Electrical system with cooling power module loop

Abstract

The invention relates to an electrical system (1702), comprising:-a switching unit (100) comprising: a power supply module (102), and a circuit (106) for cooling the power supply module, the circuit (106) comprising a cooling housing (108) defining a cooling liquid flow channel (110), an inlet conduit (118) for the cooling liquid to enter the cooling housing (108), and an outlet conduit (120) for the cooling liquid to flow into the cooling housing (108); an outlet conduit (120) for discharging the cooling liquid from the cooling housing (108), the inlet conduit (118) and the outlet conduit (120) each having a segment (1716, 1718), the segments of the inlet conduit and the segments of the outlet conduit protruding substantially parallel to each other in the same direction; and-a housing (1706) inside which the switch unit (100) is located, the housing (1706) having two passage openings (1720, 1722), into one of which a section of the inlet conduit is inserted and into the other of which a section of the outlet conduit is inserted.

Description

Technical Field

[0001] The present invention relates to an electrical system having a circuit for cooling a power module, an inverter and a mobile device comprising the electrical system. Background Art

[0002] The prior art discloses an electrical system, comprising:

[0003] -Switch unit, comprising:

[0004] At least one power module,

[0005] a circuit for cooling the power module, the circuit comprising a cooling housing defining a coolant flow channel, and

[0006] - a housing, in which the switching unit is located.

[0007] In order to position the switch unit in the housing, it is known to equip the housing with positioning means, such as positioning pins. This makes the manufacturing process complicated and makes the installation of the switch unit in the housing even more complicated.

[0008] It would therefore be desirable to provide an electrical system that allows at least some of the above-mentioned problems and limitations to be overcome. Summary of the invention

[0009] According to a first aspect of the present invention, there is provided an electrical system, the system comprising:

[0010] -Switch unit, comprising:

[0011] At least one power module, and

[0012] a circuit for cooling the power module, the circuit comprising a cooling housing defining a coolant flow channel, an inlet duct for the coolant to enter the cooling housing, and an outlet duct for the coolant to exit the cooling housing, the inlet duct and the outlet duct each having a segment, the segments of the inlet duct and the segments of the outlet duct protruding substantially parallel to each other in the same direction; and

[0013] - a housing, inside which the switching unit is located, the housing having two passage holes, into one of which the section of the inlet duct is inserted, and into the other of which the section of the outlet duct is inserted.

[0014] Thus, the inlet duct and the outlet duct allow positioning of the switch unit relative to the housing, which avoids the need to provide specific positioning means.

[0015] The invention may also have one or more of the following optional features in any technically possible combination.

[0016] Optionally, the switch unit is fastened to the housing.

[0017] Optionally, the cooling housing has an upper cooling surface and a lower cooling surface, both of which are cooled by the flow of coolant in the channel, the power module is pressed against the upper cooling surface to be cooled, and the segments of the inlet duct and the outlet duct protrude vertically downward.

[0018] Optionally, the section of the inlet duct and / or the section of the outlet duct has an end outside the housing, which end is designed to be connected to a system for circulating a coolant.

[0019] The connection of the cooling circuit is therefore made outside the overall housing in order to reduce the risk of leakage into the overall housing in the event of a poor seal in this connection.

[0020] Likewise optionally, the holes are each provided with a seal.

[0021] Also optionally, each hole is equipped with a seal placed between said hole and the segment inserted into said hole.

[0022] Also optionally, the power supply module is designed to perform a conversion between a direct voltage and an alternating voltage.

[0023] Also optionally, the switch unit further comprises a first busbar referred to as an upper busbar and a second busbar referred to as a lower busbar, the first busbar and the second busbar being connected to the power module so as to distribute a DC voltage to the power module, the upper busbar and the lower busbar each comprising a first plate, at least one capacitor having two terminals welded to the first and second busbars, respectively, and a carrier of the upper busbar and the lower busbar having a fastening pin, the first plate of the upper busbar having a hole for accommodating the fastening pin, the fastening pin being deformed and fixed (staked) to fasten the first plate of the upper busbar to the carrier.

[0024] Optionally, the carriers of the upper busbar and the lower busbar have fastening pins, the first plate of the upper busbar has holes for receiving the fastening pins, and the fastening pins are deformed and fixed to fasten the first plate of the upper busbar to the carrier.

[0025] Optionally, each fastening pin is received in a different receiving hole.

