JPH0470128A - Power feeding path switching circuit for underwater branching device and feeding method for submarine cable communication system - Google Patents

Abstract

PURPOSE:To switch feeding paths while forming both end feeding paths as much as possible when a fault is generated in the feeding path by providing specified first - third relays. CONSTITUTION:The driving part 107L of a first relay 107 is arranged at a first electric path 101, and a second connecting terminal 105 is grounded by a switching part 107L while being disconnected from a second electric path 102. The driving part 108L of the second relay 108 is arranged at a second electric path 102, and a first terminal 104 is grounded by a switching part 108L while being disconnected from the first electric path 101. The driving part 109L of the third relay 109 is arranged at a ground electric path 110 between the switching part 107L of the first relay 107 in the second electric path 102 and the ground, and the self-holding circuit 110 of the ground electric path 110 is formed by a first switching part 109C. Thus, when the fault is generated in the feeding path, the feeding path can be reset while forming both end feeding paths between cables except for the defective cable.

Description

[Detailed Description of the Invention] [Summary] A power supply path switching circuit for an underwater branching device in a submarine cable communication system that branches a submarine cable underwater and communicates between three or more landing stations, and this power supply path switching circuit. Regarding the power supply method using 1. The first and third electric paths are connected in a Y-shape and each tip is connected to the power supply path of the submarine cable. Second. In a power supply path switching circuit for an underwater branching device in which third connection terminals are respectively arranged, the first relay has a driving section disposed in the first electrical path, and the switching section switches the second connection terminal to the second connection terminal. a second relay that is separated from the second electrical path and grounded, and a second relay whose driving portion is disposed in the second electrical path.

A third relay whose switching portion disconnects the first connection terminal from the first electrical path and grounds it; and a third relay whose driving portion connects the switching portion of the first relay in the second electrical path to grounding. The switch section is disposed in a grounding electrical path between the two and forming a self-holding circuit for the grounding electrical path.

[Industrial Application Field J] The present invention relates to a power supply line switching circuit for an underwater branching device in a submarine cable communication system in which a submarine cable is branched underwater and communication is performed between three or more landing stations, and this power supply line switching circuit. Switch to a power supply method using

In submarine cable communication systems, especially optical submarine cable communication systems, optical repeaters are installed at intervals on the optical submarine cable, and these optical repeaters supply DC constant current power through the power supply line in the optical submarine cable. be done. There are two types of power feeding methods: single-ended feeding, which feeds power from only one landing station, and double-ended feeding, which feeds power from two landing stations.However, as a power feeding system, double-ended feeding is more reliable. It is necessary to be able to cope with the addition of landing stations while using the system, and it is also necessary to be able to switch the power supply line while leaving the power supply line at both ends as much as possible in the event of a failure of the power supply line.

[Prior Art] FIG. 13 shows an example of an optical submarine cable communication system with single-end power supply. As shown, landing station A and landing station 8
The optical submarine cable OMC is connected to the optical submarine cable OMC, on which optical repeaters REP are arranged at predetermined intervals and an underwater branching device BU is attached. The OMC is branched to enable communication with three or more landing stations.

In the system shown in FIG. 13, the power supply lines of the optical submarine cables OMC from each landing station A, B, and C are connected to underwater ground at an underwater branching device BU. This creates a power supply line between the power supply device of landing station A and the underwater branching device BU, a power supply path between the power supply device of landing station B and the underwater branching device BU, and a power supply path between the power supply device of landing station C and the underwater branching device BU. The power supply paths are formed independently, and each power supply path can be provided only from the landing station side, only from the landing station B side, or only from the landing station C side.
It is a single-ended power supply path where power is supplied only from the side.

With this single-ended power supply method, if the power supply device of a landing station breaks down, it is impossible to supply power from the power supply device of another landing station in place of the failed power supply device. , it is necessary to install a working power supply device and a backup power supply device at each landing station A, B, and C.

FIG. 14 shows an example of an optical submarine cable communication system with power feeding at both ends. As shown, landing station A and landing station 8
An optical submarine cable OMC is used to connect between the two, and an optical repeater REP and an underwater branch unit BU are attached to this optical submarine cable OMC. Unlike the case of single-end power feeding, this underwater branching device BU connects the power feeding path of the optical submarine cable OMC without being grounded underwater to form a power feeding path between landing stations A and 8.

