Power distribution unit equipped with at least one current busbar with square intersecting lines

Abstract

Power distribution unit (1) for vehicle battery management equipment, the power distribution unit (1) incorporating a profiled current bar (4), the current bar (4) incorporating four sides (9, 10, 11, 12), a first side (9) being connected to a second side (10) at a first line of intersection (I), the second side (10) being connected to a third side (11) at a second line of intersection (J), the third side (11) being connected to the fourth side (12) at a third line of intersection (K), the fourth side (12) being connected to the first side (9) at a fourth line of intersection (L), the lines of intersection (I, J, K, L) when projected onto a transverse plane define the vertices of a square. Figure for the abbreviation: Fig. 2

Description

Title of the invention: Power distribution unit equipped with at least one current bar with square intersecting lines

[0001] The invention relates to the technical field of vehicles comprising an electrified propulsion system, integral or coupled with a thermal propulsion system, the electrified propulsion system being powered by a battery system.

[0002] Throughout this description, the term "battery system," also referred to as "battery," refers to a device comprising a plurality of interconnected battery cells. The battery system stores and supplies electrical energy to the electrified propulsion system.

[0003] Such a battery system is generally equipped with a power distribution unit, also called a battery junction box or battery disconnect unit (BDU). Such a battery system is essential for electric and hybrid vehicles (EVs).

[0004] The power distribution unit allows the battery to be connected to or disconnected from the electrical grid, particularly high-voltage grids, and protects electrical systems against overload or short-circuit conditions. Such conditions include overvoltages, overcurrents, and short circuits that may originate from the battery, an inverter, the electric motor, or auxiliary systems. This level of protection is crucial to prevent the risk of fire or electric shock.

[0005] In an electric vehicle or a hybrid vehicle with propulsion powered by a high-voltage battery, the power distribution unit is either integrated into a single subsystem or distributed into several subsystems in the vehicle, in order to locate the protection as close as possible to certain critical systems such as the inverter, the battery and the charging system.

[0006] By strategically integrating such a distribution unit, optimal protection of critical vehicle components is planned, thereby improving the overall safety and reliability of electric and hybrid vehicles.

[0007] The invention relates to such an energy distribution unit.

[0008] Typically, a power distribution unit includes connection components, for example contactors or power relays, battery protection elements against short circuits, for example fuses, as well as irreversible cut-off devices in case of serious short circuit or accident, such as pyro-fuses or pyro-switches.

[0009] In addition, the equipment incorporates current measurement technologies such as shunts, Hall effect sensors or flux-gate devices, thus providing precise monitoring of the power supply.

[0010] In order to enable currents to be conducted within the power distribution unit, or between the power distribution unit and the electric propulsion system, or between the power distribution unit and the battery system, current-conducting bars, also called busbars, are provided.

[0011] Throughout the remainder of this text, the term “current conductive bar”, or “current bar”, “busbar”, means a component extending substantially in length, and made of a conductive material such as a metallic material, for example copper, brass or aluminium.

[0012] In general, current bars are strips of copper or aluminum, cut, bent, or folded, which establish a rigid interconnection path within the system. Generally, current bars have rectangular cross-sections, which helps to limit their size and provide a minimum cross-section suitable for the passage of a direct current or a stabilized RMS current, measured in amperes per square millimeter (A / mm²).

[0013] The dimensioning of the current bars is a critical operation. Typically, the conductive bars are dimensioned with a specific surface area and orientation to efficiently dissipate the heat generated by the passage of high currents, thus reducing energy losses and ensuring optimal system operation.

[0014] Such a design allows efficient heat dissipation by conduction, convection and radiation, thus ensuring the reliability and performance of the system in a variety of applications.

[0015] Currently, there is no simple mathematical model capable of correctly dimensioning a current bar. Indeed, to perform such a calculation, it would be necessary to take into account electrical parameters (for example current distribution, skin effect, proximity to other materials, voltage and amperage), thermal parameters (for example influence of the environment, type of cooling), metallurgical parameters (for example state of matter influencing electrical and thermal conductivity) and mechanical parameters (general shape, pressures exerted on physical bonds and heating).

[0016] Also, dimensioning tables have been created, the calculations necessary to obtain approximate results being carried out by several specialized software programs, which are expensive and require a large amount of computing power.

[0017] Cooling such current bars in electric vehicles is critical due to the high performance and safety requirements in These systems. The current bars, which carry large amounts of current, can generate considerable heat due to electrical resistance and current intensity.

