Busbar system
The busbar system with overlapping DC and AC busbars and insulation films addresses the inefficiencies in electric vehicle power conversion by reducing stray inductance and increasing power density, facilitating simpler assembly.
Patent Information
- Application Number
- PCT/EP2024/087599
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-01-29
- Filing Date
- 2024-12-19
- Publication Date
- 2025-08-07
AI Technical Summary
Electric vehicles face challenges in efficiently converting direct current from batteries to alternating current for AC motors while maintaining high power density, simplicity in assembly, and minimizing stray inductances in busbar systems.
A busbar system comprising overlapping DC and AC busbars with insulation films to reduce stray inductance and increase power density, featuring a sandwich design with receiving locations and contact clips for semiconductor components.
The solution reduces stray inductance and enhances power density, simplifies assembly, and maintains a compact design by using overlapping busbars and insulation films.
Smart Images
Figure EP2024087599_07082025_PF_FP_ABST
Abstract
Description
[0001] Busbar system
[0002] Technical area
[0003] The invention relates to a busbar system according to the preamble of claim 1. The invention further relates to a power electronics system and a vehicle according to the independent claims.
[0004] State of the art
[0005] Electric vehicles often use batteries, which provide direct current, as energy storage. However, the electric motors that power such electric vehicles are typically AC motors, such as three-phase motors. For this reason, electric vehicles typically use power electronic components to convert the direct current provided by the batteries into the alternating current required by the motors.
[0006] This presents various challenges. Firstly, this conversion from direct current to alternating current should be as energy-efficient as possible, for example, by minimizing losses caused by stray inductances. Furthermore, high power densities are desirable, for example, to minimize the space required for the power electronic components in the vehicle. Furthermore, such power electronic systems should be as simple as possible to enable easy assembly and, ideally, to keep system complexity as low as possible.
[0007] When connecting different power electronic components in electric vehicles, so-called busbars are often used. These interconnect the power electronic components in such a way that, for example, bridge circuits are realized. However, the known busbar systems each have different disadvantages, for example, with regard to their insufficient power density, their complex structure, or their energy efficiency. Instead of the English term "busbar," the purely German term "busbar" is used below. In other words, the terms "busbar" and "busbar" are used analogously and interchangeably in this patent application.
[0008] General description of the invention
[0009] The object of the invention is to eliminate or at least reduce the disadvantages of the prior art.
[0010] The object is achieved by a busbar system, wherein the busbar system comprises a first direct current busbar, a second direct current busbar and an alternating current busbar, wherein two of the three busbars are arranged at least partially overlapping.
[0011] A "busbar system" is understood in particular to mean a system of electrical conductors, which are typically plate-shaped or flat, at least in sections. Such a busbar system typically has different components, whereby the individual components can, for example, be busbars themselves or parts of busbars. A "DC busbar" is understood to mean a busbar element that is suitable for conducting direct current. An "AC busbar" is understood to mean a busbar element that is suitable for conducting alternating current.By at least partially overlapping at least two of the three busbars, it is possible to reduce the stray inductance of the busbar system and increase the power density. In addition, assembly of the busbar system can be simplified because, at least in some cases, placing busbar elements on top of one another can enable easier connection to power electronic elements than if busbar elements are arranged side by side. In advantageous embodiments, the first DC busbar and the second DC busbar and the AC busbar are arranged so as to at least partially overlap. Such at least partial overlapping of all three busbars of the busbar system has the advantage that, at least in some embodiments, a particularly good reduction in stray inductance and a particularly high power density can be achieved.However, it is of course also possible that not all three busbars overlap at least partially, but that only two of the busbars overlap at least partially.
[0012] In advantageous embodiments, the busbar system comprises a first insulation film, wherein the first insulation film preferably electrically insulates the first DC busbar and / or the second DC busbar and / or the AC busbar from one another. Such an insulation film is typically an electrically insulating plastic film, which is ideally electrically insulating but, on the other hand, is thermally conductive. Such an insulation film has the advantage that it can be easily arranged between two busbars and, for example, enables a compact design of the busbar system. The first insulation film can, for example, be arranged between the first DC busbar and the second DC busbar.Furthermore, it is possible for the first insulation film to be arranged between the AC busbar and one of the two DC busbars. The first insulation film electrically insulates the busbars between which it is arranged. Instead of an insulation film, however, it is also possible to use insulating varnishes or overmolding, for example.
