ELECTRICAL CIRCUIT DEVICE AND MOTOR VEHICLE

Abstract

Electrical circuit device comprising a power electronics circuit with at least one power electronics module, a filter device, a heat sink, a connector and at least one busbar, wherein the filter device is at least partially coupled to the busbar and the busbar electrically connects the connector to the power electronics circuit, wherein the power electronics module and at least a portion of the busbar are thermally connected to the heat sink.

Claims

1. An electrical circuit device, comprising: a power electronics circuit with at least one power electronics module, a filter device, a heat sink, a connector, and at least one busbar, wherein the filter device is at least partially coupled to the busbar and the busbar electrically connects the connector to the power electronics circuit, wherein the power electronics module and at least a portion of the busbar are thermally connected to the heat sink.

2. The electrical circuit device according to claim 1, wherein the filter device has at least one capacitor connected to the busbar and/or at least one inductance element coupled to the busbar.

3. The electrical circuit device according to claim 2, wherein the at least one inductance element is a ferrite core.

4. The electrical circuit device according to claim 2, wherein the filter device comprises at least one common mode choke, at least one common mode capacitor and/or at least one differential mode capacitor.

5. The electrical circuit device according to claim 1, wherein the filter device comprises an inductance element arranged at the connector and/or surrounding the connector.

6. The electrical circuit device according to claim 1, wherein the busbar is thermally bonded to the heat sink over at least 50% of its length.

7. The electrical circuit device according to claim 1, wherein the connector is connected to the power electronics circuit by two busbars, the busbars being arranged next to one another or one above the other on the heat sink.

8. The electrical circuit device according to claim 1, wherein the power electronics circuit comprises a direct current link capacitor, wherein the busbars are connected to the direct current link capacitor.

9. The electrical circuit device according to claim 1, wherein the heat sink has one or more cooling channels extending inside the heat sink.

10. The electrical circuit device according to claim 1, wherein the power electronics circuit is configured as an inverter.

11. The electrical circuit device according to claim 1, wherein the power electronics circuit is configured as a multiphase pulse inverter.

12. A motor vehicle comprising an electrical circuit device according to claim 1.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0034] Further advantages and details will be apparent from the embodiments described below and from the drawings.

[0035] FIG. 1 shows an embodiment of a motor vehicle.

[0036] FIG. 2 shows a circuit diagram of an embodiment of an electrical circuit device.

[0037] FIG. 3 shows a perspective view of an embodiment of an electrical circuit device.

DETAILED DESCRIPTION

[0038] FIG. 1 shows an embodiment of a motor vehicle 1. The motor vehicle 1 comprises an on-board power supply system 2 with an electric circuit device 3, which is connected between an electric machine 4 and an energy storage device 5 of the motor vehicle 1. The electric machine 4 thereby forms a traction electric motor of the motor vehicle 1.

[0039] The electrical circuit device 3 is configured as an inverter, such that a direct current taken from the energy storage device 5 can be converted into an alternating current, in particular, a multiphase alternating current, to supply current to the electrical machine 4. Conversely, it is also possible that a rectification of an alternating current generated in a generator mode of the electrical machine 4 can be carried out by the electrical circuit device 3, for example, in a recuperation mode of the motor vehicle 1 for charging the energy storage device 5. The energy storage device 5 can, for example, be configured as a traction battery of the motor vehicle 1. Alternatively, the energy storage device 5 may be configured as a fuel cell or as a rectifier connected or connectable to an alternating current network.

[0040] The electrical circuit device 3 may, for example, be configured as a three-phase pulse inverter, the operation of which may cause electrical interference. The electrical circuit device 3 therefore comprises a filter device 6 with which interference occurring on the direct current side of the electrical circuit device 3 during operation of the electrical circuit device 3 can be filtered. The filter device 6 therefore contributes to reduce the alternating current load in the direct current sub-network of the on-board power supply 2.