[0018] Inefficient thermal management can lead to overheating of the current bars, which in turn can cause material degradation, loss of energy efficiency, and in extreme cases, risks of fire or damage to surrounding electronic components. Furthermore, inadequate cooling can affect the battery's ability to deliver optimal power and reduce the overall system lifespan.

[0019] Therefore, an efficient cooling system for the current bars is essential to maintain safe operating temperatures, ensure the reliability and longevity of the electrical components, and guarantee optimal performance of the electric vehicle.

[0020] Currently, current busbars are cooled by thermal contact with an additional cooling device, such as a cooling plate made of a heat-conducting material, which absorbs heat. However, such plates have a significant size, and their use generates additional costs. Furthermore, these plates limit the possibilities for current busbar topologies. There is a growing need to reduce the use of such cooling devices.

[0021] The invention aims to address the aforementioned drawbacks.

[0022] A first objective is to propose a vehicle power distribution unit electric equipped with current bars allowing the elimination of cooling devices.

[0023] A second objective is to propose such a distribution unit with a limited cost.

[0024] A third objective is to propose such a unit which can be as compact as possible.

[0025] A fourth object is to propose a motorization module for an electric propulsion vehicle, the motorization module integrating a distribution unit as presented above.

[0026] In this respect, a power distribution unit for vehicle battery management equipment is provided firstly, the power distribution unit incorporating a profiled current bar, the current bar incorporating four sides, a first side being connected to a second side at a first line of intersection, the second side being connected to a third side at a second line of intersection, the third side being connected to the fourth side at a third line of intersection, the fourth side being connected to the first side at a fourth line of intersection, the Intersection lines, when projected onto a transverse plane, define the vertices of a square.

[0027] The additional features may be provided alone or in combination: - at least one side includes at least one notch; - at least one notch defines a U shape according to a transverse plane; - at least one notch comprises a first edge, a second edge, a third edge, the first edge and the third edge being parallel to each other, the second edge being perpendicular to the first edge and the third edge; - at least one notch defines a concave edge according to a transverse plane; - one side includes a plurality of notches; - two sides opposite each other are provided with a plurality of identical notches, uniformly distributed, uniformly spaced from each other along said sides, the notches forming on said sides a pattern exhibiting regular undulations. - the first side, the second side, the third side and the fourth side are each equipped with a notch.

[0028] Secondly, a motor vehicle drive module integrating an electric propulsion is planned, the module comprising a distribution unit as presented above.

[0029] Other features and advantages of the invention will become more apparent and concrete upon reading the following description of embodiments, given by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0030] [Fig.1] Fig.1 represents a schematic top view of an example of a power distribution unit;

[0031] [Fig.2] Fig.2 represents a schematic perspective view of an example of a current bar;

[0032] [Fig.3] Fig.3 represents a schematic perspective view of a current bar according to a first embodiment;

[0033] [Fig.4] The [Fig.4] represents a schematic side view of a current bar according to a second embodiment;

[0034] [Fig.5] The [Fig.5] represents a schematic side view of a current bar according to a third embodiment;

[0035] [Fig.6] The [Fig.6] represents a schematic side view of a current bar according to a fourth embodiment;

[0036] [Fig.7] The [Fig.7] represents a schematic side view of a current bar according to a fifth embodiment;

[0037] [Fig.8] Fig.8 represents a schematic side view of a current bar according to a sixth embodiment.

[0038] Reference is made to [Fig. 1] representing a power distribution unit 1 for an electrically powered vehicle. Such a power distribution unit 1 comprises a housing 2 receiving a plurality of electrical components 3 such as relays, fuses, and current sensors.

[0039] Advantageously, the power distribution unit 1 is integrated into a motorization module incorporating an electric propulsion, for example an electric motor.

[0040] As can be seen in [Fig.1], the various components 3 are connected to each other by current bars 4. Advantageously, the current bars 4 comprise at a minimum a junction 5 provided between two interconnection points 6.

[0041] In the embodiment shown in [Fig.2], the current bar 4 comprises a plurality of straight sections 7, separated from each other by means of curved sections 8. In this way, the current bar 4 describes a path, in the form of a broken curve evolving in space.

[0042] In other embodiments, a current bar 4 comprises only straight sections 7. The current bars 4 described below include a junction 5 comprising a single straight section 7. However, the described shapes also apply to a straight section 7 of a current bar 4 having several sections. Thus, a current bar 4 may have a straight section 7 with a geometry according to one embodiment, and another straight section with a geometry according to another embodiment.

