Lightning protection system with metal mesh series down conductor based on gradual change technology

Abstract

The application discloses a lightning protection system of metal net series down lead based on a gradient technology, relates to the technical field of wind turbine blade design, and is applied to a wind turbine blade and comprises a series connection metal net system, a down lead assembly and a lightning attraction system. The series connection metal net system comprises a main metal net and a blade root metal net grounding piece and a blade tip metal net grounding piece. The down lead assembly is in series connection with the metal net system. The lightning attraction system is arranged on the surface of the blade. The unit area mass of the metal net system is distributed in a gradient along the blade span direction, forming a low mass area, a transition area and a high mass area. The high mass area covers the blade tip area. The application basically does not change the lightning conduction performance and greatly reduces the cost. Meanwhile, the metal net gradient technology is adopted to realize integrated forming of metal nets with different mass specifications. The large mass metal net is used to reduce the width of the metal net in the blade tip area, thereby solving the problem that the metal net in the blade tip area cannot be protected and the problem of differential protection of different lightning partitions of the blade.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind turbine blade design, in particular to a lightning protection system of metal mesh series down conductor based on gradual change technology. BACKGROUND

[0002] The traditional and conventional carbon fiber blade lightning protection system includes a double-loop system of down conductor and metal mesh in parallel. Research results show that the proportion of lightning current conducted by the double-loop down conductor lightning protection system is less than 20%, and the double-loop system lightning protection design scheme has design redundancy waste and high cost.

[0003] The invention patent with the publication number CN116917618A "Lightning protection system" provides a down conductor lightning protection system for carbon fiber blade lightning protection. The above patent provides a metal mesh or metal foil as a component for conducting lightning current in the middle down conductor lightning protection system, but only provides a lightning protection scheme for carbon fiber blades. And the above patent cannot realize the coverage of the metal mesh in the 5m area of the blade tip. This phenomenon has become a problem that personnel in the field are eager to solve. SUMMARY

[0004] The purpose of the present application is to provide a lightning protection system of metal mesh series down conductor based on gradual change technology to solve the problems raised in the background art.

[0005] In order to solve the above technical problems, the present application provides the following technical scheme: a lightning protection system of metal mesh series down conductor based on gradual change technology applied to a wind turbine blade, comprising:

[0006] A series connected metal mesh system is laid along the blade span, and the metal mesh system includes a main metal mesh, a blade root metal mesh grounding piece and a blade tip metal mesh grounding piece;

[0007] A down conductor assembly is connected in series with the metal mesh system;

[0008] The lightning protection system includes a blade body lightning arrester and a blade tip lightning arrester and is arranged on the surface of the blade;

[0009] The unit area mass of the main metal mesh is distributed in a gradient along the blade span, forming a low grammage area, a transition area and a high grammage area, wherein the high grammage area covers the blade tip area, and the unit area mass of the metal mesh system is distributed in a gradient along the blade span at least including a group of transition areas.

[0010] According to the above technical scheme, the metal mesh series down conductor system is distributed on at least one surface of the blade. The metal mesh series down conductor system distributed on two surfaces is connected in a conductive suture structure through overlapping and lapping metal sheets, forming a continuous conductive path.

[0011] According to the technical scheme, the low-weight-area is arranged from the root to the middle of the blade, the transition area is arranged in the middle of the blade, and the high-weight-area is arranged in the tip of the blade.

[0012] According to the technical scheme, the high-weight-area extends to cover the tip of the blade within a range of 5m, and is directly connected with the lightning receptor or the blade lightning receptor through the metal sheet or the conductive adhesive layer.

[0013] According to the technical scheme, the unit area mass of the metal mesh system is distributed in a gradient along the span of the wind turbine blade.

[0014] According to the technical scheme, the high-weight-area extends to cover the tip of the blade within a range of 5m, and is directly connected with the lightning receptor or the blade lightning receptor through the metal sheet or the conductive adhesive layer.

[0015] According to the technical scheme, one end of the tip down conductor is connected with the lightning receptor and the blade lightning receptor arranged at the tip of the wind turbine blade, and the other end of the tip down conductor comprises a grounding base one connected with the high-weight-area of the metal mesh system.

[0016] According to the technical scheme, one end of the root down conductor is connected with the low-weight-area of the metal mesh system, and the other end of the root down conductor comprises a grounding base two connected with the blade root grounding device.

[0017] According to the technical scheme, the main metal mesh one is provided with a metal mesh grounding device one, and the main metal mesh two is provided with a metal mesh grounding device two.

[0018] According to the technical scheme, the metal mesh system is connected with the grounding base one and the grounding base two through the metal mesh grounding device one and the metal mesh grounding device two, so as to form a single-loop lightning current conduction path.

