Multi-point fuel cell voltage monitor

• US 9,911,995 B2
• Filed: 02/17/2015
• Issued: 03/06/2018
• Est. Priority Date: 12/24/2007
• Status: Active Grant

• Current Assignee: Audi AG (Volkswagen AG)
• Original Assignee: Audi AG (Volkswagen AG)
• Inventors: Reiser, Carl A.
• Primary Examiner(s): HARRIS, GARY D
• Application Number:
  US14/624,394
• Publication Number:
  US 20150162630A1
• Time in Patent Office: 1,113 Days
• Field of Search: 429479
• CPC Class Codes: H01M 8/04552 of the individual fuel cell
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04671 of the individual fuel cell
• CPC Class Codes: H01M 8/04679 of fuel cell stacks
• CPC Class Codes: H01M 8/04701 Temperature
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/04768 of the coolant
• CPC Class Codes: H01M 8/0494 of fuel cell stacks
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A fuel cell voltage monitor (12a, 12b, 40, 140, 440) detects and may respond to, a problematic operating condition at or near a fuel cell (10) or within a subset (n) of fuel cells, as in a fuel cell stack assembly (110). Two or more co-planar, spaced voltage leads or contacts in a fuel cell plane, as at a separator plate, detect the presence of a voltage difference within the plate/plane as an indication of an operating problem at or near the fuel cell. Placement of such arrangements of at least two spaced voltage leads at various subset intervals (n), of fuel cells in a stack assembly allow monitoring for such problems throughout the stack assembly, either by analysis of voltage difference between co-planar leads at respective individual fuel cells or by comparison of voltage differences between aligned pairs of voltage leads at opposite ends of a subset.

Claims

1. A system, comprising:

a rectilinearly-shaped fuel cell, including;

an anode;

a cathode;

an electrolyte between the anode and the cathode;

an anode plate; and

a cathode plate, the anode and cathode being between the anode plate and the cathode plate, at least one of the cathode plate and the anode plate including a first lead and a second lead, the first and second leads spaced from each other and positioned at opposite corners of a same side of the at least one of the cathode plate and the anode plate; and

a comparator coupled to the first and second leads to compare voltages detected from the first and second leads.

2. The system of claim 1 wherein the first and second leads are electrically and physically in contact with the cathode plate.

3. The system of claim 1 wherein the first and second leads are electrically and physically in contact with the anode plate.

4. The system of claim 1, further comprising:

a plurality of rectilinearly-shaped fuel cells arranged in a stack, at least one of the cathode plate and the anode plate of at least one of the plurality of rectilinearly-shaped fuel cells including the first lead and the second lead.

5. The system of claim 1, further comprising:

a threshold detector, the threshold detector configured to output a signal when the voltages detected from the first and second leads exceed a threshold voltage.

6. A device, comprising:

a fuel cell that includes a plurality of stacked elements, each of the elements being rectilinearly-shaped, the plurality of stacked elements including an anode, a cathode, an electrolyte, an anode plate, and a cathode plate; and

a voltage monitor coupled to a first lead extending from a first one of the elements and coupled to a second lead extending from the first one of the elements, the first lead and the second lead being positioned at opposite corners of a same side of the first one of the elements.

7. The device of claim 6 wherein the first and second leads are electrically and physically in contact with the anode plate.

8. The device of claim 6 wherein the voltage monitor is coupled to a third lead extending from a second one of the elements and coupled to a fourth lead extending from the second one of the elements, the third lead and the fourth lead being positioned at opposite corners of a same side of the second one of the elements.

9. The device of claim 8 wherein the voltage monitor includes a first comparator coupled to the first and second leads and a second comparator coupled to the third and fourth leads.

10. The device of claim 8 wherein the voltage monitor includes a first comparator coupled to the first and third leads and a second comparator coupled to the second and fourth leads.

11. The device of claim 9 wherein the first and second comparators are coupled to a threshold detector.

12. The device of claim 10 wherein the first and second comparators are coupled to a threshold detector.

13. A system, comprising:

a fuel cell including a plurality of elements, the plurality of elements including;

an anode;

a cathode;

an anode plate; and

a cathode plate, a first one of the elements being rectilinearly-shaped and having a first side, the first side having a first corner spaced from a second corner, a first lead extending from the first side at the first corner and a second lead extending from the first side at the second corner; and

a voltage monitor coupled to the first and second leads to compare voltages detected from the first and second leads.

14. The system of claim 13 wherein a second one of the elements is rectilinearly-shaped and has a second side, the second side having a third corner spaced from a fourth corner, a third lead extending from the second side at the third corner and a fourth lead extending from the second side at the fourth corner.

15. The system of claim 14 wherein the voltage monitor includes a first comparator coupled to the first and second leads and a second comparator coupled to the third and fourth leads.

16. The system of claim 14 wherein the voltage monitor includes a first comparator coupled to the first and third leads and a second comparator coupled to the second and fourth leads.

17. The system of claim 15 wherein the first and second comparators are coupled to a threshold detector.

18. The system of claim 16 wherein the first and second comparators are coupled to a threshold detector.

19. A method, comprising:

monitoring a fuel cell including a plurality of elements, the plurality of elements including an anode, a cathode, an anode plate, and a cathode plate, a first one of the elements being rectilinearly-shaped and having a first side, the first side having a first corner spaced from a second corner, a first lead extending from the first side at the first corner and a second lead extending from the first side at the second corner, the monitoring including;

detecting a voltage of the first and second leads;

comparing a voltage differential between the first and second leads with a comparator; and

providing a first output signal responsive to the voltage differential between the first and second leads to a threshold detector.

20. The method of claim 19, further comprising:

regulating operation of the fuel cell, the regulating including;

comparing the first output signal of the voltage differential with a threshold voltage; and

providing a second output signal to the fuel cell from the threshold detector when the voltage differential exceeds the threshold voltage.