CN114825246A - Branch device, submarine cable system and broken cable switching method - Google Patents

Abstract

The application provides a branching device, a submarine cable system and a broken cable switching method. The splitter is connected with a plurality of submarine cable lines through a first circuit and a second circuit, and constant-current power supply for parts such as repeaters on the lines is achieved. When a cable breaking fault occurs in the submarine cable line, the switching device can switch the power supply mode to maintain the constant-current power supply state of the line. The splitter is additionally provided with the current limiting device in front of the grounding device, the current limiting device is used for absorbing surge current generated when the power supply mode is switched under a high-voltage state, the peak value of pulse current flowing through the switching device is reduced, and on the premise of meeting the signal transmission performance of the splitter, the damage caused by the surge current when the splitter is switched under the high-voltage state is reduced.

Description

Branch device, submarine cable system and broken cable switching method

Technical Field

The application relates to the technical field of submarine optical cable transmission, in particular to a branching device, a submarine cable system and a broken cable switching method.

Background

In a multi-site landing submarine optical cable system, the distribution of part of the optical signals to branch sites needs to be achieved by means of a submarine splitter (BU). As shown in fig. 1, a submarine cable line connected between a station (station) a and a station B is defined as a trunk, a submarine cable line corresponding to a station C is defined as a branch, and the trunk and the branches are combined together by a splitter to implement signal transmission. Among them, active devices on the trunk, such as Repeaters (RPTs) and BUs, need to be powered by a station device with a constant current. During the powering process, the BU interior can form a high voltage region and a low voltage region due to the powering. There may be a potential difference of more than 15kV between the high voltage region and the low voltage region.

Due to the complex seabed environment, accidental cable breaking faults are easily caused, and communication is affected. In order to restore communication as soon as possible, when a cable breaking point is maintained, power supply paths can be changed by switching through a Power Switch Branch Unit (PSBU), power supply to parts of a system which do not have cable breaking faults is continuously supplied, and the influence of the cable breaking faults on communication is reduced. However, in the switching process, charges stored in the submarine cables at two ends of the switching point are released to the grounding device through the switching device inside the BU, and due to the high potential difference between the high-voltage area and the low-voltage area, a large surge current with a peak value of thousands of amperes can be generated instantaneously on the switching device, so that the service life of a product is influenced, and the failure probability is increased.

Therefore, after a cable breaking fault occurs, the potential difference between the input end and the output end of the BUs of the BU can be changed by repeatedly adjusting a Power Feeding Equipment (PFE) of the station end until a controller in the BU detects that the potential difference is within a voltage interval which is preset to allow the BU to be switched, and then the switching action is executed. For example, when the station a supplies a positive voltage and the station B supplies a negative voltage, the magnitudes of the positive voltage and the negative voltage need to be adjusted continuously so that the differential pressure of the BU is in a set switching interval. In practice, it has been shown that such a repeated adjustment process consumes a long recovery time, i.e. a prolonged maintenance time, which affects the communication quality.

Disclosure of Invention

The application provides a branching device, a submarine cable system and a broken cable switching method, the branching device can directly carry out high voltage switching, and supports various installation methods, so that the problems that the maintenance time of the traditional broken submarine cable is long, and normal communication is influenced are solved.

In a first aspect, the present application provides a branching device for use in a submarine cable system, comprising: switching device, first circuit, second circuit, earthing device and current limiting device. Wherein, first circuit and second circuit are connected with many submarine cable lines respectively. The switching device is arranged between the first circuit and the second circuit and used for switching the power supply modes of each submarine cable line and the first circuit and the second circuit so as to form a high-voltage area and a low-voltage area in the first circuit and the second circuit respectively. The switching device is also connected with the grounding device through the current limiting device so as to absorb surge current formed when the power supply mode is switched through the current limiting device.

The splitter is connected with a plurality of submarine cable lines through a first circuit and a second circuit, and constant-current power supply for parts such as repeaters on the lines is achieved. When a cable breaking fault occurs in a submarine cable line, the power supply mode can be switched through the switching device, and the constant-current power supply state of the line is maintained. The splitter is additionally provided with the current limiting device in front of the grounding device, the current limiting device is used for absorbing surge current generated when the power supply mode is switched under a high-voltage state, the peak value of pulse current flowing through the switching device is reduced, and on the premise of meeting the signal transmission performance of the splitter, the damage caused by the surge current when the splitter is switched under the high-voltage state is reduced.

In one implementation, the current limiting device, the switching device, the first circuit and the second circuit are assembled in a modular manner and are packaged inside a BU barrel of a splitter; the grounding device is arranged outside the BU barrel. Namely, when an actual product is formed, the current limiting device and the internal circuit of the splitter can be arranged in the BU barrel together, and the structure is convenient for realizing uniform modular assembly of all parts of the splitter so as to establish a connection relationship between the splitter and each submarine cable line.

In one implementation, the switching device, the first circuit, and the second circuit are packaged inside a BU bucket; the grounding device and the current limiting device are arranged outside the BU barrel. Also, the current limiting device may be integrated in the grounding device such that the switching device is grounded through the current limiting device. The flow limiting device is arranged outside the BU barrel, so that the space inside the BU barrel can be saved, and the whole volume of the branching device can be reduced. And, set up the current limiting device and can also concentrate on earthing device department with the heat that surge current produced when flowing through current limiting device in BU bucket outside, the branching ware of being convenient for dispels the heat, reduces the design degree of difficulty.

In order to obtain the current limiting effect, the current limiting device comprises one or more combinations of a resistor, an inductor and a semiconductor current limiting circuit. The current limiting device may be a resistor, or other electronic components capable of limiting current, such as an inductor, a semiconductor, etc., or a combination of multiple current limiting components, such as a combination of an inductor and a resistor. The resistor, the inductor and the semiconductor current limiting circuit can consume the charge quantity of surge current when the power supply mode is switched, and relieve the current impact generated by the surge current on the switching device, so that the quick hot switching can be realized when the potential difference between a high voltage area and a low voltage area is more than 15 kV.