The power feeding devices of landing stations A and B are configured so that when one has positive polarity, the other feeds negative polarity current, and as a result, landing station A and landing station A are connected to the power feeding path of optical submarine cable○MC. Power is supplied from both sides of B. In this double-ended feeding method,
Even if a failure occurs in the power supply equipment of one of the landing stations A and B and power cannot be supplied, the remaining power supply equipment of the other landing station can supply power to the full load, so each landing station There is no need for a backup power supply device at the station.

As described above, between the single-end power feeding method and the both-end power feeding method, the both-end power feeding method is preferable from the viewpoints of reliability, economy, working voltage, and the like.

By the way, in the optical submarine cable communication system, 3
In many cases, a transmission line was constructed between the landing stations of a station, but in recent years, it has become increasingly common to use multiple underwater branching devices to connect even more landing stations. As a power supply method for such an optical submarine cable communication system, for example, Japanese Patent Application Laid-Open No. 1-276
An optical submarine power supply system described in Publication No. 937 has been proposed.

[Problems to be Solved by the Invention] In the conventional general power supply system, all the power supply paths in the underwater branching device are grounded and power is supplied at one end, so there is a problem that the reliability of the power supply system becomes low. be.

The present invention has been made in view of these problems, and its purpose is to adopt a highly reliable double-end power supply as a power supply system, and to form a double-end power supply route as much as possible in the event of a failure in the power supply route. An object of the present invention is to provide a power supply path switching circuit for an underwater branching device that can switch the power supply path, and a power supply method using the power supply path switching circuit.

[Means to solve the problem] FIG. 1 is a diagram explaining the principle of the present invention.

The power supply line switching circuit for an underwater branching device according to the present invention includes a first,
First, second, and third connection terminals 104.105.106 for connecting the second and third electric paths 101.102.103 in a Y-shape and connecting them to the power supply path of the submarine cable at each tip.
In the power supply line switching circuit of the underwater branching device, each of which is equipped with
The first relay 107 has a driving section 107L that is the first relay 107.
The second relay 108 is arranged in the electric path 101 and the switching part 107C disconnects the second connection terminal 105 from the second electric path 102 and grounds it. A third relay 109, whose drive unit 109L connects the second electrical The first switch section 109C is arranged in the ground electrical path 110 between the switching section 107L of the first relay 107 in the path IO2 and the ground, and the first switch section 109C forms a self-holding circuit for the ground electrical path 110. It is.

In addition, the power supply line switching circuit of the underwater branching device according to the present invention has, as another form, the power supply line switching circuit of the above-mentioned form,
The third relay 109 connects the second electrical path 102 to the drive unit 10 of the relay 108 at the same time as the first switch unit 109C.
8C and the switching section 107C of the relay 107, the second switch section 109CC is opened.

Further, the power supply method for a submarine cable communication system according to the present invention is a power supply method for a submarine cable communication system in which a submarine cable is branched by an underwater branching device to connect three or more landing stations, and the above-mentioned power supply path switching circuit is used as a power supply path switching circuit. A feed line switching circuit of the form A power supply path is formed by supplying power from the landing station connected to the first connection terminal 105 at one end, and if a failure occurs in the power supply path from the landing station connected to the first connection terminal 104, the second and second connection terminals By performing power feeding at both ends between the landing stations connected to the third connection terminals 105 and 106, a faulty power feed path connected to the first connection terminal 104 is separated to form a power feed path.

In addition, the power supply method for the submarine cable communication system according to the present invention is such that the submarine cable is branched by two or more underwater branching devices.
In the power supply method in the submarine cable communication system that connects the above landing stations, each of the above-mentioned power supply route switching circuits is used as the power supply route switching circuit of the underwater branching device, and the first and third connection terminals of the power supply route switching circuit are used. connecting the electrical paths 101 and 103 between 104 and 106 in cascade for a plurality of underwater branching devices via submarine cables to form a main power feed path;
By performing both-end power feeding between the two landing stations connected to both ends of this main power feeding path, and then performing one-end power feeding from the landing station connected to the second connection terminal 105 of each power feeding path switching circuit. It forms a power supply path.

Further, in the power feeding method for a submarine cable communication system according to the present invention, in the above-described power feeding method, the first relays of the plurality of power feeding path switching circuits are set to have different operating currents, and the feeding current flowing through the main power feeding path is controlled. By changing this, the first relays 107 of each power supply path switching circuit are sequentially driven.