[0026] Also optionally, the switch unit further comprises a first busbar, referred to as an upper busbar, and a second busbar, referred to as a lower busbar, which are connected to the power module so as to distribute a DC voltage to the power module, the upper busbar and the lower busbar each comprising a first plate, at least one capacitor with two terminals respectively welded to the first and second busbars, the upper busbar and the lower busbar being stacked on each other, and a carrier for the upper busbars and the lower busbars, the carrier comprising a bottom, the first plate of the stacked busbars being located on the bottom, the first plate of the lower busbar having a hole exposing a portion of the first plate of the upper busbar, referred to as a connecting portion, the bottom having a hole exposing a portion of the first plate of the lower busbar, referred to as a connecting portion, and at least a portion of the hole of the first plate of the lower busbar, so as to connect the first terminal of the capacitor to the connecting portion of the lower busbar through the hole of the bottom on the one hand, and to connect the second terminal of the capacitor to the connecting portion of the upper busbar through the hole of the bottom and the hole of the lower busbar on the other hand.

[0027] Also optionally, the two terminals of the at least one capacitor are welded to the first plates of the first busbar and the second busbar, respectively.

[0028] Also optionally, the cooling housing has an upper cooling surface and a lower cooling surface, both cooling surfaces are cooled by the flow of coolant through the channel, the power module is pressed against the upper cooling surface to be cooled, and the first plate of the upper busbar is in thermal contact with the lower cooling surface to be cooled.

[0029] Also optionally, the upper busbar and the lower busbar are stacked on each other, with the first plate of the lower busbar being held between the first plate of the upper busbar and the carrier.

[0030] Also optionally, the lower busbar is designed to have a high potential, and the upper busbar is designed to have a low potential.

[0031] Also optionally, the carrier comprises a bottom on which the first plates of the stacked busbars are located, wherein the first plate of the lower busbar has a hole that exposes a portion of the first plate of the upper busbar called the connecting portion, wherein the bottom has a hole that exposes a portion of the first plate of the lower busbar called the connecting portion and at least a portion of the hole of the first plate of the lower busbar, so as to connect the first terminal of the capacitor to the connecting portion of the lower busbar through the hole of the bottom on the one hand and to connect the second terminal of the capacitor to the connecting portion of the upper busbar through the hole of the bottom and the hole of the lower busbar on the other hand.

[0032] Optionally, a first insulating layer is inserted between the first plates of the upper busbar and the lower busbar.

[0033] Optionally, a second insulating layer is positioned between the top of the first plate of the upper busbar and the lower surface of the cooling housing.

[0034] Also optionally, the thickness of the connection portion of the first plate of the lower bus bar is smaller than the thickness of the remaining portion of the first plate of the lower bus bar.

[0035] Also optionally, the first plate of the upper busbar has a protrusion extending into the hole of the first plate of the lower busbar.

[0036] Also optionally, the protrusion has a flat lower connecting wall, the thickness of which is smaller than the thickness of the remaining portion of the first plate of the upper busbar.

[0037] Also optionally, the carrier has pins for positioning the first plate of the lower busbar.

[0038] Also optionally, the positioning pins are arranged to fix the first plate of the lower busbar in a position perpendicular to the fastening pins.

[0039] Also optionally, the positioning pin is parallel to the fastening pin.

[0040] Optionally, the locating pins penetrate into the holes of the first plate of the lower bus bar and allow the lower bus bar to be fixed in place.

[0041] Optionally, the carrier has pins for positioning the first plate of the lower busbar.

[0042] Optionally, the positioning pins are arranged to fix the first plate of the lower busbar in a position perpendicular to the fastening pins.

[0043] Optionally, the locating pin is parallel to the fastening pin.

[0044] Optionally, each locating pin penetrates into a corresponding hole of the first plate of the lower busbar and allows the lower busbar to be fixed in place.

[0045] According to a second aspect of the present invention, there is also provided an inverter comprising the electrical system according to the first aspect of the present invention.

[0046] According to a third aspect of the present invention, there is also provided a mobile device comprising a voltage converter according to the second aspect of the present invention or an electrical system according to the first aspect of the present invention.

[0047] The mobile device is, for example, a land vehicle, a train, an airplane, or a drone driven by a motor or an engine.

[0048] A motor or engine driven land vehicle is, for example, a motor vehicle, a motorcycle, an electric bicycle or an electric wheelchair.

