DE102020204500A1 - Intermediate circuit capacitor for a power electronics arrangement and a power electronics arrangement - Google Patents

Abstract

The present invention relates to an intermediate circuit capacitor (10) for power electronics, with: an input contact (16) for connecting the intermediate circuit capacitor to a supply device and a module contact (18) for connecting the intermediate circuit capacitor to a power module; a housing part (12) for receiving at least one capacitor module (40); a cooler part (14) for dissipating waste heat from the at least one capacitor module, the cooler part being designed to close off the housing part and having at least one opening (20) for introducing a potting material in order to fill the housing part with the potting material in a vacuum potting process and to attach to the cooler part. The present invention also relates to a power electronics arrangement and a method for producing an intermediate circuit capacitor (10).

Description

The present invention relates to an intermediate circuit capacitor for a power electronics arrangement. The present invention also relates to a power electronics arrangement and a method for producing an intermediate circuit capacitor.

Power electronics enable the conversion of electrical energy in relation to the voltage form, the level of voltage and current as well as the frequency. In this function there are different applications in the automotive environment. In terms of installation space, packaging and manufacturing costs, the power electronics in a vehicle are heavily dependent on the design of the intermediate circuit capacitor, since this usually represents the largest independent component. An intermediate circuit capacitor usually has a housing for accommodating at least one capacitor module and a cooler for dissipating waste heat. The housing is usually filled with potting material in a potting process and then connected to the cooler. Electric vehicles in particular require the power electronics and the intermediate circuit capacitor to be designed for comparatively high outputs.

In this context, the WO 2018/233987 A1 an intermediate circuit capacitor disclosed. The intermediate circuit capacitor comprises several wound capacitors which have a first connection pole and a second connection pole. The intermediate circuit capacitor furthermore comprises a first current tapping element via which the first connection poles are contacted, and a second current tapping element via which the second connection poles are contacted. First wound capacitors are arranged in a first row and aligned such that the first connection poles are arranged on a first side and the second connection poles are arranged on a second side of the intermediate circuit capacitor. Second wound capacitors are arranged in a second row, the first row and the second row being arranged parallel to one another in a common plane.

One of the challenges in the automotive environment is ensuring that the required components are manufactured efficiently. The relevant requirements in terms of robustness and resilience should be met at the lowest possible cost.

Based on this, the present invention has the task of providing an intermediate circuit capacitor for power electronics that can be efficiently manufactured and yet meets the requirements for robustness and service life in the automotive environment. In particular, a robust intermediate circuit capacitor that can be manufactured inexpensively is to be created.

• einer Eingangskontaktierung zum Anbinden des Zwischenkreiskondensators an eine Versorgungseinrichtung und einer Modulkontaktierung zum Anbinden des Zwischenkreiskondensators an ein Leistungsmodul;
• einem Gehäuseteil zum Aufnehmen mindestens eines Kondensatormoduls;
• einem Kühlerteil zum Abführen von Abwärme des mindestens einen Kondensatormoduls, wobei
• das Kühlerteil zum Abschließen des Gehäuseteils ausgebildet ist und mindestens eine Öffnung zum Einbringen eines Vergussmaterials aufweist, um das Gehäuseteil in einem Vakuum-Vergussprozess mit dem Vergussmaterial zu verfüllen und an dem Kühlerteil zu befestigen.

To achieve this object, the present invention relates in a first aspect to an intermediate circuit capacitor for power electronics, with:

• an input contact for connecting the intermediate circuit capacitor to a supply device and a module contact for connecting the intermediate circuit capacitor to a power module;
• a housing part for receiving at least one capacitor module;
• a cooler part for dissipating waste heat from the at least one capacitor module, wherein
• the cooler part is designed to close off the housing part and has at least one opening for introducing a potting material in order to fill the housing part with the potting material in a vacuum potting process and to fasten it to the cooler part.

• einem Leistungsmodul;
• einer Versorgungseinrichtung zum Bereitstellen einer Gleichspannung; und
• einem Zwischenkreiskondensator wie zuvor beschrieben, der an das Leistungsmodul und an die Versorgungseinrichtung angebunden ist.

