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 reference voltage value set of battery cells in a target battery and a voltage value set of each battery cell in a plurality of battery cells of the target battery; the reference voltage value set comprises reference voltage values at a plurality of sampling moments in the sampling time period, and the voltage value set comprises voltage values at the plurality of sampling moments; according to the voltage value set of the plurality of battery cells and the reference voltage value set, determining an outlier state of each battery cell in each sub-time period in a plurality of sub-time periods of the sampling time period; the outlier state comprises a non-outlier state, an upward outlier state or a downward outlier state; determining the fault of the battery cell based on the outlier state of the battery cell in the plurality of sub-time periods; the fault comprises a low-capacity fault or a micro-short-circuit fault.

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 the quality of data. In some cases, the quality of battery data is low. For example, the type of data is relatively simple. In this case, the accuracy of the existing solution in determining the fault of each battery cell in the battery is low. 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 reference voltage value set of a battery cell in a target battery and a voltage value set of each battery cell in a plurality of battery cells of the target battery; the reference voltage value set comprises reference voltage values ​​at a plurality of sampling moments in a sampling time period, and the voltage value set comprises voltage values ​​at a plurality of sampling moments; determining an outlier state of each battery cell in each of a plurality of sub-time periods in a sampling time period according to the voltage value set and the reference voltage value set of the plurality of battery cells; the outlier state comprises not outlier, upward outlier or downward outlier; determining a fault of the battery cell based on the outlier state of the battery cell in a plurality of sub-time periods; the fault comprises a low capacity fault or a micro short circuit fault.

[0008] Based on this solution, compared with the existing solution that requires more comprehensive and multiple battery data to determine the failure of the battery cell, the solution of the present application obtains a voltage value set including voltage values ​​at multiple sampling moments of each battery cell of the target battery and a reference voltage value set including reference voltage values ​​at multiple sampling moments of the battery cells in the target battery, and then, based on the voltage value set and the reference voltage value set of multiple battery cells, determines the outlier state of each battery cell in each of multiple sub-time periods of the sampling time period, and then, based on the outlier state of the battery cell in multiple sub-time periods, determines the failure of the battery cell. When a low-capacity failure or a micro-short circuit failure occurs in a battery cell, the voltage value of the battery cell will be abnormal. By analyzing and processing the voltage values ​​of multiple battery cells, the outlier state of each battery cell is determined, and the failure of the battery cell is determined based on the outlier state. 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, it can improve the accuracy of determining the failure of the battery cell in the battery.

[0009] In combination with the first aspect, in certain embodiments of the first aspect, obtaining a set of reference voltage values ​​of battery cells in a target battery includes: for each sampling moment among multiple sampling moments, determining a median value of the voltage values ​​of multiple battery cells at the sampling moment as the reference voltage value.

[0010] Since the median value is not affected by the extreme values ​​in multiple data, by determining the reference voltage value by the median value of the voltage values ​​of multiple battery cells at each of the multiple sampling moments, it is possible to avoid the influence of the extreme voltage values ​​of individual faulty battery cells among the multiple battery cells on the determined reference voltage value, thereby improving the accuracy of determining the reference voltage values ​​of the battery cells in the target battery.

[0011] In combination with the first aspect, in some embodiments of the first aspect, the sub-time period includes a first sub-time period, a second sub-time period, or a third sub-time period, and the outlier state of each battery cell in each sub-time period in the multiple sub-time periods of the sampling time period is determined according to the voltage value set of the multiple battery cells and the reference voltage value set, including: determining the first sub-time period, the second sub-time period, and the third sub-time period in the sampling time period according to the reference voltage value set; the time length between any two adjacent sampling moments in the first sub-time period is greater than the first threshold value, and the absolute value of the difference between the reference voltage values ​​at any two adjacent sampling moments is less than the second threshold value, or the absolute value of the difference between the reference voltage value at any sampling moment in the first sub-time period and the reference voltage value at the start moment of the first sub-time period is less than the third threshold value, and any two adjacent sampling moments are less than the second threshold value. the absolute value of the difference between the reference voltage values ​​at the sampling moments is less than the second threshold value, and the number of sampling moments in the first sub-time period is greater than the fourth threshold value, the second sub-time period is the time period other than the first sub-time period in the sampling time period, and the reference voltage value of any sampling moment in the second sub-time period is greater than the reference voltage value of the previous sampling moment, the third sub-time period is the time period other than the first sub-time period in the sampling time period, and the reference voltage value of any sampling moment in the third sub-time period is less than the reference voltage value of the previous sampling moment; for each sub-time period, determine the characteristic vector corresponding to the sub-time period; the characteristic vector includes multiple elements, one element is determined based on multiple reference voltage values ​​in the sub-time period and the voltage value of a battery cell in the sub-time period; based on the characteristic vector, determine the outlier state of each battery cell in the sub-time period.

[0012] Based on this scheme, the first sub-time period, the second sub-time period and the third sub-time period in the sampling time period are determined according to the reference voltage value set. Since the duration between any two adjacent sampling moments in the first sub-time period is greater than the first threshold value, and the difference between the reference voltage values ​​of any two adjacent sampling moments is less than the second threshold value, or the difference between the reference voltage value of any sampling moment in the first sub-time period and the reference voltage value at the start moment of the first sub-time period is less than the third threshold value, and the difference between the reference voltage values ​​of any two adjacent sampling moments is less than the second threshold value, and the number of sampling moments in the first sub-time period is greater than the fourth threshold value, the first sub-time period can be considered as the time period when the normal cells in the target battery are in a stable state. Since the second sub-time period is a time period other than the first sub-time period in the sampling time period, and the reference voltage value of any sampling moment in the second sub-time period is greater than the reference voltage value of the previous sampling moment, the second sub-time period can be considered as the time period when the normal cells in the target battery are in a charging state. The third sub-time period is the time period other than the first sub-time period in the sampling time period, and the reference voltage value at any sampling moment in the third sub-time period is less than the reference voltage value at the previous sampling moment, so the third sub-time period can be considered as the time period when the normal battery cell in the target battery is in a discharge state. In the case of a battery cell failure, compared with the reference voltage value, the voltage value of the battery cell in the charging state, the voltage value of the battery cell in the stable state, and the voltage value of the battery cell in the discharge state will be abnormal, so for each sub-time period, the characteristic vector corresponding to the sub-time period is determined, and based on the characteristic vector, the outlier state of each battery cell in the sub-time period is determined, and the failure of the battery cell can be determined later.

[0013] In combination with the first aspect, in certain embodiments of the first aspect, determining a characteristic vector corresponding to a sub-time period includes: for each first sub-time period, determining a first characteristic vector and a second characteristic vector corresponding to the first sub-time period; the first characteristic vector includes multiple first elements, the first element is the difference between the first value and the second value, one first value is the average value of multiple voltage values ​​of a battery cell in the first sub-time period, and the second value is the average value of multiple reference voltage values ​​of the first sub-time period; the second characteristic vector includes multiple second elements, the second element is the difference between the third value and the fourth value, one third value is the average value of multiple voltage change values ​​of a battery cell in the first sub-time period, the voltage change value is the difference between the voltage value at a sampling moment and the voltage value at a previous sampling moment, the fourth value is the average value of multiple reference voltage change values ​​of the first sub-time period, and the reference voltage change value is the difference between the reference voltage value at a sampling moment and the reference voltage value at the previous sampling moment; for each second sub-time period, Determine the third eigenvector and the fourth eigenvector corresponding to the second sub-time period; the third eigenvector includes multiple third elements, the third element is the difference between the fifth value and the sixth value, a fifth value is the maximum value of multiple voltage values ​​of a battery cell in the second sub-time period, and the sixth value is the average value of multiple reference voltage values ​​of the second sub-time period; the fourth eigenvector includes multiple fourth elements, the fourth element is the difference between the seventh value and the sixth value, and a seventh value is the minimum value of multiple voltage values ​​of a battery cell in the second sub-time period; for each third sub-time period, determine the fifth eigenvector and the sixth eigenvector corresponding to the third sub-time period; the fifth eigenvector includes multiple fifth elements, the fifth element is the difference between the eighth value and the sixth value, and an eighth value is the maximum value of multiple voltage values ​​of a battery cell in the third sub-time period; the sixth eigenvector includes multiple sixth elements, the sixth element is the difference between the ninth value and the sixth value, and a ninth value is the minimum value of multiple voltage values ​​of a battery cell in the third sub-time period.

[0014] Based on this scheme, when a battery cell has a fault, compared with the reference voltage value, the voltage value of the battery cell in the charging state, the voltage value of the battery cell in the stable state, the change in the voltage value of the battery cell in the stable state, and the voltage value of the battery cell in the discharging state will all be abnormal. Therefore, by determining, for each first sub-time period, the first eigenvector and the second eigenvector corresponding to the first sub-time period, for each second sub-time period, the third eigenvector and the fourth eigenvector corresponding to the second sub-time period, and for each third sub-time period, the fifth eigenvector and the sixth eigenvector corresponding to the third sub-time period, the difference between the battery cell and the normal battery cell can be reflected, so as to subsequently determine the fault of the battery cell.

[0015] In combination with the first aspect, in certain embodiments of the first aspect, based on the feature vector, the outlier state of each battery cell in the sub-time period is determined, including: S1, determining the maximum outlier in the current feature vector based on the 3σ criterion; S2, eliminating the maximum outlier in the current feature vector to obtain an updated feature vector; S3, determining the error range corresponding to the current feature vector based on the 3σ criterion; S4, judging whether the maximum outlier is outside the error range; when the maximum outlier is outside the error range, executing S5, and when the maximum outlier is within the error range, executing S6; S5, when the maximum outlier is greater than the upper limit of the error range, determining that the outlier state of the battery cell corresponding to the maximum outlier is an upward outlier, and when the maximum outlier is less than the lower limit of the error range, determining that the outlier state of the battery cell corresponding to the maximum outlier is a downward outlier; executing S1; S6, determining that the outlier state of the battery cell corresponding to each element in the current feature vector in S1 is not an outlier.

