Battery failure diagnosis method and device

Abstract

The application discloses a battery fault diagnosis method and device. The method comprises the following steps: acquiring cumulative total equalization power increments of a plurality of battery monomers included in a target battery within a target period, and a first deviation degree coefficient corresponding to a target battery monomer at a target time and a plurality of historical times; determining a second deviation degree coefficient corresponding to the target battery monomer according to the plurality of cumulative total equalization power increments; determining a third deviation degree coefficient corresponding to the target battery monomer according to the first deviation degree coefficient corresponding to the target battery monomer at the target time and the plurality of historical times; and diagnosing the target battery monomer for an in-battery short circuit fault and a capacity attenuation fault according to the second deviation degree coefficient and the third deviation degree coefficient, and obtaining a diagnosis result. In this way, whether the target battery monomer has the in-battery short circuit fault and the capacity attenuation fault can be jointly diagnosed.

Description

Technical Field

[0001] This application belongs to the field of battery technology, and in particular relates to a battery fault diagnosis method and device. Background Technology

[0002] During use, batteries may experience internal short circuits or capacity decay due to pre-existing manufacturing defects or harsh, complex operating conditions. This can potentially lead to thermal runaway, severely impacting battery safety and user experience. To improve battery safety and user experience, fault diagnosis can be performed to detect malfunctions promptly.

[0003] In existing technologies, the diagnosis of whether a battery has experienced an internal short circuit is typically based on individual indicators such as the state of charge (SOC), voltage, equivalent internal resistance, and accumulated equalized charge of the multiple individual cells comprising the battery. Alternatively, the diagnosis of whether a battery has experienced capacity decay is based on indicators such as the differential capacitance-voltage curve, the differential capacity increment curve, and the accumulated charging capacity during the battery charging and discharging process.

[0004] However, the same effects on the above indicators may occur when the battery experiences internal short circuits and capacity decay, making it impossible for existing diagnostic methods based on these indicators to accurately distinguish between internal short circuit faults and capacity decay faults. Summary of the Invention

[0005] This application provides a battery fault diagnosis method and apparatus that can solve the problem in the prior art of not being able to accurately distinguish between internal short circuit faults and capacity decay faults in batteries.

[0006] In a first aspect, embodiments of this application provide a battery fault diagnosis method, the method comprising:

[0007] The cumulative total balanced charge increment of the target battery cells within the target time period is obtained, as well as the first deviation coefficient of the target battery cells at the target time and at multiple historical time points.

[0008] Based on the multiple cumulative total balanced power increments, a second deviation coefficient corresponding to the target battery cell is determined, and based on the first deviation coefficients corresponding to the target battery cell at the target time and the multiple historical times respectively, a third deviation coefficient corresponding to the target battery cell is determined.

[0009] Based on the second deviation coefficient and the third deviation coefficient, the target battery cell is diagnosed for internal short circuit faults and capacity degradation faults, and the diagnostic results are obtained.

[0010] Wherein, the target battery cell is any one of the plurality of battery cells, the first deviation coefficient represents the degree of deviation of the target value of the target battery cell from the first average value at the same time, the first average value is the average of the target values ​​of the plurality of battery cells, the target value includes SOC value and / or voltage value, the target time is the last time of the target time period, the target value of the target battery cell is the same at the target time and at the plurality of historical times, and the historical time period is earlier than the target time period.

[0011] Secondly, embodiments of this application provide a battery fault diagnosis device, the device comprising:

[0012] The acquisition module is used to acquire the cumulative total balanced charge increment of multiple battery cells included in the target battery during the target time period, as well as the first deviation coefficient of the target battery cells at the target time and multiple historical time periods.

[0013] The determining module is configured to determine a second deviation coefficient corresponding to the target battery cell based on multiple cumulative total balanced power increments, and to determine a third deviation coefficient corresponding to the target battery cell based on the first deviation coefficients corresponding to the target battery cell at the target time and at the multiple historical times, respectively.

[0014] The diagnostic module is used to diagnose internal short-circuit faults and capacity degradation faults in the target battery cell based on the second deviation coefficient and the third deviation coefficient, and to obtain diagnostic results.

[0015] Wherein, the target battery cell is any one of the plurality of battery cells, the first deviation coefficient represents the degree of deviation of the target value of the target battery cell from the first average value at the same time, the first average value is the average of the target values ​​of the plurality of battery cells, the target value includes SOC value and / or voltage value, the target time is the last time of the target time period, the target value of the target battery cell is the same at the target time and at the plurality of historical times, and the historical time period is earlier than the target time period.

[0016] Thirdly, embodiments of this application provide an electronic device, the device including: a processor and a memory storing computer program instructions.

[0017] When the processor executes computer program instructions, it implements the battery fault diagnosis method as shown in any embodiment of the first aspect.

[0018] Fourthly, embodiments of this application provide a computer storage medium storing computer program instructions, which, when executed by a processor, implement the battery fault diagnosis method shown in any embodiment of the first aspect.

[0019] Fifthly, embodiments of this application provide a computer program product in which instructions, when executed by a processor of an electronic device, cause the electronic device to perform the battery fault diagnosis method shown in any embodiment of the first aspect.

[0020] The battery fault diagnosis method and apparatus of this application can acquire the cumulative total balanced charge increment of multiple battery cells in a target battery during a target time period, and the first deviation coefficient of the target battery cells at the target time and multiple historical times, respectively. Then, based on the multiple cumulative total balanced charge increments, a second deviation coefficient corresponding to the target battery cell is determined, and based on the first deviation coefficients corresponding to the target battery cell at the target time and multiple historical times, a third deviation coefficient corresponding to the target battery cell is determined. Finally, based on the second and third deviation coefficients, the target battery cell is diagnosed for internal short circuit faults and capacity decay faults to obtain a diagnosis result. Since the battery fault diagnosis method and apparatus of this application can perform joint diagnosis of whether a target battery cell has experienced internal short circuit faults and capacity decay faults based on the second and third deviation coefficients, it can accurately distinguish between internal short circuit faults and capacity decay faults. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is one of the flowcharts of a battery fault diagnosis method provided in one embodiment of this application.

[0023] Figure 2 This is a schematic diagram of the SOC (State of Charge) of multiple battery cells at the same time, provided in one embodiment of this application.

[0024] Figure 3 This is a second flowchart of a battery fault diagnosis method provided in one embodiment of this application.

[0025] Figure 4 This is the third flowchart of a battery fault diagnosis method provided in one embodiment of this application.

[0026] Figure 5This is a schematic diagram of the structure of a battery fault diagnosis system provided in one embodiment of this application.

[0027] Figure 6 This is a schematic diagram of the structure of a battery fault diagnosis device according to an embodiment of this application.

[0028] Figure 7 This is a schematic diagram of the structure of an electronic device provided in one embodiment of this application. Detailed Implementation

[0029] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0030] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0031] As mentioned in the background technology, during battery use, defects in early manufacturing processes or harsh and complex usage conditions may lead to faults such as internal short circuits or capacity decay, which may in turn cause thermal runaway, seriously affecting battery safety and user experience. Typically, serious battery safety incidents develop gradually and accumulate over time. If reasonable and accurate fault diagnosis strategies and methods are adopted in the early stages before an incident occurs, serious safety faults can be detected and addressed promptly, improving battery safety and user experience.

[0032] In existing technologies, the diagnosis of internal short circuits in batteries is usually based on indicators such as inconsistency in SOC, voltage, equivalent internal resistance, and accumulated equalized charge among multiple battery cells. The diagnosis of capacity decay is usually based on indicators such as differential capacitance voltage curve, capacity increment differential curve, and accumulated charging capacity during the charging and discharging process.

[0033] The diagnostic methods in the aforementioned existing technologies all treat the effects of internal short circuits and capacity decay differently, assuming that the two are independent of each other, and use a certain method to perform a single diagnosis for either internal short circuits or capacity decay. However, internal short circuits and capacity decay can have the same impact on the aforementioned indicators during battery charging and discharging. For example, if a single battery cell experiences an internal short circuit, its SOC and open-circuit voltage will be lower than those of other battery cells, and its internal resistance will also differ. Furthermore, other cells need to activate equalization to maintain the consistency of the battery system. If that battery cell experiences capacity decay, the same situation will occur. Therefore, this single-fault diagnostic mode can lead to misdiagnosis.

