Method and device for stabilizing an on-board electrical system of a vehicle electrical system

• US 7,656,056 B2
• Filed: 08/28/2002
• Issued: 02/02/2010
• Est. Priority Date: 08/30/2001
• Status: Active Grant

• Current Assignee: Volkswagen AG
• Original Assignee: Volkswagen AG
• Inventors: Wahnschaffe, Nikolaus, Brosig, Stefan, Manz, Holger
• Primary Examiner(s): Fleming; Fritz M
• Assistant Examiner(s): Parries; Dru M
• Application Number:
  US10/488,078
• Publication Number:
  US 20040239184A1
• Time in Patent Office: 2,715 Days
• Field of Search: 307/10.1, 307/59, 307/44, 307/64, 307/65, 307/66, 307/67, 307/68
• US Class Current: 307/10.1
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A vehicle electrical system includes at least one battery, at least one fan and a device for detecting a critical state in the vehicle electrical system. The fan is activated when a critical state of the vehicle electrical system is detected. In this context, use is made of the fan'"'"'s ability to store mechanical energy in the form of inertias. The fan operates in a regenerative manner and electrically feeds the mechanically stored energy back into the on-board electrical system.

Claims

1. A method for stabilizing an on-board electrical system of a vehicle electrical system, including at least one battery, at least one rotational inertial load driven by an electric motor and a device configured to detect a state that is critical to the on-board electrical system, comprising:

detecting a critical voltage state of the on-board electrical system by the device;

in response to the detection of the critical voltage state and during the critical voltage state, driving the rotational inertial load by the electric motor such that the rotational inertial load stores rotational kinetic energy; and

during the critical voltage state of the on-board electrical system and during a subsequent voltage drop of the on-board electrical system, driving the electric motor by the stored rotational kinetic energy of the rotational inertial load to generate electrical energy and supply the electrical energy to the on-board electrical system.

2. The method as recited in claim 1, further comprising running up the rotational inertial load as a function of the detected critical state of the on-board electrical system.

3. The method as recited in claim 1, further comprising checking a functionality of the battery by the device configured to detect a critical state of the on-board electrical system.

4. The method as recited in claim 1, further comprising analyzing a ripple content of an on-board electrical voltage.

5. The method as recited in claim 1, further comprising switching off comfort loads.

6. The method as recited in claim 1, wherein the rotational inertial load includes a fan.

7. The method as recited in claim 6, wherein the fan includes a combustion-engine fan.

8. A method of claim 1, wherein the critical voltage state of the on-board electrical system corresponds to a voltage of the on-board electrical system dropping below a threshold value.

9. The method according to claim 1, wherein the rotational inertial load driven by the electric motor stores the rotational kinetic energy and supplies the electrical energy to the on-board electrical system when a second high-current load is activated.

10. The method according to claim 1, wherein the rotational inertial load driven by the electric motor is activated before activating a second high-current load.

11. The method as recited in claim 1, wherein the critical voltage state of the on-board electrical system corresponds to a malfunction state of the on-board electrical system.

12. The method as recited in claim 1, wherein the critical voltage state of the on-board electrical system corresponds to a dropped voltage of the on-board electrical system.

13. The method as recited in claim 1, wherein the electrical system includes at least one generator driven by a combustion engine, the method further comprising, during the critical voltage state of the on-board electrical system and during the subsequent voltage drop, and simultaneously with the driving of the electric motor by the stored rotational kinetic energy of the inertial load, driving the generator by the combustion engine, the electric motor and the generator simultaneously generating electrical energy and supplying the electrical energy to the on-board electrical system.

14. The method as recited in claim 1, wherein the critical voltage state corresponds to at least one of (a) a defect in the battery, (b) a disconnection of the battery from the on-board electrical system, and (c) an unavailability of the battery to the on-board electrical system.

15. A device for stabilizing an on-board electrical system of a vehicle electrical system, comprising:

at least one battery;

at least one rotational inertial load driven by an electric motor in response to detection of a critical voltage state of the on-board electrical system and during the critical voltage state of the on-board electrical system to store rotational kinetic energy by the rotational inertial load; and

a device configured to detect a critical voltage state of the on-board electrical system, the device configured to switch in, during the critical voltage state of the on-board electrical system during a subsequent voltage drop of the on-board electrical system, the rotational inertial load driven by the electric motor to drive the electrical motor by the stored rotational kinetic energy of the rotational inertial load to generate electrical energy and supply the electrical energy to the on board electrical system during a subsequent voltage drop of the on-board electrical system.

