SOC deviation acquisition method, electronic equipment, medium and product

Abstract

The invention provides an SOC deviation acquisition method, electronic equipment, a medium and a product. The method comprises the following steps: determining a first data set according to a maximum voltage data value of a battery pack under any capacity; determining a second data set according to the minimum voltage data value of the battery pack under any capacity; determining a first voltage capacity difference curve according to the first data set; determining a second voltage capacity difference curve according to the second data set; the first voltage capacity difference curve and / or the second voltage capacity difference curve are / is translated in the direction of a coordinate axis representing capacity until the peak overlap ratio of the first voltage capacity difference curve and the second voltage capacity difference curve meets a preset requirement, and the capacity translation amount is determined; and determining the SOC deviation of the battery pack according to the capacity translation amount. According to the method, the SOC deviation of the battery pack is accurately obtained.

Description

Technical Field

[0001] The present application relates to battery technology, and in particular to a method for obtaining SOC deviation, electronic equipment, medium and product. Background Art

[0002] Batteries play a vital role in electric vehicles and energy storage systems. The battery's state of charge (SOC), representing the percentage of a battery's remaining available capacity to its total capacity, is a crucial parameter in battery management.

[0003] In existing technologies, lithium batteries gradually deteriorate in consistency during use, leading to deviations in the SOC estimation algorithm. Therefore, a reliable SOC deviation calculation method is urgently needed to correct the battery's SOC. Summary of the Invention

[0004] The present application provides a method, electronic device, medium and product for obtaining SOC deviation of a battery pack to accurately obtain the SOC deviation of the battery pack.

[0005] On the one hand, an embodiment of the present application provides a method for obtaining SOC deviation, including:

[0006] Determine a first data set based on the highest voltage data value of the battery pack at any capacity; determine a second data set based on the lowest voltage data value of the battery pack at any capacity;

[0007] Determining a first voltage-capacity differential curve based on the first data set; determining a second voltage-capacity differential curve based on the second data set;

[0008] Shifting the first voltage-capacity difference curve and / or the second voltage-capacity difference curve along the direction of the coordinate axis representing the capacity until the peak overlap of the two reaches a preset requirement, and determining a capacity shift amount;

[0009] The SOC deviation of the battery pack is determined according to the capacity shift.

[0010] Optionally, the preset requirement includes: the peak overlap between the first voltage-capacity differential curve and the second voltage-capacity differential curve is maximum.

[0011] Optionally, determining a first voltage-capacity differential curve based on the first data set; and determining a second voltage-capacity differential curve based on the second data set includes:

[0012] determining a first voltage-capacity curve based on the first data set; and determining a second voltage-capacity curve based on the second data set;

[0013] A first voltage-capacity differential curve is determined based on the first voltage-capacity curve; and a second voltage-capacity differential curve is determined based on the second voltage-capacity curve.

[0014] Optionally, determining a first voltage-capacity differential curve based on the first voltage-capacity curve; and determining a second voltage-capacity differential curve based on the second voltage-capacity curve includes:

[0015] performing differential processing on the first voltage-capacity curve to determine the first voltage-capacity differential curve;

[0016] Performing differential processing on the second voltage-capacity curve to determine the second voltage-capacity differential curve.

[0017] Optionally, the first voltage-capacity differential curve includes a first voltage-capacity forward differential curve; and performing differential processing on the first voltage-capacity curve to determine the first voltage-capacity differential curve specifically includes:

[0018] For each two adjacent data points in the first voltage-capacity curve, determine a voltage difference and a capacity difference between the two adjacent data points, and divide the voltage difference by the capacity difference to obtain a differential voltage value of the preceding data point between the two adjacent data points; and determine the first voltage-capacity forward differential curve based on the capacity value and the differential voltage value of each data point in the first voltage-capacity curve;

[0019] The second voltage-capacity differential curve includes a second voltage-capacity forward differential curve; performing differential processing on the second voltage-capacity curve to determine the second voltage-capacity differential curve specifically includes:

[0020] For every two adjacent data points in the second voltage-capacity curve, determine the voltage difference and capacity difference between the two adjacent data points, and divide the voltage difference by the capacity difference to obtain the differential voltage value of the previous data point between the two adjacent data points; determine the second voltage-capacity forward differential curve based on the capacity value and differential voltage value of each data point in the second voltage-capacity curve.

[0021] Optionally, the first voltage-capacity differential curve includes a first voltage-capacity backward differential curve; and performing differential processing on the first voltage-capacity curve to determine the first voltage-capacity differential curve specifically includes:

[0022] For each two adjacent data points in the first voltage-capacity curve, determine a voltage difference and a capacity difference between the two adjacent data points, and divide the voltage difference by the capacity difference to obtain a differential voltage value of the latter of the two adjacent data points; and determine the first voltage-capacity backward differential curve based on the capacity value and the differential voltage value of each data point in the first voltage-capacity curve;

[0023] The second voltage-capacity differential curve includes a second voltage-capacity backward differential curve; performing differential processing on the second voltage-capacity curve to determine the second voltage-capacity differential curve specifically includes:

[0024] For every two adjacent data points in the second voltage-capacity curve, determine the voltage difference and capacity difference between the two adjacent data points, and divide the voltage difference by the capacity difference to obtain the differential voltage value of the latter of the two adjacent data points; and determine the second voltage-capacity backward differential curve based on the capacity value and differential voltage value of each data point in the second voltage-capacity curve.

[0025] Optionally, before determining the first voltage-capacity differential curve according to the first voltage-capacity curve and determining the second voltage-capacity differential curve according to the second voltage-capacity curve, the method further includes:

[0026] Smoothing and filtering are performed on the first voltage-capacity curve and the second voltage-capacity curve.

[0027] Optionally, the smoothing filtering of the first voltage-capacity curve and the second voltage-capacity curve includes:

[0028] Determining a neighborhood of each data point in the first voltage-capacity curve according to a preset window size, and replacing the ordinate value of each data point in the first voltage-capacity curve with the median ordinate value of all data points in the neighborhood of the data point, thereby performing smoothing filtering on the first voltage-capacity curve;

[0029] According to a preset window size, the neighborhood of each data point in the second voltage-capacity curve is determined, and the vertical coordinate value of each data point in the second voltage-capacity curve is replaced by the vertical coordinate median of all data points in the neighborhood of the data point, thereby smoothing and filtering the second voltage-capacity curve.

