Multi-point fuel cell voltage monitor
View Patent ↗A fuel cell voltage monitor ( 12 a , 12 b , 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.
1. A fuel cell voltage monitor ( 12 a , 12 b , 40 , 140 ), comprising:
a rectilinearly-shaped fuel cell ( 10 ) having a plurality of elements stacked in layered arrangement, said elements including an anode ( 14 , 14 a ), a cathode ( 16 , 16 a ), an electrolyte ( 18 ), and anode and cathode plates ( 22 , 20 ), the anode ( 14 , 14 a ) and cathode ( 16 , 16 a ) being on opposite sides of the electrolyte ( 18 ) and between the respective plates ( 22 , 20 );
first and second voltage leads ( 12 a , 12 b ) in electrical contact with a same one ( 22 , 14 ) of said elements and positioned in spaced apart (S) relation at diagonally opposite corners on the element to sense the respective voltages; and
voltage comparing circuitry ( 40 , 140 ) coupled to the first and second voltage leads ( 12 a , 12 b ) to compare the respective voltages and provide a signal ( 42 ) indicative of a difference in said respective voltages, said voltage difference associated with in-plane current flow related to an operating problem in the fuel cell ( 10 ).
2. The fuel cell voltage monitor ( 12 a , 12 b , 40 , 140 ) of claim 1 wherein said anode and cathode plates ( 22 , 20 ) are separator plates, and the first and second voltage leads ( 12 a , 12 b ) are in electrical and physical contact with one of said anode and cathode separator plates ( 22 , 20 ).
3. The fuel cell voltage monitor ( 12 a , 12 b , 40 , 140 ) of claim 2 wherein the first and second voltage leads ( 12 a , 12 b ) are in electrical and physical contact with the anode separator plate ( 22 ).
4. 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 diagonally spaced from each other at opposite corners;
a comparator coupled to the first and second leads to compare voltages detected from the first and second leads.
5. The system of claim 4 wherein the first and second leads are electrically and physically in contact with the cathode plate.
6. The system of claim 4 wherein the first and second leads are electrically and physically in contact with the anode plate.
7. 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 diagonally opposite corners of the first one of the elements.
8. The device of claim 7 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 diagonally opposite corners of the second one of the elements.
9. The device of claim 7 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 7 wherein the first and second comparators are coupled to a threshold detector.
11. The device of claim 7 wherein the first and second leads are electrically and physically in contact with the anode plate.
12. A system, comprising:
a fuel cell including a plurality of elements, the plurality of elements 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, a first one of the elements being rectilinearly-shaped and having a first corner that is diagonally spaced from a second corner, a first lead coupled to the first corner and a second lead coupled to the second corner; and
a voltage monitor coupled to the first and second leads to compare voltages detected from the first and second leads.
13. The system of claim 12 wherein a second one of the elements is rectilinearly-shaped and has a third corner that is diagonally spaced from a fourth corner, a third lead coupled to the third corner and a fourth lead coupled to the fourth corner.
14. The system of claim 13 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.