Method, apparatus and article to test fuel cells

• US 20030076110A1
• Filed: 02/14/2002
• Published: 04/24/2003
• Est. Priority Date: 10/22/2001
• Status: Active Grant

• Current Assignee: BDF IP Holdings Ltd. (Superior Plus Corporation)
• Original Assignee: Ballard Power Systems Corporation (Superior Plus Corporation)
• Inventors: Hill, Graham E., Wang, Zhaoyu, Nguyen, Hong The, Johnston Bailey, Ross W.
• Granted Patent: US 6,798,221 B2
• Time in Patent Office: Days
• US Class Current: 324/444
• CPC Class Codes: H01M 8/04671 of the individual fuel cell
• CPC Class Codes: H01M 8/04679 of fuel cell stacks
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A fuel cell resistance test system includes a contact head having a plurality of spaced electrical contacts for contacting multiple ones of the fuel cells composing the stack. In one embodiment, a plurality of selectively actuable switches produce a short between respective pairs of adjacent ones of the electrical contacts. A processor opens each of the switches, one at a time in succession, to apply a defined voltage from a voltage source, successively across pairs of adjacent ones of the electrical contacts. A current sensor measures a resulting current and the processor or other computer determines whether a short exists based on the magnitude of the defined voltage and the magnitude of the resulting current. Alternatively, the test system may include a current source and a voltage sensor.

Claims

1. A fuel cell resistance test system, comprising:

a voltage source selectively operable to produce a defined voltage;

a contact head having at least three electrical contacts;

means for applying the defined voltage produced by the voltage source successively across pairs of adjacent ones of the electrical contacts;

a current sensor coupled to the electrical contacts to measure a resulting supply current; and

a processor coupled to receive signals corresponding to at least one of the magnitude of the defined voltage and the magnitude the resulting current, the processor configured to determine whether a short exists based on the magnitude of the defined voltage and the magnitude of the resulting current.

2. The fuel cell resistance test system of claim 1 wherein the processor is configured to determine whether a short exists based on the magnitude of the defined voltage and the magnitude of the resulting current, by:

determining whether the magnitude of the resulting current is within an acceptable resulting current range for the defined voltage.

3. The fuel cell resistance test system of claim 1 wherein the processor is configured to determine whether a short exists based on the magnitude of the defined voltage and the magnitude of the resulting current, by:

determining a resistance based on the magnitude of the resulting current and the magnitude of the defined voltage; and

determining whether the determined resistance is within an acceptable resistance range for the defined voltage.

4. The fuel cell resistance test system of claim 1, further comprising

a carriage selectively positionable between a first position where all of the electrical contacts are in physical contact with respective portions of a fuel cell stack to be tested and a second position spaced from the first position.

5. The fuel cell resistance test system of claim 1, further comprising

a start switch selectively operable to operate the defined voltage applying means.

6. The fuel cell resistance test system of claim 1, further comprising:

a first connector coupled to the voltage supply; and

a second connector coupled to the electrical contacts, the first and the second connectors sized and shaped to matingly couple with one another to provide a selectively releasable connectable electrical connection between the voltage supply and the electrical contacts.

7. The fuel cell resistance test system of claim 1 wherein at least a portion of each of the electrical contacts form a coplanar array.

8. The fuel cell resistance test system of claim 1 wherein the voltage source produces a defined voltage of approximately 100 mV for testing membrane electrode assemblies having catalysts including ruthenium.

9. The fuel cell resistance test system of claim 1 wherein the voltage source produces a defined voltage of approximately 200 mV for testing membrane electrode assemblies having catalysts not including ruthenium.

10. The fuel cell resistance test system of claim 1 wherein the voltage source produces a defined voltage between approximately 100 mV and 300 mV for testing membrane electrode assemblies having catalysts including ruthenium.

11. The fuel cell resistance test system of claim 1 wherein the voltage source produces a defined voltage between approximately 200 mV and 400 mV for testing membrane electrode assemblies having catalysts not including ruthenium.

12. A fuel cell resistance test system, comprising:

a contact head having a plurality of spaced electrical contacts;

a plurality of switches, each of the switches selectively actuable to produce a short between a respective pair of adjacent ones of the electrical contacts;

a voltage source selectively operable to produce a defined voltage;

a processor coupled to open each of the switches, one at a time in succession, to apply the defined voltage from the voltage source successively across pairs of adjacent ones of the electrical contacts; and

at least one current sensor coupled to the electrical contacts to measure a resulting current; and

the processor coupled to receive signals corresponding to the magnitude of the defined voltage and the magnitude the resulting current, and configured to determine whether a short exists based on the magnitude of the defined voltage and the magnitude of the resulting current.

13. The fuel cell resistance test system of claim 12, further comprising:

a controller coupled between the processor and the switches to activate the switches in response to at least one signal from the processor.

14. The fuel cell resistance test system of claim 12, further comprising:

at least one pass/fail indicator coupled to the processor for selective activation in response to .

15. The fuel cell resistance test system of claim 12 wherein the electrical contacts take the form of spring loaded probes, extending at least partially from the test head.

16. The fuel cell resistance test system of claim 12, further comprising

a tray sized and dimensioned for receiving fuel cell stacks;

a linear guide; and

a carriage sized and dimensioned for receiving the tray, the carriage received on the linear guide for movement therealong between a first position where each of the electrical contacts are in physical contact with a respective portion of a fuel cell stack carried on the tray and a second position spaced from the first position.

17. The fuel cell resistance test system of claim 12, further comprising

a computing system including a central processing unit and a display, the computing system coupled to the processor to receive sets of voltage and current measurements and configured to display the received sets of voltage and current measurements on the display in a graphical from.

