Inverter for electrical machine

Abstract

The invention relates to an inverter (100) for an electric machine intended for vehicle propulsion, the inverter comprising: - a plurality of power modules (1), each power module (1) being equipped with a plurality of input connectors (2) for connection to an electrical energy storage unit and output connectors (4) for connection to a phase of the electric machine; - a frame (3) comprising a plurality of housings, each power module (1) being housed in one of the housings (32); - a first and a second heat exchange modules (6; 8), comprising respectively a first and a second circulation circuit (61; 81) for a heat transfer fluid; the frame (3) being fixed to each of the first and second heat exchange modules (6; 8). Figure for the abstract: 1

Description

Title of the invention: Inverter for electrical machine technical field

[0001] The invention relates to the field of inverters for electrical machines and more particularly to inverters for electrical machines intended for the propulsion of a vehicle. Technological background

[0002] An inverter is a power electronics device that allows the generation of any form of current, and in particular alternating current, from a direct current.

[0003] To do this, it includes a plurality of power modules used to implement energy conversion circuits.

[0004] These power modules heat up when the inverter is in use and it is therefore necessary to cool them optimally.

[0005] This is generally achieved using heat exchange modules. Thus, it is known to use a heat exchange module and to place it against one of the faces of the power modules. In order to increase cooling capacity, it is also known to position the power modules between two heat exchange modules.

[0006] However, when the power modules are positioned between two heat exchange modules, assembling the unit becomes complex. It is necessary to ensure proper positioning of the power modules while the two heat exchange modules are fixed to each other so as to sandwich the power modules.

[0007] There is also a need to guarantee the position of the power modules within the inverter throughout the life cycle. Summary of the invention

[0008] One idea underlying the invention is to facilitate the mounting of power modules within the inverter. Another idea underlying the invention is to ensure precise and durable positioning of the power modules of an inverter.

[0009] According to one embodiment, the invention provides an inverter for an electric machine intended for the propulsion of a vehicle, the inverter comprising: - a plurality of power modules, each power module being equipped with a plurality of input connectors intended to be connected to an electrical energy storage unit and output connectors intended to be connected to a phase of the electric machine, - a frame comprising a plurality of housings, each power module being housed in one of the housings; - a first and a second heat exchange module, each of the first and second heat exchange modules comprising respectively a first and a second circulation circuit of a heat transfer fluid; - the first heat exchange module, the frame and the second heat exchange module being stacked so that the first and second circulation circuits are positioned on either side of the power modules; the frame being fixed to each of the first and second heat exchange modules.

[0010] The frame housings thus ensure precise positioning of the power modules relative to the heat exchange modules, which facilitates the assembly of the inverter.

[0011] Furthermore, the power modules remain positioned in the desired location throughout the inverter's life cycle. Cooling by contact with the heat exchange modules remains optimal throughout the inverter's life cycle.

[0012] According to embodiments, such an inverter may include one or more of the following characteristics.

[0013] According to one embodiment, the first heat exchange module has a first external surface opposite the frame, the second heat exchange module has a second external surface opposite the frame, the frame includes a plurality of first fixing tabs, the first fixing tabs being positioned at either of the longitudinal ends of the frame and extending towards the first external surface; the first fixing tabs being in contact with the first external surface so that the first heat exchange module is held against the frame;The frame further comprises a plurality of secondary fixing lugs, the secondary fixing lugs being positioned at either of the longitudinal ends of the frame and extending towards the second external surface, the secondary fixing lugs being supported against the second external surface so that the second heat exchange module is held against the frame.

[0014] The mounting brackets allow the heat exchange modules and the frame to be held together quickly and easily. The first and second mounting brackets sandwich the heat exchange modules and the frame. This holds the heat exchange modules in position against the power modules. Thus, in addition to the housings, the mounting brackets also help to hold the power modules in position.

[0015] According to one embodiment, the inverter further comprises thermal paste positioned between the first heat exchange module and the frame and / or between the The second heat exchange module and the frame. This allows for efficient heat transfer from the power modules to the heat exchange modules.