[0019] Compared with the prior art, the present application has the following beneficial effects: the present application is not only used for carbon fiber blades, but also suitable for lightning protection of glass fiber blades. Compared with the double-loop system in parallel with the metal mesh, the cost is greatly reduced while the lightning conduction performance is basically unchanged. Meanwhile, the metal mesh gradient technology is adopted to realize the integrated forming of different weight specifications of the metal mesh, the width of the metal mesh in the tip area is reduced by using the metal mesh with large weight, and the problem that the metal mesh in the tip area cannot be protected and the problem of differential protection of different lightning partitions of the blade are solved. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, which together with the embodiments of the present application, serve to explain the present application, and do not constitute a limitation of the present application. In the drawings:

[0021] Figure 1It is the connection principle diagram of the lightning protection system of the metal net series down lead based on the gradual change technology of the application (single shell);

[0022] Figure 2 It is the wind power blade layout diagram of the lightning protection system of the metal net series down lead based on the gradual change technology of the application;

[0023] Figure 3 It is the connection principle diagram of the lightning protection system of the metal net series down lead based on the gradual change technology of the application in the thickness direction of the blade;

[0024] Figure 4 It is the connection diagram of the metal net system and the tip down lead system of the application;

[0025] Figure 5 It is the low and high specific gravity distribution diagram of the lightning protection system of the metal net series down lead based on the gradual change technology of the application (single shell);

[0026] Figure 6 It is the gradual change technology diagram of the main metal net of the application;

[0027] Figure 7 It is the layout diagram of the tip down lead system of the application (single shell);

[0028] Figure 8 It is the gradual change structure diagram of the metal net of the application.

[0029] In the figure: 1, wind turbine blade; 2, root grounding piece; 3, root down lead; 4, blade root grounding metal net one; 5, main metal net one; 6, main metal net two; 7, grounding base two; 8, blade body lightning arrester; 9, tip down lead; 10, blade tip lightning arrester; 11, metal net grounding piece one; 12, metal net grounding piece two; 13, metal sheet; 14, grounding base one; 15, grounding metal net one; 16, grounding metal net two; 17, main metal net; 18, lightning arrester system module; 19, blade shell one; 20, blade shell two; 21, metal net system; 22, low specific gravity area; 23, transition zone; 24, high specific gravity area; 25, blade root metal net grounding piece two; 26, blade tip metal net grounding piece two; 27, blade tip metal net grounding piece one. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0031] Please refer to Figures 1-8The application provides a technical scheme: a lightning protection system of a metal mesh series down conductor based on a gradual change technology, comprising a wind turbine blade 1, the wind turbine blade 1 is provided with a metal mesh series down conductor system, and the metal mesh series down conductor system comprises:

[0032] A metal mesh system 21 is arranged in series along the wind turbine blade 1, and the metal mesh system 21 comprises a main metal mesh 17, a root metal mesh grounding device and a tip metal mesh grounding device;

[0033] A down conductor assembly comprises a root down conductor 3 and a tip down conductor 9, and the down conductor assembly is connected in series with the metal mesh system 21;

[0034] A lightning arresting system comprises a blade body lightning arrester 8 and a tip lightning arrester 10, and the blade body lightning arrester 8 and the tip lightning arrester 10 are arranged on the surface of the wind turbine blade 1;

[0035] The unit area mass of the main metal mesh 17 is distributed in a gradient along the blade span direction, forming a low mass area 22, a transition area 23 and a high mass area 24, wherein the high mass area 24 covers the tip area, and the unit area mass of the metal mesh system 21 is distributed in a gradient along the blade span direction, and at least one group of transition areas 23 are included in the gradient distribution direction of the unit area mass of the metal mesh system 21 along the wind turbine blade 1.

[0036] Reference Figure 3 And Figure 4 The metal mesh system 21 extends from the root to the tip along the wind turbine blade 1, and the main metal mesh is divided into a main metal mesh one 5 and a main metal mesh two 6, and the two are connected in series through a metal sheet 13 Figure 4 The tip lightning arrester 10 is arranged at the most front end of the blade, and the blade body lightning arrester 8 is distributed on the pressure surface and the suction surface Figure 3 of the middle and rear parts of the blade, the main metal mesh 17 in the figure is one between the main metal mesh one 5 and the main metal mesh two 6, facilitating observation and understanding.

[0037] The root metal mesh grounding device comprises a root grounding metal mesh one 4 and a root metal mesh grounding device two 25;

[0038] The tip metal mesh grounding device comprises a tip metal mesh grounding device one 27 and a tip metal mesh grounding device two 26;

[0039] The material of the main metal mesh one 5 and the main metal mesh two 6 is copper, aluminum, nickel or the like, preferably copper material;

[0040] The unit area mass of the metal mesh system 21 is distributed in a gradient along the blade span direction and satisfies:

[0041] The low weight area 22 has a unit area mass of 50-500 g / m2. In one embodiment, the low weight area 22 has a unit area mass of 50 g / m2; in one embodiment, the low weight area 22 has a unit area mass of 500 g / m2; in one embodiment, the low weight area 22 has a unit area mass of 250 g / m2.

