Wind driven generator blade lightning protection grounding structure

Abstract

The utility model discloses a wind driven generator blade lightning protection grounding structure which comprises a tower, the top end of the tower is connected with a plurality of blade bodies distributed in a surrounding mode through a driving mechanism, and the outer ends of the blade bodies are sleeved with lightning arresters of a metal net sleeve structure. The lightning arrester is connected with a wiring mechanism arranged in the blade body through a conductive wire, a butt-joint frame is fixed to the inner end of the lightning arrester, a stable connecting mechanism composed of embedding pieces and clamping pieces is arranged in the butt-joint frame, the embedding pieces are symmetrically arranged on the inner walls of the front side and the rear side of the butt-joint frame, and the relative positions of the embedding pieces can be adjusted. The clamping pieces are symmetrically arranged on the inner walls of the two sides of the butt joint frame and can deform through the characteristics of the clamping pieces. According to the lightning protection grounding structure of the wind driven generator blade, the stability and the electrical connection performance between the lightning arrester and the blade are enhanced, the lightning protection effect and the current conduction efficiency are effectively improved, and potential safety hazards caused by poor contact are reduced.

Description

Technical Field

[0001] This utility model relates to the field of power, specifically to a lightning protection grounding structure for wind turbine blades. Background Technology

[0002] With the gradual expansion of clean energy applications globally, wind power is playing a vital role in distributed energy systems. Wind power equipment typically requires a high vantage point to achieve optimal wind energy capture efficiency, making it a significant lightning strike risk point in the region. As aerodynamic components directly exposed to the atmosphere, the lightning protection performance of the blade system directly affects the operational safety and lifespan of the entire power generation system.

[0003] Current mainstream lightning protection systems primarily employ a three-tiered protection structure: lightning arrester, down conductor, and grounding electrode. Specifically, a copper alloy lightning arrester is installed on the blade surface, and the lightning current is guided to the ground for discharge via pre-buried conductors. Theoretically, this traditional approach can effectively prevent direct lightning strikes from causing structural damage to the composite blades and internal generator units. However, engineering practice has revealed significant technical bottlenecks in the reliability and energy efficiency of existing protection systems.

[0004] It is worth noting that lightning arresters are often fixed using surface bonding or simple mechanical anchoring. This connection method is prone to structural fatigue damage under long-term aerodynamic loads on the blades, leading to the lightning arrester detaching and failing. Furthermore, the interfacial contact resistance between the lightning arrester and the carbon fiber reinforced polymer (CFRP) blade matrix generally exceeds the limits specified in the IEC 61400-24 standard. This increased contact impedance poses two risks: firstly, it reduces the efficiency of lightning current discharge, creating a residual voltage risk in the protected area; secondly, it induces localized Joule heating during the discharge process. Laboratory simulation data shows that under a 10kA lightning current, the temperature at poorly contacted areas can rise rapidly to 780℃ within 200μs, far exceeding the glass transition temperature of the composite material.

[0005] Ultimately, the structural design of existing lightning protection systems fails to fully consider the unique dynamic operating characteristics and material interface properties of wind turbines. Firstly, there is a mismatch between traditional rigid connection methods and the structural deformation of flexible blades. Secondly, the electrochemical compatibility of dissimilar material contact surfaces lacks systematic optimization. These technical deficiencies not only reduce the protective effectiveness of lightning protection systems but also potentially trigger secondary electrical fires. Therefore, developing a dynamically adaptable low-impedance lightning protection grounding structure has become a key technological breakthrough for improving the reliability and safety of wind power generation systems. Summary of the Invention

[0006] The purpose of this utility model is to provide a lightning protection grounding structure for wind turbine blades, including a tower. Several blade bodies arranged in a ring are connected to the top of the tower via a drive mechanism. A lightning arrester with a metal mesh structure is fitted onto the outer end of each blade body. A docking frame is fixed to the inner end of the lightning arrester. The docking frame includes front and rear side walls and two side walls. The lightning arrester is made of a high-conductivity copper alloy woven into a metal mesh with a mesh density of 10-15 meshes / cm². Its inner diameter is slightly smaller than the outer diameter of the blade body, and it is elastically fitted onto the outer end of the blade body. The docking frame is welded from stainless steel, and its front and rear side walls and two side walls form a rectangular frame. The inner dimensions of the frame match the cross-section of the outer end of the blade body, ensuring that the lightning arrester is coaxially aligned with the blade body after installation.