In one implementation, the current limiting device is a resistor; the resistance value of the resistor is positively correlated with the potential difference between the high-voltage region and the low-voltage region to limit the inrush current generated when the power supply mode is switched to be below a preset current peak value. When the current limiting device adopts a resistor for current limiting, the resistance value of the current limiting device can be set according to the potential difference between a high voltage area and a low voltage area in the splitter, so that the surge current can be limited to a safe range.

In one implementation, before the switching device performs the action of switching the power supply mode, the first circuit is connected with the two submarine cable lines to form a high-voltage area; the second circuit is connected with a submarine cable line and the grounding device to form a low-voltage area; after the switching device performs the action of switching the power supply mode, the first circuit still connects the two submarine cables to form a high-voltage area, but the connected submarine cables change after switching; the second circuit is connected to a sea cable to form a low voltage area, but the sea cable connected to the second circuit also changes along with the switching process.

The switching device can be internally provided with a plurality of interfaces, relays and other switching components, and the communication state between the interfaces and each submarine cable line and the grounding device can be adjusted through the switching components, so that the function switching of the first circuit and the second circuit as a high-voltage area or a low-voltage area is realized. Through the action of switching the power supply mode by the switching device, active equipment such as a repeater on a submarine cable line can still realize power supply through station equipment connected on other lines when a cable breaking point occurs in the submarine cable line, so that communication connection is guaranteed.

In one implementation, the splitter further includes a controller; the controller is connected with the switching device and establishes communication connection with the station equipment through a submarine cable line; the controller is configured to receive a switching command input by the station equipment and control the switching device to execute an action of switching the power supply mode according to the switching command. The controller can automatically realize switching in a remote control mode when a cable breaking fault occurs or maintenance is carried out, and the maintenance time of the cable breaking fault is shortened.

In one implementation, the grounding arrangement includes at least one grounding electrode extending to an exterior of the splitter. Because the branching device can be applied to a submarine environment, the branching device can be coated by seawater when in use, and the seawater is at a low potential, so that the grounding device can be set to be at least one grounding electrode extending out of a BU barrel of the branching device, the grounding electrode is contacted with the seawater, and the effect of leading surge current generated during switching into the seawater can be achieved, and the grounding effect is achieved.

In a second aspect, the present application further provides a submarine cable system, which includes a plurality of submarine cable lines and a station device, where the station device may be connected to the submarine cable lines to control an operation state of the line device. Each submarine cable line is provided with a plurality of repeaters, and the repeaters can be used for adjusting optical signal attenuation caused by long-distance transmission. The branch device is also arranged on the submarine cable line, and one submarine cable line is in communication connection with at least two other submarine cable lines through the branch device; and a power supply device is arranged in the station equipment and is used for supplying power to the repeater and the splitter at constant current.

The submarine cable system can establish communication connection through a plurality of submarine cable lines and is connected with different submarine cable lines through the branching unit, so that a communication network is realized, constant-current power supply is provided for the repeater and the branching unit in the whole network, and the communication function in the network is ensured. Because including above-mentioned spliter in the submarine cable system, can realize the hot switch under high pressure state, consequently when the submarine cable system breaks the cable trouble, can switch to other states in short time, submarine cable maintenance duration when practicing thrift the accident guarantees the communication of normal submarine cable circuit.

In one implementation, the submarine cable line is a multi-layer cable structure, and comprises an optical fiber layer located in the center of the cable and a power supply layer coated outside the optical fiber layer; the first circuit and the second circuit of the repeater and the splitter are connected to the power supply layer.

Through the submarine cable line of multilayer cable structure, can pass supply current and light signal simultaneously. The optical fiber layer is coated in the power supply layer, and the power supply layer can be made of more solid and durable metal materials, so that the optical fiber layer can be protected by the power supply layer. In the underwater environment, the power supply layer is damaged firstly under the influence of underwater factors, so that the cable breaking fault can be found timely, and partial communication capacity can be guaranteed. In addition, since the power supply layer is coated outside the optical fiber layer, when a cable breakage fault occurs, the power supply layer may contact seawater or contact the submarine ground, i.e., connect the ocean ground, so that a ground state may be formed at the cable breakage.

In a third aspect, the present application further provides a cable breaking switching method, where the cable breaking switching method is applied to a submarine cable system, the submarine cable system includes the splitter, and the cable breaking switching method includes:

detecting the position of a cable breaking point;

if the cable breaking point is located on a trunk line, maintaining the current power supply state until maintenance is started, sending a switching command to the splitter to drive a switching device of the splitter to execute an action of switching a power supply mode, wherein the trunk line is a submarine cable line connected with a high-voltage area of the splitter;

if the cable breaking point is located on the branch, sending a switching command to the splitter to maintain power supply to the repeater on the branch, and sending the switching command to the splitter again when maintenance is started to cancel the power supply to the branch to ensure safe maintenance, wherein the branch is a submarine cable line connected with a low-voltage area of the splitter.

The cable-breaking switching method can adopt different switching modes according to the position of a cable-breaking point so as to ensure the normal realization of a communication function, and ensure that a cable-breaking line is kept in a voltage-free state in the maintenance process so as to ensure the maintenance safety.

In one implementation, the method further comprises, at the start of the service: and performing power-off processing on the submarine cable line where the cable breaking point is located through a power supply device of the station equipment. Through carrying out the electricity processing down to the submarine cable circuit of disconnected cable point place, can keep the low voltage state of circuit in the maintenance process, be convenient for implement the maintenance.