Further, the power feeding method for a submarine cable communication system according to the present invention uses, as the power feeding path switching circuit, each of the power feeding path switching circuits of the above-described present invention and a power feeding path switching circuit having a circuit configuration other than that of the power feeding path switching circuit. It forms a power supply path.

[Function] As a basic power supply method using the power supply line switching circuit of the underwater branching device according to the present invention, in normal times, the power supply line switching circuit is connected to the first and third connection terminals 104 and 106, respectively. Power is supplied at both ends between the landing stations, which drives the first relay 107 and switches it! ! 2nd by 107C
By grounding the connection terminal 105 of the second connection terminal 105 and then supplying power from one end of the landing station connected to the second connection terminal 105, the relay 109 is driven and the power supply path is maintained while self-holding is performed by the switch section 109C. Form. If a failure occurs in the power supply path from the landing station connected to the first connection terminal 104, the power supply at both ends is switched between the landing stations connected to the second and third connection terminals 105 and 106. Relay 10 by doing
8 and the switching unit 108C disconnects the faulty power supply path connected to the first connection terminal 104 to form a power supply path.

When using the power feed line switching circuit according to the present invention in a submarine cable transmission system in which a submarine cable is branched by two or more underwater branching devices to connect four or more landing stations, Electrical path 1 between connection terminals 104 and 106 of 3
01.103 are connected in cascade to multiple underwater branching devices via submarine cables to form a main power feed path, and both ends of the power feed are provided between two landing stations connected to both ends of this main power feed path. Drives the relay 107 of the power supply path switching circuit,
The connection terminal 105 of each power supply path switching circuit is grounded by the switching contact 107C. After that, a power feeding path is formed by performing one-end power feeding from a landing station connected to the second connection terminal 105 of each power feeding path switching circuit.

In the above-mentioned power supply method, the first relays 107 of the power supply path switching circuit of each underwater branch device are set to have different operating currents, and by changing the power supply current flowing through the main power supply path, the power supply path switching circuit of each power supply path switching circuit can be adjusted. The first relays 107 are driven sequentially, thereby preventing hot switching of the relays.

As a power supply line switching circuit used in a submarine cable communication system, a combination of the power supply line switching circuit according to the present invention and a power supply line switching circuit having a circuit configuration other than that can be used.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 shows a power supply line switching circuit for an underwater branching device as an embodiment of the present invention. This embodiment is applied to an optical submarine cable communication system, and only the power supply switching circuit excluding the optical fiber circuit is shown in the figure. In Fig. 2, BU is an underwater branching device, and has three connection terminals Tl, T2, and T3.
3 are respectively connected to landing station A via the optical submarine cable power supply line.
, B, and C. Here landing stations A and B
The power supply device of C is configured to supply power supply current of positive polarity to the power supply device of landing station C, and the power supply device of landing station C is configured to supply power supply current of negative polarity to the power supply path of the optical submarine cable.

The power supply circuit in the underwater branch unit BU is electric path I, ■
, ■ are connected in a Y-shape, and the above-mentioned connection terminals T1. T2 and T3 are connected respectively. A drive coil for the relay RLI (hereinafter referred to as relay coil RLl) is inserted into the electric path I, and a drive coil for the relay RL3 (hereinafter referred to as relay coil RL3) is inserted into the electric path (2). The switching contact rβl of the relay RLI connects the connection terminal T2 in the electric path ■ and the relay coil R.
The break contact side of this switching contact rI21 is inserted between the connection terminal T2 and relay coil RL3, and the make contact side is inserted between the terminal T2 and ground. Similarly, switching contact r123 of relay RL3 is an electric path! Connection terminal T inside
The break contact side of this switching contact rI23 is inserted between the connection terminal TI and the relay coil RL1, and the meter contact side is inserted between the terminal Tl and ground.

A drive coil C of relay RL2 (hereinafter referred to as relay coil RL2) is inserted in the path between switching contact rρ1 and the ground, and make contact rQ2-2 of this relay RL2 is switched as a contact forming a self-holding circuit. It is inserted in parallel with the meter contact side of contact rJ21. Also break contact r
β2-1 is inserted between switching contact rJ21 and relay coil RLB.

Each of the relays RLI to RL3 is driven only when an operating current (moving current) flows in the direction indicated by the arrow in the figure. Furthermore, high voltage relays such as vacuum relays are used as relays RLI, RL2, and RL3.

Hereinafter, each landing station A will be
, B, and C to the optical submarine cable.
This will be explained with reference to FIGS.

