Capacitor assembly with a first to fourth individual capacitor arranged in series

Abstract

A capacitor assembly is presented comprising a first to fourth individual capacitor, each with a first cover surface defining a respective normal direction of the individual capacitor, and a second cover surface on the opposite side, wherein the first cover surface of the first individual capacitor defines a main direction, with first connection elements arranged on the first cover surface and second connection elements arranged on the second cover surface, wherein the individual capacitors are arranged side by side in a 1x4 matrix, wherein the normals of the first and third individual capacitors point in the main direction and wherein the normals of the second and fourthsingle capacitors pointing in the opposite direction to the main direction, wherein all first connection elements are connected to each other by means of a first busbar, and wherein all second connection elements are connected to each other by means of a second busbar, and wherein a first intermediate section of the first busbar and a first intermediate section of the second busbar between the first and second single capacitors, and a second intermediate section of the first busbar and a second intermediate section of the second busbar between the third and fourth single capacitors are arranged one above the other and each separated by a second insulating device.

Description

[0001] The invention describes a capacitor assembly with a first to fourth individual capacitor, each with a first cover surface defining a respective normal direction of the individual capacitor and a second cover surface opposite it, wherein the first cover surface of the first individual capacitor defines a main direction, with first connection elements arranged on the first cover surface and second connection elements arranged on the second cover surface, wherein the individual capacitors are arranged next to each other in a 1x4 matrix.

[0002] DE 10 2017 215 419 A1 discloses a capacitor unit comprising at least two opposite terminals for electrically connecting the capacitor unit to a printed circuit board or a power module. To reduce parasitic terminal inductances of the capacitor unit, each terminal has a contact element, wherein the contact elements are adjacent and parallel to each other and spaced apart, or each terminal has several parallel terminal tabs arranged in a row, with the terminal tabs of one terminal alternating with the terminal tabs of the other terminal in the row, or each terminal is designed as part of a press-fit connection.

[0003] DE 10 2022 123 261 A1 discloses a power electronic assembly with a housing and with a capacitor device arranged therein, wherein the capacitor device comprises a plurality of capacitor elements, each with a first and a second capacitor contact device, and a capacitor busbar comprising a first metal body with a first contact point and a second metal body with a second contact point, wherein the first metal body of first polarity comprises a plurality of first connection contact devices, each electrically connected to a first capacitor contact device, and the second metal body of second polarity comprises a plurality of second connection contact devices, each electrically connected to a second capacitor contact device.wherein each individual current path, formed from a first partial current path between the first contact point and a first connecting contact device and a second partial current path between the second connecting contact device assigned to the first and the second contact point, each has the same current path length.

[0004] DE 10 2019 217 976 A1 discloses a film capacitor for power electronics, comprising a first electrically conductive layer arranged on a first end face of the film capacitor, wherein the surface normal of the first electrically conductive layer is perpendicular to the surface normals of dielectric films of the film capacitor. A second electrically conductive layer is arranged on a second end face opposite the first end face, wherein the surface normal of the second electrically conductive layer is perpendicular to the surface normals of the dielectric films of the film capacitor. The film capacitor has at least one internal passage extending from the first electrically conductive layer to the second electrically conductive layer, the passage being formed by removing capacitor material. The invention also relates to a capacitor assembly.

[0005] DE 10 2019 134 650 A1 discloses a power electronic system comprising a housing, a cooling device, a power semiconductor module and a capacitor device, wherein a cooling section of a capacitor connection device is in thermally conductive contact with a cooling surface of the cooling device.

[0006] DE 10 2012 215 787 A1 discloses a power electronic system with a multi-part housing, a plurality of power electronic circuit devices, a capacitor device and a liquid cooling device.The multi-part housing consists of three housing elements that are cuboid in their basic form, a central element, and an upper and a lower cover element arranged on opposite connection surfaces of the central element. The housing has an inlet connection and an outlet connection for a coolant, and at least one upper cooling chamber is formed between the central element and the upper cover element, and at least two lower cooling chambers are formed between the central element and the lower cover element. Each cooling chamber has at least one cooling surface, and the cooling chambers are permeable to coolant entering through the inlet connection and exiting at the outlet connection, thus forming the liquid cooling device.

[0007] The invention is based on the objective of improving the arrangement of capacitors in a capacitor assembly for a power electronic system.

