A lightning protection device for wind turbines based on lightning current dissipation

Abstract

The present invention relates to a lightning protection device for a wind turbine generator set based on lightning current dissipation, comprising a wind turbine blade, a hub, and an output shaft disposed at the rear end of the hub. A main pin is disposed at the end of the wind turbine blade, the conductive end of the main pin being connected to a blade lightning protection grounding wire, one branch end of the blade lightning protection grounding wire being connected to a grounding downlead disposed in the hub, and the other branch end of the blade lightning protection grounding wire being connected to an energy storage assembly. A drive assembly is disposed within the wind turbine blade for universal rotation of the main pin using wind energy, the drive assembly comprising a drive sleeve, a first metal clamping block disposed at the end of the drive sleeve, a second metal clamping block disposed within the first metal clamping block, and a tapered block disposed at the end of the second metal clamping block. This lightning protection device for a wind turbine generator set based on lightning current dissipation can effectively discharge lightning current to the ground, reducing the thermal effect of lightning current. Furthermore, it facilitates receiving lightning from multiple directions, has a wide lightning absorption range, and exhibits excellent anti-interference performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of lightning defense, and particularly relates to a lightning defense device for wind turbines based on lightning current dissipation. Background Art

[0002] Since the 1970s, wind power generation has developed from low-power small generators to the current megawatt-level wind turbines, continuously developing in the direction of large-scale. The height of wind turbines has also increased from dozens of meters in the past to more than one hundred meters now. Among them, the height of 6000kW wind turbines has approached 200m. The increase in the single-unit power generation of wind turbines requires the increase of the hub height and the impeller diameter, and the lightning strike rate suffered by wind turbines has also been increasing continuously. Whether the wind turbine can operate normally during thunderstorm weather and whether the various equipment inside the wind turbine body is vulnerable to lightning damage is particularly important.

[0003] Due to the unique distribution characteristics of wind energy, the location selection of wind farms is generally on the seashore or the windward slope of valleys. These locations are often areas with high lightning strike density and are at great risk of suffering lightning losses.

[0004] The patent of "CN105024282B" discloses a combined lightning protection system for wind turbine blades, including a wind turbine with several blades. The lightning protection system further includes an energy storage element, which is arranged inside the hub of the wind turbine. One electrode plate of the energy storage element is connected to the pointers at the top of each blade through the lightning protection grounding wire of the wind turbine blade. The present invention can ensure that the energy storage element will not cause the dissipation of stored charges when a certain blade rotates to the lowest point before lightning strikes, and uses the charges collected by the energy storage element to trigger a discharge pulse to initiate an upward leader to intercept a downward lightning flash, avoiding the direct lightning strike on the blade.

[0005] The traditional lightning protection design for wind turbine blades is to install a lightning arrester on the wind turbine blade, which is embedded in the tip, middle and other parts of the blade. The disk surface of the lightning arrester is flush with the blade surface and is cross-connected to the down-conductor inside the blade.

[0006] Since both the wind turbine blade and the nacelle are rotating, the electrical connection of the lightning current discharge channel along the down-conductor is realized through various diversion wires, connectors and lightning protection brushes. In this case, the diversion is not smooth, not only can the lightning current not be discharged smoothly to the ground, but it will also increase the path impedance, increase the thermal effect of the lightning current. In addition, it is difficult to receive lightning from multiple directions, the lightning absorption range is small, and the anti-interference performance is poor. Summary of the Invention

[0007] The purpose of the present invention is to provide a lightning defense device for wind turbines based on lightning current dissipation to solve the above problems.

