A deep-sea high-reliability underwater distributed power supply and signal transmission system

Abstract

The application relates to a deep-sea high-reliability underwater distributed power supply and signal transmission system, which is divided into a power supply system, a transmission system and a collection system according to functions, and is constructed into a hierarchical structure according to nodes, and comprises relay nodes, power supply optoelectronic nodes, digital hydrophone nodes of the collection system and transmission nodes of the transmission system; the power supply optoelectronic nodes are divided into power supply parts and optoelectronic nodes, the optoelectronic nodes are integrated in a data transmission module, the power supply parts output high-voltage currents, the power supply parts are connected with input ends of the optoelectronic nodes through voltage reduction and current / voltage conversion circuits, and the power supply parts and the conversion circuits constitute the power supply system. The distributed power supply and signal transmission system has underwater high-reliability and high-integration degree optical relay transmission technology, realizes reliable long-distance information return, has multi-node constant-current direct-current remote power supply system technology, and realizes reliable long-distance power supply and distribution.

Description

Technical Field

[0001] This invention relates to the field of underwater acoustic equipment design and manufacturing, and in particular to a highly reliable distributed power supply and signal transmission system for deep-sea underwater applications. Background Technology

[0002] The construction and development of underwater intelligent seabed observation networks presents practical challenges such as how to reliably transmit information acquired by sensing units over long distances and the long-term reliability of underwater power supply.

[0003] Currently, the common methods for long-distance information transmission over thousands of kilometers are either wireless satellite communication or submarine optical cables. The disadvantages of wireless satellite communication are limited bandwidth, easy exposure, susceptibility to interference, and easy signal interception. Submarine optical cable transmission offers stable and high-speed signals, but the cables are easily damaged. Therefore, it is necessary to develop a technology that uses submarine optical cables to connect multiple underwater nodes to form a distributed network for backhaul.

[0004] Power supply over long distances of thousands of kilometers is also a bottleneck that urgently needs to be overcome. Currently, the mainstream method for submarine observation networks is to use submarine optical-electric composite cables to achieve negative voltage unipolar DC power supply. The advantages are high voltage long-distance transmission and low loss. The DC conversion module then converts the voltage to low voltage to supply the underwater circuit. However, the long transmission distance is prone to damage from external forces, and the insulation deteriorates, leading to abnormal power supply and seriously affecting the long-term reliability of the underwater power supply circuit. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a highly reliable distributed power supply and signal transmission system for deep-sea and ocean environments. The power supply and signal transmission system is functionally divided into a power supply system, a transmission system, and a data acquisition system. The system is structured hierarchically by nodes, including relay nodes, power optoelectronic nodes, digital hydrophone nodes of the data acquisition system, and transmission nodes of the transmission system. Each power optoelectronic node consists of a power supply section and an optoelectronic node, which is integrated into the data transmission module. The power supply section outputs a high-voltage current, which, after being stepped down and converted to a current / voltage value, is connected to the input terminal of the optoelectronic node. The power supply section and the conversion circuit constitute the power supply system, while the information acquisition port of the optoelectronic node is connected to the data acquisition system. The acquisition system includes digital hydrophones and auxiliary sensors. The power supply terminals of the digital hydrophone nodes and auxiliary sensor components are connected to the input terminals of the photoelectric nodes through a low-voltage power bus, sharing a single power supply terminal. The power supply system, photoelectric nodes, and acquisition system form an independent working unit. When the number of working units increases to a certain number, the photoelectric nodes are connected to each other through a transmission system, which includes optical fibers and relay nodes. The optical fiber in the transmission system is a bidirectional transmission structure. The optical fiber is connected to the optical port of the data transmission module in sequence. That is, the optical port is the transmission node. The optical ports of the data transmission modules at both ends are connected to the optical port on the side of the photoelectric conversion module in the relay node through the optical fiber. The relay node includes a conversion module, a repeater, and a shore-based optical amplification module. The output end of the shore-based optical amplification module communicates with the host computer through a network switch, and the data is stored and backed up for management.

