Abnormal battery cell identification method, vehicle and storage medium

Abstract

The invention relates to the technical field of battery packs, and provides an abnormal battery cell identification method, a vehicle and a storage medium. The method comprises the following steps: screening second voltage data of each battery cell from first voltage data of each battery cell in a battery cell group at multiple moments; based on the second voltage data of each battery cell and the internal resistance of the battery cell group, determining the first internal resistance of each battery cell; carrying out replacement processing on an abnormal value in the first internal resistance of each battery cell to obtain a second internal resistance of each battery cell; based on the second internal resistance of each battery cell, determining a first outlier degree and a second outlier degree of each battery cell; and on the basis of the first outlier degree and the second outlier degree, identifying an abnormal battery cell from the plurality of battery cells of the battery cell group. According to the method, the abnormal battery cell can be accurately identified.

Description

Technical Field

[0001] The present application relates to the field of battery pack technology, and in particular to a method for identifying abnormal battery cells, a vehicle, and a storage medium. Background Art

[0002] Currently, to ensure the driving stability of new energy vehicles, it is often necessary to detect abnormalities in the vehicle's battery cells. Related technologies calculate the internal resistance of the battery cells at each moment using the voltage and current at that moment. However, if there is a certain time difference between the voltage and current of the battery cells, the calculated internal resistance will be inaccurate, making it impossible to accurately identify abnormal cells. Summary of the Invention

[0003] The present application provides a method for identifying abnormal battery cells, a vehicle, and a storage medium to solve the technical problem of being unable to accurately identify abnormal battery cells.

[0004] A first aspect of an embodiment of the present application provides a method for identifying abnormal battery cells, the method comprising: screening second voltage data of each battery cell in a battery cell group at multiple moments from the first voltage data of the battery cell; determining the first internal resistance of each battery cell based on the second voltage data of each battery cell and the internal resistance of the battery cell group; replacing the abnormal values ​​in the first internal resistance of each battery cell to obtain the second internal resistance of each battery cell; determining the first outlier degree and the second outlier degree of each battery cell based on the second internal resistance of each battery cell; and identifying abnormal batteries from multiple batteries in the battery cell group based on the first outlier degree and the second outlier degree.

[0005] According to an embodiment of the present application, screening the second voltage data of each battery cell in the battery cell group from the first voltage data of each battery cell at multiple moments includes: calculating the first voltage change of each battery cell between adjacent moments based on the first voltage data of each battery cell at the multiple moments; determining the first change characteristic quantity of the battery cell group based on the first voltage change of each battery cell; and selecting the second voltage data of each battery cell from the first voltage data of each battery cell based on the absolute value of the first change characteristic quantity, the time difference between the adjacent moments, and the temperature of the battery in which the battery cell group is located.

[0006] According to an embodiment of the present application, determining the first internal resistance of each battery cell based on the second voltage data of each battery cell and the internal resistance of the battery cell group includes: calculating the second voltage change of each battery cell between adjacent moments based on the second voltage data of each battery cell; determining the second change characteristic quantity of the battery cell group based on the second voltage change of each battery cell; determining the voltage difference index of each battery cell based on the second voltage change of each battery cell and the second change characteristic quantity of the battery cell group; and calculating the first internal resistance of each battery cell based on the voltage difference index of each battery cell and the internal resistance of the battery cell group.

[0007] According to an embodiment of the present application, the replacing of the abnormal value in the first internal resistance of each battery cell to obtain the second internal resistance of each battery cell includes: dividing the first internal resistance of each battery cell according to time sequence to obtain multiple first windows; determining the low quantile internal resistance, the median internal resistance and the high quantile internal resistance of each first window; calculating the first difference between the multiple first internal resistances in each first window and the median internal resistance, the second difference between the high quantile internal resistance and the median internal resistance, and the third difference between the low quantile internal resistance and the median internal resistance; determining the first internal resistance corresponding to the first difference greater than a first threshold, or the first internal resistance corresponding to the first difference less than a second threshold as the abnormal value, the first threshold being determined based on the second difference, and the second threshold being determined based on the third difference; replacing the abnormal value with the median internal resistance, and determining the first internal resistance after replacement as the second internal resistance of each battery cell.

[0008] According to an embodiment of the present application, the process of determining the first outlier degree of each battery cell includes: dividing the second internal resistance of each battery cell according to time sequence to obtain multiple second windows; determining the first internal resistance characteristic value of each battery cell in the multiple second windows based on the second internal resistance of each battery cell; calculating the second internal resistance characteristic value of the battery cell group in the multiple second windows based on the first internal resistance characteristic value; and determining the first outlier degree of each battery cell in the multiple second windows based on the first internal resistance characteristic value and the second internal resistance characteristic value.

[0009] According to an embodiment of the present application, determining the first outlier degree of each battery cell in the multiple second windows based on the first internal resistance characteristic value and the second internal resistance characteristic value includes: selecting the largest first internal resistance characteristic value in each second window from the first internal resistance characteristic value; and determining the change value between the largest first internal resistance characteristic value and the second internal resistance characteristic value in each second window as the first outlier degree of each battery cell in each second window.

[0010] According to an embodiment of the present application, the process of determining the second outlier degree of each battery cell includes: determining the third internal resistance characteristic value of the battery cell group in the multiple second windows based on the change value of the first internal resistance characteristic value and the second internal resistance characteristic value; determining the second outlier degree of each battery cell in the multiple second windows based on the first outlier degree of each battery cell in the multiple second windows and the third internal resistance characteristic value of the battery cell group in the multiple second windows.