In a further aspect, the present invention relates to a power electronics arrangement with:

• a power module;
• a supply device for providing a DC voltage; and
• an intermediate circuit capacitor as described above, which is connected to the power module and to the supply device.

• Bereitstellen einer Eingangskontaktierung zum Anbinden des Zwischenkreiskondensators an eine Versorgungseinrichtung und einer Modulkontaktierung zum Anbinden des Zwischenkreiskondensators an ein Leistungsmodul;
• Bereitstellen eines Gehäuseteils zum Aufnehmen mindestens eines Kondensatormoduls;
• Bereitstellen eines Kühlerteils zum Abführen von Abwärme des mindestens einen Kondensatormoduls;
• Abschließen des Gehäuseteils mit dem Kühlerteil; und
• Einbringen eines Vergussmaterials durch mindestens eine Öffnung in dem Kühlerteil, um das Gehäuseteil in einem Vakuum-Vergussprozess mit dem Vergussmaterial zu verfüllen und an dem Kühlerteil zu befestigen.

In a further aspect, the invention relates to a method for producing an intermediate circuit capacitor, with the steps:

• Providing an input contact for connecting the intermediate circuit capacitor to a supply device and a module contact for connecting the intermediate circuit capacitor to a power module;
• Providing a housing part for receiving at least one capacitor module;
• Providing a cooler part for dissipating waste heat from the at least one capacitor module;
• Closing off the housing part with the cooler part; and
• Introducing a potting material through at least one opening in the cooler part in order to fill the housing part with the potting material in a vacuum potting process and to attach it to the cooler part.

Preferred embodiments of the invention are described in the dependent claims. It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination, but also in other combinations or on their own, without departing from the scope of the present invention. In particular, the power electronics arrangement and the method can be implemented in accordance with the configurations described for the intermediate circuit capacitor in the dependent claims.

In the intermediate circuit capacitor according to the invention, an opening is provided in the cooler part through which a potting material can be introduced. In this way, the housing part can be filled with potting material in a vacuum potting process and at the same time attached to the cooler part. Various materials can be used as the potting compound, in particular those that have good heat conduction. The housing part is filled in a common process and connected to the cooler part. The capacitor modules (capacitor windings) are arranged in the housing part. The intermediate circuit capacitor can in particular be used in a power electronics arrangement that is used in a vehicle, in particular in an electric vehicle.

Compared to conventional approaches, in which the cooler part is only connected to the housing part after it has been cast, for example by means of a screw connection, there are various advantages. It is no longer necessary for the casting compound in the housing part to be absolutely flat in order to ensure a good thermal connection. The potting compensates for tolerances of the individual components, so that savings can be made in the preceding manufacturing steps. In addition, lower compression forces are required in production. In addition, vibrations can be better compensated for during operation, thus ensuring a long service life. The assembly process is simplified and can be implemented more cost-effectively. Finally, the installation space can be reduced and a higher cooling performance can be achieved.

In a preferred embodiment, the housing part comprises an integrated input connector section for connecting an input connector. The input contact is passed through the input connector section. To connect the intermediate circuit capacitor to the supply device, for example a battery, an input plug can be used that is connected directly to the housing part. The housing part includes a section that allows the connection of a plug. An integrated input plug section is understood to mean a design of the input plug section as part of the housing part itself. The integrated input connector section enables, in particular, a short path or a direct connection between the supply device and the intermediate circuit capacitor to be implemented. No complex contacting solution is necessary, in particular because the joint potting of the housing part and cooler part does not result in any air or creepage distances within the intermediate circuit capacitor. In addition, the integrated input plug section can also achieve a cooling effect in this area by the cooler part. In addition, there are cost advantages in production.

In a preferred embodiment, the input plug section has an outer protrusion with an oval cross section in order to accommodate an input plug with a corresponding cross section. In particular, the input plug can have an oval cross section through which the contacts (positive pole and negative pole) of the input contacts are routed. The use of an oval plug enables simple contacting in the correct orientation. By using a protrusion that interacts with a corresponding receptacle on the input plug, a simple and secure plug connection can be implemented.

In a preferred embodiment, the input plug section comprises a latching element for latching with a counter-latching element on the input plug in order to mechanically fix the input plug. The input plug can be fastened, in particular fastened reversibly, by the latching element. A long service life and protection against slipping can be achieved. The result is a robust intermediate circuit capacitor.

