VIBRATION DAMPING OF A WIND TURBINE TOWER

Description

[0001] The present invention relates to a coupling element for fastening between a vibrating body and a tower wall of a tower of a wind turbine in order to influence a relative movement between the vibrating body and the tower wall, thereby influencing a vibration behavior of the tower. The present invention also relates to a tower of a wind turbine with a vibration device for influencing a vibration of the tower. The present invention also relates to a vibration device prepared for use in a tower of a wind turbine in order to influence a vibration of the tower. The present invention also relates to a method for influencing a tower vibration. The present invention also relates to a wind turbine.

[0002] Wind turbines are well known, and modern wind turbines consist of a wind turbine tower on which a nacelle is mounted. The nacelle has a rotor with rotor blades to generate electrical energy from the wind. Particularly during operation, the wind acts on these rotor blades, but also partly on the nacelle and tower, and the wind can also cause the wind turbine, particularly the tower, to vibrate. The rotation of the rotor can also cause or influence vibration of the tower. In the worst case, depending on the tower's natural frequencies, resonance situations can occur at certain rotor speeds. In the theoretically worst case, this can lead to a resonance catastrophe.

[0003] Such vibration problems can be addressed with an appropriate tower design. One option is to build the tower so massive or rigid that it vibrates practically not at all, or only minimally. However, such a design is usually associated with considerable expenditure, particularly in terms of materials.

[0004] Other, more modern approaches propose a tower design that prevents resonance frequencies from coinciding with wind turbine operating points where speeds that can address or correspond to these resonance frequencies occur. Such solutions are then regularly coordinated with the turbine control system, particularly so that the turbine control system can quickly manage any resonance points with the speed, for example, during wind turbine startup.

[0005] However, constructing such towers can also involve increased effort. Furthermore, such a solution limits the operating range of the wind turbine.

[0006] In principle, solutions have also been proposed for equipping a wind turbine tower with a damping system designed to dampen such tower vibrations. However, such damping systems are complex and often immature, and can also be very disruptive inside the tower. Pendulum dampers suspended centrally in the tower are particularly susceptible to collision with central cable guides and other elements located there. The necessary installation space may often be lacking, particularly for the installation of large oscillating masses, which can be achieved by filling the oscillating bodies with water. The pendulum motion may also exhibit an unfavorable degree of movement.

[0007] Solutions have also been proposed that utilize fluid damper systems in the nacelle via appropriate pipe systems to dampen vibrations. This allows fluids, especially water, to be moved, or even pumped, in such a way that they can counteract oscillating motions. Such a system is also quite complex, and there is the added problem that the force counteracting the tower vibration must be transferred from the nacelle to the tower, which can result in a load on the yaw bearing.

[0008] Furthermore, a vibration damper module is known from the German patent application DE 10 2012 222 191 A1, in which pendulum spring elements are used that run in the direction of a suspension axis of a pendulum system used there.

[0009] The German Patent and Trademark Office has searched the following prior art in the priority application for the present application: DE 198 56 500 A1 and DE 10 2012 222 191 A1.

[0010] The present invention is therefore based on the object of addressing at least one of the aforementioned problems. In particular, a solution is to be proposed that counteracts vibration problems of a wind turbine tower in a simple manner, particularly in a simple structural manner, and in particular passively. At the very least, an alternative to previously known solutions is to be proposed.

[0011] According to the invention, a tower according to claim 1 is proposed.

[0012] In principle, several coupling elements are provided for a tower and a vibrating body, e.g. six or more coupling elements, to name just one example.

[0013] The coupling thus allows for relative movement between the oscillating body and the tower wall, and this relative movement has a first and a second direction of movement. In the first direction of movement, the first and second fastening sections move toward each other, whereas in the second direction of movement, they move away from each other. In principle, the first and second directions of movement can also be defined in reverse. In any case, these two directions of movement should be understood as being opposite to each other. It is not a question of them being perpendicular to each other.

[0014] Furthermore, a spring means is provided that achieves a spring-elastic coupling between the first and second fastening portions and thus achieves a spring-elastic coupling between the tower wall and the oscillating body when the coupling element is installed. The spring-elastic coupling can be described by a spring function. The spring means is designed such that the first movement in the spring means leads to a compression of a first spring portion and an extension of a second spring portion. Furthermore, the spring means is designed such that the second movement in the spring means leads to an extension of the first spring portion and a compression of the second spring portion. Thus, two spring portions are provided, one of which is always compressed and the other extended.If the direction of movement is reversed, this function is also reversed, so that the compressed spring section stretches again and the stretched section is compressed.

[0015] This functionality via these two spring sections is designed in such a way that the spring function for the first and second directions of movement are aligned as closely as possible.

[0016] This particularly improves a spring variant in which one direction of movement stretches a spring and the opposite direction of movement compresses it, which can regularly result in spring functions that are both direction- and deflection-amplitude-dependent. The proposal of these two spring sections thus achieves a uniformity of this spring function and thus a uniformity of the mechanical coupling of this coupling element in its application between the tower wall and the oscillating body.

[0017] The spring function should therefore be essentially the same in both directions of movement. It is also consistent with the inventive concept if the spring function is achieved in another way that is essentially the same for the first and second directions of movement.