[0011] According to an embodiment of the present application, identifying abnormal battery cells from multiple battery cells in the battery cell group based on the first outlier degree and the second outlier degree includes: determining the battery cell corresponding to the first outlier degree that meets the first preset requirement and the second discrete degree that meets the second preset requirement as the abnormal battery cell.

[0012] According to a second aspect of an embodiment of the present application, there is provided an abnormal battery cell identification device, the device comprising: a screening unit for screening the second voltage data of each battery cell in the battery cell group from the first voltage data of each battery cell at multiple moments; a determination unit for determining the first internal resistance of each battery cell based on the second voltage data of each battery cell and the internal resistance of the battery cell group; a replacement unit for replacing the abnormal value in the first internal resistance of each battery cell to obtain the second internal resistance of each battery cell; the determination unit is further used to determine the first outlier degree and the second outlier degree of each battery cell based on the second internal resistance of each battery cell; and an identification unit for identifying abnormal batteries from multiple batteries in the battery cell group based on the first outlier degree and the second outlier degree.

[0013] A third aspect of an embodiment of the present application provides a vehicle, comprising: a memory storing a computer program; and a processor executing the computer program stored in the memory to implement the abnormal battery cell identification method.

[0014] A fourth aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-readable instructions, and when the computer-readable instructions are executed by a processor, the abnormal battery cell identification method is implemented.

[0015] In various embodiments of the present application, by screening the second voltage data of each cell in a cell group from the first voltage data of each cell at multiple times, the quality of the second voltage data can be ensured, thereby improving the accuracy of identifying abnormal cells. The first internal resistance of each cell is determined based on the second voltage data of each cell and the internal resistance of the cell group, and the outliers in the first internal resistance are updated, thereby improving the quality of the second internal resistance. Furthermore, the first outlier degree and second outlier degree of each cell can be accurately determined based on the second internal resistance of each cell. By combining the first outlier degree and the second outlier degree, abnormal cells can be accurately identified from the multiple cells in the cell group. Furthermore, since the current data of the cell is not required for analysis, the problem caused by the asynchrony between the voltage and current of the cell can be effectively avoided, further improving the accuracy of identifying abnormal cells. By identifying abnormal cells from the multiple cells in the cell group, embodiments of the present application can promptly detect battery packs with outliers in the internal resistance of the cell, helping after-sales personnel to respond in advance and thus avoiding power outages and other faults during vehicle operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is an application scenario diagram of the abnormal battery cell identification method provided in an embodiment of the present application.

[0017] Figure 2 This is a flow chart of the abnormal battery cell identification method provided in an embodiment of the present application.

[0018] Figure 3 Schematic diagram of the equivalent circuit of the battery pack provided in an embodiment of the present application.

[0019] Figure 4 This is a functional module diagram of the abnormal battery cell identification device provided in an embodiment of the present application.

[0020] Figure 5 It is a structural schematic diagram of a vehicle for implementing the abnormal battery cell identification method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of this application clearer, this application is described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] It should be noted that, in this application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A alone, A and B together, and B alone, where A and B can be singular or plural. The terms "first," "second," "third," "fourth," and so on (if any) in the specification, claims, and drawings of this application are used to distinguish similar objects, not to describe a specific order or precedence.

[0023] 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. The following embodiments and features in the embodiments may be combined with each other unless there is a conflict.

[0024] Currently, to ensure the driving stability of new energy vehicles, it is often necessary to detect abnormalities in the vehicle's battery cells. The battery packs in new energy vehicles typically consist of dozens or even hundreds of cells. The probability of an abnormal internal resistance in a single cell is extremely low. Assuming the probability of an abnormal internal resistance in a single cell is one in ten thousand, the probability of two cells in the same battery pack experiencing abnormal internal resistance simultaneously is approximately one in a hundred million. Therefore, it is extremely rare for multiple cells in a battery pack to experience abnormal internal resistance simultaneously. Based on this characteristic, it is possible to detect abnormalities in the vehicle's battery cells by determining whether the internal resistance of a cell significantly deviates from the internal resistance of the rest of the cell group.

[0025] In related technologies, the internal resistance of a cell at each moment is calculated by collecting the voltage and current of the cell at that moment. However, due to the large number of cells in a battery pack, the cell voltage data is usually sent in multiple different messages. This results in a certain time difference between the voltage and current of the cell collected by the cloud, resulting in inaccurate calculated cell internal resistance and making it impossible to accurately identify abnormal cells.

[0026] To address the above issues, embodiments of the present application provide a method for identifying abnormal cells. By screening the second voltage data of each cell in a cell group from the first voltage data of each cell at multiple times, the quality of the second voltage data can be ensured, thereby improving the accuracy of identifying abnormal cells. The first internal resistance of each cell is determined based on the second voltage data of each cell and the internal resistance of the cell group. The outlier value in the first internal resistance is updated, thereby improving the quality of the second internal resistance. Furthermore, the first and second outliers of each cell can be accurately determined based on the second internal resistance of each cell. By combining the first and second outliers, abnormal cells can be accurately identified from multiple cells in the cell group. Furthermore, since the current data of the cell is not required for analysis, the problem of asynchrony between the voltage and current of the cell can be effectively avoided, further improving the accuracy of identifying abnormal cells. By identifying abnormal cells from multiple cells in the cell group, embodiments of the present application can promptly detect battery packs with outliers in the internal resistance of the cell, helping after-sales personnel to respond in advance and thus avoiding power outages and other faults during vehicle operation.

[0027] like Figure 1 , which is an application scenario diagram of the abnormal battery cell identification method provided in an embodiment of the present application.