[0030] Optionally, determining the first voltage-capacity differential curve according to the capacity value and differential voltage value of each data point in the first voltage-capacity curve includes:

[0031] In a coordinate system where the horizontal axis represents capacity and the vertical axis represents differential voltage, determining the first voltage-capacity differential curve according to the capacity value and differential voltage value of each data point in the first voltage-capacity curve;

[0032] Determining the second voltage-capacity differential curve according to the capacity value and the differential voltage value of each data point in the second voltage-capacity curve includes:

[0033] In a coordinate system where the horizontal axis represents capacity and the vertical axis represents differential voltage, the second voltage-capacity differential curve is determined according to the capacity value and differential voltage value of each data point in the second voltage-capacity curve.

[0034] Optionally, translating the first voltage-capacity difference curve and / or the second voltage-capacity difference curve along a coordinate axis representing capacity includes:

[0035] The first voltage-capacity difference curve and / or the second voltage-capacity difference curve are / is translated along the horizontal axis.

[0036] Optionally, the first voltage-capacity difference curve and / or the second voltage-capacity difference curve are shifted along a coordinate axis representing the capacity until a peak overlap between the two reaches a preset requirement, and determining the capacity shift amount includes:

[0037] Determine a first peak curve based on all peak segments of the first voltage-capacity differential curve; determine a second peak curve based on all peak segments of the second voltage-capacity differential curve;

[0038] The first peak curve and / or the second peak curve are shifted, and the capacity shift corresponding to the maximum overlap is determined according to the overlap of each point in the first peak curve and the second peak curve under different relative shift amounts.

[0039] Optionally, determining the capacity translation amount corresponding to the maximum overlap according to the overlap of each point in the first peak curve and the second peak curve under different relative translation amounts includes:

[0040] determining an absolute value of a difference between each point in the first crest curve and the second crest curve under different relative translation amounts;

[0041] When the absolute value of the difference is the smallest, the overlap between the first peak curve and the second peak curve is the largest, and the relative translation at this time is used as the capacity translation.

[0042] Optionally, determining the absolute value of the difference between each point in the first peak curve and the second peak curve under different relative translation amounts specifically includes:

[0043] The sum of the absolute values ​​of the differences in the ordinates of the first peak curve and the second peak curve at each capacity under different relative translation amounts is determined as the absolute value of the difference between each point in the first peak curve and the second peak curve.

[0044] Optionally, the peak segment of the first voltage-capacity differential curve includes a curve segment extending forward and backward along the horizontal axis from the peak point of the first voltage-capacity differential curve by a predetermined length;

[0045] The peak section of the second voltage-capacity differential curve includes a curve section extending forward and backward along the horizontal axis from the peak point of the second voltage-capacity differential curve to a predetermined length.

[0046] Optionally, the predetermined length is the nominal capacity of the battery pack multiplied by 5%.

[0047] Optionally, determining the first peak curve according to all peak segments of the first voltage-capacity differential curve; and determining the second peak curve according to all peak segments of the second voltage-capacity differential curve include:

[0048] retaining curve data of all peak segments of the first voltage-capacity differential curve and clearing the ordinate values ​​of other positions of the first voltage-capacity differential curve to zero, thereby determining the first peak curve;

[0049] The curve data of all peak segments of the second voltage-capacity differential curve are retained, and the vertical coordinate values ​​of other positions of the second voltage-capacity differential curve are cleared to zero, thereby determining the second peak curve.

[0050] Optionally, determining the SOC deviation of the battery pack according to the capacity shift includes:

[0051] The absolute value of the capacity shift is divided by the nominal capacity of the battery pack to determine the SOC deviation of the battery pack.

[0052] Optionally, the method further includes:

[0053] Determine the initial capacity of each cell in the battery pack and the voltage and current at different times in the charging state;

[0054] Determining the capacity of each battery cell at different times based on the initial capacity of each battery cell in the battery pack and the current of each battery cell in the battery pack at different times, thereby determining the voltage corresponding to each battery cell at different capacities;

[0055] According to the voltages corresponding to the battery cells at different capacities, the highest voltage data value and the lowest voltage data value of the battery pack at any capacity are determined.

[0056] Optionally, determining the capacity of each battery cell at different times according to the initial capacity of each battery cell in the battery pack and the current of each battery cell in the battery pack at different times includes:

[0057] Determining the capacity increment of each battery cell at different moments relative to a previous moment based on the current of each battery cell at different moments and the time intervals between the different moments;

[0058] The capacity of each battery cell at different moments is determined according to the initial capacity of each battery cell and the capacity increment of each battery cell at different moments relative to the previous moment.

[0059] Optionally, before determining the capacity of each battery cell at different times based on the initial capacity of each battery cell in the battery pack and the current of each battery cell in the battery pack at different times, the method further includes:

[0060] The voltage and current of each cell in the battery pack at different times are sorted in ascending order according to time.

[0061] Optionally, before determining the capacity of each battery cell at different times based on the initial capacity of each battery cell in the battery pack and the current of each battery cell in the battery pack at different times, the method further includes:

[0062] Abnormal data and repeated data in the voltage and current of each battery cell at different times are removed.

[0063] On the other hand, an embodiment of the present application provides an SOC deviation obtaining device, comprising:

[0064] a determination module, determining a first data set based on a maximum voltage data value of the battery pack at any capacity; and determining a second data set based on a minimum voltage data value of the battery pack at any capacity;

[0065] A differential module determines a first voltage-capacity differential curve based on the first data set; and determines a second voltage-capacity differential curve based on the second data set;

[0066] a translation module for translating the first voltage-capacity differential curve and / or the second voltage-capacity differential curve along the direction of the coordinate axis representing the capacity until the peak overlap of the two reaches a preset requirement, thereby determining a capacity translation amount;

[0067] The deviation module is used to determine the SOC deviation of the battery pack based on the capacity shift.

[0068] In another aspect, an embodiment of the present application provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor;

[0069] The memory stores computer-executable instructions;

[0070] The processor executes the computer-executable instructions stored in the memory to implement the above method.

[0071] On the other hand, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to implement the method as described above when executed by a processor.

[0072] On the other hand, an embodiment of the present application provides a computer program product, which includes computer-executable instructions, and the computer-executable instructions are used to implement the method as described above when executed by a processor.

[0073] In the SOC deviation acquisition method, electronic device, medium and product provided in the present application, the highest voltage data value and the lowest voltage data value of the battery pack at any capacity are determined based on the charging data of the battery pack during charging, so that the best cell and the worst cell in the battery pack can be simulated, and the SOC deviation of the battery pack is determined based on the first voltage-capacity difference curve and the second voltage-capacity difference curve corresponding to the best cell and the worst cell, which can effectively reduce the data processing amount. When the number of cells in the battery pack is large, the data processing time can be effectively reduced, and the efficiency of determining the SOC deviation is improved; through the peaks of the first voltage-capacity difference curve and the second voltage-capacity difference curve, It can accurately reflect the voltage inflection points in the first voltage-capacity curve and the second voltage-capacity curve corresponding to the best battery cell and the worst battery cell. Since the actual SOCs corresponding to the voltage inflection points in the voltage-capacity curves of different battery cells are the same, the capacity shift amount of at least one of the first voltage-capacity curve and the second voltage-capacity curve can be shifted to the point where the peak overlap of the two meets the preset requirements to characterize the capacity difference between the corresponding voltage inflection points in the first voltage-capacity curve and the second voltage-capacity curve. Therefore, the SOC deviation of the battery pack can be accurately determined based on the capacity shift amount, effectively improving the accuracy and reliability of the SOC deviation determination and improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] 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.

