Lightning protection system for a wind turbine and wind turbine comprising such a lightning protection system

Abstract

Provided is a lightning protection system for a wind turbine, including a connection unit to be placed between a nacelle and at least one blade of the wind turbine for conducting lightning current and/or static energy from the at least one blade to the nacelle, the connection unit including a first end portion with at least one nacelle contacting element, a second end portion with at least one blade contacting element, at least one first support member supporting the at least one nacelle contacting element, at least one second support member supporting the at least one blade contacting element, a base portion located between the first support member and the second support member, and at least one shifting element mechanically connecting the first support member and/or the second support member slidably relative to the base portion for amending a length of the connection unit in an amending direction from the blade to the nacelle.

Claims

1. A lightning protection system for a wind turbine, comprising a connection unit to be placed between a nacelle and at least one blade of the wind turbine for conducting lightning current and/or static energy from the at least one blade to the nacelle, the connection unit comprising a first end portion with at least one nacelle contacting element, a second end portion with at least one blade contacting element, at least one first support member supporting the at least one nacelle contacting element, at least one second support member supporting the at least one blade contacting element, a base portion located between the first support member and the second support member, and at least one shifting element mechanically connecting the first support member and/or the second support member slidably relative to the base portion for amending a length of the connection unit in an amending direction from the at least one blade to the nacelle, wherein the base portion comprises an electroconductive material and conducts the lightning current and/or static energy from the second end portion to the first end portion, wherein at least one end portion of the at least one shifting element is fixed at the base portion, at least one other end portion of the at least one shifting element is fixed to the first support member and/or to the second support member, the base portion comprises at least one guiding projection, and the first support member and/or the second support member each comprise a guiding slot, in which the at least one guiding projection is slidably located.

2. The lightning protection system according to claim 1, wherein the at least one shifting element comprises a spring.

3. The lightning protection system according to claim 1, wherein the at least one nacelle contacting element and/or the at least one blade contacting element are rotatably supported on a shaft and are wheel shaped.

4. The lightning protection system according to claim 1, wherein the first support member and the second support member are arm shaped and positioned parallel to each other at least regarding a projected length direction of the same.

5. The lightning protection system according to claim 1, wherein a length of the at least one guiding projection in a moving direction of the first support member and/or the second support member is longer than a width of the at least one guiding projection in a direction perpendicular to the moving direction.

6. The lightning protection system according to claim 1, wherein the first support member and/or the second support member has a U-shaped form, wherein part of the base portion, on which the shifting element is fixed, is located form fit between two legs of the U-shaped form of the first support member and/or the U-shaped form of the second support member.

7. A wind turbine for generating electric power from wind energy, comprising a nacelle and blades, wherein at least one lightning protection system according to claim 1 is in contact with and between the nacelle and at least one of the blades.

8. The wind turbine according to claim 7, wherein the base portion is fixed at a blade mounting portion for mounting a blade to a rotor of the wind turbine.

9. The wind turbine according to claim 8, wherein the base portion is fixed at the blade mounting portion via an insulation member electrically insulating the base portion from the blade mounting portion.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

(2) FIG. 1 shows a lightning protection system arranged in a wind turbine according to embodiments of the present invention;

(3) FIG. 2 shows a part view of the inventive lightning protection system shown in FIG. 1; and

(4) FIG. 3 shows a wind turbine with the inventive lightning protection system.

DETAILED DESCRIPTION

(5) FIG. 1 shows a lightning protection system 1 for a wind turbine 4 according to embodiments of the invention. The lightning protection system 1 comprises a connection unit 5 to be placed between a nacelle 2 and a blade 9 of the wind turbine 4 for conducting lightning current from that blade 9 to the nacelle 2. As can be seen in FIG. 1, the nacelle 2 comprises a gutter ring 18, which is contacted by the first end portion 6 and the nacelle contacting elements 7 of the first end portion 6, respectively. That is, according to embodiments of the present invention, the gutter ring 18 is part of the nacelle 2.

(6) The connection unit 5 comprises a first end portion 6 with two nacelle contacting elements 7 and a second end portion 8 with two blade contacting elements 7, wherein the nacelle contacting elements 7 and the blade contacting elements 7 are each rotatably supported on a shaft (not shown) at the respective end portion and wheel shaped. Specifically, the contacting elements 7 are all made of rubber.

(7) The connection unit further comprises a first support member 10 supporting the two nacelle contacting elements 7, a second support member 11 supporting the two blade contacting elements 7, and a base portion 12 located between the first support member 10 and the second support member 11. Moreover, there is provided a shifting element 13, shown in FIG. 2, configured to mechanically connect the first support member 10 slidably relative to the base portion 12 as well as a shifting element 13, shown in FIG. 2, configured to mechanically connect the second support member 11 slidably relative to the base portion 12. The shifting elements 13 are further configured and arranged to amend a length of the connection unit 5 in an amending direction from the blade 9 to the nacelle 2 in order to adjust the length of the connection unit 5 to different gap dimensions when wind turbine 4 is operated in a power generating condition.

(8) As can be further seen in FIG. 1, the base portion 12 is fixed at a blade mounting portion 14 for mounting a blade 9 to a rotor of the wind turbine 4. Specifically, the base portion 12 is fixed at the blade mounting portion 14 via an insulation member 3 electrically insulating the base portion 12 from the blade mounting portion 14. The insulation member 3 is fixed via bearing screws to a bearing for that blade 9 and the blade mounting portion 14, respectively. As can be further drawn from FIG. 1, the first support member 10 and the second support member 11 are arm shaped and positioned parallel to each other regarding a projected length direction of the same.

(9) FIG. 2 shows a part view of the above described lightning protection system 1. As can be seen in FIG. 2 as well as in FIG. 1, the base portion 12 comprises an adapter part and/or adapter parts mounted to a core part of the base portion 12 as well as to the support members 10, 11. Specifically, the adapter part of the base portion 12 is connected to the support members 10, 11 via the shifting elements 13. As can be seen in FIG. 2, the shifting element 13 shown there comprises two coil springs, wherein one end of each coil spring is fixed to the base portion 12 and the other end is fixed to the respective first support member 10. Specifically, the coil springs are fixed to a bearing 17 of the first support member 10, wherein the first support member 10 is U-shaped by the bearing 17 and two leg portions. Part of the base portion 12, i.e., part of the adapter part, to which the shifting element 13 is fixed, is located form fit between those two legs of the first support member 10. Same applies to the second support member 11.

(10) As further shown in FIG. 2, one end portion of the shifting element 13 is fixed at the base portion 12, the other end portion of the shifting element 13 is fixed to the first support member 10, wherein the base portion 12 comprises two guiding projections 16 (only one shown) and the first support member 10 comprises two guiding slots 15 (only one shown), in which the guiding projections are slidably located. Specifically, one guiding slot 15 is formed in each leg of the first support member 10. Same applies for the second support member 11. For a better understanding of the first support member 10 and the support members 10, 11 in general, one rubber wheel was left out in the example of FIG. 2. In addition, FIG. 2 shows an example in which the length of a guiding projection 16 in a moving direction of the first support member 10 is longer than the width in a direction perpendicular to the moving direction.

(11) FIG. 3 shows a wind turbine 4 for generating electric power from wind energy, comprising a nacelle 2 and three blades 9, wherein a lightning protection system 1 as described above is in contact with and between the nacelle 2 and blades 9.

(12) Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

(13) For the sake of clarity, it is to be understood that the use of ‘a’ or ‘an’ throughout this application does not exclude a plurality, and ‘comprising’ does not exclude other steps or elements.