[0028] In an embodiment of the present application, the abnormal battery cell identification method can be applied to the vehicle 100. Information exchange can be carried out between the vehicle 100 and the server 200 through a communication network, wherein the communication mode adopted by the communication network may include: wireless communication mode and wired communication mode. Exemplarily, the server 200 can access the network through cellular mobile communication technology to communicate with the vehicle 100, wherein the cellular mobile communication technology may include the fifth generation (5G) mobile communication technology or the next generation mobile communication technology. Optionally, the server 200 can also access the network through a short-range wireless communication mode to communicate with the vehicle 100, wherein the short-range wireless communication mode includes wireless fidelity (Wi-Fi) technology.

[0029] In an embodiment of the present application, the vehicle 100 may include a battery pack 11 and a battery management system (BMS) 12. The battery pack 11 includes at least one battery cell group, each of which includes multiple battery cells. The battery management system 12 can collect voltage data of each battery cell in the battery pack 11 in real time. The battery management system 12 can send the collected voltage data of each battery cell to the server 200 in the form of a message.

[0030] It should be noted that the battery pack 11 can directly or indirectly provide power to the vehicle 100 and is a general term for rechargeable chemical energy storage devices such as lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, lithium batteries, and supercapacitors. Specifically, the battery pack 11 may include a single electrochemical cell, multiple electrochemical cells, or a battery pack, depending on the actual application and is not specifically limited in this application.

[0031] Server 200 can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers. It can also be a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, i.e., Content Delivery Network (CDN), as well as big data and artificial intelligence platforms, but is not limited to these.

[0032] The abnormal battery cell identification method provided by the exemplary embodiment of the present application is described below in combination with the above-mentioned system architecture and with reference to the accompanying drawings. It should be noted that the above-mentioned system architecture is only shown to facilitate understanding of the spirit and principles of the present application, and the implementation of the present application is not limited in this respect.

[0033] like Figure 2 FIG. 1 is a flow chart of an abnormal cell identification method provided by an embodiment of the present application. The abnormal cell identification method is applied in a vehicle, for example, Figure 1 The vehicle 100. According to different requirements, the order of the steps in the flowchart can be changed, and some steps can be omitted.

[0034] S201 , filtering second voltage data of each battery cell in a battery cell group from first voltage data of each battery cell at multiple moments.

[0035] In at least one embodiment of the present application, in order to improve the efficiency of data interaction between the vehicle and the server, the multiple cells in the battery pack in the vehicle can be grouped in advance to obtain multiple cell groups. After collecting the first voltage data of the cells in each cell group at any time, the vehicle encapsulates the first voltage data of each cell group at any time into a corresponding message. In one example, the vehicle can send multiple messages to the server. The vehicle can obtain the first voltage data of the cells at multiple times from the server. Each message includes the first voltage data of the cell group at any time. The embodiment of the present application can ensure the time synchronization of the data by encapsulating the first voltage data at the same time into corresponding messages, thereby avoiding the problem of being unable to accurately identify abnormal cells due to analysis of voltage data at different times.

[0036] In at least one embodiment of the present application, in a low-temperature environment, after a preset time from vehicle startup, the vehicle's thermal management system heats the vehicle's battery pack, causing the battery pack's temperature to exceed a temperature threshold. When the battery pack's temperature exceeds the temperature threshold, the vehicle collects first voltage data for the battery cells in the battery pack at any given moment. The temperature threshold can be set and adjusted based on actual needs; for example, the temperature threshold can be set to 0°C.

[0037] In at least one embodiment of the present application, the vehicle screens the second voltage data of each battery cell in the battery cell group from the first voltage data of each battery cell at multiple moments, including: calculating the first voltage change of each battery cell between adjacent moments based on the first voltage data of each battery cell at multiple moments; determining the first change characteristic quantity of the battery cell group based on the first voltage change quantity of each battery cell; selecting the second voltage data of each battery cell from the first voltage data of each battery cell based on the absolute value of the first change characteristic quantity, the time difference between adjacent moments, and the temperature of the battery in the battery cell group.

[0038] In some embodiments, the vehicle calculates the first voltage change of each battery cell between adjacent moments based on the first voltage data of each battery cell at multiple moments. The calculation formula for the first voltage change of each battery cell between adjacent moments can be expressed as: ,in, Can indicate the In the battery pack The battery cell in The moment and The first voltage change between moments, Can indicate the In the battery pack The battery cell in The first voltage data at a moment, Can indicate the In the battery pack The battery cell in The first voltage data at a moment. For the In the battery pack The battery cell in The first voltage change at each moment is described.

[0039] In some embodiments, when determining the first variation characteristic of the battery cell group, the vehicle sorts the first voltage variation of all the cells in the battery cell group at each moment in descending order, or in descending order, to obtain a first sequence corresponding to each moment. The vehicle determines the median of each first sequence as the first variation characteristic of the battery cell group at each moment. For the The battery pack is in the The first change feature quantity at each moment is described.

[0040] In some embodiments, in the process of selecting the second voltage data of each battery cell, if the absolute value of the first change characteristic quantity of the battery cell group at any moment is less than the voltage change threshold, the vehicle deletes the first voltage data of all battery cells in the battery cell group at any moment from the first voltage data of each battery cell in the battery cell group at multiple moments, and obtains the second voltage data of each battery cell in the battery cell group. The voltage change threshold can be set and adjusted according to actual needs. For example, the voltage change threshold can be set to 10mV. In this embodiment, when the absolute value of the first change characteristic quantity of the battery cell group is less than the voltage change threshold, the error of the voltage difference index of the battery cell will be too large. Therefore, by deleting the corresponding first voltage data, the generation of a voltage difference index with a large error can be avoided.

