Inverter for electrical machine

Abstract

The present invention relates to an inverter (1) comprising: a capacitive module (2); a first power module (3a) connected to the capacitive module (2) by a first DC connection (4a) and comprising a first AC connection (5a) located on the opposite side of the first power module (3a); a second power module (3b) connected to the capacitive module (2) by a second DC connection (4b) and comprising a second AC connection (5b) located on the opposite side of the second power module (3b); the power modules (3a, 3b) being located on the same side of the capacitive module (2), on either side of a median plane (P) of the capacitive module (2), the AC connections (5a, 5b) are closer to the median plane (P) of the capacitive module (2) than the DC connections (4a, 4b). Abstract figure: Figure 2

Description

Title of the invention: Inverter for an electric machine Technical field

[0001] The present invention relates to electrical equipment such as inverters, equipped with power modules and associated with an electrical machine, for example an electric or hybrid vehicle engine. STATE OF THE ART

[0002] As is known, an electric or hybrid motor vehicle comprises an electric drive system powered by a high-voltage power supply battery, generally greater than 100V, via a high-voltage on-board electrical network and a plurality of auxiliary electrical equipment powered by a low-voltage power supply battery via a low-voltage on-board electrical network. The high-voltage power supply battery provides a power supply function for the electric drive system enabling the vehicle to be propelled. More specifically, in order to control the electric machine driving the wheels of the vehicle, it is known to use an inverter making it possible to convert the direct voltage supplied by the high-voltage power supply battery into one or more alternating control voltages, for example sinusoidal.

[0003] It is also known to integrate within the inverter a capacitive filtering device called a link capacitor or "DC-link capacitor" for those skilled in the art, having in particular the function of stabilizing the voltage supplied to the active power electronics component of the inverter, in particular a power module supplying electrical energy to the electrical machine.

[0004] In the context of electronic or hybrid vehicles requiring high power levels, for example a utility vehicle, it is known to power an electric machine via several power modules, generally two power modules each delivering a three-phase electric current. This architecture then generally uses two connection capacitors, each being connected to a power module.

[0005] The electrical machine generally comprises six phases, each of the phases being supplied by one of the currents from one of the two power modules. However, this configuration has the disadvantage for the electrical machine of seeing two three-phase currents arriving from independent sources and whose characteristics are different, which can lead to disturbances in the operation of the electrical machine, or at least generate difficulties in its control. In addition, in the case of an inverter with three phases connected to said electrical machine, the currents of each two power modules with a similar phase shift must be combined within a connection interface to supply one phase of the electrical machine, resulting in a complex architecture of the connection interface, in particular due to the presence of other components such as electronic cards fixed to the power modules. Thus, the manufacture of an inverter under these conditions constitutes a complex arrangement, and difficult to control.

[0006] The invention aims to resolve the drawbacks of the state of the art by proposing a simplified inverter architecture, with reduced cost and improved performance. PRESENTATION OF THE INVENTION

[0007] More specifically, the invention relates to an inverter, in particular configured to be installed in a motor vehicle, comprising: • a capacitive module; • a first power module connected to the capacitive module by a first direct current connection and comprising a first alternating current connection configured for the circulation of an electric current between the capacitive module and an alternating current electric machine, the first alternating current connection being arranged on an opposite side of the first power module relative to the first direct current connection; • a second power module connected to the capacitive module by a second direct current connection, and comprising a second alternating current connection configured for the circulation of an electric current between the capacitive module and the alternating current electric machine, the second alternating current connection being arranged on an opposite side of the second power module relative to the second direct current connection; the first power module and the second power module being arranged on the same side of the capacitive module, on either side of a median plane of the capacitive module, the inverter being characterized in that the first alternating current connection of the first power module and the second alternating current connection of the second power module are closer to the median plane of the capacitive module than the first direct current connection and the second direct current connection.

[0008] Thanks to such a combination of characteristics, the power modules of such an inverter have similar operating performances, due to a generally symmetrical arrangement of the inverter, while being connected to the same capacitive module, and are therefore supplied by the same current. The first and second alternating current connections are also less likely to interfere with the arrangement of additional components of the inverter, such as electronic cards. Ironic to drive the power modules.

[0009] Advantageously, the first alternating current connection of the first power module and the second alternating current connection of the second power module extend in the median plane of the capacitive module. In such a configuration, the two power modules are closer to each other, which further improves the overall compactness of the inverter.

[0010] Advantageously, the first alternating current connection of the first power module and the second alternating current connection of the second power module are shared in a connection interface configured to power an alternating current motor. In such a configuration, the connection interface, preferably an electrical connection bar or "busbar" for those skilled in the art, has reduced dimensions for connecting to the terminals of an electrical machine compared to a standard architecture, in which the connection interfaces are shared as close as possible to the terminals of the electrical machine.

[0011] Advantageously, the first alternating current electrical connection comprises a plurality of first electrical connectors, and the second alternating current connection comprises a plurality of second electrical connectors.

