Fuel cell power systems, direct current voltage converters, fuel cell power generation methods, power conditioning methods and direct current power conditioning methods

• US 6,428,918 B1
• Filed: 04/07/2000
• Issued: 08/06/2002
• Est. Priority Date: 04/07/2000
• Status: Expired due to Term

• Current Assignee: Emergent Power Inc. (Plug Power Inc.)
• Original Assignee: Avista Laboratories Inc. (Plug Power Inc.)
• Inventors: Dodge, Jonathan, Fuglevand, William A.
• Primary Examiner(s): KALAFUT, STEPHEN J
• Application Number:
  US09/544,781
• Time in Patent Office: 851 Days
• Field of Search: 429/9, 429/12, 429/13, 429/22, 429/23, 429/34, 320/101
• US Class Current: 429/431
• CPC Class Codes: H01M 16/003 of fuel cells with other electrochemical devices, e.g. capacitors, electrolysers
• CPC Class Codes: H01M 8/04007 related to heat exchange
• CPC Class Codes: H01M 8/04228 during shut-down
• CPC Class Codes: H01M 8/04246 Short circuiting means for defective fuel cells detection of defective fuel cells H01M8/04664, methods for shunting fuel cells H01M8/04955
• CPC Class Codes: H01M 8/04335 of cathode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/0435 of cathode exhausts
• CPC Class Codes: H01M 8/04365 of other components of a fuel cell or fuel cell stacks
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04567 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04589 of fuel cell stacks
• CPC Class Codes: H01M 8/04708 of fuel cell reactants
• CPC Class Codes: H01M 8/04723 of the coolant
• CPC Class Codes: H01M 8/04888 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04955 Shut-off or shut-down of fuel cells
• CPC Class Codes: H01M 8/04992 characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence
• CPC Class Codes: H01M 8/247 Arrangements for tightening a stack, for accommodation of a stack in a tank or for assembling different tanks
• CPC Class Codes: H02J 1/102 being switching converters H02J1/108, H02J1/12 take precedence
• CPC Class Codes: H02J 2300/30 The power source being a fuel cell
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

Fuel cell power systems, direct current voltage converters, fuel cell power generation methods, power conditioning methods and direct current power conditioning methods are provided. According to one aspect of the invention, a fuel cell power system includes a plurality of terminals adapted to couple with a load; a fuel cell configured to convert chemical energy into direct current electrical energy having a variable voltage potential; and a converter coupled intermediate the fuel cell and the terminals, the converter being configured to convert the direct current electrical energy having the variable voltage potential into direct current electrical energy having a substantially constant voltage potential.

Claims

1. A fuel cell power system comprising:

a plurality of terminals adapted to couple with a load;

a plurality of fuel cells respectively electrically coupled with the terminals and configured to convert chemical energy into direct current electrical energy having a variable voltage potential, the fuel cells being configured to be individually selectively deactivated and remaining ones of the fuel cells being configured to provide electricity to the terminals with others of the fuel cells deactivated; and

a converter coupled intermediate the fuel cells and the terminals, the converter being configured to convert the direct current electrical energy having the variable voltage potential into direct current electrical energy having a substantially constant voltage potential.

2. The system according to claim 1 wherein the converter comprises a boost converter.

3. The system according to claim 1 wherein the converter comprises a buck converter.

4. The system according to claim 1 further comprising an inverter coupled with the plurality of fuel cells and configured to convert direct current electrical energy into alternating current electrical energy.

11. The system according to claim 1 further comprising:

a cartridge configured to house at least one fuel cell; and

a housing configured to receive the cartridge.

12. The system according to claim 11 wherein the cartridge is removably coupled with the housing.

13. The system according to claim 11 wherein the cartridge includes the converter.

5. The system according to claim I wherein the converter comprises:

an electrical energy storage device; and

at least one switch configured to couple at least one fuel cell with the electrical energy storage device.

6. The system according to claim 5 further comprising a controller configured to monitor a voltage potential of the electrical energy storage device and to control the at least one switch responsive to the monitoring.

7. The system according to claim 5 further comprising a controller configured to control the at least one switch to maintain the voltage potential of the electrical energy storage device above a predetermined threshold.

8. The system according to claim 5 further comprising a controller configured to monitor at least one operational parameter of at least one fuel cell power system and to control the switch responsive to the monitoring.

9. The system according to claim 8 wherein the controller is configured to monitor at least one of voltage, current and temperature of at least one fuel cell.

10. The system according to claim 5 further comprising a controller configured to pulse-width modulate a control signal applied to the at least one switch.

14. A fuel cell power system comprising:

a plurality of terminals adapted to couple with a load;

a plurality of fuel cells configured to convert chemical energy into direct current electrical energy, the fuel cells being configured to be individually selectively deactivated and remaining ones of the fuel cells being configured to provide electricity with others of the fuel cells deactivated; and

an inverter coupled intermediate at least one of the fuel cells and the terminals, the inverter being configured to convert the direct current electricity into alternating current electrical energy.