[0049] According to a fourth aspect of the present invention, there is also provided a method for assembling an electrical system according to the first aspect of the present invention, comprising:

[0050] - positioning the switch unit in the housing by inserting a segment of the inlet duct and a segment of the outlet duct into the passage hole to guide the positioning of the switch unit in the housing; and then

[0051] - Fasten the switch unit to the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The invention will be better understood from the following description, which is provided by way of example only and with reference to the accompanying drawings, in which:

[0053] - Figure 1 is a cross-sectional view of an example of a switch unit implementing the present invention,

[0054] - Figure 2 is a 3D view of the switch unit,

[0055] - Figure 3 is a 3D view of the switch unit with the controller board, cover and spring system removed.

[0056] - Figure 4 is a 3D view of the capacitor of the switching unit,

[0057] - Figure 5 is a flow chart of a method for manufacturing a capacitor,

[0058] - Figure 6 is a three-dimensional cross-sectional view of the busbar and busbar carrier of the switch unit,

[0059] - Figure 7 is a 3D view of the busbars, busbar carriers and capacitors of a switchgear unit, in which the fastening pins can be seen before their deformed fixing.

[0060] - Figure 8 is similar to Figure 7 View of the fastening pin after deformation.

[0061] - Fig. 9 This is a three-dimensional view of the busbar carrier from above.

[0062] - Fig.10 is a three-dimensional cross-sectional view of the busbar, busbar carrier and capacitor of the switch unit, showing the connection of the capacitor to the busbar,

[0063] - Fig.11 is a flow chart of the method of welding capacitors,

[0064] - Fig.12 is a cross-sectional view of one of the capacitors, the busbar and its carrier, showing a step of the welding method,

[0065] - Fig.13 is a 3D view of the switch unit power module control pins and their environment,

[0066] - Fig.14 is a 3D view of a variation of the control pin.

[0067] - Fig.15It is shown Fig.14 A 3D view of the protrusion of the control pin,

[0068] - Fig.16 is a flow chart of a method of manufacturing a switching unit,

[0069] - Fig.17 is a three-dimensional cross-section of the electrical system (such as an inverter) housing the switching unit, and

[0070] - Fig.18 is a block diagram of a method for assembling an electrical system. DETAILED DESCRIPTION

[0071] In the following description and claims, various parts and elements will be spatially positioned relative to each other with reference to an orthogonal coordinate system XYZ of arbitrary directions, which includes an X direction, a Y direction, and a Z direction. For clarity, the X direction will be referred to as the left-right direction (in the drawings, the X direction arrow points to the left), the Y direction will be referred to as the front-back direction (in the drawings, the Y direction arrow points to the back), and the Z direction will be referred to as the up-down direction (in the drawings, the Z direction arrow points to the top).

[0072] With reference to the drawings, one example of a switch unit 100 embodying the present invention will now be described.

[0073] refer to Figure 1 , the switch unit 100 firstly comprises a plurality of power supply modules 102. In the example shown, three power supply modules 102 are provided. The power supply modules 102 are placed side by side with each other, for example.

[0074] The switch unit 100 further includes a controller circuit board 104 for controlling the power module 102. The controller circuit board 104 is located above the power module 102, for example.

[0075] The switch unit 100 further includes a circuit 106 for cooling the power module 102 .

[0076] The cooling circuit 106 includes a cooling housing 108 defining a channel 110 through which a coolant flows. The cooling housing 108 has an upper cooling surface 112 and a lower cooling surface 113, both of which are cooled by the coolant flowing through the channel 110. Therefore, the power module 102 is pressed against the upper cooling surface 112 to be cooled.

[0077] In order to keep the power module 102 pressed against the upper cooling surface 112, the switch unit 100 first comprises, for example, a cover 114, which is located 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 housing 108, for example by screws. The switch unit 100 also includes a spring system inserted between the cover 114 and the power module 102. The spring system is therefore designed to abut against the cover 114 and push the power module 102 toward the upper cooling surface 112. For each power module 102, the spring system comprises, for example, a leaf spring 116, which is compressed between the cover 114 and the power module 102.

[0078] The cooling circuit 106 further comprises an inlet duct 118 for coolant to enter the cooling housing 108 and an outlet duct 120 for coolant to flow out of the cooling housing 108. The ducts 118, 120 are located, for example, on the right and left sides of the cooling housing 108, respectively, and protrude downwards from the cooling housing 108.

[0079] The switch unit 100 also includes a busbar called a positive busbar 128 and a busbar called a negative busbar 130, which are stacked on each other. Thus, one of the two busbars 128, 130 forms a lower busbar, while the other forms an upper busbar. The busbar called the positive busbar 130 and the busbar called the negative busbar 128 each include a first plate and a second plate, the first plate being made of the same material as the second plate and being formed integrally with the second plate.

