EP3014743A2

EP3014743A2 - Cooling device for an electric machine and electric machine comprising a cooling device

Info

Publication number: EP3014743A2
Application number: EP14758903.0A
Authority: EP
Inventors: Esteban Grau Sorarrain; Christian Jäkel; Mario Koebe; Matthias Kowalski; Christoph Lehmann; Andrey Mashkin; Olga Plotnikova; Carolin Schild
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2013-09-20
Filing date: 2014-09-03
Publication date: 2016-05-04
Also published as: US20160226325A1; JP2016530855A; WO2015039864A3; EP2852030A1; CN105556801A; WO2015039864A2

Abstract

The invention relates to a cooling device (1) for an electric machine (100) having a stator winding (2a) having at least one laminated stator core (2b), which at least one laminated stator core comprises at least one laminated stator core (2b) and at least one stator winding head (2c), wherein the cooling device (1) comprises a plurality of channels (6a) through which a coolant can flow, which channels are connected to a pressure accumulator (10a) at a first end (7a) and leads into an impingement cooling plate (8a) and/or into a channel of a stator winding head (2c) at a second end (7b) of the channels. The invention further relates to an electric machine (100), comprising a rotor (4) and a stator (2), which stator comprises at least one stator winding (2a), which has at least one laminated stator core (2b) and at least one stator winding head (2c); wherein the electric machine (100) comprises a cooling device (1) according to the invention. The electric machine can be a generator and/or a motor.

Description

description

Cooling device for an electric machine and electric machine comprising a cooling device

The invention relates to a cooling device for electric machines, in particular generators, and electric Ma ^¬ machine with an inventive cooling device.

FIG. 3 shows an electrical machine 101 according to the prior art; more precisely, FIG. 3 shows a cross section of a quadrant of an electrical machine. The structure of the electric machine 101 is generally rotationally symmetrical about a rotation axis 5. On the rotation axis 5 is a rotor 4. Concentric or substantially concentric to the rotor 4, a stator 2 is arranged so that upon rotation of the rotation axis 5 a electrical voltage is induced in the stator 2 in the case of a generator. Correspondingly, when an alternating voltage is applied to the stator 2, the rotor 4 can be excited to rotate about the axis of rotation 5, as is the case with an electric motor, in particular a three-phase motor. Typically, the stator 2 consists of a stator winding or stator winding 2a. The stator winding 2a consists of individual laminated cores 2b (also

Stator lamination packages or stator lamination packages) and at least one stator winding head 2c (also stator winding head or winding head). Typically, individual laminations 2b are spaced apart by a distance 2d. In operation of the electrical machine 101 occur due to Verlus ^¬ th in the conversion of mechanical to electrical energy (and vice versa) heat, which makes it necessary to efficiently cool the electrical machine the one hundred and first Cooling is required because the materials used to insulate the housing from current and / or live parts use insulation materials that retain their insulating effect only up to a limit temperature. If the Grenzwerttemperpaturen exceeded, so is the Isolation is no longer possible, and there is a short circuit and possibly damage to the electric machine 101. In addition, such an electric ^¬ machine 101 whose insulation materials no longer work, a high security risk, since for example the housing is subjected to electrical voltages and / or currents, which means an accident risk. In order to operate the electrical ^¬ specific machine 101 at a given power, sufficient cooling must take place, so that the threshold temperatures are not exceeded. It is therefore necessary to increase the output of such an electric machine 101, that an efficient cooling of the active components of the electrical machine 101, in particular the Ro ^¬ gate 4, the stator 2 and / or the Statorwicklungskopfs is required 2c. For this purpose, for example, a on the rotation axis and / or mounted on the housing fan (not ge ^¬ shows in Figure 3) are used to promote a flow of coolant from outside the electrical machine 101 to the interior of the electric machine and / or in the machine to shift. By a geometry of the individual active components rotor 4, stator 2 and / or Statorwicklungskopf 2c results in a certain ratio in which the coolant ^{mass ¬} stream flows to each of these active components and causes a corresponding cooling. This ratio of the individual mass flows of coolant can not be changed for the electric Ma ^¬ machine 101 in general. Since ^¬ by results in a restriction of the cooling of individual active components. It is known to the person skilled in the art that heat which is absorbed by the coolant, for example gas and / or cooling liquid in the electric machine 101, can be withdrawn by a corresponding radiator through a corresponding thermodynamic cycle and can be supplied to the electric machine 101 again , so that a continuous cooling of the electric machine 101 is possible. The invention has therefore set itself the task of ei ^¬ ne cooling device to provide such that in particular the stator 2 can be selectively cooled. Likewise, the ahead ^¬ invention proposes an electrical machine having a Cooling device according to the invention for cooling the stator comprises.

