laying of the cable 13 is normal in an insulated state in which the cable 13 from the terminal C is opened from the undersea ground before the terminal C feeds one end. The capacity of 13 can be easily measured.

Further, the optical demultiplexer 15 provided on at least one of the optical fiber cables 14 of the optical submarine cables for transmitting the optical signal from the terminal station C causes the terminal station C to operate.
By extracting the optical signal on which the power supply path switching control signal from is superimposed, extracting the power supply path switching control signal in the switching control circuit 16, and driving the switches SW1 to SW5,
During normal operation, the power supply path between the terminal stations A and B can be closed, and the power supply path on the side of the terminal station C can be separated from the power supply path between the terminal stations A and B and connected to the undersea ground.

When a cable failure occurs on the terminal A side or the terminal B side, the cable 1 on the side where the failure has occurred
1 and 12 are separated from the power feeding path by the operation of the switches SW1 and SW2, and are connected to the undersea ground. Then, after connecting the power supply line on the terminal station C side and the power supply line on the side where no failure has occurred by operating the switches SW3 and SW4, the switch SW5 is operated to connect the power supply line on the terminal station C side to the subsea ground. Release from. In this way, the power feeding path of the terminal station C and the terminal station B or the power feeding path of the terminal station A can be connected.

[0035]

EXAMPLES Next, examples will be described with reference to FIGS. FIG. 1 is a diagram showing a first embodiment according to the present invention, FIG. 2 is a diagram showing a second embodiment according to the present invention, and FIG. 3 is a cable fault at the terminal station A side in the embodiment of FIG. This is to show the operation in the case of occurrence of.

In the figure, the same reference numerals as those in FIG.
1, 2, 3 are terminal stations, 10 are underwater branching devices, 11, 12,
Reference numeral 13 is a first, second, and third cable (power supply path), 14 is an optical fiber cable, 15 is an optical demultiplexer, and 16 is a switching control circuit. Further, RL1 and RL are relays operated by a power supply current, rl1 and RL are relay contacts, and SW1 to SW5 are switches operated by the switching control circuit 16.

FIG. 1 shows a first embodiment of a power supply path switching circuit according to the present invention. In the figure, a relay 1RL1 is inserted between the cable 11 on the terminal station A side and the cable 12 on the terminal station B side of the undersea branching device 10, and a relay contact rl1 is placed between the cable 13 on the terminal station C side and the undersea ground. Connecting. The relay contact rl1 is closed when power is not supplied between the terminal stations A and B, and is closed when power is supplied from the terminal station A to the terminal station B when the terminal station A is set to + voltage and the terminal station B is set to −voltage, and the terminal station B is closed. Connect so as to open when power is supplied from the terminal station to the terminal station A.

When the cable 13 on the terminal C side is laid and connected to the undersea branching device 10, the cable 13
Whether or not the installation is normal is confirmed by supplying power from the terminal station B to the terminal station A, operating the relay 1RL1, and disconnecting the cable 13 on the terminal station C side from the undersea ground by the relay contact rl1. The capacity is measured from the station C and it is judged whether or not the cable laying is normal.

Further, in the case of the second embodiment of FIG. 2, the control of the power feeding path switching circuit is performed by using an optical signal, and the terminal station C
The optical signal from the optical demultiplexer 15 inserted in the optical fiber cable 14 that is transmitted from the terminal station A to the terminal station A or B, and newly operates by using the power supply current of the cable 13 on the terminal station C side as a power source. Input to the switching control circuit 16 provided,
The switching control circuit 16 converts the optical signal into an electrical signal and extracts the power supply path switching control signal. The switches SW1 to SW5 are switched and controlled by the power feeding path switching control signal. The positions of the switches SW1 to SW5 shown in FIG. 2 indicate that the power is supplied at the terminal station A side + voltage, the terminal station B side−voltage, and the one terminal power supply at the terminal station C side.

In the switching control by the optical signal, when confirming the laying state of the cable 13 before feeding to the power feeding path on the terminal C side, the switching control by the optical signal is the same as in the case of the first embodiment of FIG. By the method, the relay contact rl1 is operated by feeding power from the terminal station B to the terminal station A, the cable 13 is insulated from the undersea ground, the capacity is measured, and it is judged whether the cable laying is normal or not.

After that, power is supplied from the terminal station A to the direction between the terminal stations B, and one terminal is also supplied from the terminal station C. Next, an example of a case where a ground failure occurs in the cable 11 on the terminal A side in this power feeding state will be described with reference to FIG. (1) First, the power supply between the terminal stations A and B is cut off. It should be noted that one-end power feeding from the terminal station C is not affected and the power feeding is continued.

Further, even if there are other subsea branching devices 20 and 30 in this communication system as shown in FIG. 7, there is no effect on one-side power feeding of these submarine branching devices 20 and 30. (2) The power supply path switching control signal is superposed on the optical signal from the terminal station C and sent to the optical fiber cable 14, and the power supply path switching control signal is extracted by the switching control circuit 16 via the optical demultiplexer 15 and the switch SW1 Is operated to disconnect the cable 11 from the undersea branching device 10 and connect it to the undersea ground. (3) The switch SW4 is operated to connect the cable 12 on the terminal station B side and the cable 13 on the terminal station C side,
A power supply path between C is formed.

