Power converter, in particular configured to be embedded in a motor vehicle

Abstract

The invention relates to a power converter comprising: - a capacitive filtering device (110), - at least one power module connected to the capacitive filtering device by a positive busbar and a negative busbar, - a control board arranged on the capacitive filtering device and / or power module with a view to controlling the power module, the control board comprising a fastening orifice, - a metal heat sink housing the capacitive filtering device and the power module, and comprising a fastening pad extending between the positive busbar (121) and the negative busbar (122), the fastening pad comprising a cavity plumb with the fastening orifice of the control board, - a means for fastening the control board to the heat sink, - an electrical insulation device (160) inserted between the busbars and the fastening pad.

Description

[0001] DESCRIPTION

[0002] Title of the invention: Power converter, in particular configured for installation in a motor vehicle

[0003] The present invention relates to the field of electrical equipment, such as inverters, equipped with a power module and a capacitive filtering device, intended to be associated with an electrical machine, for example an electric or hybrid vehicle motor.

[0004] In an electric or hybrid vehicle, the electric motor system is powered by a high-voltage battery that propels the vehicle. More specifically, to control the electric motor that drives the vehicle's wheels, a power converter, such as an inverter, is used to convert the direct current (DC) voltage supplied by the high-voltage battery into alternating current (AC) voltage.

[0005] Such a power converter typically comprises a power module and a capacitive filtering device. The capacitive filtering device, also called a link capacitor and more commonly known by its English term "DC-link capacitor," smooths the DC voltage supplied to the power module. The power module is connected to the capacitive filtering device and generates an AC voltage from the smoothed DC voltage to supply electrical energy to the electric machine. The connection between the capacitive filtering device and the power module is made using at least two busbars, specifically one positive and one negative busbar. For high-power applications, one positive and one negative busbar per phase are required, meaning six busbars in total.

[0006] For optimal power module performance, the power module is located near the capacitive filtering device. The entire assembly is housed in a metallic enclosure, typically made of aluminum, called a heat sink, which contributes to the thermal integrity of the converter components.

[0007] Prior art power converters typically have multi-board architectures. They include a PU (Power Unit) board to drive the power module and a CU (Control Unit) board to control the overall operation of the converter (monitoring temperature data, transmitting signals, etc.). Consequently, the PU board is small and simply mounted on the power module.

[0008] However, the coexistence of these two boards requires additional components to connect them, such as ribbon cables clipped onto connectors and / or interconnect pins. This implies additional steps in the manufacturing process and results in a certain amount of bulk in the product.

[0009] One solution is to use a larger control board that combines the functions and components of the so-called PU board and the so-called CU board. This type of control board is advantageous because there is no longer any interconnection between boards to be made.

[0010] However, because this control board is large, it is more susceptible to mechanical stress and can suffer from vibrational resonance, particularly in automotive applications. Therefore, it is essential to provide multiple mounting points for the control board distributed across its surface to avoid any large unsupported areas.

[0011] One of the particularly sensitive areas is located above the capacitive filtering device. As mentioned previously, to ensure optimal operation of the power module, it must be positioned close to the capacitive filtering device. Since it is difficult to create mounting points above the capacitive filtering device, this solution presents the problem of leaving a large area of ​​the control board unsupported. A necessary solution is to position a mounting block between the power module and the capacitive filtering device. However, the increasing number of bus bars leaves even less space for a mounting block in this location.

[0012] Another issue with such a converter is electrical isolation. The mounting points for the control board are formed by the heatsink. In other words, protrusions on the heatsink create the mounting points, for example, cylindrical in shape, meaning they have an outer wall shaped like the side surface of a cylinder and an inner wall defining a cavity for inserting a mounting screw. Since the heatsink is grounded to the chassis, it must be positioned far enough from the bus bars to prevent arcing. This necessitates placing the mounting points near the capacitive filtering device to ensure proper support for the control board, but far enough from the bus bars to maintain electrical isolation distances and counteract the effects of creepage lines.

[0013] The present invention falls within this context and aims to provide a suitable control board mounting system within a power converter, enabling the mounting of a large control board in a space-constrained environment while meeting electrical insulation requirements.

