Battery detection method, device, equipment and system, battery module and energy storage box

Abstract

According to the battery detection method, device, equipment and system, the battery module and the energy storage box provided by the embodiment of the invention, the detection result of the battery cell is determined through the electrical parameters of the battery cells aligned in time, and the detection result is used for determining whether the battery cell has circulating current or not, so that a detection error caused by time misalignment in circulating current detection can be prevented, and the detection accuracy is improved. And the accuracy of circulation detection is improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery detection method, device, equipment, system, battery module and energy storage box. Background Art

[0002] When a battery module includes multiple cells connected in parallel, it's theoretically desirable for them to have the same electromotive force and internal resistance. However, in practice, due to manufacturing variations or varying degrees of aging, the electromotive force and internal resistance of each cell may vary. When these parameters are mismatched, circulating currents may occur in the parallel cells, affecting the safe and stable operation of the battery module.

[0003] Therefore, it is particularly important to accurately detect the circulating current of the battery cell. Summary of the Invention

[0004] Embodiments of the present application provide a battery detection method, apparatus, device, system, battery module, and energy storage box for accurately detecting whether circulating current exists in a battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery detection method, comprising:

[0006] Acquiring electrical parameters of a plurality of battery cells, wherein the electrical parameters of the battery cells are aligned in time;

[0007] Determine a detection result of the battery cell, where the detection result is obtained based on the electrical parameter, and the detection result is used to determine whether a circulating current exists in the battery cell of the battery cell.

[0008] In a possible implementation, the electrical parameter includes current.

[0009] In a possible implementation, obtaining electrical parameters of the plurality of battery cells includes:

[0010] Initial electrical parameters of multiple battery cells in a target phase are acquired, and the initial electrical parameters are interpolated to obtain the electrical parameters aligned in time.

[0011] In a possible implementation, acquiring initial electrical parameters of a plurality of battery cells in a target phase and interpolating the initial electrical parameters to obtain the time-aligned electrical parameters includes:

[0012] Obtain initial electrical parameters of multiple battery cells at the target stage using minute-level data;

[0013] The initial electrical parameters are interpolated to obtain the electrical parameters aligned with second-level data.

[0014] In a possible implementation, interpolating the initial electrical parameters includes:

[0015] The initial electrical parameters are interpolated based on a linear interpolation method.

[0016] In a possible implementation manner, the electrical parameter includes parameter values ​​at multiple moments;

[0017] Determining the detection result of the battery cell includes:

[0018] Determining an average value of parameter values ​​of the plurality of battery cells at each moment;

[0019] The detection result of the battery cell is determined according to the parameter value and the average value at each moment.

[0020] In a possible implementation, determining a detection result of the battery cell, where the detection result is used to determine whether a circulating current exists in the battery cell, includes:

[0021] Determine the absolute value of the difference between the parameter value at each moment and the average value;

[0022] When the absolute value of the difference is greater than or equal to a first preset threshold, determining that a circulating current exists in the battery cell;

[0023] When the absolute value of the difference is smaller than the first preset threshold, it is determined that no circulating current exists in the battery cell.

[0024] In one possible implementation, the method further includes:

[0025] When the detection result determines that a circulating current exists in the battery cell, the processing priority of the battery cell is determined according to the maximum value of the absolute values ​​of the difference.

[0026] In a possible implementation, determining the processing priority of the battery cell according to the maximum value of the absolute values ​​of the differences includes:

[0027] When the maximum value is greater than or equal to a second preset threshold, determining that the processing priority of the battery cell is the first priority; and the second preset threshold is greater than the first preset threshold;

[0028] When the maximum value is less than the second preset threshold, the processing priority of the battery cell is determined to be a second priority; and the second priority is lower than the first priority.

[0029] In one possible implementation, the method further includes:

[0030] When determining that the processing priority of the battery cells is the first priority, replacing at least some of the battery cells;

[0031] When it is determined that the processing priority of the battery cell is the second priority, determining a detection result of the battery cell in the next target stage according to the electrical parameters of the battery cell in the next target stage;

[0032] When the detection result of the next target stage determines that the battery cells have circulating current, at least some of the battery cells are replaced; when the detection result of the next target stage determines that the battery cells do not have circulating current, the battery cells are not replaced.

[0033] In a possible implementation, the start time of the target phase is the earliest time when the absolute value of the electrical parameter is greater than a third preset threshold, and the end time of the target phase is the latest time when the absolute value of the electrical parameter is greater than the third preset threshold.

[0034] In one possible implementation, the method further includes:

[0035] When it is determined that a circulating current exists in the battery cell, an early warning is issued.

[0036] In one possible implementation, the method further includes:

[0037] Among the multiple charging stages and discharging stages, the stage in which the current difference of the battery cells exists is determined to be the target stage.

[0038] In one possible implementation, the method further includes:

[0039] When the electrical parameter lengths of the plurality of battery cells are the same, determining the Manhattan distance between each battery cell and the other battery cells;

[0040] When the electrical parameter lengths of at least some of the battery cells are different, determining the cumulative distance between each battery cell and the other battery cells;

[0041] Determine whether a circulating current exists in the battery cell according to the Manhattan distance or the cumulative distance.

[0042] In a possible implementation, determining whether a circulating current exists in the battery cell according to the Manhattan distance or the cumulative distance includes:

[0043] When the median of the Manhattan distance or the cumulative distance is greater than or equal to a third preset threshold, determining that there is a current difference in the battery cell;

[0044] When the median is smaller than the third preset threshold, it is determined that there is no current difference among the battery cells.

