Abnormal Degradation Cell Detection Device and Abnormal Degradation Cell Detection Method

JP7874700B2Active Publication Date: 2026-06-16SAMSUNG SDI CO LTD
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Patent Information

Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
SAMSUNG SDI CO LTD
Filing Date
2024-11-15
Publication Date
2026-06-16

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Abstract

To provide an abnormally degraded cell detection device and an abnormally degraded cell detection method that are capable detecting a cell which is abnormally degraded in an early stage.SOLUTION: The present invention relates to an abnormally degraded cell detection device and a method for the same. An abnormally degraded cell detection method for a battery module containing a plurality of cells according to an embodiment of the present invention includes: a step of acquiring a first statistic value indicating a capacity deviation at a first point of time for the plurality of cells; a step of acquiring a second statistic value indicting the capacity deviation at a second point of time for the plurality of cells; and a step of comparing the first and second statistic values to each other to detect an abnormally degraded cell.SELECTED DRAWING: Figure 4
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Claims

1. A method for detecting abnormally degraded cells in a battery module containing multiple cells, A step of obtaining a first statistical value showing the capacity deviation at a first time point for the plurality of cells, A step of obtaining a second statistical value showing the capacity deviation at a second time point for the aforementioned plurality of cells, A method for detecting abnormally degraded cells, comprising the step of detecting an abnormally degraded cell by comparing the first statistical value and the second statistical value with each other, wherein the acquisition of the cell voltage of the cell used in calculating the second statistical value is performed for each rest period after charging and after discharging of the cell.

2. The step of obtaining the first statistical value is: The step includes obtaining the first statistical value using the initial capacity values ​​of each of the plurality of cells, The aforementioned initial capacity values ​​correspond to the chemical conversion capacity of each cell. The method for detecting abnormally degraded cells according to claim 1.

3. The step of obtaining the first statistical value using the initial capacity value is: A step of obtaining the mean and standard deviation of the initial capacity values ​​for the plurality of cells, For each of the aforementioned plurality of cells, the first sigma is calculated by dividing the subtracted value obtained by subtracting the average value from the initial capacity value by the standard deviation, The step includes obtaining the first sigma calculated for each of the plurality of cells as the first statistical value, The method for detecting abnormally degraded cells according to claim 2.

4. The step of obtaining the first statistical value is: For each of the aforementioned plurality of cells, the steps include detecting the first SOC (State Of Charge) change amount during the first period, A step of obtaining the mean and standard deviation of the first SOC change for the plurality of cells, For each of the plurality of cells, the second sigma is calculated by dividing the subtracted value obtained by subtracting the mean value from the first SOC change by the standard deviation, The step includes determining the second sigma calculated for each of the plurality of cells as the first statistical value, The method for detecting abnormally degraded cells according to claim 1.

5. The step of detecting the first SOC change is: The first rest period of the battery module includes the step of detecting the first SOC value of each of the plurality of cells, The steps include detecting the second SOC value of each of the plurality of cells in the second rest period following the first rest period of the battery module, The process includes the step of calculating the first SOC change amount from the difference between the first SOC value and the second SOC value for each of the plurality of cells, The method for detecting abnormally deteriorated cells according to claim 4.

6. The step of detecting the first SOC value is: For each of the plurality of cells, the step is to obtain the first cell voltage value detected at a predetermined time elapsed from the time the first rest period started, The step of determining the first SOC value for each of the plurality of cells using the first cell voltage value, The step of detecting the second SOC value is: For each of the aforementioned plurality of cells, the step of obtaining the second cell voltage value detected at a predetermined time elapsed from the time the second rest period started, The step of determining the second SOC value for each of the plurality of cells using the second cell voltage value, The method for detecting abnormally degraded cells according to claim 5.

7. The step of obtaining the second statistical value is: For each of the aforementioned plurality of cells, the step of detecting the second SOC change amount during the second period, A step of obtaining the mean and standard deviation of the second SOC change for the plurality of cells, For each of the aforementioned plurality of cells, the third sigma is calculated by dividing the subtracted value obtained by subtracting the mean value from the second SOC change by the standard deviation, The step includes determining the third sigma calculated for each of the plurality of cells as the second statistical value, The method for detecting abnormally degraded cells according to claim 1.

8. The step of detecting the second SOC change is: The third rest period of the battery module includes the step of detecting the third SOC value of each of the plurality of cells, The steps include detecting the fourth SOC value of each of the plurality of cells in the fourth rest period following the third rest period of the battery module, The process includes the step of calculating the second SOC change amount from the difference between the third SOC value and the fourth SOC value for each of the plurality of cells, The method for detecting abnormally deteriorated cells according to claim 7.