[0014] To this end, the invention relates to a power converter, in particular configured to be installed in a motor vehicle, characterized in that it comprises:

[0015] A capacitive filtering device capable of smoothing a DC voltage from a DC voltage source, the capacitive filtering device being delimited by a casing,

[0016] At least one power module connected to the capacitive filtering device by a positive busbar and a negative busbar, the busbars extending along a first horizontal axis, the power module being capable of generating an alternating voltage from the smoothed direct current voltage, and vice versa,

[0017] A control card mounted on the capacitive filtering device and / or the power module, intended to control the power module, the control card including a mounting hole,

[0018] A metallic heat sink forming a housing for the capacitive filtering device and the power module, and comprising a mounting stud extending along a first vertical axis between the positive busbar and the negative busbar, the mounting stud comprising an external wall and an internal wall delimiting a cavity at the mounting hole of the control board,

[0019] A means of attaching the control board to the heatsink arranged through the mounting hole and the cavity of the mounting stud,

[0020] An electrical insulation device, preferably made of plastic, inserted between the bus bars and the fixing post.

[0021] Thanks to these features, it is possible to mount a large control board in a highly compact power converter while protecting it from the mechanical stresses to which it is subjected. Furthermore, despite the limited free space available in such a power converter, the invention addresses the issue of electrical insulation between components and ensures that the necessary insulation distances are maintained between the mounting block and the adjacent positive and negative bus bars. The result is a compact high-voltage power converter that adheres to the required insulation distances.

[0022] According to an optional feature of the invention, the electrical insulation device forms an enclosure with an internal dimension greater than the external width of the mounting block. In addition to surrounding the mounting block to form a shield between the bus bars and the mounting block, this feature facilitates the insertion of the electrical insulation device around the mounting block.

[0023] According to an optional feature of the invention, the outer wall of the fixing block is generally cylindrical in shape and the casing of the electrical insulation device is cylindrical, the inner dimension of the casing being its diameter.

[0024] According to an optional feature of the invention, the electrical isolation device has an upper end connected to a lower surface of the control board. In this embodiment, the electrical isolation device is connected to the control board. It is installed simultaneously with the control board being placed on the capacitive filtering device and / or the power module. No additional parts need to be handled, and the electrical isolation device is inserted around the mounting stud during the installation of the control board.

[0025] According to an optional feature of the invention, the electrical isolation device is integral with the housing of the filtering device. In such a variant, the electrical isolation device is connected to the capacitive filtering device. When the capacitive filtering device is installed in the heat sink, the protrusion forming the electrical isolation device surrounds the mounting stud, thus providing protection and extending the isolation distance between the bus bars and the mounting stud.

[0026] The housing of the filtering device, for example, is made of plastic.

[0027] According to an optional feature of the invention, with the power module housed in a casing, the electrical isolation device is integral with the power module casing. In this embodiment, the electrical isolation device is connected to the power module. As before, when the power module is installed in the heat sink, the electrical isolation device is positioned around the mounting stud, between the mounting stud and the bus bars.

[0028] The power module housing is, for example, made of plastic. According to an optional feature of the invention, the outer wall of the mounting block comprises a first flat, and preferably a second flat extending on either side of the cavity.

[0029] According to an optional feature of the invention, the outer wall comprises a third flat, and preferably a fourth flat, distinct from the first and second flats, extending on either side of the cavity.

[0030] The presence of one or more flats on the outer wall of the mounting block allows for a reduction in its cross-section. This results in both an increased distance between the outer wall of the mounting block and the adjacent bus bar, and easier insertion of the electrical insulation device around the mounting block, despite variations in the mounting block's cross-section due to tolerances inherent in the manufacturing process.

[0031] According to an optional feature of the invention, the electrical insulation device has a lower wall extending from a body of said electrical insulation device so as to extend between a connection means, extending respectively through one of the busbars, and the mounting stud. This improves electrical insulation between the components and ensures that the necessary insulation distances are maintained between the mounting stud and the connection means of the positive and negative busbars adjacent to the mounting stud.

[0032] According to an optional feature of the invention, the lower wall extends beyond the connection means so that said lower wall protrudes in an axial direction relative to said connection means.

[0033] The invention also relates to a motor vehicle comprising such a power converter.

[0034] Other features and advantages of the invention will become apparent from the following description on the one hand, and from several illustrative and non-limiting examples of embodiments given with reference to the attached schematic drawings on the other hand, in which:

[0035] [Fig. 1] represents a view of a heat sink incorporating a power module of the power converter according to the invention,

[0036] [fig 2] represents a view of the heat sink in figure 1, which also incorporates the capacitive filtering device.

