Variable fuel cell power system for generating electrical power

• US 6,503,649 B1
• Filed: 04/03/2000
• Issued: 01/07/2003
• Est. Priority Date: 04/03/2000
• Status: Expired due to Term

• Current Assignee: Convergence Incorporated (Amazon.com, Inc.)
• Original Assignee: Convergence Incorporated (Amazon.com, Inc.)
• Inventors: Czajkowski, Kathleen A., Rebain, Stephen R.
• Primary Examiner(s): Brouillette, Gabrielle
• Assistant Examiner(s): Martin, Angela J.
• Application Number:
  US09/541,996
• Time in Patent Office: 1,009 Days
• Field of Search: 429/22, 429/23, 429/13, 429/12, 701/22, 702/22, 702/60, 702/65
• US Class Current: 429/430
• CPC Class Codes: H01M 8/04947 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: H02J 1/001 Hot plugging or unplugging of load or power modules to or from power distribution networks
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources
• CPC Class Codes: H02J 2300/30 The power source being a fuel cell
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• 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: Y02E 60/50 Fuel cells

Abstract

The present invention provides an apparatus and methods for variably supplying power from a stand-alone fuel cell power supply system including a power conversion unit, a power switching unit and a load control unit. Preferably, a controller manages system configuration to switch the loads, the power conversion and the delivery between the two without reducing capacity by redundantly backing up each individual portion with a bank of at least two modules for each unit. Preferably, controller actuated devices are triggered automatically in response to monitors that sense performance operating parameters and detect values operating outside a threshold range. Preferably, each of the units and the components in each unit are banked in a plurality of modular units so that individual converters may be interchanged, individual fuel cells may be interchanged, individual controllers may be interchanged, and individual storage units such as batteries may be interchanged to ensure proper operation of each bank despite changes or failures in individual components of the bank. The power system may include couplers for connecting the system to dedicated outlets such as an NEC standard 120/240 volt building circuitry. The invention monitors multiple elements from fuel supply, fuel cells, converters, storage units, and controls as well as the loads for balanced, reliably robust, high power quality, and independent power supply.

Claims

1. A variable fuel cell power supply system comprising:

a plurality of power conversion units;

a plurality of load busses;

a switch bank including a plurality of switches, each switch selectively connecting at least one power conversion unit to a selected one of said plurality of load busses;

at least one load coupler, each load coupler selectively connecting a load line to a selected one of said plurality of load busses; and

at least one process control responsive to a plurality of operating parameters from at least one of said power conversion units and said switch bank for configuring the system for selective engagement of at least one switch of said switch bank and said load coupler.

2. The invention as defined in claim 1, wherein said process control further includes a switch control comprising:

at least one sensor providing output in response to one of said operating parameters;

a detector determining when said output attains a threshold value;

an indicator demonstrating the attainment of said threshold value; and

a manipulator to change the state of at least one switch in said switch bank.

3. The invention as defined in claim 1, wherein said process control further includes a switch control comprising:

at least one sensor providing output in response to one of said operating parameters;

a detector determining when said output attains a threshold value; and

an automatic switch controller responsive to said threshold value to change the state of at least one switch in said switch bank automatically.

4. The invention as defined in claim 1, wherein said operating parameters further include at least one load coupler parameter, and wherein said process control further includes a switch control comprising:

at least one sensor providing output in response to one of said operating parameters;

a detector determining when said output attains a threshold value;

an indicator demonstrating the attainment of said threshold value; and

an adjustor to selectively switch said load line at said load coupler to operate within equipment capability and according to customer preferences.

5. The invention as defined in claim 1, wherein said operating parameters further include at least one load coupler parameter, and wherein said process control further includes a switch control comprising:

at least one sensor providing output in response to one of said operating parameters;

a detector determining when said output attains a threshold value; and

an adjustor triggered automatically in response to detection of at least one threshold operating parameter, to selectively switch said load line at said load coupler to operate within equipment capability and according to customer preferences.

6. The invention as defined in claim 1, wherein said operating parameters further include at least one load coupler parameter, and wherein said process control further includes a monitoring processor comprising:

at least one sensor providing output in response to one of said operating parameters;

a monitor to record and communicate at least one operating parameter; and

at least one communications channel to communicate said operating parameter.

7. The invention as defined in claim 1, wherein said power conversion units are banked, switchable units to provide selective backup for each said power conversion unit, and are replaceable as a unit.

8. The invention as defined in claim 1, wherein each said power conversion unit comprises a first unit including at least one oxygen source and at least one hydrogen source and at least one fuel cell coupled to said oxygen and hydrogen sources, a second unit including at least one energy storage device coupled to said fuel cell, a third unit including at least one dc-ac converter coupled to said fuel cell, said energy storage device, and switch in said switch bank, wherein each of said fuel cells, said storage devices, and said dc-ac converters are replaceable as a unit.

9. The invention as defined in claim 1, wherein each said power conversion unit comprises:

a first unit including at least one oxygen source and at least one hydrogen source and at least one fuel cell coupled to said oxygen and hydrogen sources;

a second unit including at least one energy storage device coupled to said fuel cell;

a third unit including at least one dc-ac converter coupled to said fuel cell, said energy storage device, and switch in said switch bank; and

wherein at least one of said fuel cells, said storage devices, and said dc-ac converters is individually switchable as a unit.

10. The invention as defined in claim 9 wherein at least two of said fuel cells, said storage devices, and said dc-ac converters are individually switchable as a unit.

11. The invention as defined in claim 9 wherein each of said fuel cells, said storage devices, and said dc-ac converters are individually switchable as a unit.

12. The invention as defined in claim 1, wherein at least one switch in the said switch bank is a throwover switch for selectively coupling a power conversion unit to either a first load bus or a second load bus of said plurality of load buses.

13. The invention as defined in claim 1, wherein said process control further comprises a high precision clock processor to derive accurate local time and to synchronize the output of said power conversion units.

14. The invention as defined in claim 1, wherein said switch bank further includes at least one switch connecting an outside power source to said load bus, and wherein said process control further includes an interlock switch control for disconnecting said power conversion unit from the load bus and connecting the load bus to the outside power source.

15. The invention as defined in claim 1, wherein said process control further comprises a synchronizer for synchronizing the output of said power conversion units.

16. The invention as defined in claim 15, where said synchronizer comprises a clock processor in compliance with a standard clock reference.

17. The invention as defined in claim 1, wherein at least one said load coupler is a throwover switch for selectively coupling a load line to either a first load bus or to a second load bus of said plurality of load buses.

18. The invention as defined in claim 1, wherein the process control comprises a plurality of controllers that monitor said plurality of controllers and said operating parameters for selectively switching to one of said plurality of controllers for master status.