FAILURE DETERMINATION DEVICE FOR CELL VOLTAGE MONITOR

• US 20080208490A1
• Filed: 02/27/2008
• Published: 08/28/2008
• Est. Priority Date: 02/28/2007
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Matsumoto, Yuji, Ueda, Kenichiro, Uehara, Junji
• Granted Patent: US 7,962,297 B2
• Time in Patent Office: Days
• US Class Current: 702/58
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 35/00 Testing or calibrating of apparatus covered by the other groups of this subclass
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 8/04246 Short circuiting means for defective fuel cells detection of defective fuel cells H01M8/04664, methods for shunting fuel cells H01M8/04955
• CPC Class Codes: H01M 8/04358 of the coolant
• CPC Class Codes: H01M 8/04552 of the individual fuel cell
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04671 of the individual fuel cell
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A failure determination device for a cell voltage monitor which detects cell voltages of a plurality of single cells comprising a fuel cell stack comprises: a memory for storing cell voltages detected by the cell voltage monitor; a minimum value determination unit for determining whether or not a present cell voltage which the cell voltage monitor detects is equal to or lower than a minimum value cell voltage which is in a detectable range of the cell voltage monitor; a failure determination unit for determining that the cell voltage monitor has a failure when the minimum value determination unit determines that the present cell voltage is equal to or lower than the minimum value cell voltage, and a cell voltage detected by the cell voltage monitor in the past and stored in the memory is greater than a determination cell voltage.

Claims

1. A failure determination device for a cell voltage monitor which detects cell voltages of a plurality of single cells connected in series at a predetermined interval, the device comprising:

a memory for storing the cell voltages detected by the cell voltage monitor;

a minimum value determination unit for determining whether or not a present cell voltage detected by the cell voltage monitor is equal to or lower than a minimum value cell voltage which is in a detectable range of the cell voltage monitor; and

a failure determination unit for determining that the cell voltage monitor has a failure when the minimum value determination unit determines that the present cell voltage is equal to or lower than the minimum value cell voltage, and a cell voltage detected by the cell voltage monitor in a past and stored in the memory is higher than a determination cell voltage, wherein

the determination cell voltage is higher than the minimum value cell voltage by a predetermined value.

2. The failure determination device for a cell voltage monitor according to claim 1, further comprising a determination cell voltage setting unit which sets the determination cell voltage on a basis of a total output.

3. The failure determination device for a cell voltage monitor according to claim 1, further comprising a determination cell voltage setting unit which sets the determination cell voltage on a basis of a temperature of a plurality of single cells as a whole.

4. The failure determination device for a cell voltage monitor according to claim 1, wherein the failure determination unit carries out a failure determination on a basis of a cell voltage detected just before the failure determination, out of a plurality of cell voltages stored in the memory in a past.

5. The failure determination device for a cell voltage monitor according to claim 1, wherein the failure determination unit does not determine whether or not the cell voltage monitor has a failure when a cell voltage detected just before a failure determination is unstable.

6. The failure determination device for a cell voltage monitor according to claim 1, wherein a plurality of single cells comprises a fuel cell.

7. The failure determination device for a cell voltage monitor according to claim 1, wherein a cell voltage is set based on a voltage value of a pair of single cells.

8. The failure determination device for a cell voltage monitor according to claim 1, wherein a cell voltage is set based on an averaged voltage value of a set of detected cell voltages.

9. The failure determination device for a cell voltage monitor according to claim 1, wherein the device associates all single cells with a number and uses a flag when a single cell has a failure, wherein the device stores an associated number of the damaged single cell and continues a failure determination process without detecting a cell voltage of the damaged single cell until a predetermined number of damaged single cells is counted, and wherein the device determines that the cell voltage monitor has a failure.

10. The failure determination device for a cell voltage monitor according to claim 1, wherein the device determines that a cell voltage monitor has a failure when single cells have a failure at predetermined times in a row.

11. The failure determination device for a cell voltage monitor according to claim 1, wherein the device selects a lowest cell voltage out of a plurality of cell voltages detected by a cell voltage monitor in a past and stored by a memory at predetermined times just before a failure determination, and wherein the device determines whether or not the lowest cell voltage is higher than a determination cell voltage.

12. A failure determination device for a cell voltage monitor which detects cell voltages of a plurality of single cells connected in series at a predetermined interval, the device comprising:

a memory for storing a cell voltage detected by the cell voltage monitor;

a minimum value determination unit for determining whether or not a present cell voltage detected by the cell voltage monitor is equal to or lower than a minimum value cell voltage which is in a detectable range of the cell voltage monitor; and

a failure determination unit for determining that the cell voltage monitor has a failure when the minimum value determination unit determines that the present cell voltage is equal to or lower than the minimum value cell voltage, and a potential difference between the minimum value cell voltage and a cell voltage detected by the cell voltage monitor in a past and stored in the memory is higher than a determination cell potential difference.

13. The failure determination device for a cell voltage monitor according to claim 12, further comprising a determination cell potential difference setting unit which sets the determination cell potential difference on a basis of a total output.

14. The failure determination device for a cell voltage monitor according to claim 12, further comprising a determination cell potential difference setting unit which sets the determination cell potential difference on a basis of a temperature of a plurality of single cells as a whole.

15. The failure determination device for a cell voltage monitor according to claim 12, wherein the failure determination unit carries out a failure determination on a basis of a cell voltage detected just before the failure determination, out of a plurality of cell voltages stored in the memory in a past.

16. The failure determination device for a cell voltage monitor according to claim 12, wherein the failure determination unit does not determine whether or not the cell voltage monitor has a failure when a cell voltage detected just before a failure determination is unstable.

17. The failure determination device for a cell voltage monitor according to claim 12, wherein a plurality of single cells comprises a fuel cell.

18. The failure determination device for a cell voltage monitor according to claim 12, wherein the device compares a determination cell potential difference with a potential difference lied between a minimum value cell voltage and a lowest cell voltage out of a plurality of cell voltages detected at predetermined times just before a failure determination when a cell voltage detected just before the failure determination is unstable, and wherein the device determines whether or not a cell voltage monitor has a failure.

19. A method for determining a failure of a cell voltage monitor which detects cell voltages of a plurality of single cells connected in series at a predetermined interval, the method comprising the steps of:

storing the cell voltages detected by the cell voltage monitor;

determining whether or not a present cell voltage detected by the cell voltage monitor is equal to or lower than a minimum value cell voltage which is in a detectable range of the cell voltage monitor; and

determining that the cell voltage monitor has a failure when the minimum value determination unit determines that the present cell voltage is equal to or lower than the minimum value cell voltage, and a cell voltage detected by the cell voltage monitor in a past and stored in the memory is higher than a determination cell voltage, wherein

the determination cell voltage is higher than the minimum value cell voltage by a predetermined value.

20. A method of determining a failure of a cell voltage monitor which detects cell voltages of a plurality of single cells connected in series at a predetermined interval, the method comprising the steps of:

storing a cell voltage detected by the cell voltage monitor;

determining whether or not a present cell voltage detected by the cell voltage monitor is equal to or lower than a minimum value cell voltage which is in a detectable range of the cell voltage monitor; and

determining that the cell voltage monitor has a failure when the minimum value determination unit determines that the present cell voltage is equal to or lower than the minimum value cell voltage, and a potential difference between the minimum value cell voltage and a cell voltage detected by the cell voltage monitor in a past and stored in the memory is higher than a determination cell potential difference.