Electronic power device for a drive device of a mobility vehicle

Abstract

The invention relates to an electronic power device (1) comprising: a first circuit board (2) on which a transformer (3) is arranged, a second circuit board (4) arranged in parallel with the first circuit board (2), a metal plate (5) to which the first circuit board is attached (2), the plate (5) being arranged between the printed circuit boards (2, 4) for electromagnetic shielding purposes, wherein the metal plate (5) comprises a shielding unit (6) in the form of a cavity in which the transformer is arranged (3) so as to electromagnetically isolate the transformer (3) on the first circuit board (2).

Description

[0001] transformerDescription

[0002] Title of the invention: Electronic power device intended for a drive device for a mobility device

[0003] Technical field of the invention

[0004] The present invention relates to the field of electrical equipment, in particular high voltage, such as power converters, in particular configured to be installed in a mobility device such as a hybrid or electric motor vehicle. The present invention relates in particular to a power electronic device comprising an electromagnetic shielding unit.

[0005] Technological background

[0006] Power electronic devices are known from the prior art, in particular power converters (on-board chargers, DC / DC converters, inverters) for electric vehicles comprising several electrical components such as, among others, electronic cards, electrically conductive bars, power transformer modules and capacitors. These electrical components in which currents flow, in particular at high power levels, generate emitted magnetic fields which can disturb the operation of other electrical equipment. Therefore, electromagnetic compatibility (EMC) requirements are applied to ensure that other electrical equipment is able to operate despite these electromagnetic disturbances.

[0007] Thus, as is known, such electrical components must have good electromagnetic compatibility performance. In other words, it must be ensured on the one hand that the electrical component is able to operate itself without disturbances, in its electromagnetic environment, and on the other hand that it is also able to operate without introducing electromagnetic disturbances likely to harm the proper functioning of third-party electrical components located nearby.

[0008] To this end, it is known to integrate into such electrical equipment an electromagnetic shielding support plate, in particular made of aluminum. Typically, the electronic card is mounted on one side of the plate. In particular, such an electromagnetic blocking support plate separates, on one side, a power module and, on the other, an electronic control card of said power module. A conventional solution, to ensure satisfactory electromagnetic shielding, consists of using internal shielding devices attached to the electronic card, each of the electrical components having its specific shielding device. Electromagnetic shields are thus added at various locations in the electrical equipment to ensure the shielding of each specific component.However, adding such component-specific shielding devices can be expensive and require additional operations during the manufacturing of electrical equipment.

[0009] The invention therefore aims to propose a power electronic device integrating electromagnetic shielding elements natively, by means of structural characteristics of constituent elements of such an electronic device.

[0010] Summary of the invention

[0011] The present invention thus aims to propose an electronic power device comprising:

[0012] - a first electronic card on which a transformer is placed,

[0013] - a second electronic card arranged in parallel with the first electronic card,

[0014] - a metal plate on which the first electronic card is fixed, said plate being arranged between the printed circuit cards for the purpose of electromagnetic shielding, wherein the metal plate comprises a shielding unit in the form of a cavity in which said transformer is arranged so as to electromagnetically isolate the transformer on the first electronic card.

[0015] The invention thus makes it possible to use an existing metal plate both for electromagnetic shielding purposes between the two printed circuit boards and for electromagnetically isolating the transformer on the first electronic board. The number of parts required for electromagnetic shielding is therefore lower. Thus, the present invention makes it possible to reduce manufacturing costs for a given electromagnetic shielding performance.

[0016] In the context of the present invention, the metal plate and the shielding unit are therefore formed in one piece, preferably by molding or stamping. The metal plate and the shielding unit are therefore not two independent parts. The electronic card may be a printed circuit board. For the purposes of the present invention, the term "cavity" means an empty space inside the metal plate. A cavity is therefore similar to a blind hole and not to a through opening because it has a bottom. The cavity designates the empty space but also the contours of the cavity which delimit this space. The contours of the cavity include the bottom.

[0017] The first electronic board and the second electronic board being parallel to each other, they define an axis. The first electronic board and the second electronic board are perpendicular to this axis. This axis defines an axial direction. The bottom can extend perpendicular to the axis.

[0018] The invention may further comprise one or more of the following optional features, in any technically possible combination.

[0019] Advantageously, the cavity has edges delimiting an opening, said edges being provided with fixing points. The contours of the cavity include the edges. The edges may extend substantially in the axial direction. Preferably, the fixing points include threaded openings for receiving fixing means such as screws. Preferably, mechanical fixing elements are inserted into the mechanical fixing points so as to ensure electrical contact between the cavity and the first electronic card.