Here, at the time of the following (5), in order to maintain this state even if the one-end power supply from the terminal station C is cut off,
It is necessary to use operation holding type switches for the switches SW3 and SW4. (4) The switch SW5 is operated to disconnect the power feeding path on the terminal C side from the undersea ground.

Here, the power supply path on the side of the terminal C is disconnected from the subsea ground by the switch control circuit 16 and the switch SW5 which are powered by the power supplied by itself, and the power supply current is immediately cut off. Requires the use of delayed action switches. (5) One-sided power feeding from the terminal station C is cut off. (6) Power is supplied between the terminal stations B and C by setting the terminal station C to a positive voltage and the terminal station B to a negative voltage.

By the above series of operations, the terminal station A side is disconnected,
In addition, it is possible to supply power between the terminal stations B and C in a state where the undersea earth of the undersea branching device 10 is also disconnected. Furthermore, JP-A-6
As filed in “Optical Fiber Switching Circuit” (Fujitsu Limited) published in 3-6926, an optical fiber between the terminal stations A and C and between the terminal stations A and B in the undersea branching device 10. If an optical switch is provided on the cable and an optical switch driving function is added to the switching control circuit 16, the terminal C superimposes the communication path switching control signal on the optical signal and sends it out, thereby effectively utilizing the optical transmission path. It will be available.

Note that an example of a case where a ground failure occurs in the cable 12 on the side of the terminal station B can be easily inferred from the above description, so the description thereof will be omitted. Further, in the example of the three-branched communication system in FIG. 7, for example, a cable is first provided between the terminal station A and the Bu1 (submarine branching device) 10 and between the terminal station B and the Bu3 (submarine branching device) 30. Even if a failure occurs, the power supply path can be formed with the terminal C as a + voltage and the terminal E as a − voltage.

[0047]

As described above, in the case of the conventional communication system having a plurality of subsea branching devices, it is necessary to increase the operating current of the relays of each subsea branching device in order, which results in a large number of subsea devices. Although it was not possible to connect the branching device, according to the present invention, since a relay having the same operating current can be used, it is possible to connect a large number of submarine branching devices.

Also, in the confirmation after laying and connecting the cable for branch connection, although the communication line is temporarily stopped, the cable for branch connection can be easily connected by stopping the power supply between the terminal stations AB and changing the power supply polarity. Confirmation is possible.

Further, by using an optical signal for switching the power feeding path of the submarine branching device, it is possible to switch the power feeding path without flowing the power feeding current, hot switching of the relay contact is prevented, and wear of the contact is prevented. This makes it possible to greatly contribute to extending the service life of the undersea branching device.

Further, in the power feeding path switching setting in the undersea branching device after the cable failure occurs, the power feeding path is not connected to the underwater ground, so that even if another cable failure occurs, the remaining normal cable remains. There are many effects that it is possible to enable communication in the section.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a power supply path switching circuit according to the present invention.

FIG. 2 is a diagram showing a second embodiment of the power supply path switching circuit according to the present invention.

FIG. 3 is a diagram showing an operation of a power feeding path switching circuit at the time of a cable failure on the terminal station A side in the second embodiment of FIG.

FIG. 4 is a conceptual diagram of a power feed line and an optical fiber transmission line of an undersea branching device.

FIG. 5 is a diagram showing an example of a power feeding path switching circuit of a conventional undersea branching device.

FIG. 6 is an explanatory diagram of a connection state at the time of starting power supply in an optical submarine communication system having a plurality of conventional undersea branching devices.

FIG. 7 is an explanatory diagram of a connection state before switching power supply in an optical submarine communication system having a plurality of conventional undersea branching devices.

[Explanation of reference numerals] 1, 2, 3, 4, 5 Terminal station 10, 20, 30 Submarine branching device 11, 12, 13 Cable (feeding path) 14 Optical fiber cable 15 Optical demultiplexer 16 Switching control circuit RL1, 2, 3 relays rl1, 12, 13 relay contacts SW1-5 switches

Claims (2)

[Claims] 1. An undersea earth is provided at one end of a first cable, a second cable (11, 12) fed from both end stations of the terminal station A and the terminal station B, and a third cable (13) going to the terminal station C. And a second cable (1) in a power line switching circuit for a submarine branching device, which is connected to
2) and the relay 1 (RL
1) is provided, and when power is fed from the terminal station A to the terminal station B and when power is cut off, a relay contact (rl1) is used to connect the third cable (13) and the undersea ground. Then, when power is supplied from the terminal station B to the terminal station A, the relay contact (rl1) of the relay 1 (RL1) opens the third cable (13) and the undersea ground. A power supply line switching circuit characterized in that 2. The submarine branching device according to claim 1, wherein the terminal station C and the terminal stations A and B are connected to each other, and optical fiber cables for transmission and reception are provided. An optical demultiplexer (15) for extracting the power feeding path switching control signal from the terminal station C and the power feeding path switching control signal are received by any one of the transmission optical fiber cables from the terminal station C. , Switches (SW1 to S
The switching control circuit (16) for driving W5) and the control from the switching control circuit (16) open the power feeding path between the terminal station A and the terminal station B, and the relay 1 (RL).
Five switches (SW1 to SW) for opening the undersea earth of the relay contact (rl1) of 1) to form a power feeding path between the terminal station C and the terminal station A or the terminal station B.
5) A power supply path switching circuit comprising: