Offshore wind power underwater steel structure impressed current cathodic protection system and protection method

Abstract

This invention relates to the field of offshore wind power corrosion protection technology, specifically to an impressed current cathodic protection system and method for underwater steel structures of offshore wind power projects. The system includes a distributed potential monitoring module, an adaptive current output module, a coupled microbial protection module, and a dual-control operation and maintenance platform. The distributed potential monitoring module comprises a set of reference electrode units arranged at 2-meter intervals along the underwater steel structure from the splash zone to the mud zone. Each set of reference electrode units includes one copper / saturated copper sulfate reference electrode and one zinc reference electrode, along with a matching potential acquisition and transmission subunit. This impressed current cathodic protection system and method, featuring multi-dimensional potential sensing, dynamic environmental adaptive adjustment, coupled microbial corrosion protection, and dual-system coordinated operation and maintenance, offers improved protection efficiency and reduced life-cycle costs compared to existing technologies. It is also adaptable to the protection needs of various scenarios, including nearshore, deep-sea, and floating wind power projects.

Description

Technical Field

[0001] This invention relates to the field of corrosion protection technology for offshore wind power, specifically to an impressed current cathodic protection system and protection method for underwater steel structures of offshore wind power. Background Technology

[0002] Impressed current cathodic protection (ICCP) technology is one of the mainstream technologies for corrosion protection of marine steel structures, and it has undergone three generations of technological iterations in the offshore wind power field. The first generation mainly used the sacrificial anode method, which does not require external power supply and has high reliability, but the anodes wear out quickly and the total life cycle cost is high. Large-capacity wind turbine foundations of 10MW and above need to be equipped with sacrificial anodes weighing more than 20 tons, which significantly increases the foundation load. The second generation is the conventional fixed ICCP system, which adjusts the current output through feedback from a single-point reference electrode. Compared with the sacrificial anode method, the cost is reduced by 30%, but it generally suffers from insufficient monitoring coverage and poor dynamic adaptability. According to the "White Paper on Corrosion Protection of Offshore Wind Power" published by the China Renewable Energy Society in 2025, the local underprotection rate of this type of system reaches 32%, and the coating blistering rate caused by overprotection reaches 18%. The third generation is the improved ICCP system that has emerged in recent years, which has been optimized to address single-point issues such as operation and maintenance and monitoring accuracy.

[0003] While existing improved ICCP systems have solved some single-point problems, three core pain points remain unresolved in practical engineering applications:

[0004] 1. Insufficient coverage of local potential monitoring: It cannot cover the potential differences in the splash zone, tidal zone, fully immersed zone, mud zone, as well as weak areas such as welds and flanges. The actual potential difference between the tidal zone and the mud zone can reach more than 50mV, and the problem of underprotection in the tidal zone and overprotection in the mud zone often occurs.

[0005] 2. Insufficient environmental adaptability: The current regulation relies on potential feedback and does not take into account dynamic environmental and load parameters such as ocean tidal currents, microbial attachment, sea ice impact, and structural vibration. When microbial attachment in summer causes anode output attenuation and sea ice friction in winter causes coating damage, the system cannot adjust the output current in time, resulting in protection efficiency in extreme scenarios.

[0006] 3. Isolated operation and maintenance data: The existing ICCP system is an independent operating system and is not integrated with the existing SCADA system of offshore wind turbines. Corrosion data cannot be linked with wind turbine vibration, load and operation data for analysis, making predictive maintenance impossible and resulting in high operation and maintenance costs for corrosion protection.

[0007] Therefore, there is an urgent need to develop an impressed current cathodic protection system and protection methods for underwater steel structures in offshore wind power to solve the above problems. Summary of the Invention

[0008] To address the technical problems existing in the prior art, this invention proposes an impressed current cathodic protection system and method for underwater steel structures in offshore wind power. This system and method features multi-dimensional potential sensing, dynamic environmental adaptive adjustment, microbial corrosion coupling protection, and dual-system linkage operation and maintenance. Compared with existing technologies, it improves protection efficiency, reduces the total life cycle cost, and is adaptable to the protection needs of various scenarios such as nearshore, deep-sea, and floating wind power.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] An impressed current cathodic protection system for underwater steel structures in offshore wind power is characterized by comprising: a distributed potential monitoring module, an adaptive current output module, a coupled microbial protection module, and a dual-control operation and maintenance platform;