In a preferred embodiment, the cooler part and / or the housing part is designed as an injection molded part made of plastic, preferably made of thermally conductive plastic. An injection-molded part can be manufactured cost-effectively, so that an efficiently manufacturable intermediate circuit capacitor is realized. By using thermally conductive plastic, efficient heat dissipation can take place via the cooler part and / or via the housing part.

In a preferred embodiment, the cooler part is designed as a cooler cover part which interacts with a cooler lower part, which is preferably made of metal, in particular aluminum, to dissipate the waste heat of the at least one capacitor module. The cooler part represents a part of a two-part cooler. The second part, that is to say the cooler cover, is advantageously made of metal, in particular aluminum, in order to achieve further improved heat dissipation. A two-part design of the cooler can ensure that it can be manufactured efficiently. In particular, it is possible to manufacture the two parts of the radiator (radiator cap part and radiator lower part) in one injection molding process or in one casting process. A cost-efficient production is achieved.

In a preferred embodiment, the cooler part has an inlet and an outlet in order to conduct a cooling liquid through a reservoir area of the cooler part in order to dissipate the waste heat from the at least one condenser module. The inlet is used to receive the coolant. This is led out again via the outlet after penetrating the reservoir area. To this extent, the reservoir area corresponds to a guide for the cooling liquid. In particular, water can be used as the cooling liquid. The cooling effect is achieved in particular in the reservoir area or in the areas of the intermediate circuit capacitor adjoining it.

In a preferred embodiment, the housing part has openings and the inlet and the outlet are designed as protrusions which engage in the openings of the housing part in order to guide the cooling liquid through the housing part to the reservoir area of the cooler part. The protrusions are preferably cylindrical. Because the inlet and the outlet are passed through the housing part, a simple connection to a corresponding cooling liquid system can take place. The connection is on the same side of the intermediate circuit capacitor as the input contact. There is an efficient connectivity. The other side of the intermediate circuit capacitor corresponds to the side of the contacting of the power modules, which is often difficult to access with cooling liquid.

In a preferred embodiment, the reservoir area comprises a recess in the cooler part which is open on one side and which is designed to be closed off by a lower part of the cooler. In particular, it is possible that the reservoir area is open on one side and is closed by a corresponding lower part of the cooler. The lower part of the cooler can contain the channels or corresponding counterparts to channels in the cooler part in order to guide the cooling liquid into areas with high heat development. This results in efficient cooling and efficient producibility.

In a preferred embodiment, the intermediate circuit capacitor comprises a temperature sensor, in particular four temperature sensors. The housing part includes a connection for the temperature sensor. The temperature can be monitored by using one or more temperature sensors. Appropriate control of the coolant supply can be implemented. The result is a longer service life and a higher level of resistance, especially at high power levels.

In a preferred embodiment, the cooler part comprises a module opening. The module contact is routed through the module opening. The module opening is in particular a recess in the cooler part. The power modules are connected through the module opening. There is a direct connection option with short distances. On the one hand, efficient cooling can be achieved. On the other hand, a simple and direct contact can be implemented.

In a preferred embodiment, the housing part comprises a module plug section for connecting a module plug. The module contact is routed through the module connector section. In this respect, the housing can also have a corresponding integrated module connector section for connecting the module connector, which is part of the housing part. This ensures efficient connectivity and flexible use. In addition, a direct connection with short distances can be implemented.

The manufacturing method according to the invention can in particular be carried out in a corresponding manufacturing plant. A cost reduction in the production of an intermediate circuit capacitor is implemented.

In this context, a connection is understood to mean, in particular, electrical contacting. The supply device supplies the intermediate circuit capacitor in particular with a direct voltage. The supply device can in particular be a battery. A capacitor module corresponds in particular to a wound capacitor. In particular, heat from the capacitor module, but also heat from the other components, is dissipated via the cooler part. An opening is understood to mean, in particular, a hole or a continuous recess in a part. An integrated section is understood to mean, in particular, a section which, as part of a larger unit, fulfills a specific function. The section is usually manufactured in the same manufacturing process as the larger unit.

