# Patent

## Title
Wind turbine power module mounted on the tower foundation

## Abstract

The invention relates to a method of constructing a wind energy plant and to a wind energy plant as such. In one aspect, the invention provides a method for constructing wind energy plants at lower expenses and more rapidly. According to one embodiment, a method for constructing a wind energy plant that comprises a tower that is based on a foundation and an electrical power module, the power module is mounted on the tower foundation before the tower itself is constructed. The power module includes a transformer and may optionally an inverter and/or other electrical installations, such as for example switch cabinets, that are provided for controlling the wind energy plant and/or for guiding the electrical power that is provided by the generator of the wind energy plant and that is fed to a network.

## Background
RELATED APPLICATIONS
This application is a divisional application of application Ser. No. 12/072,235, filed Feb. 25, 2008, (now U.S. Pat. No. 7,663,263), which is a divisional application of application Ser. No. 10/477,299 (now U.S. Pat. No. 7,365,446), filed Nov. 10, 2003, which is the National Stage of International Application No. PCT/EP02/10212, filed on Sep. 12, 2002, which claim priority to German Patent Application DE 101 45 414.7, filed on Sep. 14, 2001. The U.S. applications are incorporated herein by reference.


BACKGROUND INFORMATION
The invention concerns a method for constructing a wind power plant as well as the wind power plant itself in its configuration.
Thus far, when constructing wind power plants there is first produced a foundation, then the tower of the wind power plant is erected and subsequently the machine house is outfitted at the tip of the tower and the rotor is affixed with the rotor blades. After this, the electric power modules such as transformer, switch cabinets, possibly inverters, a medium-voltage system, a low-voltage distribution, etc., are installed. This is almost always done in a special small building outside the wind power plant.
In DE 198 16 483.1 it has already been proposed to accommodate the transformer inside the tower, so that it is no longer necessary to construct a special transformer building with its own foundation.
SUMMARY OF THE INVENTION
The purpose of one aspect of the invention, now, is to develop a method by which the construction of wind power plants can be done even more advantageously, but especially even faster.
According to one aspect of the invention, it is proposed, in departure from the design of wind power plants heretofore, after constructing the foundation of the wind power plant, to place the essential power modules, i.e., transformer, switch cabinets, etc., on the foundation and only then erect the tower, so that all of the power modules after the erection of the tower are protected in the region of the tower foundation or in the lower part of the tower and rest safely on the tower foundation.
The power modules are prefabricated as much as possible and mounted on carriers, so that the power modules can be set up on the tower foundation by a crane, which is needed anyway to construct a wind power plant, and the entire operational readying, especially the laying of cables and the entire operational preparation of the wind power plant, can occur in a protected space by adjustment of individual control modules, outfitting of the switch cabinets, etc., and these activities can commence once the tower has been constructed.
It is also especially advantageous for the carriers of the power modules to have support feet, which in turn rest on prepositioned plates on the tower foundation. These plates are already fitted in front of determined positions during the creation of the foundation and they are fixed to the foundation so that the power modules can also be set up afterwards in very simple way and manner.
Finally, it is also very advantageous to provide empty conduit cross arms in the foundation of the wind power plant for the cables leading out from the plant, i.e., especially the power transmission cables, control cables, etc., and to install these empty conduit cross arms in predetermined positions. For this, the cross arms are held by holding arms, which in turn are fixed in portions of the foundation or in the lower section of a tower. With these empty conduit cross arms, the region of the cable laying can be exactly predetermined and also in particular laid such that the cables extending from the power module to the foundation have the shortest and an optimal cable route.
The measures according to one aspect of the invention thus also facilitate the overall electrical equipment of the wind power plant by a prefabrication of individual modules such as the empty conduit cross arms, power module carriers, etc., as early as the construction of the foundation.
With the steps according to one aspect of the invention, the entire construction time for the wind power plant can be considerably shortened. Also, with one aspect of the invention, the costs for the overall equipment of the wind power plant can be reduced, without having to balance this with technical disadvantages of any kind.
The aspects of the invention shall be explained more closely hereafter by means of an example shown in a drawing.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top perspective view of a section of a foundation for a wind power plant, prior to filling the section of the foundation with concrete;
FIG. 2 is a perspective view of a portion of a power module positioned on the foundation of FIG. 1, after filling the foundation with concrete;
FIG. 3 is a perspective view of the power module of FIG. 2 along with a representation of the foundation of FIG. 1;
FIG. 4 is a perspective view of the power module of FIG. 2 along with a representation of the foundation of FIG. 1 and an erected tower prior to sliding the tower over the power module.