[0013] In advantageous embodiments, the busbar system comprises a second insulation film, wherein the second insulation film preferably electrically insulates the first direct current busbar and / or the second direct current busbar and / or the alternating current busbar from one another. Such an insulation film is typically an electrically insulating plastic film, which is ideally electrically insulating but, on the other hand, is thermally conductive. In advantageous embodiments, the busbar system thus comprises a first insulation film and a second insulation film, wherein two of the busbars are electrically insulated from one another by the first insulation film, and wherein the second insulation film electrically insulates the busbar already in contact with the first electrical insulation film from the busbar which has not previously been in contact with the first insulation film.In typical embodiments, the first insulation foil is in contact with both the AC busbar and the first DC busbar, as well as with the second DC busbar. In typical embodiments, the second insulation foil is in contact with the AC busbar and the first DC busbar. In typical embodiments, the first insulation foil and the second insulation foil are arranged parallel to each other.
[0014] In advantageous embodiments, the busbar system is constructed in a sandwich design. The term "sandwich design" refers to the fact that all busbars each comprise flat areas that are arranged at least partially or at least largely overlapping, with the first insulation film and / or the second insulation film preferably being arranged at least in places between the busbars.
[0015] In typical embodiments, the busbar system comprises a plurality of receiving locations for semiconductor components, wherein the busbar system preferably comprises an even number of receiving locations for semiconductor components, particularly preferably at least two such receiving locations or at least four such receiving locations or at least six such receiving locations, wherein the receiving locations preferably all have an identical shape and / or wherein the receiving locations preferably have at least a substantially rectangular shape. The term “semiconductor components” is understood to mean, for example, electrical components which comprise at least one semiconductor element. The semiconductor components can be semiconductor packages, each of which comprises a plurality of individual semiconductor components.
[0016] In typical embodiments, the busbar system comprises a plurality of contact clips, wherein the contact clips are preferably suitable for contacting semiconductor components inserted into the receiving locations from above when such semiconductor components are inserted into the receiving locations, and / or wherein the AC busbar preferably comprises three or six or nine contact clips, or wherein the first DC busbar preferably comprises two or four or six contact clips and / or wherein the second DC busbar preferably comprises no contact clips. The term “contact clip” is typically understood to mean a typically metallic component which is suitable for establishing an electrical connection between a busbar on the one hand and a semiconductor component on the other.
[0017] In advantageous embodiments, all of the contact clips of the first DC busbar are arranged parallel to one another. In advantageous embodiments, the contact clips of the AC busbar are arranged one-third parallel to the contact clips of the first DC busbar and / or two-thirds orthogonal to the contact clips of the first DC busbar. The term “arranged parallel to one another” is to be understood that the contact clips each comprise longitudinal axes which run parallel to one another. Analogously, the term “orthogonal” is to be understood that these longitudinal axes run orthogonal to one another. In advantageous embodiments, each contact clip comprises an electrically conductive metal sheet which, for example, comprises two flat regions and a bent region.In advantageous embodiments, the AC busbar is constructed such that each semiconductor component inserted into a receiving location is contacted by exactly one or exactly two contact clips of the AC busbar when the semiconductor components are inserted into the receiving locations. In advantageous embodiments, the first DC busbar is constructed such that exactly two contact clips of the first DC busbar are assigned to exactly half of the receiving locations, wherein these two contact clips are typically arranged on opposite sides of the respective receiving locations. The fact that the contact clips are suitable for contacting the semiconductor components from above also means that the contact clips typically do not contact the semiconductor components laterally.
[0018] This saves space and keeps the power loop of the busbar system small, which also keeps the stray inductance small.
