Busbar assembly and power distribution unit with such a busbar assembly

Abstract

The invention relates to a busbar assembly (100) comprising a first electrically conductive busbar (10), a second electrically conductive busbar (20) which is electrically isolated from the first busbar (10), and a heat exchanger (30) for temperature control of the busbars (10, 20), wherein the heat exchanger (30) is arranged between the first busbar (10) and the second busbar (20) and has at least one fluid channel (35) for flow with a temperature control medium, and wherein an electrically insulating layer (11, 21) is provided between the busbars (10, 20) and the heat exchanger (30).

Description

The invention relates to a busbar assembly having the features of patent claim 1.Prior ArtIn practice, busbar assemblies are known which have at least one busbar. These busbars are usually used in high-voltage applications. In particular, such busbar assemblies can be part of a current distributor for a high-voltage system in vehicle technology.High-voltage systems are systems which are operated with AC voltages of more than 30 volts or with DC voltages of more than 60 volts, in particular at least 400 volts, in particular at least 800 volts, in particular at least 1250 volts. Such high-voltage systems are used in particular in hybrid vehicles or battery-electric vehicles. The current distributor or the busbar assembly described below is designed in this respect for such voltages in the high-voltage range.In high-voltage systems, in particular in hybrid vehicles or battery-electric vehicles, high currents are often transmitted. This leads to a strong heating of the respective components, in particular also of the busbar assembly. It is therefore customary in practice to use heating devices which counteract heating of the conductor rails.For this purpose, an intermediate plate is often positioned on the housing of a power distributor, which plate cools the interior of the power distributor indirectly. However, this requires a sufficiently good heat dissipation from the heating components. For this purpose, the busbars are often generously dimensioned, so that a large heat emission surface is provided. The material outlay for the busbars is consequently high, which is disadvantageous in terms of production costs.SUMMARY OF THE INVENTIONThe object of the invention is to specify a busbar assembly which enables efficient insulation with a smaller use of material. It is a further object of the invention to specify a power distributor having such a busbar assembly.According to the invention, this object is achieved with respect to the busbar assembly by the subject matter of claim 1 and with respect to the current distributor by the subject matter of claim 11.Specifically, the invention is based on the idea of having a busbar assembly witha first electrically conductive busbar,a second electrically conductive busbar electrically separated from the first busbar, anda heat exchanger for tempering the busbars,wherein the heat exchanger is arranged between the first busbar and the second busbar and has at least one fluid channel for a temperature control medium to flow through. Furthermore, in the invention, an electrically insulating layer is provided in each case between the busbars and the heat exchanger.In contrast to the prior art, the invention therefore provides for the heat exchanger, which can serve in particular as an I<hell element, to be arranged between the busbars in order to achieve a particularly efficient heat transfer. This has the consequence that for the purpose of tempering the busbars, their surface size has a lower relevance than in the prior art. Consequently, the busbars can be made more compact, which reduces the material outlay. This also results in a lower weight of the busbar assembly.The heat exchanger is connected particularly well by the embedding between the two busbars and thus achieves a very efficient temperature control, in particular cooling. In this respect, it is particularly preferred if the electrically insulating layers are designed to be particularly thin, in particular to be well heat-transferring. In order to be able to carry away the heat transferred from the busbars to the heat exchanger well, the heat exchanger preferably has at least one fluid channel through which a temperature control medium can flow. The fluid channel can extend in this case in a multiply winding manner over the entire surface of the heat exchanger.The first busbar and the second busbar are electrically separated from one another, such that the two busbars can have different polarities. For example, the first busbar can be connected to a positive pole of a supply voltage, whereas the second busbar can be connected to an electrical negative pole or to a ground. This increases the application possibilities of the busbar assembly.In general, it can be provided that the heat exchanger has a first cover layer and a second