JP4595086B2 - Wind turbine generator having a lightning protection system for windmill blades - Google Patents

Description

  The present invention relates to a lightning protection system for a wind power generation device, and more particularly to a wind power generation device having a lightning protection system for reducing the effects of lightning strikes on a wind turbine blade.

  Since wind turbines in wind power generation facilities are installed high on flat land without obstacles, there is a high possibility of lightning strikes, and sufficient lightning protection measures are required. For example, in a large-scale wind power generation facility, a wind turbine hub having a height of 60 m and a wind turbine blade radius exceeding 30 m has been developed. Due to its shape and dimensions, it can be said that the structure has a very high probability of lightning strike when a thundercloud approaches in the vicinity.

  As lightning protection measures for conventional large wind power generation facilities, 1) a method of installing a lightning rod above the nacelle, and 2) a method of constructing a lightning protection tower near the wind turbine have been adopted. However, it has been pointed out that none of the methods is sufficient to prevent lightning strikes on the windmill blades. In other words, in the case of the method 1), it is difficult to ground a lightning rod having a height exceeding 30 m of the windmill blade radius to the top of the nacelle for structural and strength reasons. Is simply grounded. In the case of method 2), although not technically impossible, in order to protect all wind farms consisting of several to tens of windmills, it is necessary to construct lightning towers of the same number as windmills. It is not realistic in terms of profitability.

  3) When a lightning strike is applied to the windmill blade by attaching a receptor (lightning striker) or a lightning current conducting wire to the windmill blade, the lightning current is sent to the ground line in the windmill tower through the lightning current conducting wire and slip ring. There is also known a method for deriving (see Patent Document 1, for example).

  The lightning protection system for wind power generation described in Patent Document 1 will be described with reference to FIG. FIG. 3 is a cross-sectional view showing the entire structure of the wind power generation facility. 21 is a windmill tower, and a nacelle 22 is installed on the top. A rotor shaft 23 is rotatably supported by the nacelle 22, and the rotation of the windmill blade 24 installed outside the nacelle 22 is transmitted. A generator 25 is disposed inside the nacelle 22, and the rotation of the rotor shaft 23 is transmitted to the rotor to generate power. Further, power facilities such as a generator control device 26 and electronic equipment are installed in the nacelle 22. The electric power generated by the generator 25 is supplied to the outside through a power line 34 that passes through the inside of the wind turbine tower 21.

  The windmill blade 24 is made of aluminum, forms a low-resistance conductor, and has a metal tip 27 serving as a receptor (lightning receiver) at its tip. A discharge electrode 28 is provided at a proximal end portion of the windmill blade 24 adjacent to the nacelle 22. In the nacelle 22, the other discharge electrode 29 is disposed so as to face the discharge electrode 28 of the windmill blade 24. A gap 30 having an appropriate length is provided between the discharge electrode 28 and the discharge electrode 29. The discharge electrode 29 is connected to the slip ring 32 via a non-linear resistor 31 such as a zinc oxide element. The slip ring 32 makes an electrical connection to the ground line 33 via the mutually rotating locations of the nacelle 22 and the wind turbine tower 21. Grounding is performed from the grounding wire 33 through the grounding ring to the ground.

The lightning current flows from the metal tip 7 through the windmill blade 24, reaches the inside of the nacelle 22 by a sparkover (air discharge) between the discharge electrodes 28 and 29, and further passes through the non-linear resistor 31 to the slip ring 32. As a result, the inside of the nacelle 22 reaches the inside of the wind turbine tower 21, flows through the ground wire 33, and is discharged to the ground.
JP 2000-265938 A

  However, it has been pointed out that the lightning protection system in the above-mentioned conventional example is not always perfect in order to prevent dielectric breakdown accidents of power facilities and electronic equipment grounded inside the nacelle 22 and the windmill tower.

  As described above, in order to guide the lightning strike current from the windmill blade 24 to the windmill tower 21 side via the nacelle 22, between the windmill blade 24 and the nacelle 22 that rotate relative to each other, and between the nacelle 22 and the windmill tower 21. Must carry current between them. Therefore, the lightning current is guided through the inside of the nacelle and the inside of the wind turbine via the spark discharge gap and the slip ring. Therefore, the lightning stroke current path passes through the power line 34 and the electrical equipment in the nacelle and the wind turbine tower, and it is difficult to avoid the influence on the power equipment and the electronic equipment.

  In the present invention, when a windmill blade is subjected to a lightning stroke, a path for guiding a lightning current to the ground is configured without going through the nacelle and is structurally simple, and an electronic device housed in the nacelle An object of the present invention is to provide a wind turbine generator having a lightning protection system for windmill blades that can reliably prevent the influence of lightning strike current on the wind turbine blade.