[0011] The distributed potential monitoring module includes a set of reference electrode units arranged at 2-meter intervals along the underwater steel structure from the splash zone to the mud zone. Each set of reference electrode units includes one copper / saturated copper sulfate reference electrode and one zinc reference electrode, as well as a matching potential acquisition and transmission subunit. An additional set of reference electrode units is added to all weld seams, flange joints, and other corrosion-prone areas. The adaptive current output module includes a multi-channel potentiostat and an environmental factor sensing subunit. The environmental factor sensing subunit can simultaneously collect six types of environmental and structural parameters: tidal current velocity, seawater temperature, microbial attachment amount, sea ice impact force, structural vibration amplitude, and weld stress value.

[0012] In some specific embodiments, the coupled microbial protection module includes a pulsed ultrasonic generator unit and a microcurrent oxidation unit arranged on the outside of each auxiliary anode. The operating frequency of the pulsed ultrasonic generator unit can be dynamically adjusted between 20kHz and 80kHz, and the microcurrent oxidation unit can output a pulsed oxidation current with a 90° phase difference from the cathodic protection current. The trigger threshold of the pulsed ultrasonic generator unit is 0.5mm of microbial adhesion thickness. This threshold is the optimal value obtained from laboratory immersion tests. Below 0.5mm, the cleaning cost-effectiveness is low, and above 0.5mm, it will affect the anode output. After triggering, it works for 15 minutes each time, and the triggering is repeated at 2-hour intervals. It can remove more than 90% of the microorganisms attached to the anode surface without affecting the cathodic protection effect. The ultrasonic power is controlled within 100W, so it will not affect the surrounding fishery resources. Existing technologies do not have a matching active cleaning module for the anode surface. They all wait until the anode fails before replacing it. This solves the problem of anode attenuation caused by microbial adhesion.

[0013] In some specific implementations, the dual-control operation and maintenance platform includes an edge-side local control unit and a cloud-side remote analysis unit. The edge-side local control unit has a built-in 100Ah energy storage battery, which can operate independently for at least 30 days in the event of a communication interruption. The cloud-side remote analysis unit can connect to the offshore wind farm SCADA system to synchronously acquire data on wind turbine vibration, load, operating status, and power generation. The edge-side local control unit has a built-in three-level fault response mechanism. The first-level fault is when the potential deviation exceeds 10mV, automatically adjusting the current output. The second-level fault is when a single reference electrode fails, automatically switching the data source of the adjacent reference electrode. The third-level fault is when the potentiostat output is abnormal, automatically switching the backup power supply circuit. The annual availability of the system can reach over 99.9%.

[0014] In some specific embodiments, the multi-channel potentiostat of the adaptive current output module has a maximum output current of 300A and an output voltage range of 0V-36V. It can independently control the output current of at least 16 auxiliary anodes, with a current adjustment accuracy of 0.1A for each auxiliary anode. The multi-channel potentiostat has built-in compensation algorithms for temperature, salinity, and stress, which can automatically adjust the potential control reference value according to seawater temperature, salinity, and weld stress. For every 1°C change in temperature, the potential reference value is adjusted by 0.5mV; for every 1psu change in salinity, the potential reference value is adjusted by 0.2mV; and for every 10MPa increase in weld stress, the potential reference value is adjusted by 1mV. This adapts to complex environmental changes in different latitudes and sea areas, solving the problem of inaccurate potential reference under different sea areas and loads.

[0015] In some specific embodiments, the reference electrode unit of the distributed potential monitoring module adopts a modular plug-and-play design. Each reference electrode unit is equipped with an independent IP69K-level underwater sealed connector, which can be replaced by a live plug-and-play via an underwater robot without shutting down the cathodic protection system. The reference electrode unit has a built-in calibration chip that can automatically record the electrode's lifespan and cumulative deviation value. When the remaining lifespan is less than 30 days or the cumulative deviation exceeds 15mV, a replacement warning is automatically sent. The average lifespan of the reference electrode can reach more than 10 years, and it can be replaced without power interruption, so it will not affect the continuity of protection.

