US20130068496A1

US20130068496A1 - Tower for a wind turbine

Info

Publication number: US20130068496A1
Application number: US13/701,114
Authority: US
Inventors: Melanie Domesle; Sven Starke
Original assignee: Suzlon Energy GmbH
Current assignee: Suzlon Energy GmbH
Priority date: 2010-06-03
Filing date: 2011-06-03
Publication date: 2013-03-21
Also published as: AU2011260250A1; US8866330B2; AU2011260249A1; DE102011076941A1; PL2577058T3; EP2577058A2; WO2011151465A4; ZA201209723B; DK2577058T3; WO2011151465A3; DE102011076940A1; US20130105199A1; WO2011151466A2; WO2011151466A3; CN102939459A; WO2011151466A4; EP2577059A2; ZA201209722B; WO2011151465A2; EP2577058B1

Abstract

The invention relates to a tower for a wind turbine and to a cable guide therefor, wherein a nacelle is arranged on the tower such that it can rotate by means of the azimuth bearing about a vertical axis which runs in the longitudinal direction of the tower. A guide device is arranged between a cable bundle and the tower, wherein the guiding device has means for supporting the lower area of the cable bundle in a radial direction, and for supporting with respect to the tower in a circumferential direction.

Description

This application is a 371 application of PCT/EP2011/059231 filed Jun. 3, 2011, which claims foreign priority benefit under 35 U.S.C. §119 of German application 10 2010 022 581.2 filed Jun. 3, 2010.
The invention relates to a tower for a wind turbine and to a cable guide for a tower of a wind turbine, wherein a nacelle for the wind turbine is arranged on the tower such that it can rotate about an axis which runs vertically in the longitudinal direction of the tower by means of the azimuth bearing. A generator for generating electrical energy is provided which can be driven by a rotor of the wind turbine, is provided in the nacelle. The azimuth bearing allows a horizontal orientation of the nacelle according to the wind direction which is called ‘wind tracking’ of the wind turbine. For automatic alignment of the nacelle on the azimuth bearing one or more azimuth drives are provided which are non-rotatably connected to the machine carrier of the nacelle. In this case, the azimuth bearings must transmit the appearing bearing forces such as thrust, centrifugal and yaw forces, from the machine carrier of the nacelle into the tower.
During wind tracking—also described as ‘yawing’—the nacelle is rotated around a vertical axis of rotation in the horizontal plane in order rotate the rotor perpendicularly in the wind and consequently to maximize the energy output. Since the wind direction varies or even rotates it may be possible that the nacelle is rotated around its own axis several times.
In the tower of the wind turbine current conducting cables, such as power cables, are routed from electrical components out of the nacelle to the ground. These are a plurality of cables, for example a plurality of cables for electrical conduction of individual phases of alternating current, in particular three-phase alternating current, cables for earthing conductor and/or signal and control cables. The exact number of the cables—in particular the power cables—is dependent on the cross section of the individual electrical conductors and the nominal current to be transmitted. Usually the current conducting capacity of a single conductor of the power cable is too small to transmit the nominal current, and therefore the nominal current is divided to a plurality of power cables.
The statements of axial direction, radial direction, circumferential direction used below and statements about the top and bottom are valid with respect to the tower axis of the erected tower of the wind turbine.
The cables are fixedly arranged in a lower portion of the tower preferably by means of cable terminals on the tower wall. In a middle part of the tower the cables are guided through a cable support into a radially central portion of the tower interior. From there the cables extend centrally and freely suspended to an upper end of the tower and into the nacelle. To prevent the cables of excessive swinging it is known that the cables are led through a tube, preferably a polyethylene tube, and through a circular opening in the topmost platform of the tower. By guiding the cable through the tube, the cable will be collected in a large bundle. The bundling and mutual induction of closely packed current-conducting cables may result into a reduced current conducting capacity of the cables. Now if the nacelle rotates around its own axis several times because of wind tracking the cables are twisted which results in a shortening of the cables. This can result in damage or wear of the insulation due to friction between the individual cables which creates a major safety hazard. Moreover, the individual cables get closer to each other thus the current conducting capacity of the cables is reduced. This has the result that the required number of cables for transmitting the nominal current increases therefor the associated cost increase.
It is an object of the invention to provide an improved guidance of the cables which i.e. avoids the disadvantages of the prior art. In particular it is to be achieved that the current conducting capacity of the cables is secured and/or the wear between the cables is reduced.
