Plasma lightning stroke protection device of wind generating set

Abstract

According to the plasma lightning stroke protection device for the wind generating set, a blade unit comprises at least three blades, and each blade is provided with an electricity guiding conductor with at least two guiding needles; the sliding contact unit comprises a sliding ring, the sliding ring comprises at least three arc-shaped bodies evenly distributed in the circumferential direction, every two adjacent arc-shaped bodies are spaced through an insulator, and first wires electrically connected with the electricity leading conductors and the corresponding arc-shaped bodies are arranged in the blades. The ionization discharge unit comprises a cabin, a sliding block and a conductive electrode, the sliding block and the conductive electrode are arranged on the cabin and electrically connected, the sliding block abuts against the sliding ring, and the sliding block conducts electricity after making contact with the arc-shaped body and is powered off after making contact with the insulator; the grounding unit comprises a tower tube, the cabin is connected with the tower tube, and a grounding lead is arranged in the tower tube and communicated with the conductive electrode. According to the invention, the ionization discharge function is realized, the wind turbine generator is protected from lightning stroke, the damage of large current generated by direct lightning to blades and electrical equipment in a cabin is avoided, and the cost and the installation and maintenance difficulty are reduced.

Description

Technical Field

[0001] This application relates to the field of plasma lightning protection technology, and in particular to a plasma lightning protection device for wind turbine generator sets. Background Technology

[0002] Wind turbines are typically located in open fields, offshore, or mountainous areas, and lightning strikes are one of the main factors affecting their safe operation. The wind turbine blades, being at the highest point of the turbine, are highly susceptible to lightning strikes. With the development of wind power technology, the height of wind turbines is constantly increasing due to the larger rotor diameter, further increasing the risk of lightning strikes. The repair costs and power generation losses associated with damage to turbine components (mainly blades) caused by lightning strikes are extremely high; therefore, wind turbines must be equipped with lightning protection systems.

[0003] Traditional lightning protection systems are primarily located on the blades, consisting of multiple lightning rods and conductors (carbon fiber blades have metal mesh and carbon fiber layers on their surface). The conductors inside the blade are connected to the lightning rod base, and at the blade root, they connect to the overall turbine's grounding system. The blade lightning rods receive the lightning current and transmit it to the turbine's grounding system via the conductors, thus preventing lightning damage to the blades or the turbine unit. However, this method of grounding lightning has the following problems: First, under the influence of the strong electric field of the downlink leader during a lightning strike, there is a certain probability that induced charges will be generated around the grounding lead, forming a discharge path between the downlink leader and the lightning strike, potentially causing blade breakdown damage. Furthermore, if the lightning does not strike the lightning rod, it can enter the blade and form an electric arc. The enormous energy can not only cause electrical connection failures, rendering the lightning protection system ineffective, but can also break down the blade or cause it to burst internally. Second, wind turbine units typically equip each blade with a separate grounding system for grounding lightning, which is costly and complex to install and maintain. Summary of the Invention

[0004] This application provides a plasma lightning protection device for wind turbine generator sets to solve the problems existing in the prior art, realize the ionization discharge function, protect the wind turbine generator set from lightning strikes, avoid the damage to the blades and electrical equipment in the nacelle caused by the large current generated by direct lightning strikes, and reduce costs and installation and maintenance difficulties.

[0005] The wind turbine generator plasma lightning protection device provided in this application includes: a blade unit comprising at least three blades, each blade tip having a current-leading conductor with at least two guide pins; a sliding contact unit comprising a slip ring connected to the blade unit via a hub, the slip ring comprising at least three arcuate bodies evenly distributed along the circumferential direction, any two adjacent arcuate bodies being separated by an insulator, the at least three arcuate bodies corresponding one-to-one with at least three blades, each blade having a first wire electrically connecting the current-leading conductor and the corresponding arcuate body; an ionization discharge unit comprising a nacelle, a slider disposed on the nacelle and electrically connected to it, and a conductive electrode, the slider abutting against the slip ring, the slider conducting electricity upon contact with the arcuate body and de-energizing upon contact with the insulator, so that the current-leading conductor on the blade located in the ionization discharge working area is connected to the ionization discharge unit; and a grounding unit comprising a tower, the nacelle being connected to the tower, a grounding wire disposed inside the tower, the grounding wire being connected to the conductive electrode.

[0006] Optionally, the current-leading conductor further includes an inlay located inside the blade tip, with at least two guide pins mounted on the inlay, the inlay being connected to the first wire.

[0007] Optionally, at least two of the guide pins are distributed diverging from the tip of the blade.

[0008] Optionally, the conductive electrode includes a cover electrode and a core electrode, the cover electrode being disposed outside the core electrode with a distance between them; the cover electrode is connected to the slider via a second wire, and the core electrode is connected to the grounding wire.

[0009] Optionally, the cover electrode includes an arc-shaped outer surface, the second wire is mounted on the arc-shaped outer surface, the end of the core electrode is hemispherical, and the inner wall surface of the cover electrode is arc-shaped.

[0010] Optionally, the slider is mounted inside the cabin via an elastic connector.

[0011] Optionally, the outer end faces on both sides of the insulator are provided with radial guide grooves that penetrate the inner arc surface and the outer arc surface of the insulator; the outer end faces on both sides of the insulator are also provided with reversing grooves that connect to the radial guide grooves.

[0012] Optionally, an insulating scraper is provided on one side of the slip ring, the blade of the insulating scraper being spaced apart from the outer end face of the insulated body at a vertical distance of less than 2 mm; a magnetic adsorption element is provided on the insulating scraper, the magnetic adsorption element being spaced apart from the slip ring.

[0013] Optionally, the insulating scraper is detachably installed inside the cabin, the insulating scraper is provided with a collection cavity, the magnetic adsorption element is located in the collection cavity, and the side of the insulating scraper is provided with a guide groove connecting the collection cavity and the blade.

[0014] Optionally, an elastic element is embedded between the insulator and the adjacent arc-shaped body.

[0015] The above technical solution has the following beneficial effects:

[0016] The plasma lightning protection device for wind turbine generators provided in this application, as the wind turbine generator operates, the hub rotates, driving the blade units to rotate. At least three arc-shaped bodies, corresponding one-to-one with at least three blades, sequentially contact the slider to achieve conductivity between the current-carrying conductor and the grounding unit. This allows a single wind turbine generator to use only one set of ionization discharge units, resulting in low cost and convenient installation and maintenance. When the electric field of thunderclouds near the wind turbine generator reaches a certain threshold, the ionization discharge function is realized, protecting the wind turbine generator from lightning strikes and effectively avoiding the damage to the blades and electrical equipment inside the nacelle caused by the large current generated by direct lightning strikes. Attached Figure Description

[0017] The preferred embodiments of this application will now be described in detail with reference to the accompanying drawings to aid in understanding the purpose and advantages of this application, wherein:

[0018] Figure 1 This is a schematic diagram of the structure of the plasma lightning protection device for wind turbine generator sets in an optional embodiment of this application.

[0019] Figure 2 This is a schematic diagram of the structure of the slip ring and the slider in an optional embodiment of this application.

[0020] Figure 3 This is a cross-sectional view of an optional embodiment of this application showing that the electrical conductor is disposed at the tip of the blade.

[0021] Figure 4 This is a schematic diagram of the structure of the conductive electrode in an optional embodiment of this application.

[0022] Figure 5 This is a schematic diagram of the structure of a blade in the ionization discharge working region in an optional embodiment of this application.

