JP2012149569A - Lightning protection method and device for windmill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightning protection method and device for a windmill, efficiently preventing breakage by a thunderbolt, and allowing reduction of cost.SOLUTION: In this lightning protection method for the windmill 1 for leading lightning current when lightning strikes a vane 6 of the windmill 1 to a lightning reception part 7 side provided on the surface of the vane 6 by a leading means, the leading means is configured by forming level differences 11 on the flat outer surface of the vane 6 of the windmill 1 in a direction heading for the lightning reception part 7, and the lightning current when the lightning strikes the vane 6 is guided to the lightning reception part 7 side by the level differences 11.

Description

  The present invention relates to a lightning arrester that guides a lightning current when a lightning strike has occurred on a blade of a windmill to a lightning receiving side provided on the surface of the blade of the windmill by an induction unit.

  In recent years, there has been a growing need for using green energy to cope with the problems of environmental pollution and resource depletion, and wind power generators with large wings with large power generation capacity have been developed. A large windmill has a high overall height and the blades are installed at a high position, so that the probability of lightning strikes on the blades also increases.

  When the blades of the windmill are damaged by this lightning strike, it takes time and cost to repair, and wind power cannot be generated until the repair is completed, resulting in a reduction in operating rate. Especially on the coast of the Sea of Japan in the Hokuriku region, due to the temperature difference between the warm currents of the Sea of Japan and the cold air masses in the sky, a large and low-thunder thundercloud develops, and the accumulated charge is discharged all at once, and the winter thunder This problem is remarkable.

  In order to cope with such problems, a lightning current when lightning strikes on the blade of the windmill is guided to the lightning receiving side provided on the surface of the blade by the guiding means, and is released from the lightning receiving portion to the ground A windmill lightning protection method and apparatus shown in Document 1 are known.

Japanese Patent Laid-Open No. 2007-1000065

  In the lightning arrester of the above-mentioned document, even if lightning falls on a part other than the lightning receiving part on the outer surface of the blade of the windmill, it is possible to guide the lightning discharge current to the lightning receiving part side by the guiding means. While it is possible to effectively prevent damage to the blades of the windmill due to lightning strikes, a dielectric layer is superimposed on an insulating layer attached to the outer surface of the windmill with an adhesive or the like, and a conductive segment is formed on the dielectric layer at predetermined intervals. Since the guide means is configured by arranging the guides, the structure of the guide means is complicated and the cost increases.

  It is an object of the present invention to provide a wind turbine lightning arresting method and apparatus that can efficiently prevent damage due to lightning strikes and that can reduce costs.

  In order to solve the above-mentioned problems, the present invention firstly wind turbines that induce lightning currents when lightning strikes on the blades 6 of the wind turbine 1 to the lightning receiving section 7 provided on the surface of the blades 6 by induction means. In which the guide means is configured by forming a step 11 in a direction toward the lightning receiving portion 7 on the flat outer surface of the blade 6 of the wind turbine 1, and when the lightning strikes the blade 6 by the step 11. The lightning current is guided to the lightning receiving part 7 side.

  Second, it is characterized by storing water in the step 11.

  Third, a lightning arrester for a windmill in which a lightning striker 7 is installed on the blade 6 of the windmill, and a guiding means for guiding a lightning current when a lightning strikes on the blade 6 of the windmill 1 to the lightning striker 7 is provided. A belt-like convex portion extending toward the lightning receiving portion 7 is formed on the flat outer surface of the blade 6, and a step 11 formed along the boundary between the widthwise end of the convex portion and the outer surface of the blade 6. The guide means is configured by the step 11, and the step 11 guides the lightning current when a lightning strikes the blade 6 to the light receiving portion 7 side.

  Fourth, by sticking the guide sheet 9 to the flat outer surface of the blade 6 so that the strip-shaped guide sheet 9 that is flat on the front and back surfaces and extends flexibly toward the lightning receiving portion 7, The protrusion is formed.

  Fifth, the guide sheet 9 is formed of a single layer.

  Sixth, the guide sheet 9 is detachably attached to the blade 6.

  Seventh, the convex portion is formed by applying paint to the flat outer surface of the blade 6 so as to extend in a strip shape toward the lightning receiving portion 7.

