Method and device for identifying abnormal battery cell, computer equipment and storage medium

Abstract

The invention relates to the technical field of computers, and discloses a method and device for identifying an abnormal battery cell, computer equipment and a storage medium, and the method comprises the steps: obtaining the total equalization duration of each battery cell in a plurality of battery cells of a target battery pack in a target time period; determining a reference total equalization duration according to the total equalization duration of each battery cell in the target time period, and calculating a difference value between the total equalization duration of each battery cell in the target time period and the reference total equalization duration; when the difference value between the total equalization duration of a target battery cell in the multiple battery cells in the target time period and the reference total equalization duration is larger than a total equalization duration deviation threshold value, the target battery cell is determined as an abnormal battery cell, and the target battery cell is any one battery cell in the multiple battery cells.

Description

Technical Field

[0001] The present disclosure relates to the field of computer technology, and in particular to a method, device, computer equipment and storage medium for identifying abnormal battery cells. Background Art

[0002] In the related art, the abnormal cells are identified based on whether the voltage of the cells in the battery pack is greater than the high voltage threshold or the low voltage threshold. However, in some cases, the voltage of the abnormal cells is neither higher than the high voltage threshold nor lower than the low voltage threshold, resulting in the inability to identify the abnormal cells, and the accuracy of identifying the abnormal cells is low. How to improve the accuracy of identifying abnormal cells has become a problem that needs to be solved. Summary of the invention

[0003] In view of this, embodiments of the present disclosure provide a method, apparatus, computer device, and storage medium for identifying abnormal battery cells.

[0004] In a first aspect, an embodiment of the present disclosure provides a method for identifying abnormal battery cells, the method comprising:

[0005] Obtaining a total balancing time of each battery cell in a target battery pack in a target time period;

[0006] Determine a reference total balancing time according to the total balancing time of each battery cell in the target time period, and calculate a difference between the total balancing time of each battery cell in the target time period and the reference total balancing time;

[0007] When the difference between the total balancing time of a target cell among the multiple cells in the target time period and the reference total balancing time is greater than a total balancing time deviation threshold, the target cell is determined as an abnormal cell, wherein the target cell is any one of the multiple cells.

[0008] In a possible implementation, determining the reference total balancing time according to the total balancing time of each battery cell in the target time period includes:

[0009] An average of total balancing time lengths of the battery cells in a target time period is calculated, and the average value is determined as the reference total balancing time length.

[0010] In a possible implementation, it also includes:

[0011] The total balancing time deviation threshold is determined according to the maximum self-discharge rate deviation of the normal battery cell, the duration of the target time period, and the balancing current used to determine the total balancing time deviation threshold, wherein the maximum self-discharge rate deviation of the normal battery cell is the maximum self-discharge rate of the normal battery cell minus the minimum self-discharge rate of the normal battery cell.

[0012] In a possible implementation, determining the total balancing time deviation threshold according to the maximum self-discharge rate deviation of the normal battery cell, the duration of the target time period, and the balancing current used to determine the total balancing time deviation threshold includes:

[0013] The total balancing time deviation threshold is determined according to the maximum deviation of the self-discharge rate of the normal battery cell, the duration of the target time period, the preset deviation coefficient, and the balancing current used to determine the total balancing time deviation threshold.

[0014] In a possible implementation, obtaining the total balancing time of each battery cell in the target battery pack in the target time period includes:

[0015] When the accumulated working time of the target battery pack is not less than the preset time, the total balancing time of each battery cell in the plurality of battery cells of the target battery pack in the target time period is obtained.

[0016] In a possible implementation, when the difference between the total balancing time of the target cell in the target time period and the reference total balancing time is greater than the total balancing time deviation threshold, determining the target cell as an abnormal cell includes:

[0017] When the difference between the total balancing time of the target battery cell in the target time period and the reference total balancing time is greater than the total balancing time deviation threshold and meets the consistency condition, the target battery cell is determined as an abnormal battery cell, wherein the consistency condition is that the voltage difference between the battery cell with the largest voltage among the multiple battery cells when the multiple battery cells are all at rest and the battery cell with the smallest voltage among the multiple battery cells when the multiple battery cells are all at rest is less than the voltage difference threshold.

[0018] In a second aspect, an embodiment of the present disclosure provides a device for identifying abnormal battery cells, the device for identifying abnormal battery cells comprising:

[0019] An acquisition unit, used to acquire a total balancing time of each battery cell in a target battery pack in a target time period;

[0020] A determination unit, configured to determine a reference total balancing time according to the total balancing time of each battery cell in the target time period, and calculate a difference between the total balancing time of each battery cell in the target time period and the reference total balancing time;

[0021] An identification unit is used to determine a target battery cell as an abnormal battery cell when the difference between the total balancing time of a target battery cell among the multiple battery cells in a target time period and the reference total balancing time is greater than a total balancing time deviation threshold, wherein the target battery cell is any one of the multiple battery cells.

[0022] In a possible implementation manner, the determination unit is further configured to calculate an average of total balancing time durations of the battery cells in a target time period, and determine the average as the reference total balancing time duration.

[0023] In a possible implementation, the device for identifying abnormal cells further includes:

[0024] The calculation unit is used to determine the total balancing time deviation threshold according to the maximum deviation of the self-discharge rate of the normal battery cell, the duration of the target time period, and the balancing current used to determine the total balancing time deviation threshold, wherein the maximum deviation of the self-discharge rate of the normal battery cell is the maximum self-discharge rate of the normal battery cell minus the minimum self-discharge rate of the normal battery cell.

[0025] In a possible implementation, the calculation unit is further used to determine the total balancing time deviation threshold according to the maximum deviation of the self-discharge rate of the normal battery cell, the duration of the target time period, the preset deviation coefficient, and the balancing current used to determine the total balancing time deviation threshold.

[0026] In a possible implementation, the acquisition unit is further configured to acquire a total balancing duration of each of the multiple battery cells of the target battery pack in the target time period when the accumulated operating duration of the target battery pack is not less than a preset duration.

[0027] In one possible implementation, when the difference between the total balancing time of the target battery cell in the target time period and the reference total balancing time is greater than the total balancing time deviation threshold, determining the target battery cell as an abnormal battery cell includes: when the difference between the total balancing time of the target battery cell in the target time period and the reference total balancing time is greater than the total balancing time deviation threshold and meets a consistent condition, determining the target battery cell as an abnormal battery cell, wherein the consistent condition is that the voltage difference between the voltage of the battery cell with the largest voltage among the multiple battery cells when the multiple battery cells are all at rest and the voltage of the battery cell with the smallest voltage among the multiple battery cells when the multiple battery cells are all at rest is less than the voltage difference threshold.

[0028] In a third aspect, an embodiment of the present disclosure provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, computer instructions being stored in the memory, and the processor executing the method of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0029] In a fourth aspect, an embodiment of the present disclosure provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the method of the first aspect or any corresponding implementation manner thereof.

[0030] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions for causing a computer to execute the method of the first aspect or any corresponding embodiment thereof.

[0031] The method for identifying abnormal battery cells provided by the embodiments of the present disclosure determines a reference total balancing time according to the total balancing time of each battery cell in the target time period of multiple battery cells of a target battery pack, and calculates the difference between the total balancing time of each battery cell in the target time period and the reference total balancing time. When the difference between the total balancing time of a target battery cell in the target time period and the reference total balancing time is greater than a total balancing time deviation threshold, the target battery cell is determined as an abnormal battery cell.

[0032] When identifying abnormal cells, the following characteristics of abnormal cells are taken into consideration: abnormal cells have large self-discharge, the voltage of abnormal cells is the lowest voltage for a long time, abnormal cells are not balanced for a long time, and the total balance time of abnormal cells in the same time period is very short compared to the total balance time of normal cells in the same time period. The lowest voltage is relative to the voltage of normal cells.

[0033] When an abnormal cell exists in the target battery pack, most of the cells in the target battery pack are normal cells, and the reference total balancing time is close to or equal to the total balancing time of a normal cell in the target time period. The reference total balancing time may refer to the maximum difference between the total balancing time of two normal cells in the target time period. When an abnormal cell exists in the target battery pack, the difference between the total balancing time of the normal cell in the target battery pack in the target time period and the reference total balancing time will not be greater than the total balancing time deviation threshold. Since the total balancing time of the abnormal cell in the target battery pack in the target time period is very small compared to the total balancing time of the normal cell in the target battery pack in the target time period, the difference between the total balancing time of the abnormal cell in the target battery pack in the target time period and the reference total balancing time is greater than the total balancing time deviation threshold. Therefore, when the difference between the total balancing time of the target cell in the target time period and the reference total balancing time of the target cell among multiple cells is greater than the total balancing time deviation threshold, the target cell can be determined as an abnormal cell, so that the abnormal cell can be identified more accurately. Improve the accuracy of identifying abnormal cells. Avoid the situation where the voltage of abnormal cells is neither higher than the high voltage threshold nor lower than the low voltage threshold, and the abnormal cells cannot be identified. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the specific embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 is a flow chart of a method for identifying abnormal cells provided by an embodiment of the present disclosure;

