Power electronics device with cooling structure for cooling discrete capacitors; and electrical machine

Abstract

The invention relates to a power electronics device (1) for an electric machine (2), comprising several power modules (3) and several busbars (4a, 4b, 4c) connected to the power modules (3), each forming a phase and prepared for connection to the electric machine (2), wherein the busbars (4a, 4b, 4c) are arranged coplanarly to each other, at least with their first busbar sections (5a, 5b, 5c) adjacent to the power modules (3). The invention also relates to an electric machine (2) with this power electronics device (1).

Description

[0001] The invention relates to a power electronics device for an electric machine, preferably an electric drive machine of a motor vehicle, such as a purely battery-electric vehicle or a hybrid vehicle (e.g., a plug-in hybrid with a high-voltage power supply), comprising a housing, a capacitor arrangement included in the housing comprising several discrete capacitors, and a busbar unit connected to the electrical terminals of the capacitors, wherein each capacitor is coupled to the housing in such a way that waste heat generated in the capacitor during operation is dissipated via the housing to the surrounding environment. The invention also relates to an electric machine with this power electronics device.

[0002] Generic power electronic devices and electrical machines are already well known. For example, DE 10 2019 111 111 A1 discloses power electronics with hollow busbars for direct capacitor cooling. Further prior art is known from DE 10 2016 219 213 A1. Thus, various methods for cooling existing capacitors during operation are already known. However, the efficiency of existing cooling systems needs to be further increased.

[0003] It is therefore an object of the present invention to further improve the performance of the power electronic devices, while keeping the design of the power electronic device, in particular its capacitor arrangement, as simple as possible.

[0004] This is solved according to the invention by the fact that each capacitor is surrounded on at least two, preferably at least three sides (of a square / rectangle) by a cooling structure and is in contact with the cooling structure on two sides / two of these at least three sides by means of a thermal coupling material layer, and the cooling structure is connected directly or indirectly to a housing area exposed to a flow of cooling medium during operation.

[0005] The coupling material layers, preferably formed from a TIM layer and more preferably a gap pad, ensure that the surfaces of the discrete capacitors are in close contact with the cooling structure over as large an area as possible, thus dissipating the heat generated by the capacitors over a large surface area. This results in significantly more efficient cooling of the capacitors.

[0006] Further advantageous embodiments are claimed in the subclaims and explained in more detail below.

[0007] According to a preferred embodiment, it is advantageous if the capacitors of the capacitor arrangement are arranged next to each other in a (single) row.

[0008] Furthermore, it is advantageous if the capacitors are connected to the busbar unit both electrically and thermally via a connection terminal. This allows for the efficient dissipation of a significant additional portion of the heat generated in the capacitor.

[0009] The cooling structure extends preferentially into the spaces between the individual, adjacent condensers and is connected to the condensers in these spaces via the coupling material layer. This results in the most effective possible heat dissipation.

[0010] Alternatively or additionally to arranging parts of the cooling structure in the spaces between the condensers, it is also advantageous if the cooling structure is positioned with the end faces of the condensers (via the coupling material layer) oriented towards the sides of the condenser assembly. This allows the condenser assembly to be designed as compactly as possible in length.

[0011] Furthermore, it is advantageous to connect the capacitors in parallel using the busbar unit. This results in a unit that can be integrated as efficiently as possible. With the parallel connection, the capacitances of the capacitors are added. The capacitance of the DC link capacitor can be flexibly scaled by adjusting the number of discrete capacitors / elements.

[0012] Furthermore, it is advantageous if the cooling structure is positioned on the busbar unit, meaning that, in its intended installation position and when viewed from the perspective of gravity, it rests on the top of the busbar unit. It is particularly beneficial if the cooling structure rests on an insulating layer arranged on the top of the busbar unit. This results in the most compact design possible. Since the cooling structure is mounted on the busbar unit, the condenser is cooled via the busbar unit. The heat is transferred from the condenser into the busbar unit and from there dissipated into the housing containing the cooling element.

[0013] Furthermore, it is advantageous for the cooling structure to penetrate the capacitor connection terminals, which are electrically connected to a conductor of the busbar assembly. These connection terminals are preferably implemented as pins or tabs, thus enabling a convenient, space-saving connection without unnecessarily impeding heat dissipation through the cooling structure. The cooling structure does not, however, make contact with the respective connection terminal.