  Eighth, there is a lightning arrester for a windmill in which a lightning striker 7 is installed on the blade 6 of the windmill 1, and guidance means for guiding a lightning current when lightning strikes on the blade 6 of the windmill 1 to the lightning striker 7. The guide groove 12 extending toward the lightning receiving portion 7 is recessed in the flat outer surface of the windmill, and the guide means is constituted by the step 11 of the guide groove 12, and the blade 6 is subjected to lightning by the step 11. The lightning current at the time is guided to the lightning receiving part 7 side.

  Ninthly, the power receiving unit 7 is disposed at the distal end portion of the blade 6, and the step 11 is disposed closer to the base end side than the power receiving unit 7.

  Tenth, the step 11 is extended to the lightning receiving portion 7 or the vicinity thereof.

  According to the above configuration, a step toward the lightning-receiving portion is formed on the flat outer surface of the blade of the windmill, and the lightning current when lightning strikes the blade is guided to the lightning-receiving portion side by the step constituting the guiding means. Therefore, it is possible to efficiently prevent the blades from being damaged by a lightning strike, and the structure of the guiding means is simple, so that the cost can be reduced. By the way, when the inductive means is configured by superimposing a dielectric layer on an insulating layer attached to the outer surface of the windmill with an adhesive or the like and arranging conductive segments at predetermined intervals on the dielectric layer, A step is formed along the boundary between the width direction end of the body layer and the outer surface of the blade, but unevenness is formed in the vicinity of the step by a plurality of segments. I can't hope for the effect of inducing.

  Further, if water is accumulated in the step, the action of inducing lightning current is further enhanced, and damage due to lightning can be more efficiently prevented.

  Further, if the guide sheet is formed of a single layer, the configuration of the guide means is further simplified.

  Further, if the guide sheet is detachably attached to the blade, the function of the guide means can be maintained for a long time by appropriately replacing the guide sheet.

  If the lightning receiving part is arranged at the tip of the blade and the step is arranged at the base end side of the lightning receiving part, the lightning can be received more efficiently by utilizing the characteristic that lightning strikes to the tip side of the blade. Lightning current can be induced on the part side.

  Further, if the step is extended to the lightning receiving portion or the vicinity thereof, a lightning current can be induced more efficiently on the lightning receiving portion side.

It is a front view which shows a wind power generator. It is a principal part expanded side view which shows the principal part of a wind power generator. It is a principal part enlarged view which shows the front end side of the blade | wing which affixed the guidance tape. It is principal part AA sectional drawing of FIG. It is a principal part enlarged view which shows the front end side of the blade | wing with which the guide groove was recessedly provided. It is principal part BB sectional drawing of FIG. (A) And (B) is a reference figure which shows an experiment aspect. (A) is the figure which showed progress of the discharge at the time of the application of an alternating voltage, (B) is the figure which showed progress of the discharge at the time of applying an alternating voltage in the state which has a water droplet on an induction groove. It is. (A) is the figure which showed the progress of the discharge at the time of the application of an impulse voltage, (B) is the figure which showed the progress of the discharge when an impulse voltage is applied in the state where there is a water drop on the induction groove. It is. (A) is the figure which showed the relationship between the length of the induction groove from a sample edge part, and the discharge voltage measured when applying an alternating voltage, (B) has a water drop on an induction groove. It is the figure which showed the relationship between the length of the induction groove from a sample edge part, and the discharge voltage measured when an alternating voltage was applied in a state. (A) is the figure which showed the relationship between the length of the induction groove from a sample edge part, and the discharge voltage measured when the impulse voltage was applied, (B) has a water drop on an induction groove. It is the figure which showed the relationship between the length of the induction groove from a sample edge part, and the discharge voltage measured when the impulse voltage was applied in a state.

FIG. 1 is a front view showing a wind power generator, and FIG. 2 is an enlarged side view showing a main part of the wind power generator.
The wind turbine generator 1 includes a vertical support column 2, a nacelle 3 that includes a generator and is supported and fixed at the upper end of the support column 2, and a front / rear shaft that is rotatably supported by the nacelle 3 and directly connected to the generator. It is a windmill provided with the rotating shaft 4 of a direction, and the blade | wing 6 installed about the axis | shaft of the rotating shaft 4 for every predetermined pitch (every pitch in the example shown in figure).

  A plurality of (three in the illustrated example) blades 6 installed in the windmill are plate-like members that extend radially from the front-view rotation shaft 4 and receive the wind in the front-rear direction, thereby rotating the rotation shaft 4. Electric power is generated by rotating the shaft around its own axis and transmitting the rotational power of the rotating shaft 4 to the generator.