[0037] [fig 3] represents a view of the heat sink in figure 2, also incorporating the control board,

[0038] [Fig. 4] shows a view of the housing of the capacitive filtering device,

[0039] [Fig. 5] shows a view of an embodiment of a mounting block for the power converter according to the invention,

[0040] [Fig. 6] schematically represents a cross-sectional view of a mounting block for the control board of the power converter of the invention with two variants of the electrical isolation device,

[0041] [fig 7] schematically represents a cross-sectional view of a mounting block of the power converter control board of the invention with another variant of the electrical isolation device.

[0042] The features, variations, and different embodiments of the invention, as described or as they will be presented in the detailed description that follows, can be combined in various ways, provided they are not incompatible or mutually exclusive. In particular, variations of the invention may be conceived comprising only a selection of features, described hereafter in isolation from the other described features, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art. For clarity, the same elements are designated by the same reference numerals in the various figures.

[0043] Before detailing the principle of the invention, the main elements of the power converter 100 will be introduced on the basis of figures 1 to 3.

[0044] Figure 1 shows a view of a heat sink incorporating a power module of the power converter according to the invention.

[0045] The power converter 100 according to the invention is specifically configured for installation in a motor vehicle. The power converter 100 includes a metal heat sink 140. As will be seen in the following figures, the metal heat sink 140 forms a housing for a capacitive filtering device and the power module 120. A control board 130 (not shown in Figure 1) is then mounted on the capacitive filtering device 110 and / or on the power module 120 to control the power module 120. The capacitive filtering device 110 is capable of smoothing a DC voltage from a DC voltage source. The power module 120 is capable of generating an AC voltage from the smoothed DC voltage, and vice versa.

[0046] We take as an arbitrary reference the fact that the power module 120 extends in a horizontal plane, which is also the main plane along which the power converter extends.

[0047] The metal heat sink 140 includes a mounting bracket 141 extending along a first vertical axis Z, perpendicular to the previously mentioned horizontal plane. It should be noted that the mounting bracket 141 comprises an outer wall 142 and an inner wall 143 defining a cavity 144. The mounting bracket 141, detailed below, serves to allow the control board 130 to be attached to the metal heat sink 140.

[0048] Figure 2 shows a view of the heat sink of Figure 1, which also incorporates the capacitive filtering device 110. The capacitive filtering device 110 is enclosed by a plastic housing 111. Busbars 121 and 122 extend along a first horizontal axis X, perpendicular to the first vertical axis Z and parallel to the horizontal plane, from the capacitive filtering device 110 to the power module 120. The power module 120 is connected to the capacitive filtering device 110 by at least the positive busbar 121 and at least the negative busbar 122. The power module is generally positioned close to the capacitive filtering device 110 to allow their connection in a small space, resulting in a compact power converter.

[0049] As shown in Figure 2, the mounting post 141 extends between the positive busbar 121 and the negative busbar 122. In other words, on each side of the mounting post 141 is a busbar: the positive busbar on one side and the negative busbar on the other. As mentioned in the introduction, the metal heat sink 140 is grounded to the chassis. The busbars are not electrically isolated. Without taking special precautions, there is a risk of electrical interference between the busbars and the mounting post due to the short distance between them. This interference is undesirable and can damage the converter. The power converter of the invention provides a solution, explained below, which allows for adequate creepage and clearance distances between the mounting post and each busbar adjacent to the mounting post.

[0050] The clearance distance is the shortest distance in air separating electrical components, while the leakage distance is the shortest distance measured along an insulating surface arranged between these components. These distances are governed by industry standards such as IEC 60664. Typically, the higher the operating voltage of the components, the greater the leakage and clearance distances must be to prevent arcing between them. The converter of the invention solves the problem of having to place mounting pads near the capacitive filtering device to ensure proper support for the control board, but at a distance from the bus bars to maintain electrical insulation distances and counteract the effects of leakage lines. Figure 3 shows a view of the heatsink of Figure 2, which also incorporates the control board 130.In this non-limiting example, the control board 130 is placed on the power module 120 and the capacitive filtering device 110. It completely covers the power module 120 and partially covers the capacitive filtering device 110. Other configurations are possible without departing from the scope of the invention: the control board 130 can cover either of the power module and the capacitive filtering device, or the control board can only partially cover one of them. Given the trend towards combining the functions of a CU board and a PU board on a single control board, it follows that the control board has a certain size that necessitates at least partial overlap of the power module and the capacitive filtering device.

[0051] The control board 130 includes a mounting hole 131 to allow its attachment to the metal heat sink.