[0006] In one embodiment of the present invention, the step-down and current / voltage conversion circuit is constructed by a constant current / constant current (I / I) module and a constant current / constant voltage (I / V) module to form an underwater power supply module, and adopts a distributed power supply and distribution structure; in addition, the power supply method is a shore-based constant current power supply or an underwater battery pack, which can be flexibly selected according to the site installation or different design environment. The underwater battery pack is a front-end power supply design scheme, and the underwater battery pack is connected to the underwater power supply module of the power distribution through an underwater plug-in cable assembly.

[0007] In one embodiment of the present invention, the shore-based constant current power supply is a remote power supply solution, which adopts a highly reliable high-frequency switching converter circuit topology and is connected to the underwater power supply module to receive the constant current output from its port. In the shore-based constant current power supply, the output voltage and current signals are fed back to the power control circuit through Hall effect isolation sampling. After being compared and amplified with a reference voltage, they are used as the input signal of the PWM control chip to control the duty cycle of the output PWM wave of the pulse modulator, thereby realizing the adjustment of the output voltage and the setting of the constant current value.

[0008] In one embodiment of the present invention, the constant current / constant current module includes a filtering module, a constant voltage power supply module, a drive module, a control module, and a constant current conversion module. The constant current conversion module includes a high-frequency constant current conversion circuit and a rectifier-filter circuit. The control module includes a protection circuit and a startup circuit, which are respectively connected to the high-frequency constant current conversion circuit and the rectifier-filter circuit. The drive module is connected to the high-frequency constant current conversion circuit. Simultaneously, the input current passes through the filtering module and the constant voltage power supply module, directly supplying power to the control module, drive module, and constant current conversion module, respectively. The constant current / constant current conversion device corresponding to the constant current / constant current module uses push-pull or full-bridge circuits at its input. The output current is determined by the transformer's turns ratio; changing the transformer's turns ratio changes the output current.

[0009] In one embodiment of the present invention, the constant current / constant voltage module consists of a rectifier and filter module, a closed-loop control switch circuit, and a DC / DC converter module. The constant current voltage is input into the closed-loop control switch circuit through the rectifier and filter module. At the same time, the closed-loop control switch circuit and the DC / DC converter module are connected in parallel, and the sampling circuit provided in the closed-loop control switch circuit is connected to the constant current voltage to extract its voltage.

[0010] In one embodiment of the present invention, the repeaters are all housed in a sealed cylinder, and the design and testing of the sealed cylinder have passed a 20MPa water pressure test for 168 hours.

[0011] In one embodiment of the present invention, the pump drive tube MJD122 adopts a dual-pump hot backup design, with a 50% derating design, and the two pumps are balanced through pump optical feedback control.

[0012] In one embodiment of the present invention, the optical amplification module also integrates 6 pairs of optical amplifiers, which, in addition to amplifying 40-wavelength optical signals, also include wavelength channels for online monitoring of ultra-long-distance optical paths; the 2×2 5% coupling serves as both an output monitoring coupler for the amplifier and a coupler for the reverse C-OTDR wavelength.

[0013] Compared with the prior art, the above-mentioned technical solution of the present invention has the following advantages: the distributed power supply and signal transmission system of the present invention, the underwater high reliability and high integration optical relay transmission technology, realizes reliable long-distance information backhaul; the multi-node constant current DC remote power supply system technology realizes reliable long-distance power supply and distribution; all of these make it significantly superior to the current mainstream power supply and transmission systems in terms of large-scale underwater node networking and long-term working reliability. Attached Figure Description