[0023] Figure 6 This is a schematic diagram of the structure in which radial guide grooves and reversing grooves are formed on the insulator in an optional embodiment of this application.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1-Blade unit, 10-Blade, 11-Electrifying conductor, 110-Guide pin, 111-Inlay, 12-First wire;

[0026] 2-Sliding contact unit, 20-Slip ring, 200-Arc-shaped body, 201-Insulator, 202-Radial guide groove, 203-Reversing groove, 204-Hub;

[0027] 3-Ionization discharge unit, 30-Nacelle, 31-Slider, 32-Conductive electrode, 320-Shell electrode, 321-Central electrode, 33-Second conductor;

[0028] 4-Grounding unit, 40-Tower, 41-Grounding conductor;

[0029] 5-Insulated scraper. Detailed Implementation

[0030] The technical solution of the present invention will be further described in detail below with reference to embodiments and accompanying drawings. The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the structures shown in the accompanying drawings. The terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0031] The plasma lightning protection device for wind turbine generator sets provided in this application includes: blade unit 1, sliding contact unit 2, ionization discharge unit 3, and grounding unit 4.

[0032] Please refer to Figure 1 The blade unit 1 includes at least three blades 10, and the tip of any blade 10 is fitted with an electrical conductor 11 having at least two guide pins 110.

[0033] When there are at least two guide pins 110, the metal guide pins located at the tips of the wind turbine blades 10 form a "similar tip effect," increasing the surrounding electric field. When the thundercloud electric field reaches a certain threshold, the ionization discharge unit 3 utilizes the thundercloud electric field to achieve passive strong ionization, generating plasma up to 30 mc / s. The area near the ionization discharge unit 3 is filled with plasma (density 50,000 times that of the thundercloud). The plasma suppresses the initiation of the upward leader (developing upward from the ground (or blade 10)) and weakens the downward speed of the downward leader (developing downward from the thundercloud), thus preventing the upper and lower leaders from connecting, preventing the formation of a lightning channel and lightning strike, and protecting the wind turbine from lightning strikes. Simultaneously, under the attraction of the thundercloud electric field and the induced reverse polarity electric field on the ground, positive (negative) ions in the plasma drift upwards to neutralize the negative (positive) ions in the upper thundercloud, while negative (positive) ions in the plasma drift downwards to neutralize the positive (negative) ions induced by the thundercloud below. This continuous attraction and bidirectional neutralization of the thundercloud negative (positive) ions and their induced positive (negative) ions in and around the discharger (which can neutralize 9C cloud-to-ground charge within 5 minutes) causes the equivalent capacitor of the thundercloud and the ground to leak efficiently, becoming a "bad capacitor" that cannot be charged to the breakdown discharge voltage level, thus hindering the establishment of the thundercloud discharge channel. As the wind disperses, the lightning may seek another target, either flashing within the cloud, flashing between clouds, or drifting away with the wind, achieving "non-inducing lightning to the ground" lightning protection.

[0034] The sliding contact unit 2 includes a slip ring 20, which is connected to the blade unit 1 via a hub 204. The slip ring 20 includes at least three arc-shaped bodies 200 evenly distributed along the circumferential direction. Any two adjacent arc-shaped bodies 200 are separated by an insulator 201 so that there is no electrical conductivity between the two adjacent arc-shaped bodies 200. At least three arc-shaped bodies 200 correspond one-to-one with at least three blades 10. Each blade 10 is provided with a first wire 12 that electrically connects the current-leading conductor 11 and the corresponding arc-shaped body 200.

[0035] In an optional embodiment where the slip ring 20 is connected to the blade unit 1 via the hub 204, the root of the blade 10 is mounted on the hub 204, and the arc-shaped body 200 is fixed to the hub 204 via an insulated support arm. The arc-shaped body 200 rotates synchronously with the blade unit 1. An insulated conduit is embedded in the support arm, and at least three first wires 12 pass through at least three blades 10, pass through the insulated conduit, and are respectively connected to at least three arc-shaped bodies 200.

[0036] like Figure 2As shown, three arc-shaped bodies 200 and three insulators 201 are arranged at intervals. The three insulators 201 prevent any two adjacent arc-shaped bodies 200 from forming a conductive path, thus defining three unconnected conductive regions: region A, region B, and region C. The three blades 10 are connected to the arc-shaped bodies 200 located in regions A, B, and C respectively via the first conductor 12. The three blades 10 are located in the corresponding intervals of regions A, B, and C on the hub 204.