[0043] Throughout the remainder of this text, an orthogonal XYZ frame of reference comprising three axes perpendicular in pairs is defined with respect to a current bar 4 in the form of a straight section 7, namely: - an X axis, coinciding with the general direction of extension of the current bar 4, defining a longitudinal direction; - a Y axis, defining a transverse, horizontal direction, which with the X axis defines a horizontal XY plane; - a Z axis, defining a vertical direction, perpendicular to the horizontal XY plane, the YZ axes defining a transverse plane, the XZ axes defining a vertical plane.

[0044] Advantageously, a current bar 4 is made of metallic conductive materials such as copper or aluminum. Such materials offer increased conductivity and optimal heat dissipation.

[0045] Advantageously, a current bar 4 is formed by pressing it in a die to obtain a profile. The curved joints 7 are obtained, for example, by bending the profile, for example, using a press. A current bar 4 is thus obtained at low cost, allowing for mass production.

[0046] As can be seen in the figures, a current bar 4 is in the form of a profile describing a perimeter, which in space forms a surface 101, in contact with the outside. The inside of the perimeter is referred to throughout the description as core 102. The passage of current, particularly if with a high value, generates heat, notably through the Joule effect, with surface 101 allowing the heat to be dissipated.

[0047] Commonly in the various embodiments, the current bar 4 comprises a first side 9 being connected to a second side 10 in a first line of intersection I, the second side 10 being connected to a third side 11 in a second line of intersection J, the third side 11 also being connected to the fourth side 12, in a third line of intersection K, the fourth side 12 being connected to the first side 9 in a fourth line of intersection L, the lines of intersection I, J, K, L when projected onto a transverse plane define the vertices of a square.

[0048] Thus, it is possible to obtain a current bar 4 with an essentially square cross-section. Such a shape offers a surface area allowing for better thermal conduction and current distribution, which improves heat dissipation compared to current bars 4 with a rectangular cross-section.

[0049] Advantageously, a current bar 4 has a longitudinal plane of symmetry passing through the middle of the first side 9 and the third side 11. Such a symmetry feature allows a balanced distribution of the current flow and mechanical forces.

[0050] Advantageously, a current bar 4 has a vertical plane of symmetry passing through the middle of the second side 10 and the fourth side 12. Such a symmetry feature allows a balanced distribution of the current flow and mechanical forces.

[0051] In the embodiments shown, one of the sides 9, 10, 11, 12 is provided with a notch 13. Such a notch 13 is intended to increase the contact area of ​​the current bar 4 with the air. In this way, the energy dissipation capacity of the current bar 4 is improved.

[0052] In embodiments, for example those shown in Figures 3 or 4, a single notch 13 is provided on each side 9, 10, 11, 12. In order to increase the effect of the notches 13, several notches 13 are provided on each side 9, 10, 11, 12.

[0053] In embodiments, for example those shown in Figures 3 and 4, the notch 13 has a plane of symmetry, longitudinal when the notch 13 is located on the first side 9 or the third side 11, or vertical when the notch 13 is located on the second side 10 or the fourth side 12. In other embodiments, for example that shown in the figure, the notch is asymmetrical.

[0054] Advantageously, a notch 13 has a U-shape when viewed in a transverse plane, increasing the surface area exposed to the air and facilitating heat evacuation.

[0055] In some embodiments, for example the second embodiment, the notch 13 comprises a first edge 14, a second edge 15, connected to each other by a third edge 16. As can be observed, the first edge 14 and the second edge 15 are parallel to each other and extend in a longitudinal plane. In other words, the second edge 15 is perpendicular to the first edge 14 and the third edge 16, thus giving the notch 13 a crenellated shape.

[0056] In other embodiments, particularly the third embodiment, the notch 13 defines a concave curve, i.e., oriented towards the core 102. In this way, the surface area 101 is increased compared to known current bars, thus providing an additional area for heat dissipation. As a result, heat is dissipated more efficiently, allowing dissipation by natural convection in the power distribution unit 1.

[0057] In the second embodiment, shown in [Fig. 3], each side 9, 10, 11, 12 is provided with a notch 13 with a crenellation as shown above. The notches 13 are uniformly spaced and symmetrical, so that each side of the main square maintains an equal length between the notches 13.

