Offshore photovoltaic distributed impressed current cathodic protection system

Abstract

The utility model discloses an offshore photovoltaic distributed impressed current cathodic protection system, which comprises impressed current cathodic protection devices in one-to-one correspondence with matrix areas divided by a photovoltaic electric field. The system comprises a first connecting piece for electrically connecting a plurality of photovoltaic platforms in a matrix area, a power supply controller for converting alternating current into direct current, a composite cable component, a far reference electrode and a near reference electrode, the top end of the composite cable component is connected to the photovoltaic platform, the bottom end is anchored to the installation position of the seabed, and a first outgoing line of the composite cable component is electrically connected with the power controller. The far reference electrode and the near reference electrode are mounted on a steel pile foundation of the photovoltaic platform in the matrix area, and the distance between the far reference electrode and the composite cable component is greater than that between the near reference electrode and the composite cable component. According to the utility model, the impressed current cathodic protection equipment is arranged to carry out long-acting and stable protection on the steel pile foundation in the matrix area, and the number of auxiliary anodes required by a photovoltaic electric field is reduced.

Description

Technical Field

[0001] This utility model relates to the field of marine photovoltaic technology, and in particular to a marine photovoltaic distributed impressed current cathodic protection system. Background Technology

[0002] Offshore photovoltaic (PV) platforms with fixed pile foundations mainly consist of steel pile foundations, PV support structures, and PV panels. Typically, a PV site comprises hundreds to thousands of PV platforms, each equipped with four steel pile foundations. However, such a massive steel pile foundation faces severe corrosion challenges. Currently, anti-corrosion treatments mainly employ anti-corrosion coatings, cathodic protection, and composite anti-corrosion methods. However, anti-corrosion coatings are insufficient to meet the full life-cycle protection requirements of offshore PV platforms. Cathodic protection and composite anti-corrosion methods have the following drawbacks: they require a large number of sacrificial anodes, leading to the release of large amounts of heavy metal ions and pollution of the marine environment; furthermore, the underwater installation of sacrificial anodes is extremely labor-intensive and underwater welding is costly. Therefore, a protection system that can reduce installation workload and meet the full life-cycle protection requirements of offshore PV platforms needs to be designed. Utility Model Content

[0003] This invention provides a marine photovoltaic distributed impressed current cathodic protection system to solve the above-mentioned technical problems.

[0004] To achieve the above objectives, the technical solution of this utility model is as follows:

[0005] An offshore photovoltaic distributed impressed current cathodic protection system includes impressed current cathodic protection devices, the number of which matches the number of matrix areas divided by the photovoltaic electric field, with each impressed current cathodic protection device corresponding one-to-one with a matrix area. Each impressed current cathodic protection device includes: a first connector electrically connecting multiple photovoltaic platforms within the matrix area; a power controller converting AC to DC power; a composite cable component; a far reference electrode; and a near reference electrode. The composite cable component is installed at an installation position where its top end is connected to the photovoltaic platform and its bottom end is anchored to the seabed. The first lead of the composite cable component is electrically connected to the power controller. The far reference electrode and the near reference electrode are installed on the steel pile foundations of the photovoltaic platforms within the matrix area. The distance between the far reference electrode and the composite cable component is greater than the distance between the near reference electrode and the composite cable component. The second lead of the far reference electrode and the third lead of the near reference electrode are electrically connected to the power controller, respectively.

[0006] Preferably, the composite cable component includes: a second connector for connecting to the photovoltaic platform, a composite cable, an auxiliary anode disposed on the composite cable, a tension regulator for adjusting the tension of the composite cable, a third connector, and a gravity foundation; the gravity foundation is placed at the installation position on the seabed, and the composite cable is connected to the gravity foundation through the third connector.

[0007] Preferably, the second connector uses a lifting ring to connect to the bolt ball of the photovoltaic platform; the tension adjuster uses a turnbuckle, with one end of the turnbuckle connected to the lifting ring and the other end connected to the composite cable; the third connector uses a shackle.

[0008] Preferably, the third connector consists of two connected shackles, one of which connects to the composite cable and the other to the gravity foundation.

[0009] Preferably, the bottom end of the composite cable is provided with a sealing cover, and the end of the sealing cover is provided with a cable joint. The bottom end of the composite cable is connected to a third connector through the sealing cover and the cable joint.

[0010] Preferably, the top of the composite cable is connected to a tension adjuster via a wire rope clamp.

[0011] Preferably, both the far reference electrode and the near reference electrode are mounted on the steel pile foundation via mounting components.