[0036] Figure 2 is a flow chart of another method for identifying abnormal battery cells provided by an embodiment of the present disclosure;

[0037] Figure 3 is a flowchart of an example of identifying abnormal cells;

[0038] Figure 4 It is a schematic diagram of the structure of a computer device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0040] refer to Figure 1 , which shows a flow chart of a method for identifying abnormal battery cells provided in an embodiment of the present disclosure.

[0041] In step S101 , a total balancing time of each battery cell in a target battery pack in a target time period is obtained.

[0042] The target battery pack is installed on a target vehicle, and the target vehicle may be any vehicle to which the embodiments of the present disclosure may be applied.

[0043] In one possible implementation, the target vehicle is an electric vehicle.

[0044] In a possible implementation, the target battery pack is a power battery pack.

[0045] The method for identifying abnormal cells provided in the embodiment of the present disclosure can be executed by a battery management system (BMS) on a target vehicle. The battery management system on the target vehicle has a passive balancing function. The passive balancing function is used to make the power of the cells in the battery pack consistent through the passive discharge of the balancing circuit to improve the overall performance of the battery pack.

[0046] It should be noted that the balancing in the embodiments of the present disclosure may specifically refer to: balancing of the battery cells by the passive balancing function of the battery management system on the target vehicle.

[0047] In a possible implementation, the multiple battery cells of the target battery pack may be: all the battery cells of the target battery pack.

[0048] The start time of the target time period may be the time when the target battery pack is installed on the target vehicle.

[0049] In a possible implementation, the target time period may be: the time period between the time when the target battery pack is installed on the target vehicle and the current time, wherein the current time is the end time of the target time period, and wherein the current time may refer to the time when step S101 is started.

[0050] As an example, the unit of the target time period is month.

[0051] For one battery cell among the multiple battery cells, the total balancing time of the battery cell in the target time period may indicate how long the passive balancing function performs balancing on the battery cell in total in the target time period.

[0052] As an example, for one battery cell among the multiple battery cells, the unit of the total balancing time of the battery cell in the target time period may be hours.

[0053] For one battery cell among the multiple battery cells, the total balancing duration of the battery cell in the target time period may be: the sum of the durations of each balancing of the battery cell by the passive balancing function of the battery management system on the target vehicle within the target time period.

[0054] In addition, for one battery cell among the multiple battery cells, the total balancing time of the battery cell in the target time period may be: the time during which the balancing channel of the passive balancing function of the battery management system on the target vehicle is in an open state for the battery cell in the target time period.

[0055] In step S102, a reference total balancing time is determined according to the total balancing time of each battery cell in the target time period, and a difference between the total balancing time of each battery cell in the target time period and the reference total balancing time is calculated.

[0056] In a possible implementation, to determine the reference total balancing time, the maximum total balancing time among the total balancing time of the multiple battery cells in the target time period is determined as the reference total balancing time.

[0057] In another possible implementation, to determine the reference total balancing time, a median of the total balancing time of the plurality of cells in the target time period is determined as the reference total balancing time.

[0058] For one battery cell among the multiple battery cells, a difference between a total balancing time length of the battery cell in the target time period and a reference total balancing time length is: the reference total balancing time length minus the total balancing time length of the battery cell in the target time period.

[0059] In step S103 , when the difference between the total balancing time of the target cell in the target time period and the reference total balancing time is greater than the total balancing time deviation threshold, the target cell is determined to be an abnormal cell.

[0060] The target battery cell is any one of the multiple battery cells.

[0061] In step S103 , it is determined whether the difference between the total balancing time of the target battery cell in the target time period and the reference total balancing time is greater than a total balancing time deviation threshold.

[0062] It should be noted that, in the embodiment of the present disclosure, the total balancing duration deviation threshold should be understood as a variable. Before executing step S103, the total balancing duration deviation threshold is determined according to the duration of the target time period.