[0034] Improving the accuracy of diagnosing internal short circuits and capacity decay faults in batteries is a critical issue that urgently needs to be addressed in the battery field, but effective technical solutions are still lacking.

[0035] Based on this, this application provides a battery fault diagnosis method, which will be described below.

[0036] Figure 1 The diagram shows a flowchart of a battery fault diagnosis method provided in one embodiment of this application.

[0037] like Figure 1 As shown, the entity executing this battery fault diagnosis method can be a battery fault diagnosis device or a battery fault diagnosis system, and the battery fault diagnosis method may include the following steps:

[0038] S110, obtain the cumulative total balanced charge increment of multiple battery cells included in the target battery during the target time period, and the first deviation coefficient of the target battery cells at the target time and multiple historical time periods respectively.

[0039] S120: Based on multiple cumulative total balanced charge increments, determine the second deviation coefficient corresponding to the target battery cell; and based on the first deviation coefficients corresponding to the target battery cell at the target time and multiple historical times, determine the third deviation coefficient corresponding to the target battery cell.

[0040] S130, Based on the image to be inspected and the labeled image, determine the corresponding index values ​​for the quality inspection indicators of the image to be inspected.

[0041] S140, based on the second deviation coefficient and the third deviation coefficient, diagnose the internal short circuit fault and capacity decay fault of the target battery cell and obtain the diagnosis result.

[0042] Therefore, the cumulative total balanced charge increment of the target battery's multiple individual cells within the target time period can be obtained, along with the first deviation coefficients corresponding to the target battery cells at the target time and multiple historical times. Then, based on the multiple cumulative total balanced charge increments, a second deviation coefficient corresponding to the target battery cell is determined. Finally, based on the first deviation coefficients corresponding to the target battery cell at the target time and multiple historical times, a third deviation coefficient is determined. Based on the second and third deviation coefficients, the target battery cell is then diagnosed for internal short-circuit faults and capacity degradation faults, yielding a diagnostic result. Since the battery fault diagnosis method and apparatus of this application can perform joint diagnosis of whether a target battery cell has experienced internal short-circuit faults and capacity degradation faults based on the second and third deviation coefficients, it can accurately distinguish between internal short-circuit faults and capacity degradation faults.

[0043] Regarding S110, the target battery cell can be any one of multiple battery cells. A first deviation coefficient characterizes the degree of deviation of the target value of the target battery cell from a first average value at the same time. The first average value can be the average of the target values ​​of multiple battery cells, and the target value can include the SOC value and / or voltage value. The target time can be the last time of the target time period. The target value of the target battery cell at the target time and at multiple historical times can be the same, and the historical time period can be earlier than the target time period.

[0044] For example, the target time can be the current time.

[0045] In some implementations, to more accurately determine the cumulative total equalization charge increment and the first deviation coefficient of the target battery cell at the target time and multiple historical times, S110 may include:

[0046] Obtain the target equalization strategy for the target battery, and obtain the first curve corresponding to each of the multiple battery cells and the second curve corresponding to the target battery cell.

[0047] Based on the first preset relationship, determine the target segmentation rule corresponding to the target equilibrium strategy.

[0048] Based on the target segmentation rule, each first curve and second curve are divided into multiple first curve segments corresponding to each first curve and multiple second curve segments corresponding to each second curve.

[0049] Based on the target curve segments corresponding to the multiple first curves, multiple cumulative total balanced power increments are determined, and based on the multiple third curve segments among the multiple second curve segments, the first deviation coefficients corresponding to the target battery cell at the target time and multiple historical times are determined.

[0050] Here, the first curve can be the curve showing the cumulative total balanced charge changing over time, and the second curve can be the curve showing the first deviation coefficient changing with the target value. The target curve segment can be the curve segment corresponding to the target time period among multiple first curve segments corresponding to the first curve. Multiple third curve segments can be curve segments corresponding to the target time and multiple historical times respectively. Specifically, the curve segments corresponding to the target time and multiple historical times can refer to the curve segments corresponding to the SOC at the target time and multiple historical times respectively.

[0051] Specifically, different balancing strategies can correspond to different segmentation rules, and the first preset relationship can be the correspondence between balancing strategies and segmentation rules. After obtaining the target balancing strategy for the target battery, the target segmentation rule corresponding to the target balancing strategy can be determined as the segmentation rule that the target battery should adopt.

[0052] Then, each first curve and second curve can be divided according to the target segmentation rule to obtain multiple first curve segments corresponding to each first curve and multiple second curve segments corresponding to each second curve. From the multiple first curve segments corresponding to each first curve, the first curve segment corresponding to the target time period is determined as the target curve segment. From the multiple second curve segments, the second curve segment containing the target time and multiple historical times is determined as the third curve segment, where each time point in the target time and multiple historical times corresponds to one curve segment. Then, multiple cumulative total equilibrium power increments can be determined based on the target curve segment, and the first deviation coefficients corresponding to the target battery cell at the target time and multiple historical times can be determined based on the multiple third curve segments.

[0053] For example, the cumulative total balanced charge of each battery cell can be obtained, and its curve of change over time can be recorded, i.e., the first curve. The first curve can be divided according to the target segmentation rule corresponding to the target balancing strategy to obtain the change data of the cumulative total balanced charge of the battery cell in the last curve segment containing the data of the target time. Then, the increment of the cumulative total balanced charge of the target battery cell at the target time compared with the data at the beginning of the curve segment can be calculated, i.e., the increment of the cumulative total balanced charge.

[0054] For example, taking the target value as SOC as an example, for each time point, the matrix points of SOC and first deviation coefficient of each battery cell can be recorded, thereby obtaining the curve of the first deviation coefficient of each battery cell changing with SOC, that is, the second curve, with the horizontal axis being the SOC of the battery cell and the vertical axis being the first deviation coefficient of the battery cell.

[0055] The SOC of multiple battery cells at the same time can be as follows Figure 2 As shown, when the SOC of the target battery cell (SOC) i The SOC is lower than the average SOC of multiple battery cells. avg At that time, the first deviation coefficient was negative, and the SOC i The lower the value, the lower the first deviation coefficient. The larger the absolute value, the greater the SOC. i Higher than SOC avg hour, It is a positive value, and SOC i The higher, The larger the absolute value, the greater. Figure 2 The first deviation coefficients of the multiple battery cells in the data, from highest to lowest, are as follows: Among them, SOC sd The standard deviation of the SOC of multiple battery cells.

[0056] For the second curve of the target battery cell, according to the target equalization strategy, the second curves continuously recorded over a recent period need to be segmented to obtain multiple second curve segments. The curve segments containing data at the target time and the curve segments containing data at historical times constitute the aforementioned multiple third curve segments. If the target value is voltage, the processing method is the same as when the target value is SOC, and will not be repeated here. Depending on the actual situation and needs, the target value can be selected as SOC, voltage, or a combination of both.

[0057] In addition to dividing the recorded first and second curves into curve segments as described above, curve segments can also be obtained by directly recording segments, with the same rules for segmentation as for regular segmentation.

[0058] Thus, by determining the target segmentation rules and dividing the curve, the cumulative total balanced power increment and the first deviation coefficient of the target battery cell at the target time and multiple historical times can be determined more accurately.

[0059] In some implementations, to obtain a more accurate second curve, the process of obtaining the second curve corresponding to the target battery cell may include:

[0060] A second curve is generated based on the first deviation coefficient corresponding to the target battery cell at multiple time points.

[0061] The first deviation coefficient corresponding to each of the multiple time points is obtained through the following steps:

[0062] Obtain the target values ​​of multiple individual battery cells at each time step.

[0063] Determine the first average and first standard deviation of the target values ​​corresponding to multiple individual battery cells at time points.

[0064] Based on the target value, first average value, and first standard deviation of the target battery cell at time t, determine the first deviation coefficient of the target battery cell at time t.

