Systems and methods for detecting ultracapacitor cell short circuits

• US 9,037,424 B2
• Filed: 05/01/2012
• Issued: 05/19/2015
• Est. Priority Date: 05/01/2012
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Knitt, Andrew A., Kwok, Wellington Ying-Wei, Wang, Kaiyu, Dos Santos Ramos, Igor
• Primary Examiner(s): Le, John H
• Application Number:
  US13/461,193
• Publication Number:
  US 20130297237A1
• Time in Patent Office: 1,113 Days
• Field of Search: 702/58, 702/59, 702/64, 702/185, 324/76.11, 320/167
• US Class Current: 702/59
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G01R 31/64 Testing of capacitors

Abstract

A system for detecting a short-circuited ultracapacitor cell in a machine is disclosed. The system may have a memory that stores instructions and one or more processors capable of executing the instructions. The one or more processors may be configured to perform cell balancing among ultracapacitor cells arranged within two or more ultracapacitor modules, each ultracapacitor module including at least two ultracapacitor cells connected in series. The one or more processors may be further configured to measure a module voltage generated by each of the plurality of ultracapacitor modules after performing the cell balancing and before applying a load of the machine to the ultracapacitor modules, and determine whether an ultracapacitor cell among the plurality of ultracapacitor cells is short-circuited based on a comparison of the measured module voltages.

Claims

1. A computer-implemented method for detecting a short-circuited ultracapacitor cell on a machine, the method comprising:

performing, by one or more processors, cell balancing among a plurality of ultracapacitor cells arranged within a plurality of ultracapacitor modules, each ultracapacitor module including at least two ultracapacitor cells connected in series;

measuring, by the one or more processors, a module voltage generated by each of the plurality of ultracapacitor modules after performing the cell balancing and prior to applying a load of the machine to the ultracapacitor modules; and

determining, by the one or more processors, that an ultracapacitor cell among the plurality of ultracapacitor cells is short-circuited when a module unbalanced voltage exceeds a threshold voltage, the module unbalanced voltage being equal to a difference between a maximum module voltage and a minimum module voltage determined from among the measured module voltages.

2. The computer-implemented method according to claim 1, further including:

identifying the module corresponding to the minimum module voltage as the module that includes the ultracapacitor cell that is short-circuited; and

generating data for indicating that the module corresponding to the minimum module voltage includes the ultracapacitor cell that is short-circuited.

3. A computer-implemented method for detecting a short-circuited ultracapacitor cell on a machine, the method comprising:

performing, by one or more processors, cell balancing among a plurality of ultracapacitor cells arranged within a plurality of ultracapacitor modules, each ultracapacitor module including at least two ultracapacitor cells connected in series;

measuring, by the one or more processors, a module voltage generated by each of the plurality of ultracapacitor modules after performing the cell balancing and prior to applying a load of the machine to the ultracapacitor modules;

determining, by the one or more processors, whether an ultracapacitor cell among the plurality of ultracapacitor cells is short-circuited based on a comparison of the measured module voltages;

calculating, by the one or more processors, an average module voltage that is an average of two or more of the measured module voltages; and

calculating, by the one or more processors, a probability value for each module based on a difference between the average module voltage and the measured module voltage for that module, the probability value representing a probability that the ultracapacitor cell that is short-circuited is included in that module.

4. The computer-implemented method according to claim 3, further including:

identifying the module with the highest probability value as the module that includes the ultracapacitor cell that is short-circuited.

5. The computer-implemented method according to claim 3, the probability value for each module being calculated according to:

6. A computer-implemented method for detecting a short-circuited ultracapacitor cell on a machine, the method comprising:

performing, by one or more processors, cell balancing among a plurality of ultracapacitor cells arranged within a plurality of ultracapacitor modules, each ultracapacitor module including at least two ultracapacitor cells connected in series;

measuring, by the one or more processors, a module voltage generated by each of the plurality of ultracapacitor modules after performing the cell balancing and prior to applying a load of the machine to the ultracapacitor modules;

determining, by the one or more processors, whether an ultracapacitor cell among the plurality of ultracapacitor cells is short-circuited based on a comparison of the measured module voltages;

determining, by the one or more processors, a reason why the cell balancing is required; and

counting, by the one or more processors, a number of times that the cell balancing is required because of the reason.