[0045] In one possible implementation, the method further includes:

[0046] After determining the Manhattan distance or the cumulative distance, normalizing the Manhattan distance or the cumulative distance;

[0047] Based on the normalized results, the median is determined.

[0048] In a second aspect, an embodiment of the present application provides a battery detection device, the device comprising:

[0049] An acquisition module, configured to acquire electrical parameters of a plurality of battery cells, wherein the electrical parameters of the battery cells are aligned in time;

[0050] A determination module is used to determine a detection result of the battery cell, where the detection result is obtained based on the electrical parameter, and the detection result is used to determine whether a circulating current exists in the battery cell.

[0051] In a third aspect, an embodiment of the present application provides an electronic device, comprising: a memory, a processor;

[0052] The memory stores computer-executable instructions;

[0053] The processor executes the computer-executable instructions stored in the memory, so that the processor executes the above first aspect and / or various possible implementations of the first aspect.

[0054] In a fourth aspect, the present application provides a battery management system, comprising the electronic device of the third aspect.

[0055] In a fifth aspect, the present application provides an energy storage box, comprising the battery management system of the fourth aspect, and multiple battery packs.

[0056] In a sixth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the first aspect above and / or various possible implementation methods of the first aspect.

[0057] In a seventh aspect, an embodiment of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the above first aspect and / or various possible implementation methods of the first aspect.

[0058] The battery detection method, device, equipment, system, battery module and energy storage box provided in the embodiments of the present application determine the detection results of the battery cells by the electrical parameters of the battery cells aligned in time. The detection results are used to determine whether there is a circulating current in the battery cells, thereby preventing errors caused by time misalignment in the circulating current detection and improving the detection accuracy of the circulating current detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0060] Figure 1 Schematic diagram of the battery detection method provided in this application Figure 1;

[0061] Figure 2 Schematic diagram of current before and after interpolation provided by this application;

[0062] Figure 3 A schematic diagram of the structure of the battery detection device provided in this application;

[0063] Figure 4 This is a schematic diagram of the structure of the electronic device provided in this application.

[0064] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0065] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0066] Battery modules typically consist of multiple relatively independent cells connected in parallel. Maintaining relatively consistent electrical parameters across these cells not only impacts the module's service life but also directly determines its safe and stable operation. For example, inconsistent current flow across cells can cause circulating current, impacting the module's service life and safe and stable operation. Therefore, accurate detection of circulating current is crucial to identify issues promptly and ensure proper battery maintenance.

[0067] Each battery cell has a corresponding recording time for its electrical parameters. Misalignment of the recording times of the electrical parameters of each battery cell will lead to errors in circulating current detection. In particular, minute-level errors at the end of battery charging or discharging may lead to large error estimates, affecting the detection accuracy of circulating current detection.

[0068] To this end, the present application proposes a battery detection method, which determines whether there is a circulating current in the battery cell by aligning the electrical parameters of the battery cell in time, thereby accurately detecting whether there is a circulating current in the battery cell.

[0069] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0070] Figure 1 Schematic diagram of the battery detection method provided in this application Figure 1 ,like Figure 1 As shown, the method includes:

[0071] S101 : Acquire electrical parameters of a plurality of battery cells, where the electrical parameters of the battery cells are aligned in time.

[0072] The energy storage box includes multiple battery packs, which are connected in parallel.

[0073] When recording the electrical parameters of different battery cells, they are usually timed separately. Therefore, it is difficult to maintain temporal consistency between the recording times of the electrical parameters of each battery cell, and there may be temporal misalignment. For example, when recording the current of the battery packs in the energy storage box, they are usually timed separately. Therefore, it is difficult to maintain temporal consistency between the recording times of the current data of each battery pack, and there may be temporal misalignment.

[0074] In some optional embodiments, initial electrical parameters of multiple battery cells in a target phase are obtained and interpolated to obtain time-aligned electrical parameters, so that the presence of circulating current in the battery cells can be accurately detected using the time-aligned electrical parameters. The target phase may include at least one of a charging phase, a discharging phase, a period of time after the end of the charging phase, and a period of time after the end of the discharging phase.

[0075] For example, electrical parameters in at least one of the multiple charging stages and multiple discharging stages of the battery cell are interpolated to align the coarse-grained electrical parameters in time, so as to more accurately detect whether a circulating current exists in the battery cell.

[0076] In one possible implementation, the electrical parameter includes current, so that the presence of circulating current between the cells can be detected by current. In other real-time methods, the electrical parameter may also include other parameters such as voltage and temperature.

[0077] For example, the current data of each battery pack in at least one of the multiple charging stages and multiple discharging stages of the energy storage box is interpolated to align the coarse-grained current sequence data in time so that the battery circulation can be detected more accurately.

[0078] It should be noted that when the energy storage box is at rest, the current of each battery pack is zero or close to zero. However, during the charging or discharging phase, the absolute value of the current in the energy storage box is significantly greater than zero, for example, around 160A. The circulating current of the battery packs within the energy storage box mostly occurs during the charging or discharging phase of the energy storage box. However, there are exceptions. During a short period after the end of charging or discharging, due to the influence of circulating current between battery packs, even during the resting phase of the energy storage box, a large current may still exist. The circulating current of the battery packs in the energy storage box often occurs during the charging and discharging phases and within a short period after the end of charging and discharging. The frequency of charging and discharging of the energy storage box in an energy storage power station is basically one charge and one discharge. Based on a charge and discharge rate of 0.5C, the energy storage box is in a resting state for the vast majority of the time. Testing the energy storage box for the entire time period would inevitably lead to low computational efficiency. Therefore, the target phase can include at least one of the charging phase, the discharging phase, the period after the charging phase, or the period after the discharging phase. The charging phase herein may include the entire charging phase or a period of time within the charging phase. Similarly, the discharging phase herein may include the entire discharging phase or a period of time within the discharging phase. The target phase may also include a period of time consisting of multiple moments within the charging phase or the discharging phase.