According to the invention the object is solved with the features of the claim 1 wherein, while in the tower a guiding device for at least partially fixing the area of the cable bundle to the tower is effectively arranged between the cable bundle and the tower, wherein the guiding device comprises means for supporting the lower region of the cable bundle in a radial direction and for supporting in a circumferential direction relative to the tower. The guiding device is configured in such a manner that the lower region of the cable bundle is supported to be movable in the axial direction relative to the tower but is substantially fixed in the circumferential and radial direction relative to the tower. Thus the guiding device causes that an axial displacement of the cable bundle and in particular an axial displacement of the lower region of the cable bundle is achieved through the cable guide and at the same time always a defined position of the cable bundle and defined configuration of the cable of the cable bundle is ensured.
One embodiment cites that a cable loop is provided, wherein a first end of the conductor loop is directly connected to the lower region of the cable bundle approximately at the center of the tower interior and is electrically connected thereto, and a second end of the conductor loop on the tower wall is fixedly connected to the tower and electrically connected to further leading cables which are fixed with the tower. The twisting of the cables causes the cable bundle to shortened in the axial direction. The cables are guided in the cable loop so that a free rotation of the nacelle is not prevented by a clamping of the cable and the cable would not be damaged. The shortening of the cable bundle is compensated by the excess of cable in the cable loop. It is advantageous if the cables of the cable bundle, the cable loop and the cable fixed with the tower are formed continuously and in one piece and without interruption. In other words, each cable is continuously guided from the nacelle to the foot of the tower or from the upper end of the cable bundle through the lower region of the cable bundle, passing through the cable loop over to the cable guide fixed with the tower and down to electrical terminals in the base of the tower.
By fixing the cable bundle through the guiding device in the circumferential direction for the first time it is possible to effectively prevent an uncontrolled rotation of the cable of the cable loop and thus to ensure the minimum distance of the cable with respect to each other.
According to another embodiment the guiding device comprises a bundling device for bundling and fixing the cables of the cable loop. The bundling device is arranged at the lower portion of the cable bundle or at the first end of the cable loop. Here it is ensured by geometric features of the bundling devices that at least between three cables a certain minimum distance is available in each state to prevent a reduction in the current conducting capacity of different cables by mutual induction in accordance with IEC 60364-5-52 and it does not fall below the certain minimum distance. By ‘each state’ it is meant that in each operating condition of the wind turbine and in each intended azimuth position of the nacelle the cables are spaced at a minimum distance and a mutual induction is reduced and the current conducting capacity is ensured.
According to a preferred embodiment the bundling device is configured in such a manner that all the adjacent power cables are spaced at the minimum distance. In the case of a wind turbine with a doubly-fed asynchronous generator wherein the converter unit is arranged in the foot of the tower the cables can be embodied as a plurality of power cables extending from the stator, preferably also be power cables extending from the generator rotor and/or earthing cables.
In case that a multi-phase, in particular three-phase current is led through the cable, in particular through the power cable, each power cable comprises three individual conductors. These conductors may be combined together since the magnetic fields of the respective phases of the current are canceled out against each other. Within the scope of this invention this multiphase cable with combined conductors is considered as a cable or as a current-conducting cable, especially power cable. The individual conductors not necessarily have to be surrounded by a common cover. This applies for example to combine the three phases of a three-phase current in a cloverleaf structure.
According to a further embodiment the bundling device is designed in such a manner that all the adjacent cables such as power cables, earthing cables and control and signal cables are spaced with the minimum distance.
In another embodiment the bundling device comprises fastening devices for arranging the cables. These can be arranged on the bundling device in such way that the cables are arranged in a polygonal and equilateral structure. The structure can be for example the shape of an equilateral triangle, a square, a regular pentagon, or a polygonal and equilateral shape with a plurality of corners. However, the number of corners and sides must be at least the same as the number of the cables, the power cables, or the current-conducting cables to be separated by means of the minimum distance. The fastening devices are arranged in such a manner that the distance between the closest in the receptacles fastened cables shows a minimum distance for preventing a reduction of the current conducting capacity of different cables by mutual induction according to IEC 60364-5-52. By keeping the minimum distance of the cables with respect to each other the current conducting capacity of the cable is optimized so that the number of cables required for transferring the nominal current can be reduced. This is particularly important in the cable routing of wind turbines since very high power is passed through the tower.