[0063] In the embodiment of the present disclosure, the total balancing time deviation threshold may refer to: a maximum difference in the total balancing time of two normal battery cells in the target time period.

[0064] In one possible implementation, in order to determine the total balancing time deviation threshold, before the method for identifying abnormal cells provided by the embodiment of the present disclosure is executed for the first time, the total balancing time of each normal cell among multiple normal cells in a historical time period is obtained. The historical time period is before the target time period. Among them, any one of the multiple normal cells belongs to the same model as the cell of the target battery pack. The multiple normal cells are always normal during the historical time period. The total balancing time of the normal cell in the historical time period can indicate: how long the normal cell was balanced in the historical time period. The minimum total balancing time and the maximum total balancing time can be found from the total balancing time of each normal cell among the multiple normal cells in the historical time period. The maximum total balancing time is subtracted from the minimum total balancing time to obtain the difference between the maximum total balancing time and the minimum total balancing time. When determining the total balance duration deviation threshold, the length of the target time period can be divided by the length of the historical time period to obtain the ratio of the length of the target time period to the length of the historical time period. The difference between the maximum total balance duration and the minimum total balance duration can be multiplied by the ratio of the length of the target time period to the length of the historical time period to obtain a product. The product or a preset multiple of the product is determined as the total balance duration deviation threshold.

[0065] It should be noted that, usually, when there are abnormal cells in the battery pack, the number of abnormal cells in the battery pack is small, that is, when there are abnormal cells in the battery pack, most of the cells in the battery pack are normal cells, and when there are abnormal cells in the battery pack, a large number of cells in the battery pack will not be abnormal cells. When there are abnormal cells in the battery pack, the number of abnormal cells in the battery pack is usually one or two.

[0066] In the embodiment of the present disclosure, when identifying abnormal cells, the following characteristics of abnormal cells are taken into consideration: the self-discharge of abnormal cells is large, the voltage of abnormal cells is the lowest voltage for a long time, abnormal cells are not balanced for a long time, and the total equalization time of abnormal cells in the same time period is very short compared to the total equalization time of normal cells in the same time period. The lowest voltage is relative to the voltage of normal cells.

[0067] When an abnormal cell exists in the target battery pack, most of the cells in the target battery pack are normal cells, and the reference total balancing time is close to or equal to the total balancing time of a normal cell in the target time period. The reference total balancing time may refer to the maximum difference between the total balancing time of two normal cells in the target time period. When an abnormal cell exists in the target battery pack, the difference between the total balancing time of the normal cell in the target battery pack in the target time period and the reference total balancing time will not be greater than the total balancing time deviation threshold. Since the total balancing time of the abnormal cell in the target battery pack in the target time period is very small compared to the total balancing time of the normal cell in the target battery pack in the target time period, the difference between the total balancing time of the abnormal cell in the target battery pack in the target time period and the reference total balancing time is greater than the total balancing time deviation threshold. Therefore, when the difference between the total balancing time of the target cell in the target time period and the reference total balancing time of the target cell among multiple cells is greater than the total balancing time deviation threshold, the target cell can be determined as an abnormal cell, so that the abnormal cell can be identified more accurately. Improve the accuracy of identifying abnormal cells.

[0068] refer to Figure 2 , which shows a flow chart of a method for identifying abnormal battery cells provided in an embodiment of the present disclosure.

[0069] In step S201 , when the accumulated working time of the target battery pack is not less than a preset time, the total balancing time of each of the multiple battery cells of the target battery pack in the target time period is obtained.

[0070] In a possible implementation, the target time period may be: a time period between the time when the target battery pack is installed on the target vehicle and the current time.

[0071] The cumulative operation of the target battery pack may indicate how much time the target battery pack has operated since the target battery pack was mounted on the target vehicle.

[0072] In an embodiment of the present disclosure, when the cumulative working time of the target battery pack is not less than the preset time, the total balancing time of each of the multiple cells of the target battery pack in the target time period is obtained. That is to say, when the cumulative working time of the target battery pack is not less than the preset time, the method for identifying abnormal cells provided by the embodiment of the present disclosure is executed, taking into account that in the early stage of using the target battery pack, the cells of the target battery pack usually do not have abnormalities. Therefore, when the cumulative working time of the target battery pack is not less than the preset time, the method for identifying abnormal cells provided by the embodiment of the present disclosure is executed, which can save resources consumed by identifying abnormal cells.