[0041] In the process of selecting the second voltage data of each battery cell, if the time difference between any adjacent moments is greater than the time difference threshold, the vehicle determines the moment with the larger value among any adjacent moments as the target moment, and deletes the first voltage data corresponding to all batteries in the battery cell group at the target moment from the first voltage data of each battery cell in the battery cell group at multiple moments, and obtains the second voltage data of each battery cell in the battery cell group. The time difference threshold can be set and adjusted according to actual needs. For example, the time difference threshold can be set to 120 seconds. In this embodiment, when the time difference between any adjacent moments is greater than the time difference threshold, the change in the first voltage of the battery cell may also be affected by the remaining power of the battery cell. Therefore, by deleting the corresponding first voltage data, the influence of the remaining power of the battery cell can be avoided.

[0042] During the process of selecting the second voltage data for each battery cell, if the temperature of the battery in the battery cell group at any moment is less than a temperature threshold, the vehicle deletes the first voltage data of all the batteries in the battery cell group at any moment from the first voltage data of each battery cell in the battery cell group at multiple moments, and obtains the second voltage data for each battery cell in the battery cell group. The temperature threshold can be set and adjusted according to actual needs. For example, the temperature threshold can be set to 0°C. In this embodiment, when the temperature of the battery in the battery cell group at any moment is less than the temperature threshold, the internal resistance of the battery cell will increase significantly, resulting in a misjudgment of abnormal internal resistance of the battery cell.

[0043] The embodiments of the present application can quickly calculate the first voltage change of each battery cell between adjacent moments by using the first voltage data of each battery cell at multiple moments. By sorting the first voltage change of all batteries in the battery cell group at each moment, an appropriate first voltage change can be selected as the first change characteristic quantity of the battery cell group. Based on the absolute value of the first change characteristic quantity, the corresponding first voltage data can be reasonably deleted, thereby improving the quality of the second voltage data. Furthermore, by deleting the corresponding first voltage data based on multiple factors, such as the time difference between adjacent moments and the temperature of the battery in which the battery cell group is located, the quality of the second voltage data can be further improved.

[0044] S202 : Determine a first internal resistance of each battery cell based on the second voltage data of each battery cell and the internal resistance of the battery cell group.

[0045] In at least one embodiment of the present application, a vehicle can determine the internal resistance of a battery pack based on the temperature and aging of the battery pack. The vehicle can determine the corresponding resistance value from a data table based on the temperature and aging of the battery pack as the internal resistance of the battery pack.

[0046] In at least one embodiment of the present application, the vehicle determines the first internal resistance of each battery cell based on the second voltage data of each battery cell and the internal resistance of the battery cell group, including: calculating the second voltage change of each battery cell between adjacent moments based on the second voltage data of each battery cell; determining the second change characteristic quantity of the battery cell group based on the second voltage change of each battery cell; determining the voltage difference index of each battery cell based on the second voltage change of each battery cell and the second change characteristic quantity of the battery cell group; and calculating the first internal resistance of each battery cell according to the voltage difference index of each battery cell and the internal resistance of the battery cell group.

[0047] In some embodiments, the calculation method for the second voltage change of each battery cell between adjacent moments is similar to the calculation method for the first voltage change of each battery cell between adjacent moments, and this application will not further describe this. The method for determining the second characteristic value of the change of the battery cell group is similar to the method for determining the first characteristic value of the change of the battery cell group, and this application will not further describe this.

[0048] In some embodiments, the formula for determining the voltage difference index of each battery cell can be expressed as: ,in, Can indicate the In the battery pack The battery cell in Voltage difference index at each moment, Can indicate the In the battery pack The battery cell in The second voltage change at a moment, Can indicate the The battery pack is in the The second change feature quantity at a certain moment. It can also mean In the battery pack The battery cell in The first voltage change at a moment, accordingly, Can indicate the The battery pack is in the The first change feature quantity at a moment.

[0049] See also Figure 3 As shown, Figure 3 Schematic diagram of the equivalent circuit of the battery pack provided in the embodiment of the present application. The equivalent circuit includes a voltage source And DC resistance, DC resistance can represent the internal resistance of the battery pack. Each cell is in series in the battery pack, among which multiple cells in parallel can be equivalent to the same cell, so the current of each cell is equal. According to Ohm's law, ,in, Can indicate the In the battery pack The battery cell in The second voltage change at a moment, Can indicate the In the battery pack The battery cell in The first internal resistance at this moment, Can indicate the The battery pack is in the The current change at each moment. According to Ohm's law, ,in, Can indicate the The battery pack is in the The second change characteristic quantity at the moment, Can indicate the The battery pack is in the The internal resistance at a moment, Can indicate the The battery pack is in the The current change at each moment. After calculation, the resistance difference index of each battery cell can be obtained. ,in, Can indicate the In the battery pack The battery cell in Resistance difference indicator at each moment.

[0050] Vehicle according to the formula and formula , you can determine the In the battery pack The battery cell in Resistance difference index at each moment Equal to In the battery pack The battery cell in Voltage difference index at each moment .

[0051] In some embodiments, the calculation formula of the first internal resistance of each battery cell can be expressed as: ,in, Can indicate the In the battery pack The battery cell in The first internal resistance at this moment, Can indicate the In the battery pack The battery cell in Voltage difference index at each moment, Can indicate the The battery pack is in the The internal resistance at a moment.

[0052] The embodiment of the present application determines the voltage difference index of each battery cell by using the second voltage change of each battery cell and the second change characteristic of the battery cell group. Then, based on the voltage difference index of each battery cell and the internal resistance of the battery cell group, the first internal resistance of each battery cell is calculated. This can avoid the problem of poor time synchronization between the battery cell voltage and current. In addition, because the temperature of the battery in which the battery cell group is located is a slowly changing value, the time asynchrony between the temperature of the battery in which the battery cell group is located and the second voltage data of the battery cell will not affect the accuracy of the first internal resistance, thereby ensuring the accuracy of the first internal resistance.