[0079] In some optional embodiments, thresholds can be set to identify the onset time of circulating current, determine its duration, and judge its severity. The target phase begins at the earliest point in time when the absolute value of an electrical parameter exceeds a third preset threshold, and ends at the latest point in time when the absolute value of an electrical parameter exceeds the third preset threshold. Accordingly, the electrical parameters of the battery cell between the start and end times are taken, and all data between these two times that indicate the presence of circulating current in the battery cell is included.

[0080] For example, thresholds can be set to identify the onset of battery circulating current, determine its duration, and assess its severity. The target phase begins at the earliest and latest times when the absolute current value exceeds a third preset threshold. Accordingly, the battery pack's current data between the start and end times is collected. This includes all data indicating potential severe circulating current in the battery pack between these two times. Furthermore, the number of start and end times to be tested corresponds to the number of discharge phases or discharge stages in the energy storage box.

[0081] For example, if the energy storage box includes nine battery packs, the start time is the earliest time when the absolute current value of the nine battery packs is greater than or equal to a third preset threshold, and the end time is the latest time when the absolute current value of the nine battery packs is greater than or equal to the third preset threshold. The third preset threshold can be, for example, 10 A or a value close to 10 A.

[0082] In one possible implementation, the current data of the battery pack in at least one target phase of the energy storage box is interpolated to align the current data of the battery pack in the target phase in time. Continuous data at any time interval can be generated through mathematical interpolation to avoid errors caused by asynchronous sampling time.

[0083] In one possible implementation, initial electrical parameters of minute-level data of multiple battery cells in the target phase are obtained, and the initial electrical parameters are interpolated to obtain electrical parameters aligned with second-level data, thereby interpolating and completing the originally sparse minute-level electrical parameters into electrical parameters of second-level data, and achieving more accurate circulating current detection through alignment of second-level data.

[0084] Minute-level electrical parameters refer to the electrical parameters of battery cells recorded once per minute, i.e., time series data collected at a one-minute interval. Second-level data refers to the electrical parameters of battery cells at each second, and alignment of second-level data refers to aligning the parameter values ​​of the battery cells' minute-level electrical parameters at each second.

[0085] For example, the minute-level current data of the battery pack in at least one target stage of the energy storage box is interpolated to align the current data of the battery pack in the target stage with the second-level data, thereby interpolating and completing the originally sparse minute-level current data into second-level data, and achieving a more accurate battery circulation current assessment through the alignment of the second-level data.

[0086] The battery pack's minute-level current data refers to current data recorded once a minute, i.e., time series data collected at a one-minute interval. Second-level data refers to the battery pack's current data recorded every second, and alignment of the second-level data refers to aligning the battery pack's minute-level current data with the current values ​​recorded every second.

[0087] For example, Figure 2 As shown in the left figure, the recording time of the current data of the 9 battery groups is different, mainly concentrated around 21:33 minutes and 21:34 minutes. By interpolating the current data of each battery group, the current data of each battery group at each second is supplemented, as shown in the figure below. Figure 2 As shown in the right figure, after completing the data, the current data of each battery group per second can be obtained.

[0088] In another possible implementation, if the cell electrical parameters are collected at other frequencies, time alignment can also be achieved. For example, if the cell electrical parameters are collected at a frequency of seconds, the second-level electrical parameters can be aligned at the millisecond level. For example, if the cell electrical parameters are collected at a frequency of multiple minutes, minute-level alignment can also be achieved.

[0089] For example, if the current data of the battery pack is collected at other frequencies, time alignment can also be achieved. For example, if the current data of the battery pack is collected at a frequency of seconds, the second-level current data can also be aligned at the millisecond level.

[0090] In a possible implementation, the initial electrical parameters are interpolated based on a linear interpolation method to obtain time-aligned electrical parameters.

[0091] For example, the current data of the battery pack in at least one target phase of the energy storage box is interpolated, and the current data of the battery pack in the target phase is aligned in time through simple mathematical operations to improve efficiency.

[0092] For example, for any battery pack, the absolute value of the difference between the current value at the start and the current value at the end of the target phase is calculated. Based on the difference between the absolute value of the difference and the duration of the target phase, the current interval is determined. The current interval refers to the amount of current change in each time step, and the time step is, for example, seconds. Then, if the current value at the start is greater than the current value at the end, the current interval is continuously subtracted from the current value at the start until the current value at the end is reached. This will generate multiple current values ​​within the target phase, forming a linearly decreasing sequence from the beginning to the end. Conversely, if the current value at the start is less than the current value at the end, the current interval is continuously added from the current value at the start until the current value at the end is reached, forming a linearly increasing sequence.

[0093] In another possible implementation, the current data of the battery pack in the target phase may be interpolated by spline interpolation, nearest neighbor interpolation, polynomial interpolation, or the like.

[0094] S102: Determine a test result of the battery cell, where the test result is obtained based on electrical parameters and is used to determine whether a circulating current exists in the battery cell.

[0095] In the embodiment of the present application, since the electrical parameters of the battery cells are aligned in time, calculation errors caused by time misalignment can be prevented in circulating current detection, thereby improving the detection accuracy of circulating current.