[0018] Preferably, the coupling element is designed as a spring-damper element and, in addition to the spring means, has a damping section for a damping coupling between the first and second fastening sections. This damping coupling can be described by a damping function. For this purpose, it is proposed that the damping function be substantially identical for the first and second directions of movement. This also allows uniformity in the damping to be achieved, so that the first and second movements are influenced equally, i.e., symmetrically.

[0019] Preferably, the spring function is not only essentially the same in both directions of movement, but also essentially linear. The spring force of the entire spring means, i.e., the sum of the spring forces of the first and second spring sections, is thus essentially proportional in magnitude to a deflection from a central position or a rest position.

[0020] Preferably, the damping function is not only substantially equal in the first and second directions of movement, but also substantially linear. The damping force of the damping section opposing the movement is thus essentially proportional in magnitude to the speed of the relative movement between the first and second fastening sections, i.e., to the relative movement between the oscillating body and the tower wall.

[0021] As a result, especially if both the spring function and the damping function are linear, damping, especially damping with a constant damping constant, of an oscillation of the tower dynamics or the movement dynamics of the wind turbine as a whole can be achieved.

[0022] A linear spring function can be achieved, in particular, by preloading both spring sections. Of course, a linear spring function can only be achieved for a predetermined design travel distance, where the coupling element, and especially the spring means, does not reach a stop. It is therefore proposed that the spring function be essentially linear for the predetermined design travel distance.

[0023] For the damping function, linearity and symmetry can be achieved particularly through a symmetrical design.

[0024] According to one embodiment, it is proposed that the coupling element has a first and a second anchor section which are firmly connected to one another. In addition, a central section is arranged between the first and second anchor section and is movable relative to these two anchor sections. The first or second anchor section is firmly connected to the second fastening section and the central section is firmly connected to the first fastening section. The central section can therefore move between the two anchor sections and can thus move together with the oscillating body between the two anchor sections and thus relative to the tower wall. The relative movement between the oscillating body and the tower wall thus corresponds to the movement of the central section between the anchor sections.

[0025] This makes it particularly easy to achieve the even division of the spring means into two spring sections.

[0026] Preferably, the spring means comprises a first spring between the central section and the first anchor section, and a second spring between the central section and the second anchor section. The first spring forms the first spring section, and the second spring forms the second spring section. Preferably, both springs are identical. The springs can be configured, for example, as helical springs.

[0027] Preferably, the first and second springs are pre-tensioned to ensure that neither of the two springs reaches or exceeds a relaxed state during movement of the coupling element. In particular, the two springs can be clamped between the middle section and the first anchor section or between the middle section and the second anchor section. Preferably, this pre-tension is so strong that even when the first spring is compressed to a stop beyond which it can no longer be compressed, the second spring is still under tension, i.e. is still pre-tensioned. The same applies conversely, namely that the first spring is still under tension and is therefore still pre-tensioned when the second spring is completely compressed, i.e. has reached a stop. The situation in which one of the two springs is compressed to a stop no longer relates to the normal operating range.In other words, the coupling element is intended for use in which the described maximum compression is not reached.

[0028] Preferably, a distance between the first and second anchor portions is adjustable to thereby adjust the preload.

[0029] Preferably, an actuator-operated adjustment device is provided for this purpose, allowing online adjustment. This allows for response to minimal changes in the tower's vibration characteristics, which may also be caused by changes in the other elements of the wind turbine.

[0030] According to a further embodiment, it is proposed that the damping section is attached between the central section and the first anchor section, or between the central section and the second anchor section. In this case, it was particularly recognized that a damping function that is symmetrical in both directions of movement and also a linear damping function can be realized by a single damping section, which is arranged here between the two sections moving relative to one another. Alternatively, a damping section can be provided between the central section and each of the two anchor sections, which are particularly identical and at least have the same properties. This can ensure that the damping behaves identically in both directions of movement.

[0031] According to the invention, a tower for a wind turbine is also proposed. Such a tower has a tower center axis and a tower wall from which the tower is essentially constructed. Furthermore, an oscillation device is provided for influencing the oscillation of the tower. The oscillation device has an oscillating body suspended in the tower at a distance from the tower wall. Accordingly, this oscillating body hangs inside the tower and can, in principle, oscillate in different directions there relative to the tower wall. In principle, the oscillating body can be arranged in the tower in a manner other than by suspension, such as by a bearing that essentially allows movement in any direction in a plane perpendicular to the tower center axis.

[0032] The vibrating body must be suspended or otherwise supported at a distance from the tower wall so that there is sufficient space for the vibrating body to move relative to the tower.

[0033] In addition, a coupling element is attached between the vibrating body and the tower wall to influence a relative movement between the vibrating body and the tower wall. Preferably, several coupling elements, particularly four, six, or eight coupling elements, are provided. In particular, these coupling elements are of identical construction and evenly distributed around the circumference of the vibrating body. The use of six coupling elements, in particular, ensures a good, even distribution around the circumference of the vibrating body while simultaneously minimizing the material consumption, so six coupling elements are particularly preferable.

[0034] Furthermore, the oscillating body is hollow along a vertical central axis. In particular, it is hollow along the tower's central axis. This hollow design ensures that the oscillating body does not interfere with devices in the tower, such as a passenger or equipment lift. Preferably, the oscillating body is hollow enough to allow a passenger lift of a wind turbine to pass vertically and centrally through the oscillating body.

