STATOR FOR AN ELECTRICAL MACHINE, WIND TURBINE AND METHOD FOR MANUFACTURING A STATOR

Abstract

Provided is a stator for an electrical machine, in particular a generator of a wind turbine, wherein the cylindrical stator includes multiple similar stator segments, each stator segment constituting a fraction of the circumference of the stator and having at least one coil element and one pre-installed bus bar segment per phase provided to or by the electrical machine, wherein each bus bar segment is electrically connected to a coil element of the respective phase, wherein at least two circumferentially adjacent stator segments form a section and multiple subsets of an even number of radially opposing sections are respectively assigned to a connector at a respective connection position along the circumference of the stator, wherein in each section, segmented bus bars for each phase are provided by connecting bus bar segments of adjacent stator segments.

Claims

1. A stator for an electrical machine, wherein the electrical machine is a generator of a wind turbine, wherein the cylindrical stator comprises multiple similar stator segments, each stator segment constituting a fraction of the circumference of the stator and having at least one coil element and one pre-installed bus bar segment per phase provided to or by the electrical machine, wherein each bus bar segment is electrically connected to a coil element of the respective phase, wherein at least two circumferentially adjacent stator segments form a section and multiple subsets of an even number of radially opposing sections are respectively assigned to a connector at a respective connection position along the circumference of the stator, wherein in each section, segmented bus bars for each phase are provided by connecting bus bar segments of adjacent stator segments, which belong to the same phase, using segment connection, and the segmented bus bars of each section whose segmented bus bars are distanced from their associated connection position are connected to the respective connector by additional, continuous bus bars bypassing each stator segment between an end of the segmented bus bars closest to the connection position and the connection position.

2. The stator according to claim 1, wherein the additional, continuous bus bars are positioned in the same radial position as the segmented bus bars of each bypassed stator segment, but longitudinally shifted on the side of the segmented bus bars opposing the stator segments.

3. The stator according to claim 1, wherein the connection positions are at the boundary of two adjacent sections.

4. The stator according to claim 1, wherein the segmented bus bars are connected to associated additional, continuous bus bars by a cross connection, in particular bridging a longitudinal distance between the bus bars.

5. The stator according to claim 4, wherein at least one of the at least one cross connection means, is flexible and shaped to connect the in particular also circumferentially distanced respective bus bar ends.

6. The stator according to claim 1, wherein it comprises four sections, wherein the two connection positions are provided at adjacent boundaries of two adjacent sections, wherein two sets of additional, continuous bus bars are provided, each spanning one section.

7. A wind turbine, comprising at least one generator having a stator according to claim 1.

8. A method for manufacturing a stator according to claim 1, wherein the stator segments are provided with the pre-installed bus bar segments attached to them and used to build the cylindrical stator, adjacent respective bus bar segments are at least partly connected using segment connection to form the segmented bus bars, whereafter the additional, continuous bus bars are added.

Description

BRIEF DESCRIPTION

[0028] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0029] FIG. 1 is a principle frontal view of a stator according to embodiments of the invention;

[0030] FIG. 2 shows a perspective view of a first detail of the stator;

[0031] FIG. 3 shows a perspective view of a second detail of the stator;

[0032] FIG. 4 shows a perspective view of a first connector;

[0033] FIG. 5 shows a perspective view of a second connector and cross connection means or cross connection;

[0034] FIG. 6 is a perspective view of an alternative construction of the second connector area;

[0035] and

[0036] FIG. 7 shows a wind turbine according to embodiments of the invention.

DETAILED DESCRIPTION

[0037] FIG. 1 is a principle drawing of the front face of a stator according to embodiments of the invention. Combined with a rotor 2, which is only indicated in FIG. 1, an electrical machine results, in this case a generator of a wind turbine. In an example, 192 poles may be used.

[0038] The stator 1 is built from twelve segments 3, wherein three adjacent segments 3 each form a section 4, 5, 6, 7. Each segment has at least one coil element 8, as also only indicated in FIG. 1, and, as can be seen for example in the perspective view of FIG. 2, three pre-installed bus bar segments 9 made of copper, which are fixed to the segments 3. The generator, to which the stator 1 belongs, uses three phases, such that each bus bar segment 9 is associated with one phase and accordingly electrically connected to respective coil elements 8. At the boundary 10 of two segments 3, which lies inside a section 4, 5, 6, 7, segment connection means or segment connection 11 are used to connect adjacent bus bar segments, resulting in a segmented bus bar 12, wherein parts of the segmented bus bar 12 cover the whole 360° of the circumference direction of the stator 1.

[0039] In the example of 192 poles in the rotor 2, 16 poles are associated with each segment.

[0040] In the current embodiment, opposing sections 4, 5 and 6, 7 are to be connected to different electrical systems, for example converters, such that two connectors 13, 14 at different connection positions 15, 16 (one left, one right) are provided, each able to connect to six lines (two per phase). While the segmented bus bars 12 of sections 7 and 4 each end at the connection positions 15, 16 of their respective connectors 13, 14, to be also able to connect the segmented bus bars 12 of sections 6 and 5 to their respective connectors 13, 14, additional, continuous bus bars 17, one for each phase, are used to bypass the respective sections 4, 5, that is, each of the two sets of three additional, continuous bus bars 17 has the length of three segments 3, i.e. continuously passes the intra-section boundaries 10, as can be seen in FIG. 3. While assembling the stator 1, first of all, the segment connection means or segment connection 11 are used to connect the bus bar segments 9 to the segmented bus bars 12, whereafter the additional, continuous bus bars 17 are added. To obtain a compact design, the additional, continuous bus bars 17 are added at the radial positions of the segmented bus bars 12, as can also be seen from the figures.

[0041] Only two sets of three additional, continuous bus bars 17 are needed, one, namely the right one of FIG. 1, to connect the segmented bus bars 12 of section 5 to connector 14, one, namely the upper one in FIG. 1, to connect the section 6 to connector 13. Neither section 5 nor section 7 have additional, continuous bus bars 17, such that the complexity is reduced, the amount of copper is reduced and less connection parts are needed.

[0042] FIGS. 4 and 5 show perspective views of the connectors 13, 14. As can be seen from FIG. 4, in the connector 13, easy connection is provided as a direct connection to the bus bar segments 9/segmented bus bars 12 of section 7 and the additional, continuous bus bars 17 connected to the segmented bus bars 12 of section 6 is sufficient.

[0043] Regarding the connector 14, additionally, the ends of segmented bus bars 12 of section 6 need to be connected to the additional continuous bus bars 17 of section 4 leading to the connection position 15, that is, a cross connection is to be provided. In the embodiment of FIG. 5, plate-like cross connection means or cross connection 18 are used since only a longitudinal distance between the ends of the bus bar segments 9 of section 6 and the ends of the (correspondingly prolonged) additional, continuous bus bars 17 of section 4 needs to be provided.

[0044] An alternative solution is shown in the perspective view of FIG. 6, wherein the additional continuous bus bars 17 of sections 4 are also circumferentially distanced from the ends of the segmented bus bar 12 of section 6, such that connection means or connection 19 comprising a flexible bus bar have been used, wherein the flexible bus bars have been bent into 90° angles to bridge the longitudinal and circumferential distances.

[0045] The connection positions 15, 16 are, in this embodiment, located at section boundaries 20.

[0046] FIG. 7 shows a wind turbine 21 according to embodiments of the invention. The wind turbine 21 comprises a tower 22 carrying a nacelle 23. A generator 24 having a stator 1 according to embodiments of the current invention is driven using wind interacting with blades 25 of the wind turbine 21.

[0047] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0048] For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.