JP2023105777A - Lightning suppression device for windmill blade - Google Patents

Abstract

To provide a lightning suppression device for windmill blade that can be prevented from separating from a windmill blade as much as possible.SOLUTION: There is provided a lighting suppression device 7 that is a lighting suppression device for windmill blade which is provided atop of a windmill blade 6 to suppress the windmill blade 6 from being struck by lighting, and comprises an electric insulator 11 which is fitted atop of the windmill blade 6 and formed of a non-conductive material, an internal electrode 9 which is fitted to the opposite side of the electric insulator 11 from the windmill blade 6, and an external electrode 10 which is fitted to the electric insulator 11 while surrounding the internal electrode 9 at a predetermined interval, wherein the electric insulator 11 is fixed atop of the windmill blade 6 by fixing means 13, and a ground line 8 is connected to the internal electrode 9.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to a lightning strike suppression device for wind turbine blades, which suppresses damage to a wind power generator by suppressing lightning strikes to the wind turbine blades, particularly the wind turbine blades constituting the wind power generator.

Wind energy is known as one of renewable energy.

A wind power generator that generates electricity using this wind energy includes a wind turbine.
The windmill includes a high strut, a nacelle mounted on the upper end of the strut and having a generator inside, and a large number of windmill blades mounted on the nacelle for rotating the generator.

In such a wind power generator, the wind turbine blades are rotated by naturally occurring wind, and the power generator is driven to rotate in conjunction with the wind turbine blades to generate power.

Here, the struts are formed high and the wind turbine blades are provided at high positions so that the wind turbine blades can receive the wind efficiently. Also, the wind turbine blades are formed long so as to increase the amount of power generation.

Wind turbine blades are formed, for example, with lengths ranging from several tens of meters to about 100 meters.
Here, the wind turbine blades are designed such that the speed of the tip of the wind turbine blades does not exceed the speed of sound in order to avoid the generation of shock waves.
For example, if the rotation speed is 20 rpm, the upper limit of the length of the wind turbine blade is estimated to be about 110 meters for practical operation. In addition, the speed of the tip of the wind turbine blade is about 230 meters per second at this length of the wind turbine blade.

By the way, in such a wind power generator, by rotating the wind turbine blades, the tips of the wind turbine blades come to the highest position in the entire wind power generator, that is, the position closest to the thundercloud.
Therefore, lightning strikes are likely to occur toward the wind turbine blades.

As a countermeasure against such inconvenience, for example, a blade for wind power generation described in Patent Document 1 is known.

A blade for wind power generation (corresponding to a wind turbine blade) described in Patent Document 1 is provided with a metal lightning receiver at its tip, and a ground wire is electrically connected to the lightning receiver. It is buried in the ground through the inside of the wind turbine blades and columns.

The blade for wind power generation described in Patent Document 1 has the configuration described above, so that when a lightning strike occurs toward the blade for wind power generation, the lightning strike is attracted to the lightning receiving part, and the lightning strike is sent to the ground via the ground wire. can flow to
As a result, the blade for wind power generation described in Patent Document 1 can suppress damage to the wind turbine blades, the nacelle, and various devices installed in the nacelle due to lightning strikes.

JP 2012-246812 A Japanese Patent No. 5839331

By the way, such conventional wind turbine blades still have the following problems to be solved.

Even if a lightning strike occurs toward the wind turbine blade, the conventional wind turbine blade cannot always attract the lightning strike to the lightning receiver. In fact, accidents have been confirmed in which lightning strikes directed toward wind turbine blades directly hit the outer surface of the wind turbine blades.
In addition, since the lightning receiving part attracts lightning strikes, the number of direct lightning strikes toward the wind turbine blades is increasing.

Therefore, it cannot necessarily be said that the conventional wind turbine blades can effectively suppress damage to the wind turbine blades, the nacelle, various devices installed in the nacelle, and the struts.

Such problems are caused by the technical idea of attracting lightning strikes to places where there are no objects to be protected.

On the other hand, for example, a lightning strike suppression device described in Patent Document 2 is known as a new coping technique that focuses on the lightning strike generation mechanism. It is believed that such a lightning strike suppression device, when attached to the tip of the wind turbine blade, can significantly reduce the number of times lightning strikes the wind turbine blade directly.