• 1a, 1b eine schematische perspektivische Darstellung eines Zwischenkreiskondensators;
• 2a, 2b eine schematische perspektivische Darstellung des Gehäuseteils;
• 3 eine schematische perspektivische Darstellung des Gehäuseteils mit darin aufgenommenen Komponenten;
• 4 eine schematische perspektivische Schnittdarstellung des Zwischenkreiskondensators und der Kondensatormodule in dem Gehäuseteil; und
• 5 eine technische Zeichnung einer Ausführungsform des Zwischenkreiskondensators.

The invention is described and explained in more detail below with the aid of a few selected exemplary embodiments in connection with the accompanying drawings. Show it:

• 1a , 1b a schematic perspective illustration of an intermediate circuit capacitor;
• 2a , 2 B a schematic perspective view of the housing part;
• 3 a schematic perspective illustration of the housing part with components received therein;
• 4th a schematic perspective sectional illustration of the intermediate circuit capacitor and the capacitor modules in the housing part; and
• 5 a technical drawing of an embodiment of the intermediate circuit capacitor.

In the 1a and 1b is an embodiment of an intermediate circuit capacitor according to the invention 10 for power electronics shown schematically in perspective. The intermediate circuit capacitor 10 comprises a housing part 12th as well as a cooler part 14th . It is in the 1a a view shown in the housing part 12th and cooler part 14th are not connected, and in the 1b a view shown in the housing part 12th and cooler part 14th are connected so that the intermediate circuit capacitor 10 can be used. Both the housing part 12th as well as the cooler part 14th can in particular be designed as injection molded parts. But it is also possible that the cooler part 14th is designed as a metal part, in particular as an aluminum part. By using a metal part, improved heat dissipation can optionally be achieved.

The intermediate circuit capacitor 10 is suitable for use in power electronics, particularly in the automotive sector. Via an input contact 16 is the intermediate circuit capacitor 10 connected to a supply facility (not shown). The supply device can in particular be a battery or another DC voltage source. For electrical contacting of the input contacts 16 with the supply device includes the input contact 16 in this respect usually at least two electrical connections. Via a module contact 18th is the intermediate circuit capacitor 10 connected to a power module (not shown). The power module can in particular be a rectifier, an inverter or also another unit. In the representation in the 1a and 1b the module contact is located in the rear area of the intermediate circuit capacitor 10 and is not visible.

It is intended that the radiator part 14th to close the housing part 12th is trained. A vacuum potting process is used for this, in which a potting material is introduced. First of all, the radiator part 14th and the housing part 12th joined together. The housing part 12th is so far with the cooler part 14th locked or locked. Then a potting material is put through an opening 20th in the cooler part 14th brought in. In the illustrated embodiment, there are four openings 20th provided, through which the potting material in different areas of the housing part 12th can be introduced. In the casting process, all functional parts (in particular several capacitor modules) are inside the housing part 12th shed. In addition, the potting process creates a fastening between the housing part 12th and cooler part 14th achieved.

In comparison to previous approaches, in which the housing part and the components received therein were initially potted and then joined together with the cooler part, the inventive introduction of the potting material in order to fill the housing with the potting material in a vacuum potting process and to attach to the cooler part, the advantage of better thermal contact. The heat from the intermediate circuit capacitor can be dissipated more efficiently. In addition, a stable connection is realized. Furthermore, there is potential for cost savings, since a simplified manufacturing process can be implemented.

Furthermore, in the 1a and 1b shown that the radiator part 14th an inlet 22nd as well as an outlet 24 which are designed to pass cooling liquid through the radiator part 14th pass through.

In the 2a and 2 B is schematically the housing part 12th shown in perspective view. Inside the housing part 12th different capacitor modules are added, which correspond in particular to individual wound capacitors. As shown, the housing part comprises 12th an integrated input connector section 26th , which allows an input connector (not shown) to be connected. Via the input connector section 26th the input contact can be made to connect the intermediate circuit capacitor to the supply device. The input connector section 26th is as part of the housing part 12th formed or executed integrated with this. In particular, the input connector section 26th together with the housing part 12th manufactured. For example, this can be done in an injection molding process.