[0073] In step S202, an average of total balancing time of the battery cells in the target time period is calculated, the average is determined as a reference total balancing time period, and a difference between the total balancing time of each battery cell in the target time period and the reference total balancing time period is calculated.

[0074] In step S202, total balancing times of the multiple battery cells in the target time period are added together to obtain a sum of total balancing times of the multiple battery cells in the target time period, and the sum is divided by the number of battery cells included in the multiple battery cells to obtain a mean total balancing time of the battery cells in the target time period.

[0075] In step S202, for one battery cell among the multiple battery cells, the total balancing time of the battery cell in the target time period is subtracted from the average value to obtain a difference between the total balancing time of the battery cell in the target time period and a reference total balancing time period.

[0076] Calculate the average CellBalTime of the total balancing time of multiple cells in the target battery pack during the target time period avg It can be expressed as:

[0077]

[0078] Among them, CellBalTime i is the total balancing time of the i-th battery cell among the multiple battery cells in the target time period, and N is the number of battery cells included in the multiple battery cells.

[0079] The difference between the total balancing time of the i-th cell in the target time period and the reference total balancing time CellBalTimeDelta i It can be expressed as:

[0080] CellBalTimeDelta i =CellBalTime avg -CellBalTime i

[0081] In step S203, when the difference between the total balancing time of the target cell in the target time period and the reference total balancing time is greater than the total balancing time deviation threshold and meets the consistency condition, the target cell is determined as an abnormal cell.

[0082] The target battery cell is any one of the multiple battery cells.

[0083] The consistency condition may be: when the multiple battery cells are all at rest, a voltage difference between a battery cell with the largest voltage among the multiple battery cells and a battery cell with the smallest voltage among the multiple battery cells when the multiple battery cells are all at rest is less than a voltage difference threshold.

[0084] Among them, the voltage difference between the voltage of the battery cell with the largest voltage among the multiple battery cells and the voltage of the battery cell with the smallest voltage among the multiple battery cells when the multiple battery cells are all at rest is: the voltage of the battery cell with the largest voltage among the multiple battery cells minus the voltage of the battery cell with the smallest voltage among the multiple battery cells when the multiple battery cells are all at rest.

[0085] It should be noted that meeting the consistency condition can reflect that the passive balancing function of the battery management system on the target vehicle has a good balancing effect and the passive balancing function of the battery management system on the target vehicle is normal. It can avoid the situation where the difference between the total balancing time of the target battery cell in the target time period and the reference total balancing time is greater than the total balancing time deviation threshold due to the abnormal passive balancing function of the battery management system on the target vehicle, not the abnormal target battery cell. Improve the accuracy of identifying abnormal batteries.

[0086] In a possible implementation, in order to determine the total balancing time deviation threshold, the total balancing time deviation threshold can be determined according to the maximum deviation of the self-discharge rate of the normal battery cell, the duration of the target time period, and the balancing current used to determine the total balancing time deviation threshold, wherein the maximum deviation of the self-discharge rate of the normal battery cell is the maximum self-discharge rate of the normal battery cell minus the minimum self-discharge rate of the normal battery cell. The maximum deviation of the self-discharge rate of the normal battery cell can be multiplied by the duration of the target time period to obtain the product of the maximum deviation of the self-discharge rate of the normal battery cell and the duration of the target time period, and the product of the maximum deviation of the self-discharge rate of the normal battery cell and the duration of the target time period can be divided by the balancing current used to determine the total balancing time deviation threshold to obtain the total balancing time deviation threshold.

[0087] It should be noted that the total balancing time deviation threshold determined according to the maximum self-discharge rate deviation of the normal battery cell can be understood as: the difference between the total balancing time of the normal battery cell with the maximum self-discharge rate and the normal battery cell with the minimum self-discharge rate in the target time period.

[0088] The maximum self-discharge rate of a normal cell is usually provided by the cell manufacturer. The maximum self-discharge rate of a normal cell is an indicator in the qualification standard of mass-produced cells. The maximum self-discharge rate of a normal cell can also be preset or obtained by measurement. The minimum self-discharge rate of a normal cell can be preset.

