Method, apparatus, and computer storage medium for identifying cell

1. A method for identifying a cell under test, comprising:

determining, for the cell under test during a charge and discharge process, a number N of measured values of open circuit voltage (OCV) and a number N of net cumulative throughputs corresponding to the number N of measured values of OCV, based on searched historical charge and discharge data for the cell under test or test data obtained by intermittently charging and discharging the cell under test;

obtaining, for an i th target cell, a number N of first state of charge (SOC) values corresponding to the number N of measured values of OCV, according to the number N of measured values of OCV and a first correspondence between an open circuit voltage and a SOC for the i th target cell;

determining a second correspondence between the net cumulative throughputs and the states of charge for the i th target cell, according to the number N of net cumulative throughputs and the number N of first SOC values;

obtaining, for the i th target cell, a number N of second SOC values corresponding to the number N of net cumulative throughputs, according to the number N of net cumulative throughputs and the second correspondence;

obtaining, for the i th target cell, a number N of calculated values of OCV corresponding to the number N of second SOC values, according to the number N of second SOC values and the first correspondence;

obtaining an OCV mean square error between the cell under test and the i th target cell, based on the number N of measured values of OCV and the number N of calculated values of OCV;

identifying the cell under test as the i th target cell, when the OCV mean square error between the cell under test and the i th target cell is a minimum mean square error among a number M of OCV mean square errors,

wherein M represents a total number of target cells, 1≤i≤M, and both M and N are positive integers greater than 1.

2. The method according to claim 1 , wherein the determining a second correspondence between the net cumulative throughputs and the states of charge for the i th target cell, according to the number N of net cumulative throughputs and the number N of first SOC values comprises:

determining an equation set regarding the first SOC values for the i th target cell and the net cumulative throughputs, according to the number N of net cumulative throughputs, the number N of first SOC values, and a function between the net cumulative throughputs and the states of charge;

obtaining a slope and an intercept of the function, by curve fitting of the equation set based on a least square method or a gradient descent method;

determining the second correspondence according to the slope, the intercept, and the function.

3. The method according to claim 2 , wherein the obtaining, for the i th target cell, a number N of second SOC values corresponding to the number N of net cumulative throughputs, according to the number N of net cumulative throughputs and the second correspondence comprises:

obtaining the number N of second SOC values, according to the number N of net cumulative throughputs and the function with the obtained slope and intercept.

4. The method according to claim 2 , wherein, the determining that the cell under test is the i th target cell, when the OCV mean square error between the cell under test and the i th target cell is a minimum mean square error among a number M of OCV mean square errors, specifically comprises:

determining whether a preset condition is met, when the OCV mean square error between the cell under test and the i th target cell is the minimum mean square error among the number M of OCV mean square errors, and

determining that the cell under test is the i th target cell when the preset condition is met;

wherein the preset condition comprises:

a value of the OCV mean square error between the cell under test and the i th target cell is within a first preset threshold range;

the slope of the function corresponding to the i th target cell is within a second preset threshold range; and

the intercept of the function corresponding to the i th target cell is within a third preset threshold range.

5. The method according to claim 1 , wherein, after determining that the cell under test is the i th target cell, the method further comprises:

calculating a first difference value between an initial SOC value for the cell under test and an initial SOC value for another cell within a module in which the cell under test is located;

calculating a second difference value between a cell capacity for the cell under test and a cell capacity for another cell within the module in which the cell under test is located;

determining that a quality of cell group is poor, when the first difference value or the second difference value exceeds a preset threshold.

6. The method according to claim 1 , wherein the first correspondence includes an OCV-SOC curve,

after determining that the cell under test is the i th target cell, the method further comprises:

using an OCV-SOC curve for the i th target cell as an OCV-SOC curve for the cell under test.

7. The method according to claim 6 , wherein, after obtaining the OCV-SOC curve for the cell under test, the method further comprises:

when a difference in the OCV-SOC curve between the cell under test and other cells within a module in which the cell under test is located, is within a preset range,

calculating an average OCV-SOC curve of OCV-SOC curves for the cell under test and the other cells, and using the average OCV-SOC curve as an OCV-SOC curve for the module in which the cell under test is located.

8. A non-transitory computer storage medium, having computer program instructions stored thereon, which, when executed by a processor, implement the method for identifying a cell under test according to claim 1 .

9. An apparatus for cell identification, comprising:

a determination unit, configured to determine, for a cell under test during a charge and discharge process, a number N of measured values of open circuit voltage (OCV) and a number N of net cumulative throughputs corresponding to the number N of measured values of OCV, based on searched historical charge and discharge data for the cell under test or test data obtained by intermittently charging and discharging the cell under test;

a calculation unit, configured to obtain, for an i th target cell, a number N of first state of charge (SOC) values corresponding to the number N of measured values of OCV, according to the number N of measured values of OCV and a first correspondence between an open circuit voltage and a SOC for the i th target cell; determine a second correspondence between the net cumulative throughputs and the states of charge for the i th target cell, according to the number N of net cumulative throughputs and the number N of first SOC values; obtain, for the i th target cell, a number N of second SOC values corresponding to the number N of net cumulative throughputs, according to the number N of net cumulative throughputs and the second correspondence; obtain, for the i th target cell, a number N of calculated values of OCV corresponding to the number N of second SOC values, according to the number N of second SOC values and the first correspondence; obtain an OCV mean square error between the cell under test and the i th target cell, based on the number N of measured values of OCV and the number N of calculated values of OCV;

an identification unit, configured to identify the cell under test as the i th target cell when the OCV mean square error between the cell under test and the i th target cell is a minimum mean square error among a number M of OCV mean square errors,

wherein M represents a total number of target cells, 1≤i≤M, and both M and N are positive integers greater than 1.