WO2022228619A1

WO2022228619A1 - Emc filter device having a housing-mounted conductor structure; and power electronics module

Info

Publication number: WO2022228619A1
Application number: PCT/DE2022/100322
Authority: WO
Inventors: Bao Ngoc AN; Johannes Herrmann; Nicolai Gramann; Thorsten Rittgerott; Mihai Cretu; Markus Kneissler
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2021-04-29
Filing date: 2022-04-29
Publication date: 2022-11-03
Also published as: DE102021110991A1; DE112022002399A5

Abstract

The invention relates to an EMC filter device (1) for power electronics of an electric machine, comprising an electric conductor structure (2), at least one capacitor (3a, 3b) that is coupled to the conductor structure (2), and at least one inductor (4a, 4b) that cooperates with the conductor structure (2), the conductor structure (2) having at least two separate conducting layers (6a, 6b) that are insulated from one another, and the conductor structure (2) being integrally bonded to and/or interlocked with a housing-mounted portion (14) via at least one fastening projection (37). The invention also relates to a power electronics module (20) comprising said EMC filter device (1).

Description

EMC filter device with a housing-side fixed conductor structure; and power electronics module

The invention relates to an EMC filter device for power electronics of an electrical machine, preferably an electrical machine used as a drive unit in a motor vehicle.

The aim is to provide a filter device that functions as reliably as possible in the sense of a mains filter for use in power electronics, which on the one hand has a structure that is as compact as possible, in particular flat, and on the other hand is equipped with as few interfaces/contacts as possible.

According to the invention, this is achieved by the subject matter of claim 1 . Accordingly, an EMC filter device is provided for power electronics of an electrical machine, which has an electrical conductor structure, at least one capacitance coupled to the conductor structure and at least one inductance interacting with the conductor structure, the conductor structure having at least two individual conductive layers insulated from one another and having at least one Fastening projection is positively and / or non-positively attached to a housing-fixed area.

Due to its compact design, this EMC filter device according to the invention can be integrated more easily into existing installation spaces, for example in a housing of an inverter unit, or the inverter unit can be designed to be more compact overall. A housing-fixed installation is possible in a few simple steps. At the same time, the EMC filter device is designed to be as robust as possible.

The abbreviation "EMC" used herein stands for Electromagnetic Compatibility". Accordingly, an EMC filter device is a filter device that ensures or improves the electromagnetic compatibility of a device, for example a power electronics module, to which the filter device is coupled. Further advantageous embodiments are claimed with the dependent claims and explained in more detail below.

Accordingly, it is also advantageous if the at least one fastening projection is formed by a pin provided with an undercut. This enables the simplest possible assembly by clicking the conductor structure onto the area fixed to the housing.

For a robust accommodation of the conductor structure, it is also expedient if at least one fastening projection is formed in one piece with the region fixed to the housing or is fastened to the region fixed to the housing.

Furthermore, it is expedient if the conductor structure has a through hole through which the at least one fastening projection protrudes. As a result, the conductor structure can be supported at any point in a space-saving manner.

In addition, it is expedient if the at least one fastening projection is held by a locking element connected to the conductor structure on a region of the conductor structure that faces away from the region that is fixed to the housing. As a result, the conductor structure is accommodated in the form-fitting manner that is as robust as possible on the area fixed to the housing. The assembly is also further simplified.

In this regard, it is also advantageous if the locking element is designed to be resilient in such a way that it is expanded when the conductor structure is pushed onto the fastening projection and springs back into this undercut when the undercut of the fastening projection is reached, so that the fastening projection can be pulled out again from the Conductor structure is blocked directly by the locking element. This results in reliable recording of the conductor structure. In this regard, it is again expedient if the locking element is also spring-biased in such a way that the conductor structure is biased in the direction of the area fixed to the housing in the assembled position. As a result, the conductor structure rests firmly on the area fixed to the housing or is supported directly or indirectly on it.

For a further simplified structure, it is also beneficial if the at least one fastening projection and the locking element produce an electrical connection between the area fixed to the housing and the conductor structure. The at least one fastening projection, more preferably also the locking element, is preferably made of electrically conductive material.