[0008] The present invention realizes the above purpose through the following technical solutions:

[0009] A lightning protection device for wind turbines based on lightning current dissipation, comprising a wind turbine blade, a hub and an output shaft provided at the rear end of the hub. A main needle is provided at the end of the wind turbine blade. The conductive end of the main needle is connected to a blade lightning protection grounding wire. One branch end of the blade lightning protection grounding wire is connected to a grounding lead provided inside the hub, and the other branch end of the blade lightning protection grounding wire is connected to an energy storage component. A driving component for driving the universal rotation of the main needle by wind energy is provided inside the wind turbine blade. The driving component includes a driving sleeve. A first metal block is provided at the end of the driving sleeve. A second metal block is provided inside the first metal block. A conical block is provided at the end of the second metal block. The two ends of the conical block are respectively provided with a first conical end and a second conical end. The first conical end is connected to the main needle, and the second conical end is connected to the second metal block. A wind-driven impeller is provided on the outer side of the driving sleeve. The fan blades of the wind-driven impeller are higher than the surface of the wind turbine blade. When the wind turbine blade is under driving action, a high-strength air flow will be formed on the surface of the wind turbine blade, and the high-strength air flow is used to drive the rotation of the wind-driven impeller.

[0010] As a further optimized scheme of the present invention, the main needle is inclined at an angle of 45-60° with respect to the end of the wind turbine blade.

[0011] As a further optimized scheme of the present invention, a dynamic ring and an expansion ring are sequentially provided on the outer side of the driving sleeve along the lightning current diversion direction. The expansion rings are arranged at equal angles on the outer side of the driving sleeve, and insulating strips are provided between adjacent expansion rings.

[0012] As a further optimized scheme of the present invention, an adjustment component for relatively uniform expansion and contraction of the expansion ring is provided on the expansion ring. The adjustment component includes a positioning plate. A strip-shaped groove with the same number as the expansion rings is provided on the outer surface of the positioning plate. A slider is slidably provided inside the strip-shaped groove, wherein the slider is fixed to the expansion ring. A curved rod is provided on the slider. The inner end of the curved rod is connected to a rotating block. A circular through hole is provided at the central position inside the rotating block. Tooth blocks are provided on the inner side wall of the circular through hole. The inner side of the tooth blocks is connected to a gear that matches them. The central position of the gear is connected to the driving sleeve.

[0013] As a further optimized scheme of the present invention, the curved rods are arranged at equal angles on the outer side of the rotating block. The curved rods are in an "L" shape structure, and the connection modes of the curved rods with the slider and the rotating block are both rotational connections.

[0014] As a further optimized scheme of the present invention, the connection mode between the gear and the tooth blocks is meshing connection.

[0015] As a further optimization scheme of the present invention, a protective component is provided on the outer side of the lightning protection grounding wire of the blade. The protective component includes an insulating sleeve, and several groups of fireproof fibers and heat-conducting fibers are provided on the outer side of the insulating sleeve. The fireproof fibers and the heat-conducting fibers are arranged alternately, and a conduction block is provided between adjacent fireproof fibers and heat-conducting fibers.

[0016] As a further optimization scheme of the present invention, the insulating sleeve is made of high-purity glass fiber.

[0017] As a further optimization scheme of the present invention, the fireproof fibers and the heat-conducting fibers are twisted on the outer side of the insulating sleeve. The fireproof fibers are made of high-aluminum fireproof fibers, and the heat-conducting fibers are made of metallic copper.

[0018] As a further optimization scheme of the present invention, conduction fibers are provided inside the fireproof fibers. The conduction block is made of metallic copper. The conduction block penetrates through the inside of the fireproof fibers and is in contact with the conduction fibers. The connection mode between the conduction block and the heat-conducting fibers is an electrical connection.

[0019] The beneficial effects of the present invention are as follows:

[0020] (1) The present invention can utilize natural wind to realize the universal adjustment of the main needle 3, thereby facilitating the reception of lightning in multiple directions and expanding the lightning elimination range;

[0021] Furthermore, by providing several groups of expansion rings for the function of rapid conduction, when the distance between adjacent expansion rings increases, the insulating strip will be extremely stretched at this time, and the overall resistance of the expansion ring increases, which is used to quickly eliminate the interference of the discharge pulse, thereby reducing the interference of the discharge pulse on the lightning protection grounding wire of the blade; when the distance between adjacent expansion rings decreases, the insulating strip will be compressed at this time, and the overall resistance of the expansion ring decreases, which is used to quickly guide the discharge pulse, thereby reducing the damage to the fan blade caused by the temperature rise.

