APPARATUS FOR HIGH EFFICIENCY OPERATION OF FUEL CELL SYSTEMS AND METHOD OF MANUFACTURING SAME

• US 20100136379A1
• Filed: 12/02/2008
• Published: 06/03/2010
• Est. Priority Date: 12/02/2008
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: King, Robert Dean, Richter, Timothy Gerard
• Granted Patent: US 8,486,570 B2
• Time in Patent Office: Days
• US Class Current: 429/432
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H01M 16/003 of fuel cells with other electrochemical devices, e.g. capacitors, electrolysers
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 8/04619 of fuel cell stacks
• CPC Class Codes: H01M 8/0494 of fuel cell stacks
• CPC Class Codes: H01M 8/04947 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/18 Regenerative fuel cells, e.g. redox flow batteries or secondary fuel cells
• CPC Class Codes: H02J 2300/30 The power source being a fuel cell
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y02P 90/40 Fuel cell technologies in production processes
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A drive circuit comprising a DC bus configured to supply power to a load, a first fuel cell coupled to the DC bus and configured to provide a first power output to the DC bus, and a second fuel cell coupled to the DC bus and configured to provide a second power output to the DC bus supplemental to the first fuel cell. The drive circuit further includes an energy storage device coupled to the DC bus and configured to receive energy from the DC bus when a combined output of the first and second fuel cells is greater than a power demand from a load, and provide energy to the DC bus when the combined output of the first and second fuel cells is less than the power demand from the load.

Claims

1. A drive circuit comprising:

a DC bus configured to supply power to a load;

a first fuel cell coupled to the DC bus and configured to provide a first power output to the DC bus;

a second fuel cell coupled to the DC bus and configured to provide a second power output to the DC bus supplemental to the first fuel cell; and

an energy storage device coupled to the DC bus and configured to;

receive energy from the DC bus when a combined output of the first and second fuel cells is greater than a power demand from the load; and

provide energy to the DC bus when the combined output of the first and second fuel cells is less than the power demand from the load.

2. The drive circuit of claim 1 wherein the first fuel cell is configured to provide a non-varying power output in response to the power demand from the load.

3. The drive circuit of claim 1 wherein the second fuel cell is configured to provide a variable power output in response to the power demand from the load.

4. The drive circuit of claim 1 comprising a fuel cell control system configured to command one of the first fuel cell and the second fuel cell to supply no power to the DC bus in response to a decrease in power demand from the load.

5. The drive circuit of claim 1 wherein the load comprises a traction motor.

6. The drive circuit of claim 1 comprising:

a first DC-to-DC voltage converter coupled to the DC bus;

a first coupling device coupled between the first fuel cell and the first DC-to-DC voltage converter;

a second DC-to-DC voltage converter coupled to the DC bus; and

a second coupling device coupled between the second fuel cell and the second DC-to-DC voltage converter.

7. The drive circuit of claim 6 wherein the first DC-to-DC voltage converter comprises one of a boost converter and a bi-directional buck/boost converter, and wherein the second DC-to-DC voltage converter comprises one of a boost converter and a bi-directional buck/boost converter.

8. The drive circuit of claim 7 wherein at least one of the first DC-to-DC voltage converter and the second DC-to-DC voltage converter comprises a bi-directional buck/boost converter to provide power from the DC bus to power auxiliary devices or loads.

9. The drive circuit of claim 6 wherein the first coupling device comprises one of a contactor, a semiconductor switch, and a diode, and wherein the second coupling device comprises one of a contactor, a semiconductor switch, and a diode.

10. A method of manufacturing comprising:

configuring a DC link to provide electrical power to a traction motor, the traction motor having a loading on the DC link;

coupling a first fuel cell and a second fuel cell to the DC link, each fuel cell configured to output electrical power to the DC link; and

coupling a first energy storage device to the DC link, the first energy storage device configured to receive energy from the DC link when a combined power output of the first and second fuel cells is greater than a power demand from a loading and configured to provide energy to the DC link when the combined output of the first and second fuel cells is less than the power demand from the loading.

11. The method of claim 10 wherein comprising coupling a controller to each of a first and a second fuel cell to output electrical power to the DC link, and controlling one of the first and second fuel cells to output power at a rate that does not change based on a change in the loading.

12. The method of claim 11 wherein configuring each of a first and a second fuel cell to output electrical power to the DC link comprises configuring the other of the first and second fuel cells to output power at a rate that changes with the change in the loading.

13. The method of claim 10 wherein coupling the first energy storage device to the DC link comprises:

coupling a first voltage converter to the first energy storage device; and

coupling the first voltage converter to the DC link.

14. The method of claim 13 wherein coupling the first and second fuel cells to the DC link comprises:

coupling a second voltage converter to the first fuel cell;

coupling a third voltage converter to the second fuel cell; and

coupling the second and the third voltage converters to the DC link.

15. The method of claim 14 wherein coupling the second voltage converter to the first fuel cell comprises coupling a first bi-directional buck/boost converter to the first fuel cell;

and

wherein coupling the third voltage converter to the second fuel cell comprises coupling a second bi-directional buck/boost converter to the second fuel cell.

16. The method of claim 10 further comprising:

providing a second energy storage device configured to supply electrical energy;

coupling a bi-directional buck/boost converter to the second energy storage device; and

coupling the bi-directional buck/boost converter to the DC link.

17. A fuel cell propulsion system comprising:

a first fuel cell configured to output power to a vehicle traction motor load;

a second fuel cell configured to output power to the vehicle traction motor load;

an energy storage device configured to output power to the vehicle traction motor load; and

a controller configured to regulate energy to and from the energy storage device such that;

the fuel cells provide energy to the energy storage device when combined power output from the fuel cells exceeds a power demand of the vehicle traction motor, and

the energy storage device provides power to vehicle traction motor when combined power output from the fuel cells is less than the power demand of the vehicle traction motor.

18. The fuel cell propulsion system of claim 17 wherein the controller is configured to control one of the first and second fuel cells to provide a non-varying power.

19. The fuel cell propulsion system of claim 17 wherein each of the first and second fuel cells is coupled to a respective DC-to-DC voltage converter configured to supply electrical power to the traction motor.

20. The fuel cell propulsion system of claim 19 wherein the DC-to-DC voltage converters comprise bi-directional buck/boost converters.

21. The fuel cell propulsion system of claim 17 further comprising a second energy storage device configured to supply electrical energy to the traction motor via a second bi-directional buck/boost converter.

22. The fuel cell propulsion system of claim 17 comprising a first and second fuel cell configured to supply power to one of an auxiliary device and an auxiliary load.

23. The fuel cell propulsion system of claim 22 wherein the first energy storage device comprises one of a battery and an ultracapacitor, and wherein the second energy storage device comprises one of a battery, an ultracapacitor, and a flywheel.