GONDOLA OF A WIND ENERGY PLANT, AND METHOD FOR INSTALLATION

Description

[0001] The present invention relates to a nacelle of a wind turbine which is designed to be installed on a tower of the wind turbine, wherein the nacelle has a system transformer which is designed to transform electrical power generated by the wind turbine for feeding into a medium-voltage grid, and has an electrical interface for connecting at least one medium-voltage line, wherein the line runs through the tower of the wind turbine into the nacelle, has a pulling device installed in the nacelle with a pulling means which is designed to pull the line into the nacelle for connection to the electrical interface, and has a support structure installed in the nacelle which has a receiving area for the pulling means or the line and is designed to hold the line in the receiving area at a predetermined bending radius.

[0002] Wind turbines of the type described above are well known. Various turbine concepts exist on the market, including both geared and gearless wind turbines, in which the rotational movement of the wind turbine's rotor blades is directly converted into the movement of a generator's rotor, which generates electrical power. In the wake of increasing competition in the wind turbine sector and in light of the growing challenges posed by national legislation, wind turbine manufacturers are striving to reduce the production costs of the electricity generated by wind turbines, which also includes, among other things, a reduction in the manufacturing costs of the wind turbine.

[0003] Wind turbines are often operated in arrangements, so-called parks, in which several wind turbines feed the electrical power they generate into a medium-voltage grid, e.g. a wind farm network, from where it is then further distributed into the electricity grid or supply network.

[0004] The applicant has presented a wind turbine concept in which, in order to reduce the levelized cost of electricity, the turbine transformer, which converts the power generated by the wind turbine into a medium voltage, i.e., a voltage for the medium-voltage grid or wind farm grid, is relocated from the base of the wind turbine to the nacelle of the wind turbine. This significantly reduces the effort required to install low-voltage lines between the wind turbine generator and the turbine transformer. Instead of numerous low-voltage lines, only a single line, namely the medium-voltage line, needs to be laid from the turbine transformer through the wind turbine tower.

[0005] The installation of medium-voltage lines is challenging in practice because, compared to low-voltage lines, their deadweight is significantly higher, usually in the range of 9 kg / m or more, and they are less susceptible to bending stress than low-voltage lines. Therefore, the medium-voltage line is bent within the support structure at a predetermined bending radius. A prior art example is known from EP2604570A1.

[0006] The object of the invention was to improve a nacelle of the aforementioned type in such a way that the electricity generation costs during the construction of the wind turbine can be reduced without compromising the performance of the wind turbine.

[0007] The invention solves the underlying problem by proposing a gondola according to claim 1. In particular, the invention proposes that the support structure of the gondola comprise a number of rollers which are mounted on the support structure so as to be movable back and forth between an advanced first position and a retracted second position, wherein the number of rollers extends further into the receiving area in the first position than in the second position.

[0008] According to the invention, a "number of rollers" includes both one roller and several rollers.

[0009] Insofar as a medium-voltage grid or medium voltage is mentioned in connection with the invention, this refers to a voltage in the low to mid-double-digit kV range, for example, in a range from 10 kV to 50 kV. The upper and lower limits vary slightly depending on national definitions; the term "medium voltage" is therefore more functionally directed at the hierarchical level of the voltage grid, which lies at an intermediate level between the voltage of the generated electrical power on the one hand (low-voltage level) and the voltage level of the supply grid on the other (high-voltage level).

[0010] The invention is based on the finding that in the prior art, a significant amount of time during the installation of the medium-voltage line in the nacelle of the wind turbine had to be spent on pulling the medium-voltage line into the nacelle using a dedicated device, a so-called cable deflection or cable corner roller, and bending it from the vertical orientation in the tower to a horizontal orientation in the nacelle so that the connection to the electrical interface of the system transformer can be made.Since the equipment used in the prior art was not suitable or designed to remain in the system for cost and space reasons, the medium-voltage line always had to be moved from the equipment to the receiving area of ​​the support structure after being pulled into the nacelle. This required a considerable amount of effort and time given the considerable weight of the medium-voltage line at the level of the nacelle, i.e. at the upper end of a tower that was sometimes 150 m or higher.