[0022] (2) By providing an insulating sleeve sleeved on the outer side of the lightning protection grounding wire of the blade to realize the shielding treatment of the lightning protection grounding wire of the blade, the stability of the conduction of the lightning protection grounding wire of the blade can be effectively guaranteed. At the same time, when the lightning protection grounding wire of the blade conducts lightning, a large amount of heat will be generated, and the heat will quickly dissipate along the heat-conducting fibers, avoiding the influence of excessive heat on the conductivity of the lightning protection grounding wire of the blade. In addition, the fireproof fibers can effectively avoid the damage to the lightning protection grounding wire of the blade caused by high temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the main view axonometric structure schematic diagram of the present invention;

[0024] Figure 2 is the main view sectional structure schematic diagram of the present invention;

[0025] Figure 3 It is a schematic side view sectional structure diagram of the present invention;

[0026] Figure 4 It is a schematic front view axonometric structure diagram of the connection between the main needle and the drive assembly of the present invention;

[0027] Figure 5 It is a schematic front view axonometric structure diagram of the drive assembly of the present invention;

[0028] Figure 6 It is a schematic front view axonometric structure diagram of the adjustment assembly of the present invention;

[0029] Figure 7 It is a schematic front view axonometric structure diagram of the connection between the protection assembly and the blade lightning protection ground wire of the present invention;

[0030] Figure 8 It is a schematic front view axonometric structure diagram of the connection between the protection assembly and the first metal block of the present invention;

[0031] Figure 9 It is a schematic internal side view axonometric structure diagram of the protection assembly of the present invention.

[0032] In the figure: 1, fan blade; 2, hub; 3, main needle; 4, blade lightning protection ground wire; 5, grounding lead; 6, energy storage assembly; 7, drive assembly; 71, drive sleeve; 72, first metal block; 73, second metal block; 74, conical block; 75, first conical end; 76, second conical end; 77, wind-driven impeller; 8, dynamic ring; 9, expansion ring; 10, insulating strip; 11, adjustment assembly; 111, positioning plate; 112, strip groove; 113, slider; 114, curved rod; 115, rotating block; 116, circular through hole; 117, tooth block; 118, gear; 12, output shaft; 13, protection assembly; 1301, insulating sleeve; 1302, fireproof fiber; 1303, heat-conducting fiber; 1304, conduction block; 1305, conduction fiber. Detailed implementation manners

[0033] The following further describes the present application in detail with reference to the accompanying drawings. It is necessary to point out here that the following specific implementation manners are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application according to the above application content.

[0034] Embodiment 1

[0035] As Figures 1-4As shown, a lightning protection device for a wind turbine based on lightning current dissipation includes a wind turbine blade 1, a hub 2, and an output shaft 12 provided at the rear end of the hub 2. The end of the wind turbine blade 1 is provided with a main pin 3, the conductive end of the main pin 3 is connected to a blade lightning protection grounding wire 4, one branch end of the blade lightning protection grounding wire 4 is connected to a grounding lower lead 5 provided in the hub 2, and the other branch end of the blade lightning protection grounding wire 4 is connected to an energy storage component 6; the interior of the wind turbine blade 1 is provided with a drive component 7 that utilizes wind energy to drive the main pin 3 to rotate in a universal direction, the drive component 7 includes a drive sleeve 71, and the end of the drive sleeve 71 is provided with a first metal block 7 2. A second metal clamping block 73 is provided inside the first metal clamping block 72. A conical block 74 is provided at the end of the second metal clamping block 73. The two ends of the conical block 74 are respectively provided with a first conical end 75 and a second conical end 76. The first conical end 75 is connected to the main needle 3, and the second conical end 76 is connected to the second metal clamping block 73. A wind-driven impeller 77 is provided on the outside of the driving sleeve 71. The blades of the wind-driven impeller 77 are higher than the surface of the fan blade 1. When the fan blade 1 is driven, a high-strength airflow is formed on the surface of the fan blade 1. The high-strength airflow is used to drive the rotation of the wind-driven impeller 77.