[0016] Based on this scheme, compared with the existing outlier determination method based on the 3σ criterion, it is first assumed that a certain element is an outlier, and then the outlier is removed and then the element is tested again to see if it is an outlier. If the element is determined to be an outlier twice, it is confirmed that the element is indeed an outlier. By assuming first and then testing, the influence of extreme data of individual faulty battery cells on the determined error range can be reduced, thereby improving the accuracy of determining the outlier direction of the battery cell.

[0017] In combination with the first aspect, in certain embodiments of the first aspect, determining the failure of a battery cell based on the outlier states of the battery cell in multiple sub-time periods includes: taking the outlier state with the largest number among the outlier states of the battery cell corresponding to the first eigenvector as the first outlier state of the battery cell corresponding to the first sub-time period; taking the outlier state with the largest number among the outlier states of the battery cell corresponding to the second eigenvector as the second outlier state of the battery cell corresponding to the first sub-time period; taking the outlier state of the battery cell corresponding to the third eigenvector and the outlier state of the battery cell corresponding to the fourth eigenvector as the third outlier state of the battery cell corresponding to the second sub-time period; taking the outlier state of the battery cell corresponding to the fifth eigenvector and the outlier state of the battery cell corresponding to the sixth eigenvector as the fourth outlier state of the battery cell corresponding to the third sub-time period; and determining the failure of the battery cell according to the first outlier state, the second outlier state, the third outlier state, and the fourth outlier state of the battery cell.

[0018] Based on this scheme, since the first outlier state, the second outlier state, the third outlier state and the fourth outlier state are the outlier states with the largest number among the corresponding multiple outlier states, by taking the outlier state with the largest number among the outlier states of the battery cell corresponding to each characteristic vector of each sub-time period as the final outlier state corresponding to the battery cell and the sub-time period for determining the fault, the fault of the battery cell can be subsequently determined based on the first outlier state, the second outlier state, the third outlier state and the fourth outlier state.

[0019] In combination with the first aspect, in certain embodiments of the first aspect, the fault of the battery cell is determined according to the first outlier state, the second outlier state, the third outlier state, and the fourth outlier state of the battery cell, including: when the second outlier state of the battery cell is downward outlier, or when the first outlier state of the battery cell is not outlier, and the third outlier state is downward outlier, and the fourth outlier state is downward outlier, determining that the battery cell has a micro-short circuit fault; when the first outlier state of the battery cell is not outlier, and the third outlier state is upward outlier, and the fourth outlier state is downward outlier, determining that the battery cell has a low capacity fault.

[0020] Based on this scheme, when a cell has a micro-short circuit fault, the cell will self-discharge and the electric energy of the cell will be continuously consumed. Therefore, when the second out-of-group state of the cell is downward out-of-group, or when the first out-of-group state of the cell is not out-of-group, and the third out-of-group state is downward out-of-group, and the fourth out-of-group state is downward out-of-group, it can be determined that the cell has a micro-short circuit fault. When a cell has a low-capacity fault, the capacity of the cell is low and the charging and discharging speed is fast. Therefore, when the first out-of-group state of the cell is not out-of-group, and the third out-of-group state is upward out-of-group, and the fourth out-of-group state is downward out-of-group, it can be determined that the cell has a low-capacity fault.

[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 device includes: an acquisition module and a processing module; the acquisition module is used to acquire a reference voltage value set of the battery cells in the target battery and a voltage value set of each battery cell in the multiple battery cells of the target battery; the reference voltage value set includes reference voltage values ​​at multiple sampling moments in the sampling time period, and the voltage value set includes voltage values ​​at multiple sampling moments; the processing module is used to determine the outlier state of each battery cell in each sub-time period of the sampling time period according to the voltage value set and the reference voltage value set of the multiple battery cells; the outlier state includes not outlier, upward outlier or downward outlier; the processing module is also used to determine the fault of the battery cell based on the outlier state of the battery cell in multiple sub-time periods; the fault includes a low capacity fault or a micro short circuit fault.

[0023] In combination with the second aspect, in certain embodiments of the second aspect, an acquisition module is used to obtain a set of reference voltage values ​​of battery cells in a target battery, including: for each sampling moment among multiple sampling moments, determining the median value of the voltage values ​​of multiple battery cells at the sampling moment as the reference voltage value.

[0024] In combination with the second aspect, in some embodiments of the second aspect, the sub-time period includes a first sub-time period, a second sub-time period or a third sub-time period, and the processing module is used to determine the outlier state of each battery cell in each sub-time period of the multiple sub-time periods of the sampling time period according to the voltage value set of the multiple battery cells and the reference voltage value set, including: determining the first sub-time period, the second sub-time period and the third sub-time period in the sampling time period according to the reference voltage value set; the time length between any two adjacent sampling moments in the first sub-time period is greater than the first threshold, and the absolute value of the difference between the reference voltage values ​​of any two adjacent sampling moments is less than the second threshold, or the absolute value of the difference between the reference voltage value of any sampling moment in the first sub-time period and the reference voltage value of the start moment of the first sub-time period is less than the third threshold, and any adjacent The absolute value of the difference between the reference voltage values ​​at two sampling moments is less than the second threshold value, and the number of sampling moments in the first sub-time period is greater than the fourth threshold value, the second sub-time period is the time period other than the first sub-time period in the sampling time period, and the reference voltage value at any sampling moment in the second sub-time period is greater than the reference voltage value at the previous sampling moment, and the third sub-time period is the time period other than the first sub-time period in the sampling time period, and the reference voltage value at any sampling moment in the third sub-time period is less than the reference voltage value at the previous sampling moment; for each sub-time period, determine a characteristic vector corresponding to the sub-time period; the characteristic vector includes multiple elements, one element is determined based on multiple reference voltage values ​​in the sub-time period and the voltage value of a battery cell in the sub-time period; based on the characteristic vector, determine the outlier state of each battery cell in the sub-time period.

[0025] In combination with the second aspect, in certain embodiments of the second aspect, the processing module is further used to determine the characteristic vector corresponding to the sub-time period, including: for each first sub-time period, determining the first characteristic vector and the second characteristic vector corresponding to the first sub-time period; the first characteristic vector includes multiple first elements, the first element is the difference between the first value and the second value, one first value is the average value of multiple voltage values ​​of a battery cell in the first sub-time period, and the second value is the average value of multiple reference voltage values ​​of the first sub-time period; the second characteristic vector includes multiple second elements, the second element is the difference between the third value and the fourth value, one third value is the average value of multiple voltage change values ​​of a battery cell in the first sub-time period, the voltage change value is the difference between the voltage value at a sampling moment and the voltage value at a previous sampling moment, the fourth value is the average value of multiple reference voltage change values ​​of the first sub-time period, and the reference voltage change value is the difference between the reference voltage value at a sampling moment and the reference voltage value at the previous sampling moment; for each second sub-time period time period, determine the third eigenvector and the fourth eigenvector corresponding to the second sub-time period; the third eigenvector includes multiple third elements, the third element is the difference between the fifth value and the sixth value, a fifth value is the maximum value of multiple voltage values ​​of a battery cell in the second sub-time period, and the sixth value is the average value of multiple reference voltage values ​​of the second sub-time period; the fourth eigenvector includes multiple fourth elements, the fourth element is the difference between the seventh value and the sixth value, and a seventh value is the minimum value of multiple voltage values ​​of a battery cell in the second sub-time period; for each third sub-time period, determine the fifth eigenvector and the sixth eigenvector corresponding to the third sub-time period; the fifth eigenvector includes multiple fifth elements, the fifth element is the difference between the eighth value and the sixth value, and an eighth value is the maximum value of multiple voltage values ​​of a battery cell in the third sub-time period; the sixth eigenvector includes multiple sixth elements, the sixth element is the difference between the ninth value and the sixth value, and a ninth value is the minimum value of multiple voltage values ​​of a battery cell in the third sub-time period.

[0026] In combination with the second aspect, in certain embodiments of the second aspect, the processing module is also used to determine the outlier state of each battery cell in a sub-time period based on the feature vector, including: S1, determining the maximum outlier in the current feature vector based on the 3σ criterion; S2, eliminating the maximum outlier in the current feature vector to obtain an updated feature vector; S3, determining the error range corresponding to the current feature vector based on the 3σ criterion; S4, judging whether the maximum outlier is outside the error range; when the maximum outlier is outside the error range, executing S5, and when the maximum outlier is within the error range, executing S6; S5, when the maximum outlier is greater than the upper limit of the error range, determining that the outlier state of the battery cell corresponding to the maximum outlier is an upward outlier, and when the maximum outlier is less than the lower limit of the error range, determining that the outlier state of the battery cell corresponding to the maximum outlier is a downward outlier; executing S1; S6, determining that the outlier state of the battery cell corresponding to each element in the current feature vector in S1 is not an outlier.

[0027] 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 battery cell based on the outlier state of the battery cell in multiple sub-time periods, including: taking the outlier state with the largest number among the outlier states of the battery cell corresponding to the first eigenvector as the first outlier state of the battery cell corresponding to the first sub-time period; taking the outlier state with the largest number among the outlier states of the battery cell corresponding to the second eigenvector as the second outlier state of the battery cell corresponding to the first sub-time period; taking the outlier state of the battery cell corresponding to the third eigenvector and the outlier state of the battery cell corresponding to the fourth eigenvector as the third outlier state of the battery cell corresponding to the second sub-time period; taking the outlier state of the battery cell corresponding to the fifth eigenvector and the outlier state of the battery cell corresponding to the sixth eigenvector as the fourth outlier state of the battery cell corresponding to the third sub-time period; and determining the fault of the battery cell according to the first outlier state, the second outlier state, the third outlier state, and the fourth outlier state of the battery cell.