[0019] The object is further achieved by a power electronics system comprising a busbar system according to at least one of the previously described embodiments, wherein the power electronics system preferably comprises at least one DBG, wherein the DBG preferably comprises a top side, a bottom side and an insulation layer, wherein the bottom side preferably comprises a copper layer, wherein the top side preferably comprises a conductive layer, wherein the top side is preferably divided into a plurality of mutually insulated conductive surfaces, wherein a first region of the conductive surfaces is preferably conductively connected to the AC busbar and wherein a second region of the conductive surfaces is preferably conductively connected to the second DC busbar.The term “DBG” comes from English and stands for “Direct Bonded Copper”, although in German the term “DBG” or “DBC substrate” is also typically used by German experts. In advantageous embodiments, the copper layer is a copper ceramic layer. In advantageous embodiments, the top side comprises a first region which is conductively connected to the second DC busbar. In advantageous embodiments, the top side comprises a second region which is conductively connected to the AC busbar. In advantageous embodiments, the first region of the top side is part of the second DC busbar. In advantageous embodiments, the second region of the top side is part of the AC busbar. In advantageous embodiments, the top side is in contact with the first insulation film.In advantageous embodiments, the first insulation film partially insulates the first region of the upper side from the first DC busbar. In advantageous embodiments, the first insulation film electrically insulates the second region of the upper side from the first DC busbar. In advantageous embodiments, the first DC busbar is a negative DC busbar. In advantageous embodiments, the second DC busbar is a positive DC busbar. In advantageous embodiments, the power electronics system is constructed such that at least some, preferably all of the contact clips are suitable for contacting at least one semiconductor component from a side of the semiconductor component facing away from the DBG when such a semiconductor component is inserted into a receiving location.In principle, another type of substrate can be used to accommodate semiconductor components instead of a DBG.
[0020] In advantageous embodiments, the busbar system is mounted on the top side of the DBG, wherein the first insulation film preferably electrically insulates the top side of the DBG from the first DC busbar and / or from the second DC busbar and / or from the AC busbar.
[0021] A “power electronics system” is to be understood in particular as a technical system which is suitable for participating in a power electronics process and / or for incorporating at least one power electronics component.
[0022] The object is further achieved by a vehicle comprising a busbar system according to the invention and / or a power electronics system according to the invention.
[0023] Short description of the drawings
[0024] In the following, the invention is briefly explained with reference to drawings, in which: Figure 1: a schematic perspective view of an inventive
[0025] Busbar system in a first embodiment;
[0026] Figure 2: a side view of the busbar system already shown in Figure 1;
[0027] Figure 3a: a schematic representation of a cross-sectional profile through the busbar system shown in Figure 1;
[0028] Figure 3b: a schematic sectional view of the cross section shown in Figure 3a through the busbar system shown in Figure 1;
[0029] Figure 4a: a schematic representation of a cutout area from the cross-section shown in Figure 3b; and
[0030] Figure 4b: an enlarged view of the section shown in Figure 4a.
[0031] Description of preferred embodiments
[0032] Figure 1 shows a schematic perspective view of a busbar system 1 according to the invention in a first embodiment. The busbar system 1 comprises an AC busbar 2, which in the embodiment shown in Figure 1 comprises a plurality of components. This is one reason why two reference numerals in Figure 1 point to different parts of the AC busbar 2. The busbar system 1 further comprises a first DC busbar 3. This first DC busbar 3 also comprises a plurality of components in the embodiment shown in Figure 1, which is one reason why the first DC busbar 3 is provided with two reference numerals. The busbar system 1 further comprises a second DC busbar 4.In the embodiment shown in Figure 1, the first DC busbar 3 is a negative DC busbar, i.e. a busbar which is suitable for being connected to a negative potential. The second DC busbar 4 in the embodiment shown in Figure 1 is a positive busbar, which is therefore typically suitable for being connected to a positive potential. The busbar system 1 further comprises a first insulating film 5 and a second insulating film 6. Also shown in Figure 1 is a DBG 7, i.e. a direct bonded copper. The busbar system 1, together with the DBC 7, forms a power electronics system according to the invention. Alternatively, it is also possible to consider the DBC 7 as part of the busbar system 1. If such an consideration is taken, the busbar system 1 would therefore comprise the DBC 7.The first insulation film 5 is arranged on an underside of the busbar system 1 and insulates the busbar system 1 from the DBC 7. In particular, the first insulation film 5 is arranged below the first DC busbar 3. The second insulation film 6 is arranged between a part of the first DC busbar 3 and a part of the AC busbar 2. An area of the first insulation film 5 is more than twice as large as an area of the second insulation film 6. The AC busbar 2 comprises a total of six contact clips 8.1 ... 8.6. The first DC busbar 3 comprises a total of four contact clips 9.1 ... 9.4. Additionally, four semiconductor components 10.1 ... 10.4 are shown in Figure 1. Each of these semiconductor components 10.1 ... 10.4 is inserted into a receiving location of the busbar system 1. Semiconductor components 10.1... 10.4 are schematically shown as cuboid-shaped elements.For the sake of clarity, the receiving locations of the busbar system 1 are not provided with reference numerals. It is clear that each semiconductor component 10.1 ... 10.4 is contacted by a plurality of contact clips 8.1 ... 8.6, 9.1 ... 9.4, specifically from above. In other words, the busbar system 1 is preferably constructed such that at least some of the contact clips 8.1 ... 8.6, 9.1 ... 9.4 press the semiconductor components 10.1 ... 10.4 into the respective receiving locations.