[0036] The main needle 3 and the end of the fan blade 1 are inclined at an angle of 45-60 degrees.

[0037] like Figure 5 As shown, when the fan blade 1 rotates around the central axis of the hub 2, a high-strength airflow is generated on the outer surface of the fan blade 1. When the high-strength airflow impacts the blades of the wind-driven impeller 77, the wind-driven impeller 77 rotates on the surface of the fan blade 1 and drives the driving sleeve 71 to rotate. The driving sleeve 71 rotates with the main pin 3 in a universal direction. Due to the angle difference between the main pin 3 and the fan blade 1, it is used for multi-directional rotation in the lightning space. The lightning receiving end of the main pin 3 rotates in multiple directions in the lightning space, which is convenient for increasing the possibility of the main pin 3 receiving lightning and facilitating the absorption of lightning in multiple spaces. Therefore, compared with the lightning prevention device in which the main pin 3 is fixed, the present invention can utilize natural wind to achieve universal adjustment of the main pin 3, thereby facilitating the multi-directional reception of lightning and expanding the range of lightning elimination.

[0038] like Figure 5 As shown, a dynamic ring 8 and an expansion ring 9 are sequentially provided on the outside of the driving sleeve 71 and along the lightning diversion direction. The expansion rings 9 are arranged at equal angles on the outside of the driving sleeve 71, and insulating strips 10 are provided between adjacent expansion rings 9.

[0039] The dynamic loop 8 can suppress the discharge of the main needle of the fan blade before lightning is induced. When the thundercloud arrives, due to the sudden increase in the electric field of the main needle, the limitation of the dynamic loop is broken to form a powerful discharge pulse, triggering an upward leader. The upward lightning triggered has a shielding effect on the ground. However, during the use of the dynamic loop 8, due to the discharge pulse, the internal temperature of the blade lightning protection grounding wire 4 rises sharply. The solution of the present invention is provided with several expansion loops 9 for the function of rapid conduction. When the distance between adjacent expansion loops 9 increases, at this time, the insulating strip 10 will be extremely stretched, and at this time, the overall resistance of the expansion loop 9 increases, which is used to quickly eliminate the interference of the discharge pulse, thereby reducing the interference of the discharge pulse on the blade lightning protection grounding wire 4;

[0040] When the distance between adjacent expansion loops 9 decreases, at this time, the insulating strip 10 will be compressed, and the overall resistance of the expansion loop 9 decreases, which is used to quickly guide the discharge pulse, thereby reducing the damage to the fan blade 1 caused by the temperature rise.

[0041] Embodiment 2

[0042] As Figure 6 shown, a regulating component 11 for relatively uniform expansion and contraction of the expansion loop 9 is provided on the expansion loop 9. The regulating component 11 includes a positioning plate 111. A strip-shaped groove 112 with the same number as the expansion loop 9 is provided on the outer surface of the positioning plate 111. A slider 113 is slidably provided inside the strip-shaped groove 112. The slider 113 is fixed to the expansion loop 9. A curved rod 114 is provided on the slider 113. The inner end of the curved rod 114 is connected with a rotating block 115. A circular through hole 116 is provided at the central position inside the rotating block 115. Tooth blocks 117 are provided on the inner side wall of the circular through hole 116. A gear 118 that matches the tooth blocks 117 is connected to the inner side of the tooth blocks 117. The central position of the gear 118 is connected to the driving sleeve 71;

[0043] The curved rods 114 are arranged at equal angles on the outside of the rotating block 115. The curved rods 114 are in an "L" shape structure, and the connection modes of the curved rods 114 with the slider 113 and the rotating block 115 are both rotational connections;

[0044] The connection mode between the gear 118 and the tooth blocks 117 is meshing connection.