[0028] 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 battery cell according to the first outlier state, the second outlier state, the third outlier state, and the fourth outlier state of the battery cell, including: when the second outlier state of the battery cell is downward outlier, or when the first outlier state of the battery cell is not outlier, and the third outlier state is downward outlier, and the fourth outlier state is downward outlier, determining that the battery cell has a micro-short circuit fault; when the first outlier state of the battery cell is not outlier, and the third outlier state is upward outlier, and the fourth outlier state is downward outlier, determining that the battery cell has a low capacity fault.

[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 structural schematic diagram of a fault determination device provided by the present application;

[0040] Figure 8 A schematic diagram of the structure of another fault determination device provided in the present application. DETAILED DESCRIPTION

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] In order to ensure the normal operation of the battery, it is necessary to determine the faults of each cell in the battery.

[0049] 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.

[0050] This solution has high requirements on the quality of data. In some cases, the quality of battery data is low. For example, the type of data is relatively simple. In this case, the accuracy of the existing solution in determining the fault of each battery cell in the battery is low.

[0051] 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 .

[0052] 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.

[0053] Data exchange can be performed between the fault determination device 11 and the electronic device 12 .

[0054] 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.

[0055] 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".

[0056] In the following embodiments provided in the present application, the present application is described by taking the fault determination device 11 and the electronic device 12 as being independently configured.

[0057] 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.

[0058] 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.

[0059] 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:

[0060] S201 . A fault determination apparatus obtains a reference voltage value set of a battery cell in a target battery and a voltage value set of each battery cell in a plurality of battery cells of the target battery.

[0061] The reference voltage value set includes reference voltage values ​​at multiple sampling moments in a sampling time period, and the voltage value set includes voltage values ​​at multiple sampling moments.

[0062] It should be noted that the duration between two adjacent moments in the multiple moments may be the same or different.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] The reference voltage value is used to indicate the voltage value of a normal cell in the target battery. Because each cell in the target battery may have a greater or lesser fault than a normal cell, the normal cell is not necessarily a specific cell in the target battery, but a normal cell under an ideal state, that is, the normal cell can be a virtual cell.

[0067] As a possible implementation, combining Figure 1 The fault handling device receives a message from an electronic device, the message including a reference voltage value set of the battery cells in the target battery and a voltage value set of each battery cell in the multiple battery cells of the target battery, and the fault handling device obtains the reference voltage value set of the battery cells in the target battery and the voltage value set of each battery cell in the multiple battery cells of the target battery from the message.

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

[0069] The fault processing device determines, for each of the plurality of sampling moments, a median value of voltage values ​​of the plurality of cells at the sampling moment as a reference voltage value.

[0070] Alternatively, the fault handling device determines a cell whose voltage value reaches a maximum value earliest among the multiple cells as a normal cell, and determines the voltage value of the normal cell at multiple sampling moments as the reference voltage value at the multiple sampling moments.

[0071] It should be noted that if multiple battery cells reach a maximum value at the same time, the battery cell with the largest voltage value among the multiple battery cells is determined as a normal battery cell.

[0072] Alternatively, the fault handling device calculates the average voltage value of each battery cell in the multiple battery cells at multiple sampling moments, determines the battery cell with the smallest average value as a normal battery cell, and determines the voltage value of the normal battery cell at the multiple sampling moments as the reference voltage value at the multiple sampling moments.

[0073] Alternatively, the fault handling device determines, for each of the multiple sampling moments, an average of the voltage values ​​of the multiple cells at the sampling moment as the reference voltage value.

[0074] In order to determine the reference voltage value of the battery cell in the target battery, compared with the scheme of determining the battery cell whose voltage value reaches the maximum value earliest among multiple battery cells as a normal battery cell, determining the average of the voltage values ​​of multiple battery cells at the sampling moment as the reference voltage value, and determining the battery cell with the smallest average value of the voltage values ​​of multiple battery cells at multiple sampling moments of each battery cell among the multiple battery cells as a normal battery cell, since the median value is not affected by the extreme values ​​in the multiple data, by determining the reference voltage value by the median value of the voltage values ​​of multiple battery cells at the sampling moment for each of the multiple sampling moments, it is possible to avoid the influence of the extreme voltage values ​​of individual faulty battery cells among the multiple battery cells on the determined reference voltage value, thereby improving the accuracy of determining the reference voltage value of the battery cell in the target battery.

[0075] S202 . The fault handling apparatus determines, according to a voltage value set of a plurality of battery cells and a reference voltage value set, an outlier state of each battery cell in each of a plurality of sub-time periods of a sampling time period.

[0076] The outlier status includes not outlier, upward outlier or downward outlier.

[0077] As a possible implementation method, the sub-time period includes a first sub-time period, a second sub-time period or a third sub-time period, and the fault determination device determines the first sub-time period, the second sub-time period and the third sub-time period in the sampling time period according to a reference voltage value set; for each sub-time period, determines a characteristic vector corresponding to the sub-time period; based on the characteristic vector, determines the outlier state of each battery cell in the sub-time period.

[0078] Among them, the duration between any two adjacent sampling moments in the first sub-time period is greater than the first threshold, and the absolute value of the difference between the reference voltage values ​​of any two adjacent sampling moments is less than the second threshold, or the absolute value of the difference between the reference voltage value of any sampling moment in the first sub-time period and the reference voltage value at the start time of the first sub-time period is less than the third threshold, and the absolute value of the difference between the reference voltage values ​​of any two adjacent sampling moments is less than the second threshold, and the number of sampling moments in the first sub-time period is greater than the fourth threshold, the second sub-time period is the time period other than the first sub-time period in the sampling time period, and the reference voltage value of any sampling moment in the second sub-time period is greater than the reference voltage value of the previous sampling moment, the third sub-time period is the time period other than the first sub-time period in the sampling time period, and the reference voltage value of any sampling moment in the third sub-time period is less than the reference voltage value of the previous sampling moment; the characteristic vector includes multiple elements, one element is determined based on multiple reference voltage values ​​in the sub-time period and the voltage value of a battery cell in the sub-time period.

[0079] 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.

[0080] S203 . The fault determining device determines the fault of the battery cell based on the outlier states of the battery cell in multiple sub-time periods.

[0081] Among them, the fault includes low capacity fault or micro short circuit fault.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] If the battery cell is not working, the battery cell will not have abnormal voltage or abnormal voltage rate.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] As a possible implementation method, when the sub-time period includes the first sub-time period, the second sub-time period or the third sub-time period, the fault determination device takes the outlier state with the largest number among the outlier states of the battery cell corresponding to the first characteristic vector as the first outlier state of the battery cell corresponding to the first sub-time period.

[0093] The fault determination device uses the outlier state with the largest number among the outlier states of the battery cells corresponding to the second characteristic vector as the second outlier state of the battery cell corresponding to the first sub-time period.

[0094] The fault determination device uses the outlier state of the battery cell corresponding to the third eigenvector and the outlier state of the battery cell corresponding to the fourth eigenvector with the largest number as the third outlier state of the battery cell corresponding to the second sub-time period.

[0095] The fault determination device uses the outlier state of the battery cell corresponding to the fifth eigenvector and the outlier state of the battery cell corresponding to the sixth eigenvector, whichever has the largest number, as the fourth outlier state of the battery cell corresponding to the third sub-time period.

[0096] The fault determination device determines the fault of the battery cell according to the first out-of-group state, the second out-of-group state, the third out-of-group state, and the fourth out-of-group state of the battery cell.

[0097] 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.

[0098] Based on this solution, compared with the existing solution that requires more comprehensive and multiple battery data to determine the failure of the battery cell, the solution of the present application obtains a voltage value set including voltage values ​​at multiple sampling moments of each battery cell of the target battery and a reference voltage value set including reference voltage values ​​at multiple sampling moments of the battery cells in the target battery, and then, based on the voltage value set and the reference voltage value set of multiple battery cells, determines the outlier state of each battery cell in each of multiple sub-time periods of the sampling time period, and then, based on the outlier state of the battery cell in multiple sub-time periods, determines the failure of the battery cell. When a low-capacity failure or a micro-short circuit failure occurs in a battery cell, the voltage value of the battery cell will be abnormal. By analyzing and processing the voltage values ​​of multiple battery cells, the outlier state of each battery cell is determined, and the failure of the battery cell is determined based on the outlier state. 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, it can improve the accuracy of determining the failure of the battery cell in the battery.

[0099] 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.

[0100] 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, in the case where the sub-time period includes the first sub-time period, the second sub-time period or the third sub-time period, S202 provided in the specific implementation manner of the present application may specifically include the following multiple steps:

[0101] S301. A fault determination apparatus determines a first sub-time period, a second sub-time period, and a third sub-time period in a sampling time period according to a reference voltage value set.

[0102] Among them, the duration between any two adjacent sampling moments in the first sub-time period is greater than the first threshold, and the absolute value of the difference between the reference voltage values ​​at any two adjacent sampling moments is less than the second threshold, or the absolute value of the difference between the reference voltage value at any sampling moment in the first sub-time period and the reference voltage value at the start moment of the first sub-time period is less than the third threshold, and the absolute value of the difference between the reference voltage values ​​at any two adjacent sampling moments is less than the second threshold, and the number of sampling moments in the first sub-time period is greater than the fourth threshold, the second sub-time period is the time period in the sampling time period other than the first sub-time period, and the reference voltage value at any sampling moment in the second sub-time period is greater than the reference voltage value at the previous sampling moment, and the third sub-time period is the time period in the sampling time period other than the first sub-time period, and the reference voltage value at any sampling moment in the third sub-time period is less than the reference voltage value at the previous sampling moment.

