Electrical generator with dedicated cooling of stator segments

Abstract

The arrangement directed to a generator, which contains a rotor and a stator us disclosed. The stator contains at least two stator segments. At least one of the stator segments contains a number of stacked laminate plates. The stacked laminate plates contain a number of slots at a first side, while the first side of the stacked laminate plates is aligned to the rotor. The slots support a metal-winding of a stator coil. At least one hollow cooling-pipe is partly integrated into the stacked laminate plates of the stator segment to cool its laminate plates by a cooling-medium, which is located into the cooling-pipes.

Claims

1. A wind turbine electrical generator cooling arrangement, comprising: a rotor; a stator including a plurality of stator segments, each stator segment including a plurality of stacked-laminate plates, the plurality of stacked-laminate plates contain a plurality of slots at a first side of the plurality of stacked-laminate plates, the first side of the plurality of stacked-laminate plates is aligned to the rotor and the plurality of slots support a metal-winding of a stator coil; a plurality of hollow-cooling pipes, each of the plurality of hollow-cooling pipes is dedicated to one of the plurality of stator segments and each of the plurality of hollow-cooling pipes is partly integrated into the plurality of stacked-laminate plates of the dedicated stator segment in order to cool the plurality of stacked-laminate plates by a cooling-medium, which is located in each hollow-cooling pipe; and a plurality of heat exchangers, each of the plurality of heat exchangers is connected with only one of the plurality of hollow-cooling pipes of the dedicated stator segment by a respective input-connection and an output connection; wherein each partly integrated cooling pipe is disposed such that a thermal exchange between the dedicated stator segment and the cooling pipe is allowed, wherein each partly integrated hollow-cooling pipe is located on a second side of the plurality of stacked-laminate plates, wherein the second side is opposite to the first side, and wherein each partly integrated cooling pipe is exposed from the plurality of stacked-laminate plates along the second side in a longitudinal direction, wherein each partly integrated cooling pipe is partly integrated into the plurality of stacked-laminate plates along a longitudinal direction.

2. The arrangement according to claim 1, wherein each cooling pipe contains the input connection and the output connection for the cooling-medium, and wherein the cooling medium enters each hollow-cooling pipe via the input connection with a first temperature and while the cooling medium leaves each hollow-cooling pipe via the output connection with a second temperature, which is warmer than the first temperature.

3. The arrangement according to claim 1, wherein a heat transfer compound is arranged between each cooling pipe and the plurality of stacked-laminate plates of the dedicated stator segment.

4. The arrangement according to claim 1, wherein each hollow-cooling pipe contains a plurality of hairpin bends, which are shaped and arranged in the dedicated stator segment such that voltages induced in each hollow-cooling pipe are reduced.

5. The arrangement according to claim 1, wherein each hollow-cooling pipe is part of a support-structure, which is constructed to support the laminate plates of the of dedicated stator segment.

6. The arrangement according to claim 1, wherein each hollow-cooling pipe contains threads, which are constructed to tighten at least the stacked-laminate plates.

7. The arrangement according to claim 6, wherein each hollow-cooling pipe contains a supporting flange; and wherein the supporting flange is welded to each hollow-cooling pipe.

8. The arrangement according to claim 1, wherein the generator contains an outer-rotor and an inner-stator, or wherein the generator is a direct drive generator of a wind-turbine.

9. The arrangement according to claim 1, wherein the cooling medium is liquid.

10. The arrangement according to claim 9, wherein the cooling medium comprises an anti-freeze agent or oil.

11. The arrangement according to claim 1, wherein the cooling medium comprises an anti-freeze agent or oil.

12. The arrangement according to claim 1, wherein each hollow-cooling pipe is made of a non-magnetic material; and wherein each hollow-cooling pipe is made of stainless-steel.

13. The arrangement according to claim 1, each hollow-cooling pipe extends axially along a longitudinal direction of the laminate.

14. The arrangement according to claim 1, wherein the stator and the rotor are extend circumferentially about a common axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described in more detail now by the help of the figures. The figures show examples and therefore do not limit the scope of the arrangement invented.

(2) FIG. 1 shows a part of the cooling-arrangement invented,

(3) FIG. 2 shows a laminate plate according to the invention in a side-view,

(4) FIG. 3 shows in reference to FIG. 1 and FIG. 2 a 3D-view of a part of the arrangement invented,

(5) FIG. 4 illustrates schematically a first preferred configuration according to the invention,

(6) FIG. 5 illustrates schematically a second preferred configuration according to the invention,

(7) FIG. 6 and FIG. 7 show stacked laminate plates, which are fixed by help of the cooling-pipe, to be used in the arrangement invented,

(8) FIG. 8 illustrates the position of cooling-pipes CP in view of the laminate plates, and

(9) FIG. 9 shows a known laminate plate as described in the introduction.

DETAILED DESCRIPTION OF INVENTION

(10) FIG. 1 shows a part of the cooling-arrangement invented,

(11) A number of laminate plates LP are stacked. Each laminate plate LP shows a number of slots SL. Because of the stacking the slots SL form a number of channels CH, which are used to support metal-windings MW of a stator-coil.