[0052] The cavity 144 of the mounting stud is located directly opposite the mounting hole 131 of the control board 130. In other words, the cavity 144 is directly opposite the mounting hole 131 of the control board 130. The power converter 100 includes a means 150 for attaching the control board 130 to the heatsink 140. This means is positioned through the mounting hole 131 and the cavity 144 of the mounting stud 141. The means 150 may be a screw. The means 150 passes through the mounting hole 131 of the control board 130 and is inserted into the cavity 144 of the mounting stud. Thus, the control board 130 is rigidly attached to the metal heatsink. The power converter 100 may further include additional fixing devices 151, for example arranged at the four corners of the control board 130, for fixing the control board to the heat sink.

[0053] In summary, the power converter 100 includes the capacitive filtering device 110 capable of smoothing a DC voltage from a DC voltage source, the power module 120 connected to the capacitive filtering device 110 by the positive bus bar 121 and the negative bus bar 122. It can be noted that the converter 100 can include several power modules.

[0054] The power converter 100 includes the metal heat sink 140 which houses the capacitive filtering device 110 and the power module 120. It also includes the control board 130 to control the power module 120. The control board 130 is attached to the metal heat sink 140 by means of the mounting stud 141 of the heat sink 140, for example by a screw 150 which passes through the hole 131 of the control board and is inserted into the cavity 144 of the mounting stud 141.

[0055] In the prior art, and given the compact size of the power converters, electrical interference is possible between the busbars 121, 122 on the one hand and the mounting block on the other. Indeed, the distance between each busbar and the mounting block may be too short, leading to this electrical interference.

[0056] According to the invention, the power converter 100 includes an electrical insulation device 160, made of electrically insulating material, preferably plastic, interposed between the bus bars 121, 122 and the fixing block 141. The electrical insulation device 160 is visible in Figure 2.

[0057] Thanks to this feature, the power converter of the invention allows the control board to be fixed in a compact environment while ensuring the distances required to increase clearance and leakage distances in order to meet electrical insulation requirements.

[0058] The electrical isolation device 160 is arranged on one side between the bus bar 121 and the fixing post 141 and on the other side between the bus bar 122 and the fixing post 141. The electrical isolation device 160 is interposed between the bus bar adjacent to the fixing post and the fixing post and aims to lengthen the isolation distance between the bus bar and the fixing post.

[0059] The electrical insulation device 160 surrounds the mounting block 141, thus blocking any direct line between the adjacent busbar and the mounting block. Thanks to the electrical insulation device 160, the insulation distances between the mounting block and the adjacent busbars are increased. The path between each busbar and the mounting block must bypass the electrical insulation device 160, as will be explained in the detailed description of the electrical insulation device variants.

[0060] Figure 4 shows a view of the housing 111 of the capacitive filtering device 110. The busbars 121 and 122 extending along the X-axis are visible. In this embodiment, the electrical isolation device 160 is integral with the plastic housing of the filtering device. The electrical isolation device 160 can be seen as an extension of the housing 111 of the capacitive filtering device 110, or it can be an additional component added to and connected to the housing 111 of the capacitive filtering device 110. The electrical isolation device 160 has a hollow shape. In other words, the electrical isolation device 160 includes a through passage extending along the Z axis. The through passage allows the electrical isolation device 160 to fit around the mounting stud 141 and to provide an opening for the insertion of the fixing means 150 into the mounting stud in order to fix the control board to the mounting stud 141.

[0061] The electrical insulation device forms an enclosure with an internal dimension 161 greater than the external width 145 of the mounting stud 141. This internal dimension 161 corresponds to the internal dimension of the penetration. It can, for example, be the width of a section perpendicular to the Z-axis of the penetration if the penetration has a rectangular or square cross-section.

[0062] In Figure 4, the electrical isolation device 160 is associated with the capacitive filtering device 110. Alternatively, the electrical isolation device 160 can be associated with the power module 120. This variant is not shown, but based on a principle analogous to that described previously, it can be understood that, since the power module is housed in a casing, the electrical isolation device is connected to the power module casing. In this case, the electrical isolation device can be an extension of the power module casing, or it can be an additional element added and fixed to the power module casing to form a through-hole arranged around the mounting stud 141 of the metal heat sink 140, on the same principle as that explained for the capacitive filtering device.

