WIND TURBINE AND METHOD FOR CONSTRUCTING A WIND TURBINE

Abstract

Provided is a wind turbine including a tower, a tower adapter attached to the tower and a nacelle attached to the tower adapter, whereby the tower adapter houses at least one electrical device of the wind turbine for conditioning or switching power provided by a generator of the wind turbine.

Claims

1. A wind turbine comprising: a tower; a tower adapter attached to the tower; and a nacelle attached to the tower adapter, wherein the tower adapter houses at least one electrical device of the wind turbine for conditioning or switching power provided by a generator of the wind turbine; wherein the tower adapter is connected to the tower by a slip joint or a flange connection.

2. The wind turbine according to claim 1, wherein switch gear and/or a converter and/or a transformer are housed in the tower adapter as electrical equipment.

3. The wind turbine according to claim 1, wherein the wind turbine at least one power cable for transferring the power generated by the generator to an external facility and/or a communication cable for communication with the external facility, further wherein the power cable and/or the communication cable terminate in the tower adapter or in a connector that is attached to the tower and connected to a further cable that is connected to at least one electrical device housed in the tower adapter.

4. The wind turbine according to claim 3, wherein the tower comprises a cable holder below the tower adapter for holding the power and/or communication cable prior to the installation of the tower adapter.

5. The wind turbine according to claim 1, wherein the tower comprises a service platform below the tower adapter that is accessible via an opening in the tower adapter.

6. The wind turbine according to claim 1, further comprising an opening connecting the nacelle to the tower adapter.

7. The wind turbine according to claim 1, wherein the tower adapter further houses a battery back-up device and/or cooling equipment and/or a cable support to support the power and/or communication cable and/or a controller and/or a tower adapter platform.

8. The wind turbine according to claim 1, wherein the tower adapter houses an insert module comprising at least two tower adapter platforms connected by a connection element, further wherein at least one of the tower adapter platforms carries the electrical device or at least one of the electrical devices.

9. A method for constructing a wind turbine, wherein a tower adapter that is connected to a nacelle of the wind turbine and that houses at least one electrical device of the wind turbine for conditioning or switching power provided by a generator of the wind turbine is attached to a provided tower of the wind turbine, further wherein the tower adapter is connected to the tower by a slip joint or a flange connection.

10. The method according to claim 9, wherein the wind turbine is an offshore wind turbine, and the electrical device or devices installed the tower adapter are tested onshore before transferring the tower adapter to the offshore location of the tower.

11. The method according to claim 9, wherein at least one power and/or communication cable is pre-installed in the tower and connected to a connector of the tower adapter after the tower adapter is mounted to the tower.

12. The method according to claim 9, wherein multiple power and/or communication cables are pre-installed in the tower and connected to a common connector attached to the tower prior to the mounting of the tower adapter on the tower, wherein multiple further cables attached to the electrical devices, especially to switch gear, are connected to the common connector after the tower adapter is mounted to the tower.

Description

BRIEF DESCRIPTION

[0049] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0050] FIG. 1 shows an exemplary embodiment of the wind turbine according to embodiments of the present invention;

[0051] FIG. 2 shows an intermediate step of an exemplary embodiment of a method for constructing a wind turbine according to embodiments of the present invention; and

[0052] FIG. 3 shows the intermediate step shown in FIG. 2 for another exemplary embodiment of a method for constructing a wind turbine according to embodiments of the present invention.

DETAILED DESCRIPTION

[0053] FIG. 1 shows a wind turbine 1 with a tower 2 and a nacelle 3. In the example an offshore wind turbine is shown, that is attached to a seafloor 20 via the foundation 19. While the discussed approach for reducing the complexity of constructing a wind turbine is especially advantageous for offshore wind turbines, it can also be advantageously used for onshore wind turbines.

