ELECTRICAL CIRCUIT ARRANGEMENT, RAIL VEHICLE AND METHOD FOR MAKING AN ELECTRICAL CIRCUIT ARRANGEMENT

Description

[0001] The invention relates to an electrical circuit arrangement, in particular for use in a rail vehicle, a rail vehicle and a method for producing such an electrical circuit arrangement.

[0002] It is known to generate an alternating voltage using so-called inverters, which comprise power switching elements, in particular IGBTs. Typically, a so-called intermediate circuit with an intermediate circuit capacitor is provided for this purpose, which provides a direct voltage for the inverter. The alternating voltage described above is then generated from this direct voltage by switching the switching elements. This can be used, for example, to operate an electrical machine. The electrical machine can be, for example, a traction motor in a rail vehicle.

[0003] Also known are so-called commutation circuits for the power switching elements, through which a current flows, particularly after a power switching element has been switched off (blocking). Such a commutation circuit is generally arranged in parallel with a power switching element and includes at least one capacitive element. If multiple power switching elements are present in the inverter, such a commutation circuit with a capacitive element can be connected in parallel with each of these power switching elements, with the capacitive elements then being connected to one another via the intermediate circuit.

[0004] Furthermore, inductances are present in the intermediate circuit, which arise, for example, from the conductors used and their relative arrangement within the intermediate circuit. In conjunction with the previously discussed capacitive elements of commutation circuits, this can create resonant circuits, which in turn cause high compensating currents between the capacitive elements of the commutation circuits. These high compensating currents can, in turn, undesirably increase the thermal load on the capacitive elements. If the damping factor of the resonant circuits is low, the oscillations decay only slowly, which prolongs and / or increases the aforementioned thermal load. The use of capacitive elements with high capacitance and high current-carrying capacity generally results in high installation space requirements and weight, which is also undesirable.

[0005] WO 2008 / 074273 A1 discloses a device for converting an electric current with at least one phase module having an AC voltage connection and at least one DC voltage connection, wherein semiconductor modules connected in series have semiconductor valves for switching the electric current between the AC voltage connection and each DC voltage connection and at least one energy store for storing electrical energy.

[0006] US 2020 / 169186 A1 concerns the field of power electronics, in particular power converters, and concerns the design of a phase module for power converters and a power converter.

[0007] WO 2017 / 051639 A1 discloses a power converter with a power module and a snubber capacitor.

[0008] EP 3 203 625 A1 discloses a structure of an electrical power conversion device provided with a switching module, a smoothing capacitor and a bus bar.

[0009] EP 3 451 520 A1 discloses a component structure for connecting a power module and an external circuit, a power module and a power module assembly structure with the component structure.

[0010] US 5 537 074 A relates to output circuits comprising a plurality of semiconductors connected in parallel which carry a high current or carry current or operate at high frequencies, and in particular to power drivers with power ratings in the range of one kilowatt and above.

[0011] EP 2 328 391 A2 discloses a converter, in particular a multi-phase three-phase converter, with a DC link and a power module having at least one power semiconductor.

[0012] US 2020 / 028444 A1 discloses power converters each comprising a semiconductor module with a converter component containing a semiconductor element and power terminals protruding from the converter component.

[0013] The technical problem therefore arises of creating an electrical circuit arrangement, a rail vehicle and a method for producing a circuit arrangement which avoid the aforementioned disadvantages and in particular reduce a current flow through a capacitive element of a commutation branch, which in turn reduces a thermal load on this capacitive element, increases the service life of the circuit arrangement and reduces installation space requirements.

[0014] The solution to the technical problem is achieved by the subject matter having the features of the independent claims. Further advantageous embodiments of the invention are set forth in the subclaims.

[0015] An electrical circuit arrangement is proposed. This can, in particular, be part of a traction network in a vehicle, in particular a rail vehicle. In particular, the circuit arrangement can form part of an intermediate circuit in an electrical network, with at least one power switching element for generating an alternating voltage being connected to this intermediate circuit.

[0016] The electrical circuit arrangement comprises at least one power switching element, which is preferably designed as an IGBT. Of course, other power switching elements can also be used, for example MOSFETs. The circuit arrangement further comprises a high-voltage conductor and a low-voltage conductor. In the context of this disclosure, a high-voltage conductor refers to an electrical conductor which, during normal operation of the electrical circuit arrangement, has a higher potential than the low-voltage conductor, which is also an electrical conductor. The low-voltage conductor can, for example, have a ground potential of the rail vehicle. The high-voltage conductor and the low-voltage conductor can, in particular, be designed as a busbar, wherein the high-voltage conductor can then be referred to as the positive busbar and the low-voltage conductor can then be referred to as the negative busbar.The high-voltage conductor and the low-voltage conductor are preferably made of aluminum. However, it is also possible for such a conductor to be made of copper or another conductive material.