[0042] The transition area 23 has a linearly increasing unit area mass of 400-600 g / m2. In one embodiment, the transition area 23 has a linearly increasing unit area mass of 400 g / m2; in one embodiment, the transition area 23 has a linearly increasing unit area mass of 600 g / m2; in one embodiment, the transition area 23 has a linearly increasing unit area mass of 500 g / m2.

[0043] The high weight area 24 has a unit area mass of 500-1000 g / m2. In one embodiment, the high weight area 24 has a unit area mass of 500 g / m2; in one embodiment, the high weight area 24 has a unit area mass of 1000 g / m2; in one embodiment, the high weight area 24 has a unit area mass of 800 g / m2.

[0044] Referring to Figure 5 , Figure 6 , Figure 7 and Figure 8 , the low weight area 22: root to 70% blade length area, uses woven copper mesh to ensure its conductivity;

[0045] The transition area 23: 70%-75% blade length area, linearly increases the weight by gradually increasing the wire density to 200-500 g / m2. In one embodiment, the 70% blade length area linearly increases the weight by gradually increasing the wire density to 200 g / m2; in one embodiment, the 75% blade length area linearly increases the weight by gradually increasing the wire density to 500 g / m2; in one embodiment, the 72% blade length area linearly increases the weight by gradually increasing the wire density to 300 g / m2.

[0046] The high weight area 24: 75% to the tip of the blade range uses copper mesh to completely cover the periphery area of the lightning receptor 10 ( Figure 7 ).

[0047] The low weight area 22 is arranged at the root to the middle of the blade, the transition area 23 is arranged at the middle of the blade, and the high weight area 24 is arranged in the tip range of the blade.

[0048] The high weight area 24 extends to cover the blade tip 5m range, and the metal mesh stringer system distributed on two surfaces is connected directly to the lightning receptor 10 or the tip blade lightning receptor 8 through the metal sheet 13 or the conductive adhesive layer.

[0049] Reference Figure 8 As shown, the blank area on both sides of the high weight area 24 is a cutting area.

[0050] The tip down conductor 9 is connected to the tip lightning arrester 10 and the blade lightning arrester 8 arranged at the tip of the wind turbine blade 1 at one end, and the other end of the tip down conductor 9 is connected to the high weight area 24 of the metal mesh system 21 in series.

[0051] The tip reinforcement connection: the metal mesh of the high weight area 24 is fixed by tin soldering with the metal sheet 13 and extends to the blade lightning arrester base below the tip area or below the tip lightning arrester 10, which ensures that the lightning current is directly introduced into the metal mesh.

[0052] The electrical connection between the metal mesh and the lightning arrester is realized through the lightning arrester 21.

[0053] The grounding path: one end of the root down conductor 3 is bolted to the copper mesh of the low weight area 22, and the other end is connected to the blade root grounding piece 2 embedded in the carbon beam;

[0054] The metal mesh system 21 is connected to the grounding base one 14 and the grounding base two 7 through the metal mesh grounding piece one 11 and the metal mesh grounding piece two 12, forming a single-loop discharge channel. Figure 2 )。

[0055] The tip down conductor 9 is connected to the tip lightning arrester 10 at one end, and the other end of the tip down conductor 9 is connected to the high weight area 24 of the metal mesh system 21 in series.

[0056] The root down conductor 3 is connected to the low weight area 22 of the metal mesh system 21 at one end, and the other end of the root down conductor 3 is connected to the blade root grounding piece 2.

[0057] Reference Figure 2 As shown, the main metal mesh one 5 is provided with a blade root grounding metal mesh one 4, a main metal mesh 17, and a tip metal mesh grounding piece one 27, and the main metal mesh two 6 is provided with a blade root metal mesh grounding piece two 25 and a tip metal mesh grounding piece two 26. The tip metal mesh grounding piece one 27 and the tip metal mesh grounding piece two 26 have the same effect as the blade root metal mesh grounding piece one 11 and the blade root metal mesh grounding piece two 12, but are located at different positions on the wind turbine blade 1, and will not be described in detail in this application.

[0058] It should be noted that the blade root grounding metal mesh one 4 and the blade root metal mesh grounding piece two 25 are arranged on the blade root, and the tip metal mesh grounding piece one 27 and the tip metal mesh grounding piece two 26 are arranged on the tip.

[0059] The metal mesh system 21 is connected to the main metal mesh 17 through the metal mesh grounding piece one 11 and the metal mesh grounding piece two 12, and is connected to the grounding base one 14 and the grounding base two 7, forming a single-loop lightning current conduction path.

