JPH04304716A - Submarine cable system power feeding system - Google Patents

Abstract

PURPOSE:To maintain power feeding at the non-fault side station when a cable is faulty and to keep feeding with only the remaining feeder at the fault of one feeder. CONSTITUTION:This system is provided with first and 2nd constant current feeders 4, 5 provided respectively on 1st and 2nd terminal stations 1, 3 for supplying a DC current, a feeder 8 being a submerine cable connecting between the 1st and 2nd constant current feeders 4, 5 via the feeding load of a submarine repeater 7, a voltage detector 9 detecting the voltage of the feeder 8 at an intermediate station 2 provided on the halfway of the submarine cable and a switch 10 connecting the feeder 8 to ground at the intermediate station 2 when the detection voltage of the voltage detector 9 exceeds a present value.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submarine cable system power supply system, and more particularly to a submarine cable system power supply system when an intermediate station is provided between terminal stations.

0002

2 and 3 are schematic diagrams showing a conventional submarine cable system power supply system. In the feed line 8 of the submarine cable 6 that connects the terminal stations 1 and 3 via the intermediate station 12, as shown in FIG. It reaches the intermediate station 12 via the repeater 7. The power supply line 8 in the intermediate station 12 is grounded, and the current sent from the constant current power supply device 4 flows back through the ground return path 11. Similarly, the DC current I2 sent from the constant current power supply device 5 of the terminal station 3 is turned back at the ground return path in the intermediate station 12.

Furthermore, if the intermediate station 12 is not grounded as shown in FIG. The current absorbed by the constant current power supply device 5 and sent out from the constant current power supply device 5 flows through the ground and is absorbed by the constant current power supply device 4 .

[0004] Both the single-station power feeding system from each terminal station 1 and 2 shown in FIG. 2 and the dual-station power feeding system shown in FIG. There is no difference.

[0005]

[Problems to be Solved by the Invention] However, the above-mentioned conventional system has problems in two respects: early detection of a submarine cable failure and securing of a communication path on the side that is not in trouble.

First, in the one-station power supply system shown in FIG. 8 are at the same potential (earth potential), and the feeding current no longer flows, so the communication path between the intermediate station 12 and the terminal station 3 is disconnected. In this case, since the feeder line 8 is grounded at the intermediate station 12, it is difficult to determine whether the feeder line 8 has experienced a ground fault at point A or whether the submarine repeater has caused a disconnection fault. In this case, normal power supply can be maintained between the terminal station 1 and the intermediate station 12, so communication between the two stations is ensured. In addition, in this one-station power supply method, if the constant current power supply device 5 becomes impaired and power cannot be supplied, both ends of the constant current power supply device 5 are short-circuited and grounded, and only the constant current power supply device 4 is responsible for the power supply capability. cannot be applied.

In the two-station power feeding system shown in FIG. 3, if an open failure occurs at point B, for example, the power feeding current between terminal stations 1 and 3 is stopped, and all communication paths are cut off. In addition, in this dual-station power feeding system, even if the constant current power feeding device 5 becomes damaged and power cannot be supplied, if both ends of the constant current power feeding device 5 are short-circuited and grounded as shown by the broken line in FIG. It is possible to burden the power supply capacity.

As described above, both the conventional systems shown in FIGS. 2 and 3 have advantages and disadvantages in terms of redundancy in the event of a cable failure or a power supply failure.

[0009]

[Means for Solving the Problems] The power supply system of the present invention includes first and second constant current power supply devices provided at first and second terminal stations and supplying direct current, and the first and second constant current power supply devices. A power supply line of a submarine cable connected with a power supply load of a submarine repeater interposed between a second constant current power supply device, and a voltage for detecting the voltage of the power supply line at an intermediate station provided in the middle of the submarine cable. The power supply system includes a detector and a switch that short-circuits the power supply line to ground at the intermediate station when the detected voltage of the voltage detector exceeds a preset value.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a circuit diagram showing one embodiment of the present invention. A submarine repeater 7, which is a power supply load, is connected to the middle of the power feed line 8 of the submarine cable 6 that connects the terminal stations 1 and 3 via the intermediate station 2, and the terminal stations 1 and 3 DC current is supplied from constant current power supply devices 4 and 5. The intermediate station 2 includes a voltage detector 9 that detects the voltage of the feeder line 8, and when this detected voltage exceeds a predetermined value,
A switch 10 that operates to ground the power supply line 8 is provided.

