SYNCHRONOUS GENERATOR OF A GEARLESS WIND TURBINE AND METHOD FOR PRODUCING A SYNCHRONOUS GENERATOR, AND USE OF FORM COILS

Abstract

A synchronous generator of a gearless wind turbine is provided. The synchronous generator includes a rotor and a stator. The stator has a stator ring having teeth and slots arranged therebetween for receiving a stator winding. In a circumferential direction, the stator ring is divided into stator segments, each having an equal number of slots. Within a segment, the slots have a substantially equal spacing with respect to each another in the circumferential direction. In at least one connecting region of two segments, the spacing of at least two adjacent slots, which are each assigned to one of two different segments, differs from the spacing of the slots within a segment. The stator winding is formed with form coils. A method for producing a synchronous generator is provided and a use of aluminum and copper form coils in the generator is provided.

Claims

1. A synchronous generator of a gearless wind turbine, comprising: a rotor, and a stator including a stator ring having teeth and slots arranged the teeth for receiving a stator winding, wherein the stator ring is divided, in a circumferential direction, into a plurality of segments, wherein the plurality of segments have an equal number of slots, wherein slots within a segment of the plurality of segments have a substantially equal spacing with respect to each other in the circumferential direction, wherein, in a connecting region of two different segments of the plurality of segments, a first spacing between two adjacent slots, which respectively belong to the two different segments, differs from a second spacing between the slots within the segment, and wherein the stator winding includes form coils.

2. The synchronous generator as claimed in claim 1, wherein the form coils each have two legs, the two legs are connected to one another by two winding overhangs, and the form coils each have two terminals in a region of one of the two winding overhangs, wherein, apart from the two terminals, the two legs and the two winding overhangs the form coils of the stator winding have substantially the same shape.

3. The synchronous generator as claimed in claim 2, wherein the two legs of each form coil are arranged in the stator in an identical radial region the stator.

4. The synchronous generator as claimed in claim 1, wherein each segment of the plurality of segments has six form coils, or a multiple of six form coils, wherein each form coil has a first terminal and a second terminal, wherein six first terminals of the segment are connected to six second terminals of second segment arranged ahead of the segment in the circumferential direction and six second terminals of the segment are connected to six first terminal of a third segment situated after the segment the circumferential direction.

5. The synchronous generator as claimed in claim 4, wherein a connection of two terminals of different form coils is made with a U-shaped connecting element having ends configured to be connected to a terminal.

6. The synchronous generator as claimed in claim 1, wherein the form coils are made from different materials, wherein the first spacing is less than the second spacing, and wherein an adjacent slot of the two adjacent slots in the connecting region receives a leg of a first form coil having a first resistivity, and the slots within the segment receive a leg of a second form coil having a second resistivity higher resistivity then the first resistivity.

7. The synchronous generator as claimed in claim 6, wherein the first form coil is a copper form coil and the second form coil is an aluminum form coil.

8. The synchronous generator as claimed in claim 7, wherein a first terminal of the first form coil and a second terminal of the second form coil are connected by a connecting element made of aluminum and, wherein during a production of the first form coil, before the equipping of the stator, the connecting element is connected to the first terminal of the first form coil by at least one of: cold pressure welding, friction stir welding, pressure brazing or pressure welding, and wherein the connecting element is connected to the second terminal of the second form coil after the equipping of the stator.

9. The synchronous generator as claimed in claim 6, wherein the second form coil contain or is composed of aluminum and the first form coil contain or is composed of copper, wherein at least one terminal of the second form coil is connected to at least one terminal of the first form coil by a connecting element, and wherein the connecting element is made from a copper-aluminum alloy or is composed of two conductor materials connected to each other to form a single part before being connected to the at least one terminal of the first form coil and the at least one terminal of the second form coil.

10. The synchronous generator as claimed in claim 1, wherein the stator ring is joined together from a plurality of stator ring parts at at least two locations, a location of the at least two locations being in the connecting region, wherein the first spacing between the two adjacent slots, which respectively belong to the two different segments is greater than the second spacing between the slots within the segment.