[0014] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0015] Figure 1 This is a flowchart of the network architecture of the power supply and transmission system described in this invention; Figure 1-1 This is a flowchart of the architecture of the packet bidirectional redundancy design in the transmission system described in this invention; Figure 1-2 This is a block diagram of the optical amplification module described in this invention; Figure 2 This is a connection diagram of the underwater battery pack base station and power distribution system described in this invention; Figure 3 This is a schematic diagram of the constant current power supply system described in this invention; Figure 4 This is a block diagram of the principle of the shore-based constant current source described in this invention; Figure 5 This is a block diagram of the series voltage equalization principle described in this invention; Figure 6 This is a block diagram illustrating the principle of the constant current / constant current conversion device described in this invention; Figure 7 This is a schematic diagram of the network application of the constant current / constant current converter described in this invention; Figure 8 This is a schematic diagram of the main circuit of the constant current / constant current conversion device described in this invention; Figure 9 This is a theoretical schematic diagram of the current waveforms of some components in the constant current / constant current conversion device described in this invention; Figure 10 This is a theoretical schematic diagram of the voltage waveforms of some components in the constant current / constant current conversion device described in this invention. Figure 11 is a simulation diagram of the current and voltage of some components of the constant current / constant current conversion device described in this invention; Figure 12 This is a schematic diagram of the measured series voltage difference of the constant current / constant current conversion device described in this invention; Figure 13 This is an efficiency diagram of the constant current / constant current conversion device described in this invention; Figure 14 This is a schematic diagram of the constant current / constant voltage conversion device described in this invention; Figure 15 This is a schematic diagram of the main circuit of the constant current / constant voltage conversion device described in this invention; Figure 16 This is the switching transistor voltage waveform of the constant current / constant voltage converter described in this invention; Figure 17 This is the output voltage waveform of the constant current / constant voltage converter described in this invention; Figure 18 This is an efficiency diagram of the constant current / constant voltage conversion device described in this invention; Figure 19 This is the reliability curve of the constant current two-stage non-redundant scheme described in this invention; Figure 20 This is the system startup waveform described in this invention; Figure 21 This is the PFE1 output waveform (fault 1) described in this invention. Figure 22 This is the PFE2 output waveform (fault 1) described in this invention. Figure 23 This is the waveform at the input terminal of the master node 4 as described in this invention (fault 1). Figure 24 This is the waveform at the input terminal of the master node 5 as described in this invention (fault 1). Detailed Implementation

[0016] This embodiment provides a highly reliable distributed power supply and signal transmission system for deep-sea and ocean environments, such as... Figure 1 As shown, the power supply and signal transmission system is divided into a power supply system, a transmission system, and a data acquisition system according to its functions. The power supply and signal transmission system is constructed into a hierarchical structure according to nodes, including relay nodes, power optoelectronic nodes, digital hydrophone nodes of the data acquisition system, and transmission nodes of the transmission system, forming a five-layer structure.

[0017] The power opto-node is divided into a power supply section and an opto-node, and the opto-node is integrated into the data transmission module. The power supply section outputs a high-voltage current, which is connected to the input terminal of the opto-node after being stepped down and converted to a current / voltage. The power supply section and the conversion circuit form a power supply system, and the information acquisition port of the opto-node is connected to the acquisition system. Specifically, on the one hand, each level is only responsible to its superior and manages its subordinates, eliminating the need for cross-level management. This reduces the burden on superior nodes, especially the host control unit, making further expansion of the overall scale possible. On the other hand, the implementation of distributed management, distributed storage, and distributed time synchronization allows each node, except for the digital hydrophone nodes, to independently manage nodes and acquire data even without a superior node. This increases the flexibility of the acquisition system and improves the reliability of the entire system in the event of array cable failures during acquisition, ensuring data security.

[0018] Regarding the transmission system, this invention employs a multi-node bidirectional transmission ring network technology to construct a large-scale underwater node network transmission system, as follows: Figure 1-1 As shown, the detection segment is divided into several groups to form a loop, and the transmission module of each node realizes bidirectional transmission, which improves the fault isolation capability of underwater nodes.

[0019] The advantage of underwater multi-node ring networking is that when any underwater node fails, information can be transmitted back through another ring, and then transmitted over ultra-long distances through aggregation modules and digital repeaters.

[0020] The transmission distance without repeaters is no less than 300km, and each repeater can extend the transmission distance of digital optical signals by no less than 150km; the repeater is designed to operate at a water depth of no less than 4000m, enabling deep-sea operations.

[0021] Specifically, the optical amplification module uses highly reliable components and fully considers component derating design, pump thermal design, and redundant backup design for key components and circuits.

[0022] 1) Reduced quota design General-purpose components such as resistors and capacitors are derating according to company standards, while capacitors, resistors, and ICs use military-grade components. Derating of resistors and potentiometers is primarily power derating, while derating of capacitors is primarily voltage derating. Derating of linear and hybrid integrated circuits is primarily operating current or operating voltage derating, and derating of conductors is primarily operating current derating, followed by operating voltage derating.

