Auxiliary anode device and impressed current cathodic protection system

Abstract

The present invention discloses an auxiliary anode device comprising an anode housing, the inner wall of which is provided with multiple electrical connection points. The anode housing is used to pass through and coaxially connect a composite cable, and the electrical connection points are used to connect one-to-one with the power core wires within the composite cable. The present invention can reduce the drag force exerted by the auxiliary anode device on the composite cable, thereby increasing the service life of the system. While meeting current output requirements, the diameter of the composite cable can be reduced to reduce the impact of water flow on the composite cable. The present invention also discloses an impressed current cathodic protection system.

Description

Technical Field

[0001] The present invention relates to the technical field of corrosion and protection, in particular to an auxiliary anode device and an impressed current cathode protection system. Background Art

[0002] As onshore wind resources become increasingly saturated, developing clean energy, particularly offshore wind power, has become a long-term strategy for countries addressing future energy and climate change. my country boasts the world's largest offshore wind power market, leading the world in both annual new capacity additions and cumulative installed capacity. By the end of 2022, my country's cumulative installed offshore wind power capacity reached 31.5GW, with approximately 5,000 offshore wind turbines in operation. Offshore wind power operates in a complex marine environment, subject to the influence of wind loads, waves, currents, and other factors. Furthermore, offshore wind power platforms operate unmanned, making corrosion protection of offshore wind power pile foundations crucial for their safe operation.

[0003] Due to technical conditions and construction period limitations, my country currently generally adopts a fixed cathodic protection method for the protection of underwater steel structures of offshore wind power. The specific implementation form is to pre-install sacrificial anodes and external current cathodic protection systems on the newly built pile foundation cage. For newly built units, due to the large protection area required, the sacrificial anode method requires a large number of sacrificial anodes. For operating units, as the service life of the sacrificial anode protection increases, the underwater steel structures of offshore wind power will exceed the designed service life of the cathodic protection, and these cathodic protection systems will need to be repaired to extend their life. Repair technologies such as underwater welding, replacement of sacrificial anodes and auxiliary anodes are difficult, risky and expensive. As the mainstream cathodic protection technology for extending the life of offshore oil platforms, the tensioned external current system has the advantages of flexible installation and easy inspection and maintenance, but it is rarely used in cathodic protection of offshore wind power.

[0004] Because tensioned composite cables are installed vertically in a marine environment and only fixed at both ends, the system is susceptible to damage from external factors such as storms and waves. Therefore, the auxiliary structures on the composite cable have a significant impact on the gravity distribution of the composite cable. Patent CN106929862A discloses an auxiliary anode structure installed on a composite cable. Bolts and nuts clamp two semicircular titanium tubes to the composite cable. The two ends of the semicircular titanium tubes on one side of the composite cable are processed into a sealed shell with a hollow interior. A rod-shaped auxiliary anode is installed between the shells. Electrical connection to the platinum-niobium anode is achieved within the sealed shell by cold pressing. The electrical connection is sealed by adding sealing filler. Due to the small surface area of ​​the anode rod, the anode coating uses a platinum-niobium anode with a high current density and high cost. Due to the "D"-shaped structure, the weight of the auxiliary anode is concentrated on one side of the composite cable. Furthermore, when the current output is large, the core wire connected to the auxiliary anode has a large cross-sectional area, resulting in a large diameter composite cable and a high impact force from the water flow. Summary of the Invention

[0005] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide an impressed current cathodic protection system to reduce the drag force of the auxiliary anode device on the composite cable and improve the service life of the system; on the premise of meeting the current output requirements, the diameter of the composite cable can be reduced to reduce the impact of the impact force of the water flow on the composite cable.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] An auxiliary anode device comprises an anode shell, wherein the inner wall of the anode shell is provided with a plurality of electrical connection points, the anode shell is used for passing through and coaxially connecting a composite cable, and the electrical connection points are used for one-to-one connection with the power core wires in the composite cable.

[0008] In one embodiment, the electrical connection point is a terminal block, and a plurality of the terminal blocks are welded to the inner wall of the anode housing.

[0009] In one embodiment, the anode shell includes an anode barrel and a sealing cover. The anode barrel is a cylindrical structure with openings at both ends. The sealing covers are provided at both end openings of the anode barrel. The composite cable can pass through the two sealing covers. The terminal block is fixed to the inner wall of the anode barrel.

[0010] In one embodiment, the anode casing further includes a sealing gasket, which is used to be sandwiched between the composite cable, the anode barrel, and the sealing cover.

[0011] In one embodiment, the anode barrel is a metal tube, and a metal oxide coating is provided on the inner wall of the metal tube.

[0012] In one embodiment, an injection hole is provided on the sealing cover, and a sealing filler is injected into the anode shell through the injection hole. The sealing filler is used to seal the connection between the composite cable and the anode barrel.

[0013] In one embodiment, the material of the sealing filler is consistent with the material of the outermost layer of the composite cable.

[0014] The present invention also provides an impressed current cathodic protection system, comprising a composite cable, a constant potentiostat and the auxiliary anode device as described above, wherein the composite cable is arranged on one side of a wind turbine pile foundation, the composite cable is passed through and coaxially connected to the anode shell, the composite cable comprises a plurality of power core wires and a plurality of branching points, one end of the power core wire is branched out at the branching point and connected one-to-one with the electrical connection point, and the other end of the power core wire is connected to the constant potentiostat.

[0015] In one embodiment, a plurality of auxiliary anode devices are provided on the composite cable, and the plurality of auxiliary anode devices are arranged at intervals on the composite cable.

[0016] In one embodiment, the composite cable further comprises a steel wire rope, and a functional core wire layer, a first protective layer and a second protective layer are sequentially provided on the outside of the steel wire rope, and the plurality of power core wires are located in the functional core wire layer.

[0017] The beneficial effects of the present invention are as follows: the composite cable is passed through and coaxially connected to the anode shell. Compared with the auxiliary anode, the weight is concentrated on one side of the composite cable. Under the same water flow impact, the coaxial connection between the anode shell and the composite cable can effectively reduce the pulling force of the auxiliary anode device on the composite cable, thereby improving the service life of the system; multiple electrical connection points are arranged on the inner wall of the anode shell to increase the number of power core wires that can be connected. On the premise of meeting the current output requirements, multiple small-diameter power core wires can be used instead of a single large-diameter core wire, thereby reducing the diameter of the composite cable, thereby reducing the impact force of the water flow, and reducing the influence of the water flow on the composite cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 is a schematic structural diagram of the auxiliary anode device of the present invention;

[0020] Figure 2 is a schematic cross-sectional view of a composite cable of the present invention;

[0021] Figure 3a It is a schematic diagram of the cross section of a composite cable using a conventional auxiliary anode;

[0022] Figure 3b A schematic cross-sectional view of a composite cable using the auxiliary anode device of the present invention.

[0023] In the figure: 1. anode shell; 11. anode barrel; 12. sealing cover; 121. injection hole; 2. terminal; 3. sealing filler; 4. sealing gasket; 5. composite cable; 51. power core wire; 52. signal core wire; 53. branching point; 54. wire rope; 5A. functional core wire layer; 5B. first protective layer; 5C. second protective layer. DETAILED DESCRIPTION

[0024] Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the described embodiments are merely some, and not all, of the embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the description of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0025] In the description of the present invention, unless otherwise specified or limited, the terms "disposed," "installed," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of these terms based on the specific circumstances.

[0026] The directions or positional relationships indicated by terms such as "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience and simplification of description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0027] The terms "first," "second," "third," etc. are merely used to distinguish elements of similar nature and do not indicate or imply relative importance or a particular order.

[0028] The terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of elements other than the listed elements and may also include additional elements not specifically listed.