[0080] In the example described, the first plate of each of the two busbars is a planar plate.

[0081] For example, the first plate of the positive bus bar 128 is located below the first plate of the negative bus bar 130, and the first plate of the negative bus bar 130 is located below the cooling housing 108. Thus, the positive bus bar 128 forms the lower bus bar and the negative bus bar 130 forms the upper bus bar. The opposite configuration is also possible.

[0082] Additionally, a second plate of the positive bus bar 128 and a second plate of the negative bus bar 130 are placed along one side of the cooling housing 108 .

[0083] The positive busbar 128 is designed to have a high potential, while the negative busbar 130 is designed to have a low potential lower than the high potential. Therefore, the busbars 128 and 130 are designed to have a DC voltage U between them. DC .

[0084] The busbars 128, 130 are connected to each power module 102 via at least one connection terminal extending from their second boards to distribute the DC voltage U DC Assigned to the power module 102.

[0085] In order to fix the busbars 128, 130 in place, the switch unit 100 comprises, for example, a carrier 132, which is made in particular of an electrical insulator, for example of plastic. More precisely, the carrier 132 has a bottom 134 on which the first plates of the busbars 128, 130 are located. The carrier 132 is fastened to the cooling housing 108 in such a way that the first plates of the busbars 128, 130 are located between the lower cooling surface 113 of the cooling housing 108 and the bottom 134 of the carrier 132. The busbars 128, 130 can therefore be cooled by the lower cooling surface 113.

[0086] The switch unit 100 further comprises capacitors 136, each of which comprises 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 often referred to as DC link capacitors.

[0087] The capacitor 136 is, for example, placed below the busbars 128 , 130 , in particular below the bottom 134 of the carrier 132 , with its terminals 138 , 140 passing through the bottom 134 of the carrier to reach the busbars 128 , 130 , as will be described in more detail below.

[0088] refer to Figure 2 Each power module 102 is designed to implement a DC voltage U DC And the corresponding AC voltage (such as the phase voltage of the motor) conversion between.

[0089] Therefore, each power supply module 102 has an external connector 202 designed to carry this alternating voltage. The external connector 202 is, for example, in the form of a planar rod, preferably having a thickness of at least 0.8 mm.

[0090] The switch unit 100 further comprises a magnetic core 204 of a current sensor surrounding each external connector 202. The magnetic core 204 is annular and has a gap in which a Hall effect sensor, for example, can be placed to measure the current.

[0091] In order to fix the magnetic core 204 in place, the switch unit 100 further comprises a frame 206 supporting the magnetic core 204. The frame 206 is, for example, overmolded around the magnetic core and is fastened to the cooling housing 108, for example by screws.

[0092] refer to Figure 3In addition to the AC external connector 202, each power module 102 also includes an external connector 302 called a positive connector and an external connector 304 called a 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, in the form of a planar rod, preferably with a thickness of at least 0.8 mm. In the example shown, two negative external connectors 304 are provided for each power module 102.

[0093] To perform the voltage conversion, each power module 102 implements, for example, a switching arm and therefore comprises in a housing 305 two switches 306, 308 connected to one another at a midpoint, which are themselves connected to the DC external connector 202 in order to supply a DC voltage thereto. The switching arm is connected between the external connectors 302, 304 in order to supply a DC voltage U DC For clarity, these switches 306, 308 are Figure 3 A single power module used in the power module 102 is schematically shown in FIG. 1 , but not shown in other power modules.

[0094] Each switch 306, 308 is preferably a controllable semiconductor switch, for example a transistor-based switch, such as a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) or an Insulated-Gate Bipolar Transistor (IGBT), or even a Gallium Nitride Field-Effect Transistor (GaN FET).

[0095] Each power module 102 also has control pins 312, in particular allowing the controller board 104 to control the switching of switches 306, 308. These control pins 312 are bent so as to have a horizontal section extending outside the housing 305 of the power module 102 and a vertical section rising up to the controller board 104.

[0096] refer to Figure 4 , each capacitor 136 includes a body 402 , and each terminal 138 , 140 includes an inner portion 404 in the body 402 , and an outer portion 406 outside the body 402 and protruding from the body 402 .

[0097] The body 402 includes, for example, a capacitor 408 and an overmolded portion 410 covering the capacitor 408. The capacitor 408 is a portion of the capacitor 136 that stores electrical energy. The overmolded portion 410 is made of, for example, resin. Therefore, the inner portion 404 of each terminal 138, 140 extends into the overmolded portion 410, for example, so as to engage with the capacitor 408.

