JP2007077889A - Wind power generation device and wind power generation facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wind power generation device capable of improving lightning resistance by surely transmitting lightning current to a discharge channel from a blade to the ground, and a wind power generation facility provided with the wind power generation device. <P>SOLUTION: In the wind power generation facility 1, a first knit base conductor 27 is arranged to cover roughly upper half of a shaft 21 under a contact condition in electrical connection of a shaft 21 and a frame 13 of the wind power generation, with considering that lightning current is high frequency current reaching several KHz and that such high frequency current has high surface effect. Consequently, contact area of a surface of the shaft 21 and a first knit base conductor 27 is sufficiently secured, and impedance against lightning current having surface effect can be greatly reduced. Consequently, lightning current transmitting to the shaft 21 from the blade 9 surely passes through the frame 13 and lightning resistance can be improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wind power generator and a wind power generation facility using the wind power generator.

  In recent years, the momentum for effectively using natural energy has increased, and the development of wind power generators that generate power using wind power has been actively promoted. Such a wind power generator includes a blade (rotary blade) that rotates by receiving wind force, a shaft that transmits the rotation of the blade, a generator that generates power using the rotation of the shaft, a nacelle that houses the generator, and the like. It is configured with. And a wind power generator is installed in the top part of the tower structure standingly installed in the coastal part or the mountain top in order to receive strong wind force with a braid | blade regularly.

  On the other hand, coastal areas and mountain tops where wind power generators are installed are easy to obtain wind power, but are also places where lightning frequently occurs, and places where lightning strikes are likely to occur. In addition, lightning generated in such places often has a large amount of energy, and if lightning with a large amount of lightning strikes a wind turbine generator, there is a risk of damage to major equipment such as blades and generators. . For this reason, in wind turbine generators, lightning strike countermeasures for protecting major equipment such as generators from damage due to lightning strikes are an important issue.

Therefore, as a wind power generation apparatus that has taken measures against lightning strike, for example, Patent Document 1 discloses a bearing for a wind power generator in which a shaft and a nacelle are connected via a conductive roller. In the configuration of this conventional bearing for a wind power generator, the shaft and the nacelle are electrically connected to form a path for discharging the current (thunder current) generated by the lightning strike from the blade to the ground, Ensuring lightning resistance performance of wind power generators.
JP 2005-151749 A

  By the way, the lightning current generated by the lightning strike is a high-frequency current reaching several MHz, and has a characteristic of flowing only on the surface of the conductor due to the skin effect, so that the shaft and the nacelle are collided like the conventional wind power generator described above. In the case of connecting with the like, since the contact area between the shaft and the roller is small, it is difficult to sufficiently reduce the impedance of the discharge path from the shaft to the nacelle. For this reason, when a lightning with a large energy strikes the blade, such as a winter thunder on the Sea of Japan side, the lightning current could not flow quickly into the ground, possibly damaging these devices.

  The present invention has been made to solve the above-described problems. A wind power generator capable of improving lightning resistance performance by reliably transmitting a lightning current to a discharge path from a blade to the ground, and the wind power generator. It aims at providing the wind power generation equipment provided with the electric power generating apparatus.

  In order to solve the above problems, a wind turbine generator according to the present invention includes a blade that rotates by receiving wind force, a nacelle in which a generator is accommodated in a conductive outer body, and a blade and the generator. A shaft that is connected and transmits the rotational force of the blade to the generator, and a first braided conductor that covers the shaft in contact with the shaft and electrically connects the shaft and the outer body are provided.

  In this wind power generator, the shaft and the outer shell of the nacelle are electrically connected by the first braided conductor. This braided conductor is formed by weaving thin conductive wires into a mesh shape, and is a highly flexible member. And in this wind power generator, paying attention to having a skin effect with high lightning current, the 1st braid conductor is arranged so that a shaft may be covered in contact. In this way, as a result of covering the shaft with the highly flexible first braided conductor, a sufficient contact area between the surface of the shaft and the first braided conductor is secured, and a lightning current having a skin effect The impedance with respect to can be sufficiently reduced. Therefore, when there is a lightning strike on the blade, the lightning current transmitted from the blade to the shaft can be reliably passed through the ground through the outer shell of the nacelle, and transmission of the lightning current to the main equipment such as the generator can be suppressed. . Thereby, the lightning resistance performance of a wind power generator can be improved.