[0058] In the third embodiment, shown in [Fig. 4], a first side 9 and a third side 13 are provided with a notch 13 having a concave edge 18, the notches 13 being identical and symmetrical to each other with respect to a vertical plane passing through the midpoint of the second side 10 and the fourth side 12, and with respect to a longitudinal plane passing through the midpoint of the first side 9 and the third side 11. In such a third embodiment, the second side 10 and the fourth side 12 are without notches 13 and are flat. In other words, the perimeter of such a current bar 4 is narrowed at the center 17 of the notches 13.

[0059] In the fourth embodiment, each side 9, 10, 11, 12 successively comprises a first lateral division 19, a notch 13, a central division 20, another notch 13, and another lateral division 19. As can be observed, the current bar 4 has a vertical plane of symmetry passing through the middle of the central division 20.

[0060] In a fifth embodiment shown in [Fig. 6], two sides 9, 10, 11, 12 opposite each other, for example the second side 10 and the fourth side 12, are provided with a plurality of identical notches 13. Two other sides 9, 10, 11, 12, opposite each other, are without notches 13.

[0061] In such a fifth embodiment, the notches 13 are uniformly spaced from one another, forming a pattern of regular, repeating undulations. In this way, the second side 10 and the fourth side 12 exhibit a regular alternation between troughs 22 and crests 23. Such a uniform distribution of the notches 13 increases the surface area exposed to the air, improving heat dissipation. of heat. In addition, such a notch arrangement allows for a homogeneous distribution of the current over the entire surface of the current bar 4.

[0062] In the sixth embodiment, shown in [Fig. 8], all four sides 9, 10, 11, 12 are provided with notches 13, uniformly spaced from one another, forming regular, repeating undulations. In this way, all four sides 9, 10, 11, 12 exhibit a regular alternation between troughs 22 and crests 23. Such a uniform distribution of the notches 13 increases the surface area exposed to the air, improving heat dissipation. Furthermore, this arrangement of notches allows for a homogeneous distribution of the current over the entire surface of the current bar 4.

[0063] The power distribution unit 1 and the current bar 4 as shown above offer multiple advantages, including: - the possibility of having a multiplicity of possible shapes for the current bar; - the fact that a current bar 4 as disclosed above is obtained without it being necessary to considerably modify the manufacturing processes compared to the current bars 4 of the prior art, the manufacturing costs thus not being increased; - the increased cooling capacity offered by the use of current bars 4 as described above makes natural convection cooling possible, and makes it possible to do without an additional cooling device.

Claims

Demands

1. Power distribution unit (1) for vehicle battery management equipment, the power distribution unit (1) incorporating a profiled current bar (4), the current bar (4) incorporating four sides (9, 10, 11, 12), a first side (9) being connected to a second side (10) in a first line of intersection (I), the second side (10) being connected to a third side (11) in a second line of intersection (J), the third side (11) being connected to the fourth side (12) in a third line of intersection (K), the fourth side (12) being connected to the first side (9) in a fourth line of intersection (L), the lines of intersection (I, J, K, L) when projected onto a transverse plane define the vertices of a square.

2. Power distribution unit (1) according to the preceding claim, characterized in that at least one side (9, 10, 11, 12) comprises at least one notch (13).

3. Power distribution unit (1) according to the preceding claim, characterized in that at least one notch (13) defines a U shape along a transverse plane.

4. Energy distribution unit (1) according to the preceding claim, characterized in that at least one notch (13) comprises a first edge (14), a second edge (15), a third edge (16), the first edge (14) and the third edge (16) being parallel to each other, the second edge (15) being perpendicular to the first edge (14) and the third edge (16).

5. Power distribution unit (1) according to claim 2, characterized in that at least one notch (13) defines along a transverse plane a concave edge (18).

6. Power distribution unit (1) according to any one of claims 2 to 5, characterized in that one side (8, 9, 10, 11) comprises a plurality of notches (13).

7. Power distribution unit (1) according to any one of claims 2, 3, 5 or 6, two sides (9, 10, 11, 12) opposite each other are provided with a plurality of identical notches (13) uniformly distributed, uniformly spaced from each other along said sides (9, 10, 11, 12), the notches forming on said sides (8, 9, 10, 11) a pattern having regular undulations.

8. Power distribution unit (1) according to any one of the preceding claims, characterized in that the first side (9), the second side (10), the third side (11) and the fourth side (12) are each provided with a notch (13).

9. Motor vehicle drive module incorporating electric propulsion, the module comprising a distribution unit (1) according to any one of the preceding claims.

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