[0007] Threaded holes are provided on the front and rear side walls of the docking frame. The pressing bolt is screwed into the threaded hole, and the inner end of the pressing bolt presses against the pressing port opened in the middle of the inner side of the fitting. When the pressing bolt is rotated, its inner end pushes the fitting towards the blade body along the pressing port, so that the fitting is embedded in the fitting groove on the outer wall of the blade body. When the pressing bolt is rotated, the rotational motion is converted into the linear displacement of the fitting, which forces the protrusion at the outer end of the fitting to be embedded in the locking groove on the outer wall of the blade body, forming a mechanical self-locking and preventing the lightning arrester from moving axially.

[0008] The inner sides of the two side walls of the docking frame are symmetrically provided with elastic clamping members. The clamping members are U-shaped spring steel components, and their inner side walls clamp the two side edges of the blade body through elastic deformation. The opening width of the U-shaped clamping member is smaller than the thickness of the blade body, and a continuous clamping force is generated through elastic deformation during installation.

[0009] The lightning arrester has symmetrically fixed conductive plates inside its metal mesh sleeve. These plates are tightly fitted to the outer surface of the blade body, and the lightning arrester is electrically connected to the grounding line inside the blade body via conductive wires. The conductive plates are silver-plated copper sheets, arranged in multiple sets evenly along the circumference of the inner wall of the lightning arrester. The conductive wires are multi-stranded copper cables, with one end connected to the lightning arrester via a copper-aluminum transition terminal, and the other end connected to a copper grounding trunk line pre-embedded inside the blade body, ensuring that the lightning current is discharged to the ground via a low-impedance path.

[0010] Preferably, the pressing port of the fitting is a circular groove structure; the fitting groove on the outer wall of the blade body is a locking groove that matches the outer contour of the fitting. When the pressing bolt is screwed in, the end of the bolt pushes in along a circular groove, forcing the fitting to move towards the blade body. At this time, the outer contour of the fitting and the locking groove on the blade body form a geometric constraint interlock (such as the trapezoidal cross section of a dovetail groove), preventing the lightning arrester from axially loosening through mechanical interference. This design transforms the linear force driven by the thread into a multidimensional constraint force, achieving a rigid connection between the lightning arrester and the blade.

[0011] Preferably, the inner sides of the front and rear sidewalls of the docking frame are provided with symmetrically distributed mounting grooves. Both ends of the fitting are connected to the mounting grooves via U-shaped elastic metal sheets. The two ends of the U-shaped elastic metal sheets are welded and fixed to the fitting and the mounting grooves of the docking frame, respectively. The deformation direction of the elastic metal sheets is parallel to the movement direction of the fitting. The U-shaped elastic metal sheets connect the fitting and the docking frame, and their core function is to provide bidirectional elastic reset.

[0012] Pre-tightening stage: When the fitting is pushed by the pressing bolt, the elastic metal sheet is stretched and stores elastic potential energy;

[0013] Release phase: After loosening the clamping bolt, the elastic metal sheet releases its potential energy, pulling the fitting back to its original position and disengaging from the locking groove.

[0014] This design gives the connection structure adjustability and adaptability—it can compensate for manufacturing tolerances through elastic deformation during installation, and it can quickly release the locking state during maintenance. The welding fixing method ensures that the elastic element does not come out of the mounting position during repeated deformation.

[0015] Preferably, the outer side of the metal mesh sleeve of the lightning arrester is provided with multiple longitudinally extending lightning strips. The lightning strips have a streamlined structure and a teardrop-shaped cross-section, with their tops welded and fixed to the metal mesh sleeve. The streamlined structure and teardrop-shaped cross-section of the lightning strips are essentially designed to reduce wind resistance disturbance through aerodynamic shape: the streamlined profile reduces airflow separation and avoids the generation of high-frequency eddies, thereby suppressing wind vibration noise during blade rotation; the rounded leading edge and tapering trailing edge of the teardrop-shaped cross-section allow the airflow to transition smoothly along the surface, reducing pressure drag. At the same time, the longitudinal extension layout of the lightning strips is consistent with the blade rotation direction, forming a directional lightning guide channel, preferentially guiding the lightning current through the lightning strips into the grounding system, reducing direct electrothermal impact on the blade body.