[0011] This is where the invention comes in, using the fixed support structure of the nacelle itself to install the medium-voltage line. By moving the number of rollers to the first position, the support structure is placed in a position where the medium-voltage line can be pulled over the rollers through the support structure's receiving area with minimal effort. The further the number of rollers is advanced into the receiving area, the stronger the effect of lifting the traction device or medium-voltage line from the support structure and the greater the effort savings when pulling the medium-voltage line up into the nacelle through the tower.

[0012] If the rollers are then moved back into the second position after the medium-voltage line has been pulled up, the rollers extend less far into the receiving area than before, preferably no longer in the receiving area at all, and a partial or preferably complete application of the medium-voltage line to the support structure can take place, whereby a holding effect of the support structure can be absorbed.

[0013] This significantly reduces the installation time.

[0014] The number of rollers can also be pre-installed on the support structure at the factory. However, the rollers can also be stored separately as "miniature equipment" and installed on the support structure at the installation site. Equipment such as the cable corner rollers known from the prior art are completely unnecessary according to the invention.

[0015] In a preferred embodiment, the receiving region of the support structure has an arc section which extends over an angular range of 60° or more, preferably 75° or more, or particularly preferably 90° or more.

[0016] In a further preferred embodiment, the support structure has a support surface for the cable.

[0017] The further the number of rollers extends into the receiving area, the less of the support surface is contacted by the medium-voltage line or, previously, by the traction device, and the lower the frictional force that must be overcome by the traction device. Preferably, the number of rollers comprises a plurality of rollers that are distributed along the curved section, preferably with a uniform distance between adjacent rollers. Preferably, adjacent rollers are spaced from one another by an arc angle in a range of 10° to 30°, more preferably by an angle in a range of 12° to 18°. This achieves a deflection that saves force and also adequately protects the line from bending stress.

[0018] Further preferably, the number of rollers in the first position extends so far into the receiving area that the cable is spaced from the support surface.

[0019] Further preferably, the number of rollers in the second position are disengaged from the receiving area to such an extent that they are spaced from the cable. Conversely, this means that the medium-voltage line or traction device can fully rest against the support surface in the second position of the rollers, thus ensuring a holding effect due to static friction. At the same time, the rollers are no longer subjected to mechanical stress or can even be removed (see below).

[0020] In a further preferred embodiment, the number of rollers is operatively connected to a slotted guide, which defines the first and second positions, as well as an adjustment path between the two positions. The slotted guide is preferably formed in the curved section of the support structure and is designed to guide the number of rollers back and forth in the radial direction between the first position and the second position. In this sense, with multiple rollers, each roller preferably has its own slotted guide.

[0021] Preferably, the link guide additionally has an anti-tilt device in the form of several guide pins arranged laterally next to the link, which are designed to prevent the rollers from tilting.

[0022] In a further preferred embodiment, the support surface is formed from several spaced-apart surface segments. The support surface can, for example, be interrupted by several recesses in which the movable number of rollers is located, with one roller preferably arranged in each recess. One, several, or all of the surface segments preferably have a friction material that increases the friction effect. The friction material is preferably designed as a rubber pad and attached, for example, glued, to the surface segment.

[0023] In a further preferred embodiment, the pulling device comprises a winch, preferably a cable-operated winch or alternatively a drum winch, and the pulling means comprises a winch cable, for example in the form of a steel cable. In preferred embodiments, the pulling device can either be installed in the nacelle at the factory or, like the number of rollers, only be mounted in the nacelle at the site of erection of the wind turbine. After the medium-voltage line has been installed in the nacelle, the pulling device can then, for example, in preferred embodiments, be removed from the nacelle and reused for the next erection at a different site. When using a cable-operated winch, the winch cable is preferably guided or led outwards through a nacelle hatch in the central nacelle area during a lifting and lowering process. This ensures that the winch cable is guided cleanly, i.e.runs smoothly and neither causes nor sustains damage.