[0035] It was also recognized that a large amount of mass can be accommodated in an external shell. This allows for the creation of a vibrating body with a large mass while still leaving sufficient space for other necessary devices in the tower.

[0036] Preferably, the oscillating body is essentially designed as a hollow truncated cone or a hollow cylinder. This allows a large mass of the oscillating body to be accommodated in this hollow truncated cone or hollow cylinder in a simple and uniform manner. A hollow cylinder is generally proposed, but for adaptation to a conical shape of the tower, a correspondingly conical shape of the shell can also be proposed, so that the aforementioned hollow truncated cone is proposed for this purpose.

[0037] Optionally, such a hollow truncated cone has a vertical interruption in the shell to create space for a tower ladder arranged on the inside of the tower wall, so that service personnel can climb up and down the tower along this tower ladder and pass the vibrating body in the area of ​​the interruption.

[0038] For example, the hollow cylinder or hollow truncated cone can have the interruption in a region of approximately 60 degrees, relative to 360 degrees of its entire circumference. Slightly larger or smaller regions are also possible, and the interruption is preferably provided in a region of 30 to 90 degrees.

[0039] Particularly with an interruption value of 60 degrees, six coupling elements can still be arranged evenly distributed around the circumference. A value of 90 degrees is particularly preferred for a variant with four coupling elements. A value of 30 degrees is particularly recommended for large tower diameters. Even then, a member of the service personnel can still pass the oscillating body in the area of ​​its interruption when climbing a ladder located there. By defining the interruption over a range of degrees relative to the 360-degree circumference, a sufficient interruption can be provided in every case, which can create sufficient space even with only a small central hollow space. An even number of coupling elements is preferably proposed, with the coupling elements being evenly distributed around the circumference of the oscillating body. 10° is proposed as the smallest value for the interruption.

[0040] According to one embodiment, it is proposed that the oscillating body have a casing that runs interruptedly around the central axis. The wall thickness of this circumferential casing varies in the circumferential direction. The wall thickness varies such that, despite the interruption, the oscillating body has a center of gravity in the central axis. The central axis is aligned vertically and lies at a geometric center of the oscillating body. In particular, it is the central axis relative to the outer contour of the oscillating body. Additionally or alternatively, it corresponds to the central axis of the tower when the oscillating body and the tower are at rest.

[0041] To influence the turret's vibration, particularly for uniform damping, the center of mass of the oscillating body is located in the turret's central axis when at rest. The proposed interruption in the oscillating body's casing would shift the center of mass, assuming the same wall thickness in the circumferential direction. This can be compensated for by the proposed variation in the oscillating body's wall thickness. By uniformly varying the oscillating body's wall thickness, the center of mass can be brought into the turret's central axis or the central axis of the oscillating body despite the interruption. This also makes it possible to avoid the need for additional counterweights, for example.

[0042] Preferably, the oscillating body is suspended centrally from the tower wall at an average distance from the wall, wherein the wall distance is less than 1 / 4 of the tower's inner diameter in the relevant area. In particular, it is less than 1 / 8 of this tower's inner diameter. This ensures that this oscillating body is very close to the tower wall and thus has a comparatively large diameter itself. This means that the oscillating body can also have a correspondingly large volume and thus a correspondingly large significant mass in order to be able to significantly influence the tower's oscillating behavior. This distance, which is less than 1 / 4 or preferably even less than 1 / 8 of the tower's inner diameter at this point, still leaves sufficient space for relative movements between the oscillating body and the tower wall. Preferably, the distance is greater than 1 / 20 of the tower's inner diameter.This prevents the space between the vibrating body and the tower wall from being chosen too small.

[0043] Preferably, the oscillating body has a height that corresponds to at least half its diameter, preferably at least the size of its diameter, and preferably at least twice its diameter. This allows for a very high overall mass for the oscillating body. All of these solutions nevertheless still allow for efficient use of the tower's interior space, for example, for cable routing or, if necessary, an elevator.

[0044] According to the invention, the oscillating body is suspended from a mounting section, in particular a tower head flange, via pendulum rods. According to the invention, three, four, or more pendulum rods are proposed.

[0045] In particular, an even number of pendulum rods is proposed. The use of pendulum rods is intended to ensure that the oscillating body is essentially limited to translational or tilt-free movements. The pendulum rods are preferably designed on both sides with spherical rod ends, i.e. with ball joints, or a cardanic suspension. This enables pendulum movement in all horizontal directions. The joints of the pendulum rods should not influence the direction of the pendulum movement. Preferably, the pendulum rods are at least approximately as long as the oscillating body is high. This particularly ensures that the pendulum movements have no or no significant vertical component.Preferably, the pendulum rods are each at least three times as long, in particular at least five times as long and preferably at least seven times as long as a distance of the oscillating body to the tower wall in the rest state.

[0046] Due to the way the oscillating body is suspended, particularly on multiple pendulum rods, a restoring force is generated after the oscillating body is deflected by the force of gravity, which ultimately at least helps to return the oscillating body to its rest position. Accordingly, the use of return springs can be avoided or reduced.

