DE102019214218A1 - Busbar arrangement for a power converter for an at least partially electrically powered vehicle - Google Patents

Abstract

A busbar arrangement for a power converter or for an at least partially electrically driven vehicle is proposed. At least one busbar is at least partially coated with a plastic. Now the at least one busbar is coated with two different plastics.

Description

The invention relates to a busbar arrangement for a converter for an at least partially electrically driven vehicle according to the preamble of the independent claim.

Out DE 10 2010 027 955 A1 For example, an inverter having an AC busbar assembly is known in which the spaces between the busbars are filled with an epoxy resin to encapsulate the power devices and provide electrical insulation and environmental protection.

The busbar arrangement according to the invention with the features of the independent claim has the advantage that the at least one busbar is coated with two different plastics. These two different plastics make it possible to influence the physical properties of the at least one busbar with this coating so that, for example, the heat generated in the busbar by the current flowing through is optimally dissipated and at the same time the stability of this at least one Busbar is optimally designed in terms of mechanical loads.

I. E. a busbar arrangement for a power converter for an at least partially electrically driven vehicle is proposed. At least one busbar is at least partially coated with a plastic. According to the invention, the at least one busbar is now coated with two different plastics.

A busbar arrangement for a power converter denotes the busbars or even just a single rail that leads or feeds the alternating current or a direct current from a converter, in particular an inverter. I. E. the alternating current that the inverter or converter generates from a supplied direct current is diverted via this busbar. However, it is also possible for the alternating current and direct current to be conducted in the opposite direction, for example during recuperation. This inverter is particularly important for at least partially electrically driven vehicles, such as pure electric vehicles or hybrid vehicles. The so-called mild hybrid, in which the combustion engine runs continuously, even when an electric motor is switched on, also plays a special role.

The busbar is a structure made of copper and / or aluminum or another metal, which is suitable for carrying high currents, as is usually the case with inverters. With such high currents, heat dissipation is crucial. According to the invention, this is optimized by the two different plastics. The busbars can also be designed extremely differently, as can be seen, for example, from the dependent claims.

Plastics are understood to mean different types of polymers that are optimized for the corresponding physical conditions.

Advantageous improvements and developments of the busbar arrangement specified in the independent claim are specified from the dependent claims.

It is proposed that the first of the two plastics are configured for a support function and electrical insulation and the second plastic for heat conduction, the second plastic being more elastic than the first plastic. In the present case, these physical properties can therefore be set by adding substances to these respective plastics. Since the first plastic is configured for a load-bearing function and electrical insulation, the mechanical load in particular is optimized here. With the second plastic, the heat conduction is in the foreground, so that appropriate substances are added to this second plastic. At the same time, it should also be more elastic than the first plastic. The first plastic can be designed as a thermoplastic material, while the second plastic can be designed as an elastomer. In particular, silicone elastomers with fillers, preferably ceramic fillers, can have good thermal conductivity and sufficient elasticity. It is also possible to use metallic fillers in the elastomer. In this case, however, the electrical insulation must be observed.

The thermoplastic material of the first plastic can be filled with glass fibers in order to improve the mechanical properties. This glass fiber content is around 30% of the total weight or volume. The electrically insulating function of the first plastic must also be taken into account with the glass fiber content.

In addition, it is provided that the first plastic is applied on the side of the at least one busbar facing away from a cooling structure and the second plastic on the side facing the cooling structure. The stability for the busbar is therefore realized by the first plastic on the side facing away, while the heat conduction in contact with the cooling structure is optimized. The cooling structure can be a heat sink, for example Fluid is flowed through. But other structures are also possible in the present case.

Furthermore, it is provided that the at least one busbar is pressed against the cooling structure by a force and / or a form fit. In order to optimize the heat conduction, a mechanically supported contact with the cooling structure is ensured by the second plastic and the busbar. This allows the heat generated by the current in the busbar to be optimally dissipated. Such a frictional connection can be achieved, for example, by a screw connection.

In addition, it is proposed that the first plastic is additionally also applied to the side of the at least one busbar facing the cooling structure. This also increases the mechanical stability on the side of the busbar facing the cooling structure.

Furthermore, it is provided that further components are coated with the first and / or the second plastic. Better heat dissipation and mechanical stability are thus also given to these further components.

These further components are at least a part of at least one current sensor and / or at least one seal and / or at least one positioning point and / or at least one connection point. In the present case, current sensors are necessary to determine the amount of alternating current that is emitted. This can lead to an error message or to readjustment of the inverter or converter. Seals are necessary, for example, to seal the heat sink against the other parts so that the fluid cannot penetrate. The inside of the inverter can also be protected from the outside world by such a seal. The positioning or connection point enables the converter arrangement to be assembled, so that this takes place as simply and precisely as possible in production.

It can be provided that the at least part of the at least one current sensor has at least one ferrite core. This ferrite core enables the current to be measured via a magnetic effect.

It is also proposed that the busbar arrangement has 1, 2, 3 or 6 busbars. This number of busbars has proven to be practical for the design of inverters or power converters.

Furthermore, it is provided that several busbars are arranged side by side or flat and / or one above the other. In the case of the formation as standing next to one another, it is to be understood that these busbars can also be arranged overlapping at different heights.

It is also provided that the second plastic is applied with a layer thickness of less than one millimeter in order to be optimally designed for its function of heat conduction.

Embodiments of the invention are explained in more detail in the following description and are shown in the drawing.

