Switching cell

Abstract

The present invention relates to - a power module (102), - an upper bus bar (130) and a lower bus bar (128) connected to each of the power modules (102) for distributing a DC voltage (U DC ) to each of the power modules (102), wherein the upper bus bar and the lower bus bar each comprise a first plate, the upper bus bar (130) and the lower bus bar (128); - at least one capacitor (136) having two terminals welded to two bus bars (128, 130) respectively; The upper bus bar (130) and the lower bus bar (128) are laminated on each other, and the switching cell (100) comprises a carrier (132) of the upper bus bar (130) and the lower bus bar (128) having a bottom (134) on which the first plate of the laminated bus bars (128, 130) is located. The first plate of the lower bus bar (128) has an opening (902) for keeping the connection portion (904) of the first plate of the upper bus bar (130) visible. The bottom (134) has an opening (908) for connecting the first terminal (138) of the capacitor (136) to the connection portion (910) of the lower bus bar (128) through the opening (908) of the bottom (134), and for connecting the second terminal (140) of the capacitor (136) to the connection portion (904) of the upper bus bar (130) through the opening (908) of the bottom (134) and through the opening (902) of the lower bus bar (128). The switching cell (100) is characterized in that it has an opening (908) for keeping at least one part of the connection portion (910) of the first plate of the lower bus bar (128) and the opening (902) of the first plate of the lower bus bar (128) visible.

Description

Technical Field

[0001] The present invention relates in particular to a switching cell for an inverter related to an electric machine.

Background Art

[0002] The prior art includes - a power module, - a first bus bar called an upper bus bar and a second bus bar called a lower bus bar, each connected to each of the power modules to distribute a DC voltage to each of the power modules, wherein the upper bus bar and the lower bus bar each comprise a first plate, the first bus bar and the second bus bar, - at least one capacitor having two terminals welded to the first bus bar and the second bus bar, respectively, and discloses a switching cell.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The welding of the capacitor requires the use of potentially bulky equipment and access to the bus bars. Therefore, due to the constraints of welding, the bus bars are generally arranged at a distance from each other.

[0004] However, generally, it is desirable for the switching cell to be as compact as possible.

[0005] Therefore, it may be desirable to provide a switching cell that enables at least some of the aforementioned problems and constraints to be overcome.

Means for Solving the Problems

[0006] According to a first aspect of the present invention, a switching cell is provided, the switching cell comprising - a power module, -For distributing the -DC voltage to each of the power modules, a first bus bar called the upper bus bar and a second bus bar called the lower bus bar, each connected to each of the power modules, wherein the upper bus bar and the lower bus bar each comprise a first plate, the first bus bar and the second bus bar, -at least one capacitor having two terminals welded to the first bus bar and the second bus bar respectively, The upper bus bar and the lower bus bar are laminated on top of each other, and the switching cell comprises carriers of the upper bus bar and the lower bus bar, the bottom of which has the first plate of the laminated bus bars thereon, and the first plate of the lower bus bar has an opening that leaves visible a portion called the connection portion of the first plate of the upper bus bar, and the bottom, on the one hand, connects the first terminal of the capacitor to the connection portion of the lower bus bar through the opening in the bottom, and on the other hand, connects the second terminal of the capacitor to the connection portion of the upper bus bar through the opening in the bottom and through the opening in the lower bus bar, and has an opening that leaves visible at least one portion of the connection portion called the connection portion of the first plate of the lower bus bar and at least one portion of the opening of the first plate of the lower bus bar.

[0007] According to the present invention, since the bus bars are laminated, they occupy little space and are at the same time easily connected to the capacitor.

[0008] According to its first aspect, the present invention may further comprise one or more of the following optional features in any technically possible combination.

[0009] Optionally, the two terminals of the capacitor are welded to the first plate of the upper bus bar and the first plate of the lower bus bar respectively.

[0010] Optionally, the first plates of the upper bus bar and the lower bus bar are flat.

[0011] Optionally, the connection portion of the first plate of the lower bus bar has a thickness smaller than the rest of the first plate of the lower bus bar.

