WO2010048964A2

WO2010048964A2 - A wind turbine generator comprising a frame adapted to be attached to a support by a guiding system

Info

Publication number: WO2010048964A2
Application number: PCT/DK2009/050286
Authority: WO
Inventors: Allan Laursen Molbech
Original assignee: Vestas Wind Systems AS
Current assignee: Vestas Wind Systems AS
Priority date: 2008-10-31
Filing date: 2009-10-30
Publication date: 2010-05-06
Anticipated expiration: 2011-04-30
Also published as: WO2010048964A3

Abstract

This invention relates to a wind turbine generator comprising a nacelle including at least one power converter. The power converter comprises a frame adapted to be attached to a support by a guiding system, wherein the guiding system comprises a first and second connecting means allowing movement between the frame and the support in a first direction and preventing movement between the frame and the support in a second direction essentially perpendicular to said first direction. The invention also relates to a method for replacing a power converter having a frame fastened to a support in a wind turbine generator nacelle.

Description

A wind turbine generator comprising a frame adapted to be attached to a support by a guiding system

Technical field This invention relates to a wind turbine generator comprising a nacell including at least one power converter said power converter comprising a frame adapted to be attached to a support by a guiding system. The inventic also relates to a method for replacing a power converter having a frame fastened to a support in a wind turbine generator nacelle.

Background of the invention

In general, a wind turbine generator or plant comprises a tower carrying a nacelle. The nacelle is connected with the rotor via an axis which connected to a gearbox, generator, and optionally other parts located in the nacelle.

As the life span of a wind turbine plant generally exceeds twenty year and, although, frequent maintenance is carried out, parts of the plant may b( worn out during the life span and it may be necessary to replace one or mor of those parts. When the tower of the wind turbine plant is erected, it is normal procedure to use a crane to lower or hoist the parts from and to the nacelle including replacement parts for the nacelle. The crane may be an internal crane located within the nacelle or the crane may be an external crane. Whe larger and heavier parts have to be replaced, the normal procedure is to attach the part to a crane and then remove the nuts and bolts that fasten the part to a support structure. When the nuts and bolts have been removed, th part to be replaced will hang in and, thus, be controlled by the cables of the crane. The part is attached to the crane with a certain pretension in its cable ensuring that the crane carries and controls the part once the nuts and bolts are removed. The larger part in question may e.g. be a generator, a gearbo> or a transformer. Such parts may weight several tons and may constitute a potential risk to the fitters present in the nacelle during the replacement operation. The part may swing or tilt in the cables of the crane e.g. due to a movement of the nacelle or due to a sudden blast of wind. This is also the case if the pretension in the cables is incorrect or unbalanced. In the latter case the part will then make a sudden more or less uncontrolled jump. The swinging, tilting or jumping of the part may in unfortunate circumstances cause damage to the fitters or surrounding components, and the damage may be severe.

Consequently, for safety reasons it is desired to find ways in which replacement of heavy parts in the nacelle can be performed in a controlled manner without unwanted movements of the part to be replaced.

It is also an object to provide a safer working environment for fitters working in the nacelle of a wind turbine generator.

Summary of the invention

In a first aspect, the invention relates to a wind turbine generator comprising a nacelle including at least one power converter, said power converter comprising a frame adapted to be attached to a support by a guiding system, wherein said guiding system comprises a first and second connecting means allowing movement between the frame and the support in a first direction and preventing movement between the frame and the support in a second direction essentially perpendicular to said first direction.

The guiding system makes it possible to replace a power converter in a safer way as the possible options for movement of the power converter when its frame is loosened from the support is restricted to one direction only. Thus, tilting and other undesired movements of the power converter can be avoided.

The support may be a metal structure e.g. a grid forming the floor of the nacelle and having sufficient strength to support the power converter when the power converter is fastened to the support, i.e. when the frame of the power converter is fastened to the support.

The frame carries the power converter and it may have several designs, e.g. a pair of metal beams attached to the power converter. The frame may be attached to the bottom, the sides or the top of the power converter.

The power converter may e.g. be a gearbox, a generator or a transformer, which all are examples of power converters with a considerable weight, and they may cause serious damage in case of undesired and unexpected movement during replacement in a nacelle. In an embodiment the first direction is a vertical direction. This embodiment is advantageously as only a crane can move the power converter in vertical direction and gravity will serve to keep the power converter at rest when the crane is not in operation.