The performance of the EMC filter device is further increased if a thermally conductive layer/a thermally conductive material, preferably in the form of a so-called “gap pad”/a mat, is provided between the conductor structure and the area fixed to the housing. This layer is preferably elastically deformable in such a way that the conductor structure is accommodated with a certain pretension towards the area fixed to the housing. This results in the most stable possible bond between the conductor structure and the area fixed to the housing.

If an insulating film is arranged between the individual conductive layers of the conductor structure, the conductor structure is constructed as compactly as possible.

In this regard, it is also expedient if the conductor structure in its entirety is surrounded/encased by an insulating film on the outside.

It is also advantageous if the at least one inductor has a core (preferably designed as a toroidal core) and the conductor structure is inserted/projects through this core. This also results in an arrangement that is as compact as possible. Furthermore, the invention relates to a power electronics module for an electrical machine, with a capacitor arrangement and an EMC filter device according to the invention, which is electrically connected to the capacitor arrangement, according to at least one of the previously described embodiments.

It is also expedient if a plurality of capacitors are attached to the order on a top or bottom of the conductor structure. In this case, the conductor structure preferably has a corresponding extension, on which the individual capacitors are arranged in series and/or parallel to one another. As a result, the conductor structure is used even more skilfully for a compact design of the power electronics module.

It is also advantageous if a current input of the power electronics module is formed directly by the conductor structure and a current output of the power electronics module is formed by the capacitor arrangement.

In other words, a more effective assembly of a laminated bus bar (busbar/conductor structure) on a housing, for example an inverter housing, is thus realized according to the invention. The EMC filter is constructed using the laminated bus bar. The laminated bus bar has at least two electrically conductive layers that are insulated from one another. The laminated bus bar has through holes at predetermined positions. Mounting pins (mounting projections), which are preferably integrated in the inverter case or other heat sink, are pushed through these through holes. A locking member is provided to secure the laminated bus bar relative to the fastener pin. Preferably, a thermally conductive material (layer) is interposed between the laminated bus bar and the inverter case or heat sink.

The invention will now be explained in more detail below with reference to figures.

Show it: 1 shows a plan view of an EMC filter device according to the invention according to a preferred exemplary embodiment as part of an inverter unit,

2 shows a cross-sectional representation of the EMC filter device according to FIG

3 shows a sectional view of the EMC filter device according to FIG. 1 in a region of a fastening projection of the area fixed to the housing that supports the conductor structure.

4 shows an alternative embodiment of the conductor structure,

5 shows a further alternative embodiment of the conductor structure,

6 shows a further alternative embodiment of the conductor structure,

7 shows a further alternative configuration of the conductor structure,

8 shows a further alternative embodiment of the conductor structure, and

9a to 9c a further alternative configuration of the conductor structure.

The figures are only of a schematic nature and serve exclusively for understanding the invention. The same elements are given the same reference numbers.

1 shows an EMC filter device 1 according to the invention in a clear manner. In this embodiment, the EMC filter device 1 is an independent module implemented, but also immediacy bar formed in other embodiments of the invention as part of a power electronics module 20 / an inverter unit 11 from. The inverter unit 11 then in turn forms a component of the power electronics module 20 indicated generally in FIG. 1/power electronics for an electrical machine. The EMC filter device 1 is thus used in power electronics of an electrical machine of a motor vehicle, which is preferably designed as a drive machine.

The EMC filter device 1 has, as also shown in FIGS. 2 and 3 to see in more detail, a laminated conductor structure 2, which is implemented as a laminated busbar 5 here. In further versions, the conductor structure 2 is also implemented as a circuit board, namely as a high-current circuit board. The conductor structure 2, alternatively also referred to as a busbar or busbar, has a plurality of conductive layers 6a, 6b, which are indicated in FIG. 2 and are insulated from one another. The conductive layers 6a, 6b lie flat/coplanar on one another and form the conductor structure 2/busbar 5 as a whole. Between the conductive layers 6a, 6b, as also indicated in FIG. 2, an insulating film 7 is interposed, which is used directly to insulate the two conductive layers 6a, 6b relative to one another. Also, the conductor structure 2, i. H. the entirety of Leit layers 6a, 6b, sealed abge from its outside by such an insulating film 7. In further versions, the conductor structure 2 also consists of more than two, for example three or four, conductive layers 6a, 6b.