[0012] Optionally, the first plate of the upper bus bar has an embossment that extends into the opening of the first plate of the lower bus bar.

[0013] Optionally, the embossment has a flat lower connection wall having a thickness smaller than the rest of the first plate of the upper bus bar.

[0014] Optionally, the carrier has a fastening pin, the first plate of the upper bus bar has an opening for receiving the fastening pin, and the fastening pin is stacked to fasten the first plate of the bus bar to the carrier.

[0015] Optionally, the first plate of the lower bus bar is held between the first plate of the upper bus bar and the carrier.

[0016] Optionally, the lower bus bar is designed to have a high potential and the upper bus bar is designed to have a low potential.

[0017] Optionally, the carrier has a pin for positioning the first plate of the lower bus bar.

[0018] Optionally, the positioning pin is arranged to hold the first plate of the lower bus bar in a predetermined position at a right angle to the fastening pin.

[0019] Optionally, the positioning pin exists parallel to the fastening pin.

[0020] Optionally, each power module implements a switching arm designed to perform conversion between a DC voltage and an AC voltage.

[0021] Optionally, the switching cell also comprises a circuit for cooling the power module, said cooling circuit comprising a cooling casing defining channels for the flow of a coolant, the cooling casing having an upper cooling surface and a lower cooling surface, both of which are cooled by the flow of the coolant through the channels, and the power module being pressed against the upper cooling surface in order to be cooled.

[0022] Optionally, the first plate of the upper busbar is in thermal contact with the lower cooling surface.

[0023] Optionally, the cooling casing also comprises an inlet duct for introducing the coolant into the cooling casing and an outlet duct for discharging the coolant from the cooling casing, the inlet duct and the outlet duct each having segments, and the segments of the inlet duct and the segments of the outlet duct protruding in the same direction and substantially parallel to each other.

[0024] Optionally, a first insulating layer is inserted between the first plate of the upper busbar and the first plate of the lower busbar.

[0025] Optionally, a second insulating layer is disposed between the upper part of the first plate of the upper busbar and the lower surface of the cooling casing.

[0026] According to a second aspect of the invention, an inverter comprising a switching cell according to the first aspect of the invention is also provided.

[0027] Optionally, the inverter also comprises a casing within which the switching cell is disposed, the casing having two passage openings, the segment of the inlet duct being inserted into one of the two passage openings and the segment of the outlet duct being inserted into the other of the two passage openings.

[0028] According to a third aspect of the invention, a mobility device comprising a switching cell according to the first aspect of the invention or an inverter according to the second aspect of the invention is also provided.

[0029] The mobility device is, for example, a motor or engine-driven land vehicle, a train, an aircraft, or a drone.

[0030] The motor or engine-driven land vehicle is, for example, an automobile, a motorcycle, an electric bicycle, or an electric wheelchair.

Brief Description of the Drawings

[0031] The present invention will be better understood by the following description, which is provided merely by way of example and with reference to the accompanying drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

DETAILED DESCRIPTION OF THE INVENTION

[0032] In the following description and claims, various components and elements are spatially positioned relative to each other with reference to a right-handed orthogonal coordinate system XYZ in an arbitrary orientation having X, Y, and Z directions. For clarity, the X direction is referred to as the left-right direction (in the figure, the X-direction arrow points to the left), the Y direction is referred to as the front-back direction (in the figure, the Y-direction arrow points to the rear), and the Z direction is referred to as the up-down direction (in the figure, the Z-direction arrow points upward).

[0033] Next, with reference to the drawings, an example of a switching cell 100 in which the present invention is implemented will be described.

[0034] Referring to FIG. 1, the switching cell 100 first includes a plurality of power modules 102. In the illustrated example, three power modules 102 are provided. The power modules 102 are arranged adjacent to each other, for example.

[0035] The switching cell 100 further includes a controller circuit board 104 for controlling the power module 102. The controller circuit board 104 is, for example, above the power module 102.

[0036] The switching cell 100 further includes a circuit 106 for cooling the power module 102.