In the illustrated embodiment, the input connector section 26th an outer protrusion 28 with an oval cross-section. The outer supernatant 28 can engage in a correspondingly designed recess of an input connector. The input connector section 26th furthermore comprises two connector parts in the illustrated embodiment 30th through which the module contact can be routed.

In addition, there is a latching element in the illustrated embodiment 32 provided, by means of which locking can be effected with a corresponding counter-locking element on the input plug. A mechanical attachment of the input plug to the input plug section 26th can be reached. This is particularly advantageous since use in the automotive environment places high demands on vibration safety and reliability.

Furthermore, in the 2a and 2 B shown that the housing part 12th two openings 34 through which the inlet and outlet on the cooler part (cf. 1a and 1b) can be passed through. The cooling liquid can consequently through the housing part 12th be passed through. This has the effect that the cooling liquid can be introduced into the intermediate circuit capacitor from the side that is also the input contact or the input connector section 26th includes.

In the 3 is a schematic perspective view of the housing part 12th shown. Inside the housing part 12th in particular, several capacitor modules (in the 3 not visible). These capacitor modules are on a power rail 36 contacted. The actual connection of the intermediate circuit capacitor 10 to the power module via the module contact 18th takes place via a module connector section 38 .

In the 4th is a sectional view of the intermediate circuit capacitor 10 shown. In particular, it can be seen that the capacitor modules 40 in an outer area of the intermediate circuit capacitor within the housing part 12th are arranged. The power rail 36 is pushed through the housing in the direction of the module connector section (in the 4th not shown) out. The cooler part 14th has a module opening 42 up through which the power rail 36 or the module contact 18th to be led.

The intermediate circuit capacitor also includes 10 In the illustrated embodiment, at least one temperature sensor (in 4th not recognizable), by which a temperature inside the housing part 12th can be measured. In particular, a temperature of the capacitor modules 40 be measured. Referring to the 3 includes the housing part 12th a connection 44 for this temperature sensor. In particular, it is possible for several temperature sensors to record a temperature at several points within the housing part 12th determine.

the 5 shows a schematically represented technical drawing of the intermediate circuit capacitor 10 . In particular, on the left is a view from above showing the housing part 12th is recognizable, shown and on the right side a view from below, on which the cooler part 14th is recognizable, shown. The cooler part 14th has a reservoir area 46 or several reservoir areas. Into the reservoir areas is through the inlet 22nd Cooling liquid (especially water) introduced. This coolant is then passed through the reservoir areas and via the outlet 24 diverted again.

As shown is the cooler part 14th In the embodiment shown, designed as a radiator cover part. The reservoir areas are open on one side perpendicular to the image plane. The reservoir areas are recesses in the cooler part that are open on one side 14th . The radiator cap part interacts with a radiator lower part (not shown) to dissipate the waste heat. The cooler part 14th in its function as a radiator cap part, closes a radiator lower part, so to speak. Corresponding channels for the cooling liquid are provided in the lower part of the cooler, through which the reservoir areas in the cooler part 14th are connected to each other. In this exemplary embodiment, the cooler part only represents a part of the cooler. The cooler is designed in two parts. The four openings 20th of the cooler part 14th are arranged symmetrically.

Regardless of the other specific properties of the intermediate circuit capacitor shown, it is often advantageous to use a two-part cooler. Such a two-part cooler can be manufactured much more easily, in particular in an injection molding process. In addition, different materials can be used for the two parts of the cooler. This results in advantageous properties with regard to heat dissipation and with regard to the assembly effort or the production of the intermediate circuit capacitor. This also makes it possible to use an injection-molded part for the cooler part or the cooler cover part and to use a metal part for the lower part of the cooler.

The invention has been described comprehensively with reference to the drawings and the description and explained. The description and explanation are to be understood as an example and not restrictive. The invention is not limited to the disclosed embodiments. Other embodiments or variations will become apparent to those skilled in the art upon using the present invention and upon careful analysis of the drawings, the disclosure, and the following claims.

In the claims, the words “comprising” and “having” do not exclude the presence of further elements or steps. The undefined article “a” or “an” does not exclude the presence of a plural. A single element or a single unit can perform the functions of several of the units mentioned in the patent claims. An element, a unit, an interface, a device and a system can be implemented partially or completely in hardware and / or in software. The mere mention of some measures in several different dependent patent claims should not be understood to mean that a combination of these measures cannot also be used advantageously.