[0029] The present invention provides an auxiliary anode device, such as Figure 1 As shown, it includes an anode shell 1, and the inner wall of the anode shell 1 is provided with multiple electrical connection points. The anode shell 1 is used to pass through and coaxially connect the composite cable 5. The electrical connection points are used to connect one-to-one with the power core wire 51 in the composite cable 5. In this embodiment, the composite cable 5 is passed through and coaxially connected to the anode shell 1. Compared with the original auxiliary anode, the weight is concentrated on one side of the composite cable 5. Under the same water flow impact, the coaxial connection between the anode shell 1 and the composite cable 5 can effectively reduce the pulling force of the auxiliary anode device on the composite cable 5, thereby improving the service life of the system; multiple electrical connection points are provided on the inner wall of the anode shell 1 to increase the number of power core wires 51 that can be connected. Under the premise of meeting the current output requirements, multiple small-diameter power core wires 51 can be used instead of a single large-diameter power core wire 51 to connect to multiple electrical connection points, thereby reducing the diameter of the composite cable 5, reducing the impact of the water flow, and reducing the impact of the water flow on the composite cable 5.

[0030] As an implementation method, Figure 1 As shown, the electrical connection point is the terminal 2, and a plurality of the terminal 2 is welded to the inner wall of the anode shell 1, so that when the power core wire 51 is connected to the terminal 2, the connection reliability is strong and not easy to fall off.

[0031] As an implementation method, Figure 1 As shown, the anode housing 1 includes an anode barrel 11 and a sealing cover 12. The anode barrel 11 is a cylindrical structure with two openings. The two openings of the anode barrel 11 are each provided with a sealing cover 12. The composite cable 5 can pass through the two sealing covers 12. The terminal 2 is fixed to the inner wall of the anode barrel 11. The anode barrel 11 is a cylindrical structure.

[0032] As an implementation method, Figure 1 As shown, the anode housing 1 further includes a sealing gasket 4, which is used to be sandwiched between the composite cable 5, the anode barrel 11, and the sealing cover 12. The sealing gasket 4 is a wedge-shaped structure, which is sleeved on the composite cable 5. When the sealing cover 12 is tightened, the wedge-shaped sealing gasket 4 is continuously compressed to complete the sealing between the sealing cover 12 and the composite cable 5.

[0033] In one embodiment, the anode barrel 11 is a metal tube, optionally titanium, with a metal oxide coating on its inner wall. Conventional tubular auxiliary anodes and cables are typically connected by adding a copper ring between the cable and the auxiliary anode, supplemented by cold pressing to achieve electrical connection. This pressing process damages the tubular auxiliary anode coating and also physically damages the cable core. In this embodiment, during the manufacturing process of the anode barrel 11 coated with precious metal oxide (MMO), before sintering the precious metal oxide coating, a terminal block 2 is welded to the inner wall of the anode barrel 11. After thermal stress is eliminated through a heat treatment process, the coating is sintered. This prevents thermal stress concentration in the weld area, which can lead to a decrease in coating adhesion, and ensures the service life of the anode barrel 11. Specifically, during the manufacturing process of the anode barrel 11, the terminal block 2 is welded first, and after thermal stress is eliminated through a heat treatment process, the precious metal oxide coating is sintered to ensure coating adhesion in the weld area.

[0034] As an implementation method, Figure 1 As shown, the sealing cover 12 is provided with an injection hole 121 , through which a sealing filler 3 is injected into the anode shell 1 . The sealing filler 3 is used to seal the connection between the composite cable 5 and the anode barrel 11 to improve the sealing performance.

[0035] In one embodiment, the material of the sealing filler 3 is the same as that of the outermost layer of the composite cable 5. The sealing filler 3 in the gap between the anode housing 1 and the composite cable 5 is made of the same material as the outer sheath of the composite cable 5, that is, the sealing filler 3 and the second protective layer 5C are made of the same material, which can be PVDF. Through re-vulcanization, the sealing filler 3 and the composite cable 5 are completely integrated, ensuring watertightness and preventing the auxiliary anode device from falling off during the shaking of the composite cable 5.