Inside the thundercloud, charge separation occurs, and the lower part is negatively charged.
For example, if the base of a thundercloud is negatively charged, electrostatic induction will cause the surface of the earth below the thundercloud to be positively charged. At this time, since the distance from the thundercloud is short, the high positions grounded to the ground, such as lightning rods and trees, have a high density of positive charges.
Here, inside the thundercloud, the electric potential difference is very large due to charge separation, so that the electrical insulation of the atmosphere is locally destroyed and a weak electric discharge is generated.

In a lightning strike, first, a weak discharge of negative charges (step leader) extending downward from a thundercloud intermittently progresses toward the ground as it is.
On the other hand, since the potential difference between the bottom of the thundercloud and the vicinity of the surface of the ground is extremely large, the electrical insulation of the atmosphere is locally destroyed, and the ground near the surface, especially from lightning rods, trees, etc. Heh, a weak positive discharge (streamer) is occurring.
When the step leader and streamer are coupled, the discharge path electrically connects the bottom of the thundercloud and the surface of the ground, and a very strong current (return current) flows according to the potential difference. This return current is generally called a lightning strike.

The lightning strike suppression device described in Patent Document 2 includes a lower electrode and an upper electrode forming a capacitor, and the lower electrode is grounded.

In the lightning suppression device described in Patent Document 2, with the above configuration, the lower electrode is charged with the same kind of charge as the surface of the ground, and the upper electrode is charged with the same kind of charge as the bottom of the thundercloud. It is electrically charged and can reduce the potential difference with the bottom of the thundercloud.
As a result, the lightning strike suppression device described in Patent Document 2 can suppress the generation of streamers and suppress direct lightning strikes as return currents.

Here, the lightning strike suppression device described in Patent Document 2 is formed to have a substantially spherical outer shape, so that it is possible to suppress the formation of local areas with high charge densities on the upper electrode. .
This also allows the lightning strike suppression device described in Patent Document 2 to suppress the generation of streamers and suppress direct lightning strikes as return currents.

However, in order to attach such a lightning strike suppression device to the tip of a wind turbine blade, the following problems should be solved.

When the wind turbine blade rotates, a strong centrifugal force acts on the lightning strike suppression device attached to the tip of the wind turbine blade in a direction to detach from the tip of the wind turbine blade.
For example, if the rotation speed is 20 rpm and the length of the wind turbine blades is 110 meters, the magnitude of the centrifugal force acting on the lightning suppression device is approximately 49 times the magnitude of the gravity acting on the lightning suppression device. calculated as double.

Further, when the wind turbine blade rotates, a strong wind pressure is applied to the lightning strike suppression device attached to the tip of the wind turbine blade.
For example, if the rotational speed is 20 revolutions per minute and the length of the wind turbine blades is 110 meters, the wind pressure on the lightning suppression device is calculated to be about 33 kilonewtons per square meter.
At this time, if the lightning suppression device has a spherical outer shape and a diameter of 20 centimeters, the wind pressure resistance acting on the lightning suppression device is about 530 Newtons, that is, it acts on a mass of about 54 kg. It is estimated to be about the same as the magnitude of the force of gravity.

A lightning suppression device attached to the tip of a wind turbine blade may easily come off from the tip of the wind turbine blade due to the above-mentioned centrifugal force and wind pressure resistance, thereby impairing its lightning suppression effect.

In view of the above circumstances, it is an object of the present invention to provide a lightning strike suppression device for wind turbine blades that can prevent detachment from the wind turbine blades as much as possible.
In addition, in providing the above-described lightning strike suppression device for wind turbine blades, the present invention has a further problem to be solved to minimize the influence on the aerodynamic characteristics of the wind turbine blades.

In order to solve the above-described problems, the present invention provides a lightning suppression device for wind turbine blades, which is provided at the tip of a wind turbine blade to suppress lightning strikes to the wind turbine blade, and is attached to the tip of the wind turbine blade. An electrical insulator made of a conductive material, an internal electrode attached to the electrical insulator on the opposite side of the wind turbine blade, and an external electrode attached to the electrical insulator so as to surround the internal electrode with a predetermined spacing. , wherein the electrical insulator is fixed to the tip of the wind turbine blade by a fixing means, and the internal electrode is connected to the grounding means.

A lightning strike suppression effect can be achieved by a mechanism similar to the lightning strike suppression device described in Patent Document 2.

For example, if the base of a thundercloud is negatively charged, electrostatic induction will cause the surface of the earth below the thundercloud to be positively charged.
At this time, since the internal electrode is positively charged because it is electrically connected to the ground surface, the external electrode is negatively charged due to electrostatic induction.