[0065] Specifically, the battery parameters of the target battery can be acquired in real time. These parameters can be used to calculate the cumulative total equalization capacity and the first deviation coefficient of each battery cell. The cumulative total equalization capacity at a certain moment can be the sum of the accumulated equalized capacity at that moment and the capacity to be equalized at that moment. The calculation results can then be stored for subsequent calculations.

[0066] The battery parameters mentioned above may include, but are not limited to, current time, data acquisition / acquisition cycle, battery cycle count, balancing strategy, voltage of each cell, SOC, balancing enable flag, balancing resistor value, balancing enable duty cycle, accumulated balanced charge storage value, accumulated balanced charge calculated value, charge to be balanced storage value, and charge to be balanced calculated value.

[0067] Battery cycle count can refer to the cumulative number of discharge cycles, the cumulative number of charge cycles, or the average of the cumulative number of discharge cycles and the cumulative number of charge cycles. The cumulative number of discharge or charge cycles can refer to the ratio between the cumulative integral of the discharge or charge current over time and the nominal capacity of the battery during the discharge or charge process.

[0068] Accumulated balanced charge refers to the cumulative charge that the battery has consumed during use, balancing out the charge it has already consumed.

[0069] The amount of power to be equalized can refer to the amount of power that is planned to be consumed when equalization is initiated to achieve a certain consistency of battery cells (such as consistent rechargeable capacity, consistent dischargeable capacity, consistent SOC or consistent cell voltage) based on the current state parameters.

[0070] The cumulative total equalization capacity is the sum of the accumulated equalized capacity and the capacity to be equalized. It can reflect the comprehensive inconsistency information of each cell of the battery accumulated during the entire life cycle of the battery. It is one of the important evaluation parameters for the joint diagnosis of short circuit fault and capacity decay fault in the battery in the embodiments of this application.

[0071] In some implementations, the formula for calculating the first deviation coefficient of the target battery cell at that moment can be:

[0072]

[0073] in, X represents the first deviation coefficient of the target battery cell at that moment. i X represents the target value of the target battery cell at that moment. avg X is the first average value. sd This is the first standard deviation.

[0074] Thus, through the above process, the first deviation coefficient of the target battery cell at any time can be accurately calculated, thereby obtaining a more accurate second curve.

[0075] In some implementations, to more accurately divide the first curve and the second curve, the aforementioned determination of the target segmentation rule corresponding to the target equilibrium strategy based on the first preset relationship may include:

[0076] When the target equalization strategy aims to maintain the same rechargeable capacity across multiple battery cells, the target segmentation rule is a segmentation rule based on a first preset range.

[0077] When the target equalization strategy aims to maintain the consistent discharge capacity of multiple battery cells, the target segmentation rule is a segmentation rule based on a second preset range.

[0078] When the target balancing strategy aims to maintain consistency in the target values ​​of multiple battery cells, the target segmentation rule is a segmentation rule based on a third preset range.

[0079] In some implementations, the segmentation rules can be:

[0080] Given that the target battery has N+C battery cycle counts, determine the target time corresponding to N+C battery cycle counts, where N is the battery cycle count corresponding to the first point of the curve to be divided, the first point is the starting point or the latest dividing point of the curve to be divided, N is a non-negative integer, and C is a positive integer.

[0081] Determine whether the curve segment from the first point to the target point at the target time contains target data. Target data includes curve data when the target value of the battery cell corresponding to the curve to be divided is within a target preset range. The target preset range is a first preset range, a second preset range, or a third preset range.

[0082] If the curve segment does not contain the target data, update N to N+C, and return to the point where the target battery has N+C battery cycle counts, determining the target time corresponding to N+C battery cycle counts.

[0083] If the curve segment contains the target data, determine the target point as the segmentation point, and return to the point where the target battery has N+C battery cycle counts, determining the target time corresponding to N+C battery cycle counts.

[0084] The curve to be divided is divided based on the dividing points.

[0085] In other words, the balancing strategy can include three types: maintaining the rechargeable capacity of multiple battery cells, maintaining the discharge capacity of multiple battery cells, and maintaining the target value of multiple battery cells.

[0086] For example, maintaining the rechargeable capacity of multiple battery cells can be achieved by simultaneously charging multiple battery cells to 100%. Maintaining the discharge capacity of multiple battery cells can be achieved by simultaneously discharging multiple battery cells to 0%. Maintaining the target value of multiple battery cells can be achieved by maintaining the real-time SOC or individual cell voltage of multiple battery cells.

[0087] Different equilibrium strategies correspond to different segmentation rules. The difference between the three segmentation rules lies in the different preset target ranges. Specifically, the segmentation rules can be as follows:

[0088] Starting from the data starting point on the curve to be divided, and following the order of time from farthest to closest, a dividing point is formed when both condition 1 and condition 2 are met simultaneously. The data between every two adjacent dividing points is the curve segment after segmentation.

[0089] Condition 1: The number of battery cycles increases to N+C for the first time.

[0090] Round down the battery cycle count (e.g., 23.1 to 23.9 are all rounded down to 23). If the battery cycle count at the start of this segment is N, then when the battery cycle count first increases to N+C, it can be determined whether condition 2 is met. If condition 2 is met, a segmentation point can be formed. If condition 2 is not met, N can be updated to the current cycle count, and wait for the next time condition 1 is met.

[0091] Condition 2: The curve data corresponding to each curve segment contains target data. This target data can include all curve data when the target value of the battery cell corresponding to the curve to be divided is within the target preset range.

[0092] For example, such as Figure 3As shown, S310, obtain the battery cycle count. S320, record the initial battery cycle count N. S330, determine if the battery cycle count is N+C; if yes, proceed to S340; otherwise, return to S330. S340, determine if the curve data corresponding to the current curve segment contains all curve data when the target value is within the target preset range; if yes, proceed to S350; otherwise, proceed to S360. S350, form the segmentation point and return to S320. S360, update N to N+C and return to S330.

[0093] For example, if N = 23 and C = 1, it means that when the number of battery cycles first equals N + C = 23 + 1 = 24, it is determined whether condition 2 is satisfied. If condition 2 is not satisfied at this time, N can be updated to 24. When the number of battery cycles first equals N + C = 24 + 1 = 25, it is determined again whether condition 2 is satisfied, until both conditions 1 and 2 are satisfied, forming a dividing point. Similarly, if C = 2, it means that when the number of battery cycles first equals N + C = 23 + 2 = 25, it is determined whether condition 2 is satisfied. If condition 2 is not satisfied at this time, N can be updated to 25. When the number of battery cycles first equals N + C = 25 + 2 = 27, it is determined again whether condition 2 is satisfied, until both conditions 1 and 2 are satisfied, forming a dividing point.

[0094] The difference in the segmentation rules corresponding to different balancing strategies lies in the target preset range in condition 2. If the target balancing strategy is to keep the rechargeable capacity of multiple battery cells consistent, then the target preset range in condition 2 is the first preset range; if the target balancing strategy is to keep the discharge capacity of multiple battery cells consistent, then the target preset range in condition 2 is the second preset range; if the target balancing strategy is to keep the target value of multiple battery cells consistent, then the target preset range in condition 2 is the third preset range.

[0095] For example, if the target value is SOC, the first preset range can be 30% ≤ SOC ≤ 60%, the second preset range can be 50% ≤ SOC ≤ 80%, and the third preset range can be 20% ≤ SOC ≤ 40% and 70% ≤ SOC ≤ 90%.

[0096] Thus, based on the above segmentation rules, the first curve and the second curve can be divided more accurately.

[0097] Regarding S120, the second deviation coefficient corresponding to the target battery cell can be determined based on multiple cumulative total balanced power increments. Based on the first deviation coefficients corresponding to the target battery cell at the target time and multiple historical times, the third deviation coefficient corresponding to the target battery cell can be determined.

[0098] In some implementations, to more accurately determine the second deviation coefficient, the above-mentioned determination of the second deviation coefficient corresponding to the target battery cell based on multiple cumulative total balanced charge increments may include:

[0099] Determine the second average and second standard deviation of multiple cumulative total equilibrium power increments.

[0100] The second deviation coefficient is determined based on the cumulative total balanced charge increment of the target battery cell, the second average value, and the second standard deviation.