In FIG. 4, an arrester 13 is used as the voltage detector 9 in FIG. 1, and a relay 1 is used as the switch 10.
FIG. 5 is a voltage distribution diagram for explaining the operation of this embodiment. If no fault occurs in the power supply route while power is being supplied from the constant current power supply devices 4 and 5 of both terminal stations 1 and 3, the output voltage of terminal station 1 will be +V, as shown in voltage distribution 20 in FIG. The output voltage of station 3 is -V, and the power supply voltage of intermediate station 2 is V1.

If a failure occurs in the constant current power supply device 5 and power cannot be supplied, the power supply capability of the constant current power supply device 5 can be fixed by grounding the terminal station 3 as shown by the broken line. The current power supply device 4 bears the burden. That is, the output voltage of the constant current power supply device 4 becomes +2V as shown in the voltage distribution 21 of FIG.

If the constant current power supply device 4 becomes a failure and the constant current power supply device 5 is responsible for its power supply capability, the voltage distribution 22 shown in FIG. 5 will result.

As described above, the power supply voltage at the intermediate station 2 is V1 under normal conditions, and when power is supplied only from the constant current power supply device 4 (when the constant current power supply device 5 is in trouble and is grounded in the terminal station 3) ), it becomes V2, and when power is supplied only from the constant current power supply device 5 (when the constant current power supply device 4 is grounded in the terminal station 1 due to a failure), it becomes V3.

On the other hand, if a cable open failure occurs, for example, at point C between the intermediate station 2 and the terminal station 3, the power supply current of the constant current power supply device 4 is stopped, but the output voltage of the constant current power supply device 4 remains at the maximum output capacity value. rises to. In response to this voltage rise, the arrester 13 is discharged, and the current S from the constant current power supply device 4 flows through the relay winding 15 of the relay 14 and returns to the ground. In response to this, the relay contact 16 turns on, and the arrester 13 stops discharging, but the relay winding 15
The power supply current begins to flow through the relay contact 16 and the relay contact 16 is held in the on state. As a result, power supply between the terminal station 1 and the intermediate station 2 is ensured, and the communication path is also maintained. Note that the discharge starting voltage of the arrester 13, which is a voltage detector, is V in FIG.
It is sufficient to set it to 2 or more.

Furthermore, in this embodiment, if a ground fault occurs at point C, the power supply currents sent from the constant current power supply devices 4 and 5 are turned back at point C where the fault occurs, so that the fault occurs in communication. Communication will be maintained as long as it does not reach the road.

[0018]

[Effects of the Invention] As explained above, according to the present invention, it is possible to maintain power supply between stations on the non-faulty side in the event of a cable failure, and it is also possible to maintain power supply with only the remaining power supply device in the event of a failure in one power supply device. .

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention.

FIG. 2 is a circuit diagram of a conventional method.

FIG. 3 is a circuit diagram of a conventional method.

FIG. 4 is a circuit diagram of an embodiment of the present invention.

FIG. 5 is a voltage distribution diagram of an embodiment of the present invention.

[Explanation of symbols]

1, 3 Terminal 2,12 Intermediate station 4,5 Constant current power supply device 6 Submarine cable 7 Submarine repeater 8 Power supply line 9 Voltage detection path 10 Switch 13 Arrester 14 Relay 15 Relay drive winding 16 Relay contact

Claims (2)

[Claims] 1. A submarine relay between first and second constant current power supply devices provided at first and second terminal stations and supplying direct current, and the first and second constant current power supply devices, respectively. A power supply line of a submarine cable connected through a power supply load of the equipment, a voltage detector that detects the voltage of the power supply line at an intermediate station provided in the middle of the submarine cable, and a detected voltage of the voltage detector. a switch that short-circuits the power supply line to ground at the intermediate station when the power exceeds a preset value. 2. The voltage detector is an arrester,
the switch is a relay, the arrester is connected between the power supply line and the ground via a winding of the relay;
2. The submarine cable system power supply system according to claim 1, wherein the relay contacts are connected between the power supply line and the ground via the winding.