Underwater beacon based subsea cable fault location system

Abstract

The application is a submarine cable fault positioning system based on underwater beacon, comprising a head grounding box, a current transformer, an underwater beacon, a pressure-proof box, a tail grounding box, a current collector and a pulse signal receiver; the head grounding box and the tail grounding box are connected with the head and tail of the submarine cable respectively, the head grounding box is connected with the ground substation or ground communication equipment, and the tail grounding box is connected with the ground cable of the offshore platform; the current transformer is installed on the three-phase power line near the head of the submarine cable, and the current transformer is connected with the current collector; a plurality of pressure-proof boxes are installed on the submarine cable at intervals, and the underwater beacon is inserted in each pressure-proof box, the underwater beacon sends the pulse signal to the pulse signal receiver when powered, and the pulse signal receiver transmits the pulse signal to the upper computer; the inductive power taking module and the chemical battery are installed in the pressure-proof box, the inductive power taking module supplies power for the underwater beacon when the cable is normal, and the chemical battery supplies power for the underwater beacon when the cable is faulty. The current transformer and the underwater positioning beacon work cooperatively to accurately position the fault position.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of submarine cable fault detection, and particularly relates to a submarine cable fault positioning system based on underwater beacon. BACKGROUND

[0002] With the rapid development of submarine cable technology, the application of submarine cables is becoming more and more extensive, mainly for transmitting electric energy and optical fiber communication. However, the working environment of submarine cables is complex. On the one hand, with the increasing displacement of ships, large ship anchors can often reach the depth of submarine cable laying when they are lowered and parked, and when the winch is used to collect the anchor, it is easy to cause the submarine cable to break. On the other hand, as the depth of submarine cable laying increases, the submarine cable bears more pressure and is corroded by seawater faster, and the submarine cable can also be damaged by silt abrasion and fatigue due to free suspension. Once the cable fails, the loss is huge, so timely positioning of the fault location can realize the rapid operation and maintenance of the submarine cable.

[0003] In the marine environment, it is difficult to locate the fault of the submarine cable. Some existing technologies use a sounder to detect the cable and find the fault location through sound feedback, but the sounder needs to be carried by a patrol robot, and the positioning accuracy depends on the accuracy of the patrol path of the patrol robot, and also increases the complexity of the positioning device. Some others use a fault detector to locate the fault, but the fault detector can only determine the approximate range of the fault, and the specific location needs to be positioned by an underwater vehicle.

[0004] In summary, the existing technologies have problems such as inaccurate fault positioning and complex positioning devices, so the application proposes a submarine cable fault positioning system based on underwater beacon, which is not only simple in structure, but also realizes rapid detection while accurately positioning. SUMMARY

[0005] In view of the deficiencies of the prior art, the technical problem to be solved by the application is to provide a submarine cable fault positioning system based on underwater beacon.

[0006] In order to achieve the above purpose, the application adopts the following technical scheme:

[0007] A submarine cable fault positioning system based on underwater beacon, comprising a first end grounding box, a current transformer, an underwater beacon, a pressure-proof box, a terminal grounding box, a current collector and a pulse signal receiver.

[0008] The first end grounding box and the last end grounding box are connected with the first end and the last end of the submarine cable respectively, the first end grounding box is connected with the ground transformer substation or ground communication equipment, and the last end grounding box is connected with the ground cable of the offshore platform; a current transformer is installed on the three-phase power line close to the first end of the submarine cable, a current collector is located in the first end grounding box, the current collector is connected with the current transformer and simultaneously performs data transmission with the upper computer;

[0009] A plurality of pressure-proof boxes are installed on the submarine cable at intervals, an underwater beacon is inserted in each pressure-proof box, the underwater beacon supplies power to send a pulse signal to a pulse signal receiver installed on the offshore platform, the pulse signal receiver transmits the pulse signal to the upper computer; an inductive power supply module and a chemical battery are installed in the pressure-proof box, the inductive power supply module supplies power for the underwater beacon when the submarine cable is not faulty, and the chemical battery supplies power for the underwater beacon when the submarine cable is faulty.