15. The system according to claim 14 further comprising a converter coupled with at least one of the fuel cells and the inverter and configured to convert the direct current electrical energy into direct current electrical energy having a substantially constant voltage potential.

16. A direct current voltage converter comprising:

an input adapted to receive direct current electrical energy from a plurality of fuel cells having a variable voltage potential;

converter circuitry coupled with the input and configured to convert the direct current electrical energy having the variable voltage potential into direct current electrical energy having a substantially constant voltage potential; and

an output coupled with the converter circuitry and configured to receive the direct current electrical energy having the substantially constant voltage, wherein the plurality of fuel cells are configured to be individually selectively deactivated and remaining ones of the fuel cells being configured to provide electricity to the input with others of the fuel cells deactivated.

17. The converter according to claim 16 wherein the converter circuitry comprises:

an electrical energy storage device; and

a switch configured to couple the input with the electrical energy storage device.

18. The converter according to claim 17 further comprising a controller configured to monitor a voltage potential of the electrical energy storage device and to control the switch responsive to the monitoring.

19. The converter according to claim 17 further comprising a controller configured to control the switch to maintain the voltage potential of the electrical energy storage device above a predetermined threshold.

20. A fuel cell power system comprising:

a housing;

a plurality of output terminals;

a plurality of cartridges configured to be selectively received within and removed from the housing and individually comprising;

a fuel cell configured to convert chemical energy into electrical energy; and

power conditioning circuitry configured to electrically condition the electrical energy; and

an electrical connection configured to couple the power conditioning circuitry with the output terminals.

21. The system according to claim 20 wherein the cartridge is removably coupled with the housing.

22. The system according to claim 20 wherein the at least one cartridge comprises a plurality of cartridges.

23. The system according to claim 20 wherein the power conditioning circuitry comprises DC-DC converter circuitry.

24. The system according to claim 20 wherein the power conditioning circuitry comprises inverter circuitry.

25. The system according to claim 20 wherein the power conditioning circuitry comprises:

an electrical energy storage device; and

a switch configured to couple the fuel cell with the electrical energy storage device.

26. The system according to claim 25 further comprising a controller configured to monitor at least one operational parameter of the fuel cell power system and to control the switch responsive to the monitoring.

27. The system according to claim 26 wherein the controller is configured to monitor at least one of voltage, current and temperature of the fuel cell.

28. The system according to claim 25 further comprising a controller configured to pulse-width modulate. a control signal applied to the switch.

29. A fuel cell power system comprising:

a fuel cell configured to convert chemical energy into electrical energy and to be selectively deactivated, and wherein a cartridge is configured to house the fuel cell, and a housing is provided and which is configured to receive the cartridge; and

power conditioning circuitry coupled with the fuel call and configured to electrically condition the electrical energy, the power conditioning circuitry comprising a controller configured to monitor an operational parameter of the fuel call power system, and to control the conditioning of the electrical energy responsive to the monitoring, and wherein the power conditioning circuitry is provided within the cartridge.

30. A fuel cell power system comprising:

a housing;

a plurality of terminals adapted to couple with a load;

a plurality of cartridges, removeably supported by the housing, and wherein each cartridge includes at least one fuel cell which is configured to convert chemical energy into direct current energy having a variable voltage potential; and

a plurality of power conditioning circuits coupled with the fuel cell and configured to increase the voltage of the electrical energy from the fuel cell, and wherein the fuel cell cartridges house the respective power conditioning circuits.

31. A fuel cell power system, comprising:

a housing;

a plurality of terminals adapted to couple with a load;

a plurality of cartridges, removably supported by the housing, and wherein each of the cartridges include at least one fuel cell which is configured to convert chemical energy into direct current electrical energy having a variable voltage potential; and

a plurality of power conditioning circuits which are individually configured to couple with the at least one fuel cell and to increase the voltage of the electrical energy from the at least one fuel cell.

32. A fuel cell power system comprising:

a housing;

a plurality of terminals adapted to couple to a load;

a plurality of cartridges which are removably supported by the housing, and wherein each cartridge includes at least one fuel cell which is configured to convert chemical energy into direct current energy having a variable voltage potential; and

a plurality of power conditioning circuits coupled in parallel with the terminals.

33. A fuel cell power system comprising:

a plurality of terminals adapted to couple with a load;

a plurality of fuel cells configured to convert chemical energy into electrical energy and to provide the electrical energy to the terminals, the fuel cells being further configured to be individually selectively deactivated and remaining ones of the fuel cells being configured to provide electricity to the terminals with others of the fuel cells deactivated; and

a plurality of power conditioning circuits electrically coupled with respective fuel cells and configured to condition electrical energy from respective fuel cells.