[0098] The outer part 406 of each terminal 138, 140 firstly has a support section 412. The support section 412 is located, for example, in continuation of the inner part 404. The support section 412 is, for example, planar.

[0099] The outer portion 406 of each terminal 138, 140 also has a connection section 414 designed to be welded to a corresponding one of the 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 away from the body 402. The connection section 414 has an upper surface intended to be pressed against the associated busbar 128, 130 so as to be welded thereto, for example by laser welding.

[0100] In order to prevent the heat from welding from reaching the main body 402 through the connecting section 414, the outer portion 406 of each terminal 138, 140 also has a protection section 416, which is attached to the connecting section 414 through a bent portion so as to be folded between the connecting section 414 and the main body 402. For example, the bent portion between the connecting section 414 and the protection section 416 faces the bent portion between the supporting section 412 and the connecting section 414.

[0101] The outer portion 406 of each of the terminals 138 , 140 further comprises, for example, at least one auxiliary support section 418 attached to the connection section 414 by a bend so as to protrude toward the body 402 , for example vertically downward in the example shown.

[0102] The auxiliary support section 418 has an end opposite to the connecting section 414, which end is in contact with the main body 402 and, for example, extends into the main body 402. For example, this end is engaged in the overmolded part 410, as shown in the example.

[0103] Furthermore, the end portion preferably has a hook 420, i.e. a protrusion. This protrusion is covered by the overmolded part 410 in the protruding direction of the auxiliary support section 418, i.e. in the vertical direction in the example shown. When the auxiliary support section 418 is pulled parallel to the protruding direction, the hook 420 limits the risk of the auxiliary support section 418 being pulled out of the overmolded part 410 and the risk of the connection section 414 being deformed.

[0104] The connecting section 414 is thus carried by the supporting section 412 and, where appropriate, by one or more auxiliary supporting sections 418 .

[0105] Preferably, each terminal 138, 140, or at least an outer portion 406 thereof, is formed from a single folded flat sheet.

[0106] refer to Figure 5 , one example of a method 600 for fabricating capacitor 136 will now be described.

[0107] In step 602, terminals 138, 140 are obtained, for each terminal, the protection section 416 is in the continuum of the connection section 414. For example, each obtained terminal 138, 140 is planar, such as cut from a board. Therefore, before folding the board, the outer portion 406 and the inner portion 404 are coplanar and continuous with each other.

[0108] In step 604, the outer portion 406 is bent between the protection section 416 and the connection section 414, so that the protection section 416 is below the connection section 414. In step 604, other bending operations may also be performed on the outer portion 406 of the terminal 138, 140 to have, for example, Figure 4 For example, after the protection segment 416 has been folded under the connecting segment 414, one or more auxiliary support segments 418 can be bent relative to the connecting segment 414. Finally, also for example, the entirety of the inner portion 404 and the support segment 412 can be bent relative to the connecting segment 414.

[0109] In step 606, the inner portion 404 of the terminal 138, 140 is secured to the capacitive device 408. Thus, the protection section 416 is located between the connection section 414 and the body 402, without the overmolded portion 410.

[0110] In step 608 , the overmold portion 410 is formed around the capacitive device 408 , the inner portion 404 of the terminals 138 , 140 , and the hooks 420 , if present.

[0111] refer to Figure 6 , an insulating layer 502 is provided, for example, above the first plate of the upper busbar 130 to insulate it from the cooling housing 108. Likewise, an insulating layer 504 is interposed between the busbars 128, 130.

[0112] refer to Figure 7 , the carrier 132 has fastening pins 702, which are respectively received in holes produced in the first plate of the upper busbar 130. The fastening pins 702 protrude upward from the bottom 134 of the carrier 132, for example.

[0113] The carrier 132 also has, for example, pins 704 for positioning the lower busbar 128. Each positioning pin 704 penetrates into a corresponding hole of the first plate of the lower busbar 128 and allows the lower busbar 128 to be fixed in place. In particular, the positioning pins 704 are arranged to fix the first plate of the lower busbar 128 in a position perpendicular to the fastening pins 702. For example, the positioning pins 704 extend parallel to the fastening pins 702, that is, extend upward.

[0114] refer to Figure 8 , the fastening pins 702 are each deformed and fixed to fasten the first plate of the upper busbar 130 to the carrier 132. In doing so, the lower busbar 128 is fixed in place because the first plate of the lower busbar 128 is clamped between the first plate of the upper busbar 130 and the bottom 134 of the carrier 132. Deformation fixing includes deforming, for example, deforming the end of each locating pin 704 when heated to form a seat for the first plate of the upper busbar 130.