[0037] The cooling circuit 106 includes a cooling casing 108 that defines a channel 110 for the flow of a coolant. The cooling casing 108 has an upper cooling surface 112 and a lower cooling surface 113 that are both cooled by the flow of the coolant through the channel 110. Accordingly, the power module 102 is pressed against the upper cooling surface 112 to be cooled.

[0038] To hold the power module 102 in a state pressed against the upper cooling surface 112, the switching cell 100 first includes, for example, a cover 114 above the power module 102, for example, between the controller circuit board 104 and the power module 102. The cover 114 is fastened to the cooling casing 108, for example, by screws. The switching cell 100 further includes a spring system inserted between the cover 114 and the power module 102. Accordingly, this spring system is designed to compress the cover 114 and push the power module 102 against the upper cooling surface 112. The spring system includes, for example, for each power module 102, one plate spring 116 compressed between the cover 114 and the power module 102.

[0039] The cooling circuit 106 further includes an inlet duct 118 for allowing the coolant to flow into the cooling casing 108 and an outlet duct 120 for allowing the coolant to flow out of the cooling casing 108. The ducts 118, 120 are, for example, located on the right side and the left side of the cooling casing 108, respectively, and protrude vertically downward from the cooling casing.

[0040] The switching cell 100 further includes a bus bar called a positive bus bar 128 and a bus bar called a negative bus bar 130, which are stacked on top of each other. Therefore, one of the two bus bars 128, 130 forms a lower bus bar and the other forms an upper bus bar. The bus bar called the positive bus bar 130 and the bus bar called the negative bus bar 128 each include a first plate and a second plate. The first plate is made of the same material as the second plate and is integrally formed with the second plate.

[0041] In the example being described, the first plate of each of the two bus bars is a flat plate.

[0042] For example, the first plate of the positive bus bar 128 is below the first plate of the negative bus bar 130, and the first plate of the negative bus bar 130 is below the cooling casing 108. Therefore, the positive bus bar 128 forms a lower bus bar and the negative bus bar 130 forms an upper bus bar. The reverse configuration is also possible.

[0043] Furthermore, the second plate of the positive bus bar 128 and the second plate of the negative bus bar 130 are present along one side of the cooling casing 108.

[0044] The positive bus bar 128 is designed to have a high potential, and the negative bus bar 130 is designed to have a low potential lower than the high potential. Therefore, the bus bars 128, 130 are designed to have a DC voltage U DC therebetween.

[0045] Both bus bars 128, 130 are connected to each of the power modules 102 via at least one connection terminal extending from their second plates in order to distribute the DC voltage U DC to each of the power modules 102.

[0046] To hold the busbars 128, 130 in place, the switching cell 100 comprises, for example, a carrier 132 made especially of an electrical insulator, for example plastic. More precisely, the carrier 132 has a bottom 134 on which a first plate of the busbars 128, 130 is located. The carrier 132 is fastened to the cooling casing 108 such that the first plates of the busbars 128, 130 are between the lower cooling surface 113 of the cooling casing 108 and the bottom 134 of the carrier 132. Thus, the busbars 128, 130 can be cooled through the lower cooling surface 113.

[0047] The switching cell 100 each further comprises a capacitor 136 having two terminals 138, 140 connected to the busbars 128, 130 to receive a DC voltage U DC . These capacitors 136 are designed to smooth the DC voltage U DC and are generally referred to as DC link capacitors.

[0048] The capacitor 136 is arranged, for example, below the busbars 128, 130, especially below the bottom 134 of the carrier 132, and its terminals 138, 140 reach the busbars 128, 130 through the bottom 134 of the carrier as will be explained in more detail below.

[0049] Referring to FIG. 2, each power module 102 is designed to perform a conversion, for example, between a DC voltage U DC and a respective AC voltage, for example the phase voltage of an electrical machine.

[0050] Thus, each power module 102 has an external connector 202 designed to have this AC voltage. The external connector 202 takes the form of, for example, a flat bar preferably having a thickness of at least 0.8 mm.

[0051] The switching cell 100 further comprises a magnetic core 204 of a current sensor around each external connector 202. The magnetic core 204 is loop-shaped and has a gap where, for example, a Hall effect sensor can be arranged to measure current.