For the purpose of moving the power converter with a crane the frame or the power converter has mountings to be fixed to a crane. In an embodiment of the wind turbine generator according to the invention, the first connecting means are located on the frame, and the second connecting means are located on the support. This is an embodiment that facilitates the fastening between the frame and the support and also serves to ensure a safer connection between the frame and the support. In a further embodiment the first connecting means comprises at least one gripping means to engage with at least one recess and the second connecting means comprises a protrusion with at least one recess. Consequently, the gripping means of the first connecting means may engage with the recess of the second connection means and, thereby, serve to connect the frame and the support in a safe connection. As such the first and the second connection means may form a dovetail connection.

The at least one recess in the protrusion can be orientated in the vertical direction and, thereby, the recess determines the direction of the first direction to be a vertical direction. In an alternative embodiment of the wind turbine generator according to the invention, the first connecting means comprises at least one hook and the second connecting means comprises receiving means for receiving the at least one hook located on the first connecting means. The term hook in this context is to be interpreted in a broad sense as the hook may simply be in the form of an U-profile or alternatively a L-profile or the hook may have a more sophisticated design as long as it can engage with the receiving means on the second connecting means. The receiving means may e.g. be a recess or a hole in the second connecting means.

Moreover, the invention also comprises an embodiment where the support comprises a protrusion adapted to support the frame. Although the first and the second connecting means may hold the frame with the power converter connected to the support with a stable connection, in some situations it is desirable with a further support of the frame, in particular at the bottom part of the frame. This protrusion supporting the frame at the bottom part may reduce the risk that the power converter suddenly tilts, although it is connected to the support with the first and second connecting means. In a further preferred embodiment of the wind turbine generator according to the invention the guiding system comprises a third connecting means adapted to connect the frame to the support and prevent movement of the frame in relation the support. The first and the second connecting means can be considered to provide a temporarily attachment of the power converter to the support, and provides an excellent solution for the limited period of replacing the power converter. However, for longer terms a more secure and permanent attachment is required, and consequently, the third connecting means can provide an attachment based on welding, rivets, screws, or bolts and nuts. Preferably the third connecting means comprises bolts and nuts.

The invention also relates to a method for replacing a power converter having a frame fastened to a support in a wind turbine generator nacelle. The method comprises the step of: removing the fastening means fastening the frame of the power converter to be replaced to the support; lifting the power converter free from a guiding system; placing a replacement power converter to engage with the guiding system; fastening the frame of the replacement power converter to the support with fastening means; wherein the guiding system allows a movement of the power converter in first direction and prevents movement in a second direction substantially perpendicular to the first direction when the power converter is not fastened with fastening means. The method provides a safer way of replacing a power converter, as the method restricts the possible and desirable movements of a power converter during replacement.

The method allows only movement of the power converter in a first direction and, thereby, undesired movement is avoided. The term "direction" in this context means a longitudinal or linear direction where the movement is possible in two directions, i.e. back and forth. A crane may control the movement in the first direction and, thus, in an embodiment the method comprises the further step of attaching the frame and the power converter to a crane. As a crane is highly suitable of moving goods in a vertical direction it is preferred that the first direction is a vertical direction. In this manner the embodiment ensures an easy and safe replacement of the power converter. Moreover, this embodiment has the advantage that the gravity helps to keep the power converter at rest, when it not is moved by a crane.

Although the fastening means may be screws, welds or the like it is preferred the fastening means are bolts and nuts, as these easy can be loosened and fastened.

In an embodiment of the method according to the invention the guiding system comprises a receiving member having one or more recesses located on the support and at least one hooked member located on the frame, wherein the at least one hooked member is adapted to engage with the one or more recesses on the receiving member. The guiding system may provide a dovetail-like connection and, thus, the guiding system is capable of connecting the support and the frame and keeps them in a substantially fixed position in relation to each other.

In some situations the guiding system may not be sufficient to avoid sudden and dangerous tilting of the power converter when the fastening means have been removed, i.e. the guiding system is not alone sufficient to carry the load of the frame and the power converter. Therefore, in an embodiment the support comprises a protrusion that abuts and further supports the frame. Preferably the protrusion is placed in a position to abut the frame at the bottom of the frame in which position the protrusion provides a good support that in cooperation with the guiding system can prevent the frame from tilting.

