METHOD FOR DETERMINING THE OPERATING STATE OF AN ENERGY-STORAGE BATTERY

• US 20030112010A1
• Filed: 12/12/2002
• Published: 06/19/2003
• Est. Priority Date: 12/14/2001
• Status: Active Grant

• Current Assignee: VB Autobatterie GmbH
• Original Assignee: VB Autobatterie GmbH
• Inventors: Koch, Ingo
• Granted Patent: US 6,674,266 B2
• Time in Patent Office: Days
• US Class Current: 324/427
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/388 involving voltage measurements

Abstract

A method for determining the operating state of an energy-storage battery in assumed temperature and state of charge conditions, which has the following steps: a) measurement of a temperature variable (T_ACT) which is correlated with the battery temperature (T_BAT), b) determination of the state of charge (SOC_ACT) of the energy-storage battery, c) determination of a further state variable (A_ACT) of the energy-storage battery, d) formation of a reference value (B_V) from the reference between the determined state variable (A_ACT) and a corresponding state variable (A_NEW) of an identical, new energy-storage battery with the same temperature variable (T_ACT) and the same state of charge (SOC_ACT), and e) determination of a predicted state variable (A_P) as a measure of the operating state for an assumed temperature variable (T_P) and an assumed state of charge (SOC_P) from known comparison reference values (B_T), which have been recorded as a function of temperature variables (T), states of charge (SOC) and the aging state of identical energy-storage batteries.

Claims

1. A method for determining the operating state of an energy-storage battery in assumed temperature and state of charge conditions comprising:

a) measuring a temperature variable (T_ACT) which is correlated with a battery temperature (T_BAT);

b) determining a state of charge (SOC_ACT) of the energy-storage battery;

c) determining a further state of variable (A_ACT) of the energy-storage battery;

d) forming a reference value (B_V) from a reference between the further state variable (A_ACT) and a corresponding state variable (A_NEW) of a substantially identical, new energy-storage battery with the same temperature variable (T_ACT) and the same state of charge (SOC_ACT); and

(e) determining a predicted state variable (A_P) as a measure of operating state for an assumed temperature variable (T_P) and an assumed state of charge (SOC_P) from known comparison reference values (B_T), which have been recorded as a function of temperature variables (T), states of charge (SOC) and the aging state of identical energy-storage batteries.

2. The method of claim 1, wherein the comparison reference values (B_T) are recorded as a value matrix.

3. The method of claim 1, wherein the comparison reference values (B_T) are recorded functionally.

4. The method of claim 3, wherein coefficients of the functions for the comparison reference values (B_T) are stored in a coefficient value matrix as a function of the aging state.

5. The method of claim 1, wherein the reference value (B_V) is calculated from a ratio between the determined state variable (A_ACT) and the corresponding state variable (A_NEW) of a substantially identical new energy-storage battery.

6. The method of claim 1, wherein the reference value (B_V) is calculated from the differences between the determined state variable (A_ACT) and the corresponding state variable (A_NEW) of a substantially identical new energy-storage battery.

7. The method of claim 1, wherein state variable (A) is the internal resistance (R_I) of the energy-storage battery.

8. The method of claim 7, wherein the state variable (A) is a voltage minimum of a terminal voltage of the energy-storage battery for a known load.

9. The method of claim 1, wherein the comparison reference values (B_T) are obtained empirically from operating experience with substantially identical elderly energy-storage batteries.

10. The method of claim 1, wherein the comparison reference values (B_T) are calculated from a mathematical battery model of the energy-storage batteries.

11. The method of claim 1, further comprising:

determining an aging state of the storage battery from reference values (B_V) and from comparison reference values (B_T) for a defined temperature variable (T) and a defined state of charge (SOC).

12. The method of claim 1, further comprising:

determining a reference value (B_V) by the assumed temperature variable (T_P) and the assumed state of charge (SOC_P) by transformation of a functional relationship between the comparison reference values (B_T) and the state variable (A_ACT) determined for the measured temperature variable (T_ACT) and the determined state of charge (SOC_ACT), and calculating a predicted state variable (A_P) from the reference between the reference value (B_V) and the state variable (A_NEW) of a substantially identical new storage battery.