[0054] The wind turbine 1 comprises a tower adapter 4 that connects the tower 2 to a nacelle 3. The tower adapter 4 houses multiple electrical devices 5, 6 used for conditioning and switching the power provided by the generator 7. For reasons of clarity only two of the devices 5, 6 are shown. It is however advantageous to install all components for switching and conditioning the power of the generator 7 within the tower adapter 4 or within the tower adapter 4 and the nacelle 3.

[0055] The devices 5, 6 can include switch gear, at least one converter and/or at least one transformer. The conditioning of the power is performed to provide a power with the necessary parameters to internal equipment and via the power cable 13 to an external facility, for example, a substation of an offshore wind park, an onshore facility etc. While only a single power cable 13 is shown that connects the wind turbine 1 to an external facility, this limitation is only due to clarity. Typically, the wind turbine 1 will be connected by multiple power cables 13 and typically also by at least one communication cable. For the further power cables 13 and the communication cables the following discussion concerning the connection of the power cable 13 also holds true.

[0056] The electrical devices 5, 6 can already be installed within the tower adapter 4 before the tower adapter 4 is connected to the tower 2. It is also advantageous to connect the nacelle 3 to the tower adapter before the tower adapter 4 is connected to the tower 2. The installation of the electrical devices 5, 6 and optionally also the connection between tower adapter 4 and nacelle 3 can be performed onshore.

[0057] To allow for an easy installation of the devices 5, 6 within the tower adapter 4 the devices 5, 6 can be installed as a pre-configured insert module 8 that can be pre-assembled and tested before attaching it to the tower adapter 4. The insert module 8 comprises multiple tower adapter platforms 9, 10 and a connection element 11 connecting these platforms. The electrical devices 5, 6 used for the conditioning and switching of the power provided by the generator 7 can be pre-installed on these platforms 9, 10. It is also possible to install additional equipment 21 used to operate the wind turbine 1, for example a battery back-up device, cooling equipment, a controller of the wind turbine, etc. onto these platforms 9, 10 or on other parts of the insert module 8 or the tower adapter 4.

[0058] The insert module 8 is inserted into the tower adapter 4 from the top before the nacelle 3 is attached to the top of the tower adapter 4. Protrusions 12 in the wall of the tower adapter 4 can than support the platforms 9, 10. While it can be advantageous to bolt or otherwise fix the platforms 9, 10 to the protrusions 12 or otherwise fixed the inside module 8 to the walls of the tower adapter 4, a major part of the load of the insert module 8 is already carried by the protrusions 12 therefore simplifying the attachment of the insert module 8 to the tower adapter 4.

[0059] Slip joints 17, 18 are used to connect the tower 2 to the foundation 19 and the tower adapter 4 to the tower 2. This allows for a very fast and easy installation of these components. Since the electrical devices 5, 6 and other equipment 21 is already pre-installed and tested within the tower adapter 4 only a very limited electrical installation is necessary on site. This is especially true if the nacelle 3 is already connected to the tower adapter 4 onshore, since in this case only a connection to power cables 13 or communication cables to external facilities needs to be completed. These power cables 13 and communication cables can be provided with a connector 14 that connects to a connector 15 of the tower adapter 4. To allow for an easy access to this connection the tower 2 can be provided with a service platform 16 which allows easy access for service personal to the connectors 14, 15 and optionally other equipment installed below the platform 9.

[0060] Details concerning the attachment of the tower adapter 4 to the tower 2 are now discussed with reference to FIG. 2. While FIG. 2 shows a slightly different configuration of a nacelle 3 and the tower adapter 4, both embodiments are based on the same principals and individual features can be freely transferred between the embodiments.

[0061] In the embodiment shown in FIG. 2 the tower adapter 4 is not yet attached to the tower 2. It is however already connected to the nacelle 3 and the resulting combination of these two components is lifted by the crane 22 onto the top of the tower 2. The tower adapter 4 is lowered as shown by the arrow 23. At some point the outer diameter of the top of the tower 2 will be larger than the inner diameter of the tower adapter 4 as indicated by the dashed lines 24. The distance 25 that the tower adapter 4 needs to be lifted above its final resting position to attach it to the tower is relatively small. Therefore, the requirements concerning the crane 22 are limited. The small distance 25 also limits the potential damage if the tower adapter 4 should drop due to a malfunction of the crane 22.