[0103] It should be noted that the first sub-time period may also be referred to as a rest time period, the second sub-time period may also be referred to as a charging time period, and the third sub-time period may also be referred to as a discharging time period.

[0104] The number of the first sub-time period, the second sub-time period or the third sub-time period may be one or more, and this application does not impose any specific limitation on this.

[0105] As a possible implementation manner, for the first sub-time period, firstly, the fault determination device determines the start time of the first sub-time period.

[0106] Specifically, in order from early to late, the fault determination device determines whether the duration between the second sampling moment in the sampling time period and the first sampling moment in the sampling time period is greater than the first threshold, and determines whether the absolute value of the difference between the reference voltage value at the second sampling moment and the reference voltage value at the first sampling moment is less than the second threshold.

[0107] If at least one of the judgment results is negative, the fault determination device determines whether the duration between the third sampling moment and the second sampling moment is greater than the first threshold, and determines whether the absolute value of the difference between the reference voltage value at the third sampling moment and the reference voltage value at the second sampling moment is less than the second threshold. And so on, in the order from early to late, until a certain sampling moment and the previous sampling moment meet the above conditions, the fault determination device uses the previous sampling moment as the starting moment of the first sub-time period.

[0108] If both judgment results are yes, the first sampling moment of the fault determination device is used as the starting moment of the first sub-time period.

[0109] Secondly, after the fault determination device determines the starting time of the first sub-time period, the fault determination device determines, in order from early to late, whether the duration between the second sampling time after the starting time and the first sampling time after the starting time is greater than the first threshold, and determines whether the absolute value of the difference between the reference voltage value at the second sampling time after the starting time and the reference voltage value at the first sampling time after the starting time is less than the second threshold.

[0110] If at least one judgment result is negative, the fault determination device uses the first sampling time after the start time as the end time of the first sub-time period.

[0111] If both judgment results are yes, the fault determination device determines whether the duration between the third sampling moment after the start time and the second sampling moment after the start time is greater than the first threshold, and determines whether the absolute value of the difference between the reference voltage value at the third sampling moment after the start time and the reference voltage value at the second sampling moment after the start time is less than the second threshold. This is repeated until at least one judgment result corresponding to a certain sampling moment and the previous sampling moment is no, and the previous sampling moment is used as the end time of the first sub-time period.

[0112] Alternatively, for the first sub-time period, firstly, the fault determination device determines a start time of the first sub-time period.

[0113] Specifically, in order from early to late, the fault determination device determines whether the absolute value of the difference between the reference voltage value at the second sampling moment in the sampling time period and the reference voltage value at the first sampling moment in the sampling time period is less than the third threshold, and determines whether the absolute value of the difference between the reference voltage value at the second sampling moment and the reference voltage value at the first sampling moment is less than the second threshold.

[0114] If at least one of the judgment results is negative, the fault determination device determines whether the absolute value of the difference between the reference voltage value at the third sampling moment and the reference voltage value at the second sampling moment is less than the third threshold, and determines whether the absolute value of the difference between the reference voltage value at the third sampling moment and the reference voltage value at the second sampling moment is less than the second threshold. And so on, in order from early to late, until a certain sampling moment and the previous sampling moment meet the above conditions, the fault determination device uses the previous sampling moment as the starting moment of the first sub-time period to be determined.

[0115] If both judgment results are yes, the first sampling moment of the fault determination device is used as the starting moment of the first sub-time period to be determined.

[0116] Secondly, after the fault determination device determines the starting time of the first sub-time period to be determined, it determines, in order from early to late, whether the absolute value of the difference between the reference voltage value at the second sampling time after the starting time and the reference voltage value at the starting time is less than the third threshold, and determines whether the absolute value of the difference between the reference voltage value at the second sampling time after the starting time and the reference voltage value at the first sampling time after the starting time is less than the second threshold.

[0117] If at least one judgment result is negative, the fault determination device uses the first sampling time after the start time as the end time of the first sub-time period to be determined.

[0118] If both judgment results are yes, the fault determination device determines whether the absolute value of the difference between the reference voltage value at the third sampling moment after the start time and the reference voltage value at the start time is less than the third threshold, and determines whether the absolute value of the difference between the reference voltage value at the third sampling moment after the start time and the reference voltage value at the second sampling moment after the start time is less than the second threshold. This is repeated until at least one judgment result corresponding to a certain sampling moment and the previous sampling moment is no, and the previous sampling moment is used as the end time of the first sub-time period to be determined.

[0119] Secondly, after determining the start time and the end time of the first sub-time period to be determined, the fault determination device determines whether the number of sampling moments in the first sub-time period is greater than a fourth threshold.

[0120] If so, the pending first sub-time period is the first sub-time period; if not, the pending first sub-time period is not the first sub-time period.

[0121] After the fault determination device determines the first first sub-time period, the above processing is also performed for subsequent sampling moments to obtain one or more first sub-time periods.

[0122] In some embodiments, in order to avoid determining the time period of slow charging and discharging as the first sub-time period, after determining the start time and end time of the first sub-time period, the fault determination device can determine the difference between the reference voltage value at each sampling moment in the first sub-time period and the reference voltage value at the previous sampling moment, determine whether multiple differences are all positive or negative, and determine whether the maximum value among the multiple differences is greater than the fifth threshold.

[0123] If at least one judgment result is yes, the fault determination device determines that the time period corresponding to the start time and the end time is not the first sub-time period.

[0124] If both judgment results are negative, the fault determination device determines that the time period corresponding to the start time and the end time is the first sub-time period.

[0125] For the second sub-time period, firstly, the fault determination device removes the first sub-time period in the sampling time period to obtain the remaining sampling time period.

[0126] Next, the fault determination device determines a start time of the second sub-time period.

[0127] Specifically, in order from early to late, the fault determination device determines whether the reference voltage value at the second sampling moment in the remaining sampling time period is greater than the reference voltage value at the first sampling moment.

[0128] If not, the fault determination device determines whether the reference voltage value at the third sampling moment in the remaining sampling time period is greater than the reference voltage value at the second sampling moment. In order from early to late, and so on, until a certain sampling moment and the previous sampling moment meet the above conditions, the fault determination device uses the previous sampling moment as the starting moment of the second sub-time period.

[0129] If yes, the fault determination device uses the first sampling time as the starting time of the second sub-time period.

[0130] Secondly, after the fault determination device determines the start time of the second sub-time period, the fault determination device determines whether the reference voltage value at the second sampling time after the start time is greater than the reference voltage value at the first sampling time after the start time.

[0131] If so, the fault determination device determines whether the reference voltage value at the third sampling moment after the start moment is greater than the reference voltage value at the second sampling moment after the start moment. And so on, in order from early to late, until the reference voltage value at a certain sampling moment is not greater than the reference voltage value at the previous sampling moment, the previous sampling moment is taken as the end moment of the second sub-time period.

[0132] If not, the fault determination device uses the first sampling time after the start time as the end time of the second sub-time period.

[0133] After the fault determination device determines a second sub-time period, the above processing is also performed for the subsequent sampling moments in the remaining sampling time period to obtain one or more second sub-time periods.

[0134] For the third sub-time period, the fault determination device determines a time period other than the first sub-time period and the second sub-time period in the sampling time period as the third sub-time period.

[0135] Alternatively, first, the fault determination device removes the first sub-time period in the sampling time period to obtain the remaining sampling time period.

[0136] Next, the fault determination device determines a start time of the third sub-time period.

[0137] Specifically, in order from early to late, the fault determination device determines whether the reference voltage value at the second sampling moment in the remaining sampling time period is smaller than the reference voltage value at the first sampling moment.

[0138] If not, the fault determination device determines whether the reference voltage value at the third sampling moment in the remaining sampling time period is less than the reference voltage value at the second sampling moment. And so on, in the order from early to late, until a certain sampling moment and the previous sampling moment meet the above conditions, the fault determination device uses the previous sampling moment as the starting moment of the third sub-time period.

[0139] If yes, the fault determination device uses the first sampling time as the starting time of the third sub-time period.

[0140] Secondly, after the fault determination device determines the start time of the third sub-time period, the fault determination device determines whether the reference voltage value at the second sampling time after the start time is smaller than the reference voltage value at the first sampling time after the start time.

[0141] If so, the fault determination device determines whether the reference voltage value at the third sampling moment after the start moment is less than the reference voltage value at the second sampling moment after the start moment. And so on, in order from early to late, until the reference voltage value at a certain sampling moment is not less than the reference voltage value at the previous sampling moment, the previous sampling moment is taken as the end moment of the third sub-time period.

[0142] If not, the fault determination device uses the first sampling time after the start time as the end time of the third sub-time period.

[0143] After the fault determination device determines a third sub-time period, the above processing is also performed for the subsequent sampling moments in the remaining sampling time periods to obtain one or more third sub-time periods.

[0144] In some embodiments, after determining the first sub-time period, the fault determination device may first determine the second sub-time period, or first determine the third sub-time period, or determine the second sub-time period and the third sub-time period in parallel.

[0145] In some embodiments, if the fault determination device determines the second sub-time period first after determining the first sub-time period, the fault determination device may eliminate the first sub-time period and the second sub-time period in the sampling time period, and determine the third sub-time period based on the remaining sampling time period obtained at this time. For example, the remaining sampling time period is directly determined as the third sub-time period, or the above steps of determining the third sub-time period are performed based on the remaining sampling time period to obtain the third sub-time period.

[0146] In some embodiments, if the fault determination device determines the third sub-time period first after determining the first sub-time period, the fault determination device may eliminate the first sub-time period and the third sub-time period in the sampling time period, and determine the second sub-time period based on the remaining sampling time period obtained at this time. For example, the remaining sampling time period is directly determined as the second sub-time period, or the above-mentioned steps of determining the second sub-time period are performed based on the remaining sampling time period to obtain the second sub-time period.