[0014] In a preferred embodiment, it is further advantageous if the busbar unit is connected to a layer of thermal coupling material on the underside (relative to the intended installation position) of the housing. This further improves thermal heat transfer.

[0015] Therefore, it is also advantageous if the respective capacitor is in direct or indirect contact with a top surface (in relation to the intended installation position) of the housing by means of a thermal coupling material layer.

[0016] In a further preferred embodiment, it has also proven advantageous if the cooling structure is an integral part of the housing and forms a cooling channel directly with a surface facing away from one of the condensers. This results in the most direct possible dissipation of waste heat during operation.

[0017] It has also proven advantageous if the respective condenser is surrounded by a U-shaped receiving / enclosing area of ​​the cooling structure. The spaced-apart legs of the U-shaped receiving area are either positioned along one longitudinal side of the condenser (preferably indirectly), meaning they are also located in the spaces between adjacent condensers, or alternatively, along the end faces of the condenser (preferably indirectly). Depending on the application, this results in a compact design combined with efficient cooling.

[0018] Furthermore, it is advantageous if a bottom wall / transverse wall of the cooling structure is positioned facing either the top / upper side of the housing or the bottom / lower side of the housing. This allows the cooling structure to be used in the most space-saving way possible.

[0019] For configurations where the base wall of the cooling structure faces the side of the condensers closest to the housing cover, it is also advantageous to position a layer of thermal coupling material on the side of the base wall opposite the condensers, or between the base wall and the cover. Depending on the application, this further increases heat dissipation.

[0020] Furthermore, it is advantageous if the leg sections of the U-shaped receiving area of ​​the cooling structure are either parallel to each other or slightly angled / conical. In the conical configuration, the leg sections advantageously extend away from the base wall, increasing their distance from each other. The capacitors are then preferably shaped with their sides / outer surfaces that abut (preferably indirectly) the leg sections in a complementary manner. This allows for easy centering of the individual capacitors.

[0021] It is also advantageous if the respective capacitor is pre-tensioned / supported within the cooling structure by means of a spring element. This presses the capacitor firmly and tightly against the thermal coupling material layers, further improving heat dissipation. The spring element can be designed either as a helical compression spring or as an elastically compressible layer (preferably made of a TIM, for example as a gap pad).

[0022] Furthermore, the invention relates to an electric machine with a stator, a rotor and a power electronics device according to the invention connected to a coil arrangement of the stator or the rotor according to at least one of the embodiments described above, wherein electrical connections of the capacitors are coupled to the coil arrangement by means of power modules (of the power electronics device).

[0023] The invention will now be explained in more detail below with reference to figures, in which context various embodiments are also illustrated.

[0024] They show: Fig. 1 a sectional view of a power electronics device according to the invention, implemented according to a first embodiment, along a capacitor arrangement inserted therein, wherein discrete capacitors of the capacitor arrangement are thermally coupled via a common cooling structure and this cooling structure is further arranged on a busbar unit which in turn rests against a housing, Fig. 2 a top view of the in Fig. 1 Capacitor arrangement shown, with which individual thermal coupling material layers between the cooling structure and the capacitors are clearly visible, Fig. 3 a perspective representation of the in Fig. 1 installed capacitor arrangement in a full view, Fig. 4. A perspective view of the entire power electronics device, with a housing cover hidden and the internal structure of the power electronics device visible. Fig. 5 a sectional view of a power electronics device according to a second embodiment according to the invention, again in the area of ​​a capacitor arrangement inserted therein, wherein the section plane now runs transversely to a longitudinal axis of the capacitor arrangement and thus it can be seen that the cooling structure with two mutually spaced leg areas is in contact with the end faces of the capacitors, Fig. 6 a perspective representation of the in Fig. 5 capacitor arrangements in a full view, Fig. 7 A sectional view of a power electronics device according to the invention in a third embodiment, again in the area of ​​a capacitor arrangement used therein, wherein the cooling structure is now no longer as in Fig. 5 is placed on the capacitors from a bottom, but from a top, and wherein the busbar unit is arranged flat on the bottom and the discrete capacitors are placed on the busbar unit, Fig. 8 a perspective view of a power electronics device according to a fourth embodiment according to the invention, again in the area of ​​a capacitor arrangement used therein, wherein two conductors of the busbar unit are arranged at least partially perpendicular to each other, Fig. 9 a sectional view of a power electronics device according to the invention in a fifth embodiment, again in the area of ​​a capacitor arrangement used therein, wherein the cooling structure now directly forms a part of the housing, Fig. 10 a sectional view of a power electronics device according to the invention in a sixth embodiment, again in the area of ​​a capacitor arrangement inserted therein, wherein leg areas / side walls of the cooling structure now run conically and the capacitor designed to complement this is pre-tensioned into the cooling structure by means of a mechanical spring element in the form of a helical spring, Fig. 11 a sectional view of a power electronics device according to the invention in a seventh embodiment, again in the area of ​​a capacitor arrangement used therein, wherein in comparison to the embodiment of the Fig. 10 the spring element is now designed as an elastically compressible thermal coupling material layer, as well as Fig. 12 comprising a schematic representation of an electrical machine and a power electronics device according to the invention.