11. The synchronous generator as claimed in claim 1, wherein a form coil of the form coils, in a region of a winding overhang, has: legs, outside the stator ring, that are offset in opposite directions and extend in parallel as far as a 180 degree bend which connects the legs, or the legs, outside the stator ring, are bent in the same direction with different spacings and then extend in parallel as far as a 180 degree bend which connects the legs, wherein the bend has an angle in a range of from 0 to 90 degrees in the same direction, or the legs, outside the stator ring, are bent in the same direction with different spacings and then extend in parallel as far as a 180 degree bend which connects the legs, wherein the bend has an angle of 90 degrees in the same direction.

12. A method for making a synchronous generator, comprising: inserting, into each segment, of a plurality of segments of a stator ring of the synchronous, a plurality of form coils, a number of the plurality of form coils of each segment of the plurality of segments is six or a multiple of six, each plurality of form coils having a respective plurality of first terminals and a respective plurality of second terminals, connecting the plurality of first terminals of a first segment of the plurality of segments to the plurality of second terminals of a second segment of the plurality of segments arranged ahead of the first segment in a circumferential direction, and connecting the plurality of second terminals of the first segment of the plurality of segments to the plurality of first terminals of a third segment of the plurality of segments arranged after the first segment in the circumferential direction.

13. The method as claimed in claim 12, wherein the plurality of form coils are each wound before being inserted into slots by winding one or more wires arranged in parallel around a winding core and a resulting coil is spread apart until a desired spacing of two legs corresponding to a spacing of the slots within a segment is obtained, and wherein winding overhangs are bent by fixing sections of a form coil in fixtures and moving the fixtures relative to each another until a desired shape of the form coil is obtained by plastic deformation.

14. The method as claimed in claim 13, wherein the plurality of form coils are offset form coils, and a coil in the region of the winding overhang is offset first in the opposite direction before the legs are separated.

15. The method as claimed in claim 12, comprising: connecting the plurality of first terminals of the first segment to the respective plurality of second terminals of the second segment by cold welding, pressure brazing or friction stir welding U-shaped connecting parts.

16. (canceled)

17. The method as claimed in claim 13, wherein the one or more wires are flat wires and the winding core is formed from two mandrels.

18. The method as claimed in claim 13, wherein the winding core is formed from two mandrels.

19. The method as claimed in claim 12, comprising: connecting the plurality of second terminals of the first segment to the respective plurality of first terminals of the third segment by cold welding, pressure brazing or friction stir welding U-shaped connecting parts.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0032] Further embodiments will become apparent from the illustrative embodiments described in greater detail in the figures.

[0033] FIG. 1 shows a wind turbine,

[0034] FIG. 2 shows a schematic side view of a synchronous generator designed as a ring generator,

[0035] FIG. 3 shows a form coil of one illustrative embodiment of the synchronous generator according to the invention,

[0036] FIG. 4 shows an enlargement of the end winding of the coil from FIG. 3,

[0037] FIG. 5 shows an end winding wound in a different way from the illustrative embodiment in FIGS. 3 and 4,

[0038] FIG. 6 shows another embodiment of the shape of a form coil,

[0039] FIG. 7 shows three segments of a stator ring shown by way of example in side view, and

[0040] FIG. 8 shows an illustrative view of three segments of a stator in a view of the stator from the outside.

DETAILED DESCRIPTION

[0041] FIG. 1 shows a schematic illustration of a wind turbine according to the invention. The wind turbine 100 has a tower 102 and a nacelle 104 on the tower 102. An aerodynamic rotor 106 with three rotor blades 108 and a spinner 110 is provided on the nacelle 104. During the operation of the wind turbine, the aerodynamic rotor 106 is set in rotation by the wind and thus also rotates a rotor or runner of a generator, which is coupled directly or indirectly to the aerodynamic rotor 106. The electric generator is arranged in the nacelle 104 and generates electric energy. The pitch angles of the rotor blades 108 can be changed by means of pitch motors at the rotor blade roots 108b of the respective rotor blades 108.

[0042] FIG. 2 shows a generator 130 schematically in a side view. It has a stator 132 and an electrodynamic rotor 134 mounted rotatably relative to the latter and is attached to a machine support 138 by means of its stator 132 via an axle journal 136. The stator 132 has a stator support 140 and laminated stator cores 142, which form stator poles of the generator 130 and are attached to the stator support 140 via a stator ring 30.