cover layer, wherein the cover layers are preferably each directly connected to one of the electrically insulating layers. A formed metal sheet preferably extends between the cover layers, forming the fluid channel. Such a structure of a heat exchanger is possible in a particularly simple and cost-effective manner. In addition, such a heat exchanger has a high temperature transmission efficiency. Alternatively, the heat exchanger can comprise only the first cover layer and a formed sheet metal.A particularly cost-effective production of the heat exchanger is achieved by a so-called roll bonding method. In the roll bonding method, two sheets are joined together under high pressure, with specific regions being cut out.In particular, separating agents can be used for this purpose, which are applied in individual regions between the sheets. During the pressure joining, those sheet metal regions which are not treated with the separating agent are then joined to one another. The areas treated with separating agent are subsequently "inflated", so that channels are formed therein. This method can be carried out particularly simply and very cost-effectively, which significantly reduces the overall costs for the busbar assembly.In this respect, in a preferred embodiment of the invention, it is provided that the first cover layer forms a roll bond composite with the formed metal sheet. The second cover layer can then preferably form a carrier plate which is connected to the roll bond composite, in particular in a materially bonded manner. The heat exchanger thus results with two cover layers, between which the formed sheet metal is arranged, wherein the first cover layer is connected to the formed sheet metal, at least in regions, by pressure joining. The formed metal sheet is equipped with the fluid channel as part of the roll bond composite.The electrically insulating layers can each be formed by an insulating film. This is possible in a particularly cost-effective manner, achieves sufficient electrical insulation and additionally has the effect that good heat transfer from the busbars to the heat exchanger is maintained.For good heat transfer, it is also advantageous if the heat exchanger, in particular the carrier plate and the roll bond composite, comprises or consists of a metal, in particular an aluminum alloy. Aluminum has a low heat capacity but a good heat transfer performance, so that this material is well suited for efficient heat transfer. In addition, aluminum can be used well, in particular in the roll bonding process, and thus contributes to the cost-effective production of the busbar assembly.It is particularly preferred in the invention if the heat exchanger, the electrically insulating layers and the busbars together form a sandwich structure. A sandwich structure is preferably a layer composite of layers connected to one another. In the invention, the layers are formed by the heat exchanger, the electrically insulating layers and the busbars.These are preferably connected to one another over their entire surface. The connection can be effected in particular in a materially integral manner, for example by pressure joining, welding and / or adhesive bonding. The sandwich structure is particularly compact and stable and is therefore suitable in particular for mobile applications, in particular in vehicles in which high-voltage electrical systems are used.The busbars can also comprise receiving sections for electrical and / or electronic components, in particular protective elements. In particular, the busbars can comprise receiving sections which enable a mechanical and electrical connection to electrical or electronic components. Such components can be, for example, electrical contactors or fuses.Quite generally, the busbar arrangement preferably forms a plate-shaped structure which can have a plurality of receiving sections in the form of exceptions.A further improvement, in particular for mobile applications, is achieved if the busbars are each connected on a side facing away from the heat exchanger to an electrically insulating carrier, in particular a plastic carrier. In particular, the sandwich structure comprising heat exchangers, electrically insulating layers and busbars can be embedded between two electrically insulating carriers. The electrically insulating carriers, which are preferably formed from an inert material, damp oscillations which can arise in the busbars or the electrical and / or electronic components. Conversely, the electrically insulating carriers also provide protection against vibrations which are introduced into the busbar assembly from the outside. This increases, in particular, the reliability of electrical or electronic components.The electrically insulating carriers, in particular the plastic carriers, can each be covered with a cover on an outer side opposite the respective busbar. The cover can in particular comprise a metallic material, preferably an aluminum