[0017] According to the invention, the circuit arrangement comprises a commutation branch, wherein the commutation branch comprises a high-voltage connection section electrically connected to the high-voltage conductor, a low-voltage connection section electrically connected to the low-voltage conductor, and at least one capacitive element. Both the high-voltage connection section and the low-voltage connection section can also be mechanically connected to the corresponding high-voltage or low-voltage conductor, for example, by a screw connection.

[0018] In particular, the high-voltage connection section can connect a high-voltage terminal of the capacitive element to a high-voltage terminal of the power switching element. Furthermore, the low-voltage connection section can connect a low-voltage terminal of the capacitive element to a low-voltage terminal of the power switching element.

[0019] The capacitive element is designed as a capacitor. The capacitance of such a capacitor can be selected depending on the application. Typically, the capacitance can be in the range of 1-20 µF. This type of capacitor is called a snubber capacitor.

[0020] The capacitive element is electrically arranged between the high-voltage connection section and the low-voltage connection section.

[0021] Furthermore, a high-voltage terminal of the power switching element is electrically connected to the high-voltage conductor, and a low-voltage terminal of the power switching element is electrically connected to the low-voltage conductor. Thus, the commutation branch in the proposed circuit arrangement is arranged electrically parallel to the power switching element.

[0022] Furthermore, the high-voltage connection section of the commutation branch is formed at least partially or entirely from a material whose electrical conductivity is lower than the electrical conductivity of the material of the high-voltage conductor. Alternatively or cumulatively, the low-voltage connection section of the commutation branch is formed at least partially or entirely from a material whose electrical conductivity is lower than the electrical conductivity of the material of the low-voltage conductor.

[0023] In other words, the resistivity of the material of the high-voltage connection section is greater than the resistivity of the material of the high-voltage conductor. Alternatively, or cumulatively, the resistivity of the material of the low-voltage connection section is greater than the resistivity of the material of the low-voltage conductor.

[0024] This advantageously allows a desired (high) resistance of the commutation branch to be achieved with very little space required, whereby the previously discussed current oscillations rapidly decrease in amplitude due to the resonant circuit formed by the commutation branch and the intermediate circuit, and the maximum amplitude of such oscillations is also reduced. This, in turn, advantageously reduces thermal loading of the capacitive element in the commutation branch, allowing the use of capacitive elements that require little space and lower manufacturing costs.

[0025] Furthermore, it is clear that a separation can be made between load current, i.e. the current flowing through the high-voltage conductor, the power switching element and the low-voltage conductor, and snubber capacitor current.

[0026] Further according to the invention, the high-voltage connection section and / or the low-voltage connection section is at least partially plate-shaped. This can mean that the connection section is designed as a printed circuit board or comprises a printed circuit board. The printed circuit board or the plate-shaped section can have a predetermined thickness, in particular in the range from 0.2 mm to 2.0 mm, preferably in the range from 0.5 mm to 1.5 mm.

[0027] This advantageously results in a cost-effective and easy-to-manufacture connection section with the desired conductivity properties that requires little installation space.

[0028] Furthermore, according to the invention, at least a partial section of the high-voltage connection section is slotted and / or at least a partial section of the low-voltage connection section is slotted. In particular, the previously explained plate-shaped section of the connection section can be at least partially slotted. A slotted partial section can comprise or form conductor webs, with an electrically non-conductive or less conductive section being arranged between the conductor webs. For example, air can be arranged between two such webs made of the material of the connection section. In this case, the slotted partial section can also have through-openings in the form of slots.

[0029] This advantageously results in a mechanically simple production of the connection section with the desired electrical conductivity, since the slotted design allows electrical conductivity to be reduced by simple mechanical manufacturing measures.

[0030] Furthermore, according to the invention, an edge region of the high-voltage connection section is formed over the entire surface. In a further embodiment, at least one edge region of the low-voltage connection section is formed over the entire surface. This can mean that the edge region is neither slotted nor perforated and, in particular, also has no tapered thickness. Furthermore, this can mean that the edge region is formed as a solid body made of the material of the connection section. According to the invention, the high-voltage connection section and, in a further embodiment, the low-voltage connection section, in particular a plate-shaped connection section, comprise two edge regions formed over the entire surface in this way, with a slotted partial region arranged between these edge regions.A first edge region is electrically and mechanically connected to the high-voltage conductor, while the second edge region is electrically and mechanically connected to the capacitive element.