[0115] refer to Fig. 9 For each capacitor 136, the first plate of the lower busbar 128 has a hole 902 (e.g., a window or even a cutout) which makes visible a portion 904 of the first plate of the upper busbar 130. This portion 904 is designed to be connected to one of the terminals 138, 140 of the capacitor 136 and will be referred to below as "connection portion 904".

[0116] The connection portion 904 of the upper bus bar 130 has, for example, a protrusion 906 that extends into the hole 902 of the first plate of the lower bus bar 128 .

[0117] Likewise, for each capacitor 136, the bottom 134 of the carrier 132 has a hole 908 (e.g., a window or even a cutout) which makes visible a portion 910 of the first plate of the lower busbar 128. This portion 910 is designed to be connected to the other of the terminals 138, 140 of the capacitor 136 and will be referred to below as the "connection portion 910". Preferably, the connection portion 910 of the first plate of the lower busbar 128 has a smaller thickness than the rest of the first plate of the lower busbar 128, for example a thickness at least 25% smaller. For example, the connection portion 910 has a thickness of at most 0.6 mm, while the first plate of the lower busbar 128 has a thickness of at least 1 mm around the connection portion 910. This smaller thickness makes it easier to solder the terminals 138, 140 of the capacitor 136.

[0118] The hole 908 of the bottom 134 further makes the hole 902 of the first plate of the lower busbar 128 visible. Therefore, through the hole 908 of the bottom 134 and through the hole 902 of the first plate of the lower busbar 128, the connecting portion 904 of the first plate of the upper busbar 130, in particular the protrusion 906, can be seen.

[0119] The protrusion 906 has, for example, a connection plane lower wall 912. Preferably, the connection wall 912 has a smaller thickness than the rest of the first plate of the upper busbar 130, for example, at least 25% smaller thickness. For example, the connection wall 912 has a thickness of at most 0.6 mm, while the first plate of the lower busbar 128 has a thickness of at least 1 mm around the protrusion 906. This smaller thickness makes it easier to solder the terminals 138, 140 of the capacitor 136.

[0120] Furthermore, for each connection portion 910 of the first plate of the lower busbar 128 , the first plate of the upper busbar 130 has a hole (eg a window or even a cutout) making the connection portion 910 visible.

[0121] refer to Fig.10 For each capacitor 136, one of the terminals (in the example shown, the negative terminal 140) is connected, for example, by welding, to the connection portion 904 of the upper busbar 130, more specifically, to the connection wall 912 of the protrusion 906. The other of the terminals (in the example shown, the positive terminal 138) is connected, for example, by welding, to the connection portion 910 of the lower busbar 128.

[0122] refer to Fig.11 , one example of a method 1100 for welding the capacitor 136 to the bus bars 128 , 130 will now be described.

[0123] In step 1102, the terminals 138, 140 of the capacitor 136 are pressed against the busbars 128, 130, respectively. For example, the connecting sections 414 of the terminals 138, 140 abut against the connecting wall 912 of the protrusion 906 against the upper busbar 130 and the connecting portion 910 against the lower busbar 128, respectively. Preferably, the abutment is plane to plane, for example, abutting at least 20 mm. 2 of board.

[0124] In step 1104 , in order to weld each terminal 138 , 140 to the bus bar 128 , 130 against which the terminal 138 , 140 is pressed, a laser beam is transmitted to the bus bar 128 , 130 opposite the crimped terminal 138 , 140 .

[0125] refer to Fig.12 , laser beam 1202 is transmitted by laser 1204 in direction 1206, which sequentially passes through busbars 128, 130, connection section 414 of crimped terminals 138, 140, protection section 416 of crimped terminals 138, 140, and body 402 of capacitor 136. Therefore, direction 1206 is perpendicular to connection section 414.

[0126] Furthermore, the presence of the hole in the first plate of the upper busbar 130 allows the laser beam to directly reach the connection portion 910 of the first plate of the lower busbar 128 in order to weld it to the terminal of the capacitor 136 against which it is pressed.

[0127] refer to Fig.13 In the frame 206, for each control pin 312, a notch 1302 is provided for positioning the control pin 312. For the sake of clarity, the positioning notch 1302 is only used for one of the control pins in the drawings.

[0128] By means of the positioning notch, the position of the control pin 312 can be ensured, which makes it easier to connect the control pin 312 to the circuit board 104. In addition, when such connection is achieved via forced insertion, the positioning notch 1302 reduces the risk of the control pin 312 twisting during its forced insertion.