[0016] According to one embodiment, the frame has a plurality of openings provided on both of its longitudinal edges, opening into the interior of the housings and from which extend, respectively, the input connectors and the output connectors.

[0017] According to one embodiment, the second heat exchange module includes an inlet coupler for the heat transfer fluid intended to be coupled to a supply pipe and an outlet coupler for the heat transfer fluid intended to be connected to a drain pipe; the inlet coupler and the outlet coupler being respectively in fluidic communication with an inlet and an outlet of the second circulation circuit.

[0018] According to one embodiment, the first heat exchange module comprises a first inlet port in communication with an inlet of the first circulation circuit and a first outlet port in communication with an outlet of the first circulation circuit, the second heat exchange module comprising a second inlet port in communication with an inlet of the second circulation circuit and a second outlet port in communication with an outlet of the second circulation circuit, the frame comprising at least a first fluidic connection port linking the first and second inlet ports and a second fluidic connection port linking the first and second outlet ports.

[0019] According to one embodiment, the first and second fluidic connection ports are respectively provided at one and the other of the longitudinal ends of the frame. Brief description of the figures

[0020] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from the following description of several particular embodiments of the invention, given solely by way of illustration and not limitation, with reference to the accompanying drawings.

[0021] Fig. 1 represents a perspective view of an inverter according to one embodiment of the invention.

[0022] Fig. 2 represents a cross-sectional view along a transverse section plane of the inverter of Fig. 1.

[0023] Fig. 3 is a diagram of a frame comprising housings within which power modules are housed. Description of the implementation methods

[0024] An inverter, such as inverter 100, is a power electronics device that can generate any form of current, including, for example, alternating current, from direct current.

[0025] The inverter 100 comprises: a frame 3, a plurality of power modules 1 and two heat exchange modules 6 and 8.

[0026] A power module is one of the elementary parts used in electronics to make energy conversion circuits, such as those of an inverter like the inverter 100.

[0027] A power module may notably consist of the following elements: semiconductor chips, a metallized ceramic substrate, a base plate, solder joints, internal connection elements, electrical terminals, and an encapsulant. These components have different electrical, thermal, and mechanical properties, which may affect the overall performance of the power module.

[0028] Each power module 1 is equipped with a plurality of input connectors 2 and a plurality of output connectors 4. The input connectors 2 are intended to be electrically connected to an electrical energy storage unit, for example, a vehicle battery. The output connectors 4 are each intended to be connected, or electrically connected, to one phase of an electrical machine, for example, an electric motor.

[0029] The frame 3 comprises a plurality of housings 31. Each housing 31 accommodates a power module 1.

[0030] It is possible to provide a plurality of openings 10 formed on both of the longitudinal edges. These openings 10 lead into the housings 31 and thus allow the passage of the input connectors 2 and output connectors 4 in order to electrically connect the power modules 1.

[0031] Fig. 3 schematically illustrates the housings 31 within the frame 3. Each housing 31 receives a power module 1. Thanks to this housing 31, the power modules 1 have a fixed and permanent position throughout the life cycle of the inverter 100.

[0032] In one embodiment, the frame 3 is made of a plastic material such as a polymer. For example, the frame 3 is made of polyphenylene sulfide (PPS), and in particular of polyphenylene sulfide filled with 30% glass fiber, or of polybutylene terephthalate (PBT), and in particular of polybutylene terephthalate filled with 30% glass fiber. In an advantageous embodiment, the frame 3 can be overmolded onto the power modules 1.

[0033] The inverter 100 also includes a first heat exchange module 6 and a second heat exchange module 8. These heat exchange modules 6 and 8 have the function of dissipating the heat emitted by the power modules 1 during the operation of inverter 100. For this purpose, each of the first and second heat exchange modules 6 and 8 includes respectively a first and a second circulation circuit 61 and 81 of a heat transfer fluid, visible on the [Fig.1].

