Fan blade lightning receiving system and thunder and lightning protection method of fan blade

Abstract

The invention relates to the technical field of wind power equipment, and discloses a fan blade lightning receiving system and a thunder and lightning protection method of a fan blade. According to the wind turbine blade lightning arresting system, the lightning arresting device, the downlead and the metal coating are arranged, so that the damage degree of thunder and lightning to the blade structure can be remarkably reduced, and even if the surface of the blade is directly struck by the thunder and lightning, the blade is prevented from being directly punctured by the thunder and lightning by forming the electromagnetic shielding layer; therefore, the generated electric arc can be discharged under the attraction of the lightning arrester and the diversion effect of the down lead. And meanwhile, the blade can be prevented from being perforated due to electric and thermal composite breakdown, and the lightning stroke protection capability of the blade is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power equipment, and in particular to a lightning protection system for wind turbine blades and a lightning protection method for wind turbine blades. Background Art

[0002] Wind farms are mostly built in mountainous and hilly areas with complex terrain and climate, where lightning activities are more frequent. Blades are the most exposed parts of wind turbines. When struck by lightning, they are easily damaged, such as piercing the blades. When the blades are damaged, the wind turbines need to be shut down, causing economic losses to the wind farm. Therefore, improving the lightning protection of blades is of great significance to ensure the safe operation of wind turbines.

[0003] In conventional schemes, in order to increase the lightning protection range of the blade, when the lightning receptor is installed at the tip of the blade, a guide strip is bonded to the outer surface of the blade. The guide strip is composed of segmented discontinuous thin metal sheets and is pasted near the lightning receptor. When the lightning receptor is successfully connected, the lightning current is guided by the guide strip and enters the down conductor through the lightning receptor, and the current is discharged in a time limit.

[0004] However, the coverage area of ​​the guide strip is small, and its lightning protection capability is limited. When lightning strikes the blade, under the impact of high amplitude and large charge, the electric field strength between the lightning strike point and the down conductor in the blade increases rapidly. When the field strength exceeds the air breakdown field strength, the air is ionized to produce space charge, which further induces electric field distortion. When the composite field strength borne by the blade is higher than the damage threshold of the blade composite material layer, the blade will be electrically broken down. That is, exposed blades without guide strips indicate that there is still a risk of electrical breakdown. Therefore, it is urgent to develop new blade lightning protection technology to improve the lightning protection level of wind turbine blades, thereby reducing the risk of failures and ensuring the economic benefits and sustainable development of wind farms. Summary of the invention

[0005] In view of this, the present invention provides a wind turbine blade lightning protection system and a wind turbine blade lightning protection method to solve the problem that the blades are easily electrically broken down in the existing solutions.

[0006] In the first aspect, the present invention provides a wind turbine blade lightning arrester system, comprising a blade, a lightning arrester, a down conductor and a metal coating. The lightning arrester is installed at the tip of the blade; the down conductor is located inside the blade, and the down conductor is electrically connected to the lightning arrester; the material of the metal coating is a high-conductivity metal or a high-conductivity alloy, and the metal coating is applied to the inner wall surface of the blade.

[0007] Beneficial effect: Since the tip of the blade is the area with the highest probability of lightning hitting the blade, by installing the lightning receptor in the tip area of ​​the blade, it can effectively absorb lightning and guide it to the down conductor, reducing the probability of lightning directly hitting the rest of the blade. By applying a metal coating on the inner wall of the blade, and the material of the metal coating is a high-conductivity metal or a high-conductivity alloy, when lightning strikes the blade, the electrons in the metal coating move rapidly to form an electric field with the opposite polarity to the electric field formed by the lightning current, thereby forming an electromagnetic shielding layer, preventing lightning from directly penetrating the blade, and allowing the arc generated by lightning to enter the lightning receptor first and be led out through the down conductor. That is, by setting up lightning rods, down conductors and metal coatings, the path of arc discharge can be changed, significantly reducing the degree of damage to the blade structure caused by lightning. Even if the lightning current directly hits the blade, the electromagnetic shielding layer can be formed so that the generated arc will be discharged under the attraction of the lightning rod and the guidance of the down conductor, preventing the lightning from directly penetrating the blade. At the same time, it can avoid electrical and thermal composite breakdown and perforation of the blade, thereby improving the lightning protection capability of the blade.