List of reference symbols

10

DC link capacitor

12th

Housing part

14th

Radiator section

16

Input contacting

18th

Module contacting

20th

Opening in the cooler part

22nd

inlet

24

Outlet

26th

Input connector section

28

Got over

30th

Connector parts

32

Snap-in element

34

Opening in the housing part

36

Busbar

38

Module connector section

40

Capacitor module

42

Module opening

44

Connection for temperature sensor

46

Reservoir area

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

• WO 2018/233987 A1 [0003]

Claims (14)

Intermediate circuit capacitor (10) for power electronics, with: an input contact (16) for connecting the intermediate circuit capacitor to a supply device and a module contact (18) for connecting the intermediate circuit capacitor to a power module; a housing part (12) for receiving at least one capacitor module (40); a cooler part (14) for dissipating waste heat from the at least one capacitor module, wherein the cooler part is designed to close off the housing part and has at least one opening (20) for introducing a potting material in order to fill the housing part with the potting material in a vacuum potting process and to fasten it to the cooler part. Intermediate circuit capacitor (10) Claim 1 wherein the housing part (12) comprises an integrated input connector section (26) for connecting an input connector; and the input contact (16) is passed through the input connector section. Intermediate circuit capacitor (10) Claim 2 wherein the input plug section (26) has an outer protrusion (28) with an oval cross-section in order to receive an input plug with a corresponding cross-section. Intermediate circuit capacitor (10) according to one of the Claims 2 and 3 wherein the input plug section (26) comprises a latching element (32) for locking with a counter-latching element on the input plug in order to effect a mechanical fixing of the input plug. Intermediate circuit capacitor (10) according to one of the preceding claims, wherein the cooler part (14) and / or the housing part (12) is designed as an injection molded part made of plastic, preferably made of thermally conductive plastic. Intermediate circuit capacitor (10) according to one of the preceding claims, wherein the cooler part (14) is designed as a cooler cover part which cooperates with a cooler lower part, preferably made of metal, in particular aluminum, to dissipate the waste heat of the at least one capacitor module (40). Intermediate circuit capacitor (10) according to one of the preceding claims, wherein the cooler part (14) has an inlet (22) and an outlet (24) in order to dissipate the waste heat of the at least one capacitor module (40) a cooling liquid through a reservoir area (46) of the Pass through the cooler part. Intermediate circuit capacitor (10) Claim 7 , wherein the housing part (12) has openings (34) and the inlet (22) and the outlet (24) are designed as protrusions which engage in the openings of the housing part in order to convey the cooling liquid through the housing part to the reservoir area (46) to direct the cooler part (14); and the protrusions are preferably cylindrical. Intermediate circuit capacitor (10) according to one of the Claims 7 and 8th wherein the reservoir area (46) comprises a depression in the cooler part (14) which is open on one side and which is designed to be closed off by a cooler lower part. Intermediate circuit capacitor (10) according to one of the preceding claims, with a temperature sensor, in particular four temperature sensors, the housing part (12) comprising a connection for the temperature sensor. Intermediate circuit capacitor (10) according to one of the preceding claims, wherein the cooler part (14) comprises a module opening (42); and the module contact (18) is passed through the module opening. Intermediate circuit capacitor (10) according to one of the preceding claims, wherein the housing part (12) comprises a modular plug section (38) for connecting a modular plug; and the module contact (18) is passed through the module plug section. Power electronics arrangement with: a power module; a supply device for providing a DC voltage; and an intermediate circuit capacitor (10) according to one of the preceding claims, which is connected to the power module and to the supply device. A method for producing an intermediate circuit capacitor (10), comprising the steps of: providing an input contact (16) for connecting the intermediate circuit capacitor to a supply device and a module contact (18) for connecting the intermediate circuit capacitor to a power module; Providing a housing part (12) for receiving at least one capacitor module (40); Providing a cooler part (14) for dissipating waste heat from the at least one capacitor module; Closing off the housing part with the cooler part; and introducing a potting material through at least one opening (20) in the cooler part in order to fill the housing part with the potting material in a vacuum potting process and to fasten it to the cooler part.

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