Drawings

FIG. 1 is a schematic diagram of a typical splitter configuration;

fig. 2 is a schematic diagram of a power supply path when the splitter switches the power supply mode in the embodiment of the present application;

fig. 3 is a schematic diagram illustrating distribution of internal high-voltage regions and low-voltage regions when a splitter switches a power supply mode according to an embodiment of the present application;

FIG. 4 is a schematic diagram of the embodiment of the present application illustrating the voltage in the high voltage region being adjusted in a predetermined region;

fig. 5 is a schematic structural diagram of a high-voltage switchable splitter in an embodiment of the present application;

FIG. 6 is a schematic diagram of a high voltage state switching power supply mode in an embodiment of the present application;

fig. 7 is a schematic view of a branching device of a flow restricting device inside a BU barrel according to an embodiment of the present application;

fig. 8 is a schematic view of a splitter of a flow restricting device outside a BU barrel according to an embodiment of the present application;

FIG. 9 is a schematic diagram of a trunk break cable fault in an embodiment of the present application;

FIG. 10 is a schematic diagram illustrating a switching power supply state during a main line cable break maintenance in an embodiment of the present application;

FIG. 11 is a schematic diagram of a branch cable break fault in an embodiment of the present application;

FIG. 12 is a schematic diagram illustrating a switching power supply state before a branch cable is broken for maintenance in the embodiment of the present application;

fig. 13 is a schematic diagram illustrating a switching power supply state during branch cable breaking maintenance in the embodiment of the present application.

Detailed Description

In the embodiments of the present application, a submarine cable system, that is, an undersea optical cable system, refers to a communication network system formed by a plurality of communication cables. The communication cable in the system is laid on the seabed, and therefore can be called as a submarine cable line to transmit optical signal communication, so as to realize a cross-sea area communication function. Submarine cable systems can enable long distance communications, for example, data communications can be accomplished across the ocean for tens of thousands of kilometers. It should be noted that the submarine cable system described in the embodiment of the present application can also be used in relatively close communication areas such as crossing rivers, lakes, and the like.

Each submarine cable line in the submarine cable system can be connected with station equipment, and the station equipment is control equipment and can control, convert, forward and the like signals transmitted in the submarine cable line. And power supply, maintenance and control strategy modification can be carried out on the submarine cable line through the station equipment so as to ensure the normal operation of the communication function.

Submarine cable lines laid on the seabed can realize signal transmission through single-station landing and multi-station landing. The single-station landing means that a submarine cable line laid on the seabed is connected to a unified station device, and then signal shunting is carried out through the station device and transmitted to other station devices. The multi-station landing means that a submarine cable line laid on the seabed is branched on the seabed through a splitter and other components, so that a plurality of station equipment can be connected with each other to realize signal transmission. The site arrangement position of the multi-site landing mode is more flexible, and the communication area can be larger, so that the multi-site landing mode is mostly adopted in the submarine cable system in order to meet the requirements of geographic positions and landforms.

When a plurality of stations are registered in a submarine cable system, a plurality of submarine cable lines need to be connected through a splitter, and a part of optical signals need to be distributed to station equipment on other lines. For example, as shown in fig. 1, station a, station B, and station C are connected together by three submarine cable lines through a splitter BU, so that station a, station B, and station C can communicate with each other.

Besides the connection circuit, the splitter may also include other active components, such as a switching device. These components require power to perform their function, and the submarine cable line may also be provided with a plurality of repeaters to accommodate optical signal attenuation due to long distance transmission. The realization of the signal regulation function of the repeater also needs power supply, so that a power supply device can be arranged in the station equipment to realize the power supply of the repeater and the splitter on the line. For example, in fig. 1, each of a station a, a station B, and a station C is provided with a power supply apparatus PFE for supplying power to a repeater RPT and a splitter BU on each of the submarine cables.

In order to ensure that each active component on the submarine cable line can work normally, the station equipment can adopt a constant-current power supply mode for the connected lines, namely, the current supplied in the submarine cable line is constant no matter how many components are arranged on the submarine cable line, so that the stable power supply of each component is ensured. According to different connection modes of the submarine cable line on the splitter, power supply modes of the station equipment to the submarine cable line are different. For example, the station a supplies positive electricity to the connected submarine cable line, and the station B supplies negative electricity to the connected submarine cable line, so that the power supply parameters are adjusted together in the station a and the station B to realize constant-current power supply of the whole line from the station a to the station B; and site C may independently power the connected submarine cable lines. Thus, the constant current power supply requirements can be met without supplying excessive voltage in the site A, the site B and the site C.

In the above power supply method, the branch device may be provided therein with a connection circuit that connects each of the submarine cables and the ground device according to the respective power supply methods, and a ground device that is used to access the Sea Earth (SE), so that a relative potential difference is formed in the circuit. In the normal power mode, the connecting circuit can form a high-voltage zone and a low-voltage zone depending on the connected submarine cable line. In some embodiments, the connection circuit may include a first circuit and a second circuit, which may be connected to the sea line and the ground, respectively.

The first circuit and the second circuit are respectively connected with a plurality of submarine cable lines, two submarine cables connected with the first circuit are in a high-voltage state, and submarine cables connected with the second circuit are in a low-voltage state according to different power supply configurations of submarine cable communication systems.

For example, one end of the first circuit is connected to the site a and its corresponding submarine cable line, and the other end is connected to the site B and its corresponding submarine cable line; one end interface of the second circuit is connected with the grounding device, and the other end interface is connected with the station C and the corresponding submarine cable line, so that the communication connection between the stations A, B, C is realized, and the power supply of components on each submarine cable line is realized. In the normal supply mode, a positive voltage can be supplied at station a and a negative voltage can be supplied at station B, so that a constant current supply is formed in the path from station a to the submarine cable line and from the first circuit to the submarine cable line to station B, at which time a high-voltage zone is formed in the first circuit due to the submarine cable impedance as a result of the supply voltages at station a and station B. Another submarine line can be supplied with power via station C and a zero potential can be established in the second circuit, i.e. a low voltage area is established in the second circuit, since the supply line goes from station C to the submarine line and then to the second circuit to the earthing device.