[0045] When the driving sleeve 71 rotates, it drives the gear 118 to rotate. At this time, the rotation of the gear 118 drives the rotating block 115 to change its angle and drives the curved rod 114 to move in conjunction. At this time, the slider 113 will slide inside the strip-shaped groove 112 to adjust the distance between the expansion loops 9,

[0046] When the slider 113 drives the expansion ring 9 to slide towards the inner side of the strip groove 112, the distance between adjacent expansion rings 9 decreases. At this time, the insulating strip 10 will be compressed, and the overall resistance of the expansion ring 9 decreases, which is used to quickly guide the discharge pulse, thereby reducing the damage to the fan blade 1 caused by the temperature rise.

[0047] When the slider 113 drives the expansion ring 9 to slide towards the outer side of the strip groove 112, the distance between adjacent expansion rings 9 increases. At this time, the insulating strip 10 will be extremely stretched. At this time, the overall resistance of the expansion ring 9 increases, which is used to quickly eliminate the interference of the discharge pulse, thereby reducing the interference of the discharge pulse on the blade lightning protection grounding wire 4.

[0048] Embodiment 3

[0049] As Figures 7-9 shown, a protection component 13 is provided on the outer side of the blade lightning protection grounding wire 4. The protection component 13 includes an insulating sleeve 1301. A plurality of groups of fireproof fibers 1302 and heat-conducting fibers 1303 are provided on the outer side of the insulating sleeve 1301. The fireproof fibers 1302 and the heat-conducting fibers 1303 are arranged alternately. A conduction block 1304 is provided between adjacent fireproof fibers 1302 and heat-conducting fibers 1303.

[0050] The material of the insulating sleeve 1301 is high-purity glass fiber.

[0051] The fireproof fibers 1302 and the heat-conducting fibers 1303 are twisted on the outer side of the insulating sleeve 1301. The material of the fireproof fibers 1302 is high-aluminum fireproof fiber, and the material of the heat-conducting fibers 1303 is metallic copper.

[0052] A conduction fiber 1305 is provided inside the fireproof fiber 1302. The material of the conduction block 1304 is metallic copper. The conduction block 1304 penetrates through the inside of the fireproof fiber 1302 and is in contact with the conduction fiber 1305. The connection mode of the conduction block 1304 and the heat-conducting fiber 1303 is electrical connection.

[0053] The insulating sleeve 1301 is sleeved on the outer side of the blade lightning protection grounding wire 4 to realize the shielding treatment of the blade lightning protection grounding wire 4, which can effectively ensure the conduction stability of the blade lightning protection grounding wire 4. At the same time, when the blade lightning protection grounding wire 4 conducts lightning, a large amount of heat will be generated. The heat will quickly dissipate along the heat-conducting fiber 1303, avoiding the influence of excessive heat on the conductivity of the blade lightning protection grounding wire 4. In addition, the fireproof fiber 1302 can effectively avoid the damage to the blade lightning protection grounding wire 4 caused by high temperature.

[0054] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention.