[0052] To hold the magnetic core 204 in place, the switching cell 100 further comprises a frame 206 that supports the magnetic core 204. This frame 206 is, for example, overmolded around the magnetic core and fastened to the cooling casing 108, for example by screws.

[0053] Referring to FIG. 3, each power module 102 comprises, in addition to the AC external connector 202, an external connector 302 called the positive connector and an external connector 304 called the negative connector, which are designed to be connected to the positive busbar 128 and the negative busbar 130, respectively. These external connectors 302, 304 are, for example, preferably in the form of flat bars having a thickness of at least 0.8 mm. In the example shown, two negative external connectors 304 are provided for each power module 102.

[0054] To perform voltage conversion, each power module 102, for example, implements a switching arm and thus comprises two switches 306, 308 connected to each other at an intermediate point and connected to the AC external connector 202 itself to deliver an AC voltage within the casing 305. The switching arm is connected between the external connectors 302 and 304 to deliver a DC voltage U DC These switches 306, 308 are schematically shown in FIG. 3 for a single power module of the power module 102 and are not shown for others for clarity.

[0055] Each switch 306, 308 is preferably a controllable semiconductor switch, such as, for example, a switch based on a transistor such as a metal-oxide-semiconductor field-effect transistor (MOSFET), or in practice an insulated-gate bipolar transistor (IGBT), or further a gallium nitride field-effect transistor (GaN FET).

[0056] Each power module 102 further has control pins 312 that enable the controller board 104 to control the switching of switches 306, 308 in particular. These control pins 312 are bent so as to have a horizontal segment extending from the casing 305 of the power module 102 and a vertical segment rising upward with respect to the controller board 104.

[0057] Referring to FIG. 4, each capacitor 136 includes a body 402, and each terminal 138, 140 includes an internal portion 404 within the body 402 and an external portion 406 that is outside the body 402 and protrudes from the body.

[0058] The body 402 includes, for example, a capacitive device 408 and an overmolded portion 410 that covers the capacitive device 408. The capacitive device 408 is the portion of the capacitor 136 where electrical energy is stored. The overmolded portion 410 is made of, for example, resin. Thus, the internal portions 404 of each of the terminals 138, 140 extend to the overmolded portion 410, for example, to join with the capacitive device 408.

[0059] Each external portion 406 of the terminals 138, 140 first has a support section 412. The support section 412 is, for example, continuous with the internal portion 404. The support section 412 is, for example, planar.

[0060] Each external portion 406 of terminals 138, 140 further has a connection section 414 designed to be welded to respective busbars 128, 130, as will be described in detail below. The connection section 414 is attached to the support section 412 via a bend and is located away from the body 402. The connection section 414 has an upper surface intended to be pressed against the busbars 128, 130 for welding to the associated busbars 128, 130, for example by laser welding.

[0061] To prevent heat from the welding from passing through the connection section 414 and reaching the body 402, each external portion 406 of terminals 138, 140 further has a protection section 416 attached to the connection section 414 by a bend so as to be bent between the connection section 414 and the body 402. For example, the bend between the connection section 414 and the protection section 416 is located facing the bend between the support section 412 and the connection section 414.

[0062] Each external portion 406 of terminals 138, 140 further comprises at least one auxiliary support section 418 attached to the connection section 414 by a bend so as to project, for example, vertically downward, towards the body 402, as in the illustrated example.

[0063] The auxiliary support section 418 contacts the body 402 on the opposite side of the connection section 414 and has, for example, an end portion extending towards the body. For example, this end portion engages the overmold portion 410, as in the illustrated example.

[0064] Furthermore, the end portion preferably has a hook 420, i.e., a protrusion. This protrusion is covered by the overmold portion 410 in the direction of protrusion of the auxiliary support section 418, i.e., vertically in the illustrated example. This hook 420 limits the risk of the auxiliary support section 418 being pulled out of the overmold portion 410 and the risk of the connection section 414 being deformed if the auxiliary support section 418 is pulled parallel to the direction of protrusion.

[0065] Accordingly, the connection section 414 is supported by the support section 412 and, where appropriate, by one or more auxiliary support sections 418.