The cooling device for an electrical machine and in particular a cooling device for an electrical machine with a stator, the stator at least one stator coil with at least one stator core and Minim ^¬ least comprises a stator winding head. The stator is also referred to as a stand, according to the Stän- derwicklungskopf as stator end and the STAs ^¬ rough lech package as a stator lamination. The corresponding terms are to be understood in the following as a synonym.

The cooling device according to the invention comprises a multiplicity of channels through which coolant can flow. The plurality of channels is connected at a first end or end portion to a pressure accumulator. A second end and a second end portion of the plurality of the channels opens out either in a baffle-cooling plate and / or ends in a channel of a stator winding ^¬ head, this function preferably takes the impingement cooling plate. Such a cooling device is before ^¬ geous, as this can be a targeted cooling of the stator set. Preferably, a selection of the plurality of channels between each of the stator laminations can run.

Likewise, alternatively or additionally, a selection of the plurality of channels in openings within the stator 2 duri ^¬ fen, for example, run in channels between each of the stator lamination. The ability to choose which From ^¬ selection of the plurality of channels in channels between each of the stator cores and / or in openings of the stator, particularly the Statorwicklungskopfs passes, can be adjusted to a cooling of individual of the stator winding heads, the relative cooling of each of the stator cores. In this case, the first selection of the channels which run between individual stacks of stator cores may be equal to the selection which extends in openings of the stator winding head. Similarly, the selection of the openings in the

Stator head also has a range of channels be from the running between each of the stator laminations plurality of channels.

Likewise, and without limitation, a second selection of the plurality of channels in channels within the stator duri ^¬ fen. As already stated, can be achieved to a single one of the stator end by entspre ^¬ sponding selections of the plurality of channels, a weighting of an individual cooling of the stator cores.

Preferably, the cooling device comprises outlet means. The off ^¬ lassmittel can be provided on the impingement cooling plate. Alternatively or additionally, the outlet means may be provided on the at least one channel of the stator winding head by terminating at least a selection of the plurality of channels.

Preferably, the cooling device comprises a coolant, which flows from the pressure accumulator to the second end of the channels, provided there is a lower static pressure at the second end of the channels than in the pressure accumulator. The provision of a lower pressure at the second end of the channels is therefore advantageous, since a direction in which the coolant flows is defined so that a flow direction of the coolant can be imparted to a corresponding cooling circuit.

Preferably, the outlet means may be designed so that in the cooling mode, the static pressure at the second end of the channels is less than in the pressure accumulator 10a. A corresponding provision of the outlet means is advantageous, since the desired flow direction of the coolant is achieved in the thermodynamic cycle. In addition, with sufficient design or dimensioning of the outlet means, for example on the impingement cooling plate, effective cooling of the stator results.

Preferably, the impingement cooling plate may be attachable to an end portion of the at least one stator core. Thereby can be an efficient heat transfer between the impingement cooling plate and the at least the stator core Errei ^¬ surfaces, resulting in an effective cooling of the stator core.

Preferably, the cooling device may comprise a second plurality of channels through which a coolant can pass, which are connected in a first end or end section to a second pressure accumulator, and at a second end or end section in each case in a second impingement cooling plate and / or in a channel of the second Ständerwicklungskopfs end.

An advantage of this embodiment is that both ends of a stator winding package can be effectively cooled by the first and second baffle cooling plates. Also, stator winding heads can be effectively cooled by either the second ends of the first channels and / or the second ends of the second channels, each terminating in a channel of the stator winding head.

Preferably, at least one selection can also run for the second channels between individual stator core stacks and / or a selection of the second channels can extend in openings of the stator lamination stack. Alternatively or additionally, a second selection of the second channels, at least portion ^¬ example in the channels of the Statorwicklungskopfs extend. Such an arrangement of the first selection of the second channels and / or the second selection of the second channels enables a weighting of the relative cooling of the Ständerwicklungs- packages to a cooling of the stator winding heads einzustel ^¬ len.