[0101] Here, the average of multiple cumulative total balanced power increments can be calculated to obtain a second average value, and the standard deviation of multiple cumulative total balanced power increments can be calculated to obtain a second standard deviation. Then, based on the second average value, the second standard deviation, and the cumulative total balanced power increment of the target battery cell, a second deviation coefficient can be determined.

[0102] In some implementations, the formula for calculating the second deviation coefficient can be:

[0103]

[0104] in, The second deviation coefficient, The cumulative total balanced charge increment of the target battery cell. The second average, This is the second standard deviation.

[0105] Thus, through the above process, the second deviation coefficient can be determined more accurately.

[0106] In some implementations, to more accurately determine the third deviation coefficient, the determination of the third deviation coefficient corresponding to the target battery cell based on the first deviation coefficients corresponding to the target battery cell at the target time and multiple historical times may include:

[0107] Target balancing strategy for obtaining the target battery

[0108] Based on the second preset relationship, determine the target activation conditions corresponding to the target equilibrium strategy.

[0109] If the target initiation conditions are not met, the third deviation coefficient is set to 0.

[0110] Under the condition that the target initiation conditions are met, determine the third mean and third standard deviation of the first deviation coefficient corresponding to multiple historical time points.

[0111] The third deviation coefficient is determined based on the first deviation coefficient, the third average value, and the third standard deviation of the target battery cell at the target time.

[0112] Here, the activation condition can be the condition for starting the calculation of the third deviation coefficient. Different balancing strategies can correspond to different activation conditions, and the first preset relationship can be the correspondence between the balancing strategy and the activation condition. After obtaining the target balancing strategy for the target battery, the target activation condition corresponding to the target balancing strategy can be determined as the activation condition that the target battery should adopt.

[0113] Specifically, if the target activation conditions are not met, the calculation of the third deviation coefficient is not initiated, and the third deviation coefficient is directly set to 0. If the target activation conditions are met, the calculation of the third deviation coefficient is initiated, and the calculation result is used as the third deviation coefficient.

[0114] Specifically, the average of the first deviation coefficients corresponding to multiple historical moments can be calculated to obtain a third average. The standard deviation of the first deviation coefficients corresponding to multiple historical moments can be calculated to obtain a third standard deviation. Then, based on the third average, the third standard deviation, and the first deviation coefficient of the target battery cell at the target moment, a third deviation coefficient is calculated. In some embodiments, the formula for calculating the third deviation coefficient can be:

[0115]

[0116] in, The third deviation coefficient, The first deviation coefficient of the target battery cell at the target time. It is the third average. This is the third standard deviation.

[0117] For example, taking the target value as SOC, when the SOC of the target battery cell meets the target start-up conditions, the third curve corresponding to the SOC of the target battery cell at the target time and the third curves corresponding to multiple historical times are obtained, along with the first deviation coefficient of the SOC at the target time and the first deviation coefficient of the SOC at multiple historical times. Then, the third average and third standard deviation of the first deviation coefficients of the SOC at multiple historical times can be calculated, and the third deviation coefficient can be calculated using the following formula:

[0118]

[0119] in, The third deviation coefficient, The first deviation coefficient of the target battery cell at the target time. It is the third average. This is the third standard deviation.

[0120] Thus, through the above process, the third deviation coefficient can be determined more accurately.

[0121] In some implementations, to further improve the accuracy of the third deviation coefficient, the above-mentioned determination of the target activation condition corresponding to the target equilibrium strategy based on the second preset relationship may include:

[0122] When the target balancing strategy aims to maintain the same rechargeable capacity across multiple battery cells, the target activation condition is that the target value of the target battery cell falls within the fourth preset range.

[0123] When the target balancing strategy aims to maintain the same discharge capacity of multiple battery cells, the target activation condition is that the target value of the target battery cell falls within the fifth preset range.

[0124] When the target balancing strategy aims to keep the target values ​​of multiple battery cells consistent, the target activation condition is that the target value of the target battery cell belongs to the sixth preset range.

[0125] In other words, the balancing strategy can include three types: maintaining the rechargeable capacity of multiple battery cells, maintaining the discharge capacity of multiple battery cells, and maintaining the target value of multiple battery cells.

[0126] Different equilibrium strategies correspond to different activation conditions, and the difference between the three activation conditions lies in the different preset ranges.

[0127] Specifically, if the target balancing strategy is to maintain the rechargeable capacity of multiple battery cells being consistent, then the target activation condition can be that the target value of the target battery cell belongs to the fourth preset range; if the target balancing strategy is to maintain the dischargeable capacity of multiple battery cells being consistent, then the target activation condition can be that the target value of the target battery cell belongs to the fifth preset range; if the target balancing strategy is to maintain the target value of multiple battery cells being consistent, then the target activation condition can be that the target value of the target battery cell belongs to the sixth preset range.

[0128] For example, if the target value is SOC, the fourth preset range can be SOC≤60%, the fifth preset range can be SOC≥50%, and the sixth preset range can be SOC≤40% or SOC≥70%.

[0129] Therefore, by determining whether to use the calculated value or the default value of 0 for the third deviation coefficient based on the target initiation conditions, the accuracy of the third deviation coefficient can be further improved.

[0130] Regarding S130, based on the second and third deviation coefficients, a joint diagnosis of internal short-circuit faults and capacity degradation faults can be performed on the target battery cell to obtain a diagnostic result. This diagnostic result can be used to characterize whether the target battery cell has an internal short-circuit fault, a capacity degradation fault, or no internal short-circuit fault or capacity degradation fault.

[0131] In some implementations, to obtain more accurate diagnostic results, S130 may include:

[0132] Target balancing strategy for obtaining the target battery

[0133] Based on the third pre-defined relationship, determine the target diagnosis rules corresponding to the target equilibrium strategy.

[0134] Based on the second and third deviation coefficients, the target battery cell is diagnosed for internal short circuit faults and capacity decay faults according to the target diagnosis rules, and the diagnosis results are obtained.

[0135] Here, different balancing strategies can correspond to different diagnostic rules, and the third preset relationship can be the correspondence between balancing strategies and diagnostic rules. After obtaining the target balancing strategy for the target battery, the target diagnostic rule corresponding to the target balancing strategy can be determined as the diagnostic rule that the target battery should adopt. Then, based on the target diagnostic rule, the second deviation coefficient and the third deviation coefficient can be judged to obtain the diagnostic result of the target battery cell.

[0136] Therefore, by using different diagnostic rules for fault diagnosis of batteries employing different balancing strategies, more accurate diagnostic results can be obtained.

[0137] In some implementations, to improve the accuracy of fault diagnosis, the above-mentioned diagnosis of internal short-circuit faults and capacity degradation faults of the target battery cell based on the target diagnosis rules according to the second deviation coefficient and the third deviation coefficient, and the resulting diagnosis results, may include:

[0138] Given that the target balancing strategy is to maintain the same rechargeable capacity among multiple battery cells, it is determined whether the second deviation coefficient is less than the first threshold.

[0139] If the second deviation coefficient is less than the first threshold, it is determined that the target battery cell has an internal short circuit fault.

[0140] If the second deviation coefficient is not less than the first threshold, determine whether the third deviation coefficient is less than the second threshold.

[0141] If the third deviation coefficient is less than the second threshold, it is determined that the target battery cell has experienced a capacity degradation fault.

[0142] Given that the target balancing strategy is to maintain the consistent discharge capacity of multiple battery cells, it is determined whether the second deviation coefficient is less than the third threshold.

[0143] If the second deviation coefficient is less than the third threshold, determine whether the third deviation coefficient is less than the fourth threshold.

[0144] If the third deviation coefficient is less than the fourth threshold, it is determined that the target battery cell has an internal short circuit fault.

[0145] If the third deviation coefficient is not less than the fourth threshold, determine whether the third deviation coefficient is greater than the fifth threshold.

[0146] If the third deviation coefficient is greater than the fifth threshold, it is determined that the target battery cell has experienced a capacity degradation fault.

[0147] Under the target balancing strategy of maintaining the consistency of target values ​​for multiple battery cells, the first fault flag, second fault flag, and third fault flag of the target battery cell are determined, and it is determined whether the second deviation coefficient is less than the sixth threshold.