[0096] In some optional embodiments, the electrical parameter includes parameter values ​​at multiple moments, an average value of the parameter values ​​of multiple cells at each moment is determined, and a cell detection result is determined based on the parameter value at each moment and the average value. By calculating the average value of the parameter value at each moment, the electrical parameter distribution between cells can be monitored in real time, which helps to promptly detect electrical parameter imbalances between cells and quickly identify circulation conditions.

[0097] For example, the electrical parameters include current, that is, the current values ​​at multiple moments. Accordingly, the average current of multiple battery packs at each moment can be determined, and based on the current value and average current at each moment, it can be determined whether there is battery circulation in the energy storage box. By calculating the average current at each moment, the current distribution between battery packs can be monitored in real time, which helps to promptly detect current imbalance between battery packs and thus quickly identify battery circulation phenomena.

[0098] It should be noted that each battery pack requires interpolation, and the interpolated current data for each battery pack includes current values ​​at multiple moments. The average current at each moment can then be determined based on the current values ​​of each battery pack. The average current at each moment and the current values ​​of each battery pack can then be used to determine whether the energy storage box has battery circulation.

[0099] In one possible implementation, the absolute value of the difference between the parameter value and the average value at each moment is determined. When the absolute value of the difference is greater than or equal to a first preset threshold, it is determined that there is a circulating current in the battery cell. When the absolute value of the difference is less than the first preset threshold, it is determined that there is no circulating current in the battery cell.

[0100] For example, the absolute value of the difference between the current value at each moment and the average current is determined. When the maximum value of the absolute value of the difference is greater than or equal to a first preset threshold, it is determined that battery circulating current exists in the energy storage box. When the maximum value of the absolute value of the difference is less than the first preset threshold, it is determined that battery circulating current does not exist in the energy storage box. The maximum value of the absolute value of the difference can be understood as the estimated battery circulating current when the battery pack voltage and battery pack internal resistance are unknown.

[0101] It should be noted that since the energy storage box includes multiple battery packs, the absolute value of the difference between the current value and the average current of each battery pack at each moment can correspond to multiple absolute values ​​of the difference. When the maximum of the absolute values ​​of the difference corresponding to any moment is greater than or equal to a first preset threshold, the energy storage box is determined to have battery circulating current. When the maximum of the absolute values ​​of the difference corresponding to each moment is less than the first preset threshold, the energy storage box is determined to have no battery circulating current. The first preset threshold can be determined based on actual conditions, for example, it can be 40A or a value close to 40A.

[0102] For example, if an energy storage tank includes nine battery packs, the current values ​​of the nine battery packs at each moment in the target phase are obtained, and the average current of the nine battery packs at each moment is calculated, thus obtaining the average current at each moment. The absolute value of the difference between the current values ​​of the nine battery packs and the average current at each moment is then calculated, thus obtaining nine absolute values ​​of the difference at each moment. The maximum value of these absolute values ​​of the difference at each moment is then determined, and based on the comparison of this maximum value with a first preset threshold, it is determined whether the energy storage tank has battery circulation.

[0103] In a possible implementation, when the detection result determines that a circulating current exists in the battery cell, the processing priority of the battery cell is determined according to the maximum absolute value of the difference, so that corresponding measures can be taken in time to improve the service life of the battery cell.

[0104] For example, when it is determined that battery circulation exists in the energy storage box, the processing priority of the battery circulation is determined according to the maximum value of the absolute value of the difference, so that corresponding measures can be taken in time.

[0105] In one possible implementation, when the maximum value is greater than or equal to a second preset threshold, the processing priority of the battery cell is determined to be the first priority, and the second preset threshold is greater than the first preset threshold. When the maximum value is less than the second preset threshold, the processing priority of the battery cell is determined to be the second priority, and the second priority is lower than the first priority. Accordingly, corresponding measures can be taken based on the processing priority of the battery cell to maintain safe and stable operation of the battery cell.

[0106] For example, when the maximum absolute value of the difference is greater than or equal to a first preset threshold and greater than or equal to a second preset threshold, the battery circulating current processing priority is determined to be the first priority. When the maximum absolute value of the difference is greater than or equal to the first preset threshold and less than the second preset threshold, the battery circulating current processing priority is determined to be the second priority. The second preset threshold is greater than the first preset threshold, and the second priority is lower than the first priority. Accordingly, appropriate measures can be taken based on the battery circulating current processing priority to maintain the safe and stable operation of the energy storage box. The second preset threshold can be determined based on actual conditions, for example, it can be 70A or a value close to 70A.

[0107] It is understandable that when the battery circulating current processing priority is first, the battery circulating current is more serious, and when the battery circulating current processing priority is second, the battery circulating current is less serious. Due to the inconsistency between energy storage battery packs, battery circulating current is inevitable between parallel energy storage battery packs. Small battery circulating current has little impact on the energy storage battery pack, but severe battery circulating current has a significant impact on energy storage safety and battery pack life.

[0108] It should be noted that because battery current changes abruptly rather than linearly, sudden changes in battery current at the end or start of charging, or the end or start of discharging, may cause large deviations in the interpolated data. However, these deviations are short-lived and do not represent a persistent battery circulation problem. This means that the battery circulation phenomenon is pseudo-battery circulation. Therefore, a time window threshold can be set. When the battery circulation duration is less than the time window threshold, the battery circulation phenomenon is considered pseudo-battery circulation.