Other objectives, features and advantages of the present invention will appear from the following detailed disclosure, from the attached claims as well as from the drawings.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the [means, step, etc]" are to be interpreted openly as referring to at least one instance of said means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

Brief description of the drawings

The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the present invention, with reference to the appended drawings, where the same reference numerals will be used for similar elements, wherein:

Fig 1 illustrates an embodiment of the guiding system according to the invention;

Fig 2 illustrates the embodiment of Fig 1 seen from above;

Fig 3 illustrates engagement of the connecting means seen in Fig 1 and 2;

Fig 4 illustrates an alternative embodiment of the guiding system according to the invention;

Fig 5 shows an embodiment of a protrusion to support a frame from tilting.

Detailed description of preferred embodiments Fig 1 illustrates an embodiment of the guiding system 1 according to the invention. The guiding system 1 comprises a first connecting means 2 and a second connecting means 3. The first connecting means 2 is attached to a frame 4 carrying a power converter 5. The second connecting means is attached to a support 6. A recess 7 is seen in the second connecting means 3. The recesses 7 are formed in the vertical direction and therefore restricts movement of the first connecting means 2 to the vertical direction. All the parts mentioned are located within a nacelle of a wind turbine generator (not shown). Moreover the frame 4 is attached to a crane by means of cables (not shown). In this illustrative embodiment the frame 4 is shown as a pair of beams attached to the power converter 5. The frame 4 may be attached to the power converter by any suitable means, e.g. by welding, screws, and nuts and bolt, or the frame 4 may be fully integrated in the power converter 5. As such, it is not important how the frame 4 and the power converter 5 is located in relation to each other, however in the illustrated embodiment the frame 4 is located at the bottom of the power converter 5. The support 6 may form the floor or part of the floor in the nacelle. The support 6 may have a grid-like structure and be formed by profiled metal beams preferably welded together. The support 6 should have sufficient strength to support one or more power converters 5 in the nacelle. Fig 2 shows the embodiment of Fig 1 seen from the above. Two pairs of first connecting means 2 and second connecting means 3 are shown. The first connecting means 2 is attached to the frame 4 carrying the power converter 5. The second connecting means 3 are attached to the support 6. As seen the first connecting means 2 comprises hook-like L-profiles 8 to engage with the recesses 7 of the second connecting means 3.

Fig 3a and 3b illustrate the engagement between the first connecting means 2 and the second connecting means 3. In Fig 3a it can be seen that during the engagement the L-profiles 8 of the first connecting means 2 are located in the recesses 7 of the second connecting means forming a dovetail- like connection. In Fig 3b the engagement is seen from the side.

Fig 4a and 4 b illustrate an alternative embodiment of the guiding system according to the invention. The first connecting means 2 comprises a hook constituted by a L-profile 8 adapted to engage with a hole or recess 7 in the second connecting means 3. Fig 4a shows the connecting means 2 and 3 apart. Fig 4b and 4c shows the connecting means engaging. Fig 4b shows the engagement from the side and Fig 4c shows the engagement from above. When a power converter 5 has to be attached to a support 6 in a nacelle, this is carried by attaching the frame 4 of the power converter 5 to a crane , e.g. by means of cables, and hoisting the frame 4 with the power converter 5 to a position in the nacelle where the first connecting means 2 on the frame 4 and the second connecting means 3 on the support 6 are in the vicinity of each other. This position is illustrated in Fig 1 , 2 and 4a. In principal it is only desirable to maintain the frame 4 and the power converter 5 in this position the shortest time possible, as the frame 4 and the power converter 5 are able to make undesired movements in this position. Therefore, the frame 4 and the power converter 5 are moved to a position where the first connecting means 2 is just above the second connecting means 3 and by a movement downwards in vertical direction the hook 8 catches the recess 7 and, thereby, forming engagement between the first connecting means 2 and the second connecting means 3. When the hook 8 occupies the recess 7 the engagement is completed. This situation is illustrated in Fig 3a, 3b, 4b and 4c. The frame 4 can only move in vertical direction due to the vertical direction of the recesses 7, and as gravity will force the frame 4 downwards in the second connecting means 3 the frame 4 will only be able to move by the action of the crane. When the engagement is completed the frame 4 may be disconnected from the crane. However, in must cases it is preferred to maintain the attachment to the crane until the frame 4 has been further attached to the support 6 with nuts and bolts, which further attachment will prevent movement of the frame 4 in relation to the support 6. In case the frame with the power converter has to be removed from the support, substantially the same steps are carried out but in reverse order.