Since the external electrode carries a negative charge that is the same as the charge carried by the bottom of the thundercloud, when the wind turbine blade rotates and the tip of the wind turbine blade faces the thundercloud, the bottom of the thundercloud carrying a negative charge , and the potential difference with the external electrode, which is also negatively charged, is relaxed.
Therefore, generation of streamers from the external electrodes is suppressed, thereby suppressing direct hits of lightning strikes as feedback currents to the external electrodes.

Such a lightning strike suppression effect is achieved by the negative charge distribution area of the external electrode acting as a barrier that protects the area below from direct lightning strikes. It is expected that it will extend to

A user of the present invention can fix the electrical insulator to the tip of the wind turbine blade without obstructing the inner electrode and the outer electrode by the above configuration.
That is, since the inner electrode and the outer electrode are attached to the side of the electrical insulator opposite to the wind turbine blade, the electrical insulator has a wide area for fixing means to the tip of the wind turbine blade.

Therefore, the user of the present invention can relatively freely select the installation position and fixing form of the fixing means, and can firmly fix the electrical insulator and the tip of the wind turbine blade.
Accordingly, the present invention can sufficiently resist the centrifugal force and the wind pressure resistance force, prevent the wind turbine blades from being detached from the tips, and ensure the soundness of the wind turbine.

Moreover, in one embodiment of the present invention, the internal electrode is formed in a plate shape.
A user of the present invention can form the outer shape of the external electrode into a flat shape according to the shape of the internal electrode by the above configuration.
As a result, the present invention can more sufficiently resist the wind pressure resistance when the wind turbine blades rotate, prevent the wind turbine blades from coming off from the tips, and further ensure the soundness of the wind turbine.

Moreover, in one embodiment of the present invention, the internal electrode is formed in a hollow shape.
A user of the present invention can increase the electrode plate area of the capacitor formed by the internal electrodes and the external electrodes and increase the capacitance thereof.
As a result, the present invention can further enhance the lightning strike suppression effect by inducing more electric charges in the external electrodes and by expanding the electric charge distribution area in the external electrodes.

Further, in the present invention, preferably, a reinforcing member is integrally provided at the tip of the wind turbine blade, and the reinforcing member and the electrical insulator are fixed by fixing means.
According to the present invention, the fixing between the electrical insulator and the wind turbine blades is further strengthened by the above configuration, preventing the wind turbine blades from being detached from the tips, and further ensuring the soundness of the wind turbine.

Moreover, in the present invention, preferably, the outer surface of the external electrode is formed so as to substantially follow the extended surface of the outer surface of the wind turbine blade.
According to the present invention, by maintaining the outer shape of the tip of the wind turbine blade with the above configuration, it is possible to achieve a lightning strike suppression effect while minimizing the influence on the aerodynamic characteristics of the wind turbine blade.

Moreover, in the present invention, preferably, the fixing means also serves as the grounding means.
According to the present invention, the number of components can be reduced and the assembly process can be simplified by the above configuration.

Moreover, in the present invention, more preferably, a plurality of fixing means are provided.
According to the above configuration, the internal electrodes are supported by a plurality of fixing means and fixed to the electrical insulator in a more stable manner, thereby ensuring soundness of the lightning strike suppression device itself.

The lightning strike suppression device for wind turbine blades of the present invention can secure soundness of the wind turbine blades by making the fixation to the tip of the wind turbine blades strong.
Further, in the wind turbine blade lightning suppression device of the present invention, the outer surface of the external electrode is formed so as to substantially follow the extended surface of the outer surface of the wind turbine blade, thereby minimizing the influence on the aerodynamic characteristics of the wind turbine blade. However, the effect of suppressing lightning strikes can be achieved.

1 is an overall view of a wind turbine generator to which a first embodiment of the present invention is applied; FIG. 1 is a cross-sectional view of a wind turbine blade to which a first embodiment of the invention is applied; FIG. 1 is a cross-sectional view of a tip of a wind turbine blade to which a first embodiment of the invention is applied; FIG. FIG. 4 is a sectional view taken along line IV-IV of FIG. 3; 4 is a cross-sectional view taken along line VV of FIG. 3; FIG. FIG. 4 is a cross-sectional view of the tip of a wind turbine blade to which a second embodiment of the present invention is applied; FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 6; FIG. 7 is a cross-sectional view taken along line VIII-VIII of FIG. 6; FIG. 4 is a cross-sectional view of the tip of a wind turbine blade to which a third embodiment of the present invention is applied; FIG. 10 is a cross-sectional view taken along the line XX of FIG. 9; FIG. 10 is a cross-sectional view taken along line XI-XI of FIG. 9; FIG. 4 is a schematic side view for explaining the path of the grounding wire extending from the connecting rod of the lightning strike suppression device of the present invention;

A first embodiment of the present invention will be described below with reference to the drawings.
In FIG. 1, reference numeral 1 indicates the wind power generation facility to which this embodiment is applied, and reference numeral A indicates the ground on which the wind power generation device 1 is erected.

