System comprising a bus bar device and a power converter housing, and method for the production thereof, power converter for a vehicle, and vehicle

Abstract

The invention relates to a system, including a bus bar device and a power converter housing, wherein the bus bar device includes a stack made of at least two bus bars and an electrically insulating insulation body, which encloses the bus bars in two insulating regions of the bus bar device, wherein each bus bar includes two opposing base surfaces extending in the direction of current flow and lateral surfaces connecting the base surfaces and extending in the direction of current flow, wherein the bus bar device includes a temperature control region formed between the insulating regions, in which the insulation body has an opening that exposes one of the lateral surfaces and a portion of at least one of the base surfaces of a respective bus bar, wherein the bus bars are thermally connected to the power converter housing in the temperature control region by a heat transfer means.

Claims

1. A system (5), comprising a bus bar device (7) and a power converter housing (6), the bus bar device comprising a stack made of at least two bus bars (7a-7c) and an electrically insulating insulation body (9), which encloses the bus bars (7a-7c) in two insulating regions (10a-10d) of the bus bar device (7), each bus bar (7a-7c) comprising two opposing base surfaces (14a, 14b) extending in the direction of current flow and lateral surfaces (13a, 13b) connecting the base surfaces (14a, 14b) and extending in the direction of current flow, wherein the bus bar device (7) comprises a temperature control region (11a-11c) formed between the insulating regions (10a-10d), in which the insulation body (9) has an opening (12), which exposes one of the lateral surfaces (13a) and a portion of at least one of the base surfaces (14a, 14b) of a respective bus bar (7a-7c), wherein the bus bars (7a-7c) are thermally connected to the power converter housing (6) in the temperature control region (11a-11c) by a heat transfer means (19).

2. The system according to claim 1, wherein the insulation body (9) includes a protrusion (16) in the temperature control region (11a-11c) between each pair of adjoining bus bars (7a-7c), the protrusion extending along the base surfaces (14a, 14b) beyond the exposed lateral surface (13a).

3. The system according to claim 1, wherein the insulation body (9) comprises a spacer (17) in the insulating region (10a-10d), which rests on the power converter housing (6) and spaces the bus bars (7a-7c) apart from the power converter housing (6) in the temperature control region (11a-11c).

4. The system according to claim 1, wherein the power converter housing (6) has a depression (20) receiving the heat transfer means (19).

5. The system according to claim 1, wherein the heat transfer means (19) is a gap filler.

6. The system according to claim 1, wherein the bus bar device (7) includes a further temperature control region (11c) that is separated from the first insulating region (10a) by a further insulating region (10c), the bus bars (7a-7c) extending in an angled manner, in particular by 90, in the further insulating region (10c).

7. The system according to claim 1, wherein a further temperature control region (11b, 11c), which is separated from the first insulating region (10a) by a further insulating region (10b, 10c, 10d), is provided, the stack comprising a further bus bar (7c) in the further temperature control region (11b, 11c), which is enclosed by the insulation body (9) in the first temperature control region (11a) and/or is not thermally connected to the power converter housing (6) by the heat transfer means (19).

8. A method for producing a system (5) comprising a bus bar device (7) and a power converter housing (6), comprising the following steps: providing a power converter housing (6); applying a heat transfer means (19) to the power converter housing (6); providing a bus bar device (7), which comprises a stack made of at least two bus bars (7a-7c) and an electrically insulating insulation body (9), which encloses the bus bars (7a-7c) in two insulating regions (10a-10d) of the bus bar device (7), wherein each bus bar (7a-7c) comprises two opposing base surfaces (14a, 14b) extending in the direction of current flow and lateral surfaces (13a, 13b) connecting the base surfaces (14a, 14b) and extending in the direction of current flow, wherein the bus bar device (7) includes a temperature control region (11a-11c) formed between the insulating regions (10a-10d) in which the insulation body has an opening (12) that exposes one of the lateral surfaces (13a) and a portion of at least one of the base surfaces (14a, 14b) of a respective bus bar (7a-7c); and introducing the bus bars (7a-7c) exposed in the temperature control region (11a-11c) into the heat transfer means (19).