[0041] FIG. 2 shows a circuit diagram of an embodiment of the electrical circuit device 3. The circuit device 3 comprises the filter device 6, a power electronics circuit 14 comprising three power electronics modules 7, 8, 9, as well as two busbars 10, 11. The power electronics modules 7, 8, 9 of the power electronics circuit 14 each comprise two switching elements S.sub.1-S.sub.6, which are connected within a power electronics module 7, 8, 9 in the form of a half bridge. The switching elements S.sub.1-S.sub.6 are configured, for example, as transistors. A freewheeling diode D.sub.1-D.sub.6 is connected in parallel to each of the switching elements S.sub.1-S.sub.6 to also enable rectification of an alternating current in a freewheeling mode of the electric machine 4 connected to the bridge points of the half bridges.

[0042] The connectors marked HV+ and HV− on the direct current side of the electrical circuit device 3 are connected to a connector 13 (not shown here) of the electrical circuit device 3. The electrical circuit device 3 is connected to the energy storage device 5 by means of the connector 13. The electrical circuit device 3 can, for example, be connected to the energy storage device 5 by means of one or a plurality of further busbars and/or by means of one or a plurality of cables. The filter device 6 comprises a plurality of components which are configured as condensers or alternatively as inductance elements and which form different filter stages of the filter device 6.

[0043] To suppress common mode interference, the filter device 6 comprises a common mode choke L.sub.cm, which is arranged around the busbars 10, 11. The common mode choke L.sub.cm can, for example, be formed as a ferrite core which encompasses the busbars 10, 11.

[0044] A common mode capacitor C.sub.x, which is connected between the busbars 10, 11, is further provided for filtering common mode interference. The common mode capacitor C.sub.x is used, in particular, for filtering high-frequency common mode interference, since low-frequency common mode interference can be filtered, in particular, by means of a direct current link capacitor C.sub.zk of the power electronics circuit 3. Furthermore, the filter device 6 comprises two capacitors C.sub.y for filtering differential mode interference. The capacitors C.sub.y are each connected between one of the busbars 10, 11 and a ground potential.

[0045] FIG. 3 shows a perspective view of the electrical circuit device 3. The electrical circuit device 3 comprises a heat sink 12 as well as the connector 13. The connector 13 is configured as a direct current plug and forms the direct current connector of the electrical circuit device 3, which is used to connect the electrical circuit device 3 to the energy storage device 5. The connector 13 is connected to the power electronics circuit 14 by means of the busbars 10, 11. The busbars 10, 11 are made of a conductive metal, for example, copper or aluminum, and can also be referred to as conductor bars. In the present case, the connection of the connector 13 is made by means of the busbars 10, 11 to the direct current link capacitor C.sub.zk of the power electronics circuit 14.

[0046] In this connection, the busbars 10, 11 are each thermally coupled by means of a section 15 of their length to a first section 16 of a top surface 17 of the heat sink 12. The power electronics modules 7, 8, 9 are thermally coupled to a second section 18 of the top surface 17 of the heat sink 12. The direct current link capacitor C.sub.zk is likewise thermally coupled to the heat sink 12, wherein in the present case, the coupling occurs to a side surface of the heat sink 12 adjacent to the sections 16, 18.

[0047] It is possible that the top surface 17 of the heat sink 12 has one or a plurality of further sections 18 in which, as shown schematically, one or a plurality of further components 19 of the electrical circuit arrangement 14, by way of example sensors, control circuits or the like, can be arranged. The section 16 and the further sections 18 are thereby located on the same side surface of the heat sink 12.

[0048] The heat sink 12 may comprise one or a plurality of cooling channels (not shown here) extending inside the heat sink 12. This makes it possible, for example, to connect the heat sink 12 to a cooling circuit of the motor vehicles 1 such that active cooling of the components arranged on the heat sink 12 can take place with the aid of a cooling medium, in particular a liquid cooling medium.

[0049] By arranging the busbars 10, 11 in such a way that at least one section 15 of their length is thermally coupled to the heat sink 12, cooling of the busbars 10, 11 by means of the heat sink 12 is enabled. In order to enable good heat dissipation from the busbars 10, 11, the length of the section 15 can correspond in each case to at least 50% of the length of the respective busbar 10, 11.

