FEED LINE BRANCHING APPARATUS AND FEED LINE BRANCHING METHOD

• US 20170331516A1
• Filed: 12/07/2015
• Published: 11/16/2017
• Est. Priority Date: 12/10/2014
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: YAMAGUCHI, Shohei
• Granted Patent: US 10,355,744 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 4/00 Circuit arrangements for mains or distribution networks not specified as ac or dc
• CPC Class Codes: H04B 3/44 Arrangements for feeding power to a repeater along the transmission line

Abstract

Provided is a feedline branching apparatus that makes it possible for additional submarine cables to be installed easily, and with which cost increases can be restricted. For these purposes, the feedline branching apparatus comprises a branching unit and an earth unit. First, second and third terminal stations are connected to the branching unit via first, second and third cables, respectively. When the first and second cables are normal, the branching unit connects a feedline of the first cable to a feedline of the second cable, thereby forming a feedline using a first current. If one of the first and second cables is faulty, the branching unit grounds the feedline of the one of the first and second cables, while connecting the feedline of the other cable to the earth unit. The earth unit grounds a feedline of the third cable, thereby forming a feedline using a second current. When the feedline of the other cable is connected to the earth unit from the branching unit, the earth unit grounds the feedline of the other cable, thereby forming a feedline using the first current.

Claims

1. A feed line branching apparatus coupled with a first terminal station, a second terminal station, and a third terminal station respectively via a first cable, a second cable, and a third cable, the terminal stations each comprising a function for supplying power for a cable from a constant current source, the feed line branching apparatus comprising:

a branching unit configured to, when the first and the second cables are in a normal state, establish a feed line of a first electric current between the first terminal station and the second terminal station by coupling a feed line of the first cable with a feed line of the second cable, and to, when a fault has occurred in one of the first and the second cables, ground the feed line of the one of the cables and couple the feed line of the other of the first and the second cables to a grounding unit; and

the grounding unit configured to establish a feed line of a second electric current between the third terminal station and the grounding unit by grounding a feed line of the third cable and to, when the feed line of the other cable from the branching unit is coupled to the grounding unit, establish a feed line of the first electric current between the first or the second terminal station coupled with the other cable and the grounding unit by grounding the feed line of the other cable.

2. The feed line branching apparatus according to claim 1, wherein the first electric current and the second electric current are different.

3. The feed line branching apparatus according to claim 1, wherein the first, second, and third cables are submarine cables, the feed line branching apparatus is a submarine branching apparatus installed on a seabed, the first, second, and third terminal stations are land stations, and the grounding unit grounds the feed lines to sea earth.

4. A cable system comprising:

a first terminal station, a second terminal station, and a third terminal station each comprising a function for supplying power from a constant current source, and

a feed line branching apparatus according to claim 1 coupled with the first to third terminal stations respectively via a first cable, a second cable, and a third cable.

7. The feed line branching apparatus according to claim 2,

wherein the first, second, and third cables are submarine cables, the feed line branching apparatus is a submarine branching apparatus installed on a seabed, the first, second, and third terminal stations are land stations, and the grounding unit grounds the feed lines to sea earth.

8. A cable system comprising:

a first terminal station, a second terminal station, and a third terminal station each comprising a function for supplying power from a constant current source, and

a feed line branching apparatus according to claim 2 coupled with the first to third terminal stations respectively via a first cable, a second cable, and a third cable.

9. A cable system comprising:

a first terminal station, a second terminal station, and a third terminal station each comprising a function for supplying power from a constant current source, and

a feed line branching apparatus according to claim 3 coupled with the first to third terminal stations respectively via a first cable, a second cable, and a third cable.

10. A cable system comprising:

a first terminal station, a second terminal station, and a third terminal station each comprising a function for supplying power from a constant current source, and

a feed line branching apparatus according to claim 7 coupled with the first to third terminal stations respectively via a first cable, a second cable, and a third cable.

5. A feed line branching method used in a feed line branching apparatus coupled with a first terminal station, a second terminal station, and a third terminal station respectively via a first cable, a second cable, and a third cable, the terminal stations each comprising a function for supplying power from a constant current source, the method comprising:

establishing, by grounding a feed line of the third cable, a feed line of a second electric current between the third terminal station and a ground point of the feed line of the third cable;

when the first and the second cables are in a normal state, establishing a feed line of a first electric current between the first terminal station and the second terminal station by coupling a feed line of the first cable with a feed line of the second cable; and

when a fault has occurred in one of the first and the second cables, grounding the feed line of the one of the cables and grounding the feed line of the other of the first and the second cables to establish a feed line of the first electric current between the first or second terminal station coupled with the other cable and a ground point of the feed line of the other cable.

6. A non-transitory storage medium storing a control program for a feed line branching apparatus coupled with a first terminal station, a second terminal station, and a third terminal station respectively via a first cable, a second cable, and a third cable, the first, second and third terminal stations each comprising a function for supplying power from a constant current source, wherein the control program causes a computer of the feed line branching apparatus to execute:

a procedure of establishing, by grounding a feed line of the third cable, a feed line of a second electric current between the third terminal station and a ground point of the feed line of the third cable;

a procedure of, when the first and the second cables are in a normal state, establishing a feed line of a first electric current between the first terminal station and the second terminal station by coupling a feed line of the first cable and a feed line of the second cable; and

a procedure of, when a fault has occurred in one of the first and the second cables, grounding the feed line of the one of the cables and grounding the feed line of the other of the first and the second cables to establish a feed line of the first electric current between the first or second terminal station coupled with the other cable and a ground point of the feed line of the other cable.