[0066] Preferably, each terminal 138, 140, or at least the external portion 406 thereof, is formed from a single bent planar plate.

[0067] Next, with reference to FIG. 5, an example of a method 600 for manufacturing the capacitor 136 is described.

[0068] In step 602, the terminals 138, 140 are obtained, for each of them, by a protection section 416 that is continuous with the connection section 414. For example, each obtained terminal 138, 140 is planar and is cut out from, for example, a plate. Thus, before the plate is bent, the external portion 406 and the internal portion 404 are in the same plane, each being continuous with the other.

[0069] In step 604, the external portion 406 is bent between the protection section 416 and the connection section 414, in particular to place the protection section 416 under the connection section 414. For example, other bending operations may also be performed on the external portions 406 of the terminals 138, 140 in step 604 to give the shape shown in FIG. 4. For example, after the protection section 416 is bent under the connection section 414, one or more auxiliary support sections 418 may be bent with respect to the connection section 414. Finally, for example, again, the entire internal portion 404 and the support section 412 may be bent with respect to the connection section 414.

[0070] In step 606, the internal portions 404 of the terminals 138, 140 are fastened to the capacitive device 408. Accordingly, the protection section 416 is between the connection section 414 and the body 402 without the overmolded portion 410.

[0071] In step 608, the overmolded portion 410 is formed around the capacitive device 408, around the inner portion 404 of the terminals 138, 140, and around the hook 420 if it is provided.

[0072] Referring to FIG. 6, an insulating layer 502 is provided above the first plate of the upper bus bar 130, for example, to insulate the first plate from the cooling casing 108. Similarly, an insulating layer 504 is inserted between the bus bars 128 and 130.

[0073] Referring to FIG. 7, each carrier 132 has a fastening pin 702 that is received in an opening formed in the first plate of the upper bus bar 130. The fastening pin 702 projects upward, for example, from the bottom 134 of the carrier 132.

[0074] The carrier 132 further has, for example, pins 704 for positioning the lower bus bar 128. Each positioning pin 704 penetrates into an opening in the first plate of the lower bus bar 128, enabling the lower bus bar 128 to be held in a predetermined position. In particular, the positioning pins 704 are arranged to hold the first plate of the lower bus bar 128 in a predetermined position at a right angle to the fastening pins 702. For example, the positioning pins 704 extend parallel to, i.e., upward from, the fastening pins 702.

[0075] Referring to FIG. 8, the fastening pins 702 are each stacked to fasten the first plate of the upper bus bar 130 to the carrier 132. By doing so, the lower bus bar 128 is held in a predetermined position because its first plate is clamped between the first plate of the upper bus bar 130 and the bottom 134 of the carrier 132. The staking consists of deforming the ends of each positioning pin 704, for example, during high temperature, to form a contact portion for the first plate of the upper bus bar 130.

[0076] Referring to FIG. 9, the first plate of the lower bus bar 128 has an opening 902 (e.g., a window, or even a notch) for each capacitor 136 that leaves visible a portion 904 of the first plate of the upper bus bar 130. This portion 904 is designed to be connected to one of the terminals 138, 140 of the capacitor 136 and is hereinafter referred to as the "connection portion 904".

[0077] The connection portion 904 of the upper bus bar 130 has, for example, an emboss 906 that extends into the opening 902 of the first plate of the lower bus bar 128.

[0078] Again for each capacitor 136, the bottom 134 of the carrier 132 has an opening 908 (e.g., a window, or even a notch) that leaves visible a portion 910 of the first plate of the lower bus bar 128. This portion 910 is designed to be connected to the other of the terminals 138, 140 of the capacitor 136 and is hereinafter referred to as the "connection portion 910". Preferably, the connection portion 910 of the first plate of the lower bus bar 128 has a thickness that is smaller than the rest of the first plate of the lower bus bar 128, for example at least 25% smaller. For example, the connection portion 910 has a maximum thickness of 0.6 mm, and the first plate of the lower bus bar 128 has a thickness of at least 1 mm around the connection portion 910. This smaller thickness facilitates welding the terminals 138, 140 of the capacitor 136.