Fig 5 shows a protrusion 9 that supports the frame 4 at the bottom when connecting means 2 and 3 connects the support 6 and the frame 4. The protrusion 9 comprises an edge 10 that improves the supporting action on the frame 4. This embodiment is advantageously if the first and second connecting means 2, 3 are unable to carry the load of the frame 5 and the power converter 5. Thus a wedging action between the first and second connecting means 2, 3 may appear as the result of the centre of gravity is outside the guiding means 2,3. This may lead to a tilting of the frame 4 and the power converter 5.

The tilting can be avoided by use of the protrusion 9, where the edge 10 abuts the bottom of the frame 4 and provides a further support that in combination with the guiding means prevents the tilting. The embodiments shown in Fig 1 to 5 are meant to illustrate the principle of the invention and the dimensions of the connecting means in relations to the dimensions of the frame and the support are exaggerated.

By using the guiding system that only allows movement of the frame and power converter in one direction when the frame is not fastened to the support with nuts and bolts it is possible to improve the safety in the nacelle in case the power converter has to be replaced.

The invention has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims.

Claims

1. A wind turbine generator comprising a nacelle including at least one power converter, said power converter comprising a frame adapted to be attached to a support by a guiding system, wherein said guiding system comprises a first and second connecting means allowing movement between the frame and the support in a first direction and preventing movement between the frame and the support in a second direction essentially perpendicular to said first direction.

2. A wind turbine generator according to claim 1 , where the first direction is the vertical direction

3. A wind turbine generator according to claim 1 or 2, wherein the frame carries the power converter.

4. A wind turbine generator according to any of the claims 1-3, wherein the frame or the power converter have mountings to be fixed to a crane.

5. A wind turbine generator according to any of the claims 1 -4, wherein the first connecting means are located on the frame, and the second connecting means are located on the support.

6. A wind turbine generator according to any of the claims 1-5, wherein the first connecting means comprises at least one gripping means adapted to engage with at least one recess being formed on said second connecting means..

7. A wind turbine generator according to any of the claims 1-6, wherein the second connecting means comprises a protrusion with at least one recess adapted to engage said first connecting means.

8. A wind turbine generator according to claim 7, wherein the at least one recess in the protrusion is orientated in the vertical direction.

9. A wind turbine generator according to any of the claims 1-5, wherein the first connecting means comprises at least one hook adapted to engage said second connecting means.

10. A wind turbine generator according to any of the claims 1 -5 and 9, wherein the second connecting means comprises receiving means for receiving at least one hook located on the first connecting means.

11. A wind turbine generator according to any of the claim 1 , wherein the support comprises a protrusion adapted to support the frame.

12. A wind turbine generator according to any of the claims 1-11 , wherein the guiding system comprises a third connecting means adapted to connect the frame to the support and prevent movement of the frame in relation the support.

13. A wind turbine generator according to claim 12, wherein the third connecting means comprises bolts and nuts.

14. A method for replacing a power converter having a frame fastened to a support in a wind turbine generator nacelle, said method comprises the steps of: removing fastening means fastening the frame of the power converter to be replaced to the support; lifting the power converter free from a guiding system; placing a replacement power converter to engage with the guiding system; fastening the frame of the replacement power converter to the support with fastening means; wherein the guiding system allows a movement of the power converter or the replacement power converter in first direction and prevents movement in a second direction substantially perpendicular to the first direction when the power converter or the replacement power converter is not fastened with fastening means.

15. A method according to claim 14, wherein the method comprises the further step of attaching the frame and the power converter to a crane.

16. A method according to claim 14 or 15, wherein the first direction is a vertical direction.

17. A method according to any of the claims 14 to 15, wherein the fastening means is bolts and nuts

18. A method according to any of the claims 14-17, where the guiding system comprises a receiving member having one or more recesses located on the support and at least one hooked member located on the frame, wherein the at least one hooked member is adapted to engage with the one or more recesses on the receiving member.

19. A method according to any of the claims 14-18, wherein the support comprises a protrusion supporting the frame.