[0047] The vibrating body is preferably made of a material with a higher density than water. At least its overall density is higher than water. In particular, it is proposed that the density be at least twice that of water. Concrete is suggested as the preferred material for this purpose. In particular, the vibrating body is made essentially of concrete, preferably reinforced concrete. However, a receiving body for filling with concrete can also be provided. In this case, it is particularly conceivable that only concrete is used or filled, without the use of reinforced concrete. The rigidity and strength as well as the provision of suspensions or suspension points can be achieved by this receiving body.

[0048] Another advantage of using a receiving body together with concrete is that liquid, not yet set concrete is pumpable, making it possible to install the vibrating body as an empty receiving body in the erected tower and then pump up the desired concrete.

[0049] According to one embodiment, however, it is provided that the vibrating body is provided as a prefabricated element, in particular as a precast concrete part.

[0050] The tower is preferably characterized in that several coupling elements are arranged between the vibrating body and the tower wall and distributed circumferentially around the vibrating body. Each of these coupling elements is attached to the vibrating body and the tower wall. This creates a mechanical coupling between the vibrating body and the tower wall, whereby the coupling allows for, but influences, a horizontal relative movement between the vibrating body and the tower wall.

[0051] The oscillating body, including its suspension, together with the coupling elements, forms the oscillating device for influencing the vibration of the tower. This oscillating device can preferably be designed as a damper system that can reduce occurring vibrations or, in the best case, even eliminate them. This oscillating device, in particular the damper system, is adjusted or tuned to the expected vibrations of the tower, particularly the frequency, by selecting the oscillating body and the coupling elements. To influence this, the mass of the oscillating body, the spring stiffness of the coupling elements, the damping properties (in particular the damping constant of a damping section of each coupling element), the number of coupling elements, the position of the coupling elements, and the length of the pendulum rods can be adjusted or selected accordingly.

[0052] Preferably, coupling elements according to at least one embodiment of the coupling elements described above are used. Thus, the advantages described for the coupling elements can be used accordingly for modifying, damping, and absorbing vibrations of the wind turbine tower.

[0053] Preferably, the coupling elements are arranged above and also or alternatively below the oscillating body. This makes it particularly possible to use coupling elements that have a significantly greater extension than the space between the oscillating body and the tower wall. Particularly preferably, one or the central section of each coupling element is attached to an upper or lower edge of the oscillating body, whereas one of the two anchor sections is attached to the tower wall, and the remaining anchor section protrudes freely into the interior of the tower, in particular also into an area above the inner cavity of the oscillating body.The entire construction, i.e. the oscillating body installed in the tower with the coupling elements, nevertheless leaves sufficient space inside the tower to use the interior of the tower for various technical equipment, but especially for routing electrical cables, especially cable bundles.

[0054] Preferably, the oscillating body has a center of mass and the oscillating body is suspended in the tower at such a height that the center of mass is located in an upper half, in particular in the upper three-fifths of the tower. Additionally or alternatively, it is provided that the oscillating body is suspended from one or more fastening sections which are arranged on the tower head flange. An arrangement near the tower head flange is also conceivable, although this should be understood to mean that the fastening may not be directly on the tower head flange, but in the immediate vicinity of the tower head flange. For example, on the last tower segment, the fastening section can be provided as a circumferential fastening flange, with an intermediate ring thereon and the tower head flange thereon. Preferably, however, fastening of the fastening sections to the tower head flange is proposed.

[0055] First, this vertical position of the center of mass of the oscillating body is set at a position where a first eigenfrequency has a large deflection, i.e., where its eigenmode has a large deflection. Different eigenmodes can also occur during the bending vibration of the tower.

[0056] Preferably, the oscillation device is designed to dampen the oscillation of the tower with respect to its natural frequencies. As described above, a corresponding design can be adjusted via the mass of the oscillating body, the spring function of the coupling elements, the damping function of the coupling elements, the number of coupling elements, the pendulum rod length, and also the vertical position of the center of mass of the oscillating body.

[0057] Furthermore, a vibration device is proposed which is designed for use in a tower of a wind turbine to influence a vibration of the tower. This vibration device has a vibration body which can be suspended in the tower at a distance from the tower wall, and it has at least one coupling element for fastening between the vibration body and the tower wall in order to thereby influence a relative movement between the vibration body and the tower wall. For this purpose, it is proposed that the vibration body be hollow along a vertical central axis and, additionally or alternatively, each coupling element has a spring function, and the spring function is essentially the same for a first and a second direction of movement which are opposite to one another.In particular, at least four, in particular exactly four or exactly six or exactly eight coupling elements can be provided, which are distributed uniformly around the oscillating body in a circumferential direction, preferably above the oscillating body and / or below the oscillating body.

[0058] This oscillating device is preferably prepared for use in a tower according to an embodiment described above. In particular, the oscillating device has at least one feature as described in connection with the description of the embodiments of the tower in connection with the oscillating device.

[0059] Additionally or alternatively, the oscillating device comprises at least one coupling element, as described in at least one embodiment of a coupling element described above.

[0060] Furthermore, a method for influencing a tower vibration or a natural frequency of a tower of a wind turbine is proposed, wherein this tower has a vibration device with multiple coupling elements. This method proposes detecting a natural frequency of the tower, then specifying a desired damper frequency, and subsequently adjusting the coupling elements to the damper frequency. These steps of detecting, specifying, and adjusting are preferably repeated to improve the behavior.