7. A system for detecting a short-circuited ultracapacitor cell on a machine, the system comprising:

a non-transitory computer-readable memory storing instructions; and

one or more processors capable of executing the instructions and configured to;

perform cell balancing among a plurality of ultracapacitor cells arranged within a plurality of ultracapacitor modules, each ultracapacitor module including at least two ultracapacitor cells connected in series;

measure a module voltage generated by each of the plurality of ultracapacitor modules after performing the cell balancing and before applying a load of the machine to the ultracapacitor modules; and

determine that an ultracapacitor cell among the plurality of ultracapacitor cells is short-circuited when a module unbalanced voltage exceeds a threshold voltage, the module unbalanced voltage being equal to a difference between a maximum module voltage and a minimum module voltage determined from among the measured module voltages.

8. The system according to claim 7, the one or more processors being further configured to:

identify the module corresponding to the minimum module voltage as the module that includes the ultracapacitor cell that is short-circuited; and

generate data for indicating that the module corresponding to the minimum module voltage includes the ultracapacitor cell that is short-circuited.

9. The system according to claim 7, further including the plurality of ultracapacitor modules.

10. A system for detecting a short-circuited ultracapacitor cell on a machine, the system comprising:

a non-transitory computer-readable memory storing instructions; and

one or more processors capable of executing the instructions and configured to;

perform cell balancing among a plurality of ultracapacitor cells arranged within a plurality of ultracapacitor modules, each ultracapacitor module including at least two ultracapacitor cells connected in series;

measure a module voltage generated by each of the plurality of ultracapacitor modules after performing the cell balancing and before applying a load of the machine to the ultracapacitor modules;

determine whether an ultracapacitor cell among the plurality of ultracapacitor cells is short-circuited based on a comparison of the measured module voltages;

calculate an average module voltage that is an average of two or more of the measured module voltages; and

calculate a probability value for each module based on a difference between the average module voltage and the measured module voltage for that module, the probability value representing a probability that the ultracapacitor cell that is short-circuited is included in that module.

11. The system according to claim 10, the one or more processors being further configured to:

identify the module with the highest probability value as the module that includes the ultracapacitor cell that is short-circuited.

12. The system according to claim 10, the probability value for each module being calculated according to:

13. A system for detecting a short-circuited ultracapacitor cell on a machine, the system comprising:

a non-transitory computer-readable memory storing instructions; and

one or more processors capable of executing the instructions and configured to;

perform cell balancing among a plurality of ultracapacitor cells arranged within a plurality of ultracapacitor modules, each ultracapacitor module including at least two ultracapacitor cells connected in series;

measure a module voltage generated by each of the plurality of ultracapacitor modules after performing the cell balancing and before applying a load of the machine to the ultracapacitor modules;

determine whether an ultracapacitor cell among the plurality of ultracapacitor cells is short-circuited based on a comparison of the measured module voltages;

determine a reason why the cell balancing is required; and

maintain a counter that counts a number of times that the cell balancing is required because of the reason.

14. A non-transitory computer-readable storage device storing instructions that, when executed, enable one or more processors to:

perform cell balancing among a plurality of ultracapacitor cells arranged within a plurality of ultracapacitor modules, each ultracapacitor module including at least two ultracapacitor cells connected in series;

measure a module voltage generated by each of the plurality of ultracapacitor modules after performing the cell balancing and before applying a load of a machine to the ultracapacitor modules; and

determine that an ultracapacitor cell among the plurality of ultracapacitor cells is short-circuited when a module unbalanced voltage exceeds a threshold voltage, the module unbalanced voltage being equal to a difference between a maximum module voltage and a minimum module voltage determined from among the measured module voltages.

15. The non-transitory computer-readable storage device according to claim 14, the instructions further enabling the one or more processors to:

identify the module corresponding to the minimum module voltage as the module that includes the ultracapacitor cell that is short-circuited; and

generate data for indicating that the module corresponding to the minimum module voltage includes the ultracapacitor cell that is short-circuited.

16. A non-transitory computer-readable storage device storing instructions that, when executed, enable one or more processors to:

perform cell balancing among a plurality of ultracapacitor cells arranged within a plurality of ultracapacitor modules, each ultracapacitor module including at least two ultracapacitor cells connected in series;

measure a module voltage generated by each of the plurality of ultracapacitor modules after performing the cell balancing and before applying a load of a machine to the ultracapacitor modules;

determine whether an ultracapacitor cell among the plurality of ultracapacitor cells is short-circuited based on a comparison of the measured module voltages;

calculate an average module voltage that is an average of two or more of the measured module voltages; and

calculate a probability value for each module based on a difference between the average module voltage and the measured module voltage for that module, the probability value representing a probability that the ultracapacitor cell that is short-circuited is included in that module.

17. The non-transitory computer-readable storage device according to claim 16, the instructions further enabling the one or more processors to:

identify the module with the highest probability value as the module that includes the ultracapacitor cell that is short-circuited.