  The lightning arrester includes lightning receiving portions 7 provided on both front and back (front and back) both sides of the front end portion (end portion far from the rotation axis) of the blade 6 and a ground conductor (not shown) provided in the ground. And a conductive wire 8 connecting the lightning receiving part 7 and the ground conductor, and a guiding means for guiding a lightning current when a lightning strikes around the lightning receiving part 7 to the lightning receiving part 7, A lightning current (discharge current) when a lightning strikes the lightning portion 7 is transmitted to the ground conductor via a lightning conductor that is routed by the conductive wire 8 between the inside of the blade 6, the nacelle 3, and the support 2. Reach and escape to the ground.

  Further, the guiding means forms a convex portion by sticking a strip-shaped guiding tape 9 (guide sheet) that is deformed flexibly in the vicinity of the lightning receiving portion 7 on the outer surface side of the flat blade 6, and the convex portion It is comprised by the level | step-difference part 11 (step) formed along the boundary of the width direction edge part and the outer surface side of a blade | wing.

Next, the guiding means will be described based on FIG. 3 and FIG.
FIG. 3 is an enlarged view of a main part showing a tip side of a blade to which a guide tape is attached, and FIG. 4 is a cross-sectional view of the main part AA in FIG. The guide tape 9 is a sheet-like member whose both front and back surfaces are flat, and the guide tape 9 is affixed to the outer surface of the blade 6 which is a smooth flat surface or a curved surface having no unevenness. More specifically, a guide tape 9 is affixed from the midway part on the outer surface of the blade 6 toward the tip side where the lightning receiving part 7 is located. In the illustrated example, the guide tape 9 disposed closer to the base end than the lightning receiving portion 7 on the outer surface of the blade 6 extends to a position where the tip end side is close to the lightning receiving portion 7. Is extended in the direction toward the lightning receiving portion 7, the induction effect can be expected even if the distance between the lightning receiving portion 7 and the induction tape 9 is somewhat distant, and the induction tape 9 is in contact with the lightning receiving portion 7. It may be.

  By affixing the guide tape 9 to the outer surface side of the blade 6 along the longitudinal direction of the blade 6, the guide tape 9 is attached to the boundary between the widthwise end of the guide tape 9 and the outer surface side of the attached blade 6. The step portion 11 having a height difference corresponding to the thickness of the guide tape 9 is formed along the boundary. The step portions 11 are formed on both side ends in the width direction of the induction tape 9 and extend toward the lightning receiving portion 7, respectively, and serve as guiding means for guiding the lightning current to the lightning receiving portion 7. At this time, the height difference of the stepped portion 11, that is, the thickness of the guide tape 9 is desirably 100 micrometers or more.

  With the above configuration, when a lightning strike occurs in the vicinity of the lightning receiving portion 7 provided on the blade 6 and in the vicinity of the stepped portion 11, the lightning current due to the lightning strikes a step on both end sides in the width direction of the induction tape 9. The lightning current is guided to the light receiving portion 7 along the step portion 11. Thereby, since the lightning current which generate | occur | produced when the lightning strike to the blade | wing 6 is guided to the light receiving part 7, the damage by the lightning strike to the blade | wing 6 can be prevented.

  At this time, when water droplets accumulate along the stepped portion 11 due to thunderstorms or the like, the lightning current is more likely to propagate along the stepped portion 11, and the lightning current is efficiently guided to the lightning receiving portion 7. Will be able to.

  The inductive means with this configuration induces a lightning current by projecting a large number of segments made of conductors at regular intervals on a strip-shaped dielectric layer described in the prior art document 1, and generating a discharge between the segments. Unlike the method, the step portion 11 is formed on both end sides in the width direction of the guide tape 9 affixed to the blade 6, and portions other than the step portion 11 (specifically, the surface of the guide tape 9 and the outer surface of the blade 6 By flattening a portion other than the step portion 11, a lightning current when a lightning strike is made on the outer surface of the blade 6 can be guided to the lightning receiving portion 7 along the step portion 11. For this reason, the guiding means of the present invention can guide the lightning current to the lightning receiving portion 7 efficiently and at low cost with a simpler configuration.

  Therefore, since the induction tape 9 can exhibit the effect of inducing lightning current if the step portion 11 can be formed, the induction tape 9 can be made from a conductor such as a metal even if it is a non-conductor such as a masking tape. It may be a tape. Further, since the step portion 11 can be formed by applying the guide tape 9, the guide means can be easily provided on the blade 6 of the existing windmill, and the step portion 11 is formed by replacing the guide tape 9. Since it can be redone, maintenance is easy. Furthermore, since the effect of inducing the lightning current to the lightning receiving portion 7 can be exhibited simply by sticking a thin tape, the power generation efficiency of the wind turbine generator 1 is not affected.