[0063] Figure 5 shows a view of an embodiment of a mounting block 141 of the power converter according to the invention. In this embodiment, the mounting block has a squircle-shaped cross-section in the PI plane perpendicular to the Z-axis. A squircle is a mathematical shape intermediate between a square and a circle; it is a contraction of "square" and "circle." It is also referred to as a rounded square or a square with the same curvature at each of its vertices. Alternatively, the cross-section of the mounting block in the PI plane can be circular or polygonal, for example, rectangular or square. In the case of a squircle-shaped cross-section, the outside width 145 of the mounting block is the distance between two opposite sides of the squircle. In the case of a circular cross-section, the outside width 145 is the diameter of the cross-section.

[0064] According to an optional feature of the invention, the outer wall of the mounting block comprises a first flat 146, and preferably a second flat 147, both extending on either side of the cavity 144. In other words, the flat(s) are located on the outer wall of the mounting block and extend over at least part of its height from its upper surface. The presence of a flat 146 reduces the cross-section of the mounting block. The presence of flats 146 and 147 opposite each other with respect to the Z-axis further reduces the cross-section of the mounting block.

[0065] In another variant, the outer wall may include a third flat, and preferably a fourth flat, distinct from the first and second flats, extending on either side of cavity 144. The third and fourth flats may be identical to the first and second flats, but are offset around the Z-axis relative to the positioning of the first and second flats. The third and fourth flats reduce the cross-section of the mounting block. The flats of the mounting block allow the dimension of the mounting block to be reduced along a cross-section perpendicular to the Z-axis. This is equivalent to saying that machining flats reduces the width of the mounting block (or the diameter in the case of a circular cross-section of the mounting block).This reduction in width has a dual effect: it increases the distance between the fixing block and the adjacent bus bar, and it facilitates the insertion of the fixing block into the through passage of the electrical isolation device.

[0066] Figure 6 schematically represents a cross-sectional view of a mounting block 141 of the control board 130 of the power converter of the invention with two variants of the electrical isolation device. One variant is illustrated on the left side of the figure and another variant is illustrated on the right side of the figure.

[0067] In what follows, we will discuss the outer wall of a mounting block that is generally cylindrical in shape, in which case the casing of the electrical insulation device is cylindrical, and the inner dimension of the casing is its diameter. However, the same principle applies in the case of an outer wall of the mounting block with a polygonal cross-section, for example, rectangular or square.

[0068] In the variant shown on the left of the figure, the electrical isolation device 160 is positioned between the busbar adjacent to the mounting block and the mounting block itself. This can be an extension of the capacitive filtering device or the power module, as explained previously.

[0069] In the variant illustrated on the right of the figure, the electrical isolation device 160 has an upper end 162 connected to a lower surface 132 of the control board 130. In this variant, the electrical isolation device 160 is attached to the control board 130 at its lower surface 132. When the control board 130 is positioned for attachment to the metal heat sink, the electrical isolation device 160 is positioned around the mounting stud, encircling it to form a complete envelope around its upper portion. Regardless of the variant, the electrical isolation device 160 is interposed between a busbar adjacent to the mounting stud and the mounting stud itself.

[0070] Figure 7 schematically represents a cross-sectional view of a mounting block 141 of the control board 130 of the power converter of the invention with another variant of the electrical isolation device 160.

[0071] In this variant, the electrical insulation device 160 has a lower wall 163 extending from the body 164 of said electrical insulation device. The lower wall 163 extends between a connection means 123, 124 extending respectively through one of the bus bars 121, 122, and the fixing stud 141.

[0072] The bus bars 121, 122 can each be crossed by means of connection, such as screws, rivets, nuts in order to electrically connect said bus bars 121, 122 to another element of the power converter, such as for example, the capacitive filtering device 110.

[0073] For example, the electrical insulation device 160 extends over the entire length of the connection means 123, 124 so that all the minimum distances between each portion of the connection means 123, 124 and each portion of the fixing stud 141 are crossed by the electrical insulation device 160. In other words, a projection, along a direction perpendicular to an extension direction of the stud 141, of the connection means 123, 124 onto the stud 141 is completely covered by the electrical insulation device 160.

[0074] For example, the connection means 123, 124 extends opposite the body 164 and the lower wall 163.

[0075] In particular, the lower wall 163 extends beyond the connecting means 123, 124 so that said lower wall protrudes in an axial direction relative to the connecting means 123, 124.