The wind power generation facility 1 includes a wind turbine 2 for wind power generation, a power supply/distribution facility 3 for supplying and distributing the electric energy generated by the wind turbine 2, and a transmission line 4 in its configuration.

Further, the wind turbine 2 includes a support 5, a nacelle 51 provided at the upper end of the support 5, a hub 52 connected to a drive shaft (not shown) of a generator installed in the nacelle 51, and a hub 52 a plurality of wind turbine blades 6 mounted on the .

With the above configuration, the wind turbine 2 rotates the plurality of wind turbine blades 6 in response to the wind, thereby rotating the drive shaft of the generator via the hub 52 and generating power.

As shown in FIG. 2, the wind turbine blade 6 is provided with a lightning strike suppression device 7 at its tip, and a grounding wire 8 is provided inside.

As shown in FIGS. 3 to 5, the lightning strike suppression device 7 includes an internal electrode 9 (not shown in cross section) formed in a semicircular plate shape, and a substantially flat shape having a substantially hemispherical shell shape in cross section. , an external electrode 10 arranged so as to surround the internal electrode 9 with a predetermined interval L, and an external electrode 10 fixed to the tip of the wind turbine blade 6 , and the internal electrode 9 and the external electrode 10 are attached on the opposite side of the wind turbine blade 6 . and an electrical insulator 11 having a

Here, the tip of the wind turbine blade 6 is closed, but it is preferable that the wind turbine blade 6 has a reinforcing plate 12 embedded from the tip to the peripheral wall.

Further, here, the substantially hemispherical shell-shaped cross section of the external electrode 10 is preferably formed so as to substantially follow the extended surface of the outer surface of the wind turbine blade 6 .

The lower ends of the internal electrode 9 and the external electrode 10 are fitted into the electrical insulator 11 at a predetermined depth and fixed by adhesive or the like.

The internal electrode 9 and the external electrode 10 are made of a conductive material such as stainless steel.
Also, the electrical insulator 11 is made of a non-conductive material such as fiber reinforced plastic (FRP).

The electrical insulator 11 is arranged in surface contact with the tip surface of the wind turbine blade 6 and is firmly crimped and fixed by a fixing means 13 (not shown in cross section).

Here, in the present embodiment, the fixing means 13 is a bolt that penetrates the tip surface of the wind turbine blade 6 and the reinforcing plate 12 from the inside of the wind turbine blade 6 and is screwed to the electrical insulator 11 . As a result, the electrical insulator 11 is firmly crimped and fixed to the tip of the wind turbine blade 6 .

Continuous through holes are formed in the tip surface of the wind turbine blade 6 , the electrical insulator 11 , and the central portion of the reinforcing plate 12 . not shown) is inserted.
At this time, a connecting portion into which the connecting rod 14 can be screwed is fitted to the lower end portion of the internal electrode 9 and fixed by welding or the like.

The connecting rod 14 is made of a conductive material such as stainless steel.

The connecting rod 14 has its tip screwed to a connecting portion provided at the lower end of the internal electrode 9 .
The connecting rod 14 thereby supports the internal electrode 9 .

A fixing nut 15 (not shown in cross section) is screwed to the intermediate portion of the connecting rod 14 .

The fixing nut 15 is pressed against the inner surface of the tip surface of the wind turbine blade 6 , and cooperates with the internal electrode 9 to sandwich and fix the tip of the wind turbine blade 6 , the electrical insulator 11 and the reinforcing plate 12 .

One end of the ground wire 8 is electrically connected to the connecting rod 14 inside the wind turbine blade 6 .
Here, in the present embodiment, the ground wire 8 is connected to the crimp terminal and is pressed and clamped by two fixing nuts separate from the fixing nut 15 which are screwed to the connecting rod 14 .