The polygonal and equilateral feature of the bundling device has the advantage that the distance of the individual cables with respect to each other is maximal when the overall size of the bundling device is minimal and consequently the electromagnetic interference of the cable with each other is minimized. The smallest possible diameter of the bundling device is most favorable with regard to the shortening of the cable bundle caused by twisting. The distance between the receptacles of the clamping clips therefore should be kept as short as possible so that the excess of cables for compensating the shortening of the bundle can be kept as small as possible.
In a preferred embodiment, the fastening devices are arranged in such a manner that the structure of the receptacles has an additional corner and side. The receptacle which is thereby available additionally, serves to accommodate the cable of the neutral conductor in such so that a minimum distance according to IEC 60364-5-52 is also available between the cable of the neutral conductor and the nearest current-conducting cables.
In a particularly preferred embodiment, the fastening devices are arranged in such a manner that the structure of the receptacles has exactly the same number of corners and sides as the number of the existing cables. The receptacles which are thereby available additionally, serves to accommodate signal lines so that between signal lines and the closest current-conducting cables or cables of the neutral conductor a minimum distance according to IEC 60364-5-52 is also available.
In one embodiment, the bundling device comprises a carrier on which the fastening devices are arranged to attach the cables to the bundling device. In this case, the fastening device has a receptacle for receiving the cables. The carrier may be formed in one piece or multi-piece. It is also conceivable that the carrier is formed at least partially through the fastening devices or the fastening devices are formed at least partially through the carrier. Thereby for example, several fastening devices would be assembled together so that this combined structure takes over the function of the carrier. The bundling device can be extended by attaching more clamping clips easily to the existing number of cables which saves money on installation and storage of spare parts for the bundling device.
The fastening devices are preferably configured as clamping clips which can be attached to the carrier by means of fastening elements. The fastening elements can e.g. be screws. In a first embodiment the clamping clips are non-rotatably connected to the carrier and formed in one piece so that the clamping clips together with the carrier form the fastening device. The clamping clips are advantageously formed in an arc shape so that a receptacle for a cable or for a cable with a plurality of conductors is formed. The cable which is situated in the receptacle, is clamped between the clamping clip and the carrier when mounting the clamping clip onto the carrier so that the bundling device is firmly connected to the cable.
In a preferred embodiment the clamping clip is formed as a V-shaped arc so that the receptacle has a triangular cross-section. This has the advantage that in a three-phase cable comprising three conductors the current-conducting cable is fixed by the clamping clip in the cloverleaf structure. In the case that cables with smaller diameters, for example signal cables, are available the receptacles may comprise an insert that reduces the size of the receptacle.
In one embodiment, the fastening devices are in each case arranged on the carrier to be rotatable about an axis which substantially extends in radial direction. Through the rotatable arrangement of the fastening devices the fastening devices can rotate with the twisting of the cable so that a normal axis to the triangular cross section of the receptacle of the fastening devices extends always parallel to a longitudinal axis of the cables. Thus, both the load on the cable as well as the load on the fastening devices and their connection elements can be reduced. The fastening device in this embodiment is configured in several pieces.
The features of the bundling devices act not in a limiting way onto the following embodiments.
A further aspect of the invention discloses that a cable support for arranging the individual cables of the cable loop is provided to be connected to the tower. This cable support is configured in such a manner that the cable can be arranged thereon so that at least three cables in the cable loop have in each state a minimum distance for preventing a reduction of the current conducting capacity of different cables by mutual induction according to IEC 60364-5-52. Analogous to the above-described, the cable support can also be configured in such a manner that all adjacent cables such as power cables, earthing cables and control and signal cables are at least partially spaced at a minimum distance.