[0033] Figure 2 shows a side view of the busbar system 1 already shown in Figure 1. In particular, Figure 2 again shows the AC busbar 2, the first DC busbar 3 and the second DC busbar 4. Furthermore, it can be seen that the AC busbar 2 and the first DC busbar 3 comprise different components, which is also indicated in Figure 2 by several reference numerals. Furthermore, Figure 2 shows the first insulation film 5 and the second insulation film 6. The DBG 7 is also shown in Figure 2. The more precise structure of the DBG 7 can also be seen in Figure 2. The DBG 7 comprises, in particular, a bottom side 11 and a top side, wherein the top side comprises a first region 12 and a second region 13. A flat insulation layer 14 is arranged between the bottom side 11 and the top side 12, 13.This insulation layer 14 is typically electrically insulating but thermally conductive. Furthermore, Figure 2 shows the contact clip 8.3 of the AC busbar 2 and the contact clip 9.4 of the first DC busbar 3. Furthermore, Figure 2 shows that the second DC busbar 4 is attached to the first region 12. Furthermore, Figure 2 shows that the AC busbar 2 is attached to the second region 13. Figure 2 also shows the contact clip 8.2 of the AC busbar 2. This contact clip 8.2 connects the second region 13 of the top side of the DBG 7 to a part of the AC busbar 2. Figure 2 also shows that the first insulation film 5 insulates the top side of the DBG 7 from a bottom side of the busbar system 1.It can also be seen that the second insulation film 6 is arranged between the AC busbar 2 and the first DC busbar 3 and electrically insulates the AC busbar 2 and the first DC busbar 3 from one another.
[0034] Figure 3a shows a schematic representation of a cross-sectional profile through the busbar system 1 shown in Figure 1.
[0035] Figure 3b shows a schematic view of the cross section indicated in Figure 3a through the busbar system 1 shown in Figure 1. Figure 3b again shows the AC busbar 2 and the first DC busbar 3. The second insulation film 6 is arranged between the AC busbar 2 and the first DC busbar 3. This second insulation film 6 thus electrically insulates the AC busbar 2 from the first DC busbar 3. Figure 3b also shows a section of the DBG with part of the first region 12 of the top side of the DBG and part of the bottom side 11 of the DBG. The insulation layer 14 is arranged between the bottom side 11 and the first region 12. The first region 12 is electrically connected to the second DC busbar 4, although this is not visible in Figure 3b due to the cross-sectional view.The first insulation film 5 is arranged between the first region 12 and the first DC busbar 3. The first insulation film 5 thus electrically insulates the first region 12 of the DBG from the first DC busbar 3. Figure 3b also shows the contact clips 8.3, 8.4, 8.5, and 8.6 of the AC busbar 2. Furthermore, Figure 3b shows the semiconductor components 10.3 and 10.4. The contact clips 8.3, 8.4 contact a top side of the semiconductor component 10.3. The contact clips 8.5, 8.6 contact a top side of the semiconductor component 10.4.
[0036] Figure 4a shows a schematic representation of a cutout area from the cross-section shown in Figure 3b. The cutout area is represented in Figure 4a by a dashed rectangle.
[0037] Figure 4b shows an enlarged view of the section indicated in Figure 4a. Figure 4b thus again shows a part of the busbar system 1. The AC busbar 2 and the first DC busbar 3 are again shown. The second insulation film 6 is arranged between the AC busbar 2 and the first DC busbar 3. The contact clips 8.5, 8.6 of the AC busbar 2 are also visible in Figure 4b. The section of the DBG, already shown in Figure 3b, with the first region 12, the underside 11, and the insulation layer 14 is also shown. It can again be seen that the contact clips 8.5, 8.6 contact the semiconductor component 10.4 from above and thus press the semiconductor component 10.4 into its receiving location in the busbar system 1 (or in other words: fix it in its receiving location), with one end of the contact clips 8.5, 8.6 is connected to the AC busbar 2, and the other end of the contact clips 8.5, 8.6 contacts the semiconductor component 10.4 from above. Figure 4b also shows the first insulation film 5, which is arranged between the first region 12 of the top side of the DBG on the one hand and the first DC busbar 3 on the other.