[0147] S302: The fault determination device determines, for each sub-time period, a feature vector corresponding to the sub-time period.

[0148] The characteristic vector includes a plurality of elements, and one element is determined based on a plurality of reference voltage values ​​within a sub-time period and a voltage value of a battery cell within the sub-time period.

[0149] As a possible implementation method, the fault determination device determines, for each first sub-time period, a first eigenvector and a second eigenvector corresponding to the first sub-time period; for each second sub-time period, determines a third eigenvector and a fourth eigenvector corresponding to the second sub-time period; and for each third sub-time period, determines a fifth eigenvector and a sixth eigenvector corresponding to the third sub-time period.

[0150] Among them, the first eigenvector includes multiple first elements, the first element is the difference between the first value and the second value, a first value is the average of multiple voltage values ​​of a battery cell in the first sub-time period, and the second value is the average of multiple reference voltage values ​​in the first sub-time period.

[0151] The second eigenvector includes multiple second elements, the second element is the difference between the third value and the fourth value, a third value is the average of multiple voltage change values ​​of a battery cell in the first sub-time period, the voltage change value is the difference between the voltage value at a sampling moment and the voltage value at the previous sampling moment, and the fourth value is the average of multiple reference voltage change values ​​of the first sub-time period, and the reference voltage change value is the difference between the reference voltage value at a sampling moment and the reference voltage value at the previous sampling moment.

[0152] The third eigenvector includes multiple third elements, the third element is the difference between the fifth value and the sixth value, the fifth value is the maximum value of multiple voltage values ​​of a battery cell in the second sub-time period, and the sixth value is the average value of multiple reference voltage values ​​of the second sub-time period. The fourth eigenvector includes multiple fourth elements, the fourth element is the difference between the seventh value and the sixth value, and the seventh value is the minimum value of multiple voltage values ​​of a battery cell in the second sub-time period.

[0153] The fifth eigenvector includes multiple fifth elements, the fifth element is the difference between the eighth value and the sixth value, and the eighth value is the maximum value among the multiple voltage values ​​of a battery cell in the third sub-time period. The sixth eigenvector includes multiple sixth elements, the sixth element is the difference between the ninth value and the sixth value, and the ninth value is the minimum value among the multiple voltage values ​​of a battery cell in the third sub-time period.

[0154] 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.

[0155] S303 . The fault determination device determines the outlier state of each battery cell in the sub-time period based on the feature vector.

[0156] As a possible implementation manner, S1. The fault determination device determines the maximum outlier in the current feature vector based on the 3σ criterion.

[0157] S2. The fault determination device removes the largest outlier in the current feature vector to obtain an updated feature vector.

[0158] S3. The fault determination device determines the error range corresponding to the current feature vector based on the 3σ criterion.

[0159] S4, the fault determination device determines whether the maximum outlier point is outside the error range; if the maximum outlier point is outside the error range, S5 is executed, and if the maximum outlier point is within the error range, S6 is executed. .

[0160] S5. When the maximum outlier point is greater than the upper limit of the error range, the fault determination device determines that the outlier state of the battery cell corresponding to the maximum outlier point is an upward outlier; when the maximum outlier point is less than the lower limit of the error range, the fault determination device determines that the outlier state of the battery cell corresponding to the maximum outlier point is a downward outlier.

[0161] The fault determination device executes S1.

[0162] S6. The fault determination device determines that the outlier state of the battery cell corresponding to each element in the current feature vector in S1 is not an outlier.

[0163] 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.

[0164] As another possible implementation method, the fault determination device calculates the mean and standard deviation of multiple elements in the feature vector, and regards the elements that exceed the upper and lower limits of 3 times the standard deviation as outliers. When the outlier is greater than the upper limit, the outlier state of the battery cell corresponding to the outlier is determined to be an upward outlier. When the outlier is less than the lower limit, the outlier state of the battery cell corresponding to the outlier is determined to be a downward outlier.

[0165] As another possible implementation, the fault determination device determines the maximum outlier in the feature vector based on the 3σ criterion. When the maximum outlier is greater than an upper limit, the outlier state of the battery cell corresponding to the maximum outlier is determined to be an upward outlier, and when the maximum outlier is less than a lower limit, the outlier state of the battery cell corresponding to the outlier is determined to be a downward outlier.

[0166] The fault determination device removes the maximum outlier in the feature vector to obtain a new feature vector.

[0167] The fault determination device determines the maximum outlier in the new feature vector based on the 3σ criterion. When the maximum outlier is greater than the upper limit, the outlier state of the battery cell corresponding to the maximum outlier is determined to be an upward outlier, and when the maximum outlier is less than the lower limit, the outlier state of the battery cell corresponding to the outlier is determined to be a downward outlier.

[0168] The fault determination device removes the maximum outlier in the new feature vector to obtain a new feature vector.

[0169] And so on, until there are no outliers in the new eigenvector.

[0170] Based on this scheme, the first sub-time period, the second sub-time period and the third sub-time period in the sampling time period are determined according to the reference voltage value set. Since the duration between any two adjacent sampling moments in the first sub-time period is greater than the first threshold value, and the difference between the reference voltage values ​​of any two adjacent sampling moments is less than the second threshold value, or the difference between the reference voltage value of any sampling moment in the first sub-time period and the reference voltage value at the start moment of the first sub-time period is less than the third threshold value, and the difference between the reference voltage values ​​of any two adjacent sampling moments is less than the second threshold value, and the number of sampling moments in the first sub-time period is greater than the fourth threshold value, the first sub-time period can be considered as the time period when the normal cells in the target battery are in a stable state. Since the second sub-time period is a time period other than the first sub-time period in the sampling time period, and the reference voltage value of any sampling moment in the second sub-time period is greater than the reference voltage value of the previous sampling moment, the second sub-time period can be considered as the time period when the normal cells in the target battery are in a charging state. The third sub-time period is the time period other than the first sub-time period in the sampling time period, and the reference voltage value at any sampling moment in the third sub-time period is less than the reference voltage value at the previous sampling moment, so the third sub-time period can be considered as the time period when the normal battery cell in the target battery is in a discharge state. In the case of a battery cell failure, compared with the reference voltage value, the voltage value of the battery cell in the charging state, the voltage value of the battery cell in the stable state, and the voltage value of the battery cell in the discharge state will be abnormal, so for each sub-time period, the characteristic vector corresponding to the sub-time period is determined, and based on the characteristic vector, the outlier state of each battery cell in the sub-time period is determined, and the failure of the battery cell can be determined later.

[0171] In one design, Figure 4 A flowchart of another fault determination method provided by the present application is shown as follows: Figure 4 As shown, S302 provided in the specific implementation manner of the present application may specifically include the following multiple steps:

[0172] S401. A fault determining apparatus determines, for each first sub-time period, a first characteristic vector and a second characteristic vector corresponding to the first sub-time period.

[0173] Among them, the first eigenvector includes multiple first elements, the first element is the difference between the first value and the second value, a first value is the average of multiple voltage values ​​of a battery cell in the first sub-time period, and the second value is the average of multiple reference voltage values ​​in the first sub-time period.

[0174] The second eigenvector includes multiple second elements, the second element is the difference between the third value and the fourth value, a third value is the average of multiple voltage change values ​​of a battery cell in the first sub-time period, the voltage change value is the difference between the voltage value at a sampling moment and the voltage value at the previous sampling moment, and the fourth value is the average of multiple reference voltage change values ​​of the first sub-time period, and the reference voltage change value is the difference between the reference voltage value at a sampling moment and the reference voltage value at the previous sampling moment.

[0175] As a possible implementation manner, for the first characteristic vector, for each first sub-time period, the fault determination device uses an average value of multiple reference voltage values ​​in the first sub-time period as the second value.

[0176] The fault determination device takes the average value of multiple voltage values ​​of a battery cell in the first sub-time period as a first value, takes the average value of multiple voltage values ​​of another battery cell in the first sub-time period as another first value, and so on. The fault determination device determines the first value corresponding to each battery cell for each battery cell.

[0177] The fault determination device uses the difference between a first value and a second value as a first element, uses the difference between another first value and the second value as another first element, and so on, to determine multiple first elements and obtain a first eigenvector.

[0178] For the second characteristic vector, for each first sub-period in the plurality of first sub-periods, the fault determination device uses an average value of a plurality of reference voltage change values ​​in the first sub-period as the fourth value.

[0179] The fault determination device takes the average value of multiple voltage change values ​​of a battery cell in the first sub-time period as a third value, takes the average value of multiple voltage change values ​​of another battery cell in the first sub-time period as another third value, and so on. The fault determination device determines the third value corresponding to each battery cell for each battery cell.

[0180] The fault determination device uses a difference between a third value and a fourth value as a second element, uses a difference between another third value and the fourth value as another second element, and so on, to determine multiple second elements and obtain a second eigenvector.

[0181] S402: The fault determination device determines, for each second sub-time period, a third eigenvector and a fourth eigenvector corresponding to the second sub-time period.

[0182] Among them, the third eigenvector includes multiple third elements, the third element is the difference between the fifth value and the sixth value, a fifth value is the maximum value among multiple voltage values ​​of a battery cell in the second sub-time period, and the sixth value is the average value of multiple reference voltage values ​​in the second sub-time period.

[0183] The fourth eigenvector includes multiple fourth elements, where the fourth element is a difference between the seventh value and the sixth value, and a seventh value is a minimum value among multiple voltage values ​​of a battery cell in the second sub-time period.

[0184] As a possible implementation manner, for the third characteristic vector, for each second sub-time period, the fault determination device uses an average value of multiple reference voltage values ​​in the second sub-time period as the sixth value.

