FUEL CELL SYSTEM AND FUEL CELL STATUS DETECTION METHOD

• US 20110151347A1
• Filed: 08/19/2009
• Published: 06/23/2011
• Est. Priority Date: 08/20/2008
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Araki, Yasushi
• Granted Patent: US 9,337,504 B2
• Time in Patent Office: Days
• US Class Current: 429/431
• CPC Class Codes: H01M 8/04358 of the coolant
• CPC Class Codes: H01M 8/04552 of the individual fuel cell
• CPC Class Codes: H01M 8/04582 of the individual fuel cell
• CPC Class Codes: H01M 8/04671 of the individual fuel cell
• CPC Class Codes: H01M 8/04992 characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A fuel cell system (100) is provided with a voltage detection device (41) that detects a cell voltage of a cell group containing one or more cells (11), a current density detection device (42) that detects a generated current density of the cell group, and a determination portion (52) that determines the presence or absence of an inflection point of a change in the cell voltage relative to the generated current density based on the detection results of the voltage detection device and the current density detection device.

Claims

1. (canceled)

17. A method for detecting the status of a fuel cell, comprising:

a voltage detection step of detecting a cell voltage of a cell group containing one or more cells;

a current density detection step of detecting a generated current density of the cell group; and

a determination step of determining the presence or absence of an inflection point of a change in the cell voltage relative to the generated current density based on the detection results in the voltage detection step and the current density detection step.

18. The status detection method according to claim 17, wherein

in the determination step, the presence or absence of the inflection point is determined based on the difference between a primary regression voltage of the cell voltage of the cell group and the voltage detected in the voltage detection step under prescribed conditions.

19. The status detection method according to claim 17, wherein

in the determination step, the presence or absence of the inflection point in the cell group is determined using the relationship between the cell voltage of the cell group and a standard voltage of a standard cell group containing one or more cells.

20. The status detection method according to claim 19, wherein

in the determination step, the inflection point is determined to be present in the case the slope of the cell voltage of the cell group relative to the current density has become larger than the slope of the standard voltage of the standard cell group relative to the current density by a prescribed amount.

21. The status detection method according to claim 19, wherein

in the determination step, the presence or absence of the inflection point is determined in a rate of divergence between the cell voltage of the cell group and the standard voltage of the standard cell group at the same current density.

22. The status detection method according to claim 21, wherein

in the determination step, the inflection point is determined to be present in the case the slope of the rate of divergence relative to the current density has become negative.

23. The status detection method according to claim 21, wherein

in the determination step, the inflection point is determined to be present in the case an intercept of a regression line of the rate of divergence relative to the current density is equal to or greater than a prescribed value.

24. The status detection method according to claim 19, wherein

the standard cell group has higher power generation performance than the average power generation performance in a fuel cell stack.

25. The status detection method according to claim 19, wherein

the standard cell group has higher power generation durability than the average power generation durability in a fuel cell stack.

26. A fuel cell system comprising:

a voltage detection device that detects a cell voltage of a cell group containing one or more cells;

a current density detection device that detects a generated current density of the cell group; and

a determination portion that determines the presence or absence of an inflection point of a change in the cell voltage relative to the generated current density based on the detection results of the voltage detection device and the current density detection device.

2. The fuel cell system according to claim 26, wherein

the determination portion determines the presence or absence of the inflection point based on the difference between a primary regression voltage of the cell voltage of the cell group and the voltage detected by the voltage detection device under prescribed conditions.

3. The fuel cell system according to claim 26, wherein

the inflection point is determined to be present when the voltage detected by the voltage detection device has become larger than the primary regression voltage of the cell voltage of the cell group.

4. The fuel cell system according to claim 2, wherein

the inflection point is determined to be present in the case the difference between the primary regression voltage of the cell voltage of the cell group and the voltage detected by the voltage detection device is equal to or greater than a prescribed value.

5. The fuel cell system according to claim 26, wherein

the determination portion determines the presence or absence of the inflection point in the cell group using the relationship between the cell voltage of the cell group and a standard voltage of a standard cell group containing one or more cells.

6. The fuel cell system according to claim 5, wherein

the determination portion determines the inflection point to be present in the case the slope of the cell voltage of the cell group relative to the current density has become larger than the slope of the standard voltage of the standard cell group relative to the current density by a prescribed amount.

7. The fuel cell system according to claim 5, wherein

the determination portion determines the presence or absence of the inflection point in the a rate of divergence between the cell voltage of the cell group and the standard voltage of the standard cell group at the same current density.

8. The fuel cell system according to claim 7, wherein

the determination portion determines the inflection point to be present in the case the slope of the rate of divergence relative to the current density has become negative.

9. The fuel cell system according to claim 7, wherein

the determination portion determines the inflection point to be present in the case an intercept of a regression line of the rate of divergence relative to the current density is equal to or greater than a prescribed value.

10. The fuel cell system according to claim 3, wherein

the standard cell group has higher power generation performance than the average power generation performance in a fuel cell stack.

11. The fuel cell system according to claim 10, wherein

the standard cell group is a cell group having the highest voltage among the cell groups in the fuel cell.

12. The fuel cell system according to claim 10, wherein

the standard cell group is a cell group having the fewest number of cells among the cell groups in the fuel cell.

13. The fuel cell system according to claim 3, wherein

the standard cell group has higher power generation durability than the average power generation durability in a fuel cell stack.

14. The fuel cell system according to claim 3, wherein

a cell group which is compared with the standard cell group is a cell group having the lowest voltage in a fuel cell stack.

15. The fuel cell system according to claim 26, wherein

the determination portion determines that an abnormality in the fuel cell is to be avoided when a prescribed condition is satisfied and determines the presence or absence of the inflection point.

16. The fuel cell system according to claim 15, wherein

the prescribed condition includes at least one of whether a temperature of a coolant flowing through the fuel cell is within a prescribed range, whether acceleration or deceleration of the cell voltage or generated current is within a prescribed range, and whether a reaction gas pressure within the fuel cell is less than a prescribed value.