Claims:We Claim:

1. A beacon light (12, 12a) for a building (1) having a light source (16) and a moveable aperture (13) for illuminating a sector (14) of a de-tected flying object (15).

2. The beacon light according to claim 1, characterized in that the ap-erture (13) can be opened or closed for extending or reducing the il-luminated sector (14).

3. The beacon light according to claim 1 or 2, characterized in that the aperture (13) is high-adjustable and/or side-adjustable.

4. The beacon light according to one of the claims 1 to 3, character-ized in that the aperture (13) is provided by one or a plurality of moveable lamellae (17) or mirrors (17).

5. The beacon light according to one of the claims 1 to 4, character-ized in that the lamellae (17) or mirrors (17) overlaps each other.

6. The beacon light according to one of the claims 1 to 5, character-ized in that the lamellae (17) or mirrors (17) are concave shaped.

7. The beacon light according to one of the claims 1 to 6, character-ized in that the lamellae (17) or mirrors (17) are arranged in circum-ference around the light source (16).

8. The beacon light according to one of the preceding claims, charac-terized by a drive arrangement (19) for driving the lamellae (17) or mirrors (17).

9. A beacon light arrangement (23) for a building (1) comprises:
- one or more beacon lights (12a) according to one of the claims 1 to 8,
- a detection device (21a) for detecting a flying object (15) and for determining position data of the flying object (15) and
- a control device (22a) for controlling the one or more beacon lights (12a) depending from an control signal.

10. The beacon light arrangement according to claim 9, characterized in that the control device (22a) receives position data from the detec-tion device (21a).

11. The beacon light arrangement according to claim 9 or 10, character-ized in that the control device (22a) is connected with the drive ar-rangement (19) of the beacon light (12a).

12. The beacon light arrangement according to one of the claims 9 to 11, characterized in that the detection device (21a) is a radar system or a communication element for receiving position data from the pilot of the flying object (15).

13. The beacon light arrangement according to one of the claims 9 to 12, characterized in that the control signal is generated by position data determined by the detection device (21a).

14. The beacon light arrangement according to one of the claims 9 to 13, characterized in that the position data are chosen from declination and azimuth position of the flying object (15).

15. A method for a directed illumination of a sector (14) from a building (1) comprising the steps of:
- providing a beacon light (12, 12a) according to one of the claims 1 to 8 or a beacon light arrangement (23) according to one of the claims 9 to 14,
- detecting a flying object (15),
- determining position data of the flying object (15),
- illuminating the sector (14) in located direction of the flying ob-ject (15) via one or more beacon lights (12, 12a),
- therefor moving the aperture (13) of the one or more beacon lights (12, 12a) according to the determined position data.

16. A building characterized by a one or more beacon lights (12, 12a) according to one of the claims 1 to 8 or a beacon light arrangement (23) according to one of the claims 9 to 14 or a configuration to pro-cedure the method according to claim 15.
, Description:FIELD OF INVENTION

The present invention is directed to a beacon light for a wind turbine, a beacon light arrangement for a wind turbine and a method for a directing illumination of a sector from a wind turbine.

BACKGROUND

Because of law requirements buildings, especially wind turbines, must have a beacon light, also called as obstacle light or aviation light, for warning flying objects. For a night-time illumination this is realized by a bright red light, which especially is active at night. This bright red light, which should have a luminous intensity around 2000 cd (candela), can be seen from a whole sector around the wind turbine, especially from the ground. For a day-time illumination the beacon light is realized as a white light, which can have a luminous intensity up to 20000cd. In result, around such a wind turbine existing a high light pollution, which is not accepted by the residents.

For increasing the acceptance of the wind turbine by the people the light pollution has to be reduced. Some solutions for reducing the light pollution provide a detection device for detecting a flying object. Is a flying object detected the beacon light will be activate and when the flying object has passed than the beacon light will be deactivate. A disadvantage of this solution is that the beacon light can still be seen from the ground by the residents.

OBJECT OF THE INVENTION

One object of the invention is to provide a beacon light which allows an illumination of a sector in which a flying object is detected.

SUMMARY OF THE INVENTION

One aspect of the invention is directed to a beacon light for a building like a wind turbine having a light source and a moveable aperture for illuminating a sector of a detected flying object. One benefit is that the aperture is configured for directing illumination of a sector of a flying object. Thus, depending on the height of the flying object the light is at least viewable for a short time, namely the time the flying object needs to pass the wind turbine(s), respectively the light is not be viewable from the ground. Further the light impact for birds and other animals are reduced. The acceptance of the wind turbine is increased. It should be pointed out that the phrase illuminating a sector, illuminated sector and the same means in this context that a light of a beacon light can be recognized. It should be pointed out that in view of the present invention the term aperture means the free opening or diameter through which light travels. In photography the aperture is adjusted by an aperture diaphragm.

In a preferred embodiment, the aperture can be opened or closed for ex-tending or reducing the illuminated sector. Advantageously this allows an illumination of the whole or at least most of the surrounding of the flying object.