[0031] This advantageously results in less heat being generated in these edge regions due to this configuration of the edge regions and their higher conductivity compared to a further (intermediate) region of the connection section that is not fully covered. This advantageously reduces thermal loading of the capacitive element and / or the power switching element, which may be arranged directly near the previously explained first edge region, and, in particular, prevents desired operating temperatures from being exceeded. This advantageously increases the operational reliability of the circuit arrangement and its service life.

[0032] In a preferred embodiment, the high-voltage connection section of the commutation branch and / or the low-voltage connection section is at least partially formed from stainless steel. Thus, a high-voltage connection plate or a low-voltage connection plate can be a stainless steel plate. This advantageously results in a cost-effective design of the connection section using generally readily available materials.

[0033] In a further embodiment, the high-voltage conductor and the low-voltage conductor each comprise at least one plate-shaped section, wherein the plate-shaped sections are arranged parallel to one another.

[0034] Furthermore, the high-voltage connection section and / or the low-voltage connection section of the commutation branch—as previously explained—comprises at least one plate-shaped subsection, which is arranged parallel to the plate-shaped sections of the high-voltage conductor and the low-voltage conductor and on a side of the low-voltage conductor facing away from the high-voltage conductor. Preferably, the plate-shaped sections are flat, i.e., uncurved. However, it is also possible for said sections to be curved. An insulating material for electrical insulation can be arranged between the plate-shaped sections. This can be in the form of a film, a coating, or a filler material, such as plastic, for example.

[0035] This arrangement advantageously results in a geometric relative arrangement, which allows the desired low inductance of the circuit arrangement to be achieved, which in turn allows the previously discussed current oscillations to be reduced as desired. Furthermore, a high level of structural integration and thus a small installation space requirement for the entire arrangement are technically advantageous.

[0036] In a further embodiment, the thickness of the plate-shaped section of the connection section is less than the thickness of the plate-shaped section of the high-voltage conductor. Alternatively or cumulatively, the thickness of the plate-shaped section can be less than the thickness of the plate-shaped section of the low-voltage conductor. Exemplary ranges for the thickness / strength of the connection section were explained above. The thickness of a plate-shaped section of the high-voltage conductor or the low-voltage conductor can be in the range from 3 mm to 7 mm, preferably 5 mm.

[0037] This advantageously results in a simple adjustment of the desired lower conductivity due to the mechanical design, since the smaller thickness of the plate-shaped section results in a higher electrical resistance than the plate-shaped sections of the high-voltage conductor or the low-voltage conductor, which, however, also results mainly from the material of the high-voltage conductor and / or the low-voltage conductor.

[0038] In a further embodiment, a distance between the plate-shaped section of the connection section and the plate-shaped section of the low-voltage conductor is equal to the distance between the plate-shaped section of the connection section and the plate-shaped section of the high-voltage conductor. This distance can, for example, be in a range from 2 mm to 6 mm, preferably 4 mm. Of course, such a distance can also be selected depending on the application, in particular such that the desired insulation properties between the sections are ensured, but the distance is as small as possible. This advantageously results in a very low inductance of the proposed circuit arrangement with the technical advantages already explained above.

[0039] In a further embodiment, a high-voltage terminal of the power switching element is connected to the high-voltage conductor via the high-voltage terminal section. Alternatively or cumulatively, a low-voltage terminal of the power switching element is connected to the low-voltage conductor via the low-voltage terminal section. In this case, a load current flowing via this element during operation of the power switching element can flow from the high-voltage conductor via the high-voltage terminal section, in particular the previously explained edge region, to the high-voltage terminal of the power switching element. The load current flowing via this element during operation of the power switching element can also flow from the low-voltage terminal of the power switching element via the low-voltage terminal section, in particular the previously explained edge region, to the low-voltage conductor.This advantageously results in a high level of structural integration and thus a low installation space requirement for the proposed circuit arrangement.

[0040] Further according to the invention, the high-voltage connection section has or forms a through-opening, wherein this through-opening is designed for the arrangement of the low-voltage connection section. In particular, a connecting element / section / means extends from a low-voltage connection of the capacitive element to the low-voltage conductor through the through-opening.

[0041] Additionally, the low-voltage connection section has or forms a through-opening, wherein this through-opening is designed to accommodate the high-voltage connection section. In particular, a connecting element / section / means can extend from a high-voltage connection of the capacitive element to the high-voltage conductor through the through-opening.

