JP2008101587A - Lightning protection device for windmill blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightning protection device for windmill blades facilitating maintenance such as repair or replacement of lightning receiving portions without using a vehicle for elevated-place work. <P>SOLUTION: The lightning protection device for the windmill blades has the lightning receiving portions 15 provided on the blades 12 of a windmill 10 and leads lightning current received at the lightning receiving portions 15 to a hub 11 through lightning conductors and further to the ground through a tower 14, wherein the lightning receiving portions 15 are detachably constructed at the tips of the blades 12 to be slung up and down with a sling member 16 and the lightning receiving portions 15 are constructed to be installed at predetermined places of the tips of the slung-up blades. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lightning protection device for a windmill blade, which is provided with a lightning power receiving unit on the windmill blade and guides a lightning current that has been lightened to the lightning power receiving unit to the ground via a lightning conductor. Further, the present invention relates to a lightning strike protection device for a windmill blade capable of maintaining a lightning power receiving unit.

  Even though the blades of windmills used in wind power generation facilities are made of non-conductive materials such as glass fiber reinforced plastic, lightning falls on the blades, and an arc caused by lightning strikes is formed in the blades Serious damage. Therefore, for lightning protection of wind turbine blades, it is necessary to guide the lightning current from the lightning strike point to the hub so as to avoid the formation of lightning arc inside the blade, and further to the ground via the tower. For this purpose, a metal lightning receiving part is provided on the surface of the blade, lightning strikes are concentrated on the lightning receiving part, and a lightning conductor is installed in the blade from the lightning receiving part to the hub.

  1 and 2 are diagrams showing a configuration example of a lightning power receiving unit of a conventional lightning protection device. The lightning strike protection device shown in FIG. 1 is provided with a metal block 103 in the tip of a windmill blade 101, and metal bolts 102 and 102 serving as a lightning power receiving unit are screwed into the metal block 103. A lightning conductor 104 is connected to the metal block 103. The lightning current that strikes the bolts 102 and 102 is led to the hub (not shown) through the lightning conductor 104 and further to the ground via the tower. 1A is a plan view of the blade tip, and FIG. 1B is a cross-sectional view taken along the line AA.

In a lightning protection structure in which a metal block 103 is provided in the tip portion of the blade 101 and metal bolts 102 and 102 serving as a lightning power receiving unit are screwed into the metal block 103, lightning strikes are not necessarily applied to the metal bolts 102 and 102. First, lightning strikes may occur at the tip of the other blade 101, particularly at the blade edge of the blade. This is because the blade of the blade 101 is generally acute and has a shape that is easy to strike. As a countermeasure against this, there is a lightning protection structure described in Patent Document 1. In this lightning protection structure, as shown in FIG. 2, the tip portion 105 of the wind turbine blade 101 is made of metal made of aluminum or an aluminum alloy, and this portion serves as a lightning power receiving portion. A lightning conductor 104 is connected to the metal tip 105. The lightning current that strikes the lightning power receiving unit 105 is led to the hub through the lightning conductor 104, and further to the ground via the tower. 2A is a plan view of the blade tip, and FIG. 2B is a side view of the blade tip.
JP 2005-113735 A

  Also in the lightning protection structure of the above-mentioned Patent Document 1, the metal blade tip member, which is a lightning power receiving unit, melts and deforms due to lightning strikes when used for a long time. In particular, when a lightning having high energy such as winter lightning strikes, the lightning power receiving part melts and deforms, and in the case of a bolt type lightning power receiving part, the bolt head disappears. If the lightning power receiving part is melted and deformed by lightning in this way, the function as the lightning power receiving part is lowered, or abnormal noise is generated during rotation of the windmill. Therefore, maintenance such as regular repair or replacement is indispensable. However, the bolt 102, which is a lightning power receiving unit provided at the tip of the blade 101 of the windmill, and the metal tip 105 of the blade 101 are several tens of meters above the ground. There is a problem that the operation is accompanied by a cost and the cost is high.

  The present invention has been made in view of the above points, and an object thereof is to provide a lightning strike protection device for a windmill blade that can easily perform maintenance such as repairing or replacing a lightning power receiving unit without using an aerial work vehicle. And

  In order to solve the above-mentioned problem, the invention according to claim 1 is provided with a lightning power receiving part on a blade of a windmill, the lightning current that has struck the lightning power receiving part is guided to a hub via a lightning conductor, and further to the ground surface via a tower. A lightning strike protection device for a windmill blade, wherein the lightning power receiving portion is configured to be detachable from a tip portion of the blade and can be lifted and lowered by a lifting member. It is configured to be able to be lifted and attached to a predetermined part of the blade tip.

  According to a second aspect of the present invention, in the lightning strike protection device for a wind turbine blade according to the first aspect, the lightning receiving portion constitutes a tip portion of the blade in a state of being attached to the tip of the blade. .