  A wind turbine generator having a lightning arrester system for windmill blades according to the present invention relates to a windmill tower, a nacelle installed rotatably on the windmill tower, a generator installed in the nacelle, and a power generation function thereof An electronic device, a windmill supported by the nacelle, a rotation transmission mechanism for transmitting rotation of the windmill to the generator, and a power line for guiding the power generated by the generator to the outside through the inside of the windmill tower With.

  In order to solve the above problems, as a lightning arresting system for the windmill blade, a receptor and a lightning current conducting wire provided on the blade of the windmill, and the windmill via an insulator concentrically with the rotating shaft of the windmill. A windmill side ring electrode fixed and connected to the lightning current conducting wire, and fixed to the windmill tower via an insulator concentrically with the rotation axis of the nacelle, and in part, the windmill side ring electrode and the gap Between the windmill side ring electrode and the tower side ring electrode, the tower side ring electrode facing each other, and a ground wire connected to the tower side ring electrode and installed along the wall surface of the windmill tower. The gap is set in a range where an air discharge can be generated by a lightning strike on the receptor.

  According to the wind turbine generator having the above-described configuration, the lightning current passes from the receptor through the lightning current conductive line, and passes through the gap between the windmill side ring electrode and the windmill side ring electrode by sparkover (air discharge), so that the tower side ring electrode Is discharged to the ground through the ground wire outside the windmill tower. Therefore, the lightning strike current is directly guided from the windmill to the windmill tower without passing through the nacelle. Therefore, the lightning protection system is structurally simplified, and the influence of the lightning strike current on the electronic device accommodated in the nacelle can be reliably prevented.

  Furthermore, since all the lightning strike currents flow outside the windmill tower, the risk that the electronic device will cause a dielectric breakdown accident through the power line inside the windmill tower is reduced.

  In the wind turbine generator according to the present invention, preferably, the gap between the windmill side ring electrode and the tower side ring electrode is such that the windmill side ring electrode and the tower side ring electrode are in rotation when the nacelle and the windmill are rotated. The range is set so that they do not touch each other.

  Preferably, the gap between the windmill side ring electrode and the tower side ring electrode is set within a range of 10 cm to 100 cm.

  Hereinafter, a wind power generator according to an embodiment of the present invention will be specifically described with reference to the drawings. FIG. 1 is a perspective view showing the overall structure of the wind turbine generator, and FIG. 2 is a front view showing the main part thereof. However, only the portion of the nacelle 2 is shown in cross section.

  A nacelle 2 is rotatably installed above the windmill tower 1. The rotation axis 3 of the nacelle 2 is vertical, so the nacelle 2 rotates in a horizontal plane. A windmill 4 is supported adjacent to the nacelle 2. The windmill 4 has a horizontal rotation shaft 5, and therefore the blade 6 provided on the windmill 4 rotates in a vertical plane. The rotating shaft 3 of the nacelle 2 and the rotating shaft 5 of the windmill 4 are orthogonal. However, it is not essential that the rotating shaft 3 of the nacelle 2 and the rotating shaft 5 of the windmill 4 are orthogonal.

  As shown in FIG. 2, the nacelle 2 is provided with a generator 7 and a rotation transmission unit 8 for transmitting the rotation of the windmill 4 to the generator 7. A power line 9 is attached from the generator 7 through the inside of the nacelle 2 and the windmill tower 1, and is used to guide the generated power to the outside of the windmill tower 1. Further, inside the nacelle 2 and the windmill tower 1, a generator control device 10, other electric power equipment, electronic equipment, and the like are arranged as necessary.

  Next, a lightning protection system for the blade 6 of the windmill 4 in this wind power generator will be described. A receptor 11 is provided at the tip of the blade 6 of the windmill 4 (see FIG. 1). A windmill side ring electrode 12 is installed on the main body of the windmill 4 adjacent to the base end of the blade 6. The windmill side ring electrode 12 is connected to the receptor 11 by a lightning current conductive wire 13. The windmill side ring electrode 12 is fixed to the windmill 4 via an insulating member 14 concentrically with the rotating shaft 5 of the windmill 4. A tower-side ring electrode 15 is provided at the upper end of the windmill tower 1 so as to be close to the windmill-side ring electrode 12. The tower side ring electrode 15 is fixed concentrically with the rotating shaft 3 of the nacelle 2 via an insulating member 16. A ground line 17 is connected to the tower side ring electrode 15. The ground wire 17 is supported by an insulating member 18 along the wall surface of the wind turbine tower 1.

  The windmill-side ring electrode 12 and the tower-side ring electrode 15 are opposed to each other at a part of the circumference of the windmill-side ring electrode 12 and are arranged with a gap 19 set to a predetermined length between them. Since the windmill side ring electrode 12 is concentric with the rotating shaft 5 of the windmill 4 and the tower side ring electrode 15 is concentric with the rotating shaft 3 of the nacelle 2, one or both of the windmill 4 and the nacelle 2 are rotating. Even in the state, the gap 19 between the two is kept constant.