[0008] In an optional embodiment, the blade is made of a composite material with a high dielectric constant.

[0009] Beneficial effects: By making the blades made of composite materials with high dielectric constants, the lightning arc generated when the blades are struck by lightning can easily move on the surface of the blades, which helps to guide the lightning arc to the lightning receptor and safely lead it out through the down conductor, thereby improving the phenomenon of blade damage caused by the lightning arc directly penetrating the blades. At the same time, because composite materials with high dielectric constants usually have good weather resistance and corrosion resistance, the blades can maintain stable performance under harsh climatic conditions.

[0010] In an optional embodiment, the metal coating consists of a wear-resistant layer and a high-conductivity layer.

[0011] Beneficial effects: The outer wear-resistant layer can effectively resist mechanical wear and environmental erosion, extend the service life of the lightning termination system, and reduce the maintenance frequency. The inner high conductivity layer forms an electric field shield when lightning occurs, preventing lightning from directly penetrating the blades.

[0012] In an optional embodiment, the wear-resistant layer in the metal coating includes at least one wear-resistant material selected from the group consisting of aluminum oxide, silicon nitride, hard chromium, and nickel-based alloy.

[0013] In an optional embodiment, the high conductivity layer in the metal coating includes at least one high conductivity material selected from the group consisting of copper, aluminum, copper-nickel alloy, copper-zinc alloy, and nickel-chromium alloy.

[0014] In an optional embodiment, the metal coating is applied to the inner wall surface of the blade by spraying or electroplating.

[0015] Beneficial effects: The spraying method can not only achieve uniform coverage, but also maintain good adhesion on complex geometric shapes to ensure the durability of the coating. By adopting the spraying method, large-area coating can be quickly completed, reducing the overall construction cost and time, and improving production efficiency. In addition, the adjustability of the coating after spraying also provides convenience for subsequent maintenance and repair, which is suitable for overall processing before blade installation. The electroplating method is suitable for laying in local areas of the blade. The electroplating method lays a high-conductivity metal layer through electrochemical deposition, has strong adhesion and good coating uniformity, and is suitable for local coating repair or thickening after blade installation.

[0016] In an optional embodiment, during the installation process, the metal coating is applied to the inner wall surface of the blade using at least one of the following laying methods: full coverage, grid coverage, horizontal laying, and longitudinal laying.

[0017] Beneficial effects: By fully covering the metal coating, an effective electromagnetic shield can be formed for any outer surface of the blade tip that is struck by lightning, achieving arc path guidance and blade breakdown protection. It is suitable for areas with frequent lightning activities and high lightning current amplitudes; by applying the metal coating in a grid-like manner, compared with the full coverage of the coating, it can reduce the blade load and reduce the impact of the lightning termination system on the blade output, which is suitable for areas with frequent lightning activities but low lightning current amplitudes; by using a horizontal or vertical coverage method for the metal coating, it can be adjusted according to the actual operating environment of the wind turbine, optimize the current flow path, and improve the conductivity. When lightning strikes the blade, the specific coverage direction can effectively guide the current to flow along the predetermined path, further reducing damage to the blade material.

[0018] In an optional implementation, the metal coating is electrically isolated from the lightning receptor and the down conductor.

[0019] Beneficial effects: It can effectively avoid performance loss caused by current interference between the lightning receptor and the metal coating, thereby ensuring the independence and stability of the coating during lightning events. This non-connected design also helps reduce the maintenance cost and complexity of the lightning receptor, while reducing the probability of potential failures and ensuring the long-term safe operation of the wind turbine.

[0020] In an optional implementation, the grounding device is electrically connected to the down conductor.