[0024] In a further preferred embodiment, the number of rollers is reversibly detachably mounted on the support structure. This allows for reuse of the number of rollers, which are generally not significantly worn after only one installation of a medium-voltage line in the nacelle of the wind turbine, and can therefore support a large number of installation operations. Preferably, the number of rollers is arranged on the support structure in such a way that the rollers can be removed from the turbine when they are in the second, retracted position.

[0025] In a further preferred embodiment, the support structure has a receptacle for a cable holder. For this purpose, the support structure preferably has a first end on the tower side and a second end on the interface side, with the receptacle for the cable holder being arranged at the second end.

[0026] With a distance between the second end of the support structure and the nearest cable holding element in the tower of 15 to 18 m in the vertical direction, this would correspond to a weight of that part of the medium-voltage line of 150 to 180 kg, assuming a cable weight of 10 kg / m. However, part of this weight would not have to be absorbed by the cable holder, but would already be absorbed by the support structure if the cable holder is arranged accordingly at the second end, in particular by its contact surface when the rollers are in the retracted second position. This allows the use of a mechanically simple cable holder with small dimensions. In addition, the torsions generated in the cable during azimuthal movement of the nacelle can be absorbed by the support structure.

[0027] Preferably, a cable holder such as that shown in WO 2020 / 224909 A1 is used.

[0028] Further preferably, several cable holders are used, which are distributed along the support structure and attached to the support structure. The cable holders are preferably arranged at a distance from the rollers. This improves the introduction and distribution of the cable weight into the support structure.

[0029] Particularly preferably, several cable holders are arranged in the area of ​​the second—i.e., the upper—end. A substantially horizontal orientation of the cable holders has a beneficial effect on their load-bearing capacity.

[0030] The invention has been described above in a first aspect with reference to the gondola itself.

[0031] In a second aspect, the invention further relates to a method for laying a voltage-carrying line into a nacelle of a wind turbine, wherein the nacelle is designed according to one of the preferred embodiments described above and is installed on a tower of the wind turbine.

[0032] The invention solves the problem described above with regard to this method by comprising the following steps: Moving the number of rollers into the advanced first position, lowering the traction means, wherein the traction means is guided in the receiving area and runs over the number of rollers, connecting the traction means to the live line in an area outside the nacelle, in particular below the nacelle, preferably inside the tower, pulling the live line into the nacelle by means of the traction means, wherein the line is bent from the first extension direction into the second extension direction in the predetermined bending radius, moving the number of rollers into the second, retracted position, wherein the line is held in the bent state, and connecting the live line to the electrical interface.

[0033] With regard to the method, the invention utilizes the same advantages and considerations as the gondola according to the invention. Preferred embodiments of the gondola according to the invention are also preferred embodiments of the method, and vice versa; therefore, to avoid repetition, reference is made to the above explanations.

[0034] The method is advantageously further developed by additionally including the steps: Attaching the number of rollers to the support structure before lowering the traction means, in particular before moving the number of rollers into the first position, and / or removing the number of rollers from the support structure after pulling the cable into the nacelle, in particular after moving the number of rollers into the second position.

[0035] The invention is described in more detail below with reference to a preferred embodiment of the invention and the accompanying figures. Herein: Fig. 1 a schematic spatial view of a wind turbine according to the preferred embodiment, Fig. 2 a schematic cross-sectional view through a nacelle of the wind turbine according to Fig. 1 , Fig. 3 a detailed view of a support structure of the gondola according to the Figures 1 and 2 , Fig. 4 a further detailed view of the support structure according to Fig. 3 , Fig. 5 a further detailed view of the support structure according to Fig. 3 and 4 , and Fig. 6 an interior view of the gondola according to Fig. 1 to 5 .

