Fault determination method and device and computer readable storage medium

Abstract

The invention provides a fault determination method and device and a computer readable storage medium, relates to the technical field of batteries, and can improve the accuracy of determining the fault of each battery cell in a battery under the condition that the quality of the data of the battery is relatively low. The method comprises the following steps: acquiring a voltage value set of each battery cell in a plurality of battery cells of a target battery; the voltage value set comprises voltage values at multiple moments; determining an abnormal battery cell in the plurality of battery cells according to the voltage value set of the plurality of battery cells; for each abnormal battery cell, determining a fault of the abnormal battery cell based on the plurality of first voltage characteristic values of each battery cell in the plurality of battery cells; the fault comprises a low-capacity fault or a micro-short-circuit fault, the first voltage characteristic comprises a maximum voltage value or a voltage average value, the maximum voltage value is the maximum value in the voltage values of the battery cell at multiple moments, and the voltage average value is the average value of the voltage values of the battery cell at multiple moments.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a fault determination method, device, and computer-readable storage medium. Background Art

[0002] In order to ensure the normal operation of the battery, it is necessary to determine the faults of each cell in the battery.

[0003] In order to determine the fault of each cell in the battery, the existing solution is to collect a variety of relatively comprehensive data of the battery and analyze the multiple data to determine the fault of each cell in the battery.

[0004] This solution has high requirements on data quality. In some cases, the quality of battery data is low, for example, the collection interval is long, the data type is relatively single and / or the data is incoherent. In this case, the existing solution has low accuracy in determining the faults of individual cells in the battery. Summary of the invention

[0005] The present application provides a fault determination method, device and computer-readable storage medium, which can improve the accuracy of determining the fault of each battery cell in a battery when the quality of battery data is low.

[0006] In order to achieve the above objectives, this application adopts the following technical solutions:

[0007] In a first aspect, a fault determination method is provided, the method comprising: obtaining a voltage value set of each battery cell in a plurality of battery cells of a target battery; the voltage value set comprising voltage values ​​at a plurality of moments; determining an abnormal battery cell among a plurality of battery cells according to the voltage value set of the plurality of battery cells; for each abnormal battery cell, determining a fault of the abnormal battery cell based on a plurality of first voltage characteristic values ​​of each battery cell in the plurality of battery cells; the fault comprises a low capacity fault or a micro short circuit fault, the first voltage characteristic comprising a maximum voltage value or a voltage mean value, the maximum voltage value being the maximum value of the voltage values ​​of the battery cell at a plurality of moments, and the voltage mean value being the average value of the voltage values ​​of the battery cell at a plurality of moments.

[0008] Based on this solution, compared with the existing solution that requires more comprehensive and multiple data of the battery to determine the fault of the battery cell, the solution of the present application obtains a voltage value set including voltage values ​​at multiple moments of each battery cell of the target battery, and then determines the abnormal battery cell among the multiple battery cells according to the voltage value set of the multiple battery cells, and then, for each abnormal battery cell, determines the fault of the abnormal battery cell based on multiple first voltage characteristic values ​​of each battery cell in the multiple battery cells. When a low-capacity fault or a micro-short circuit fault occurs in a battery cell, the voltage value of the battery cell will be abnormal. Since the first voltage characteristic includes a maximum voltage value or a voltage mean, the maximum voltage value is the maximum value of the voltage values ​​of the battery cell at multiple moments, and the voltage mean is the average value of the voltage values ​​of the battery cell at multiple moments. By analyzing and processing the voltage values ​​of multiple battery cells, there is no need to collect other types of battery data, and it does not rely on the consistency of the data. In the case of low-quality battery data, the accuracy of determining the fault of each battery cell in the battery is improved.

[0009] In combination with the first aspect, in certain embodiments of the first aspect, the fault of an abnormal battery cell is determined based on multiple first voltage characteristic values ​​of each battery cell in multiple battery cells, including: when the maximum voltage value of the abnormal battery cell is greater than a first average value, determining that the abnormal battery cell has a low capacity fault; the first average value is the average value of the maximum voltage values ​​of multiple battery cells; when the voltage mean value of the abnormal battery cell is less than a second average value, determining that the abnormal battery cell has a micro short circuit fault; the second average value is the average value of the voltage mean values ​​of multiple battery cells.

[0010] Based on this scheme, the voltage of the abnormal battery cell with a low-capacity fault will be quickly charged due to its low capacity. Compared with the normal battery cell, the voltage value of the abnormal battery cell with a low-capacity fault will be higher. Therefore, when the maximum voltage value of the abnormal battery cell is greater than the first average value, it can be determined that the abnormal battery cell has a low-capacity fault; the abnormal battery cell with a micro-short circuit fault will self-discharge due to an internal short circuit. Compared with the normal battery cell, the voltage mean value of the abnormal battery cell with a micro-short circuit fault will be smaller. Therefore, when the voltage mean value of the abnormal battery cell is less than the second average value, it can be determined that the abnormal battery cell has a micro-short circuit fault.

[0011] In combination with the first aspect, in certain embodiments of the first aspect, an abnormal battery cell among a plurality of battery cells is determined based on a set of voltage values ​​of the plurality of battery cells, including: for each battery cell among the plurality of battery cells, determining a difference index of the battery cell based on the set of voltage values ​​of the plurality of battery cells; the difference index is used to indicate the degree of difference between the voltage value of the battery cell and the voltage values ​​of the plurality of battery cells; and determining the abnormal battery cell among the plurality of battery cells based on the difference index of the plurality of battery cells.

[0012] Based on this scheme, under normal circumstances, most of the battery cells in the battery are in a normal state, and abnormal battery cells will have voltage differences from normal battery cells. By determining the difference index of each battery cell, since the difference index is used to indicate the degree of difference between the voltage value of the battery cell and the voltage values ​​of multiple battery cells, the abnormal battery cells among multiple battery cells can be determined based on the difference indexes of multiple battery cells.

[0013] In combination with the first aspect, in certain embodiments of the first aspect, the difference index is the outlier distance, and the difference index of the battery cell is determined according to a set of voltage values ​​of multiple battery cells, including: determining multiple second voltage characteristic values ​​of the battery cell according to the set of voltage values ​​of the battery cell; the second voltage characteristic includes a maximum voltage value, a voltage mean or a voltage variance value, and the voltage variance value is the variance value of the voltage value of the battery cell at multiple moments; determining multiple adjacent battery cells according to the multiple second voltage characteristic values ​​of the multiple battery cells; the Euclidean distance between adjacent battery cells is less than the Euclidean distance between non-adjacent battery cells in the multiple battery cells; determining the sum of multiple target Euclidean distances as the outlier distance of the battery cell; the target Euclidean distance is the Euclidean distance between adjacent battery cells.

[0014] Based on this scheme, multiple second voltage characteristic values ​​of the battery cell, including the maximum voltage value, the voltage mean or the voltage variance value, are determined according to the voltage value set of the battery cell. Subsequently, multiple adjacent battery cells of the battery cell are determined according to the multiple second voltage characteristic values ​​of the multiple battery cells. Subsequently, the sum of the Euclidean distances between the multiple adjacent battery cells and the battery cell is determined as the outlier distance of the battery cell. On the one hand, the maximum voltage value, the voltage mean or the voltage variance value of the battery cell can well distinguish the battery cells. On the other hand, by determining multiple adjacent battery cells and determining the sum of the Euclidean distances between the multiple adjacent battery cells and the battery cell as the outlier distance of the battery cell, the influence of accidental factors on the outlier distance of the battery cell can be reduced, thereby improving the accuracy of the determined outlier distance of the battery cell.

[0015] In combination with the first aspect, in certain embodiments of the first aspect, the difference index is an outlier distance, and determining an abnormal cell among multiple cell according to the difference index of multiple cells includes: determining a first outlier distance and a second outlier distance based on the outlier distances of the multiple cells; the first outlier distance is located at the upper quartile of the multiple outlier distances, and the second outlier distance is located at the lower quartile of the multiple outlier distances; for each cell among the multiple cells, determining a magnitude relationship between the outlier distance of the cell and a difference between the first outlier distances; the first outlier distance difference is the product of the second outlier distance difference and a first coefficient, the second outlier distance difference is the difference between the first outlier distance and the second outlier distance, and the first coefficient is determined based on the minimum time interval between multiple moments; when the outlier distance of the cell is greater than the first outlier distance difference, determining the cell as an abnormal cell.