[0037] During the rotation of blade unit 1, the three blades 10 pass through as follows: Figure 5 The ionization discharge working area shown is a region where the angle between the slider 31 and the two sides of the vertical direction is approximately 60°. The slider 31 is located at the top of the slip ring 20. When the slider 31 contacts the arc-shaped body 200 in area A, the blade 10 corresponding to the arc-shaped body 200 in area A is in the position shown... Figure 5 The ionization discharge working area is shown. At this time, a connected circuit is formed between the arc-shaped body 200 in area A and the blade 10 in the ionization discharge working area, and a plasma protection state can be formed through the blade 10. In areas B and C, the arc-shaped body 200 and the corresponding blade 10 are in a disconnected circuit state.

[0038] Figure 1 and Figure 2 The embodiment shown in which the number of blades 10 and arc-shaped bodies 200 are both three is an optional implementation. On the basis of satisfying the one-to-one correspondence between the number of blades 10 and arc-shaped bodies 200, the specific number can be set according to construction or power generation needs.

[0039] The ionization discharge unit 3 includes a nacelle 30, a slider 31 disposed on the nacelle 30 and electrically connected to it, and a conductive electrode 32. The slider 31 abuts against the slip ring 20. The slider 31 conducts electricity after contacting the arc-shaped body 200 and de-energizes after contacting the insulator 201, so that the current-leading conductor 11 on the blade 10 located in the ionization discharge working area is connected to the ionization discharge unit 3.

[0040] The grounding unit 4 includes a tower 40, the nacelle 30 is connected to the tower 40, and a grounding wire 41 is provided inside the tower 40. The grounding wire 41 is connected to the conductive electrode 32.

[0041] The wheel hub 204 can be connected to the engine compartment 30 using existing installation methods, which will not be described in detail here.

[0042] The plasma lightning protection device for wind turbine generators provided in this application, as the wind turbine generator operates, the hub 204 rotates, driving the blade unit 1 to rotate. At least three arc-shaped bodies 200, corresponding one-to-one with at least three blades 10, sequentially contact the slider 31 to achieve conduction between the current-carrying conductor 11 and the grounding unit 4. This allows a single wind turbine generator to use only one set of ionization discharge units 3, resulting in low cost and convenient installation and maintenance. When the electric field of thunderclouds near the wind turbine generator reaches a certain threshold, the ionization discharge function is realized, protecting the wind turbine generator from lightning strikes and effectively preventing the damage to the electrical equipment inside the blades 10 and nacelle 30 caused by the large current generated by direct lightning strikes.

[0043] As an optional embodiment, the current-leading conductor 11 further includes an inlay 111 located inside the tip of the blade 10, with at least two guide pins 110 mounted on the inlay 111. The inlay 111 is connected to the first wire 12. The inlay 111 can be mounted inside the blade 10 by adhesive bonding, bolting, or interference fit. Please refer to [reference needed]. Figure 3 The first wire 12 is connected to the inlay 111, and is laid from the inner cavity of the blade 10 to the root of the blade 10 (blade root). After passing through the manhole plate of the blade root and entering the hub 204, it is connected to the arc-shaped body 200.

[0044] As an optional embodiment, at least two of the guide pins 110 are distributed radially from the tip of the blade 10. Please refer to... Figure 3 , Figure 3 The cross-sectional view is along the length of the blade 10. There are four guide pins 110 on this cross-section. The four guide pins 110 are evenly distributed in the circumferential direction within a semi-circular area centered on the tip of the blade 10. In the three-dimensional state, the tip of the blade 10 has multiple intersecting cross-sections. The guide pins 110 on the multiple cross-sections are distributed in a hemispherical area at the tip of the blade 10. Each guide pin 110 forms an angle with the plane perpendicular to the length of the blade 10 at the tip of the blade within the range of 0°≤θ≤90°.

