SYNCHRONOUS GENERATOR OF A GEARLESS WIND TURBINE

Abstract

A synchronous generator, in particular a multiple-pole synchronous ring generator of a gearless wind turbine, for generating electric current, comprising a rotor and a stator is provided. The stator has a large number of slots for receiving a stator winding in the form of conductor bundles, wherein the slots each have a slot base, whose surface is profiled in such a way that, during filling, a first layer on the slot base side of conductor bundles assumes an orientation which is preset by the profile. A stator for such a generator and to a wind turbine comprising such a generator is provided.

Claims

1. A synchronous generator, of a wind turbine for generating electric current, the synchronous generator comprising: a rotor and a stator, wherein the stator has a plurality of slots for receiving a stator winding in the form of conductor bundles, wherein each of the plurality of slots has a slot base having a surface that is profiled in such a way that, during filling, a first layer on the slot base side of conductor bundles assumes an orientation that is preset by the profile.

2. The synchronous generator according to claim 1, wherein the profile has one or more projections that protrude from the slot base.

3. The synchronous generator according to claim 2, wherein the profile is designed to position the conductor bundles on the slot base side at a spacing from one another, wherein the spacing is selected such that a maximum number of conductor bundles that is configured to be arranged in the first layer is reduced in comparison with a slot not having a surface that is profiled.

4. The synchronous generator according to claim 3, wherein the one or more projection are a plurality of projections, wherein a spacing between in each adjacent projections is substantially equal to the spacing between the adjacent conductor bundles.

5. The synchronous generator according to claim 3, wherein the one or more projection are a plurality of projections wherein the spacing between adjacent projections is selected depending on a diameter of the conductor bundles such that each conductor bundle of a second layer that is stacked onto the first layer rests on two adjacent conductor bundles from the first layer therebeneath.

6. The synchronous generator according to claim 5, wherein the spacing is in a range of from 1.5 to 1.85 times a diameter of the conductor bundle.

7. The synchronous generator according to claim 5, wherein the spacing is in a range of from 1.7 to 1.75 times a diameter of the conductor bundle.

8. The synchronous generator according to claim 5, wherein the spacing is √{square root over (3)} times a diameter of the conductor bundle.

9. The synchronous generator according to claim 1, wherein the plurality of slots each extend inwards from a circumferential surface of the stator and each have a slot width.

10. The synchronous generator according to claim 9, wherein the slot width results, sectionally or completely, from the equation
B=d(1+n.Math.C), wherein: d is the conductor bundle diameter, n is a positive natural number, and C is a coefficient in the range of from 0.85 to 0.95.

11. The synchronous generator according to claim 10, wherein C is in a range of from 0.86 to 0.87.

12. The synchronous generator according to claim 10, wherein $C=\frac{\sqrt{3}}{2}.$

13. The synchronous generator according to claim 2, wherein the one or more projections have a height above the slot base that is at most half a height of the conductor bundle diameter.

14. The synchronous generator according to claim 2, wherein the one or more projections have side faces that are beveled towards the slot base.

15. A stator of a synchronous generator, the stator comprising: a plurality of slots for receiving a stator winding in the form of conductor bundles, wherein each of the plurality of slots have a slot base including a surface that is profiled in such a way that, during filling, a first layer on the slot base side of conductor bundles assumes an orientation that is preset by the profile.

16. A wind turbine, comprising a synchronous generator according to claim 1.

17. The synchronous generator according to claim 1, wherein the profile has one or more recesses spaced apart from each other.

18. The synchronous generator according to claim 17, wherein the one or more recesses have a depth in the slot base that is less than a height of the conductor bundle diameter.

19. The synchronous generator according to claim 17, wherein the one or more recesses are a plurality of recesses, wherein a spacing between in each adjacent recess is substantially equal to the spacing between the adjacent conductor bundles.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0023] The invention will be explained in more detail below on the basis of preferred exemplary embodiments with reference to the attached figures, in which:

[0024] FIG. 1 shows a wind turbine schematically in a perspective view,

[0025] FIG. 2 shows a nacelle of the wind turbine shown in FIG. 1 schematically in a perspective sectional view,

[0026] FIG. 3 shows, in simplified form, a schematic perspective view of a stator of the wind turbine shown in FIGS. 1 and 2,

[0027] FIG. 4a shows a schematic cross-sectional view of a slot in a stator in accordance with the prior art, and

[0028] FIG. 4b shows a schematic cross-sectional view of a slot in a stator according to the invention of a synchronous generator according to the invention.

DETAILED DESCRIPTION

[0029] Identical reference symbols can be used below to identify similar but not identical elements. In addition, the same elements can be represented on a different scale.