16. The device as recited in claim 15, wherein the rotational inertial load includes a fan.

17. The device as recited in claim 16, wherein the fan includes a combustion-engine fan.

18. The device as recited in claim 15, wherein the device configured to detect the critical voltage state of the on-board electrical system is configured to check a functionality of the battery.

19. The device as recited in claim 15, wherein the device is configured to detect and analyze a ripple content of an on-board electrical voltage.

20. The device according to claim 15, wherein the rotational inertial load driven by the electric motor stores rotational kinetic energy and supplies electrical energy to the on-board electrical system when a second high-current load is activated.

21. The device according to claim 15, wherein the device configured to detect the critical voltage state of the on-board electrical system is configured to switch in the rotational inertial load driven by the electric motor before activation of a second high-current load.

22. The device as recited in claim 15, wherein the critical voltage state of the on-board electrical system corresponds to a malfunction state of the on-board electrical system.

23. The device as recited in claim 15, wherein the critical voltage state of the on-board electrical system corresponds to a dropped voltage of the on-board electrical system.

24. A device for stabilizing an on-board electrical system of a vehicle electrical system, comprising:

at least one battery;

at least one rotational inertial load driven by an electric motor in response to detection of a critical voltage state of the on-board electrical system and during the critical voltage state of the on-board electrical system o store rotational kinetic energy by the rotational inertial load; and

means for detecting a critical state of the on-board electrical system and for switching in, during the critical voltage state of the on-board electrical system and during a subsequent voltage drop of the on-board electrical system, the rotational inertial load driven by the electric motor to drive the electric motor by the stored rotational kinetic energy of the rotational inertial load to generate electrical energy and supply the electrical energy to the on-board electrical system during a subsequent voltage drop of the on-board electrical system.

25. The device according to claim 24, wherein the rotational inertial load driven by the electric motor stores rotational kinetic energy and supplies electrical energy to the on-board electrical system when a second high-current load is activated.

26. The device according to claim 24, wherein the means switches in the rotational inertial load driven by the electric motor before activation of a second high-current load.

27. The device as recited in claim 24, wherein the critical voltage state of the on-board electrical system corresponds to a malfunction state of the on-board electrical system.

28. The device as recited in claim 24, wherein the critical voltage state of the on-board electrical system corresponds to a dropped voltage of the on-board electrical system.

29. A method for stabilizing an on-board electrical system of a vehicle electrical system, comprising:

detecting a critical voltage state of the on-board electrical system;

in response to the detection of the critical voltage state and during the critical voltage state, driving a rotational inertial load by an electric motor, the rotational inertial load driven at a rotational speed based on a vehicle electrical voltage, rotation of the rotational inertial load storing rotational kinetic energy;

generating electrical energy by continued rotation of the rotational inertial load due to the stored rotational kinetic energy after a voltage drop in the on-board electrical system and during the critical voltage state of the on-board electrical system; and

supplying the electrical energy generated in the generating step to the on-board electrical system during the critical voltage state of the on-board electrical system.

30. The method as recited in claim 29, wherein the critical voltage state of the on-board electrical system corresponds to a malfunction state of the on-board electrical system.

31. The method as recited in claim 29, wherein the critical voltage state of the on-board electrical system corresponds to a dropped voltage of the on-board electrical system.

32. A method for stabilizing an on-board electrical system of a vehicle electrical system, including at least one battery, a generator, at least one electrical load having a rotating mass and drivable by an electrical motor, at least one high current load, and a device configured to detect a state that is critical for the on-board electrical system, comprising:

detecting a critical state of the on-board electrical system;

in response to the detection of the critical state and during the critical voltage state, activating the electrical load having the rotating mass by driving the electrical motor;

during the critical state of the on-board electrical system, storing kinetic energy by the electrical load inducing back the stored energy as electrical energy to the electrical system if the high current load is switched on.

33. The method as recited in claim 32, wherein the voltage state of the on-board electrical system corresponds to a malfunction state of the on-board electrical system.

34. The method as recited in claim 32, wherein the voltage state of the on-board electrical system corresponds to a dropped voltage of the on-board electrical system.