[0016] Based on the scheme, a first outlier distance and a second outlier distance are determined based on outlier distances of a plurality of battery cells. Subsequently, for each of the plurality of battery cells, a magnitude relationship between the outlier distance of the battery cell and the difference between the first outlier distance is determined. When the outlier distance of the battery cell is greater than the difference between the first outlier distance, the battery cell is determined to be an abnormal battery cell. Since the first outlier distance is located in the upper quartile of the plurality of outlier distances and the second outlier distance is located in the lower quartile of the plurality of outlier distances, the difference between the first outlier distance is the product of the difference between the second outlier distance and a first coefficient, the difference between the second outlier distance is the difference between the first outlier distance and the second outlier distance, and the first coefficient is determined based on the minimum time interval between a plurality of moments. Therefore, an abnormal battery cell having a larger outlier distance among the plurality of battery cells can be determined based on the minimum time interval between a plurality of moments.

[0017] In combination with the first aspect, in certain embodiments of the first aspect, before determining the abnormal battery cell among the multiple battery cells based on the set of voltage values ​​of the multiple battery cells, the method also includes: determining, for each of the multiple moments, the median voltage value of the multiple battery cells at the moment; determining the weighted sum of the voltage differences of the target battery based on the multiple median voltage values; and determining that the target battery is in an abnormal state when the weighted sum of the pressure differences is greater than a first threshold value.

[0018] Based on this solution, for each of the multiple moments, the median voltage values ​​of the multiple cells at the moment are determined, and then the weighted sum of the voltage difference of the target battery is determined based on the multiple median voltage values. Since the voltage difference of the battery can reflect the state of the battery, it can be determined that the target battery is in an abnormal state when the weighted sum of the voltage difference is greater than the first threshold. By first determining whether the target battery is in an abnormal state, and then determining the abnormality of the cells in the target battery when the target battery is in an abnormal state, the faults of the cells in the abnormal battery can be determined in a targeted manner, thereby improving the efficiency of fault determination.

[0019] In combination with the first aspect, in certain embodiments of the first aspect, a weighted sum of the pressure difference of the target battery is determined based on multiple median voltage values, including: for each median voltage value among the multiple median voltage values, when the median voltage value is greater than the second threshold, the product of the pressure difference value and the second coefficient is used as the first pressure difference score at the moment, and when the median voltage value is less than or equal to the second threshold, the product of the pressure difference value and the third coefficient is used as the second pressure difference score at the moment; the pressure difference value is the difference between the first voltage value and the second voltage value, the first voltage value is the maximum voltage value among the voltage values ​​of the multiple battery cells at the moment, the second voltage value is the minimum voltage value among the voltage values ​​of the multiple battery cells at the moment, and the third coefficient is greater than the second coefficient; the sum of the target first pressure difference score and the target second pressure difference score is determined as the weighted sum of the pressure difference; the target first pressure difference score is any one of the multiple first pressure difference scores, and the target second pressure difference score is any one of the multiple second pressure difference scores.

[0020] Based on this scheme, in some cases, for example, when the target battery is a lithium iron phosphate battery, since the fault characteristics of the lithium iron phosphate battery are not obvious in the plateau period, by comparing the median voltage value with the second threshold value, the situations where the voltage of the battery cell is higher and lower are taken into account, and when more battery cells are in the plateau period, the abnormal characteristics of the battery cells with higher and lower voltages can be highlighted, thereby improving the accuracy of determining that the battery is in an abnormal state.

[0021] In a second aspect, a fault determination device is provided for implementing the fault determination method of the first aspect. The fault determination device includes a module, unit, or means corresponding to the method, which can be implemented by hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

[0022] In combination with the second aspect, in certain embodiments of the second aspect, the fault determination device includes: an acquisition module and a processing module; the acquisition module is used to acquire a voltage value set of each battery cell in a plurality of battery cells of a target battery; the voltage value set includes voltage values ​​at a plurality of moments; the processing module is used to determine an abnormal battery cell among a plurality of battery cells according to the voltage value set of the plurality of battery cells; the processing module is also used to determine, for each abnormal battery cell, the fault of the abnormal battery cell based on a plurality of first voltage characteristic values ​​of each battery cell in the plurality of battery cells; the fault includes a low capacity fault or a micro short circuit fault, the first voltage characteristic includes a maximum voltage value or a voltage mean, the maximum voltage value is the maximum value of the voltage values ​​of the battery cell at a plurality of moments, and the voltage mean is the average value of the voltage values ​​of the battery cell at a plurality of moments.

[0023] In combination with the second aspect, in certain embodiments of the second aspect, the processing module is also used to determine the fault of the abnormal battery cell based on multiple first voltage characteristic values ​​of each battery cell in the multiple battery cells, including: when the maximum voltage value of the abnormal battery cell is greater than the first average value, determining that the abnormal battery cell has a low capacity fault; the first average value is the average value of the maximum voltage values ​​of the multiple battery cells; when the voltage mean value of the abnormal battery cell is less than the second average value, determining that the abnormal battery cell has a micro short circuit fault; the second average value is the average value of the voltage mean values ​​of the multiple battery cells.

[0024] In combination with the second aspect, in certain embodiments of the second aspect, a processing module is used to determine an abnormal battery cell among multiple battery cells based on a set of voltage values ​​of the multiple battery cells, including: for each battery cell among the multiple battery cells, determining a difference index of the battery cell based on the set of voltage values ​​of the multiple battery cells; the difference index is used to indicate the degree of difference between the voltage value of the battery cell and the voltage values ​​of the multiple battery cells; and determining the abnormal battery cell among the multiple battery cells based on the difference index of the multiple battery cells.

[0025] In combination with the second aspect, in certain embodiments of the second aspect, the difference index is an outlier distance, and the processing module is further used to determine the difference index of the battery cell based on a set of voltage values ​​of multiple battery cells, including: determining multiple second voltage characteristic values ​​of the battery cell based on the set of voltage values ​​of the battery cell; the second voltage characteristic includes a maximum voltage value, a voltage mean or a voltage variance value, and the voltage variance value is the variance value of the voltage value of the battery cell at multiple moments; determining multiple adjacent battery cells of the battery cell based on the multiple second voltage characteristic values ​​of the multiple battery cells; the Euclidean distance between adjacent battery cells is less than the Euclidean distance between non-adjacent battery cells in the multiple battery cells; determining the sum of multiple target Euclidean distances as the outlier distance of the battery cell; the target Euclidean distance is the Euclidean distance between adjacent battery cells.

[0026] In combination with the second aspect, in certain embodiments of the second aspect, the difference index is an outlier distance, and the processing module is further used to determine an abnormal cell among multiple cell according to the difference index of the multiple cells, including: determining a first outlier distance and a second outlier distance based on the outlier distances of the multiple cells; the first outlier distance is located at the upper quartile of the multiple outlier distances, and the second outlier distance is located at the lower quartile of the multiple outlier distances; for each cell among the multiple cells, determining a magnitude relationship between the outlier distance of the cell and a difference between the first outlier distances; the first outlier distance difference is the product of the second outlier distance difference and a first coefficient, the second outlier distance difference is the difference between the first outlier distance and the second outlier distance, and the first coefficient is determined based on the minimum time interval between multiple moments; when the outlier distance of the cell is greater than the first outlier distance difference, determining the cell as an abnormal cell.

[0027] In combination with the second aspect, in certain embodiments of the second aspect, before determining the abnormal battery cell among the multiple battery cells based on the set of voltage values ​​of the multiple battery cells, the processing module is also used to: determine, for each of the multiple moments, the median voltage value of the multiple battery cells at the moment; determine the weighted sum of the pressure difference of the target battery based on the multiple median voltage values; and determine that the target battery is in an abnormal state when the weighted sum of the pressure difference is greater than a first threshold.