  Moreover, the wind power generation facility according to the present invention includes the above-described wind power generation device mounted on the top of the tower structure, and includes a conductive portion that extends from the ground to the top of the tower structure. Are electrically connected.

  In this wind power generation facility, the adoption of the wind power generation apparatus ensures that the lightning current transmitted from the blade to the shaft flows to the outer shell of the nacelle. Further, in this wind power generation facility, a conductive portion extending from the ground to the top of the tower structure is provided, and the outer body of the nacelle and the conductive portion provided in the tower structure are electrically connected. Yes. Thereby, the lightning current transmitted to the conductive portion is surely discharged into the ground.

  The nacelle is provided on a stage that can rotate around the vertical axis at the top of the tower structure, and the conductive portion and the outer body are electrically connected by the second braided conductor, The braided conductor is preferably formed in a rope shape and has a bend between the outer body and the conductive portion.

  According to this configuration, the lightning current transmitted to the outer body of the nacelle can surely flow to the conductive portion by the second braided conductor, and the lightning resistance can be improved. Further, the nacelle may be placed on a stage that can rotate around the vertical axis at the top of the tower structure so that the direction of the blade can be changed in accordance with the wind direction. In this case, the second braided conductor is formed in a rope shape and is bent, thereby maintaining the reliability of the connection between the outer body of the nacelle and the conductive portion of the tower structure, and by rotating the nacelle. The load on the second braid conductor can be suppressed.

  As described above, according to the wind power generator and the wind power generation facility according to the present invention, the lightning resistance can be improved by reliably transmitting the lightning current to the discharge path from the blade to the ground.

  Hereinafter, preferred embodiments of a wind turbine generator and a wind turbine facility according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a side view showing an embodiment of a wind power generation facility according to the present invention. As shown in FIG. 1, the wind power generation facility 1 is a facility installed in a windy region such as a coastal area or a mountain top, and is made of concrete erected on a base 2 provided on the ground surface G. The tower structure 3 is provided.

  The tower structure 3 has a cylindrical shape that is reduced in diameter as the altitude increases, and a plurality of (for example, four) tower wall reinforcements 4 extending in the vertical direction are arranged inside the tower structure 3. Yes. The tower wall reinforcement 4 increases the strength of the tower structure 3 and has a function as a conductive part 7 extending from the ground to the top 6 of the tower structure 3. And the lower end part of the tower wall reinforcement 4 is connected to the slab reinforcement (not shown) of the base 2, and is grounded by using the base 2 as a ground electrode. A wind power generator 8 that generates power using wind power is installed at the top 6 of the tower structure 3. As shown in FIG. 2, the wind power generator 8 includes a blade 9 and a nacelle 10.

  The blade 9 has a metal rotary head 11 and three blades 12. The blades 12 are formed of an insulating resin such as FRP (Fiber Reinforced Plastic), for example, and are attached around the rotary head 11 at equal intervals. The blade 9 rotates about the rotary head 11 when the wind speed received by each blade 12 is about 3 m or more per second. Further, when the wind speed is about 20 m or more per second, control is performed so that the rotation is stopped by a brake mechanism (not shown), and damage to the blades 12 due to excessive rotation is prevented.

  The nacelle 10 has a metal outer body 16 in which a streamlined casing 14 is placed on a gantry 13, and a generator 17 is accommodated inside the casing 14. Between the generator 17 and the rotary head 11 of the blade 9, for example, in order from the blade 9 side, a metal shaft 21, a low-speed shaft coupling 18, a connection shaft 25 A, a speed increasing device 19, a connection shaft 25 B, a high speed The shaft coupling 20 and the connection shaft 25C are connected. With such a configuration, the rotational force of the blade 9 rotated by wind power is increased to about 1000 revolutions per minute and transmitted to the generator 17, and the generator 17 generates power using this rotational force.