[0016] As part of the same inventive concept, this invention also provides a method for impressed current cathodic protection of underwater steel structures for offshore wind power, including:

[0017] S1. System initialization calibration: Activate all distributed reference electrode units in sequence, continuously collect initial potential data of the entire area for 24 hours, generate potential reference distribution curve after cross-validation of adjacent units, and record the initial environmental parameters and structural parameters as reference values.

[0018] S2. Real-time acquisition of environmental and structural factors: Simultaneously acquire six types of parameters, including tidal current velocity, seawater temperature, microbial attachment amount, sea ice impact force, structural vibration amplitude, and weld stress value, as well as the operating status and power generation data transmitted by the wind turbine SCADA system.

[0019] S3. Dynamic current regulation: Based on the potential reference distribution curve and real-time acquired parameters, the optimal output current value of each auxiliary anode is calculated through a pre-trained machine learning model and sent to the multi-channel potentiostat for execution.

[0020] S4 Coupling Protection Trigger: When the thickness of microbial attachment exceeds 0.5 mm or the tidal flow velocity is below 0.2 m / s, the pulse ultrasonic generator and microcurrent oxidation unit are automatically activated to perform anode surface cleaning and microbial killing operations.

[0021] S5, Operation and Maintenance Prediction and Emergency Response: Based on historical data, predict corrosion rate and remaining anode lifespan, generate operation and maintenance suggestions, and monitor potential anomalies in real time to trigger emergency adjustments.

[0022] In some specific implementations, the system initialization calibration in step S1 also includes a cross-validation process. Two adjacent reference electrode units in each group serve as calibration references for each other. When the potential difference between two adjacent units exceeds 15mV, a secondary calibration is automatically triggered. If the difference still exceeds the threshold after the secondary calibration, the unit is determined to be faulty, automatically marked, and a replacement warning is sent. The potential reference distribution curve generated by the initial calibration is updated quarterly, and the reference value is adjusted in combination with seasonal changes, seawater salinity changes, and marine organism attachment cycles. If extreme weather such as typhoons or cold waves occurs, an additional reference curve calibration is performed to ensure the long-term accuracy of potential control and solve the problem of inaccurate data due to single electrode failure.

[0023] In some specific implementations, the machine learning model in step S3 adopts a hybrid algorithm combining gradient boosting decision trees and long short-term memory networks. The training dataset contains at least 10 years of corrosion monitoring data from different sea areas, seasons, and basic types, with a dataset size exceeding 10 million records. The error of the optimal current value output by the model is controlled within ±5%. The response interval for current adjustment is 10 minutes, and the current change amplitude for each adjustment does not exceed 10% of the current output value. This avoids damage to the passivation film on the steel structure surface caused by sudden current changes, while also reducing the power fluctuation of the potentiostat and lowering system energy consumption.

[0024] In some specific embodiments, the pulse oxidation current density output by the microcurrent oxidation unit in step S4 is controlled at 5 mA / cm². 2Within a certain timeframe, each operation lasts no more than 5 minutes, acting only on the anode surface area and will not negatively impact the cathodic protection effect on the steel structure. Simultaneously, it can kill microbial spores within a 50cm radius around the anode, reducing subsequent adhesion rates. The operating frequency of the pulsed ultrasonic generator unit is dynamically adjusted according to the tidal flow velocity. The lower the tidal flow velocity, the lower the frequency used, improving microbial removal efficiency. 20kHz is used when the flow velocity is below 0.5m / s, 40kHz when it is between 0.5 and 1m / s, and 80kHz when it is between 1 and 1.5m / s. When the tidal flow velocity is above 1.5m / s, the ultrasonic unit automatically shuts off, relying on water flow for natural cleaning, further reducing system energy consumption.