[0061] Alternatively, a tower vibration amplitude is recorded, a desired maximum tower vibration amplitude is specified, and the coupling elements are adjusted so that the tower vibration amplitude remains below the desired maximum tower vibration amplitude. In this case, a change in the damping function is particularly considered in order to reduce the vibration amplitude. Here, too, the steps of recording, specifying, and adjusting can be repeated. In particular, it is proposed to continuously record the tower natural frequency or the tower vibration amplitude and, depending on this, to decide whether the next steps are necessary or not. In particular, it is also possible to adjust the coupling elements again, which in this respect can also be referred to as readjustment, without specifying a desired absorber natural frequency or a new desired maximum tower vibration amplitude.However, it is also possible to adjust not only the setting of the coupling elements, but also the desired natural frequency of the absorber or the desired maximum tower vibration amplitude, i.e. to change the setpoints for this purpose.

[0062] Furthermore, a wind turbine is proposed which has an oscillation device with coupling elements according to an embodiment of the coupling elements described above, has a tower according to an embodiment of a tower described above, has an oscillation device according to an embodiment of an oscillation device described above and also or alternatively has a control device which is prepared to carry out a method for influencing a tower oscillation described above according to an embodiment.

[0063] It is also proposed that the method for influencing a tower vibration be used together with a vibration device and coupling elements according to an embodiment described above for coupling elements, that it be used together with a tower according to an embodiment described above to form a tower, and that it be additionally or alternatively used together with a vibration device according to an embodiment described above to form a vibration device. Thus, the advantages of the respective embodiments described can be utilized for the proposed method or the proposed wind turbine.

[0064] As a result, a solution is proposed that changes the vibration of a wind turbine tower or the vibration of an entire wind turbine, which is particularly noticeable in the tower, in a simple yet efficient manner. The change can affect the frequency response or the amplitude. This solution is particularly designed as a passive solution that can influence at least one property of the tower or wind turbine in relation to vibration behavior. This can particularly achieve a change in the system behavior of the tower or wind turbine in relation to vibration behavior. The solution is efficient and designed in such a way that the interior of the tower in particular is not unnecessarily obstructed. Adjustment can also be provided, via which the influence on the vibrations can be set and adapted, especially on site.

[0065] The invention will now be explained in more detail below using exemplary embodiments with reference to the accompanying figures. Figure 1 shows a wind turbine in a perspective view. Figure 2 shows a section of a wind turbine tower in a sectional view. Figure 3 shows a section of the Figure 2 with further details. Figure 4 shows another section of the Figure 2 with further details. Figure 5 shows a horizontal section through the tower section according to Figure 2 Figure 6 shows a coupling element in a side sectional view.

[0066] Figure 1 shows a wind turbine 100 with a tower 102 and a nacelle 104. A rotor 106 with three rotor blades 108 and a spinner 110, which is part of a hub, is arranged on the nacelle 104. During operation, the rotor 106 is set into rotation by the wind and thereby drives a generator in the nacelle 104.

[0067] Figure 2 shows a tower section 2 with a tower wall 4, which can vary in type and thickness over the height. The tower section 2 is closed by a tower head flange 6. The tower head flange 6 is designed as a circumferential flange and is specifically designed to accommodate an azimuth bearing for the rotatable support of a nacelle.

[0068] Suspension attachments 8 are attached to the tower head flange 6, each pivotably supporting a pendulum rod 10, and an oscillating body 12 is suspended from the pendulum rods 10. For this purpose, the pendulum rods 10 are also pivotably attached to the oscillating body 12 via oscillating body attachments 14.

[0069] The pendulum rods 10 thus act as a suspension for the oscillating body 12. The suspension fastenings 8 can also be referred to as tower head flange fastenings.

[0070] The oscillating body 12 can thus oscillate essentially in a horizontal plane in all directions thanks to the comparatively long pendulum rods 10. In addition to longitudinal oscillations in different directions, circular movements, i.e., a superposition of several longitudinal oscillations, are also possible.

[0071] The oscillating body 12 is essentially formed by an oscillating body shell 16, which surrounds an oscillating body cavity 18. The oscillating body shell 16 can, as shown in Figure 2 and some other figures, may be designed as a vibrating body container 20 with container filling 22.

[0072] In Figure 2 A tower center axis 24 is also shown, which thus forms a center axis for the tower and thus the tower section 2. Here, it coincides with a body center axis 26, which forms a vertical center axis for the oscillating body 12.

[0073] The oscillating body 12 can be coupled to the tower wall 4 at a lower edge 28 and an upper edge 30 via coupling elements 32. Details of the coupling in the area of ​​the upper edge 30 are shown in the Figure 3 shown and details of the coupling in the area of ​​the lower edge 28 are shown in Figure 4 shown.

[0074] The attachment of each coupling element 32 to the tower wall 4 is achieved, in the case of the coupling elements 32 attached to the upper edge 30, by means of an attachment to a tower bulkhead 34. Such a tower bulkhead 34 is generally used to create a platform in the wind turbine tower on which work can be carried out or on which a rest break can be taken. Such a tower bulkhead 34 also prevents anything from falling down from the nacelle 104 in the tower. The tower bulkhead is attached evenly in the circumferential direction to the tower wall 4 and can also form a stiffening ring or a stiffening surface for the tower. By attaching the coupling elements 32 to the tower bulkhead 34, a point-like force introduction into the tower wall can be avoided. Instead, force is introduced into the tower bulkhead 34, which in turn can transmit this force evenly in the circumferential direction to the tower wall 4 of the tower section 2.