[0023] 2) Thermal Design The pump heat dissipation surface is in close contact with the housing through thermal grease. A copper heat dissipation strip is installed under the pump drive tube, and heat is dissipated through the solder pads.

[0024] 3) Backup design for critical components The heat-generating component is the MJD122 pump driver transistor, employing a dual-pump hot-backup design with a 50% derating. Pump optical feedback control ensures balanced output from both pumps. If the performance of one pump degrades, the other pump automatically adjusts its output, thus maintaining consistent amplification performance across all channels. Furthermore, redundant design has been added to critical control loops, increasing the overall amplifier's reliability.

[0025] 4) Implementation path of high integration Designed for underwater engineering, this system integrates six pairs of optical amplifiers. Besides amplifying 40 wavelengths of optical signals, it also includes wavelength channels for long-distance online monitoring of optical paths. The 2×2 5% coupling serves both as the amplifier's output monitoring coupler and as a coupler for the reverse C-OTDR wavelength.

[0026] 5) EDFA low-power gain compensation technology To address the issue of constant current power supply for the entire submarine relay link, a novel pump control method was developed. Leveraging the characteristic that the pump laser is a current source device, a direct output pump source mode from the constant current source was proposed, reducing power loss and instability caused by power conversion. The constant current source is distributed as needed through a protection module, rationally allocating current to various control modules to ensure the normal operation of the pump drive current, temperature control, and circuit breaker protection modules. Simultaneously, the use of low-power devices combined with the constant current drive method reduces the power consumption of the fiber amplifier.

[0027] Figure 1-2 This is a block diagram of the optical amplifier module. The optical repeater amplifier design employs constant gain control and utilizes a gain flattening filter to ensure a basic balance of gain across wavelengths. The amplifier pump uses a highly reliable uncooled pump. The amplifier gain control loop is an analog control loop.

[0028] Furthermore, for analog / digital optical transmission, six pairs of optical amplification modules were developed. In conjunction with fiber optic array testing, simulated optical repeater inter-level distance and transmission level tests were conducted, successfully completing inter-level distance tests of 75km and unidirectional 4-level and bidirectional 8-level tests.

[0029] Simultaneously, research on deep-sea repeater sealing cylinder technology was carried out, and a 20MPa repeater sealing cylinder prototype was successfully manufactured and passed the 20MPa hydrostatic test with a pressure holding time of 168 hours.

[0030] Specifically, transmission distance testing and bit error rate testing: The optical amplification performance of the repeater was tested in the laboratory, and all results met the technical specifications. The test items and results are shown in Table 1 below: Table 1 Test Items and Results The test involved gradually increasing the fiber length in 150km increments, along with the corresponding increase in the number of optical repeaters. The test aimed to measure the maximum transmission distance, the system's optical signal flatness, output power stability, and bit error rate.

[0031] The system's maximum transmission distance test record is shown in Table 2 below.

[0032] Table 2 System Maximum Transmission Distance In summary, the maximum transmission distance of the system is 2100km.

[0033] In addition, a reliability assessment should be conducted: The repeater underwent 862.6 hours of accelerated reliability testing, achieving a reliability of 1.13 years and 0.9. It operated without errors for 667.6 hours at 50°C.

[0034] Meanwhile, the power supply system includes power photoelectric nodes, which adopt underwater source power supply and constant current DC power distribution technology; the existing mainstream constant voltage power supply method is prone to seawater grounding short circuit fault when the submarine cable is damaged by external force, resulting in the paralysis of the entire system and poor long-term survival ability at sea. like Figure 2 As shown, this invention proposes an innovative pre-source power supply mode, utilizing replaceable battery packs deployed near the sensor array. The battery pack base station is connected to the power distribution system via an underwater pluggable cable assembly, which can significantly shorten the underwater power supply distance. Through an underwater ROV robot and the wet pluggable assembly, the underwater battery pack base station can be periodically retrieved and recharged.