  Further, a plurality of the induction tapes 9 attached to the outer surface of the blade 6 toward the lightning receiving portion 7 are provided radially around the lightning receiving portion 7 so that lightning current caused by lightning strikes the lightning receiving portion 7 in a wider range. You may comprise so that it can. The induction tape 9 is affixed to a position where it is directly connected to the lightning receiving portion 7, so that the lightning current can be more reliably guided to the lightning receiving portion 7, and the induction tape 9 Even if it is affixed discontinuously with a certain interval, it is possible to induce a lightning current when a lightning strikes on the surface of the blade 6 to the lightning receiver 7.

  Further, since lightning strikes to the wind turbine generator 1 are highly likely to strike near the tip of the blade 6, the guide tape 9 is stretched within a range of several meters from the lightning receiving portion 7 provided at the tip of the blade 6. A sufficient lightning protection effect can be obtained.

  Further, in the case of a large wind turbine having a lightning receiving portion 7 not only at the tip portion of the blade 6 but also at the intermediate portion, the guide tape 9 is applied radially from the lightning receiving portion 7 provided at the intermediate portion of the blade 6. By doing so, the range in which the lightning strike received by the blade 6 can be received by the lightning receiver 7 and escaped to the ground can be made wider.

  In the above-described example, the guide tape 9 is stuck on the flat outer surface of the blade 6 to form the convex portion extending toward the lightning receiving portion 7. The convex portion may be formed by affixing a linear guide thread instead of the strip-shaped guide tape, or by applying a paint to the flat outer surface of the blade 6. A convex portion may be formed.

Next, another example of the guiding means will be described with reference to FIGS.
FIG. 5 is an enlarged view of a main part showing the leading end side of a blade having a recessed guide groove, and FIG. 6 is a cross-sectional view of the main part BB in FIG. From the illustrated example, the guide groove 12 extending from the base end side to the power receiving unit 7 from the installation location of the lightning receiving portion 7 is formed on the outer surface of the blade 6 that is a smooth flat surface or curved surface that is not uneven and has no undulations. The step portion 11 is formed by being directly recessed, and the step portion 11 constitutes a dielectric means. Incidentally, the arrangement configuration of the guide groove 12 is the same as the arrangement configuration of the guide tape described above.

  With this configuration, when a lightning strike is made in the vicinity of the guide groove 12 recessed in the blade 6, a lightning current due to the lightning is guided to the guide groove 12 and guided to the lightning receiving portion 7 along the guide groove 12. In addition, since water droplets accumulate in the induction groove 12 due to a thunderstorm or the like, a lightning current can be induced more efficiently.

  Further, since the step portion 11 is formed by recessing the induction groove 12 directly on the surface of the blade 6, it is possible to provide lightning current induction means at a low cost and to perform maintenance frequently. Even if it is not, since the level | step-difference part 11 is maintained, a running cost can also be suppressed.

Next, based on FIGS. 7 to 11, an experiment was conducted to observe the difference in the progress direction of the discharge depending on the presence or absence of the induction groove.
FIG. 7 is a reference diagram showing the experimental mode. Specifically, as shown in FIGS. 7A and 7B, a single guide groove is provided from the end of a circular sample having a radius of 20 mm toward the center of the circle, and is arranged at the center of the circular sample. The discharge voltage was measured by applying an AC voltage or impulse voltage from the prepared electrode, and the progress of the discharge was observed. Here, the length (x) of the induction groove provided in the circular sample was 5 mm, 10 mm, 15 mm, and the peak value of the discharge voltage was measured when no groove was provided (0 mm).

  FIG. 8A is a diagram showing the progress of discharge when an AC voltage is applied, and FIG. 8B is the progress of discharge when an AC voltage is applied with water droplets on the induction groove. FIG. 9A is a diagram showing the progress of discharge when an impulse voltage is applied, and FIG. 9B is a diagram showing the impulse voltage with water droplets on the induction groove. It is the figure which showed progress of the discharge at the time of applying.

  From the figure, even when any voltage of AC voltage and impulse voltage is applied, the discharge from the electrode arranged at the center of the circular sample is guided from the electrode to the induction groove, and along the induction groove. The state of being guided to the end of the circular sample can be confirmed. Similarly, when there is a water drop on the induction groove, the discharge is guided to the induction groove and guided to the end of the circular sample.

