METHOD FOR PRODUCING A FORM-WOUND COIL FOR A LAMINATED STATOR CORE

Abstract

A method for producing a form-wound coil for fitting into a laminated stator core of a synchronous generator of a gearless wind turbine, comprising the steps of cutting out at least one first flat strip conductor from a metal sheet with a first slot-strip portion, for inserting into a first slot of the laminated core, cutting out at least one second flat strip conductor from a metal sheet with a second slot-strip portion, for inserting into a second slot of the laminated core, and angling away the first and/or second cut-out strip conductor in such a way as to create an angled-away winding head portion, for connecting the first and second slot-strip portions.

Claims

1. A method comprising: producing a form-wound coil for fitting into a laminated stator core of a synchronous generator of a gearless wind turbine, wherein producing comprises: cutting out at least one first flat strip conductor from a metal sheet with a first slot-strip portion configured to be inserted into a first slot of the laminated stator core, cutting out at least one second flat strip conductor from a metal sheet with a second slot-strip portion, configured to be inserted into a second slot of the laminated stator core, angling away at least one of the first and second cut-out strip conductors in such a way that creates an angled-away winding head portion and configured to couple the first and second slot-strip portions together.

2. The method according to claim 1, further comprising: connecting the first and second slot-strip portions together by way of the winding head portion in such a way that the first and second slot-strip portions are arranged plane-parallel to one another in different planes.

3. The method according to claim 2, wherein: each of the first and second slot-strip a winding head subportion and a slot leg, and connecting the first and second slot-strip portions connecting at regions of winding head subportions in such a way that the winding head subportions form the winding head portion.

4. A method comprising: producing a form-wound coil for fitting into a laminated stator core of a synchronous generator of a gearless wind turbine, comprising the steps of cutting out a flat strip conductor from a metal sheet, angling away the cut-out flat strip conductor in such a way as to create: a first slot-strip portion configured to be inserted into a first slot of the laminated core, a second slot-strip portion configured to be inserted into a second slot of the laminated core, and at least one winding head portion configured to connect the slot-strip portions together and to be arranged outside the slots, and fitting the form-wound coil into the laminated stator core by inserting the first slot-strip portion into the first slot of the laminated stator core and inserting the second slot-strip portion into the second slot of the laminated stator core, the first and second slot-strip portions being displaced parallel to one another by the angling away.

5. The method according to claim 4, wherein: the first and second slot-strip portions each have a strip surface, that forms part of a surface of the metal sheet during the cutting out, and in that the form-wound coil is configured to fit into the laminated core in a direction parallel to this strip surface.

6. The method according to claim 4, wherein: the metal sheet is produced from aluminum.

7. The method according to claim 1 wherein: cutting out comprises water cutting or lasering.

8. The method according to claim 1 wherein: the first and second slot-strip portions are separated into a plurality of parallel conducting portions, and the separating occurs before the angling away.

9. The method according to claim 8, further comprising: introducing an electrical insulating material into interspaces between the parallel conducting portions of the separated slot-strip portions.

10. The method according to claim 8 wherein: a first parallel conducting portion reaches from the first slot-strip portion to the second slot-strip portion and is arranged with the first slot-strip portion in a base region of the first slot and arranged with the second slot-strip portion in an opening region of the second slot.

11. The method according to claim 8 wherein: the parallel conducting portions of a slot-strip portion have different cross sections.

12. The method according to claim 1 wherein: in the connecting region between the coils the parallel conducting portions are separated non-electrically into a plurality of lines.

13. A form-wound coil, produced by a method according to claim 1.

14. A winding assembly with a plurality of form-wound coils according to claim 13.

15. The winding assembly according to claim 14, with a plurality of connecting portions, a connecting portion respectively connecting two of the form-wound coils and the connecting portion being produced by cutting out a flat conducting region from a metal sheet and angling away the flat conducting region in such a way that it is attached to two slot-strip portions for connecting to reach over a plurality of slots between the two form-wound coils.

16. The winding assembly according to claim 15, wherein the connecting portion corresponds in structure to the winding head portion.