DETAILED DESCRIPTION
FIG. 1 shows a top view of a prearranged foundation (without concrete fill) with a steel reinforcement 1 and 2, on an empty conduit 3, which is supported via a brace 4 with a lowermost tower section adjoining the reinforcement. Furthermore, one notices carrier plates 5, which are arranged for holding arms 6 in the lowermost tower section (which will no longer be visible after constructing the wind power plant).
The empty conduit 3 afterwards serves to accommodate cables, such as the power cable, by means of which the entire electric energy of the wind power plant is taken away to the network via ground cables. Often, several pipes are provided for this, rather than only one pipe.
FIG. 2 shows the foundation section after filling the concrete. Here, one notices that the empty conduits remain in their previously fixed position and the carrier plates have also been invested with concrete; during the concreting, it is important that the carrier plates lie snug on the structural concrete and thus afford a load support spread out over a surface. The concrete reaches to the upper edge of the carrier plates and is carefully worked at the edge of the plate.
After the hardening of the concrete, the holding arms for holding the carrier plates and also the cross arms for attachment of the empty conduits can be dismantled and used again to construct other plants.
After the hardening of the concrete, when constructing the rest of the wind power plant, the tower is not placed on the lowermost foundation for the tower section—as was usual heretofore—but instead a power module 7 is first placed on the carrier plates 5 (FIGS. 2, 3 and 4).
Such a power module 7 is shown in FIG. 3 in a two-part design, although the power module can also consist of additional parts.
The two parts of the power module 7 are placed one on the other in the depicted example and the overall power module consists of two fitted-together carriers 8, which in turn support important parts of the power modules, i.e., the transformer, inverter, switch cabinets, medium-voltage layout, etc.
The fitted-together carriers 8 are constructed in the manner of a frame and fit together exactly, so that a reliable securing to each other is also assured.
The individual carriers have four vertically oriented spars—subtending a rectangle—joined together at the bottom. These spars are screwed together at their lower and upper end.
After mounting the electric power module on the foundation, the tower 9 is erected (FIG. 4) and slipped over the power module. For this, the outer dimensions of the power module in terms of width and length are smaller than the inner diameter of the tower in the lower tower region/foundation region.
After erecting the tower, the wind power plant is outfitted with the machine house, as usual, the rotor is mounted, and appropriate electrical connections are produced between the generator and the power module 7 to enable operation and the power module (output of the transformer) is also hooked up to the power supply network.
When the above described empty conduits or devices provided for laying the cables have been previously secured in particular prescribed position, the connection between the power module and the network can also be produced extremely fast and advantageously, with minimal overall cable lengths, because the empty conduits are positioned where they mate precisely with the corresponding parts of the power module.
In the wind power plant of one aspect of the invention, it is also advantageous for the access to the wind power plant to no longer necessarily be through a conventional door in the fixed region of the foundation, but instead through a door (access) which is positioned so that it emerges in the region above the parts of the power module carrying the high or medium voltage. For this, a corresponding ladder or stairs can be provided on the outside of the tower. This positioning of the access door has the advantage that the personnel who have to visit the plant frequently do not have to constantly walk past the parts of the power module carrying high or medium voltage when the plant is in operation. This also ensures that no one is in direct proximity to the power module by accident or mistake during the operation of the wind power plant and makes contact with the parts carrying voltage or current, which might cause a major accident.
In the region of the access door of the tower, an appropriate intermediate platform is then provided, which can be used by personnel entering the tower, so that they can move up higher in the wind power plant on the inside of the tower or make adjustments to various control devices or read off measurement data.
A wind power plant of the invented type generally has available more than 100 kW of rated power, preferably a power rating in the range of 500 kW, 1 MW, 1.5 MW, or considerably more. Preferably, the intermediate platform is provided with a locking plate, through which the personnel can enter the lower region of the power module. Locking of the hatch affords further protection of the lower part of the power module against unauthorized access.
The inner diameter of the tower in the foundation region can be several meters, so that the overall surface there is 100 m2 or more and therefore a sufficiently large area is also available to accommodate the power modules. Insofar as the term “power module” is used in this application, it means the medium and high voltage carrying part of the wind power plant. These are, in particular, the units such as transformer or inverter or emergency switch and the medium voltage switch cabinet or also the low voltage distributor.

## Claims

1. A method of constructing a wind power plant having (i) a foundation, (ii) a tower, (iii) a generator disposed on the tower, (iv) a transformer, and (v) a switch cabinet which is electrically coupled to the transformer, the method comprising:
arranging a form of the foundation;
providing the foundation;
placing the transformer on the foundation;
placing the switch cabinet on the foundation;
erecting or constructing the tower on the foundation after placing the transformer and the switch cabinet on the foundation, wherein the tower is erected or constructed around the transformer;
mounting the generator on the tower; and
mounting rotor blades on the rotor, wherein the rotor blades are exposed to wind.

2. The method of claim 1 further including arranging at least a portion of a conduit at a predetermined location within the form of the foundation and prior to providing the foundation so that the portion of the conduit is fixed in the foundation after providing the foundation.