[0025] The figures are purely schematic and serve solely to illustrate the invention. The same elements are identified by the same reference numerals. Furthermore, the various features of the different embodiments can, in principle, be freely combined.

[0026] In connection with the Fig. 4 and Fig. 12. First, the preferred application of the power electronics device 1 according to the invention should be noted. The power electronics device 1 is preferably part of an electric machine 2. The power electronics device 1 thus preferably serves to control the electric machine 2 in its operating state. The electric machine 2 is preferably used as a drive machine of a (more preferably purely battery-electrically powered) motor vehicle.

[0027] In Fig. Figure 12 also shows that the power electronics device 1, with its output-side connections (here three), is electrically connected to phase connections 38a, 38b, 38c of the electric machine 2, namely a coil arrangement 26 of the electric machine 2. In this embodiment, the coil arrangement 26 is designed as part of a stator 24, but can alternatively also be part of a rotor 25 of the electric machine 2. It should also be noted that although three phases / phase connections 38a, 38b, 38c are present in this embodiment, this number of phases can, in principle, vary.

[0028] A basic structure of the power electronics device 1 according to the invention is shown in Fig. 4. A housing 3 of the power electronics device 1 is only partially illustrated (namely, its lower half when viewed in the installed position), so that in particular the structure inside the housing 3 can be seen.

[0029] With Fig. In the power electronics device 1, power modules 3 connected to the outputs can be seen. A capacitor arrangement 4 according to the invention, described in more detail below (designed as a capacitor module, preferably a DC-link capacitor module), is connected upstream of the power modules 3.

[0030] The power modules 3 are connected to (AC) outputs of the capacitor assembly 4. The outputs of the capacitor assembly 4 are formed, in particular, by (second) connections / outputs of individual capacitors 5 of the capacitor assembly 4. A (DC) input of the capacitor assembly 4 is connected to a current coupling 39. The input of the capacitor assembly 4 is formed, in particular, by a (first) connection / input of the respective capacitor 5 of the capacitor assembly 4.

[0031] The current coupling 39 is preferably designed as a busbar. A DC current sensor 40 is arranged on the current coupling 39. Furthermore, an EMC filter 41 is connected upstream of the capacitor module 20, which is directly connected to input-side connections of the power electronics device 1 (not shown in detail here).

[0032] A first embodiment of a power electronics device 1 according to the invention is now described in conjunction with the Fig. Figures 1 to 3 are recognizable. The power electronics device 1 is illustrated in particular with regard to its capacitor arrangement 4. The capacitor arrangement 4 has several discrete capacitors 5 arranged side by side in series. The capacitors 5 are all implemented as identical components. As in Fig. As can be clearly seen in Figure 3, the capacitors 5 are each essentially cuboid in shape (as a rectangle with longer and shorter sides). The capacitors 5 have an elongated extent and their longitudinal direction is oriented transversely / perpendicular to a longitudinal direction of the capacitor arrangement 4.

[0033] The end faces 30a, 30b of each capacitor 5 are thus arranged on the sides of the capacitor arrangement 4. The end faces 30a, 30b are in turn connected to each other via longitudinal sides 31a, 31b and transverse sides 32a, 32b.

[0034] Each capacitor 5 is at least partially surrounded by a cooling structure 10 / attached to this cooling structure 10. It can be seen that in the first embodiment, the cooling structure 10 is formed as a heat sink comprising several U-shaped receiving areas 19, which is preferably made of a single piece of material. The cooling structure 10 is preferably formed from a thermally conductive material, preferably a metal.