[0012] Preferably, the mounting assembly includes a mounting base and a cable tie. The mounting base has binding holes, and the cable tie passes through the binding holes to secure the mounting base to the outer periphery of the steel pile foundation. The mounting base also has mounting holes for connecting the far reference electrode and the near reference electrode.

[0013] Preferably, the mounting base has a mounting surface on the side facing the steel pile foundation for fitting against the outer periphery of the steel pile foundation.

[0014] Preferably, the first connector is made of flat steel or cable.

[0015] Beneficial effects:

[0016] This application discloses a distributed impressed current cathodic protection system for marine photovoltaic systems. This system protects the steel pile foundations within a matrix area by installing impressed current cathodic protection equipment. The system reduces the number of auxiliary anodes required for the photovoltaic field and eliminates the need for periodic replacement. Furthermore, both current and voltage can be continuously adjusted, allowing for flexible adjustment of output parameters according to actual needs, adapting to changes in the corrosive environment and the protected object, and ensuring long-term stable protection. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a marine photovoltaic distributed impressed current cathodic protection system disclosed in this utility model;

[0019] Figure 2 This is a schematic diagram of the structure of a composite cable component of a marine photovoltaic distributed impressed current cathodic protection system disclosed in this utility model;

[0020] Figure 3 This is a schematic diagram of the installation of the remote reference electrode of a marine photovoltaic distributed impressed current cathodic protection system disclosed in this utility model;

[0021] Figure 4 This is a cross-sectional view of the remote reference electrode and mounting assembly of a marine photovoltaic distributed impressed current cathodic protection system disclosed in this utility model.

[0022] 11. Power controller; 12. Composite cable component; 121. Second connector; 122. Composite cable; 123. Auxiliary anode; 124. Tension regulator; 125. Third connector; 126. Gravity foundation; 127. Sealing cover; 128. Cable joint; 129. Wire rope clamp; 13. Far reference electrode; 14. Near reference electrode; 2. Matrix area; 21. Photovoltaic platform; 211. Steel pile foundation; 212. Bolt ball; 31. Mounting base; 311. Binding hole; 312. Mounting hole; 313. Mounting surface; 32. Cable tie. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] A marine photovoltaic distributed impressed current cathodic protection system, combined with Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, the system includes an impressed current cathodic protection device, the number of which is consistent with the number of matrix regions 2 divided by the photovoltaic electric field. Each impressed current cathodic protection device corresponds one-to-one with a matrix region 2. The impressed current cathodic protection device includes: a first connector that electrically connects multiple photovoltaic platforms 21 set in the matrix region 2; a power controller 11 that converts AC power to DC power; a composite cable component 12; a far reference electrode 13; and a near reference electrode 14. The composite cable component 12 is installed with its top end connected to the photovoltaic platform 21 and its bottom end anchored to the seabed. The first lead of the composite cable component 12 is electrically connected to the power controller 11. The far reference electrode 13 and the near reference electrode 14 are installed on the steel pile foundation 211 of the photovoltaic platform 21 in the matrix region 2. The distance between the far reference electrode 13 and the composite cable component 12 is greater than the distance between the near reference electrode 14 and the composite cable component 12. The second lead of the far reference electrode 13 and the third lead of the near reference electrode 14 are electrically connected to the power controller 11, respectively. This system electrically connects multiple photovoltaic platforms 21 within each matrix region 2 of the photovoltaic electric field into a whole through a first connector. Multiple impressed current cathodic protection devices are then installed to protect the steel pile foundations 211 of the multiple photovoltaic platforms 21 within the matrix region 2. This reduces the number of auxiliary anodes 123 required for the photovoltaic electric field and eliminates the need for periodic replacement. Furthermore, the current and voltage of the impressed current cathodic protection devices can be continuously adjusted, facilitating adjustments to output parameters according to actual needs and flexibly responding to changes in the corrosive environment and the protected object, ensuring long-term stable protection. Although the initial investment is high, the long-term operating cost is low, making it particularly suitable for the large-scale steel pile foundation corrosion protection requirements in the offshore photovoltaic field.

[0025] Specifically, the power controller 11 is positioned on the maintenance access channel of the photovoltaic platform 21 directly above the composite cable component 12 or on a nearby inverter platform to reduce voltage drop. The negative terminal of the power controller 11 is electrically connected to the cathode terminal of the photovoltaic platform 21 via a cathode return cable. The internal zero-position cathode terminal of the power controller 11 is electrically connected to the zero-position cathode terminal of the photovoltaic platform 21 via a measurement grounding cable.