(12) The stacked laminate plates LP are part of stator-segment. The stacked laminate plates LP show a first side S1, which is aligned to the rotor of the generator. The slots SL are located on this first side S1.

(13) At least one cooling-pipe CP is partly integrated into the stacked laminate plates LP. The partly integrated cooling-pipes CP penetrate the laminate plates LP on a second side S2 of the stacked laminate plates LP. The second side S2 is opposite to the first side S1.

(14) A heat transfer compound (not shown here) is arranged between the cooling-pipe CP and the stacked laminate plates LP. Thus the thermal conductivity of the thermal interface between irregular surfaces of the stacked laminate plates and the cooling-pipes is enhanced. Air gaps between the components are reduced or even eliminated, thus the cooling is improved.

(15) The compound may be ceramic, metal, carbon or a liquid.

(16) FIG. 2 shows a laminate plate LP according to the invention in a side-view.

(17) A first side S1 of the laminate plate LP is aligned or aimed to an air gap, while the air gap is between the stator and the rotor of the generator. The first side S1 contains a number of slots SL. The slots SL may be punched out from a sheet of metal. The laminate plate LP may be manufactured by the same way.

(18) With reference to FIG. 1 a number of stacked laminate plates LP will form channels CH due to the slots SL. This channels CH are used to support the metal windings MW of the stator-coil.

(19) Each metal winding MW is formed by a conductor CON, which is surrounded by a conductor-isolation CONI. Each slot SL shows a slot isolation lining SIL to insulate the bundle of metal windings MW.

(20) On top of each slot SL there is a recess RC. The recess RC is built to support a wedge WDG. When the metal windings MW of the electrical coils are inserted they are kept in place by help of the wedge WDG.

(21) A number of cooling-pipes CP is partly integrated into the (stacked) laminate plates LP and on the second side S2, which is opposite to the first side S1.

(22) Preferably the cross-section of the cooling-pipes CP is integrated by more than 50% into the (stacked) laminate-plates LP.

(23) This FIG. 2 shows only a part of the stator segment, which comprises the stacked laminate plates. The stacked laminate plates are shaped circular.

(24) FIG. 3 shows in reference to FIG. 1 and FIG. 2 a 3D-view of a part of the arrangement invented.

(25) FIG. 4 illustrates schematically a first preferred configuration according to the invention.

(26) The generator (not shown here) contains a common cooling means like a heat exchanger HX for example.

(27) The common heat exchanger HX is connected to four segments seg1, seg2, seg3 and seg4 of the segmented stator of the generator.

(28) Each of the segments seg1 to seg4 shows a cool input and a hot output of the dedicated cooling-pipe, which are connected appropriate as shown here. Thus long connection-lines between the stator-segments seg1 to seg4 and the heat exchanger HX are avoided.

(29) The cooling-medium is divided and brought into four cooling-paths, each cooling path is dedicated to one of the segments seg1 to seg4.

(30) The divided cooling medium is combined after it leaved the dedicated cooling-path.

(31) Seen from the heat exchanger FIX the cooling-pipes are regarded to be parallel coupled.

(32) FIG. 5 illustrates schematically a second preferred configuration according to the invention.

(33) The generator (not shown here) contains a number of four cooling means like heat exchangers HXX for example.

(34) Each heat exchanger HXX is connected to a dedicated segment seg1, seg2, seg3 and seg4 of the segmented stator of the generator.

(35) Thus a number of four independent cooling-circuits are built, while each circuit contains a cooling-pipe of one of the segments seg1 to seg4.

(36) Preferably the cooling system according to FIG. 1 and according to FIG. 5 may be combined.

(37) As an example if the stator is partitioned into 8 segments, the cooling-system may comprise two cooling means. Each of the cooling means may supply and receive cooling medium from the cooling pipes of 4 stator segments.

(38) FIG. 6 and FIG. 7 show stacked laminate plates LP, which are fixed by help of the cooling-pipe CP, to be used in the arrangement invented,

(39) FIG. 8A illustrates schematically cooling-pipes CP, which are arranged in slots SL of the laminate plates LP according to the invention.

(40) FIG. 8B illustrates schematically cooling-pipes CP, which are mounted on a surface of the laminate plates LP. This configuration is known before.

(41) According to FIG. 8A the cooling-pipes CP are integrated part of the laminate plates LP. The cooling-pipe CP contains an inner perimeter with a length L1.

(42) The length L2 represents the distance between two adjacent cooling pipes CP. As shown here the perimeter length L1 is substantial equal to the length L2.

(43) According to FIG. 8B the cooling pipes CP are no integrated part of the laminate plates LP, they are located on heat transferring plates HT substantially on the inner surface of the stator. The maximum width of the plates HT is equal to the distance of L2.

(44) The illustration in FIG. 8A show an improved cooling efficiency compared to the illustration in FIG. 8B.