9. A power converter (3) for a vehicle (1), comprising a system (5) according to claim 1 and a power unit (8a) accommodated in the power converter housing (6).

10. A vehicle (1), comprising an electrical machine (2), which is configured to drive the vehicle (1), and a power converter (3) according to claim 9, which is configured to provide an alternating current for the electrical machine (2).

Description

(1) Further advantages and details of the present invention will be apparent from the exemplary embodiments described hereafter and based on the drawings. These are schematic illustrations. In the drawings:

(2) FIG. 1 shows a schematic diagram of an exemplary embodiment of the vehicle according to the invention comprising an exemplary embodiment of the power converter according to the invention;

(3) FIG. 2 shows a side view of a bus bar device of an exemplary embodiment of the system according to the invention;

(4) FIG. 3 shows a top view onto the bus bar device shown in FIG. 2;

(5) FIG. 4 shows a cut view of the bus bar device shown in FIG. 2 along a line IV-IV in FIG. 3;

(6) FIG. 5 shows a cut partial view of the system along a line V-V in FIG. 3;

(7) FIG. 6 shows a top view onto a bus bar device according to a further exemplary embodiment of the system according to the invention; and

(8) FIG. 7 shows a perspective partial view of the bus bar device shown in FIG. 6.

(9) FIG. 1 shows a schematic diagram of an exemplary embodiment of a vehicle 1, comprising an electrical machine 2, which is configured to drive the vehicle 1, and an exemplary embodiment of a power converter 3, which is configured to provide an alternating current for the electrical machine 2.

(10) The power converter 3 is configured as an inverter and used to convert a direct current, provided by a high voltage battery 4, into a three-phase or polyphase alternating current. The power converter 3 comprises a system 5 including a power converter housing 6 and a bus bar device 7 comprising multiple bus bars 7a, 7b, 7c. Furthermore, a power unit 8a including multiple power semiconductor elements is accommodated in the power converter housing 6. The power converter housing 6 comprises connections for liquid cooling, wherein a cooling unit 8b of the vehicle 1 is connected thereto, which additionally is also configured to cool the electrical machine 2.

(11) The system 5 corresponds to one of the exemplary embodiments described hereafter:

(12) FIGS. 2 to 4 show a bus bar device 7 according to a first exemplary embodiment of the system 5 (see FIG. 5), FIG. 2 showing a side view, FIG. 3 showing a top view, and FIG. 4 showing a cut view along a line IV-IV in FIG. 3.

(13) The bus bar device 7 comprises the bus bars 7a-7c, of which only the bus bar 7a is visible in FIG. 2. As is apparent from FIG. 3, the bus bars 7a-7c form a stack in which the respective base surfaces 14a, 14b (see FIG. 4) of the bus bars 7a-7c are situated opposite from and parallel to one another.

(14) In addition, the bus bar device 8 comprises an electrically insulating insulation body 9, which is created by insert molding the bus bars 7a-7c with a thermoplastic material. The insulation body forms a first insulating region 10a, a second insulating region 10b, a third insulating region 10c, and a fourth insulating region 10d, which is only visible in FIG. 3.

(15) Between a respective pair of adjoining insulating regions 10a-10d, the insulation body 9 forms temperature control regions 11a, 11b and a third temperature control region 11c, which is only visible in FIG. 3. For this purpose, the insulation body 9 has an opening 12 in each temperature control region 11a-11c, which exposes a lateral surface 13a (see FIG. 4) and a portion of the base surfaces 14a, 14b (see FIG. 4) of a respective bus bar 7a-7c. A lateral surface 13b situated opposite the lateral surfaces 13a and the remaining portions of the base surfaces 14a, 14b are enclosed in the temperature control region 11a-11c by the insulation body 9.