  Further, such a nacelle 10 is provided on a stage 22 that is rotatable around the vertical axis in a range of 180 ° in both directions at the top of the tower structure 3. The rotation of the stage 22 is adjusted based on the wind direction observed by a wind direction observation meter (not shown) provided in the upper rear part of the nacelle 10. That is, the rotation of the stage 22 is adjusted so that the direction of the nacelle 10 matches the wind direction observed by the wind direction observation meter. Thereby, even if the wind direction around the wind power generation facility 1 changes every moment, the blade 9 can receive wind force constantly.

  By the way, wind power generation facilities such as those described above are often installed on windy coastal areas or mountain tops for the purpose of enabling the steady supply of electric power. However, such coastal areas and mountain tops are easy to obtain wind power, but are also places where lightning frequently occurs, and places where lightning strikes are likely to occur. In addition, lightning generated in such places often has large energy, and when lightning with large energy strikes a wind power generator, there is a risk of damage to major equipment such as blades and generators. . For this reason, in wind power generation facilities, it is an important issue to improve the lightning resistance by forming a discharge path for reliably discharging the current (lightning current) generated by lightning strikes into the ground.

  Regarding the formation of this discharge path, in the wind power generation facility 1 in this embodiment, as shown in FIGS. 1 and 2, first, a lightning rod 24 made of copper is provided at the tip of each blade 12 in the blade 9. In addition, a metal mesh 26 electrically connected to the lightning rod 24 is provided on the main body portion of each blade 12. The metal mesh 26 of each blade 12 is electrically connected to the metal rotary head 11.

  The shaft 21 and the gantry 13 are electrically connected by a first braid conductor 27. As shown in FIG. 3, the first braided conductor 27 is formed into a strip shape having a width of about 50 mm to about 100 mm by knitting a thin conductive wire having a diameter of about 0.1 mm into a mesh shape. It has conductivity. At both ends in the longitudinal direction of the first braid conductor 27, metal attachment plates 28 are respectively provided. Then, as shown in FIG. 4, the first braid conductor 27 is disposed on the front side of the low-speed shaft coupling 18 so as to cover the substantially upper half of the shaft 21 in a contact state, and each mounting plate 28 is The bolts are fixed to the gantry 13 on both sides of the shaft 21. Note that the low-speed shaft coupling 18, the speed increaser 19, and the high-speed shaft coupling 20 are also connected to the gantry 13 by equipotential bonding (see FIG. 2).

  Further, the gantry 13 and the conductive portion 7 of the tower structure 3 are electrically connected before and after the nacelle 10 by two second braided conductors 29 as shown in FIGS. 2 and 5. . The second braided conductor 29 is formed in a rope shape with the same mesh-like conductive wire as the first braided conductor 27. The second braided conductor 29 is bolted to the lower surface side of the gantry 13 and the base of the stage 22 in a state where the intermediate portion is sufficiently bent, and is electrically connected to the conductive portion 7 via the stage 22. Connected.

  By forming such a discharge path, in the wind power generation facility 1, when a lightning strike occurs on the lightning rod 24 or the metal mesh 26 of the blade 9, a lightning current due to the lightning strikes from the lightning rod 24 or the metal mesh 26 of the blade 12 through the rotary head 11. And flows to the shaft 21. Next, the lightning current that has flowed to the shaft 21 flows to the gantry 13 through the first braided conductor 27. At this time, the lightning current that has not been able to flow through the first braided conductor 27 flows to the gantry 13 sequentially through the bonding of the low-speed shaft coupling 18, the speed increaser 19, and the high-speed shaft coupling 20. Then, the lightning current that has flowed to the gantry 13 flows to the tower wall reinforcement 4 through the second braided conductor 29 and is discharged from the lower end of the tower wall reinforcement 4 to the ground.

  In the discharge path of the wind power generation facility 1, paying attention to the fact that the lightning current is a high-frequency current reaching several MHz, and such a high-frequency current has a high skin effect, as described above, the shaft 21 The first braided conductor 27 is disposed so as to cover substantially the upper half of the shaft 21 in the state of contact with each other in electrical connection with the gantry 13. As described above, as a result of covering the shaft with the flexible first braided conductor, the contact area between the surface of the shaft 21 and the first braided conductor 27 is sufficiently secured, and the skin effect is high. Impedance against lightning current can be greatly reduced. As a result, the lightning current transmitted from the blade 9 to the shaft 21 surely flows to the gantry 13, and the lightning current can be quickly discharged into the ground. Therefore, in the wind power generation facility 1, even when a lightning having a large energy strikes the blade 9 or the metal mesh 26 as in the winter lightning on the Sea of Japan side, the connection portion between the shaft 21 and the gantry 13 is discharged. The bottleneck of the path is suppressed, and main devices such as the blade 9 and the generator 17 can be reliably protected.