[0036] The present invention also provides an impressed current cathodic protection system, comprising a composite cable 5, a potentiostat (not shown), and the auxiliary anode device described above. The composite cable 5 is arranged on one side of a wind turbine pile foundation (not shown), and is passed through and coaxially connected to the anode shell 1. The composite cable 5 includes multiple power core wires 51 and multiple branching points 53. One end of the power core wire 51 branches out at the branching point 53 and is connected to an electrical connection point in a one-to-one correspondence, and the other end of the power core wire 51 is connected to the potentiostat. In this embodiment, multiple electrical connection points are provided on the inner wall of the anode shell 1, so that one electrical connection point corresponds to one power core wire 51, thereby increasing the number of connectable power core wires 51. Under the premise of meeting the current output requirements, multiple small-diameter power core wires 51 can be used instead of a single large-diameter power core wire 51 to connect to multiple electrical connection points, thereby reducing the diameter of the composite cable 5, thereby reducing the impact force of the water flow and reducing the impact of the water flow on the composite cable 5.

[0037] As an embodiment, the impressed current cathodic protection system also includes a reference electrode (not shown). The reference electrode and the auxiliary anode are spaced apart on the composite cable 5. The composite cable 5 is also passed through and coaxially connected to the reference electrode. The composite cable 5 also includes a signal core wire 52 connected to the reference electrode. The composite cable 5 includes a plurality of branching points 53. The signal core wire 52 branched out at the branching point 53 is connected to the reference electrode, and the power core wire 51 branched out at the branching point 53 is connected to the auxiliary anode device. The potentiostat is electrically connected to the reference electrode through the signal core wire 52, and is electrically connected to the auxiliary anode through the power core wire 51. The potentiostat is electrically connected to the wind turbine pile foundation and the external power supply through a wire. When working, the cathodic protection system adjusts the current output of the auxiliary anode in real time according to the working potential of the wind turbine pile foundation detected by the reference electrode, thereby realizing cathodic protection of the wind turbine pile foundation.

[0038] As an embodiment, a plurality of auxiliary anode devices are provided on the composite cable 5 , and the plurality of auxiliary anode devices are arranged at intervals on the composite cable 5 . The installation position and number of the auxiliary anode devices are determined according to the exposed area of ​​the wind turbine pile foundation and environmental parameters.

[0039] As an implementation method, Figure 2As shown, the composite cable 5 also includes a steel wire rope 54. A functional core layer 5A, a first protective layer 5B, and a second protective layer 5C are sequentially provided on the outside of the steel wire rope 54. Multiple power cores 51 are located in the functional core layer 5A. The tensile steel wire rope 54 is located at the center of the composite cable 5. The steel wire rope 54 has an anti-rotation structure and a galvanized surface. The steel wire rope 54 is sequentially provided on the outside of the steel wire rope 54. Multiple power cores 51 and multiple signal cores 52 are all provided in the functional core layer 5A. The first protective layer 5B is a polyethylene (PE) layer to prevent seawater penetration and mechanical damage. The second protective layer 5C is a PVDF layer to prevent corrosion of the composite cable 5 by sodium hypochlorite generated by the auxiliary anode. The PVDF layer also has certain high-temperature and wear resistance, and can also prevent marine biofouling, avoiding biological attachment caused by long-term immersion of the composite cable 5 in seawater, thereby reducing the load on the composite cable 5.

[0040] Specifically, during the design phase of the composite cable 5, after determining the diameter of the steel wire rope 54 based on the mechanical load of the composite cable 5, the total area of ​​the required power core wire 51 is determined based on the maximum output current of the composite cable 5. The diameter of the power core wire 51 is then determined based on the principle of uniform arrangement along the outer diameter of the steel wire rope 54, minimizing the use of filler wire. The number of auxiliary anodes is determined based on the cathodic protection requirements of the protected object, and branch points 53 for the power core wire 51 are set at appropriate locations in the composite cable 5.