[0042] The through-opening is formed in the previously explained slotted portion of the connection section.

[0043] This advantageously results in a further improvement in structural integration and a further saving in installation space requirements.

[0044] It is of course also possible for a connecting element / section / means to extend from a terminal of the capacitive element to the high- or low-voltage conductor without a through-hole in the connecting section. For example, the connecting element / section / means can be routed around the connecting section or arranged next to the connecting section.

[0045] Further proposed is a rail vehicle with an electrical circuit arrangement according to one of the embodiments described in this disclosure. The rail vehicle can, in particular, have a traction network comprising an intermediate circuit with an intermediate circuit capacitor, wherein the circuit arrangement explained is connected to the intermediate circuit, in particular to the intermediate circuit capacitor. For example, the high-voltage conductor of the intermediate circuit can be connected to a high-voltage terminal of the intermediate circuit capacitor, and the low-voltage conductor of the intermediate circuit can be connected to a low-voltage terminal of the intermediate circuit capacitor.

[0046] It is conceivable that the circuit arrangement comprises more than one power switching element and more than one commutation branch, wherein a high-voltage terminal of each power switching element is connected to the high-voltage conductor and a low-voltage terminal of the corresponding power switching element is connected to the low-voltage conductor. Furthermore, a commutation branch can be connected in parallel to each power switching element according to one of the embodiments described in this disclosure.

[0047] In the rail vehicle, the power switching element can be part of an inverter which serves to provide an alternating voltage for the operation of an electrical machine, in particular a traction machine.

[0048] Further proposed is a method for producing an electrical circuit arrangement according to one of the embodiments described in this disclosure. Here, at least one power switching element, at least one high-voltage conductor, at least one low-voltage conductor, and, according to the invention, at least one commutation branch with a high-voltage connection section, a low-voltage connection section, and at least one capacitive element electrically arranged between the high-voltage connection section and the low-voltage connection section are provided. Furthermore, the high-voltage connection section is electrically connected to the high-voltage conductor, and the low-voltage connection section is electrically connected to the low-voltage conductor.

[0049] Further according to the invention, the high-voltage connection section of the commutation branch is formed at least partially from a material whose electrical conductivity is lower than the electrical conductivity of the material of the high-voltage conductor. Alternatively or cumulatively, the low-voltage connection section of the commutation branch is formed at least partially from a material whose electrical conductivity is lower than the electrical conductivity of the material of the low-voltage conductor.

[0050] This advantageously results in a simple manufacture of the electrical circuit arrangement with the advantages described above.

[0051] The invention is explained in more detail using exemplary embodiments. The figures show: Fig. 1 is a schematic side view of a circuit arrangement according to the invention, Fig. 2 is a further schematic side view of a circuit arrangement according to the invention, Fig. 3 is a schematic plan view of a high-voltage connection section according to a first embodiment, Fig. 4 is a perspective view of a proposed circuit arrangement, Fig. 5 is a perspective view of a circuit arrangement according to the invention in a further embodiment and Fig. 6 is a schematic plan view of a high-voltage connection section in a further embodiment.

[0052] In the following, the same reference symbols designate elements with the same or similar technical features.

[0053] In Fig. 1 A schematic side view of a proposed electrical circuit arrangement 1 is shown. The circuit arrangement 1 comprises a high-voltage conductor 2 designed as a busbar and a low-voltage conductor 3, also designed as a busbar. The circuit arrangement 1 also comprises a commutation branch 4, which comprises a commutation capacitor 5, a high-voltage connection section 6, and a low-voltage connection section 7. It can be seen that the commutation capacitor 5 is electrically arranged between the high-voltage connection section 6 and the low-voltage connection section 7.

[0054] It can also be seen that the high-voltage connection section 6 is electrically connected to the high-voltage conductor 2 and the low-voltage connection section 7 is electrically connected to the low-voltage conductor 3.

[0055] Also shown is a power switching element 8 designed as an IGBT, whose high-voltage connection 20 is electrically connected to the high-voltage conductor 2 and whose low-voltage connection 21 is electrically connected to the low-voltage conductor 3.

[0056] It can also be seen that the high-voltage connection section 6 comprises a plate-shaped subsection 9. The material of the high-voltage connection section 6, in particular of the plate-shaped subsection 9, can be stainless steel, while the material of the high-voltage conductor 2 and the low-voltage conductor 3 can be aluminum or copper.