[0079] The opening 908 in the bottom 134 further leaves visible the opening 902 in the first plate of the lower bus bar 128. Thus, the connection portion 904 of the first plate of the upper bus bar 130, and in particular the emboss 906, is visible through the opening 908 in the bottom 134 and through the opening 902 in the first plate of the lower bus bar 128.

[0080] The emboss 906 has, for example, a connecting flat lower wall 912. Preferably, this connecting wall 912 has a thickness that is smaller than the remainder of the first plate of the upper bus bar 130, for example at least 25% smaller. For example, the connecting wall 912 has a maximum thickness of 0.6 mm, and the first plate of the lower bus bar 128 has a thickness of at least 1 mm around the emboss 906. This smaller thickness facilitates welding the terminals 138, 140 of the capacitor 136.

[0081] Furthermore, the first plate of the upper bus bar 130 has an opening (for example, a window, or even a notch) that leaves the connecting portion 910 of the first plate of the lower bus bar 128 visible for each connecting portion 910.

[0082] Referring to FIG. 10, for each capacitor 136, one of the terminals (the negative terminal 140 in the illustrated example) is connected to the connecting portion 904 of the upper bus bar 130, more specifically to the connecting wall 912 of the emboss 906, for example by welding. The other of the terminals (the positive terminal 138 in the illustrated example) is connected to the connecting portion 910 of the lower bus bar 128, for example by welding.

[0083] Next, referring to FIG. 11, an example of a method 1100 for welding the capacitor 136 to the bus bars 128, 130 is described.

[0084] In step 1102, the terminals 138, 140 of the capacitor 136 are pressed against the bus bars 128, 130 respectively. For example, the connecting sections 414 of the terminals 138, 140 are brought into contact with the connecting wall 912 of the emboss 906 of the upper bus bar 130 and the connecting portion 910 of the lower bus bar 128 respectively. Preferably, the contact is planar with respect to, for example, a plate of at least 20 mm 2 between planes.

[0085] In step 1104, in order to weld each of the terminals 138, 140 to the bus bars 128, 130 against which the terminals 138, 140 are pressed, a laser beam is transmitted to the bus bars 128, 130 on the side opposite to the pressed terminals 138, 140.

[0086] Referring to FIG. 12, the laser beam 1202 is transmitted by the laser 1204 in the direction 1206 and continuously passes through the bus bars 128, 130, the connection section 414 of the pressed terminals 138, 140, the protection section 416 of the pressed terminals 138, 140, and the body 402 of the capacitor 136. Therefore, the direction 1206 is perpendicular to the connection section 414.

[0087] Furthermore, due to the presence of an opening in the first plate of the upper bus bar 130, the laser beam can directly reach the connection portion 910 of the first plate of the lower bus bar 128 in order to weld the connection portion 910 to the terminal of the capacitor 136 against which it is pressed.

[0088] Referring to FIG. 13, the frame 206 is provided with a notch 1302 for positioning each control pin 312. For clarity, this positioning notch 1302 is only referred to in the drawing for one of the control pins.

[0089] The positioning notch can ensure the position of the control pin 312, which makes it easier to connect the control pin 312 to the circuit board 104. Furthermore, when this connection is made by forced insertion, the positioning notch 1302 reduces the risk of the control pin 312 being twisted during its forced insertion.

[0090] For example, the positioning notch 1302 has two walls 1304, 1306 that form an angle of 80° to 100°, preferably 90° to 95°, more preferably 90° between them to accurately position the control pin 312. Thus, the control pin 312 has an end segment 1308 that ends at the tip 1310. The control pin 312 is designed to be inserted through its tip 1310 into each receiving hole of the circuit board 104. This end segment 1308 is, for example, linear (vertical in the illustrated example), has a positioning portion 1312, the positioning portion 1312 has a length of at least 5 mm, and extends over its entire length within a maximum of 0.5 mm from each of the walls 1304, 1306 of the positioning notch 1302.

[0091] Thus, the control pin 312 shown in FIG. 13 is designed to be freely (not forcibly) inserted into the receiving holes and then soldered to the circuit board 104, for example.