In the embodiment of the present application, the submarine cable path with double-end power supply is called trunk, and the submarine cable path with single-end power supply and ocean ground is called branch. It should be noted that the trunk/branch, high-voltage/low-voltage areas are determined by the actual sea cable route and the location of the BU in the sea cable. For example, when the station B and the station C are connected by the first circuit, the power supply path from the station B to the station C is a main path, and a high voltage region is formed in the first circuit; when the station a and the grounding device are connected through the second circuit, the power supply path from the station a to the grounding device is branched and forms a low voltage region in the second circuit.

The submarine cable system can realize a communication function according to the above power supply method, but due to the complex seabed environment, during the service life of the submarine cable line of nearly 25 years, cable breakage failure may occur due to an unexpected situation. For example, fishing operations, volcanoes in the sea, earthquakes, reef wear, fish bites, hot springs, etc. can all cause cable break failures. Typically, a cable break fault includes an overall cable break as well as a partial cable break. Wherein, whole disconnected cable is that the submarine cable circuit breaks completely in a certain department, will directly lead to the communication interruption of partial circuit, for guaranteeing communication function, needs timely maintenance processing in order to resume communication, this application disconnected cable trouble for the power supply metal layer in the submarine cable expose, the condition of lug connection sea water.

For the cable-breaking fault with the exposed power supply metal layer, the power supply state can be switched, so that the submarine cable system maintains the communication function before the maintenance ship arrives, that is, in some embodiments of the application, the splitter further includes a switching device, and the switching device can switch the connection relationship between each submarine cable line and the connection circuit through components such as a relay and a port, so as to change the power supply mode.

For example, as shown in fig. 2 and 11, when a cable disconnection fault occurs in the submarine cable line corresponding to station C, that is, a cable disconnection fault occurs between stations C and BU of the submarine cable system, the power supply path may be changed by the switching device, so that station B and station C are connected, and the a-side submarine cable is connected to SE. At this point, station B may power the repeater RPTN (i.e., RPT numbered N) between the cable disconnect and BU, and station C may power the repeater RPTM (i.e., RPT numbered M) between the cable disconnect and station C. Therefore, the repeaters and BUs on the submarine cable lines can still maintain normal operation states, and the communication function is guaranteed.

Because in the maintenance process, the voltage in the submarine cable line cannot be too high, the safety of maintenance personnel is ensured. During the repair process, the lines that are generally to be repaired are connected to the low voltage area and are electrically processed at the site to reduce the voltage of the marine cable lines. Therefore, the circuit connection condition of the high-voltage area and the low-voltage area inside the splitter can be changed through the switching device, and the line to be maintained can be correspondingly connected to the circuit corresponding to the low-voltage area.

For example, as shown in fig. 3 and fig. 9, when a cable breaking fault occurs in the submarine cable line corresponding to station a, that is, a cable breaking fault occurs between station a and BU of the submarine cable system a, the power supply path can be changed by the switching device, station B and station C are connected, and the submarine cable at the a end is connected to SE, so that normal communication between station B and station C is ensured, and then station a is powered off, so that the submarine cable line between station a and BU is in a safe state in the maintenance process.

In the embodiment of the present application, the real-time switching device may be remotely controlled by a station device or other control devices to implement an automatic switching power supply manner, and such a splitter that implements a switching function through electrical switching control is called an electrical switching splitter (PSBU).

Since the switching device can change the circuit connection state as the high voltage region and the low voltage region in the splitter, a large potential difference change occurs before and after the switching. For example, depending on where the splitter is located in the submarine cable system, the high voltage region has a potential difference of up to 15kV with respect to the low voltage region, which is connected to the grounding means of the BU, at a potential close to 0V. Because the existence of this potential difference, at the switching process, the electric charge of storing in the submarine cable at switching point both ends can release to earthing device through the inside switching device of BU on, the high potential difference can produce surge current in the twinkling of an eye on switching device, and surge current's peak value can reach more than 1000A, damages switching device very easily, influences the normal operating of BU, reduces product life, increases the probability of inefficacy, damages whole spliter even.

To reduce the inrush current, the marine line may be voltage regulated before the switching process is performed, so that the potential difference between the high-voltage and low-voltage regions is controlled within a reasonable range. After the station power supply equipment is adjusted, the BU detects the voltage value of the high-voltage area relative to the low-voltage area, and if the detected voltage value is in a set interval, the BU is controlled to switch, and if the detected voltage value is not in the set interval, the BU does not operate.

For example, as shown in fig. 4, when a cable disconnection fault is detected, the target state can be switched by repeatedly adjusting the PFE output voltages of the station a and the station B until the controller inside the BU detects that the voltage difference is within a set (e.g., ± 500V). The voltage can be regulated by providing a positive voltage at site a and a negative voltage at site B, and setting the switching interval between positive and negative voltage on the BU on which the switching action is to be performed. It can be seen that, due to the repeated adjustment and debugging, the operation process takes much time, and especially when the switching voltage window of the BU is small, it needs to be adjusted many times to control the voltage difference in the BU within the switching interval, which is not favorable for the implementation of the switching operation. A + + and B- -in FIG. 4 represent magnitude values of the PFE supply voltage.

In order to alleviate the damage to the switching device or the whole splitter caused by the switching process, some embodiments of the present application provide a splitter that can perform switching in a high-voltage state, and the splitter can be applied to a submarine cable system. As shown in fig. 5, the splitter includes: switching device, first circuit, second circuit, earthing device and current limiting device. The first circuit and the second circuit are respectively connected with a plurality of submarine cable lines for realizing communication connection and power supply line connection among the submarine cable lines. For example, the first circuit is used for realizing connection of a submarine cable line between a station A and a station B to form a trunk line; and the second circuit is used for realizing connection of a submarine cable line between the station C and the grounding device to form a branch.