[0016] Preferably, a metal ring is fixedly connected to the outer end of the lightning arrester, and the metal ring is uniformly provided with a plurality of heat dissipation holes. The uniform heat dissipation holes on the metal ring are not simply for heat dissipation; their design integrates multiple functional objectives. First, the perforated structure increases the surface area, utilizing air convection to accelerate the dissipation of localized high temperatures after a lightning strike. Second, the uniformly distributed holes reduce the weight of the metal ring, preventing the lightning arrester end from becoming unbalanced due to excessive inertial centrifugal force. Finally, it achieves electric field homogenization; the ring conductor and the discrete holes work together to make the electric field distribution at the edge of the lightning arrester more uniform, reducing the probability of lightning strikes in non-lightning-affected areas. Therefore, the metal ring, as an extension structure of the lightning arrester, essentially constructs a composite protective boundary integrating current conduction, heat dissipation, and mechanical stability.

[0017] Preferably, a conductive rubber pad is bonded to the clamping surface of the clamping member, and the surface of the conductive rubber pad is provided with a diamond-shaped anti-slip pattern. The diamond-shaped anti-slip pattern increases the friction coefficient of the contact surface through micro-deformation, suppressing the relative sliding between the clamping member and the blade under vibration; while the conductive rubber material forms a tight conductive interface with the blade surface under pressure, and its flexible properties can fill the micro-uneven areas, significantly reducing the contact resistance.

[0018] Compared with existing technologies, the beneficial effects of this utility model are as follows: This wind turbine blade lightning protection grounding structure enhances the stability and electrical connection performance between the lightning arrester and the blade, effectively improving the lightning protection effect and current conduction efficiency, and reducing safety hazards caused by poor contact. The wind turbine blade lightning protection grounding structure installs lightning arresters with metal mesh structures at the ends of the blades, which not only improves the efficiency of lightning current capture but also ensures that the current can be rapidly and evenly distributed and conducted through conductive wires to the wiring mechanism inside the blade, further guaranteeing electrical continuity. The synergistic effect of the fitting and clamping components makes the connection between the docking frame and the blade body more robust and reliable, maintaining stability even under extreme weather conditions, and greatly reducing the risk of lightning arrester detachment. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a lightning protection grounding structure for wind turbine blades according to the present invention.

[0020] Figure 2 This is a schematic diagram of the connection structure between the lightning arrester and the blade body in a lightning protection grounding structure for wind turbine blades according to this utility model.

[0021] Figure 3 This is a schematic diagram of the internal structure of the docking frame of a lightning protection grounding structure for wind turbine blades according to this utility model.

[0022] Figure 4 This is a schematic diagram of the internal structure of the lightning arrester in the lightning protection grounding structure for wind turbine blades according to this utility model.

[0023] In the diagram: 1. Tower; 2. Blade body; 3. Lightning arrester; 4. Conductive wire; 5. Docking frame; 6. Fitting component; 7. Clamping component; 8. Conductive sheet; 9. Lightning arrester strip; 10. Metal ring; 11. Pressure bolt; 12. Elastic component. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] Please see Figure 1-4 This utility model provides a technical solution: a lightning protection grounding structure for wind turbine blades, including a tower 1. Several blade bodies 2 arranged in a ring are connected to the top of the tower 1 via a drive mechanism. A lightning rod 3 with a metal mesh structure is fitted onto the outer end of each blade body 2. The lightning rod 3 is connected to a wiring mechanism inside the blade body 2 via a conductive wire 4. The wiring mechanism inside the blade body 2 is mainly used to collect and conduct the lightning current transmitted by the lightning rod 3 through the conductive wire 4, ensuring that the current can be safely guided to the ground.