3. The method of claim 2 further including connecting an electrical cable to the transformer wherein at least a portion of the electrical cable is disposed in the portion of the conduit which is fixed in the foundation.

4. The method of claim 1 further including:
arranging at least a portion of a conduit at a predetermined location within the form of the foundation and prior to providing the foundation so that the portion of the conduit is fixed in the foundation after providing the foundation; and
connecting electrical cables to the transformer and the switch cabinet wherein at least a portion of the electrical cables are disposed in the portion of the conduit which is fixed in the foundation.

5. The method of claim 1 further including:
mounting the transformer in a carrier prior to placing the transformer on the foundation;
placing the carrier on the foundation after mounting the transformer therein; and
securing the carrier to the foundation.

6. The method of claim 1 further comprising transferring the electrical power to a power network located outside the wind power plant via an electrical cable.

7. The method of claim 1 wherein providing the foundation includes filling the form of the foundation with concrete.

8. The method of claim 1 further including:
arranging a plurality of carrier plates at predetermined locations within the form of the foundation so that carrier plates are fixed in, on or to the foundation after providing the foundation;
mounting the transformer in a carrier prior to placing the transformer on the foundation;
placing the carrier on the foundation after mounting the transformer therein; and
securing the carrier to the carrier plates.

9. An offshore wind power plant manufactured according to a method comprising the method of claim 1.

10. A method of constructing a wind power plant having (i) a foundation, (ii) a tower, (iii) a generator disposed on the tower, and (iv) a transformer, the method comprising:
arranging a form of the foundation;
providing the foundation;
mounting the transformer in a carrier;
placing the carrier on the foundation after mounting the transformer therein, wherein the transformer is mounted in the carrier prior to placing the carrier and transformer on the foundation;
securing the carrier to the foundation;
erecting or constructing the tower on the foundation after placing the carrier and transformer on the foundation, wherein the tower is erected or constructed around the carrier and transformer;
mounting the generator on the tower; and
mounting rotor blades on the rotor, wherein the rotor blades are exposed to wind.

11. The method of claim 10 further including arranging at least a portion of a conduit at a predetermined location within the form of the foundation and prior to providing the foundation so that the portion of the conduit is fixed in the foundation after providing the foundation.

12. The method of claim 11 further including connecting an electrical cable to the transformer wherein at least a portion of the electrical cable is disposed in the portion of the conduit which is fixed in the foundation.

13. The method of claim 10 wherein the wind power plant further includes a switch cabinet which is electrically coupled to the transformer, and wherein the method further includes:
arranging at least a portion of a conduit at a predetermined location within the form of the foundation and prior to providing the foundation so that the portion of the conduit is fixed in the foundation after providing the foundation; and
connecting electrical cables to the transformer and the switch cabinet wherein at least a portion of the electrical cables are disposed in the portion of the conduit which is fixed in the foundation.

14. The method of claim 10 further comprising transferring the electrical power to a power network located outside the wind power plant via an electrical cable.

15. The method of claim 10 wherein providing the foundation includes filling the form of the foundation with concrete.

16. The method of claim 10 further including:
arranging a plurality of carrier plates at predetermined locations within the form of the foundation so that carrier plates are fixed in, on or to the foundation after providing the foundation;
mounting the transformer in a carrier prior to placing the transformer on the foundation;
placing the carrier on the foundation after mounting the transformer therein; and
securing the carrier to the carrier plates.

17. An offshore wind power plant manufactured according to a method comprising the method of claim 10.

18. A method of constructing a wind power plant having (i) a foundation, (ii) a tower, (iii) a generator disposed on the tower, and (iv) a transformer, the method comprising:
arranging a form of the foundation;
providing the foundation;
arranging a plurality of carrier plates at predetermined locations within the form of the foundation so that carrier plates are fixed in, on or to the foundation after providing the foundation;
mounting the transformer in a carrier;
placing the carrier on the foundation after mounting the transformer therein, wherein the transformer is mounted in the carrier prior to placing the carrier on the foundation;
securing the carrier to the carrier plates;
erecting or constructing the tower on the foundation after placing the carrier and transformer on the foundation, wherein the tower is erected or constructed around the carrier and transformer;
mounting the generator on the tower; and
mounting rotor blades on the rotor, wherein the rotor blades are exposed to wind.

19. The method of claim 17 further including arranging at least a portion of a conduit at a predetermined location within the form of the foundation and prior to providing the foundation so that the portion of the conduit is fixed in the foundation after providing the foundation.

20. The method of claim 19 further including connecting an electrical cable to the transformer wherein at least a portion of the electrical cable is disposed in the portion of the conduit which is fixed in the foundation.

21. The method of claim 18 further comprising transferring the electrical power to a power network located outside the wind power plant via an electrical cable.

22. The method of claim 18 wherein providing the foundation includes filling the form of the foundation with concrete.

23. An offshore wind power plant manufactured according to a method comprising the method of claim 18.