18. A method of testing fuel cell stacks, comprising:

simultaneously coupling a plurality of spaced electrical contacts to respective portions of a fuel cell stack;

successively applying a defined voltage between each respective pair of adjacent ones of the electrical contacts;

successively measuring a respective current resulting from each of the applied defined voltages before reaching a steady state condition; and

determining whether a short exists based on the defined voltages and the resulting currents.

19. The method of claim 18 wherein at least a portion of each of the electrical contacts are co-planar and simultaneously coupling a plurality of spaced electrical contacts to respective portions of a fuel cell stack includes moving the fuel cell stack along a linear guide toward a plane defined by the co-planar portions of the electrical contacts.

20. The method of claim 18 wherein successively applying a defined voltage between each respective pair of adjacent ones of the electrical contacts includes:

closing each of a plurality of switches to short each of the electrical contacts; and

opening each of the switches, one at a time, in succession.

21. The method of claim 18 wherein determining whether a short exists based on the defined voltages and the resulting currents includes:

determining whether the magnitude of the resulting current is within an acceptable resulting current range for the defined voltage.

22. The method of claim 18 wherein determining whether a short exists based on the defined voltages and the resulting currents includes:

determining a resistance based on the magnitude of the resulting current and the magnitude of the defined voltage; and

determining whether the determined resistance is within an acceptable resistance range for the defined voltage.

23. A system for testing fuel cell stacks, comprising:

a current source operable to produce a defined current;

a contact head having plurality of pairs of electrical contacts;

means for applying a defined current to through successive ones of the pairs of electrical contacts while grounding at least some of the others ones of the pairs of electrical contacts;

at least one voltage sensor to measure a resulting voltage across adjacent ones of the pairs of electrical contacts; and

a processor coupled to receive signals corresponding to at least one of a magnitude of the defined current and a magnitude the resulting voltage, the processor configured to determine whether a short exists based on the magnitude of the defined current and the magnitude of the resulting voltage.

24. The fuel cell resistance test system of claim 23 wherein the processor is configured to determine whether a short exists based on the magnitude of the defined current and the magnitude of the resulting voltage, by:

determining whether the magnitude of the resulting voltage is within an acceptable resulting voltage range for the defined current.

25. The fuel cell resistance test system of claim 23 wherein the processor is configured to determine whether a short exists based on the magnitude of the defined current and the magnitude of the resulting voltage, by:

determining a resistance based on the magnitude of the defined current and the magnitude of the resulting voltage; and

determining whether the determined resistance is within an acceptable resistance range for the defined current.

26. The fuel cell resistance test system of claim 23, further comprising

a carriage selectively positionable between a first position where all of the electrical contacts are in physical contact with respective portions of a fuel cell stack to be tested and a second position spaced from the first position.

27. The fuel cell resistance test system of claim 23, further comprising

a start switch selectively operable to operate the defined current applying means.

28. The fuel cell resistance test system of claim 23, further comprising

a first connector coupled to the current supply;

and

a second connector coupled to the electrical contacts, the first and the second connectors sized and shaped to matingly couple with one another to provide a selectively connectable electrical connection between the current supply and the electrical contacts.

29. The fuel cell resistance test system of claim 23 wherein at least a portion of each of the electrical contacts form a coplanar array.

30. The fuel cell resistance test system of claim 23, further comprising:

at least one pass/fail indicator coupled to the processor for selective activation in response to .

31. The fuel cell resistance test system of claim 23 wherein the electrical contacts take the form of spring loaded probes, extending at least partially from the test head.

32. The fuel cell resistance test system of claim 23, further comprising

a tray sized and dimensioned for receiving fuel cell stacks;

a linear guide; and

a carriage sized and dimensioned for receiving the tray, the carriage received on the linear guide for movement therealong between a first position where each of the electrical contacts are in physical contact with a respective portion of a fuel cell stack carried on the tray and a second position spaced from the first position.

33. The fuel cell resistance test system of claim 23 wherein the current source produces the defined current such that the resulting voltage is approximately 100 mV for testing membrane electrode assemblies having catalysts including ruthenium.

34. The fuel cell resistance test system of claim 23 wherein the current source produces the defined current such that the resulting voltage is approximately 200 mV for testing membrane electrode assemblies having catalysts not including ruthenium.

35. The fuel cell resistance test system of claim 23 wherein the current source produces the defined current such that the resulting voltage is between approximately 100 mV and 300 mV for testing membrane electrode assemblies having catalysts including ruthenium.

36. The fuel cell resistance test system of claim 23 wherein the current source produces the defined current such that the resulting voltage is between approximately 200 mV and 400 mV for testing membrane electrode assemblies having catalysts not including ruthenium.

37. A method of testing fuel cell stacks, comprising:

simultaneously coupling a plurality of spaced pairs of electrical contacts to respective portions of a fuel cell stack;

successively applying a defined current through each respective pair of the electrical contacts;

measuring a respective voltage across resulting from each of the applied defined voltages across adjacent ones of the pairs of electrical contacts before reaching a steady state condition; and

determining whether a short exists based on the defined currents and the resulting voltages.

38. The method of claim 37 wherein at least a portion of each of the electrical contacts are co-planar and simultaneously coupling a plurality of spaced electrical contacts to respective portions of a fuel cell stack includes moving the fuel cell stack along a linear guide toward a plane defined by the co-planar portions of the electrical contacts.

39. The method of claim 37 wherein determining whether a short exists based on the defined voltages and the resulting currents includes:

determining whether the magnitude of the resulting voltage is within an acceptable resulting voltage range for the defined current.

40. The method of claim 37 wherein determining whether a short exists based on the defined currents and the resulting voltages includes:

determining a resistance based on the magnitude of the defined current and the magnitude of the resulting voltage and;

determining whether the determined resistance is within an acceptable resistance range for the defined current.