POWER ELECTRONICS FOR AN ELECTRICAL MACHINE, DRIVETRAIN, MOTOR VEHICLE

Abstract

An inverter (1) for operating an electrical machine (10) has at least one power semiconductor (2) and a drain contact (5) arranged on an underside of the power semiconductor (2). The drain contact (5) is arranged in a coolant channel (6) for impingement by a coolant. Also proposed are a drivetrain (20) and a motor vehicle (100).

Claims

1. An inverter for operating an electrical machine (10), comprising: at least one power semiconductor; and a drain contact arranged on an underside of the power semiconductor, the drain contact being arranged in a coolant channel for impingement by a coolant.

2. The inverter of claim 1, further comprising a cooling device for cooling the drain contact, the cooling device supplying a coolant suitable for impinging on the drain contact.

3. The inverter of claim 2, wherein the inverter comprises a dielectric as coolant.

4. The inverter of claim 1, wherein the inverter comprises a sheath enclosing the power semiconductor.

5. The inverter of claim 4, wherein the sheath is produced from a plastic.

6. The inverter of claim 1, wherein the drain contact comprises a cooling structure projecting into the coolant channel.

7. The inverter of claim 6, wherein the cooling structure includes a lamellar structure.

8. The inverter of claim 6, wherein the cooling structure includes a pin-fin structure.

9. The inverter of claim 1, wherein the drain contact comprises a conductor rail.

10. The inverter of claim 1, wherein the conductor rail comprises copper or aluminum.

11. The inverter of claim 1, further comprising a gate contact arranged on a top side of the power semiconductor, at least part of the gate contact being arranged in the coolant channel for impingement by the coolant.

12. The inverter of claim 11, further comprising a source contact arranged on the top side of the power semiconductor, at least part of the source contact being arranged in the coolant channel for impingement by the coolant.

13. The inverter of claim 12, wherein at least one of the gate contact and the source contact comprise a conductor rail that comprises copper or aluminum.

14. The inverter of claim 1, wherein the power semiconductor is an SiC semiconductor.

15. A drivetrain for a motor vehicle, comprising an electrical machine and the inverter of claim 1.

16. A motor vehicle comprising the drivetrain of claim 14.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 schematically illustrates an inverter in accordance with one exemplary embodiment of the present invention.

[0021] FIG. 2 schematically illustrates a motor vehicle in accordance with one exemplary embodiment of the present invention comprising a drivetrain in accordance with one exemplary embodiment of the present invention.

DETAILED DESCRIPTION

[0022] FIG. 1 illustrates an inverter 1 for operating an electrical machine (see FIG. 2) in accordance with one embodiment of the invention. The inverter 1 comprises a power semiconductor 2 embodied here as an SiC semiconductor. A gate contact 3 and a source contact 4 are arranged at the top side of the power semiconductor 2. The gate contact 3 and the source contact 4 in this embodiment are busbars composed of copper. Alternatively, the gate contact 3 and/or the source contact 4 can be made from aluminum.

[0023] A drain contact 5 is arranged on an underside of the power semiconductor 2 opposite the top side. The drain contact 5 also is embodied here as a busbar composed of copper and can alternatively be produced from aluminum. The drain contact 5 is arranged in a coolant channel 6 of the inverter 1. An electrically nonconductive coolant, preferably a dielectric, is pumped through the coolant channel 6. For this purpose, a cooling device 7 of the inverter 1 comprises a coolant pump. The use of an electrically nonconductive coolant makes it possible to omit an insulator, for example a ceramic layer below the drain contact 5.

[0024] The gate contact 3 and the source contact 4 also are impinged on by the coolant to achieve very efficient cooling of the power semiconductor 2. For further improvement of the cooling, the drain contact 5 comprises a cooling structure 9, preferably in the form of a pin-fin structure or a lamellar structure. The cooling structure enlarges the surface area on which the coolant impinges, and thus enables more heat to be dissipated. The heat path is illustrated by arrows in FIG. 1.

[0025] To protect the sensitive structures of the power semiconductor 2, the power semiconductor 2 is encapsulated by molding in a sheath 8 composed of plastic. This prevents the coolant from coming into direct contact with the power semiconductor 2.

[0026] FIG. 2 schematically illustrates a motor vehicle 100 in accordance with one embodiment of the invention comprising a drivetrain 20 in accordance with one embodiment of the invention. The drivetrain 20 comprises an inverter 1 in accordance with an embodiment of the invention and an electrical machine 10.