Also, the ground wire 8 is embedded in the ground A at the other end through the inside of the support 5 .
As an example shown in FIG. 12, when the inner surface 5b of the post 5 is made of a conductive metal, the ground wire 8 may be electrically connected to the inner surface 5b instead of being embedded in the ground A. good.

In addition, as shown in FIG. 12, the ground wire 8 is provided with a slip brush 81 inside the nacelle 51 so that even when the wind turbine blades 6 are rotating, the electrical connection is maintained.

In the lightning suppression device 7 of this embodiment configured as described above, the user first places the electrical insulator 11 to which the internal electrode 9 and the external electrode 10 are attached on the tip surface of the wind turbine blade 6. Arrange in a state of surface contact.
Next, the user crimps and fixes this electrical insulator 11 to the tip surface of the wind turbine blade 6 by the fixing means 13 .
Next, the user screws the connecting rod 14 to the connecting portion provided at the lower end of the internal electrode 9 .
By pressing the fixing nut 15 against the inner surface of the tip surface of the wind turbine blade 6, the user causes the fixing nut 15 and the internal electrode 9 to work together, and clamps and fixes the tip of the wind turbine blade 6 and the electrical insulator 11. do.

According to the above flow, the user can assemble the lightning strike suppression device 7 and fix it to the tip of the wind turbine blade 6 .

Here, the user of the lightning strike suppression device 7 can fix the electrical insulator 11 to the tip of the wind turbine blade 6 without obstructing the inner electrode 9 and the outer electrode 10 .
That is, since the internal electrode 9 and the external electrode 10 are attached to the opposite side of the wind turbine blade 6 of the electrical insulator 11, the electrical insulator 11 is provided with a bolt as a fixing means 13 to the tip of the wind turbine blade 6. It has a wide range of parts.

Therefore, the user of the lightning strike suppression device 7 can relatively freely select the installation position and the number of the bolts, which are the fixing means 13, to firmly fix the electrical insulator 11 and the tip of the wind turbine blade 6. can.
As a result, the lightning strike suppression device 7 can sufficiently resist the centrifugal force and the wind pressure resistance force, prevent the detachment from the tip of the wind turbine blade 6 , and ensure the soundness of the wind turbine 2 .

When a thundercloud approaches and the bottom of the thundercloud is negatively charged, the surface of the ground A located below the thundercloud is positively charged due to electrostatic induction.
At this time, since the internal electrode 9 is positively charged because it is electrically connected to the surface of the ground A, the external electrode 10 is negatively charged by electrostatic induction.

Since the external electrode 10 is charged with the same kind of negative charge as the bottom of the thundercloud, when the wind turbine blades 6 rotate and the tip of the wind turbine blade 6 faces the thundercloud, the thundercloud is negatively charged. and the external electrode 10, which is also negatively charged, the potential difference is relaxed.
Therefore, the generation of streamers from the external electrode 10 is suppressed, thereby suppressing the direct hit of the lightning strike as the return current to the external electrode 10 .

Such a lightning strike suppressing effect is achieved by the negative charge distribution area of the external electrode 10 acting as a barrier that protects the area below from direct lightning strikes. and is expected to extend to the transmission line 4 as well.

As a second embodiment of the present invention, as shown in FIGS. 6 to 8, unlike the internal electrode 9, the internal electrode 16 is formed in a hollow shape. It is modified from the outer electrode 10 so as to keep the distance from the electrode 16 constant.
Note that the fixing structure and the like of the electric insulator 11 are substantially the same as those of the first embodiment, so the same reference numerals are given to simplify the description.

The internal electrode 16 has a substantially flattened shape with a substantially hemispherical shell-shaped cross section, and is hollow. there is

The fixed nut 15 screwed onto the connecting rod 14 is pressed against the inner surface of the tip surface of the wind turbine blade 6 or pressed against the electrical insulator 11 inside the internal electrode 16 . , cooperate with each other to clamp and fix the tip of the wind turbine blade 6 and the electrical insulator 11 .

In the second embodiment of the present invention, the user can increase the plate area of the capacitor formed by the internal electrode 16 and the external electrode 17 to increase its capacitance.
As a result, the lightning strike suppression device 7 according to the second embodiment of the present invention induces more electric charges in the external electrodes 17 and expands the electric charge distribution area in the external electrodes 17, thereby suppressing lightning strikes. The suppression effect can be further enhanced.

As a third embodiment of the present invention, as shown in FIGS. 9 to 11, the fixing structure of the internal electrode 18 is changed from that of the internal electrode 9. FIG.
Note that the fixing structure and the like of the external electrode 10 and the electrical insulator 11 are substantially the same as in the first embodiment, so the same reference numerals are given to simplify the description.