The switching device is arranged between the first circuit and the second circuit and used for switching the power supply modes of each submarine cable line and the first circuit and the second circuit so as to form a high-voltage area and a low-voltage area in the first circuit and the second circuit respectively. The switching device is internally provided with components such as a relay and a controller, and can control the first circuit and the second circuit to be connected with different submarine cable lines, so that the power supply mode switching is realized. For example, as shown in fig. 6, in the normal power supply mode, the station a and the station B are connected by a first circuit, and the station C and the grounding device are connected by a second circuit, so that a high voltage region is formed in the first circuit and a low voltage region is formed in the second circuit due to the particularity of the power supply mode. By means of the switching means, station a can be connected to the earthing means by means of a second circuit, and station B can be connected to station C by means of a first circuit, so that a high-voltage area is formed in the first circuit and a low-voltage area is formed in the second circuit.

It should be noted that in some embodiments, different connection modes may be applied to implement connection between different submarine cable lines, so as to switch power supply modes. For example, station a may be connected to station C by a first circuit via a switching device, station B may be connected to a grounding device by a second circuit, and so on. And the specific power supply mode can be determined according to the output type and the output range of the power supply device in each station device in the actual submarine cable system. For example, two station devices connected to each other on a trunk may supply two voltages of opposite polarities, respectively, thereby facilitating constant current supply.

The switching device is also connected with the grounding device through the current limiting device so as to absorb surge current formed by the high-voltage region when the power supply mode is switched through the current limiting device. The current limiting device can reduce the peak value of surge current flowing through the switching device through the arranged current limiting circuit. The method is realized in a submarine cable system, if a certain section of submarine cable breaks down, a power supply unit (PFE) in station equipment does not need to adjust voltage, and directly sends a switching command to the BU, so that the BU is switched into a target state to supply power through an internal switching device. The current limiting device is arranged between the grounding device and the switching device, so that the power supply mode switching of the splitter can be realized under the condition of potential difference of more than 15kV, the operation time is saved, and the normal operation of the submarine cable communication equipment is ensured.

The current limiting device can absorb surge current to control the current peak value at the switching moment to be a lower value, so that the current limiting device can be formed by various electronic devices capable of realizing current limiting, such as a resistor, an inductor, a semiconductor and the like. The current limiting device may also be composed of a current limiting circuit composed of various electronic devices, for example, the current limiting device may be a combination of a resistor and an inductor, a combination of a resistor and a semiconductor current limiting circuit, a combination of an inductor and a semiconductor current limiting circuit, or the like.

In order to achieve effective limitation of the inrush current in the connection circuit between the switching device and the grounding device, the current limiting device needs to meet certain electrical parameter requirements. For example, when the current limiting device is a resistor, the current can be limited by connecting a resistor in series with a circuit corresponding to the switching device. The resistor absorbs current pulse caused by high voltage switching in the switching process, so that the purpose of current limiting is achieved. The resistor should have a resistance value such that the generated inrush current is limited below a preset current peak value, i.e. the current up to 1000 class a is limited within an acceptable range, such as less than 40A, by adjusting the resistance value, the influence of the inrush current on the switching device is reduced, so that the energy of the inrush current is mainly concentrated on the current limiting device, and the reliability of the switching device is increased.

Since the magnitude of the surge current depends on the potential difference between the high-voltage region and the low-voltage region, i.e., the larger the potential difference, the larger the surge current is formed. Therefore, in order to achieve a good current limiting effect, the resistance value of the resistor is positively correlated with the potential difference between the high voltage region and the low voltage region, i.e., the larger the potential difference, the larger the resistance value of the current limiting device.

Similarly, for a current limiting device comprising an inductor, a semiconductor current limiting circuit and a combination thereof, the equivalent resistance value of the current limiting device is also positively correlated with the potential difference between the high voltage region and the low voltage region, so as to limit the surge current generated when the power supply mode is switched to be less than the preset current peak value.

The arrangement of the flow-limiting device in the splitter may vary depending on the actual configuration of the splitter. In one implementation, as shown in fig. 7, the current limiting device is modularly assembled with the switching device, the first circuit, and the second circuit and packaged inside the same splitter BU barrel, while the grounding device is disposed outside the BU barrel.

For example, the splitter may include a splitter BU barrel having a cylindrical structure, one submarine cable line connected to one end of the splitter BU barrel, and two submarine cable lines connected to the other end of the splitter BU barrel, and the first circuit, the second circuit, and the switching device are packaged in the splitter BU barrel. And packaging the current limiting device in a BU barrel of the branching device, and completing grounding treatment through a grounding circuit of the grounding device. The current limiting device, the switching device and the like are uniformly packaged into the BU barrel of the splitter, so that uniform modular assembly is facilitated, the position of an interface unit of the switching device is convenient to arrange, and the structure of the switching device is facilitated to be simplified.

Because the current limiting device can produce certain heat because of surge current's effect, these heats can produce whole temperature rise in BU inside for the heat dissipation is handled the degree of difficulty and is enlarged. Thus, in one implementation, as shown in fig. 8, the switching device, the first circuit, and the second circuit can be packaged inside a BU barrel, while the grounding device and the current limiting device are disposed outside the BU barrel, i.e., the current limiting device can be disposed with the grounding device. The current limiting device and the grounding device are arranged outside the BU barrel so as to simplify the connection interface of the current limiting device on the branching device. The structure not only saves the inner space of the BU barrel, but also can concentrate heat generated by surge current on the grounding device, and the grounding device is directly contacted with seawater or seabed ground, so that quick heat dissipation is easily realized, and the overall design difficulty of the branching device is reduced.

