WIND ENERGY INSTALLATION AND POLE STACK FOR A SYNCHRONOUS GENERATOR OF A WIND ENERGY INSTALLATION AND SYNCHRONOUS GENERATOR

Abstract

A synchronous generator and a pole pack for a rotor of a synchronous generator of a wind power plant are disclosed The pole pack has a plurality of pole pack laminations, where each pole pack lamination includes a pole shank region and a pole head region. The pole head region projects laterally beyond the pole shank region and has a side which faces the pole shank region and a side which faces away from the pole shank region. A contour of the pole head region is ellipsoidal at least on the side which faces away from the pole shank region.

Claims

1. A wind power plant comprising: a synchronous generator that has a power of at least 500 kilowatts and an air gap diameter of at least three meters, the synchronous generator including: a stator; and a rotor having a plurality of pole packs, wherein: each pole pack of the plurality of pole packs has a plurality of pole pack laminations and each pole pack lamination of the plurality of pole pack laminations includes a pole shank region and a pole head region, the pole head region projects laterally beyond the pole shank region, and the pole head region has a side facing the pole shank region and a side facing away from the pole shank region, and a contour of the pole head region is ellipsoidal or has a semi-elliptical path at least on the side facing away from the pole shank region.

2. The wind power plant according to claim 1, wherein the contour of the pole head region on the side facing away from the pole shank region is ellipsoidal or has a semi-elliptical path, and wherein at least an adjoining portion of a contour of the pole head region projecting beyond the pole shank region and facing the side which faces the pole shank region is ellipsoidal or has a semi-elliptical path.

3. The wind power plant according to claim 1, wherein a ratio of a semi-major axis in relation to a semi-minor axis of an ellipse defined by the contour of the pole head region has a value ranging from 4 to 6.

4. The wind power plant according to claim 3, wherein the ratio of the semi-major axis in relation to the semi-minor axis of the ellipse defined by the contour of the pole head region has a value ranging from 4.8 to 5.2.

5. The wind power plant according to claim 1, wherein: the pole pack of the plurality of pole packs includes a plurality of pole pack segments and each pole pack segment includes one or more pole pack laminations of the plurality of pole pack laminations, each pole shank region of the pole pack laminations has a first center line and each pole head region has a second center line, and a distance between the first center line and the second center line is different in at least two adjacent pole pack segments.

6. The wind power plant according to claim 5, wherein an arrangement of the pole pack segments is at least one of: in a shape of an arrow and is mirror-symmetrical in plane view.

7. The wind power plant according to claim 1, wherein an air gap between the stator and the rotor has a non-constant width in a circumferential direction in the region of the pole packs.

8. A pole pack for a rotor of a synchronous generator of a wind power plant, comprising: a plurality of pole pack laminations, each pole pack lamination of the plurality of pole pack laminations includes: a pole shank region; and a pole head region, wherein: the pole head region projects laterally beyond the pole shank region, and the pole head region has a side which faces the pole shank region and a side facing away from the pole shank region, and wherein the contour of the pole head region is at least one of: ellipsoidal or has an elliptical path at least on the side facing away from the pole shank region.

9. A synchronous generator for a wind power plant, having a stator and a rotor with a plurality of pole packs according to claim 8.

10. The wind power plant according to claim 1, wherein the synchronous generator is a ring generator.

11. The wind power plant according to claim 4, wherein the ratio of the semi-major axis in relation to the semi-minor axis of the ellipse defined by the contour of the pole head region has a value of 5.1.

12. The synchronous generator according to claim 9, wherein an air gap between the stator and the rotor has a non-constant width in the circumferential direction in a region of pole packs.

Description

DETAILED DESCRIPTION

[0038] FIG. 1 shows a schematic illustration of a wind power plant. The wind power plant 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 operation of the wind power plant, the aerodynamic rotor 106 is made to rotate by the wind, and, therefore, a rotor of a generator, in particular of a synchronous generator, which is directly or indirectly coupled to the aerodynamic rotor 106 also rotates. The electric generator is arranged in the nacelle 104 and generates electrical energy. The pitch angle of the rotor blades 108 can be changed by pitch motors at the rotor blade roots 108b of the respective rotor blades 108.

[0039] The pole packs described below are used for a rotor of a synchronous generator or a rotor of a ring generator.

[0040] FIG. 2 shows a schematic sectional view through a pole pack of a rotor of a synchronous generator according to a first exemplary embodiment. The pole pack 10 has a number of pole pack segments 12, 14, 16. Each pole pack segment 12, 14, 16 has a pole pack lamination 22 or a plurality of identical pole pack laminations 22. Each pole pack lamination 22 has a pole head region 18 and a pole shank region 20.

[0041] In FIG. 2, the pole head region 18 and the pole shank region 20 are illustrated such that they are separated by a separating line 23, wherein this separating line 23 does not represent a seam in the pole pack lamination 22, but rather is illustrated to ease understanding. The pole pack laminations 22 are, accordingly, preferably each integrally formed and, in particular, punched out for production purposes. The pole shank region 20 is substantially rectangular and optionally has two lugs 24 in the lower region.

