Method and apparatus for fuel cell systems

• US 20040229095A1
• Filed: 05/16/2003
• Published: 11/18/2004
• Est. Priority Date: 05/16/2003
• Status: Active Grant

• Current Assignee: Ballard Power Systems Corporation (Superior Plus Corporation)
• Original Assignee: Ballard Power Systems Corporation (Superior Plus Corporation)
• Inventors: Pearson, Martin T.
• Granted Patent: US 7,419,734 B2
• Time in Patent Office: Days
• US Class Current: 429/23
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 8/04007 related to heat exchange
• CPC Class Codes: H01M 8/04679 of fuel cell stacks
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/04917 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04947 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/249 comprising two or more groupings of fuel cells, e.g. modular assemblies
• 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 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

An array of fuel cell systems are electrically couplable in series and/or parallel combinations to provide a variety of output powers, output current and/or output voltages. The fuel cell systems are “hot swappable” and redundant fuel cell systems may automatically replace faulty fuel cell systems to maintain output power, current and/or voltage, with or without switching. The configuration of fuel cell systems may be automatic and may be based on desired power, current and/or voltage, and/or based on the operating parameters of the fuel cell systems and/or power supply system.

Claims

1. A power supply system, comprising:

a first set of fuel cell systems electrically coupled in series to one another and operable to produce a first voltage there across; and

a second set of fuel cell systems electrically coupled in series to one another and operable to produce a voltage there across, where each of the fuel cell systems in the second set of fuel cell systems is electrically coupled in parallel to a respective one of the fuel cell systems in the first set of fuel cell systems,

wherein each of the fuel cell systems comprises a fuel cell stack, an ultracapacitor electrically coupled in parallel with the fuel cell stack, a charging current limiter electrically coupled to limit a charging current from the fuel cell stack to the ultracapacitor and a charging current limiter bypass device electrically coupled to provide a discharge path from the ultracapacitor bypassing the charging current limiter.

2. The power supply system of claim 1, further comprising:

a third set of fuel cell systems electrically coupled in series to one another and operable to produce a voltage there across, where each of the fuel cell systems in the third set of fuel cell systems is electrically coupled in parallel to a respective one of the fuel cell systems in the second set of fuel cell systems.

3. The power supply system of claim 2 wherein the number of fuel cell systems in the first set of fuel cell systems is equal to the number of fuel cell systems in the second set of fuel cell systems and wherein the number of fuel cell systems in the third set of fuel cell systems is less than the number of fuel cell systems in the second set of fuel cell systems.

4. The power supply system of claim 2, further comprising:

a first tap electrically coupled to a first end of the first and the second sets of fuel cell systems to provide a first potential;

a second tap electrically coupled to a second end of the first and the second set of fuel cell systems to provide a second potential; and

a third tap electrically coupled to a first end of the third set of fuel cell systems to provide a third potential, different from the first and the second potentials, where the first tap and second tap form a first voltage bus and the first tap and the third tap form a second voltage bus.

5. The power supply system of claim 2, further comprising:

a fourth set of fuel cell systems electrically coupled in series to one another and operable to produce a voltage there across, where each of the fuel cell systems in the fourth set of fuel cell systems is electrically coupled in parallel to a respective one of the fuel cell systems in the third set of fuel cell systems.

6. The power supply system of claim 5 wherein the number of fuel cell systems in the fourth set is one.

7. The power supply system of claim 5 wherein the number of fuel cell systems in the first set of fuel cell systems is equal to the number of fuel cell systems in the second set of fuel cell systems and wherein the number of fuel cell systems in the third set of fuel cell systems is less than the number of fuel cell systems in the second set of fuel cell systems and the number of fuel cell systems in the fourth set of fuel cell systems is less than the number of fuel cell systems in the third set of fuel cell systems.

8. The power supply system of claim 5, further comprising:

a first tap electrically coupled to a first end of the first and the second sets of fuel cell systems to provide a first potential;

a second tap electrically coupled to a second end of the first and the second set of fuel cell systems to provide a second potential;

a third tap electrically coupled to a first end of the third set of fuel cell systems to provide a third potential, different from the first and the second potentials; and

a fourth tap electrically coupled to a first end of the fourth set of fuel cell systems to provide a fourth potential, where the first tap and second tap form a first voltage bus, the first tap and the third tap form a second voltage bus, and the first tap and the fourth tap forms a third voltage bus.

9. The power supply system of claim 5, further comprising:

a first tap electrically coupled between a first and a second end of the first and the second sets of fuel cell systems to provide a reference potential;

a second tap electrically coupled to the first end of the first and the second sets of fuel cell systems to provide a first potential, the first potential above the reference potential;

a third tap electrically coupled to the second end of the first and the second sets of fuel cell systems to provide a second potential, the second potential below the reference potential;

a fourth tap electrically coupled to a first end of the third set of fuel cell systems to provide a third potential, the third potential above the reference potential and below the first potential;

a fifth tap electrically coupled to a first end of the fourth set of fuel cell systems to provide a fourth potential, the fourth potential above the reference potential and below the third potential; and

a sixth tap electrically coupled to a second end of the fourth set of fuel cell systems to provide a fifth potential, the fifth potential below the reference potential and above the second potential.

10. The power supply system of claim 9 wherein the third tap is further electrically coupled to the second end of the third set of fuel cell systems.

11. The power supply system of claim 9 wherein the first tap and second tap form a first voltage bus, the first tap and the third tap form a second voltage bus, and the first tap and the fourth tap forms a third voltage bus, the first tap and the fifth tap form a fourth voltage bus, and the first tap and the sixth tap form a fifth voltage bus.