[0008] This problem is solved according to the invention by a capacitor assembly comprising a first to fourth individual capacitor, each with a first cover surface defining a respective normal direction of the individual capacitor, and a second cover surface on the opposite side, wherein the first cover surface of the first individual capacitor defines a main direction, with first connection elements arranged on the first cover surface and second connection elements arranged on the second cover surface, wherein the individual capacitors are arranged side by side in a 1x4 matrix, wherein the normals of the first and third individual capacitors point in the main direction and wherein the normals of the second and fourth individual capacitors point opposite to the main direction, and wherein all first connection elements are connected to each other by means of a first busbar and wherein all second connection elements are connected to each other by means of a second busbar.wherein a first intermediate section of the first busbar and a first intermediate section of the second busbar between the first and second individual capacitors and a second intermediate section of the first busbar and a second intermediate section of the second busbar between the third and fourth individual capacitors are arranged one above the other and each separated by a second insulating device.

[0009] The term "arranged side by side" is to be understood in particular as meaning that the top surface of adjacent individual capacitors forms, in mathematical terms and within the limits of technical feasibility, partial surfaces of a plane. It is understood that the arrangement in a 1x4 matrix also includes embodiments in a 1x(2+2n) matrix, as long as the inventive configuration is given for 4 of the 2+2n capacitors.

[0010] It can be advantageous if the individual capacitors are arranged in the order first, second, third and fourth individual capacitor or in the order first, second, fourth and third individual capacitor.

[0011] It can also be advantageous if the first connection elements of each individual capacitor are arranged in a first surface section of the first cover surface, and the second connection elements of each individual capacitor are arranged in a second surface section of the second cover surface. It is preferred if the first and second surface sections of each individual capacitor are arranged symmetrically to each other. It is particularly preferred if the symmetry is point symmetry about the center of the individual capacitor or mirror symmetry about a cross-sectional surface of the individual capacitor.

[0012] In principle, it can be advantageous if the first and second rails are designed as flat metal bodies. Furthermore, it is beneficial if the first and second rails are arranged in sections, overlapping one above the other and separated by a first insulating device.

[0013] It may also be preferred if the first busbar has an additional first connection section and the second busbar has an additional second connection section, which are arranged one above the other in a section and these connection sections are designed to simultaneously supply power to all individual capacitors.

[0014] It can be advantageous if the first rail has additional first module sections and the second rail has additional second module sections, and these module sections are designed for simultaneous power supply from the power semiconductor modules from the individual capacitors.

[0015] Finally, it can be advantageous if the respective contact sections of the busbars are connected to the associated connection elements of the individual capacitors by a material bond, preferably by welding.

[0016] Of course, unless explicitly or per se excluded or contrary to the idea of ​​the invention, the features or groups of features mentioned in the singular may be present multiple times in the capacitor assemblies according to the invention.

[0017] It is understood that the features and configurations of the capacitor assembly mentioned above and below can be implemented individually or in any combination to achieve improvements. In particular, the features mentioned above and explained here or below can be used not only in the combinations specified, but also in other non-mutually exclusive combinations or individually, without departing from the scope of the present invention.

[0018] Further explanations of the invention, advantageous details and features will become apparent from the following description of the invention contained in the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. 7 schematically illustrated embodiments of the invention or of respective parts thereof. Fig. Figure 1 shows a schematic representation of a power electronic system with a capacitor assembly according to the invention in exploded view. Fig. Figure 2 shows a side view of a first embodiment of a capacitor assembly according to the invention. Fig. Figure 3 shows a side view of a second embodiment of a capacitor assembly according to the invention. Fig. 4 and Fig. Figure 5 shows the rail connections of a first embodiment of a capacitor assembly according to the invention. Fig. Figure 6 shows a three-dimensional view of a second embodiment of a capacitor assembly according to the invention. Fig. Figure 7 shows a single capacitor from a capacitor assembly.

[0019] Fig. Figure 1 shows a schematic exploded view of a power electronic system with a capacitor assembly according to the invention. Viewed from bottom to top, this system comprises an arrangement stacked in the main direction H, consisting of a cup-shaped first housing part 40, the capacitor assembly 1, a cooling device 5, an insulation layer 7, a power semiconductor module 6, a control switching device 660, and a second housing part 42.

