SECONDARY BATTERY DEVICE AND BATTERY CAPACITY ESTIMATION SYSTEM

• US 20140084867A1
• Filed: 02/26/2013
• Published: 03/27/2014
• Est. Priority Date: 09/24/2012
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: HAMAOKA, Yoshiyuki, Shimada, Toshiro
• Application Number:
  US13/777,093
• Publication Number:
  US 20140084867A1
• Time in Patent Office: Days
• US Class Current: 320/116
• CPC Class Codes: H02J 5/00 Circuit arrangements for transfer of electric power between ac networks and dc networks H02J3/36 takes precedence
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Certain embodiments provide a secondary battery device comprising: a battery module including a plurality of secondary battery cells; a battery monitoring circuit that measures a cell voltage value and a cell temperature value of each cell; a current measurement circuit that measures a current value flowing through the battery module; a time addition unit that adds time information to the current value, the cell voltage value and the cell temperature value, respectively; a memory that stores the current value, the cell voltage value and the cell temperature value, each value being associated with time information; and an operation unit that calculates a time difference between the cell temperature value and the cell voltage value, or a time difference between the cell temperature value and the current value stored in the memory, and determines a degree of deterioration for each cell according to the time difference.

Claims

1. A secondary battery device comprising:

a battery module including a plurality of secondary battery cells;

a battery monitoring circuit configured to measure a cell voltage value and a cell temperature value of each of the cells of the battery module;

a current measurement circuit configured to measure a current value flowing through the battery module in timing substantially identical to measurement timing by the battery monitoring circuit;

a time addition unit configured to add time information to the current value, the cell voltage value and the cell temperature value, respectively;

a memory configured to store the current value, the cell voltage value and the cell temperature value, each value being associated with the time information; and

an operation unit configured to calculate a time difference between the cell temperature value and the cell voltage value, or a time difference between the cell temperature value and the current value stored in the memory, the operation unit determining a degree of deterioration for each of the cells according to the time difference.

2. The secondary battery device of claim 1, wherein

the operation unit configured to perform estimation operation of a state of health for each of the cells in accordance with a battery deterioration model that estimates an intertemporal degree of deterioration of the cell based on the cell temperature values, the cell voltage values and the current values.

3. The secondary battery device of claim 2, wherein

the operation unit configured to use a first evaluation function that defines each of the cell temperature values and the cell voltage values as an element of deterioration of the cells.

4. The secondary battery device of claim 2, wherein

the operation unit configured to use a second evaluation function that defines each of the cell temperature values and the current values as an element of deterioration of the cells.

5. The secondary battery device of claim 2, wherein

the operation unit configured to identify a deteriorated cell among the cells according to a result of the estimation operation.

6. The secondary battery device of claim 2, wherein

the operation unit configured to predict lifetimes of the cells according to a result of the estimation operation.

7. The secondary battery device of claim 1, further comprising:

an equalization circuit configured to equalize each cell voltage.

8. The secondary battery device of claim 1, further comprising:

a battery management unit configured to estimate a capacity of the battery module according to measurement history information including the current value, the cell voltage value and the cell temperature value.

9. The secondary battery device of claim 1, further comprising:

a compression unit configured to compress the current value, the cell voltage value and the cell temperature value stored in the memory unit.

10. The secondary battery device of claim 1, further comprising:

a transmission unit configured to add a destination address to data including the current value, the cell voltage value and the cell temperature value stored in the memory unit.

11. The secondary battery device of claim 1, wherein

the current measurement circuit comprises:

a resistor connected to the battery module in series;

an A/D converter configured to have a resolution expressed in a plurality of bits, the A/D converter converting analog voltage between both ends of the resistor into digital voltage; and

a charge quantity counter configured to generate detection current from an output voltage of the A/D converter, and integrate the detection current.

12. The secondary battery device of claim 1, wherein

the battery monitoring circuit is provided at each battery module.

13. The secondary battery device comprising:

a battery module including a plurality of secondary battery cells;

a battery monitoring circuit configured to measure a cell voltage value and a cell temperature value of each of the cells of the battery module;

a time addition unit configured to add time information to the cell voltage value and the cell temperature value, respectively;

a memory configured to store the cell voltage value and the cell temperature value, each value being associated with the time information; and

an operation unit configured to calculate a time difference between the cell temperature value and the cell voltage value stored in the memory, and determine a degree of deterioration for each of the cells according to the time difference.

14. The secondary battery device of claim 13, wherein

the operation unit configured to perform estimation operation of a state of health for each of the cells in accordance with a battery deterioration model that estimates an intertemporal degree of deterioration of the cell based on the cell temperature value and the cell voltage value.

15. The secondary battery device of claim 13, further comprising:

a battery management unit configured to estimate a capacity of the battery module according to measurement history information including the cell voltage value and the cell temperature value.

16. A battery capacity estimation system comprising:

a motor;

a plurality of battery modules supplying electric power to the motor, each including a plurality of secondary battery cells, the plurality of battery modules being connected in series;

a battery monitoring circuit configured to measure a cell voltage value and a cell temperature value of each of the cells for each of the battery modules;

a current measurement circuit configured to measure a current value flowing through the battery module in timing substantially identical to measurement timing by the battery monitoring circuit;

a time addition unit configured to add time information to the current value, the cell voltage value and the cell temperature value, respectively;

a memory configured to store the current value, the cell voltage value and the cell temperature value, each value being associated with the time information;

an operation unit configured to calculate a time difference between the cell temperature value and the cell voltage value, or a time difference between the cell temperature value and the current value stored in the memory, the operation unit determining a degree of deterioration for each of the cells according to the time difference; and

a battery management unit configured to estimate a capacity of the battery module according to measurement history information including the current value, the cell voltage value and the cell temperature value.

17. The battery capacity estimation system of claim 16, wherein

the operation unit configured to perform estimation operation of a state of health for each of the cells in accordance with a battery deterioration model that estimates an intertemporal degree of deterioration of the cell based on the cell temperature value, the cell voltage value and the current value.

18. The battery capacity estimation system of claim 17, wherein

the operation unit configured to use a first evaluation function that defines each of the cell temperature value and the cell voltage value as an element of deterioration of the cells.

19. The battery capacity estimation system of claim 17, wherein

the operation unit configured to use a second evaluation function that defines each of the cell temperature value and the current value as an element of deterioration of the cells.

20. The battery capacity estimation system of claim 16, further comprising:

an electronic controller configured to create indicative data of a result of operation by the operation unit.