In a further preferred embodiment, the aperture is adjustable declination and/or adjustable azimuth. Advantageously this allows a declination ad-justment and/or azimuth adjustment of the illuminated sector in direction of the flying object. Further this configuration allows a following of the flying object. So it is ensured that the pilot knows how the wind turbine stands.

In further preferred embodiment, the aperture is provided by one or a plu-rality of moveable lamellae or mirrors.

In a further preferred embodiment, the lamellae or mirrors overlaps each other.

In a further preferred embodiment, the lamellae or mirrors are concave shaped.

In a further preferred embodiment, the lamellae or mirrors are arranged in circumference around the light source.

In a further preferred embodiment, the beacon light comprises a drive ar-rangement for driving the lamellae or mirrors. In particular, the drive ar-rangement comprises one or more drive device like an electric motor and one or more gears, wherein each gear has a couple for connecting one lamella or more lamellae or mirrors to with the gear. There are different arrangements of the one or more electric motors possible. One arrange-ment could be that each lamella or mirror has an own electric motor with a gear for open or close and/or a declination adjustment or an azimuth ad-justment. Another arrangement could be that one central electric motor is provide for open or close and/or a declination adjustment or a azimuth adjustment.

A further aspect of the invention is directed to a beacon light arrangement for a building like a wind turbine. The beacon light arrangement comprises one or more beacon lights according to one of the embodiments described above, a detection device for detecting a flying object and for determining position data of the flying object and a control device for controlling the one or more beacon lights depending from a control signal.

In a further preferred embodiment of the arrangement, the control device receives position data from the detection device.

In a further preferred embodiment of the arrangement, the control device connected with the drive arrangement of the beacon light.

In a further preferred embodiment of the arrangement, the detection de-vice is a radar system or a communication element for receiving flight data from the pilot of the flying object.

In a further preferred embodiment of the arrangement, the control signal is generated by position data determined by the detection device.

In a further preferred embodiment of the arrangement, the position data are chosen from direction, height and/or speed of the flying object.

A method for a directing illumination of a sector from a building like a wind turbine comprising the steps of:
- providing a beacon light according to one of the above de-scribed embodiment or a beacon light arrangement according to one of the above described embodiment,
- detecting a flying object,
- determining position data of the flying object,
- illuminating the sector in located direction of the flying object via one or more beacon lights,
- therefor moving the aperture of the one or more beacon lights according to the determined position data.

Advantageously the position data of the flying object is selected from the declination and azimuth position.

A further aspect is directed to a wind turbine characterized by a one or more beacon lights according to one of the claims 1 to 8 or a beacon light arrangement according to one of the claims 9 to 14 or a configuration to procedure the method according to claim 15.

In particular, one or more beacon lights according to one embodiment de-scribed above is arranged outside of the nacelle, tower or blade.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be explained in more detail with respect to exem-plary embodiments with reference to the enclosed drawings, wherein:

Figure 1 (PRIOR ART) shows a perspective view of a wind turbine;

Figure 2 shows a perspective view of a beacon light;

Figure 3 shows a top view of a beacon light according to Fig. 2;

Figure 4 shows a view of the beacon light according to Fig. 2, wherein the lamellae are in different positions;

Figure 5 shows a wind turbine of Fig. 1 having a beacon light arrangement and

Figure 6 shows a detailed view of a beacon light according to Fig. 5.

The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 depicts a schematic view of a wind turbine (1) with a tower (2) and a nacelle (3). Depending on given requirements the wind turbine (1) can be used for offshore or onshore applications. The nacelle (3) is rotatable mounted on the tower (2). The nacelle (3) incorporates a number of components of a drive train chain (4) comprising a rotor shaft (not shown) for example. The nacelle (3) also incorporates a generator (not shown) connected with a plurality of electrical components (not shown).Further the nacelle (3) comprises a yaw system (not shown) for rotating the nacelle (3). Said rotor shaft is connected to a rotor (5). The rotor (5) comprises three rotor blades (6) which are mounted to a hub (7). The hub (7) is connected to the rotor shaft of the drive train chain (4). The rotor blades (6) are adjustably mounted on the hub (7). The nacelle (3) is covered by a nacelle cover (9). The hub (7) is covered by a spinner (11).

At the wind turbine (1) there are arranged one or more beacon lights. One beacon light (12) is shown in Figs. 2 and 3. The beacon light (12) has an aperture (13) for illuminating a sector (14) of a detected flying object (15) (see Fig. 4) and a light source (16). This light source (16) can be used for a day-time illumination and/or for a night-time illumination. The aperture (13) can be opened or closed for extending or reducing the illuminated sector (14). Additional to this, the aperture (13) is high-adjustable and side-adjustable. Therefor the aperture (13) is provided by a plurality of moveable lamellae (17) or mirrors (17), which are arranged in circumfer-ence around the light source (16) and overlapping each other. The lamel-lae (17) or mirrors (17) are concave shaped. The different between the lamellae (17) and mirrors (17) is that the mirrors (17) have a mirrored inner side (18), so the light from the light source will be more reflected compared with the lamellae. In result, the illumination is increased. All features for the lamellae (17) described before or hereinafter also apply for mirrors, so if it will be referred to lamellae (17) than mirrors (17) are also included.