[0035] In the first embodiment, the cooling structure 10 of each condenser 5 is formed with two leg regions 29a, 29b and a transverse wall / bottom wall 20 connecting these leg regions 29a, 29b, forming the U-shaped receiving area 19. The leg regions 29a, 29b are arranged along the condenser assembly 4 in spaces 37 between two adjacent condensers 5 and at the end faces of the condenser assembly 4. In each space 37, a web region forms two leg regions 29a, 29b of two adjacent receiving areas 19.

[0036] In this embodiment, the two leg regions 29a, 29b of a receiving area 19 are aligned parallel to each other. The two leg regions 29a, 29b of a receiving area 19 abut two sides 9a, 9b, here the two longitudinal sides 31a, 31b of the capacitor 5. Upon closer inspection, the two leg regions 29a, 29b indirectly abut the capacitor 5, namely via an interposition of thermal coupling material layers, which are preferably implemented in the form of a TIM layer / a gap pad. Each discrete capacitor 5 thus indirectly abuts the cooling structure 10 via the coupling material layers 11. Furthermore, as described below, the capacitor 5 is surrounded on another side 9c, here a first transverse side 32a, by a bottom wall 20 of the cooling structure 10.

[0037] It can also be seen that the respective condenser 5 is arranged in the cooling structure 10 / the receiving area 19 by at least half its height (extent between its top and bottom in its installation position and considered in an acting gravitational field) / with the leg areas 29a, 29b (indirectly) in alignment.

[0038] The cooling structure 10 is further penetrated by at least one connection terminal 13, preferably by two connection terminals 13 (in the form of pins or tabs / contact feet) for each capacitor 5, which electrically couple the respective capacitor 5 to a busbar unit 7. It is also advantageous that thermal coupling with the busbar unit 7 occurs via the connection terminals, whereby a significant portion of the capacitor's waste heat is transferred to the busbar unit 7.

[0039] With regard to the busbar unit 7, it should be noted that this is implemented as a laminated busbar and therefore has several individual conductor layers. Fig. 1 can be seen in particular that this busbar unit 7 has two conductors 14, 34 which form a first terminal 6 / input (DC input) of the capacitor 5 / capacitor assembly 4.

[0040] The conductors 34 and 14 are implemented in a rail-like and planar configuration and are further connected to the input-side connection of the power electronics device 1. The layered conductors 14 and 34 are electrically decoupled from each other, as well as from the cooling structure 10 and the housing 3 of the power electronics device 1, by means of insulating layers 33. Furthermore, the coplanar and planar design of the busbar unit 7 enables a low-inductance connection of the discrete capacitors 5.

[0041] With regard to the planned installation position and the acting gravitational field, the cooling structure 10 is mounted on a top side of the busbar unit 7, while the housing 3, namely a bottom 22 / lower part of the housing 3 (forming a bottom 15 of the housing 3), connects to a bottom side of the busbar unit 7.

[0042] It is further preferred that an additional thermal coupling material layer 11 is present between the busbar unit 7 and the housing 3 / base 22.

[0043] The housing 3 is preferably directly surrounded by a cooling medium, such as a coolant, on its side / outside 35 facing away from the condenser arrangement 4 during operation, so that waste heat generated in the respective condenser 5 during operation is specifically dissipated via the cooling structure 10 and the busbar unit 7 through the housing 3 to an environment 8 of the housing 3.

[0044] In the exemplary embodiment of the Fig. Figure 1 further shows that the capacitor arrangement 4 / the individual capacitors 5 are covered on one side by, or in contact with, a further coupling material layer 11. This further coupling material layer 11 is inserted between the capacitors 5 and a cover 21 / upper part of the housing 3 (forming a top surface 16 of the housing 3). This coupling material layer 11 is significantly thicker than the other coupling material layers 11 between the capacitors 5 and the cooling structure 10, as well as between the busbar unit 7 and the base 22.

[0045] Thus, during operation, heat is dissipated to the surroundings 8 of the housing through the contact of the capacitors 5 via the coupling material layers 11 with the cooling structure 10 and the housing 3 / cover 21. The cooling structure 10 therefore selectively conducts the waste heat generated by the capacitors 5 to a specific housing area 12 (base 20, or alternatively cover 21) of the housing 3, which is surrounded by cooling fluid during operation.

[0046] The following alternative embodiments of the power electronics device 1 are intended to show that the cooling structure 10, in particular, can also be used or designed in other ways. However, the embodiments described below are fundamentally similar in structure and function to the first embodiment, so for the sake of brevity, only the differences between these embodiments are described below.