[0148] If the second deviation coefficient is less than the sixth threshold, determine whether both the first fault flag and the second fault flag are target flags.

[0149] If both the first fault flag and the second fault flag are target flags, it is determined that the target battery cell has experienced an internal short circuit fault.

[0150] If neither the first fault flag nor the second fault flag is a target flag, determine whether both the first fault flag and the third fault flag are target flags.

[0151] If both the first and third fault flags are target flags, it is determined that the target battery cell has experienced a capacity decay fault.

[0152] The determination of the first fault indicator, second fault indicator, and third fault indicator of the target battery cell includes:

[0153] If the target value of the target battery cell falls within the seventh preset range, determine whether the third deviation coefficient is less than the seventh threshold.

[0154] If the third deviation coefficient is less than the seventh threshold, the first fault flag is updated to the target flag.

[0155] If the target value of the target battery cell falls within the eighth preset range, determine whether the third deviation coefficient is less than the eighth threshold, and determine whether the third deviation coefficient is greater than the ninth threshold.

[0156] If the third deviation coefficient is less than the eighth threshold, the second fault flag is updated to the target flag; and if the third deviation coefficient is greater than the ninth threshold, the third fault flag is updated to the target flag.

[0157] In other words, if the target equalization strategy is to maintain the rechargeable capacity of multiple battery cells in a consistent manner, it can be determined whether the second deviation coefficient is less than the first threshold. If so, it is determined that the target battery cell has experienced an internal short circuit fault. If not, it is determined whether the third deviation coefficient is less than the second threshold. If so, it is determined that the target battery cell has experienced a capacity decay fault.

[0158] If the target equalization strategy is to maintain the same discharge capacity of multiple battery cells, then it can be determined whether the second deviation coefficient is less than the third threshold. If so, it can be further determined whether the third deviation coefficient is less than the fourth threshold. If so, it can be determined that the target battery cell has an internal short circuit fault. If the third deviation coefficient is not less than the fourth threshold, it can be further determined whether the third deviation coefficient is greater than the fifth threshold. If so, it can be determined that the target battery cell has a capacity decay fault.

[0159] If the target balancing strategy is to keep the target values ​​of multiple battery cells consistent, then the fault flags for the three cases can be determined separately, as follows:

[0160] If the target value of the target battery cell is within the seventh preset range, determine whether the third deviation coefficient is less than the seventh threshold. If so, update the first fault flag to the target flag.

[0161] If the target value of the target battery cell is within the eighth preset range, determine whether the third deviation coefficient is less than the eighth threshold. If so, update the second fault flag to the target flag.

[0162] If the target value of the target battery cell is within the eighth preset range, determine whether the third deviation coefficient is greater than the ninth threshold. If so, update the third fault flag to the target flag.

[0163] Among them, the target indicator can characterize the potential failure of the target battery cell.

[0164] For example, the default values ​​of the first fault flag, the second fault flag, and the third fault flag can all be represented by 0, and the target flag can be represented by 1.

[0165] For example, if the target value is SOC, the seventh preset range can be SOC≤60%, and the eighth preset range can be SOC≥70%.

[0166] Then, it can be determined whether the second deviation threshold is less than the sixth threshold. If so, it can be further determined whether the first fault flag and the second fault flag are both target flags. If so, it can be determined that the target battery cell has an internal short circuit fault. If the first fault flag and the second fault flag are not both target flags, it can be determined whether the first fault flag and the third fault flag are both target flags. If so, it can be determined that the target battery cell has a capacity decay fault.

[0167] For example, the first threshold, the second threshold, the third threshold, the fourth threshold, the sixth threshold, the seventh threshold, and the eighth threshold can all be -3, and the fifth threshold and the ninth threshold can all be 3.

[0168] For example, the fault diagnosis process can be as follows: Figure 4 As shown, the details are as follows:

[0169] S401, Determine the target equilibrium strategy.

[0170] If the target equilibrium strategy is equilibrium strategy 1, then execute S402; if the target equilibrium strategy is equilibrium strategy 2, then execute S406; if the target equilibrium strategy is equilibrium strategy 3, then execute S411.

[0171] Among them, balancing strategy 1 aims to keep the rechargeable capacity of multiple battery cells consistent, balancing strategy 2 aims to keep the discharge capacity of multiple battery cells consistent, and balancing strategy 3 aims to keep the target value of multiple battery cells consistent.

[0172] S402, determine whether the second deviation coefficient is less than the first threshold.

[0173] If yes, then execute S403; otherwise, execute S404.

[0174] S403, determine that the target battery cell has an internal short circuit fault and execute S416.

[0175] S404, determine whether the third deviation coefficient is less than the second threshold.

[0176] If yes, then execute S405; otherwise, execute S416.

[0177] S405, determine that the target battery cell has a capacity decay fault and execute S416.

[0178] S406, determine whether the second deviation coefficient is less than the third threshold.

[0179] If yes, then execute S407; otherwise, execute S416.

[0180] S407, determine whether the third deviation coefficient is less than the fourth threshold.

[0181] If yes, then execute S408; otherwise, execute S409.

[0182] S408, determine that the target battery cell has an internal short circuit fault and execute S416.

[0183] S409, is the third deviation coefficient greater than the fifth threshold?

[0184] If yes, then execute S410; otherwise, execute S416.

[0185] S410, determine that the target battery cell has a capacity decay fault and execute S416.

[0186] S411, determine whether the second deviation coefficient is less than the sixth threshold.

[0187] If yes, then execute S412; otherwise, execute S416.

[0188] S412, determine whether both the first fault flag and the second fault flag are target flags.

[0189] If yes, then execute S413; otherwise, execute S414.

[0190] S413, determine that the target battery cell has an internal short circuit fault and execute S416.

[0191] S414, determine whether the first fault flag and the third fault flag are both target flags.

[0192] If yes, then execute S415; otherwise, execute S416.

[0193] S415, determine that the target battery cell has a capacity decay fault and execute S416.

[0194] S416, confirm that no internal short circuit fault or capacity decay fault has occurred at the current moment, and continue fault diagnosis at the next moment.

[0195] Therefore, by performing fault diagnosis through the above process, the accuracy of fault diagnosis can be improved.

[0196] The battery fault diagnosis method provided in this application takes into account the influence of battery equalization strategies and combines equalization statistics to perform targeted diagnosis of internal short circuit and capacity decay faults under various typical equalization strategies. Compared with traditional single fault diagnosis methods, it can improve the applicability and accuracy of fault diagnosis.

[0197] This application also provides a battery fault diagnosis system. The following embodiments, in conjunction with... Figure 5 The battery fault diagnosis system provided in the embodiments of this application will be described in detail.

[0198] Figure 5 A schematic diagram of the structure of a battery fault diagnosis system provided in one embodiment of this application is shown.

[0199] like Figure 5 As shown, the battery fault diagnosis device may include: a battery parameter acquisition unit 510, a fault parameter calculation unit 520, a fault joint diagnosis unit 530, and a data storage unit 540.

[0200] Among them, the battery parameter acquisition unit 510 can be used to acquire battery parameters in real time, such as current time, data acquisition / acquisition cycle, battery cycle count, balancing strategy, voltage of each cell, SOC, balancing activation flag, balancing resistor value, balancing activation duty cycle, accumulated balanced charge storage value, accumulated balanced charge calculation value, charge storage value to be balanced, and charge calculation value to be balanced.

[0201] The fault parameter calculation unit 520 can be used to calculate the cumulative total balanced power increment, the first deviation coefficient, the second deviation coefficient and the third deviation coefficient, the curve division and all other calculation processes involved in the embodiments of this application.

[0202] The fault joint diagnosis unit 530 can be used to diagnose internal short circuit faults and capacity decay faults of the target battery cell based on the second deviation degree coefficient and the third deviation degree coefficient, and obtain the diagnosis results. The specific process will not be described in detail.

[0203] The data storage unit 540 can be used to store data including but not limited to balancing strategies, segmentation rules, start conditions, diagnostic rules, first preset relationships, second preset relationships, third preset relationships, preset ranges, and thresholds.

