Partitioned autonomous marine dynamic balance corrosion protection system

Abstract

The invention belongs to the technical field of ship corrosion protection and intelligent control crossing, and relates to a partition autonomous marine dynamic balance corrosion protection system, the main body structure comprises an upper consensus coordination module and a plurality of lower partition autonomous units which are connected through a dual-channel CAN bus, the independence of partition decision is guaranteed, and the reliability of the partition decision is improved. By constructing a completely electrically isolated partition autonomous unit and deconstructing a centralized control system, the influence of long cable voltage drop is thoroughly eliminated, and based on a dynamic potential equalization mechanism of a consensus algorithm, the potential fluctuation range of the whole ship is compressed to be within + / -10mV, so that self-adaptive protection under extreme working conditions is realized; and stable protection is still maintained through the local response module when the coating breakage rate exceeds 5%, the technical bottlenecks of a traditional cathode protection system in the aspects of architecture redundancy, potential deviation and environmental adaptability are fundamentally broken through, a large ship intelligent anti-corrosion system with the global cooperative capability is established, and the ship anti-corrosion field is promoted to enter a brand new era.

Description

Technical field:

[0001] The present invention belongs to the technical field of intersection of ship corrosion protection and intelligent control, and relates to a partitioned autonomous ship dynamic balanced corrosion protection system. It performs ship impressed current cathodic protection based on a partitioned autonomous architecture and a dynamic consensus algorithm, and is suitable for special ships with strict requirements on corrosion protection precision. Background technology:

[0002] The key measure for corrosion protection of marine vessel hulls is the use of an impressed current cathodic protection system, whose core components include a potentiostat, auxiliary anodes, reference electrodes, and a grounding device. Its corrosion protection mechanism is that the potentiostat outputs direct current, which is released into the seawater medium through the auxiliary anodes and eventually flows back to the hull. The output protection current intensity is automatically adjusted according to external environmental factors. This process causes the hull to undergo cathodic polarization. When the hull polarization potential reaches the set value, the occurrence of corrosion reactions can be effectively curbed. This adaptive adjustment ensures that the underwater part of the hull and its ancillary structures are always maintained within the optimal protection potential range, thereby achieving a highly effective corrosion protection effect. It is suitable for ships during navigation and mooring in seawater environments. As the mainstream technology for ship corrosion protection, the impressed current cathodic protection system has been widely used in a variety of ship types, including bulk carriers, container ships, roll-on / roll-off ships, oil and gas tankers, and ocean liners, after years of practical accumulation. It plays an indispensable and important role in ensuring the corrosion resistance and safety of hull structures.

[0003] However, the centralized constant potentiostat control mode adopted by the conventional impressed current cathodic protection system in the existing technology has significant limitations when dealing with large ships: the primary problem is low energy efficiency. When the output current of a single constant potentiostat exceeds 1000 amperes, the conduction loss of power devices such as IGBT (insulated gate bipolar transistor) increases significantly, causing the overall energy efficiency ratio of the system to fall below 80%. The accompanying high-power heat dissipation produces noise pollution that cannot be ignored. Secondly, there are serious hidden dangers in the uneven distribution of hull potential. Since the protection current needs to flow through long-distance cables, based on the principle of cable voltage drop, the voltage drop value is proportional to the cable length and resistivity. The potential difference between the bow and stern is inversely proportional to the cross-sectional area. It can easily exceed 100 millivolts, causing the potential in local areas of the hull to be too negative, below -1.20 volts (relative to the silver / silver chloride reference electrode), triggering overprotection and causing the anti-corrosion coating to peel off. It may also cause the potential in local areas to be positive above -0.80 volts, which is in an underprotected state and accelerates corrosion. Finally, the system control strategy is rigid and difficult to adapt to complex environments. Although there are improved plans that attempt to adjust the current in different zones through a central controller, they are still essentially still within the centralized decision-making framework and lack the real-time response and adaptive adjustment capabilities to dynamic conditions such as sudden damage to the hull coating and instantaneous fluctuations in seawater conductivity.

[0004] To address the aforementioned industry challenges of uneven hull protection potential distribution, anti-corrosion engineering practices have shown that the key lies in deconstructing traditional centralized or distributed cathodic protection control systems. While the mainstream approach is to mitigate the increased potential gradients caused by larger ships by disassembling the control unit, related patents are extremely limited.