The splitter provided in the above embodiment may absorb the surge current through the current limiting device, thereby enabling the splitter to perform a switching action at a high voltage. Before the switching device performs the action of switching the power supply mode, the first circuit is connected with the two submarine cable lines to form a high-voltage area; the second circuit is connected to a sea cable line and to ground to form a low voltage region. After the switching device performs the action of switching the power supply mode, the submarine cable lines connected with the first circuit and the second circuit are changed, so that the two submarine cables connected with the first circuit are in a high-voltage area, and the submarine cables connected with the second circuit are in a low-voltage area.

The branching device can implement switching action according to actual working conditions. For example, when a cable breaking fault occurs on the branch, in order to ensure the communication function, a switching action may be performed after the cable breaking fault is detected, so that the corresponding repeater at the cable breaking point position can still supply power normally.

Obviously, in order to implement the switching action in time, a controller is also included in the splitter. The controller is connected with the switching device and establishes communication connection with the station equipment through a submarine cable line so as to receive a control command sent by the station equipment and control the switching device to complete switching action. Therefore, the controller is configured to receive a switching command input by the station device, and control the switching device to perform an action of switching the power supply manner according to the switching command.

For example, after a detected cable breakage fault occurs in a branch where the station C is located, the operation and maintenance personnel or the automatic control system may send a switching command through the station a or B. The switching command may be transmitted along the sea cable line to the controller of the splitter. The controller may generate a control instruction by executing the switching command and send the control instruction to the switching device. The switching device then performs a switching action in response to the received control command.

The specific switching method for the controller to control the switching device to perform the switching action may be determined according to the structure and principle of the switching device used by the splitter. For example, the controller outputs an electric signal with a specific voltage, and the electric signal is sent to the relay to control the relay to act and adjust the contact position of the electric shock switch so as to change the connection state of the circuit path. In addition, according to the number of the submarine cable lines connected to the branching device, the switching device can also perform switching actions in different modes, and correspondingly, switching commands in different modes can be set.

Based on the splitter, some embodiments of the present application further provide a submarine cable system, which includes a submarine cable line, a station device, and a splitter. The plurality of submarine cable lines can be connected through the plurality of splitters, namely, one submarine cable line is in communication connection with at least two other submarine cable lines through the splitters. In order to realize the hot switching under the high-voltage condition, the splitter comprises a switching device, a first circuit, a second circuit, a current limiting device and a grounding device. The current limiting device is arranged between the switching device loop and the grounding device so as to absorb surge current formed by a high-voltage area when the power supply mode is switched through the current limiting device.

And a plurality of repeaters are arranged on each submarine cable line so as to adjust the optical signal attenuation caused in the long-distance transmission process through the repeaters. And station equipment is connected to the plurality of submarine cable lines respectively so as to control each submarine cable line through the station equipment. And a power supply device is also arranged in the station equipment and is used for supplying power to the repeater and the splitter at constant current.

In order to realize the transmission of optical signals and power supply electric energy, the submarine cable line at least comprises an optical fiber line and a power supply line. In one implementation, the submarine cable line is a multi-layer cable structure, and includes an optical fiber layer located in the center of the cable and a power supply layer coated outside the optical fiber layer. The first circuit and the second circuit of the repeater and the splitter are connected to the power supply layer. That is, the repeater can obtain power from the power supply layer, and the power supply layer of a different submarine cable line connects the first circuit or the second circuit of the splitter, implementing a specific power supply mode.

The power supply layer is arranged on the submarine cable line coated with the optical fiber layer, so that the optical fiber layer can be protected by the power supply layer, and the power supply layer can be damaged before the optical fiber layer is damaged when the submarine cable line is damaged by friction, impact and the like due to the influence of submarine environmental factors. Before the optical fiber layer is damaged, the damage of the power supply layer can be detected firstly, so that the optical fiber layer is maintained in time before being damaged, and the normal operation of the communication function is ensured.

According to the technical scheme, the splitter and the submarine cable system provided by the embodiment can use current limiting devices such as resistors to absorb surge current during switching, reduce the peak value of the surge current, and effectively reduce the damage caused by the surge current during high-voltage switching of the BU. And is connected to the ocean ground using a current limiting device to ensure a bleed path for current during switching so that normal operation of other circuits in the BU is not affected.

In addition, the splitter and the submarine cable system can realize direct switching to different power supply states through the switching device of the splitter in the shortest time when a submarine cable is broken, ensure the communication function and strive for the maintenance time of the accident submarine cable. The offshore construction ship has high cost, and the maintenance cost can be saved by saving the maintenance time, so the offshore construction ship has great practical value.

Based on the above submarine cable system, some embodiments of the present application further provide a cable disconnection switching method, where the cable disconnection switching method may be used to guide an operation and maintenance worker to perform maintenance operation, and may also be configured in a station device, and is used to automatically send a control command to a splitter. The cable breaking switching method comprises the following steps:

s1: detecting the position of a cable breaking point;

s2: if the cable breaking point is positioned on the trunk, maintaining the current power supply state until maintenance is started, sending a switching command to the splitter so as to drive a switching device of the splitter to execute an action of switching a power supply mode;

s3: if the cable breaking point is located on the branch, a switching command is sent to the splitter to maintain power supply to the repeater on the branch, and the switching command is sent to the splitter again when maintenance is started to remove power supply to the branch to ensure maintenance safety.

The trunk line is a submarine cable line connected with a high-pressure area of the splitter, and the branch line is a submarine cable line connected with a low-pressure area of the splitter. When a cable breaking fault is sent in the submarine cable system, the position of a cable breaking point can be detected through detection equipment built in the submarine cable system. The cable break point location may also include the specific location of the submarine cable line at which the cable break point is located. The splitter performing the switching is determined according to the specific location where the splitter is located, for example, the splitter closest to the cable breaking point may be used as the splitter performing the switching action, and the switching command is sent to the splitter through the station device.