[0034] The heat transfer fluid may in particular be a gas, such as air or a liquid, such as water or a mixture of water and glycol.

[0035] Furthermore, a heat transfer fluid inlet coupler 84 and a heat transfer fluid outlet coupler 86, visible in [Fig. 1], are connected to one or the other of the first and second circulation circuits 61 and 81 of the heat transfer fluid. The heat transfer fluid inlet coupler 84 is intended to be coupled to a supply pipe, while the heat transfer fluid outlet coupler 86 is intended to be connected to a drain pipe.

[0036] The inlet coupler 84 and the outlet coupler 86 are respectively in fluidic communication with an inlet and an outlet of one or the other of the first and second circulation circuits 61 and 81 of the heat transfer fluid.

[0037] For example, in [Fig. 1], the second heat exchange module 8 is equipped with the heat transfer fluid inlet coupler 84 and the heat transfer fluid outlet coupler 86. The inlet coupler 84 and the outlet coupler 86 are then respectively in fluidic communication with an inlet and an outlet of the second circulation circuit 81.

[0038] According to this embodiment, the first heat exchange module 6 has on its face facing the frame 3, a first inlet orifice, not visible, in communication with an inlet of the first circulation circuit 61 and a first outlet orifice, also not visible, in communication with an outlet of the first circulation circuit 61. Similarly, the second heat exchange module 8 has, on its face facing the frame 3, a second inlet orifice in communication with an inlet of the second circulation circuit 81 and a second outlet orifice in communication with an outlet of the second circulation circuit 81.

[0039] The first and second inlet ports are connected by a first fluid connection port 32, visible in [Fig. 3], provided in the frame 3. Similarly, a second fluid connection port 33, also visible in [Fig. 3], provided in the frame 3, connects the first and second outlet ports. Thus, the first and second circulation circuits 61, 81 are connected to the single inlet coupler 84 and the single outlet coupler 86. In one embodiment, the frame 3 has male elements around the first and second fluid connection ports 32, 33, each of which fits into one of the inlet or outlet ports of the heat exchange modules 6, 8. This ensures the fluid connection between the two circulation circuits 61, 81 is sealed. Alternatively, the male elements may to be positioned on the heat exchange modules 6, 8 and fit into the fluidic connection ports 32, 33 of the frame.

[0040] According to one embodiment, the first and second fluidic connection ports 32, 33 are respectively provided at one and the other of the longitudinal ends of the frame 3.

[0041] The frame 3 is fixed to the two heat exchange modules 6 and 8 so that the first heat exchange module 6, the frame 3 and the second heat exchange module 8 are stacked one on top of the other in a direction of thickness of the inverter 100. Thus, the first heat exchange module 6 and the second heat exchange module are positioned on either side of the frame 3 and therefore, in the end, on either side of the power modules 1 retained in the housings 31.

[0042] Thus, the housings 31 maintain in position a first face of the power modules 1 opposite the first heat exchange module 6 and a second face of the power modules 1 opposite the second heat exchange module 8.

[0043] Each heat exchange module 6, 8 has an external surface opposite the frame 3. Thus, the first heat exchange module 6 has a first external surface 62 opposite the frame 3, and the second heat exchange module 8 has a second external surface 82 opposite the frame 3.

[0044] Furthermore, as illustrated in [Fig. 1], the frame 3 includes mounting tabs 63 and 83, which are respectively positioned at one or the other of the longitudinal ends of the frame 3. Each longitudinal end of the frame 3 has a mounting tab 63 that bears against the first external surface 62 and a mounting tab 83 that bears against the second external surface 82. The heat exchange modules 6 and 8, as well as the frame 3, also have openings 64, visible in [Fig. 1], through which fasteners, such as screws, pass. The mounting tabs 63 and 83 thus allow the first heat exchange module 6 and the second heat exchange module 8 to be held against the frame 3, respectively, before the fasteners are positioned.