[0109] In one possible embodiment, when it is determined that the processing priority of the battery cells is the first priority, at least some of the battery cells are replaced; when it is determined that the processing priority of the battery cells is the second priority, the detection results of the battery cells in the next target stage are determined according to the electrical parameters of the battery cells in the next target stage, and when the detection results of the next target stage determine that the battery cells have battery circulation, at least some of the battery cells are replaced, and when the detection results of the next target stage determine that the battery cells do not have battery circulation, the battery cells are not replaced.

[0110] For example, if the priority for battery circulating current is determined to be the first, at least some of the battery packs are replaced, for example, battery packs with consistency anomalies are replaced to maintain safe and stable operation of the energy storage box. If the priority for battery circulating current is determined to be the second, whether battery circulating current exists is determined based on current data from the next target phase. If so, at least some of the battery packs are replaced; otherwise, the battery packs are not replaced.

[0111] For example, when it is determined according to the current data of the next target stage that there is no battery circular current, it indicates that the battery circular current determined in the current target stage is a false battery circular current.

[0112] In a possible implementation, when it is determined that a circulating current exists in a battery cell, an early warning is issued so that an operator or an automated system can be promptly reminded to take measures to reduce the risk caused by the circulating current.

[0113] For example, after determining that battery circulation exists in the energy storage box, an early warning may be issued so that an operator or an automation system can be promptly reminded to take measures to reduce the risks brought by the battery circulation.

[0114] The battery detection method provided in the embodiment of the present application determines whether there is a circulating current in the battery cell through time-aligned electrical parameters, thereby preventing calculation errors caused by time misalignment and improving the accuracy of circulating current detection.

[0115] This application provides a battery detection method. Figure 1 Based on the embodiment shown, the method further includes:

[0116] S301 . Among multiple charging stages or discharging stages, determine a stage in which a current difference exists in a battery cell as a target stage.

[0117] In one possible implementation, when the electrical parameter lengths of multiple cells are the same, the Manhattan distance between each cell and the other cells is determined; when the electrical parameter lengths of at least some of the cells are different, the cumulative distance between each cell and the other cells is determined; and based on the Manhattan distance or the cumulative distance, whether there is a current difference between the cells is determined. Because cells are relatively sparse before interpolation, calculating distances is relatively fast, and therefore determining whether there is a current difference between cells based on distance is highly efficient.

[0118] For example, when the current data lengths of multiple battery groups are the same, the Manhattan distance between each battery group and the other battery groups is determined. When the current data lengths of at least some battery groups are different, the cumulative distance between each battery group and the other battery groups is determined. Then, based on the Manhattan distance or the cumulative distance, it is determined whether there is a current difference between each battery group and the other battery groups. The current consistency is calculated based on the distance to determine whether there is a current difference between the battery groups. Furthermore, because the battery groups are relatively sparse before interpolation, the distance calculation is relatively fast, making the method of determining whether there is a current difference between the battery groups based on distance more efficient.

[0119] The current data length refers to the number of current values ​​recorded during the target phase. If the number of current values ​​corresponding to each battery pack during the target phase is the same, the current data lengths of each battery pack are the same. If the number of current values ​​corresponding to some battery packs during the target phase is different, the current data lengths of at least some battery packs are different.

[0120] It should be noted that whether the current data lengths of each battery pack are the same can also be understood as whether the current data of each battery pack is aligned in the time dimension. The Manhattan distance between each battery pack and other battery packs includes the Manhattan distance between any two battery packs in the energy storage box. The cumulative distance between any battery pack and other battery packs includes the cumulative distance between any two battery packs in the energy storage box.

[0121] For example, if the current data length is the same, it can be approximately considered that the time when all battery packs record the current data is consistent. In this case, the Manhattan distance between the current data of two battery packs can be calculated. Assume that the current time series data of the first battery pack and the second battery pack are X and Y respectively, X=[x1,x2,...,x n ],Y=[y1,y2,...,y m ], where x1,x2,...,x n are the current values ​​of the first battery pack at different times, y1, y2, ..., y mis the current value of the second battery pack at different times. At this time, n and m are equal. Then the Manhattan distance d(X, Y) between the current data of the first battery pack and the second battery pack can be expressed as:

[0122] d(X,Y)=|x1-y1|+|x2-y2|+...+|x n -y m |.

[0123] For example, when the current data lengths of at least some battery groups are different, the dynamic time warping algorithm can be used to calculate the cumulative distance between the currents of two battery groups. The goal of the dynamic time warping algorithm is to find a path that connects the points in two sequences so that the cumulative distance on the path is minimized. d(x1, y1) also represents the Manhattan distance, but the Manhattan distance between the two points x1 and y1 is . The cumulative distance between the dynamic time warping is:

[0124] D(n,m)=d(x n ,y m )+min(D(n-1,m),D(n,m-1),D(n-1,m-1))

[0125] Here, D(n,m) represents the cumulative distance between the nth point in X and the mth point in Y, where n and m are not equal. Here, D(1,1) = d(x1,y1).

[0126] In practical applications, due to the differences in the methods of calculating the distance between data of the same and different lengths, we can manually set an appropriate coefficient to help balance the difference between the two:

[0127]

[0128] s is used to describe the consistency between the two, and α is a coefficient greater than 0. For example, α is set to 1.

[0129] In a possible implementation, when the median of the Manhattan distance or the cumulative distance is greater than or equal to a third preset threshold, it is determined that there is a current difference in the battery cells; when the median is less than the third preset threshold, it is determined that there is no current difference in the battery cells.