First, as shown in FIG. 3, power is supplied between landing station C and landing station A, and a power supply current is passed in the direction of the arrow in the figure, thereby exciting and operating relay RLI. Therefore, a power supply path is formed between the landing station C and the landing station A in which power is supplied at both ends. Further, by the operation of relay RLI, its switching contact rβ1 is switched to ground connection terminal T2 (that is, the power supply path of the optical submarine cable from landing station B).

Next, as shown in FIG. 4, power is supplied from landing station B to the optical submarine cable on the landing station B side. As a result, relay RL2 is excited and operates. Then, the meter contact rI22-2 is closed to form a self-holding circuit of the ground path, and the break contact rj22-2 is opened to disconnect the relay coil RL3 from the switching contact rβl.

This relay RL2 serves to prevent the power supply path from being switched in the event that a failure occurs in the optical submarine cable on the landing station A or landing station C side during operation, and the meter contact r! 22-2 serves as a self-holding contact. The break contact rβ2-1 is a contact for preventing the switching contact rβ■ from being damaged by arc discharge that occurs at the contact when the switching contact rI21 returns from the ground side to the relay coil RLa side.
During self-holding by relay RL2, switching contact rβ1 is disconnected from relay coil RLl side by break contact r92-1. A relay with a bending function is also described in, for example, Japanese Patent Laid-Open No. 189025/1983.

Assume now that a failure has occurred in the optical submarine cable on the landing station A side, as shown in FIG. In this case, relay RL
Since I is no longer excited, the switching contact rffl returns from the ground side to the relay coil RLB side, but the power supply path from landing station B is maintained by the self-holding function of relay RL2.

Here, in order to perform both-end power supply between the remaining landing stations B and C,
Power supply is temporarily stopped at all landing stations, and then power supply is started between landing station C and landing station 8 as shown in FIG.

This energizes relay RL3, and its switching contact rf
f3 switches to the ground side and disconnects the optical submarine cable on the landing station A side from the power supply line. As a result, a power feeding path is established between landing station B and landing station C with power feeding at both ends.

In this system, if a failure occurs in the optical submarine cable on the landing station C side, it becomes impossible to supply power to any of the landing stations, and the system goes down. Therefore, it can be said that the route that is not affected by failures in other places is between landing stations A and C. During this period, power is supplied to both ends.

FIG. 7 shows an example in which the above-mentioned power supply line switching circuit is applied to an optical submarine cable communication system that uses two underwater branching devices BU to connect four landing stations A, B, C, and D. It will be done. Here, BUI and BO2 are underwater branching devices, and their power supply path switching circuits have the same configuration as that of the embodiment shown in FIG.

In this communication system, a main optical submarine cable is set up between landing station A and landing station 8, and power is supplied at both ends between them.
Undersea branching devices BUI and BO2 are used to branch this main optical submarine cable from two points along the way and connect the optical submarine cables to landing station C1, respectively.
Each landing station C1D is configured to supply power at one end.

In a normal operation method, as shown in FIG. 8, power is first supplied between landing station A and landing station 8, and then to the main optical submarine cable. As a result, the relay RLI■ of the underwater branching device BUI and the relay RLI■ of the underwater branching device BU2 are energized, and the respective switching contacts rI21■ and rβ1■ are switched to the ground side, thereby connecting the power supply path from the landing station C. Ground each power supply line from the landing station. Next, the ninth
As shown in the figure, the landing station C and the landing station each start supplying power, and supply power to each branch optical submarine cable. As a result, relays RL2■ and RL2■ are each excited, and the power supply path is self-maintained.

Here, the relays RLI■ and RLI■ of the power supply path switching circuits of the underwater branching devices BLII and BO2 are configured to operate with different operating currents (sensing currents), respectively. This is to prevent hot switching of the relay.

That is, when driving the relay of the underwater branching device BU, when the contact is switched to the ground side, if the ground potential of the power supply line where the contact is located is large, the relay contact may be damaged during switching due to the potential difference.

In order to prevent this relay contact from being damaged, it is necessary to make sure that the ground potential of the power supply path of the underwater branch unit BU becomes zero when driving the relay. For example, when feeding power between landing stations A and B at both ends of the main optical submarine cable, the power supply voltage/current of each landing station A and B should be adjusted while taking into account the voltage drop across the optical submarine cable. This method adjusts the voltage to an appropriate value so that the power supply potential becomes zero at the underwater branch unit BU, but if there are two underwater branch units BU, this method will cause the two underwater branch units BUl, BU to
2 cannot be set to zero ground potential at the same time.