[0075] In the area of ​​the lower edge 28, the coupling elements 32 are attached to the tower wall 4 via a stiffening ring 36. This connection to the tower wall 4 via the stiffening ring 36 also prevents the point-like introduction of forces into the tower wall 4 via the respective coupling element 32. When the oscillating body 12 oscillates relative to the tower section 2, it also oscillates relative to the tower bulkhead 34 and the stiffening ring 36. Since the oscillating body 12 is located below the tower bulkhead 34, the pendulum rods 10 are guided through corresponding openings in the tower bulkhead 34.

[0076] Figure 3 shows in an enlarged section the coupling of the oscillating body 12 via coupling elements 32, of which Figure 3 only one is shown, with the tower wall 4. The coupling element 32, which in Figure 6shown in a more detailed illustration, is attached with a central section 38 to the upper edge 30 of the oscillating body 12 or its oscillating body shell 16.

[0077] The central section 38 is resiliently arranged between a first anchor section 41 and a second anchor section 42. The first and second anchor sections 41, 42 are rigidly connected to one another. The first anchor section 41 is attached to the tower bulkhead 34 via a mounting bracket 44.

[0078] During an oscillating movement of the oscillating body 12 relative to the tower wall 4, a force is introduced from the oscillating body 12 via the central section 38 into the coupling element 32, which transmits this force elastically to the first anchor section 41 and then, via the fastening angle 44, to the tower bulkhead 34 and thus to the tower wall 4. As a result, the oscillating body 12 is elastically coupled to the tower wall 4.

[0079] Furthermore, in the Figure 3 Also indicated is a cable bundle 46, which can be guided through the tower bulkhead 34 and in particular also through the inner cavity, namely the oscillating body cavity 18 of the oscillating body 12. For this purpose, an opening can be provided in the tower bulkhead 34, in which the cable bundle 46 is guided through a cable guide 48.

[0080] The structure in the area of ​​the lower edge 28 is Figure 4 and is very similar to the structure in the area of ​​the upper edge 30. Also in the area of ​​the lower edge 28, the oscillating body 12 is coupled to the central portion 38 of the coupling element 32. The coupling element 32 is in turn coupled to the stiffening ring 36 via the first anchor portion 41 and a fastening bracket 44. The stiffening ring 36 can also be referred to as a buckling stiffener.

[0081] The oscillating body 12 can also have a cable guide 49 on its underside.

[0082] The top view of the Figure 5 The shape of the oscillating body 12 is particularly evident. It essentially has a circular-cylindrical shape, which is provided with a vertical interruption 50. This vertical interruption 50 serves to create space in the area of ​​a tower ladder 52. Due to its comparatively large outer diameter, the oscillating body 12 can thus have a large volume and thus a high mass. The interior of the tower thus remains usable, and in particular, ascent via the tower ladder 52 is not hindered.

[0083] In order to achieve a central center of mass of the oscillating body 12 despite the interruption 50, the wall thickness of the oscillating body 12 can be somewhat greater in the area of ​​the tower ladder 52 than in an area facing away from the tower ladder 52. For explanation, an area 54 close to the tower ladder 52 and an area 56 far from the tower ladder 52 are shown. Mass compensation can thus be achieved by providing a particularly high wall thickness in the area 54 close to the tower ladder, whereas the smallest possible wall thickness is provided in the area 56 far from the tower ladder.

[0084] The Figure 6shows a side sectional view of the coupling element 32 with further details. The first and second anchor sections 41, 42 are firmly connected to one another via tie rods 58. The middle section 38 can be moved relative to the two anchor sections 41 and 42. The tie rods 58 can also form a guide for the middle section 38 for such a movement. Furthermore, each anchor section can also be referred to as an end plate, and the middle section 38 can be referred to as the middle plate.

[0085] A first spring 61 is arranged between the central section 38 and the first anchor section 41, forming a first spring section. A second spring 62 is arranged between the central section 38 and the second anchor section 42, forming a second spring section.

[0086] These two springs 61 and 62 together form a common spring means of the coupling element 32. Both springs 61 and 62 are essentially identical and both springs 61 and 62 are preloaded. Figure 6 shows a rest position of the coupling element 32. The two springs 61 and 62 are designed as helical springs and are each received in a receiving section on the first or second anchor section 41, 42 and the central section 38.

[0087] The fact that the two springs 61 and 62 are pre-tensioned means that they are in the Figure 6shown position are already compressed. Both springs 61 and 62 therefore already exert a force from the first and second armature sections 41 and 42 respectively onto the central section 38, or vice versa, although these two forces cancel each other out in the rest position shown. A movement of the central section 38 along the tie rods 58 experiences an essentially linear relationship between deflection and spring force due to this preload. By moving in one direction, e.g. towards the first armature section 41, the spring force of the first spring 61 increases, while the spring force of the second spring 62 decreases. If the central section 38 moves from the rest position shown in the opposite direction, the same effect occurs, with the force from the second spring 62 increasing and that from the first spring 61 decreasing.The resulting force on the central section 38 and thus also on the oscillating body 12 results from the difference between the spring forces of the two springs 61 and 62. The force relationships are therefore the same for both deflection directions.