In an advantageous manner the supporting means of the guiding device can be configured as a pivot arm. This pivot arm is connected to the tower at a side facing a tower inner wall in a way of being rotatable about a pivot axis and is connected to the cable bundle at a side facing the tower interior in a way of being rotatable about a rotation axis, particularly connected to the bundling device at the lower end of the cable bundle. The pivot axis and/or the rotation axis extend substantially horizontally and perpendicularly to the axial direction. In this way, the guiding device can be realized in a simple manner.
If the cable bundle is not rotated, the pivot arm is located in a substantially horizontal position wherein the bundling device is substantially coaxially aligned with the tower axis. If the cable bundle is shortened due to the rotation of the cable bundle, the pivot arm is pulled upwards with the lower region of the cable bundle. The compensation of axial shortening is achieved by the cable loop.
A further embodiment cites that the pivot arm in not rotated cable bundle is slightly inclined downwards. Thereby, the lower region of the cable bundle is arranged to be slightly radially offset to the tower axis. This has the advantage that with increasing rotation the maximum radial displacement of the pivot arm is reduced in relation to the preceding embodiment. This allows for an increased range of angles for the wind tracking.
In an alternative manner, the said guide means may comprise means for supporting which are formed as a rail arrangement. This rail arrangement comprises a first rail element and a second rail element. Here a first rail member is connected to the lower region of the cable bundle, and a second rail element is connected to the tower. Both of the rail elements engage in the radial direction and in the circumferential direction in a form-locking way so that a support of the lower region of the cable bundle in the radial direction and circumferential direction relative to the tower is possible, and wherein the first rail element and the second rail element are configured to be geometrically uncrossed in the axial direction so that a axial displacement of the lower region of the cable bundle with respect to the tower is possible. In the case of the shortening of the cable bundle, the rail element connected to the cable bundle slides axially upwardly, wherein the compensation of the length is carried out by the cable loop. It is conceivable that a plurality of rail assemblies is provided.
It is advantageous, but not acting in a limiting way on the following and preceding embodiments if the tower has at least two bundling devices which are suitable for combining the individual cables which extends longitudinally in the tower to a mutually fixed cable bundle. The bundling devices are mounted on the cables between the upper and the lower region of the cable bundle.
Advantageously, the tower comprises a plurality of bundling devices which are fastened to the cables with regular distances between the upper and the lower region of the cable bundle. The distance between the bundling devices is selected in such a manner that a twisting of the cables is indeed allowed, but the cables still have the prescribed minimum distance with respect to each other even at a maximum rotation of the nacelle.
The cable bundles advantageously have an axial distance of 500 to 1000 mm with respect to each other, particularly advantageous the distances are between 500 and 600 mm. The cable bundle hangs for the most part freely in the tower of the wind turbine, and is non-rotatably connected to the nacelle only at the upper part and non-rotatably connected to a guiding device at the lower region. The cable bundle is self-supporting and is stabilized by the bundling devices.
Due to movement of the tower and due to resonance, it can result in a swinging of the cable bundle in the radial direction. In order to limit the radial movement of cable bundle, in another embodiment, the tower includes at least one axially effective ring guide which is fixedly connected to the tower. The cable bundle is guided through the ring guide and then hangs for the most part freely in the tower of the wind turbine. Conveniently, several ring guides are used, preferably two, particularly preferably three, and most preferably four ring guides. This support also serves to preserve the cable distance from a possibly metallic guide ring.
In a further embodiment, the radial support can connect at least two successive bundling devices. In this embodiment, the axial length of the radial support must be greater than the axial shortening of the cable bundle which is generated in the actual section. Because only in this way it can be ensured that the support may be in contact with the ring guide during the entire axial movement of the cable bundle.
In particular, the distances between the bundling devices connected by the axial ring guide may be greater than the axial shortening of the cable bundle generated in the actual section. Thus, in this embodiment, the bundling devices may be also secured on the cables at irregular distances.
Since the radial support is connected to two bundling devices which are arranged to be rotatable relative to each other according to the longitudinal axis of the cable bundle the radial support may be bent during a twisting of the cable bundle. In order to prevent this, the two bundling devices may be additionally connected by a stiffener except the connecting radial support. Through this stiffener the two bundling devices, which are connected with the radial support, are non-rotatably connected to each other which prevents a twisting of the cable bundle in this area and a bending of the radial support.