Claims

1. A lightning protection device for wind turbines based on lightning current dissipation, characterized in that: It includes a wind turbine blade (1), a hub (2) and an output shaft (12) provided at the rear end of the hub (2). A main needle (3) is provided at the end of the wind turbine blade (1). The conductive end of the main needle (3) is connected to a blade lightning protection grounding wire (4). One branch end of the blade lightning protection grounding wire (4) is connected to a grounding lead (5) provided inside the hub (2), and the other branch end of the blade lightning protection grounding wire (4) is connected to an energy storage component (6); inside the wind turbine blade (1), there is a driving component (7) that uses wind energy to drive the main needle (3) to rotate in all directions. The driving component (7) includes a driving sleeve (71). A first metal block (72) is provided at the end of the driving sleeve (71). A second metal block (73) is provided inside the first metal block (72). A tapered block (74) is provided at the end of the second metal block (73). The two ends of the tapered block (74) are respectively provided with a first tapered end (75) and a second tapered end (76). The first tapered end (75) is connected to the main needle (3), and the second tapered end (76) is connected to the second metal block (73). A wind-driven impeller (77) is provided on the outer side of the driving sleeve (71). The fan blades of the wind-driven impeller (77) are higher than the surface of the wind turbine blade (1). When the wind turbine blade (1) is under driving action, a high-strength air flow will be formed on the surface of the wind turbine blade (1), and the high-strength air flow is used to drive the rotation of the wind-driven impeller (77). A dynamic ring (8) and an expansion ring (9) are sequentially provided on the outer side of the driving sleeve (71) along the lightning current conduction direction. The expansion rings (9) are arranged at equal angles on the outer side of the driving sleeve (71), and an insulating strip (10) is provided between adjacent expansion rings (9). An adjusting component (11) for relatively uniformly expanding and contracting the expansion ring (9) is provided on the expansion ring (9). The adjusting component (11) includes a positioning plate (111). Strip-shaped grooves (112) with the same number as the expansion rings (9) are provided on the outer surface of the positioning plate (111). Sliders (113) are slidably provided inside the strip-shaped grooves (112), where the sliders (113) are fixed to the expansion rings (9). A curved rod (114) is provided on the slider (113). The inner end of the curved rod (114) is connected to a rotating block (115). A circular through hole (116) is provided at the central position inside the rotating block (115). Tooth blocks (117) are provided on the inner side wall of the circular through hole (116). Gears (118) that match the tooth blocks (117) are connected to the inner sides of the tooth blocks (117). The central position of the gears (118) is connected to the driving sleeve (71).

2. The lightning protection device for wind turbines based on lightning current dissipation according to claim 1, characterized in that: The main needle (3) is inclined at an angle of 45 - 60° with respect to the end of the wind turbine blade (1).

3. The lightning protection device for wind turbines based on lightning current dissipation according to claim 1, characterized in that: The curved rods (114) are arranged at equal angles on the outer side of the rotating block (115). The curved rods (114) are in an "L" shape structure, and the connection modes of the curved rods (114) with the sliders (113) and the rotating blocks (115) are both rotational connections.

4. A lightning protection device for a wind turbine based on lightning current dissipation according to claim 1, characterized in that: The connection between the gear (118) and the tooth block (117) is a meshing connection.

5. The lightning protection device for wind turbines based on lightning current dissipation according to claim 1, characterized in that: A protection component (13) is provided on the outer side of the blade lightning protection grounding wire (4). The protection component (13) includes an insulating sleeve (1301). A plurality of groups of fireproof fibers (1302) and heat-conducting fibers (1303) are provided on the outer side of the insulating sleeve (1301). The fireproof fibers (1302) and the heat-conducting fibers (1303) are arranged alternately. A conduction block (1304) is provided between adjacent fireproof fibers (1302) and heat-conducting fibers (1303).

6. The lightning protection device for wind turbines based on lightning current dissipation according to claim 5, characterized in that: The material of the insulating sleeve (1301) is high-purity glass fiber.

7. The lightning protection device for wind turbines based on lightning current dissipation according to claim 5, characterized in that: The fireproof fibers (1302) and the heat-conducting fibers (1303) are twisted on the outer side of the insulating sleeve (1301). The material of the fireproof fibers (1302) is high-aluminum fireproof fiber. The material of the heat-conducting fibers (1303) is metallic copper.

8. A lightning protection device for a wind turbine based on lightning current dissipation according to claim 5, characterized in that: A conduction fiber (1305) is provided inside the fireproof fiber (1302). The material of the conduction block (1304) is metallic copper. The conduction block (1304) penetrates through the inside of the fireproof fiber (1302) and is in contact with the conduction fiber (1305). The connection between the conduction block (1304) and the heat-conducting fiber (1303) is an electrical connection.

Images