[0036] In Fig. 1 A wind turbine 100 is shown. The wind turbine 100 has a tower 102, on top of which a nacelle 104 is arranged. A rotatably mounted hub 106 with a number of rotor blades 108 is arranged on the nacelle 104, which drive a generator 107 to generate electrical power.

[0037] A system transformer 1 is arranged in the nacelle 104. The system transformer 1 is located on a side of the nacelle 104 facing away from the hub 106 relative to the tower axis.

[0038] The system transformer 1 has an electrical interface 3, which is designed for connection to a medium-voltage line 5 (hereinafter: line 5). Line 5 is indicated by a dashed line. Modified description page (fair copy)

[0039] Furthermore, a pulling device 7 is installed in the gondola 104, which has a pulling means 9 which can be retracted and extended in the direction of the arrow P 1 in order to be lowered and pulled up through the tower 102 in order to be able to install the line 5 in the gondola 104.

[0040] The line 5 has a first line section 15, which is oriented substantially parallel to the tower 102, i.e., substantially vertically, and a deflection section 17, in which the line 5 must be bent. Finally, the line 5 has a third section 19 at its transformer-side end, which is oriented substantially horizontally and can extend, for example, along the ceiling of the nacelle 104.

[0041] The schematic layout of the internal structure of the nacelle 104 is shown in Fig. 2shown in more detail. Extending from the tower 102 of the wind turbine 100 is a machine support 105, to which the hub 106 and the generator 107 are also attached. In a direction away from the hub side, the cable 5 extends to the system transformer 1, to which it is connected via the electrical interface 3. In the deflection section 17, there is a support structure 21 that is permanently installed in the nacelle 104 and has a number of rollers 23, namely a plurality of rollers 23, the functioning of which will be discussed in more detail in the following figures. Furthermore, a number of control cabinets 11 and a low-voltage distribution structure 13 are arranged in the nacelle 104.

[0042] The arched support structure 21 is in Fig. 3shown in more detail. The rollers 23 of the support structure 21 are arranged in an arcuate section 25, which extends over an angular range of α = 90°. A total of six rollers 23 are provided. The rollers 23 are spaced from each other at an angle β, which preferably lies in a range between 12° and 18°. Each of the rollers 23 is radially arranged in the direction of the arrows P 2 between a Fig. 3 shown advanced first position S 1 and one in Fig. 5 shown retracted position S 2 movable.

[0043] The support structure 21 has a first, tower-side end 33 and an oppositely arranged interface-side second end 35, wherein the second end 35 is designed to receive a cable holder which is in Fig. 6 is shown in more detail.

[0044] Fig. 4 shows the mechanism of one of the rollers 23, which in Fig. 4are hidden, in the support structure 21. Each of the rollers 23 is rotatably mounted about an axis 37 and in a slotted guide 39 between the shown first position S 1 and a second position S 2 (cf. Fig. 5 ) is movable. The slotted guide 39 defines an adjustment path 40 between the first position S 1 and the second position S 2 . In the illustrated embodiment, the adjustment path of the slotted guide 39 runs in the radial direction, in the direction of the arrows P.

[0045] The guide rail 39 is additionally provided with an anti-tilt device 41, which is intended to prevent the axle 37 from tilting sideways. The anti-tilt device 41 has two lateral pins 43, which engage opposite one another on a movable plate 45, which supports the axle 37 on both sides of the support structure 21. Locking the rollers 23 in the first position S 1 or the second position S 2 can be achieved, for example, by means of screw connections 49 attached to the ends.

[0046] The rollers 23, together with the axle 37, can also be removed from the support structure 21 by removing the screw connections 49, preferably in the second position S 2 , in order to reuse them in a wind turbine after the cable 5 has been installed. The effort required to remove the rollers 23 is minimal, and the transport effort required to transport the rollers to the next wind turbine is also very favorable compared to the cable corner rollers known from the prior art.