[0092] Referring to FIG. 14, another example of an embodiment is shown.

[0093] In this other example, the control pin 312 is designed to be forcibly inserted into the receiving holes of the circuit board 104, for example.

[0094] For this purpose, the end segment 1308 has a portion 1402 for forced insertion, and this portion has a width larger than the receiving holes of the circuit board. For example, the portion 1402 for forced insertion comprises two stems that are joined at their ends and separated by a space in the middle.

[0095] Preferably, the frame 206 has at least one chamfered portion 1404 for guiding the control pin 312, more specifically its elbow, towards the positioning notch 1302. Thus, the chamfered portion 1404 facilitates inserting the control pin 312 particularly vertically into the positioning notch 1302.

[0096] Referring to FIG. 15, the end segment 1308 further has a protrusion 1502 that protrudes at a right angle to the vertical direction such that it is above the support portion in the vertical direction, preferably at a distance of less than 0.1 mm vertically from the frame 206, and preferably in contact with the frame 206.

[0097] Thus, during the forced insertion of the control pin 312, the protrusion 1502 abuts against the support portion, which enables a reaction to be applied to the pin. This avoids the need to temporarily provide a removable abutment during the operation of the forced insertion. In particular, the absence of this temporary abutment can significantly simplify the tools used to perform the forced insertion.

[0098] This protrusion 1502 is located, for example, between the portion 1402 for forced insertion and the positioning portion 1312.

[0099] Referring to FIG. 16, a method 1600 for manufacturing the switching cell 100 comprises, for example, the following steps.

[0100] In step 1602, a power module 102 having control pins 312 protruding from the casing 305 is obtained.

[0101] In step 1604, a circuit board 104 having one hole for receiving each control pin 312 is obtained.

[0102] In step 1606, the power module 102 is fastened to a cooling casing that supports the frame 206. During this fastening operation, the power module 102 is lowered vertically, and as a result, the control pins 312 guided particularly by the chamfered portion 1502 penetrate into the positioning notches 1302 respectively.

[0103] In step 1608, the circuit board 104 is lowered vertically with respect to the power module 102, and as a result, the control pins within the positioning notches are inserted into the receiving holes respectively.

[0104]

[0105] Referring to FIG. 17, the switching cell 100 is designed to form part of, for example, an electrical system, such as an inverter 1702.

[0106] The inverter 1702 includes, for example, an electromagnetic compatibility (EMC) filter 1704 connected between two busbars 128, 130, and a casing called a general casing 1706 in which the EMC filter 1704 and the switching cell 100 are arranged.

[0107] The general casing 1706 includes, for example, a main portion 1708 having an upper opening 1710, and a cover (not shown) designed to close the upper opening 1710. The general casing 1706 further includes, for example, a lower opening 1712 for passing the capacitor 136, and a cover 1714 for closing the lower opening 1712.

[0108] The inlet duct 118 and the outlet duct 120 each have two segments 1716, 1718 that project substantially parallel to each other in the same direction.

[0109] The general casing 1706 then has two openings 1720, 1722 for passing the segments 1716, 1718, respectively. Each opening 1720, 1722 has seals 1724, 1726, for example, intended to interact with the inserted segments 1716, 1718.

[0110] Accordingly, segments 1716, 1718 have respective ends 1728, 1730 that are designed to be connected to a system for circulating a coolant outside of the common casing 1706. These ends 1728, 1730 may have, for example, an inlet chamfer. Accordingly, the connection of the cooling circuit is made outside of the common casing 1706 so as to reduce the risk of leakage to the common casing if this connection is not adequately sealed.

[0111] Next, with reference to FIG. 18, a method 1800 for assembling the electrical system 1702 is described.

[0112] In step 1802, the switching cell 100 is inserted into the common casing 1706 through the upper opening 1710. At this point, segments 1716, 1718 of the ducts 118, 120 are inserted into openings 1720, 1722 formed in the main portion 1708 to guide the positioning of the switching cell 100 within the main casing 1706, respectively.

[0113] In step 1804, the switching cell 100 is fastened to the main portion 1708 of the common casing 1706, for example, by screwing.