  FIG. 10A is a diagram showing the relationship between the length of the induction groove from the end of the sample and the discharge voltage measured when an AC voltage is applied, and FIG. FIG. 6 is a diagram showing the relationship between the length of the induction groove from the end of the sample and the discharge voltage measured when an AC voltage is applied in a state where there are water droplets. FIG. 11A is a diagram showing the relationship between the length of the induction groove from the end of the sample and the discharge voltage measured when the impulse voltage is applied, and FIG. FIG. 6 is a diagram showing the relationship between the length of the induction groove from the sample end and the discharge voltage measured when an impulse voltage is applied in a state where there is a water droplet on the top.

  From the figure, when an AC voltage or impulse voltage is applied, a circular sample is not provided with an induction groove, and an induction groove is provided to induce discharge along the induction groove to the end of the circular sample. , It can be seen that the value of the measured discharge voltage is smaller when the guide groove is provided. In addition, it was confirmed that when the distance of the induction groove from the sample end is long, that is, as the distance between the electrode contact position and the induction groove is shorter, the measured discharge voltage value tends to be smaller.

  In addition, when AC voltage is applied or impulse voltage is applied, comparing the state where there are no water droplets in the induction groove with the state where there are water droplets in the induction groove, the case where there are water droplets in the induction groove is measured. It was confirmed that the value of the discharge voltage was small.

1 Wind power generator (windmill)
6 Blade 7 Lightning receiving part 9 Guiding tape (guidance sheet)
11 Steps (steps)
12 Guide groove

Claims (10)

  A lightning arresting method for a windmill in which a lightning current when lightning strikes on a blade (6) of a windmill (1) is guided to a lightning receiving part (7) side provided on the surface of the blade (6) by a guiding means. The guide means is formed by forming a step (11) on the flat outer surface of the blade (6) of the windmill (1) in the direction toward the lightning receiving portion (7), and the step (11) 6) A lightning arresting method for a windmill that guides the lightning current when a lightning strikes to the lightning receiving part (7) side.   The wind turbine lightning protection method according to claim 1, wherein water is stored in the step (11).   A windmill provided with a light-receiving section (7) on the blade (6) of the windmill, and provided with guiding means for guiding a lightning current when lightning strikes on the blade (6) of the windmill (1) to the lightning-receiving section (7) A band-shaped convex portion extending toward the lightning-receiving portion (7) is formed on the flat outer surface of the blade (6), and the widthwise end of the convex portion and the outside of the blade (6) A guide means is constituted by a step (11) formed along the boundary with the side surface, and the lightning current when lightning strikes on the blade (6) is guided to the light receiving part (7) side by the step (11). Windmill lightning arrester.   The guide sheet (9) is affixed to the flat outer surface of the blade (6) so that the strip-shaped guide sheet (9) that has a flat front and back surface and is deformed flexibly extends toward the lightning receiving portion (7). The lightning arrester of the windmill according to claim 3, wherein the convex portion is formed.   Wind turbine lightning arrester according to claim 4, wherein the induction sheet (9) is formed of a single layer.   The lightning arrester of a windmill in any one of Claim 4 or 5 which stuck the said guidance sheet | seat (9) on the blade | wing (6) so that attachment or detachment was possible.   The lightning arrester of the windmill of Claim 3 which formed the said convex part by apply | coating a coating material on the flat outer surface of a blade | wing (6) so that it may extend in strip shape toward the said lightning receiving part (7).   The lightning receiving part (7) is installed on the blade (6) of the windmill (1), and a guiding means for guiding a lightning current when a lightning strikes on the blade (6) of the windmill (1) to the lightning receiving part (7) A lightning arrester for a windmill provided, wherein a guide groove (12) extending toward the lightning receiving portion (7) is recessed in a flat outer surface of the windmill, and the step (11) of the guide groove (12) A lightning arrester for a windmill that constitutes guiding means and guides a lightning current when a lightning strikes the blade (6) to the lightning receiving part (7) side by the step (11).   The lightning arrester of the windmill according to any one of claims 3 to 8, wherein the power reception unit (7) is disposed at a tip end portion of the blade (6), and the step (11) is disposed at a base end side with respect to the power reception unit (7). apparatus.   The lightning arrester of a windmill according to any one of claims 3 to 9, wherein the step (11) is extended to the lightning receiving part (7) or the vicinity thereof.