alloy. However, it is also possible for the cover to be formed from steel, for example. The cover essentially offers protection against external influences, in particular against liquids and / or dirt.An independent aspect of the invention relates to a power distributor or a PDU (Power Distribution Unit) for a motor vehicle having a busbar assembly described above. Such a power distributor can in particular have a housing in which the busbar assembly is embedded. The busbar arrangement preferably extends over at least 50%, preferably over at least 65%, particularly preferably over at least 80% of a base area of the housing of the current distributor. It is also possible for the electrically insulating carriers to form the housing of the current distributor with their respective cover of the busbar assembly.From the following detailed description and the totality of the patent claims, further advantageous embodiments and combinations of features of the invention result.Brief Description of the DrawingsThe invention is explained in more detail below on the basis of an exemplary embodiment with reference to the appended schematic drawings. Shown therein are FIG. 1 shows a cross-sectional view through a busbar assembly according to the invention according to a preferred exemplary embodiment; and FIG. 2 shows a detail of the busbar assembly according to FIG. 1.In principle, identical parts are provided with identical reference numerals in the figures.WAYS OF CARRYING OUT THE INVENTIONIn FIG. 1, a busbar assembly 100 is shown in a cross-sectional view. The busbar assembly 100 is preferably configured as a planar structure which can be handled substantially in the manner of a sandwich plate. A plate-like busbar assembly 100 usually has a length and a width which are each greater than the height visible in FIG. 1.The busbar assembly 100 comprises a first electrically conductive busbar 10 and a second electrically conductive busbar 20.A heat exchanger 30 is provided between the busbars 10, 20, which makes it possible to temperature-control the busbars 10, 20. The heat exchanger 30 can be used in particular for cooling the busbars 10, 20. However, it is also conceivable to heat the busbars 10, 20 by means of the heat exchanger 30, for example in order to assist the preheating of a vehicle battery before a rapid charging process.The busbars 10, 20 are electrically separated from one another. Thus, the first electrically conductive busbar 10 can be assigned, for example, to a positive pole of a voltage supply and the second electrically conductive busbar 20 can be assigned to a negative pole of a voltage supply or a ground. In order to ensure this electrical separation, insulating layers 11, 21 are provided in each case between the heat exchanger 30 and the busbars 10, 20. These will be explained in more detail below in connection with FIG. 2.As can also be seen in FIG. 1, different electrical or electronic components are connected to the second busbar 20. In the exemplary embodiment shown, a contactor 44 is provided, for example, which is mechanically and electrically connected to the second busbar 20 via a screw connection. For this purpose, the second busbar 20 has a corresponding receptacle in the form of a recess. Furthermore, the second busbar 20 is equipped with a receptacle for a fuse 45. The receptacle for the fuse 45 is likewise designed as a recess in the otherwise plate-like second busbar 20. The connection between the fuse 45 and the second busbar 20 is likewise effected by screws 50, which mechanically and electrically couple the fuse 45 to the second busbar 20.In the exemplary embodiment shown, the heat exchanger 30 is arranged only in a region in which both busbars 10, 20 are present. However, it is also possible for the heat exchanger 30 to extend into the fastening region of the electrical or electronic components, in particular of the contactor 44 and / or the fuse 45. Specifically, the heat exchanger 30 can also be connected to the electronic or electrical components in a heat-conducting manner. Heat can thus also be dissipated from these electrical and electronic components directly via the heat exchanger 30. The thermally conductive connection can be effected in that the electrical or electronic components are screwed directly to the heat exchanger 30 or are coupled to the heat exchanger 30 via a corresponding adapter part, in particular an insert. The screwing can also be effected directly with the screws 50. Additionally or alternatively, a heat-conducting paste can be used to produce a heat-conducting connection between the electrical or electronic components and the heat exchanger 30.In order to ensure that the first busbar 10 is electrically insulated from the electrical or electronic component, the first busbar 10 likewise has recesses which generously bypass the region of the receiving sections of the second busbars 20. The two busbars 10, 20 therefore have corresponding openings in their