[0114] In step 1806, the upper opening 1710 of the main portion 1708 is closed by a cover (not shown) of the common casing 1706.

[0115] It should be noted that, as a conclusion, the present invention is not limited to the embodiments described above. Specifically, it will be apparent to those skilled in the art that various modifications can be made to the embodiments described above, in light of the teachings just disclosed therein.

[0116] In particular, the order of the steps of the methods described above can be changed to any technically possible order.

[0117] In the detailed presentation of the invention provided above, the terms used should not be construed as limiting the invention to the embodiments described herein, but rather should be construed to include all equivalents that could be provided by one of ordinary skill in the art by applying their general knowledge to the practice of the teachings just disclosed therein.

Claims

Claim 1 A switching cell (100), comprising: - a power module (102); and - DC voltage (U ＤＣ ) to distribute to each of the power modules (102), a first bus bar (130) called the upper bus bar and a second bus bar (128) called the lower bus bar, each connected to each of the power modules (102), wherein the upper bus bar and the lower bus bar each comprise a first plate, the first bus bar (130) and the second bus bar (128); - at least one capacitor (136) having two terminals respectively welded to the first bus bar (130) and the second bus bar (128), wherein the upper bus bar (130) and the lower bus bar (128) are laminated on top of each other, the switching cell (100) comprises a carrier (132) of the upper bus bar (130) and the lower bus bar (128) having a bottom (134) on which the first plate of the laminated bus bars (128, 130) lies, the first plate of the lower bus bar (128) has an opening (902) that leaves visible a portion called the connection portion (904) of the first plate of the upper bus bar (130), and the bottom (134) has an opening (908) that, on the one hand, connects the first terminal (138) of the capacitor (136) to the connection portion (910) of the lower bus bar (128) through the opening (908) of the bottom (134), and on the other hand, connects the second terminal (140) of the capacitor (136) to the connection portion (904) of the upper bus bar (130) through the opening (908) of the bottom (134) and through the opening (902) of the lower bus bar (128), and the opening (908) is provided to keep visible at least one portion of the connection portion (910) of the first plate of the lower bus bar (128) and the opening (902) of the first plate of the lower bus bar (128). The switching cell (100) is characterized by this. Claim 2 The switching cell (100) according to claim 1, wherein the connection portion (910) of the first plate of the lower bus bar (128) has a thickness smaller than the rest of the first plate of the lower bus bar (128). Claim 3 The switching cell (100) according to claim 1 or 2, wherein the first plate of the upper bus bar (130) has an embossment (906) extending into the opening (902) of the first plate of the lower bus bar (128). Claim 4 The switching cell (100) according to claim 3, wherein the embossment (906) has a flat lower connection wall (912) having a thickness smaller than the remainder of the first plate of the upper bus bar (130).

5. The switching cell (100) according to any one of claims 1 to 4, wherein the carrier (132) has fastening pins (702), the first plate of the upper bus bar (130) has an opening for receiving the fastening pins (702), and the fastening pins are overlapped so as to fasten the first plate of the bus bar (130) to the carrier (132).

6. The switching cell (100) according to claim 5, wherein the first plate of the lower bus bar (128) is held between the first plate of the upper bus bar (130) and the carrier (132).

7. The switching cell (100) according to any one of claims 1 to 6, wherein the carrier (132) has pins (704) for positioning the first plate of the lower bus bar (128).

8. The switching cell (100) according to any one of claims 1 to 7, further comprising a circuit (106) for cooling the power module, the cooling circuit (106) comprising a cooling casing (108) defining channels (110) for the flow of a coolant, the cooling casing (108) having an upper cooling surface (112) and a lower cooling surface (113) both of which are cooled by the flow of the coolant through the channels (110), the power module (102) being pressed against the upper cooling surface (112) to be cooled, and the first plate of the upper bus bar (130) being in thermal contact with the lower cooling surface (113).

9. An inverter comprising the switching cell according to any one of claims 1 to 8.

10. A mobility device comprising the switching cell according to any one of claims 1 to 8 or the inverter according to claim 9.

Images