[0130] For example, after determining the Manhattan distance or cumulative distance between each battery group and the other battery groups, if the median of the corresponding Manhattan distance or cumulative distance for any battery group is greater than or equal to a third preset threshold, a current difference is determined to exist, and the energy storage box may have a battery circulation situation. If the median of the corresponding Manhattan distance or cumulative distance for any battery group is less than the third preset threshold, a current difference is determined to exist, and subsequent interpolation processing may not be performed.

[0131] For example, the energy storage box includes 9 battery groups, namely the first battery group to the ninth battery group, the other battery groups corresponding to the first battery group include the second battery group to the ninth battery group, the other battery groups corresponding to the second battery group include the first battery group and the third battery group to the ninth battery group, the other battery groups corresponding to the third battery group include the first battery group, the second battery group and the fourth battery group to the ninth battery group, the other battery groups corresponding to the fourth battery group include the first battery group to the third battery group and the fifth battery group to the ninth battery group, the other battery groups corresponding to the fifth battery group include the first battery group to the fourth battery group and the sixth battery group to the ninth battery group, the other battery groups corresponding to the sixth battery group include the first battery group to the fifth battery group and the seventh battery group and the ninth battery group, the other battery groups corresponding to the seventh battery group include the first battery group to the sixth battery group and the eighth battery group and the ninth battery group, the other battery groups corresponding to the eighth battery group include the first battery group to the seventh battery group and the ninth battery group, and the other battery groups corresponding to the ninth battery group include the first battery group to the eighth battery group.

[0132] Accordingly, the Manhattan distance or cumulative distance between each of the 9 battery groups is determined as shown in the following matrix:

[0133]

[0134] Among them, s 11 -s 19 is the Manhattan distance or cumulative distance between the first battery group and other battery groups corresponding to the first battery group, s 91 -s 99 is the Manhattan distance or cumulative distance between the ninth battery group and other battery groups corresponding to the ninth battery group.

[0135] Then, if s 11 -s 19 The median of is greater than or equal to the third preset threshold, and it is determined that there is a current difference between the first battery group and other battery groups corresponding to the first battery group. If s 11 -s 19 The median of is less than the third preset threshold, and it is determined that there is no current difference between the first battery group and the other battery groups corresponding to the first battery group. Similarly, if s 91 -s 99 The median of is greater than or equal to the third preset threshold, and it is determined that there is a current difference between the ninth battery group and other battery groups corresponding to the ninth battery group. If s 91 -s 99 The median of is less than a third preset threshold, and it is determined that there is no current difference between the ninth battery group and other battery groups corresponding to the ninth battery group.

[0136] For example, due to the large differences in the charging or discharging time of the energy storage box, the sequence length of the battery pack current also varies greatly. The calculation of Manhattan distance and cumulative distance is related to the sequence length. To eliminate the differences caused by sequence length, the consistency values ​​between each battery pack need to be normalized.

[0137] Therefore, in one possible implementation, after determining the Manhattan distance or the cumulative distance, the Manhattan distance or the cumulative distance is normalized, and the median is determined based on the normalization result.

[0138] For example, the Manhattan distance or cumulative distance can be normalized based on the following formula:

[0139]

[0140] in, represents a normalized value, s represents the Manhattan distance or cumulative distance between the first battery group and the second battery group, m represents the number of current values ​​in the first battery group in the target stage, and n represents the number of current values ​​in the second battery group in the target stage.

[0141] A normalized value can be calculated between each battery pack, and the calculated results can form a matrix S, where It represents the normalized value between the i-th battery pack and the j-th battery pack, so the 9 battery packs can be composed of the following matrix:

[0142]

[0143] in

[0144] Accordingly, we can The median of is compared with a third preset threshold value to determine whether there is a current difference between the first battery group and other battery groups corresponding to the first battery group. The median of the values ​​is compared with a third preset threshold value to determine whether there is a current difference between the ninth battery group and other battery groups corresponding to the first battery group.

[0145] In one possible implementation, the current data of each battery pack in all energy storage boxes of the entire site (such as an energy storage power station, a charging station, etc.) within one week is obtained, and the normalized value corresponding to the Manhattan distance or cumulative distance of each battery pack is calculated. Then, the third preset threshold is determined using the box plot method. The box plot is a statistical chart used to display data distribution characteristics, which can intuitively reflect the central tendency, dispersion degree and abnormal values ​​of the data. The determination of the third preset threshold is related to multiple factors such as the selected battery model and the site environment. It often needs to be determined in combination with the data image and the experience of the engineering personnel. According to the box plot, the abnormal points may exist above the upper limit and below the lower limit, but in this method, due to The smaller it is, the higher the degree of consistency and the smaller the degree of battery circulation, so outliers only exist above the upper limit.

[0146] For example, the upper limit value (ie, the third preset threshold) is set to Q3+3IQR, where Q3 is the normalized value corresponding to each battery pack in the entire station. The third quartile in , IQR is the interquartile range, If it is greater than Q3+3IQR, it can be judged that there is a current difference.

[0147] For example, for any charging stage or discharging stage, if there is a current difference between any battery pack and the corresponding other battery packs, the charging stage or discharging stage is determined to be the target stage; if there is no current difference between each battery pack and the corresponding other battery packs, the charging stage or discharging stage is determined not to be the target stage.

[0148] In this embodiment, a target stage is screened from a plurality of charging stages or discharging stages, so that it can be determined whether the electrical parameters of the battery cells are consistent based on the electrical parameters of the target stage.