[0053] S203 , replacing the abnormal value in the first internal resistance of each battery cell to obtain the second internal resistance of each battery cell.

[0054] In at least one embodiment of the present application, the vehicle replaces the abnormal value in the first internal resistance of each battery cell to obtain the second internal resistance of each battery cell, including: dividing the first internal resistance of each battery cell according to time sequence to obtain multiple first windows; determining the low quantile internal resistance, the median internal resistance and the high quantile internal resistance of each first window; calculating the first difference between the multiple first internal resistances and the median internal resistance, the second difference between the high quantile internal resistance and the median internal resistance, and the third difference between the low quantile internal resistance and the median internal resistance in each first window; determining the first internal resistance corresponding to the first difference greater than a first threshold, or the first internal resistance corresponding to the first difference less than a second threshold as an abnormal value, the first threshold being determined based on the second difference, and the second threshold being determined based on the third difference; replacing the abnormal value with the median internal resistance, and determining the first internal resistance after replacement as the second internal resistance of each battery cell.

[0055] In some embodiments, during the process of dividing the first internal resistance, the vehicle divides the first internal resistance of each battery cell into First windows, wherein the number of first internal resistances in each first window can be indivual. It can be set according to the temperature change of the battery in which the cell is located. For example, in each first window, the temperature change of the battery in which the cell is located is less than the preset temperature. The preset temperature can be set and adjusted according to actual needs. For example, the preset temperature can be set to 4°C.

[0056] In some embodiments, in the process of determining the low percentile internal resistance, the median internal resistance, and the high percentile internal resistance of each first window, the vehicle sorts the first internal resistance in each first window in ascending order to obtain a second sequence. The vehicle selects the first internal resistance at the first preset position from the second sequence as the low percentile internal resistance, selects the first internal resistance at the second preset position as the median internal resistance, and selects the first internal resistance at the third preset position as the high percentile internal resistance. The first preset position can be determined based on the total number of first internal resistances in the second sequence and a first preset percentage, the second preset position can be determined based on the total number of first internal resistances in the second sequence and a second preset percentage, and the third preset position can be determined based on the total number of first internal resistances in the second sequence and a third preset percentage. The first preset percentage, the second preset percentage, and the third preset percentage can be set and adjusted according to actual needs. For example, the first preset percentage can be set to 20%, the second preset percentage can be set to 50%, and the third preset percentage can be set to 80%.

[0057] In some embodiments, the vehicle calculates a second difference between the high-percentile internal resistance and the median internal resistance, and calculates the product of the second difference and a first preset ratio to obtain a first threshold value. The vehicle calculates a third difference between the low-percentile internal resistance and the median internal resistance, and calculates the product of the third difference and a second preset ratio to obtain a second threshold value. The first and second preset ratios can be set and adjusted based on actual needs. For example, the first and second preset ratios can be set to any value between [1, 3].

[0058] For example, if the first internal resistance of each battery cell includes 10 resistance values ​​from R1 to R10, if the abnormal values ​​in the first internal resistance of each battery cell include the first internal resistance R3 and the first internal resistance R5, assuming that the median internal resistance is R', the vehicle replaces the abnormal values ​​in the first internal resistance of each battery cell, and the second internal resistance of each battery cell includes R1 to R2, R', R4, R', R6 to R10.

[0059] Since the internal resistance of a battery cell does not change suddenly in a short period of time, the embodiment of the present application divides the first internal resistance of each battery cell according to the time sequence, which can avoid long time changes in the first window, thereby accurately determining the low quantile internal resistance, the median internal resistance, and the high quantile internal resistance of each first window, and further accurately determining the outliers in the first internal resistance. Replacing the outliers with the median internal resistance can improve the reliability of the second internal resistance.

[0060] S204 : Determine a first outlier degree and a second outlier degree of each battery cell based on the second internal resistance of each battery cell.

[0061] In at least one embodiment of the present application, during the process of determining the first outlier degree of each battery cell, the vehicle divides the second internal resistance of each battery cell into multiple second windows based on a chronological order. The vehicle determines the first internal resistance characteristic value of each battery cell in the multiple second windows based on the second internal resistance of each battery cell, and calculates the second internal resistance characteristic value of the battery cell group in the multiple second windows based on the first internal resistance characteristic value. The vehicle determines the first outlier degree of each battery cell in the multiple second windows based on the first internal resistance characteristic value and the second internal resistance characteristic value.

[0062] In some embodiments, during the process of dividing the second internal resistance, the vehicle divides the second internal resistance of each battery cell into second windows, wherein the number of second internal resistances in each second window can be indivual. It can be set and adjusted according to actual needs.

[0063] In some embodiments, in the process of determining the first internal resistance characteristic value of each battery cell in multiple second windows, the first internal resistance characteristic value is affected by factors such as voltage sampling error. In the battery pack The battery cell in The second voltage change at a moment Pass the exam The battery pack is in the The second change characteristic value at the moment There are errors. and All conform to the normal distribution, then It can be expressed as: , It can be expressed as: According to the error propagation law, we can get Also follows a normal distribution, It can be expressed as: , where the vehicle is based on the formula , we can get , Ignore the internal resistance of the battery pack The error influence, according to the relationship between the second internal resistance of each battery cell and the voltage difference index of each battery cell, it can be determined that the second internal resistance of each battery cell also conforms to the normal distribution, and the second internal resistance of each battery cell It can be expressed as: , . After calculation, and When the second internal resistance of each cell changes Variance will also change. For example, and When lowered, Will increase. When the second internal resistance increases, the reliability of the corresponding second internal resistance decreases. Based on this, in order to accurately determine the first internal resistance characteristic value of each battery cell in multiple second windows, the vehicle can be based on the second internal resistance of each battery cell. Variance , is the second internal resistance Set different weights.