[0075] Figure 1 Schematic diagram of the voltage-capacity curve of the battery cell provided in an embodiment of the present application is exemplarily shown in FIG.

[0076] Figure 2 exemplarily shows a flow chart of the SOC deviation acquisition method provided in an embodiment of the present application;

[0077] Figure 3Schematic diagram of the voltage-capacity differential curve provided by the embodiment of the present application is exemplarily shown in FIG.

[0078] Figure 4 Schematic diagram of the peak curve provided by the embodiment of the present application is exemplarily shown in FIG.

[0079] Figure 5 exemplarily shows a structural diagram of the SOC deviation obtaining device provided in an embodiment of the present application;

[0080] Figure 6 Schematic diagram of the structure of the electronic device provided in an embodiment of the present application is shown in FIG.

[0081] 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

[0082] 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.

[0083] A module in this application refers to a functional module or a logical module. It can be in software form, where a processor executes program code to implement its functionality, or it can be in hardware form. "And / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0084] Batteries play a vital role in electric vehicles and energy storage systems. The battery's state of charge (SOC), which represents the percentage of a battery's remaining available capacity to its total capacity, is a crucial parameter in battery management.

[0085] In existing technologies, lithium batteries gradually deteriorate in consistency during use, leading to deviations in the SOC estimation algorithm. Therefore, a reliable SOC deviation calculation method is urgently needed to correct the battery's SOC.

[0086] The inventors discovered that the worst-performing cell in a battery pack determines the overall performance of the battery pack. Take a battery pack with 5 cells in series and 1 in parallel as an example. Assume that, among the 5 cells, the cell with the lowest capacity is 3000mAh, while the other 4 cells have a capacity of 4000mAh. When the battery pack is discharged, these 5 cells are discharged at the same time, and the voltage of the cells decreases as the capacity decreases. When the discharge of the cell with the lowest capacity reaches 3000mAh, the voltage of the cell will reach the over-discharge protection voltage. Therefore, even if there is still capacity left in other cells, the battery management system will still turn on the battery pack over-discharge protection, and the entire battery pack will stop discharging, resulting in the discharge capacity of the entire battery pack being only 3000mAh. Therefore, the SOC deviation of the battery pack can be determined based on the capacity gap between the cell with the highest capacity and the cell with the lowest capacity in the battery pack.

[0087] Figure 1 This is a schematic diagram of the voltage-capacity curve of the battery cell provided in the embodiment of the present application. Figure 1 As shown in the figure, the battery pack includes multiple cells. The voltage and capacity of each cell can be obtained in real time during the charging process of the battery pack, so as to determine the voltage-capacity curve of each cell. Taking LFP battery as an example, the voltage-capacity curve of each cell will have three intervals with slow voltage changes, which are called voltage platform areas ( Figure 1 Only one plateau period is shown as an example). There is a region between the two voltage platform areas where the voltage changes rapidly. The point where the voltage changes fastest in this region is called the voltage inflection point. These inflection points often correspond to phase changes or chemical reactions of the internal materials of the battery, such as the lithium insertion and delithiation processes in LFP batteries. For multiple cells connected in series in a battery pack, the actual SOC corresponding to the corresponding voltage inflection points in the voltage-capacity curves of different cells is the same. The order in which the inflection points appear represents the difference in their actual SOCs, and the cells with lower capacity will have inflection points later. Therefore, the SOC deviation of the battery pack can be determined based on the position of the voltage inflection points in the voltage-capacity curves of different cells.

[0088] The following specific embodiments are used to illustrate the technical solution of the present application. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0089] Figure 2 This is a flow chart of a method for obtaining SOC deviation provided in one embodiment of the present application. Figure 2 As shown, the SOC deviation acquisition method provided in this embodiment may include:

[0090] S201, determining a first data set based on the highest voltage data value of the battery pack at any capacity; determining a second data set based on the lowest voltage data value of the battery pack at any capacity;

[0091] S202, determining a first voltage-capacity differential curve based on the first data set; determining a second voltage-capacity differential curve based on the second data set;

[0092] S203: Shift the first voltage-capacity difference curve and / or the second voltage-capacity difference curve along the coordinate axis representing the capacity until the peak overlap of the two reaches a preset requirement, and determine a capacity shift amount;

[0093] S204: Determine the SOC deviation of the battery pack according to the capacity shift.

[0094] In a specific implementation, the voltage and capacity data of each cell in the battery pack can be obtained in real time during the battery pack charging process, and the charging data of each cell in the battery pack can be obtained based on the corresponding relationship between voltage and capacity. Among the charging data of each cell in the battery pack, the highest voltage data value and the lowest voltage data value of the battery pack corresponding to each cell at each capacity are determined, and are respectively used as the first data set and the second data set. The first data set includes the set of the highest voltages of the battery pack at each capacity, and the second data set includes the set of the lowest voltages of the battery pack at each capacity. The voltage-capacity curve of the cell with lower capacity in the battery pack will be shifted to the right as a whole compared to the voltage-capacity curve of the cell with higher capacity, and the voltage inflection point will appear later. Moreover, at the same capacity, the voltage of the cell with lower capacity will be smaller. Therefore, the first data set can be used as the voltage data of the best cell in the simulated battery pack, and the second data set can be used as the voltage data of the worst cell in the simulated battery pack.

[0095] Based on the first data set and the second data set, a first voltage-capacity differential curve (dVmax / dQ-Q) and a second voltage-capacity differential curve (dVmin / dQ-Q) can be determined. The voltage-capacity differential curve can reflect the speed at which the voltage changes with the capacity in the voltage-capacity curve. Therefore, the peak of the voltage-capacity differential curve corresponds to the voltage inflection point in the voltage-capacity curve. At least one of the first voltage-capacity differential curve and the second voltage-capacity differential curve is shifted along the coordinate axis representing the capacity until the overlap of the two peaks is the highest. At this point, it can be determined that the overlap of the two peaks meets the preset requirements, that is, the overlap of the voltage inflection points of the first voltage-capacity curve and the second voltage-capacity curve is the highest. This allows the capacity gap between the corresponding voltage inflection points in the first voltage-capacity curve and the second voltage-capacity curve to be accurately obtained, and the SOC deviation of the battery pack can be accurately determined based on the capacity shift.