[0010] Further, the underwater beacon comprises a pressure-proof shell, a sealed shell and a pulse signal emitting chip; one end of the pressure-proof shell is connected with one end of the sealed shell, the other end of the sealed shell is inserted in the pressure-proof box, and the pulse signal emitting chip is embedded in the pressure-proof shell and the sealed shell.

[0011] Further, the inductive power supply module comprises an electromagnet core, an induction coil, a rectifier circuit, a filter circuit, a voltage stabilizing circuit and a control chip; the induction coil is embedded in the pressure-proof box, and the electromagnet core is located at the center of the induction coil; the rectifier circuit, the filter circuit, the voltage stabilizing circuit and the control chip are integrated on a circuit board, and the circuit board is built in the pressure-proof box; the inductive voltage generated by the induction coil supplies power for the underwater beacon after rectification, filtering and voltage stabilization; the control chip is used to control the inductive power supply module or the chemical battery to supply power for the underwater beacon.

[0012] Further, the service life of the system is related to the marine environment coefficient ξ e , which is expressed as:

[0013]

[0014] Wherein, a i represents the concentration of the i-th marine pollutant, A i represents the standard concentration of the i-th marine pollutant, I represents the type of marine pollutant, S QI represents the quality index of submarine sediments, S BI represents the index of marine habitat organisms; and a represents correlation, which is positive correlation here.

[0015] Compared with the prior art, the beneficial effects of the present application are:

[0016] (1) The application accurately locates the fault position through the cooperative working mode of the three-phase current transformer and the underwater positioning beacon; the three-phase current collected by the three-phase current transformer is used for judging whether the submarine cable is faulty, the position of the underwater beacon is determined according to the different changes of the frequency of the pulse signal sent by the underwater beacon, and then the fault position is determined, thereby providing information for operation and maintenance. In addition, the position of the submarine cable can also be located according to the sending position of the pulse signal.

[0017] (2) When the submarine cable is faulty, the upper computer can issue a pre-warning, so that the ground substation or ground communication equipment can reduce the energy output power, and the damage degree of the three-phase core of the submarine cable can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is the overall structure diagram of the application;

[0019] Figure 2 is the internal structure diagram of the underwater beacon;

[0020] Figure 3 is the internal schematic diagram of the front end of the pressure prevention groove;

[0021] In the figure, 1 is a first end grounding box; 2 is a current transformer; 3 is an underwater beacon; 4 is a pressure prevention box; 5 is a terminal grounding box; 6 is a wire clamp;

[0022] 301 is a pressure prevention shell; 302 is a sealing shell; 303 is a pulse signal emitting chip; 401 is an electromagnetic core; 402 is an electromagnetic coil. DETAILED DESCRIPTION

[0023] The technical solutions of the application will be described in detail below in combination with the drawings and specific embodiments, but the protection scope of the application is not limited thereto.

[0024] The application is a submarine cable fault positioning system based on an underwater beacon, comprising a first end grounding box 1, a current transformer 2, an underwater beacon 3, a pressure prevention box 4, a terminal grounding box 5, a current collector (not shown in the figure) and a pulse signal receiver (not shown in the figure);

[0025] The first end grounding box 1 and the last end grounding box 5 are connected with the first end and the last end of the submarine cable respectively, the first end grounding box 1 is located on the coast, and the first end grounding box 1 is connected with the ground transformer substation or the ground communication equipment, so as to realize the connection between the ground transformer substation or the ground communication equipment and the submarine cable; the last end grounding box 5 is located on the offshore platform, and the last end grounding box 5 is connected with the ground cable of the offshore platform, so as to realize the connection between the ground cable of the offshore platform and the submarine cable; the current transformers 2 are respectively installed on the three-phase power lines close to the first end of the submarine cable, the current collector is located in the first end grounding box 1, the current collector is connected with the current transformers 2, the current transformers 2 collect the three-phase currents of the submarine cable and transmit to the current collector, the current collector converts the analog signals of the three-phase currents into digital signals, and then transmits to the upper computer in a wireless mode; when the three-phase unbalanced current occurs, that is, the three-phase currents exceed the threshold value, it indicates that the submarine cable has a fault;