[0064] In one example, the vehicle Determine the weight corresponding to each second internal resistance. Can indicate the In the battery pack The battery cell in In the second window The weight corresponding to the second internal resistance is, Can indicate the In the battery pack The battery cell in In the second window The standard deviation of the second internal resistance is Can be achieved through In the battery pack The battery cell in In the second window The second internal resistance and the In the battery pack The battery cell in The average value of all the second internal resistances in the second window is determined. Can indicate the In the battery pack The battery cell in The total number of all second internal resistances in the second window.

[0065] Vehicle basis , calculate the first internal resistance characteristic value of each battery cell in multiple second windows. Can indicate the In the battery pack The battery cell in The first internal resistance characteristic value of the second window, Can indicate the In the battery pack The battery cell in In the second window The weight corresponding to the second internal resistance is, Can indicate the In the battery pack The battery cell in In the second window A second internal resistance.

[0066] In some embodiments, the internal resistance of the battery pack The error effect, It also conforms to the normal distribution. It can be expressed as: , , .

[0067] In other embodiments, the vehicle may further calculate an average value of the second internal resistance in each first window to obtain a characteristic value of the first internal resistance of each battery cell in multiple second windows.

[0068] In some embodiments, the vehicle sorts the first internal resistance characteristic values ​​in each second window in order of size to obtain a third sequence, and selects a characteristic value of the first internal resistance characteristic value from the third sequence as the second internal resistance characteristic value of the battery cell group.

[0069] In some embodiments, when determining the first outlier degree of each battery cell, the vehicle selects the largest first internal resistance characteristic value in each second window from the first internal resistance characteristic values. The vehicle determines the change between the largest first internal resistance characteristic value and the second internal resistance characteristic value in each second window as the first outlier degree of each battery cell in each second window. This embodiment accurately determines the first outlier degree of each battery cell in each second window by using the change between the largest first internal resistance characteristic value and the second internal resistance characteristic value in each second window.

[0070] The embodiment of the present application divides the second internal resistance of each battery cell by time sequence, which can avoid long time changes in the second window, so that the first internal resistance characteristic value can be accurately determined. By setting different weights for the second internal resistance of each battery cell based on the variance of the second internal resistance, the first internal resistance characteristic value can be further accurately determined based on the second internal resistance and the corresponding weight. The first internal resistance characteristic value can be reasonably determined based on the first internal resistance characteristic value, further improving the accuracy of the first outlier degree.

[0071] In at least one embodiment of the present application, the process of determining the second outlier degree of each battery cell includes: determining the third internal resistance characteristic value of the battery cell group in multiple second windows based on the change value of the first internal resistance characteristic value and the second internal resistance characteristic value; determining the second outlier degree of each battery cell in multiple second windows based on the first outlier degree of each battery cell in multiple second windows and the third internal resistance characteristic value of the battery cell group in multiple second windows.

[0072] In some embodiments, a formula for determining the third internal resistance characteristic value of the battery cell group in multiple second windows can be expressed as: ,in, Can indicate the The battery pack is in the The third internal resistance characteristic value of the second window, Can indicate the In the battery pack The battery cell in The first internal resistance characteristic values ​​other than the largest first internal resistance characteristic value in the second window are The change value of the second internal resistance characteristic value of each battery cell group, Can indicate the In the battery pack The battery cell in The total number of first internal resistance characteristic values ​​in the second window. When calculating the third internal resistance characteristic value, this embodiment does not use all the first internal resistance characteristic values ​​in the second window, but uses the first internal resistance characteristic values ​​in the second window except for the largest first internal resistance characteristic value. This can effectively avoid the situation where the number of cells in the cell group is small and the third internal resistance characteristic value increases due to the abnormal internal resistance of a single cell, thereby causing the cell with abnormal internal resistance in the cell group to be missed.

[0073] In some embodiments, a formula for determining the second outlier degree of each battery cell in a plurality of second windows can be expressed as: ,in, Can indicate the In the battery pack The battery cell in The second outlier degree of the second window, Can indicate the In the battery pack The battery cell in The first outlier degree of the second window, Can indicate the The battery pack is in the The third internal resistance characteristic value of the second window.

[0074] The embodiment of the present application can accurately determine the third internal resistance characteristic value of the battery cell group through the change value of the first internal resistance characteristic value and the second internal resistance characteristic value, and then combine the quantification of the second outlier degree of the battery cell with the first outlier degree of the battery cell to reasonably determine the second outlier degree.

[0075] S205 : Identify abnormal cells from the plurality of cells in the cell group based on the first outlier degree and the second outlier degree.

[0076] In at least one embodiment of the present application, due to the influence of sampling error and calculation error, in the process of identifying abnormal cells from multiple cells in the cell group, the vehicle can set a first preset requirement based on the first outlier degree, and the first preset requirement can include multiple different first standard thresholds. For example, the vehicle can set three first standard thresholds based on the first outlier degree. For example, the vehicle can set the first standard threshold , the first standard threshold , the first standard threshold , Accordingly, the vehicle may also set a second preset requirement according to the second outlier degree. The second preset requirement may include a plurality of different second standard thresholds. For example, the vehicle may set a second standard threshold. , the second standard threshold , the second standard threshold , .