[0096] In the embodiment of the present application, the highest voltage data value and the lowest voltage data value of the battery pack at any capacity are determined according to the charging data of the battery pack during charging, so that the best cell and the worst cell in the battery pack can be simulated, and the SOC deviation of the battery pack is determined according to the first voltage-capacity differential curve and the second voltage-capacity differential curve corresponding to the best cell and the worst cell, which can effectively reduce the amount of data processing. When the number of cells in the battery pack is large, the data processing time can be effectively reduced, and the efficiency of determining the SOC deviation can be improved; the peaks of the first voltage-capacity differential curve and the second voltage-capacity differential curve can accurately reflect the best cell and the worst cell. The voltage inflection point in the first voltage-capacity curve and the second voltage-capacity curve corresponding to the worst battery cell. Since the actual SOC corresponding to the corresponding voltage inflection points in the voltage-capacity curves of different battery cells is the same, the capacity difference between the corresponding voltage inflection points in the first voltage-capacity curve and the second voltage-capacity curve can be characterized by the capacity shift amount when at least one of the first voltage-capacity curve and the second voltage-capacity curve is shifted to the point where the peak overlap of the two meets the preset requirements. Therefore, the SOC deviation of the battery pack can be accurately determined based on the capacity shift amount, thereby effectively improving the accuracy and reliability of the SOC deviation determination and improving the calculation efficiency.

[0097] In some embodiments, determining a first voltage-capacity differential curve based on the first data set and determining a second voltage-capacity differential curve based on the second data set includes:

[0098] Determining a first voltage-capacity curve based on the first data set; determining a second voltage-capacity curve based on the second data set;

[0099] A first voltage-capacity differential curve is determined based on the first voltage-capacity curve; and a second voltage-capacity differential curve is determined based on the second voltage-capacity curve.

[0100] In a specific implementation, a first voltage-capacity differential curve (Vmax-Q) can be determined based on the highest voltages and their corresponding capacities in the first data set; a second voltage-capacity differential curve (Vmin-Q) can be determined based on the lowest voltages and their corresponding capacities in the second data set. Based on the first and second voltage-capacity curves, the corresponding first and second voltage-capacity differential curves can be determined.

[0101] Figure 1 A first voltage-capacity curve (highest voltage) and a second voltage-capacity curve (lowest voltage) are exemplarily shown. Figure 3 This is a schematic diagram of the voltage-capacity differential curve provided in the embodiment of the present application. Figure 1 After processing the first voltage-capacity curve and the second voltage-capacity curve, we can get the following Figure 3The first voltage capacity difference curve (the highest voltage capacity difference curve) and the second voltage capacity difference curve are shown.

[0102] In one possible implementation, determining a first voltage-capacity differential curve based on the first voltage-capacity curve; and determining a second voltage-capacity differential curve based on the second voltage-capacity curve include:

[0103] performing differential processing on the first voltage-capacity curve to determine the first voltage-capacity differential curve;

[0104] Performing differential processing on the second voltage-capacity curve to determine the second voltage-capacity differential curve.

[0105] In practice, differential processing is a mathematical operation applied to discrete sequences or functions, generating a new sequence or function by calculating the differences between adjacent elements. By performing differential processing on the first voltage-capacity curve and the second voltage-capacity curve, the first voltage-capacity difference curve and the second voltage-capacity difference curve can be obtained.

[0106] Exemplarily, the first voltage-capacity differential curve includes a first voltage-capacity forward differential curve; performing differential processing on the first voltage-capacity curve to determine the first voltage-capacity differential curve specifically includes:

[0107] For every two adjacent data points in the first voltage-capacity curve, determine the voltage difference and capacity difference between the two adjacent data points, and divide the voltage difference by the capacity difference to obtain the differential voltage value of the previous data point between the two adjacent data points; determine the first voltage-capacity forward differential curve based on the capacity value and differential voltage value of each data point in the first voltage-capacity curve.

[0108] The second voltage-capacity differential curve includes a second voltage-capacity forward differential curve. Performing differential processing on the second voltage-capacity curve to determine the second voltage-capacity differential curve specifically includes:

[0109] For every two adjacent data points in the second voltage-capacity curve, determine the voltage difference and capacity difference between the two adjacent data points, and divide the voltage difference by the capacity difference to obtain the differential voltage value of the previous data point between the two adjacent data points; determine the second voltage-capacity forward differential curve based on the capacity value and differential voltage value of each data point in the second voltage-capacity curve.

[0110] In a specific implementation, a forward differential method can be used to perform differential processing on the first voltage-capacity curve and the second voltage-capacity curve. Specifically, for every two adjacent data points in the first voltage-capacity curve, the voltage difference (dV) and capacity difference (dQ) between the two adjacent data points are determined, and the voltage difference is divided by the capacity difference (dV / dQ) as the differential voltage value of the previous data point between the two adjacent data points; based on the capacity value and differential voltage value of each data point in the first voltage-capacity curve, the first voltage-capacity forward differential curve can be determined. For every two adjacent data points in the second voltage-capacity curve, the voltage difference (dV) and capacity difference (dQ) between the two adjacent data points are determined, and the voltage difference is divided by the capacity difference (dV / dQ) as the differential voltage value of the previous data point between the two adjacent data points; based on the capacity value and differential voltage value of each data point in the second voltage-capacity curve, the second voltage-capacity forward differential curve can be determined.

[0111] Exemplarily, the first voltage-capacity differential curve includes a first voltage-capacity backward differential curve; performing differential processing on the first voltage-capacity curve to determine the first voltage-capacity differential curve specifically includes:

[0112] For each two adjacent data points in the first voltage-capacity curve, determine the voltage difference and capacity difference between the two adjacent data points, and divide the voltage difference by the capacity difference to obtain the differential voltage value of the latter of the two adjacent data points; determine the first voltage-capacity backward differential curve based on the capacity value and differential voltage value of each data point in the first voltage-capacity curve;

[0113] The second voltage-capacity differential curve includes a second voltage-capacity backward differential curve. Performing differential processing on the second voltage-capacity curve to determine the second voltage-capacity differential curve specifically includes:

[0114] For every two adjacent data points in the second voltage-capacity curve, determine the voltage difference and capacity difference between the two adjacent data points, and divide the voltage difference by the capacity difference to obtain the differential voltage value of the latter of the two adjacent data points; determine the second voltage-capacity backward differential curve based on the capacity value and differential voltage value of each data point in the second voltage-capacity curve.