The following describes a processing method of an ocean cable anomaly by combining specific examples in two different scenarios, that is, a switching method implemented by the splitter in the above embodiment is applied when a cable break fault occurs and during a maintenance process. In the following example, RPT is used as an optical signal conditioner in a submarine cable system, and needs uninterrupted power supply to ensure the submarine cable communication quality.

In one exemplary embodiment, as shown in fig. 9, if the cable break point is located on the trunk, i.e., on the submarine cable line between the stations a and BU (or on the submarine cable line between the stations B and BU), since the power supply layer of the submarine cable line at the cable break point is broken, the broken power supply layer is in contact with the sea water or the submarine ground, which is equivalent to the cable break point being in a grounded state. At the moment, because the site A adopts constant current power supply, the power supply of the repeater RPTM on the submarine cable line between the site A and the cable breaking point is not influenced; similarly, since the station B also supplies the main line with the constant current, the repeater RPTN and the splitter BU on the submarine cable line between the cable breaking point and the BU can supply power through the station B. Namely, when the cable breaking point is positioned on the trunk line, the cable breaking fault does not influence the normal power supply of the submarine cable system in a short time, and the power supply state can be maintained until the maintenance ship arrives.

After the maintenance ship arrives, the operation and maintenance personnel maintain the submarine cable. At this time, in order to ensure the safety of the maintenance environment, the power supply device of the station equipment needs to perform power-down processing on the submarine cable line where the cable breaking point is located. Namely, the operation and maintenance personnel can control the switching device in the splitter to execute the switching action by sending the switching command. As shown in fig. 10, after the switching is completed, the power supply mode of the submarine cable system is switched from the original power supply mode of the station a and the station B to the power supply mode of the station B and the station C, so that the normal power supply of the submarine cable lines corresponding to the station B and the station C is ensured, and the communication function of the corresponding lines is maintained. At this point, the PFE at site A is powered down to reduce the voltage on the line at the cable break point, so that it is maintained at a safe voltage condition. Obviously, since power down processing is done at site a, all optical communications at site a will be completely interrupted during maintenance until maintenance is complete.

It can be seen that, in the above example, during the switching action performed by the switching device, attention does not need to be paid to the voltage difference of the internal high-voltage region of the BU to the SE, and the surge current caused during the switching process can be suppressed by the current limiting device, so that a lot of time is saved for maintenance personnel.

In another exemplary embodiment, as shown in fig. 11, if the cable breaking point is located on the sea cable line of the branch, i.e. the sea cable line between the station C and the BU, and the cable breaking fault occurs, since both end lines of the RPTN on the sea cable line between the cable breaking point and the BU are grounded, the RPTN between the BU and the cable breaking point cannot obtain power supply, and the operation is stopped.

In order to maintain the power supply of the repeater RPTN, after detecting that the branch submarine cable line has a cable-breaking fault, a switching command may be sent to the splitter to control the splitter to perform the first switching. As shown in fig. 12, after the first switching is completed, the power supply mode of the submarine cable system is changed from the original station a and station B power supply mode to station B and station C power supply mode, so that the repeater RPTN between the cable breaking point and the BU can be supplied with power by station B, and the repeater RPTM between the cable breaking point and station C can be supplied with power by station C, thereby ensuring normal power supply of submarine cable lines corresponding to station B and station C, and maintaining the communication function of corresponding lines.

After the first switching is completed, the submarine cable system can maintain normal communication of the system for a short time and wait for a maintenance ship to arrive. As shown in fig. 13, after the maintenance ship arrives, in order to ensure the safety of the maintenance environment, the splitter needs to perform a second switching operation, that is, the power supply modes of the station B and the station C need to be switched back to the original power supply modes of the station a and the station B, so as to ensure the normal communication of the submarine cable line between the station a and the station B, thereby maintaining the branch independently, and similarly, the PFE of the station C needs to perform power-off processing, so as to ensure the maintenance safety.

It can be seen that, in the above example, the power supply path in the splitter is changed in both the switching processes, the voltage difference of the switching is large, and due to the arrangement of the current limiting device, the surge current flows into the grounding device through the internal switching device and the current limiting device, so as to complete high voltage switching, reduce the damage to the switching device in the switching process, and reduce the maintenance time on the premise of ensuring the communication function as much as possible.

In an exemplary embodiment, a station device is further provided, where the station device has a built-in controller, and the controller may be configured to execute the cable breaking switching method, that is, after detecting a cable breaking point, sending a switching command according to the cable breaking point; if the cable breaking point is positioned on the trunk, maintaining the current power supply state until maintenance is started, sending a switching command to the splitter so as to drive a switching device of the splitter to execute an action of switching a power supply mode; if the cable breaking point is located on the branch, a switching command is sent to the splitter to maintain power supply to the repeater on the branch, and the switching command is sent to the splitter again when maintenance is started to remove the power supply to the branch to ensure the maintenance safety.

The controller may be internally provided with a processor and a memory, wherein the memory may store a control program corresponding to the cable disconnection switching method, and the processor may call the corresponding control program from the memory and perform pre-coding on the downlink data by executing the control program. The processor may be a Central Processing Unit (CPU), a Network Processor (NP), or a combination of the CPU and the NP. The processor may also further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a Programmable Logic Device (PLD), or a combination thereof.

The PLD may be a Complex Programmable Logic Device (CPLD), a field-programmable gate array (FPGA), a General Array Logic (GAL), or any combination thereof.

The memory may include volatile memory, such as random-access memory (RAM); the memory may also include non-volatile memory, such as read-only memory (ROM), flash memory, a hard disk, or a solid state disk; the memory may also comprise a combination of the above kinds of memories.