[0028] In combination with the second aspect, in certain embodiments of the second aspect, the processing module is also used to determine the weighted sum of the pressure difference of the target battery based on multiple median voltage values, including: for each median voltage value among the multiple median voltage values, when the median voltage value is greater than the second threshold, the product of the pressure difference value and the second coefficient is used as the first pressure difference score at the moment; when the median voltage value is less than or equal to the second threshold, the product of the pressure difference value and the third coefficient is used as the second pressure difference score at the moment; the pressure difference value is the difference between the first voltage value and the second voltage value, the first voltage value is the maximum voltage value among the voltage values ​​of the multiple battery cells at the moment, the second voltage value is the minimum voltage value among the voltage values ​​of the multiple battery cells at the moment, and the third coefficient is greater than the second coefficient; the sum of the target first pressure difference score and the target second pressure difference score is determined as the weighted sum of the pressure difference; the target first pressure difference score is any one of the multiple first pressure difference scores, and the target second pressure difference score is any one of the multiple second pressure difference scores.

[0029] According to a third aspect, a fault determination device is provided, comprising: at least one processor and a memory for storing instructions executable by the processor; wherein the processor is configured to execute instructions to implement the method provided in the first aspect and any possible implementation manner thereof.

[0030] In a fourth aspect, a computer-readable storage medium is provided. When instructions in the computer-readable storage medium are executed by a processor of a fault determination device, the fault determination device is enabled to perform the method provided in the first aspect and any possible implementation manner thereof.

[0031] In a fifth aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the computer to execute the method provided in the first aspect and any possible implementation manner thereof.

[0032] Among them, the technical effects brought about by any implementation of the second to fifth aspects can refer to the technical effects brought about by different implementations of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of the architecture of a fault determination system provided in this application;

[0034] Figure 2 A flowchart of a fault determination method provided by the present application;

[0035] Figure 3 A flowchart of another fault determination method provided by the present application;

[0036] Figure 4 A flowchart of another fault determination method provided by the present application;

[0037] Figure 5 A flowchart of another fault determination method provided by the present application;

[0038] Figure 6 A flowchart of another fault determination method provided by the present application;

[0039] Figure 7 A flowchart of another fault determination method provided by the present application;

[0040] Figure 8 A structural schematic diagram of a fault determination device provided in this application;

[0041] Fig. 9 A schematic diagram of the structure of another fault determination device provided in the present application. DETAILED DESCRIPTION

[0042] In the description of this application, unless otherwise specified, "plurality" means two or more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0043] In addition, in order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish the same items or similar items with substantially the same functions and effects. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit the difference.

[0044] Meanwhile, in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete manner for ease of understanding.

[0045] It is understood that the "embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the various embodiments in the entire specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It is understood that in various embodiments of the present application, the size of the sequence number of each process does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0046] It can be understood that in the present application, "when", "if" and "if" all mean that corresponding processing will be carried out under certain objective circumstances, but do not limit the time, nor do they require judgment actions when implementing them, nor do they mean the existence of other limitations.

[0047] It can be understood that some optional features in the embodiments of the present application may be implemented independently in certain scenarios without relying on other features, such as the solution on which they are currently based, to solve corresponding technical problems and achieve corresponding effects, or may be combined with other features according to needs in certain scenarios. Accordingly, the devices provided in the embodiments of the present application may also realize these features or functions accordingly, which will not be elaborated here.

[0048] In this application, unless otherwise specified, the same or similar parts between the various embodiments can refer to each other. In the various embodiments in this application, and the various implementation methods in each embodiment, if there is no special description and logical conflict, the terms and / or descriptions between different embodiments and the various implementation methods in each embodiment are consistent and can be referenced to each other. The technical features in different embodiments and the various implementation methods in each embodiment can be combined to form new embodiments, implementation methods, implementation methods, or implementation methods according to their inherent logical relationships. The following implementation methods of this application do not constitute a limitation on the scope of protection of this application.

[0049] In order to ensure the normal operation of the battery, it is necessary to determine the faults of each cell in the battery.

[0050] In order to determine the fault of each cell in the battery, the existing solution is to collect a variety of relatively comprehensive data of the battery and analyze the multiple data to determine the fault of each cell in the battery.

[0051] This solution has high requirements on data quality. In some cases, the quality of battery data is low, for example, the collection interval is long, the data type is relatively single and / or the data is incoherent. In this case, the existing solution has low accuracy in determining the faults of individual cells in the battery.

[0052] To solve the above problems, the present application provides a fault determination method, which can be applied to Figure 1 The fault determination system shown. Figure 1 This is a schematic diagram of the architecture of a fault determination system provided by the present application. The technical solution of the embodiment of the present application can be applied to Figure 1 The fault determination system shown, such as Figure 1 As shown, the fault determination system 10 includes a fault determination device 11 and an electronic device 12 .

[0053] The fault determination device 11 is directly or indirectly connected to the electronic device 12. In this connection relationship, a wired connection or a wireless connection may be adopted, which is not limited in the embodiment of the present application.

[0054] Data can be exchanged between the fault determination device 11 and the electronic device 12 .

[0055] It should be noted that the fault determination device 11 and the electronic device 12 can be independent devices or integrated into the same device, and this application does not make any specific limitation on this.

[0056] When the fault determination device 11 and the electronic device 12 are integrated into the same device, the communication between the fault determination device 11 and the electronic device 12 is the communication between the internal modules of the device. In this case, the communication process between the two is the same as "the communication process between the two when the fault determination device 11 and the electronic device 12 are independent of each other".

[0057] In the following embodiments provided in the present application, the present application is described by taking the example that the fault determination device 11 and the electronic device 12 are independently configured.

[0058] In practical applications, the fault determination method provided in the embodiment of the present application can be applied to the fault determination device 11, and can also be applied to the device included in the fault determination device 11.

[0059] The fault determination method provided in the embodiment of the present application is described below with reference to the accompanying drawings, taking the application of the fault determination method to the fault determination device 11 as an example.

[0060] Figure 2 A flowchart of a fault determination method provided in this application is shown in FIG. Figure 2 As shown, the method comprises the following steps:

[0061] S201. A fault determination apparatus obtains a voltage value set of each battery cell in a plurality of battery cells of a target battery.

[0062] The voltage value set includes voltage values ​​at multiple moments.

[0063] It should be noted that the duration between two adjacent moments in the multiple moments may be the same or different.

[0064] For example, the duration between the first moment and the second moment is 10 minutes, and the duration between the second moment and the third moment is 20 minutes.

[0065] The target battery includes a plurality of battery cells.

[0066] The target battery may be a battery pack of an electric vehicle or an uninterruptible power supply (UPS). Of course, the target battery may also be a battery with other names, and this application does not impose any specific restrictions on this.

[0067] The type of the target battery may be a lithium iron phosphate battery or a ternary lithium battery. Of course, the target battery may also be other types of batteries, and this application does not impose any specific restrictions on this.

[0068] As a possible implementation, combining Figure 1 The fault determination device receives a message from an electronic device, the message including a set of voltage values ​​of each of the multiple cells of the target battery, and the fault determination device obtains the set of voltage values ​​of each of the multiple cells of the target battery from the message.

[0069] S202. The fault determination device determines an abnormal cell among the plurality of cells according to a set of voltage values ​​of the plurality of cells.

[0070] As a possible implementation manner, the fault determination device determines, for each battery cell among the multiple battery cells, a battery cell difference index according to a set of voltage values ​​of the multiple battery cells; and determines an abnormal battery cell among the multiple battery cells according to the difference indexes of the multiple battery cells.

[0071] The difference index is used to indicate the degree of difference between the voltage value of the battery cell and the voltage values ​​of multiple battery cells.

[0072] It should be noted that the specific description of this possible implementation method can refer to the relevant description in the subsequent part of the specific implementation method of this application, and this application will not explain it here.

[0073] S203 . The fault determining device determines, for each abnormal battery cell, the fault of the abnormal battery cell based on a plurality of first voltage characteristic values ​​of each battery cell in a plurality of battery cells.

