ROTOR OF A GEARLESS WIND TURBINE

Abstract

A preformed coil of a rotor of a synchronous generator of a gearless wind power plant is provided. The preformed coil may be arranged around a pole shoe defining a central axis. The preformed coil has a plurality of windings and is made up of laminations.

Claims

1. A preformed coil of a rotor of a synchronous generator of a gearless wind turbine, the preformed coil comprising: a plurality of windings, a winding of the plurality of windings being made up of one or more laminations, and the preformed coil being operable to be arranged around a pole shoe having a central axis.

2. The preformed coil according to claim 1, wherein the plurality of windings are layered in an axial direction along the central axis of the pole shoe.

3. The preformed coil according to claim 1, wherein the laminations are configured such that the preformed coil has outward surfaces that are larger compared to flat surfaces.

4. The preformed coil according to claim 1, wherein the winding of the plurality of windings or a half of the winding consists of one lamination, and the one or more laminations of the winding of the plurality of windings are assembled together with laminations of remaining windings of the plurality of windings to form the preformed coil.

5. The preformed coil according to claim 1, wherein the one or more laminations are aluminum or copper.

6. The preformed coil according to claim 1, wherein the preformed coil is dipped in a bath including an insulating varnish for insulating the preformed coil.

7. The preformed coil according to claim 1, wherein the winding of the plurality of windings includes two L-shaped laminations connected to each other by a connecting joint form the winding, and wherein the two L-shaped laminations have an identical shape.

8. A synchronous generator of the gearless wind turbine, the synchronous generator comprising a rotor with at least one preformed coil according to claim 1.

9. A wind turbine comprising the synchronous generator according to claim 8.

10. A method comprising: punching or cutting out at least two laminations, and connecting the at least two laminations to form one or more windings of a preformed coil.

11. The method according to claim 10, comprising: after connecting the at least two laminations, dipping the one or more windings in a bath containing an insulating varnish.

12. The method according claim 10 further comprising: placing the preformed coil on a pole shoe, and filling interspaces between the preformed coil and the pole shoe.

13. The method according to claim 12, comprising: making the preformed coil from aluminum, and dimensioning the preformed coil such that the preformed coil is positioned loosely on the pole shoe with an amount of clearance.

14. The method according to claim 10, comprising connecting the at least two laminations to form a complete winding of the preformed coil.

15. The method according to claim 12, comprising: filling the interspaces between the preformed coil and the pole shoe with synthetic resin.

16. The preformed coil according to claim 2, wherein the windings are layered exclusively in the axial direction of the pole shoe.

17. The preformed coil according to claim 3, wherein the one or more laminations have beveled edges.

18. The preformed coil according to claim 17, wherein the outward surfaces are corrugated or ribbed due to the beveled edges of the one or more laminations.

19. The preformed coil according to claim 3, wherein two or more adjacent laminations of two or more adjacent windings have different widths.

20. The preformed coil according to claim 19, wherein the outward surfaces are corrugated or ribbed due to the two or more adjacent laminations of the two or more adjacent windings having different widths.

21. The preformed coil according to claim 6, wherein the preformed coil is dipped in the bath including the insulating varnish without the pole shoe.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0032] The invention is now explained in greater detail below by way of example with reference to the attached figures.

[0033] FIG. 1 shows a wind turbine in a perspective illustration.

[0034] FIG. 2 shows schematically two L-shaped laminations for a preformed coil.

[0035] FIG. 3 shows a preformed coil or winding of a preformed coil consisting of laminations as shown in FIG. 2, in a perspective and schematic illustration.

[0036] FIGS. 4 and 5 illustrate different corrugated surfaces in a side view to illustrate the contours.

[0037] FIG. 6 shows part of a winding of a preformed coil in a perspective illustration.

[0038] FIG. 7 shows a detail of a generator arranged in a nacelle.

DETAILED DESCRIPTION

[0039] FIG. 1 shows a wind turbine 100 having a tower 102 and a nacelle 104. A rotor 106 having three rotor blades 108 and a spinner 110 is arranged on the nacelle 104. In operation, rotation is imparted by the wind to the rotor 106, which thereby drives a generator in the nacelle 104.

[0040] FIG. 2 shows a plan view of two L-shaped laminations 2. These two L-shaped laminations 2 can be identical in shape and are connected to one another at the connecting joint 4 to form a winding 3. It is thereby possible to avoid overlaps from one winding to the next. At further connecting edges 6 and 7, the two L-shaped laminations 2 can be connected to other laminations, namely at a higher or lower level or plane, to produce a preformed coil, although this is not shown here in FIG. 2.

[0041] FIG. 3 then shows schematically a finished winding 8, which is made up of eight layers and hence 16 L-shaped laminations 2 according to FIG. 2. The winding 8 thus essentially already forms a preformed coil.

[0042] FIG. 4 shows four layers of a winding 8 in a side view, which corresponds to a view from the right of the winding 8 shown in FIG. 3. However, no connecting joint 4 is shown in FIG. 4 or in FIG. 5 either. Instead, FIG. 4 is intended to illustrate the outer surface 10 by showing its contours. This outer surface 10 is formed by edges of the individual laminations 2, which have a curved edge 12 due to a pressing operation. The layering of these laminations 2 with their curved edges 12 leads to the corrugated surface 10 shown, of which the contours are shown in FIG. 4 by virtue of the perspective selected.

[0043] FIG. 4 also shows a detail of a winding 8, an air channel 14 is formed between these two windings 8, the side walls of said channel being defined by the contours of the outer surfaces 10.