[0021] Beneficial effect: By adding a grounding device and electrically connecting the grounding device to the down conductor, since the down conductor is also electrically connected to the lightning receptor, the lightning arc generated by lightning striking the surface of the blade will be absorbed by the lightning receptor and guided to the ground, preventing the lightning arc from generating secondary discharge inside the blade or between other electrical equipment, thereby reducing physical damage.

[0022] In the second aspect, the present invention also provides a lightning protection method for wind turbine blades, which is applied to the wind turbine blade lightning protection system provided in the first aspect. The lightning protection method for wind turbine blades includes: installation: installing a lightning arrester at the tip of the blade, installing a down conductor inside the blade and laying a metal coating; protection: when lightning strikes the blade, the electrons in the metal coating move rapidly to form an electric field with the opposite polarity to the electric field of the lightning current, forming an electromagnetic shielding structure inside the blade to prevent the lightning arc from penetrating the blade, and the lightning arrester receives the lightning arc and discharges it through the down conductor.

[0023] Beneficial effect: Because the lightning protection method for wind turbine blades is applied to the wind turbine blade lightning protection system of the first aspect, it has the same effect as the wind turbine blade lightning protection system, and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the specific implementation modes of the present invention, the drawings required for use in the description of the specific implementation modes will be briefly introduced below. Obviously, the drawings described below are some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of a blade of a wind turbine blade lightning termination system in a conventional solution being penetrated but not absorbed by the lightning termination device;

[0026] Figure 2 A schematic diagram of the wind turbine blade lightning arrester system provided in the present application, in which the arc is absorbed by the lightning arrester after the metal coating is applied inside the blade;

[0027] Figure 3 A schematic diagram of different laying methods of the metal coating in the wind turbine blade lightning protection system provided in this application.

[0028] Description of reference numerals:

[0029] 1. Blade; 2. Lightning receptor; 3. Down conductor; 4. Metal coating;

[0030] K, the direction of the lightning arc movement; M, the lightning strike position;

[0031] A. Full coverage; B. Grid coverage; C. Horizontal coverage; D. Vertical coverage. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] Blades are the most exposed parts of wind turbines. When struck by lightning, they are easily damaged. Therefore, in order to increase the lightning protection range of blades, when the lightning receptor is installed at the tip of the blade, a guide strip is applied externally. The guide strip is composed of segmented and discontinuous thin metal sheets and is pasted near the lightning receptor. The lightning that is not successfully received by the lightning receptor is directed to the lightning receptor along the guide strip. When the lightning receptor is successfully received, the lightning current is guided by the guide strip and enters the down conductor through the lightning receptor, and the current is discharged in a time-limited manner.

[0037] However, the coverage area of ​​the guide bar is small and its lightning protection capability is limited. The exposed blades without the guide bar still show the risk of electrical breakdown. Figure 1As shown in the figure, when a blade is struck by lightning, under the impact of high amplitude and large charge, the electric field strength between the lightning strike point and the down conductor in the blade increases rapidly. When the field strength exceeds the air breakdown field strength, the air is ionized to produce space charge, which further causes electric field distortion. When the composite field strength borne by the blade is higher than the damage threshold of the blade's composite material layer, the blade will be electrically broken down, and the arc will move directly from the lightning strike point to the down conductor along the breakdown channel, causing lightning damage to the blade.

[0038] To this end, the present application forms an electromagnetic shielding structure inside the blade to eliminate the influence of space charge, so that the arc generated when lightning strikes the blade is absorbed by the lightning receptor and guided to the ground through the down conductor.

[0039] Figure 1 A schematic diagram showing a conventional solution in which a blade of a wind turbine blade lightning termination system is not absorbed by a lightning termination device when being struck; Figure 2 A schematic diagram showing the wind turbine blade lightning arrester system provided by the present application showing that the arc is absorbed by the lightning arrester after the metal coating is applied inside the blade. Figure 3 The schematic diagram shows different laying methods of the metal coating in the wind turbine blade lightning protection system provided by the present application, A, full coverage; B, grid coverage; C, horizontal coverage; D, longitudinal coverage. The K direction shown in the figure is the moving direction of the lightning arc generated by the lightning blade, and M is the lightning strike position.

