USE OF A TUNED MASS DAMPER IN A NACELLE FOR A WIND TURBINE

Abstract

A nacelle for a wind turbine is provided, whereby the nacelle includes a nacelle support structure inside of the nacelle, to which at least one tuned mass damper is attached, whereby the at least one tuned mass damper is tuned to target at least one mode of motion of the nacelle in a frequency range below 50 Hz.

Claims

1. A nacelle for a wind turbine, comprising: a nacelle support structure inside of the nacelle, to which at least one tuned mass damper is attached, wherein the at least one tuned mass damper is tuned to target at least one mode of motion of the nacelle in a frequency range below 50 Hz.

2. The nacelle according to claim 1, wherein at least part of a motion of the nacelle is from an up-down motion of the nacelle.

3. The nacelle according to claim 1, wherein at least part a motion of the nacelle is from a twisting motion of the nacelle.

4. The nacelle according to claim 1, wherein at least part of a motion of the nacelle includes a motion of the nacelle support structure.

5. The nacelle according to claim 1, wherein at least part of a motion of the nacelle includes a motion of a housing of the nacelle.

6. The nacelle according to claim 1, wherein the at least one tuned mass damper is tuned to target modes of motion of multiple nacelle components separately attached to the nacelle support structure inside the nacelle.

7. The nacelle according to claim 1, wherein the at least one motion is caused by an external load.

8. The nacelle according to claim 7, wherein the external load is caused by a turbulent wind, a shut-down event, or a seismic event.

9. The nacelle according to claim 1, wherein a motion occurs in a rear-end portion of the nacelle support structure, the rear-end portion of the nacelle support structure being disposed behind an attachment point to a tower of the wind turbine in a direction along the nacelle from a rotor of the wind turbine to a rear-end of the nacelle.

10. The nacelle according to claim 1, wherein the at least one tuned mass damper is attached to a rear-end portion of the nacelle support structure, the rear-end portion of the nacelle support structure being disposed behind an attachment point to a tower of the wind turbine in a direction along the nacelle from a rotor of the wind turbine to a rear-end of the nacelle.

11. The nacelle according to claim 1, wherein the nacelle comprises multiple tuned mass dampers attached to the nacelle support structure.

12. The nacelle according to claim 11, wherein the multiple tuned mass dampers are tuned to target different modes of motion of the nacelle in the frequency range below 50 Hz.

13. A wind turbine comprising the nacelle according to claim 1 and a tower, wherein the nacelle is attached to the tower.

14. A method comprising: utilizing at least one tuned mass damper in a nacelle for a wind turbine, wherein the at least one tuned mass damper is attached to a nacelle support structure inside of the nacelle and tuned to target at least one motion of the nacelle in a frequency range below 50 Hz.

15. A method, for dampening at least one motion of a nacelle according to claim 1, wherein at least one motion of the nacelle in a frequency range below 50 Hz is damped by the at least one tuned mass damper.

Description

BRIEF DESCRIPTION

[0032] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0033] FIG. 1 shows a schematic representation of a wind turbine according to embodiments of the invention.

DETAILED DESCRIPTION

[0034] The wind turbine 1 comprises a nacelle 10 attached to a tower 2 by a bedframe 13 of a nacelle support structure 11 located in the interior space 6 of the nacelle 10. The nacelle support structure 11 further comprises a frame or beam attached to the bedframe 13 in this particular embodiment. However, the nacelle support structure 11 may comprise other or further structural parts attached to each other, which do not necessarily have to be a frame or beam. It is to be noted that the illustration in FIG. 1 is schematic and the size, orientation and positioning of the elements such as the nacelle support structure 11 and the bedframe 13 is only chosen for illustration purposes. For example, the nacelle support structure 11 with its frame or beam may be positioned lower and closer to the tower 2 than shown in FIG. 1.

[0035] The nacelle support structure 11 supports the drive unit of the wind turbine 1. In this case, the wind turbine 1 is a direct-drive wind turbine 1 and does not have a gearbox. However, the wind turbine 1 may alternatively have any other drive unit such as geared drive unit. The rotor 5 together with the rotor blades 3, 4, which are fixed to the rotor 5, are attached to a drive shaft 16 of that drive unit. In this exemplary embodiment, only two rotor blades 3, 4 are shown. However, the number of rotor blades 3, 4 may be greater, such as three, for example. The drive shaft 16 is connected to a generator 19 and supported on bearings 17, 18, which are supported on the nacelle support structure 11 in the front of the nacelle 10, the front being where the rotor 5 is provided.

[0036] The nacelle 10 comprises a housing 8 surrounding the interior space 6 of the nacelle 10 with the components of the nacelle 10 located therein. The nacelle 10 has a rear-end 9, which is located opposite to the rotor 5. The nacelle 10 extends from the rotor 5 or shortly before the rotor 5 at the drive shaft 16 to the rear-end 9. Along this direction, the nacelle 10 has a rear-end section 7. The rear-end section 7 of the nacelle 10 is not rested on the tower 2 but is arranged freely above the ground.

[0037] In the rear-end section 7, the nacelle support structure 11 comprises a rear-end portion 12. The rear-end portion 12 extends inside of the rear-end section 7 along the direction from the rotor 5 to the rear-end 9 and up to or before the rear-end 9 of the nacelle 10. The rear-end portion 12 is a portion of the afore-mentioned frame or beam, in exemplary embodiment. However, as previously explained, the rear-end portion 12 may also be a portion of the bedframe 13 or any other suitable structural part of the nacelle support structure 12, by which the nacelle components are supported resting on the tower 2.

[0038] The rear-end portion 12 of the nacelle support structure 11 supports a cooling system 15 in this embodiment, which is merely one example of one of multiple nacelle components, which may be separately attached to the nacelle support structure 11 at its rear-end portion 12. Accordingly, there may be more nacelle components such as electrical systems, a cabin and a crane, for example, which may be supported on the nacelle support structure 11 at its rear-end portion 12.

[0039] The rear-end portion 12 of the nacelle 10 is particularly susceptible to cyclic vibrations from external loads possibly leading to damages of the nacelle support structure 11. For this purpose, the nacelle 10 comprises a tuned mass damper 20. The tuned mass damper 20 is attached to the rear-end portion 12 of the nacelle 10 and is tuned to target a mode from an up-down motion 14 indicated at the end of the rear-end portion 12, which is in the frequency range below 20 Hz. The tuned mass damper 20 thereby dissipates energy in those specific nacelle modes, which in turn reduce the vibration levels experienced by the nacelle support structure 11 at its rear-end portion 12. The tuned mass damper 20 mainly targets the up-down internal nacelle motion 14 and as such does not damp the vibrations of the tower 2, which are caused by side-to-side motions. Also, the tuned mass damper 20 does not target any noise or other vibrations having a frequency of 20 Hz or higher.

[0040] Of course, it is possible to attach further or alternative tuned mass dampers 20 to the nacelle support structure 11 for even further dissipation of energy in extreme events with high fatigue and extreme loads or to target other specific nacelle modes, such as from twisting motions of the nacelle support structure 11, for example.

[0041] Although the present invention has been disclosed in the form of 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.

[0042] 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.