[0035] The power distribution system is designed as a multi-node constant current DC remote power supply system. Figure 3 This is a schematic diagram of a constant current power supply device.

[0036] The advantage of this power supply method is that it has high power supply reliability. When underwater equipment and power supply modules fail, the fault is automatically isolated and will not affect the normal operation of other parts of the system.

[0037] Underwater power supply modules mainly include constant current / constant current (I / I) modules and constant current / constant voltage (I / V) modules. I / I modules operate in a constant current network, converting one constant current into another or several constant currents, thus achieving multiple branches of constant current and meeting the networking requirements of constant current circuits. I / V modules are converters that convert constant current into constant voltage. They are simple and effective in design, requiring no complex conversion process, and offer high efficiency and reliability.

[0038] The DC constant current remote unidirectional power supply distance is not less than 1000km (the power supply conductor impedance is not greater than 1Ω / km), and it has the ability to isolate branch-to-ground short circuit, open circuit and main-to-ground short circuit faults.

[0039] The shore-based constant current power supply employs a highly reliable high-frequency switching converter circuit topology to achieve constant current output. The block diagram of a single power supply is shown below. Figure 4 As shown; The output voltage and current signals are isolated and sampled by Hall effect devices and fed back to the power control circuit. After being compared and amplified with the reference voltage, they are used as the input signal of the PWM control chip to control the duty cycle of the output PWM wave of the pulse modulator, thereby realizing the adjustment of the output voltage and the setting of the constant current value.

[0040] The power supply employs a dual closed-loop sampling circuit for output voltage and current, allowing it to operate in both voltage regulation and constant current (constant current) modes. This enables adjustable output voltage even when the constant current source is not in constant current mode, facilitating the slow and controlled application of power to the load. This avoids damage to the load caused by uncontrolled output voltage during power-up when the voltage loop of the constant current source is open. Specifically, for example... Figure 5 As shown.

[0041] Regarding constant current / constant current (I / I) module technology: 1) Structural Design like Figure 6 As shown, constant current / constant current converters can be divided into filtering modules, constant voltage power supply modules, drive modules, control modules, and constant current conversion modules according to their internal functions.

[0042] Using a Zener diode to extract voltage is a traditional method for obtaining stable voltage in DC circuits. The constant voltage power supply module adopts an innovative design, in which the control circuit changes the constant current flow path and controls the energy storage time of the energy storage unit, thereby outputting a stable voltage.

[0043] The input terminals of constant current / constant current converters employ push-pull, full-bridge, or other circuit types, such as... Figure 7 As shown, the magnitude of the output current is determined by the turns ratio of the transformer. Changing the turns ratio of the transformer can change the magnitude of the output current.

[0044] 2) Main Circuit Analysis The main circuit of the constant current / constant current converter is as follows: Figure 8 As shown. The constant current converter main module adopts a push-pull switching circuit design. Field-effect transistors (FETs) are also present. and The gate-source voltages are respectively and The drain-source voltages are respectively and The conduction current is and Transformer isolation conversion is used, with the primary and secondary windings of the transformer having the same number of turns. Let the inductances of the primary windings be... and Assume the input current is a constant current. The starting circuit current is The current flowing into the transformer is .

[0045] Let the equivalent capacitance of the starting circuit be... A qualitative analysis of the high-frequency constant current converter circuit can be performed. (1) Once the converter is operating stably, the drive module drives the high-frequency constant current circuit switching transistor. and The circuit operates alternately, with a dead zone in the drive pulse, and a switching transistor is included. and The conduction times are respectively and Because the converter operates in an underwater environment with limited space, it must possess a high power density. The change is small, capacitance will be It performs small-amplitude charging and discharging at the reference voltage, thus enabling... Equivalent to Then there is (2) Let the voltages of the primary winding of the transformer be respectively and The secondary winding voltage is The output voltage of the rectifier filter circuit is Through electromagnetic induction, the voltage across the conducting transistor is 0, and the voltage across the cutting transistor is... The converter voltage change process is as follows: Figure 10 As shown, the current change process is as follows Figure 9 As shown.