Further details of the invention will become apparent from the description of the drawings.

In the drawings:

FIG. 1 shows a wind turbine,

FIG. 2 shows an upper part of the tower of the wind turbine,

FIG. 3 a shows a first embodiment of a bundling device,

FIG. 3 b shows a carrier of the bundling device,

FIG. 3 c shows a cross-section of the bundling device,

FIG. 4 shows a clamping clip of the bundling device,

FIG. 5 shows an insert of the clamping clip,

FIG. 6 a shows an axial plan view of a second embodiment of the bundling device,

FIG. 6 b shows a radial plan view of a second embodiment of the bundling device

FIG. 7 shows bundling device with loose guides

FIG. 8 a shows bundling device with radial supports,

FIG. 8 b shows ring guide for the radial guidance of the cable bundle,

FIG. 9 a shows a perspective view of the guiding device,

FIG. 9 b shows another perspective view of the guiding device,

FIG. 10 shows a perspective view of the bundling device,

FIG. 11 a shows a simplified side view of the guide device of FIG. 9,

FIG. 11 b shows a simplified plan view of the guiding device shown in FIG. 9,

FIG. 12 a shows a simplified side view of a further embodiment of a guiding device, and

FIG. 12 b shows simplified plan view of the guide device of FIG. 12 a.