[0040] Combine the following Figure 2 , describing an embodiment of the present invention.

[0041] According to an embodiment of the present invention, in a first aspect, a wind turbine blade lightning arrester system is provided, which includes a blade 1, a lightning arrester 2, a down conductor 3 and a metal coating 4.

[0042] Among them, the lightning receptor 2 is installed at the tip of the blade 1; the down conductor 3 is located inside the blade 1, and the down conductor 3 is electrically connected to the lightning receptor 2; the material of the metal coating 4 is a high-conductivity metal or a high-conductivity alloy, and the metal coating 4 is applied to the inner wall surface of the blade 1.

[0043] By using the wind turbine blade lightning arrester system of the present embodiment, since the tip of the blade 1 is the area with the highest probability of lightning striking the blade 1, by installing the lightning arrester 2 in the tip area of ​​the blade 1, it is possible to effectively absorb lightning and guide it to the down conductor 3, thereby preventing lightning from directly striking the remaining areas of the blade 1. In addition, by applying a metal coating 4 on the inner wall surface of the blade 1, and the material of the metal coating 4 is a high-conductivity metal or a high-conductivity alloy, when lightning strikes the blade 1, the electrons in the metal coating 4 move rapidly to form an electric field with a polarity opposite to that formed by the lightning current, thereby forming an electromagnetic shielding layer, preventing lightning from directly penetrating the blade 1, and allowing the arc generated by the lightning to preferentially enter the lightning arrester 2 and be led out through the down conductor 3.

[0044] That is, by providing the lightning receptor 2, the down conductor 3 and the metal coating 4, the degree of damage to the structure of the blade 1 caused by lightning can be significantly reduced, even if lightning concentrates on the blade 1, an electromagnetic shielding layer can be formed.

[0045] At the same time, by releasing the generated arc under the attraction of the lightning receptor 2 and the conduction of the down conductor 3, it is also possible to avoid electrical and thermal composite breakdown and perforation of the blade 1, thereby improving the lightning protection capability of the blade 1.

[0046] At the same time, since the present application does not adopt the setting method of the guide strips and metal mesh in the conventional solution, the blade load can be reduced, thereby reducing the impact of the blade load on the output efficiency of the wind turbine.

[0047] In addition, since the arc striking system itself is not used as a carrier of lightning current in the present application, under a lightning strike with high amplitude and large charge, the arc striking system will not be blown due to significant thermal effects, thereby causing lightning termination failure and failure of the arc striking system.

[0048] Preferably, the metal coating 4 extends to the tip of the blade 1 .

[0049] Such an arrangement helps to efficiently guide the lightning arc generated by the lightning-strike blade 1 to the lightning arrester 2 at the blade tip and safely conduct it, thereby significantly improving the lightning protection level and operational safety of the blade 1 of the wind turbine blade lightning arrester system.

[0050] It can be explained that, in the present application, the blade 1 is made of a composite material with a high dielectric constant.

[0051] By utilizing the wind turbine blade lightning arrester system of this embodiment, by making the blade 1 made of a composite material with a high dielectric constant, when the blade 1 is struck by lightning, the generated lightning arc can easily move on the surface of the blade 1, which helps to guide the lightning arc to the lightning arrester 2 and safely conduct it through the down conductor 3, thereby improving the phenomenon of damage to the blade 1 caused by the lightning arc directly penetrating the blade 1.

[0052] At the same time, since composite materials with high dielectric constants generally have good weather resistance and corrosion resistance, the blade 1 can maintain stable performance under severe climatic conditions.

[0053] It can be explained that, in the present application, the metal coating 4 is a two-layer structure: the outer layer is a wear-resistant layer, and the inner layer is a high-conductivity layer.