[0046] like Figure 11As shown in the simulation diagram, the input constant current is set to 1.5A, and the load at the output of the rectifier and filter circuit is 100Ω. After the converter stabilizes, the drive circuit controls... and On, capacitor Then it charges and discharges, and its voltage fluctuates slightly around 150V depending on the switching of the diode.

[0047] 3) Hardware circuit experiment analysis Due to limitations in size and component performance, the power of a single device cannot be increased indefinitely. If the total power demand of the observation equipment is large, multiple devices can be connected in series to increase the output power. Therefore, the devices must have good consistency; otherwise, uneven voltage distribution will occur. In extreme cases, this may cause one device to be overloaded, affecting the reliability of the system.

[0048] like Figure 12 As shown in the figure, the voltage difference between board B and boards A and C in a series configuration is relatively small, indicating that the output power is distributed evenly. This demonstrates that the device can be used with multiple boards in series to increase output power. When connected in series, the voltage distribution between the two boards is even, preventing any one board from being overloaded and causing damage. Furthermore, as... Figure 13 Efficiency diagram.

[0049] Regarding constant current / constant voltage (I / V) module technology: 1) Structural Design The converter mainly consists of three parts: a rectifier and filter module, a closed-loop control switching circuit, and a DC / DC converter module. The specific structure is as follows: Figure 14 As shown.

[0050] The rectifier and filter module further smooths the input current. Due to the limited size of underwater equipment caused by the working environment, it must possess high power density, conversion efficiency, and reliability. Traditional Zener diode power supply methods are unsuitable for underwater power supply. The main function of the closed-loop control switching circuit is to extract voltage from the constant current circuit by controlling the current flow path, completing the primary current / voltage conversion. The main function of the DC / DC converter module is to isolate the input and output voltages, improve reliability, and modulate the primary voltage to the equipment's standard operating voltage. The closed-loop control switching circuit is the key and challenging aspect of the design of constant current / constant voltage conversion equipment.

[0051] 2) Main Circuit Analysis like Figure 15 As shown, the main design concept of this converter is to achieve a stable output voltage by controlling and changing the constant current flow path through a certain method, thereby affecting the energy storage of the energy storage circuit and meeting the rated power requirements of the electrical equipment.

[0052] The control circuit contains circuits such as an error amplifier, a PWM comparator, and an oscillator.

[0053] Underwater networks can be categorized into five topologies: point-to-point, linear, ring-to-ring, tree-to-tree, and mesh. Constant current / constant voltage converters can be combined with other constant current / constant current converters to be applied to underwater networks of various topologies. Therefore, this type of equipment has broad application value.

[0054] 3) Hardware circuit experiment analysis like Figure 16 The voltage waveform shown indicates the switching transistor. and The circuit controls the alternating conduction of the circuit. When... and When the circuit is turned on, the input current flows out through the switching transistor. When and When turned off, part of the input current is stored in the energy storage circuit, and the other part flows out through the circuit output terminal. The converter maintains a constant output voltage and controls the direction of current flow by controlling the dead time, thereby controlling the magnitude of the output current to meet the power requirements of the observation equipment.

[0055] Figure 17 The waveform shown indicates that the closed-loop control switching circuit outputs 173V. This voltage is modulated by the DC / DC converter module into various standard voltages, including 5V, 12V, and 24V, with each output voltage remaining stable.

[0056] at the same time Figure 18 The efficiency graph shown illustrates that, within the rated power range, the higher the load power demand, the higher the output efficiency of the closed-loop control switching circuit and the converter. When the output current of the closed-loop control switching circuit is greater than 1A, its output efficiency exceeds 90%. The closed-loop control switching circuit is connected to a DC / DC converter module to form a constant current / constant voltage converter. The DC / DC converter module used in the experiment has an output efficiency of approximately 85%, and when the output current of the closed-loop control switching circuit is greater than 0.8A, the converter's output efficiency exceeds 75%.

[0057] The reliability of the underwater constant current power supply trunk circuit is designed to be no less than 0.9 for continuous operation over 10 years.

[0058] Assuming the operating time before a main circuit failure follows an exponential distribution, and the failure rate of each component is constant, then according to the mathematical model of reliability and its failure rate: Criterion 1: If any one node fails, the main road fails; The system's mean time between failures (MTBF) is 45.0804 years.