[0041] After the composite cable 5 is processed, the anode barrel 11 of the precious metal oxide (MMO) and the sealing covers 12 at both ends are moved along the composite cable 5 to the vicinity of the branching point 53 of the power core wire 51 of the composite cable 5, and the power core wire 51 led out from the branching point 53 is connected to the terminal 2. A heat shrink tubing is installed at the connection to prevent the added sealing filler 3 from penetrating into the connection and affecting its conductivity. Tighten the sealing caps 12 at both ends and install a wedge-shaped sealing gasket 4 between the sealing caps 12 and the composite cable 5. As the sealing caps 12 are tightened and moved, the wedge-shaped sealing gasket 4 is continuously compressed, thereby completing the seal between the sealing caps 12 and the composite cable 5. The auxiliary anode device is initially fixed to the composite cable 5. The sealing filler 3 is injected into the cavity between the anode shell 1 and the composite cable 5 through the injection molding hole 121. The sealing filler 3 is made of the same material as the second protective layer 5C of the outer sheath of the composite cable 5. After re-vulcanization, the composite cable 5 and the anode shell 1 form an organic whole, ensuring the waterproofness of the connection between the power core 51 of the composite cable 5 and the auxiliary anode device, while preventing relative displacement between the composite cable 5 and the anode shell 1 during the shaking of the composite cable 5. The terminal 2 is embedded in the sealing filler 3 to prevent the anode shell 1 from falling off longitudinally. The number of terminal 2 can be set according to the number of power cores 51.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. First, the auxiliary anode device is coaxially installed with the composite cable 5. The center of gravity of the auxiliary anode coincides with the center of gravity of the composite cable 5. Compared with the D-type structure (the center of gravity of the auxiliary anode is located on one side of the composite cable 5), under the same water flow impact, the drag force of the auxiliary anode on the composite cable 5 can be reduced.

[0044] 2. Multiple terminal blocks 2 are welded on the inside of the auxiliary anode device to increase the number of connectable wires. On the premise of meeting the current output requirements, multiple small-diameter core wires can be used instead of a single large-diameter core wire, thereby reducing the diameter of the composite cable 5 and reducing the impact force of the water flow.

[0045] 3. Compared to the D-type structure (single rod-shaped auxiliary anode), the cylindrical auxiliary anode of the present invention has a larger diameter, resulting in a larger auxiliary anode area. Under the same protection current density requirements, the auxiliary anode volume and total weight can be reduced, reducing the load on the composite cable 5. At the same time, metal oxide anodes with low current density and low cost can be used to replace platinum-niobium anodes with high current density and extremely high cost.

[0046] 4. The sealing filler 3 between the anode shell 1 and the composite cable 5 is made of the same material as the outer sheath of the composite cable 5. Through re-vulcanization, the composite cable 5 and the anode shell 1 form an organic whole, ensuring the waterproofness of the connection between the power core wire 51 of the composite cable 5 and the anode shell 1, while avoiding relative displacement between the composite cable 5 and the auxiliary anode device during the shaking of the composite cable 5.

[0047] Example 1

[0048] The center of the tensioned impressed current composite cable 5 is the tensile steel wire rope 54, and the power core wires 51 are evenly arranged around it. In order to maintain the roundness and tightness of the bundle, several filler wires are added to the gaps between the core wires. When four sets of auxiliary anodes are installed on the tensioned composite cable 5, the cathodic protection current needs to be about 16mm in total. 2 Copper wire, such as each auxiliary anode is connected to a single power core wire 51, then 4 strands with a cross-sectional area of ​​4mm are required. 2 The power core wire 51 (such as Figure 3a ), the power core wires 51 must be filled with filling wires, the outer diameter Φ1 of the composite cable 5 is 8.54mm, and the radius R1 of the power core wire 51 is 1.13mm. The auxiliary anode device designed by the present invention can be provided with a total of 8 terminal blocks 2 on the inner wall of the 4 anode barrels 11, with 2 terminal blocks 2 for each anode barrel 11, using 8 strands of 2mm 2 The power core wire 51 (such as Figure 3b), the power core wires 51 are evenly arranged around the steel wire rope 54. The outer diameter Φ2 of the composite cable 5 is 7.1 mm, and the radius R2 of the power core wires 51 is 0.8 mm. This shows that, under the premise of maintaining the same current output, the diameter of the composite cable 5 is effectively reduced. Since the impact of water flow in the marine environment is positively correlated with the cross-sectional area of ​​the composite cable 5, the stress on the composite cable 5 is reduced, thereby improving the service life of the composite cable 5.