[0062] Due to the conical shape of the tower 2 and the tower adapter 4 the opening on the bottom of the tower adapter 4 is relatively wide. Therefore, the positioning of the tower adapter 4 and the nacelle 3 above the tower 2 does not need to be perfect but only with a certain amount of tolerance. Once the inner walls of the tower adapter 4 contact the outer walls of the tower 2 the tower adapter 4 will automatically be centered and therefore end up in a perfect position even if the initial positioning is within a certain tolerance.

[0063] Once the tower adapter 4 is lowered onto the tower the finalising steps can be performed by personal that can be transferred to the nacelle by a helicopter or by a crane lifting a platform 28. The example in FIG. 1 shows a landing spot 26 for personal landing via a helicopter and a crane 27 of the nacelle 3 that can be used to lift and lower the platform 28 to raise personal from a boat. Once the personal is in the nacelle 3 it can access the interior of the tower adapter 4 via the opening 29 and from there the service platform 16 via the opening 30. The openings 29, 30 can be closed by hatches 31, 32 or similar devices.

[0064] As already discussed with reference to FIG. 1 the tower adapter 4 includes electrical devises 5, 6 for conditioning or switching power provided by the generator 7 and further components 21. Instead of installing these components via an insert module 8 as discussed with respect to FIG. 1, FIG. 2 shows an example of these components being directly installed within the tower adapter 4. This configuration also allows a testing of the components onshore in the installed position.

[0065] The power cable 13 as well as any other power cables or communication cables can be pre-installed in the tower 2, preferably onshore. The free end of the cable 13 with its connector 14 can be attached to a cable holder 33 installed in such a way that it is easily reachable from the service platform 16. Once the tower adapter 4 is lowered onto the tower 2, service personal can reach the service platform 16 via the openings 29, 30, remove the cable 13 from the cable holder 33 and attach the connector 14 to the connector 15. Once all cables are connected, the installation of the wind turbine is complete. This allows for a very fast installation of a wind turbine.

[0066] It can be advantageous to close the openings 34 for the cables 13 in an air tight manner to close of the interior of the tower 2 below the service platform 16 against air. This can be used to avoid corrosion of the tower 2, even when the tower 2 is not coated on its interior.

[0067] A slight variation of the method discussed in the previous embodiments is now discussed with reference to FIG. 3. FIG. 3 shows essentially the same situation as shown in FIG. 2 with some minor modifications. Therefore, only the differences between the two examples will be discussed.

[0068] Instead of the slip joint 17 used in the previous examples to connect the tower adapter 4 to the tower 2, a flange connection 35 is used in FIG. 3. The tower adapter is arranged by the crane 22 such that the flange 36 of the tower adapter 4 overlaps the flange 37 of the tower 2. The flanges 36, 37 can then be connected by bolting or welding, to fix the tower adapter 4 to the tower 2.

[0069] In the example inside flanges 36, 37 are used for the connection. Service personal can access these flanges 36, 37 from the service platform 16. Alternatively, it would be possible to use outside flanges.

[0070] FIG. 3 also shows an approach for further streamlining the connection of multiple cables 13 to the tower adapter. Multiple cables 13, for example, all array cables for the wind turbine 1, can be preinstalled in the tower 2 and connected to a common connector 38 or junction box. Further cables 40 can then be pre-installed on electrical devices 5, 6 housed in the tower adapter 4, especially switch gear, and provided with a respective connector 39 or a common connector connected to all further cables 40. Once the tower adapter 4 is attached to the tower the electrical installation can then simply be completed by connecting the connectors 39 or a common connector for the further cables 40 to the common connector 38 mounted to the tower. Please note that while FIG. 3 shows freely hanging further cables 40 for reasons of clarity, those cables 40 will typically be fixed to the tower adapter during installation, by a cable holder.

[0071] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0072] For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.