Group of three stator windings for a stator of an electric machine, a stator arrangement, a generator, and wind turbine
In one aspect, a stator is provided having a first cylindrical surface with a plurality circumferentially spaced winding slots, each winding slot extending along an axial length of the first cylindrical surface and formed to embed a segment of a single stator winding, Each stator winding is pre-formed as a closed loop and two substantially parallel segments of each stator winding formed to be embedded in a first and a second winding slot of the stator, with the second winding slot being the third adjacent winding slot to the first winding slot. Each of the three stator windings has a first winding head segment leaving the winding slots in axial direction of the stator, the first winding head segment of a first winding of the three stator windings describing in space in parts a combination of a rotation about an axis and a translation along that axis.
1. A group of three stator windings for a stator of an electric machine, wherein
the stator comprises a first cylindrical surface with a plurality circumferentially spaced winding slots, each winding slot extends along an axial length of the first cylindrical surface and formed to embed a segment of a single stator winding,
each stator winding is pre-formed as a closed loop, two substantially parallel segments of each stator winding are formed to be embedded in a first and a second winding slot of the stator, with the second winding slot being the third adjacent winding slot to the first winding slot,
each of the three stator windings includes a first winding head segment extending from the winding slots in axial direction of the stator, and
the first winding head segment of a first winding of the three stator windings is at least partially rotated and translated about an axis,
wherein the planes of the connections of the second and the third stator windings are out of parallel alignment.
2. A group of three stator windings according to claim 1 ,
wherein each of the three stator windings comprises a second winding head segment extending the winding slots in opposite axial direction of the stator than the first winding head segment, and
wherein the second winding head segment of one of the windings of the three stator windings is at least partially rotated and translated about an axis.
3. A group of three stator windings according to claim 1 , wherein the part of the first and/or second winding head segment, which is the combination of the rotation and the translation is substantially screw axis symmetric.
4. A group of three stator windings according to claim 1 , wherein the electric machine is a generator.
5. A group of three stator windings according to claim 1 , wherein a second winding and a third winding of the three stator windings are reflection symmetric with the axis of symmetry being parallel to the winding slots.
6. A group of three stator windings according to claim 1 , wherein the first and the second winding head segments are reflection symmetric and/or point symmetric to each other.
7. A group of three stator windings according to claim 1 , wherein the first winding head segment of one of the three stator windings is identical in form as the second winding head segment of another one of the three stator windings.
8. A group of three stator windings according to claim 1 , wherein the first and/or the second winding head segments of a second winding of the three stator windings extend in the plane of the two substantially parallel segments of each stator winding.
9. A group of three stator windings according to claim 1 , wherein the first and/or the second winding head segments of a third of the three stator windings comprising a section that is continuously tilted on a curvature.
10. A group of three stator windings according to claim 9 , wherein the curvature is a 90 degree segment of a substantially circular arc.
11. A group of three stator windings according to claim 1 , wherein for the second and the third winding the first and/or the second winding head segments comprises a substantially straight connection between a curvature section within the plane of the first winding slot of the stator and a curvature section within the plane of the second winding slot of the stator, the connection being arranged in a plane substantially perpendicular to the planes of the first and second winding slots.
12. A group of three stator windings according to claim 1 , wherein the first and/or the second winding head segments of the first stator winding being continuously tilted on a curvature until the curvature is substantially a 90 degree segment of a substantially circular arc, then being continuously tilted on a curvature in the opposite direction in the same plane, leading to the combination of the rotation about the axis and the translation along that axis of the respective winding head of the first stator winding.
13. A stator arrangement, comprising:
a plurality of groups of three stator windings according to claim 1 .
14. A wind turbine, comprising:
a generator comprising a stator arrangement according to claim 13 .
15. A group of three stator windings according to claim 1 ,
wherein the first winding head segment of each of the three stator windings has a geometry, and
wherein each of the first winding head segments has an unsimilar geometry.
16. A group of three stator windings for a stator of an electric machine, wherein
the stator comprises a first cylindrical surface with a plurality circumferentially spaced winding slots, each winding slot extends along an axial length of the first cylindrical surface and formed to embed a segment of a single stator winding;
each stator winding is pre-formed as a closed loop, two substantially parallel segments of each stator winding are formed to be embedded in a first and a second winding slot of the stator, with the second winding slot being the third adjacent winding slot to the first winding slot,
each of the three stator windings includes a first winding head segment extending from the winding slots in axial direction of the stator, and
the first winding head segment of a first winding of the three stator windings is at least partilly rotated and translated about an axis,
wherein for the second and the third winding the first and/or the second winding head segments comprises a substantially straight connection between a curvature section within the plane of the first winding slot of the stator and a curvature section within the plane of the second winding slot of the stator, the connection being arranged in a plane substantially perpendicular to the planes of the first and second winding slots; and
wherein the planes of the connections of the second and the third stator windings are out of parallel alignment.
17. A group of three stator windings according to claim 12 , wherein the combination of the rotation about the axis and the translation along that axis is continued for the respective winding head of the first stator winding until the winding cross section faces the longitudinal extension of the second winding slot and being in the same plane as the winding slots.