[0026] Preferably, the composite cable component 12 includes: a second connector 121 connecting the photovoltaic platform 21, a composite cable 122, an auxiliary anode 123 disposed on the composite cable 122, a tension adjuster 124 for adjusting the tension of the composite cable 122, a third connector 125, and a gravity foundation 126; the gravity foundation 126 is placed at the installation position on the seabed, and the composite cable 122 is connected to the gravity foundation 126 through the third connector 125. This system can reduce the number of auxiliary anodes 123 and avoid underwater welding work, thereby reducing the amount of anti-corrosion construction work; it can provide effective protection for the photovoltaic platform 21 throughout its entire life cycle, and also help reduce the anti-corrosion costs during the construction and operation and maintenance periods.

[0027] Specifically, the gravity foundation 126 may be made of concrete or steel structure, and includes a gravity base and lugs embedded in the gravity base.

[0028] Specifically, the lower end of the composite cable 122 integrates several auxiliary anodes 123. The composite cable 122 internally integrates the first lead-out wire of each auxiliary anode 123 and a tensile steel wire rope. The composite cable 122 possesses both current transmission capability and tensile strength. The auxiliary anodes 123 output cathodic protection current, and their specifications can be determined based on theoretical calculations of the required cathodic protection current. The auxiliary anodes 123 can be titanium-based metal oxide anodes, platinum-niobium composite anodes, or platinum-titanium composite anodes.

[0029] Specifically, the power controller 11 is electrically connected to the prefabricated substation via a power supply cable. The prefabricated substation provides AC power to the power controller 11, and the power controller 11 provides DC power to the composite cable component 12. The power controller 11 contains multiple standardized power control modules, each capable of independently controlling one auxiliary anode 123. The power controller 11 also includes a signal acquisition, processing, and display device, which can display and store the feedback signals from the far reference electrode 13 and the near reference electrode 14 in real time, achieving integrated protection and monitoring, and adjusting the protection current in real time based on monitoring information. The power controller 11 also includes a wireless transmission module, which transmits signals to the corresponding land-based central control terminal, enabling remote centralized monitoring and control.

[0030] Preferably, the second connector 121 is connected to the bolt ball 212 of the photovoltaic platform 21 using a lifting ring; the tension adjuster 124 uses a turnbuckle, with one end connected to the lifting ring and the other end connected to the composite cable 122; the third connector 125 uses a shackle. The lifting ring and the bolt ball 212 are threaded together, the upper end of the turnbuckle is engaged with the lifting ring, and the lower end is connected to the composite cable 122. The lower end of the composite cable 122 is engaged with the lifting lug of the gravity foundation 126 via a shackle. By adjusting the turnbuckle, the upper end of the composite cable 122 is moved, thereby adjusting the tension of the composite cable 122, limiting the deflection deformation of the composite cable 122, and preventing the composite cable 122 and the auxiliary anode 123 from colliding with the steel pile foundation 211 and being damaged by wind, waves, and currents.

[0031] Preferably, the third connector 125 consists of two connected shackles, one of which connects to the composite cable 122 and the other to the gravity foundation 126. One shackle can rotate slightly after engaging with the lug of the gravity foundation 126, and the other shackle can rotate slightly relative to the first shackle. The axes of rotation of the two shackles are perpendicular to each other. The engagement of the two shackles allows the bottom end of the composite cable 122 to rotate slightly in two directions, preventing the composite cable 122 from twisting under the influence of ocean currents when only one shackle is engaged with the lug.

[0032] Preferably, the bottom end of the composite cable 122 is provided with a sealing cover 127, and the end of the sealing cover 127 is provided with a cable joint 128. The bottom end of the composite cable 122 is connected to the third connector 125 through the sealing cover 127 and the cable joint 128. The sealing cover 127 seals and protects the bottom end of the composite cable 122. In this embodiment, the top end of the composite cable 122 is also provided with a branch cover, which serves to guide the first lead wire and seal the top end of the composite cable 122.

[0033] Preferably, the top end of the composite cable 122 is connected to the second connector 121 via a wire rope clamp 129. A rope loop is created at the top end of the composite cable 122 using the wire rope clamp 129 to connect to the turnbuckle. In this embodiment, a certain length of tensile steel wire rope is left at the top end of the composite cable 122 after removing the outer sheath and core. The tensile steel wire rope passes through the loop of the turnbuckle, is bent, and fixed by multiple wire rope clamps 129.