[0149] Figure 3 This is a schematic diagram of the structure of the battery circulation detection device provided in this application, as shown in Figure 3 As shown, the battery circulating current detection device 40 provided in this embodiment includes:

[0150] An acquisition module is used to obtain the electrical parameters of multiple battery cells, and the electrical parameters of the battery cells are aligned in time;

[0151] The determination module is used to determine the detection result of the battery cell. The detection result is obtained based on the electrical parameters and is used to determine whether there is a circulating current in the battery cell.

[0152] In one possible implementation, the electrical parameter includes current.

[0153] In a possible implementation, the acquisition module 11 is specifically configured to acquire initial electrical parameters of a plurality of battery cells in a target phase, and interpolate the initial electrical parameters to obtain time-aligned electrical parameters.

[0154] In a possible implementation, the acquisition module 11 is specifically configured to acquire initial electrical parameters of minute-level data of multiple battery cells in a target phase; and interpolate the initial electrical parameters to obtain electrical parameters aligned with second-level data.

[0155] In a possible implementation, the acquisition module 11 is specifically configured to interpolate the initial electrical parameters based on a linear interpolation method.

[0156] In a possible implementation, the electrical parameters include parameter values ​​at multiple moments; the determination module 12 is specifically configured to determine an average value of the parameter values ​​of multiple battery cells at each moment; and determine the detection result of the battery cell based on the parameter value at each moment and the average value.

[0157] In one possible embodiment, the determination module 12 is specifically used to determine the absolute value of the difference between the parameter value and the average value at each moment; when the absolute value of the difference is greater than or equal to a first preset threshold, it is determined that there is a circulating current in the battery cell; when the absolute value of the difference is less than the first preset threshold, it is determined that there is no circulating current in the battery cell.

[0158] In a possible implementation, the determination module 12 is further configured to determine a processing priority of the battery cell according to a maximum value of the absolute values ​​of the differences when the detection result determines that a circulating current exists in the battery cell.

[0159] In one possible embodiment, the determination module 12 is specifically used to determine that the processing priority of the battery cell is the first priority when the maximum value is greater than or equal to the second preset threshold; the second preset threshold is greater than the first preset threshold; when the maximum value is less than the second preset threshold, the processing priority of the battery cell is determined to be the second priority; the second priority is lower than the first priority.

[0160] In one possible embodiment, the determination module 12 is also used to replace at least part of the battery cells when it is determined that the processing priority of the battery cells is the first priority; when it is determined that the processing priority of the battery cells is the second priority, determine the detection results of the battery cells in the next target stage according to the electrical parameters of the battery cells in the next target stage; when the detection results of the next target stage determine that there is circulating current in the battery cells, replace at least part of the battery cells, and when the detection results of the next target stage determine that there is no circulating current in the battery cells, do not replace the battery cells.

[0161] In one possible implementation, the start time of the target phase is the earliest time when the absolute value of the electrical parameter is greater than the third preset threshold, and the end time of the target phase is the latest time when the absolute value of the electrical parameter is greater than the third preset threshold.

[0162] In a possible implementation, the determination module 12 is further configured to issue an early warning when it is determined that a circulating current exists in the battery cell.

[0163] In a possible implementation, the determination module 12 is further configured to determine, among the multiple charging stages and discharging stages, a stage in which current differences exist in the battery cells as a target stage.

[0164] In one possible embodiment, the determination module 12 is further used to determine the Manhattan distance between each battery cell and other battery cells when the electrical parameter lengths of multiple battery cells are the same; determine the cumulative distance between each battery cell and other battery cells when the electrical parameter lengths of at least some battery cells are different; and determine whether there is a circulating current in the battery cell based on the Manhattan distance or the cumulative distance.

[0165] In a possible implementation, the determination module 12 is specifically configured to determine that there is a current difference in the battery cells when the median of the Manhattan distance or the cumulative distance is greater than or equal to a third preset threshold; and to determine that there is no current difference in the battery cells when the median is less than the third preset threshold.

[0166] In a possible implementation, the determination module 12 is further configured to normalize the Manhattan distance or the cumulative distance after determining the Manhattan distance or the cumulative distance; and determine the median based on the normalization result.

[0167] The battery detection device 40 provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effects are similar and will not be described in detail in this embodiment.

[0168] Figure 4 This is a schematic diagram of the structure of the electronic device provided in this application. Figure 4 As shown, the electronic device 50 provided in this embodiment includes: at least one processor 501 and a memory 502. Optionally, the electronic device 50 further includes a communication component 503. The processor 501, the memory 502 and the communication component 503 are connected via a bus.

[0169] In a specific implementation process, at least one processor 501 executes the computer-executable instructions stored in the memory 502, so that the at least one processor 501 performs the above method.

[0170] The specific implementation process of the processor 501 can be found in the above method embodiment. Its implementation principle and technical effects are similar and will not be repeated here in this embodiment.

[0171] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly implemented by a hardware processor or implemented by a combination of hardware and software modules in the processor.

[0172] The memory may include a high-speed memory (Random Access Memory, RAM), and may also include a non-volatile memory (NVM), such as at least one disk memory.

[0173] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be classified into address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just one type of bus.

[0174] The present application also provides a battery management system, comprising the above-mentioned electronic device.

[0175] The present application also provides a battery module, comprising the above-mentioned battery management system.

[0176] For example, a battery module may include a battery pack, a battery group, a battery cluster, etc. A battery pack may include multiple battery groups connected in parallel, a battery group may include multiple battery cells connected in parallel, and a battery cluster may include multiple battery cells connected in parallel.

[0177] The present application also provides an energy storage box, comprising the above-mentioned battery module.

[0178] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0179] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0180] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile memory device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0181] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist in a device as discrete components.