FIG. 1 shows a wind turbine 1 with a tower 2, with a nacelle 8 which is rotatably mounted on the tower 2 about a tower axis 4 of the tower 2, and a rotor 9 which is connected to a generator located in the nacelle 8. During the wind tracking—also known as “yawing”—the nacelle 8 is rotated about the tower axis 4 of the tower 2 in the horizontal plane in order to perpendicularly rotate the rotor 9 in the wind and consequently maximize the energy output. Since the wind direction varies during the operation of the wind turbine 1 or even rotates, it may be possible that the nacelle 8 is rotated around its own axis several times.
The statements used below about an axial direction 5, radial direction 6, and circumferential direction 7 and the statements about the top and bottom apply to the longitudinal axis of the erected tower 2 of the wind turbine 1.
FIG. 2 shows an upper part of the tower 2 of a wind turbine 1. In the tower 2 of the wind turbine 1, a plurality of current-conducting cables 10, 11, 12, 13 are guided out of electrical components from the nacelle 8 to the ground. This current-conducting cables 10, 11, 12, 13 are, for example, cable 10 for electrically transmitting of three-phase alternating current (power cable 10), cable for ground conductor 11 and/or signal and control cable 12. The current-conducting cables 10, 11, 12, 13 are combined together to a cable bundle 14 in the upper part of the tower 2 through a plurality of bundling devices 17, 27. This cable bundle 14 is non-rotatably connected at the upper end 15 to the nacelle 8 which is rotatably mounted on the tower 2 and non-rotatably connected at the lower region 16 of the cable bundle 14 to the tower 2 but hangs essentially freely in the tower 2. In order to support a radial movement of the cable bundle 14, the tower 2 also comprises a plurality of ring guides 19 which are fixedly connected to the tower 2 and guided through the cable bundle 14.
FIGS. 3 a and 3 c show a bundling device 17 comprising a two-part carrier 18 and a plurality of clamping clips 20. The annular carrier 18 consists of two parts which are screwed together. The carrier 18 has in the radial direction 6 a plurality of bores 21 which are used to fasten the clamping clips 20. Furthermore, the carrier 18 also has bores 21 for securing, for example, radial supports 22. The individual parts of the carrier 18 are also shown in FIG. 3 b. The clamping clips 20 are formed in a substantial V-shape and comprise two flanges with bores for attaching the clamping clips 20 to the carrier 18. The clamping clips 20 are non-rotatably connected to the carrier 18 by means of screws 23 and form together with the carrier 18 a fastening device 24 for cables 10, 11, 12. The fastening devices 24 are arranged so that they form an equilateral and polygonal structure. Through this structure the cables 10, 11, 12 mounted in the fastening devices 24 have a distance D with respect to each other at any time. By the V-shape of the clamping clip 20 a receptacle 26 for cables 10, 11, 12 between the carrier 18 and the clamping clip is 20 is formed. Through the substantially triangular cross-section of the receptacle 26, particularly three- phase cables 10, 12—each comprising three conductors 10 a, 10 b, 10 c, each of which leads a phase—are held in an advantageous cloverleaf structure. The clamping clip 20 and the cloverleaf structure of the cables 10, 12 are also shown in FIG. 4. The fastening device 24 may also include an insert 25. Through the insert 25, the size of the receptacle 26 of the fastening device 24 is reduced so that cables 12 with a smaller cross-section can also be fastened. Such cables 12 may be three-phase cables of a rotor of a double-fed asynchronous generator. FIG. 5 shows the insert 25 in a removed state.
FIGS. 6 a and 6 b show a further embodiment of the bundling device 27. FIG. 6 a shows the bundling device 27 based on an axial plan view and FIG. 6 b based on a radial plan view. In this embodiment, the fastening devices 29 are each rotatably fixed about an axis 30 which extends in the radial direction 6 of the carrier 28. The fastening devices 29 form alone the receptacle 26 for the cables 10, 11, 12. Through the rotatable fixing, the fastening devices 29 can rotate with an oblique position of the cables 10, 11, 12 rotate so that the longitudinal axes of the receptacle 26 of the fastening device 29 and cables 10, 11, 12 fastened therein also remain parallel even during an oblique position of the cables 10, 11, 12. Thereby, the loads acting on the cables 10, 11, 12 and the fastening devices 29 are reduced.
The bundling device 17 shown in FIG. 7 includes a radially inner, circle-like cross-section 31. In accordance with a further embodiment, this cross-section 31 may be used to guide further cables 14, such as data, control, or the signal cables. For this purpose, a further loose guide 33 is mounted on the carrier 18 of the bundling device 17, for example in the form of a round steel bar bent into a helix which is fixed in radial bores 21 of the carrier 18. In FIG. 7, the cloverleaf formation of the cables 10, 11, 12 which are fastened in the fastening devices 24 and the distance D of the cables 10, 11, 12 with respect to each other can also be seen.
In FIG. 8 a, a cable bundle 14 with bundling devices 17 and radial support 22 is shown. In this embodiment, the radial supports 22 are formed as U-shaped rods which are respectively connected to two bundling devices 17 following one another in axial direction 5. The radial supports 22 are arranged to be movable with the ring guide 19 shown in FIG. 8 b and connected to the tower 2. Through the radial support 22, it is prevented that the bundling devices 17 hook in a ring guide 19 during an axial movement.