  According to a third aspect of the present invention, in the lightning strike protection device for a windmill blade according to the second aspect, a tapered concave portion is formed at a tip of the blade, and a tapered shape is inserted into the concave portion of the lightning receiving portion. It is characterized by forming the convex part.

  According to a fourth aspect of the present invention, in the lightning strike protection device for a windmill blade according to any one of the first to third aspects, a mounting force of the lightning power receiving unit to the tip of the blade is applied to the lightning power receiving unit. It is the tension of the connected lightning conductor.

  According to a fifth aspect of the present invention, in the wind turbine blade lightning protection device according to any one of the first to fourth aspects, the lifting member is connected to an end portion on the opposite side of the lightning receiving portion of the lightning conductor. It is characterized by comprising a wire or a rope made.

  According to the first aspect of the present invention, the lightning power receiving unit is configured to be detachable from the tip of the blade, and can be suspended by the lifting member, and the lightning power receiving unit is further provided at the predetermined end of the lifting blade. Since it can be attached to the site, the lightning power receiving part is lowered to the ground by its weight via the lifting member during maintenance, and after repairing or replacing on the ground (on the ground surface), the tip of the lifting blade is again Since the replacement and repair of the lightning power reception unit can be performed on the ground, maintenance such as replacement and repair of the lightning power reception unit can be easily performed without using an aerial work vehicle.

  According to the second aspect of the present invention, since the lightning receiving portion is configured at the tip of the blade while being attached to the tip of the blade, abnormal noise can be generated by making the lightning receiving portion the same shape as the plate tip. It does not occur and the appearance is improved.

  According to the invention described in claim 3, since the tapered concave portion is formed at the tip of the blade, and the tapered convex portion inserted into the concave portion is formed in the lightning power receiving portion, By lowering, the convex part of the lightning power receiving part can be easily detached from the concave part at the blade tip, and by lifting, the convex part of the lightning power receiving part can be inserted into the concave part of the blade and firmly attached.

  According to the fourth aspect of the present invention, since the mounting force of the lightning power receiving portion to the tip of the blade is the tension of the lightning conductor connected to the lightning power receiving portion, the anti-lightning power receiving portion of the lightning conductor is fixed. By applying tension to the lightning conductor, the lightning receiving part can be attached to the tip of the blade without providing any member for attaching the lightning power receiving part.

  According to the fifth aspect of the present invention, since the lifting member is a wire or rope connected to the lightning conductor and the opposite end of the lightning receiving portion of the lightning conductor, the already installed lightning conductor is lifted. It will be used as a part of the lowering member, and the attachment work of the lifting / lowering member to the lightning power receiving unit becomes easy.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a diagram showing a configuration example of a wind turbine facility equipped with a lightning strike protection device according to the present invention. As shown in the figure, the wind turbine 10 has a configuration in which a plurality of (for example, three) blades 12 are radially attached to a hub 11. The hub 11 is supported by a rotation shaft of a transmission (not shown) accommodated in the nacelle 13, and a generator (not shown) is rotated via the transmission when the windmill 10 is rotated. . The nacelle 13 is supported on the top of the tower 14 so as to be rotatable in the horizontal direction.

  Reference numeral 15 denotes a lightning power receiving unit that receives lightning. The lightning power receiving unit 15 constitutes the tip of the blade 12, and is configured to be detachable from the tip of the blade 12, as will be described in detail later. In a state where the rotor of the windmill 10 is locked and stopped at the time of maintenance, the lightning power receiving unit 15 can be lowered to the ground (surface) by its weight by the lifting and lowering member 16, and the maintenance is performed on the ground. It is lifted by a lifting / lowering member 16 and can be attached to the tip of the blade 12.

  FIG. 4 is a view showing a state in which the lightning power receiving unit 15 is attached to the tip of the blade 12. As shown in the figure, the lightning power reception unit 15 constitutes the tip of the blade 12 (the outer surface shape is configured to be the outer surface shape of the tip of the blade 12). The material of the lightning power receiving unit 15 is stainless steel, aluminum casting considering weight reduction, or the like. However, when a lightning having high energy such as winter lightning strikes as described above, in the case of a bolt-type lightning power receiving unit, the bolt head disappears. Therefore, in order to improve the durability of the lightning receiving unit 15, a spark plug technology is applied, and a metal having a melting temperature of about 1,500 ° C. or more such as platinum or iridium is plated on the surface of the metal base material of the lightning receiving unit 15. By performing the depositing process by welding, it is possible to prevent the surface of the lightning receiving unit 15 from being melted by a high-temperature arc during lightning strike. A tapered concave portion 17 is formed on the front end surface of the blade 12, and a tapered convex portion 18 inserted into the concave portion 17 is formed on a surface of the lightning power receiving unit 15 that contacts the front end surface of the blade 12. . One end of a lightning conductor 19 is connected to the center of the projection 18, and the other end of the lightning conductor 19 is connected to the engagement member 22 through the guide pipe 20.