[0129] For example, the positioning recess 1302 has two walls 1304, 1306, between which an angle of between 80° and 100° is formed, preferably between 90° and 95°, more preferably 90°, in order to correctly position the control pin 312. Therefore, the control pin 312 has an end section 1308 terminating in a tip 1310. The control pin 312 is designed to be inserted into a corresponding receiving hole of the circuit board 104 via its tip 1310. This end section 1308 is, for example, straight (vertical in the example shown) and has a positioning portion 1312 having a length of at least 5 mm and extending at most 0.5 mm from each of the walls 1304, 1306 of the positioning recess 1302 over its entire length.

[0130] therefore, Fig.13 The control pin 312 shown in FIG. 1 is designed to be freely (not forcibly) inserted into the receiving hole and then welded to the circuit board 104 , for example.

[0131] refer to Fig.14 , another example of an embodiment is shown.

[0132] In this other example, the control pin 312 is designed to be forcibly inserted into the receiving hole of the circuit board 104 , for example.

[0133] To this end, the end section 1308 has a portion 1402 for forced insertion, the width of which is greater than the receiving hole of the circuit board. For example, the portion 1402 for forced insertion includes two rods, which are connected at their ends and separated by a space in the middle.

[0134] Preferably, the frame 206 has at least one chamfer 1404 for guiding the control pin 312, more particularly the bend thereof, towards the positioning recess 1302. Thus, the chamfer 1404 makes it easier to insert the control pin 312 into the positioning recess 1302, particularly vertically.

[0135] refer to Fig.15 The end section 1308 also has a protrusion 1502 that protrudes perpendicularly to the vertical direction so as to be located above the support portion in the vertical direction, preferably less than 0.1 mm from the frame 206 in the vertical direction, and preferably in contact with the frame 206.

[0136] Thus, during forced insertion of the control pin 312, the projection 1502 abuts against the support portion, which allows a reaction force to be applied to the pin. This avoids the need to temporarily provide a removable support during the forced insertion operation. In particular, the absence of such a temporary support greatly simplifies the tool used to perform the forced insertion.

[0137] The protrusion 1502 is located, for example, between the portion 1402 for forced insertion and the positioning portion 1312 .

[0138] refer to Fig.16 , the method 1600 for manufacturing the switch unit 100 includes, for example, the following steps.

[0139] In step 1602 , a power module 102 having a control pin 312 protruding from a housing 305 is obtained.

[0140] In step 1604 , a circuit board 104 is obtained, wherein one hole accommodates each control pin 312 .

[0141] In step 1606, the power module 102 is fastened to the cooling housing of the support frame 206. During this fastening operation, the power module 102 is lowered vertically so that the control pins 312, which are guided in particular by the chamfers 1502, penetrate into the positioning recesses 1302, respectively.

[0142] In step 1608 , the circuit board 104 is vertically lowered toward the power module 102 , so that the control pins located in the positioning recesses are respectively inserted into the receiving holes.

[0143] refer to Fig.17 , the switch unit 100 is for example designed to form a part of an electrical system, such as an inverter 1702 .

[0144] The inverter 1702 comprises, for example, an electromagnetic compatibility (EMC) filter 1704 connected between the two busbars 128 , 130 and a housing referred to as a general housing 1706 , in which the EMC filter 1704 and the switch unit 100 are placed.

[0145] The overall housing 1706 includes, for example, a body portion 1708 having an upper hole 1710 and a cover (not shown) designed to close the upper hole 1710. The overall housing 1706 also includes, for example, a lower hole 1712 for the capacitor 136 to pass through and a cover 1714 for closing the lower hole 1712.

[0146] The inlet duct 118 and the outlet duct 120 have two sections 1716, 1718, respectively, which protrude substantially parallel to each other in the same direction.

[0147] The overall housing 1706 then has two holes 1720, 1722 for the passage of the segments 1716, 1718, respectively. Each hole 1720, 1722 has, for example, a seal 1724, 1726 for interacting with the inserted segments 1716, 1718.

[0148] Thus, the segments 1716, 1718 have respective ends 1728, 1730 outside the overall housing 1706, which are designed to be connected to a system for circulating a coolant. These ends 1728, 1730 may, for example, have an inlet chamfer. Thus, the connection of the cooling circuit is made outside the overall housing 1706 in order to reduce the risk of leakage into the overall housing in the event of a poor seal of the connection.