A plurality of connecting rods 19 (not shown in cross section) are fitted to the lower ends of the internal electrodes 18 and fixed together with a support plate 20 (not shown in cross section) by welding or the like.
Along with this, a plurality of continuous through-holes are formed in the tip surface of the wind turbine blade 6 and the electrical insulator 11 , and the connecting rod 19 is inserted from the inside of the wind turbine blade 6 .
At this time, the support plate 20 is embedded in the electrical insulator 11 .

A fixed nut 21 (not shown in cross section) and a fixed nut 22 (not shown in cross section) are screwed to the connecting rod 19 .

The fixing nut 21 is pressed against the inner surface of the tip surface of the wind turbine blade 6 , and cooperates with the internal electrode 18 to sandwich and fix the tip of the wind turbine blade 6 and the electrical insulator 11 .

Further, the fixing nut 21 cooperates with the fixing nut 22 to hold the ground wire 8 under pressure.

In the third embodiment of the present invention, the internal electrode 18 is supported by a plurality of connecting rods 19 and a support plate 20, and is further stably fixed to the electrical insulator 11, thereby improving the soundness of the lightning strike suppression device 7 itself. can be ensured.

By the way, the user of the wind turbine generator 1 is obliged to check once a year that the grounding wire 8 is not cut. In order to confirm continuity between the rod 19) and the ground A, access to the connecting rod 14 is required.

In this case, as an example shown in FIG. 12, the wind turbine blade 6 is preferably provided with an opening 61 with a lid in the vicinity of its tip.
Here, the lid (not shown) of the opening 61 has such a structure that the wind pressure resistance force due to the rotation of the wind turbine blades 6 acts in the direction to close the opening 61 .

With the above configuration, the user of the wind turbine generator 1 can access the connecting rods 14 inside the wind turbine blades 6 from the outside of the wind turbine blades 6 through the openings 61 for inspection, and access the connecting rods 14 for the continuity test. of probes can be connected.

In each of the above embodiments, the user adds a substantially streamlined structure made of a non-conductive material to the lightning suppression device 7 so as to have a wind turbine winglet structure, thereby improving the aerodynamic characteristics of the wind turbine blades. good too.

It should be noted that the various shapes and the like of each component shown in each of the above embodiments are examples, and can be variously changed based on design requirements and the like.

REFERENCE SIGNS LIST 1 wind power generation facility 2 wind turbine 3 power supply and distribution facility 4 power transmission line 5 strut 51 nacelle 52 hub 6 wind turbine blade 61 opening 7 lightning suppression device 8 grounding wire 81 slip brush 9 inner electrode 10 outer electrode 11 electrical insulator 12 reinforcing plate 13 fixing means 14 connecting rod 15 fixing nut 16 internal electrode 17 external electrode 18 internal electrode 19 connecting rod 20 supporting plate 21 fixing nut 22 fixing nut A ground L interval

Claims (7)

A lightning suppression device for wind turbine blades, which is provided at the tip of a wind turbine blade and suppresses lightning strikes to the wind turbine blade,
an electrical insulator made of a non-conductive material and attached to the tip of the wind turbine blade; an internal electrode attached to the electrical insulator on the opposite side of the wind turbine blade; an external electrode attached to said electrical insulator so as to surround it;
The electrical insulator is fixed to the tip of the wind turbine blade by a fixing means,
A lightning strike suppression device for a wind turbine blade, wherein the internal electrode is connected to a grounding means. The lightning strike suppression device for a wind turbine blade according to claim 1, wherein the internal electrode is plate-shaped. The lightning strike suppression device for a wind turbine blade according to claim 1, wherein the internal electrode is hollow. A lightning strike suppression for a wind turbine blade according to any one of claims 1 to 3, wherein a reinforcing member is integrally provided at the tip of said wind turbine blade, and said reinforcing member and said electrical insulator are fixed by said fixing means. Device. The lightning strike suppression device for wind turbine blades according to any one of claims 1 to 3, wherein said external electrode is formed so that its outer surface is substantially along an extended surface of the outer surface of said wind turbine blade. The lightning strike suppression device for wind turbine blades according to any one of claims 1 to 3, wherein said fixing means also serves as said grounding means. The lightning strike suppression device for wind turbine blades according to claim 6, wherein a plurality of said fixing means are provided.