[0025] In some specific implementations, the corrosion rate prediction accuracy in step S5 can reach over 90%, predicting localized corrosion risk areas up to 6 months in advance. The predicted remaining service life of the anode is linked to the wind farm's operation and maintenance plan, automatically matching the optimal maintenance window, reducing the number of times maintenance vessels need to go to sea, and lowering operation and maintenance costs. The emergency response mechanism is as follows: when the potential is below -1100mV for more than 30 minutes, an over-protection warning is triggered, and the anode output current in the corresponding area is reduced until the potential returns to the normal range of -850mV to -1100mV; when the potential is above -850mV for more than 30 minutes, an under-protection warning is automatically triggered, and the output current in the corresponding area is gradually increased. If it still does not return to normal after 30 minutes, maintenance personnel are notified to investigate; when the sea ice impact force exceeds 0.5MPa or the structural vibration amplitude exceeds the threshold, the output current in the corresponding area is automatically increased by 5% to 15% to offset the corrosion risk caused by structural friction and coating damage, solving the problems of untimely emergency response and high operation and maintenance costs.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. In this invention, a distributed multi-point reference electrode layout is adopted, which can realize potential monitoring of the entire underwater steel structure without dead angles. It can completely cover different corrosive environments such as splash zone, tidal zone, full immersion zone, and mud zone, as well as corrosion-prone areas such as welds, flanges, and joints. It avoids the local under-protection and over-protection problems that are common in traditional systems from the root, greatly reduces the risk of structural damage and repair costs caused by sudden local corrosion, and extends the overall service life of underwater steel structures.

[0028] 2. The multi-parameter linkage adaptive current regulation logic in this invention can adapt to the dynamic changes of various complex marine environments. Whether it is the rapid attachment of microorganisms caused by high temperature and humidity in summer, the impact and friction of sea ice caused by low temperature in winter, or the structural vibration and silt erosion caused by extreme weather such as typhoons and cold waves, the system can automatically sense environmental changes and adjust the protection parameters in real time to maintain a stable protection effect. This avoids the problem of protection failure caused by sudden environmental changes in traditional systems and greatly improves the stability of corrosion protection under extreme working conditions.

[0029] 3. The coupled active anode cleaning function in this invention can significantly reduce the adhesion and accumulation of marine organisms on the anode surface, slow down the rate of anode performance degradation, extend the anode replacement cycle, and reduce the cost of consumable replacement during long-term operation; at the same time, it can realize underwater non-stop replacement of parts, avoid the risk of protection interruption when replacing parts in traditional systems, and further reduce operation and maintenance costs.

[0030] 4. This invention integrates with the existing SCADA system of the wind farm, enabling the linkage analysis of corrosion protection data and unit operation data. It supports predictive maintenance, significantly reducing unnecessary underwater inspections and tower climbing inspections, thereby reducing the offshore operation risks for maintenance personnel and the overall operation and maintenance costs. At the same time, it can identify potential corrosion risks in advance, making it easier for maintenance personnel to address potential problems simultaneously during routine inspection windows, preventing small problems from evolving into major structural failures and reducing unplanned downtime losses.

[0031] 5. The system of this invention can flexibly adjust the number of reference electrodes, anode configuration scheme and adjustment logic parameters according to different foundation types, water depths and marine environments, without redesigning the overall architecture, which greatly reduces the customized development cost in different scenarios. It can be widely adapted to various offshore wind power scenarios such as nearshore, deep sea and floating wind power, and can also be extended to corrosion protection of other marine engineering steel structures. Attached Figure Description

[0032] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0033] Figure 1 This is a schematic diagram of the impressed current cathodic protection system architecture for underwater steel structures in offshore wind power according to the present invention;

[0034] Figure 2 This is a flowchart of the impressed current cathodic protection method for underwater steel structures in offshore wind power according to the present invention;

[0035] Figure 3 This is a schematic diagram of the distributed potential monitoring module layout of the present invention;

[0036] Figure 4This is a schematic diagram of the coupled microbial protection module structure of the present invention;

[0037] Figure 5 This is a schematic diagram of the SCADA linkage of the dual-control operation and maintenance platform of the present invention;

[0038] Figure 6 This is a schematic diagram of the reference electrode arrangement for a floating wind power foundation according to Embodiment 3 of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0040] This invention provides a detailed description of the technical solution through embodiments of two typical application scenarios. All technical features described in the claims are fully implemented in the following embodiments. These embodiments are only used to explain this invention and are not intended to limit the scope of protection of this invention.

[0041] Example 1

[0042] This embodiment provides an impressed current cathodic protection system and protection method for underwater steel structures of offshore wind power. It is based on the application scenario of a 100MW nearshore offshore wind farm monopile foundation. This scenario is characterized by rapid attachment of marine organisms in summer and short-term sea ice phenomena in winter, which is a typical complex nearshore marine environment.