[0057] It is also shown that the high-voltage conductor 2 and the low-voltage conductor 3 each comprise plate-shaped sections that are arranged parallel to one another and parallel to the plate-shaped partial section 9 of the high-voltage connection section 6. It is further shown that the plate-shaped partial section 9 of the high-voltage connection section 6 of the commutation branch 4 is arranged on a side of the low-voltage conductor 3 facing away from the high-voltage conductor 2. Thus, the high-voltage connection section 6 is arranged between the low-voltage conductor 3 and the commutation capacitor 5.

[0058] Fig. 2 shows a further schematic side view of a circuit arrangement 1. The high-voltage conductor 2, the low-voltage conductor 3 and the commutation branch 4, which comprises a plate-shaped high-voltage connection section 6, the commutation capacitor 5 and a low-voltage connection section 7, can again be seen.

[0059] It is shown that the thickness of the plate-shaped section 9 of the high-voltage connection section 6 is less than the thickness of the plate-shaped section of the high-voltage conductor 2, to which the plate-shaped section 9 of the high-voltage connection section 6 is oriented parallel. Its thickness is also less than the thickness of the plate-shaped section of the low-voltage conductor 3.

[0060] It can also be seen that the high-voltage connection section 6 is mechanically connected to the high-voltage conductor 2 via a screw 10, wherein a spacer sleeve 11 is further arranged between the high-voltage conductor 2 and the high-voltage connection section 6, which ensures a desired distance between the power switching element 8 and the high-voltage conductor 2. This spacer sleeve 11 extends through a through-opening in the plate-shaped section of the low-voltage conductor 3 and serves to electrically connect the high-voltage conductor 2 and the high-voltage connection section 6. Therefore, this spacer sleeve 11 is made of an electrically conductive material, preferably with the same conductivity as the material of the high-voltage conductor 2.

[0061] It is further shown that the high-voltage terminal 20 of the power switching element 8 is connected to the high-voltage conductor 2 via the high-voltage terminal section 6 of the commutation branch 4. Thus, a load current can flow from the high-voltage conductor 2 via the spacer sleeve 11, the high-voltage terminal section 6, in particular its plate-shaped section 9, to the high-voltage terminal 20 of the power switching element 8.

[0062] It is further shown that the high-voltage connection section 6 of the commutation branch 2 is mechanically connected to the high-voltage connection of the commutation capacitor 5 via a screw 12. The connecting sleeve 11 also serves as a spacer to ensure the desired distance between the high-voltage connection section 6 and the high-voltage conductor 2.

[0063] It is further shown that the low-voltage terminal of the commutation capacitor 5 is connected to the low-voltage conductor 3 via a screw 13. Furthermore, a further spacer sleeve 14 is arranged between the low-voltage terminal of the commutation capacitor 5 and the plate-shaped section of the low-voltage conductor 3, which ensures a desired distance between the commutation capacitor 5 and the low-voltage conductor 3 and also establishes an electrical connection between them.

[0064] This spacer sleeve 14 extends through a through-opening in the plate-shaped section 9 of the high-voltage connection section 6. Thus, a screw 13, which mechanically connects the low-voltage conductor 3 to the low-voltage connection of the commutation capacitor 5 and which is arranged in the spacer sleeve 14, also extends through this through-opening.

[0065] It is also shown that the low-voltage conductor 3 is connected to the low-voltage connection of the power switching element 8 via a screw 16, wherein a spacer sleeve 17 is also arranged between these components 3, 8, which ensures a desired distance between the power switching element 8 and the low-voltage conductor 3 and their electrical connection.

[0066] Fig. 3 shows a schematic plan view of a high-voltage connection section 6 of the commutation branch 4 (see Fig. 1 ) according to a first embodiment. Also shown are the commutation capacitor 5 and the screw 12 for connecting the high-voltage terminal of the commutation capacitor 5 to the high-voltage connection section 6, as well as the screw 22 for connecting the low-voltage terminal of the commutation capacitor 5 to the low-voltage conductor 3.

[0067] It is shown that the plate-shaped partial section 9 of the high-voltage connection section 6 has a first edge region 23 which is designed as a full-surface or solid body and is electrically and mechanically connected to the high-voltage conductor 2 and the high-voltage connection of the power switching element 8. Also shown is a second edge region 24 of the high-voltage connection section 6 which is designed as a full-surface or solid body and is electrically and mechanically connected to the high-voltage connection of the commutation capacitor 5. Furthermore, the high-voltage connection section 6, in particular its plate-shaped partial section 9, comprises a slotted region 17, which has webs 18 and slots 19 arranged between the webs. The previously explained first edge region 23 and the second edge region 24 are connected by the webs 18. Alternatively, however, it is also possible for the entire high-voltage connection section 6 to be fully oris designed as a solid body.