[0047] Regarding the second embodiment of the Fig. 5 and Fig. Figure 6 shows that the cooling structure 10, particularly with its receiving areas, can also be positioned relative to the capacitors 5 in other ways. In this embodiment, the leg sections 29a, 29b are now (indirectly) in contact with the end faces 30a, 30b of the capacitors 5. In this embodiment, the leg sections 29a, 29b also have such a length that the capacitors 5 make contact over significantly more than half their height. Between the respective leg sections 29a, 29b and the capacitor 5, a coupling material layer 11 is inserted, which has almost the same length / height as the leg sections 29a, 29b.

[0048] In conjunction with the third embodiment of the Fig. Figure 7 also shows that, unlike the first two embodiments, the cooling structure 10 does not necessarily have to be attached to the underside of the capacitors 5, but can also, in principle, be attached to the top side of the capacitors 5. Thus, the bottom wall 20 of the cooling structure 10, which connects the leg sections 29a and 29b, is arranged between the housing 3 and the capacitors 5, facing the top side. In this embodiment, a thermal coupling material layer 11 is again inserted between the housing 3 and the cooling structure 10.

[0049] Furthermore, it becomes clear that in this embodiment, the capacitors 5 are positioned at a distance from the busbar unit 7 by means of a corresponding selection of the length of the connection terminals 13, thus forming a void 36. However, the connection terminals 13 of the discrete capacitors 5 can also, in principle, be designed / bent in such a way that this void 36 almost disappears, and preferably, the respective capacitor 5 rests directly on the busbar unit 7.

[0050] In Fig. In this example, the busbar unit 7, at least partially positioned on the underside, is configured differently. The second conductor 34 (also designated as the DC+ connection) is located below the capacitors 5, and the first conductor 14 (also designated as the DC- connection) is bent / offset by 90° relative to this second conductor 34. The first conductor 14 is thus positioned laterally to the capacitor assembly 4. The capacitors 5 are also rotated by 90° compared to the previous embodiments, so that the capacitor 5 is cooled directly at the (first) end face 30a. Furthermore, the capacitor 5 is also cooled directly via the busbar unit 7 (through the second conductor 34), as this / the second conductor 34 is thermally connected to the housing 3.

[0051] The winding of capacitor 5 / film capacitor points towards the end face. Since the capacitor is tilted by 90°, the end face points directly downwards. Heat can be dissipated three times more effectively in the direction of the winding axis than perpendicular to the winding axis.

[0052] On the (second) end face 30b opposite the second conductor 34, the capacitor 5 is thermally connected to the cover 21 of the housing 3 via the coupling material layer 11 (TIM (Thermal Interface Material) e.g. Gappad).

[0053] In this setup, the laminated busbar unit 7 is electrically contacted to the capacitor 5 via one terminal / section of a conductor (e.g., the first conductor 14 as shown here). The other terminal / section of the other conductor (e.g., the second conductor 34 as shown here) of the capacitor 5 is bent so that it can be electrically connected to the DC+ terminal.

[0054] In this design, the heat is primarily dissipated directly via the (first) end face / end side 30a of the capacitor 5.

[0055] When considering the further examples of the Fig. Figures 9 to 11 also show that it is alternatively possible to design the cooling structure 10 as a single, integral component of the housing 3. In these embodiments, the cooling structure 10 is thus directly integrated into the housing 3, namely the base 22, as a corresponding basin area. The cooling structure 10 therefore directly forms a cooling channel 18 with its surface 17 facing away from the condensers 5.

[0056] In the exemplary embodiment of the Fig. Thermal coupling material layers 11 are arranged both between the capacitor 5 and the leg regions 29a, 29b of the receiving area 19 and between the capacitor 5 and the bottom wall 20 of the receiving area 19. Preferably, the cooling structure 10 is thus integrated into the underside 15 of the housing 3.

[0057] The busbar unit 7 is then preferably arranged towards the top of the housing 3 / the capacitors 5.

[0058] In conjunction with the exemplary embodiment of the Fig. 10 is in comparison to the embodiment of the Fig. It can be seen in Figure 9 that a spring element 23 can also be inserted between the cover 21 of the housing 3 and the respective capacitor 5, which serves to press the capacitor 5 into the receiving area 19 of the cooling structure 10. Fig. 10, for example, the spring element is designed as a coil spring.