[0049] Example 2

[0050] According to the design requirements of cathodic protection, the required cathodic protection current of a certain marine steel structure is about 50A. With the auxiliary anode device of the present invention, the diameter of the anode barrel 11 is about 60mm. 2 Under the output current density of , the anode barrel 11 of the auxiliary anode device can be selected to have a diameter of 60 mm and a length of 44 mm. The smaller volume of the anode barrel 11 can effectively reduce the mechanical load at the connection between the anode barrel 11 and the composite cable 5, thereby improving its service safety.

[0051] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with this profession can make some changes or modifications to the technical contents disclosed above without departing from the scope of the technical solution of the present invention, which are equivalent embodiments of equivalent changes. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. An auxiliary anode device, characterized in that: The invention comprises an anode shell (1), wherein the inner wall of the anode shell (1) is provided with a plurality of electrical connection points, the anode shell (1) is used for passing through and coaxially connecting a composite cable (5), the composite cable (5) comprising a plurality of power core wires (51) and a plurality of branching points (53), one end of the power core wire (51) branches out at the branching point (53), and the electrical connection points are used for one-to-one corresponding connection with the power core wires (51) branched out at the branching point (53) in the composite cable (5).

2. The auxiliary anode device according to claim 1, wherein: The electrical connection points are wiring terminals (2), and a plurality of the wiring terminals (2) are welded to the inner wall of the anode housing (1).

3. The auxiliary anode device according to claim 2, wherein: The anode shell (1) comprises an anode barrel (11) and a sealing cover (12). The anode barrel (11) is a cylindrical structure with openings at both ends. The sealing covers (12) are provided at both openings of the anode barrel (11). The composite cable (5) can pass through the two sealing covers (12). The terminal (2) is fixed to the inner wall of the anode barrel (11).

4. The auxiliary anode device according to claim 3, wherein: The anode shell (1) further comprises a sealing gasket (4), and the sealing gasket (4) is used to be sandwiched between the composite cable (5), the anode barrel (11), and the sealing cover (12).

5. The auxiliary anode device according to claim 3, wherein: The anode barrel (11) is a metal tube, and a metal oxide coating is provided on the inner wall of the metal tube.

6. The auxiliary anode device according to claim 3, wherein: The sealing cover (12) is provided with an injection hole (121), through which a sealing filler (3) is injected into the anode shell (1), and the sealing filler (3) is used to seal the connection between the composite cable (5) and the anode barrel (11).

7. The auxiliary anode device according to claim 6, wherein: The material of the sealing filler (3) is consistent with the material of the outermost layer of the composite cable (5).

8. An impressed current cathodic protection system, characterized in that: The invention comprises a composite cable (5), a constant potential instrument and an auxiliary anode device as described in any one of claims 1 to 7, wherein the composite cable (5) is arranged on one side of a wind power pile foundation, the composite cable (5) is passed through and coaxially connected to the anode shell (1), the composite cable (5) comprises a plurality of power core wires (51) and a plurality of branching points (53), one end of the power core wire (51) is branched at the branching point (53) and connected to the electrical connection point in a one-to-one correspondence, and the other end of the power core wire (51) is connected to the constant potential instrument.

9. The impressed current cathodic protection system according to claim 8, wherein: A plurality of auxiliary anode devices are provided on the composite cable (5), and the plurality of auxiliary anode devices are arranged at intervals on the composite cable (5).

10. The impressed current cathodic protection system according to claim 8, wherein: The composite cable (5) further comprises a steel wire rope (54), wherein a functional core wire layer (5A), a first protective layer (5B) and a second protective layer (5C) are sequentially provided on the outside of the steel wire rope (54), and the plurality of power core wires (51) are located in the functional core wire layer (5A).

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