[0074] Among them, the fault includes a low capacity fault or a micro short circuit fault, and the first voltage characteristic includes a maximum voltage value or a voltage average value, the maximum voltage value is the maximum value of the voltage values ​​of the battery cell at multiple times, and the voltage average value is the average value of the voltage values ​​of the battery cell at multiple times.

[0075] It should be noted that there is a difference between low-capacity failure of battery cells and natural aging of battery cells, but there is a certain connection between them. The reason why low-capacity failure of battery cells is partly due to manufacturing differences among battery cell manufacturers during the production process, which results in certain differences in the capacity of the battery cells themselves. However, the main reason is the abnormal charging and discharging of the battery cells caused by the abuse of the battery cells, which accelerates the aging of the battery cells, thereby further expanding the capacity differences of different battery cells in the battery, and then evolving into low-capacity failures.

[0076] When a cell has a low capacity fault, if the cell is charged, the cell capacity will decrease, and according to the manifestation of cell aging on the resistor, the cell resistance will increase. The voltage change caused by the current on the resistor will make the cell voltage rise faster during the charging process, and the maximum value that the voltage can reach will also increase.

[0077] If the battery cell is discharged, based on the same theoretical analysis, the voltage drop rate of the battery cell will become faster and the lowest value that the voltage can reach will also decrease.

[0078] If the battery cell is not working, the battery cell will not have abnormal voltage or abnormal voltage rate.

[0079] The micro short circuit failure of the battery cell is mainly caused by tiny conductive particles or foreign matter inside the battery cell, which leads to the formation of an abnormal weak current path between the positive and negative electrodes. The inducing causes include diaphragm failure, lithium dendrite formation, electrolyte decomposition products, etc.

[0080] When a battery cell has a micro-short circuit fault, if the battery cell is charged, the short-circuit resistance will continuously consume electrical energy, causing the voltage rise rate of the battery cell to slow down and the maximum value that the voltage can reach to also decrease.

[0081] If the battery is over-discharged, the circuit resistance will continue to consume energy, causing the voltage of the battery to drop faster. At the same time, in the case of lithium iron phosphate batteries, due to the unique plateau characteristics of lithium iron phosphate batteries, the battery can easily discharge out of the plateau, causing a sharp drop in voltage; however, this abnormal drop rate is not due to the drastic loss of battery energy, but due to the abnormal rate of voltage drop caused by the internal material characteristics of the battery. This also causes the lowest voltage value that the battery can reach during the discharge process to decrease.

[0082] If the battery cell is not working, there is a short circuit inside the battery cell. The existence of the short-circuit resistance will cause energy loss, so the voltage of the battery cell will slowly drop during the stable process.

[0083] The plateau period refers to the stage in which the voltage of the cells in the lithium iron phosphate battery remains basically constant during the discharge process. This feature is due to the unique electrochemical properties of lithium iron phosphate. When the cell is discharged or charged, the voltage will not drop or rise as quickly as the cells of traditional lithium batteries, but will remain in a relatively stable voltage range for a long time.

[0084] Specifically, the discharge voltage platform of lithium iron phosphate batteries is usually around 3.2V. In the early stage of discharge, the voltage of the battery cell drops rapidly to around 3.4V, then enters a plateau period and remains relatively stable at around 3.2V until the power gradually decreases to a certain level (about 20%-30% of the remaining capacity). After that, the voltage begins to drop rapidly until the discharge termination voltage.

[0085] As a possible implementation method, the fault determination device determines that the abnormal battery cell has a low capacity fault when the maximum voltage value of the abnormal battery cell is greater than a first average value; and determines that the abnormal battery cell has a micro short circuit fault when the voltage average value of the abnormal battery cell is less than a second average value.

[0086] The first average value is the average value of the maximum voltage values ​​of the multiple battery cells; and the second average value is the average value of the voltage mean values ​​of the multiple battery cells.

[0087] As an example, the fault determination device determines the maximum voltage value of the ith battery cell among the plurality of battery cells by using the following first relationship:

[0088]

[0089] Among them, F 1,i represents the maximum voltage value of the i-th battery cell, k represents the time, U i,k Represents the voltage value of the i-th battery cell at time k.

[0090] The fault determination device determines the voltage mean value of the i-th battery cell among the multiple battery cells by using the following second relationship:

[0091]

[0092] Among them, F 2,i represents the average voltage of the ith cell, and T represents multiple moments.

[0093] Afterwards, the fault determination device determines the first average value by the following third relationship:

[0094]

[0095] Among them, F 1,c represents the first average value, and N represents the number of the plurality of battery cells.

[0096] The fault determination device determines the second average value by the following fourth relationship:

[0097]

[0098] Among them, F 2,c Indicates the second average value.

[0099] Afterwards, the fault diagnosis device determines whether the maximum voltage value of the abnormal battery cell is greater than the first average value. If so, it is determined that the abnormal battery cell has a low capacity fault; and determines whether the voltage average value of the abnormal battery cell is less than the second average value. If so, it is determined that the abnormal battery cell has a micro short circuit fault.

[0100] Based on this possible implementation method, the voltage of the abnormal battery cell with a low-capacity fault will be quickly charged due to its low capacity. Compared with the normal battery cell, the voltage value of the abnormal battery cell with a low-capacity fault will be higher. Therefore, when the maximum voltage value of the abnormal battery cell is greater than the first average value, it can be determined that the abnormal battery cell has a low-capacity fault; the abnormal battery cell with a micro-short circuit fault will self-discharge due to an internal short circuit. Compared with the normal battery cell, the voltage mean value of the abnormal battery cell with a micro-short circuit fault will be smaller. Therefore, when the voltage mean value of the abnormal battery cell is less than the second average value, it can be determined that the abnormal battery cell has a micro-short circuit fault.

[0101] Optionally, if the fault determination device determines that the maximum voltage value of the abnormal battery cell is less than or equal to the first average value, and the voltage mean value of the abnormal battery cell is greater than or equal to the second average value, it can be determined that the abnormal battery cell is in a natural aging state.

[0102] Based on S201-S203, compared with the existing solutions that require more comprehensive and multiple battery data to determine the fault of the battery cell, the solution of the present application obtains a voltage value set including voltage values ​​at multiple moments for each battery cell of the target battery, and then determines the abnormal battery cell among the multiple battery cells based on the voltage value set of the multiple battery cells, and then, for each abnormal battery cell, determines the fault of the abnormal battery cell based on multiple first voltage characteristic values ​​of each battery cell in the multiple battery cells. When a low-capacity fault or a micro-short circuit fault occurs in the battery cell, the voltage value of the battery cell will be abnormal. Since the first voltage characteristic includes a maximum voltage value or a voltage mean, the maximum voltage value is the maximum value of the voltage values ​​of the battery cell at multiple moments, and the voltage mean is the average value of the voltage values ​​of the battery cell at multiple moments. By analyzing and processing the voltage values ​​of multiple battery cells, there is no need to collect other types of battery data, and it does not rely on the consistency of the data. In the case of low quality of battery data, the accuracy of determining the fault of each battery cell in the battery is improved.

[0103] The above is a general description of the fault determination method provided in the present application. The fault determination method provided in the present application will be further described below in conjunction with the accompanying drawings.

[0104] In one design, Figure 3 A flowchart of another fault determination method provided by the present application is shown as follows: Figure 3 As shown, S202 provided in the specific implementation manner of the present application may specifically include the following multiple steps:

[0105] S301 . A fault determination device determines, for each battery cell among a plurality of battery cells, a battery cell difference index according to a set of voltage values ​​of the plurality of battery cells.

[0106] The difference index is used to indicate the degree of difference between the voltage value of the battery cell and the voltage values ​​of multiple battery cells.

[0107] It should be noted that the difference index may be the outlier distance. Of course, the difference index may also be other parameters that can indicate the degree of difference, and the present application does not impose any specific limitation on this.