[0204] Therefore, the cumulative total balanced charge increment of the target battery's multiple individual cells within the target time period can be obtained, along with the first deviation coefficients corresponding to the target battery cells at the target time and multiple historical times. Then, based on the multiple cumulative total balanced charge increments, a second deviation coefficient corresponding to the target battery cell is determined. Finally, based on the first deviation coefficients corresponding to the target battery cell at the target time and multiple historical times, a third deviation coefficient is determined. Based on the second and third deviation coefficients, the target battery cell is then diagnosed for internal short-circuit faults and capacity degradation faults, yielding a diagnostic result. Since the battery fault diagnosis method and apparatus of this application can perform joint diagnosis of whether a target battery cell has experienced internal short-circuit faults and capacity degradation faults based on the second and third deviation coefficients, it can accurately distinguish between internal short-circuit faults and capacity degradation faults.

[0205] Based on the same inventive concept, this application also provides a battery fault diagnosis device. The following describes... Figure 6 The battery fault diagnosis device provided in the embodiments of this application will be described in detail.

[0206] Figure 6 A schematic diagram of the structure of a battery fault diagnosis device provided in one embodiment of this application is shown.

[0207] like Figure 6 As shown, the battery fault diagnosis device may include:

[0208] The acquisition module 601 is used to acquire the cumulative total balanced charge increment of multiple battery cells included in the target battery during the target time period, and the first deviation coefficient of the target battery cells at the target time and multiple historical times respectively.

[0209] The determining module 602 is used to determine a second deviation coefficient corresponding to the target battery cell based on multiple cumulative total equalization power increments, and to determine a third deviation coefficient corresponding to the target battery cell based on the first deviation coefficients corresponding to the target battery cell at the target time and multiple historical times.

[0210] The diagnostic module 603 is used to diagnose internal short-circuit faults and capacity degradation faults in the target battery cell based on the second deviation coefficient and the third deviation coefficient, and obtain the diagnostic results.

[0211] The target battery cell is any one of multiple battery cells. The first deviation coefficient represents the degree of deviation of the target value of the target battery cell from the first average value at the same time. The first average value is the average of the target values ​​of multiple battery cells. The target value includes the SOC value and / or voltage value. The target time is the last time of the target period. The target value of the target battery cell is the same at the target time and at multiple historical times. The historical period is earlier than the target period.

[0212] Therefore, the cumulative total balanced charge increment of the target battery's multiple individual cells within the target time period can be obtained, along with the first deviation coefficients corresponding to the target battery cells at the target time and multiple historical times. Then, based on the multiple cumulative total balanced charge increments, a second deviation coefficient corresponding to the target battery cell is determined. Finally, based on the first deviation coefficients corresponding to the target battery cell at the target time and multiple historical times, a third deviation coefficient is determined. Based on the second and third deviation coefficients, the target battery cell is then diagnosed for internal short-circuit faults and capacity degradation faults, yielding a diagnostic result. Since the battery fault diagnosis method and apparatus of this application can perform joint diagnosis of whether a target battery cell has experienced internal short-circuit faults and capacity degradation faults based on the second and third deviation coefficients, it can accurately distinguish between internal short-circuit faults and capacity degradation faults.

[0213] In some implementations, to more accurately determine the cumulative total equalization charge increment and the first deviation coefficient of the target battery cell at the target time and multiple historical times, the acquisition module 601 may include:

[0214] The first acquisition submodule is used to acquire the target balancing strategy of the target battery, and to acquire the first curve corresponding to multiple battery cells and the second curve corresponding to the target battery cell respectively. The first curve is the curve of the cumulative total balancing capacity changing over time, and the second curve is the curve of the first deviation coefficient changing with the target value.

[0215] The first determining submodule is used to determine the target segmentation rule corresponding to the target equilibrium strategy based on the first preset relationship.

[0216] The segmentation submodule is used to divide each first curve and second curve based on the target segmentation rules, resulting in multiple first curve segments corresponding to each first curve and multiple second curve segments corresponding to each second curve.

[0217] The second determining submodule is used to determine multiple cumulative total balanced power increments based on the target curve segments corresponding to the multiple first curves, and to determine the first deviation coefficients of the target battery cell at the target time and multiple historical time based on the multiple third curve segments among the multiple second curve segments. The target curve segment is the curve segment corresponding to the target time period among the multiple first curve segments corresponding to the first curve, and the multiple third curve segments are the curve segments corresponding to the target time and multiple historical time.

[0218] In some implementations, to obtain a more accurate second curve, the acquisition submodule may include:

[0219] The generation unit is used to generate a second curve based on the first deviation coefficient corresponding to the target battery cell at multiple time points.

[0220] Specifically, the generation unit can be used to obtain the first deviation coefficient for each of multiple time points through the following steps:

[0221] Obtain the target values ​​of multiple individual battery cells at each time step.

[0222] Determine the first average and first standard deviation of the target values ​​corresponding to multiple individual battery cells at time points.

[0223] Based on the target value, first average value, and first standard deviation of the target battery cell at time t, determine the first deviation coefficient of the target battery cell at time t.

[0224] In some implementations, to more accurately divide the first curve and the second curve, a first determining submodule may be used specifically for:

[0225] When the target equalization strategy aims to maintain the same rechargeable capacity across multiple battery cells, the target segmentation rule is a segmentation rule based on a first preset range.

[0226] When the target equalization strategy aims to maintain the consistent discharge capacity of multiple battery cells, the target segmentation rule is a segmentation rule based on a second preset range.

[0227] When the target balancing strategy aims to maintain consistency in the target values ​​of multiple battery cells, the target segmentation rule is a segmentation rule based on a third preset range.

[0228] The segmentation rules are as follows:

[0229] Given that the target battery has N+C battery cycle counts, determine the target time corresponding to N+C battery cycle counts, where N is the battery cycle count corresponding to the first point of the curve to be divided, the first point is the starting point or the latest dividing point of the curve to be divided, N is a non-negative integer, and C is a positive integer.

[0230] Determine whether the curve segment from the first point to the target point at the target time contains target data. Target data includes curve data when the target value of the battery cell corresponding to the curve to be divided is within a target preset range. The target preset range is a first preset range, a second preset range, or a third preset range.

[0231] If the curve segment does not contain the target data, update N to N+C, and return to the point where the target battery has N+C battery cycle counts, determining the target time corresponding to N+C battery cycle counts.

[0232] If the curve segment contains the target data, determine the target point as the segmentation point, and return to the point where the target battery has N+C battery cycle counts, determining the target time corresponding to N+C battery cycle counts.

[0233] The curve to be divided is divided based on the dividing points.

[0234] In some implementations, to more accurately determine the second deviation coefficient, the determining module 602 may include:

[0235] The third determination submodule is used to determine the second average and second standard deviation of multiple cumulative total balanced power increments.

[0236] The fourth determination submodule is used to determine the second deviation coefficient based on the cumulative total balanced charge increment of the target battery cell, the second average value, and the second standard deviation.

[0237] In some implementations, to more accurately determine the third deviation coefficient, the determining module 602 may include:

[0238] The second acquisition submodule is used to acquire the target balancing strategy for the target battery.

[0239] The fifth determining submodule is used to determine the target activation conditions corresponding to the target equilibrium strategy based on the second preset relationship.

[0240] The sixth determination submodule is used to determine that the third deviation coefficient is 0 if the target start-up conditions are not met.

[0241] The seventh determination submodule is used to determine the third average and third standard deviation of the first deviation coefficient corresponding to multiple historical time points, provided that the target activation conditions are met.

[0242] The eighth determination submodule is used to determine the third deviation coefficient based on the first deviation coefficient, the third average value, and the third standard deviation of the target battery cell at the target time.

[0243] In some implementations, to further improve the accuracy of the third deviation coefficient, the fifth determining submodule can be specifically used for:

[0244] When the target balancing strategy aims to maintain the same rechargeable capacity across multiple battery cells, the target activation condition is that the target value of the target battery cell falls within the fourth preset range.