[0088] In addition, a damping section 64 is provided, which essentially comprises a damping cylinder 66 in which a damping piston 68 moves. The damping piston 68 has a resistance piston 70, whose movement in the damping cylinder 66 is braked by the fact that a fluid in the damping cylinder 66 must pass this resistance piston 70. The damping effect, i.e. the movement-speed-dependent resistance, is essentially independent of the direction of movement of the damping piston 68 and thus the direction of movement of the resistance piston 70.

[0089] The coupling of the damping piston 68 and thus of the resistance piston 70 is effected via a sleeve tube 72, which is attached to the central section 38 and thus moves together with the movement of the central section 38, thereby also driving the damping piston 68. Guide cylinders 74 are also provided to guide the central section 38 on the tie rods 58.

[0090] It can also be seen that the coupling element is designed so that the amplitude of movement between the oscillating body 12 and the tower wall 4, and thus between the central section 38 and the first anchor section 41, is at most half the distance between the first anchor section 41 and the central section 38 in its rest position. This also ensures that the two springs 61 and 62 are not brought to their maximum deflection limit, whereby essentially linearity can be achieved in the operating range for the intended range of movement.

[0091] In addition, the Figure 6The connection of the coupling element 32 is shown, according to which the coupling element 32 is fastened with its central section 38 to the upper side of an oscillating body 12. With its anchor section 41, it is fastened via a joint head 43 to the tower wall 4 of the tower whose vibration is to be damped. An oscillating movement of the tower leads to a relative movement between the tower wall 4 and the oscillating body 12 and thus to a relative movement between the anchor section 41 and the central section 38. A slight vertical movement of the oscillating body 12 can also occur, which can be taken into account by the joint head 43.

[0092] Please note that for the sake of clarity, the same reference numerals are used for similar, but possibly not identical, elements. This applies to the description of all figures. Thus, a solution has been created and proposed that can influence, or at least dampen, the natural frequencies of the tower, thus creating more freedom in the design of a new tower. Since vibration dampers have been omitted, when designing new towers, it is necessary to ensure that the natural frequencies of the tower's bending vibration do not coincide with the excitation frequencies from the plant's operation, or do not come too close, in order to avoid harmful resonances.

[0093] When designing a tower with a vibration damper, no consideration needs to be given to the position of the natural frequency to which the damper is tuned, thus allowing greater freedom in design.

[0094] The hollow cylinder-shaped vibrating body, also known as a damper mass, allows for a central cable feedthrough in the tower. By using the largest possible damper mass radius, the installation space is optimally utilized, or at least very well, and a large amount of mass can be accommodated in the vibrating body. A star-shaped arrangement of the spring-damper elements, i.e., a star-shaped arrangement of the coupling elements, allows for an omnidirectional, i.e., virtually direction-independent, effect of the vibration damper, i.e., the coupling element.

[0095] The suspension of the oscillating body on the pendulum rods described above also enables a nearly omnidirectional effect and ensures a tilt-free movement of the oscillating body, i.e., the damper mass. The directional independence of the effect increases with the number of vibration dampers, i.e., the coupling elements.

Claims

1. A tower (102) of a wind turbine (100), having a tower central axis (24), a tower wall (4) and a vibratory apparatus for influencing a vibration of the tower (102), wherein the vibratory apparatus - has a vibratory body (12) which is suspended in the tower (102) so as to be spaced apart from the tower wall (4), and - at least one coupling element, which is fastened between the vibratory body (12) and the tower wall (4) and which serves for influencing a relative movement between the vibratory body (12) and the tower wall (4), wherein - the vibratory body (12) is formed so as to be hollow along a vertical body central axis (26), characterized in that - the vibratory body (12) is suspended by means of pendulum rods (10) on a fastening portion, wherein - three, four or more pendulum rods (10) are provided such that the vibratory body is restricted to translational or tilt-free movements.

2. The tower (102) as claimed in claim 1, characterized in that the vibratory body (12) is formed substantially as a hollow truncated cone or hollow cylinder and optionally has a vertical aperture (50) in the shell in order to provide space for a tower ladder (52) arranged at the inside on the tower wall (4), such that service personnel can climb up and down in the tower (102) along said tower ladder (52) and, in so doing, can pass the vibratory body in the region of the aperture.

3. The tower (102) as claimed in claim 1 or 2, characterized in that the vibratory body (12) has a vibratory body wall which encircles the central axis (26) and which has a wall thickness, and the wall thickness varies in a circumferential direction such that the vibratory body (12) has a center of gravity in the central axis (26), wherein the central axis (26) corresponds to a geometrical center of the vibratory body (12) and / or coincides, in the rest state of the vibratory body (12), with the tower central axis (24).

4. The tower (102) as claimed in any of the preceding claims, characterized in that the vibratory body (12) is suspended so as to be spaced apart from the tower wall (4) centrally with a mean wall spacing, and the wall spacing is in each case smaller than one quarter of a tower inner diameter in the respective region, in particular in each case smaller than one eighth of said tower inner diameter.

5. The tower (102) as claimed in any of the preceding claims, characterized in that the vibratory body (12) is suspended on a tower top flange (6), wherein the pendulum rods are equipped preferably at both sides with spherical joint heads or a cardanic suspension, such that a movement in all horizontal directions is made possible.