• 1 eine erste Ansicht der erfindungsgemäßen Stromschienenanordnung;
• 2 einen Schnitt durch die Stromschienenanordnung und den Wechselrichter;
• 3 eine zweite Schnittdarstellung;
• 4 eine weitere Ansicht der Stromschienenanordnung;
• 5 eine weitere Schnittdarstellung der erfindungsgemäßen Stromschienenanordnung und
• 6 eine weitere Ansicht der Stromschienenanordnung.

Show it

• 1 a first view of the busbar arrangement according to the invention;
• 2 a section through the busbar arrangement and the inverter;
• 3 a second sectional view;
• 4th another view of the busbar assembly;
• 5 a further sectional view of the busbar arrangement according to the invention and
• 6th another view of the busbar assembly.

1 shows the busbar arrangement according to the invention in a first view. 3 power rails B1 , B2 and B3 are presently arranged standing next to one another, in particular it is clear that they are arranged at different heights and then lead out to a connection structure. An IMS circuit board, on which the alternating current is converted from the direct current, is preferably connected to this busbar arrangement. In general, the busbar arrangement is connected to a power module, which can consist of several substrates or just one printed circuit board. In 1 is also shown how connection points AP are provided in order to screw the busbar arrangement onto the housing, for example. These are distributed over this busbar arrangement. Furthermore, the plastic encapsulation K Shown on the busbar arrangement, which produces at least the mechanical stability and the electrical insulation to each other.

2 shows a sectional view through the inverter according to the invention. Busbar arrangement B is shown here schematically with its 3 busbars. There is a first plastic encapsulation K1 shown for the production of mechanical stability and electrical insulation, but also a plastic encapsulation K2 that conduct heat to the housing G optimized. Furthermore this is second plastic K2 more elastic than the first plastic K1 executed. With KK is called a heat sink.

In 3 a further sectional view of the busbar arrangement according to the invention is shown. Again, the same reference symbols denote the same elements. Here is compared to the arrangement in 2 the plastic layer K2 also intended for isolation. Therefore, the rails also protrude into this plastic.

On the case G the cooling structure can furthermore also be arranged, for example by a cooling body, which dissipates the heat from the housing.

4th shows a further representation of the busbar arrangement according to the invention. There are now also sheet metal stacks at the connections for the power rail BP for current sensors with the plastic K1 encased. This also fixes these components mechanically. Also a seal D. In the present case, this plastic can be coated at the exit of the busbar arrangement. This is a seal, for example around the housing G of the inverter from the outside world. The busbar arrangement is usually used to provide power, for example for an electric motor that is located outside the housing.

5 shows a further sectional view. Again, the same reference symbols denote the same elements. Here, in addition to the plastics K1 and K2 that coat the busbar arrangement B, now also laminated cores BP and magnets M. coated with this plastic for stability.

6th Figure 10 shows another view of the bus bar assembly. The three power rails B1-B3 have their connections at the same height. Then the rail leads all the way down in the arrangement for all three busbars. The conductor rail B3 then leads to a further connection on this lower level B4 which is connected to the electric motor, for example. From the lower level of the conductor rail B2 the rail becomes the connection B5 over the rail B3 raised and runs over this and then kinks to the connection B5 from. The conductor rail B1 is also raised from the lower level via the power rail B2 and runs over this to connection B6. The busbars are thus arranged flat on top of one another.

List of reference symbols

B1 - 3

Busbars

B4-5

Connections of the busbars

K, K1, K2

plastic

AP

Connection points

G

casing

M.

magnet

BP

Laminated core

D.

poetry

KK

Heat sink

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102010027955 A1 [0002]

Claims (11)

Conductor rail arrangement for a converter for an at least partially electrically driven vehicle, at least one conductor rail (B) being at least partially coated with a plastic (K), characterized in that the at least one conductor rail (B) is coated with two different plastics (K1, K2) is coated. Busbar arrangement according to Claim 1 , characterized in that the first of the two plastics for a support function and electrical insulation and the second plastic (K2) are configured for heat conduction, the second plastic (K2) being more elastic than the first plastic (K1). Busbar arrangement according to Claim 1 or 2 , characterized in that the first plastic is applied to the side of the at least one busbar (B) facing away from a cooling structure and the second plastic (K2) is applied to the side facing the cooling structure. Busbar arrangement according to Claim 3 , characterized in that the at least one busbar (B) is pressed against the cooling structure by a force and / or a form fit. Busbar arrangement according to Claim 3 or 4th , characterized in that the first plastic (K1) is additionally also applied to the side of the at least one busbar facing the cooling structure. Busbar arrangement according to one of the preceding claims, characterized in that further components are coated with the first and / or the second plastic (K1, K2). Busbar arrangement according to Claim 6 , characterized in that the further components are at least a part of at least one current sensor and / or at least one seal and / or a positioning point and / or at least one connection point (AP). Busbar arrangement according to Claim 7 , characterized in that the at least one part of the at least one current measuring sensor is at least one ferrite core. Busbar arrangement according to one of the preceding claims, characterized in that the at least one busbar arrangement has 1, 2, 3 or 6 busbars. Busbar arrangement according to one of the preceding claims, characterized in that several busbars (B1, B2, B3) are arranged side by side or flat and / or one above the other. Busbar arrangement according to one of the preceding claims, characterized in that the second plastic is applied with a layer thickness of less than 1 millimeter.

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