JPH0376322A - Feeder switching circuit - Google Patents

Abstract

PURPOSE:To repair a faulty part safely by inserting a 2nd relay coil between a relay contact and 1st and 2nd cables and connecting the contact in parallel with a 1st relay contact. CONSTITUTION:When a fault takes place in a submarine cable 11 at an end station A, the direction of the current is inverted by the operation of a switch 25 to energize a relay coil RL 1, whose contact rl1 is closed. As a result, a current flows a path of undersea earth G contact rl1 coil RL2 cable 12 terminal station B power supply 22 to energize a relay coil RL 2, whose contact rl2 is closed. Thus, the cables 12, 13 are energized to attain the communication between terminal stations C and B and the faulty cable 11 is repaired during that time. Similarly, even anywhere of cables is faulty, the faulty location is repaired safely while keeping the operation between cables without any fault.

Description

[Detailed Description of the Invention] [Summary of the Invention] An object of the present invention is to provide a power feed line switching circuit for a submarine transmission system using an underwater branching device, and to enable safe repair of a faulty part. The first terminal is powered at both ends by the terminal station and the second terminal station. One end of a third cable that is inserted into the second cable, branches off from the cable, and goes to the third terminal station is connected to the underwater ground, and the third terminal station is supplied with power at one end with switchable polarity. Furthermore, a relay coil having diodes connected in parallel is inserted into the third cable, and the contacts of the relay are connected to the first cable. Second
In the power supply switching circuit of a submarine transmission system having an underwater branching device connected between the cable and the underwater earth,
A second relay coil is inserted between the relay contact and the fifteenth second cable, and the contact is connected in parallel to the first relay contact.

[Industrial application field]

The present invention relates to a power supply line switching circuit for a submarine transmission system using an underwater branching device.

Optical submarine transmission systems have recently come into use, and if there are three or more landing stations, submarine cables may be shortened by using underwater branching equipment to create a Y-shaped line or the like. Repeaters are inserted at appropriate locations on the submarine cable, and power is supplied to these from the landing station through the submarine cable.

[Conventional technology]

The present inventors have already proposed this kind of underwater branch power supply system (Japanese Patent Laid-Open No. 196126/1983). To explain this overview using Figure 10, A, B, and C are terminal stations (landing stations).
, 1O is an underwater branching device, and 11.12°13 is a submarine cable. This branching device IO connects terminal stations A-C to the seabed.
A Y-shaped line is constructed to connect the terminal stations A, B, and C, and communication between terminal stations A, B, and C is possible. A large number of repeaters R are inserted in the submarine cables 11 to 13 at appropriate intervals, but only one is shown in the figure.

21-23 connect submarine cables 11-13 to these repeaters.
This is a power supply (constant current source) that supplies power through the

(a) shows normal operation (no failure), and as shown in the figure, the switch 15 of the underwater branching device 10 is open, so the cables 11 and 12 are connected to the power supply 21° terminal station A, ．． Power is supplied through the path of terminal station B and power supply 22, and cable 13 is connected to underwater ground G and diode 14. Cable 13. Power is supplied through the route of the terminal station C1 power supply 23, and these two power supply routes are separate and independent. Arrows of power supplies 21 to 23 indicate the power supply direction.

This power feeding system allows for easy multi-branching. That is, when the underwater branching device 10 is inserted into the cables 11 and/or 12, the cable 13 becomes a branch line, and multi-branching in a comb-like shape is possible. Undersea earth G has the problem of galvanic corrosion, but to deal with this, it is better to choose a material.For example, if the earth G is 10, use a titanium alloy, and if the earth G is negative, use beryllium copper.

Cables 11 and 12 are connected in series to which power supply 2 is connected.
1.22 powers both ends. Therefore, if there is a fault in these cables (Cur line), the power supply will be cut off. Figure 10~)
In this case, there is a failure in the cable 12, and if this continues, the power supply to the cables 11 and 12 will be stopped, and communication between the terminal stations A, B, and C will be disabled. In this system, the polarity of the power supply 23 of the terminal station C is reversed by the switch 25 in this case. In this way, a current flows through the path of the power supply 23, the terminal C1 cable 13, the relay coil RL, and the underwater earth G, energizing the relay coil RL and closing its contact 15.

Therefore, a current flows through the path of the power supply 2L terminal station A, the cable 11, the contact 15, and the underwater earth G, and the cable 11 is supplied with power. Of course, the cable 13 is also powered by the above path, thus excluding the faulty cable 12, the other healthy cables 11.1
3 is supplied with power, and communication between terminal stations A and C becomes possible. Note that the direction of the current flowing through the cable is reversed, but the repeater is designed to accommodate this (for example, by taking the current through a full-wave rectifier).