[0068] In the Fig. 3 In the illustrated embodiment, air is arranged between the webs 18. However, it is also possible to arrange an electrically non-conductive material other than air there. In a central area of ​​the slotted area 17, this forms a through-opening 25 through which the connecting screw 22 and the spacer sleeve 14 can extend.

[0069] Furthermore, the width of the webs 18 in the slotted region 17 varies. The width of the webs 18 decreases from an edge region toward the central region. This allows the resistances of the various webs 18 to be set to a desired value, in particular the same value, in order to achieve a desired current distribution among the webs 18. The width of the slots 19 in the slotted region 17 also varies, with the width of the spaces / slots between adjacent webs 18 increasing toward the central region. However, this variation in the width of the slots 19 is optional.

[0070] Fig. 4 shows a perspective view of a circuit arrangement 1 according to the invention. This can comprise a plurality of power switching elements 8 connected in parallel, each of which is connected to a high-voltage conductor 2 and a low-voltage conductor 3, wherein for the sake of clarity only one power switching element 8 is shown in full. A commutation capacitor 5 is also visible. Also shown are the connecting screws 10, 16, 13 for connecting terminals and the high-voltage or low-voltage conductor 2, 3. What is not shown is that the high-voltage conductor 2 and / or the low-voltage conductor 3 can be slotted, with slots extending from one longitudinal edge of the respective conductor 2 towards, but not all the way to, the opposite longitudinal edge. Such slots can, for example, be arranged in partial regions of the high-voltage conductor 2 that cover two adjacent power switching elements 8.

[0071] In the Fig. 4 In the embodiment shown, the power switching elements 8 each have two high-voltage connections 20 (not shown in Fig. 5 visible) and two low-voltage connections 21 (also not in Fig. 5 visible). The two high-voltage terminals 20 of a power switching element 8 are each electrically and mechanically connected to the high-voltage conductor 2 via a screw 10 and a spacer sleeve 11 (not visible). The two low-voltage terminals 21 of a power switching element 8 are each electrically and mechanically connected to the low-voltage conductor 3 via a screw 16 and a spacer sleeve (not visible).

[0072] Fig. 5 shows a perspective view of the circuit arrangement 1 in a further embodiment. This can also comprise several parallel-connected power switching elements 8, each connected to a high-voltage conductor 2 and a low-voltage conductor 3. For the sake of clarity, only one power switching element 8 is shown in its entirety.

[0073] In contrast to the Fig. 4 In the illustrated embodiment, each power switching element 8 has only one high-voltage connection 20 and one low-voltage connection 21. The high-voltage connection 20 of a power switching element 8 is electrically and mechanically connected to the high-voltage conductor 2 via a screw 10 and a spacer sleeve 11. A low-voltage connection 21 of the power switching element 8 is then electrically and mechanically connected to the low-voltage conductor 3 via a screw 16 and a spacer sleeve.

[0074] Continue in Fig. 5 Shown is a screw 13 which is used to connect a low-voltage connection of the Fig. 6 not visible commutation capacitor 5 with the low-voltage conductor 3.

[0075] In an area above this screw 13, the high-voltage conductor 2 has a through-hole to ensure accessibility to the screw 13. The direction "above" refers to a vertical direction oriented from the low-voltage conductor 3 toward the high-voltage conductor 2, with the high-voltage conductor 2 being arranged vertically above the low-voltage conductor 3.

[0076] It is further shown that the high-voltage conductor 2 has a recess in an area above the low-voltage connection 21 of the power switching element 8 or above the screw 16, with the screw 16 being partially arranged in this recess. This ensures accessibility to the screw 16. At the same time, it ensures that a desired distance is maintained between parts with low-voltage potential, namely the screw 16, and parts with high-voltage potential, namely the high-voltage conductor 2.

[0077] Furthermore, the low-voltage conductor 3 has a recess in an area above the high-voltage connection 20, with the screw 10 and the spacer sleeve 11 extending through this recess. This ensures that a desired distance is maintained between parts with low-voltage potential (here the low-voltage conductor 3) and parts with high-voltage potential (here the spacer sleeve 11).

[0078] Fig. 6 shows a top view of high-voltage connection sections 6 of the Fig. 5 illustrated embodiment of the circuit arrangement 1 according to the invention.