The conductor structure 2 has an essentially plate-shaped construction. According to the design as an EMC filter device 1, the conductor structure 2 has two inductances 4a, 4b. A first inductor 4a has a first core 8a, and a second inductor 4b has a second core 8b. Each core 8a, 8b is designed as a ring core/ring-shaped. A section of the conductor structure 2 extends centrally through these cores 8a, 8b arranged next to one another.

Two connections 10a, 10b are implemented on the conductor structure 2 towards a common side of the two inductances 4a, 4b and form a current input during operation. The two terminals 10a, 10b are in operation, as also indicated, with a Power supply 9, preferably connected to a high voltage battery. The two connections 10a, 10b form not only a current input of the EMC filter device 1, but also a current input 16 of the inverter unit 11 and the power electronics module 20.

Furthermore, two capacitances 3a, 3b in the form of capacitors are placed/applied on the conductor structure 2. The two capacitances 3a, 3b thus form two first electronic components 21, which are accommodated/mounted on the conductor structure 2. The respective first electronic component 21 is preferably cohesively fixed on the conductor structure 2, for example soldered or welded on.

Another second electronic component 22, which is taken up / attached to the conductor structure 2, is implemented as a current sensor 24 and is thus used to detect an electric current (Fig. 1 and 2). The current sensor 24 is attached to the conductor structure 2 via a weld point 36 .

Furthermore, a third electronic component 23 in the form of a discharge resistor 25 is accommodated/attached to the conductor structure 2 (FIG. 1). The third electronic component 23 is also preferably fixed to the conductor structure 2 in a materially bonded manner.

As an alternative to the form-fit connection of the respective component 21, 22, 23, another connection of the respective component 21, 22, 23 is also provided in further embodiments, for example force-fit via fastening means such as screws.

1 also shows that the conductor structure 2 is connected to a capacitor arrangement 12 of the inverter unit 11 . A corresponding connection takes place, for example, in the area of a dividing line 33 . In a further preferred exemplary embodiment, however, the conductor structure 2 is also formed in one piece with a rail 35 of the capacitor arrangement 12 , so that a plurality of capacitors 26 of the capacitor arrangement 12 are also arranged on the conductor structure 2 . The EMC The filter device 1 is then a direct component of an inverter unit 11 having the capacitor arrangement 12. The capacitors 26 are implemented as discrete capacitors 26 and are arranged, for example, in two parallel rows.

The inverter unit 11 has a housing 13, which is also referred to as an inverter housing. This housing 13 encloses both the capacitor arrangement 12 and the EMC filter device 1 with the conductor structure 2. However, it should again be pointed out that in further versions the EMC filter device 1 has its own housing, which is then fixed to the housing 13 is attached.

In this respect, it can be seen in FIG. 2 that the conductor structure 2 with its electronic components 21, 22, 23 and the inductances 4a, 4b is placed on a region 14 fixed to the housing. The area 14 fixed to the housing is implemented here directly as a plate-shaped area and is assigned as part of the EMC filter device 1 .

The area 14 fixed to the housing is further connected directly to the housing 13 when used in the inverter unit 11 . In further embodiments, the housing-fixed area 14 is also formed in another way as a heat sink, which is connected to the housing 13 ter.

FIG. 2 also shows that there is a cover 29 which then accommodates the EMC filter device 1 together with the housing 13 . When viewed in the plane of the drawing, the conductor structure 2 rests with its underside 19 (here indirectly) on the area 14 fixed to the housing. At its top 18 through the electronic's components 21, 22, 23 are attached.

Furthermore, the two cores 8a, 8b are connected to the area 14 fixed to the housing via an adhesive connection 34. It can also be seen here that the two connections 10a, 10b are implemented as so-called pins and protrude at least through the cover 29. In addition, it should be noted that in a further preferred embodiment, a cover 27 that forms a shield is also formed by the cover 29 . The cover 27 is formed by the cover 29 and a side wall 30 fastened to the cover 29 . The cover 29 and side wall 30 thus form a shielding hood which is placed on the conductor structure 2 and is supported on the latter via the side walls 30 .