17. A stator of a generator of a gearless wind turbine comprising: a stator with a laminated stator core and a winding assembly according to claim 14 fitted into the laminated stator core.

18. The stator according to claim 17, wherein the laminated stator core has slots for receiving the slot-strip portions and the slots have a corresponding shape to the slot-strip portions.

19. A synchronous generator of a wind turbine with a stator according to claim 17.

20. A wind turbine with a synchronous generator according to claim 19.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0054] The invention is explained in more detail below by way of example on the basis of exemplary embodiments with reference to the accompanying figures.

[0055] FIG. 1 shows a wind turbine in a perspective view.

[0056] FIG. 2 schematically shows a generator of a gearless wind turbine in a side view.

[0057] FIG. 3 schematically shows a stator of a generator of a gearless wind turbine in a side view.

[0058] FIG. 4 schematically shows a detail of a stator of a generator of a gearless wind turbine with two fitted form-wound coils.

[0059] FIGS. 5 and 6 respectively show a slot-strip portion of a first loop in a perspective view.

[0060] FIG. 7 shows the two slot-strip portions of FIGS. 5 and 6 in a state of being assembled into a first loop.

[0061] FIGS. 8 and 9 show a third slot-strip portion and a fourth slot-strip portion of a form-wound coil.

[0062] FIG. 10 shows the two slot-strip portions of FIGS. 8 and 9 in a state of being assembled into a second loop.

[0063] FIG. 11 shows a form-wound coil, assembled from the four slot-strip portions of FIGS. 5, 6, 8 and 9.

[0064] FIG. 12 shows two form-wound coils, respectively according to FIG. 11, connected to one another by way of a connecting portion.

DETAILED DESCRIPTION

[0065] FIG. 1 shows a wind turbine 100 with a tower 102 and a nacelle 104. Arranged on the nacelle 104 is a rotor 106 with three rotor blades 108 and a spinner 110. During operation, the rotor 106 is set in a rotational movement by the wind and thereby drives a generator in the nacelle 104.

[0066] FIG. 2 schematically shows in a side view a generator 1 with a rotor 2 with a rotor carrier 4 and a rotor pole region 6, which, separated by an air gap 8, can rotate in the stator 10 of the generator 1. The stator 10 is held by a stator carrier 14, which, like the rotor carrier 4, is preferably of a star-shaped form. A winding head 16 is also indicated on both sides of the stator 10. To this extent, the region of the winding that respectively establishes a connection between individual slots is referred to as the winding head.

[0067] FIG. 3 shows an unwound stator 10 in a side view, which may also be referred to as an axial view. Unwound slots 12 are likewise schematically represented there. The slots 12 alternate with teeth 18 and, together with a base region 20, the teeth 18 are formed by stacking many individual metal sheets, specifically stacked to form a laminated stator core.

[0068] FIG. 4 then shows a laminated stator core 40 in a perspective detail, with a large number of slots or stator slots 42 of a substantially rectangular cross section. In some of these slots 42 there are fitted two form-wound coils 44, given by way of example, and these two form-wound coils 44 are connected by a connecting portion 46.

[0069] FIG. 4 is an illustrative representation and does not necessarily reflect the sequence in which the laminated stator core 40 is wound or loaded with components. The two form-wound coils 44 that are shown form part of the wound unit of one of six phases. The two form-wound coils 44 are respectively assembled from four slot-strip portions 48. Two slot-strip portions or a part thereof, specifically the slot legs 66, are respectively accommodated in one of the slots 44. For the sake of simplicity, the same reference sign, that is 48, is used here for the slot-strip portions, even though the slot-strip portions 48 differ in some details, as can already be seen in FIG. 4.

[0070] Each slot-strip portion 48 also has at least one winding head subportion 50, which are respectively arranged outside the slots 42. Two winding head subportions 50 are respectively assembled into a winding head portion 52. This assembly is achieved by welding at the weld seam 54.

[0071] It can be seen that the winding head portions 52 very strongly resemble the connecting portion 46. The two differences are essentially only that the connecting portion 46 is respectively fastened, specifically welded, at connecting legs 56 to a slot-strip portion. And, as a second difference, this ultimately also results in the connecting portion 46 not having a weld seam like the weld seam 54 of the winding head portions 52.