[0079] The plate-shaped sections 9 of the high-voltage connection sections 6 are visible. Also shown are the commutation capacitors 5 and the screw 12 for connecting the high-voltage connection section 6 with a high-voltage connection of the commutation capacitor 6 as well as the screw 13 for connecting the low-voltage connection of the commutation capacitor 5 with the Fig. 5 shown low-voltage conductor 3.

[0080] Also shown are the high-voltage connection 20 and the low-voltage connection 21 of a power switching element 8. Again, for the sake of clarity, reference symbols are shown only for one of the six power switching elements 8 connected in parallel.

[0081] In contrast to the Fig. 3 In the embodiment shown, the plate-shaped section 9 of the high-voltage connection section 6 is not slotted. In the Fig. 6 In the embodiment shown, the plate-shaped section 9 has a substantially L-shaped profile, wherein the Fig. 5 The spacer sleeve 12 shown contacts a first leg of the L-shaped profile in the region of a free end section of this first leg, in particular in a region above the high-voltage connection section 20 of the power switching element 8. A further leg of the L-shaped profile element is mechanically and electrically connected to the high-voltage connection of the commutation capacitor 5 via the screw 12.

[0082] Furthermore, the plate-shaped section 9 forms a partially circular through-opening 25 through which the screw 13 and a spacer sleeve (not shown) extend from the low-voltage connection of the commutation capacitor 5 to the low-voltage conductor 3. Due to the partially circular through-opening 25, the width of the legs of the L-shaped plate-shaped section 9 varies.

[0083] The Fig. 5 and Fig. 6 The embodiment shown is used in particular for the electrical connection of an intermediate circuit capacitor with power switching elements, whereby an intermediate circuit voltage can be up to 3,600 V. The Fig. 4 The embodiment shown is preferably used for designs with intermediate circuit voltages up to 1,800 V.

[0084] For the illustrated embodiments, it is only described that the high-voltage connection section 6 of the commutation branch 4 is at least partially formed from a material whose electrical conductivity is lower than the electrical conductivity of the material of the high-voltage conductor 2. However, it is alternatively or cumulatively also possible for the low-voltage connection section 7 of the commutation branch 4 to be at least partially formed from a material whose electrical conductivity is lower than the electrical conductivity of the material of the low-voltage conductor 3. List of reference symbols

[0085] 1Circuit arrangement 2High-voltage conductor 3Low-voltage conductor 4Commutation branch 5(Commutation) capacitor 6High-voltage connection section 7Low-voltage connection section 8Power switching element 9Plate-shaped section 10Screw 11Spacer sleeve 12Screw 13Screw 14Spacer sleeve 16Screw 17Slotted section 18Web 19Gap 20High-voltage connection 21Low-voltage connection 23First edge section 24Second edge section 25Through opening

Claims

1. Electrical circuit arrangement, comprising at least one power switching element (8), a high-voltage conductor (2), a low-voltage conductor (3) and at least one commutation branch (4), the commutation branch (4) comprising a high-voltage connection section (6) electrically connected to the high-voltage conductor (2), a low-voltage connection section (7) electrically connected to the low-voltage conductor (3) and at least one capacitive element (5) which is in the form of a snubber capacitor and is electrically arranged between the high-voltage connection section (6) and the low-voltage connection section (7), the high-voltage connection section (6) of the commutation branch (4) being formed at least partially by a material whose electrical conductivity is lower than the electrical conductivity of the material of the high-voltage conductor (2), and / or the low-voltage connection section (7) of the commutation branch (4) is formed at least partially by a material whose electrical conductivity is lower than the electrical conductivity of the material of the low-voltage conductor (2), the high-voltage connection section (6) and / or the low-voltage connection section (7)) is at least partially plate-shaped and at least one partial section (17) of the high-voltage connection section (6) and / or the low-voltage connection section (7) is slotted, the high-voltage connection section (6) having two edge regions (23, 24) that are full-surface, the slotted partial section (17) being arranged between these edge regions (23, 24 ), wherein a first edge area (23) being electrically and mechanically connected to the high-voltage conductor (2) and a second edge area (24) being electrically and mechanically connected to the capacitive element (5), the slotted partial area (17) having webs (18) and slots (19) arranged between the webs (18), the edge regions (23, 24) being connected by the webs (18), the webs (18) being designed such that their resistances are set to achieve a desired current distribution, and, in a central region of the slotted sub-region (17), the latter forming a through-opening (25) through which a connecting screw (22) for connecting a low-voltage connection (21) of the power switching element (8) to the low-voltage conductor (3) and a spacer sleeve (14), which ensures a desired distance between the capacitive element (5) and the low-voltage conductor (3) and also produces an electrical connection between them, extend.