More preferably, the second baffle cooling plate of Kühlvor ^¬ direction at a second end portion of the stator core (also laminated stator core or laminated core) can be attached. Since ^¬ forth can advantageously the stator winding package at the ends ^¬ effectively by means of the first and second baffle cool cooling plate, which allows more efficient heat dissipation.

As with the first pressure accumulator, the second pressure accumulator may also contain a coolant which flows from the second pressure accumulator to the second end of the second passage, provided there is a lower static pressure at the second end of the second passage than in the second pressure accumulator. Such an embodiment is advantageous because the thermodynamic cycle for cooling by the cooling device according to Inventive ^¬ a direction of coolant flow is imparted without the need for special driving means, in the form of pumps would be required. Preferably, the cooling device may take second outlet to ^¬ which are designed so that in the cooling operation of the stati ^¬ specific pressure at the second end of the second channels is smaller than in the second accumulator, as has already been explained for the first outlet. For both the first outlet means and the second outlet means

Cooling operation designed so that a measurable cooling of the electric machine takes place by the cooling device. This can be done during operation of the electrical machine and / or at standstill of the electrical machine.

Preferably, in a cooling device according to the invention in a circumferential direction within the stator 2 first channels and second channels alternate, allowing a space ^¬ saving cooling of the stator. In particular, by the use of the two cooling circuits and / or the alternating arrangement of first channels and / or second channels, a uniform cooling of the stator can take place in an advantageous manner. In addition, the invention relates to an electrical machine. This electric machine comprises a rotor and a stator, wherein the stator comprises at least one stator winding with at least one stator core and at least one stator winding head. The electric machine according to the invention further comprises a described above cooling device according to the present invention. The electrical machine according to the invention may preferably be a generator and / or a motor.

The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the embodiments given in connection with the drawings

1 shows a section of the cooling device 1 according to the invention, which is attached to a quadrant of a stator 2,

Figure 2 shows a second embodiment of the erfindungsge ^¬ MAESSEN cooling apparatus 1 to a section of a quadrant of a stator 2 of an electrical ma- machine 100, and

FIG. 3 shows a section of a quadrant of FIG

Electric machine 101 according to the prior art.

1 shows a detail of an electric machine 100, in particular a section of a stator 2, which comprises a cooling device 1 according to the present invention in a first embodiment. The stator 2 consists of a multiplicity of stator laminations 2b (also laminated cores or stator lamination packages) as shown. The individual STAs ^¬ stator lamination packs 2B are arranged so as to extend between these first channels 6a. The first channels 6a are connected at ers ^¬ th ends or first end portions 7a with a Druckspei- rather 10. At second ends or second end portions 7b, the first channels with either a baffle 6a ^¬ cooling plate 8 are fluidically connected and / or located in a channel of a Statorwicklungskopfs 2c. If in the Pressure vessel 10 (shown on the right in FIG. 1) has a higher static pressure than at the second ends 7b of the first channels 6a, then a coolant in the pressure vessel 10 flows from the pressure vessel 10 to the second ends 7b of the first channels 6a indicated by the arrows. The skilled worker knows how the baffle-cooling plate is to be dimensio ^¬ kidney 8, in order to guarantee the reduced pressure at the ending in the impingement cooling plate 8 second ends 7b of the channels 6a. To 8 appropriate education can look at the impingement plate be provided let medium (not shown) so that we ^¬ kung full cooling, that is achieved impingement cooling who can ^¬. By impingement cooling the adjacent stator cores 2b which are in contact to be cooled with the impingement cooling plate ^¬. 8 It is of interest to maintain a flow of the coolant to effectively dissipate the heat from the stator 2. Further, it is ensured by the provided on the baffle plate 8 and / or at the second ends 7b of the first channels 6a lower static pressure that the coolant flows within the first channels 6a in a desired direction, whereby the heat dissipation ^¬ port and thus the desired cooling the stator laminations 2b is achieved. For the second ends 7b of the first channels 6a ending in the stator winding head 2c, a sufficiently large outlet must be provided so that the first end opening in the stator winding head 2c is also at the second end 7b

Channels 6a of the lower static pressure, that is insbeson ^¬ particular lower than in the pressure accumulator 10 is maintained. The person skilled in the art knows suitable outlet means which ensure that coolant flowing out of the second ends 7b can be discharged in sufficient quantity to ensure, in the cooling mode, the lower static pressure at the second ends 7b of the first channels 6a.

