Electrical energy system in a hybrid car

• US 7,419,020 B2
• Filed: 05/10/2005
• Issued: 09/02/2008
• Est. Priority Date: 05/10/2004
• Status: Active Grant

• Current Assignee: Volkswagen AG
• Original Assignee: Volkswagen AG
• Inventors: Holz, Matthias, Pott, Ekkehard, Zillmer, Michael, Hladun, Marc
• Primary Examiner(s): Ellis; Christopher
• Assistant Examiner(s): WALTERS, JOHN DANIEL
• Application Number:
  US11/125,466
• Publication Number:
  US 20050279544A1
• Time in Patent Office: 1,211 Days
• Field of Search: 180/65.1, 180/65.2, 180/65.3, 903/903, 903/907, 903/943, 320/117, 320/122, 320/126, 318/139
• US Class Current: 180/65.1
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: H02J 1/08 Three-wire systems; Systems having more than three wires
• CPC Class Codes: H02J 1/082 Plural DC voltage, e.g. DC supply voltage with at least two different DC voltage levels
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/907 Electricity storage, e.g. battery, capacitor

Abstract

An electrical energy system (1) in a hybrid car comprises an electrical motor (3), a capacitor (4) and a battery (5). The capacitor (4) is connected electrically to the electrical motor (3) and the capacitor (4) is switched in parallel with the battery (5) and the capacitor (4) has a rated voltage greater than 60V and the battery (5) has a rated voltage of less than 60V.

Claims

1. An electrical energy system for use in a hybrid car, said system comprising:

an electrical motor;

a capacitor having a rated voltage greater than 60V;

a battery having a rated voltage of less than 60V, and

a DC-DC converter coupled between the capacitor and the battery wherein the capacitor is in electrical communication with the electrical motor and the capacitor can be switched in parallel with the battery via at least one switch thereby bypassing said DC-DC converter.

2. An electrical energy system according to claim 1, wherein the capacitor is located next to the electrical motor.

3. An electrical energy system according to claim 1, wherein the rated voltage of the battery is between 32 and 58 V and the rated voltage of the capacitor is between 65 and 115V.

4. An electrical energy system according to claim 3, wherein the rated voltage of the battery is 36V or 48 V and the rated voltage of the capacitor is 72V or 96V.

5. An electrical energy system according to claim 1, wherein the energy content of the battery is between 600 and 2200 VAh per ton vehicle deadweight and the energy content of the capacitor is between 10 and 80 VAh per ton vehicle deadweight.

6. An electrical energy system according to claim 1, wherein the electrical motor has a total output of about 7-25 kW.

7. An electrical energy system according to claim 1, wherein the electrical motor is a crankshaft starter generator.

8. An electrical energy system according to claim 1, wherein the ratio between useful capacitor store energy content and electrical motor output is between 5 and 25 kJ/kW.

9. An electrical energy system according to claim 1, wherein the ratio between battery energy content and output of the electrical motor is below 900 kJ/kW.

10. An electrical energy system for use in a hybrid car, said system comprising:

an electrical motor;

a capacitor, said capacitor having a rated voltage greater than 60V and an energy content between 10 and 80 VAh per ton vehicle deadweight;

a battery, said battery having a rated voltage of less than 60V and an energy content between 600 and 2200 VAh per ton vehicle deadweight, wherein the capacitor is in electrical communication with the electrical motor and located next to the electrical motor, and

a DC-DC converter between the capacitor and the battery, wherein the capacitor can be switched in parallel with the battery via at least one switch thereby bypassing said DC-DC converter.

11. An electrical energy system according to claim 10, wherein the rated voltage of the battery is between 32 and 58 V and the rated voltage of the capacitor is between 65 and 115V.

12. An electrical energy system according to claim 11, wherein the rated voltage of the battery is 36V or 48V and the rated voltage of the capacitor is 72V or 96V.

13. An electrical energy system according to claim 10, wherein the electrical motor has a total output of about 7-25 kW.

14. An electrical energy system according to claim 10, wherein the electrical motor is designed as a crankshaft starter generator.

15. An electrical energy system according to claim 10, wherein the ratio between useful capacitor store energy content and electrical motor output is between 5 and 25 kJ/kW.

16. An electrical energy system according to claim 10, wherein the ratio between battery energy content and output of the electrical motor is below 900 kJ/kW.

17. An electrical energy system for use in a hybrid car, said system comprising:

an electrical motor;

a capacitor having a rated voltage between 65 and 115V;

a battery having a rated voltage between 32 and 58V, and

a DC-DC converter coupled between the capacitor and the battery wherein the capacitor is in electrical communication with the electrical motor and the capacitor can be switched in parallel with the battery via at least one switch thereby bypassing said DC-DC converter.

18. An electrical energy system according to claim 17, wherein the capacitor is located next to the electrical motor.

19. An electrical energy system according to claim 17, wherein the rated voltage of the battery is 36V or 48 V and the rated voltage of the capacitor is 72V or 96V.

20. An electrical energy system according to claim 17, wherein energy content of the battery is between 600 and 2200 VAh per ton vehicle deadweight and energy content of the capacitor is between 10 and 80 VAh per ton vehicle deadweight.