[0072] FIGS. 5 and 6 then respectively show a slot-strip portion 48. FIG. 5 has in this case a winding head subportion 50 and also a connection region 58. At the connection region 58, a connection to a connecting portion 46 can be established or, in the case of the last form-wound coil, it will be possible to provide a connection there for electrically connecting the generator.

[0073] The slot-strip portion 48 of FIG. 6 has two winding head subportions 50, which can be respectively connected to a winding head subportion of a further slot-strip portion, specifically on the one hand to that of FIG. 5 and on the other hand to that of FIG. 8.

[0074] FIG. 7 then shows the two slot-strip portions 48 of FIGS. 5 and 6 assembled. For this purpose, they are welded in their two winding head subportions 50 at the weld seam 54. Correspondingly, the winding head portion 52 is also created there.

[0075] FIGS. 8 and 9 likewise show two slot-strip portions 48, and here the slot-strip portion 48 of FIG. 8 has two winding head subportions 50 and the slot-strip portion 48 of FIG. 9 has only one winding head subportion 50.

[0076] FIG. 10 shows the connection of these two slot-strip portions 48 of FIGS. 8 and 9. Here, too, the connection takes place at the weld seam 54, so as to create a stable overall part and also create the winding head portion 52.

[0077] These two form-wound part-coils 60 of FIGS. 7 and 10 are then assembled into a form-wound coil 44 such as that shown in FIG. 11. For this purpose, the weld seam 54 that is represented on the right in FIG. 11 must have been made.

[0078] The form-wound coil 44 shows two lowered regions 62 in the region of its three winding head portions 52, specifically two in the left-hand region of FIG. 11 and one in the right-hand region of FIG. 11. This lowered region 62 can be seen very well on the left-hand side in FIG. 11 and can only be seen with difficulty in the side on the right because it is covered by part of a slot-strip portion. This lowered region 62 is achieved by a diverting portion 64. This diverting portion 64 diverts the slot leg 66 concerned of the slot-strip portion 48 concerned appropriately downwards. The part of the slot-strip portion that lies as a straight portion in the respective slot is referred to here, and not only in the case of the embodiment shown, as the slot leg 66. From here, the diverting portion 64 diverts the slot-strip portion downwards, essentially by a width of the slot leg 66.

[0079] The purpose can probably be seen best in FIG. 4. FIG. 4 shows two fitted form-wound coils 44, which both belong to the same phase. In the state of the stator 40 in which it has been completely fitted with components or wound, there are six times as many form-wound coils 44 in the same region. If, according to FIG. 4, the first form-wound coil 44 lies in the first slot N1 and the seventh slot N7, a form-wound coil 44 (not shown here) of a next phase would lie in the second slot N2 and the eighth slot N8. In order to realize this configuration, this form-wound coil 44 that is not shown must cross the form-wound coil 44 shown in the first slot N1 and the seventh slot N7 at the lowered region 62. This is made possible by this lowering of the lowered region 62.

[0080] It can be seen that consequently firstly all of the form-wound coils 44, that is to say not only those of the first phase but those of all the phases, are fitted, and then the form-wound coils of the respective phases are connected by the connecting portions 46.

[0081] Incidentally, to provide a better overview in FIG. 12, the arrangement of the two form-wound coils 44 together with the connecting portion 46 is shown without the laminated stator core 40.

[0082] The form-wound coil represented in the figures, specifically a sheet-metal coil, has two turns. It therefore consists within a slot of two sheet-metal strips, for example each of 6 mm. A coil with, for example, five turns can also be realized by the technique described, in that five sheet-metal strips each of 3 mm lie in a slot.

[0083] It is to use sheet metal instead of wire and using methods that can be automated well, lasering, or waterjet cutting, angling and welding.

[0084] It has also been recognized that, with an existing slot geometry, the same electrical resistance as with round wires can be achieved with aluminum as a result of the improvement in the filling ratio. With sheet-metal coils of copper, a smaller overall construction could be obtained.