[0077] In at least one embodiment of the present application, the vehicle determines a battery cell corresponding to a first outlier degree that meets a first preset requirement and a second discrete degree that meets a second preset requirement as an abnormal battery cell.

[0078] In one example, if the first outlier degree of any second window is greater than the first standard threshold , and the second outlier degree of any second window is greater than the second standard threshold , or the first outlier degree of any second window is greater than the first standard threshold , and the second outlier degree of any second window is greater than the second standard threshold , or the first outlier degree of any second window is greater than the first standard threshold , and the second outlier degree of any second window is greater than the second standard threshold The vehicle determines that the first outlier degree of any second window meets the first preset requirement, and the second outlier degree of any second window meets the second preset requirement. The vehicle determines that the second internal resistance corresponding to the largest first internal resistance characteristic value in any second window is an outlier internal resistance, and determines the battery cell corresponding to any second window as an abnormal battery cell. This embodiment of the present application combines the first outlier degree and the second outlier degree to identify abnormal batteries from multiple batteries in a battery cell group, thereby improving the accuracy of identifying abnormal batteries.

[0079] In another example, if the first outlier degree of any second window does not meet the first preset requirement, or the second outlier degree of any second window does not meet the second preset requirement, the vehicle determines that no outlier internal resistance occurs in any second window.

[0080] In at least one embodiment of the present application, if the number of windows of the multiple second windows is greater than or equal to the preset number, it is detected whether the first outlier degree of any battery cell in at least two second windows meets the first preset requirement, and the second outlier degree of at least two second windows meets the second preset requirement. If the first outlier degree of any battery cell in at least two second windows meets the first preset requirement, and the second outlier degree of at least two second windows meets the second preset requirement, it is determined that any battery cell is an abnormal battery cell. The preset number can be set and adjusted according to actual needs. For example, the preset number can be set to 3. In the embodiment of the present application, when the number of windows of the multiple second windows is greater than or equal to the preset number, the situation of at least two second windows can avoid the erroneous determination of abnormal batteries due to false alarms, thereby improving the accuracy of identifying abnormal batteries.

[0081] In other embodiments, if the number of windows of the multiple second windows is less than a preset number, and the first outlier degree of any battery cell in at least one second window meets the first preset requirement, and the second outlier degree of at least one second window meets the second preset requirement, any battery cell is determined to be an abnormal battery cell.

[0082] In multiple embodiments of the present application, by screening the second voltage data of each cell in the cell group from the first voltage data of each cell at multiple times, the quality of the second voltage data can be ensured, thereby improving the accuracy of identifying abnormal cells. The first internal resistance of each cell is determined based on the second voltage data of each cell and the internal resistance of the cell group, and the outliers in the first internal resistance are updated, thereby improving the quality of the second internal resistance. Furthermore, the first outlier and second outlier of each cell can be accurately determined based on the second internal resistance of each cell. By combining the first and second outlier degrees, abnormal cells can be accurately identified from multiple cells in the cell group. In addition, since the current data of the cell does not need to be used in the analysis, the problem caused by the asynchrony between the voltage and current of the cell can be effectively avoided, thereby further improving the accuracy of identifying abnormal cells. By identifying abnormal cells from multiple cells in the cell group, the embodiments of the present application can promptly detect battery packs with outliers in the internal resistance of the cell, helping after-sales personnel to respond in advance, thereby avoiding the occurrence of power outages and other faults during vehicle driving.

[0083] like Figure 4 The figure shows a functional module diagram of the abnormal cell identification device provided by the embodiment of the present application. The abnormal cell identification device 11 is operated on the vehicle. The abnormal cell identification device 11 includes a screening unit 110, a determination unit 111, a replacement unit 112 and an identification unit 113. The module / unit referred to in the present application refers to a device that can be processed by a processor (e.g. Figure 5 A series of computer program segments are obtained by the processor 1101 shown in FIG. 1 and are capable of completing fixed functions, which are stored in a memory (eg Figure 5 1102).

[0084] In one embodiment, the screening unit 110 is used to screen the second voltage data of each battery cell in the battery cell group from the first voltage data of each battery cell at multiple moments; the determination unit 111 is used to determine the first internal resistance of each battery cell based on the second voltage data of each battery cell and the internal resistance of the battery cell group; the replacement unit 112 is used to replace the abnormal value in the first internal resistance of each battery cell to obtain the second internal resistance of each battery cell; the determination unit 111 is also used to determine the first outlier degree and the second outlier degree of each battery cell based on the second internal resistance of each battery cell; the identification unit 113 is used to identify abnormal batteries from multiple batteries in the battery cell group based on the first outlier degree and the second outlier degree.

[0085] In one embodiment, the screening unit 110 is specifically used to: calculate the first voltage change of each battery cell between adjacent moments based on the first voltage data of each battery cell at multiple moments; determine the first change characteristic quantity of the battery cell group based on the first voltage change quantity of each battery cell; and select the second voltage data of each battery cell from the first voltage data of each battery cell based on the absolute value of the first change characteristic quantity, the time difference between adjacent moments, and the temperature of the battery in which the battery cell group is located.

[0086] In one embodiment, the determination unit 111 is further specifically used to: calculate the second voltage change of each battery cell between adjacent moments based on the second voltage data of each battery cell; determine the second change characteristic quantity of the battery cell group based on the second voltage change of each battery cell; determine the voltage difference index of each battery cell based on the second voltage change of each battery cell and the second change characteristic quantity of the battery cell group; and calculate the first internal resistance of each battery cell according to the voltage difference index of each battery cell and the internal resistance of the battery cell group.

