DEVICE AND METHOD FOR DISCHARGING AN ENERGY ACCUMULATOR IN A HIGH-VOLTAGE GRID

• US 20130320755A1
• Filed: 12/29/2011
• Published: 12/05/2013
• Est. Priority Date: 02/08/2011
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Peuser, Thomas, Fassnacht, Jochen
• Granted Patent: US 9,948,093 B2
• Time in Patent Office: Days
• US Class Current: 307/10.1
• CPC Class Codes: B60L 2270/20 Inrush current reduction, i.e. avoiding high currents when connecting the battery
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H

Abstract

The invention relates to a device and method for discharging an energy accumulator (C), in particular an intermediate circuit capacitor, in a high-voltage grid (3), in particular in a direct current intermediate circuit in a motor vehicle, having a direct current converter (5) connected downstream of the high-voltage grid (3), a low-voltage grid (4) connected downstream of the direct current converter (5), an power grid (7) connected downstream of the direct current converter (5) and parallel to the low-voltage grid (4) for supplying energy to a control circuit (9) of the direct current converter (5), and a first controllable switching element (S) which is connected to the connecting line between the direct current converter (5) and the low-voltage grid (4) and by means of which, in the event of a disturbance of the low-voltage grid (4), the direct current converter (5) and the power grid (7) can be disconnected from the low-voltage grid (4). The power grid (7) is connected to the direct current converter (5) via a first electrical component (10; 20) which prevents a backflow of current from the power grid (7) into the direct current converter (5).

Claims

1. A device for discharging an energy storage device (C) in a high-voltage network (3), having

a direct-current converter (5) connected downstream of the high-voltage network (3),

a low-voltage network (4) connected downstream of the direct-current converter (5),

an energy supply network (7) connected downstream of the direct-current converter (5) and connected in parallel to the low-voltage network (4) for supplying energy to a control circuit (9) of the direct-current converter (5) and

a first controllable switching element (S) that is connected in the connecting line between the direct-current converter (5) and the low-voltage network (4) wherein in the case of a malfunction of the low-voltage network (4) the direct-current converter (5) and the energy supply network (7) can be separated from the low-voltage network (4).

2. The device as claimed in claim 1, wherein the energy supply network (7) is connected to the direct-current converter (5) by a first electric component (10;

20) that prevents a backflow of current from the energy supply network (7) into the direct-current converter (5).

3. The device as claimed in claim 2, wherein the first electric component (10;

20) is embodied as a diode (10).

4. The device as claimed in claim 1, wherein the energy supply network (7) is connected to the low-voltage network (4) by a second electric component (11;

21) that prevents a backflow of current from the energy supply network (7) into the low-voltage network (4).

5. The device as claimed in claim 4, wherein the second electric component (11;

21) is embodied as a diode (11).

6. The device as claimed in claim 1, wherein the first controllable switching element (S) provides inverse-polarity protection.

7. The device as claimed in claim 1, wherein the high-voltage network (3) is connected by way of an alternating-current converter (2) to an electric machine (1) and the energy supply network (7) is used to supply energy to a control circuit of the alternating-current converter (2).

8. The device as claimed in claim 1, wherein the energy supply network (7) is used to supply energy to further electrical consumers.

9. A method for discharging an energy storage device (C) in a high-voltage network (3) as claimed in claim 1, wherein in the event of a malfunction of the low-voltage network (4) the direct-current converter (5) and the energy supply network (7) are separated from the low-voltage network (4).

10. The method as claimed in claim 9, wherein the energy supply network is connected to the low-voltage network (4) by a third controllable switching element (21) and the third controllable switching element (21) is closed for starting up the system in the event of the energy storage device not being charged.

11. The device as claimed in claim 1, wherein the energy storage device (C) is an intermediate circuit capacitor.

12. The device as claimed in claim 1, wherein the high-voltage network (3) is a direct-current intermediate circuit in a motor vehicle.

13. The device as claimed in claim 3, wherein the diode (10) is a Schottky diode.

14. The device as claimed in claim 2, wherein the first electric component (10;

20) is embodied as a second controllable switching element (20).

15. The device as claimed in claim 4, wherein the second electric component (11;

21) is embodied as a third controllable switching element (21).

16. The device as claimed in claim 5, wherein the diode (11) is a Schottky diode.

17. The device as claimed in claim 7, wherein the alternating-current converter (2) is a pulse-controlled alternating-current converter.

18. The device as claimed in claim 9, wherein the energy storage device (C) is an intermediate circuit capacitor.

19. The device as claimed in claim 9, wherein the high-voltage network (3) is a direct-current intermediate circuit in a motor vehicle.