[0047] As can be seen from Fig. 5As can be clearly seen, the rollers 23 on the support structure 21 in the second position S 2 are disengaged from the receiving area 31 to such an extent that a cable 5, if laid in the receiving area 31, would no longer touch the rollers 23, but would rest exclusively on the surface segments 27' of the support surface 27. If a cable holder 53 is then installed in the interface-side end 35 in the receptacle 51 provided for this purpose, the support surface 27 additionally contributes to holding the cable 5 by means of static friction.

[0048] In the Fig. 6In the schematic spatial representation shown, the winch 7 is shown once again from a different orientation. The winch 7 is still connected to the cable 5 by its traction means 9, which is, for example, a steel cable, in order to emphasize the linkage. However, the cable 5 is already installed in the nacelle 104 and is guided near a ceiling of the nacelle 104 in the direction of the system transformer 1. The entire installation process can be carried out using the support structure 21 permanently installed in the wind turbine 100, wherein only the number of rollers 23 for this purpose either have to be inserted into the support structure 21 or have already been inserted and only have to be moved into the first position S 1.

[0049] During operation, the following procedure is preferably carried out: First, the winch 7 with its traction device 9 is provided in the nacelle 104, either ex works or at the installation site. The traction device 9 is then introduced into the receiving area 31 of the support structure 21 and guided through this into the tower 102 of the wind turbine 100. In the base area of ​​the wind turbine 100, the cable 5 is connected to the traction device 9 and then pulled upwards through the tower 102 into the nacelle 104 by means of the winch 7. The traction device 9 and later the cable 5 are guided into the receiving area 31 during the upward pulling into the nacelle 104 and run over the rollers 23, which are in the first position S 1.

[0050] Once the cable 5 has been sufficiently pulled into the nacelle 104, the cable 5 can be connected to the electrical interface 3 of the system transformer 1.

[0051] Afterwards, or even before, the rollers 23 can be retracted from the first position S 1 into the second position S 2 in order to cause the cable 5 to rest on the support surface 27 of the support structure 21 and to achieve a holding effect. The holding effect is preferably increased by inserting a cable holder into the receptacle 51, which prevents the cable 5 from slipping axially, in particular in the direction of the tower 102, i.e. following the force of gravity. After the cable 5 has been installed, the rollers 23 can either remain in the second position S 2 or, preferably, be removed from the support structure 21 and prepared for reuse in another wind turbine. From this it is clear that the invention brings with it significant advantages in the handling of the cable 5.Although the number of manual steps required to install and move the rollers 23 into their respective first position S 1 may initially appear to be a disadvantage, it has been found that this handling is significantly more time- and cost-saving than using a separate operating device in the form of a cable corner roller due to the use of the support structure 21 which is already required in the wind turbine, because the energy- and time-consuming process of transferring the cable 5 from such an operating device to the support structure can be completely eliminated. List of reference symbols

[0052] 1System transformer 3Interface 5Cable 7Winch 9Traction device 11Control cabinet 13Low-voltage distribution structure 15Cable section 17Deflection section 19Third section 21Support structure 23Rollers 25Curved section 27Support surface 27Surface segment 31Support area 33First end 35Second end 37Axle 39Sliding guide 40Adjustment path 41Anti-tilt device 43Pin 45Plate 49Screw connection 51Receiver 53Cable holder 100Wind turbine 102Tower 104Nacelle 105Main frame 106Hub 107Generator 108Rotor blade P 1 , P 2 Arrow S 1 first position S 2 second position αAngle βAngle

Claims

1. Nacelle (104) that forms part of a wind power installation (100) and is configured to be installed on a tower (102) of the wind power installation (100), wherein the nacelle (104) has an installation transformer (1) that is configured to transform electrical power generated by the wind power installation (100) for feeding into a medium-voltage grid, and has an electrical interface (3) for connecting at least one medium-voltage line (5), wherein the line (5) runs through the tower (102) of the wind power installation (100) into the nacelle (104), has a pulling device (7) that is installed in the nacelle (104) and comprises a pulling means (9), which is configured to pull the line (5) into the nacelle (104) for connection to the electrical interface (3), and has a supporting structure (21) that is installed in the nacelle (104), has a receiving region (31) for the pulling means (9) or the line (5) and is configured to keep the line (5) within a predetermined bending radius in the receiving region (31), characterized in that the supporting structure (21) has a number of rollers (23) that are mounted on the supporting structure (21) so as to be able to move back and forth between an advanced, first position (S1) and a retracted, second position (S2), wherein, in the first position (S1), the number of rollers (23) extend further into the receiving region (31) than in the second position (S2).