  The gap length between the windmill-side ring electrode 12 and the tower-side ring electrode 15 is short enough to cause a spark over (air discharge) in the gap 19 due to a lightning strike to the receptor 11 due to the lightning strike current. Is set to Although the gap length that can be specifically applied varies depending on the dimensions and arrangement conditions of each part, it is desirable that the gap length be in the range of 10 cm to 100 cm in normal practical use. If it is 100 cm or less, the windmill side ring electrode 12 and the tower side ring electrode 15 are sufficiently close to each other, and a sparkover is surely generated during a lightning strike. Moreover, if it is 10 cm or more, the state which does not contact each other and the rotation of the braid | blade 6 and the rotation of the nacelle 2 can be ensured.

  In the above configuration, when a lightning strike occurs at the tip of the windmill blade 6, the lightning strike current (in the case of positive lightning) passes from the receptor 11 through the lightning current conductive line 13 and reaches the windmill side ring electrode 12. In the gap 19 between the windmill-side ring electrode 12 and the tower-side ring electrode 15, sparkover (air discharge) easily occurs due to a potential increase due to lightning strike. Therefore, the lightning strike current is promptly guided to the tower side ring electrode 15. Thereafter, the light is guided from the tower-side ring electrode 15 through the ground wire 17 outside the wind turbine tower to the ground electrode sufficiently separated from the foundation of the wind turbine tower 1.

  As described above, the lightning strike current is directly guided from the windmill 4 to the windmill tower 1 side. That is, as shown in the conventional example of FIG. 3, it is compared with the path from the windmill blade 24 to the inside of the nacelle 22 by the spark over via the discharge electrodes 28 and 29, and further to the ground line 33 via the slip ring 32. Then, there is no path portion passing through the nacelle 22. Therefore, the structure is simplified and the influence on the electronic device accommodated in the nacelle 2 can be surely prevented.

  Furthermore, since all lightning currents flow outside the windmill tower 1 and no lightning current flows inside the nacelle 2 and the windmill tower, there is a risk that the power equipment and electronic equipment inside the windmill tower 1 will cause an insulation breakdown accident. Extremely reduced.

  In the lightning arrester system for wind turbine blades of the present invention, the path for guiding the lightning current to the ground is configured without going through the nacelle, and is structurally simple, and the influence of the lightning current on the electronic devices inside the nacelle is ensured. This is useful for ensuring the safety of the operation of the wind turbine generator.

The perspective view which shows the wind power generator which has the lightning arrester system for windmill blades in embodiment of this invention Front view showing the main part of the wind turbine generator Sectional drawing which shows the wind power generator which has a lightning protection system for windmill blades of a prior art example

Explanation of symbols

1, 2 1 Windmill tower 2, 22 Nacelle 3, 5 Rotating shaft 4 Windmill 6, 24 Blade 7, 25 Generator 8 Rotation transmission unit 9, 34 Power line 10, 26 Generator control device 11 Receptor 12 Windmill side ring electrode 13 Lightning current Conductive wires 14, 16, 18 Insulating member 15 Tower side ring electrodes 17, 33 Ground wire 19 Gap 23 Rotor shaft 27 Metal tip 28, 29 Discharge electrode 30 Gap 31 Non-linear resistor 32 Slip ring

Claims (3)

A windmill tower, a nacelle rotatably installed at the top of the windmill tower, a generator installed in the nacelle and an electronic device related to the power generation function, a windmill supported by the nacelle, and the windmill In a wind turbine generator comprising a rotation transmission mechanism for transmitting rotation to the generator, and a power line for guiding the power generated by the generator to the outside through the inside of the windmill tower,
As a lightning protection system for the windmill blade,
A receptor and a lightning current conducting wire provided on the blade of the windmill;
A windmill-side ring electrode fixed to the windmill via an insulator concentrically with the rotating shaft of the windmill, and connected to the lightning current conductive line;
A tower-side ring electrode fixed to the windmill tower through an insulator concentrically with the rotation axis of the nacelle, and facing a part of the windmill-side ring electrode via a gap,
A ground wire installed along the wall surface of the wind turbine tower and connected to the tower-side ring electrode;
The gap between the windmill side ring electrode and the tower side ring electrode is set in a range in which an air discharge can be generated by a lightning strike on the receptor. Power generation device.   The gap between the windmill side ring electrode and the tower side ring electrode is set in a range in which the windmill side ring electrode and the tower side ring electrode do not contact each other when the nacelle and the windmill rotate. A wind turbine generator having the lightning protection system for windmill blades according to Item 1. The wind turbine generator having a lightning arrester system for wind turbine blades according to claim 1, wherein the gap between the wind turbine ring electrode and the tower ring electrode is 10 cm to 100 cm.

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