9. The step of detecting the third SOC value is: For each of the aforementioned plurality of cells, the step of obtaining the third cell voltage value detected at a predetermined time elapsed from the time the third rest period started, The step of determining the third SOC value for each of the plurality of cells using the third cell voltage value, The step of detecting the fourth SOC value is: For each of the plurality of cells, the step of obtaining the fourth cell voltage value detected at a predetermined time after the start of the fourth rest period, The step of determining the fourth SOC value for each of the plurality of cells using the fourth cell voltage value, The method for detecting abnormally degraded cells according to claim 8.

10. The step of detecting the second SOC change is: For each of the aforementioned plurality of cells, the step of detecting the fourth SOC change amount between the post-charge rest period and the post-discharge rest period for each charge-discharge cycle, The step includes determining the second SOC change from the average value of the fourth SOC change detected during the second period, The second period includes at least one charge-discharge cycle. The method for detecting abnormally deteriorated cells according to claim 7.

11. The step of detecting the abnormally degraded cell is: A step of comparing the difference between the first statistical value and the second statistical value with a threshold, The step includes determining cells whose difference value is greater than or equal to the threshold value as abnormally degraded cells, The method for detecting abnormally degraded cells according to claim 1.

12. The step of detecting the abnormally degraded cell is: A step of calculating the difference between the first statistical value and the second statistical value for each of the plurality of cells, A step of detecting outliers from the differences between each of the multiple cells using the Grubbs' test method, The step includes determining, from among the plurality of cells, a cell whose difference value is an outlier as an abnormally degraded cell, The method for detecting abnormally degraded cells according to claim 1.

13. A device for detecting abnormally degraded cells in a battery module containing multiple cells, The control device includes a first statistical value that shows the capacity deviation at a first time point for the plurality of cells, a second statistical value that shows the capacity deviation at a second time point for the plurality of cells, and a control device that detects abnormally degraded cells by comparing the first statistical value and the second statistical value with each other. The cell voltage of the cell used in calculating the second statistical value is obtained after each rest period following charging and discharging of the cell. Abnormally degraded cell detection device.

14. The system further includes a storage device for storing the initial capacity values ​​of the plurality of cells, The control device calculates the first sigma for each of the plurality of cells by subtracting the average value of the initial capacity values ​​of the plurality of cells from the initial capacity value of each of the plurality of cells, and then divides the resulting subtraction by the standard deviation, and uses the first sigma calculated for each of the plurality of cells as the first statistical value. The aforementioned initial capacity values ​​correspond to the chemical conversion capacity of each cell. The abnormal deterioration cell detection device according to claim 13.

15. The control device is For the plurality of cells, the first SOC change amount during the first period is detected, The mean and standard deviation of the first SOC change amount are calculated for the plurality of cells. The second sigma of each of the multiple cells is calculated by subtracting the mean value from the first SOC change and dividing the result by the standard deviation. The second sigma calculated for each of the aforementioned plurality of cells is used as the first statistical value. The abnormal deterioration cell detection device according to claim 13.

16. The control device is The first SOC value in the first post-charge rest period is determined using the first cell voltage value detected for each of the plurality of cells at a predetermined time after the start of the first post-charge rest period. The second SOC value in the first post-discharge rest period is determined using the second cell voltage value detected for each of the plurality of cells at a predetermined time after the start of the first post-discharge rest period. The amount of change in the first SOC is determined from the difference between the first SOC value and the second SOC value. The abnormal deterioration cell detection device according to claim 15.

17. The control device is For the aforementioned plurality of cells, the second SOC change amount during the second period is detected, The mean and standard deviation of the second SOC change amount are calculated for the plurality of cells. The third sigma of each of the multiple cells is calculated by subtracting the mean value from the second SOC change and dividing the resulting subtracted value by the standard deviation, The third sigma calculated for each of the aforementioned plurality of cells is used as the second statistical value. The abnormal deterioration cell detection device according to claim 13.

18. The control device is The third SOC value in the second post-charge rest period is determined using the third cell voltage value detected for each of the aforementioned plurality of cells at a predetermined time after the start of the second post-charge rest period. The fourth SOC value in the second post-discharge rest period is determined using the fourth cell voltage value detected for each of the plurality of cells at a predetermined time after the start of the second post-discharge rest period. The second SOC change is determined from the difference between the third SOC value and the fourth SOC value. The abnormal deterioration cell detection device according to claim 17.

19. The control device is For each of the plurality of cells, the amount of change in the fourth SOC between the post-charge rest period and the post-discharge rest period is detected for each charge-discharge cycle during the second period, and the amount of change in the second SOC is determined from the average value of the amount of change in the fourth SOC detected during the second period. The second period includes at least one charge-discharge cycle. The abnormal deterioration cell detection device according to claim 17.

20. The control device is The difference between the first statistical value and the second statistical value is compared with a threshold, Cells whose difference value is greater than or equal to the threshold are determined to be abnormally degraded cells. The abnormal deterioration cell detection device according to claim 13.