[0043] First, a set of reference electrode units is arranged every 2 meters along the monopile foundation from the splash zone to the mud zone, for a total of 20 sets of conventional reference electrode units. Additionally, 8 sets of reference electrode units are added in weak areas such as all welds and flange joints. Each set includes one copper / saturated copper sulfate reference electrode and one zinc reference electrode. Eight auxiliary anodes are evenly arranged along the circumference of the monopile foundation, each with a rated output current of 25A. Each anode is equipped with a pulsed ultrasonic generator and a micro-current oxidation unit. The environmental factor sensing subunit, including tidal current sensors, temperature sensors, salinity sensors, microbial adhesion sensors, sea ice impact sensors, vibration sensors, and stress sensors, is positioned 5m below the mean sea level, with a data acquisition frequency of once per minute. The edge-side control unit is connected to the wind farm's SCADA system via fiber optic cable for bidirectional data transmission. The cloud-side operation and maintenance platform is deployed in the wind farm's central control center, capable of simultaneously managing the cathodic protection systems of all 25 wind turbines in the farm.

[0044] After system installation, initial calibration is performed first. All 28 reference electrode units are activated sequentially, and potential data is continuously collected for 24 hours. Each reference electrode unit is cross-validated with its two adjacent units. The potential difference between the 7th reference electrode unit and its adjacent units reached 18mV. After triggering a second calibration, the difference still did not decrease to within the threshold, indicating a seal failure during installation. The unit was replaced under power using an ROV and recalibrated. Finally, a potential reference distribution curve for the entire area is generated. The reference potential in the splash zone is -900mV, in the tidal zone -920mV, in the fully immersed zone -930mV, in the submerged zone -880mV, and in the weld zone -950mV. The overall error range is controlled within ±3mV. After calibration, the system automatically stores the reference curve. The reference curve is updated on the last day of each quarter, and the reference value is adjusted according to seasonal temperature and salinity changes. An additional calibration is performed after each typhoon.

[0045] During normal system operation, potential data, environmental factor data, and wind turbine vibration, load, and power generation data transmitted by the SCADA system for all reference electrodes are collected every 10 minutes. These data are then input into a pre-trained hybrid machine learning model to calculate the optimal output current for each group of anodes. In summer, when seawater temperatures are high, the rate of microbial attachment accelerates. When the detected microbial attachment thickness reaches 0.6 mm, the system automatically activates the pulsed ultrasonic generator unit, operating at a frequency of 30 kHz for 15 minutes to remove microbial attachment from the anode surface. Simultaneously, the microcurrent oxidation unit outputs 4 mA / cm². 2The pulsed current operates for 3 minutes to kill residual microbial spores and reduce the subsequent adhesion rate. During tidal periods, when the water flow velocity is below 0.2 m / s, the system automatically reduces the ultrasonic operating frequency to 20 kHz to improve the cleaning effect. When the water flow velocity is above 1.5 m / s, the ultrasonic unit is turned off, relying on the natural rinsing of the water flow to clean the anode surface. During the winter sea ice season, when the sea ice impact sensor detects an impact force exceeding 0.5 MPa, the system automatically increases the output current of the corresponding area by 10% to offset the corrosion risk caused by coating damage due to sea ice friction.

[0046] After the system in this embodiment has been running for a period of time, the average corrosion rate of the steel structure is much lower than that of the traditional ICCP system, the anode loss rate is lower than that of the traditional system, and no local under-protection or over-protection problems have occurred throughout the year. Only one system inspection is required during the annual scheduled maintenance. The operation and maintenance cost is lower than that of the traditional system, saving protection costs. Compared with the traditional ICCP system used in the same wind farm, the protection efficiency of this embodiment is significantly improved.

[0047] Example 2

[0048] This embodiment provides an impressed current cathodic protection system and protection method for underwater steel structures of offshore wind power. It is based on the application scenario of a 300MW offshore wind farm jacket foundation in deep sea. The sea area where this scenario is located has high temperature and high salinity all year round, the maximum tidal current speed can reach 2.5m / s, typhoons occur frequently, and the attachment rate of marine microorganisms is more than twice that of nearshore sea areas, which is a typical highly corrosive deep sea environment.

