Mounting system for busbars on stators or stator segments of dynamoelectric machines

Description

[0001] The invention relates to a holding system for busbars on stators or stator segments of dynamoelectric machines, in particular wind power generators, as well as to such a stator of a dynamoelectric machine and a wind turbine.

[0002] Coils, especially those of larger dynamoelectric machines, are electrically combined into coil groups or coil systems. This typically required busbars, which, due to their increased weight, could no longer be directly attached to the winding heads. Wind turbines, especially direct-drive wind turbines, typically use massive busbars, which further increase the weight problem.

[0003] Such busbars of a directly driven wind turbine generator, which has a segmented structure, are known, for example, from WO 2019 / 185224 A1.

[0004] US Pat. No. 4,321,497 A discloses a stator with several stacked coils. Each coil has two coil sides with ends protruding axially from the stator, which are connected to each other at the head end of the stator by a C-shaped connecting ring. Retaining elements are provided that are screwed to the head end of the stator, with several receptacles for connecting rings formed on the retaining elements by means of spacers. The spacers are made of an insulating material.

[0005] From DE 2 161 139 A1 an elastic winding head support is known in which coils are held axially movable relative to the stator.

[0006] From CN 106 253 538 A a holding element for an electrically conductive ring on a stator is known.

[0007] A support for stator windings is known from US 3 348 085 A.

[0008] From EP 0 375 419 A2 a conductor ring arrangement for a dynamoelectric machine is also known.

[0009] DE 1 200 932 A discloses a holder for busbars on a stator press plate, in which the busbars are clamped between a spacer block, angle pieces, and a support piece with initially deformable padding in between. The padding adapts to the shape of the busbars and is then hardened.

[0010] Based on this, the invention is based on the object of creating a holding system suitable for busbars of a dynamoelectric machine, in particular for a directly driven generator of a wind turbine. Above all, the required insulation strength / insulation distances of these busbars should be maintained within this holding system, and sufficient cooling for the busbars and the dynamoelectric machine should be ensured. Furthermore, the holding system should be integrated into the structure of the dynamoelectric machine as far as possible in order to provide a compact generator in a nacelle of a wind turbine.

[0011] The solution to the problem is achieved by a holding system for busbars with the following elements: a base element that can be fastened to an end face of a stator or stator segment of a dynamoelectric machine and a predetermined number of fixing elements by means of which the busbars can be fixed to the base element.

[0012] The solution to the problem is also achieved by a stator or stator segment of a dynamoelectric machine, wherein there is provided a winding system in substantially axially extending grooves of a laminated core, which forms winding heads on the end faces, wherein the laminated core is arranged on a support system which has pressure plates in the region of the end face, which are fixed by means of connecting elements, wherein a holding system of busbars according to claim 1 is provided, which can be fastened to a end face of a stator or stator segment of the dynamoelectric machine by means of a base element and busbars can be fixed to the base element by means of a predetermined number of fixing elements.

[0013] The task can also be solved by a wind turbine generator with a stator or stator segment.

[0014] The task can also be solved using a wind turbine with a generator.

[0015] The inventive holding system, which is primarily made of steel, allows for load-bearing holes relevant for fastening to be drilled directly into the base elements and fixing elements. Additional fixing components are no longer required, significantly simplifying assembly work. This increases the rigidity of the holding system, particularly its components such as the base element and fixing elements, so that the entire connection surfaces for busbars are subject to less vibration.

[0016] The route of the busbars on the front side of the stator or stator segment can thus also be optimized with regard to the required insulation distances, so that an optimized design of the dimensions of the holding system benefits the ventilation of the winding head of the stator.

[0017] The arrangement of the busbars represents the respective supply line to a phase of a coil group of the winding system of the dynamoelectric machine, in particular the generator.

[0018] Electrical contacting of the busbars in the circumferential direction can be achieved by plugging them together, welding them, or by using stranded wires.

[0019] In order to further reduce the weight of the busbars, their cross-section can be reduced starting from the feed-in point.

[0020] Data cables can also be easily installed on the holding system by attaching them to the holding system with cable ties.

[0021] The support system, with its busbars, star-point connections, grounding lines, and data lines, is essentially arranged radially beneath the winding head of a stator segment or the stator itself. This results in a more compact design. This design also allows the busbars to be integrated into any cooling arrangement for the winding heads.

[0022] The stator segment with a ready-to-use winding system and pre-assembled busbars on the stator segment enables almost complete factory-tested pre-assembly, which reduces the assembly time on the plant side.

[0023] By arranging the busbars on the front side of the stator, a compact design of the dynamoelectric machine, in particular a generator of a wind turbine, can be provided.

[0024] This allows for a compact design of this generator while ensuring sufficient ventilation of its winding system and busbars.

[0025] The invention and further advantageous embodiments of the invention are explained in more detail using exemplary embodiments shown in principle, in which: FIG 1Elements of the holding system, FIG 2Perspective view of busbars in the holding system, FIG 3Stator segment FIG 4Basic arrangement of stator segments, FIG 5Directly driven generator, FIG 6Wind turbine.

[0026] FIG 1 shows a holding system 1 according to claim 1, which is basically constructed from a base element 2 and fixing elements 3 made of steel. These base elements 2 are fastened to a pressure plate 16 by means of screw connections 4 in the installed state. The fixing elements 3 are fastened to the respective base element 2 in the installed state. The fixing elements 3 have feet 10 for enclosing a cam 9 of the base element 2, wherein an asymmetrically arranged bore 8 ensures that confusion of the installation position of the fixing elements 3 is excluded.

