Battery insulation resistance measurement methods, insulation resistance measurement methods, insulation resistance determination apparatuses, and articles of manufacture

• US 8,421,467 B2
• Filed: 11/19/2009
• Issued: 04/16/2013
• Est. Priority Date: 11/19/2009
• Status: Active Grant

• Current Assignee: Lithion Battery Incorporated
• Original Assignee: Valence Technology Incorporated (Lithium Werks B.V.)
• Inventors: Klijn, Arun
• Primary Examiner(s): WILLIAMS, ARUN C
• Application Number:
  US12/622,134
• Publication Number:
  US 20110115490A1
• Time in Patent Office: 1,244 Days
• Field of Search: 324/430
• US Class Current: 324/430
• CPC Class Codes: G01R 27/025 Measuring very high resistances, e.g. isolation resistances, i.e. megohm-meters
• CPC Class Codes: G01R 27/18 Measuring resistance to earth , i.e. line to ground
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Battery insulation resistance measurement methods, insulation resistance measurement methods, insulation resistance determination apparatuses, and articles of manufacture are described. According to one aspect, a battery insulation resistance measurement method includes determining a voltage of a battery, determining a voltage of a first terminal of the battery with respect to a ground reference, determining a voltage of a second terminal of the battery with respect to the ground reference, and using the voltages of the battery, the first terminal and the second terminal, determining an insulation resistance of the battery with respect to the ground reference.

Claims

1. A battery insulation resistance measurement method comprising:

determining a voltage of a battery;

determining a voltage of a first terminal of the battery with respect to a ground reference;

determining a voltage of a second terminal of the battery with respect to the ground reference;

using the voltages of the battery, the first terminal and the second terminal, determining an insulation resistance of the battery with respect to the ground reference; and

wherein the determining the voltage of the battery comprises summing voltages of respective ones of the first and second terminals of the battery with respect to the ground reference after the determining the voltage of the first terminal and after the determining the voltage of the second terminal.

2. The method of claim 1 wherein the determining the insulation resistance of the battery comprises determining the insulation resistance of at least one of the first and second terminals with respect to the ground reference.

3. The method of claim 2 wherein the determining the insulation resistance of the at least one of the first and second terminals comprises determining using the voltages of the battery, the first terminal and the second terminal.

4. The method of claim 2 wherein the determining the insulation resistance of the at least one of the first and second terminals comprises determining the insulation resistance of each of the first and second terminals with respect to the ground reference.

5. The method of claim 4 wherein the determining the insulation resistance further comprises determining the parallel equivalent resistance of the insulation resistances of the first and second terminals with respect to the ground reference.

6. An insulation resistance measurement method comprising:

controlling a coupling of a first known resistance between a first terminal of a battery and a ground reference;

determining a voltage of a second terminal of the battery with respect to the ground reference with the first known resistance coupled between the first terminal of the battery and the ground reference;

controlling a coupling of a second known resistance between the second terminal of the battery and the ground reference;

determining a voltage of the first terminal of the battery with respect to the ground reference with the second known resistance coupled between the second terminal of the battery and the ground reference; and

using the voltages of the first terminal and the second terminal, determining an insulation resistance of the battery with respect to the ground reference.

7. The method of claim 6 further comprising de-coupling the first known resistance after the determining the voltage of the second terminal of the battery and de-coupling the second known resistance after the determining the voltage of the first terminal of the battery, and wherein the determining the voltage of the second terminal comprises determining with the second known resistance de-coupled from the second terminal and the determining the voltage of the first terminal comprises determining with the first known resistance de-coupled from the first terminal.

8. The method of claim 6 wherein the determining the voltage of the first terminal comprises determining without the first known resistance coupled with the first terminal and the determining the voltage of the second terminal comprises determining without the second known resistance coupled with the second terminal.

9. The method of claim 6 further comprising:

comparing the insulation resistance of the first terminal with respect to a threshold; and

generating an alarm as a result of the insulation resistance of the first terminal triggering the threshold.