Further as can be seen in Fig. 2 the beacon light (12) comprises a drive arrangement (19) for driving the lamellae (17). The drive arrangement (19) comprises one or more drive device (20) like an electric motor and one or more gears (not shown), wherein each gear has a couple for connecting one lamella (17) or a plurality of lamellae (17) with the gear. This drive arrangement (19) allows to open, close and a declination-adjustment as well as a azimuth-adjustment of the aperture (13) for illuminating a sector (14).

The gear could comprise two rings, which are arrange at the surface of the lamella (17) respectively lamellae (17). Each of the rings could be me-chanically or magnetically coupled the lamellae (17). Both rings are height adjustable between at least a basic position and an operation position. One of the rings will be set to the working position when a low flying flying object will be detected. Hereby the light is viewable also from the ground. The other ring will be set in operation position when a high flying flying object will be detected. In this event the light is not viewable from the ground.

As indicated in Fig. 4, alternatively every lamella (17) could comprises an own gear (not shown). In this embodiment the lamella (17) could be set in in three positions, namely a basic position, wherein the lamella (17-1) is close, an interim operation position, wherein the lamella (17-2) is half opened and the light not viewable from the ground, and an operation position, wherein the lamella (17-3) is fully opened and the light is viewable from the ground.

Flying objects (15) will be detected by a detection device (21). The detec-tion device (21) is configured for determining position data from the flying object (15) like flight height, direction and/or speed and the like. Therefor the detection device can be an active or passive radar system. Additional or alternative to this, the pilot can send the position data to the detection device (21). Therefor the detection device (21) comprises a communica-tion element (not shown). Independent from this, the detection device (21) stays in signal communication with a control device (22), which stays in signal communication with the drive device (20). The control device (22) receives position data from the detection device (21). After this, the control device (22) processed the incoming position data to a control signal for the drive device (20). This control signal will be send to the drive device (20). In result the lamellae (17) will be aligned accordingly so that the sector (14) of the flying object (15) will be illuminated.

In following the Fig. 5 and 6 should be explained in detail, wherein the Fig. 4 depicts a wind turbine (1) comprising a beacon light arrangement (23) and Figure 5 depicts a detailed view of the beacon light arrangement (23). Components described before which have the same functions, but differs under constructions, are numbered with an “a”.

On top of the nacelle (3) of the wind turbine (1) the beacon light arrange-ment (23) is mounted. At the sectors (14) between the dotted lines (24) there are flying objects (15) detected. Consequently these sectors (14) will be illuminated by the beacon light arrangement (23). However, an envi-ronmental sector (26) below the illuminated sector (14) will not be illumi-nated. In particular, the light of the beacon light arrangement (23) will not be recognized by the residents in the houses (27). For illuminating the sectors (14) in different directions the beacon light arrangement (23) has more than one beacon light (12a) (see Fig. 5). Preferably, the plurality of beacon lights (12a) are arranged in circumference around the symmetry axes (25) of the beacon light arrangement (23). Additional or alternative to the shown embodiment the beacon light (12a) respectively the beacon light arrangement (23) can be arranged at the tower (2) and/or at the blades (6).

In reference to Fig. 6 the beacon light arrangement (23) comprises a plu-rality of beacon lights (12a), which are arranged in circumference around the symmetry axes (25). Each beacon light (12a) is coupled with a drive arrangement (19), which was described above. For controlling the drive arrangement (19) the beacon light arrangement further comprises a detection device (21a) and a control device (22a). The detection device (21a) is in signal communication with the control device (22a), wherein the control device (22a) is in signal communication with each of the drive arrangement (19), especially with the drive device (20) of the drive arrangement (19). The detection device (21a) and the control device (22a) works in the same way as described above. The difference is, that depending on the received position data the control device (22a) generates a different control signal for each drive arrangement (19) of the beacon light (12a).

List of reference signs

1 Wind turbine
2 Tower
3 Nacelle
4 Drive train chain
5 Rotor
6 Rotor blades
7 Hub
9 Nacelle cover
11 Spinner
12; 12a Beacon light
13 Aperture
14 Illuminated sector
15 Flying object
16 Light source
17 Lamellae; Mirrors
17-1 lamella in basic position
17-2 lamella in interim op-eration position
17-3 lamella in operation position
18 Mirrored inner side
19 Drive arrangement
20 Drive device
21; 21a Detection device
22; 22a Control device
23 beacon light arrange-ment
24 Dotted lines
25 Symmetry axes
26 Not-illuminated sector
27 Houses