[0043] The electrodynamic rotor 134 has rotor pole shoes 146, which form the rotor poles and are mounted so as to be rotatable on the axle journal 136 about the axis of rotation 152 by means of a rotor support 148 and bearings 150. The laminated stator cores 142 and the rotor pole shoes 146 are separated only by a narrow air gap 154, which is a few millimeters thick, in particular less than 6 mm, but has a diameter of several meters, in particular more than 4 m.

[0044] The laminated stator cores 142 and the rotor pole shoes 146 each form a ring and, together, are also annular, with the result that the generator 130 is a ring generator. In line with its intended purpose, the electrodynamic rotor 134 of the generator 130 rotates together with the rotor hub 156 of the aerodynamic rotor, of which initial portions of rotor blades 158 are indicated.

[0045] FIG. 3 shows a first illustrative embodiment of a form coil 10 for the synchronous generator 130. The form coil 10 has two legs 12. Moreover, the coil 10 has two end windings 14. Two terminals 16 are illustrated in the region 18 of the end winding 14 illustrated on the left-hand side. The region 18 of the form coil 10, namely the two legs 12 in this region 18, are subsequently inserted into the slots 32 of one and the same segment of a stator 132 of a synchronous generator 130. The segments just mentioned are described below in connection with the description of FIGS. 7 and 8. The end windings 14 correspond to bends in the legs 12 in order to connect the two legs 12 to one another.

[0046] FIG. 4 shows an enlarged illustration of one of the end windings 14 of the form coil 10 from FIG. 3. This end winding 14 corresponds to the end winding illustrated on the right-hand side in FIG. 3, where the rear view is illustrated here as compared with FIG. 3. The end winding 14 comprises the legs 12 being bent in the same direction with different spacings, namely according to spacing 20, on the one hand, and spacing 22, on the other hand. In a region 24, the two bent legs 12 once again run parallel and are connected to one another by a 180 degree bend 26. Here, the bend in the legs 12 in the same direction is about 40 degrees.

[0047] An alternative embodiment of the form coil 10 is illustrated in FIG. 5, in which the end winding 14 is bent through 90 degrees according to spacings 20, 22. By means of these illustrated form coils 10, it is possible to insert any desired number of these coils 10 formed in this way into the slots 32 of a stator 132 without the individual windings touching and nevertheless to arrange the legs 12 at the same radial distance from or in the same radial region with respect to the center of a stator 132.

[0048] FIG. 6 shows yet another illustrative embodiment of an end winding 14 of a form coil 10, in which the legs 12 are offset in opposite directions with the same spacing, i.e., initially being bent through 90 degrees in opposite directions and then being bent again through 90 degrees in the same direction. A region 24 is thereby likewise produced, in which the two offset regions of the legs 12 run substantially parallel. Once again, a 180 degree bend 26 is provided, which connects the two legs 12.

[0049] FIG. 7 shows, by way of example, a detail of a stator ring 30, which is shown without curvature for greater clarity. The stator ring 30 has slots 32 and teeth 34. Here, three segments 36 are illustrated. Form coils 10 are inserted into the slots 32 of the segments 36. Each of the segments 36 has six form coils 10. The legs 12 of the form coils 10 and the slots 32 within a segment 36 each have the same spacing 33 with respect to one another. In connecting region 38 and in connecting region 40, however, the slots 32 have a spacing 42 which is different from the spacing 33 of the slots 32 within a segment 36. In connecting region 38, for example, the spacing of the two slots 32 is equal to zero and is thus smaller than the spacing 33 of the slots 32 within a segment 36. In connecting region 40, on the other hand, the spacing 42 of the slots 32 is approximately twice as wide as the spacing 33 of the slots 32 within a segment. In the illustration, the upper side 45 of the stator ring 30 corresponds to the radially inner side of the stator 132.

[0050] FIG. 8 shows a view of the stator 132 radially from the outside. Here too, by way of example, only the region with three segments 36 is illustrated. According to the illustrative embodiment shown in FIG. 8, the two form coils 44 are produced from copper. The remaining form coils 10 are produced from aluminum. By virtue of the copper form coils 44, the legs 12 of which are very close together in the connecting region 38, 40 of the two segments 36, there is less heat generation during operation than if these two coils were manufactured from aluminum, since copper has a lower resistivity than aluminum. With the use of aluminum form coils and copper form coils, a relatively advantageous stator 132 or synchronous generator 130 can be produced, which has advantageous properties in respect of heat distribution.