[0026] The submarine cable is provided with a plurality of pressure-proof boxes 4 which are spaced apart by wire hoops 6, and each of the pressure-proof boxes 4 is inserted with an underwater beacon 3; the pressure-proof box 4 is provided with an inductive power supply module and a chemical battery for supplying power to the underwater beacon 3; when the submarine cable has no fault, the inductive power supply module obtains an induced voltage according to electromagnetic induction to supply power to the underwater beacon 3; when the submarine cable has a fault, the chemical battery supplies power to the underwater beacon 3; the underwater beacon 3 is powered on to send a pulse signal to the pulse signal receiver installed on the offshore platform, the pulse signal receiver modulates the pulse signal and then transmits to the upper computer in a wireless mode; since the frequencies of the pulse signals sent by the underwater beacon 3 under the two power supply modes are different, the upper computer can lock the position of the underwater beacon 3 according to the different frequencies of the pulse signals, and then realize fault positioning.

[0027] The underwater beacon 3 comprises a pressure-proof shell 301, a sealed shell 302 and a pulse signal emitting chip 303; one end of the pressure-proof shell 301 is connected with one end of the sealed shell 302, the pulse signal emitting chip 303 is embedded in the pressure-proof shell 301 and the sealed shell 302, and the other end of the sealed shell 302 is inserted into the pressure-proof box 4, so that most of the underwater beacon 3 is located outside the pressure-proof box 4, and the attenuation rate of the pulse signal can be effectively reduced; the pressure-proof shell 301 is used for blocking the impact force of seawater on the underwater beacon 3, so as to ensure the sensitivity of the pulse signal emitting chip 303; the sealed shell 302 is used for preventing seawater from entering the inside of the underwater beacon 3 and preventing corrosion, and provides a dry and sealed packaging environment for the pulse signal emitting chip 303.

[0028] The induction power module comprises an electromagnet core 401, an induction coil 402, a rectifier circuit, a filter circuit, a voltage stabilizing circuit and a control chip; the induction coil 402 is embedded in the pressure-proof box 4, the electromagnet core 401 is located at the center of the induction coil 402, and the electromagnet core 401 plays a role of magnetic concentration; the rectifier circuit, the filter circuit, the voltage stabilizing circuit and the control chip are integrated on a PCB, and the PCB is built in the pressure-proof box 4; the rectifier circuit, the filter circuit and the voltage stabilizing circuit are all conventional circuits in the field, and will not be described here. Due to the existence of the alternating magnetic field around the submarine cable, the alternating magnetic field generates an induced voltage in the induction coil 402 according to the principle of electromagnetic induction, the induced voltage supplies power to the underwater beacon 3 after rectification, filtering and voltage stabilization, so the underwater beacon 3 has two power supply branches, one of which is connected with the chemical battery, and the other of which is connected with the induction power module, and a switch is arranged on each of the two power supply branches, and the switch is controlled to be turned on and off by the control chip, so as to control the corresponding power supply branch to be connected. When the submarine cable is not faulty, the induced voltage generated by the induction coil 402 is a standard voltage (the power supply voltage of the underwater beacon), which supplies power to the underwater beacon 3, and the pulse signal transmitting chip 303 sends a pulse signal of a specific frequency to the pulse signal receiver; when the submarine cable is faulty, the alternating magnetic field around the submarine cable is unstable, and the induced voltage formed on the induction coil 402 is difficult to reach the standard voltage, so it is difficult to supply power to the underwater beacon 3, and therefore the chemical battery supplies power, and the pulse signal transmitting chip 303 sends a pulse signal of another frequency to the pulse signal receiver; the frequencies of the pulse signals sent by the pulse signal transmitting chip 303 are different in the two power supply modes, so the position of the underwater beacon 3 sending the pulse signal of the different frequency can be quickly locked according to the different frequencies of the pulse signals, and then the fault position is determined.