[0030] FIG. 1 shows a wind turbine 100 comprising a tower 102 and a nacelle 104. A rotor 106 having three rotor blades 108 and a spinner 110 is arranged on the nacelle 104. The rotor 106 is set in rotary motion by the wind during operation and thus drives a generator 1 (FIG. 2) in the nacelle 104.

[0031] The nacelle 104 is shown in FIG. 2. The nacelle 104 is mounted rotatably on the tower 102 and is connected so as to be driven in a generally known manner by means of an azimuthal drive 7. In a further generally known manner, a machine mount 9, which holds a synchronous generator 1, is arranged in the nacelle 104. The synchronous generator 1 is designed in accordance with the present invention and is in particular a slowly rotating, multiple-pole synchronous ring generator. The synchronous generator 1 has a stator 3 and an internally rotating rotor 5, also referred to as an armature. The rotor or armature 5 is connected to a rotor hub 13, which transfers the rotational movement of the rotor blades 108 caused by the wind to the synchronous generator 1.

[0032] FIG. 3 shows the stator 3 on its own. The stator 3 has a stator ring 16 having an inner circumferential surface 18. The inner circumferential surface is delimited by a first end face 14 and a second end face 16, which is opposite the first end face 14. A large number of slots 17 is provided in the inner circumferential surface 18, said slots being designed to receive the stator winding in the form of conductor bundles 25, 27, 29 (FIG. 4b). The structural design of the slots 17 is shown in FIG. 4b. The slots 17 extend between the first end face 14 and the second end face 16 and are aligned parallel to a longitudinal axis A. The longitudinal axis A is the axis of rotation of the rotor 5 in the generator 1.

[0033] The configuration of the slots 17 will be explained below in particular also with comparable consideration with respect to a non-profiled slot N which is not in accordance with the invention, as shown in FIG. 4a. In the case of the slot N shown in FIG. 4a, it can clearly be seen that a large number of conductor bundles L is introduced into the slot N with a substantially unordered arrangement. This results in regions with a low packing density, for example regions B.sub.1 and B.sub.2. Overall, therefore, only suboptimal filling takes place in the case of the slot N shown in FIG. 4a.

[0034] In contrast to this, FIG. 4b shows a slot 17 in a stator 3 according to an embodiment of the invention or synchronous generator 1. The slot 17 has a slot width B. The slot is laterally delimited by two parallel side walls 19a, b, which extend from the circumferential surface 18 (FIG. 3) towards a slot base 21. A plurality of, in this case four, for example, inwardly projecting projections 23 are formed on the surface of the slot base 21, which projections each have a height h with respect to the slot base 21. The projections 23 are arranged in each case at a spacing of A′ with respect to one another. Owing to the arrangement of the projections 23, a first layer 25 of conductor bundles L on the slot base side is arranged right at the bottom in the slot 17. The conductor bundles in the first layer 25 are arranged in each case at a spacing A with respect to one another, determined by the projections 23. Preferably, the spacing A corresponds to the spacing A′ of the projections with respect to one another, wherein in this case in each case the spacings of the center points with respect to one another are considered.

[0035] Owing to the orientation of the conductor bundles L in the first layer 25 which is preset by the projections 23, as filling is continued, conductor bundles L in a second layer 27 are in each case inserted into the slot in such a way that they are arranged in the gaps or “valleys” between two adjacent conductor bundles L in the first layer 25. Uniform spacing of the projections 23 with respect to one another therefore results also in uniform spacing of the conductor bundles L in the second layer 27 as well as in uniform spacing of the conductor bundles L in the first layer 25. This is continued successively for a third layer 29 of conductor bundles and further layers. The conductor bundles all have the same diameter d.

[0036] In the exemplary embodiment shown, the height h is less than or equal to half the conductor bundle diameter d. The spacing A between two adjacent conductor bundles is in a range of from 1.5 times to 1.85 times the conductor bundle diameter d.

[0037] As can be seen directly from FIG. 4b, the center points of all of the conductor bundles in the cross-sectional view shown slot into a uniform lattice so that each conductor bundle, with the exception of the conductor bundles arranged at the rims of the slot 17—side walls 19a, b and slot base 21 —, has six nearest neighbors, wherein ideally in each case three most closely adjacent conductor bundles span an equilateral triangle with one another. As a result, a filling or packing density which is optimized in comparison with the illustration shown in FIG. 4a is achieved. Particularly preferably, the projections 23 are formed from the same material as the conductor bundles L, as a result of which the space taken up by the projections 23 can still also be used.

[0038] Each conductor bundle in the second layer 27 and in each following layer 29 preferably rests on in each case conductor bundles lying therebeneath at two points of contact. The conductor bundles L in the second layer 27 can in the individual case also come into contact with the projections 23, wherein the formation of an irregularity is restricted, however, owing to the restricted height h of the projections 23.

[0039] The width B of the slot 17 shown in FIG. 4b in the present case is d(1+7C), where C is in the range of from 0.85 to 0.95.