[0049] Firstly, considering the multi-pile, multi-node structural characteristics of the jacket foundation, a set of reference electrode units is arranged every 2 meters along each jacket leg from the splash zone to the subsurface mud zone, totaling 30 sets of conventional reference electrode units per leg. An additional 15 sets of reference electrode units are added at all nodes, welds, and strut locations, for a total of 135 sets of reference electrode units per jacket foundation. Sixteen auxiliary anodes are evenly arranged along the circumference of the jacket, each with a rated output current of 30A. Each anode is equipped with a coupled microbial protection module on its outer side. The multi-channel potentiostat adopts a 16-channel design with a maximum output current of 300A. The environmental factor sensing subunit deploys three sensor sets at different water depths, specifically at 10m, 30m, and 50m below sea level, to collect environmental parameters at different water layers, addressing the significant differences in temperature, salinity, and microbial attachment levels at different depths in the deep sea. The edge-side control unit is located on a platform at the top of the jacket and is connected to the cloud-based operation and maintenance platform of the onshore control center via a marine wireless communication network. It is also connected to the wind turbine SCADA system to synchronously acquire data on jacket vibration, stress, and unit operation.

[0050] To address the unstable communication characteristics of deep-sea environments, the edge-side control unit is equipped with a large-capacity energy storage battery, enabling it to operate independently for 90 days even during communication outages or external power supply interruptions, ensuring continuous system protection. To accommodate the environmental differences between different water layers, the system's machine learning model independently optimizes the current output for each layer's environmental parameters, avoiding the problems of underprotection in upper layers and overprotection in lower layers caused by a uniform current output in traditional systems. In response to the frequent occurrence of typhoons, the system automatically increases the output current by 15% upon receiving a typhoon warning, proactively forming a more stable passivation film to resist structural vibrations and silt erosion that can damage the coating during typhoons.

[0051] After the system in this embodiment has been running for a period of time, the overall corrosion rate of the jacket is much lower than that of the traditional ICCP system. The anode loss rate is reduced by nearly half compared to the traditional system. No potential abnormality problems have occurred. The protection efficiency has been stably maintained at over 97%. The operation and maintenance cost is reduced by two-thirds compared to the traditional system. This embodiment reduces a large amount of sacrificial anode material and the self-weight of a single jacket foundation is reduced, effectively reducing the foundation load and installation cost, resulting in significant overall economic benefits.

[0052] Example 3

[0053] This embodiment provides an impressed current cathodic protection system and protection method for underwater steel structures of offshore wind power. It is based on the application scenario of a semi-submersible foundation in a floating wind power demonstration project. This scenario is characterized by swells all year round and large six-degree-of-freedom motion of the foundation. Traditional cathodic protection systems cannot adapt to the dynamic motion characteristics of floating foundations.

[0054] Firstly, considering the dynamic characteristics of the floating foundation, the reference electrode unit adopts a follow-up installation design. Each reference electrode unit is equipped with a flexible mounting bracket, which can adaptively adjust its angle to follow the foundation's sway, ensuring that the electrode always maintains a fixed distance from the steel structure surface and avoiding potential monitoring errors caused by movement. One set of reference electrode units is arranged every 3 meters along the underwater surface of the floating foundation, for a total of 40 sets. An additional 12 sets are added at all weld seams and mooring chain connection nodes. The auxiliary anodes adopt a flexible installation design, allowing them to follow the foundation's movement without collision damage. A total of 12 auxiliary anodes are arranged, each with a rated output current of 25A. The environmental factor sensing subunit adds an additional foundation motion attitude monitoring sensor, incorporating the foundation's roll, pitch, and heave data into the current regulation logic to solve the potential fluctuation problem caused by foundation movement. The edge-side control unit is located on the upper platform of the floating foundation, connected to the land-side operation and maintenance platform via satellite communication, and simultaneously integrated with the floating foundation's motion control system and the wind turbine SCADA system to acquire all operational data synchronously.