6. The tower (102) as claimed in any of the preceding claims, characterized in that the vibratory body (129) is produced from a material with a density higher than or equal to water, in particular with a density at least twice that of water, wherein, in particular, concrete is used as material and, in particular, the vibratory body is manufactured substantially from reinforced concrete.

7. The tower (102) as claimed in any of the preceding claims, characterized in that multiple coupling elements (32) are arranged between the vibratory body (12) and the tower wall (4) and are distributed in a circumferential direction around the vibratory body (12), and are in each case fastened to the vibratory body (12) and to the tower wall (4) in order to produce a mechanical coupling between the vibratory body (12) and the tower wall (4), wherein the coupling permits a horizontal relative movement between vibratory body (12) and tower wall (4).

8. The tower (102) as claimed in any of the preceding claims, characterized in that the multiple coupling elements (32) or some of said coupling elements are arranged above and furthermore or alternatively below the vibratory body (12), wherein preferably an even number of coupling element is provided, in particular six coupling elements.

9. The tower (102) as claimed in any of the preceding claims, characterized in that the vibratory body (12) has a center of mass and the vibratory body is suspended at such a height in the tower (102) that the center of mass is situated in an upper half, in particular in an upper three-fifths, of the tower (102) and is furthermore or alternatively suspended on a fastening portion which is arranged on the tower top flange (6) or in the vicinity thereof.

10. A vibratory apparatus designed for use in a tower (102) of a wind turbine (100) for the purposes of influencing a vibration of the tower (102), wherein the vibratory apparatus - has a vibratory body (12) which can be suspended in the tower (102) so as to be spaced apart from the tower wall (4), and - at least one coupling element (32) for fastening between the vibratory body (12) and the tower wall (4) in order to influence a relative movement between the vibratory body (12) and the tower wall (4), wherein - the vibratory body (12) is formed so as to be hollow along a vertical central axis (26), characterized in that - the vibratory apparatus has three, four or more pendulum rods (10) and is prepared for the vibratory body (12) to be suspended by means of pendulum rods (10) on a fastening portion in the tower, such that - the vibratory body is restricted to translational or tilt-free movements.

11. A vibratory apparatus as claimed in claim 10, characterized in that the coupling element, comprising - a first fastening portion for fastening to the vibratory body (12) and - a second fastening portion for fastening to the tower wall (4) in order to produce a mechanical coupling between the vibratory body (12) and the tower wall (4) via the coupling element (32), wherein - the coupling permits a relative movement between vibratory body (12) and tower wall (4), and the relative movement - has a first movement direction, in the case of which the first and the second fastening portion move toward one another, and - has a second movement direction, in the case of which the first and the second fastening portion move away from one another, and the coupling element (32) - has a spring means for resiliently elastic coupling between the first and second fastening portions, wherein the resiliently elastic coupling is described by a spring function, and the spring means is formed such that - the spring function is substantially identical for the first and second movement directions and, said coupling element (32) - has a first and a second anchor portion (41, 42), which are fixedly connected to one another, and - a central portion (38) which is arranged between the first and second anchor portions (41, 42) and which is movable relative to the first and second anchor portions (41, 42), wherein - the first or second anchor portion (41, 42) is fixedly connected to the second fastening portion and - the central portion (38) is fixedly connected to the first fastening portion, such that the relative movement corresponds to a movement of the central portion (38) between the anchor portions (41, 42), and furthermore or alternatively, the spring means is formed such that - a movement in the first movement direction in the spring means leads to a compression of a first spring portion and to an extension of a second spring portion, and - a movement in the second movement direction in the spring means leads to an extension of the first spring portion and to a compression of the second spring portion, in order to thus equalize the spring function for the first and second movement directions with one another.

12. The coupling element (32) as claimed in claim 11, characterized in that the coupling element (32) is formed as a spring-damper element and - has a damping portion (64) for coupling with damping action between the first and second fastening portions, wherein the coupling with damping action is described by a damping function, and wherein - the damping function is substantially equal for the first and second movement directions, and / or that - the spring function and / or the damping function is linear.

13. The vibratory apparatus as claimed in claim 11, wherein as spring means of the coupling element, - a first spring (61) is arranged between the central portion (38) and the first anchor portion (41), and - a second spring (62) is arranged between the central portion (38) and the second anchor portion (42), wherein the first spring (61) forms the first spring portion and the second spring (62) forms the second spring portion, and both springs (61, 62) are preferably identical, and preferably - the first and second springs (61, 62) are prestressed such that neither of the two springs reaches or overshoots a relaxed state during the movement of the coupling element (32) and / or a spacing between the first and second anchor portions (41, 42) is adjustable in order to adjust the prestress.

14. A tower as claimed in any of claims 1 to 9, comprising a vibratory apparatus as claimed in any of claims 10 to 13.

15. A wind turbine (100) having a nacelle (104) with an aerodynamic rotor (106) and having a tower (102) with a tower central axis (24), a tower wall (4) and a vibratory apparatus for influencing a vibration of the tower (102), wherein the wind turbine (100) is characterized by at least one of the features selected from the list comprising that - the tower (102) is designed as claimed in any of claims 1 to 9 or 14, and - a vibratory apparatus is formed as claimed in any of claims 10 to 13.