[0029] The submarine cable is used for transmitting electric energy and communication, and comprises a wire core, a metal sheath, an inner protective layer and an outer protective layer from inside to outside. When the submarine cable is faulty, including single-phase short circuit, two-phase ground short circuit and three-phase short circuit, the current collected by the current transformer of the corresponding phase will far exceed the threshold value, and the upper computer will prompt that a fault occurs. During the process of transmitting electric energy and communication by the submarine cable, a leakage current will appear in the inner protective layer of the submarine cable. When no fault occurs, the leakage current of the inner protective layer is small. Since the submarine cable is mostly used for long-distance transmission, the capacitive current is far greater than the inductive current, so the capacitive current of the inner protective layer is used as an index of normal transmission of the line. The capacitive current w is the angular frequency, C is the wire core capacitance, U i is the phase voltage; when a fault occurs, the leakage current will increase sharply and far exceed the normal threshold value.

[0030] The service life of the system is not only related to the service life of the device, but also related to the marine environment coefficient ξ e , and the marine environment coefficient ξ eThe marine pollutant concentration, the seabed sediment quality index and the marine habitat index are positively correlated, and the specific correlation is Wherein, a i represents the concentration of the i-th marine pollutant, A i represents the standard concentration of the i-th marine pollutant, I represents the type of marine pollutant, represents the correlation, S QI represents the seabed sediment quality index, S BI represents the marine habitat index. Marine pollutants can directly affect the protective layer on the surface of the submarine cable, thereby affecting the service life of the system. The seabed sediment will accumulate on the surface of the submarine cable, increasing the weight of the submarine cable. The secretions of marine habitats are corrosive and can corrode the cable, thereby affecting the service life of the system. Therefore, when deploying the system, the marine environment should be fully considered, high-pollution areas should be avoided, and sufficient length of cable should be reserved to prevent too much seabed sediment from attaching to the surface of the cable to reduce the mechanical strength of the core. When arranging the cable route, the sinking depth of the cable needs to be controlled to reduce the influence of marine habitats. The deeper the sinking depth, the fewer the marine habitats.

[0031] Since the submarine cable is provided with a plurality of underwater beacons 3 at intervals, the route position of the full length of the submarine cable can be obtained according to the position of the pulse signal. The route here refers to the route passed by the submarine cable. When a passing ship is encountered, the intensity of the pulse signal attenuates, and the intensity of the pulse signal received by the upper computer is lower than the normal value. Therefore, the upper computer can send a warning signal to the passing ship to remind the passing ship to prohibit anchoring. In addition, the change of ocean current will cause the position of the submarine cable to change, so the position of the pulse signal emitted by the underwater beacon 3 will change, so the position of the submarine cable can be obtained, and the positioning of the submarine cable can be realized.

[0032] The working principle and working process of the application are as follows:

