Apparatus and method for hybrid power module systems

• US 20050249988A1
• Filed: 06/23/2004
• Published: 11/10/2005
• Est. Priority Date: 05/07/2004
• 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 7,521,138 B2
• Time in Patent Office: Days
• US Class Current: 429/431
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/6563 with forced flow, e.g. by blowers
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 8/04373 of auxiliary devices, e.g. reformers, compressors, burners
• CPC Class Codes: H01M 8/04395 of cathode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/04447 of anode reactants at the inlet or inside the fuel cell
• 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 8/04597 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/0491 of fuel cell stacks
• CPC Class Codes: H01M 8/04917 of auxiliary devices, e.g. batteries, capacitors
• 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 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A hybrid power module suitable for use in an array of hybrid power modules comprises a fuel cell stack, an energy storage device, charger circuit operable to charge the energy storage device from the fuel cell stack and/or an external power source at approximately a defined voltage; a stack disconnect switch operable to provide and remove an electrical path between the fuel cell stack and a terminal of the power module, and a unidirectional current flow device electrically coupled to provide a unidirectional current path from the charger circuit to the terminal of the power module when forward biased.

Claims

1. A hybrid power module, comprising:

a module power bus comprising at least a first bus terminal and a second bus terminal;

a plurality of fuel cells electrically coupled to one another as a fuel cell stack, the fuel cell stack comprising a first pole and a second pole, the fuel cell stack selectively operable to produce electrical power, and electrically couplable to provide the electrical power on the module power bus;

an energy storage device comprising a first pole and a second pole; and

the energy storage device operable to store and release electrical power;

a first linear regulator electrically coupled between the first pole of the fuel cell stack and the first bus terminal of the module power bus, and operable to regulate a flow of current from the fuel cell stack to the first bus terminal;

at least two input terminals; and

a charger circuit electrically coupled across the battery and operable to supply electrical power to the energy storage device at approximately a defined voltage and charging regime, the charger circuit comprising a second linear regulator electrically coupled between the first pole of the energy storage device and a node electrically located between the first pole of the fuel cell stack and at least one of the at least two input terminals, the second linear regulator operable to regulate a flow of current to the energy storage device from the fuel cell stack and from the input terminals via the node according to the charging regime.

2. The hybrid power module of claim 1, further comprising:

a stack disconnect switch operable to selectively provide and remove an electrical path between the second bus terminal of the module power bus and the fuel cell stack in a first state and a second state, respectively.

3. The hybrid power module of claim 1, further comprising:

a first controller communicatively coupled to control the first linear regulator based on a number of system operational parameters.

4. The hybrid power module of claim 3, further comprising:

a second controller communicatively coupled to control the second linear regulator based on a number of energy storage device operational parameters.

5. The hybrid power module of claim 1 wherein the first linear regulator comprises a plurality of regulating transistors electrically coupled in parallel with one another between the first pole of the fuel cell stack and the first bus terminal of the module power bus.

6. The hybrid power module of claim 1, further comprising:

a stack protection diode electrically coupled between the first pole of the fuel cell stack and the first bus terminal of the module power bus such that the stack protection diode substantially protects the fuel cell stack from currents received from the first bus terminal and from the energy storage device.

7. The hybrid power module of claim 1, further comprising:

a redundancy diode electrically coupled between the first pole of the energy storage device and the first bus terminal of the module power bus to allow current to flow from the first pole of the energy storage device to the first bus terminal when the redundancy diode is forward biased, and to prevent current from flowing from the first bus terminal to the first pole of the redundancy diode when reversed biased.

8. The hybrid power module of claim 1, further comprising:

a first diode electrically coupled between the node and the first pole of the fuel cell stack to allow a current flow from the first pole of the fuel cell stack to the first linear regulator when the first diode is forward biased; and

a second diode electrically coupled between the node and one of the at least two input terminals to allow a current flow from the one of the at least two input terminals to the first linear regulator when the second diode is forward biased.

9. The hybrid power module of claim 1 wherein the first and second bus terminals are externally accessible from the hybrid power module to electrical couple to loads that are external to, and distinct from, the hybrid power module.

10. The hybrid power module of claim 1, further comprising:

a power supply electrically coupled to receive power from an external power source via the at least two input terminals, and electrically coupled to provide converted power to the energy storage device via the charger circuit.