[0059] Meanwhile, the reliability assessment is shown in the table below: Table 3 System Reliability of Constant Current Two-Level Redundancy-Free Scheme Simultaneously draw as Figure 19 The reliability curve shown.

[0060] In this embodiment of the invention, the remote DC constant current power supply technology was verified. A shore-based constant current power supply, an underwater constant current / constant current, and a constant current / constant voltage power supply module were manufactured. System connection test, main circuit fault simulation, and branch circuit fault simulation test were completed. The longest loop power supply distance exceeded 800km. The experimental results met the relevant technical requirements.

[0061] Furthermore, a fault isolation simulation test was conducted: To verify the backbone fault self-adjustment capability of the constant current circuit based on a ring topology, fault types were simulated. Fault 1 is a broken submarine cable between main nodes 4 and 5, and a short circuit to seawater grounding; such as... Figure 20 The system startup waveform shown is shown.

[0062] at the same time Figure 21 and 22 These are the output waveforms of the shore-based PFE before and after fault 1 occurred. Figure 23 and 24 These are the input current and voltage waveforms of main nodes 4 and 5, located at both ends of the fault point. The upper half of each figure shows the overall change curve of the output waveform, while the lower half is an enlarged view of the state before and after the fault (the rectangular part in the upper half).

[0063] Before fault 1, both PFEs were supplying power at equal voltage, sharing the system voltage. After fault 1, the breakpoint was grounded to seawater, forming two new power supply loops with the two PFEs. The load power borne by PFE1 decreased, while the load power borne by PFE2 increased. Therefore, the voltage changed accordingly. Before and after the fault, the total output voltage of the PFEs was equal. Figure 23 and 24 It can be seen that fault 1 has minimal impact on the master node; the input waveform of the master node remains essentially unchanged. Combined with... Figure 21-24 It can be seen that the system was able to maintain stable operation after fault 1 occurred.

[0064] Further, constant current power supply reliability assessment: Research was conducted on the reliability assessment method of underwater constant current power supply, and a reliability assessment scheme was proposed. By applying test stress higher than normal operating conditions to the underwater constant current power supply system, the task reliability index of the constant current power supply system was evaluated using accelerated models and corresponding statistical assessment methods. The reliability accelerated test verification of the underwater constant current power supply backbone was completed, verifying the reliability of the underwater constant current power supply backbone and providing a basis for its engineering application.

[0065] Test method: The test specimen (I / I module and I / V module) is placed in a temperature chamber. The test specimen and the auxiliary test specimen together form a power supply circuit, namely a "1 to 10" constant current power supply system. The test specimen is subjected to the specified temperature conditions for a specified time. The test specimen is measured by the test instrument according to the specified test method and test timing. The test results are analyzed according to the specified fault criteria, fault classification and statistical methods to count the number of faults that occurred in the test and to evaluate the reliability level of the test specimen.

[0066] Test parameter selection: Considering the product's high reliability, long lifespan, small sample size, and time constraints, a statistical test scheme was designed using a combination of accelerated testing and fault-free data analysis to verify the 10-year reliability requirement of 0.9 for the underwater constant current power supply main circuit. The statistical test scheme is shown in Table 4 below.

[0067] Table 4: Statistical Experimental Design If, under a test chamber temperature of 65℃, 10 test samples operate continuously for 1567 hours without any faults, and the reliability of the test system reaches 0.9 within 10 years with a confidence level of 0.8, an acceptance decision can be made.

[0068] In summary, the distributed power supply and signal transmission system described in this embodiment has been verified through accelerated reliability testing, and the main circuit of the underwater constant current power supply system meets the reliability requirement of 0.9 over 10 years.