[0149] refer to Fig.18 , a method 1800 for assembling the electrical system 1702 will now be described.

[0150] In step 1802, the switch unit 100 is inserted into the main housing 1706 through the upper hole 1710. At this time, the sections 1716, 1718 of the conduits 118, 120 are respectively inserted into the holes 1720, 1722 formed in the body portion 1708 to guide the positioning of the switch unit 100 in the main housing 1706.

[0151] In step 1804, the switch unit 100 is fastened to the body portion 1708 of the overall housing 1706, such as by threading.

[0152] In step 1806 , the upper hole 1710 of the main body portion 1708 is closed by a cover (not shown) of the overall housing 1706 .

[0153] In summary, it should be noted that the present invention is not limited to the above-described embodiments. In particular, it is obvious to those skilled in the art that various modifications can be made to the above-described embodiments based on the teachings just disclosed to them.

[0154] In particular, the order of the steps of the above-described methods may be changed into any technically possible order.

[0155] In the detailed description of the invention provided above, the terms used must not be construed to limit the invention to the embodiments described in this specification, but must be construed to include all equivalents that those skilled in the art can provide by applying their common knowledge to the embodiments of the teachings just disclosed to them.

Claims

1. An electrical system (1702), comprising: - A switch unit (100), comprising: at least one power module (102), and a circuit (106) for cooling the power module, the circuit (106) comprising a cooling housing (108) defining a coolant flow channel (110), an inlet duct (118) for the coolant to enter the cooling housing (108), and an outlet duct (120) for the coolant to be discharged from the cooling housing (108), the inlet duct (118) and the outlet duct (120) each having a segment (1716, 1718), the segments of the inlet duct and the segments of the outlet duct protruding substantially parallel to each other in the same direction; and - a housing (1706), the switch unit (100) being located inside the housing (1706), the housing (1706) having two channel holes (1720, 1722), the segment of the inlet duct being inserted into one of the two channel holes, and the segment of the outlet duct being inserted into the other of the two channel holes.

2. The electrical system (1702) of claim 1, wherein: The cooling housing (108) has an upper cooling surface (112) and a lower cooling surface (113), both of which are cooled by the flow of the coolant in the channel (110), the power module (102) is pressed against the upper cooling surface (112) to be cooled, and the section of the inlet duct and the section of the outlet duct protrude vertically downward.

3. The electrical system (1702) according to any one of the preceding claims, wherein: The section of the inlet duct and / or the section of the outlet duct have ends (1728, 1730) outside the housing, which are designed to be connected to a system for circulating a coolant.

4. The electrical system (1702) according to any one of the preceding claims, wherein: The holes (1720, 1722) are each provided with a seal (1724, 1726).

5. The electrical system (1702) according to any of the preceding claims, the at least one power supply module (102) being designed to perform a conversion between a direct voltage and an alternating voltage.

6. The electrical system according to any one of claims 1 to 5, wherein: The switch unit further comprises a first busbar (130) called an upper busbar and a second busbar (128) called a lower busbar, the first busbar (130) and the second busbar (128) being connected to the power module (102) so as to distribute a direct current voltage (UDC) to the power module (102), the upper busbar and the lower busbar each comprising a first plate, at least one capacitor (136) having two terminals welded to the first and second busbars (128, 130), respectively, and a carrier (132) of the upper busbar and the lower busbar (128, 130) having a fastening pin (702), the first plate of the upper busbar (128, 130) having a hole for accommodating the fastening pin (702), the fastening pin (702) being deformed and fixed to fasten the first plate of the upper busbar (130) to the carrier (132).

7. The electrical system (1702) of claim 6, wherein: The cooling housing (108) has an upper cooling surface (112) and a lower cooling surface (113), both of which are cooled by the flow of the coolant in the channel (110), the power module (102) is pressed against the upper cooling surface (112) to be cooled, and the first plate of the upper busbar is in thermal contact with the lower cooling surface (113) to be cooled.

8. An inverter comprising the electrical system (1702) according to any one of claims 1 to 6.

9. A mobile device comprising the electrical system according to any one of claims 1 to 6 or the inverter according to claim 7.

10. A method for assembling an electrical system (1702) according to any one of claims 1 to 6 or for assembling an inverter according to claim 7, comprising: - positioning the switch unit (100) in the housing by inserting the sections (1716, 1718) of the inlet and outlet conduits (118, 120) into the passage holes (1720, 1722) to guide the positioning of the switch unit (100) in the housing; and then - Fastening the switch unit (100) to the housing (1706).

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