[0055] The system's current regulation algorithm incorporates motion compensation logic, dynamically adjusting the current output based on the foundation's motion amplitude and speed to offset potential fluctuations caused by motion, while maintaining potential control accuracy within ±8mV. Addressing the limitation of floating foundations not being regularly docked for maintenance, all modules employ redundant design. The reference electrode, potentiostat, and power supply circuit are all configured with 100% redundancy, ensuring that single-point failures will not affect system operation. The long electrode lifespan significantly reduces maintenance requirements. To address the corrosion protection requirements of the mooring chain, the system additionally provides an independent current output channel for the mooring chain, achieving independent protection for both the mooring chain and the foundation structure.

[0056] After the system in this embodiment has been running for a period of time, it has high protection efficiency and fully meets the protection requirements of floating wind power, solving the industry pain point that traditional ICCP systems cannot adapt to dynamic scenarios of floating foundations.

[0057] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An impressed current cathodic protection system for underwater steel structures in offshore wind power, characterized in that, The system includes a distributed potential monitoring module, an adaptive current output module, a coupled microbial protection module, and a dual-control operation and maintenance platform. The distributed potential monitoring module consists of a set of reference electrode units arranged at 2-meter intervals along the underwater steel structure from the splash zone to the mud zone. Each set of reference electrode units includes one copper / saturated copper sulfate reference electrode and one zinc reference electrode, as well as a matching potential acquisition and transmission subunit. An additional set of reference electrode units is added to all corrosion-prone areas such as welds and flange joints. The adaptive current output module includes a multi-channel potentiostat and an environmental factor sensing subunit. The environmental factor sensing subunit can simultaneously collect six types of environmental and structural parameters: tidal current velocity, seawater temperature, microbial attachment amount, sea ice impact force, structural vibration amplitude, and weld stress value.

2. The impressed current cathodic protection system and protection method for underwater steel structures of offshore wind power according to claim 1, characterized in that, The coupled microbial protection module includes a pulsed ultrasound generating unit and a microcurrent oxidation unit arranged on the outside of each auxiliary anode. The operating frequency of the pulsed ultrasound generating unit can be dynamically adjusted between 20kHz and 80kHz. The microcurrent oxidation unit can output a pulsed oxidation current with a phase difference of 90° from the cathodic protection current. The trigger threshold of the pulsed ultrasound generating unit is 0.5mm of microbial adhesion thickness. After triggering, it works for 15 minutes each time, and the triggering is repeated at 2-hour intervals.

3. The impressed current cathodic protection system and protection method for underwater steel structures of offshore wind power according to claim 1, characterized in that, The dual-control operation and maintenance platform includes an edge-side local control unit and a cloud-side remote analysis unit. The edge-side local control unit has a built-in 100Ah energy storage battery, and the cloud-side remote analysis unit can connect to the offshore wind farm SCADA system to synchronously acquire data on wind turbine vibration, load, operating status, and power generation. The edge-side local control unit has a built-in three-level fault response mechanism. The first-level fault is when the potential deviation exceeds 10mV, automatically adjusting the current output. The second-level fault is when a single reference electrode fails, automatically switching the data source of the adjacent reference electrode. The third-level fault is when the potentiostat output is abnormal, automatically switching the backup power supply circuit.

4. The impressed current cathodic protection system and protection method for underwater steel structures of offshore wind power according to claim 1, characterized in that, The multi-channel potentiostat of the adaptive current output module has a maximum output current of 300A and an output voltage range of 0V-36V. It can independently control the output current of at least 16 auxiliary anodes, with a current adjustment accuracy of 0.1A for each auxiliary anode. The multi-channel potentiostat has built-in compensation algorithms for temperature, salinity, and stress. It can automatically adjust the potential control reference value according to seawater temperature, salinity, and weld stress. For every 1°C change in temperature, the potential reference value is adjusted by 0.5mV; for every 1psu change in salinity, the potential reference value is adjusted by 0.2mV; and for every 10MPa increase in weld stress, the potential reference value is adjusted by 1mV. This adapts to complex environmental changes in different latitudes and sea areas.

5. The impressed current cathodic protection system and protection method for underwater steel structures of offshore wind power according to claim 1, characterized in that, The reference electrode unit of the distributed potential monitoring module adopts a modular plug-and-play design. Each reference electrode unit is equipped with an independent IP69K-level underwater sealed connector, which can be replaced by a live plug-and-play via an underwater robot. The reference electrode unit has a built-in calibration chip that can automatically record the electrode's lifespan and cumulative deviation value.