[0069] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A highly reliable distributed power supply and signal transmission system for deep-sea and ocean environments, wherein the power supply and signal transmission system is functionally divided into a power supply system, a transmission system, and a data acquisition system, characterized in that... The power supply and signal transmission system is constructed in a hierarchical structure according to nodes, including relay nodes, power optoelectronic nodes, digital hydrophone nodes of the acquisition system, and transmission nodes of the transmission system. The power optoelectronic node is divided into a power supply section and an optoelectronic node, and the optoelectronic node is integrated into the data transmission module. The power supply section outputs high-voltage current, which is connected to the input terminal of the optoelectronic node after being stepped down and converted by current / voltage. The power supply section and the conversion circuit constitute the power supply system. At the same time, the information acquisition port of the optoelectronic node is connected to the acquisition system. The circuit for step-down and current / voltage conversion is constructed from constant current / constant current modules and constant current / constant voltage modules to form an underwater power supply module, and adopts a distributed power distribution structure. In addition, the power supply method is either a shore-based constant current power supply or an underwater battery pack. The underwater battery pack is a front-end power supply design, and the underwater battery pack is connected to the underwater power supply module for power distribution through an underwater plug-in cable assembly. The shore-based constant current power supply is a remote power supply solution. It adopts a highly reliable high-frequency switching converter circuit topology and is connected to the underwater power supply module to receive the constant current output from its port. In the shore-based constant current power supply, the output voltage and current signals are fed back to the power control circuit through Hall effect isolation sampling. After being compared and amplified with the reference voltage, they are used as the input signal of the PWM control chip to control the duty cycle of the output PWM wave of the pulse modulator, thereby realizing the adjustment of the output voltage and the setting of the constant current value. The data acquisition system includes digital hydrophone nodes and auxiliary sensors. The power supply terminals of the digital hydrophone nodes and auxiliary sensors are connected to the input terminals of the photoelectric nodes through a low-voltage power bus, sharing a single power supply terminal. The power supply system, photoelectric nodes, and data acquisition system form an independent working unit. When the number of working units increases to a certain number, the photoelectric nodes are connected to each other through a transmission system, which includes optical fibers and relay nodes. The optical fiber in the transmission system is a bidirectional transmission structure. The optical fiber is connected to the optical port of the data transmission module in sequence. That is, the optical port is the transmission node. The optical ports of the data transmission modules at both ends are connected to the optical port on the side of the photoelectric conversion module in the relay node through the optical fiber. The relay node includes a conversion module, a repeater, and a shore-based optical amplification module. The output end of the shore-based optical amplification module communicates with the host computer through a network switch, and the data is stored and backed up for management.

2. The distributed power supply and signal transmission system according to claim 1, characterized in that: The constant current / constant current module includes a filter module, a constant voltage power supply module, a drive module, a control module, and a constant current conversion module. The constant current conversion module includes a high-frequency constant current conversion circuit and a rectifier filter circuit. The control module includes a protection circuit and a startup circuit, which are connected to the high-frequency constant current conversion circuit and the rectifier filter circuit, respectively. The drive module is connected to the high-frequency constant current conversion circuit. The input current passes through the filter module and the constant voltage power supply module and directly supplies power to the control module, drive module, and constant current conversion module, respectively.

3. The distributed power supply and signal transmission system according to claim 1, characterized in that: The constant current / constant voltage module consists of a rectifier and filter module, a closed-loop control switch circuit, and a DC / DC converter module. The constant current voltage is input into the closed-loop control switch circuit through the rectifier and filter module. At the same time, the closed-loop control switch circuit and the DC / DC converter module are connected in parallel, and the sampling circuit of the closed-loop control switch circuit is connected to the constant current voltage to extract its voltage.

4. The distributed power supply and signal transmission system according to claim 1, characterized in that: The repeaters are all housed in sealed cylinders, and the design and testing of the sealed cylinders have passed the 20MPa water pressure test for 168 hours.

5. The distributed power supply and signal transmission system according to claim 1, characterized in that: The pump drive tube MJD122 adopts a dual-pump hot backup design and is designed with a 50% derating. Through pump optical feedback control, the two pumps are balanced in output.

6. The distributed power supply and signal transmission system according to claim 1, characterized in that: The optical amplification module also integrates 6 pairs of optical amplifiers, which, in addition to amplifying 40-wavelength optical signals, also include wavelength channels for online monitoring of ultra-long-distance optical paths; the 2×2 5% coupling serves as both an output monitoring coupler for the amplifier and a coupler for the reverse C-OTDR wavelength.

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