[0089] As an example, the maximum self-discharge rate of a normal battery cell is 3 Ah / month, and the minimum self-discharge rate of a normal battery cell is 0 Ah / month. The maximum deviation of the self-discharge rate of a normal battery cell = 3-0 = 3 Ah / month.

[0090] In a possible implementation, the balancing current used to determine the total balancing time deviation threshold is preset.

[0091] In another possible implementation, the passive balancing function of the battery management system on the target vehicle performs N balancing operations within the target time period, and the average value of the balancing currents used in the N balancing operations can be used as the balancing current for determining the total balancing time deviation threshold.

[0092] In the disclosed embodiment, the total balancing time deviation threshold is determined by using the self-discharge rate of the normal battery cell with a high correlation with the balancing time, so as to improve the accuracy of the total balancing time deviation threshold, i.e., the maximum difference of the total balancing time of two normal batteries in the target time period. The total balancing time of the target battery cell in the target time period is compared with the maximum difference of the total balancing time of two normal batteries in the target time period, which is more accurate, to identify the abnormal battery cell. Thus, the accuracy of identifying the abnormal battery cell is improved.

[0093] In one possible implementation, determining the total balancing time deviation threshold according to the maximum self-discharge rate deviation of the normal battery cell, the duration of the target time period, and the balancing current used to determine the total balancing time deviation threshold includes: determining the total balancing time deviation threshold according to the maximum self-discharge rate deviation of the normal battery cell, the duration of the target time period, a preset deviation coefficient, and the balancing current used to determine the total balancing time deviation threshold. The maximum self-discharge time deviation of the normal battery cell in the target time period can be obtained by multiplying the product of the maximum self-discharge rate deviation of the normal battery cell and the duration of the target time period by the preset deviation coefficient. The total balancing time deviation threshold is obtained by dividing the maximum self-discharge time deviation of the normal battery cell in the target time period by the balancing current used to determine the total balancing time deviation threshold.

[0094] The preset deviation coefficient may reflect the multiple relationship between the maximum deviation of the self-discharge duration of the normal battery cell in the target time period and the total balancing duration deviation threshold.

[0095] That is, the preset deviation coefficient can reflect how many times the total balancing time deviation threshold is the maximum deviation of the self-discharge time of the normal battery cell in the target time period.

[0096] According to the maximum deviation of the self-discharge rate of the normal battery cell, the duration of the target time period, the preset deviation coefficient, and the balancing current used to determine the total balancing time deviation threshold, the total balancing time deviation threshold TimeThd can be expressed as:

[0097]

[0098] Among them, QMaxMonth is the maximum deviation of the self-discharge rate of a normal battery cell, M is the duration of the target time period, CorrFactor is the preset deviation coefficient, and BalCurrent is the balancing current used to determine the total balancing time deviation threshold.

[0099] The unit of the maximum deviation of the self-discharge rate of the normal battery cell may be Ah / month, the unit of the duration of the target time period may be month, and the unit of the balancing current used to determine the total balancing time deviation threshold may be A.

[0100] The preset deviation coefficient can reflect the multiple relationship between the maximum deviation of the self-discharge time of a normal battery cell in the target time period and the total balancing time deviation threshold, and can flexibly adjust the multiple relationship between the maximum deviation of the self-discharge time of a normal battery cell in the target time period and the total balancing time deviation threshold, thereby improving the flexibility of obtaining the total balancing time deviation threshold.

[0101] As an example, the target battery pack consists of 100 cells. The target time period is the time period between the moment when the target battery pack is installed on the target vehicle and the current moment. The duration of the target time period is 10 months. The maximum deviation of the self-discharge rate of a normal cell is 3Ah / month, and the preset deviation coefficient is 2. The balancing current used to determine the total balancing time deviation threshold is 0.05A.

[0102] In this example, the total balancing time deviation threshold TimeThd = 3*10*2 / 0.05 = 1200 hours

[0103] In this example, the battery management system on the target vehicle calculates the total balancing time of each of the 100 cells in the target battery pack during the target time period as shown in Table 1:

[0104] Table 1

[0105]

[0106]

[0107] In this example, the average CellBalTime of the total balancing time of the cells in the target battery pack in the target time period is calculated. avg .

[0108]

[0109] In this example, an average of total balancing time lengths of the battery cells in the target time period is a reference total balancing time length.