FIG. 2 shows, by way of example, a cooling device 1 according to a further embodiment of the invention, which is mounted in an electric machine 100, FIG. 2, as already shown in FIG. 1, showing only a section of a quadrant of the electric machine 100, as far as is necessary for the understanding of the invention. According to the invention cooling device 1 and / or the electric machine 100 according to the invention is required. In addition to the first channels 6a between a first pressure accumulator 10a and a first pressure plate 8a and / or a first stator winding head 2c, a plurality of second channels 6b are provided, which start from a second pressure accumulator 10b. First ends 7a of the second channels 6b terminate in the second pressure accumulator 10b. A second end 7b of the second channels 6b terminates in a second baffle cooling plate 8b and / or in a stator winding head 2c. The arrangement of Ständerwicklungs ^¬ head 2c and / or the first impingement cooling plate 8a, and the second impingement cooling plate 8b is given only by way of example in Figure 2 and is intended to explain the principle of the second embodiment of the invention. By using the first and second pressure accumulators 10a, 10b in conjunction with the first and second impingement cooling plates 8a, 8b, an effective cooling of the stator laminations 2b can be achieved from both sides, that is to say from both ends of the respective stator laminations 2b between the first and second impingement cooling plates 8a, 8b to reach. The more effective cooling of the laminated stator laminates 2b also results in more effective cooling of the stator. It is inte ^¬ ress at the respective second end portions 7b of the first channels 6 and / or on the respective second end portions 7b of the second channels 6b a lower static pressure provided as in the respective associated first or second pressure vessels 10a, 10b to the Coolant in the interior of the first channels 6a and / or inside the second channels 6b to impose a desired flow direction and thus without further drive means, such as pumps, a flow direction of the thermodynamic cycle process, as used for cooling the stator 2, provide.

The skilled person will understand that other arrangement with two impingement cooling plates 8a, 8b and two pressure vessels 10a, 10b, are possible. It is advisable to alternate in a circumferential direction of the stator 2 first channels 6a and second channels 6b. Without limitation, more than just first and second channels 6a, 6b could be used, respectively with a further pressure vessel (not shown) and possibly egg ner further impact cooling plate (not shown) are connected.

Those skilled in the art will understand that as a refrigerant for the embodiments of the invention, either a gaseous refrigerant may be used, for example, air, oxygen and / or hydrogen. Hydrogen would be particularly of pre ^¬ partly due to the high heat capacity and high capacity heat from the laminated stator cores 2b and / or refer to the stator winding heads 2c. It is known to those skilled in the art that safety precautions are required when using hydrogen as a coolant in order to avoid a blast gas explosion. Such safety devices are known in the art, are not required for the understanding of the present invention and are therefore not further explained in connection with the present invention.

It would also be possible to use a liquid as coolant, which flows in first channels 6a and / or second channels 6b and in other channels. Comes into consideration in this context, a non-conductive FLÜS ^¬ sigkeit, for example, distilled water. Alternatively and / or additionally, generator oil can also be used. When using electrically conductive coolants which flow out of the second ends 7b within the stator winding heads 2c, it is necessary to ensure that this coolant does not short circuit between electrically conductive components of the stator winding 2a or of the stator 2 causes. It must also be excluded that a routing ^¬ efficient cooling means causes a short circuit between the stator 2 and / or the rotor, as well as between other electrically conductive components of the electrical machine 1. Appropriate steps are known in the art, however, and are therefore in connection with the this description is not further explained. Although the cooling device 1 according to the invention has been explained in connection with stator laminations 2b (also stator laminations, stator laminations, stator laminations, or stator), it is conceivable oh ^¬ ne restriction to provide the cooling device 1 on sheet metal packages of the rotor 4. However, in a cooling of the rotor 4 according to the invention, the pressure vessels 10a, 10b would have to be mounted on the rotation axis 5 and co-rotate with the rotation of the rotation axis 5, which makes it difficult to arrange the cooling device 1 on the rotor 4.

For the skilled person it is obvious that the cooling apparatus 1 described in connection with Figures 1 and 2 can be combined 100 with other cooling devices of an electrical machine to Errei 2c so a required cooling of the stator 2, the rotor 4 and / or the stator winding heads ^¬ chen.