[0054] By using the wind turbine blade lightning arrester system of this embodiment, the outer wear-resistant layer can effectively resist mechanical wear and environmental erosion, extend the service life of the lightning arrester system, and reduce the maintenance frequency. The inner high conductivity layer forms an electric field shield when lightning occurs, preventing lightning from directly penetrating the blade 1.

[0055] Specifically, the wear-resistant layer in the metal coating 4 includes at least one wear-resistant material selected from the group consisting of aluminum oxide, silicon nitride, hard chromium, and nickel-based alloy.

[0056] Specifically, the high conductivity layer in the metal coating 4 includes at least one high conductivity material selected from the group consisting of copper, aluminum, copper-nickel alloy, copper-zinc alloy, and nickel-chromium alloy.

[0057] It can be explained that, in the present application, the metal coating 4 is applied to the inner wall surface of the blade 1 by a spraying method.

[0058] Utilizing the wind turbine blade lightning arrester system of this embodiment, the spraying method can not only achieve uniform coverage, but also maintain good adhesion on complex geometric shapes, ensuring the durability of the coating. By adopting the spraying method, large-area coating can be quickly laid, reducing the overall construction cost and time, and improving production efficiency. In addition, the adjustability of the coating after spraying also provides convenience for subsequent maintenance and repair, and is suitable for overall processing of the blade 1 before installation.

[0059] It can be explained that, in the present application, the metal coating 4 can also be applied to the inner wall surface of the blade 1 by electroplating.

[0060] Using the wind turbine blade lightning arrester system of this embodiment, the electroplating method is suitable for laying in a local area of ​​the blade 1. The electroplating method lays a high-conductivity metal layer through electrochemical deposition, has strong adhesion and good coating uniformity, and is suitable for local coating repair or thickening treatment after the blade 1 is installed.

[0061] Specifically, in this application, Figure 3 As shown in A, during the installation process, the metal coating 4 can be used to fully cover the inner wall surface of the blade 1, including the inner wall surface of the blade tip.

[0062] By utilizing the wind turbine blade lightning protection system of this embodiment, by fully covering the metal coating 4, an effective electromagnetic shield can be formed for any outer surface of the blade tip that is struck by lightning, thereby achieving arc path guidance and breakdown protection for the blade 1; it is suitable for areas with frequent lightning activities and high lightning current amplitudes.

[0063] It can be explained that in this application, Figure 3 As shown in B, during the installation process, the metal coating 4 can also be selected to grid-cover the inner wall surface of the blade 1, including the inner wall surface of the blade tip.

[0064] By using the wind turbine blade lightning protection system of this embodiment, the metal coating 4 is grid-coated, which can reduce the load on the blade 1 and the impact of the lightning protection system on the output of the blade 1 compared to the full coverage of the coating. It is suitable for areas with frequent lightning activities but low lightning current amplitude.

[0065] Of course, if Figure 3 C or Figure 3 As shown in D, a horizontal laying method or a longitudinal laying method can also be selected to lay it on the inner wall surface of the blade 1, including the inner wall surface of the blade tip.

[0066] By utilizing the wind turbine blade lightning protection system of this embodiment, the metal coating 4 can be adjusted according to the actual operating environment of the wind turbine by using a horizontal or vertical covering method, thereby optimizing the current flow path and improving the conductivity. When lightning strikes the blade 1, the specific covering direction can effectively guide the current to flow along a predetermined path, further reducing damage to the blade 1 material.

[0067] In addition, in other optional embodiments, the metal coating 4 may also be applied to the inner wall surface of the blade 1 by combining two or more of full coverage, grid coverage, horizontal laying and longitudinal laying.

[0068] In an optional implementation, the metal coating 4 is electrically isolated from the lightning receptor 2 and the down conductor 3 .

[0069] The wind turbine blade lightning arrester system of this embodiment can effectively avoid performance loss caused by current interference between the lightning arrester 2 and the metal coating 4, thereby ensuring the independence and stability of the coating during lightning events. This non-connected design also helps to reduce the maintenance cost and complexity of the lightning arrester 2, while reducing the probability of potential failures, and ensuring the long-term safe operation of the wind turbine.