[0026] The lightning arrester 3 has a docking frame 5 fixed to its inner end. Inside the docking frame 5, there is a stable connecting mechanism consisting of fitting parts 6 and clamping parts 7. The fitting parts 6 are symmetrically arranged on the inner walls of the front and rear sides of the docking frame 5 and their relative positions can be adjusted. The clamping parts 7 are symmetrically arranged on the inner walls of both sides of the docking frame 5 and can be deformed by their own characteristics. The clamping parts 7 are U-shaped structures made of spring steel, and rubber pads are glued and fixed to the inner walls of both sides.

[0027] In the process of using the tower 1 and the blade body 2 together, the lightning arrester 3, as the main component of lightning protection, can effectively capture the lightning current when struck by lightning, and quickly guide the current to the conductive wire 4 through its metal mesh structure, and then conduct it to the wiring mechanism inside the blade body 2. At the same time, the lightning arrester 3 is firmly installed on the blade body 2 through the docking frame 5. The fitting 6 fits tightly with the corresponding structure on the blade body 2, ensuring that it will not loosen or fall off even under strong wind conditions; the clamping part 7 further enhances the stability of this connection through its own elastic properties, ensuring the mechanical strength and electrical continuity of the entire system.

[0028] Furthermore, due to the compact design and good contact between the components, the resistance is effectively reduced, the current conduction efficiency is improved, and the risk of local overheating and potential fire caused by poor contact is avoided. This solves the problem of unstable connection between the lightning arrester and the blade in the existing technology and the resulting safety hazards, thereby improving the overall lightning protection effect and safety.

[0029] Both the front and rear sides of the mating frame 5 have threaded bolts 11 inserted in the middle, and the inner side of the fitting 6 has a pressing port that matches the structure of the bolts 11. The outer wall of the blade body 2 has a fitting groove that matches the structure of the fitting 6. The inner wall of the mating frame 5 on both sides of the bolts 11 has grooves, and the grooves on the inner wall of the mating frame 5 are connected to the corresponding connection points of the fitting 6 with the grooves. The elastic elements 12 are symmetrically connected at both ends of the fitting 6 and are U-shaped structures made of elastic metal sheets.

[0030] When the position of the fitting 6 needs to be adjusted on the blade body 2, the relative position of the fitting 6 can be adjusted by rotating the clamping bolt 11. At this time, the elastic element 12 will stretch synchronously, providing the necessary support force and stability. After the clamping bolt 11 is loosened, due to the rebound characteristics of the elastic element 12, it can drive the fitting 6 to automatically retract to the initial position or the required new position, ensuring that the fitting 6 fits tightly against the fitting groove on the blade body 2, forming a stable mechanical connection.

[0031] Conductive sheets 8 are symmetrically bonded and fixed to the inner sides of the metal surfaces on both the front and rear sides of the lightning arrester 3, and the conductive sheets 8 are in contact with the outer surface of the blade body 2. The conductive sheets 8 not only increase the electrical connection points between the lightning arrester 3 and the blade body 2, but also greatly reduce the contact resistance between them, improving current conduction efficiency. The contact between the conductive sheets 8 and the surface of the blade body 2 allows the current to be evenly distributed across the entire contact surface, preventing localized overheating and reducing the risk of fire.

[0032] Several lightning rods 9 are bonded and fixed to the outer side of the metal surface on both the front and rear sides of the lightning arrester 3. The lightning rods 9 are streamlined structures made of highly conductive aluminum alloy. The lightning rods 9 not only increase the lightning current capture area, but also reduce air resistance through their streamlined structure, enabling the lightning arrester 3 to work stably under various wind speed conditions without being easily damaged.

[0033] A metal ring 10 is welded and fixed to the outer end of the lightning arrester 3, and the metal ring 10 has several evenly distributed heat dissipation holes. The metal ring 10 not only enhances the overall structural strength of the lightning arrester 3, but also provides an additional conductive path to help disperse the lightning current and reduce the current density and heat accumulation on a single path. When the lightning current passes through the lightning arrester 3, part of the current is conducted to the metal ring 10, and the generated heat is quickly dissipated through its evenly distributed heat dissipation holes, thereby preventing local overheating and reducing the risk of material damage due to high temperature.