[0108] As a possible implementation method, when the difference index is the outlier distance, the fault determination device determines multiple second voltage characteristic values ​​of the battery cell based on the voltage value set of the battery cell; the second voltage characteristic includes a maximum voltage value, a voltage mean or a voltage variance value, and the voltage variance value is the variance value of the voltage value of the battery cell at multiple moments; multiple adjacent battery cells are determined based on the multiple second voltage characteristic values ​​of the multiple battery cells; the Euclidean distance between adjacent battery cells is less than the Euclidean distance between non-adjacent battery cells in the multiple battery cells; the sum of multiple target Euclidean distances is determined as the outlier distance of the battery cell; the target Euclidean distance is the Euclidean distance between adjacent battery cells.

[0109] It should be noted that the specific description of this possible implementation method can refer to the relevant description in the subsequent part of the specific implementation method of this application, and this application will not explain it here.

[0110] S302: The fault determination device determines an abnormal cell among the plurality of cells according to the difference indexes of the plurality of cells.

[0111] As a possible implementation method, when the difference index is the outlier distance, the fault determination device determines a first outlier distance and a second outlier distance based on the outlier distances of multiple battery cells; the first outlier distance is located at the upper quartile of the multiple outlier distances, and the second outlier distance is located at the lower quartile of the multiple outlier distances; for each of the multiple battery cells, the size relationship between the outlier distance of the battery cell and the difference between the first outlier distance is determined; the first outlier distance difference is the product of the second outlier distance difference and a first coefficient, the second outlier distance difference is the difference between the first outlier distance and the second outlier distance, and the first coefficient is determined based on the minimum time interval between multiple moments; when the outlier distance of the battery cell is greater than the first outlier distance difference, the battery cell is determined to be an abnormal battery cell.

[0112] It should be noted that the specific description of this possible implementation method can refer to the relevant description in the subsequent part of the specific implementation method of this application, and this application will not explain it here.

[0113] Based on S301-S302, under normal circumstances, most of the battery cells in the battery are in a normal state, and abnormal battery cells will have voltage differences from normal battery cells. By determining the difference index of each battery cell, since the difference index is used to indicate the degree of difference between the voltage value of the battery cell and the voltage values ​​of multiple battery cells, the abnormal battery cells among multiple battery cells can be determined based on the difference indexes of multiple battery cells.

[0114] In one design, where the dissimilarity index is the outlier distance, Figure 4 A flowchart of another fault determination method provided by the present application is shown as follows: Figure 4 As shown, S301 provided in the specific implementation manner of the present application may specifically include the following multiple steps:

[0115] S401. A fault determination device determines a plurality of second voltage characteristic values ​​of a battery cell according to a voltage value set of the battery cell.

[0116] The second voltage feature includes a maximum voltage value, a voltage mean value or a voltage variance value, and the voltage variance value is a variance value of voltage values ​​of the battery cell at multiple moments.

[0117] As a possible implementation manner, the fault determination device determines the maximum voltage value through the third relationship in S203, that is, the maximum voltage value is called the first voltage characteristic in S203, and the maximum voltage value is called the second voltage characteristic in S401.

[0118] The fault determination device determines the voltage mean value through the fourth relationship in S203 , that is, the voltage mean value is called the first voltage characteristic in S203 , and the voltage mean value is called the second voltage characteristic in S401 .

[0119] In some embodiments, after the fault determination device determines the maximum voltage value and the average voltage value of the battery cell in S401, the maximum voltage value and the average voltage value of the battery cell can be directly obtained in S203 without recalculating.

[0120] The fault determination device determines the voltage variance value through the following fifth relationship:

[0121]

[0122] Among them, F 3,i Indicates the voltage variance value.

[0123] S402. The fault determination device determines a plurality of adjacent battery cells according to a plurality of second voltage characteristic values ​​of a plurality of battery cells.

[0124] The Euclidean distance between adjacent cells is smaller than the Euclidean distance between non-adjacent cells in the plurality of cells.

[0125] It should be noted that the number of the plurality of adjacent battery cells may be 3, 4 or 5. Of course, the number of the plurality of adjacent battery cells may also be other values, and the present application does not impose any specific limitation on this.

[0126] As a possible implementation manner, taking the number of adjacent battery cells as 3 as an example, the fault determination device normalizes and standardizes multiple second voltage characteristics of each point in the multiple battery cells to obtain the third voltage characteristic of each battery cell.

[0127] The fault determination device constructs a Euclidean space according to multiple third voltage characteristic values ​​of each battery cell in the multiple battery cells, and uses a K-nearest neighbor algorithm to select three battery cells in the multiple battery cells that are closest to the battery cell in terms of Euclidean distance as adjacent battery cells.

[0128] For example, taking the battery cell as the i-th battery cell, the fault determination device determines the Euclidean distance between the j-th battery cell and the i-th battery cell among the multiple battery cells through the following sixth relationship:

[0129] d i,j =||[F 1,i ,F 2,i ,F 3,i ]-[F 1,j ,F 2,j ,F 3,j ]||

[0130] Among them, d i,j represents the Euclidean distance between the jth cell and the ith cell, F 1,j Indicates the maximum voltage value of the jth battery cell, F 2,j represents the mean voltage of the jth cell, F 3,jRepresents the voltage variance value of the jth battery cell.

[0131] S403: The fault determination device determines the sum of the multiple target Euclidean distances as the outlier distance of the battery cell.

[0132] The target Euclidean distance is the Euclidean distance between adjacent cells.

[0133] As a possible implementation manner, the fault determination device determines the outlier distance of the battery cell through the following seventh relationship:

[0134]

[0135] Among them, D i represents the outlier distance, and M represents the number of adjacent cells.

[0136] Based on S401-S403, multiple second voltage characteristic values ​​of the battery cell, including a maximum voltage value, a voltage mean or a voltage variance value, are determined according to the voltage value set of the battery cell. Subsequently, multiple adjacent battery cells of the battery cell are determined according to the multiple second voltage characteristic values ​​of the multiple battery cells. Subsequently, the sum of the Euclidean distances between the multiple adjacent battery cells and the battery cell is determined as the outlier distance of the battery cell. On the one hand, the maximum voltage value, the voltage mean or the voltage variance value of the battery cell can well distinguish the battery cells. On the other hand, by determining multiple adjacent battery cells and determining the sum of the Euclidean distances between the multiple adjacent battery cells and the battery cell as the outlier distance of the battery cell, the influence of accidental factors on the outlier distance of the battery cell can be reduced, thereby improving the accuracy of the determined outlier distance of the battery cell.

[0137] In one design, where the dissimilarity index is the outlier distance, Figure 5 A flowchart of another fault determination method provided by the present application is shown as follows: Figure 5 As shown, S302 provided in the specific implementation manner of the present application may specifically include the following multiple steps:

[0138] S501. A fault determining apparatus determines a first outlier distance and a second outlier distance based on outlier distances of a plurality of battery cells.

[0139] The first outlier distance is located at an upper quartile of the multiple outlier distances, and the second outlier distance is located at a lower quartile of the multiple outlier distances.

[0140] In some embodiments, the first outlier distance may also be located at the upper quintile or upper sixth quartile of the multiple outlier distances, and the second outlier distance may be located at the lower quintile or lower sixth quartile of the multiple outlier distances, and the present application does not impose any specific limitation on this.

[0141] By adjusting the positions of the first outlier distance and the second outlier distance in the plurality of outlier distances, the robustness of determining abnormal cells may be adjusted.

[0142] As a possible implementation manner, the fault determination device performs box plot clustering on the outlier distances of the plurality of battery cells, uses the box plot to describe the outlier distances of the respective battery cells, and sorts the outlier distances of the plurality of battery cells by the following eighth relationship:

[0143] A=sort(D1,D2,...,D N )

[0144] Wherein, A represents the outlier distance queue, and N represents the number of multiple battery cells.

[0145] The fault determination device determines the first outlier distance and the second outlier distance through the following ninth relationship:

[0146] Q1=A[floor(0.25N)], Q3=A[floor(0.75N)]

[0147] Among them, Q1 represents the first outlier distance, and Q3 represents the second outlier distance.

[0148] S502: The fault handling apparatus determines, for each battery cell among the plurality of battery cells, a magnitude relationship between an outlier distance of the battery cell and a first outlier distance difference.