[0245] When the target balancing strategy aims to maintain the same discharge capacity of multiple battery cells, the target activation condition is that the target value of the target battery cell falls within the fifth preset range.

[0246] When the target balancing strategy aims to keep the target values ​​of multiple battery cells consistent, the target activation condition is that the target value of the target battery cell belongs to the sixth preset range.

[0247] In some implementations, to obtain more accurate diagnostic results, the diagnostic module 603 may include:

[0248] The third acquisition submodule is used to acquire the target balancing strategy for the target battery.

[0249] The ninth submodule is used to determine the target diagnostic rules corresponding to the target equilibrium strategy based on the third preset relationship.

[0250] The diagnostic submodule is used to diagnose internal short-circuit faults and capacity decay faults of the target battery cell based on the target diagnostic rules according to the second deviation degree coefficient and the third deviation degree coefficient, and obtain the diagnostic results.

[0251] In some implementations, to improve the accuracy of fault diagnosis, the diagnostic submodule can specifically be used for:

[0252] Given that the target balancing strategy is to maintain the same rechargeable capacity among multiple battery cells, it is determined whether the second deviation coefficient is less than the first threshold.

[0253] If the second deviation coefficient is less than the first threshold, it is determined that the target battery cell has an internal short circuit fault.

[0254] If the second deviation coefficient is not less than the first threshold, determine whether the third deviation coefficient is less than the second threshold.

[0255] If the third deviation coefficient is less than the second threshold, it is determined that the target battery cell has experienced a capacity degradation fault.

[0256] Given that the target balancing strategy is to maintain the consistent discharge capacity of multiple battery cells, it is determined whether the second deviation coefficient is less than the third threshold.

[0257] If the second deviation coefficient is less than the third threshold, determine whether the third deviation coefficient is less than the fourth threshold.

[0258] If the third deviation coefficient is less than the fourth threshold, it is determined that the target battery cell has an internal short circuit fault.

[0259] If the third deviation coefficient is not less than the fourth threshold, determine whether the third deviation coefficient is greater than the fifth threshold.

[0260] If the third deviation coefficient is greater than the fifth threshold, it is determined that the target battery cell has experienced a capacity degradation fault.

[0261] Under the target balancing strategy of maintaining the consistency of target values ​​for multiple battery cells, the first fault flag, second fault flag, and third fault flag of the target battery cell are determined, and it is determined whether the second deviation coefficient is less than the sixth threshold.

[0262] If the second deviation coefficient is less than the sixth threshold, determine whether both the first fault flag and the second fault flag are target flags.

[0263] If both the first fault flag and the second fault flag are target flags, it is determined that the target battery cell has experienced an internal short circuit fault.

[0264] If neither the first fault flag nor the second fault flag is a target flag, determine whether both the first fault flag and the third fault flag are target flags.

[0265] If both the first and third fault flags are target flags, it is determined that the target battery cell has experienced a capacity decay fault.

[0266] The determination of the first fault indicator, second fault indicator, and third fault indicator of the target battery cell includes:

[0267] If the target value of the target battery cell falls within the seventh preset range, determine whether the third deviation coefficient is less than the seventh threshold.

[0268] If the third deviation coefficient is less than the seventh threshold, the first fault flag is updated to the target flag.

[0269] If the target value of the target battery cell falls within the eighth preset range, determine whether the third deviation coefficient is less than the eighth threshold, and determine whether the third deviation coefficient is greater than the ninth threshold.

[0270] If the third deviation coefficient is less than the eighth threshold, the second fault flag is updated to the target flag; and if the third deviation coefficient is greater than the ninth threshold, the third fault flag is updated to the target flag.

[0271] Figure 7 A schematic diagram of the structure of an electronic device provided in one embodiment of this application is shown.

[0272] like Figure 7 As shown, the electronic device 7 is a structural diagram of an exemplary hardware architecture of an electronic device capable of implementing the battery fault diagnosis method and battery fault diagnosis device according to the embodiments of this application. This electronic device may refer to the electronic device in the embodiments of this application.

[0273] The electronic device 7 may include a processor 701 and a memory 702 storing computer program instructions.

[0274] Specifically, the processor 701 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0275] Memory 702 may include mass storage for data or instructions. For example, and not limitingly, memory 702 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 702 may include removable or non-removable (or fixed) media. Where appropriate, memory 702 may be internal or external to an integrated gateway disaster recovery device. In a particular embodiment, memory 702 is non-volatile solid-state memory. In a particular embodiment, memory 702 may include read-only memory (ROM), random access memory (RAM), disk storage media device, optical storage media device, flash memory device, electrical, optical, or other physical / tangible memory storage device. Thus, generally, memory 702 includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to one aspect of this application.

[0276] The processor 701 reads and executes computer program instructions stored in the memory 702 to implement any of the battery fault diagnosis methods in the above embodiments.

[0277] In one example, the electronic device may also include a communication interface 703 and a bus 704. Wherein, as... Figure 7As shown, the processor 701, memory 702, and communication interface 703 are connected through bus 704 and complete communication with each other.

[0278] The communication interface 703 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0279] Bus 704 includes hardware, software, or both, that couples components of an electronic device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 704 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, any suitable bus or interconnect is contemplated herein.

[0280] The electronic device can execute the battery fault diagnosis method in the embodiments of this application, thereby achieving the combination of Figures 1 to 6 The battery fault diagnosis method and apparatus are described.

[0281] Furthermore, in conjunction with the battery fault diagnosis methods in the above embodiments, this application embodiment can provide a computer storage medium for implementation. This computer storage medium stores computer program instructions, which, when executed by a processor, implement any of the battery fault diagnosis methods in the above embodiments.

[0282] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0283] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0284] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0285] The aspects of this application have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by dedicated hardware performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0286] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A battery fault diagnosis method, characterized in that, The method includes: The cumulative total balanced charge increment of the target battery cells within the target time period is obtained, as well as the first deviation coefficient of the target battery cells at the target time and at multiple historical time points. Based on the multiple cumulative total balanced power increments, a second deviation coefficient corresponding to the target battery cell is determined, and based on the first deviation coefficients corresponding to the target battery cell at the target time and the multiple historical times respectively, a third deviation coefficient corresponding to the target battery cell is determined. Based on the second deviation coefficient and the third deviation coefficient, the target battery cell is diagnosed for internal short circuit faults and capacity degradation faults, and the diagnostic results are obtained. Wherein, the target battery cell is any one of the plurality of battery cells, the first deviation coefficient represents the degree of deviation of the target value of the target battery cell from the first average value at the same time, the first average value is the average of the target values ​​of the plurality of battery cells, the target value includes the battery state of charge (SOC) value and / or voltage value, the target time is the last time of the target time period, the target value of the target battery cell is the same at the target time and at the plurality of historical times, and the historical times are earlier than the target time; The step of determining the second deviation coefficient corresponding to the target battery cell based on multiple cumulative total balanced power increments includes: Determine the second average and second standard deviation of the multiple cumulative total balanced power increments. The second deviation coefficient is determined based on the cumulative total balanced charge increment of the target battery cell, the second average value, and the second standard deviation. The step of determining the third deviation coefficient corresponding to the target battery cell based on the first deviation coefficient corresponding to the target battery cell at the target time and the plurality of historical times respectively includes: Obtain the target balancing strategy for the target battery. Based on the second preset relationship, the target activation condition corresponding to the target equilibrium strategy is determined. If the target activation condition is not met, the third deviation coefficient is determined to be 0. If the target initiation conditions are met, determine the third average and third standard deviation of the first deviation coefficient corresponding to the plurality of historical time points, respectively. The third deviation coefficient is determined based on the first deviation coefficient, the third average value, and the third standard deviation of the target battery cell at the target time.