[0110] In this example, the difference between the total balancing time of the target time period for each of the 100 cells in the target battery pack and the reference total balancing time is shown in Table 2:

[0111] Table 2

[0112] Cell number The difference between the total balancing time of the battery cell in the target time period and the reference total balancing time (hours) 1 3371 2～50 471 51～100 -529

[0113] In this example, only the difference between the total balancing time of battery cell 1 in the target time period and the reference total balancing time, i.e., 3371 hours, is greater than the total balancing time deviation threshold, i.e., 1200 hours. Therefore, battery cell 1 can be determined to be an abnormal battery cell, and the self-discharge of battery cell 1 is too large.

[0114] refer to Figure 3 , which shows a flowchart of an example of identifying abnormal batteries.

[0115] In this example, when the cumulative operating time of the target battery pack is not less than 10 months, the identification of abnormal cells in the target battery pack is started.

[0116] In this example, the average of the total balancing time of the cells in the target time period among the 100 cells of the target battery pack is calculated, and the difference between the total balancing time of each cell in the target time period and the average is calculated.

[0117] In this example, the total balancing time deviation threshold is determined according to the maximum self-discharge rate deviation of the normal battery cell, the duration of the target time period, the preset deviation coefficient, and the balancing current used to determine the total balancing time deviation threshold.

[0118] When the difference between the total balancing time of the i-th battery cell in the target time period and the mean value is greater than the total balancing time deviation threshold and meets the consistency condition, the i-th battery cell is determined as an abnormal battery cell.

[0119] The embodiments of the present disclosure provide a device for identifying abnormal battery cells. The device for identifying abnormal battery cells is used to implement the above-mentioned embodiments and preferred embodiments, and the descriptions that have been made will not be repeated. As used below, the term "unit" can be a combination of software and / or hardware that implements a predetermined function. Although the system described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0120] The device for identifying abnormal cells comprises:

[0121] An acquisition unit, used to acquire a total balancing time of each battery cell in a target battery pack in a target time period;

[0122] A determination unit, configured to determine a reference total balancing time according to the total balancing time of each battery cell in the target time period, and calculate a difference between the total balancing time of each battery cell in the target time period and the reference total balancing time;

[0123] An identification unit is used to determine a target battery cell as an abnormal battery cell when the difference between the total balancing time of a target battery cell among the multiple battery cells in a target time period and the reference total balancing time is greater than a total balancing time deviation threshold, wherein the target battery cell is any one of the multiple battery cells.

[0124] In a possible implementation manner, the determination unit is further configured to calculate an average of total balancing time durations of the battery cells in a target time period, and determine the average as the reference total balancing time duration.

[0125] In a possible implementation, the device for identifying abnormal cells further includes:

[0126] The calculation unit is used to determine the total balancing time deviation threshold according to the maximum deviation of the self-discharge rate of the normal battery cell, the duration of the target time period, and the balancing current used to determine the total balancing time deviation threshold, wherein the maximum deviation of the self-discharge rate of the normal battery cell is the maximum self-discharge rate of the normal battery cell minus the minimum self-discharge rate of the normal battery cell.

[0127] In a possible implementation, the calculation unit is further used to determine the total balancing time deviation threshold according to the maximum deviation of the self-discharge rate of the normal battery cell, the duration of the target time period, the preset deviation coefficient, and the balancing current used to determine the total balancing time deviation threshold.

[0128] In a possible implementation, the acquisition unit is further configured to acquire a total balancing duration of each of the multiple battery cells of the target battery pack in the target time period when the accumulated operating duration of the target battery pack is not less than a preset duration.

[0129] In one possible implementation, when the difference between the total balancing time of the target battery cell in the target time period and the reference total balancing time is greater than the total balancing time deviation threshold, determining the target battery cell as an abnormal battery cell includes: when the difference between the total balancing time of the target battery cell in the target time period and the reference total balancing time is greater than the total balancing time deviation threshold and meets a consistent condition, determining the target battery cell as an abnormal battery cell, wherein the consistent condition is that the voltage difference between the voltage of the battery cell with the largest voltage among the multiple battery cells when the multiple battery cells are all at rest and the voltage of the battery cell with the smallest voltage among the multiple battery cells when the multiple battery cells are all at rest is less than the voltage difference threshold.

[0130] In this embodiment, the device is presented in the form of a functional unit, where the unit refers to an ASIC circuit, a processor and a memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0131] The further functional description of each of the above units is the same as that of the above corresponding embodiments and will not be repeated here.