[0115] In a specific implementation, a backward difference method can also be used to perform differential processing on the first voltage-capacity curve and the second voltage-capacity curve. Specifically, for every two adjacent data points in the first voltage-capacity curve, the voltage difference (dV) and capacity difference (dQ) between the two adjacent data points are determined, and the voltage difference is divided by the capacity difference (dV / dQ) as the differential voltage value of the latter data point of the two adjacent data points; based on the capacity value and differential voltage value of each data point in the first voltage-capacity curve, the first voltage-capacity backward difference curve can be determined. For every two adjacent data points in the second voltage-capacity curve, the voltage difference (dV) and capacity difference (dQ) between the two adjacent data points are determined, and the voltage difference is divided by the capacity difference (dV / dQ) as the differential voltage value of the latter data point of the two adjacent data points; based on the capacity value and differential voltage value of each data point in the second voltage-capacity curve, the second voltage-capacity backward difference curve can be determined.

[0116] In a possible implementation, before performing differential processing on the first voltage-capacity curve and the second voltage-capacity curve to obtain the first voltage-capacity differential curve and the second voltage-capacity differential curve, the method further includes:

[0117] Smoothing filtering is performed on the first voltage-capacity curve and the second voltage-capacity curve.

[0118] In a specific implementation, after determining the first voltage-capacity curve and the second voltage-capacity curve, the first voltage-capacity curve and the second voltage-capacity curve can be smoothed and filtered first, and then differential processing can be performed. This can effectively eliminate the noise of the first voltage-capacity curve and the second voltage-capacity curve, improve the data quality of the first voltage-capacity curve and the second voltage-capacity curve, and thus accurately obtain the first voltage-capacity differential curve and the second voltage-capacity differential curve.

[0119] Exemplarily, smoothing and filtering the first voltage-capacity curve and the second voltage-capacity curve includes:

[0120] Determine, according to a preset window size, a neighborhood of each data point in the first voltage-capacity curve, and replace the ordinate value of each data point in the first voltage-capacity curve with the median ordinate value of all data points in the neighborhood of the data point, thereby performing smooth filtering on the first voltage-capacity curve;

[0121] According to a preset window size, the neighborhood of each data point in the second voltage-capacity curve is determined, and the vertical coordinate value of each data point in the second voltage-capacity curve is replaced by the vertical coordinate median of all data points in the neighborhood of the data point, thereby smoothing and filtering the second voltage-capacity curve.

[0122] In a specific implementation, an appropriate window size (for example, a window length of 5) is selected. Starting from the first point of the first voltage-capacity curve, a certain number of data points are selected around this point based on the selected window size. If the point being processed is on the boundary, the value of the data point closest to the boundary is used to fill the space outside the boundary to meet the window requirements. All data points within the window are sorted, and the value in the middle is found as the median, and the value of the original data point is replaced with this median. The above process is repeated until all data points of the entire first voltage-capacity curve are traversed. The specific filtering process for the second voltage-capacity curve is similar and will not be repeated here. Using the median smoothing filter method, the first and second voltage-capacity curves can be reliably smoothed.

[0123] In some embodiments, determining a first voltage-capacity differential curve according to the capacity value and the differential voltage value of each data point in the first voltage-capacity curve includes:

[0124] In a coordinate system where the horizontal axis represents capacity and the vertical axis represents differential voltage, a first voltage-capacity differential curve is determined according to the capacity value and differential voltage value of each data point in the first voltage-capacity curve;

[0125] Determining a second voltage-capacity differential curve according to the capacity value and the differential voltage value of each data point in the second voltage-capacity curve includes:

[0126] In a coordinate system where the horizontal axis represents capacity and the vertical axis represents differential voltage, a second voltage-capacity differential curve is determined according to the capacity value and differential voltage value of each data point in the second voltage-capacity curve.

[0127] In a specific implementation, a coordinate system can be established with capacity as the horizontal axis and differential voltage as the vertical axis. In the coordinate system, the first voltage-capacity differential curve is determined based on the capacity value and differential voltage value of each data point in the first voltage-capacity curve; and the second voltage-capacity differential curve is determined based on the capacity value and differential voltage value of each data point in the second voltage-capacity curve.

[0128] Exemplarily, translating the first voltage-capacity difference curve and / or the second voltage-capacity difference curve along a coordinate axis representing capacity includes:

[0129] The first voltage-capacity difference curve and / or the second voltage-capacity difference curve are / is translated along the horizontal axis.

[0130] In some embodiments, the preset requirement includes: the peak overlap between the first voltage-capacity difference curve and the second voltage-capacity difference curve is maximized.

[0131] In a specific implementation, in order to improve accuracy and reduce errors, the peak points of the first voltage-capacity differential curve and the second voltage-capacity differential curve can be determined to coincide when the peak overlap of the first voltage-capacity differential curve and the second voltage-capacity differential curve is at its maximum. The relative shift of the first voltage-capacity differential curve and the second voltage-capacity differential curve at this time is used as the capacity shift, thereby determining the SOC deviation.

[0132] In one possible implementation, the first voltage-capacity differential curve and / or the second voltage-capacity differential curve are shifted until the peak overlap of the two reaches a preset requirement, and the capacity shift amount is determined, including:

[0133] Determine a first peak curve based on all peak segments of the first voltage-capacity differential curve; determine a second peak curve based on all peak segments of the second voltage-capacity differential curve;

[0134] The first peak curve and / or the second peak curve are shifted, and the capacity shift corresponding to the maximum overlap is determined according to the overlap of each point in the first peak curve and the second peak curve under different relative shift amounts.

[0135] In a specific implementation, at least one of the first voltage-capacity difference curve and the second voltage-capacity difference curve is shifted until the peak overlap between the two curves is the highest. This is to determine the capacity gap between the corresponding voltage inflection points in the first voltage-capacity curve and the second voltage-capacity curve. Therefore, only the data of the peak segment where all the peak points of the first voltage-capacity difference curve and the data of the peak segment where all the peak points of the second voltage-capacity difference curve are located can be retained to obtain the first peak curve and the first peak curve. One of the first peak curve and the second peak curve is shifted until the peak overlap between the two curves is the highest. At this time, it can be considered that the peak overlap between the first voltage-capacity difference curve and the second voltage-capacity difference curve is the highest. The capacity shift amount is obtained, which can eliminate the influence of voltage changes at other data points other than the voltage inflection points in the first voltage-capacity curve and the second voltage-capacity curve, while retaining some voltage change data near the voltage inflection points in the first voltage-capacity curve and the second voltage-capacity curve, so that the capacity gap between the corresponding voltage inflection points in the first voltage-capacity curve and the second voltage-capacity curve can be accurately determined.