[0012] Advantageously, the first connectors of the first alternating current connection and the second connectors of the second alternating current connection, the electric currents of which have equal phase shift angles, are associated two by two in a connection interface, said connection interface comprising at least three outputs configured to supply the respective phases of a three-phase alternating current electric machine. In such a configuration, the supply of the phases of a three-phase electric motor is done as close as possible to the power modules, and the association of two by two connectors having electric currents of the same phase shift under these conditions guarantees similar characteristics delivered by the two power modules.

[0013] Advantageously, the outputs of the connection interface extend parallel to the median plane of the capacitive module. In such a configuration, the orientation and direction of the outputs of the connection interface correspond directly to an orientation and direction of the phase connections of an electric motor located outside the inverter.

[0014] Advantageously, the outputs of the connection interface are arranged on the same side of the first power module as the first direct current connection.

[0015] Advantageously, the first power module and the second power module are identical.

[0016] Advantageously, the capacitive module is a connecting capacitor. In such a configuration, the direct current supplying the two power modules comes from of the same link capacity, which further reinforces the performance symmetry between the two power modules.

[0017] Advantageously, the outputs of the connection interface are arranged on the same side of the first power module as the first alternating current connection.

[0018] Advantageously, the inverter further comprises an electronic card for controlling the power modules extending perpendicular to the median plane, the connection interface then extending parallel to said electronic card between the power modules and the electronic card and the outputs of the connection interface extending parallel to the median plane passing through a passage orifice of the electronic card.

[0019] According to another aspect of the invention, it relates to a mobility device such as an electric or hybrid vehicle. PRESENTATION OF FIGURES

[0020] The invention will be better understood on reading the following description, given solely by way of example, and referring to the appended drawings given by way of non-limiting examples, in which identical references are given to similar objects and in which:

[0021] [Fig.l] is a schematic perspective representation of an inverter according to one embodiment of the invention;

[0022] [Fig.2] is a schematic representation in front view of the inverter of [Fig.l] in a position removed from a chassis and an inverter cover;

[0023] [Fig.3] is a schematic representation in top view of the inverter of [Fig.l], in the position removed from an electronic card.

[0024] It should be noted that the figures set out the invention in detail to enable the invention to be implemented; although not limiting, said figures serve in particular to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0025] [Fig.l] illustrates an inverter 1, for example for an electric or hybrid vehicle engine. The inverter 1 comprises a chassis 100 and a cover 200 removable between a removed position in which an interior space of the chassis 100 is accessible and a closed position which corresponds to an operating position of the inverter 1.

[0026] Figures 2 and 3 illustrate the inverter 1 in the position removed from the chassis 100 and the cover 200. The inverter 1 comprises a capacitive module 2, here a connecting capacitor. The connecting capacitor 2 has a generally substantially prismatic parallelepiped shape, a length of the connecting capacitor 2 extending in a horizontal direction X, a width of the connecting capacitor 2 extending in a transverse direction Y and a height of the connecting capacitor 2 extending in a vertical direction Z. The connecting capacity 2 has a median plane P extending along a vertical plane Z, Y, so that the length of the capacity 2 corresponds to a median of the median plane P.

[0027] The inverter 1 further comprises a first power module 3a connected to the connecting capacitor 2 by a first direct current connection 4a. By "power module" is meant an assembly comprising components through which passes energy supplying the electrical machine. These components may comprise electronic switches, such as for example semiconductor transistors, arranged in an electrical circuit to allow a controlled passage of electrical energy between the power supply battery and the electrical machine. In particular, the components are bare semiconductor chips for which encapsulation is carried out. In other words, a power module is an assembly comprising a plurality of semiconductor chips forming an electrical circuit encapsulated in the same housing. The first power module 3a extends parallel to a plane X, Y, vertically above the connecting capacitor 2.

[0028] The first direct current connection 4a allows the connecting capacitor 2 to supply the first power module 3a with a filtered and stabilized direct current. The first direct current connection 4a extends vertically in the Z direction. The first power module 3a further comprises a first alternating current connection 5a. In the described embodiment, the first alternating current connection 5a comprises a plurality of first electrical connectors 50a, 50b, 50c, each of the first electrical connectors 50a, 50b, 50c being supplied with an alternating electric current having a different phase shift. The first connectors 50a, 50b, 50c are arranged on an opposite side of the first power module 3a relative to the first direct current connection 4a.

[0029] The inverter 1 further comprises a second power module 3b connected to the connecting capacitor 2 by a second direct current connection 4b. The second power module 3b extends parallel to the plane X, Y vertically above the connecting capacitor 2 on a different side of the median plane P of the connecting capacitor 2 than the first power module 3a. Here, the first power module 3a and the second power module 3b are identical.

[0030] The second direct current connection 4b allows the connecting capacitor 2 to supply the second power module 3b with a filtered and stabilized direct current. The second direct current connection 4b extends vertically in the Z direction. The second power module 3b further comprises a second alternating current connection 5b. In the described embodiment, the second alternating current connection 5b comprises a plurality of second electrical connectors 52a, 52b, 52c, each of the second electrical connectors 52a, 52b, 52c being powered by an alternating electric current having a different phase shift. The second connectors 52a, 52b, 52c are arranged on an opposite side of the second power module 3b relative to the second direct current connection 4b.