As shown in Figures 1 and 2 is disclosed, the present ^¬ invention (seen in Fig. 3) and an electrical machine 100 with a rotor 4 and a stator 2, wherein the stator comprises at least a stator winding 2 with at least ei ^¬ nem laminated stator core 2b , as shown in Figures 1 and 2, where ^¬ in the electric machine 100, the inventive cooling ^¬ device 1, as explained in connection with Figures 1 and 2, comprises.

The electric machine according to the invention may be without limitation a generator and / or a motor.

The present invention is not limited to the ^{embodiments of} the cooling device 1 and / or the electric machine 100. Although the invention in detail by the preferred embodiments of the Kühlvorrich- device 1 as well as preferred embodiments of the electrical machine 100 has been illustrated and described, the He ^¬ invention is not disclosed by the examples herein limited. Rather, variations are those disclosed herein Embodiments can be derived by the person skilled in the art without departing from the scope of the invention.

Claims

claims

1. Cooling device (1) for an electrical machine (100) having a stator (2) comprising at least one Statorwick ^¬ lung (2a), with at least one laminated stator core (2b) and at least one stator end (2c); the Kühlvorrich ^¬ device (1) comprising:

a plurality of through-flow with a coolant channel (6a) attached to a first end portion (7a) with egg ^¬ nem-pressure accumulator (10a) are connected, and at its second end portion (7b) in an impingement cooling plate and / or in a channel of a stator winding head (2c) end.

2. Cooling device (1) according to claim 1,

at least one selection of the plurality of channels (6a) extending between individual ones of the stator laminations (2b); and / or at least one selection of the plurality of channels (6a) extends in openings of the stator winding head (2c).

3. Cooling device (1) according to one of the preceding claims,

wherein outlet means are provided on the impingement cooling plate (8a) and / or the at least one channel of the stator winding head (2c).

4. Cooling device (1) according to one of the preceding claims,

wherein a coolant flows from the accumulator (10a) to the second end portion (7b) of the channels (6a), provided that the second end portion (7b) has a lower static pressure than in the pressure accumulator.

5. Cooling device (1) according to claim 3 or 4,

wherein the outlet means are designed so that in Kühlbe ^¬ drive the static pressure at the second end portion (7b) of the channels (6a) is lower than in the pressure accumulator

(10a).

6. Cooling device according to one of the preceding claims, wherein the impingement cooling plate at an end portion of the mindes ^¬ least a stator lamination stack (2b) is attachable.

7. Cooling device (1) according to one of the preceding claims, further comprising:

a plurality of second passages (6b) through which a coolant can pass, which are connected to a second pressure reservoir (10b) at a first end (7a) and at a second end section (7b) in a second impact cooling plate (8b) and / or in one Channel of the at least one stator winding head (2c) end.

8. Cooling device (1) according to claim 7,

wherein at least a selection of the second channels (6b) Zvi ^¬ rule each of the stator cores (2a) runs and / or at least a selection of the second channels (6b) runs in the openings of the stator cores.

9. Cooling device according to one of claims 7 or 8,

wherein at least a second selection of the second channels (6b) at least partially extends in the channels of the stator winding ^¬ head (2c).

10. Cooling device according to one of claims 7 to 9,

wherein the second baffle cooling plate (8b) on a second end ^¬ section (7b) of the stator core (2b) is attachable.

11. A cooling device (1) according to one of claims 7 to 10, wherein the second accumulator (10b) holding a coolant ent ^¬, from said second accumulator (10b) to the second end portion (7b) of the second channels (6b) flows, so ^¬ far at the second end portions (7b) of the second channels (6b), a lower static pressure than in the second pressure accumulator (10b) prevails.

12. Cooling device (1) according to one of claims 7 to 11, wherein second outlet means are provided, which are laid out so ^¬ that in the cooling mode, the static pressure at the second end portions (7b) of the second channels (6b) is lower as in the second pressure accumulator.

13. Cooling device (1) according to one of claims 8 to 12, wherein in a circumferential direction first channels (6a) and second channels within the stator (2), in particular between stator laminations (2b) alternate.

14. An electric machine (100) comprising a rotor (4) and a stator (2) with at least one stator winding (2a) with at least one stator lamination stack (2b) and at least one stator winding head (2c);

wherein the electrical machine (100) comprises a Kühlvorrich ^¬ device (1) according to one of claims 1 to 13.

15. Electrical machine (100) according to claim 14,

wherein the electric machine (100) is a generator and / or a motor.