[0185] The fault determination device takes the maximum value among multiple voltage values ​​of a battery cell in the second sub-time period as a fifth value, takes the maximum value among multiple voltage values ​​of another battery cell in the second sub-time period as another fifth value, and so on. The fault determination device determines the fifth value corresponding to each battery cell for each battery cell.

[0186] The fault determination device uses a difference between a fifth value and a sixth value as a third element, uses a difference between another fifth value and the sixth value as another third element, and so on, to determine multiple third elements and obtain a third eigenvector.

[0187] For the fourth eigenvector, for each second sub-time period, the fault determination device takes the minimum value among the multiple voltage values ​​of a battery cell in the second sub-time period as a seventh value, and takes the minimum value among the multiple voltage values ​​of another battery cell in the second sub-time period as another seventh value, and so on. The fault determination device determines the seventh value corresponding to each battery cell for each battery cell.

[0188] The fault determination device uses a difference between a seventh value and a sixth value as a fourth element, uses a difference between another seventh value and the sixth value as another fourth element, and so on, to determine multiple fourth elements and obtain a fourth eigenvector.

[0189] S403: The fault determination device determines, for each third sub-time period, a fifth eigenvector and a sixth eigenvector corresponding to the third sub-time period.

[0190] The fifth eigenvector includes multiple fifth elements, the fifth element is the difference between the eighth value and the sixth value, and an eighth value is the maximum value of multiple voltage values ​​of a battery cell in the third sub-time period.

[0191] The sixth eigenvector includes multiple sixth elements, where the sixth element is a difference between the ninth value and the sixth value, and a ninth value is a minimum value among multiple voltage values ​​of a battery cell in the third sub-time period.

[0192] As a possible implementation method, for the fifth eigenvector, for each third sub-time period, the fault determination device takes the maximum value among multiple voltage values ​​of a battery cell in the third sub-time period as an eighth value, and takes the maximum value among multiple voltage values ​​of another battery cell in the third sub-time period as another eighth value, and so on. The fault determination device determines the eighth value corresponding to each battery cell for each battery cell.

[0193] The fault determination device uses a difference between an eighth value and a sixth value as a fifth element, uses a difference between another eighth value and the sixth value as another fifth element, and so on, to determine multiple fifth elements and obtain a fifth eigenvector.

[0194] For the sixth eigenvector, for each third sub-time period, the fault determination device takes the minimum value among the multiple voltage values ​​of a battery cell in the third sub-time period as a ninth value, and takes the minimum value among the multiple voltage values ​​of another battery cell in the third sub-time period as another ninth value, and so on. The fault determination device determines the ninth value corresponding to each battery cell for each battery cell.

[0195] The fault determination device uses a difference between a ninth value and a sixth value as a sixth element, uses a difference between another ninth value and the sixth value as another sixth element, and so on, to determine multiple sixth elements and obtain a sixth eigenvector.

[0196] Based on this scheme, when a battery cell has a fault, compared with the reference voltage value, the voltage value of the battery cell in the charging state, the voltage value of the battery cell in the stable state, the change in the voltage value of the battery cell in the stable state, and the voltage value of the battery cell in the discharging state will all be abnormal. Therefore, by determining, for each first sub-time period, the first eigenvector and the second eigenvector corresponding to the first sub-time period, for each second sub-time period, the third eigenvector and the fourth eigenvector corresponding to the second sub-time period, and for each third sub-time period, the fifth eigenvector and the sixth eigenvector corresponding to the third sub-time period, the difference between the battery cell and the normal battery cell can be reflected, so as to subsequently determine the fault of the battery cell.

[0197] It should be noted that the fault determination device can execute S401, S402, and S403 in parallel, or the fault determination device can execute S401, S402, and S403 sequentially. When executing sequentially, this application does not make any specific restrictions on the execution order of S401, S402, and S403.

[0198] In one design, Figure 5 A flowchart of another fault determination method provided by the present application is shown as follows: Figure 5 As shown, S303 provided in the specific implementation manner of the present application may specifically include the following multiple steps:

[0199] S1. The fault determination device determines the maximum outlier in the current feature vector based on the 3σ criterion.

[0200] As a possible implementation method, the fault determination device calculates the mean and standard deviation of multiple elements in the current feature vector, takes the elements that exceed the upper and lower limits of 3 times the standard deviation as outliers, and takes the outlier with the largest absolute value of the difference between the upper and lower limits as the maximum outlier.

[0201] Exemplarily, taking the current feature vector including [A, B, C, D, E, F, G] as an example, the fault determination device determines that the maximum outlier is A.

[0202] S2. The fault determination device removes the largest outlier in the current feature vector to obtain an updated feature vector.

[0203] Exemplarily, taking the current feature vector including [A, B, C, D, E, F, G] as an example, if the maximum outlier is A, the fault determination device determines that the updated feature vector is [B, C, D, E, F, G].

[0204] S3. The fault determination device determines the error range corresponding to the current feature vector based on the 3σ criterion.

[0205] It should be noted that the error range includes an upper limit and a lower limit.

[0206] As a possible implementation, the fault determination device calculates the mean and standard deviation of multiple elements in the current feature vector, takes positive 3 times the standard deviation as the upper limit of the error range, and takes negative 3 times the standard deviation as the lower limit of the error range.

[0207] Exemplarily, taking the updated feature vector in S2 as [B, C, D, E, F, G], the fault determination device determines the error range of [B, C, D, E, F, G] based on the 3σ criterion.

[0208] S4. The fault determination device determines whether the maximum outlier point is outside the error range.

[0209] When the maximum outlier point is outside the error range, S5 is executed, and when the maximum outlier point is within the error range, S6 is executed.

[0210] Exemplarily, taking the current feature vector including [B, C, D, E, F, G] as an example, the fault determination device determines whether the maximum outlier point A is outside the error range of [B, C, D, E, F, G].

[0211] S5. When the maximum outlier point is greater than the upper limit of the error range, the fault determination device determines that the outlier state of the battery cell corresponding to the maximum outlier point is an upward outlier; when the maximum outlier point is less than the lower limit of the error range, the fault determination device determines that the outlier state of the battery cell corresponding to the maximum outlier point is a downward outlier.

[0212] Afterwards, the fault determination device executes S1;

[0213] Exemplarily, taking the example in S4 as an example, if A is greater than the upper limit of the error range of [B, C, D, E, F, G], the fault determination device determines that the outlier state of the battery cell corresponding to A is an upward outlier, and if A is less than the lower limit of the error range of [B, C, D, E, F, G], the fault determination device determines that the outlier state of the battery cell corresponding to A is an upward outlier. Thereafter, the fault determination device executes S1.

[0214] S6. The fault determination device determines that the outlier state of the battery cell corresponding to each element in the current feature vector in S1 is not an outlier.

[0215] Exemplarily, taking the example in S4 as an example, if A is within the error range of [B, C, D, E, F, G], the fault determination device determines that there is no outlier in [A, B, C, D, E, F, G].

[0216] Based on this scheme, compared with the existing outlier determination method based on the 3σ criterion, it is first assumed that a certain element is an outlier, and then the outlier is removed and then the element is tested again to see if it is an outlier. If the element is determined to be an outlier twice, it is confirmed that the element is indeed an outlier. By assuming first and then testing, the influence of extreme data of individual faulty battery cells on the determined error range can be reduced, thereby improving the accuracy of determining the outlier direction of the battery cell.

[0217] 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, in the case where the sub-time period includes the first sub-time period, the second sub-time period or the third sub-time period, S203 provided in the specific implementation of the present application may specifically include the following multiple steps:

[0218] S601. A fault determining apparatus uses the outlier state with the largest number among the outlier states of the battery cells corresponding to the first characteristic vector as the first outlier state of the battery cells corresponding to the first sub-time period.

[0219] As a possible implementation method, for each battery cell, the fault determination device counts the outlier state of the battery cell in each first characteristic vector. If the number of downward outliers among multiple outlier states is the largest, the first outlier state is determined to be a downward outlier. If the number of upward outliers among multiple outlier states is the largest, the first outlier state is determined to be an upward outlier. If the number of non-outliers among multiple outlier states is the largest, the first outlier state is determined to be a non-outlier.

[0220] S602: The fault determination apparatus uses the outlier state with the largest number among the outlier states of the battery cells corresponding to the second characteristic vector as the second outlier state of the battery cells corresponding to the first sub-time period.

[0221] As a possible implementation method, for each battery cell, the fault determination device counts the outlier state of the battery cell in each second characteristic vector. If the number of downward outliers among multiple outlier states is the largest, the second outlier state is determined to be a downward outlier. If the number of upward outliers among multiple outlier states is the largest, the second outlier state is determined to be an upward outlier. If the number of non-outliers among multiple outlier states is the largest, the second outlier state is determined to be a non-outlier.

[0222] S603: The fault determination apparatus uses the outlier state of the battery cell corresponding to the third eigenvector and the outlier state of the battery cell corresponding to the fourth eigenvector with the largest number as the third outlier state of the battery cell corresponding to the second sub-time period.

[0223] As a possible implementation method, for each battery cell, the fault determination device counts the outlier state of the battery cell in each third eigenvector and each fourth eigenvector; if the number of downward outliers among multiple outlier states is the largest, the third outlier state is determined to be a downward outlier; if the number of upward outliers among multiple outlier states is the largest, the third outlier state is determined to be an upward outlier; if the number of non-outliers among multiple outlier states is the largest, the third outlier state is determined to be a non-outlier.

[0224] S604: The fault determination apparatus uses the outlier state of the battery cell corresponding to the fifth eigenvector and the outlier state of the battery cell corresponding to the sixth eigenvector, whichever has the largest number, as the fourth outlier state of the battery cell corresponding to the third sub-time period.