[0132] refer to Figure 4 , which shows a schematic diagram of the structure of a computer device provided by an embodiment of the present disclosure, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. The various components are connected to each other using different buses for communication, and can be installed on a common motherboard or installed in other ways as needed. The processor can process instructions executed in the computer device, including instructions stored in or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system).

[0133] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0134] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0135] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0136] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0137] The computer device further includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means.

[0138] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0139] The embodiments of the present disclosure also provide a computer-readable storage medium. The above-mentioned method according to the embodiments of the present disclosure can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium and downloaded through a network, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state drive, etc.; further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0140] A portion of the embodiments of the present disclosure may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can execute or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of computer program instructions in computer-readable media includes, but is not limited to, source files, executable files, installation package files, etc., and accordingly, the way in which computer program instructions are executed by a computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0141] Although the embodiments of the present disclosure have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present disclosure, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for identifying abnormal battery cells, characterized in that: The method comprises: Obtaining a total balancing time of each battery cell in a target battery pack in a target time period; Determine a reference total balancing time according to the total balancing time of each battery cell in the target time period, and calculate a difference between the total balancing time of each battery cell in the target time period and the reference total balancing time; When the difference between the total balancing time of a target cell among the multiple cells in the target time period and the reference total balancing time is greater than a total balancing time deviation threshold, the target cell is determined as an abnormal cell, wherein the target cell is any one of the multiple cells.

2. The method according to claim 1, characterized in that Determining a reference total balancing time according to the total balancing time of each battery cell in the target time period includes: An average of total balancing time lengths of the battery cells in a target time period is calculated, and the average value is determined as the reference total balancing time length.

3. The method according to claim 1, characterized in that The method further comprises: The total balancing time deviation threshold is determined according to the maximum self-discharge rate deviation of the normal battery cell, the duration of the target time period, and the balancing current used to determine the total balancing time deviation threshold, wherein the maximum self-discharge rate deviation of the normal battery cell is the maximum self-discharge rate of the normal battery cell minus the minimum self-discharge rate of the normal battery cell.

4. The method according to claim 3, characterized in that According to the maximum deviation of the self-discharge rate of the normal battery cell, the duration of the target time period, and the balancing current used to determine the total balancing time deviation threshold, determining the total balancing time deviation threshold includes: The total balancing time deviation threshold is determined according to the maximum deviation of the self-discharge rate of the normal battery cell, the duration of the target time period, the preset deviation coefficient, and the balancing current used to determine the total balancing time deviation threshold.

5. The method according to claim 2, characterized in that: Obtaining the total balancing time of each of the multiple cells of the target battery pack in the target time period includes: When the accumulated working time of the target battery pack is not less than the preset time, the total balancing time of each battery cell in the plurality of battery cells of the target battery pack in the target time period is obtained.

6. The method according to any one of claims 1 to 5, characterized in that When a difference between a total balancing time of a target cell among the multiple cells in a target time period and the reference total balancing time is greater than a total balancing time deviation threshold, determining the target cell as an abnormal cell includes: When the difference between the total balancing time of the target battery cell in the target time period and the reference total balancing time is greater than the total balancing time deviation threshold and meets the consistency condition, the target battery cell is determined as an abnormal battery cell, wherein the consistency condition is that the voltage difference between the battery cell with the largest voltage among the multiple battery cells when the multiple battery cells are all at rest and the battery cell with the smallest voltage among the multiple battery cells when the multiple battery cells are all at rest is less than the voltage difference threshold.

7. A device for identifying abnormal battery cells, characterized in that: include: An acquisition unit, used to acquire a total balancing time of each battery cell in a target battery pack in a target time period; A determination unit, configured to determine a reference total balancing time according to the total balancing time of each battery cell in the target time period, and calculate a difference between the total balancing time of each battery cell in the target time period and the reference total balancing time; An identification unit is used to determine a target battery cell as an abnormal battery cell when the difference between the total balancing time of a target battery cell among the multiple battery cells in a target time period and the reference total balancing time is greater than a total balancing time deviation threshold, wherein the target battery cell is any one of the multiple battery cells.

8. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method according to any one of claims 1 to 6 by executing the computer instructions.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method according to any one of claims 1 to 6.

10. A computer program product, characterized in that The method comprises computer instructions for causing a computer to execute the method according to any one of claims 1 to 6.

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