[0020] Advantageously, the cavity has edges delimiting an opening, walls extending from said edges towards the first electronic card. The walls make it possible to limit as much as possible the clearance between the electronic card towards which they are directed and the metal plate. Preferably, the walls occupy only part of the edges. This allows the heat generated by the transformer to pass through in order to avoid having a confined area when the walls occupy the entire edges of the cavity.

[0021] Advantageously, the shielding unit extends in the opposite direction from the first electronic card. Advantageously, the shielding unit extends axially away from the first electronic card. Advantageously, the shielding unit extends axially towards the second electronic card.

[0022] Advantageously, the shielding unit extends further than the second electronic board. Advantageously, the shielding unit extends further axially than the second electronic board. Advantageously, the second electronic board is axially between the bottom and the first electronic board. Thus, the second electronic board has a free area opposite the first electronic board in which the shielding unit can extend. Thanks to such an overlap, this makes it possible to obtain a more compact device. Advantageously, the first electronic board is a control board and the second electronic board is a power board. By control board is meant a board with low voltage potential and by power board, a board with high voltage potential. In other words, low voltage potentials are present on the control board and high voltage potentials are present on the power board.

[0023] Advantageously, the second electronic card is connected to at least one power module.

[0024] Advantageously, the electronic device further comprises a housing containing the first and second electronic card and the metal plate, said metal plate being fixed to the housing.

[0025] The invention also relates to a drive device for a mobility device comprising an electric machine arranged to drive the device and a power electronics device according to the invention in which the power electronics device is arranged to supply the electric machine with an alternating voltage.

[0026] The invention also relates to a mobility device comprising the aforementioned drive device. The mobility device may be a vehicle for transporting goods or people, such as an automobile, a truck, an electric bicycle, a drone, an electric scooter, etc.

[0027] According to one aspect of the invention, the power electronic device consists of a power converter such as an inverter.

[0028] Brief description of the figures

[0029] The invention will be better understood by reading the following description and examining the accompanying figures. These figures are given only for illustrative purposes but in no way limit the invention.

[0030] [Fig. 1] represents a detailed sectional view of the power electronic device according to the invention.

[0031] [Fig. 2] represents a perspective and top view of the shielding unit of the power electronic device shown in Figure 1.

[0032] [Fig. 3] represents a diagram of an embodiment of the mobility device with a drive device according to the invention. Identical, similar or analogous elements retain the same reference from one figure to another.

[0033] Detailed description of the invention

[0034] In the description which will be given below, the invention will be described mainly with a view to the production of an inverter, in particular intended to power a rotating electrical machine. However, the invention also relates to any electronic power device compatible with the characteristics of the invention.

[0035] Figure 1 represents a power electronic device 1 comprising:

[0036] - a first electronic card 2 on which a transformer 3 is arranged,

[0037] - a second electronic card 4 arranged in parallel with the first electronic card 2,

[0038] - a metal plate 5 on which the first electronic card 2 is fixed, said plate 5 being arranged between the printed circuit cards 2, 4 for the purposes of electromagnetic shielding.

[0039] The metal plate 5 comprises a shielding unit 6 in the form of a cavity (in the remainder of the description we can therefore use the term shielding unit 6 or cavity 6 which designate the same element) in which said transformer 3 is arranged so as to electromagnetically isolate it on the first electronic card 2. Thus, the metal plate 5 makes it possible to electromagnetically separate the first electronic card 2 from the second electronic card 4 and at the same time to separate the transformer 3 of the first electronic card 2 from the other third-party electrical components of this same card.

[0040] The metal plate 5 and therefore by extension the shielding unit 6 formed within it are preferably made of aluminum. The metal plate 5 is substantially flat except for the shielding unit 6 which projects from it.

[0041] The shielding unit 6 shields the electromagnetic radiation generated outwardly by the transformer 3, thereby reducing the electromagnetic interference caused by the transformer 3 to an external device arranged on the electronic board 2 and improving the EMC performance of the electronic device 1.

[0042] The first electronic card 2 is fixed by screwing onto the metal plate 5. The first electronic card 2 corresponds to the low voltage part of the electronic device 1. Preferably, the first electronic card 2 is a control card and the second electronic card 4 is a power card. The second electronic card 4 corresponds to the high voltage of the electronic device 1.

[0043] The power card is connected to at least one, preferably several power modules 20 configured to convert direct electrical energy into alternating electrical energy to power an electric motor powered by the electronic power device 1. These power modules 20 comprise in particular semiconductor components such as diodes and / or transistors, encapsulated in the same envelope and through which the electrical energy powering the electric motor passes. Such a power module is configured to allow a controlled passage of electrical energy between a high-voltage power supply battery and the electric machine.

[0044] The control board comprises electronic control circuits capable of controlling the power modules 20 of the power board.

[0045] The shielding unit 6 extends in the opposite direction from the first electronic board 2.