2. Electrical circuit arrangement according to claim 1, characterised in that at least one edge region of the low-voltage connection section (7) is formed over the full surface area.

3. Electrical circuit arrangement according to one of the preceding claims, characterised in that the high-voltage connection section (6) and / or the low-voltage connection section (7) of the commutation branch (4) is / are formed at least partially by stainless steel.

4. Electrical circuit arrangement according to one of the preceding claims, characterised in that the high-voltage conductor (2) and the low-voltage conductor (3) each comprise at least one section which is designed in the form of a plate, the sections which are designed in the form of a plate being arranged parallel to one another, the high-voltage connection section (6) and / or the low- low-voltage connecting section (7) of the commutation branch (4) comprises at least one plate-shaped partial section (9) which is arranged parallel to the plate-shaped sections of the high-voltage and low-voltage conductors (2, 3) and on a side of the low-voltage conductor (3) facing away from the high-voltage conductor (2).

5. Electrical circuit arrangement according to claim 4, characterised in that a thickness of the plate-shaped sub-section (9) is less than a thickness of the plate-shaped section of the high-voltage conductor (2) and / or less than a thickness of the plate-shaped section of the low-voltage conductor (3).

6. Electrical circuit arrangement according to claim 4 or 5, characterised in that a distance between the plate-shaped sub-section (9) and the plate-shaped section of the low-voltage conductor (3) is equal to the distance between the plate-shaped sub-section (9) and the plate-shaped section of the high-voltage conductor (2).

7. Electrical circuit arrangement according to one of the preceding claims, characterised in that a high-voltage connection (20) of the power switching element (8) is connected to the high-voltage conductor (2) via the high-voltage connection section (6) and / or a low-voltage connection of the power switching element (8) is connected to the low-voltage conductor (3) via the low-voltage connection section (7).

8. Electrical circuit arrangement according to one of the preceding claims, characterised in that the high-voltage connection section (6) has or forms a through-opening (25) which is designed for the arrangement of the low-voltage terminal section (7), and / or that the low-voltage terminal section (7) has or forms a through-opening which is designed for the arrangement of the high-voltage terminal section (6).

9. Electrical circuit arrangement according to one of the preceding claims, characterised in that a width of the webs (18) in the slotted region (17) varies in order to adjust the resistances of the webs (18) to the desired value.

10. Electrical circuit arrangement according to claim 9, characterised in that the width of the webs (18) decreases from an edge region towards the central region.

11. Rail vehicle having an electrical circuit arrangement according to one of claims 1 to 10.

12. Method for producing an electrical circuit arrangement (1), wherein at least one power switching element (8), at least one high-voltage conductor (2), at least one low-voltage conductor (3) and at least one commutation branch (4) being provided with a high-voltage connection section (6), a low-voltage connection section (7) and at least one capacitive element ( 5), which is electrically arranged between the high-voltage connection section (6) and the low-voltage connection section (7), are provided, wherein, furthermore, the high-voltage connection section (6) is electrically connected to the high-voltage conductor (2) and the low-voltage connection section (7) is electrically connected to the low-voltage conductor (3), wherein the high-voltage connection section (6) of the commutation branch is formed at least partially by a material whose electrical conductivity is lower than the electrical conductivity of the material of the high-voltage conductor (2), and / or the low-voltage connection section (7) of the commutation branch (4) is formed at least partially by a material whose electrical conductivity is lower than the electrical conductivity of the material of the low-voltage conductor (2), wherein the high-voltage connection section (6) and / or the low-voltage connection section (7) is / are at least partially plate-shaped and at least one subsection (17) of the high-voltage connection section (6) and / or of the low-voltage connection section (7) is / are slotted, the high-voltage connection section (6) having two edge regions (23, 24) that are full-surface, the slotted partial section (17) being arranged between these edge regions (23, 24), wherein a first edge area (23) being electrically and mechanically connected to the high-voltage conductor (2) and a second edge area (24) being electrically and mechanically connected to the capacitive element (5), the slotted partial area (17) having webs (18) and slots (19) arranged between the webs (18), the edge regions (23, 24) being connected by the webs (18), the webs (18) being designed such that their resistances are set to achieve a desired current distribution, and, in a central region of the slotted sub-region (17), the latter forming a through-opening (25) through which a connecting screw (22) for connecting a low-voltage connection (21) of the power switching element (8) to the low-voltage conductor (3) and a spacer sleeve (14), which ensures a desired distance between the capacitive element (5) and the low-voltage conductor (3) and also produces an electrical connection between them, extend.