[0034] The workflow of this utility model is as follows:

[0035] When using this wind turbine blade lightning protection grounding structure, firstly, the lightning arrester 3 is fitted onto the outer end of the blade body 2 through its metal mesh structure, ensuring that the conductive sheets 8, symmetrically bonded and fixed to the inner side of the metal surface on both the front and rear sides of the lightning arrester 3, are tightly adhered to the outer surface of the blade body 2. Next, by rotating the two pressing bolts 11 on the docking frame 5, the position of the fitting 6 is adjusted so that it can accurately match the fitting groove on the blade body 2. The elastic element 12 will stretch synchronously to provide the necessary support force, ensuring a tight fit between the fitting 6 and the blade body 2, and the clamping element 7 will also rely on elastic force to engage at the corresponding positions on both sides of the blade body 2.

[0036] Finally, the conductive wire 4 is connected between the lightning arrester 3 and the wiring mechanism inside the blade body 2. When a lightning strike occurs, the lightning current is first captured by the lightning arrester 9 and the lightning arrester 3, and then transmitted through the conductive sheet 8 and the conductive wire 4 to the wiring mechanism inside the blade body 2, and finally safely guided to the ground, completing a series of processes from lightning current capture, conduction to safe release.

[0037] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A lightning protection grounding structure for wind turbine blades, comprising a tower (1), the top end of the tower (1) being connected with a plurality of blade bodies (2) distributed in a ring shape through a driving mechanism, characterized in that: a lightning receptor (3) of a metal mesh sleeve structure is sleeved on the outer end of the blade body (2), the inner end of the lightning receptor (3) is fixed with a butt joint frame (5), the butt joint frame (5) comprises front and back side walls and two side walls; screw holes are formed in the front and back side walls of the butt joint frame (5), a pressing bolt (11) is screwed into the screw holes, and the inner end of the pressing bolt (11) presses a pressing opening formed in the middle of the inner side of a fitting part (6); when the pressing bolt (11) is rotated, the inner end thereof pushes the fitting part (6) to move in the direction of the blade body (2) along the pressing opening, so that the fitting part (6) is embedded into a fitting groove on the outer wall of the blade body (2); elastic clamping parts (7) are symmetrically arranged on the inner sides of the two side walls of the butt joint frame (5), the clamping parts (7) are U-shaped spring steel members, and the two inner walls thereof clamp the two side edge positions of the blade body (2) through elastic deformation; conductive sheets (8) are symmetrically fixed on the inner side of the metal mesh sleeve of the lightning receptor (3), the conductive sheets (8) are tightly attached to the outer surface of the blade body (2), and the lightning receptor (3) is electrically connected with a grounding line inside the blade body (2) through a conductive wire (4). The pressing opening of the fitting part (6) is a circular groove; the fitting groove on the outer wall of the blade body (2) is a locking groove matched with the outer contour of the fitting part (6). Symmetrically distributed mounting grooves are arranged on the inner sides of the front and back side walls of the butt joint frame (5), the two ends of the fitting part (6) are connected with the mounting grooves through U-shaped elastic metal sheets (12), the two ends of the U-shaped elastic metal sheets (12) are respectively welded and fixed on the fitting part (6) and in the mounting grooves of the butt joint frame (5), and the deformation direction of the elastic metal sheets (12) is parallel to the moving direction of the fitting part (6). A plurality of longitudinally extending lightning strips (9) are arranged on the outer side of the metal mesh sleeve of the lightning receptor (3), the lightning strips (9) are of a streamline structure, the cross section thereof is in the shape of a water droplet, and the top thereof is welded and fixed with the metal mesh sleeve. A metal ring (10) is fixedly connected with the outer end of the lightning receptor (3), and a plurality of heat dissipation holes are uniformly arranged on the metal ring (10).

2. The lightning grounding structure for a blade of a wind driven generator according to claim 1, characterized in that: An electrically conductive rubber pad is attached to the clamping surface of the clamping part (7), and a rhombic anti-skid pattern is arranged on the surface of the electrically conductive rubber pad.

3. The lightning grounding structure for a blade of a wind driven electric generator according to claim 2, characterized in that: ​ 4. The lightning grounding structure for a blade of a wind driven generator according to claim 1, characterized in that: ​ 5. The lightning grounding structure for a blade of a wind driven generator according to claim 1, characterized in that: ​ 6. The lightning grounding structure for a blade of a wind driven electric generator according to claim 1, wherein: ​

Images