Self-supporting capacitor structure

• US 20060146480A1
• Filed: 10/07/2004
• Published: 07/06/2006
• Est. Priority Date: 11/07/2003
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Maxwell Technologies Incorporated (Tesla Inc.)
• Inventors: Thrap, Guy C.
• Granted Patent: US 7,180,726 B2
• Time in Patent Office: Days
• US Class Current: 361/522
• CPC Class Codes: H01G 11/18 against thermal overloads, e.g. heating, cooling or ventilating
• CPC Class Codes: H01G 11/74 Terminals, e.g. extensions of current collectors
• CPC Class Codes: H01G 11/78 Cases; Housings; Encapsulations; Mountings
• CPC Class Codes: H01G 11/82 Fixing or assembling a capacitive element in a housing, e.g. mounting electrodes, current collectors or terminals in containers or encapsulations
• CPC Class Codes: H01G 2/04 specially adapted for mounting on a chassis
• CPC Class Codes: H01G 9/08 Housing; Encapsulation
• CPC Class Codes: H01G 9/14 Structural combinations or circuits for modifying, or compensating for, electric characteristics of electrolytic capacitors
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A plurality of high capacitance capacitors are coupled to supply or accept large currents. Bus bars are welded to the capacitors to provide improved thermal performance as well as self-supporting rigidity to the geometrical structure formed by the capacitors and the bus bars.

Claims

1. A capacitor based system, comprising

at least three double-layer capacitors, the capacitors comprising terminals through which a high current may flow safely;

and

at least two bus bars, each bus bar comprising two attachment points, wherein at the two attachment points a double-layer capacitor and the bus bar form an integral structure that passes the high current,

wherein the at least three capacitors and the at least two bus bars comprise a self supporting-structure.

2. The system of claim 1, wherein the high current is greater than 2000 amps.

3. The system of claim 2, wherein the at least one bus bar comprises a relatively ductile metal.

4. The system of claim 1, wherein the system comprises a vehicle, the vehicle comprising an electrical device, wherein two of the terminals are coupled to the electrical device.

5. The system of claim 1, wherein the at least three capacitors are interconnected in series and provide about 42 volts when charged.

6. The system of claim 1, wherein the at least three double-layer capacitors are connected in series by the at least two bus bars.

7. The system of claim 2, wherein at least one bus bar comprises an increased surface area.

8. The system of claim 7, wherein the increased surface area comprises one or more rib.

9. The system of claim 1, wherein between terminals of the at least three capacitors are interconnected two capacitor balancing circuits.

11. The system of claim 1, wherein the self-supporting structure comprises welds.

12. The system of claim 11, wherein the welds are laser welds.

13. The system of claim 11, wherein the welds are ultrasonic welds.

14. The system of claim 11, wherein the welds are cold formed.

15. The system of claim 1, wherein two terminals are disposed along one axis of each double layer capacitor.

16. The system of claim 1, wherein the terminals and the at least two bus bars comprise the same metal.

10. (canceled)

17. A method of using a plurality of capacitors, comprising the steps of:

providing a first and a second double-layer capacitor;

providing a first bus bar; and

welding a first end of the first bus bar to the first

double-layer capacitor to form a self-supporting structure; and

welding a second end of the first bus bar to the second double-layer capacitor to form the self-supporting structure.

18. The method of claim 17, further comprising the step of passing a current of at least 250 amps through the first bus bar.

19. The method of claim 17, further providing a third double-layer capacitor;

providing a second bus bar; and

welding a first end of the second bus bar to the third capacitor to form the self-supporting structure; and

welding a second end of the bus bar to the second capacitor to form the self-supporting structure.

20. The method of claim 19, further comprising the steps of:

providing an electrical device; and

coupling the double-layer capacitors to the electrical device to pass current between the capacitors and the electrical device.

21. The method of claim 20, wherein the electrical device comprises a propulsion engine.

22. The method of claim 17, wherein the first and second capacitors are connected by the bus bar in series.

23. The method of claim 20, wherein the self-supporting structures comprised of double-layer capacitors and bus bars are oriented in any orientation.

24. A capacitor structure, comprising:

a plurality of capacitors; and

a plurality of bus bars for carrying a current between the plurality of capacitors, wherein the plurality of bus bars and the plurality of capacitors form an integrally interconnected self-supporting structure.

25. The structure of claim 24, wherein one or more of the bus bars comprise an increased surface area.

26. The structure of claim 24, wherein the bus bars are welded to the plurality of capacitors.

27. The structure of claim 26, wherein the current is at least 250 amps.

28. The structure of claim 26, wherein the capacitors are double-layer capacitors.

29. The structure of claim 24, wherein the capacitors comprise terminals and the integral interconnected structure is comprised of the bus bars and the terminals.

30. The structure of claim 29, wherein the capacitors comprise an aluminum housing and aluminum lid, wherein the housing and lid each comprise a terminal.

31. The structure of claim 31, wherein the self-supporting structure includes at least one capacitor balancing circuit connected between two of the capacitors.

32. A capacitor based system, comprising:

at least two double-layer capacitors, the capacitors having axially disposed terminals through which current may flow safely; and

at least one bus bar, the bus bar comprising two attachment points, the at least one bus bar for carrying the current between the double-layer capacitors, the at least one bus bar welded at the two attachment points to respective terminals of the double-layer capacitors.

33. The system of claim 32, wherein the at least one bus bar comprises at least one void within which one of the terminals is disposed.