[0149] The first outlier distance difference is the product of the second outlier distance difference and the first coefficient, the second outlier distance difference is the difference between the first outlier distance and the second outlier distance, and the first coefficient is determined based on the minimum time interval between the multiple moments.

[0150] It should be noted that the first coefficient may be negatively correlated with the duration of the minimum time interval between the multiple moments.

[0151] For example, taking the target battery as a lithium iron phosphate battery, if the minimum time interval between multiple moments exceeds 8 hours, the first coefficient can be 20. If the minimum time interval between multiple moments does not exceed 8 hours, the first coefficient can be 50. Of course, the first coefficient can also be other values, and this application does not impose specific restrictions on this.

[0152] As a possible implementation manner, the fault processing device determines the second outlier distance difference through the following tenth relationship:

[0153] IQR=Q3-Q1

[0154] Wherein, IOR represents the second outlier distance difference.

[0155] The fault processing device determines the first outlier difference through the following eleventh relationship:

[0156] D t =b×IQR

[0157] Among them, D t represents the first outlier difference, and b represents the first coefficient.

[0158] The fault determination device compares the outlier distance of the battery cell with the first outlier distance to determine the magnitude relationship of the difference between the outlier distance of the battery cell and the first outlier distance.

[0159] S503: When the outlier distance of the battery cell is greater than the first outlier distance difference, the fault determination device determines that the battery cell is an abnormal battery cell.

[0160] Based on S501-S503, a first outlier distance and a second outlier distance are determined based on outlier distances of a plurality of battery cells. Subsequently, for each of the plurality of battery cells, a magnitude relationship between the outlier distance of the battery cell and the difference between the first outlier distance is determined. When the outlier distance of the battery cell is greater than the difference between the first outlier distance, the battery cell is determined to be an abnormal battery cell. Since the first outlier distance is located in the upper quartile of the plurality of outlier distances and the second outlier distance is located in the lower quartile of the plurality of outlier distances, the difference between the first outlier distance is the product of the difference between the second outlier distance and a first coefficient, the difference between the second outlier distance is the difference between the first outlier distance and the second outlier distance, and the first coefficient is determined based on the minimum time interval between a plurality of moments. Therefore, an abnormal battery cell having a larger outlier distance among the plurality of battery cells can be determined based on the minimum time interval between a plurality of moments.

[0161] In one design, Figure 6 A flowchart of another fault determination method provided by the present application is shown as follows: Figure 6 As shown, before S202, the fault determination method provided by the present application may further include the following steps:

[0162] S601. A fault determination device determines, for each of a plurality of moments, a median voltage value of a plurality of cells at that moment.

[0163] As a possible implementation manner, the fault determination device calculates, for each of the multiple moments, a median voltage value of the voltage values ​​in the multiple cells at that moment.

[0164] S602: The fault processing apparatus determines a weighted sum of voltage differences of a target battery based on a plurality of median voltage values.

[0165] As a possible implementation method, the fault handling device uses, for each median voltage value among multiple median voltage values, the product of the pressure difference value and the second coefficient as the first pressure difference score at the moment when the median voltage value is greater than the second threshold value, and uses the product of the pressure difference value and the third coefficient as the second pressure difference score at the moment when the median voltage value is less than or equal to the second threshold value; the pressure difference value is the difference between the first voltage value and the second voltage value, the first voltage value is the maximum voltage value among the voltage values ​​of the multiple battery cells at the moment, the second voltage value is the minimum voltage value among the voltage values ​​of the multiple battery cells at the moment, and the third coefficient is greater than the second coefficient; the sum of the target first pressure difference score and the target second pressure difference score is determined as the weighted sum of the pressure differences; the target first pressure difference score is any one of the multiple first pressure difference scores, and the target second pressure difference score is any one of the multiple second pressure difference scores.

[0166] It should be noted that the specific description of this possible implementation method can refer to the relevant description in the subsequent part of the specific implementation method of this application, and this application will not explain it here.

[0167] S603: When the weighted sum of the pressure differences is greater than a first threshold, the fault determination device determines that the target battery is in an abnormal state.

[0168] As a possible implementation, the fault determination device determines whether the weighted sum of the pressure differences is greater than a first threshold value, and if so, determines that the target battery is in an abnormal state; if not, determines that the target battery is in a normal state.

[0169] Based on S601-S602, the median voltage values ​​of multiple battery cells at each of the multiple moments are determined, and then the weighted sum of the voltage differences of the target battery is determined based on the multiple median voltage values. Since the voltage difference of the battery can reflect the state of the battery, it is possible to determine that the target battery is in an abnormal state when the weighted sum of the pressure difference is greater than a first threshold.

[0170] In some embodiments, after determining that the target battery is in an abnormal state, the fault determination device executes S201, and if it is determined that the target battery is in a normal state, S201 is not executed. Since when the battery is in a normal state, the cells inside it usually will not fail, by first determining whether the target battery is in an abnormal state, and then determining the abnormality of the cells in the target battery when the target battery is in an abnormal state, the fault determination of the cells in the abnormal battery can be carried out in a targeted manner, thereby improving the efficiency of fault determination.

[0171] In one design, Figure 7 A flowchart of another fault determination method provided by the present application is shown as follows: Figure 7 As shown, S602 provided in the specific implementation of the present application may specifically include the following multiple steps:

[0172] S701. The fault determination device uses, for each median voltage value among multiple median voltage values, the product of the pressure difference value and the second coefficient as the first pressure difference score at the moment when the median voltage value is greater than the second threshold value; and uses the product of the pressure difference value and the third coefficient as the second pressure difference score at the moment when the median voltage value is less than or equal to the second threshold value.

[0173] Among them, the voltage difference value is the difference between the first voltage value and the second voltage value, the first voltage value is the maximum voltage value among the voltage values ​​of multiple battery cells at a moment, the second voltage value is the minimum voltage value among the voltage values ​​of multiple battery cells at a moment, and the third coefficient is greater than the second coefficient.

[0174] It should be noted that the second threshold value is related to the type of the target battery. For example, when the target battery is a lithium iron phosphate battery, the second threshold value may be 3100 mV.

[0175] As a possible implementation method, the fault determination device determines, for each of the multiple moments, a maximum voltage value among the voltage values ​​of the multiple battery cells at that moment, and uses it as the first voltage value, and determines a minimum voltage value among the voltage values ​​of the multiple battery cells at that moment, and uses it as the second voltage value.

[0176] The fault determination device subtracts the second voltage value from the first voltage value to obtain a voltage difference value.

[0177] The fault determination device determines, for each of the plurality of median voltage values, whether the median voltage value is greater than a second threshold.

[0178] If the median voltage value is greater than the second threshold, the fault determination device uses the product of the pressure difference value at that moment and the second coefficient as the first pressure difference score at that moment.

[0179] If the median voltage value is less than or equal to the second threshold, the fault determination device uses the product of the pressure difference value at that moment and the third coefficient as the second pressure difference score at that moment.

[0180] That is, one moment corresponds to a first pressure difference fraction or a second pressure difference fraction.

[0181] S702: The fault determination device determines the sum of the target first pressure difference score and the target second pressure difference score as a weighted sum of pressure differences.

[0182] The target first pressure difference score is any one of a plurality of first pressure difference scores, and the target second pressure difference score is any one of a plurality of second pressure difference scores.

[0183] Preferably, the target first pressure difference score may be a maximum value among a plurality of first pressure difference scores, and the target second pressure difference score may be a maximum value among a plurality of second pressure difference scores.

[0184] As a possible implementation manner, the fault determination device adds the target first pressure difference score and the target second pressure difference score to obtain a weighted sum of pressure differences.

[0185] Based on S701-S702, in some cases, for example, when the target battery is a lithium iron phosphate battery, since the fault characteristics of the lithium iron phosphate battery are not obvious in the plateau period, by comparing the median voltage value with the second threshold value, the situations where the voltage of the battery cell is higher and lower are taken into consideration. When more battery cells are in the plateau period, the abnormal characteristics of the battery cells with higher and lower voltages can be highlighted, thereby improving the accuracy of determining that the battery is in an abnormal state.