[0005] Chinese patent 201420833212.3 discloses a distributed impressed current cathodic protection device, which includes an anode group, a reference electrode group, a power supply unit, a controller and an alarm device. The anode groups are divided into multiple groups and are evenly arranged from the bow to the stern of the ship. Each anode group has two anodes arranged on both sides of the hull below the waterline. The reference electrode groups are divided into multiple groups and are evenly arranged from the bow to the stern of the ship. Each reference electrode group has two reference electrodes arranged on the left and right sides of the hull below the waterline. The power supply unit includes independent power supplies corresponding to the number of anode groups. Each power supply supplies power to one anode group. The controller is used to collect the potential of the hull relative to each reference electrode of the reference electrode group, and control the power supply in the power supply unit to provide the required current to the anodes in the anode group. There are 6 anode groups in total, which are located at the bow, midship and stern of the hull. Two groups of anode groups are arranged in each section of the section, and there are three groups of reference electrode groups in total. One group of reference electrode groups is arranged in each section of the bow section, midship section and stern section of the hull. The power supply unit includes six independent power supplies, and each power supply provides the required DC power to its corresponding group of anode groups. It also includes an alarm device, which includes six sound and light alarms, each sound and light alarm corresponds to a power supply in the power supply unit. When the power supply fails, the controller controls the corresponding sound and light alarm to alarm. The chassis shell of the power supply is made of one-piece molding, and the upper surface of the bottom plate of the chassis shell has a groove. The transformer and inductor of the power supply are installed in the groove. The lower surface of the bottom plate has heat dissipation blades, and the heat dissipation blades have multiple rows. The single blades of each row of heat dissipation blades are arranged in parallel to form a "V" shape, and the gaps between the single blades form a heat dissipation air duct. It divides the hull into three independent control loops: bow, midship, and stern. Although this can improve the phenomenon of local over-protection or under-protection, it has not broken through the centralized decision-making framework and still relies on central control. It has failed to build a truly autonomous partitioned control unit, and has inherent problems such as high power loss, low energy efficiency, delayed response, cable redundancy, and insufficient intelligence.

[0006] Chinese Patent 202110418149.1 discloses a cathodic protection system for a station control platform, including a station control platform, a cathodic protection device and an intelligent test pile. The station control platform includes a central processing unit, a host computer operation interface, a historical database, a system process flow chart and an early warning device; the station control platform is an operation platform built based on a computer system and serves the cathodic protection system; the cathodic protection device includes a main control module, a D / A conversion module, a power supply module, a reference electrode module, an anode bed, a pipeline module and a pipeline potential sensor; the cathodic protection device is used to monitor the pipeline potential in real time, adjust the output protection current according to the change of the pipeline potential, and send the data to the station control platform; the cathodic protection device also executes the command signal sent by the station control platform; the intelligent test pile includes a main control module, a pipeline potential sensor, a D / A conversion module, a power supply module, a reference electrode module, an anode bed, a pipeline module and a pipeline potential sensor. Sensors, temperature sensors, humidity sensors, and stray current sensing coils; intelligent test piles monitor pipeline potential at fixed locations and transmit the monitoring signals in real time to the station control platform. The station control platform, consisting of an ARM processor and peripheral circuits, has a central processing unit responsible for data processing, reception, and transmission, and uses an embedded database for data storage. The user interface is built using LabVIEW engineering software. The main control module chip of the cathodic protection device, composed of an STM32 microcontroller and peripheral circuits, performs signal acquisition and conversion, stabilizes power output through PID control, and achieves two-way communication with the station control platform via a communication module. Intelligent test piles are placed at predetermined locations to monitor the status of the protected pipeline and transmit the signals to the station control platform via the communication module, with one-way communication with the station control platform. This utilizes the station control platform data acquisition solution, which only expands the monitoring function and does not address the structural flaws of the control layer: the execution unit lacks local decision-making capabilities and still needs to wait for central command responses. Furthermore, the lack of a multi-region coordination mechanism prevents dynamic optimization of the ship's potential balance based on changes in the navigation environment.

[0007] Therefore, it is necessary to develop and design a partitioned autonomous marine dynamic balanced corrosion protection system to meet the intelligent corrosion protection needs of large ships. Summary of the invention:

[0008] The purpose of the present invention is to overcome the shortcomings of the existing technology, develop and design a partitioned autonomous marine dynamic balanced corrosion protection system, construct a completely electrically isolated partitioned autonomous unit, deconstruct the centralized control system, and completely eliminate the influence of long cable voltage drop.