11. The hybrid power module of claim 10 wherein the power supply comprises a rectifier.

12. The hybrid power module of claim 10 wherein the power supply comprises a universal power supply configured to convert both AC and DC power within a first voltage range to DC power of a defined nominal voltage.

13. The hybrid power module of claim 1 wherein the at least two input terminals comprise a first, a second, and a third input terminals, the first, the second and the third input terminals electrically coupled to a three phase alternating current power source, the three phase alternating current power source being external to, and distinct from, the hybrid power module.

14. The hybrid power module of claim 1 wherein the energy storage device comprises a plurality of battery cells electrically coupled to one another as a battery.

15. The hybrid power module of claim 1 wherein the first and the second bus terminals are further electrically coupled in an array of hybrid power modules.

16. The hybrid power module of claim 1 wherein the first and the second bus terminals are further electrically coupled to at least one external energy storage device that is external to, and distinct from, the hybrid power module.

17. The hybrid power module of claim 1, further comprising:

at least subsystem that comprises a portion of a balance of plant of the hybrid power module, the subsystem comprising at least one device electrically coupled across the module power bus to receive power from the module power bus.

18. A method of operating a hybrid power module, the hybrid power module comprising a fuel cell stack, a module power bus comprising at least two bus terminals, an energy storage device, at least two input terminals, and a charger circuit, the input terminals electrically couplable to an external power source that that is distinct and separate from the hybrid power module, the method comprising:

in a first mode,

receiving power from the external power source at the charger circuit of the hybrid power module; and

regulating a current flow from the external power source to the energy storage device of the hybrid power module with the charger circuit according to a defined charging regime;

in a second mode,

producing power from the fuel cell stack of the hybrid power module;

supplying power produced by the fuel cell stack to the bus terminals of the module power bus;

from time-to-time in the second mode, supplying power from the fuel cell stack to the charger circuit; and

regulating a current flow from the fuel cell stack to the energy storage device with the charger circuit according to the defined charging regime.

19. The method of claim 18 wherein the power is received from the external power source via an internal power supply that is part of the hybrid power module.

20. The method of claim 18, further comprising:

from time-to-time in the second mode, supplying power from the energy storage device to the bus terminals of the module power bus.

21. The method of claim 18, further comprising:

in the first mode, converting power received from the external power source to a voltage suitable for the charger circuit.

22. The method of claim 18, further comprising:

in the first mode, rectifying the power received from the external power source to a direct current suitable for the charger circuit.

23. The method of claim 18 wherein the defined charging regime is specific to the energy storage device.

24. The method of claim 18 wherein the defined charging regime is stored as instructions in a controller.

25. The method of claim 24, further comprising:

reprogramming the controller to execute a different defined charging regime.

26. The method of claim 24, further comprising:

replacing the controller with another controller storing instructions that define a different charging regime.

27. The method of claim 18, further comprising:

preventing current flow from at least one of the bus terminals to the fuel cell stack, while permitting current flow from the fuel cell stack to at least one of the bus terminals.

28. The method of claim 18 wherein the hybrid power module further comprises at least one power module disconnection switch, the method further comprising:

selectively operating at least one power module disconnect switch to electrically couple the hybrid power module to an external power bus in a first state of the power module disconnect switch, and to electrically uncouple the hybrid power module from the external power bus in a second state of the power module disconnect switch.

29. The method of claim 18 wherein the hybrid power module further comprises at least one stack disconnect switch, the method further comprising:

selectively operating the stack disconnect switch to electrically couple and uncouple the fuel cell stack from the power module bus.

30. A hybrid power module, comprising:

a fuel cell stack operable to produce electrical power;

a module power bus comprising at least two bus terminals, the module power bus coupled to supply electrical power from the fuel cell stack to the bus terminals;

means for regulating a current flow from the fuel cell stack to at least one of the bus terminals;

energy storage means for storing electrical energy;

at least two input terminals electrically couplable to receive power from an external power source that is distinct from the hybrid power module; and

charger circuit means for regulating a current flow to the energy storage means from the fuel cell stack and from the external power source, according to the defined charging regime.

31. The hybrid power module of claim 30 wherein means for regulating a current flow from the fuel cell stack to at least one of the bus terminals comprises a first linear regulator means and a first controller coupled to control the first linear regulator means.

32. The hybrid power module of claim 31 wherein first linear regulator means comprises at least two transistors electrically coupled in parallel.

33. The hybrid power module of claim 31 wherein the charger circuit means comprises a second linear regulator means and a second controller coupled to control the second linear regulator means.