[0042] The pole head region 18 is subdivided into an upper part 30 and a lower part 32 along the dashed line 26 which runs through the vertices 28a, 28b of the first pole pack segment 12. In this case, the upper part 30 of the pole head region 18 corresponds to a side 30, which faces away from the pole shank region 20, and has an ellipsoidal contour 31, wherein the lower part 32, which corresponds to a side 32 which faces the pole shank region 20, also at least partially has an ellipsoidal contour 31. The pole head region 18 extends laterally beyond the pole shank region 20.

[0043] Accordingly, the contour 31 of the pole head region 18 on that side 30 which is away from the pole shank region 20, specifically the upper side 30 of the pole head region 18, is ellipsoidal. Furthermore, an adjoining portion of the contour 31 of the pole head region 18, which projects beyond the pole shank region 20, and on the side 32 of the pole head region 18 which faces the pole shank region 20 and, therefore, corresponds to the lower part 32 of the pole head region 18 is also ellipsoidal.

[0044] For the illustrated first pole pack segment 12, the pole head region 18, accordingly, has an ellipsoidal form from the point 35 to the point 36 along the contour 31 of the pole head region 18 as seen in the clockwise direction.

[0045] The ratio of the semi-major axis 37 in relation to the semi-minor axis 38 of the contour of the pole head region, which contour is in the form of an elliptical path, corresponds to a value in the range of from 4 to 6.

[0046] Each of the pole pack segments 12, 14, 16 has a pole pack lamination 22 or a plurality of identical pole pack laminations 22, wherein the pole pack shanks 20 of the pole pack segments 12, 14, 16 have a common center line 39, while the pole pack regions 18 of the pole packs 12, 14, 16 each have a center line 40 which runs parallel to the center line 39 of the pole shank region 20 and in each case runs through the center point of the ellipse which is formed by the pole head region. This center line 40 of the pole head regions 18 of adjacent pole pack segments 12, 14, 16 are at different distances from the center line 39 of the pole shank region.

[0047] Accordingly, the pole head regions 18 of adjacent pole pack segments 12, 14, 16 are offset in relation to one another. Accordingly, the positions of the pole shank regions 20 of a pole pack segment 12, 14, 16 relative to the respective pole head regions 18 in adjacent pole pack segments 12, 14, 16 are different.

[0048] FIG. 3 shows a schematic plan view of a pole pack 10 with a plurality of pole pack segments 12, 14, 16, wherein the pole packs 10 in the upper region 44 are arranged in a mirror-symmetrical manner in relation to the pole packs 10 in the lower region 46. The entire pole pack 10 has an arrow-shaped arrangement.

[0049] FIG. 4 shows a side view of the pole pack 10. The pole packs 10 are each provided with a winding and this winding is supplied with an electric current, so that the pole packs 10 and the corresponding winding together with a field current generate magnetic excitation. This magnetic excitation leads to the pole pack 10 with the winding serving as a magnetic pole. Accordingly, the pole of an electrical machine with a pole pack 10, a winding and a field current is formed.

[0050] According to one embodiment, the pole pack laminations 22 are produced using separation methods, wherein the separation involves a punching-out operation, a lasering operation, a water-jet cutting operation or a cutting-out operation. The pole pack 10 serves to generate excitation fields on a rotor of a synchronous generator, in particular of an externally excited synchronous generator.

[0051] The synchronous generator of the wind power plant, that is to say of the wind power plant synchronous generator, is preferably a ring generator or a synchronous ring generator. A multi-pole synchronous ring generator of this kind of a gearless wind power plant has a large number of stator poles, in particular at least 48 stator teeth, frequently even considerably more stator teeth, such as, in particular, 96 stator teeth or even more stator teeth.

[0052] The magnetically active region of the ring generator, specifically both of the rotor and of the stator, is arranged in an annular region around the rotation axis of the synchronous generator. Therefore, in particular, a region of from 0 to at least 50 percent of the radius of the air gap is free of materials which carry electric current or electric field of the synchronous generator. In particular, this interior space is completely free and, in principle, also accessible. This region is often also more than 0 to 50 percent of the air gap radius, in particular up to 0 to 70 percent or even 0 to 80 percent of the air gap radius. Depending on the design, there may be a carrying structure in this inner region, but the carrying structure can be axially offset in some embodiments.

[0053] The pole packs are used in a synchronous generator rotor or in a ring generator rotor. Both the synchronous generator and the ring generator represent a slowly rotating synchronous generator with a rotation speed of less than 30, 25 or even 20 revolutions per minute.

[0054] The diameter of the synchronous generator rotor or of the ring generator rotor is typically several meters, wherein the air gap diameter is at least 3 or even more than 5 meters. The synchronous generator or the ring generator has a power of at least 100 kilowatts, at least 500 kilowatts, or preferably at least 1 megawatt (MW), but can also be 3 MW or up to 10 MW.