[0060] It should be noted that the metal mesh substrate: copper, aluminum, nickel and other metals, preferably copper material.

[0061] Working principle: when lightning strikes the blade tip lightning arrester 10 or the blade lightning arrester 8:

[0062] Lightning current is introduced:

[0063] The blade tip lightning current is directly introduced into the copper mesh of the high grammage area 24 through the tip down conductor 9;

[0064] The blade lightning current is introduced into the metal mesh system 21 by the blade lightning arrester 8.

[0065] Gradient conduction process:

[0066] The high grammage area 24 uses high electrical conductivity (copper mesh) and dense structure to carry the initial high amplitude lightning current (200kA level);

[0067] During the current conduction process to the blade root, the linear grammage increasing structure of the transition zone 23 suppresses the current mutation and avoids local arc;

[0068] The current attenuated to low amplitude (<50kA) reaches the low grammage area 22 and is conducted to the root down conductor 3 by the copper mesh.

[0069] Grounding discharge:

[0070] The current is finally discharged to the fan tower cylinder grounding system through the blade root grounding piece 2, completing the single-loop conduction ( Figure 2 ).

[0071] The gradient technology strengthens the protection in the high lightning risk area of the blade tip through the differential grammage design, while reducing the weight in the blade root area, realizing the optimized balance of lightning protection performance and blade load.

[0072] It should be noted that in this document, the terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply that these entities or operations have any such actual relationship or order. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0073] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that the technical solutions described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalent ones. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A lightning protection system based on the gradient technology of metal mesh down conductor, comprising a wind turbine blade (1), a root grounding device (2), characterized in that: The wind turbine blade (1) is provided with a lightning protection system of metal mesh series down conductor, comprising: A metal mesh system (21) is laid along the blade span and arranged in series, which comprises a main metal mesh (17), a root metal mesh grounding device and a tip metal mesh grounding device; A down conductor assembly comprising a root down conductor (3) and a tip down conductor (9) is connected in series with the metal mesh system (21); A lightning arresting system comprising a blade body lightning arrester (8) and a tip lightning arrester (10) is arranged on the surface of the wind turbine blade (1); The unit area mass of the main metal mesh (17) is distributed in a gradient along the blade span, forming a low grammage area (22), a transition area (23) and a high grammage area (24), wherein the high grammage area (24) covers the tip area, and the unit area mass of the metal mesh system (21) is distributed in a gradient along the blade span in at least one transition area (23); One end of the tip down conductor (9) is connected to the tip lightning arrester (10) and the blade body lightning arrester (8) arranged at the tip of the wind turbine blade (1), and the other end of the tip down conductor (9) comprises a grounding base one (14) connected in series to the high grammage area (24) of the metal mesh system (21); One end of the root down conductor (3) is connected to the low grammage area (22) of the metal mesh system (21), and the other end of the root down conductor (3) comprises a grounding base two (7) connected to the blade root grounding device (2).

2. The lightning protection system based on the metal mesh down conductor with the gradient technology according to claim 1, characterized in that: The lightning protection system of metal mesh series down conductor is distributed on at least one surface of the wind turbine blade (1), and the lightning protection system of metal mesh series down conductor distributed on two surfaces is connected in a conductive stitching structure through overlapping and lapping metal sheets (13), forming a continuous conductive path.

3. The lightning protection system based on the metal mesh down conductor with the gradient technology according to claim 2, characterized in that: The low grammage area (22) is arranged from the root to the middle section of the blade, the transition area (23) is arranged in the middle section of the blade, and the high grammage area (24) is arranged in the tip section of the blade.

4. The lightning protection system based on the metal mesh down conductor with the gradient technology according to claim 3, characterized in that: The unit area mass of the metal mesh system (21) is distributed in a gradient along the blade span.

5. The lightning protection system based on the metal mesh down conductor with the gradient technology according to claim 4, characterized in that: The high grammage area (24) extends to cover the tip of the blade and is directly connected to the tip lightning arrester (10) or the blade body lightning arrester (8) through the metal sheet (13) or the conductive adhesive layer.

6. The lightning protection system based on the metal mesh down conductor with the gradient technology according to claim 1, characterized in that: The main metal mesh (17) is divided into a main metal mesh one (5) and a main metal mesh two (6), which are connected in series through lapping and lapping of the metal sheet (13), the main metal mesh one (5) is provided with a metal mesh grounding device one (11), and the main metal mesh two (6) is provided with a metal mesh grounding device two (12).

7. The lightning protection system based on the metal mesh down conductor with the gradient technology according to claim 6, characterized in that: The metal mesh system (21) is connected to the grounding base one (14) and the grounding base two (7) through the metal mesh grounding device one (11) and the metal mesh grounding device two (12), forming a single-loop lightning current conduction path.

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