plate-like structure for receiving electrical and electronic components, in which openings the electrical and electronic components, for example the contactor 44 and the fuse 45, can be received on the one hand and these regions are recessed on the other hand in order to avoid electrical contacting between the first busbar 10 and the second busbar 20.In the busbar assembly 100 according to FIG. 1, the layer composite between the first busbar 10, the insulating layers 11, 21, the heat exchanger 30 and the second busbar 20 is preferably embedded between two electrically insulating carriers 41, 42. The electrically insulating carriers 41 are preferably designed as plastic carriers, wherein a first plastic carrier 41 is arranged on the first busbar 10 and also fills the gaps to the electrical or electronic components and to the second busbar 20. The second plastic carrier 42 is arranged on the second busbar 20 and likewise engages around the electrical and electronic components. In this way, the layer composite bounded by the busbars 10, 20, including the electrical and electronic components, is completely embedded between the plastic carriers 41, 42. This stabilizes the busbar assembly 100 and prevents the introduction of vibrations into the layer composite of the busbars 10, 20 and the electrical or electronic components.In order to protect the plastic carriers 41, 42 from mechanical action, covers 43 are preferably provided on both sides, which are each arranged on the plastic carriers 41, 42. These covers 43 can be connected to the plastic carriers 41, 42 over the entire surface and firmly.In general, it is preferred that the busbars 10, 20 are connected to the respective insulating layers 11, 21 over the full surface and firmly, for example by means of an adhesive bond. The insulating layers 11, 12 can also be connected to the heat exchanger 30 over the entire surface and firmly. The connection can be effected in a materially integral manner via an adhesive bond. Likewise, the plastic carriers 41, 42 can be firmly glued to the busbars 10, 20.In FIG. 2, the layer structure of the sandwich-like busbar assembly 100 is again shown in detail. The layer structure comprises the two plastic carriers 41, 42 which are each arranged on an outer side of the busbars 10, 20. The inert material carriers 41, 42 preferably bear directly on the busbars 10, 20.On a side of the busbars 10, 20 arranged opposite the respective plastic carrier 41, 42, the electrically insulating layers 11, 21 are respectively arranged. The electrically insulating layers 11, 21 are preferably formed as plastic foils. The thickness of the plastic foils for the insulating layers 11, 21 is selected such that good electrical insulation takes place on the one hand, but heat transfer is possible efficiently on the other hand. The plastic foils of the electrically insulating layers 11, 21 are preferably bonded both to the respectively assigned busbar 10, 20 and to the heat exchanger 30.The heat exchanger 30 is preferably formed from a material with good thermal conductivity, for example from aluminum sheet. For this purpose, preferably three aluminum sheets are connected to one another, wherein two covering layers 31, 32 are produced, between which a formed metal sheet 33 extends. The formed metal sheet 33 forms at least one fluid channel 35 due to the corresponding forming. The fluid channel 35 opens at an edge region of the heat exchanger 30 into a fluid inlet connection and a fluid outlet connection, respectively.The fluid channel 35 can extend in meandering fashion over the surface of the heat exchanger 30, in order to be able to dissipate the heat introduced into the heat exchanger 30 over the entire surface. For this purpose, a temperature control medium, preferably an I<hall medium, can flow through the fluid channel 35. The tempering medium can be gaseous or liquid.In the exemplary embodiment described here, the heat exchanger 30 is preferably produced by a so-called roll bonding method. For this purpose, the first covering layer 31, which preferably comprises an aluminum sheet, is connected to a second sheet by pressure joining. However, a separating agent is applied beforehand in regions which are intended to form the fluid channel 35 later, so that these regions of the I<on tact surfaces do not connect to one another during the pressure joining. After the pressure joining, the regions machined with the separating agent are then inflated or deep-drawn, so that the fluid channel 35 is formed. The first cover layer 31 remains flat, whereas the further sheet metal pressure-joined therewith is formed into the formed sheet metal 33, resulting in the fluid channel 35. The first cover layer 31 and the formed metal sheet 22 thus form a roll bond composite 34. such a roll bond composite 34 is simple and cost-effective to manufacture in mass production and thus reduces the production costs of the busbar assembly 100.The roll bond composite 34 is