FIG. 9 a shows a perspective detail of the guiding device 34 and cable guide of the tower 2 of the wind turbine 1. FIG. 9 b also cites a perspective detail of the guiding device 34 and cable guide of the tower 2. The tower wall 3 itself is not shown. Here the transition of the cable guiding from the cable bundle 14 into the cable guide 39 fixed to the tower wall 3 is in the focus of consideration. The cable bundle 14 and the lower region 16 of the cable bundle 14 are shown. The lower region of the cable bundle 14 merges into the cable loop 36 which subsequently merges into the cable guide 39 fixed with the tower. With reference to the simplified FIGS. 11 a and 11 b, a side view and an axial plan view of the guiding device 34, its function and arrangement is illustrated.
The cable bundle 14 leads downwards from the upper part of the tower 2, where the cable bundle 14 is fixedly connected to the rotatable nacelle 8. The lower region 16 of the cable bundle 14 is arranged on the guiding device 34 by means of the bundling device 37 to be rotation-fixed in the axial direction 5.
The guiding device 34 comprises a pivot arm 40 which is firstly arranged on the tower 2 in a way of being rotatable about the horizontal pivot axis 41. Moreover, the pivot arm 40 carries the bundling device 37 which is attached via a support 42 on the pivot arm 40 i in a way of being rotatable about the rotation axis 43. In this embodiment (FIG. 10), the bundling device 37 comprises a carrier 38, the support 42 connected to the carrier and also on the carrier 38 arranged fastening devices 24 for fastening the cables 10, 11, 12 of the cable bundle 14. The fastening devices 24 are arranged in two axially offset rows on the carrier 38.
As already described, the cable bundle 14 is rotated corresponding to the position of the nacelle 8 in the case of a rotation of the nacelle 8 during the wind tracking. Here, the entire cable bundle 14 and the system of cable guiding are designed in such a manner that a maximum rotation of a twisting in a clockwise direction to a counterclockwise twisting, or vice versa, of 2×900°, namely five revolutions is possible. With respect to the zero degree untwisted position, this means a maximum possible twisting of the cable bundle 14 of 900 degrees in both directions. To be able to compensate for the axial shortening H of the cable bundle 14 associated with the twisting without negative limitation, the guiding device 34, cable loop 36 and the cable support 35 are arranged at the transition from the lower region 16 of the cable bundle 14 into the cable guide 39 fixed with the tower. The cable support 35 is connected to the tower wall 3.
If the cable bundle 14 is untwisted, the pivot arm 40 is located in a substantially horizontal position, wherein the bundling device 37 is substantially coaxially aligned with the tower axis 4. Now, if there is a wind tracking, then the nacelle 8 rotates and the cable bundle 14 is twisted. In this case, the cable bundle 14 is shortened in the axial direction 5 and the lower region 16 of the cable bundle 14 is pulled upwards in the direction of the nacelle 8. This causes that the bundling device 37 is moved with the pivot arm 40 upwardly, and the compensation of the shortening is carried out by the cable loop 36 which provides a supply cable reserve.
A further non-illustrated embodiment discloses that the pivot arm is slightly inclined downwards in an untwisted cable bundle. Thereby, the lower region of the cable bundle is disposed slightly radially offset from the tower axis 4. This has the advantage that, with increasing rotation, the maximum deflection of the pivot arm is reduced in relation to the preceding embodiment.
The cables 10, 11, 12, 13 of the cable bundle 14 are connected to the respective cables 10, 11, 12, 13 of the cable loop 36. The cable loop 36 is transferred via the cable support 35 into the cable guide 39 fixed with the tower. Preferably, the cables 10, 11, 12, 13 of the cable bundle 14 or the cable 10, 11, 12, 13 of the cable loop 36 is configured to be uninterrupted and integral with the respective cables 10, 11, 12, 13 of the cable loop 36 or the cable guide 29 fixed with the tower. Ergo preferably, the cable 10, 11, 12, 13 are so constructed that these uninterruptedly run from nacelle 8 down to the lower end of the tower 2.
The cable support 35 is designed in such a manner that the cables 10, 11, 12, 13 of the cable loop 36 are disposed thereon such that between at least between the essential cables 10, 11, 12, such as power cables 10, a minimum distance D is ensured. This configuration using the bundling device 14 on the guiding device 34 in conjunction with the cable loop 36 which is sorted on the cable support 35 and merges into the tower-fixed cable guide 39, enables that the required distance D of the cables 10, 11, 12, (13) with respect to each other is always observed even in the cable loop 36 which is difficult to control.
FIG. 12 a and FIG. 12 b illustrate an alternative guiding device 44. Here, the means for supporting are formed as three rail assemblies 45, and each comprises a first rail element, e.g. a sliding carriage 46, and a second rail element which is formed for example as sliding rail 47 which embraces the slide carriage 46 in the radial direction 6 and in the circumferential direction 7. The sliding carriage 46 is mounted slidably in the axial direction 5 in the sliding rail 47 but fixed by the sliding rail 47 in the circumferential and radial direction 6, 7.
The sliding carriage 46 is connected to the lower region 16 of the cable bundle 14 and in particular to the bundling device 37 which comprises the carrier 38 and fastening devices 24 arranged thereon. The sliding rail 47 is fixedly arranged in the tower 2. When the cable bundle 14 is shortened, the sliding carriage 46 slides upwards in the axial direction 5 wherein the compensation of the displacement H is performed by the cable loop 36.
The combinations of features disclosed in the embodiments should not act on the invention in a limiting way, but the features of the different embodiments can also be combined.