[0182] The division of units is merely a logical functional division; actual implementations may employ alternative divisions, such as combining or integrating multiple units or components into another system, or omitting or disabling certain features. Furthermore, any direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or units, either through an interface, electrical, mechanical, or other means.

[0183] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0184] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0185] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program code.

[0186] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0187] Finally, it should be noted that those skilled in the art will readily identify other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. A battery detection method, characterized in that: include: Acquiring electrical parameters of a plurality of battery cells, wherein the electrical parameters of the battery cells are aligned in time; Determine a detection result of the battery cell, where the detection result is obtained based on the electrical parameter, and the detection result is used to determine whether a circulating current exists in the battery cell.

2. The method according to claim 1, characterized in that The electrical parameter includes current.

3. The method according to claim 1 or 2, characterized in that The obtaining of electrical parameters of the plurality of battery cells includes: Initial electrical parameters of multiple battery cells in a target phase are acquired, and the initial electrical parameters are interpolated to obtain the electrical parameters aligned in time.

4. The method according to claim 3, characterized in that The acquiring initial electrical parameters of the plurality of battery cells in the target phase and interpolating the initial electrical parameters to obtain the time-aligned electrical parameters includes: Obtain initial electrical parameters of multiple battery cells at the target stage using minute-level data; The initial electrical parameters are interpolated to obtain the electrical parameters aligned with second-level data.

5. The method according to claim 3, characterized in that The interpolating the initial electrical parameters includes: The initial electrical parameters are interpolated based on a linear interpolation method.

6. The method according to claim 3, characterized in that The electrical parameters include parameter values ​​at multiple moments; Determining the detection result of the battery cell includes: Determining an average value of parameter values ​​of the plurality of battery cells at each moment; The detection result of the battery cell is determined according to the parameter value and the average value at each moment.

7. The method according to claim 6, characterized in that Determining a detection result of the battery cell, where the detection result is used to determine whether a circulating current exists in the battery cell, includes: Determine the absolute value of the difference between the parameter value at each moment and the average value; When the absolute value of the difference is greater than or equal to a first preset threshold, determining that a circulating current exists in the battery cell; When the absolute value of the difference is smaller than the first preset threshold, it is determined that no circulating current exists in the battery cell.

8. The method according to claim 7, characterized in that The method further comprises: When the detection result determines that a circulating current exists in the battery cell, the processing priority of the battery cell is determined according to the maximum value of the absolute values ​​of the difference.

9. The method according to claim 8, characterized in that Determining the processing priority of the battery cell according to the maximum value of the absolute values ​​of the differences includes: When the maximum value is greater than or equal to a second preset threshold, determining that the processing priority of the battery cell is the first priority; and the second preset threshold is greater than the first preset threshold; When the maximum value is less than the second preset threshold, the processing priority of the battery cell is determined to be a second priority; and the second priority is lower than the first priority.

10. The method according to claim 9, characterized in that The method further comprises: When determining that the processing priority of the battery cells is the first priority, replacing at least some of the battery cells; When it is determined that the processing priority of the battery cell is the second priority, determining a detection result of the battery cell in the next target stage according to the electrical parameters of the battery cell in the next target stage; When the detection result of the next target stage determines that the battery cells have circulating current, at least some of the battery cells are replaced; when the detection result of the next target stage determines that the battery cells do not have circulating current, the battery cells are not replaced.

11. The method according to claim 3, characterized in that The start time of the target phase is the earliest time when the absolute value of the electrical parameter is greater than the third preset threshold, and the end time of the target phase is the latest time when the absolute value of the electrical parameter is greater than the third preset threshold.

12. The method according to claim 1, characterized in that The method further comprises: When it is determined that a circulating current exists in the battery cell, an early warning is issued.

13. The method according to claim 3, characterized in that The method further comprises: Among the multiple charging stages and discharging stages, the stage in which the current difference of the battery cells exists is determined to be the target stage.

14. The method according to claim 13, characterized in that The method further comprises: When the electrical parameter lengths of the plurality of battery cells are the same, determining the Manhattan distance between each battery cell and the other battery cells; When the electrical parameter lengths of at least some of the battery cells are different, determining the cumulative distance between each battery cell and the other battery cells; It is determined whether there is a current difference between the battery cells according to the Manhattan distance or the cumulative distance.

15. The method according to claim 14, characterized in that The determining whether there is a current difference in the battery cells according to the Manhattan distance or the cumulative distance includes: When the median of the Manhattan distance or the cumulative distance is greater than or equal to a third preset threshold, determining that there is a current difference in the battery cell; When the median is smaller than the third preset threshold, it is determined that there is no current difference among the battery cells.

16. The method according to claim 15, characterized in that The method further comprises: After determining the Manhattan distance or the cumulative distance, normalizing the Manhattan distance or the cumulative distance; Based on the normalized results, the median is determined.

17. A battery detection device, characterized in that: The device comprises: An acquisition module, configured to acquire electrical parameters of a plurality of battery cells, wherein the electrical parameters of the battery cells are aligned in time; A determination module is used to determine a detection result of the battery cell, where the detection result is obtained based on the electrical parameter, and the detection result is used to determine whether a circulating current exists in the battery cell.

18. An electronic device, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 16.

19. A battery management system, characterized in that: The electronic device comprising the electronic device according to claim 18.

20. A battery module, characterized in that: Including the battery management system described in claim 19.

21. An energy storage box, characterized in that: A battery module comprising the battery module according to claim 20.

22. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 16 when executed by a processor.

23. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 16 when executed by a processor.

Images