[0034] Preferably, both the far reference electrode 13 and the near reference electrode 14 are mounted on the steel pile foundation 211 via mounting components, which facilitates underwater installation.

[0035] Specifically, the second lead of the far reference electrode 13 and the third lead of the near reference electrode 14 are both protected by cable conduits. The cable conduits of the second and third leads are laid along the steel pile foundation 211 to the top with cable ties, so that the second and third leads are connected to the power controller 11.

[0036] Specifically, the far reference electrode 13 is positioned on the steel pile foundation 211 furthest from the composite cable 122 within the matrix region 2, while the near reference electrode 14 is positioned on the steel pile foundation 211 closest to the composite cable 122 within the matrix region 2. The far reference electrode 13 and the near reference electrode 14 measure the potential of their respective target areas to ensure the target areas are under good cathodic protection, and transmit the potential signal to the power controller 11. The feedback potentials of the far reference electrode 13 and the near reference electrode 14 are the most positive and most negative potentials within the entire matrix region 2, respectively, so that the output current can be adjusted according to the feedback potential to achieve intelligent control and avoid over-protection when close to the auxiliary anode 123 and under-protection when far from the auxiliary anode 123. Furthermore, this also helps optimize the number of reference electrodes required for photovoltaic field cathodic protection, reducing the workload of underwater operations.

[0037] Preferably, the mounting assembly includes a mounting base 31 and cable ties 32. The mounting base 31 has binding holes 311, and the cable ties 32 pass through the binding holes 311 to secure the mounting base 31 to the outer periphery of the steel pile foundation 211. The mounting base 31 has mounting holes 312 for connecting the far reference electrode 13 and the near reference electrode 14. In this embodiment, the mounting base 31 has two binding holes 311, one above the other, and two cable ties 32 are used to secure the mounting base 31 to the outer periphery of the steel pile foundation 211. The far reference electrode 13 and the near reference electrode 14 are connected to the corresponding mounting holes 312 through sealing joints.

[0038] Preferably, the mounting base 31 has an arc-shaped mounting surface 313 on the side facing the steel pile foundation 211 to fit the outer circumference of the steel pile foundation 211, ensuring that the mounting base 31 is installed stably and reliably.

[0039] Preferably, the first connector is made of flat steel or cable.

[0040] The working principle of the device in this application is as follows:

[0041] First, based on the distribution of the photovoltaic field, the protection area is divided into multiple matrix regions, and each matrix region is equipped with an impressed current cathodic protection device. Specifically, the auxiliary anode arrangement is optimized based on numerical simulation calculations of cathodic protection. Through iterative calculations, the number and range of steel pile foundations of the photovoltaic platform that can be protected by one set of impressed current cathodic protection devices are determined. Based on the distribution of steel pile foundations throughout the photovoltaic field, the system protection effect and economy of different division combinations are calculated to determine the optimal impressed current cathodic protection system layout scheme.

[0042] Secondly, based on the environmental parameters of the sea area where the photovoltaic platform is located, hydrodynamic performance calculations were performed on the impressed current cathodic protection equipment, and the weight of the gravity foundation and the required tension of the composite cable were determined based on the calculation results.

[0043] Finally, impressed current cathodic protection devices are installed in each matrix area of ​​the entire photovoltaic power plant using the photovoltaic platform's own structure, and each impressed current cathodic protection device transmits signals wirelessly to the land-based central control terminal to achieve remote centralized monitoring and control.

[0044] Installation steps of the device in this application:

[0045] 1. Fix the power controller to the operation and maintenance channel of the photovoltaic platform or a nearby inverter platform, and connect and fix all cables inside the power controller cabinet.

[0046] 2. Lay cables along the maintenance access road, photovoltaic platform support purlins, and poles using cable ties. The cables to be laid include power supply cables, first lead-out cables, second lead-out cables, third lead-out cables, cathode return cables, and measurement grounding cables.

[0047] 3. Weld a set of female terminals and a set of zero-position female terminals onto the photovoltaic platform.

[0048] 4. Install lifting rings on the bolt balls at the designed installation locations to reserve lifting points for the installation of composite cables at sea.

[0049] 5. After the photovoltaic platform's grid structure is installed, the composite cable components and gravity foundation are placed on the installation vessel and transported to the installation location for installation. The lower end of the composite cable is connected to the gravity foundation, and a crane is used to lower the composite cable, all connecting structures, and the gravity foundation to the installation location.