List of reference signs

1	wind turbine
2	tower
3	tower wall
4	tower axis
5	axial direction
6	radial direction
7	circumferential direction
8	nacelle
9	rotor
10	power cable
11	earthing conductor
12	cable
13	signal and control cable
14	cable bundle
15	end
16	lower region
17	bundling device
18	carrier
19	ring guide
20	clamping clip
21	bore
22	support
23	screws
24	fastening device
25	insert
26	receptacle
27	bundling device
28	carrier
29	fastening device
30	axis
31	cross section
33	guide
34	guiding device
35	cable support
36	Cable loop
37	bundling device
38	carrier
39	tower fixed cabling
40	pivot arm
41	pivot axis
42	support
43	rotation axis
44	guiding device
45	rail arrangement
46	sliding carriage
47	sliding rail
D	distance
H	displacement 1

Claims

1-8. (canceled)

9. Tower for a wind turbine comprising,

an upper end, on which a nacelle can be arranged to be rotatably supported,

wherein at least three cables are arranged along a axial direction in the tower and thus form a cable bundle,

an upper end of the cable bundle non-rotatably connectable to the nacelle,

and a lower region of the cable bundle non-rotatably connected to the tower,

wherein a guiding device for at least partially fixing the lower region of the cable bundle on the tower is effectively arranged between the cable bundle and the tower,

wherein:

the guiding device has a pivot arm for supporting the lower region of the cable bundle in a radial direction and for supporting in a circumferential direction relative to the tower,

the pivot arm is connected rotatably about a pivot axis to the tower at its side facing a tower wall,

the pivot axis extends substantially horizontally and perpendicularly to the axial direction,

and the guiding device is configured such that the lower region of the cable bundle is movably mounted in axial direction relative to the tower, but is substantially fixed in circumferential direction and radial direction relative to the tower.

10. A tower according to claim 9, wherein a first end of cable loop is connected directly to the lower region of the cable bundle and thereby connected electrically therewith, and a second end of the cable loop is fixedly connected to the tower and electrically connected to further cables fixed with the tower.

11. A tower according to claim 9, wherein the guiding device comprises a bundling device with fastening devices for receiving the cable wherein the bundling device is arranged at the lower region of the cable bundle, and wherein the bundling device is configured in such a manner that in each state at least three cables in the cable bundle have a minimum distance (D) with respect to each other.

12. A tower according to claim 10, wherein a cable support for arranging individual cables of the cable loop is provided to be connected to the tower, wherein the cable support is configured in such a manner and the cables can be arranged thereon in such a manner that in each state at least three cables in the cable loop have a minimum distance (D) with respect to each other.

13. A tower according to claim 11, wherein a number of fastening devices corresponds at least to the number of the cables.

14. A tower according to claim 11, wherein the bundling device comprises a carrier, wherein the fastening devices are arranged on the carrier, and/or the carrier is formed at least partially by the fastening devices or the fastening devices are formed at least partially by the carrier.

15. A tower according to claim 14, wherein the fastening devices are configured as clamping clips which are fastened on, in particular screwed onto, the carrier, and each of which comprises a receptacle for cables.

16. A tower according to claim 9, wherein the bundling device is arranged at a side of the pivot arm facing the tower interior in a way of being rotatable about a rotation axis, wherein the rotational axis extends substantially horizontally and perpendicularly to the axial direction.