[0027] When assembled, the holding system 1 now provides installation spaces 6 for the busbars 7, as well as for star point connections or grounding lines, if required. When assembled, the holding system 1 has openings 5. This suppresses eddy currents when the busbars 7 are energized, since there are no closed metallic connections between the individual elements.

[0028] FIG 2 shows, in a partial perspective view, the arrangement of the busbars 7 within the holding system 1, wherein the holding system 1 is attached to the pressure plates 16 of a stator 22 or a stator segment 13. In the area of ​​the base element 2 and the fixing elements 3, the busbars 7 have insulation elements 12, which have different thicknesses depending on the applied voltage.

[0029] FIG 3 shows an exemplary stator segment 13 in a perspective view, not to scale, with holding system 1, but without busbars 7, wherein the laminated core 14 is constructed in the axial direction from partial laminated cores. The laminated core 14 is delimited and fixed in the axial direction by pressure plates 16, with connecting elements 17 holding the pressure plates 16 together at the end faces of the stator segment 13. Form-wound coils 18, whose winding heads have different offsets, are arranged in slots (not shown in detail) of the laminated core 14. Electrical energy is now supplied to or dissipated from these form-wound coils 18. This occurs via the busbars 7, which are positioned on the end face of the holding system 1, in particular on the pressure plates 16.

[0030] The busbars 7 extend over the entire circumferential width of a stator segment 13, thus corresponding approximately to the length of the pressure plate 16. Depending on the type of connection to the circumferentially adjacent stator segments, the busbars 7 can be longer or shorter.

[0031] FIG 4 shows a basic representation of a stator 22 which is constructed from stator segments 13, wherein the respective coils 18 or coil groups of each stator segment 13 are contacted via this busbar system from a holding system 1 which has three busbars 7.

[0032] The busbars 7 are curved and essentially follow the radius of the stator 22. Each stator segment 13 can have its busbars 7 already positioned in the holding system 1. When assembling the stator segments 13 to form a stator 22, the respective busbars 7 are subsequently contacted.

[0033] However, individual busbar sections extending circumferentially over two, three, or more segments are also possible. Thus, quarter circles or even semicircles are possible. The electrical connecting lines 20 must be adapted accordingly.

[0034] Contact elements 21 establish electrical contact between busbar sections of a phase. Such electrical contact between the busbar sections in the circumferential direction can be achieved by plugging them together, welding them together, using stranded wire connections, etc.

[0035] The compact structure can now be sufficiently cooled by fans through appropriately guided air flows over or through the laminated core 14, as well as in the area of ​​the winding heads and the busbars 7.

[0036] FIG 5 shows a basic arrangement of a directly driven generator 24 of a wind turbine 27, wherein the rotation of the wind turbine 25 drives a rotor 23 which, through electromagnetic interaction with a winding system of the stator 22, generates electrical energy which is made available to a supply network 26 via a converter unit 30.

[0037] Such an arrangement is used, for example, in wind turbines 27 according to FIG 6 to be provided, a generator 24 is arranged in a nacelle 29 on a tower 28.

Claims

1. A retaining system (1) for bus bars (7), comprising the following elements: a basic element (2) that can be fastened to an end face of a stator (22) or stator segment (13) of a dynamoelectric machine (24), and a predefined number of fixing elements (3) by means of which the bus bars (7) can be fixed to the basic element (2), wherein, when assembled, the retaining system (1) has openings (5), in order to suppress eddy currents when the bus bars (7) are energized, characterized in that the fixing elements (3) are each individually fastened to the base element (2), and wherein the fixing elements (3) are fixed to the base element (2) by means of screws.

2. A stator (22) or stator segment (13) of a dynamoelectric machine, - wherein, provided there, in substantially axially extending grooves of a laminated core (14), there is a winding system that forms winding overhangs at the end faces, - wherein the laminated core (14) is arranged on a support system (15) which, in the region of the end face, has pressure plates (16) that are fixed by means of connection elements (17), - wherein a retaining system (1) for bus bars (7) as claimed in claim 1 is provided, which can be fastened with a basic element (2) to an end face of a stator (22) or stator segment (13) of the dynamoelectric machine, and bus bars (7) can be fixed to the basic element (2) by means of a predefined number of fixing elements (3), wherein the fixing elements (3) are each individually fastened to the base element (2), and wherein the fixing elements (3) are fixed to the base element (2) by means of screws - wherein, when assembled, the retaining system (1) has openings (5), in order to suppress eddy currents when the bus bars (7) are energized.

3. The stator (22) or stator segment (13) of a thermoelectric machine, as claimed in claim 2, characterized in that the bus bars (7) extend substantially radially beneath the winding overhangs.

4. The stator (22) or stator segment (13) of a thermoelectric machine, as claimed in claim 2 or 3, characterized in that the basic element (2) at the end face of a stator (22) or stator segment (13) of the dynamoelectric machine is fixed to the pressure plates (16), and / or the fixing element (3) is fixed to the basic element (2), by means of screws.

5. The stator (22) or stator segment (13) of a thermoelectric machine, as claimed in any one of claims 2 to 4, characterized in that the bus bars (7) have insulation elements (12, at least in the region of the basic elements (2) and the fixing elements (3).

6. A generator (24) of a wind power plant (27) comprising a stator (22) or stator segments (13) as claimed in any one of claims 2 to 5.

7. A wind power plant (27) comprising a generator (24) as claimed in claim 6.