2. Nacelle (104) according to Claim 1, characterized in that the receiving region (31) has a curved portion (25) that extends over an angular range of 60° or more, preferably 75° or more, particularly preferably 90° or more.

3. Nacelle (104) according to either of the preceding claims, characterized in that the supporting structure (21) has a bearing surface (27) for the line (5).

4. Nacelle (104) according to one of the preceding claims, characterized in that the number of rollers (23) have a multiplicity of rollers (23) that are distributed along the curved portion (25), preferably with an even spacing between respectively adjacent rollers (23).

5. Nacelle (104) according to Claim 3 or 4, characterized in that, in the first position (S1), the number of rollers (23) extend into the receiving region (31) to such an extent that the line (5) is spaced apart from the bearing surface (27).

6. Nacelle (104) according to one of the preceding claims, characterized in that, in the second position (S2), the number of rollers (23) are withdrawn from the receiving region (31) to such an extent that the number of rollers (23) are spaced apart from the line (5).

7. Nacelle (104) according to one of the preceding claims, characterized in that the number of rollers (23) are operatively connected to a slot guide (39) that defines the first and second positions (S1, S2) as well as an adjustment path (40) between the two positions (S1, S2).

8. Nacelle (104) according to Claim 7, wherein the slot guide (39) is configured to guide the number of rollers (23) in a radial direction back and forth between the first position (S1) and the second position (S2).

9. Nacelle (104) according to one of the preceding claims, characterized in that the bearing surface (27) is formed from a plurality of spaced-apart surface segments (27').

10. Nacelle (104) according to one of the preceding claims, characterized in that the pulling device (7) has a winch, preferably a drum winch, and in that the pulling means (9) has a winch cable.

11. Nacelle (104) according to one of the preceding claims, characterized in that the number of rollers (23) are mounted in a reversibly releasable manner on the supporting structure (21).

12. Nacelle (104) according to one of the preceding claims, characterized in that the supporting structure (21) has a receptacle (51) for a cable holder (53).

13. Nacelle (104) according to Claim 12, characterized in that the supporting structure (21) has a tower-side, first end and an interface-side, second end, and in that the receptacle for the cable holder is arranged at the second end.

14. Method for routing a live line (5) into a nacelle (104) of a wind power installation (100), wherein the nacelle (104) is designed according to one of the preceding claims and installed on a tower (102) of the wind power installation (100), the method comprising the steps of: - moving the number of rollers (23) into the advanced, first position (S1), - lowering the pulling means (9), wherein the pulling means (9) is guided in the receiving region (31) and runs over the number of rollers (23), - connecting the pulling means (9) to the live line (5) in a region outside of the nacelle (104), in particular beneath the nacelle (104), preferably within the tower, - pulling the live line (5) into the nacelle (104) by way of the pulling means (9), wherein the line (5) is bent from the first direction of extent into the second direction of extent within the predetermined bending radius, - moving the number of rollers (23) into the retracted, second position, wherein the line (5) is kept in the bent state, and - connecting the live line (5) to the electrical interface (3).

15. Method according to Claim 14, comprising: - attaching the number of rollers (23) to the supporting structure (21) before the pulling means (9) has been lowered, in particular before the number of rollers (23) have been moved into the first position, and / or - removing the number of rollers (23) from the supporting structure (21) after the line (5) has been pulled into the nacelle (104), in particular after the number of rollers (23) have been moved into the second position.