[0044] Thus, on the one hand, it is ensured that the surface area of the outer surface 10 is enlarged by the curved edges 12 and, furthermore, that an air channel 14 with guide grooves or guide slots is obtained.

[0045] FIG. 5 shows an alternative embodiment of the laminations 2. These laminations 2 have cut edges 16, which thus also lead to an outer surface 18 with an enlarged surface area.

[0046] In addition to a sub-winding 8, two further sub-windings 8 are shown in the detail. The illustration thereof in FIG. 5 is merely intended to illustrate various possibilities for resulting air channels 20 and 20. In the case of air channel 20, i.e., that illustrated on the left in FIG. 5, the cut edges 16 are oriented in the same direction on both sides of air channel 20 and thereby give air channel 20 its shape.

[0047] In the air channel 20 illustrated on the right, the adjacent cut edges 16 and 16 are aligned in the opposite direction, which has no effect on the size of the outer surface 18 or 18 but affects the shape of the air channel 20.

[0048] Finally, FIG. 6 shows, in a perspective view, part of a winding 68, which is assembled from five L-shaped laminations 62, in each case at connecting joints 64. The winding 68 or sub-winding 68 in FIG. 6 is furthermore shown somewhat spread apart. In this position, this sub-winding 68 can be dipped effectively into a bath of insulating varnish. However, this is shown here only by way of illustration, and such an insulation dipping process is preferably proposed only for a complete winding, i.e., when further laminations 62 have been added.

[0049] FIG. 7 shows a generator 130 schematically in a side view. It has a stator 132 and an electrodynamic rotor 134, which is mounted so as to be rotatable relative thereto, and is secured by means of its stator 132 on a machine support 138 using an axle journal 136. The stator 132 has a stator support 140 and stator lamination assemblies 142, which form stator poles of the generator 130 and are secured on the stator support 140 using a stator ring 144. The electrodynamic rotor 134 has rotor pole shoes 146, which form the rotor poles and are mounted on the axle journal 136 using a rotor support 148 and bearings 150 so as to be rotatable about the axis of rotation 152. The stator lamination assemblies 142 and rotor pole shoes 146 are separated only by a narrow air gap 154, which is a few mm wide, in particular less than 6 mm, but has a diameter of several meters, in particular more than 4 m. The stator lamination assemblies 142 and the rotor pole shoes 146 each form a ring and are also annular together, and therefore the generator 130 is a ring-type generator. In accordance with its purpose, the electrodynamic rotor 134 of the generator 130 rotates together with the rotor hub 156 of the aerodynamic rotor, of which the initial sections of rotor blades 158 are indicated.

[0050] A preformed coil made up of assembled laminations is proposed. This preformed coil can also be referred to as a pole shoe coil. Such pole shoe coils consisting of complete or half windings cut from metal sheets, are preferably joined together by means of suitable connection techniques. A laminated coil is thus obtained. Welding, e.g., friction stir welding, and soldering are particularly suitable connection techniques because it is thereby possible to produce the required electrically conducting joint.

[0051] Laser cutting, water cutting and punching, for example, are suitable cutting techniques for consideration. In the case of cutting, half windings have the advantage that they can be cut in an L shape or as similarly as possible from sheets and, as a result, involve very little waste.

[0052] When using complete windings, there is the advantage in comparison with half windings that only half as many joints are required, whereas there is considerably more waste when cutting to size.

[0053] One significant advantage is providing improved cooling of the pole shoe coils in comparison to coils wound from wire. In particular, this is achieved by virtue of the fact that the heat can flow directly to the coil surface in each winding of the proposed solution. In contrast to coils that are wound edgeways, that is to say in which sheets or similar conductive materials are arranged with the surface around the central axis and not perpendicularly to the central axis, cut laminated coils can be produced in any desired two dimensional geometry and therefore do not require any bending gradients. Otherwise, however, coils that are wound edgeways could have similar advantages as regards heat flux as the solution proposed here.

[0054] For the preformed coils or laminated coils or pole shoe coils proposed, where these terms can be used synonymously, copper but also aluminum are suitable. Here, aluminum is preferably proposed for reasons already explained above.

[0055] It is furthermore proposed that the coils can be given contours suitable for cooling by means of suitable cutting tools or suitable aftertreatment. For example, the coils can be cut obliquely at the outer edge, giving rise to a zigzag surface at the outer surface of the coil through windings lying one above the other. The surface area enlarged in this way leads to increased heat transfer to the cooling medium, which is generally air between the poles. The individual windings of sheet metal can likewise be pressed into a shape such that a cooling tab or cooling rib of suitable geometry is formed at the outer edges, for example.

[0056] Thus, better cooling of the coils is achieved, in particular. By virtue of the very good heat flux within the conductor material, i.e., from the inside outward within the laminations of a winding, the heat produced can be dissipated directly at the coil surface.

[0057] Apart from dipping the winding produced from the laminations, the use of pre-insulated laminations can also be considered. However, re-insulation would then have to be performed at weld seams.

[0058] Moreover, not only are good thermal conductivity and heat dissipation obtained but also a somewhat better filling factor in comparison with conventionally wound coils is obtained with the solution proposed.

[0059] The solution proposed can furthermore lead to a larger or taller winding head, but there is generally sufficient space for this in a generator of a gearless wind turbine. Any increase in magnetic losses which occurs can easily be compensated for by one or two further windings.