Energy management system for a motor vehicle electrical system

• US 6,982,540 B2
• Filed: 05/03/2002
• Issued: 01/03/2006
• Est. Priority Date: 05/05/2001
• Status: Active Grant

• Current Assignee: Clarios Germany GmbH & Co. KG (Michael Tojner, PhD, LLD)
• Original Assignee: VB Autobatterie GmbH
• Inventors: Rosenkranz, Christian, Richter, Gerolf
• Primary Examiner(s): Sparks, Donald
• Assistant Examiner(s): Luk, Lawrence
• Application Number:
  US10/138,198
• Publication Number:
  US 20020171392A1
• Time in Patent Office: 1,341 Days
• Field of Search: 320/104, 320/103, 320/132, 320/137, 180/65.1, 180/65.2, 180/65.3, 180/65.4, 340/635, 340/636, 123/316
• US Class Current: 320/104
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: H02J 7/1438 in combination with power supplies for loads other than batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

An energy management system for an electrical system of a motor vehicle subjected to a large number of loads including at least one generator, at least one storage battery, a controller of energy distribution in the system which bases such control at least on efficiency of individual components of the motor vehicle involved in power generation, energy storage and power consumption. In order to determine the overall efficiency of the energy storage unit, which comprises at least one energy store, the state of charge, the temperature of the store and the absolute magnitude of the charging and discharging currents are taken into account. In addition to mechanically driven generators, the system can possess a fuel cell and, in addition to an electrochemical energy store, further physical stores such as double-layer capacitors.

Claims

1. An energy management system for an electrical system of a motor vehicle subjected to a large number of loads, comprising:

at least one generator;

at least one storage battery; and

a controller of energy distribution in the, system which bases such control at least on efficiency of individual components of the motor vehicle involved in power generation, energy storage and power consumption;

wherein during selected instants of operation of the motor vehicle, two efficiency chains determined from products of (a) current individual efficiencies for an internal combustion engine in the motor vehicle in combination with the generator driven by the internal combustion engine, and (b) the generator driven by braking energy in combination with the electric store, are compared by the controller.

2. The energy management system according to claim 1, wherein determinations required at the selected instants about current source of an electrical supply in the electrical system depend on the magnitude of the efficiency chains.

3. The energy management system according to claim 2, further comprising an energy storage unit which comprises at least one energy store, wherein the controller determines overall efficiency of the energy storage unit based at least partially on state of charge of the store, temperature of the store and absolute magnitude of charging and discharging currents of the store.

4. The energy management system according to claim 3, further comprising at least one double-layer capacitor in the electrical system.

5. The energy management system according to claim 3, wherein electrical loads can be switched on and off in accordance with a predefined priority list or energy consumption of motor vehicle components can be restricted by the controller.

6. The energy management system according to claim 2, further comprising a fuel cell.

7. The energy management system according to claim 2, further comprising at least one double-layer capacitor in the electrical system.

8. The energy management system according to claim 2, wherein electrical loads can be switched on and off in accordance with a predefined priority list or energy consumption of motor vehicle components can be restricted by the controller.

9. The energy management system according to claim 1, further comprising an energy storage unit which comprises at least one energy store, wherein the controller determines overall efficiency of the energy storage unit based at least partially on state of charge of the store, temperature of the store and absolute magnitude of charging and discharging currents of the store.

10. The energy management system according to claim 9, further comprising a fuel cell.

11. The energy management system according to claim 9, further comprising at least one double-layer capacitor in the electrical system.

12. The energy management system according to claim 9, wherein electrical loads can be switched on and off in accordance with a predefined priority list or energy consumption of motor vehicle components can be restricted by the controller.

13. The energy management system according to claim 1, further comprising a fuel cell.

14. The energy management system according to claim 1, further comprising at least one double-layer capacitor in the electrical system.

15. The energy management system according to claim 1, wherein electrical loads can be switched on and off in accordance with a predefined priority list or energy consumption of motor vehicle components can be restricted by the controller.