[0070] In a second aspect, the present invention further provides a lightning protection method for wind turbine blades, which is applied to the wind turbine blade lightning protection system provided in the first aspect. The lightning protection method for wind turbine blades includes: installation: installing a lightning receptor 2 at the tip of the blade 1, and installing a down conductor 3 inside the blade 1 and laying a metal coating 4; protection: when lightning strikes the blade 1, the electrons in the metal coating 4 move rapidly to form an electric field with a polarity opposite to that of the lightning current electric field, forming an electromagnetic shielding structure inside the blade 1 to prevent the lightning arc from penetrating the blade 1, so that the lightning arc moves on the surface of the blade 1, and the moving direction is Figure 2 As shown in the K direction, the lightning arrester 2 receives the lightning arc and discharges it through the down conductor 3.

[0071] The lightning protection method for wind turbine blades of the present embodiment has the same effect as the wind turbine blade lightning protection system of the previous aspect because the lightning protection method for wind turbine blades is applied to the wind turbine blade lightning protection system of the previous aspect, and will not be described in detail here.

[0072] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A wind turbine blade lightning protection system, characterized in that: include: Leaf blade (1); A lightning receptor (2), the lightning receptor (2) being mounted at the tip of the blade (1); A down conductor (3), the down conductor (3) being located inside the blade (1), and the down conductor (3) being electrically connected to the lightning receptor (2); A metal coating (4), wherein the material of the metal coating (4) is a high-conductivity metal or a high-conductivity alloy, and the metal coating (4) is applied on the inner wall surface of the blade (1).

2. The wind turbine blade lightning protection system according to claim 1, characterized in that: The blade (1) is made of a composite material with a high dielectric constant.

3. The wind turbine blade lightning protection system according to claim 1, characterized in that: The metal coating (4) consists of a wear-resistant layer and a high-conductivity layer.

4. The wind turbine blade lightning arrester system according to claim 3, characterized in that: The wear-resistant layer in the metal coating (4) comprises at least one wear-resistant material selected from the group consisting of aluminum oxide, silicon nitride, hard chromium and nickel-based alloy.

5. The wind turbine blade lightning protection system according to claim 3, characterized in that: The high-conductivity layer in the metal coating (4) comprises at least one high-conductivity material selected from the group consisting of copper, aluminum, copper-nickel alloy, copper-zinc alloy, and nickel-chromium alloy.

6. The wind turbine blade lightning protection system according to claim 3, characterized in that: The metal coating (4) is applied to the inner wall surface of the blade (1) by spraying or electroplating.

7. The wind turbine blade lightning protection system according to any one of claims 2 to 6, characterized in that: During the installation process, the metal coating (4) is applied to the inner wall surface of the blade (1) by at least one of the following laying methods: full coverage, grid coverage, horizontal laying and longitudinal laying.

8. The wind turbine blade lightning protection system according to any one of claims 1 to 6, characterized in that: The metal coating (4) is electrically isolated from the lightning receptor (2) and the down conductor (3).

9. The wind turbine blade lightning protection system according to any one of claims 1 to 6, characterized in that: Also includes: A grounding device, wherein the grounding device is electrically connected to the down conductor (3).

10. A lightning protection method for wind turbine blades, applied to the wind turbine blade lightning protection system according to any one of claims 1 to 9, characterized in that: Lightning protection methods for wind turbine blades include: Installation: installing a lightning receptor (2) at the tip of the blade (1), installing a down conductor (3) inside the blade (1) and applying a metal coating (4); Protection: When lightning strikes the blade (1), the electrons in the metal coating (4) move rapidly, forming an electric field with a polarity opposite to that of the lightning current, thereby forming an electromagnetic shielding structure inside the blade (1) to prevent the lightning arc from penetrating the blade (1). The lightning receptor (2) receives the lightning arc and discharges it through the down conductor (3).

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