12. The power supply system of claim 9 wherein the first potential is approximately 120 volts above the reference potential, the second potential is approximately 48 volts below the reference potential, the third potential is approximately 48 volts above the reference potential, the fourth potential is approximately 24 volts above the reference potential and the fifth potential is approximately 24 volts below the reference potential.

13. A power supply system, comprising:

a first voltage bus;

a first column of fuel cell systems electrically coupled in series to one another across the first voltage bus and operable to produce a voltage across the first voltage bus equal to a first voltage, where the number of fuel cell systems in the first column is equal to a number i and the number i is greater than 1;

a second column of fuel cell systems electrically coupled in series to one another across the first voltage bus in parallel with the first number of fuel cell systems, the second number of fuel cell systems operable to produce current at a first voltage across the first voltage bus, where the number of fuel cell systems in the second column is equal to the number i; and

a number of links electrically coupling each of the fuel cell systems in the second column in parallel with a respective one of the fuel cell systems in the first column,

wherein each fuel cell system comprises a fuel cell stack, an electrical power storage device electrically coupled in parallel with the fuel cell stack, and means for controlling a flow of current from the fuel cell stack to the electrical power storage device and the first voltage bus.

14. The power supply system of claim 13, further comprising:

a third column of fuel cell systems electrically coupled in series to one another across the first voltage bus and operable to produce additional current at a voltage across the first voltage bus approximately equal to the first voltage, where the number of fuel cell systems in the third column is equal to the number i; and

a number of links electrically coupling each of the fuel cell systems in the third column to a respective one of the fuel cell systems in the second column.

15. The power supply system of claim 13, further comprising:

a second voltage bus;

a third column of fuel cell systems electrically coupled in series to one another across the second voltage bus and operable to produce current at a second voltage across the second voltage bus different from the first voltage, where the number of fuel cell systems in the third column is equal to a number j and the number j is less than the number i; and

a number of links electrically coupling each of the fuel cell systems in the third column to a respective one of the fuel cell systems in the second column.

16. The power supply system of claim 13, further comprising:

a second voltage bus;

a third column of fuel cell systems electrically coupled in series to one another across the second voltage bus and operable to produce current at a second voltage across the second voltage bus different from the first voltage, where the number of fuel cell systems in the third column is equal to a number j and the number j is less than the number i; and

a number of links electrically coupling each of the fuel cell systems in the third column to a respective one of the fuel cell systems in the second column;

a fourth column of fuel cell systems electrically coupled in series to one another across the second voltage bus and operable to produce additional current at approximately the second voltage across the second voltage bus different from the first voltage, where the number of fuel cell systems in the fourth column is equal to the number j; and

a number of links electrically coupling each of the fuel cell systems in the fourth column to a respective one of the fuel cell systems in the third column.

17. The power supply system of claim 13, further comprising:

a second voltage bus;

a third column of fuel cell systems electrically coupled in series to one another across the second voltage bus and operable to produce current at a second voltage across the second voltage bus different from the first voltage, where the number of fuel cell systems in the third column is equal to a number j and the number j is less than the number i; and

a number of links electrically coupling each of the fuel cell systems in the third column to a respective one of the fuel cell systems in the second column; and

a third voltage bus;

a fourth column of fuel cell systems electrically coupled in series to one another across the third voltage bus and operable to produce current at a third voltage across the third voltage bus different from the first and the second voltages, where the number of fuel cell systems in the fourth column is equal to a number k and the number k is less than the number j; and

a number of links electrically coupling each of the fuel cell systems in the fourth column to a respective one of the fuel cell systems in the third column.

18. The power supply system of claim 17 wherein the voltage across the first voltage bus is approximately 120 volts, the voltage across the second voltage bus is approximately 48 volts and the voltage across the third voltage bus is approximately 24 volts.

19. The power supply system of claim 17 wherein the number k is equal to one.

20. A power supply system, comprising:

a first array of serially coupled fuel cell systems, operable to produce a first voltage there across;

a second array of serially coupled fuel cell systems, operable to produce a first voltage there across;

a third array of serially coupled fuel cell systems, operable to produce a second voltage there across; and

a fourth array of serially coupled fuel cell systems, operable to produce a third voltage there across, wherein at least one of fuel cell systems from each of the first, the second, the third and the fourth arrays are electrically coupled in parallel, at least another one of fuel cell systems from each of the first, the second and the third arrays are electrically coupled in parallel, and at least a further one of the fuel cell systems from each of the first and the second arrays are electrically coupled in parallel.

21. The power supply system of claim 20 wherein the number of fuel cell systems in each of the two arrays of the first, the second, the third and the fourth arrays having the most number of fuel cell systems is the same.

22. The power supply system of claim 20, further comprising:

a first tap electrically coupled between a first and a second end of the first and the second arrays of fuel cell systems to provide a reference potential;

a second tap electrically coupled to the first end of the first and the second arrays of fuel cell systems to provide a first potential, the first potential above the reference potential;

a third tap electrically coupled to the second end of the first and the second arrays of fuel cell systems to provide a second potential, the second potential below the reference potential;

a fourth tap electrically coupled to a first end of the third array of fuel cell systems to provide a third potential, the third potential above the reference potential and below the first potential;

a fifth tap electrically coupled to a first end of the fourth array of fuel cell systems to provide a fourth potential, the fourth potential above the reference potential and below the third potential; and

a sixth tap electrically coupled to a second end of the fourth array of fuel cell systems to provide a fifth potential, the fifth potential below the reference potential and above the second potential.