[0186] The above mainly introduces the scheme provided by the embodiment of the present application from the perspective of the fault determination device executing the fault determination method. In order to achieve the above functions, the fault determination device includes hardware structures and / or software modules corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the embodiments of the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0187] The embodiment of the present application can divide the functional modules of the fault determination device according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware or in the form of software functional modules. Optionally, the division of modules in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, the "module" here may refer to a specific application-specific integrated circuit (ASIC), a circuit, a processor and memory that executes one or more software or firmware programs, an integrated logic circuit, and / or other devices that can provide the above functions.

[0188] In the case of functional module division, Figure 8 FIG. 1 shows a schematic diagram of the structure of a fault determination device. Figure 8 As shown, the fault determination device 80 includes an acquisition module 801 and a processing module 802 .

[0189] In some embodiments, the fault determination device 80 may further include a storage module ( Figure 8 ), for storing program instructions and data.

[0190] Among them, the acquisition module 801 is used to obtain a set of voltage values ​​of each battery cell in a plurality of battery cells of a target battery; the voltage value set includes voltage values ​​at a plurality of moments; the processing module 802 is used to determine an abnormal battery cell among a plurality of battery cells according to the set of voltage values ​​of a plurality of battery cells; the processing module 802 is also used to determine, for each abnormal battery cell, the fault of the abnormal battery cell based on a plurality of first voltage characteristic values ​​of each battery cell in a plurality of battery cells; the fault includes a low capacity fault or a micro short circuit fault, the first voltage characteristic includes a maximum voltage value or a voltage mean, the maximum voltage value is the maximum value of the voltage values ​​of the battery cell at a plurality of moments, and the voltage mean is the average value of the voltage values ​​of the battery cell at a plurality of moments.

[0191] Optionally, the processing module 802 is also used to determine the fault of the abnormal battery cell based on multiple first voltage characteristic values ​​of each battery cell in the multiple battery cells, including: when the maximum voltage value of the abnormal battery cell is greater than a first average value, determining that the abnormal battery cell has a low capacity fault; the first average value is the average value of the maximum voltage values ​​of the multiple battery cells; when the voltage mean value of the abnormal battery cell is less than a second average value, determining that the abnormal battery cell has a micro short circuit fault; the second average value is the average value of the voltage mean values ​​of the multiple battery cells.

[0192] Optionally, the processing module 802 is used to determine an abnormal battery cell among multiple battery cells based on a set of voltage values ​​of the multiple battery cells, including: for each battery cell among the multiple battery cells, determining a difference index of the battery cell based on the set of voltage values ​​of the multiple battery cells; the difference index is used to indicate the degree of difference between the voltage value of the battery cell and the voltage values ​​of the multiple battery cells; and determining the abnormal battery cell among the multiple battery cells based on the difference index of the multiple battery cells.

[0193] Optionally, the difference index is the outlier distance, and the processing module 802 is also used to determine the difference index of the battery cell according to the voltage value set of multiple battery cells, including: determining multiple second voltage characteristic values ​​of the battery cell according to the voltage value set of the battery cell; the second voltage characteristic includes a maximum voltage value, a voltage mean or a voltage variance value, and the voltage variance value is the variance value of the voltage value of the battery cell at multiple moments; determining multiple adjacent battery cells according to the multiple second voltage characteristic values ​​of the multiple battery cells; the Euclidean distance between adjacent battery cells is less than the Euclidean distance between non-adjacent battery cells in the multiple battery cells; determining the sum of multiple target Euclidean distances as the outlier distance of the battery cell; the target Euclidean distance is the Euclidean distance between adjacent battery cells.

[0194] Optionally, the difference index is the outlier distance, and the processing module 802 is further used to determine the abnormal battery cell among the multiple battery cells according to the difference indexes of the multiple battery cells, including: determining a first outlier distance and a second outlier distance based on the outlier distances of the multiple battery cells; the first outlier distance is located at the upper quartile of the multiple outlier distances, and the second outlier distance is located at the lower quartile of the multiple outlier distances; for each battery cell among the multiple battery cells, determining the size relationship between the outlier distance of the battery cell and the difference between the first outlier distance; the first outlier distance difference is the product of the second outlier distance difference and a first coefficient, the second outlier distance difference is the difference between the first outlier distance and the second outlier distance, and the first coefficient is determined based on the minimum time interval between multiple moments; when the outlier distance of the battery cell is greater than the first outlier distance difference, determining the battery cell as an abnormal battery cell.

[0195] Optionally, before determining the abnormal battery cell among the multiple battery cells based on the set of voltage values ​​of the multiple battery cells, the processing module 802 is also used to: determine, for each of the multiple moments, the median voltage value of the multiple battery cells at the moment; determine the weighted sum of the pressure differences of the target battery based on the multiple median voltage values; and determine that the target battery is in an abnormal state when the weighted sum of the pressure differences is greater than a first threshold value.

[0196] Optionally, the processing module 802 is also used to determine the weighted sum of the pressure difference of the target battery based on multiple median voltage values, including: for each median voltage value among the multiple median voltage values, when the median voltage value is greater than the second threshold, the product of the pressure difference value and the second coefficient is used as the first pressure difference score at the moment; when the median voltage value is less than or equal to the second threshold, the product of the pressure difference value and the third coefficient is used as the second pressure difference score at the moment; the pressure difference value is the difference between the first voltage value and the second voltage value, the first voltage value is the maximum voltage value among the voltage values ​​of the multiple battery cells at the moment, the second voltage value is the minimum voltage value among the voltage values ​​of the multiple battery cells at the moment, and the third coefficient is greater than the second coefficient; the sum of the target first pressure difference score and the target second pressure difference score is determined as the weighted sum of the pressure difference; the target first pressure difference score is any one of the multiple first pressure difference scores, and the target second pressure difference score is any one of the multiple second pressure difference scores.

[0197] All relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, and will not be repeated here.

[0198] When the functions of the above functional modules are implemented in the form of hardware, Fig. 9 FIG. 2 shows a schematic diagram of the structure of another fault determination device. Fig. 9 As shown, the fault determination device 90 includes a processor 901, a memory 902 and a bus 903. The processor 901 and the memory 902 may be connected via the bus 903.

[0199] The processor 901 is the control center of the fault determination device 90, and can be a processor or a general term for multiple processing elements. For example, the processor 901 can be a general-purpose central processing unit (CPU) or other general-purpose processors. The general-purpose processor can be a microprocessor or any conventional processor.

[0200] As an embodiment, the processor 901 may include one or more CPUs, such as Fig. 9 CPU 0 and CPU 1 are shown in .

[0201] The memory 902 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited to these.

[0202] As a possible implementation, the memory 902 may exist independently of the processor 901, and the memory 902 may be connected to the processor 901 via a bus 903, and is used to store instructions or program codes. When the processor 901 calls and executes the instructions or program codes stored in the memory 902, the fault determination method provided in the embodiment of the present application can be implemented.

[0203] In another possible implementation, the memory 902 may also be integrated with the processor 901 .

[0204] The bus 903 may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig. 9 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0205] It should be pointed out that Fig. 9 The structure shown does not constitute a limitation on the fault determination device 90. Fig. 9 In addition to the components shown, the fault determination device 90 may include more or fewer components than shown, or combine certain components, or arrange the components differently.

[0206] As an example, combining Figure 8 The functions implemented by the acquisition module 801 and the processing module 802 in the fault determination device 80 are similar to those Fig. 9 The function of processor 901 in is the same.

[0207] Optional, such as Fig. 9 As shown, the fault determination device 90 provided in the embodiment of the present application may further include a communication interface 904 .

[0208] The communication interface 904 is used to connect with other devices through a communication network. The communication network may be Ethernet, wireless access network, wireless local area network (WLAN), etc. The communication interface 904 may include a receiving unit for receiving data and a sending unit for sending data.

[0209] In a possible implementation, in the fault determination device 90 provided in the embodiment of the present application, the communication interface 904 may also be integrated in the processor 901, and the embodiment of the present application does not specifically limit this.