[0020] The capacitor assembly 1 shows, see below. Fig. 2, a first to fourth individual capacitor 11, 12, 13, 14. Each individual capacitor has a first cover surface 111, 121, 131, 141 defining a respective normal direction N1, N2, N3, N4 of the individual capacitor and a second cover surface 112, 122, 132, 142 opposite the first cover surface 111, 121, 131, 141, wherein the first cover surface 111 of the first individual capacitor 11 defines the main direction H. The individual capacitors 11, 12, 13, 14 of the capacitor assembly 1 each have first connection elements 113, 123, 133, 143 arranged on the associated first cover surface 111, 121, 131, 141 and second connection elements 114, 124, 134, 144 arranged on the associated second cover surface 112, 122, 132, 142.The individual capacitors 11, 12, 13, 14 are arranged side by side in a 1x4 matrix, with the normals N1, N4 of the first and fourth individual capacitors 11, 14 pointing in the main direction H, and the normals N2, N3 of the second and third individual capacitors 12, 13 pointing opposite to the main direction H. All first terminal elements 113, 123, 133, 143 are connected to each other by means of a first busbar 30. Likewise, all second terminal elements 114, 124, 134, 144 are connected to each other by means of a second busbar 32.

[0021] The cooling device 5 has a first cooling contact surface 500 which is in direct thermal contact with the capacitor assembly 1. This thermal contact, without limitation of generality, is direct, i.e., separated only by the insulation layer 7, with a first and second main section 300, 320, as part of a first and second busbar 30, 32. The individual capacitors 11, 12, 13, 14 are then, again without limitation of generality, in indirect thermal contact with the first cooling contact surface 500 via the main sections 300, 320.

[0022] In the design of the busbar 30,32, a first intermediate section 302 of the first busbar 30 and a first intermediate section 322 of the second busbar 32 are arranged between the first and second individual capacitors 11,12 and a second intermediate section 302 of the first busbar 30 and a second intermediate section 322 of the second busbar 32 are arranged one above the other and each separated by a second insulating device.

[0023] A second cooling contact surface 520 of the cooling device 5, opposite the first, is in direct thermal contact with the power semiconductor module 6. This module is arranged directly on the second cooling contact surface 502. Typically, a thermal paste may also be applied between the power semiconductor module 6 and the second cooling contact surface 520.

[0024] The power semiconductor module 6 has DC load connection elements 60,62 which are electrically conductively connected to associated module sections 306,326 of the first and second busbars 30,32 in the correct polarity.

[0025] The power semiconductor module 6 is connected to the control switching device 660 by means of auxiliary contact elements 66. This control switching device 660 is designed as a standard printed circuit board and serves to control the power semiconductor module 6 and receives the associated control signal via a connector (not shown) to a higher-level control system, in particular a vehicle control system, if the power electronic system is part of a powertrain of an electric vehicle.

[0026] A second sub-housing 42, cooperating with the first sub-housing 40, covers the cooling device 5, the power semiconductor module 6, and the control switching device 660. This second sub-housing 42 has feedthroughs 420 for AC load connection elements 64 and also the plug connections for control signals (not shown).

[0027] Fig. Figure 2 shows a side view of a first embodiment of a capacitor assembly 1 according to the invention, arranged in the first partial housing 40. This housing is filled with an insulating compound 400, which covers the entire capacitor assembly 1 as well as the main sections 300, 320 of the rail system 30, 32. In addition, a section of the cooling device 5, which is adjacent to the capacitor assembly 1, is embedded in the insulating compound 400.

[0028] The individual capacitors 11, 12, 13, 14 are arranged here in the order first, second, third and fourth individual capacitor 11, 12, 13, 14 and have the normals N1, N2, N3, N4 shown, wherein the normals N1, N4 of the first and fourth individual capacitor 11, 14 are aligned in the main direction H, while the normals N2, N3 of the second and third individual capacitor 12, 13 are aligned opposite to the main direction H.

[0029] Fig. Figure 3 shows a side view of a second embodiment of a capacitor assembly 1 according to the invention. In contrast to the first embodiment according to Fig. 2. The individual capacitors 11, 12, 13, 14 are arranged in the order first, second, fourth and third individual capacitor 11, 12, 14, 13 and have the normals N1, N2, N3, N4 shown below. Fig. The two mentioned orientations.

[0030] Fig. 4 and Fig. Figures 5 show the variations 30 and 32 of a first embodiment, cf. Fig. 2, a condenser assembly 1 according to the invention in a three-dimensional view from the direction of the cooling device 5, cf. Fig. 1. Shown here is a capacitor assembly 1 in the form of a 1x6 matrix, which contains the capacitor assembly 1 according to the invention in the form of a 1x4 matrix with a first to fourth individual capacitor 11, 12, 13, 14. Fig. Figure 4 shows this capacitor assembly 1 with the second busbar 32, but without the first busbar 30. Fig. Figure 5 also shows the first rail 30. The remaining design basically corresponds to that shown in Figure 5. Fig. 2.