In this regard, it can also be seen in FIG. 2 that an EMC seal 28 is interposed between an end face 31 of the side walls 30 and the conductor structure 2 / the top side 18 of the conductor structure 2 . This EMC seal 28 has a sealing strip 32 or is implemented as such a sealing strip 32 . The EMC seal 28 extends over the entire circumference of the side wall 30 and thus seals off an interior of the cover 27 from interference signals to the environment.

The side walls 30 are formed separately from the cover 29 and attached to it. For example, the side wall 30 is welded to the cover 29 or attached in a non-positive manner, for example by means of fastening means. In further embodiments, however, the side walls 30 are also designed as a one-piece material component of the cover 29 .

It can also be seen from FIG. 2 that a thermally conductive layer 15, which is implemented as a “gap pad” in a preferred variant, is inserted between the conductor structure 2 and the area 14 fixed to the housing. The layer 15 thus formed as a mat thus serves to dissipate waste heat from the conductor structure 2 in the direction of the area 14 fixed to the housing. The layer 15 is elastically deformable and is inserted between the conductor structure 2 and the area 14 fixed to the housing in a compressed manner. The layer 15 consists of some thermally conductive material, such as a thermally conductive filled composite. In further embodiments, the layer 15 is alternatively implemented as a gel layer or as a casting compound.

In this context, it should also be pointed out that the conductor structure 2 is also non-positively and positively connected to the housing-fixed conductor structure 2 at a number of attachment points Area 14 is fixed. In this case, a plurality of fastening projections 37 distributed over the plane of the conductor structure 2 are arranged on the area 14 fixed to the housing and are connected to the conductor structure 2 .

Those fastening projections 37 are implemented as pins 39 and penetrate the conductor structure 2 through through-holes 40 (in the form of bores/Ausstanzun gene). Each fastening projection 37 has an undercut 38 which is supported by a locking element 42 . The locking element 42 is on the conductor structure 2, on a region 14 which is fixed to the housing, facing away from the side 41 of the conductor structure 2. Each attachment projection 37 is preferably made of an electrically conductive material.

The locking element 42 is implemented in a resilient manner and has a plurality of spring arms 43 . After the fastening projection 37 has been pushed through the conductor structure 2 (in the respective through-hole 40), the locking element 42/the spring arms 43 automatically snap into place in the rear section 38 (corresponds to form-fitting fixing).

Furthermore, each locking element 42 is also designed to be resilient in such a way that, in the fastened state, it presses/prestresses the conductor structure 2 with a spring prestress in the direction of the area 14 fixed to the housing. As a result, the conductor structure 2 rests against the area 14 fixed to the housing via the corresponding prestressing and the layer 15 (corresponds to non-positive fixing).

While the connections 10a, 10b, as already mentioned, form the entire current input 16 of the inverter unit 11/of the power electronics module 20, an output of the capacitor arrangement 12 typically forms a current output 17 of the inverter unit 11/of the power electronics module, indicated schematically in FIG 20

In other words, a laminated busbar (busbar) has a mounting hole (through hole) at several defined points 40). Several mounting pins (pins 39) are integrated into the inverter case (case-mounted area 14) or a heatsink/heatsink. In this case, these mounting pins are part of the inverter housing. In another embodiment variant, these mounting pins can be attached to the housing in some other way (eg by plugging, screwing). During assembly, the laminated busbar is guided through the assembly pins through the assembly holes.

A locking element 42 is applied to the laminated busbar (e.g. integrated into the laminated busbar or soldered or welded to the laminated busbar).

Furthermore, a thermally conductive material (e.g. gap pad) is applied between the laminated bus bar and the inverter housing.

The locking unit works on the principle of a barb and presses the laminated busbar onto the soft thermally conductive material (layer 15).

The laminated bus bar consists of two or more coplanar conductive plates (e.g. copper plates; also referred to as conductive layers 6a, 6b) with the intermediate and outer insulating foils 7 laminated.

