Abstract
The following relates to a Foundation for a wind turbine, including base means with a center zone and an outer zone, wherein the outer zone is configured for carrying most of the weight of the wind turbine. In the center zone, the base means include a chamber, wherein the foundation further includes energy storage means, wherein the energy storage means includes a flywheel pivotally arranged within the chamber for storing rotational energy, is provided. The energy storage means further includes transmission means for transforming energy of a wind turbine into rotational energy of the flywheel and for transforming rotational energy of the flywheel into electrical energy. The following further relates to a wind turbine and to a method for storing and using energy generated by a wind turbine.
Claims
1. A foundation for a wind turbine, comprising: a base means with a center zone and an outer zone, wherein the outer zone is configured for carrying all of a weight of the wind turbine, wherein in the center zone, the base means comprise a chamber; and an energy storage means, wherein the energy storage means comprise a flywheel pivotally arranged within the chamber for storing rotational energy, and a transmission means for transforming energy of the wind turbine into rotational energy of the flywheel and for transforming rotational energy of the flywheel into electrical energy, wherein the transmission means comprise a flywheel electric motor for transforming electrical energy into rotational energy of the flywheel, and the transmission means comprise electric control means for providing electrical energy from the grid to the flywheel electric motor.
2. The foundation according to claim 1, wherein the transmission means comprise a flywheel generator for transforming rotational energy of the flywheel into electrical energy.
3. The foundation according to claim 1, wherein the energy storage means comprise a clutch for mechanically separating the flywheel from transmission means of the energy storage means.
4. The foundation according to claim 1, wherein the energy storage means comprise magnetic bearings for pivoting the flywheel with respect to the chamber.
5. The foundation according to claim 1, wherein the chamber is configured as a vacuum chamber.
6. The foundation according to claim 1, wherein the energy storage means comprise a plurality of flywheels.
7. A foundation according to claim 1, wherein each flywheel has a cylindrical or at least substantially cylindrical shape.
8. A wind turbine, comprising: a rotor with rotor blades for converting wind energy into rotational energy of the rotor; a generator for converting rotational energy of the rotor into electrical energy; a tower for carrying the rotor and the generator; and the foundation according to claim 1 for carrying the tower.
9. A method for storing and using energy generated by a wind turbine comprising: closing a clutch for coupling a flywheel of a foundation of the wind turbine with a motor rotor of a flywheel electric motor of the foundation; providing electrical energy produced by a generator of the wind turbine to the flywheel electric motor by electric control means of the foundation; operating the flywheel electric motor with the provided electrical energy and thereby generating rotational energy of the flywheel; and driving a flywheel generator by the rotating flywheel for converting the rotational energy of the flywheel into electrical energy; wherein the electrical energy produced by the flywheel generator is used for driving an electric motor for supporting rotation of a rotor of the wind turbine.
Description
BRIEF DESCRIPTION
[0043] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:
[0044] FIG. 1 depicts a schematic side view of a prior art foundation of a wind turbine;
[0045] FIG. 2 depicts a schematic sectional side view of an exemplary first embodiment of the present invention;
[0046] FIG. 3 depicts a schematic perspective view of a first configuration of the present invention;
[0047] FIG. 4 depicts a schematic perspective view of a second configuration of the present invention;
[0048] FIG. 5 depicts a schematic side view of an electric configuration according to the present invention;
[0049] FIG. 6 depicts a schematic sectional side view of an exemplary second embodiment of the present invention;
[0050] FIG. 7 depicts a schematic side view of an exemplary embodiment of a wind turbine according to the present invention; and
[0051] FIG. 8 depicts a schematic flow plan of an exemplary embodiment of the method according to the present invention.
DETAILED DESCRIPTION
[0052] Elements with the same function and effectiveness are denoted each in FIGS. 1 to 8 with the same reference numbers.
[0053] In FIG. 1, a prior art foundation 1 of a wind turbine 2 is shown in a schematic side view. The foundation 1 comprises a base means 3 with a center zone 4 and an outer zone 5. On the center zone 4 a tower 18 of the wind turbine 2 is mounted. Basically all of the load of the tower 18 is carried by the outer zone 5, wherein the inner zone 4 is a non-working load area. The base means 3 of the foundation 1 is configured as a solid steel-concrete block with an inclined upper surface in the outer zone 5 and a horizontal upper surface in the center zone 4.
[0054] FIG. 2 shows an exemplary first embodiment of the present invention in a schematic sectional side view. In this figure, the center zone 4 of the base means 3 of the foundation 1 is shown in detail, wherein the outer zone 5 is cut-off for reasons of better overview. The foundation 1 of the wind turbine 2 comprises base means 3 that comprise or consist of concrete, steel-concrete or the like. In the center zone 4 of the foundation 1, energy storage means 7 of the foundation 1 are located. The energy storage means 7 located inside a chamber 6 that is formed within the base means 3. The energy storage means 7 comprise a flywheel 8 with a vertical rotation axis R. The flywheel 8 has a substantially cylindrical shape. The flywheel 8 is pivotally arranged within the chamber 6 by means of magnetic bearings 14 on the sides and the bottom of the flywheel 8, supporting the flywheel 8 against inner walls of the chamber 6. The energy storage means 7 further comprise transmission means 9, comprising a flywheel electric motor 10 with a motor rotor 19 and a clutch 13, configured as magnetic clutch 13, for mechanically connecting and disconnecting the motor rotor 19 with the flywheel 8. The flywheel electric motor 10 is further configured as flywheel generator 12. By means of the flywheel electric motor 10, the flywheel 8 can be rotated to convert electric energy into rotational energy. By means of the flywheel generator 12, the rotational energy of the flywheel 8 can be converted into electric energy.