[0136] In one possible implementation, determining the capacity shift corresponding to the maximum overlap according to the overlap of each point in the first peak curve and the second peak curve under different relative shifts includes:

[0137] Determine the absolute value of the difference between each point in the first peak curve and the second peak curve under different relative translation amounts;

[0138] When the absolute value of the difference is the smallest, the overlap between the first peak curve and the second peak curve is the largest, and the relative shift at this time is taken as the capacity shift.

[0139] In a specific implementation, the second peak curve can be shifted to the left and / or the first peak curve can be shifted to the right. The capacity value △Q of the relative shift of the two curves is recorded, and the absolute value X of the difference between the shifted second peak curve and the first peak curve is determined, thereby obtaining the relationship between the shifted capacity △Q and X, F(△Q)=X. The capacity shift △Q0 is determined when the absolute value X of the difference between each point in the shifted second peak curve and the first peak curve is the smallest. At this time, it can be considered that the overlap between the shifted second peak curve and the first peak curve is the highest. The size of the capacity shift △Q0 can be used to measure the size of the battery pack SOC deviation.

[0140] In a possible implementation, determining the absolute value of the difference between each point in the first peak curve and the second peak curve at different translation positions specifically includes:

[0141] The sum of the absolute values ​​of the differences in the ordinates of the first peak curve and the second peak curve at each capacity under different translation positions is determined as the absolute value of the difference between each point in the first peak curve and the second peak curve.

[0142] In a specific implementation, after at least one of the first peak curve and the second peak curve is relatively shifted by △Q, the difference in the vertical coordinates of the first peak curve and the second peak curve at each capacity after the shift can be determined, and the absolute value of the difference in the vertical coordinates at each capacity is taken and summed to obtain the absolute value X of the difference between the second peak curve and the first peak curve after the shift.

[0143] In a possible implementation, the peak segment of the first voltage-capacity differential curve includes a curve segment extending forward and backward along the horizontal axis from the peak point of the first voltage-capacity differential curve by a predetermined length;

[0144] The peak section of the second voltage-capacity differential curve includes a curve section extending forward and backward along the horizontal axis from the peak point of the second voltage-capacity differential curve to a predetermined length.

[0145] In a specific implementation, after determining the peak points of the first voltage-capacity differential curve and the second voltage-capacity differential curve, a curve segment of a predetermined length can be extended forward and backward along the horizontal axis at the peak point to determine the peak segment of the first voltage-capacity differential curve and the peak segment of the second voltage-capacity differential curve.

[0146] Exemplarily, the predetermined length is the nominal capacity of the battery pack multiplied by 5%, that is, the peak segment includes curve data of 5 SOCs before and after the peak point.

[0147] In one possible implementation, determining the first peak curve based on all peak segments of the first voltage-capacity differential curve; and determining the second peak curve based on all peak segments of the second voltage-capacity differential curve include:

[0148] retaining curve data of all peak segments of the first voltage-capacity differential curve and clearing the ordinate values ​​of other positions of the first voltage-capacity differential curve to zero, thereby determining the first peak curve;

[0149] The curve data of all peak segments of the second voltage-capacity differential curve are retained, and the vertical coordinate values ​​of other positions of the second voltage-capacity differential curve are cleared to zero, thereby determining the second peak curve.

[0150] In a specific implementation, after determining all peak segments of the first voltage-capacity differential curve and all peak segments of the second voltage-capacity differential curve, only the curve data of all peak segments of the first voltage-capacity differential curve and all peak segments of the second voltage-capacity differential curve are retained, and the vertical coordinate values ​​of the data points at other positions are cleared to zero, thereby obtaining the first peak curve and the second peak curve that effectively reflect the voltage inflection point characteristics. Figure 4 Schematic diagram of the peak curve provided in the embodiment of the present application. Figure 3 The first voltage capacity difference curve and the second voltage capacity difference curve shown in FIG. Figure 4 The first crest curve (highest crest curve) and the second crest curve (lowest crest curve) are shown.

[0151] In one possible implementation, determining the SOC deviation of the battery pack according to the capacity shift includes:

[0152] The absolute value of the capacity shift is divided by the nominal capacity of the battery pack to obtain the SOC deviation of the battery pack.

[0153] In a specific implementation, after determining the capacity shift ΔQ0, the battery pack's SOC deviation is calculated as: capacity shift ΔQ0 / nominal capacity. Based on the battery pack's SOC deviation, the battery pack's SOC can be accurately obtained.

[0154] In some embodiments, the method further comprises:

[0155] Determine the initial capacity of each cell in the battery pack and the voltage and current at different times under charging conditions;

[0156] Determine the capacity of each cell at different times based on the initial capacity of each cell in the battery pack and the current of each cell in the battery pack at different times, thereby determining the voltage corresponding to each cell at different capacities;

[0157] According to the voltage corresponding to each battery cell at different capacities, the highest voltage data value and the lowest voltage data value of the battery pack at any capacity are determined.

[0158] In a specific implementation, a cloud-based big data platform or a battery management system (BMS) can monitor the current, voltage, temperature, and other data of each cell in the battery pack. After identifying the charging identifier, the data of each cell in the battery pack can be obtained, and based on the voltage, it can be determined whether the current charging is AC or DC, where the voltage of AC charging is lower than that of DC charging. During AC charging, the initial capacity of each cell in the battery pack at the start of charging is obtained, and the voltage and current of each cell at different times are obtained as the AC charging data of the battery pack. Based on the initial capacity of each cell in the battery pack and the current of each cell in the battery pack at different times, the capacity of each cell at different times can be determined. Based on the capacity and voltage of each cell at different times, the voltage corresponding to each cell at different capacities can be determined, thereby obtaining the charging data of each cell.

[0159] Exemplarily, before determining the capacity of each battery cell at different times based on the initial capacity of each battery cell in the battery pack and the current of each battery cell in the battery pack at different times, the method further includes:

[0160] Sort the voltage and current of each cell in the battery pack at different times in ascending order according to time.

[0161] Specifically, after obtaining the AC charging data of the battery pack, the voltage and current data of each battery cell can be sorted in ascending order according to time to obtain high-quality voltage and current that change with time.

[0162] Exemplarily, before determining the capacity of each battery cell at different times based on the initial capacity of each battery cell in the battery pack and the current of each battery cell in the battery pack at different times, the method further includes:

[0163] Remove abnormal and duplicate data from the voltage and current of each battery cell at different times.

[0164] Specifically, after obtaining the AC charging data of the battery pack, the AC charging data of the battery pack can be preprocessed first, the charging data can be cleaned, some data outliers caused by hardware failure or communication failure can be removed, and data streams at the same time can be deleted, thereby improving the reliability of the charging data.