The passive components (e.g. capacitors) can be soldered directly onto the laminated busbar. Current sensor 24 (DC side) and discharge resistor 25 can be connected directly to the laminated busbar (e.g. by means of laser welding).

In one embodiment variant, a DC link capacitor can be connected as a parallel circuit of discrete capacitors (capacitors 3a, 3b) via the laminated current collector.

The busbar is placed close to the housing 13 and thermally connected to the inverter housing 13 via thermally conductive materials (eg gap pad). The cores 8a, 8b are placed in the inverter housing 13 and fixed with an adhesive (for example using epoxy adhesive) or with a casting material and thermally connected to the inverter housing 13.

An EMC shielding wall (side wall 30) is integrated into the inverter cover (cover 27) and provided with an EMC seal 28. After the cover 29 is closed, the EMC filter and the DC input connector are protected from electromagnetic radiation coupling.

The following is a description of various conductor structures 200 to 205 which can be used as an alternative to the conductor structure 2 described above.

Fig. 4 shows an alternative embodiment of the conductor structure 200.

The conductor structure 200 is a multi-layer high-current printed circuit board or PCB 200. In this conductor structure 200, several thick conductor layers 600a, 600b, two of which are shown in FIG. These conductor layers 600a, 600b can include copper. Preferably, thin conductor layers 800 can be arranged on the outer surfaces of the printed circuit board material 700 in addition to the conductor layers 600a, 600b arranged or embedded on the inside. These thin conductor layers 800 may include copper.

Fig. 5 shows a further alternative configuration of the conductor structure 201.

The conductor structure 201 has two or more single-layer printed circuit boards. In this conductor structure 201, between single-layer printed circuit boards, which have a conductor layer 601a and an insulating printed circuit board material 701a or a conductor layer 601b and an insulating printed circuit board material 701b, there is a distance for maintaining a air gap available. The distance is ensured by a spacer 803. The printed circuit boards 601a, 601b are fastened to one another, for example by means of a screw 801, which is electrically insulated from at least one of the conductor layers 601a, 601b by means of an insulation 802.

Fig. 6 shows a further alternative configuration of the conductor structure 202.

The conductor structure 202 has two or more single-layer printed circuit boards. In this conductor structure 202, an adhesive layer 901 is arranged between single-layer circuit boards, which have a conductor layer 602a and an insulating circuit board material 702a or a conductor layer 602b and an insulating circuit board material 702b, in order to attach the circuit boards to one another.

Fig. 7 shows a further alternative configuration of the conductor structure 203.

The conductor structure 203 has a plurality of conductor layers 603a, 603b and insulation layers 703a, 703b, 703c stacked one on top of the other. The stacking is such that one of the conductor layers 603a, 603b and one of the insulation layers 703a, 703b, 703c alternate in each case. The number of conductor layers 603a, 603b and insulating layers 703a, 703b, 703c is not limited to the number shown in FIG. The stacked conductor layers 603a, 603b and insulating layers 703a, 703b, 703c are not laminated with each other and are not firmly connected to each other.

Fig. 8 shows a further alternative embodiment of the conductor structure 204.

The conductor structure 204 has a plurality of conductor layers 604a, 604b and insulation layers 704a, 704b, 704c stacked on top of one another. The stacking is such that one of the conductor layers 604a, 604b and one of the insulation layers 704a, 704b, 704c alternate in each case. The number of conductor layers 604a, 604b and insulating layers 704a, 704b, 704c is not limited to the number shown in FIG. The stacked conductor layers 604a, 604b and insulation layers 704a, 704b, 704c are bonded together by respective adhesive layers 904 between respective adjacent layers.

9a to 9c show a further alternative configuration of the conductor structure 205. More precisely, Fig. 9a and Fig. 9b show method steps for producing the conductor structure 205 shown in Fig. 9c.

As shown in FIG. 9a, a plurality of conductor layers 605a, 605b and at least one insulation layer 705 are stacked one on top of the other. The stacking is such that one of the conductor layers 605a, 605b and the at least one insulation layer 705 alternate. The number of conductor layers 605a, 605b and insulating layer 705 is not limited to the number shown in Figs. 9a to 9c. The conductor layers 605a, 605b and insulation layer 705 stacked on top of one another are arranged in a molding mold 1000. FIG.