(16) In the third insulating region 10c, the bus bars 7a-7c extend angled by 90. Moreover, the third bus bar 7c ends in the first temperature control region 10a and, at the free end thereof, forms a tab-like connecting section 15 for making contact with the power unit 8a. This likewise takes place, consecutively, in the second insulating region 10b for the second bus bar 7b and the first bus bar 7a. As is apparent, in particular, from FIG. 2, the stack has a vertical offset in the second insulating region 10b.

(17) As can be derived from the cut illustration from FIG. 4, the insulation body has a protrusion 16 in the temperature control region 11a, and two protrusions 16 in each of the temperature control regions 11b, 11c, which are located between a respective pair of adjoining bus bars 7a-7c. The protrusion 16 extends along the base surfaces 14a, 14b beyond the exposed lateral surfaces 13a and rests in each case against one of the bus bars 7a-7c.

(18) As is apparent from FIG. 3, the protrusion 16 has a central offset, as a result of which the bus bar 7a-7c against which the protrusion 16 rests changes. This offset facilitates the formation of the protrusion 16 during injection molding, in which a protrusion 16 standing freely between the bus bars 7a, 7b could only be implemented with undue complexity.

(19) Moreover, the first insulating region 10a, the second insulating region 10b and the fourth insulating region 10d each comprise a spacer 17. The spacers 17 are formed on the side of the insulation body 9 which has the opening 12.

(20) Moreover, the insulation body 9 comprises multiple attachment means 18 in the form of protruding tabs having a through-hole, so as to attach the bus bar device 7 to the power converter housing 6, for example by means of a screw.

(21) FIG. 5 shows a cut partial view of the system 5 along a line V-V in FIG. 3, which shows a detail of the bus bar device 7 in a position in which it is accommodated in the power converter housing 6. In a respective temperature control region, which is the first temperature control region 11a here, the system 5 comprises a heat transfer means 19 in the form of a gap filler processed in liquid form. Exposed sections of the bus bars 7a, 7b, 7c protrude into the heat transfer means 19 in the temperature control regions 11a-11c and are thus thermally connected to the power converter housing 6.

(22) The protrusion 16 protruding beyond the first lateral surface 13a implements an extended creepage distance between the bus bars 7a-7c. The spacer 17 ensures an increased distance between the bus bar 7a-7c and the power converter housing 6, which increases the dielectric strength. So as to further increase the distance, additionally a depression 20 is formed in the power converter housing 6.

(23) FIG. 6 shows a top view onto a bus bar device 7 according to a further exemplary embodiment of a system 5. Identical or like-acting components compared to the bus bar device 7 shown in FIGS. 2 to 5 are denoted by identical reference numerals.

(24) In the exemplary embodiment according to FIG. 6, three bus bars 7a-7c extend in a rectilinear manner through a total of two temperature control regions 11a, 11b and an interposed insulating region 10a, in particular without a bus bar branching off in the temperature control regions 11a, 11b for forming a connecting section 15. Moreover, no depression is provided in the power converter housing in this exemplary embodiment. The heat transfer means is arranged on a planar surface of the power converter housing, on which the spacers 17 also rest.

(25) FIG. 7 shows a perspective partial illustration of the temperature control regions 11a, 11b of the bus bar device 7, in which it is apparent particularly clearly that the opening 12 on the outer base surfaces 14a, 14b is formed by a cut-out from the insulation body 9. The cut-out initially extends in an arc-shaped manner from an insulating region 10b or 10a in the direction of current flow, then extends parallel to the direction of current flow, and at the end of a respective temperature control region 11a, 11b ends in an arc-shaped manner in the opposite insulating region 10a or 10c. This also applies to the temperature control region 11a shown in FIGS. 2 and 3; however, the temperature control region 11b shown there transitions at a right angle into the insulating region 10c. Furthermore, the offset can be seen very well in FIG. 7, wherein it is not arranged centrally here.

(26) Even though the systems 5 described in the preceding exemplary embodiments each comprise three bus bars 7a-7c for the alternating-current-side contacting of the power unit 8a, corresponding systems typically comprising two bus bars can also be designed for the direct-current-side contacting of the power unit 8a.