  The engagement member 22 is coupled to one end of the tension gauge 26 via the engagement pin 25, and the other part of the tension gauge 26 is connected to the bolt member 21 b of the turnbuckle 21. The turnbuckle 21 includes a nut member 21a and two bolt members 21b and 21c that are screwed to both ends of the nut member 21a. When the nut member 21a is rotated in a predetermined direction, the bolt member 21b and the bolt member 21c When the nut member 21a is moved away from each other and the nut member 21a is rotated in the opposite direction, the bolt member 21b and the bolt member 21c are moved in directions approaching each other. The opposite end of the bolt member 21c to the nut member 21a is fixed to the support frame 24 at the rear end of the blade 12.

  As described above, the other end of the lightning conductor 19 is connected to the turnbuckle 21 via the tension gauge 26. By rotating the nut member 21a of the turnbuckle 21 in the direction in which the bolt member 21b and the bolt member 21c approach each other and tightening the turnbuckle 21, a strong tension is applied to the lightning conductor 19 via the tension gauge 26. The lightning power receiving unit 15 is prevented from being detached from the tip of the plate 12 due to centrifugal force when the windmill 10 rotates. If the lightning conductor 19 is used for a long period of time, the wind turbine 10 is operated, so that the lightning conductor 19 is loosened due to vibration, vibration, and tensile force due to centrifugal force. When the base portion of the lightning conductor 19 is subjected to repeated bending stress due to vibration or the like, the lightning conductor 19 may be cut. Therefore, by using the tension gauge 26 and the turnbuckle 21 in combination as described above, the turnbuckle 21 can be constantly applied with a constant tension while managing the tension applied to the lightning conductor 19 with the tension gauge periodically. The tension can be adjusted.

  A support frame 24 at the rear end of the blade 12 is attached to the hub 11. The lightning receiving unit 15 is electrically connected to one end of a mounting bolt 28 with the blade 12 via a lightning conductor 19 and a bypass lightning conductor 27 passing through the guide pipe 20, and further electrically connected to the hub 11 (here. The reason for using the bypass lightning conductor 27 is that when a large current flows through the engaging member 22, the engaging pin 25 and the tension gauge 26, an arc is generated at the fitting portion of the engaging pin 25 or the tension gauge 26. This is because a large current is directly led to the bolt 28 to which the blade 12 is attached through the bypass lightning conductor 27). The hub 11 is electrically connected to a grounding member (not shown) embedded in the ground via a lightning conductor (not shown) passing through the tower 14.

As a result, when there is a lightning strike in the lightning power receiving unit 15, the lightning current passes through the lightning conductor 19, the bypass lightning conductor 27, the bolt 28 to which the blade 12 is attached, the hub 11, and the lightning conductor passing through the tower 14. Led to. When a high current flows through the lightning conductor 19, the inside of the guide pipe 20 and the blade 12 covering the lightning conductor 19 is damaged due to the temperature rise of the conductor. Therefore, in order to reduce the temperature rise, the lightning conductor 19 and the bypass lightning conductor 27 use a 75 mm ² conductor thicker than the cross-sectional area (50 mm ² ) recommended by the IEC standard (the larger the temperature, the more advantageous it is). However, considering the increase in weight and ease of handling, the upper limit is about 100 mm ² ). In addition, the type of the lightning conductor 19 is a stainless steel wire in consideration of prevention of rusting and ease of handling.

  The concave portion 17 on the tip surface of the blade 12 and the convex portion 18 of the lightning power receiving unit 15 also have a positioning action for the lightning power receiving unit 15. That is, the surface of the plate 12 and the surface of the lightning power receiving part 15 are continuous with the convex part 18 of the lightning power receiving part 15 inserted in the concave part 17 of the blade 12 and the lightning power receiving part 15 mounted on the tip of the blade 12. Thus, the cross-sectional shape of the concave portion 17 and the convex portion 18 is formed in, for example, a square shape so as to exert a positioning action.

  Maintenance of the lightning power receiving unit 15 is performed according to the following procedure. The blade 12 that performs maintenance of the lightning power receiving unit 15 is leveled with respect to the ground surface and locked so that the rotor does not rotate. After the connection between the bypass lightning conductor 27 and the lightning conductor 19 is released, the engagement pin 25 is pulled out to release the coupling between the engagement member 22 and the tension gauge 26, and the other end of the lightning conductor 19 is then removed as shown in FIG. One end of a wire or rope 23 that is a part of the lifting member 16 is connected to the engaging member 22 to which is connected. After that, the blade 12 is made perpendicular to the ground surface and the rotor is locked again. Then, by drawing out the wire or rope 23, the lightning power receiving unit 15 is detached from the end face of the blade 12, and descends to the ground as shown in FIG. 3 due to its weight. Here, the blade 12 does not need to be strictly vertical, and about ± 5 degrees with respect to the vertical is allowed.

