DEVICE AND METHOD FOR DETECTING ABNORMALITY OF ELECTRIC STORAGE DEVICE

• US 20100004885A1
• Filed: 02/06/2008
• Published: 01/07/2010
• Est. Priority Date: 02/08/2007
• Status: Active Grant

• Current Assignee: Panasonic EV Energy Company, Limited (Toyota Motor Corporation)
• Original Assignee: Panasonic EV Energy Company, Limited (Toyota Motor Corporation)
• Inventors: Nakanishi, Toshiaki
• Granted Patent: US 8,463,562 B2
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: B60L 2260/56 Temperature prediction, e.g. for pre-cooling
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 58/14 Preventing excessive discharging
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Provided is an abnormality detecting device for detecting an abnormality of electric storage devices such as a battery pack. Comparators (140-1) to (140-n) detect a time when a voltage reaches a prescribed voltage, for each block of a battery pack (100). A judging section (160) detects a current at a time when the voltage reaches the prescribed voltage, and a representative current value is calculated for each block. The deviation of the representative current value of each block is compared with the threshold value, and when the deviation is large, it is judged that there are abnormalities such as short-circuiting, minute short-circuiting, IR (internal resistance) increase, capacitance reduction, and the like.

Claims

1. A detecting device which detects abnormality of an electric storage device having a plurality of blocks which are connected in series, each block having one or a plurality of electric storage units, the detecting device comprising:

a measurement unit which measures, for each block, a current value at a time when a voltage of the block becomes equal to a predetermined voltage; and

a detecting unit which detects abnormality of the electric storage device based on a deviation of the measured current value of each block.

2. The abnormality detecting device for an electric storage device according to claim 1, wherein

the detecting unit comprises:

a calculating unit which calculates a representative current value of each block through a predetermined statistical process based on a plurality of the measured current values of each block; and

a comparing unit which compares a deviation of the calculated representative current value of each block with a predetermined value to detect abnormality of the electric storage device.

3. The abnormality detecting device for an electric storage device according to claim 2, wherein

the representative value is one of an average value, an intermediate value, a minimum value, and a maximum value of the plurality of the current values of each block.

4. The abnormality detecting device for an electric storage device according to claim 1, wherein

the detecting unit detects, as the abnormality, at least one of short-circuiting, increase in internal resistance, and reduction in capacitance.

5. The abnormality detecting device for an electric storage device according to claim 1, wherein

the electric storage device is one of a battery and a capacitor.

8. The abnormality detecting device for an electric storage device according to claim 1, wherein

as the predetermined voltage, at least two predetermined voltages including a first predetermined voltage and a second predetermined voltage are set;

and

the detecting unit detects the abnormality of the electric storage device based on a deviation of the current value of each block at a time when the voltage becomes equal to the first predetermined voltage and a deviation of the current value of each block at a time when the voltage becomes equal to the second predetermined voltage.

9. The abnormality detecting device for an electric storage device according to claim 1, wherein

the measurement unit measures a current value having a time lag within 100 msec as the current value at the time when the voltage of the block becomes equal to the predetermined voltage.

10. The abnormality detecting device for an electric storage device according to claim 2, wherein

the calculating unit extracts only a current value within a predetermined range from among the plurality of measured current values of each block and calculates the representative value of each block through the predetermined statistical process.

11. The abnormality detecting device for an electric storage device according to claim 2, wherein

the calculating unit calculates the representative current value only for a plurality of current values having a distribution degree of a predetermined value or less, among the plurality of measured current values of each block.

6. A method of detecting abnormality of an electric storage device having a plurality of blocks which are connected in series, each block having one or a plurality of electric storage units, the method comprising the steps of:

measuring, for each block, a current value at a time when a voltage of the block becomes equal to a predetermined voltage; and

detecting abnormality of the electric storage device by comparing a deviation of the measured current value of each block with a threshold value.

7. A computer-readable recording medium storing a computer program for detecting abnormality of an electric storage device having a plurality of blocks which are connected in series, each block having one or a plurality of electric storage units, which, when executed, causes a computer to execute a process comprising:

measuring, for each block, a current value at a time when a voltage of the block becomes equal to a predetermined voltage;

sequentially storing the measured current value of each block in a memory;

causing a calculating device to calculate a representative current value of each block through a predetermined statistical process based on a plurality of the current values of each block stored in the memory;

causing the calculating device to calculate a deviation of the representative current value of each block obtained through the calculation; and

detecting abnormality of the electric storage device by comparing in size the deviation obtained through the calculation and a threshold value.

12. A detecting device which detects abnormality of an electric storage device having a plurality of blocks which are connected in series, each block having one or a plurality of electric storage units, the detecting device comprising:

a measurement unit which measures a current value at a time when a voltage difference between adjacent blocks among the plurality of blocks becomes equal to a predetermined voltage; and

a detecting unit which detects abnormality of the electric storage device based on a size of the measured current value.

13. The abnormality detecting device for electric storage device according to claim 12, wherein

the detecting unit detects, as the abnormality, at least one of short-circuiting, increase in internal resistance, and reduction of capacitance.

14. The abnormality detecting device for electric storage device according to claim 12, wherein

the electric storage device is one of a battery and a capacitor.