[0165] For example, the SOC of each battery cell at the start of charging may be obtained, and the nominal capacity may be multiplied by the SOC to obtain the initial capacity of each battery cell at the start of charging.

[0166] In one possible implementation, determining the capacity of each battery cell at different times according to the initial capacity of each battery cell in the battery pack and the current of each battery cell in the battery pack at different times includes:

[0167] Determine the capacity increment of each battery cell at different times relative to the previous time based on the current of each battery cell at different times and the time intervals at different times;

[0168] The capacity of each battery cell at different moments is obtained based on the initial capacity of each battery cell and the capacity increment of each battery cell at different moments relative to the previous moment.

[0169] In a specific implementation, the current and the interval time can be multiplied to obtain the capacity increment at each moment, and the capacity increment is added to the capacity of the previous moment to obtain the capacity value at each moment.

[0170] Figure 5 This is a schematic diagram of the structure of the SOC deviation acquisition device provided in the embodiment of the present application. Figure 5 As shown, the SOC deviation obtaining device provided in this embodiment may include:

[0171] The determining module 51 determines a first data set based on the highest voltage data value of the battery pack at any capacity; and determines a second data set based on the lowest voltage data value of the battery pack at any capacity;

[0172] The differential module 52 determines a first voltage-capacity differential curve based on the first data set; and determines a second voltage-capacity differential curve based on the second data set;

[0173] The translation module 53 translates the first voltage-capacity differential curve and / or the second voltage-capacity differential curve along the coordinate axis representing the capacity until the peak overlap of the two reaches a preset requirement, and determines the capacity translation amount;

[0174] The deviation module 54 is configured to determine the SOC deviation of the battery pack according to the capacity shift.

[0175] In practical applications, the SOC deviation acquisition device can be implemented through a computer program, such as application software, etc.; or, it can be implemented as a medium storing relevant computer programs, such as a USB flash drive, a cloud disk, etc.; or, it can be implemented through a physical device integrated or installed with relevant computer programs, such as a chip, a server, etc.

[0176] It should be noted that the SOC deviation acquisition device provided in the embodiment of the present application is used to execute the method as described above. Its specific implementation method can be found in the method embodiment provided in the embodiment of the present application, and will not be repeated here.

[0177] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application, such as Figure 6 As shown, the electronic device includes:

[0178] The electronic device includes a processor 291 and a memory 292. It may also include a communication interface 293 and a bus 294. The processor 291, memory 292, and communication interface 293 can communicate with each other via bus 294. Communication interface 293 can be used for information transmission. The processor 291 can invoke logic instructions in memory 292 to execute the methods of the above embodiments.

[0179] In addition, the logic instructions in the memory 292 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product.

[0180] Memory 292, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of the present application. Processor 291 executes the software programs, instructions, and modules stored in memory 292 to perform functional applications and data processing, thereby implementing the methods in the above-mentioned method embodiments.

[0181] Memory 292 may include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function; the data storage area may store data generated based on the use of the terminal device. Memory 292 may also include high-speed random access memory and non-volatile memory.

[0182] An embodiment of the present application provides a non-transitory computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are executed by a processor, they are used to implement the method described in the above embodiment.

[0183] An embodiment of the present application provides a computer program product, including a computer program. When the computer program is executed by a processor, the method provided in any of the above embodiments of the present application is implemented.

[0184] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0185] It should be understood that the present application is not limited to the exact structure described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for obtaining SOC deviation, characterized in that: include: Determine a first data set according to the highest voltage data value of the battery pack at any capacity; Determining a second data set according to the lowest voltage data value of the battery pack at any capacity; Determining a first voltage-capacity differential curve based on the first data set; determining a second voltage-capacity differential curve based on the second data set; Shifting the first voltage-capacity difference curve and / or the second voltage-capacity difference curve along the direction of the coordinate axis representing the capacity until the peak overlap of the two reaches a preset requirement, and determining a capacity shift amount; The SOC deviation of the battery pack is determined according to the capacity shift.

2. The method according to claim 1, characterized in that The preset requirement includes: the peak overlap between the first voltage-capacity differential curve and the second voltage-capacity differential curve is maximum.

3. The method according to claim 1, characterized in that determining a first voltage-capacity differential curve based on the first data set; Determining a second voltage-capacity differential curve according to the second data set includes: determining a first voltage-capacity curve based on the first data set; and determining a second voltage-capacity curve based on the second data set; A first voltage-capacity differential curve is determined based on the first voltage-capacity curve; and a second voltage-capacity differential curve is determined based on the second voltage-capacity curve.

4. The method according to claim 3, characterized in that Determining a first voltage-capacity differential curve based on the first voltage-capacity curve; and determining a second voltage-capacity differential curve based on the second voltage-capacity curve includes: performing differential processing on the first voltage-capacity curve to determine the first voltage-capacity differential curve; Performing differential processing on the second voltage-capacity curve to determine the second voltage-capacity differential curve.

5. The method according to claim 4, characterized in that The first voltage-capacity differential curve includes a first voltage-capacity forward differential curve; performing differential processing on the first voltage-capacity curve to determine the first voltage-capacity differential curve specifically includes: For each two adjacent data points in the first voltage-capacity curve, determine a voltage difference and a capacity difference between the two adjacent data points, and divide the voltage difference by the capacity difference to obtain a differential voltage value of the preceding data point between the two adjacent data points; and determine the first voltage-capacity forward differential curve based on the capacity value and the differential voltage value of each data point in the first voltage-capacity curve; The second voltage-capacity differential curve includes a second voltage-capacity forward differential curve; performing differential processing on the second voltage-capacity curve to determine the second voltage-capacity differential curve specifically includes: For every two adjacent data points in the second voltage-capacity curve, determine the voltage difference and capacity difference between the two adjacent data points, and divide the voltage difference by the capacity difference to obtain the differential voltage value of the previous data point between the two adjacent data points; determine the second voltage-capacity forward differential curve based on the capacity value and differential voltage value of each data point in the second voltage-capacity curve.

6. The method according to claim 4, characterized in that The first voltage-capacity differential curve includes a first voltage-capacity backward differential curve; performing differential processing on the first voltage-capacity curve to determine the first voltage-capacity differential curve specifically includes: For each two adjacent data points in the first voltage-capacity curve, determine a voltage difference and a capacity difference between the two adjacent data points, and divide the voltage difference by the capacity difference to obtain a differential voltage value of the latter of the two adjacent data points; and determine the first voltage-capacity backward differential curve based on the capacity value and the differential voltage value of each data point in the first voltage-capacity curve; The second voltage-capacity differential curve includes a second voltage-capacity backward differential curve; performing differential processing on the second voltage-capacity curve to determine the second voltage-capacity differential curve specifically includes: For every two adjacent data points in the second voltage-capacity curve, determine the voltage difference and capacity difference between the two adjacent data points, and divide the voltage difference by the capacity difference to obtain the differential voltage value of the latter of the two adjacent data points; and determine the second voltage-capacity backward differential curve based on the capacity value and differential voltage value of each data point in the second voltage-capacity curve.