[0050] 6. Use a crane to lift the upper end of the composite cable to the lifting ring of the bolt ball. Connect the upper end of the composite cable to the lifting ring through various connecting structures. According to the actual water depth and elevation, use wire rope to clamp the upper end of the composite cable to make a rope loop. Use turnbuckles and shackles to fix the upper end of the composite cable to the bolt ball. Tighten the composite cable with turnbuckles to ensure that the composite cable remains taut.

[0051] 7. Connect the photovoltaic platforms in each matrix area electrically using flat steel or cables.

[0052] 8. When divers are diving, they install the far reference electrode and the near reference electrode. The far reference electrode and the near reference electrode are fixed to the corresponding steel pile foundation by cable ties and mounting brackets, and then laid along the steel pile foundation to the top by cable conduit and cable ties.

[0053] 9. Finally, perform wiring and debugging.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A marine photovoltaic distributed impressed current cathodic protection system, characterized in that, The number of impressed current cathodic protection devices is consistent with the number of matrix regions (2) divided by the photovoltaic electric field, and the impressed current cathodic protection devices correspond one-to-one with the matrix regions (2); The impressed current cathodic protection device includes: a first connector that electrically connects multiple photovoltaic platforms (21) set in the matrix area (2); a power controller (11) that converts AC power to DC power; a composite cable component (12); a far reference electrode (13); and a near reference electrode (14); the top end of the composite cable component (12) is connected to the photovoltaic platform (21), and the bottom end is anchored to the seabed; the first lead of the composite cable component (12) is electrically connected to the power controller (11); the far reference electrode (13) and the near reference electrode (14) are installed on the steel pile foundation (211) of the photovoltaic platform (21) in the matrix area (2); the distance between the far reference electrode (13) and the composite cable component (12) is greater than the distance between the near reference electrode (14) and the composite cable component (12); the second lead of the far reference electrode (13) and the third lead of the near reference electrode (14) are electrically connected to the power controller (11).

2. The offshore photovoltaic distributed impressed current cathodic protection system according to claim 1, characterized in that, The composite cable component (12) includes: a second connector (121) connecting to the photovoltaic platform (21), a composite cable (122), an auxiliary anode (123) disposed on the composite cable (122), a tension adjuster (124) for adjusting the tension of the composite cable (122), a third connector (125), and a gravity foundation (126); the gravity foundation (126) is placed at the installation position on the seabed, and the composite cable (122) is connected to the gravity foundation (126) through the third connector (125).

3. The offshore photovoltaic distributed impressed current cathodic protection system according to claim 2, characterized in that, The second connector (121) is connected to the bolt ball (212) of the photovoltaic platform (21) by means of a lifting ring; the tension adjuster (124) is a turnbuckle, one end of which is connected to the lifting ring and the other end is connected to the composite cable (122); the third connector (125) is a shackle.

4. A marine photovoltaic distributed impressed current cathodic protection system according to claim 3, characterized in that, The third connector (125) consists of two connected shackles, one of which connects to the composite cable (122) and the other connects to the gravity foundation (126).

5. A marine photovoltaic distributed impressed current cathodic protection system according to claim 2, characterized in that, The composite cable (122) is provided with a sealing cover (127) at the bottom end, and a cable joint (128) is provided at the end of the sealing cover (127). The bottom end of the composite cable (122) is connected to a third connector (125) through the sealing cover (127) and the cable joint (128).

6. A marine photovoltaic distributed impressed current cathodic protection system according to claim 3, characterized in that, The top end of the composite cable (122) is connected to the tension adjuster (124) via a wire rope clamp (129).

7. A marine photovoltaic distributed impressed current cathodic protection system according to claim 1, characterized in that, Both the far reference electrode (13) and the near reference electrode (14) are mounted on the steel pile foundation (211) via mounting components.

8. A marine photovoltaic distributed impressed current cathodic protection system according to claim 7, characterized in that, The mounting assembly includes a mounting base (31) and a cable tie (32). The mounting base (31) has a binding hole (311). The cable tie (32) passes through the binding hole (311) to tighten the mounting base (31) to the outer periphery of the steel pile foundation (211). The mounting base (31) has a mounting hole (312) for connecting the far reference electrode (13) and the near reference electrode (14).

9. A marine photovoltaic distributed impressed current cathodic protection system according to claim 8, characterized in that, The mounting base (31) has a mounting surface (313) on the side facing the steel pile foundation (211) for fitting the outer periphery of the steel pile foundation (211).

10. A marine photovoltaic distributed impressed current cathodic protection system according to claim 1, characterized in that, The first connector is made of flat steel or cable.

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