[0009] In order to achieve the above-mentioned purpose, the main structure of a partitioned autonomous marine dynamic balanced corrosion protection system according to the present invention adopts a hierarchical control architecture, such as Figure 1 As shown, it includes a consensus coordination module on the top and several partitioned autonomous units on the bottom, which are connected via a dual-channel CAN bus (Controller Area Network bus);

[0010] Among them, the consensus coordination module is deployed in the ship's centralized control room and connected to the host computer through the CAN bus;

[0011] Each partitioned autonomous unit adopts an independent power supply design, including a highly integrated DSP (digital signal processing) control board and IGBT power module. It is installed below the waterline at the bottom of the cabin and is equipped with three auxiliary anodes and one reference electrode. The physical distance between the partitioned autonomous unit and its equipped auxiliary anode does not exceed 5 meters.

[0012] The operation of the consensus coordination module involved in the present invention is a second-order dynamic diffusion algorithm improved based on the theory of ship dynamic positioning: a i (t)=-a ij [x i (t)-x j (t-τ ij )]-γa ij [v i (t)-v j (t-τ ij )], taking the real-time potential value and its change rate of each partition autonomous unit as the consensus variable, and processing the bus communication delay through the time delay compensation mechanism;

[0013] Every 200 milliseconds, the consensus coordination module collects the potential values ​​and their change rate data of all partitioned autonomous units and calculates the potential deviation gradient, generates collaborative control instructions and broadcasts them to all partitioned autonomous units;

[0014] The potential of the entire ship automatically converges to a specific value within the specified protection potential range (such as -0.90 volts), and the maximum fluctuation amplitude does not exceed ±10 millivolts, achieving dynamic equilibrium of the hull potential;

[0015] Among them, a i represents the adjustment change rate of the parameters of the i-th partition, a ij represents the average partition parameter adjustment change rate, t represents the set control period, τij represents the actual average control period, x n Indicates the real-time potential value of the nth partition, v n It represents the rate of change of potential of the nth partition, and r represents the artificial compensation coefficient.

[0016] Each partitioned autonomous unit of the present invention constitutes an independent closed-loop control system, which collects the hull potential signal in real time through its own reference electrode and adopts an improved adaptive PID (Process Controller) algorithm: Perform dynamic adjustment, introduce coating damage rate as a key variable, and automatically increase the proportional coefficient gain when the coating damage rate exceeds the preset threshold, with the maximum adjustment range reaching 40%;

[0017] The Infineon FF450R12ME4 high-performance IGBT power module converts control instructions into DC output, driving the auxiliary anode to generate protection current;

[0018] The entire control process is completely localized, with a response time of less than 100 milliseconds, completely eliminating the delay caused by long cable transmission;

[0019] Among them, k p Indicates the proportional gain value, k i Indicates the integral gain value, k d represents the differential gain value, f represents the coating damage rate, u i Indicates the control quantity at the current moment, e i represents the error value at the current moment, t represents the set control period, and τ represents the actual control period.

[0020] Compared with the existing technology, the present invention realizes the physical separation of the control layer and the execution layer, which not only ensures the independence of partition decision-making, but also maintains the global coordination capability. By constructing a completely electrically isolated partition autonomous unit, deconstructing the centralized control system, and completely eliminating the influence of long cable voltage drop, the dynamic potential balancing mechanism based on the consensus algorithm compresses the potential fluctuation range of the entire ship to within ±10mV, realizing adaptive protection under extreme working conditions, and maintaining stable protection when the coating damage rate exceeds 5% through the local response module. It fundamentally breaks through the technical bottlenecks of traditional cathodic protection systems in architectural redundancy, potential deviation and environmental adaptability, establishes a large-scale ship intelligent anti-corrosion system with full-domain coordination capability, and promotes the field of ship anti-corrosion into a new era of high precision, low energy consumption and intelligence; through the coordinated cooperation of partition autonomous architecture and consensus control algorithm, it fundamentally breaks through the limitations of traditional cathodic protection systems in large-scale ship applications, such as energy efficiency bottlenecks, control delays and operation and maintenance rigidity. Description of the drawings:

[0021] Figure 1 It is a schematic diagram of the main structural principle of the present invention.

[0022] Figure 2 This is a schematic diagram of the main structural principle of Example 1 of the present invention. Specific implementation method:

[0023] The present invention will be further described below through examples with reference to the accompanying drawings.

[0024] Example 1:

[0025] The main structure of a partitioned autonomous marine dynamic balanced corrosion protection system involved in this embodiment is as follows: Figure 2As shown, it includes a consensus coordination module and a host computer connected thereto and twelve partition autonomous units. The consensus coordination module is connected to the host computer via a CAN bus and is connected to each partition autonomous unit via a meshed CAN bus network. Each partition autonomous unit is equipped with three auxiliary anodes and one reference electrode.