34. The system according to claim 33 further comprising a plurality of fuel cell cartridges individually comprising at least one of the fuel cells.

35. The system according to claim 34 wherein the fuel cell cartridges individually comprise a plurality of the fuel cells.

36. The system according to claim 34 wherein the fuel cell cartridges house respective power conditioning circuits.

37. The system according to claim 33 wherein the power conditioning circuits comprise boost converters.

38. The system according to claim 33 wherein the power conditioning circuits comprise buck converters.

39. The system according to claim 33 wherein the power conditioning circuits are coupled in parallel with the terminals.

40. A fuel cell power system comprising:

a plurality of terminals adapted to couple with a load;

a plurality of fuel cell cartridges individually comprising at least one fuel cell which is configured to convert chemical energy into electrical energy, and wherein the fuel cell cartridges are coupled in parallel with the terminals; and

a plurality of power conditioning circuits configured to condition the electrical energy generated by the respective fuel cell cartridges.

41. A power conditioning method comprising:

receiving direct current electrical energy having a variable voltage potential within a direct current converter from a plurality of fuel cells configured to convert chemical energy into electricity, the fuel cells being configured to be individually selectively deactivated and remaining ones of the fuel cells being configured to provide electricity with others of the fuel cells deactivated;

converting the direct current electrical energy having the variable voltage potential into direct current electrical energy having a substantially constant voltage potential using the direct current converter; and

outputting the direct current electrical energy having the substantially constant voltage potential.

42. The method according to claim 41 wherein the converting comprises storing the electrical energy having the variable voltage potential using an electrical energy storage device.

43. The method according to claim 41 wherein the converting comprises:

monitoring a voltage potential of an electrical energy storage device; and

applying the electrical energy having the variable voltage potential to the electrical energy storage device responsive to the monitoring.

44. The method according to claim 43 wherein the applying comprises maintaining a voltage potential of the electrical energy storage device above a predetermined threshold.

45. A fuel cell power generation method comprising:

providing a plurality of fuel cells, the fuel cells being configured to be individually selectively deactivated and remaining ones of the fuel cells being configured to provide electricity with others of the fuel cells deactivated;

converting chemical energy into electrical energy using the fuel cells;

conditioning the electrical energy;

monitoring an operational parameter of the fuel cells; and

controlling the conditioning responsive to the monitoring.

46. The method according to claim 45 wherein the conditioning comprises supplying electrical energy to an electrical energy storage device.

47. The method according to claim 46 wherein the controlling comprises controlling the supplying.

48. The method according to claim 45 wherein the monitoring comprises monitoring the operational parameter comprising at least one of voltage, current and temperature of the fuel cells.

49. A fuel cell power generation method, comprising:

providing a plurality of fuel cells;

converting chemical energy to electrical energy using the fuel cells;

increasing the voltage potential of the electrical energy from the plural fuel cells by using a plurality of power conditioning circuits coupled in parallel with the terminals; and

after the increasing, supplying the electrical energy to a plurality of terminals which are adapted to be coupled to a load.

50. A fuel cell power generation method comprising:

providing a plurality of fuel cells;

converting chemical energy to electrical energy using the fuel cells;

increasing the voltage potential of the electrical energy generated from the plural fuel cells using a plurality of power conditioning circuits corresponding to the respective fuel cells; and

after the increasing, supplying the electrical energy to a plurality of terminals which are adapted to be coupled to a load.

51. A fuel cell power generation method comprising:

providing a plurality of fuel cells;

converting chemical energy to electrical energy using the fuel cells;

conditioning the electrical energy using a plurality of power conditioning circuits corresponding to respective fuel cells; and

supplying the electrical energy to a plurality of terminals adapted to be coupled to a load after the conditioning.

52. The method according to claim 51 wherein the providing comprises providing a plurality of fuel cell cartridges individually comprising at least one of the fuel cells.

53. The method according to claim 51 wherein the providing comprises providing a plurality of fuel cell cartridges individually comprising plural fuel cells.

54. The method according to claim 51 wherein the providing comprises providing a plurality of fuel cell cartridges individually including at least one of the fuel cells and at least one power conditioning circuit.

55. The method according to claim 51 wherein the supplying comprises supplying using the power conditioning circuits coupled in parallel with the terminals.

56. The method according to claim 51 wherein the conditioning comprises. increasing the voltage potential of the electrical energy.

57. A fuel cell power generation method comprising:

providing a plurality of fuel cell cartridges individually including at least one fuel cell;

converting chemical energy into electrical energy utilizing the fuel cells;

conditioning the electrical energy by utilizing a plurality of power conditioning circuits corresponding to the respective fuel cell cartridges; and

supplying the electrical energy using the fuel cell cartridges and which are coupled in parallel to a plurality of terminals which are electrically coupled to a load.