[0225] As a possible implementation method, for each battery cell, the fault determination device counts the outlier state of the battery cell in each fifth eigenvector and each sixth eigenvector; if the number of downward outliers among multiple outlier states is the largest, the fourth outlier state is determined to be a downward outlier; if the number of upward outliers among multiple outlier states is the largest, the fourth outlier state is determined to be an upward outlier; if the number of non-outliers among multiple outlier states is the largest, the fourth outlier state is determined to be a non-outlier.

[0226] S605 . The fault determining device determines the fault of the battery cell according to the first outlier state, the second outlier state, the third outlier state, and the fourth outlier state of the battery cell.

[0227] As a possible implementation manner, the fault determination device determines that the battery cell has a micro-short circuit fault when the second outlying state of the battery cell is downward outlying, or when the first outlying state of the battery cell is not outlying, the third outlying state is downward outlying, and the fourth outlying state is downward outlying.

[0228] The fault determination device determines that the battery cell has a low capacity fault when the first outlier state of the battery cell is not outlier, the third outlier state is upward outlier, and the fourth outlier state is downward outlier.

[0229] Based on this possible implementation, when a cell has a micro-short circuit fault, the cell will self-discharge and the cell's electric energy will be continuously consumed. Therefore, when the cell's second out-of-group state is downward out-of-group, or when the cell's first out-of-group state is not out-of-group, and the third out-of-group state is downward out-of-group, and the fourth out-of-group state is downward out-of-group, it can be determined that the cell has a micro-short circuit fault. When a cell has a low-capacity fault, the cell's capacity is low and the charging and discharging speed is fast. Therefore, when the cell's first out-of-group state is not out-of-group, and the third out-of-group state is upward out-of-group, and the fourth out-of-group state is downward out-of-group, it can be determined that the cell has a low-capacity fault.

[0230] It should be noted that the fault determination device can execute S601, S602, S603, and S604 in parallel, or the fault determination device can execute S601, S602, S603, and S604 sequentially. When executing sequentially, this application does not make any specific restrictions on the execution order of S601, S602, S603, and S604.

[0231] Based on this scheme, since the first outlier state, the second outlier state, the third outlier state and the fourth outlier state are the outlier states with the largest number among the corresponding multiple outlier states, by taking the outlier state with the largest number among the outlier states of the battery cell corresponding to each characteristic vector of each sub-time period as the final outlier state corresponding to the battery cell and the sub-time period for determining the fault, the fault of the battery cell can be subsequently determined based on the first outlier state, the second outlier state, the third outlier state and the fourth outlier state.

[0232] 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.

[0233] 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.

[0234] In the case of functional module division, Figure 7 FIG. 1 shows a schematic diagram of the structure of a fault determination device. Figure 7 As shown, the fault determination device 70 includes an acquisition module 701 and a processing module 702 .

[0235] In some embodiments, the fault determination device 70 may further include a storage module ( Figure 7 ), for storing program instructions and data.

[0236] Among them, the acquisition module 701 is used to obtain a reference voltage value set of the battery cells in the target battery and a voltage value set of each battery cell in the multiple battery cells of the target battery; the reference voltage value set includes reference voltage values ​​at multiple sampling moments in the sampling time period, and the voltage value set includes voltage values ​​at multiple sampling moments; the processing module 702 is used to determine the outlier state of each battery cell in each sub-time period of multiple sub-time periods of the sampling time period according to the voltage value set and the reference voltage value set of the multiple battery cells; the outlier state includes not outlier, upward outlier or downward outlier; the processing module 702 is also used to determine the fault of the battery cell based on the outlier state of the battery cell in multiple sub-time periods; the fault includes low capacity fault or micro short circuit fault.

[0237] Optionally, the acquisition module 701 is used to acquire a reference voltage value set of battery cells in the target battery, including: for each sampling moment among multiple sampling moments, determining a median value of voltage values ​​of multiple battery cells at the sampling moment as the reference voltage value.

[0238] Optionally, the sub-time period includes a first sub-time period, a second sub-time period or a third sub-time period, and the processing module 702 is used to determine the outlier state of each battery cell in each sub-time period of the multiple sub-time periods of the sampling time period according to the voltage value set of the multiple battery cells and the reference voltage value set, including: determining the first sub-time period, the second sub-time period and the third sub-time period in the sampling time period according to the reference voltage value set; the time length between any two adjacent sampling moments in the first sub-time period is greater than the first threshold, and the absolute value of the difference between the reference voltage values ​​of any two adjacent sampling moments is less than the second threshold, or the absolute value of the difference between the reference voltage value of any sampling moment in the first sub-time period and the reference voltage value of the start moment of the first sub-time period is less than the third threshold, and the time length between any two adjacent sampling moments is greater than the first threshold. The absolute value of the difference in the reference voltage values ​​is less than the second threshold value, and the number of sampling moments in the first sub-time period is greater than the fourth threshold value, the second sub-time period is the time period other than the first sub-time period in the sampling time period, and the reference voltage value of any sampling moment in the second sub-time period is greater than the reference voltage value of the previous sampling moment, the third sub-time period is the time period other than the first sub-time period in the sampling time period, and the reference voltage value of any sampling moment in the third sub-time period is less than the reference voltage value of the previous sampling moment; for each sub-time period, determine a characteristic vector corresponding to the sub-time period; the characteristic vector includes multiple elements, one element is determined based on multiple reference voltage values ​​in the sub-time period and the voltage value of a battery cell in the sub-time period; based on the characteristic vector, determine the outlier state of each battery cell in the sub-time period.

[0239] Optionally, the processing module 702 is also used to determine the characteristic vector corresponding to the sub-time period, including: for each first sub-time period, determining the first characteristic vector and the second characteristic vector corresponding to the first sub-time period; the first characteristic vector includes multiple first elements, the first element is the difference between the first value and the second value, one first value is the average value of multiple voltage values ​​of a battery cell in the first sub-time period, the second value is the average value of multiple reference voltage values ​​of the first sub-time period, the second characteristic vector includes multiple second elements, the second element is the difference between the third value and the fourth value, one third value is the average value of multiple voltage change values ​​of a battery cell in the first sub-time period, the voltage change value is the difference between the voltage value at a sampling moment and the voltage value at a previous sampling moment, the fourth value is the average value of multiple reference voltage change values ​​of the first sub-time period, and the reference voltage change value is the difference between the reference voltage value at a sampling moment and the reference voltage value at a previous sampling moment; for each second sub-time period, determining the first characteristic vector and the second characteristic vector corresponding to the first sub-time period; The third eigenvector and the fourth eigenvector corresponding to the second sub-time period; the third eigenvector includes multiple third elements, the third element is the difference between the fifth value and the sixth value, a fifth value is the maximum value of multiple voltage values ​​of a battery cell in the second sub-time period, and the sixth value is the average value of multiple reference voltage values ​​of the second sub-time period; the fourth eigenvector includes multiple fourth elements, the fourth element is the difference between the seventh value and the sixth value, and a seventh value is the minimum value of multiple voltage values ​​of a battery cell in the second sub-time period; for each third sub-time period, the fifth eigenvector and the sixth eigenvector corresponding to the third sub-time period are determined; the fifth eigenvector includes multiple fifth elements, the fifth element is the difference between the eighth value and the sixth value, and an eighth value is the maximum value of multiple voltage values ​​of a battery cell in the third sub-time period; the sixth eigenvector includes multiple sixth elements, the sixth element is the difference between the ninth value and the sixth value, and a ninth value is the minimum value of multiple voltage values ​​of a battery cell in the third sub-time period.

[0240] Optionally, the processing module 702 is also used to determine the outlier state of each battery cell in the sub-time period based on the feature vector, including: S1, determining the maximum outlier in the current feature vector based on the 3σ criterion; S2, eliminating the maximum outlier in the current feature vector to obtain an updated feature vector; S3, determining the error range corresponding to the current feature vector based on the 3σ criterion; S4, judging whether the maximum outlier is outside the error range; when the maximum outlier is outside the error range, executing S5, and when the maximum outlier is within the error range, executing S6; S5, when the maximum outlier is greater than the upper limit of the error range, determining that the outlier state of the battery cell corresponding to the maximum outlier is an upward outlier, and when the maximum outlier is less than the lower limit of the error range, determining that the outlier state of the battery cell corresponding to the maximum outlier is a downward outlier; executing S1; S6, determining that the outlier state of the battery cell corresponding to each element in the current feature vector in S1 is not an outlier.

[0241] Optionally, the processing module 702 is also used to determine the fault of the battery cell based on the outlier states of the battery cell in multiple sub-time periods, including: taking the outlier state with the largest number among the outlier states of the battery cell corresponding to the first eigenvector as the first outlier state of the battery cell corresponding to the first sub-time period; taking the outlier state with the largest number among the outlier states of the battery cell corresponding to the second eigenvector as the second outlier state of the battery cell corresponding to the first sub-time period; taking the outlier state of the battery cell corresponding to the third eigenvector and the outlier state of the battery cell corresponding to the fourth eigenvector as the third outlier state of the battery cell corresponding to the second sub-time period; taking the outlier state of the battery cell corresponding to the fifth eigenvector and the outlier state of the battery cell corresponding to the sixth eigenvector as the fourth outlier state of the battery cell corresponding to the third sub-time period; and determining the fault of the battery cell according to the first outlier state, the second outlier state, the third outlier state, and the fourth outlier state of the battery cell.

[0242] Optionally, the processing module 702 is also used to determine the fault of the battery cell according to the first outlier state, the second outlier state, the third outlier state, and the fourth outlier state of the battery cell, including: when the second outlier state of the battery cell is downward outlier, or when the first outlier state of the battery cell is not outlier, and the third outlier state is downward outlier, and the fourth outlier state is downward outlier, determining that the battery cell has a micro-short circuit fault; when the first outlier state of the battery cell is not outlier, and the third outlier state is upward outlier, and the fourth outlier state is downward outlier, determining that the battery cell has a low capacity fault.

