Method of Testing an Electrochemical Device

• US 20080238430A1
• Filed: 03/24/2005
• Published: 10/02/2008
• Est. Priority Date: 03/26/2004
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Power Quality Corporation (Eaton Corporation PLC.)
• Inventors: Al-Anbuky, Adnan, Krumdieck, Susan Pran, Page, Shannon Charles
• Granted Patent: US 8,125,193 B2
• Time in Patent Office: Days
• US Class Current: 324/425
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: G01R 31/64 Testing of capacitors
• CPC Class Codes: H01M 8/04305 Modeling, demonstration models of fuel cells, e.g. for training purposes
• CPC Class Codes: H01M 8/04552 of the individual fuel cell
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

Methods and associated apparatus for testing an electrochemical device, such as a fuel cell. A first method involves charging the fuel cell during a charge period; discharging the fuel cell during a discharge period; and monitoring the response of the fuel cell during at least part of the discharge period or the open-circuit response of the fuel cell. Another method involves testing the fuel cell when the fuel cell is in a passive state in which substantially no electrochemical reactions are taking place in the fuel cell. simultaneously applying a stimulus to all of the devices, and independently monitoring the response of each of the devices to the stimulus. Further methods involve obtaining test data from a device being tested; obtaining equivalent circuit values; calculating sets of simulation data for each equivalent circuit value; comparing sets of simulation data with the test data; and selecting one of the equivalent circuit values based on the comparison. This method allows all circuit parameters of each cell in a stack to be obtained from only one quick test.

Claims

1. A method of testing a fuel cell, the method including charging the fuel cell during a charge period;

discharging the fuel cell during a discharge period; and

monitoring the response of the fuel cell during at least part of the discharge period.

2. A method according to claim 1 wherein the response of the fuel cell is monitored by monitoring a step change in the voltage across the fuel cell during the at least part of the discharge period.

3. A method according to claim 1 further including making the fuel cell open-circuit after the charge period, and monitoring the open-circuit response of the fuel cell.

4. A method according to claim 1 wherein the fuel cell is discharged during the at least part of the discharge period through one or more passive test components.

20. Apparatus for testing an electrochemical device, the apparatus being programmed to perform a method according to claim 1.

5. A method of testing a fuel cell, the method including charging the fuel cell during a charge period;

and after the charge period making the fuel cell open-circuit and monitoring the open-circuit response of the fuel cell.

6. A method according to claim 5 wherein the open-circuit response of the fuel cell is monitored by monitoring the rate of change of voltage across the fuel cell.

7. A method according to claim 5 further including calculating one or more equivalent circuit values in accordance with the monitored response of the fuel cell.

8. A method of testing a fuel cell, the method including testing the fuel cell when the fuel cell is in a passive state in which substantially no electrochemical reactions are taking place in the fuel cell.

9. A method of testing two or more electrochemical devices, the method including simultaneously applying a stimulus to all of the devices, and independently monitoring the response of each of the devices to the stimulus.

10. A method according to claim 9 further including calculating one or more equivalent circuit parameters for each device in accordance with the monitored response of the respective device.

11. A method according to claim 9 wherein the devices are fuel cells or double-layer capacitors.

12. A method of testing an electrochemical device, the method including obtaining test data from the device;

obtaining two or more equivalent circuit values;

calculating a respective set of simulation data for each equivalent circuit value;

comparing each set of simulation data with the test data; and

selecting one of the equivalent circuit values based on the comparison.

13. A method according to claim 12 wherein each equivalent circuit value is a parameter indicative of the value of a circuit component in an equivalent circuit model.

14. A method according to claim 12 wherein each equivalent circuit value is a condition indicative of an initial value of a time varying circuit condition.

15. A method according to claim 14 wherein the time varying circuit condition is a voltage.

16. A method according to claim 12 wherein the device is a fuel cell or double-layer capacitor.

17. A method of testing an electrochemical device, the method including obtaining test data from the device;

and calculating equivalent circuit parameters from the test data;

wherein the equivalent circuit parameters includes a. one or more values, each being indicative of the value of a circuit component in an equivalent circuit model, and b. one or more conditions, each condition being indicative of an initial value of a time varying circuit condition.

18. A method according to claim 17 wherein the time varying circuit condition is a voltage.

19. A method according to claim 17 wherein the device is a fuel cell or double-layer capacitor.