6. The method for impressed current cathodic protection of underwater steel structures for offshore wind power according to claims 1-5, characterized in that, Includes the following steps: S1. System initialization calibration: Activate all distributed reference electrode units in sequence, continuously collect initial potential data of the entire area for 24 hours, generate potential reference distribution curve after cross-validation of adjacent units, and record the initial environmental parameters and structural parameters as reference values. S2. Real-time acquisition of environmental and structural factors: Simultaneously acquire six types of parameters, including tidal current velocity, seawater temperature, microbial attachment amount, sea ice impact force, structural vibration amplitude, and weld stress value, as well as the operating status and power generation data transmitted by the wind turbine SCADA system. S3. Dynamic current regulation: Based on the potential reference distribution curve and real-time acquired parameters, the optimal output current value of each auxiliary anode is calculated through a pre-trained machine learning model and sent to the multi-channel potentiostat for execution. S4 Coupling Protection Trigger: When the thickness of microbial attachment exceeds 0.5 mm or the tidal flow velocity is below 0.2 m / s, the pulse ultrasonic generator and microcurrent oxidation unit are automatically activated to perform anode surface cleaning and microbial killing operations. S5, Operation and Maintenance Prediction and Emergency Response: Based on historical data, predict corrosion rate and remaining anode lifespan, generate operation and maintenance suggestions, and monitor potential anomalies in real time to trigger emergency adjustments.

7. The method for impressed current cathodic protection of underwater steel structures for offshore wind power according to claim 6, characterized in that, The system initialization calibration in step S1 also includes a cross-validation process. Two adjacent reference electrode units in each group serve as calibration references for each other. When the potential difference between two adjacent units exceeds 15mV, a secondary calibration is automatically triggered. If the difference still exceeds the threshold after the secondary calibration, the unit is determined to be faulty, automatically marked, and a replacement warning is sent. The potential reference distribution curve generated by the initial calibration is updated quarterly. The reference value is adjusted in combination with seasonal changes, seawater salinity changes, and marine organism attachment cycles. If extreme weather such as typhoons or cold waves occurs, an additional reference curve calibration is performed to ensure the long-term accuracy of potential control.

8. The impressed current cathodic protection system and protection method for underwater steel structures of offshore wind power according to claim 6, characterized in that, The machine learning model in step S3 adopts a hybrid algorithm combining gradient boosting decision tree and long short-term memory network. The training dataset contains at least 10 years of corrosion monitoring data for different sea areas, seasons and basic types. The error of the optimal current value output by the model is controlled within ±5%. The response interval of the current adjustment is 10 minutes, and the current change amplitude of each adjustment does not exceed 10% of the current output value.

9. The impressed current cathodic protection system and protection method for underwater steel structures of offshore wind power according to claim 6, characterized in that, In step S4, the pulse oxidation current density output by the microcurrent oxidation unit is controlled at 5 mA / cm². 2 Within a certain timeframe, each working session shall not exceed 5 minutes. The operating frequency of the pulse ultrasound generator unit will be dynamically adjusted according to the tidal flow velocity. The lower the tidal flow velocity, the lower the frequency used. When the flow velocity is below 0.5 m / s, 20 kHz is used; when it is between 0.5 and 1 m / s, 40 kHz is used; when it is between 1 and 1.5 m / s, 80 kHz is used; and when the flow velocity is above 1.5 m / s, the ultrasound will be automatically shut off.

10. The impressed current cathodic protection system and protection method for underwater steel structures of offshore wind power according to claim 6, characterized in that, In step S5, the predicted remaining service life of the anode will be linked with the wind farm's operation and maintenance plan to automatically match the optimal maintenance window. The emergency response mechanism is as follows: when the potential is below -1100mV for more than 30 minutes, an over-protection warning is triggered, and the anode output current in the corresponding area is reduced until the potential returns to the normal range of -850mV to -1100mV; when the potential is above -850mV for more than 30 minutes, an under-protection warning is automatically triggered, and the output current in the corresponding area is gradually increased. If it still does not return to normal after 30 minutes, the operation and maintenance personnel are notified to investigate; when the sea ice impact force exceeds 0.5MPa or the structural vibration amplitude exceeds the threshold, the output current in the corresponding area is automatically increased by 5% to 15%.

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