[0045] As an optional embodiment, such as Figure 4 As shown, the conductive electrode 32 includes a cover electrode 320 and a core electrode 321. The cover electrode 320 covers the outside of the core electrode 321 with a gap. The cover electrode 320 is connected to the slider 31 via a second wire 33, and the core electrode 321 is connected to the grounding wire 41. A gap is provided between the cover electrode 320 and the core electrode 321 to form a capacitor structure. The two ends of the second wire 33 can be electrically connected to the cover electrode 320 and the slider 31 respectively.

[0046] As an optional embodiment, such as Figure 4As shown, the cover electrode 320 includes an arc-shaped outer surface, the second wire 33 is mounted on the arc-shaped outer surface, the end of the core electrode 321 is hemispherical, and the inner wall surface of the cover electrode 320 is arc-shaped, which helps to increase the conductive cross-section and reduce the high-frequency impedance. The second wire 33 can be connected to the arc-shaped outer surface of the cover electrode 320 by laser welding.

[0047] As an optional embodiment, the slider 31 is installed inside the nacelle 30 via an elastic connector. The elastic connector can be a spring or an elastic rubber component, etc. The elastic connector is connected to the tower 40 or the inner wall of the nacelle 30 and is in a compressed state, so that the slider 31 is stably abutted against the slip ring 20 while also buffering a certain amount of vibration.

[0048] As an optional embodiment, the outer end faces of both sides of the insulator 201 are provided with radial guide grooves 202 that penetrate the inner and outer arc surfaces of the insulator 201; the outer end faces of both sides of the insulator 201 are also provided with reversing grooves 203 that communicate with the radial guide grooves 202. Figure 6 As shown, in this embodiment of the application, the fog, toner, magnetic metal powder, etc., that accumulate on the outer end face of the insulator 201 can be collected by the radial guide groove 202 and the reversing groove 203 and quickly discharged through the radial guide groove 202, thereby solving the problem that the insulator 201 mis-conducts the arc-shaped bodies (200) on both sides due to the accumulation of fog, toner, or metal powder.

[0049] As an optional embodiment, an insulating scraper 5 is provided on one side of the slip ring 20. The blade of the insulating scraper 5 is spaced apart from the outer end face of the insulator 201, and the vertical distance between them is less than 2 mm. A magnetic adsorption element is provided on the insulating scraper 5, and the magnetic adsorption element is spaced apart from the slip ring 20. The insulating scraper 5 can be made as follows: Figure 2 The arrangement shown is such that the blade of the insulating scraper 5 is spaced apart from the outer end face of the insulator 201, preventing damage to the outer end face of the insulator 201. The blade's width is less than 2mm, allowing it to scrape away magnetic metal powder, raindrops, or paint dust adhering to the outer end face of the insulator 201, preventing these particles from conducting to adjacent curved bodies 200. The magnetic adsorption component effectively attracts the scraped-off carbon powder or magnetic metal powder, preventing it from re-adhering to the insulator 201.

[0050] The magnetic adsorption component can be a structure such as a magnet that has an adsorption effect on magnetic metals and toner. A slot can be provided on the end face of the insulating scraper 5, and the magnetic adsorption component is snapped into the slot for positioning.

[0051] As an optional embodiment, the insulating scraper 5 is detachably mounted inside the cabin. The insulating scraper 5 has a collection chamber, and the magnetic adsorption component is located within the collection chamber. A guide groove is formed on the side of the insulating scraper 5, connecting the collection chamber and the blade. In this embodiment, the metal powder scraped off the blade can be adsorbed into the collection chamber by the magnetic adsorption component and cleaned periodically by disassembling the insulating scraper 5. The insulating scraper 5 can be made of materials such as ceramic or glass and is bolted to the mounting components of the cabin 30 for positioning and detachment.