10. The method of claim 6 further comprising:

comparing the insulation resistance of the battery with respect to a threshold; and

generating an alarm as a result of the insulation resistance of the battery triggering the threshold.

11. An insulation resistance measurement method comprising:

determining an insulation resistance of a first terminal of a battery with respect to a ground reference;

determining an insulation resistance of a second terminal of the battery with respect to the ground reference;

using the insulation resistances of the first and second terminals of the battery with respect to the ground reference, determining an insulation resistance of the battery with respect to the ground reference; and

wherein the determining the insulation resistances of the first terminal, the second terminal and the battery with respect to the ground reference individually comprise calculating the insulation resistance.

12. The method of claim 11 wherein the determining the insulation resistance of the battery comprises determining the parallel equivalent resistance of the insulation resistances of the first and second terminals with respect to the ground reference.

13. An insulation resistance determination apparatus comprising:

processing circuitry configured to access a voltage of a battery with respect to a ground reference, to access a voltage of a first terminal of the battery with respect to the ground reference, to access a voltage of a second terminal of the battery with respect to the ground reference, and to determine an insulation resistance of the first terminal with respect to the ground reference using the voltage of the battery with respect to the ground reference, the voltage of the first terminal of the battery with respect to the ground reference, and the voltage of the second terminal of the battery with respect to the ground reference; and

wherein the processing circuitry is configured to sum voltages of the first and second terminals of the battery with respect to the ground reference to calculate the voltage of the battery after the accessing the voltage of the first terminal and after the accessing the voltage of the second terminal.

14. The apparatus of claim 13 wherein the processing circuitry is configured to determine an insulation resistance of the second terminal with respect to the ground reference.

15. The apparatus of claim 14 wherein the processing circuitry is configured to determine an insulation resistance of the battery with respect to the ground reference using the insulation resistances of the first and second terminals.

16. The apparatus of claim 13 further comprising known resistance circuitry configured to couple a known resistance with the first terminal during the accessing of the voltage of the second terminal and to couple a known resistance with the second terminal during the accessing of the voltage of the first terminal.

17. An article of manufacture comprising:

non-transitory media comprising programming configured to cause processing circuitry to perform processing comprising;

determine a first voltage of a first terminal of a battery;

determine a first voltage of a second terminal of the battery;

determine a voltage of the battery using the first voltages of the first and second terminals;

determine a second voltage of the first terminal with a resistance coupled with the second terminal;

determine a second voltage of the second terminal with the resistance coupled with the first terminal; and

determine an insulation resistance of the battery using the voltage of the battery and the second voltages of the first and second terminals.

18. The article of claim 17 wherein the determining the voltage of the battery comprises summing the first voltages of the first and second terminals after the determining the first voltages of the first and second terminals.

19. The article of claim 17 wherein the determining the insulation resistance comprises determining the insulation resistance for at least one of the first and the second terminals.

20. The article of claim 19 wherein the determining the insulation resistance comprises determining the insulation resistance for both of the first and the second terminals.

21. The article of claim 20 wherein the determining the insulation resistance comprises determining the insulation resistance of the battery using the insulation resistances of the first and second terminals.

22. The article of claim 17 wherein the programming is configured to cause processing circuitry to perform processing comprising de-coupling the resistance from the second terminal after the determining the second voltage of the first terminal and de-coupling the resistance from the first terminal after the determining the second voltage of the second terminal, and wherein the determining the second voltage of the first terminal comprises determining with the resistance de-coupled from the first terminal and the determining the second voltage of the second terminal comprises determining with the resistance de-coupled from the second terminal.

23. The article of claim 22 wherein the determinings of the first voltages of the first and second terminals comprise determining without the resistance coupled with the first and second terminals.

24. The article of claim 17 wherein the programming is configured to cause processing circuitry to perform processing comprising controlling coupling of different resistances with respective ones of the first and second terminals during the determinings of the first voltages of the first and second terminals, and de-coupling the different resistances from the first and second terminals after the determinings of the first voltages of the first and second terminals.