[0050] The components of the filter device 6, for example, the illustrated common mode capacitors C.sub.y, are also cooled in this way, since the heat input into the capacitors C.sub.y by means of the busbars 10, 11 is reduced. This also applies to other components of the filter device 6, for example, the schematically illustrated differential mode capacitor C.sub.x, as well as any further capacitors and/or inductance elements such as coils and/or ferrite cores of the filter device 6 that may be present.

[0051] As common mode choke L.sub.cm, the filter device 6 further comprises an inductance element 20 which surrounds the connector 13. The connector 13 is thereby at least partially surrounded by the inductance element 20 having an opening, wherein the connector 13 is arranged within the opening of the inductance element 20. The spatially close arrangement of the inductance element 20 at the connector 13 enables filtering, in particular, of interference coupled onto the busbars 10, 11, which is caused by the function of the power electronics modules 7, 8, 9. This interference can also, in particular, couple in in the area of the further filter stages of the filter device 6, which is to say the capacitor C.sub.x or alternatively the capacitors Cy, such that they can be filtered by the inductance element 20 through the connector 13 before leaving the electrical circuit device 3. Alternatively to an arrangement of the inductance element 20 around the connector 13, an arrangement directly at or alternatively behind the connector 13 is also possible.

[0052] The busbars 10, 11 are arranged one above the other on the heat sink 12. The first busbar 10, which is arranged between the top surface 17 of the heat sink 12 and the second busbar 11, can be in direct contact with the heat sink 12. Alternatively, it is also possible to arrange an intermediate layer between the first busbar 10 and the top surface 17 of the heat sink 12. The intermediate layer can, for example, be a layer of a thermal paste, a gap filler or a gap pad.

[0053] An intermediate layer is also arranged between the busbar 10 and the further busbar 11, which intermediate layer is configured as a thermally conductive, electrically insulating insulation element 21. The insulating element 21 electrically insulates the busbars 10, 11 from each other. Due to the thermal conductivity of the insulation element 21, cooling of the further busbar 11 arranged opposite the heat sink 12 on the busbar 10 can also take place. As an alternative to the insulating element 21, an intermediate layer of a heat-conducting paste, a gap filler or a gap pad can also be arranged between the busbars 10, 11.

[0054] As an alternative to arranging the busbars 10, 11 one above the other on the first section 16 of the heat sink 12, it is also possible to arrange the busbars 10, 11 next to each other. In this case, both busbars 10, 11 can be in direct contact with the top surface 17 of the heat sink 12 or in indirect or mediate contact by means of an intermediate layer. A gap can remain between the busbars 10, 11 to ensure a sufficient creepage distance between the busbars 10, 11.

[0055] The power electronics circuit 3 can have a housing (not shown) which surrounds the components of the electrical circuit device 3 illustrated in FIG. 3. The connector 13 can be accessible from outside the housing, such that a connection of the power electronics circuit 3, in particular with the energy storage device 5, is possible.

[0056] Due to the cooling of the busbars 10, 11 by the thermal connection of their section 15, which in particular corresponds to at least 50% of the length of the busbars 10, 11, a thermal connection of the components of the filter device 6, or alternatively a thermal connection of the components that make up the bodies of the components of the filter device 6, with the housing can be dispensed with. This facilitates the assembly of the electrical circuit device 3 and has the particular effect that the temperatures of the components of the filter device 6 do not depend, or at least do not depend significantly, on a temperature of the housing or alternatively on an environment of the electrical circuit device 3. Moreover, by means of the cooling of the busbars 10, 11 it is possible to dispense with the use of special high-temperature building elements as components of the filter device 6.

[0057] It is possible that the busbars 10, 11 and/or the power electronics modules 7, 8, 9 are arranged at sections 16, 18, which are located at different side surfaces of the heat sink 12. By way of example, the busbars 10, 11 can also be arranged on a side surface of the heat sink 12 opposite the power electronics modules 7, 8, 9.

[0058] German patent application no. 10 2021 130733.3, filed Nov. 24, 2021, to which this application claims priority, is hereby incorporated herein by reference, in its entirety.

[0059] Aspects of the various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled.