Electrical arrangement containing a cooling device

Abstract

The invention relates to an arrangement (1) comprising an electrical component (32) and a cooling device (2), which cooling device comprises: - a heat sink (21); - a first thermal conductor (22); - a first surface of the first conductor being in contact with a first surface of the component; - a second surface of the first conductor being in contact with a first surface of a second thermal conductor (23); - a second surface of the second conductor being in contact with a surface of the heat sink, the second conductor containing a heat-transfer fluid such that: - heat transfer fluid close to the first surface of the second conductor is capable of gasifying by recovering a certain amount of heat from the second surface of the first conductor; then - heat transfer fluid close to the second surface of the second conductor is capable of liquefying by transferring the amount of heat recovered to the first surface of the heat sink.

Description

Description Title of the invention: Electrical arrangement containing a cooling device

[0001] The present invention relates to an electrical arrangement containing a cooling device. The invention further relates to an electric or hybrid vehicle equipped with such an arrangement.

[0002] In electric and hybrid vehicles, current electric powertrains utilize increasingly efficient battery systems. Within these battery systems, a junction box is typically connected to both the vehicle's drive system and the charging system. Rapidly charging the battery in such a system requires high power and a high current. This power can generate hot spots in the junction box. Excessive temperature increases can lead to malfunctions in the junction box and even damage its electrical components. Therefore, cooling these components is necessary to maintain the temperature of these hot spots below a predetermined threshold.

[0003] The present invention falls within this context and aims to provide an efficient and economical cooling solution. One objective of the invention is therefore to provide an arrangement containing an efficient and economical cooling device that precisely targets the hot spots of the connection box to keep them below a maximum temperature.

[0004] To this end, the invention proposes an arrangement comprising a cooling device and at least one electrical component intended to be cooled by the cooling device, the cooling device comprising, - a heat sink, specifically a cooling plate for a traction battery, - a first thermal conductor made, at least in part, of an electrically and thermally conductive material, in particular made of copper, - a first surface of the first thermal conductor being in contact with a first surface of at least one electrical component, - a second surface of the first thermal conductor being in contact with a first surface of a second thermal conductor, - a second surface of the second thermal conductor being in contact with a first surface of the heat sink, and the second thermal conductor hermetically enclosing a heat transfer fluid such as: - a first quantity of heat transfer fluid located near the first surface of the second thermal conductor is able to change from a liquid state to a gaseous state by absorbing a quantity of heat from the second surface of the first thermal conductor, then - a second quantity of heat transfer fluid located near the second surface of the second thermal conductor is able to change from a gaseous state to a liquid state by transferring, to the first surface of the heat sink, the quantity of heat taken from it.

[0005] In one embodiment, the first thermal conductor is arranged so as to be electrically isolated from the heat sink.

[0006] In one embodiment, the first thermal conductor comprises: - a first copper strip suitable for electrically connecting F at least one electrical component to an electrical circuit, in particular suitable for electrically connecting F at least one electrical component to another electrical component, and - a second copper strip forming a T with the first copper strip, the second copper strip being in contact with the first surface of the second thermal conductor.

[0007] In one embodiment, the first and second copper strips are together capable of transferring to the second thermal conductor a first quantity of heat emitted by F from at least one electrical component.

[0008] In one embodiment, the first copper strip is capable of transferring a second quantity of heat emitted by at least one electrical component to air surrounding the first copper strip, the surrounding air being air located in contact with the first copper strip or air located in a volume surrounding the first copper strip.

[0009] In one embodiment, an angle measured between the first copper strip and the second copper strip is substantially equal to 90 degrees, or between 45 degrees and 90 degrees, or even between 30 degrees and 45 degrees.

[0010] In one embodiment, at least one electrical component to be cooled includes an electrical relay, and / or an emergency switch, and / or a fuse of a connection box of a traction battery of a motor vehicle.

[0011] In one embodiment, the arrangement comprises four first heat conductors, each collaborating with a second heat conductor disposed in contact with a traction battery cooling plate, the first and second heat conductors being arranged such that - to allow electrical conduction between two adjacent electrical components, and - to allow thermal conduction between each electrical component and the cooling plate.

[0012] The invention further relates to an electric or hybrid motor vehicle comprising an arrangement according to the invention.

[0013] Further details, features and advantages will become clearer upon reading the detailed description given below, which is indicative and not exhaustive, in relation to the various implementation examples illustrated in the following figures:

[0014] Fig. 1 is a schematic representation of an arrangement according to the invention.

[0015] Figure [Fig. 2] illustrates one embodiment of an arrangement according to the invention.

[0016] Figure 3 is a first illustration of an embodiment of a first thermal conductor and a second thermal conductor.

[0017] Figure 4 is a second illustration of an embodiment of a first thermal conductor and a second thermal conductor.

[0018] Figure 5 illustrates a first step in assembling an arrangement according to the invention.

[0019] Figure 6 illustrates a second step in assembling an arrangement according to the invention.

[0020] Figure 7 illustrates a third assembly step of an arrangement according to the invention.

[0021] Figure 8 illustrates a fourth assembly step of an arrangement according to the invention.

[0022] Figure 9 illustrates a fifth step in assembling an arrangement according to the invention.

[0023] An embodiment of a motor vehicle 100 equipped with the invention is described with reference to [Fig.1].

[0024] The 100 motor vehicle is an electric or hybrid vehicle, equipped with a traction battery.

[0025] The vehicle is equipped with an arrangement 1 according to the invention.

[0026] The arrangement 1 comprises a cooling device 2 and at least one electrical component 31, 32, 33 intended to be cooled by the cooling device 2, the cooling device 2 comprising, - a heat sink 21, in particular a cooling plate 21 for a traction battery, - a first thermal conductor 22 made, at least in part, of an electrically and thermally conductive material, in particular made of copper, - a first surface 221 of the first thermal conductor 22 being in contact with a first surface 311, 321, 331 of at least one electrical component 31, 32, 33, - a second surface 222 of the first thermal conductor 22 being in contact with a first surface 231 of a second thermal conductor 23, - a second surface 232 of the second thermal conductor 23 being in contact with a first surface 211 of the heat sink 21, the second thermal conductor 23 hermetically enclosing a heat transfer fluid such as: - a first quantity of heat transfer fluid located near the first surface 231 of the second thermal conductor 23 is capable of changing from a liquid state to a gaseous state by absorbing a quantity of heat from the second surface 222 of the first thermal conductor 22, then - a second quantity of heat transfer fluid located near the second surface 232 of the second thermal conductor is able to pass from the gaseous state to the liquid state by transferring to the first surface 211 of the heat sink 21 the quantity of heat taken from it.

[0027] In this document, the expressions "first surface" and "second surface" are used to refer to distinct surfaces.

[0028] Thus, the cooling device 2 according to the invention comprises a plurality of surfaces among which - a first and a second surface 221, 222 of the first thermal conductor 22, the first surface 221 being distinct from the second surface 222, - a first and a second surface 231, 232 of the second thermal conductor 23, the first surface 231 being distinct from the second surface 232, - a first surface 211 of the heat sink 21 - a first surface 311, 321, 331 of F at least one electrical component 31, 32, 33, in particular a first surface 311 of a relay 31, a first surface 321 of a pyro-switch, and a first surface 331 of a fuse 33.

[0029] Figure 4 illustrates an embodiment of a cooling device 2 according to the invention, and in particular a relative arrangement of the surfaces 221, 222, 231, 232, 211, 311, 321, 331 previously listed: - a first surface 321 of a pyro-switch 32 is disposed against or in contact with the first surface 221 of the first conductor 22, - the second surface 222 of the first conductor 22 is disposed against or in contact with the first surface 231 of the second conductor 23, and - the second surface 232 of the second conductor 23 is disposed against or disposed in contact with the first surface 211 of the heat sink 21.

[0030] In the remainder of this document, the term "heat pipe" refers to a heat transfer device comprising a hermetically sealed enclosure containing a fluid in a liquid-vapor equilibrium state and operating according to the principle described below. In one embodiment, the hermetically sealed enclosure may be made of copper. The circulating fluid in the heat pipe cannot circulate in direct contact with a component to be cooled or heated.

[0031] The interposition of a heat pipe 23 between a hot spot and a cold spot makes it possible to greatly increase the amount of heat transferred between the hot spot and the cold spot and / or the rate of heat transfer between the hot spot and the cold spot.

[0032] When a surface of the heat pipe is located near a component to be cooled, the liquid heat transfer fluid changes into vapor by absorbing thermal energy emitted by the component. The vapor then flows through the heat pipe 23 to another surface of the heat pipe 23 located near a heat sink 21, where it condenses back into a liquid state. The condensation of the heat transfer fluid releases thermal energy to the heat sink 21.

[0033] In the remainder of this document, the expression "near" can mean "against", "in contact with", "opposite". Additionally, or alternatively, the expression "near" can be used to describe a relative arrangement of two elements, in which a distance measured between two points or surfaces respectively closest to the two elements is strictly less than a distance threshold, for example, the threshold being equal to 5 millimeters, or the threshold being equal to 2 millimeters, or the threshold being equal to 0.5 millimeters.

[0034] An embodiment of an arrangement 1 according to the invention is described below with reference to [Fig.2].

[0035] In this embodiment, at least one component intended to be cooled is part of a connection box. The role of the connection box is to connect the battery to the various current-consuming components of the motor vehicle 100, in particular to connect the battery to the traction motor or the battery charging device. The connection box acts as a switch for the connection between the battery and the motor vehicle 100.

[0036] The first thermal conductor 22 is made partially or entirely of an electrically and thermally conductive material. In particular, in the embodiment of the invention, the first thermal conductor 22 is implemented by at least one copper part 10 forming part of the connection housing.

[0037] Furthermore, in the embodiment of the invention, the second thermal conductor 23 is implemented by at least one heat pipe 23.

[0038] Furthermore, in the embodiment of the invention, the heat sink 21 is a cooling plate 21 of the traction battery of the motor vehicle 100. The cooling plate 21 can be an extruded aluminum plate in which a refrigerant fluid can circulate, in particular in tubes.

[0039] An embodiment of a connection box is schematically represented in [Fig.2]. Only electrical components likely to generate a heating point are shown, in particular an emergency switch 32, a relay 31 and a fuse 33.

[0040] During certain phases of vehicle use, particularly during fast charging of the motor vehicle 100, the electrical components of the connection box are likely to heat up, the heat power dissipated by a component being, for example, between 10 Watts and 80 Watts.

[0041] The components of the connection box are electrically connected to each other by copper links. In the remainder of this document, these copper links are referred to as "copper part 10". As explained later in this document, the copper parts 10 also serve to dissipate heat generated at the electrical components of the box by the passage of current. In other words, in the arrangement 1 according to the invention, at least one first thermal conductor 22 is implemented by at least one copper part 10.

[0042] In one embodiment more specifically illustrated by [Fig. 3], a first thermal conductor 22 comprises - a first copper strip 223 suitable for electrically connecting F at least one electrical component 31, 32, 33 to an electrical circuit, in particular suitable for electrically connecting F at least one electrical component 31, 32, 33 to another electrical component 31, 32, 33, and - a second copper strip 224 forming a T with the first copper strip 223, the second surface 222 of the second copper strip 224 (i.e. the second surface 222 of the first thermal conductor 22) being in contact with the first surface 231 of the second thermal conductor 23.

[0043] The first and second copper strips 224 are together able to transfer to the second thermal conductor 23, i.e. to a heat pipe 23, a first quantity of heat emitted by an electrical component 31, 32, 33. Thus, the first copper strip 223, the second copper strip 224 and the heat pipe 23 are together able to transfer a first quantity of heat emitted by at least one electrical component 31, 32, 33 to the heat sink 21.

[0044] Furthermore, the first copper strip 223 is capable of transferring to a second quantity of heat emitted by F at least one electrical component 31, 32, 33 to air surrounding the first copper strip 223.

[0045] In one embodiment, a thickness and / or a surface area of ​​the first copper strip 223 are respectively greater than a thickness and / or a surface area of ​​the second copper strip 224.

[0046] Thus, the first copper strip 223 has the primary function of electrically connecting the electrical component 31, 32, 33 to an electrical circuit, specifically the circuit implemented in the connection box. Furthermore, the second function of the first copper strip 223 is to dissipate some of the heat emitted by the electrical component 31, 32, 33 into the ambient air. Finally, the third function of the first copper strip 223 is to transfer a quantity of heat to the second copper strip 224, which is then transferred to the heat sink 21.

[0047] Each copper piece 10 is advantageously equipped with a heat pipe 23 such that a surface of the second copper strip 224, in particular the second surface 222 of the first thermal conductor 22, is in contact with a surface of the heat pipe 23, in particular the first surface 231 of the second heat sink. The second copper strip 224 thus functions to transfer heat from the first copper strip 223 to a heat pipe 23.

[0048] Advantageously, a measured angle 225 between the first copper strip 223 and the second copper strip 224 is substantially equal to 90 degrees. Thus, as illustrated by [Fig. 4], the first copper strip 223 of a part 10 can be arranged in a plane substantially perpendicular to the cooling plate 21, while the second copper strip 224 is arranged parallel to the cooling plate 21. In other embodiments, the measured angle 225 between the first copper strip 223 and the second copper strip 224 could be between 45 degrees and 90 degrees, or even between 30 degrees and 45 degrees.

[0049] Thus, in one embodiment of arrangement 1 more particularly described by Figures 3 and 4, a first face of a given component is disposed near the cooling plate 21, and parallel to the cooling plate 21, - the first copper strip 223 being arranged in a first plane, the first plane being perpendicular to the cooling plate 21 and in contact with a second face of the component, the second face also being in a plane perpendicular to the cooling plate 21, - the second copper strip 224 being arranged in a second plane, the second plane being parallel to the cooling plate 21.

[0050] In other words, the measured angle 225 between the first and second copper strips 224 allows the various functions of the first thermal conductor 22 to be implemented. - to allow electrical and thermal exchange between the first copper strip 223 and the surface of an electrical component 31, 32, 33 to be cooled, - allow heat exchange of the second band with a surface of a heat pipe 23 arranged parallel to the cooling plate 21.

[0051] Furthermore, each copper piece 10 is arranged in the connection housing so as to be electrically isolated from the heat sink 21, i.e. isolated from the cooling plate 21. In one embodiment, an electrical insulator is disposed on the cooling plate 21. Alternatively, an electrical insulator is disposed around the heat pipe 23, the copper piece being in contact only with the heat pipe 23, and not being in contact with the cooling plate 21.

[0052] Various methods of making a connection between the second copper strip 224 and a heat pipe 23 are possible, such as a connection by brazing, by welding, by gluing or by clamping.

[0053] Assembly steps for an arrangement according to the invention are described below with reference to figures 5 to 8.

[0054] In the first step illustrated in [Fig. 5], brackets 4 (also called "plates") are mounted on the battery's cooling plate 21. The brackets 4 are made of a non-conductive material, such as ABS (acronym for "Acrylonitrile Butadiene Styrene"). The brackets 4 include brass inserts for the passage of fixing screws, specifically 6 mm in diameter.

[0055] The brackets 4 are screwed onto the cooling plate 21. The brackets 4 are intended to support the mounting of the connection box equipment onto the cooling plate 21. The brackets 4 contain mounting surfaces and bores for receiving fixing screws for attaching the equipment 31, 32, 33 and the copper parts 10. Advantageously, the screws arranged on the brackets 4 serve not only to fix the components and the copper parts 10, but also to provide contact for current transmission between the components and the copper parts 10.

[0056] In a second step illustrated in [Fig. 6], the relay 31 is directly connected to the cooling plate 21 by screws. Since the housing of the relay 31 is made of a non-conductive material, it can be fixed to the cooling plate 21 without creating a short circuit. Contact between the relay 31 and the plate is facilitated by a layer of thermally conductive material placed between the relay 31 and the cooling plate 21. This arrangement of the relay 31 in contact with the plate is advantageous for cooling the control coil of the relay 31.

[0057] In contrast, as can be seen in [Fig.7], in a third step, the fuse 33 and the emergency switch 32 are fixed to the cooling plate 21 by means of supports 4 which keep them away from the cooling plate 21. The fuse 33 and the emergency switch 32 are thus electrically isolated from the cooling plate 21.

[0058] In a fourth step, four copper pieces 10a, 10b, 10c, lOd are used. A heat pipe 23 is fixed, notably by welding, to the second copper strip 224 of each copper piece 10a, 10b, 10c, lOd.

[0059] Then, as illustrated by [Fig. 8], the four copper pieces 10a, 10b, 10c, 10d, each equipped with a heat pipe 23, are arranged so as to act - on the one hand, as an electrical conductor between two adjacent electrical components - on the other hand, as a thermal conductor between each of the electrical components and the cooling plate 21.

[0060] Notably, - a first copper piece 10a is placed between a first support and a second support on which the emergency switch 32 is fixed, - a second copper piece 10b is arranged between a third support, on which the emergency switch 32 is fixed, and a first fixing surface 221 arranged on the relay housing 31, - a third copper piece 10c is positioned between a second mounting surface on the relay housing 31, and a fourth support on which the fuse 33 is fixed, then - a fourth copper piece lOd is arranged between the fourth support on which fuse 33 is fixed and a fifth support.

[0061] So, - the first copper part 10a allows some of the heat generated by the emergency switch 32 to be dissipated towards the cooling plate 21, - the second copper part 10b allows some of the heat generated by the emergency switch 32, and some of the heat generated by the relay 31, to be dissipated towards the cooling plate 21. - the third copper piece 10c allows some of the heat generated by the relay 31, and some of the heat generated by the fuse 33, to be dissipated to the cooling plate 21, and - the fourth copper piece lOd allows part of the heat generated by the fuse 33 to be evacuated towards the cooling plate 21.

[0062] A layer of thermally conductive material is disposed under each heat pipe 23 (i.e., on an area of ​​the cooling plate 21 located under each heat pipe 23). A layer of thermally conductive material is also disposed under each heat pipe 23.

[0063] Figure 9 illustrates a further step in which, for each heat pipe 23, a flange 5, in particular made of aluminum, is arranged to cover the heat pipe 23, the flange 5 being fixed to the cooling plate 21 by screws.

[0064] Finally, such an arrangement 1 according to the invention makes it possible to evacuate - via the first copper piece 10a, a quantity of thermal power approximately equal to 10 Watts, - via the second copper part 10b, a quantity of thermal power approximately equal to 40 Watts, - via the third copper piece 10c, a quantity of thermal power approximately equal to 50 Watts, - via the fourth copper piece lOd, a quantity of thermal power approximately equal to 30 Watts.

[0065] More generally, such an arrangement 1 according to the invention makes it possible to evacuate a quantity of thermal power substantially between 10 Watts and 80 Watts.

[0066] Thanks to the presence of a heat pipe 23 between the copper parts 10 and the cooling plate 21, the cooling efficiency of the electrical components of the connection box is greatly increased.

[0067] A first advantage of this increase in cooling efficiency is the ability to meet new requirements in terms of the amount of heat to be dissipated at the level of a traction battery connection box.

[0068] A second advantage lies in limiting the amount of copper required for cooling, and therefore reducing the manufacturing cost of a connection box. Indeed, the technical solution implemented in the invention meets cooling requirements without increasing the amount of copper used. Furthermore, limiting the amount of copper needed reduces the weight of the device according to the invention, thus reducing the weight of the motor vehicle.

[0069] A third advantage relates to the optimization of existing products thanks to the invention. Indeed, by improving cooling efficiency, the invention makes it possible to reduce the cross-section of the copper parts. This reduction in the volume of the copper parts allows the electrical components to be placed closer together, and therefore reduces the overall size of the equipment.

[0070] The arrangement 1 according to the invention further offers the advantage of implementing targeted cooling of the hot spots of a traction battery using the battery's cooling plate 21, and therefore without the need to route coolant to the hot spots. Moreover, cooling is improved by using components already present in the vehicle. For example, the cooling of the relay 31 is improved by placing it directly on the cooling plate 21.

[0071] Finally, the solution implemented by arrangement 1 according to the invention only very slightly increases the weight of a cooling system for a connection box.

Claims

Demands [Claim 1] An arrangement (1) comprising a cooling device (2) and at least one electrical component (31, 32, 33) intended to be cooled by the cooling device (2), the cooling device (2) comprising, - a heat sink (21), in particular a cooling plate (21) for a traction battery, - a first thermal conductor (22) made, at least in part, of an electrically and thermally conductive material, in particular made of copper, - a first surface (221) of the first thermal conductor (22) being in contact with a first surface (311, 321, 331) of at least one electrical component (31, 32, 33), - a second surface (222) of the first thermal conductor (22) being in contact with a first surface (231) of a second thermal conductor (23), - a second surface (232) of the second thermal conductor (23) being in contact with a first surface (211) of the heat sink (21), characterized in that the second thermal conductor (23) hermetically seals a heat transfer fluid such that: - a first quantity of heat transfer fluid located near the first surface (231) of the second thermal conductor (23) is capable of changing from a liquid state to a gaseous state by absorbing a quantity of heat from the second surface (222) of the first thermal conductor (22), then - a second quantity of heat transfer fluid located near the second surface (232) of the second thermal conductor is able to pass from the gaseous state to the liquid state by transferring, to the first surface (211) of the heat sink (21), the quantity of heat taken from it. [Claim 2] Arrangement (1) according to claim 1, characterized in that the first thermal conductor (22) is arranged so as to be electrically isolated from the heat sink (21). [Claim 3] An arrangement (1) according to any one of the preceding claims, characterized in that the first thermal conductor (22) comprises - a first copper strip (223) suitable for electrically connecting F at least one electrical component (31, 32, 33) to an electrical circuit, in particular suitable for electrically connecting F at least one electrical component (31, 32, 33) to another electrical component (31, 32, 33), and - a second copper strip (224) forming a T with the first copper strip (223), the second copper strip (224) being in contact with the first surface (231) of the second thermal conductor (23). [Claim 4] Arrangement (1) according to the preceding claim, characterized in that the first and second copper strips (223, 224) are together able to transfer to the second thermal conductor (23) a first quantity of heat emitted by F at least one electrical component (31, 32, 33). [Claim 5] Arrangement (1) according to any one of claims 3 or 4, characterized in that the first copper strip (223) is capable of transferring a second quantity of heat emitted by F at least one electrical component (31, 32, 33) to air surrounding the first copper strip (223), the surrounding air being air located in contact with the first copper strip (223) or air located in a volume surrounding the first copper strip (223). [Claim 6] Arrangement (1) according to any one of claims 3 to 5, characterized in that a measured angle (225) between the first copper strip (223) and the second copper strip (224) is substantially equal to 90 degrees, or between 45 degrees and 90 degrees, or even between 30 degrees and 45 degrees. [Claim 7] Arrangement (1) according to any one of the preceding claims, characterized in that at least one electrical component (31, 32, 33) to be cooled comprises an electrical relay (31), and / or an emergency switch (32), and / or a fuse (33) of a connection box of a traction battery of a motor vehicle. [Claim 8] An arrangement (1) according to the preceding claim, characterized in that it comprises four first heat conductors (22) each collaborating with a second heat conductor (23) disposed in contact with a cooling plate (21) of the traction battery, the first and second heat conductors (22, 23) being arranged such that - to allow electrical conduction between two adjacent electrical components, and - allow thermal conduction between each electrical component and the cooling plate (21). [Claim 9] Motor vehicle (100) with electric or hybrid powertrain comprising an arrangement (1) according to any one of the preceding claims.

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