[0031] Fig. Figure 6 shows a three-dimensional view of a second embodiment, see Figure 6. Fig. 3, a condenser assembly 1 according to the invention in a three-dimensional view looking towards the cooling device 5, cf. Fig. 1. Shown here is a capacitor assembly 1 in the form of a 1×6 matrix, which contains the capacitor assembly 1 according to the invention in the form of a 1×4 matrix with a first to fourth individual capacitor 11, 12, 13, 14. The remaining design corresponds in principle to that according to Fig. 3.

[0032] Fig. Figure 7 shows a single capacitor 11,12,13,14 of a capacitor assembly 1 and the position of a plane of symmetry or of an intersection of the first surface section 115,125,135,145 on the first top surface 111,121,131,141 to the second surface section 116,126,136,146 on the second top surface 112,122,132,142, with a substantially cuboid design of the single capacitor 11,12,13,14.

Claims

[1] Capacitor assembly (1) comprising a first to fourth individual capacitor (11, 12, 13, 14), each with a first cover surface (111, 121, 131, 141) defining a respective normal direction (N1, N2, N3, N4) of the individual capacitor (11, 12, 13, 14) and a second cover surface (112, 122, 132, 142) on the opposite side, wherein the first cover surface (111) of the first individual capacitor (11) defines a main direction (H), with first connection elements (113, 123, 133, 143) arranged on the first cover surface (111, 121, 131, 141) and second connection elements (114, 124, 134, 144) arranged on the second cover surface (112, 122, 132, 142), wherein the Individual capacitors (11, 12, 13, 14) are arranged side by side in a 1x4 matrix, wherein the normals (N1, N3) of the first and third individual capacitors (11, 13) point in the main direction (H) and wherein the normals (N2, N4) of the second and fourth individual capacitors (12,14) pointing against the main direction (H) and wherein all first connection elements (113, 123, 133, 143) are connected to each other by means of a first busbar (30) and wherein all second connection elements (114, 124, 134, 144) are connected to each other by means of a second busbar (32) and wherein a first intermediate section (302) of the first busbar (30) and a first intermediate section (322) of the second busbar (32) between the first and second individual capacitors (11, 12) and a second intermediate section (302) of the first busbar (30) and a second intermediate section (322) of the second busbar (32) between the third and fourth individual capacitors (13, 14) are arranged one above the other and each separated by a second insulating device. [2] Capacitor assembly according to claim 1, wherein the individual capacitors (11, 12, 13, 14) are arranged in the sequence first, second, third and fourth individual capacitor (11, 12, 13, 14) or in the sequence first, second, fourth and third individual capacitor (11, 12, 14, 13). [3] Capacitor assembly according to one of the preceding claims, wherein the first connection elements (113, 123, 133, 143) of each individual capacitor (11, 12, 13, 14) are arranged in a first surface section (115, 125, 135, 145) of the first cover surface (111, 121, 131, 141) and the second connection elements (114, 124, 134, 144) of each individual capacitor (11, 12, 13, 14) are arranged in a second surface section (116, 126, 136, 146) of the second cover surface (112, 122, 132, 142). [4] Capacitor assembly according to claim 3, wherein the first surface section (115,125,135,145) and second surface section (116,126,136,146) of a single capacitor (11,12,13,14) are arranged symmetrically to each other. [5] Capacitor assembly according to claim 4, wherein the symmetry is point symmetry about the center of the individual capacitor (11,12,13,14) or mirror symmetry about a cross-sectional surface of the individual capacitor (11,12,13,14). [6] Capacitor assembly according to one of the preceding claims, wherein the first and second busbars (30,32) are designed as planar metal bodies. [7] Capacitor assembly according to claim 6, wherein the first and second busbars (30, 32) are arranged in sections one above the other and separated by a first insulating device. [8] Capacitor assembly according to one of the preceding claims, wherein the first busbar (30) has an additional first connection section and the second busbar (32) has an additional second connection section, which are arranged one above the other in a section and these connection sections are designed to provide power to all individual capacitors (11, 12, 13, 14) simultaneously. [9] Capacitor assembly according to one of the preceding claims, wherein the first busbar (30) has additional first module sections (306) and the second busbar (32) has additional second module sections (326) and these module sections (306,326) are designed for simultaneous power supply from the power semiconductor modules from the individual capacitors (11,12,13,14). [10] Capacitor assembly according to one of the preceding claims, wherein the respective contact sections of the busbars (30, 32) are connected to the associated connection elements (113, 114, 123, 124, 133, 134, 143, 144) of the individual capacitors (11, 12, 13, 14) by a material bond, preferably by welding.

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