[0038] The invention is not limited to the described embodiments. The scope of protection is defined by the patent claims.
[0039] Reference symbol
[0040] Busbar system
[0041] AC busbar first DC busbar second DC busbar first insulation film second insulation film
[0042] DBG
[0043] AC busbar contact clips
[0044] Contact clips of the first DC busbar
[0045] Semiconductor components
[0046] Bottom (of the DBG) first area (of the top) second area (of the top)
[0047] Insulation layer
Claims
Patent claims 1. Busbar system (1), wherein the busbar system (1) comprises a first direct current busbar (3), a second direct current busbar (4) and an alternating current busbar (2), characterized in that two of the three busbars (2, 3, 4) are arranged at least partially overlapping.
2. Busbar system (1) according to claim 1, characterized in that the first direct current busbar (3) and the second direct current busbar (4) and the alternating current busbar (2) are arranged at least partially overlapping.
3. Busbar system (1) according to one of the preceding claims, characterized in that the busbar system (1) comprises a first insulating film (5), wherein the first insulating film (5) preferably electrically insulates the first direct current busbar (3) and / or the second direct current busbar (4) and / or the alternating current busbar (2) from one another.
4. Busbar system (1) according to claim 4, characterized in that the busbar system (1) comprises a second insulation film (6), wherein the second insulation film (6) preferably electrically insulates the first direct current busbar (3) and / or the second direct current busbar (4) and / or the alternating current busbar (2) from one another.
5. Busbar system (1) according to one of the preceding claims, characterized in that the busbar system (1) is constructed in a sandwich design.
6. Busbar system (1) according to one of the preceding claims, characterized in that the busbar system (1) comprises a plurality of receiving locations for semiconductor components (10.1... 10.4), wherein the Busbar system (1) preferably comprises an even number of receiving locations for semiconductor components (10.1... 10.4), particularly preferably at least two such receiving locations or at least four such receiving locations or at least six such receiving locations, wherein the receiving locations preferably all have an identical shape and / or wherein the receiving locations preferably have at least substantially a rectangular shape.
7. Busbar system (1) according to one of the preceding claims, characterized in that the busbar system (1) comprises a plurality of contact clips, wherein the contact clips are preferably suitable for contacting semiconductor components (10.1... 10.4) inserted into the receiving locations from above when such semiconductor components (10.1... 10.4) are inserted into the receiving locations, and / or wherein the AC busbar (2) preferably comprises three or six or nine contact clips (8.1... 8.6) and / or wherein the first DC busbar (3) preferably comprises two or four or six contact clips (9.1... 9.4) and / or wherein the second DC busbar (4) preferably does not comprise any contact clips.
8. Power electronics system, comprising a busbar system (1) according to one of the preceding claims, characterized in that the power electronics system preferably comprises at least one DBG (7), wherein the DBG (7) preferably comprises a top side, a bottom side (11) and an insulation layer (14), wherein the bottom side (11) preferably comprises a copper layer, wherein the top side preferably comprises a conductive layer, wherein the top side is preferably divided into a plurality of mutually insulated conductive surfaces (12, 13), wherein a first region (12) of the conductive surfaces (12, 13) is preferably conductively connected to the AC busbar (2) and wherein a second region (13) of the conductive surfaces (12, 13) is preferably conductively connected to the second DC busbar (4).
9. Power electronics system according to claim 8, characterized in that the busbar system (1) is mounted on the top side of the DBG (7), wherein the first insulation film (5) preferably electrically insulates the top side of the DBG (7) from the first DC busbar (3) and / or from the second DC busbar (4) and / or from the AC busbar (2).
10. Vehicle comprising a busbar system (1) according to one of claims 1 to 7 and / or a power electronics system according to one of claims 8 to 9.
Citation Information
Patent Citations
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EP2364580B1
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EP3357089B1
Power module
US20190237440A1
Electric vehicle inverter module laminated bus bar
US20190334334A1