Therefore, the operating currents of relays RLl■ and RLI■ of the underwater branching devices BUI and BU2 are set to different values. For example, the operating current of relay RLI■ is set to be smaller than the operating current of relay RLI■. In order to supply power between landing station A and landing station B, first adjust the power supply voltage of landing stations A and B so that the ground potential of the power supply path becomes zero at the underwater branch unit BUI, and then adjust the power supply current. For example, a current having the magnitude of the operating current of relay RLI■ is applied. As a result, relay RLI■ of underwater branch unit BUI operates, but
Since relay RLI■ of U2 has a larger operating current than relay RLl■, it does not operate with the current power supply current. Therefore, even if the ground potential of the power supply line of the underwater branching device BU2 at this time is not zero, the relay RLI■ does not operate, so the switching contact r9.1■ is not damaged.

After operating the relay RL1■ of the underwater branch unit BUI in this way, the power supply potential of the landing station A and the landing station B is adjusted so that the ground potential of the power supply path of the underwater branch unit BU2 becomes zero. At the same time, a current having the magnitude of the operating current of relay RLI2 is supplied as a power supply current. As a result, relay RLI■ of underwater branching device BU2 is activated. As described above, hot switching of the relays of the underwater branching devices But and BU2 can be prevented.

The power supply path that can be set in the communication system of FIG. 7 is shown in FIG. 10, including when there is a failure. In the figure, (a) is normal, (
b) to (f) are at the time of failure. Optical submarine cables that can be supplied with power are shown as solid lines, and their arrows indicate the direction of power supply. Optical submarine cables that are unusable due to failure are indicated by dotted lines.

Normally, as shown in (a), power is supplied at both ends between landing station A and landing station B, and power is supplied at one end from landing station C and the landing station. If a failure occurs in the optical submarine cable on the landing station C side or the landing station side as shown in (b) or (e), the remaining power supply path will continue to be supplied without any changes. be exposed. As shown in (C), if a failure occurs in the optical submarine cable on the landing station A side, only the underwater branch unit BU2 side can supply power, and in that case,
The power supply path is switched so that power is supplied at both ends between the landing station and the landing station B. Similarly, as shown in (f), if a failure occurs in the optical submarine cable on the landing station B side, only the underwater branch unit BUl side can supply power, and the landing station A
The power supply path is switched so that power is supplied at both ends between the landing station C and the landing station C. Undersea branching device B as shown in (d)
If a failure occurs in the optical submarine cable connecting Ul and the underwater branching unit BU2, there will be a problem between landing stations A and C on the underwater branching unit BUI side, and between landing stations A and C on the underwater branching unit BU2 side. The power supply path is switched so that power is supplied at both ends between landing station A and landing station B. In this way, even if a failure occurs in the optical submarine cable at any location, a two-end power supply path can be formed between the remaining landing stations.

FIG. 11 shows a power supply circuit in an optical submarine cable communication system in which the number of underwater branching units BU is increased to four and the number of landing stations is increased to six. As shown in the figure, a main optical submarine cable is installed between landing station A and landing station B, and four underwater branching devices BUI to BU4 connect this main optical submarine cable to each landing station C, Branch optical submarine cables to D, E, and F. In this system, power is supplied at both ends between landing station A and landing station 8, and power is supplied at one end from each of the other landing stations C, D, E, and F. Also, each underwater branch unit BUI~
BU4 relay RLI■, RL1■, RLI■, RLI
(2) have different operating currents for the same reason as mentioned above.

In this way, as conceptually shown in Fig. 12, once the main optical submarine cable power feeding route (in Fig. 12, the power feeding route between landing station A and landing station 8) is determined, the power feeding route is determined. By varying the operating currents of the relays that enter the road (relays RLI■ to RLI■ of each underwater branch device BUI-BTJ4), any number of branch power supply routes can be obtained from the main power supply route. Therefore, by further increasing the number of underwater branching devices with different magnitudes of relay operating currents, it is possible to construct an optical submarine cable communication system that can branch to more landing stations than the above embodiment.