[0055] In FIG. 3, a first configuration of the embodiment of the present invention is shown in a schematic perspective view. In this first configuration, the foundation 1 comprises just one single flywheel 8, pivotally arranged in the center zone 4. The flywheel 8 has a substantially cylindrical shape and is of a size to almost completely fill the center zone 4.
[0056] In FIG. 4, a second configuration of the embodiment of the present invention is shown in a schematic perspective view. In this second configuration, the foundation 1 comprises nine flywheels 8, pivotally arranged in the center zone 4. The flywheels are evenly distributed over the center zone 4, wherein one flywheel 8 is located in the middle axis of the center zone 4 and the other eight flywheels 8 are evenly distributed along a circle around the middle axis. The flywheels 8 have a substantially cylindrical shape, wherein the diameter of the flywheels 8 according to the second configuration are much smaller than the diameter of the flywheel 8 according to the first configuration as shown in FIG. 3.
[0057] FIG. 5 shows an electric configuration according to the embodiment of the present invention in a schematic perspective view. The flywheel 8 is connected with the flywheel electric motor 10, wherein the flywheel electric motor 10 is configured as flywheel generator 12. A clutch 13 is not illustrated in this figure, however, it is preferred that there is a clutch 13 between the flywheel 8 and the motor rotor 19. A rotor 15 with rotor blades 16 is mechanically connected with a generator 17. The generator 17 is configured for transforming rotational energy of the rotor 15 into electrical energy. The generator 17 is further configured as an electric motor 20 for driving the rotor 15. The generator 17 is connect ed via electric lines and an electric control means 11 to a grid G and to the flywheel motor 10. The electric configuration comprises several electric switches 21 for switching between different operation configurations, such as driving the flywheel 8 with the flywheel motor 10, generating electricity with the flywheel generator 12 for driving the electric motor 20 for driving the rotor 15 or providing electricity to the grid G.
[0058] In FIG. 6, an exemplary second embodiment of the present invention is shown in a schematic side view. In this figure, the center zone 4 of the base means 3 of the foundation 1 is shown in detail, wherein the outer zone 5 is cut-off for reasons of better overview. The foundation 1 of the wind turbine 2 comprises base means 3 that comprise or consist of concrete, steel-concrete or the like. In the center zone 4 of the foundation 1, energy storage means 7 of the foundation 1 are located. The energy storage means 7 located inside a chamber 6 that is formed within the base means 3. The energy storage means 7 comprise a flywheel 8 with a horizontal rotation axis R. The flywheel 8 has a substantially cylindrical shape. The flywheel 8 is pivotally arranged within the chamber 6 by means of magnetic bearings 14 on the sides of the flywheel 8, supporting the flywheel 8 against inner walls of the chamber 6. The energy storage means 7 further comprise transmission means 9, comprising a flywheel electric motor 10 with a motor rotor 19 and a clutch 13, configured as magnetic clutch 13, for mechanically connecting and disconnecting the motor rotor 19 with the flywheel 8. The flywheel electric motor 10 is further configured as flywheel generator 12. By means of the flywheel electric motor 10, the flywheel 8 can be rotated to convert electric energy into rotational energy. By means of the flywheel generator 12, the rotational energy of the flywheel 8 can be converted into electric energy.
[0059] FIG. 7 shows an exemplary embodiment of a wind turbine 2 according to the embodiment of the present invention in a schematic side view. The wind turbine 2 comprises a foundation 1, a tower 18 and a rotor unit 22 with a rotor 15, rotor blades 16 and a generator 17 that is configured as electric motor 20 as well. The tower 18 is mounted onto the foundation 1. The rotor unit 22 is mounted onto an upper end of the tower 18.
[0060] In FIG. 8, an exemplary embodiment of the method according to the embodiment of the present invention is shown in a schematic flow plan. In a first step 100, a clutch 13 is closed. Thereby, a flywheel 8 of a foundation 1 of the wind turbine 2 is mechanically coupled with a motor rotor 19 of a flywheel electric motor 10 of the foundation 1. In a second step 200, electrical energy produced by a generator 17 of the wind turbine 2 is provided to the flywheel electric motor 10 by electric control means 11 of the foundation 1. In a third step 300, the flywheel electric motor 10 is operated with the provided electrical energy. By these means, electrical energy is converted into rotational energy of the flywheel 8. In a fourth step 400, the clutch 13 is opened. As a result, the flywheel 8 is mechanically uncoupled from the motor rotor 19 and can rotate freely. In this state, the flywheel 8 can rotate for several hours, storing rotational energy. In a fifth step 500, the clutch 13 is closed again and the flywheel 8 is mechanically coupled with the motor rotor 19 again. The fifth step 500 is initiated, when wind speeds are not sufficient or unsteady for driving the rotor 15, the rotor 15 shall be started and/or there is demand for electrical energy by the grid G. In a sixth step 600, the flywheel generator 12 generates electrical energy by converting rotational energy of the flywheel 8. In a seventh step 700, the generated electrical energy is provided to the electric motor 20 for driving the rotor 15 and/or to the grid G for providing the grid with electrical energy. For providing the grid G witch electrical energy, a converter is used to condition the power generated by the flywheel so that it matches the grid requirements.
[0061] 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.
[0062] 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.