further connected to a carrier plate that forms the second cover layer 32. The carrier plate is preferably likewise designed as an aluminum sheet and can be connected in a materially integral manner to the raised points of the formed metal sheet 22, which form the fluid channel 35. The connection can be effected, for example, by welding or adhesive bonding.With the direct embedding of the heat exchanger 30 between the busbars 10, 20 which are electrically insulated from one another, a particularly efficient temperature control, in particular cooling, of the busbars 10, 20 is achieved. This makes it possible to dimension the busbars 10, 20 smaller, since due to the direct connection by means of the heat exchanger 30, a good heat dissipation is possible even with a small dimensioning of the surface of the busbars 10, 20. At the same time, the energy consumption for I<hing is reduced on account of the good connection between heat exchanger 30 and busbars 10, 20. The heat generated in the busbars 10, 20 can thus be dissipated very efficiently.By embedding the busbars 10, 20 including the heat exchanger 30 between two electrically insulating carriers 41, 42, the oscillations occurring in a vehicle can be well absorbed and thus an oscillation of the busbar assembly 100, in particular of the electrical and electronic components integrated therein, can be avoided. This increases the longevity of the busbar assembly 100.Reference numerals denote reference numerals100 Busbar assembly 10 First busbar 11 First electrically insulating layer 20 Second busbar 21 Second electrically insulating layer 30 Heat exchanger 31 First covering layer 32 Second covering layer 33 Formed metal sheet 34 Roll bond composite 35 Fluid channel 41 First carrier 42 Second carrier 43 Cover 44 Contactor 45 Fuse 50 Screw

Claims

Busbar assembly (100) having - a first electrically conductive busbar (10), - a second electrically conductive busbar (20) which is electrically separated from the first busbar (10), and - a heat exchanger (30) for tempering the busbars (10, 20), wherein the heat exchanger (30) is arranged between the first busbar (10) and the second busbar (20) and has at least one fluid channel (35) for a tempering medium to flow through, and wherein an electrically insulating layer (11, 21) is in each case provided between the busbars (10, 20) and the heat exchanger (30).Conductor rail assembly (100) according to Claim 1, characterized in that the heat exchanger (30) has a first covering layer (31) and a second covering layer (32), which are each directly connected to one of the electrically insulating layers (11, 21), wherein a formed metal sheet (33), which forms the fluid channel (35), extends between the covering layers (31, 32).Conductor rail assembly (100) according to Claim 2da characterized in that the first covering layer (31) forms a roll bond composite (34) with the formed metal sheet (22) and the second covering layer (32) forms a carrier plate which is connected, in particular in a materially bonded manner, to the roll bond composite (34).Conductor rail assembly (100) according to one of the preceding claims, characterized in that the electrically insulating layers (11, 21) are each formed by an insulation film.Conductor rail assembly (100) according to one of the preceding claims, characterized in that the conductor rails (10, 20), the electrically insulating layers (11, 21) and the heat exchanger (30) are connected to one another in a planar manner, in particular mechanically and / or materially bonded manner.Conductor rail assembly (100) according to one of the preceding claims, characterized in that the heat exchanger (30), in particular the carrier plate and the roll bond composite (34), comprises or consists of a metal, in particular an aluminium alloy.The busbar assembly (100) according to any one of the preceding claims, characterized in that the heat exchanger (30), the electrically insulating layers (11, 21) and the busbars (10, 20) together form a sandwich structure.Conductor rail assembly (100) according to one of the preceding claims, characterized in that the conductor rails (10, 20) comprise receiving sections for electrical and / or electronic components (45, 46), in particular protective elements.Conductor rail assembly (100) according to one of the preceding claims, characterized in that the conductor rails (10, 20) are each connected on a side facing away from the heat exchanger (30) to an electrically insulating carrier (41, 42), in particular a plastic carrier.Busbar assembly (100) according to Claim 9da, characterized in that the electrically insulating carriers (41, 42) are each covered on an outer side opposite the respective busbar (10, 20) with a cover (43) which in particular has a metallic material, preferably an aluminium alloy.Power distributor for a motor vehicle having a busbar assembly (100) according to one of the preceding claims.

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