[0046] The shielding unit 6 extends further than the second electronic card 4. Thus, the second electronic card 4 has, opposite the first electronic card, a free zone 4a in which the shielding unit 6 extends.

[0047] In a variant not shown, the shielding unit 6 extends less far than the second electronic card 4. Thus, the second electronic card 4 may not include a free zone 4a. The shielding unit 6 then extends between the two electronic cards 2, 4 which are superimposed on each other.

[0048] Preferably, the device further comprises mechanical fixing zones, for example gluing, and / or cooling 25 between the metal plate 5 and the transformer 3. These zones correspond to free spaces located between the transformer 3 and the metal plate 5 facing it. Three zones 25 are shown in Figure 1. One of these zones 25 is filled with a thermal interface material 26 which allows the heat generated by the transformer 3 to be evacuated. The thermal interface material 26 is for example a thermal paste or grease.

[0049] As can be seen in Figure 2, the cavity 6 has edges 7 delimiting an opening 8. The edges 7 are provided with fixing points 10a. Preferably, the fixing points 10a comprise threaded openings for receiving fixing means 10b such as screws (visible in Figure 1). Preferably, the mechanical fixing elements 10b are inserted into the mechanical fixing points 10a so as to ensure electrical contact between the cavity 6 and the first electronic card 2.

[0050] In the example considered, walls 9 extend from the edges 7 towards the first electronic card 2. Preferably, the walls 9 occupy only part of the edges 7. The walls 7 extend perpendicular to the metal plate 5 and are in contact with the electronic card 2. Preferably, the walls 7 are in one piece with the metal plate 5.

[0051] The cavity 6 has a bottom 11 which extends parallel to the first electronic card 2. The bottom 11 also extends parallel to the second electronic card 4.

[0052] As can be seen, the electronic device 1 further comprises a housing 12 containing the first and second electronic card 2, 4 and the metal plate 5, said metal plate 5 being fixed to the housing 12.

[0053] Figure 3 represents a diagram of an embodiment of a mobility device 13 with a drive device 14 according to the invention.

[0054] The drive device 14 is arranged to drive the mobility device 13. The drive device comprises an electric machine 15 arranged to drive the device 13 and a power electronics device 1. The power electronics device 1 is arranged to supply the electric machine 15 with an alternating voltage, three-phase here by way of example.

[0055] Of course, the preceding description has been given by way of example only and does not limit the scope of the invention, which would not be exceeded by replacing the various elements with any other equivalents.

[0056] Furthermore, the various features, variations, and / or embodiments of the present invention may be combined with each other in various combinations, provided that they are not incompatible or mutually exclusive.

Claims

CLAIMS Electronic power device (1) comprising: - a first electronic board (2) on which a transformer (3) is placed, - a second electronic board (4) arranged in parallel with the first electronic board (2), - a metal plate (5) on which the first electronic card (2) is fixed, said plate (5) being arranged between the printed circuit boards (2, 4) for electromagnetic shielding purposes, characterized in that the metal plate (5) comprises a shielding unit (6) in the form of a cavity, the cavity being a blind hole, in which said transformer (3) is disposed so as to electromagnetically isolate the transformer (3) from the first electronic card (2), the metal plate and the shielding unit being formed as a single unit. Power electronic device (1) according to claim 1, characterized in that the cavity has edges (7) delimiting an opening (8), said edges (7) being provided with mechanical fixing points (10a).A power electronic device (1) according to the preceding claim, characterized in that mechanical fastening elements (10b) are inserted into the mechanical fastening points (10a) so as to ensure electrical contact between the cavity and the first electronic board (2). A power electronic device (1) according to any one of the preceding claims, characterized in that the cavity has edges (7) delimiting an opening (8), and walls (9) extend from said edges (7) towards the first electronic board (2). A power electronic device (1) according to any one of the preceding claims, characterized in that the shielding unit (6) extends in the opposite direction from the first electronic board (2). A power electronic device (1) according to claim 5, characterized in that the shielding unit (6) extends beyond the second electronic board (4). A power electronic device (1) according to any one of the preceding claims, characterized in that the first electronic board (2) is a control board and the second electronic board (4) is a power board. A power electronic device (1) according to any one of the preceding claims, characterized in that the second electronic board is connected to at least one power module (20). A power electronic device (1) according to any one of the preceding claims, characterized in that it comprises a housing (12) enclosing the first and second electronic boards (2, 4) and the metal plate (5), said metal plate being fixed to the housing.A drive device (14) for a mobility device (13) comprising an electric machine (15) arranged to drive the device (13) and a power electronics device (1) according to any one of the preceding claims, wherein the power electronics device (1) is arranged to supply the electric machine with an alternating voltage. A mobility device (13) comprising the drive device (14) according to the preceding claim.

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