[0031] The first connectors 50a, 50b, 50c are closer to the median plane P of the connecting capacitor 2 than the first connector 4a. The second connectors 52a, 52b, 52c are closer to the median plane P of the connecting capacitor 2 than the second direct current connection 4b. Due to this substantially symmetrical arrangement, the power modules 3a, 3b have similar operating performances.

[0032] The first connectors 50a, 50b, 50c and the second connectors 52a, 52b, 52c whose electric currents have equal phase shift angles are associated two by two in a connection interface 6 comprising three outputs 60a, 60b, 60c configured to supply the respective phases of a three-phase alternating current motor. In the embodiment described, the connection interface 6 is an electrical connection bar, or "busbar" for those skilled in the art. The connection interface 6 extends perpendicular to the median plane P of the connection capacitor 2 and the outputs of the connection interface 60a, 60b, 60c extend parallel to the median plane P and on the side of the second direct current connection 4b. Advantageously, the outputs of the connection interface 60a, 60b, 60c are arranged on the side of the first direct current connection 4a.

[0033] In particular, that the first alternating current connection 5a of the first power module 3a and the second alternating current connection 5b of the second power module 3b extend in the median plane P. In this case, the power modules 3a, 3b have even more similar, in particular substantially identical, operating performances.

[0034] [Fig.2] differs from [Fig.3] in that in [Fig.2] an electronic card 7 is illustrated extending perpendicular to the median plane P. The electronic card 7 is located vertically above the control modules 3a, 3b, the connection interface 6 extends between the power modules 3a, 3b and the electronic card 7. The outputs of the connection interface 60a, 60b, 60c also extend through a passage hole in the electronic card 7.

[0035] It will also be noted that the invention is not limited to the embodiments described above. It will indeed appear to those skilled in the art that various modifications can be made to the embodiment described above, in light of the teaching which has just been disclosed to them.

[0036] In the detailed presentation of the invention given above, the terms used should not be interpreted as limiting the invention to the embodiment set forth in the present description, but should be interpreted to include all equivalents which can be predicted by a person skilled in the art by applying his general knowledge to the implementation of the teaching which has just been disclosed to him.

Claims

Claims

1. Inverter (1), in particular configured to be installed in a motor vehicle, comprising: • a capacitive module (2); • a first power module (3a) connected to the capacitive module (2) by a first direct current connection (4a) and comprising a first alternating current connection (5a) configured for the circulation of an electric current between the capacitive module (2) and an alternating current electric machine (5a), the first alternating current connection (5a) being arranged on an opposite side of the first power module (3a) relative to the first direct current connection (4a); • a second power module (3b) connected to the capacitive module (2) by a second direct current connection (4b), and comprising a second alternating current connection (5b) configured for the circulation of an electric current between the capacitive module (2) and the alternating current electric machine, the second alternating current connection (5b) being arranged on an opposite side of the second power module (3b) relative to the second direct current connection (4b); the first power module (3a) and the second power module (3b) being arranged on the same side of the capacitive module (2), on either side of a median plane (P) of the capacitive module (2), the inverter (1) being characterized in that the first alternating current connection (5a) of the first power module (3a) and the second alternating current connection of the second (5b) power module (3b) are closer to the median plane (P) of the capacitive module (2) than the first direct current connection (4a) and the second direct current connection (4b).

2. Inverter (1) according to the preceding claim, characterized in that the first alternating current connection (5a) of the first power module (3a) and the second alternating current connection (5b) of the second power module (3b) extend in the median plane (P) of the capacitive module (2).

3. Inverter (1) according to any one of the preceding claims, characterized in that the first alternating current connection (5a) of the first power module (3a) and the second alternating current connection (5b) of the second power module (3b) are shared in a connection interface (6) configured to power an alternating current motor.

4. An inverter (1) according to any preceding claim, characterized in that the first alternating current electrical connection (5a) comprises a plurality of first electrical connectors (50a, 50b, 50c), and the second alternating current connection (5b) comprises a plurality of second electrical connectors (52a, 52b, 52c).

5. Inverter (1) according to claim 4, characterized in that the first connectors (50a, 50b, 50c) of the first alternating current connection (5a) and the second connectors (52a, 52b, 52c) of the second alternating current connection (5b) whose electric currents have equal phase shift angles are associated two by two in a connection interface (6), said connection interface (6) comprising at least three outputs (60a, 60b, 60c) configured to supply the respective phases of a three-phase alternating current motor.

6. Inverter (1) according to the preceding claim, characterized in that the outputs (60a, 60b, 60c) of the connection interface (6) extend parallel to the median plane (P) of the capacitive module (2).

7. Inverter (1) according to any one of claims 5 to 6, characterized in that the outputs of the connection interface (60a, 60b, 60c) are arranged on the same side of the first power module (3a) as the first direct current connection (4a).

8. Inverter (1) according to any one of the preceding claims, characterized in that the first power module (3a) and the second power module (3b) are identical.

9. Inverter (1) according to any one of the preceding claims, characterized in that the capacitive module (2) is a connecting capacitor (2).

10. Mobility device characterized in that it comprises an inverter (1) according to any one of the preceding claims.

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