[0076] In this example, the lower wall 163 extends globally axially with respect to the axis of the mounting stud 141. In this embodiment, the internal dimension of the lower wall 163 is greater than the internal dimension 161 of the body 164. In particular, in the example illustrated in Figure 7, the diameter of the lower portion 163 is greater than the diameter of the body 164 to adapt to the shape of the mounting stud 141.

[0077] Busbar 121 is a positive busbar; it can be high voltage, for example, between 400 and 800V. Busbar 122 is a negative busbar. Heat sink 111 is metallic.

[0078] The dashed arrows represent the creepage distance between the bus bars and the heat sink mounting point. It can be seen that, thanks to the insertion of the electrical isolation device, the creepage distance is greater than without the device. In other words, the electrical isolation device 160 increases the isolation distance between a bus bar and the mounting point, even though these two elements are adjacent and physically separated by a small distance. This is referred to as an extended creepage distance. The electrical isolation device is made of an electrically insulating material, preferably plastic. It forms a shield between the mounting point and the bus bars 121, 122.

[0079] Thanks to the invention, it is possible to integrate a large control board into a compact power converter and, despite everything, to maintain the required isolation distances between the mounting block and the bus bars adjacent to the mounting block located between a positive bus bar and a negative bus bar.

[0080] Of course, the invention is not limited to the examples just described, and many modifications can be made to these examples without departing from the scope of the invention. In particular, the features of different embodiments of the invention can be combined to carry out the invention, provided that these embodiments are not incompatible with each other.

Claims

DEMANDS 1- Power converter (100), in particular configured for installation in a motor vehicle, characterized in that it comprises: A capacitive filtering device (110) capable of smoothing a DC voltage from a DC voltage source, the capacitive filtering device (110) being delimited by a housing (111), At least one power module (120) connected to the capacitive filtering device (110) by a positive busbar (121) and a negative busbar (122), the busbars (121, 122) extending along a first horizontal axis (X), the power module (120) being capable of generating an alternating voltage from the smoothed direct voltage, and vice versa, A control card (130) disposed on the capacitive filtering device (110) and / or the power module (120) and intended to control the power module (120), the control card (130) including a mounting hole (131), A metallic heat sink (140) forming a housing for the capacitive filtering device (110) and the power module (120), and comprising a mounting stud (141) extending along a first vertical axis (Z) between the positive bus bar (121) and the negative bus bar (122), the mounting stud (141) comprising an outer wall (142) and an inner wall (143) defining a cavity (144) at the mounting hole (131) of the control board (130), A means for fixing (150) the control board (130) to the heat sink (140) disposed through the fixing hole (131) and the cavity (144) of the fixing post (141), An electrical insulation device (160), preferably made of plastic, interposed between the omnibus bars (121, 122) and the fixing block (141). 2- Power converter (100) according to claim 1, in which the electrical insulation device (160) forms an enclosure with an internal dimension (161) greater than an external width (145) of the fixing stud (141). 3- Power converter (100) according to claim 2, in which the outer wall (142) of the fixing block (141) is generally cylindrical in shape and the enclosure of the electrical insulation device (160) is cylindrical, the inner dimension of the enclosure being its diameter. 4- Power converter (100) according to any one of claims 1 to 3, wherein the electrical isolation device (160) has an upper end (162) connected to a lower surface (132) of the control board (130). 5- Power converter (100) according to any one of claims 1 to 3, wherein the electrical isolation device (160) is integral with the housing (111) of the filtering device (110). 6- Power converter (100) according to any one of claims 1 to 3, the power module (120) being housed in a casing, in which the electrical isolation device (160) is integral with the casing of the power module. 7- Power converter (100) according to any one of claims 1 to 6, in which the outer wall (142) of the mounting block (141) comprises a first flat (146), and preferably a second flat (147) extending on either side of the cavity (144). 8- Power converter (100) according to claim 7, in which the outer wall (142) comprises a third flat, and preferably a fourth flat, distinct from the first and second flats, extending on either side of the cavity (144). 9- Power converter (100) according to any one of the preceding claims, wherein the electrical insulation device (160) has a lower wall (163) extending from a body (164) of said electrical insulation device (160) so as to extend between a connection means (123, 124), extending respectively through one of the omnibus bars (121, 122), and the fixing block (141). 10- Power converter (100) according to claim 9, wherein the lower wall (163) extends beyond the connection means (123, 124) such that said lower wall protrudes in an axial direction relative to said connection means (123, 124). 11- Motor vehicle comprising a power converter (100) according to any one of the preceding claims.

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