[Problem to be solved by the invention]

In this submarine transmission system, when a submarine cable failure occurs, for example cable 12, the remaining cable 11 is
．． 13 to ensure communication between terminal stations A and C. During this time, it would be desirable to pull up the faulty cable 12 on board and repair it to restore the normal state, but this poses the following problems.

That is, if a fault occurs in the cable 13 during this operation, no current will flow through the cable 13, so the relay coil RL will be deenergized and the contact 15 will open. Therefore, the current flowing through the cable 11 also disappears, but since the power supply 21 is a constant current power supply, it tries to maintain a constant current and the voltage goes up to the limit (even if the voltage between A and 8 is 10KV at all times) high voltage). This high voltage extends to the faulty end of cable 12. Therefore, the work is dangerous and repair work cannot be carried out at this point.

The object of the present invention is to improve these points and to enable safe repair of the faulty part.

[Means to solve the problem]

As shown in FIG. 1, in the present invention, a relay contact RL.

(This corresponds to 15 in Figure 10) and submarine cable 11.
A second relay coil RL2 is inserted between the contacts r1. The first relay coil RLl (this is the first O
Connect in parallel with contact r11 (corresponding to R1 in the figure). The rest is the same as in FIG. 10.

As is the case throughout all figures, parts that are the same as in other figures are given the same reference numerals.

[Effect]

According to this configuration, repair work on the faulty part can be safely performed without fear of coming into contact with high voltage. This will be explained below with reference to FIGS. 2 to 4.

FIG. 2(a) shows a case where a failure occurs on the terminal station A side (submarine cable 1.1 side). In this case, operate the switch 25 to reverse the direction of the current, energize the relay coil RLI, and connect the contacts r1. Close it and it's Undersea Earth G.
, contact rlI, relay coil RL2, cable 12, terminal station 12, and power supply 22.
L2 is energized closing its contact rffi2. The cables 12 and 13 are now supplied with power and communication between the terminal stations C and B becomes possible, and during this time the faulty cable 11 is repaired.

In this state, if a new fault occurs on the terminal B side (cable 12 side) as shown in FIG. 2(b), the cable 12
The current is cut off, relay coil RL2 is deenergized, and contact r
1□ is opened, but there is a healthy cable 13, so contact rE
l remains on, and the submarine cables 11.12 of the 10 underwater branching devices from the faulty part are brought to ground potential by the underwater earth G, so there is no danger in repairing the faulty part.

Furthermore, if a new fault occurs on the terminal C side (cable 13 side) in the state (a) as shown in FIG. 2(C), the current in the cable 13 is cut off, so the relay coil RL1 is deenergized. The contact rl+ is opened, but since the contact r1.2 is closed, the underwater branch device side of the cable 11.12 is kept at ground potential, and no high voltage is applied to the faulty part of the cable 11. In either case, the terminal station side of the faulty section can remove the high voltage q1 by turning off the terminal power supply (21, etc.).
There is no addition.

If a fault occurs in the cable on the terminal station B side, the situation will be as shown in Fig. 3. In this case as well, the current direction is reversed by operating the switch 25, energizing the relay coil RLI and closing the contact rff.
, contact r1. ．． ．． A current is passed through the path of the underwater earth G, energizing the relay coil RL2, and closing the contact rffiz.

This is shown in FIG. 3(a), and communication between A and C is possible.

In this state, as shown in Fig. 3(b), if a new cable fault occurs on the terminal A side cable, relay coil RL2 is deenergized and contact r12 opens, but since contact r11 is closed, the fault The submarine cables 11, 12 on the branch device side are held at ground potential. Furthermore, if a new fault occurs in the terminal C side cable in the state shown in FIG. 3(a) as shown in FIG. 3(C), relay contact r1. opens, but the contact rlz
Since the cable 13 is closed, the branching device side of the cable 13 is at ground potential, and the branching device side of the faulty part of the cable 12 does not become high voltage. In this way, the faulty part can be safely repaired in either case (b) (C:). Terminal C
If a failure occurs in the side cable, the situation will be as shown in Figure 4.

In the case of a failure in the terminal C side cable, the current reversal by the switch 25 is unexpected, and therefore, as shown in FIG.
2. ．． r/! , is open\. Cable 11.1
2 is supplied with power at both ends from a power source of 21.22 V, and communication between A and B is possible.

