Using a fuel cell as energy storage for inverter and converter systems

• US 20060057441A1
• Filed: 09/07/2005
• Published: 03/16/2006
• Est. Priority Date: 09/10/2004
• Status: Abandoned Application

• Current Assignee: Plug Power Inc.
• Original Assignee: Plug Power Inc.
• Inventors: Wills, Robert Henry
• Application Number:
  US11/220,505
• Publication Number:
  US 20060057441A1
• Time in Patent Office: Days
• US Class Current: 429/430
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 8/04537 Electric variables
• CPC Class Codes: H01M 8/04552 of the individual fuel cell
• CPC Class Codes: H01M 8/04858 Electric variables
• CPC Class Codes: H01M 8/0491 of fuel cell stacks
• CPC Class Codes: H01M 8/0494 of fuel cell stacks
• CPC Class Codes: H02M 7/44 by static converters
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A technique that is usable with a fuel cell stack includes using a capacitance of the fuel cell stack as a main component of an input capacitance of an inverter. The technique may include, in some embodiments of the invention, using the capacitance of the fuel cell stack as a capacitance for a converter. For example, in these embodiments of the invention, the capacitance may be an input capacitance or an output capacitance of the converter.

Claims

1. A method usable with a fuel cell stack, comprising:

using a capacitance of the fuel cell stack as a main component of the energy storage of an inverter.

2. The method of claim 1, wherein the using comprises:

coupling the fuel cell stack directly to input terminals of the inverter.

3. The method of claim 1, wherein the using comprises:

coupling a converter between the fuel cell stack and the inverter.

4. The method of claim 1, wherein the main component comprises at least approximately 90 percent of a total capacitance present at input terminals of the inverter.

5. The method of claim 1, further comprising:

coupling at least one additional capacitor to an input terminal of the inverter to filter a voltage associated with a switching frequency of the inverter.

6. A method usable with a fuel cell stack, comprising:

using a capacitance of the fuel cell stack as a main component of the energy storage of a converter.

7. The method of claim 6, wherein the capacitance comprises an input capacitance of the converter.

8. The method of claim 6, wherein the capacitance comprises an output capacitance of the converter.

9. The method of claim 6, further comprising:

operating an inverter in a mode of operation in which power flows from an AC source back to the fuel cell stack.

10. The method of claim 6, further comprising:

using the fuel cell stack to power a DC load.

11. A system comprising:

an inverter; and

a fuel cell stack coupled to the inverter to provide a main component of the input capacitance of the inverter.

12. The system of claim 11, wherein the fuel cell stack is directly connected to input terminals of the inverter.

13. The system of claim 11, further comprising:

a converter coupled between the fuel cell stack and the inverter.

14. The system of claim 11, wherein the main component comprises at least approximately 90 percent of a total capacitance present at input terminals of the inverter.

15. The system of claim 11, further comprising:

at least one capacitor coupled to an input terminal of the inverter to filter a frequency component associated with a switching frequency of the inverter.

16. A system comprising:

an inverter; and

a fuel cell stack coupled to the converter to provide a main component of the capacitance of the converter.

17. The system of claim 16, wherein the capacitance comprises an input capacitance of the converter.

18. The system of claim 16, wherein the capacitance comprises an output capacitance of the converter.

19. The system of claim 16, wherein the converter comprises an inverter adapted to flow power from an AC source back to the fuel cell stack.

20. The system of claim 16, wherein the fuel cell stack is directly connected to at least one input terminal of the inverter.

21. The system of claim 16, further comprising:

an external DC load coupled to the system to be powered with power from the fuel cell stack.