7. The method according to claim 3, characterized in that Before determining the first voltage-capacity differential curve according to the first voltage-capacity curve and determining the second voltage-capacity differential curve according to the second voltage-capacity curve, the method further includes: Smoothing and filtering are performed on the first voltage-capacity curve and the second voltage-capacity curve.

8. The method according to claim 7, characterized in that The smoothing filtering of the first voltage-capacity curve and the second voltage-capacity curve includes: Determining a neighborhood of each data point in the first voltage-capacity curve according to a preset window size, and replacing the ordinate value of each data point in the first voltage-capacity curve with the median ordinate value of all data points in the neighborhood of the data point, thereby performing smoothing filtering on the first voltage-capacity curve; According to a preset window size, the neighborhood of each data point in the second voltage-capacity curve is determined, and the vertical coordinate value of each data point in the second voltage-capacity curve is replaced by the vertical coordinate median of all data points in the neighborhood of the data point, thereby smoothing and filtering the second voltage-capacity curve.

9. The method according to claim 5 or 6, characterized in that Determining the first voltage-capacity differential curve according to the capacity value and the differential voltage value of each data point in the first voltage-capacity curve includes: In a coordinate system where the horizontal axis represents capacity and the vertical axis represents differential voltage, determining the first voltage-capacity differential curve according to the capacity value and differential voltage value of each data point in the first voltage-capacity curve; Determining the second voltage-capacity differential curve according to the capacity value and the differential voltage value of each data point in the second voltage-capacity curve includes: In a coordinate system where the horizontal axis represents capacity and the vertical axis represents differential voltage, the second voltage-capacity differential curve is determined according to the capacity value and differential voltage value of each data point in the second voltage-capacity curve.

10. The method according to claim 9, characterized in that The translating the first voltage-capacity difference curve and / or the second voltage-capacity difference curve along a coordinate axis representing capacity includes: The first voltage-capacity difference curve and / or the second voltage-capacity difference curve are / is translated along the horizontal axis.

11. The method according to claim 2, characterized in that The step of translating the first voltage-capacity difference curve and / or the second voltage-capacity difference curve along a coordinate axis representing the capacity until a peak overlap between the two reaches a preset requirement, and determining a capacity translation amount, includes: Determine a first peak curve based on all peak segments of the first voltage-capacity differential curve; determine a second peak curve based on all peak segments of the second voltage-capacity differential curve; The first peak curve and / or the second peak curve are shifted, and the capacity shift corresponding to the maximum overlap is determined according to the overlap of each point in the first peak curve and the second peak curve under different relative shift amounts.

12. The method according to claim 11, characterized in that The determining, based on the overlap of each point in the first peak curve and the second peak curve under different relative translation amounts, the capacity translation amount corresponding to the maximum overlap includes: determining an absolute value of a difference between each point in the first crest curve and the second crest curve under different relative translation amounts; When the absolute value of the difference is the smallest, the overlap between the first peak curve and the second peak curve is the largest, and the relative translation at this time is used as the capacity translation.

13. The method according to claim 12, characterized in that The determining of the absolute value of the difference between each point in the first peak curve and the second peak curve under different relative translation amounts specifically includes: The sum of the absolute values ​​of the differences in the ordinates of the first peak curve and the second peak curve at each capacity under different relative translation amounts is determined as the absolute value of the difference between each point in the first peak curve and the second peak curve.

14. The method according to claim 11, characterized in that The peak section of the first voltage-capacity differential curve includes a curve section extending forward and backward along the horizontal axis from the peak point of the first voltage-capacity differential curve to a predetermined length; The peak section of the second voltage-capacity differential curve includes a curve section extending forward and backward along the horizontal axis from the peak point of the second voltage-capacity differential curve to a predetermined length.

15. The method according to claim 14, characterized in that The predetermined length is the nominal capacity of the battery pack multiplied by 5%.

16. The method according to claim 11, characterized in that determining a first peak curve according to all peak segments of the first voltage-capacity differential curve; Determining a second peak curve according to all peak segments of the second voltage-capacity differential curve includes: retaining curve data of all peak segments of the first voltage-capacity differential curve and clearing the ordinate values ​​of other positions of the first voltage-capacity differential curve to zero, thereby determining the first peak curve; The curve data of all peak segments of the second voltage-capacity differential curve are retained, and the vertical coordinate values ​​of other positions of the second voltage-capacity differential curve are cleared to zero, thereby determining the second peak curve.

17. The method according to claim 1, wherein The determining the SOC deviation of the battery pack according to the capacity shift includes: The absolute value of the capacity shift is divided by the nominal capacity of the battery pack to determine the SOC deviation of the battery pack.

18. The method according to any one of claims 1 to 17, characterized in that The method further comprises: Determine the initial capacity of each cell in the battery pack and the voltage and current at different times in the charging state; Determining the capacity of each battery cell at different times based on the initial capacity of each battery cell in the battery pack and the current of each battery cell in the battery pack at different times, thereby determining the voltage corresponding to each battery cell at different capacities; According to the voltages corresponding to the battery cells at different capacities, the highest voltage data value and the lowest voltage data value of the battery pack at any capacity are determined.

19. The method according to claim 18, characterized in that The determining the capacity of each battery cell at different times according to the initial capacity of each battery cell in the battery pack and the current of each battery cell in the battery pack at different times includes: Determining the capacity increment of each battery cell at different moments relative to a previous moment based on the current of each battery cell at different moments and the time intervals between the different moments; The capacity of each battery cell at different moments is determined according to the initial capacity of each battery cell and the capacity increment of each battery cell at different moments relative to the previous moment.

20. The method according to claim 18, wherein Before determining the capacity of each battery cell at different times based on the initial capacity of each battery cell in the battery pack and the current of each battery cell in the battery pack at different times, the method further includes: The voltage and current of each cell in the battery pack at different times are sorted in ascending order according to time.

21. The method according to claim 18, wherein Before determining the capacity of each battery cell at different times based on the initial capacity of each battery cell in the battery pack and the current of each battery cell in the battery pack at different times, the method further includes: Abnormal data and repeated data in the voltage and current of each battery cell at different times are removed.

22. An electronic device, characterized in that: include: a processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 21.

23. 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 21 when executed by a processor.

24. A computer program product, characterized in that The program product comprises computer-executable instructions, which are used to implement the method according to any one of claims 1 to 21 when executed by a processor.

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