  In addition, the length of the wire or rope 23 needs to be long enough for the lightning power receiving unit 15 to reach the ground surface. As a result, it is possible to perform maintenance such as repairing the melted and deformed portion on the ground due to a lightning strike of the lightning power receiving unit 15 or replacing the lightning power receiving unit 15 with a new one.

  When the maintenance of the lightning power receiving unit 15 is finished, the lightning power receiving unit 15 is lifted by pulling up the wire or rope 23, and the tapered convex portion 18 is inserted into the tapered concave portion 17 on the end face of the blade 12. Next, the blade 21 is leveled with respect to the ground surface and locked so that the rotor does not rotate. Further, the engaging member 22 to which the other end of the lightning conductor 19 is connected is coupled to one end of the tension gauge 26 by the engaging pin 25. Thereafter, while confirming the tension applied to the lightning conductor 19 with the tension gauge 26, the nut member 21a of the turnbuckle 21 is rotated in the direction in which the bolt member 21b and the bolt member 21c approach each other, and the tension required for the lightning conductor 19 is tightened. And preventing the lightning power receiving unit 15 from being separated from the plate 12 by centrifugal force during the operation of the wind turbine 10, and at the same time, preventing the lightning conductor 19 from swinging. Finally, the bypass lightning conductor 27 is connected to the lightning conductor 19.

  In the above embodiment, the lightning power reception unit 15 is configured as the tip portion of the blade 12, but the lightning power reception unit may not be configured as the tip portion of the blade 12, for example, a lifting member 16 (wire or rope). 23 and the lightning conductor 19) are not required to be configured as a part of the blade 12 as long as they can be easily detached and attached to the surface of the front end portion of the blade 12 from the predetermined portion. Alternatively, the wire or rope 23 may be connected to the lightning power receiving unit 15 in parallel with the lightning conductor 19. Further, although the turnbuckle 21 is used as means for applying tension to the lightning conductor 19, the present invention is not limited to this.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible.

It is a figure which shows the example of the lightning strike protection apparatus provided with the conventional lightning power receiving part. It is a figure which shows the example of the lightning strike protection apparatus provided with the conventional lightning power receiving part. It is a figure which shows the structural example of the windmill equipment provided with the lightning strike protection apparatus which concerns on this invention. It is a figure which shows the structural example of the state with which the lightning power receiving part of the lightning strike protection apparatus which concerns on this invention was mounted | worn at the blade front-end | tip. It is a figure which shows the structural example of the state which the lightning receiving part of the lightning strike protection apparatus which concerns on this invention removed from the blade front-end | tip.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Windmill 11 Hub 12 Blade 13 Nacelle 14 Tower 15 Lightning receiving part 16 Lifting member 17 Concave part 18 Convex part 19 Lightning conductor 20 Guide pipe 21 Turnbuckle 22 Engaging member 23 Wire or rope 24 Support frame 25 Engaging pin 26 Tension gauge 27 Lightning conductor for bypass 28 Volts

Claims (5)

A lightning strike protection device for a windmill blade in which a lightning power receiving part is provided on the blade of the windmill, and the lightning current that has fallen on the lightning power receiving part is guided to the hub via a lightning conductor, and further to the ground via a tower,
The lightning power receiving part is configured to be detachable from the tip of the blade, can be lifted and lowered by a lifting member, and the lightning power receiving part can be lifted and attached to a predetermined part of the blade tip. A lightning protection device for windmill blades. The lightning strike protection device for windmill blades according to claim 1,
A lightning strike protection device for a windmill blade, wherein the lightning power receiving unit constitutes the tip of the blade in a state of being attached to the tip of the blade. The lightning strike protection device for a windmill blade according to claim 2,
A lightning strike protection device for a windmill blade, wherein a tapered concave portion is formed at a tip of the blade, and a tapered convex portion to be inserted into the concave portion is formed at the lightning receiving portion. The lightning strike protection device for a windmill blade according to any one of claims 1 to 3,
A lightning strike protection device for a windmill blade, wherein a mounting force of the lightning receiving unit to the tip of the blade is a tension of the lightning conductor connected to the lightning receiving unit. In the lightning strike protection device of the windmill blade according to any one of claims 1 to 4,
The lightning strike protection device for a windmill blade, wherein the lifting member is composed of the lightning conductor and a wire or a rope connected to an end of the lightning conductor opposite to the lightning receiving part.

Images