  Further, in the discharge path of the wind power generation facility 1, the gantry 13 and the tower wall reinforcement 4 are electrically connected by a rope-like second braid conductor 29. The lightning current transmitted to the gantry 13 surely flows to the tower wall reinforcement 4 by the second braid conductor 29, so that the lightning resistance can be further improved. In addition, the second braided conductor 29 is bent between the gantry 13 and the tower wall reinforcement 4. With such a configuration, even when the direction of the nacelle 10 is adjusted on the stage 22, the second due to the rotation of the nacelle 10 while maintaining the reliability of the connection between the gantry 13 and the tower wall reinforcement 4. Generation of an excessive load on the braided conductor 29 can be suppressed.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the metal mesh 26 is formed on each blade 12 as a discharge path from the lightning rod 24 to the rotary head 11, but instead of this metal mesh 26, a metal net is put on each blade 12. Alternatively, a conductive paint or a conductive seal may be applied in a mesh shape or a line shape.

  Further, it is preferable to apply conductive grease to the contact portion between the shaft 21 and the first braid conductor 27. Thereby, the friction between the shaft 21 and the first braid conductor 27 can be reduced. Further, from the same viewpoint, a means for detecting the electric field of the thundercloud and a switching means for switching contact / non-contact of the first braid conductor 27 with respect to the shaft 21 are provided, for example, only when the approach of the thundercloud is detected. One braided conductor 27 may be placed on the shaft 21.

  The tower wall reinforcement 4 as the conductive portion 7 is preferably arranged in a circular shape in consideration of the skin effect of lightning current. Instead of the tower wall reinforcement 4, the tower structure 3 may be assembled with metal columns, and the entire tower structure 3 may be used as the conductive portion 7. Furthermore, a pile foundation (not shown) may be used for the grounding electrode of the conductive portion 7 instead of a so-called solid foundation using slab reinforcement. Generally, when a pile foundation is used as a ground electrode, the ground resistance is smaller than when a solid foundation is used as a ground electrode, and lightning current can be discharged more reliably into the ground.

It is a side view which shows one Embodiment of the wind power generation equipment which concerns on this invention. It is a side view which shows the wind power generator mounted in the wind power generation equipment shown in FIG. It is a top view showing the 1st braid conductor. It is the IV-IV sectional view taken on the line in FIG. It is a figure which shows the attachment state of a 2nd braided conductor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wind power generation equipment, 3 ... Tower structure, 4 ... Tower wall reinforcement (conductive part), 6 ... Top part, 7 ... Conductive part, 8 ... Wind power generator, 9 ... Blade, 10 ... Nacelle, 13 ... Mount ( (Outer body), 14 ... casing (outer body), 16 ... outer body, 17 ... generator, 22 ... stage, 27 ... first braid conductor, 29 ... second braid conductor, G ... ground surface.

Claims (3)

A blade that rotates in response to wind,
A nacelle in which a generator is housed inside a conductive enclosure;
A shaft connected between the blade and the generator and transmitting the rotational force of the blade to the generator;
A wind turbine generator comprising: a first braided conductor that covers the shaft in contact with the shaft and electrically connects the shaft and the outer body. The wind turbine generator according to claim 1 is placed on the top of the tower structure.
A conductive portion extending from the ground to the top of the tower structure;
The wind power generation facility, wherein the outer body and the conductive portion are electrically connected. The nacelle is provided on a stage rotatable around a vertical axis at the top of the tower structure,
The conductive portion and the outer body are electrically connected by a second braided conductor,
3. The wind power generation facility according to claim 2, wherein the second braided conductor is formed in a rope shape and has a bend between the outer body and the conductive portion.

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