[0243] 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.

[0244] When the functions of the above functional modules are implemented in the form of hardware, Figure 8 FIG. 2 shows a schematic diagram of the structure of another fault determination device. Figure 8 As shown, the fault determination device 80 includes a processor 801, a memory 802 and a bus 803. The processor 801 and the memory 802 may be connected via the bus 803.

[0245] The processor 801 is the control center of the fault determination device 80, and can be a processor or a general term for multiple processing elements. For example, the processor 801 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.

[0246] As an embodiment, the processor 801 may include one or more CPUs, such as Figure 8 CPU 0 and CPU 1 are shown in .

[0247] The memory 802 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.

[0248] As a possible implementation, the memory 802 may exist independently of the processor 801, and the memory 802 may be connected to the processor 801 via a bus 803, and is used to store instructions or program codes. When the processor 801 calls and executes the instructions or program codes stored in the memory 802, the fault determination method provided in the embodiment of the present application can be implemented.

[0249] In another possible implementation, the memory 802 may also be integrated with the processor 801 .

[0250] The bus 803 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, Figure 8 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.

[0251] It should be pointed out that Figure 8 The structure shown does not constitute a limitation on the fault determination device 80. Figure 8 In addition to the components shown, the fault determination device 80 may include more or fewer components than shown, or combine certain components, or arrange the components differently.

[0252] As an example, combining Figure 7 The functions implemented by the acquisition module 701 and the processing module 702 in the fault determination device 70 are similar to those Figure 8 The function of processor 801 in is the same.

[0253] Optional, such as Figure 8 As shown, the fault determination device 80 provided in the embodiment of the present application may further include a communication interface 804 .

[0254] The communication interface 804 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 804 may include a receiving unit for receiving data and a sending unit for sending data.

[0255] In a possible implementation, in the fault determination device 80 provided in the embodiment of the present application, the communication interface 804 may also be integrated in the processor 801, and the embodiment of the present application does not specifically limit this.

[0256] 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.

[0257] 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.

[0258] 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.

[0259] 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.

[0260] 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.

[0261] 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.

[0262] 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.

[0263] 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.

[0264] 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 reference voltage value set of a cell in a target battery and a voltage value set of each cell in a plurality of cells of the target battery; the reference voltage value set includes reference voltage values ​​at a plurality of sampling moments in a sampling time period, and the voltage value set includes voltage values ​​at the plurality of sampling moments; Determine, according to the voltage value sets of the plurality of battery cells and the reference voltage value set, an outlier state of each battery cell in each sub-time period of the plurality of sub-time periods of the sampling time period; the outlier state includes not outlier, upward outlier or downward outlier; Based on the outlier state of the battery cell in the multiple sub-time periods, a fault of the battery cell is determined; the fault includes a low capacity fault or a micro short circuit fault.

2. The method according to claim 1, characterized in that: The step of obtaining a reference voltage value set of cells in a target battery includes: For each sampling moment among the plurality of sampling moments, a median value of the voltage values ​​of the plurality of battery cells at the sampling moment is determined as the reference voltage value.

3. The method according to claim 1 or 2, characterized in that: The sub-time period includes a first sub-time period, a second sub-time period or a third sub-time period, and determining, according to the voltage value sets of the plurality of battery cells and the reference voltage value set, the outlier state of each battery cell in each sub-time period of the plurality of sub-time periods of the sampling time period, includes: The first sub-time period, the second sub-time period and the third sub-time period in the sampling time period are determined according to the reference voltage value set; the duration between any two adjacent sampling moments in the first sub-time period is greater than the first threshold, and the absolute value of the difference between the reference voltage values ​​at any two adjacent sampling moments is less than the second threshold, or the absolute value of the difference between the reference voltage value at any sampling moment in the first sub-time period and the reference voltage value at the start moment of the first sub-time period is less than the third threshold, and the absolute value of the difference between the reference voltage values ​​at any two adjacent sampling moments is less than the second threshold, and the number of sampling moments in the first sub-time period is greater than a fourth threshold, the second sub-time period is a time period other than the first sub-time period in the sampling time period, and the reference voltage value at any sampling moment in the second sub-time period is greater than the reference voltage value at a previous sampling moment, and the third sub-time period is a time period other than the first sub-time period in the sampling time period, and the reference voltage value at any sampling moment in the third sub-time period is less than the reference voltage value at a previous sampling moment; For each sub-time period, determining a feature vector corresponding to the sub-time period; the feature vector includes a plurality of elements, one element being determined based on a plurality of reference voltage values ​​within the sub-time period and a voltage value of a battery cell within the sub-time period; Based on the feature vector, an outlier state of each battery cell in the sub-time period is determined.

4. The method according to claim 3, characterized in that Determining the feature vector corresponding to the sub-time period includes: For each first sub-time period, determine a first eigenvector and a second eigenvector corresponding to the first sub-time period; the first eigenvector includes a plurality of first elements, the first element is a difference between a first value and a second value, a first value is an average value of a plurality of voltage values ​​of a battery cell in the first sub-time period, and the second value is an average value of a plurality of reference voltage values ​​of the first sub-time period; the second eigenvector includes a plurality of second elements, the second element is a difference between a third value and a fourth value, a third value is an average value of a plurality of voltage change values ​​of a battery cell in the first sub-time period, the voltage change value is a difference between a voltage value at a sampling moment and a voltage value at a previous sampling moment, the fourth value is an average value of a plurality of reference voltage change values ​​of the first sub-time period, and the reference voltage change value is a difference between a reference voltage value at a sampling moment and a reference voltage value at a previous sampling moment; For each second sub-time period, determine a third eigenvector and a fourth eigenvector corresponding to the second sub-time period; the third eigenvector includes a plurality of third elements, the third element is a difference between a fifth value and a sixth value, a fifth value is a maximum value among a plurality of voltage values ​​of a battery cell in the second sub-time period, the sixth value is an average value of a plurality of reference voltage values ​​of the second sub-time period, and the fourth eigenvector includes a plurality of fourth elements, the fourth element is a difference between a seventh value and the sixth value, and a seventh value is a minimum value among a plurality of voltage values ​​of a battery cell in the second sub-time period; For each third sub-time period, determine the fifth eigenvector and the sixth eigenvector corresponding to the third sub-time period; the fifth eigenvector includes multiple fifth elements, the fifth element is the difference between the eighth value and the sixth value, and an eighth value is the maximum value among multiple voltage values ​​of a battery cell in the third sub-time period; the sixth eigenvector includes multiple sixth elements, the sixth element is the difference between the ninth value and the sixth value, and a ninth value is the minimum value among multiple voltage values ​​of a battery cell in the third sub-time period.

5. The method according to claim 3, characterized in that: The determining, based on the feature vector, the outlier state of each battery cell in the sub-time period includes: S1, determine the maximum outlier in the current feature vector based on the 3σ criterion; S2, remove the largest outlier in the current feature vector to obtain an updated feature vector; S3, determine the error range corresponding to the current eigenvector based on the 3σ criterion; S4, determining whether the maximum outlier is outside the error range; if the maximum outlier is outside the error range, executing S5, and if the maximum outlier is within the error range, executing S6; S5. When the maximum outlier point is greater than the upper limit of the error range, determine that the outlier state of the battery cell corresponding to the maximum outlier point is an upward outlier; when the maximum outlier point is less than the lower limit of the error range, determine that the outlier state of the battery cell corresponding to the maximum outlier point is a downward outlier; Execute S1; S6. Determine that the outlier state of the cell corresponding to each element in the current feature vector in S1 is not an outlier.

6. The method according to claim 4, characterized in that The determining the fault of the battery cell based on the outlier state of the battery cell in the multiple sub-time periods includes: The outlier state with the largest number among the outlier states of the battery cell corresponding to the first eigenvector is used as the first outlier state of the battery cell corresponding to the first sub-time period; The outlier state with the largest number among the outlier states of the battery cell corresponding to the second eigenvector is used as the second outlier state of the battery cell corresponding to the first sub-time period; The outlier state of the battery cell corresponding to the third eigenvector and the outlier state of the battery cell corresponding to the fourth eigenvector having the largest number are used as the third outlier state of the battery cell corresponding to the second sub-time period; The outlier state of the battery cell corresponding to the fifth eigenvector and the outlier state of the battery cell corresponding to the sixth eigenvector having the largest number are used as the fourth outlier state of the battery cell corresponding to the third sub-time period; A fault of the battery cell is determined according to the first out-of-group state, the second out-of-group state, the third out-of-group state, and the fourth out-of-group state of the battery cell.

7. The method according to claim 6, characterized in that The determining the fault of the battery cell according to the first out-of-group state, the second out-of-group state, the third out-of-group state, and the fourth out-of-group state of the battery cell comprises: When the second outlier state of the battery cell is downward outlier, or when the first outlier state of the battery cell is not outlier, and the third outlier state is downward outlier, and the fourth outlier state is downward outlier, it is determined that the battery cell has a micro short circuit fault; When the first outlier state of the battery cell is not outlier, the third outlier state is upward outlier, and the fourth outlier state is downward outlier, it is determined that the battery cell has a low capacity fault.

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 reference voltage value set of a battery cell in a target battery and a voltage value set of each battery cell in a plurality of battery cells of the target battery; the reference voltage value set includes reference voltage values ​​at a plurality of sampling moments in a sampling time period, and the voltage value set includes voltage values ​​at the plurality of sampling moments; The processing module is used to determine the outlier state of each battery cell in each sub-time period of multiple sub-time periods of the sampling time period according to the voltage value sets of the multiple battery cells and the reference voltage value set; the outlier state includes not outlier, upward outlier or downward outlier; The processing module is further used to determine the fault of the battery cell based on the outlier state of the battery cell in the multiple sub-time periods; the fault includes a low capacity fault or a micro short circuit fault.

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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