[0045] As illustrated in [Fig.2], the inverter 100 includes thermal paste 9 positioned between the first heat exchange module 6 and the frame 3 and / or between the second heat exchange module 8 and the frame 3.

[0046] Thermal paste 9 allows better heat exchange between the power modules 1 and the heat exchange modules 6 and 8.

[0047] The inverter 100 can be integrated into the propulsion system of an electric car, in particular between an electric motor and an electric battery. The input connectors 2 are then connected to the vehicle's electric battery and the output connectors 4 to the vehicle's electric motor.

[0048] Although the invention has been described in connection with several particular embodiments, it is clearly evident that it is by no means limited to them and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0049] The use of the verb "comprise", "comprendre" or "include" and its conjugated forms does not exclude the presence of other elements or other steps than those stated in a claim.

[0050] In the claims, any reference sign in parentheses shall not be interpreted as a limitation of the claim.

Claims

Demands

1. Inverter (100) for an electric machine intended for the propulsion of a vehicle, the inverter comprising: - a plurality of power modules (1), each power module (1) being equipped with a plurality of input connectors (2) intended to be connected to an electrical energy storage unit and output connectors (4) each intended to be connected to a phase of the electric machine, - a frame (3) comprising a plurality of housings (31), each power module (1) being housed in one of the housings (31); - a first and a second heat exchanger module (6;8), each of the first and second heat exchanger modules (6;8) comprising respectively a first and a second circulation circuit (61;81) of a heat transfer fluid; the first heat exchanger module (6), the frame (3) and the second heat exchanger module (8) being stacked so that the first and second circulation circuits (61;81) are positioned on either side of the power modules (1); the frame (3) being fixed to each of the first and second heat exchange modules (6;8).

2. Inverter (100) according to the preceding claim, wherein: the first heat exchange module (6) has a first external surface (62) opposite the frame (3), the second heat exchange module (8) has a second external surface (82) opposite the frame (3), the frame (3) comprises a plurality of first mounting tabs (63), the first mounting tabs (63) being positioned at either of the longitudinal ends of the frame (3) and extending towards the first external surface (62); the first mounting tabs (63) bearing against the first external surface (62) so that the first heat exchange module (6) is held against the frame (3); the frame (3) further comprises a plurality of second mounting tabs (83), the second mounting tabs (83) being positioned at either of the longitudinal ends of the frame (3) and extending towards the second external surface (82), the second fixing lugs (83) being in contact with the second external surface (82) so that the second heat exchange module (8) is held against the frame (3).

3. Inverter (100) according to any one of the preceding claims, further comprising thermal paste (9) positioned between the first heat exchange module (6) and the frame (3) and / or between the second heat exchange module (8) and the frame (3).

4. Inverter (100) according to any one of the preceding claims in which the frame (3) has a plurality of openings (10) provided on either of its longitudinal edges, opening into the interior of the housings (31) and from which extend, respectively, the input connectors (2) and the output connectors (4).

5. Inverter according to any one of the preceding claims in which the second heat exchange module (8) comprises an inlet coupler (84) of the heat transfer fluid intended to be coupled to a supply pipe and an outlet coupler (86) of the heat transfer fluid intended to be connected to a discharge pipe; the inlet coupler (84) and the outlet coupler (86) being respectively in fluidic communication with an inlet and an outlet of the second circulation circuit (81).

6. Inverter according to the preceding claim, wherein the first heat exchange module (6) has a first inlet port in communication with an inlet of the first circulation circuit and a first outlet port in communication with an outlet of the first circulation circuit, the second heat exchange module (8) has a second inlet port in communication with an inlet of the second circulation circuit and a second outlet port in communication with an outlet of the second circulation circuit, the frame (3) has at least one first fluidic connection port (32) connecting the first and second inlet ports and a second fluidic connection port (33) connecting the first and second outlet ports.

7. Inverter according to claim 6 in which the first and second fluidic connection ports (32, 33) are respectively provided at one and the other of the longitudinal ends of the frame (3).

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