[0033] The whole system works cooperatively through the three-phase current transformer and the underwater beacon to realize accurate positioning of the fault; on the one hand, the high pressure in the inner sheath of the submarine cable will cause a leakage current, and the leakage current is within the normal threshold range when no fault occurs, when the outer sheath of the submarine cable is broken, the leakage current increases sharply and far exceeds the normal threshold, thereby causing three-phase unbalanced current, so the three-phase current transformer 2 installed on the outgoing line end of the first end grounding box 1 collects the three-phase current, the collected three-phase current is transmitted to the current collector, the current collector converts the analog signal of the three-phase current into a digital signal and sends it to the upper computer, when three-phase unbalanced current occurs, it indicates that the submarine cable has a fault; on the other hand, when a fault occurs, the alternating magnetic field around the submarine cable is unstable, the induced voltage formed on the induction coil 402 is difficult to reach the standard voltage size, and it is difficult to power the underwater beacon 3, so the chemical battery is powered, and the pulse signal transmitting chip 303 sends another frequency pulse signal to the pulse signal receiver; the frequency of the pulse signal transmitted by the pulse signal transmitting chip 303 is different under the two power supply modes, and the upper computer can quickly lock the position of the underwater beacon 3 according to the frequency difference of the pulse signal, and then determine the fault position, provide information for the operation and maintenance of the submarine cable; at the same time, the upper computer can issue an early warning to reduce the energy output power of the ground substation or ground communication equipment, and reduce the damage degree of the three-phase wire core of the submarine cable.

[0034] The unmentioned part of the application is applicable to the prior art.

Claims

1. A submarine cable fault location system based on underwater beacons, characterized in that, The system includes a front grounding box, a current transformer, an underwater beacon, a pressure relief box, a rear grounding box, a current acquisition device, and a pulse signal receiver; The head-end grounding box and the tail-end grounding box are connected to the head and tail of the submarine cable, respectively. The head-end grounding box is connected to the ground substation or ground communication equipment, and the tail-end grounding box is connected to the ground cable of the offshore platform. Current transformers are installed on the three-phase power lines near the head of the submarine cable. The current collector is located in the head-end grounding box and is connected to the current transformers. At the same time, it transmits data with the host computer. When a three-phase unbalanced current occurs, the submarine cable is considered to be faulty. Multiple pressure relief boxes are installed at intervals along the submarine cable. Each pressure relief box contains an underwater beacon. When powered, the underwater beacon sends pulse signals to a pulse signal receiver installed on the offshore platform. The pulse signal receiver then transmits the pulse signals to a host computer. The pressure relief box contains an inductive power harvesting module and a chemical battery. When the submarine cable is functioning normally, the inductive power harvesting module powers the underwater beacon. When a fault occurs, the chemical battery powers the underwater beacon. The frequency of the pulse signals sent by the underwater beacon differs between the two power supply methods.

2. The submarine cable fault location system based on underwater beacons according to claim 1, characterized in that, The underwater beacon includes a pressure-resistant housing, a sealed housing, and a pulse signal transmitting chip; one end of the pressure-resistant housing is connected to one end of the sealed housing, the other end of the sealed housing is inserted into the pressure-resistant housing, and the pulse signal transmitting chip is embedded in the pressure-resistant housing and the sealed housing.

3. The submarine cable fault location system based on underwater beacons according to claim 1 or 2, characterized in that, The inductive energy harvesting module includes an electromagnet core, an induction coil, a rectifier circuit, a filter circuit, a voltage regulator circuit, and a control chip. The induction coil is embedded in a pressure-resistant box, and the electromagnet core is located at the center of the induction coil. The rectifier circuit, filter circuit, voltage regulator circuit, and control chip are integrated on a circuit board, which is also built into the pressure-resistant box. The induced voltage generated by the induction coil is rectified, filtered, and regulated to power the underwater beacon. The control chip is used to control the inductive energy harvesting module or chemical battery to power the underwater beacon.

4. The submarine cable fault location system based on underwater beacons according to claim 1, characterized in that, The system's service life and marine environmental factor ξ e The marine environmental coefficient is expressed as follows: Among them, a i A represents the concentration of the i-th marine pollutant. i S represents the standard concentration of the i-th marine pollutant, I represents the type of marine pollutant, and S represents the standard concentration of the i-th marine pollutant. QI S represents the mass index of seabed sediments. BI Indicates the marine habitat index; This indicates a correlation, specifically a positive correlation.

Images