As shown in FIG. 9b, the mold is closed with a lid. A molding material is placed in the molding mold 1000 . After the molding material has hardened, the conductor structure 205 is removed from the molding mold.

As shown in Figure 9c, the result is the conductor structure 205 surrounded by the molding material 1100, such as an epoxy material.

List of reference symbols EMC filter device conductor structure a first capacitance b second capacitance a first inductance b second inductance busbar a first conductive layer b second conductive layer insulating film a first core b second core power supply 0a first connection 0b second connection 1 inverter unit 2 capacitor arrangement 3 housing 4 area fixed to the housing 5 layer 6 Current input 7 current output 8 top 9 bottom 0 power electronics module 1 first electronic component 2 second electronic component 3 third electronic component 4 current sensor Discharge resistor Capacitor Cover EMC seal Cover Side wall Front face Sealing tape Separating line Adhesive joint Rail Welding point Fastening protrusion Undercut Pin Through hole Side Locking element Spring arm Conductor structure a Conductor layer b Conductor layer Circuit board material Thin conductor layer Conductor structure a Conductor layer b Conductor layer a Circuit board materialb Circuit board material Screw Insulation Spacer 02 conductor structure 02a conductor layer 02b conductor layer 02a circuit board material 02b circuit board material 01 adhesive layer 03 conductor structure 03a conductor layer 03b conductor layer 03a circuit board material 03b circuit board material 03c circuit board material 04 conductor structure 04a conductor layer 04b conductor layer 04a circuit board material 704b circuit board material 704c circuit board material 704 adhesive layer 05ba conductor layer conductor structure 05ba insulation layer

1000 Molding Mold

1001 lid

1100 molding material

Claims

Expectations

1. EMC filter device (1) for power electronics of an electrical machine, having an electrical conductor structure (2), at least one capacitance (3a, 3b) coupled to the conductor structure (2) and at least one capacitance (3a, 3b) coupled to the conductor structure (2) interacting inductance (4a, 4b), wherein the conductor structure (2) has at least two individual conductive layers (6a, 6b) insulated from one another and is fixed positively and/or non-positively via at least one fixing projection (37) to an area (14) fixed to the housing .

2. EMC filter device (1) according to claim 1, characterized in that the at least one fastening projection (37) is formed by a pin (39) provided with an undercut (38).

3. EMC filter device (1) according to claim 1 or 2, characterized in that the at least one fastening projection (37) is formed in one piece with the housing-fixed region (14) or is fastened to the housing-fixed region (14).

4. EMC filter device (1) according to any one of claims 1 to 3, characterized in that the conductor structure (2) has a through hole (40) through which the at least one fastening projection (37) protrudes.

5. EMC filter device (1) according to one of Claims 1 to 4, characterized in that the at least one fastening projection (37) on a side (37) of the conductor structure (2) facing away from the region (14) fixed to the housing is (2) connected locking element (42) is held.

6. EMC filter device (1) according to claim 5, characterized in that the locking element (42) is spring-biased in such a way that the conductor structure (2) is biased in the direction of the area (14) fixed to the housing.

7. EMC filter device (1) according to claim 5 or 6, characterized in that the at least one fastening projection (37) and the locking element (42) produce an electrical connection between the area (14) fixed to the housing and the conductor structure (2). . (Mounting projection and the locking element made of electrically conductive material)

8. EMC filter device (1) according to any one of claims 1 to 7, characterized in that between the conductor structure (2) and the housing-fixed area (14) a thermally conductive layer (15) is inserted.

9. Power electronics module (20) for an electrical machine, with a capacitor arrangement (12) and with the capacitor arrangement (12) electrically connected EMC filter device (1) according to any one of claims 1 to 8.

10. Power electronics module (20) according to claim 9, characterized in that a plurality of capacitors (26) of the capacitor arrangement (12) are attached to an upper side (18) or an underside (19) of the conductor structure (2).