[0210] As a possible product form, the fault determination device of the embodiment of the present application can also be implemented using the following: one or more field programmable gate arrays (FPGA), programmable logic devices (PLD), controllers, state machines, gate logic, discrete hardware components, any other suitable circuits, or any combination of circuits capable of performing the various functions described throughout the present application.

[0211] Through the description of the above implementation methods, those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above functional units is used as an example. In practical applications, the above functions can be assigned to different functional units as needed, that is, the internal structure of the device can be divided into different functional units to complete all or part of the functions described above. The specific working process of the system, device and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0212] An embodiment of the present application also provides a computer-readable storage medium on which a computer program or instruction is stored. When the computer program or instruction is executed, the computer executes each step in the method flow shown in the above method embodiment.

[0213] An embodiment of the present application provides a computer program product including instructions. When the instructions are executed on a computer, the computer is caused to execute each step in the method flow shown in the above method embodiment.

[0214] An embodiment of the present application provides a chip system, including: a processor and an interface circuit; the interface circuit is used to receive a computer program or instruction and transmit it to the processor; the processor is used to execute the computer program or instruction so that the chip system executes each step in the method flow shown in the above method embodiment.

[0215] Among them, the computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection with one or more wires, a portable computer disk, and a hard disk. Random Access Memory (RAM), Read-Only Memory (ROM), Erasable Programmable Read Only Memory (EPROM), registers, hard disks, optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any other form of computer-readable storage media in a suitable combination of the above, or numerical values ​​in the art. An exemplary storage medium is coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in a specific-purpose ASIC. In the embodiments of the present application, a computer-readable storage medium may be any tangible medium that contains or stores a program, which may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0216] Since the fault determination device, computer-readable storage medium, and computer program product provided in this embodiment can be applied to the fault determination method provided by this embodiment, the technical effects that can be obtained can also refer to the above-mentioned method embodiments, and the embodiments of this application will not be repeated here.

[0217] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other changes to the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0218] Although the present application has been described in conjunction with specific features and embodiments thereof, it is obvious that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the drawings are merely exemplary illustrations of the present application as defined by the appended claims, and are deemed to have covered any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art may make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A fault determination method, characterized in that: The method comprises: Acquire a voltage value set of each battery cell in a plurality of battery cells of a target battery; the voltage value set includes voltage values ​​at a plurality of moments; Determining an abnormal cell among the plurality of cells according to a set of voltage values ​​of the plurality of cells; For each abnormal battery cell, the fault of the abnormal battery cell is determined based on multiple first voltage characteristic values ​​of each battery cell in multiple battery cells; the fault includes a low capacity fault or a micro short circuit fault, and the first voltage characteristic includes a maximum voltage value or a voltage mean value, the maximum voltage value is the maximum value of the voltage values ​​of the battery cell at multiple moments, and the voltage mean value is the average value of the voltage values ​​of the battery cell at multiple moments.

2. The method according to claim 1, characterized in that The determining the fault of the abnormal battery cell based on a plurality of first voltage characteristic values ​​of each battery cell in the plurality of battery cells comprises: When the maximum voltage value of the abnormal battery cell is greater than a first average value, it is determined that the abnormal battery cell has a low capacity fault; the first average value is an average value of the maximum voltage values ​​of multiple battery cells; When the voltage average value of the abnormal battery cell is less than a second average value, it is determined that the abnormal battery cell has a micro short circuit fault; the second average value is an average value of the voltage average values ​​of multiple battery cells.

3. The method according to claim 1, characterized in that The step of determining an abnormal cell among the plurality of cells according to a set of voltage values ​​of the plurality of cells comprises: For each of the plurality of battery cells, determining a difference index of the battery cell according to a set of voltage values ​​of the plurality of battery cells; the difference index is used to indicate a degree of difference between the voltage value of the battery cell and the voltage values ​​of the plurality of battery cells; An abnormal cell among the plurality of cells is determined according to the difference indexes of the plurality of cells.

4. The method according to claim 3, characterized in that The difference index is an outlier distance, and determining the difference index of the battery cell according to a set of voltage values ​​of a plurality of battery cells includes: Determine a plurality of second voltage characteristic values ​​of the battery cell according to the voltage value set of the battery cell; the second voltage characteristic includes the maximum voltage value, the voltage mean value or the voltage variance value, and the voltage variance value is the variance value of the voltage value of the battery cell at multiple moments; Determine a plurality of adjacent cells of the cell according to a plurality of second voltage characteristic values ​​of a plurality of cells; the Euclidean distance between the adjacent cells and the cell is smaller than the Euclidean distance between the non-adjacent cells in the plurality of cells and the cell; The sum of multiple target Euclidean distances is determined as the outlier distance of the battery cell; the target Euclidean distance is the Euclidean distance between the adjacent battery cell and the battery cell.

5. The method according to claim 3, characterized in that: The difference index is an outlier distance, and determining an abnormal cell among the plurality of cells according to the difference indexes of the plurality of cells includes: Determine a first outlier distance and a second outlier distance based on outlier distances of a plurality of battery cells; wherein the first outlier distance is located at an upper quartile of the plurality of outlier distances, and the second outlier distance is located at a lower quartile of the plurality of outlier distances; For each of the plurality of battery cells, determining a magnitude relationship between an outlier distance of the battery cell and a first outlier distance difference; the first outlier distance difference is a product of a second outlier distance difference and a first coefficient, the second outlier distance difference is a difference between the first outlier distance and the second outlier distance, and the first coefficient is determined based on a minimum time interval between the plurality of moments; When the outlier distance of the battery cell is greater than the first outlier distance difference, the battery cell is determined to be an abnormal battery cell.

6. The method according to any one of claims 1 to 5, characterized in that: Before determining an abnormal cell among the plurality of cells according to a set of voltage values ​​of the plurality of cells, the method further includes: For each of the multiple moments, determining a median voltage value of the multiple cells at the moment; Determining a weighted sum of voltage differences of the target battery based on a plurality of median voltage values; In a case where the weighted sum of the voltage differences is greater than a first threshold, it is determined that the target battery is in an abnormal state.

7. The method according to claim 6, characterized in that The step of determining the weighted sum of the voltage differences of the target battery based on a plurality of median voltage values ​​comprises: For each median voltage value among the multiple median voltage values, when the median voltage value is greater than the second threshold, the product of the pressure difference value and the second coefficient is used as the first pressure difference score at the moment, and when the median voltage value is less than or equal to the second threshold, the product of the pressure difference value and the third coefficient is used as the second pressure difference score at the moment; the pressure difference value is the difference between the first voltage value and the second voltage value, the first voltage value is the maximum voltage value among the voltage values ​​of the multiple battery cells at the moment, the second voltage value is the minimum voltage value among the voltage values ​​of the multiple battery cells at the moment, and the third coefficient is greater than the second coefficient; The sum of a target first pressure difference score and a target second pressure difference score is determined as the pressure difference weighted sum; the target first pressure difference score is any one of a plurality of first pressure difference scores, and the target second pressure difference score is any one of a plurality of second pressure difference scores.

8. A fault determination device, characterized in that: The device comprises: an acquisition module and a processing module; The acquisition module is used to acquire a voltage value set of each battery cell in a plurality of battery cells of a target battery; the voltage value set includes voltage values ​​at a plurality of moments; The processing module is used to determine an abnormal cell among the multiple cells according to a set of voltage values ​​of the multiple cells; The processing module is also used to determine the fault of each abnormal battery cell based on multiple first voltage characteristic values ​​of each battery cell in multiple battery cells; the fault includes a low capacity fault or a micro short circuit fault, and the first voltage characteristic includes a maximum voltage value or a voltage mean value, the maximum voltage value is the maximum value of the voltage values ​​of the battery cell at multiple moments, and the voltage mean value is the average value of the voltage values ​​of the battery cell at multiple moments.

9. A fault determination device, characterized in that: The fault determination device comprises: a processor, the processor is coupled to a memory, the memory is used to store programs or instructions, when the program or instructions are executed by the processor, the device executes the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instructions are executed, the computer is caused to perform the method according to any one of claims 1 to 7.

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