[0052] As an optional embodiment, an elastic element is embedded between the insulator 201 and the adjacent arcuate body 200. The elastic element can absorb the thermal expansion and contraction between the insulator 201 and the arcuate body 200 through its own deformation, thereby increasing the relative stability between the insulator 201 and the arcuate body 200. The elastic element can be elastic rubber, with its two ends bonded to the insulator 201 and the arcuate body 200 respectively; or, the elastic element can be a spring, with its two ends embedded in the insulator 201 and the arcuate body 200 respectively.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A plasma lightning protection device for wind turbine generator sets, characterized in that, include: The blade unit (1) includes at least three blades (10), and the tip of each blade (10) is fitted with an electrical conductor (11) having at least two guide pins (110); The sliding contact unit (2) includes a slip ring (20), which is connected to the blade unit (1) through a hub (204). The slip ring (20) includes at least three arc-shaped bodies (200) evenly distributed along the circumferential direction. Any two adjacent arc-shaped bodies (200) are separated by an insulator (201). At least three arc-shaped bodies (200) correspond one-to-one with at least three blades (10). Each blade (10) is provided with a first wire (12) that electrically connects the current-leading conductor (11) and the corresponding arc-shaped body (200). The ionization discharge unit (3) includes a nacelle (30), a slider (31) disposed on the nacelle (30) and electrically connected to it, and a conductive electrode (32). The slider (31) abuts against the slip ring (20). The slider (31) conducts electricity after contacting the arc-shaped body (200) and de-energizes after contacting the insulator (201), so that the current-carrying conductor (11) on the blade (10) located in the ionization discharge working area is connected to the ionization discharge unit (3). The grounding unit (4) includes a tower (40), the nacelle (30) is connected to the tower (40), and a grounding wire (41) is provided inside the tower (40), the grounding wire (41) is connected to the conductive electrode (32).

2. The plasma lightning protection device for wind turbine generator sets according to claim 1, characterized in that, The current-leading conductor (11) also includes an inlay (111) located inside the tip of the blade (10), at least two of the guide pins (110) are mounted on the inlay (111), and the inlay (111) is connected to the first wire (12).

3. The plasma lightning protection device for wind turbine generator sets according to claim 1, characterized in that, At least two of the guide pins (110) are distributed outward from the tip of the blade (10).

4. The plasma lightning protection device for wind turbine generator sets according to claim 1, characterized in that, The conductive electrode (32) includes a cover electrode (320) and a core electrode (321), wherein the cover electrode (320) covers the outside of the core electrode (321) and leaves a distance; The cover electrode (320) is connected to the slider (31) via a second wire (33), and the core electrode (321) is connected to the grounding wire (41).

5. The plasma lightning protection device for wind turbine generator sets according to claim 4, characterized in that, The cover electrode (320) includes an arc-shaped outer surface, the second wire (33) is mounted on the arc-shaped outer surface, the end of the core electrode (321) is hemispherical, and the inner wall surface of the cover electrode (320) is arc-shaped.

6. The plasma lightning protection device for wind turbine generator sets according to claim 1, characterized in that, The slider (31) is installed inside the cabin (30) via an elastic connector.

7. The plasma lightning protection device for wind turbine generator sets according to claim 1, characterized in that, The outer end faces of both sides of the insulator (201) are provided with radial guide grooves (202) that penetrate the inner arc surface and the outer arc surface of the insulator (201); The outer end faces on both sides of the insulator (201) are also provided with reversing grooves (203) that connect to the radial guide groove (202).

8. The plasma lightning protection device for wind turbine generator sets according to claim 1, characterized in that, An insulating scraper (5) is provided on one side of the slip ring (20), and the blade of the insulating scraper (5) is spaced apart from the outer end face of the insulator (201) at a vertical distance of less than 2 mm. The insulating scraper (5) is provided with a magnetic adsorption element, which is spaced apart from the slip ring (20).

9. The plasma lightning protection device for wind turbine generator sets according to claim 1, characterized in that, The insulating scraper (5) is detachably installed in the cabin (30). The insulating scraper (5) is provided with a collection cavity, the magnetic adsorption component is located in the collection cavity, and the side of the insulating scraper (5) is provided with a guide groove connecting the collection cavity and the blade.

10. The plasma lightning protection device for wind turbine generator sets according to any one of claims 1-9, characterized in that, An elastic element is embedded between the insulator (201) and the adjacent arc-shaped body (200).

Images