In one exemplary embodiment, a communication apparatus is also provided, which may be a terminal or a chip in a terminal or a system on a chip. The communication device can realize the functions of the cable-breaking switching method, and the functions can be realized through hardware. The communication apparatus may include: logic circuitry and an input-output interface, wherein the input-output interface can be used to obtain data and send data. The processor may be configured to support the communication device to implement the cable-break switching method.

In an exemplary embodiment, a computer-readable storage medium is also provided, which may be a readable non-volatile storage medium having stored therein instructions, which when run on a computer, cause the computer to perform the above-described cable-break switching method.

In an exemplary embodiment, a computer program product containing instructions is also provided, which when run on a computer, enables the computer to perform the above-described cable break switching method.

In one exemplary embodiment, there is also provided a communication apparatus, which may be a terminal or a chip or a system on a chip in a terminal, including one or more processors and one or more memories. The one or more memories are coupled to the one or more processors and the one or more memories are configured to store computer program code comprising computer instructions that, when executed by the one or more processors, cause the communication device to perform the cable disconnect switching method described above. The memory and the processor may be independent of each other and connected via a communication bus, or may be integrated together, that is, the computer program is directly stored in the processor.

The communication device may execute different computer programs by the processor to act as a sending end or a receiving end, respectively. For example, the memory may have stored therein both a computer program for transmitting data and a computer program for receiving data. When the communication device serves as a receiving end, the power supply information data detected by the sensor can be received in real time so as to detect the position of a cable breaking point. When the communication device is used as a sending end, the processor can extract the computer program code for sending data from the memory, so that after the cable breaking point position is obtained, the cable breaking point position is judged, and the switching command transmission is completed.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part.

The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wire, such as coaxial cable, fiber optic cable, digital subscriber line, or wireless, such as infrared, wireless, microwave, etc. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk), among others.

Embodiments of the present application are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the embodiments of the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present application and their equivalents, the present application is also intended to encompass such modifications and variations.

Claims (13)

1. A branching device applied to a submarine cable system, comprising: the circuit comprises a switching device, a first circuit, a second circuit, a grounding device and a current limiting device;

the first circuit and the second circuit are respectively connected with a plurality of submarine cable lines;

the switching device is arranged between the first circuit and the second circuit and used for connecting or disconnecting the first circuit and the second circuit so as to switch the power supply mode of each submarine cable line with the first circuit and the second circuit, and a high-voltage area or a low-voltage area is formed in the first circuit and the second circuit respectively;

the switching device is also connected with the grounding device through the current limiting device so as to absorb surge current formed by the high-voltage area when the power supply mode is switched through the current limiting device.

2. The splitter according to claim 1, wherein said current limiting device is assembled in a modular fashion with said switching device, said first circuit and said second circuit and enclosed inside a splitter BU barrel; the grounding device is arranged outside the BU barrel.

3. The splitter according to claim 1, wherein said switching device, said first circuit and said second circuit are packaged inside a BU bucket; the grounding device and the current limiting device are arranged outside the BU barrel.

4. A splitter according to claim 3, wherein the current limiting device is integrated within the grounding device such that the switching device is grounded via the current limiting device.

5. A splitter according to claim 1, wherein the current limiting means comprises a combination of one or more of a resistor, an inductor and a semiconductor current limiting circuit.

6. A splitter according to claim 5, wherein the current limiting device is a resistor; the resistance value of the resistor is positively correlated with the potential difference between the high-voltage area and the low-voltage area so as to limit the surge current formed when the power supply mode is switched to be below a preset current peak value.

7. The splitter according to claim 1,

before the switching device performs the action of switching the power supply mode, the first circuit is connected with the two submarine cable lines to form a high-voltage area; said second circuit being connected to one of said sea cable lines and to ground to form a low voltage region;

after the switching device performs an operation of switching a power supply method, changing the two submarine cable lines connected to the first circuit to form a high-voltage area; altering a sea cable line connected to the second circuit to form a low voltage region.

8. The splitter of claim 1, further comprising a controller; the controller is connected with the switching device and establishes communication connection with the station equipment through the submarine cable line; the controller is configured to receive a switching command input by the station equipment and control the switching device to execute an action of switching the power supply mode according to the switching command.

9. The splitter according to claim 1,

the grounding device comprises at least one grounding electrode extending to the outside of the branching device, and the grounding electrode is in contact with the seawater and is used for guiding surge current generated during switching into the seawater.

10. A submarine cable system comprising a plurality of submarine cable lines, and a plurality of site devices connecting said submarine cable lines;

each of the sea cable lines is provided with a plurality of repeaters and the splitter of any one of claims 1 to 9; one submarine cable line is in communication connection with at least two other submarine cable lines through the splitter;

and a power supply device is arranged in the station equipment and is used for supplying power to the repeater and the splitter at constant current.

11. A submarine cable system according to claim 10, wherein the submarine cable line is a multi-layer cable structure comprising an optical fiber layer at the center of the cable and a power supply layer coated outside the optical fiber layer; the first circuit and the second circuit of the repeater and the splitter are connected to the power supply layer.

12. A cable breakage switching method applied to a submarine cable system including the splitter according to any one of claims 1 to 9, the cable breakage switching method comprising:

detecting the position of a cable breaking point;

if the cable breaking point is located on a trunk line, maintaining the current power supply state until maintenance is started, sending a switching command to the splitter to drive a switching device of the splitter to execute an action of switching a power supply mode, wherein the trunk line is a submarine cable line connected with a high-voltage area of the splitter;

if the cable breaking point is located on a branch, sending a switching command to the splitter to maintain power supply to the repeater on the branch, and sending the switching command to the splitter again when maintenance is started to cancel power supply to the branch to ensure safe maintenance, wherein the branch is a submarine cable line connected with a low-voltage area of the splitter.

13. The cable break switching method according to claim 12, wherein the method further comprises, at the start of maintenance: and performing power-off treatment on the submarine cable line where the cable breaking point is located through a power supply device of the station equipment.

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