DIELECTRIC BREAKDOWN DETECTOR FOR HEV BATTERY APPLICATION

• US 20090212780A1
• Filed: 02/22/2008
• Published: 08/27/2009
• Est. Priority Date: 02/22/2008
• Status: Active Grant

• Current Assignee: Battery Patent Trust
• Original Assignee: Cobasys LLC (Robert Bosch GmbH)
• Inventors: Theofanopoulos, John, Lieske, John, Szuba, Stefan F., Galvin, Robert A., Anzicek, Joshua M.
• Granted Patent: US 8,129,999 B2
• Time in Patent Office: Days
• US Class Current: 324/426
• CPC Class Codes: G01R 31/1227 of components, parts or materials G01R31/1209, G01R31/1218, G01R31/18 take precedence; circuits therefor G01R31/14; testing vessels of electrodes G01R31/16
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A circuit that indicates an impedance of a battery dielectric includes a signal generator module that flows a first current from a ground to a first terminal of a battery. A sensor circuit generates a signal based on a second current that flows from a second terminal of the battery through a resistance to ground. The second current includes the first current and a third current that flows to ground via an impedance presented by a battery dielectric housing. A signal conversion module generates an output signal based on the signal. The output signal represents the impedance presented by the battery dielectric housing.

Claims

1. A circuit that indicates an impedance of a battery dielectric, comprising:

a signal generator module that flows a first current from a ground to a first terminal of a battery;

a sensor circuit that generates a signal based on a second current that flows from a second terminal of the battery through a resistance to ground, the second current including the first current and a third current that flows to ground via an impedance presented by a battery dielectric housing; and

a signal conversion module that generates an output signal based on the signal wherein the output signal represents the impedance presented by the battery dielectric housing.

2. The circuit of claim 1 wherein the output signal is one or more of a pulse width modulated signal, a period modulated signal, and a network message.

3. The circuit of claim 1 wherein the first current is alternating current.

5. The circuit of claim 1 further comprising an amplifier that amplifies the signal.

6. The circuit of claim 5 further comprising an isolated power supply that provides power to the amplifier and the signal conversion module.

7. The circuit of claim 6 wherein the isolated power supply comprises a switching power supply.

8. The circuit of claim 1 wherein the signal conversion module includes an analog to digital converter.

4. The circuit of claim 4 wherein a frequency of the alternating current is between one and two hertz.

9. A circuit that indicates an impedance of a battery dielectric, comprising:

a bias circuit that establishes a bias current through first and second terminals of a battery;

a sensor circuit that generates a signal based on the bias current and a leakage current that flows through an impedance presented by a dielectric housing of the battery; and

a signal conversion module that generates an output signal based on the signal wherein the output signal represents the impedance presented by the dielectric housing.

10. The circuit of claim 9 wherein the output signal is one or more of a pulse width modulated signal, a period modulated signal, and a network message.

11. The circuit of claim 9 wherein the bias circuit comprises a resistor.

12. The circuit of claim 11 wherein the sense circuit comprises a resistor that conducts the bias current and the leakage current.

13. The circuit of claim 9 further comprising an amplifier that amplifies the signal.

14. The circuit of claim 13 further comprising an isolated power supply that provides power to the amplifier and the signal conversion module.

15. The circuit of claim 14 wherein the isolated power supply includes a switching power supply.

16. The circuit of claim 9 further comprising a fault detection module that receives the output signal and that determines whether the impedance of the dielectric housing is greater than a threshold impedance, wherein the threshold impedance is based on a voltage of the battery.

18. The method of claim 9 wherein the output signal is one or more of a pulse width modulated signal, a period modulated signal, and a network message.

19. The method of claim 9 wherein establishing a bias current includes conducting the bias current through a resistor that is connected in series with the battery.

17. A method of indicating an impedance of a battery dielectric comprising:

establishing a bias current through first and second terminals of a battery;

generating a signal based on the bias current and a leakage current that flows through an impedance presented by a dielectric housing of the battery; and

generating an output signal based on the signal wherein the output signal represents the impedance presented by the dielectric housing.

20. A circuit that indicates an impedance of a battery dielectric, comprising:

bias circuit means for establishing a bias current through first and second terminals of a battery;

sensor circuit means for generating a signal based on the bias current and a leakage current that flows through an impedance presented by a dielectric housing of the battery; and

signal conversion means for generating an output signal based on the signal wherein the output signal represents the impedance presented by the dielectric housing.

21. The circuit of claim 20 wherein the output signal is one or more of a pulse width modulated signal, a period modulated signal, and a network message.

22. The circuit of claim 20 further comprising amplifier means for amplifying the signal.

23. The circuit of claim 22 further comprising isolated power supply means for providing power to the signal conversion module, wherein the power is isolated from the battery.

24. The circuit of claim 23 wherein the isolated power supply means includes a switching power supply.

25. The circuit of claim 20 wherein the signal conversion means includes analog to digital converter means for generating a digital representation of the signal.