[0026] When operating on a pilot platform, the host computer was connected to the ship's central control system via the MODBUS TCP / OPC UA dual protocol. The partitioned autonomous units leveraged a local closed-loop control mechanism and compressed the potential feedback response speed to less than 100 milliseconds via a potential sensor. Combined with an adaptive PID algorithm, the system dynamically compensated for coating damage, keeping the ship's potential fluctuation range within the industrial limit of ±10 millivolts. This represents a tenfold improvement in accuracy compared to traditional systems, completely resolving the issues of over-protection coating peeling and under-protection accelerated corrosion caused by uneven potential.

[0027] Calculations show that cable usage is reduced by over 70% compared to traditional systems. Combining the high-frequency switching characteristics of third-generation SiC power devices with a dynamic voltage optimization strategy driven by a consensus algorithm, overall energy consumption is reduced to 0.75 kWh per square meter per year, representing a 50% energy saving compared to centralized solutions. Furthermore, the ship's load is reduced, and the cable life can be extended to 20 years.

[0028] Based on mesh communication topology and fault-tolerant mechanism, it can guarantee a 98% command delivery rate. Through MODBUS TCP / OPC UA protocol, it is deeply integrated with the ship's central control system. It can also connect the partitioned autonomous units with the digital twin platform. With the help of the digital twin platform, it can perform anode loss warning, remote collaborative parameter adjustment and digital twin modeling of the whole ship's anti-corrosion model, which can provide core support for improving the energy efficiency management of intelligent ships.

Claims

1. A zoned autonomous marine dynamic balanced corrosion protection system, characterized in that: It adopts a hierarchical control architecture, including a consensus coordination module and several partitioned autonomous units that are interconnected.

2. A zoned autonomous marine dynamic balanced corrosion protection system according to claim 1, characterized in that: The consensus coordination module above and several partitioned autonomous units below are connected via a dual-channel CAN bus.

3. A zoned autonomous marine dynamic balanced corrosion protection system according to claim 1 or 2, characterized in that: The consensus coordination module is deployed in the ship's control room and connected to the host computer via the CAN bus.

4. The partitioned autonomous marine dynamic balanced corrosion protection system according to claim 3 is characterized in that: Each partitioned autonomous unit adopts an independent power supply design, including a highly integrated DSP control board and IGBT power module. It is installed below the waterline at the bottom of the cabin and is equipped with three auxiliary anodes and one reference electrode. The physical distance between the partitioned autonomous unit and its equipped auxiliary anode does not exceed 5 meters.

5. The partitioned autonomous marine dynamic balanced corrosion protection system according to claim 3, characterized in that: The consensus coordination module operates on a second-order dynamic diffusion algorithm based on the ship dynamic positioning theory: a i (t)=-a ij [x i (t)-x j (t-τ ij )]-γa ij [v i (t)-v j (t-τ ij )], taking the real-time potential value and its change rate of each partition autonomous unit as the consensus variable, and processing the bus communication delay through the time delay compensation mechanism; Every 200 milliseconds, the consensus coordination module collects the potential values ​​and their change rate data of all partitioned autonomous units and calculates the potential deviation gradient, generates collaborative control instructions and broadcasts them to all partitioned autonomous units; The potential of the entire ship automatically converges to a specific value within the specified protection potential range, and the maximum fluctuation amplitude does not exceed ±10 mV.

6. The partitioned autonomous marine dynamic balanced corrosion protection system according to claim 3, characterized in that: Each autonomous unit in each partition constitutes an independent closed-loop control system, which collects the hull potential signal in real time through its own reference electrode and adopts an improved adaptive PID algorithm: Dynamic adjustment is performed, with the coating damage rate as the key variable. When the coating damage rate exceeds the preset threshold, the proportional coefficient gain is automatically increased, with the maximum adjustment range reaching 40%; The control command is converted into DC output through the IGBT power module to drive the auxiliary anode to generate protection current; The entire control process is completed locally, with a response time of less than 100 milliseconds.

7. The partitioned autonomous marine dynamic balanced corrosion protection system according to claim 5, characterized in that: a i represents the adjustment change rate of the parameters of the i-th partition, a ij represents the average partition parameter adjustment change rate, t represents the set control period, τij represents the actual average control period, x n Indicates the real-time potential value of the nth partition, v n It represents the rate of change of potential of the nth partition, and r represents the artificial compensation coefficient.

8. The partitioned autonomous marine dynamic balanced corrosion protection system according to claim 6, characterized in that: k p Indicates the proportional gain value, k i Indicates the integral gain value, k d represents the differential gain value, f represents the coating damage rate, u i Indicates the control quantity at the current moment, e i represents the error value at the current moment, t represents the set control period, and τ represents the actual control period.

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