Self-supporting capacitor structure

• US 7,180,726 B2
• Filed: 10/07/2004
• Issued: 02/20/2007
• Est. Priority Date: 11/07/2003
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Maxwell Technologies Incorporated (Tesla Inc.)
• Inventors: Thrap, Guy
• Primary Examiner(s): Thomas; Eric W.
• Application Number:
  US10/960,034
• Publication Number:
  US 20060146480A1
• Time in Patent Office: 866 Days
• Field of Search: 361/502, 361/522, 361/521, 361517-519, 361535-537, 361/538, 361329-330, 361513-515, 361/320, 361/301.4, 361/541
• US Class Current: 361/502
• 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 and the at least three double-layer capacitors are connected in series by the at least two bus bars.

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 2, wherein at least one bus bar comprises an increased surface area.

5. The system of claim 4, wherein the increased surface area comprises one or more rib.

6. 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.

7. The system of claim 1, wherein the at least three capacitors provide about 42 volts when charged.

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

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

10. The system of claim 9, wherein the welds are laser welds.

11. The system of claim 9, wherein the welds are ultrasonic welds.

12. The system of claim 9, wherein the welds are cold formed.

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

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

15. 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 in which the plurality of capacitors are connected in series by the plurality of bus bars.

16. The structure of claim 15, wherein one or more of the bus bars comprise an increased surface area.

17. The structure of claim 15, wherein the bus bars are welded to the plurality of capacitors.

18. The structure of claim 17, wherein the current is at least 250 amps.

19. The structure of claim 17, wherein the capacitors are double-layer capacitors.

20. The structure of claim 15, wherein the capacitors comprise terminals and the integral interconnected structure is comprised of the bus bars and the terminals.

21. The structure of claim 20, wherein the capacitors comprise an aluminum housing and aluminum lid, wherein the housing and lid each comprise a terminal.

22. The structure of claim 15, wherein the self-supporting structure includes at least one capacitor balancing circuit connected between two of the capacitors.

23. 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,

wherein a charge balancing circuit is electrically interposed between the respective terminals of the double lever capacitors.

24. The system of claim 23, wherein the at least one bus bar comprises at least one void within which one of the terminals is disposed.

25. 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 and at least one bus bar comprises an increased surface area.

26. The system of claim 25, wherein the increased surface area comprises one or more rib.

27. 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 from 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 and two capacitor balancing circuits are interconnected between the terminals of the at least three capacitors.

28. 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, 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 and the terminals and the at least two bus bars comprise the same metal.