2. The method according to claim 1, characterized in that, The step of obtaining the cumulative total balanced charge increment of multiple battery cells included in the target battery during the target time period, and the first deviation coefficient of the target battery cells at the target time and multiple historical time periods respectively, includes: The target balancing strategy for the target battery is obtained, and a first curve corresponding to each of the plurality of battery cells and a second curve corresponding to the target battery cell are obtained respectively. The first curve is the curve of cumulative total balanced charge changing over time, and the second curve is the curve of the first deviation coefficient changing with the target value. Based on the first preset relationship, the target segmentation rule corresponding to the target equilibrium strategy is determined. Based on the target segmentation rule, each first curve and second curve is divided to obtain multiple first curve segments corresponding to each first curve and multiple second curve segments corresponding to each second curve. Based on the target curve segments corresponding to the multiple first curves, a plurality of cumulative total balanced power increments are determined, and based on the multiple third curve segments among the multiple second curve segments, the first deviation coefficients corresponding to the target battery cell at the target time and the multiple historical times are determined, where the target curve segment is the curve segment among the multiple first curve segments corresponding to the first curve that corresponds to the target time period, and the multiple third curve segments are the curve segments corresponding to the target time and the multiple historical times, respectively.

3. The method according to claim 2, characterized in that, Obtaining the second curve corresponding to the target battery cell includes: The second curve is generated based on the first deviation coefficient corresponding to the target battery cell at multiple times. The first deviation coefficient corresponding to each of the plurality of times is obtained through the following steps: The target values ​​corresponding to the plurality of individual battery cells at the given time are obtained respectively. Determine the first average value and the first standard deviation of the target value corresponding to the plurality of individual battery cells at the respective time points. Based on the target value, the first average value, and the first standard deviation of the target battery cell at that time, the first deviation coefficient of the target battery cell at that time is determined.

4. The method according to claim 2, characterized in that, The step of determining the target segmentation rule corresponding to the target equilibrium strategy based on the first preset relationship includes: When the target equalization strategy is to maintain the same rechargeable capacity of the multiple battery cells, the target segmentation rule is a segmentation rule based on a first preset range. When the target equalization strategy is to maintain the consistent discharge capacity of the multiple battery cells, the target segmentation rule is a segmentation rule based on a second preset range. When the target equalization strategy aims to maintain the consistency of the target values ​​of the multiple battery cells, the target segmentation rule is a segmentation rule based on a third preset range. The segmentation rule is as follows: Given that the target battery has N+C battery cycle counts, determine the target time corresponding to N+C battery cycle counts, where N is the battery cycle count corresponding to the first point of the curve to be divided, the first point being the starting point or the latest dividing point of the curve to be divided, N is a non-negative integer, and C is a positive integer. Determine whether the curve segment from the first point to the target point corresponding to the target time contains target data. The target data includes curve data when the target value of the battery cell corresponding to the curve to be divided is within a target preset range. The target preset range is the first preset range, the second preset range, or the third preset range. If the curve segment does not contain the target data, N is updated to N+C, and the process returns to determining the target time corresponding to the battery cycle count of N+C, assuming the target battery has N+C battery cycle counts. If the curve segment contains the target data, determine the target point as the segmentation point, and return to the step of determining the target time corresponding to the number of battery cycles of N+C when the number of battery cycles of the target battery is N+C. The curve to be divided is divided based on the dividing points.

5. The method according to claim 1, characterized in that, The step of determining the target activation condition corresponding to the target equilibrium strategy based on the second preset relationship includes: When the target balancing strategy aims to maintain the same rechargeable capacity among the multiple battery cells, the target activation condition is that the target value of the target battery cell falls within a fourth preset range. When the target balancing strategy aims to maintain the consistent discharge capacity of the multiple battery cells, the target activation condition is that the target value of the target battery cell falls within a fifth preset range. When the target balancing strategy is to keep the target values ​​of the multiple battery cells consistent, the target activation condition is that the target value of the target battery cell belongs to a sixth preset range.

6. The method according to claim 1, characterized in that, The diagnosis of internal short-circuit faults and capacity degradation faults in the target battery cell is performed based on the second deviation coefficient and the third deviation coefficient, and the diagnostic results are obtained, including: Obtain the target balancing strategy for the target battery. Based on the third preset relationship, determine the target diagnosis rule corresponding to the target equilibrium strategy. Based on the second deviation coefficient and the third deviation coefficient, the target battery cell is diagnosed for internal short circuit faults and capacity decay faults according to the target diagnosis rule, and the diagnosis results are obtained.

7. The method according to claim 6, characterized in that, The step of diagnosing the target battery cell for internal short-circuit faults and capacity degradation faults based on the second deviation coefficient and the third deviation coefficient, according to the target diagnosis rule, and obtaining the diagnosis results includes: When the target balancing strategy is to maintain the same rechargeable capacity of the multiple battery cells, it is determined whether the second deviation coefficient is less than the first threshold. If the second deviation coefficient is less than the first threshold, it is determined that the target battery cell has an internal short circuit fault. If the second deviation coefficient is not less than the first threshold, determine whether the third deviation coefficient is less than the second threshold. If the third deviation coefficient is less than the second threshold, it is determined that the target battery cell has a capacity degradation fault. Given that the target balancing strategy is to maintain the consistent discharge capacity of the multiple battery cells, it is determined whether the second deviation coefficient is less than a third threshold. If the second deviation coefficient is less than the third threshold, determine whether the third deviation coefficient is less than the fourth threshold. If the third deviation coefficient is less than the fourth threshold, it is determined that the target battery cell has an internal short circuit fault. If the third deviation coefficient is not less than the fourth threshold, determine whether the third deviation coefficient is greater than the fifth threshold. If the third deviation coefficient is greater than the fifth threshold, it is determined that the target battery cell has a capacity decay fault. When the target balancing strategy aims to maintain consistency in the target values ​​of the multiple battery cells, the first fault flag, the second fault flag, and the third fault flag of the target battery cell are determined, and it is determined whether the second deviation coefficient is less than the sixth threshold. If the second deviation coefficient is less than the sixth threshold, determine whether both the first fault flag and the second fault flag are target flags. If both the first fault flag and the second fault flag are the target flag, it is determined that the target battery cell has an internal short circuit fault. If neither the first fault flag nor the second fault flag is the target flag, determine whether both the first fault flag and the third fault flag are the target flag. If both the first fault flag and the third fault flag are the target flag, it is determined that the target battery cell has experienced a capacity degradation fault. The determination of the first fault flag, the second fault flag, and the third fault flag of the target battery cell includes: If the target value of the target battery cell falls within a seventh preset range, determine whether the third deviation coefficient is less than a seventh threshold. If the third deviation coefficient is less than the seventh threshold, the first fault flag is updated to the target flag. If the target value of the target battery cell falls within an eighth preset range, determine whether the third deviation coefficient is less than an eighth threshold, and determine whether the third deviation coefficient is greater than a ninth threshold. If the third deviation coefficient is less than the eighth threshold, the second fault flag is updated to the target flag; and if the third deviation coefficient is greater than the ninth threshold, the third fault flag is updated to the target flag.

8. A battery fault diagnosis device, characterized in that, The device includes: The acquisition module is used to acquire the cumulative total balanced charge increment of multiple battery cells included in the target battery during the target time period, as well as the first deviation coefficient of the target battery cells at the target time and multiple historical time periods. The determination module is used to determine the second average value and the second standard deviation of the multiple cumulative total balanced power increments, and to determine a second deviation coefficient based on the cumulative total balanced power increment, the second average value, and the second standard deviation of the target battery cell; and to obtain the target balancing strategy of the target battery, and to determine the target activation condition corresponding to the target balancing strategy based on a second preset relationship. If the target activation condition is not met, the third deviation coefficient is determined to be 0. If the target activation condition is met, the third average value and the third standard deviation of the first deviation coefficients corresponding to the multiple historical times are determined respectively. The third deviation coefficient is determined based on the first deviation coefficient, the third average value, and the third standard deviation of the target battery cell at the target time. The diagnostic module is used to diagnose internal short-circuit faults and capacity degradation faults in the target battery cell based on the second deviation coefficient and the third deviation coefficient, and to obtain diagnostic results. Wherein, the target battery cell is any one of the plurality of battery cells, the first deviation coefficient represents the degree of deviation of the target value of the target battery cell from the first average value at the same time, the first average value is the average of the target values ​​of the plurality of battery cells, the target value includes SOC value and / or voltage value, the target time is the last time of the target time period, the target value of the target battery cell is the same at the target time and at the plurality of historical times, and the historical times are earlier than the target time.

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