If a fault occurs in the terminal station A (!! In the case of (b) and (c), the branch device side of the faulty part of cable 13 is grounded with underwater earth G, so repairs can be carried out safely.In addition, in (b) and (c), high voltage is generated at the faulty part of cable 11 and 12. Although there is a danger of
2 (a) and 3 (a).
Repair the faulty part. In addition, Fig. 4(b) (
C) is a diagram showing the possibility of a double failure, and the repair target is first (
a).

Thus, according to the present invention, it is possible to safely repair any faulty portion of a submarine cable.

〔Example〕

FIG. 5 shows an embodiment of the present invention. R is optical submarine cable 1
1, 12, and 13, which are installed in large numbers at appropriate intervals.

) It is better to change the material of the electrode plate depending on whether the ground in i6 is on the + side or one side, but in this system, it can be either + or - depending on the situation. Therefore, as shown in the diagram, connect diodes 16 and 17.
The ground electrode plates G l, G ! It is recommended to connect to Also, if terminal A is also provided with a switch that reverses the current direction, cable 13-
11 can be supplied with power at both ends, and it is possible to reduce the current to the underwater earth G to zero.

Although the underwater branching device IO may have an optical cable switching mechanism, a relay (amplification) function, etc., only the power supply system is shown in the figure.

There is a method of supplying power from the terminal station, for example, supplying 2 amperes from A to the positive terminal, and supplying 1 ampere each from B and C to the negative terminal, but with this, the current flowing through the submarine cable is not uniform, and it changes in the event of a fault. Therefore, supplying power to the repeater is difficult. In this regard, in the system of the present invention, since each terminal station is supplied with I ampere as positive or negative terminal, the current flowing through the cable is uniform, and it is easy to supply power to the repeater.

The startup and disconnection procedures during operation of this system are as shown in Figure 6. As shown in (a), cables 11 and 12 are powered at both ends at terminal stations A and B, and as shown in (b). The cable 13 is powered at one end at the terminal station C.

If there is a cable failure on the terminal A side, the procedure is as shown in Figure 7.

That is, as shown in (a), operate the switch 25 to connect the terminal C.
Reversing the current direction of relay RLI of underwater branching device IO
is energized to close its contact rl.

If you supply power to terminal B in this state, will there be power between G and I3 as well? A flows, and communication between terminal stations B and C becomes possible. In addition, relay RL2 is energized by the current between G and B, and contact rj2z is closed.

If there is a cable failure on the terminal station B side, do as shown in Figure 8.

As shown in (a), switch 25 is also operated to reverse the current direction, energize relay RLI, and contact r1. Close. When power is supplied from terminal A in this state, a current flows between A and G, and communication between A and C becomes possible. Also relay RL
2 is energized and contact r12 closes.

When there is a cable failure on the terminal station C side, the situation will be as shown in Fig. 9.

In other words, cables 11 and 12 are powered at both ends from terminal stations A and B, power supply to cable 13 is stopped, and communication is possible between A and B.
become.

6 to 9 are explanatory diagrams of the operation of FIG. 5 in each case, and FIG. 1O is an explanatory diagram of the conventional example.

In Figure 1, 10 is an underwater branching device, 11 to 13 are cables,
21 to 23 are power supplies, 25 is a changeover switch, G is an underwater ground, and A to C are terminal stations.

〔Effect of the invention〕

As explained above, according to the present invention, even if a fault occurs in any part of the cable of a submarine transmission system using an underwater branching device, the fault point can be repaired while continuing operation in the cable section where there is no fault. Persons repairing the point of failure can safely perform the repair without risking exposure to high voltages.

[Brief explanation of drawings]

Figure 1 is a diagram explaining the principle of the present invention, Figures 2 to 4 are diagrams explaining the operation of Figure 1 in each case,

Claims (1)

[Claims] 1. It is inserted into the first and second cables (11, 12) which are supplied with power at both ends by the first terminal station (A) and the second terminal station (B), and the third cable is branched from the cables. One end of the third cable (13) going to the terminal station (C) is connected to the underwater ground (G) to provide one end power supply with switchable polarity to the third terminal station, and a diode is connected to the third cable. Insert the relay coil (RL1) connected in parallel, and connect the relay's contact (r
In a feed line switching circuit of a submarine transmission system having an underwater branching device (10) in which the relay contact (rl_1) is connected between the first and second cables and the underwater ground, the relay contact (rl_
1) and the first and second cables (11, 12), and insert the second relay coil (RL2) between the contacts (rl
_2) is connected in parallel to a first relay contact (rl_1).