In the above embodiment, a mechanical contact relay such as a vacuum relay was used as the relay of the underwater branching device, but the present invention is of course not limited to this, and a non-contact relay such as a solid state relay may be used. It may be something. In this case, a semiconductor switch is used instead of a switching contact or a make/break switching contact.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a highly reliable power supply system using double-end power supply that can cope with the addition of landing stations. Furthermore, in the event of a failure in the power supply path, the power supply path can be reset while forming a power supply path at both ends between cables other than the faulty cable.

[Brief explanation of drawings]

Fig. 1 is a diagram illustrating the principle of the present invention, Fig. 2 is a diagram showing a power supply line switching circuit of an underwater branching device as an embodiment of the present invention, and Figs. Figure 7 is a diagram showing the power supply circuit of an optical submarine cable communication system using two of the apparatuses according to the embodiment shown in Figure 2, and Figures 8 and 9 are diagrams explaining the operation of the apparatus according to the embodiment shown in Figure 7. , Figure 1O is a diagram explaining the power supply path that can be set for the embodiment device in Figure 7, Figure 11 is a diagram showing the power supply circuit of an optical submarine cable communication system using four units of the embodiment equipment in Figure 2, Figure 12 is a diagram conceptually explaining the power supply circuit of an optical submarine cable communication system using multiple underwater branching devices, Figure 13 is a diagram explaining the conventional single-end power supply system, and Figure 14 is the conventional double-end power supply system. FIG. In the figure, RLI, RL2, RL3... - relay coil rffl,
r122-1%rI22-2, rI23...Relay contacts BU, BUl, BU2, BU3, BU4--Undersea branching device

Claims (1)

[Claims] 1, first, second, and third electric paths (101, 102, 10
3) in a Y-shape and each end has first, second, and third connection terminals (104
, 105, 106), the first relay (107) and its drive section (107L
) is arranged in the first electrical path (101), and the switching part (107C) separates the second connection terminal (105) from the second electrical path (102) and grounds it; 2 relay (108) and its driving part (108L
) is arranged in the second electric path (102), and the first connection terminal (104) is disconnected from the first electric path (101) and grounded by the switching part (108C); 3 relay (109) and its driving part (109L)
) is the switching section (10) of the first relay in the second electrical path.
7C) and a device disposed in the grounding electrical path (110) between the ground and forming a self-holding circuit of the grounding electrical path (110) by its first switch section (109C). road switching circuit. 2. The third relay (109) is connected to the first switch section (10
9C), simultaneously connect the second electrical path (102) to the relay (1
08) and the switching section (107C) of the relay (107).
9CC). The power supply path switching circuit for an underwater branching device according to claim 1, further comprising: 9CC). 3. In a power supply method in a submarine cable communication system in which a submarine cable is branched by an underwater branching device to connect three or more landing stations, the power supply line switching circuit according to claim 1 or 2 is used, and normally the The first and third connection terminals of the power supply path switching circuit (
104, 106), and then one-end power feeding from the landing station connected to the second connection terminal (105) to form a power feeding path; If a failure occurs in the power supply line from the landing station connected to the first connection terminal (104), the power supply line between the landing stations connected to the second and third connection terminals (105, 106) A power feeding method for a submarine cable communication system in which a power feeding path is formed by disconnecting a faulty power feeding path connected to the first connection terminal (104) by performing power feeding at both ends. 4. Branch the submarine cable with two or more underwater branching devices.
A power feeding method in a submarine cable communication system connecting the above landing stations, wherein the power feeding path switching circuit according to claim 1 or 2 is used, and the first and third connection terminals of the feeding path switching circuit are used. (104, 1
06) A main power feed path is formed by cascading the electrical paths between the two via submarine cables for multiple underwater branching devices, and both ends of the power feed are connected between two landing stations connected to both ends of this main power feed path. A power feeding method for a submarine cable communication system in which a power feeding path is formed by performing one-end power feeding from a landing station connected to a second connection terminal (105) of each of the feeding path switching circuits. 5. The power supply method for a submarine cable communication system according to claim 4, wherein the first relays (107) of the plurality of power supply path switching circuits are set to have different operating currents, and the power supply current flowing through the main power supply path is set to be different. By changing the
A power supply method for a submarine cable communication system in which relays (107) are sequentially driven. 6. In the power feeding method for a submarine cable communication system according to claim 4, a power feeding path is established using the power feeding path switching circuit according to claim 1 or 2 and a power feeding path switching circuit having a circuit configuration other than that of claim 1 or 2 as the power feeding path switching circuit. A power supply method for submarine cable communication systems to be formed.