[0059] Furthermore, it can be seen that the leg sections 29a, 29b are slightly angled in this embodiment. Thus, the cooling structure 10 is ultimately formed with conical side walls (leg sections 29a, 29b), which are implemented here in a complementary manner to the similarly conical end faces 30a, 30b of the condenser. In conjunction with the spring element 23, this results in each condenser 5 being pressed against the coupling material layers 11 both on the bottom wall 20 and on the leg sections 29a, 29b.

[0060] In Fig. 11 can also be seen that, in comparison to the embodiment of the Fig.10. The spring element 23 can also be designed as an elastically deformable coupling material layer 11. This significantly reduces the required height. Furthermore, the busbar unit 7 is connected to the housing 3 via the elastic, thermally conductive coupling material layer 11 for optimized cooling of the busbar unit 7, which also creates an additional heat path for the capacitor 5. Reference symbol list 1 Power electronics device 2 electric machine 3 housings 4 Capacitor arrangement 5 discrete capacitor 6. First connection / input of the capacitor 7 busbar unit 8 Environment 9a first page 9b second page 9c third page 10 Cooling structure 11 Coupling material location 12 Housing area 13 Connection terminal 14 first leader 15 Underside 16 Top 17 Surface 18 Cooling channel 19 Recording area 20 floor wall 21 lids 22 Floor 23 Spring element 24 Stator 25 Rotor 26 Coil arrangement 27 second connection / output of the capacitor 28 Power module 29a first thigh area 29b second thigh area 30a first front 30b second front 31a first long side 31b second long side 32a first transverse side 32b second transverse side 33 Insulation layer 34 second conductor 35 Outside 36 empty spaces 37 space 38a first phase connection 38b second phase connection 38c third phase connection 39 Current coupling 40 DC current sensor 41 EMC filters QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2019 111 111 A1

[0002] DE 10 2016 219 213 A1

[0002]

Claims

[1] Power electronics device (1) for an electrical machine (2), comprising a housing (3), a capacitor arrangement (4) accommodated in the housing (3) and comprising a plurality of discrete capacitors (5) and a busbar unit (7) connected to electrical connections (6) of the capacitors (5), wherein each capacitor (5) is coupled to the housing (3) in such a way that waste heat generated in the capacitor (5) during operation is dissipated in a targeted manner via the housing (3) to an environment (8) of the housing (3), characterized by that each capacitor (5) is surrounded on at least two sides (9a, 9b, 9c) by a cooling structure (10) and on two of these at least two sides (9a, 9b, 9c) is in contact with the cooling structure (10) by means of a thermal coupling material layer (11), and the cooling structure (10) is connected directly or indirectly to a housing area (12) against which cooling medium flows during operation. [2] Power electronics device (1) according to claim 1, characterized by that the cooling structure (10) is positioned on the busbar unit (7). [3] Power electronics device (1) according to claim 1 or 2, characterized by that the cooling structure (10) is penetrated by connection terminals (13) of the capacitors (5), which connection terminals (13) are electrically connected to a conductor (14) of the busbar unit (7). [4] Power electronics device (1) according to one of claims 1 to 3, characterized by that the busbar unit (7) rests against an underside (15) of the housing (3) by means of a thermal coupling material layer (11). [5] Power electronics device (1) according to one of claims 1 to 4, characterized by that the respective capacitor (5) is directly or indirectly in contact with an upper side (16) of the housing (3) by means of a thermal coupling material layer (11). [6] Power electronics device (1) according to claim 1, characterized bythat the cooling structure (10) is a one-piece component of the housing (3) and directly forms a cooling channel (18) with a surface (17) facing away from one of the capacitors (5). [7] Power electronics device (1) according to one of claims 1 to 6, characterized by that the respective capacitor (5) is surrounded by a U-shaped receiving area (19) of the cooling structure (10). [8] Power electronics device (1) according to claim 7, characterized by that a bottom wall (20) of the cooling structure (10) is arranged towards a side of the capacitors (5) facing a cover (21) of the housing (3) or towards a side of the capacitors (5) facing a bottom (22) of the housing (3). [9] Power electronics device (1) according to claim 7 or 8, characterized by that the respective capacitor (5) is pre-tensioned into the cooling structure (10) by means of a spring element (23). [10] Electrical machine (2) with a stator (24), a rotor (25) and a power electronics device (1) connected to a coil arrangement (26) of the stator (24) or the rotor (25) according to one of claims 1 to 9, wherein electrical connections (27) of the capacitors (5) are coupled to the coil arrangement (26) by means of power modules (3).

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