Device for controlling assembled battery

Patent metadata

Field	Value
Publication number	US-9490646-B2
Application number	US-201013885134-A
Country	US
Kind code	B2
Filing date	Dec 9, 2010
Priority date	Nov 17, 2010
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

In a device for controlling an assembled battery provided with a plurality of single batteries, the device includes a capacity adjustment section for adjusting a capacity such that voltages of the single batteries are equalized at a targeted voltage, an internal state detection section for detecting terminal voltages or SOC of the single batteries and for detecting, based on the detected terminal voltages/SOC, a voltage/SOC difference among the single batteries as voltage-difference/SOC-difference data, and a time-series data storage for storing the voltage-difference/SOC-difference data in time-series. Also provided is a prediction section for more appropriately predicting time when the assembled battery becomes an abnormal state, based on a time-dependent change in the voltage-difference/SOC-difference data detected in a voltage/SOC region different from the targeted voltage by a predetermined voltage, among the stored time-series voltage-difference/SOC-difference data.

First claim

The invention claimed is:

1. A device for controlling an assembled battery system having an assembled battery provided with a plurality of single batteries, comprising:
the assembled battery;
a targeted voltage setting means for setting a targeted voltage to equalize voltages of the plurality of single batteries constructing the assembled battery;
a capacity adjustment means for adjusting a capacity such that the voltages of the plurality of single batteries constructing the assembled battery are equalized at the targeted voltage;
an internal state detection means for detecting terminal voltages or SOC of the plurality of single batteries and for detecting, based on the detected terminal voltages or the detected SOC, a voltage difference or a SOC difference among the plurality of single batteries as voltage-difference data or SOC-difference data;
a time-series data storage means for storing the voltage-difference data or the SOC-difference data, detected by the internal state detection means, in time-series; and
a prediction means for predicting, prior to an occurrence of a first abnormal state of the assembled battery, time when the first abnormal state occurs, based on (a) a time-dependent change in the voltage-difference data detected in a voltage region different from the targeted voltage by a predetermined voltage or more, or (b) a time-dependent change in the SOC-difference data detected in a SOC region corresponding to voltage region different from a targeted voltage by the predetermined voltage or more, among the voltage-difference data or the SOC-difference data stored in the time-series data storage means.

2. The device for controlling the assembled battery system as claimed in claim 1 , wherein:
the time-series data storage means has a SOC-section table that a SOC range of the single battery from a full charge to a discharge lower limit is classified into a plurality of SOC sections;
the time-series data storage means stores the voltage-difference data or the SOC-difference data detected by the internal state detection means in time-series, while correlating the detected voltage-difference data or the detected SOC-difference data with the SOC section corresponding to the SOC when having detected, based on the SOC-section table, the voltage-difference data or the SOC-difference data; and
the prediction means predicts the time when the assembled battery becomes the first abnormal state, based on the time-dependent change in the voltage-difference data or the SOC-difference data belonging to a same SOC section, among the voltage-difference data or the SOC-difference data.

3. The device for controlling the assembled battery system as claimed in claim 2 , wherein:
each of the plurality of SOC sections is set to narrow a SOC range, as a ratio of a voltage change with respect to a SOC change increases.

4. The device for controlling the assembled battery system as claimed in claim 3 , wherein:
the prediction means predicts the time when the assembled battery becomes the first abnormal state, based on the time-dependent change in the voltage-difference data or the SOC-difference data belonging to the same SOC section, among the voltage-difference data or the SOC-difference data belonging to the SOC section whose SOC range is less than or equal to a predetermined range.

5. The device for controlling the assembled battery system as claimed in claim 4 , wherein:
the prediction means predicts the time when the assembled battery becomes the first abnormal state, based on the time-dependent change in the voltage-difference data or the SOC-difference data belonging to the same SOC section, among the voltage-difference data or the SOC-difference data belonging to the SOC section whose SOC range is less than or equal to the predetermined range and which SOC section has the ratio of the voltage change with respect to the SOC change, which ratio is different from that of the SOC section to which the SOC corresponding to the targeted voltage belongs.

6. The device for controlling the assembled battery system as claimed in claim 1 , which further comprises:
a SOC-voltage table storage means for storing a table showing a relationship between the SOC and the terminal voltage of each of the plurality of single batteries,
wherein the internal state detection means calculates normalized terminal voltages by normalizing the SOC of each of the single batteries of the plurality of single batteries, subjected to detection, with respect to a prescribed SOC, using the table stored in the SOC-voltage table storage means when detecting the voltage-difference data, and then detects the voltage-difference data based on the normalized terminal voltages.

7. The device for controlling the assembled battery system as claimed in claim 6 , wherein:
the prescribed SOC for normalization is a given SOC in a SOC region in which a ratio of a voltage change with respect to a SOC change is greater than or equal to a predetermined value.

8. The device for controlling the assembled battery system as claimed in claim 7 , wherein:
the prescribed SOC for normalization is a given SOC in a SOC region in which the ratio of the voltage change with respect to the SOC change is greater than or equal to the predetermined value and which has the ratio different from the ratio of the voltage change with respect to the SOC change in the SOC region corresponding to the targeted voltage.

9. The device for controlling the assembled battery system as claimed in claim 1 , wherein:
the internal state detection means detects the voltage-difference data or the SOC-difference data in a SOC region in which a ratio of a voltage change with respect to a SOC change is greater than or equal to a predetermined value and which has the ratio different from the ratio of the voltage change with respect to the SOC change in the SOC region corresponding to the targeted voltage or in the voltage region corresponding to the SOC region.

10. The device for controlling the assembled battery system as claimed in claim 1 , wherein:
the prediction means predicts time when the assembled battery becomes a second abnormal state different from the first abnormal state, based on the time-dependent change in the voltage-difference data or the SOC-difference data detected in a voltage region in which a deviation of the terminal voltage with respect to the targeted voltage is less than the predetermined voltage or in a SOC region corresponding to the voltage region.

11. The device for controlling the assembled battery system as claimed in claim 1 , wherein:
the prediction means obtains a regression line by performing linear regression of the time-dependent change in the voltage-difference data or the SOC-difference data stored in the time-series data storage means, and predicts the time when the assembled battery becomes the first abnormal state, based on the obtained regression line.

12. The device for controlling the assembled battery system as claimed in claim 10 , wherein:
the prediction means obtains a regression line by performing linear regression of the time-dependent change in the voltage-difference data or the SOC-difference data stored in the time-series data storage means, and predicts the time when the assembled battery becomes the second abnormal state, based on the obtained regression line.

13. The device for controlling the assembled battery system as claimed in claim 12 , wherein:
the prediction means determines a reliability of the regression line, and calculates, based on the regression line, time when the voltage difference or the SOC difference among the plurality of single batteries becomes greater than

Assignees

• Kubota Tomoya
• Miyazaki Yasuhito
• Kato Yukinari
• Shimoida Yoshio
• Nissan Motor

Inventors

• Kubota Tomoya
• Miyazaki Yasuhito
• Kato Yukinari
• Shimoida Yoshio

Classifications

• H02J7/54

  Passive balancing, e.g. using resistors or parallel MOSFETs · CPC title

• H01M10/4207

  for several batteries or cells simultaneously or sequentially · CPC title

• G01R31/396

  Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery · CPC title

• G01R31/392

  Determining battery ageing or deterioration, e.g. state of health · CPC title

• G01R31/382

  Arrangements for monitoring battery or accumulator variables, e.g. SoC · CPC title