[0087] In one embodiment, the replacement unit 112 is specifically used to: divide the first internal resistance of each battery cell according to the time sequence to obtain multiple first windows; determine the low quantile internal resistance, the median internal resistance and the high quantile internal resistance of each first window; calculate the first difference between the multiple first internal resistances and the median internal resistance, the second difference between the high quantile internal resistance and the median internal resistance, and the third difference between the low quantile internal resistance and the median internal resistance in each first window; determine the first internal resistance corresponding to the first difference greater than the first threshold, or the first internal resistance corresponding to the first difference less than the second threshold as an abnormal value, the first threshold is determined based on the second difference, and the second threshold is determined based on the third difference; replace the abnormal value with the median internal resistance, and determine the first internal resistance after the replacement process as the second internal resistance of each battery cell.

[0088] In one embodiment, the determination unit 111 is further specifically used to: divide the second internal resistance of each battery cell according to a time sequence to obtain a plurality of second windows; determine the first internal resistance characteristic value of each battery cell in the plurality of second windows based on the second internal resistance of each battery cell; calculate the second internal resistance characteristic value of the battery cell group in the plurality of second windows based on the first internal resistance characteristic value; and determine the first outlier degree of each battery cell in the plurality of second windows based on the first internal resistance characteristic value and the second internal resistance characteristic value.

[0089] In one embodiment, the determination unit 111 is further specifically used to: select the largest first internal resistance characteristic value in each second window from the first internal resistance characteristic values; and determine the change value between the largest first internal resistance characteristic value and the second internal resistance characteristic value in each second window as the first outlier degree of each battery cell in each second window.

[0090] In one embodiment, the determination unit 111 is further specifically used to: determine the third internal resistance characteristic value of the battery cell group in multiple second windows based on the change value of the first internal resistance characteristic value and the second internal resistance characteristic value; determine the second outlier degree of each battery cell in multiple second windows based on the first outlier degree of each battery cell in multiple second windows and the third internal resistance characteristic value of the battery cell group in multiple second windows.

[0091] In one embodiment, the identification unit 113 is specifically configured to determine a battery cell corresponding to a first outlier degree that meets a first preset requirement and a second dispersion degree that meets a second preset requirement as an abnormal battery cell.

[0092] In multiple embodiments of the present application, by determining the second voltage data of each cell in the cell group from the first voltage data of each cell at multiple times, the quality of the second voltage data can be ensured, thereby improving the accuracy of identifying abnormal cells. The first internal resistance of each cell is determined based on the second voltage data of each cell and the internal resistance of the cell group, and the outliers in the first internal resistance are updated, thereby improving the quality of the second internal resistance. Furthermore, the first outlier and second outlier of each cell can be accurately determined based on the second internal resistance of each cell. By combining the first and second outliers, abnormal cells can be accurately identified from multiple cells in the cell group. In addition, since the current data of the cell does not need to be used in the analysis, the problem caused by the asynchrony between the voltage and current of the cell can be effectively avoided, thereby further improving the accuracy of identifying abnormal cells. By identifying abnormal cells from multiple cells in the cell group, the embodiments of the present application can promptly detect battery packs with outliers in the internal resistance of the cell, helping after-sales personnel to respond in advance, thereby avoiding the occurrence of power outages and other faults during vehicle driving.

[0093] like Figure 5 , which is a schematic structural diagram of a vehicle according to a preferred embodiment of the abnormal battery cell identification method implemented in the present application.

[0094] In one embodiment of the present application, the vehicle 100 includes, but is not limited to, a memory 1102 , a processor 1101 , and a computer program stored in the memory 1102 and executable on the processor 1101 , such as an abnormal cell identification program.

[0095] Those skilled in the art will understand that the schematic diagram is merely an example of the vehicle 100 and does not constitute a limitation on the vehicle 100 . The vehicle 100 may include more or fewer components than shown in the diagram, or a combination of certain components, or different components. For example, the vehicle 100 may also include input and output devices, network access devices, buses, etc.

[0096] Processor 1101 may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor. Processor 1101 is the computing core and control center of vehicle 100, connecting various components of vehicle 100 via various interfaces and lines, and accessing the vehicle 100's operating system, various installed applications, program code, etc.

[0097] The processor 1101 obtains the operating system of the vehicle 100 and various installed applications. The processor 1101 obtains the application to implement the steps in the above-mentioned embodiments of the abnormal battery cell identification method, for example Figure 2 Steps shown.

[0098] For example, the computer program may be divided into one or more modules / units, which are stored in memory 1102 and retrieved by processor 1101 to implement the present application. One or more modules / units may be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the process of retrieval of the computer program in vehicle 100.

[0099] Memory 1102 can be used to store computer programs and / or modules. Processor 1101 implements various functions of vehicle 100 by running or accessing computer programs and / or modules stored in memory 1102 and accessing data stored in memory 1102. Memory 1102 may primarily include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function (such as audio playback or image playback); the data storage area may store data generated based on vehicle usage. Memory 1102 may also include non-volatile memory, such as a hard drive, internal memory, a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device.

[0100] The memory 1102 may be an external memory and / or an internal memory of the vehicle 100. Furthermore, the memory 1102 may be a physical memory such as a memory stick, a TF card (Trans-flash Card), and the like.

[0101] If the modules / units integrated into vehicle 100 are implemented as software functional units and sold or used as independent artifacts, they can be stored in a computer-readable storage medium. Based on this understanding, the present application can also implement all or part of the processes in the above-mentioned method embodiments by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of each of the above-mentioned method embodiments.

[0102] The term "computer program" includes computer program code, which may be in source code form, object code form, executable file, or some intermediate form. Computer-readable media may include any entity or device capable of carrying computer program code, recording media, USB flash drives, removable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), and random access memory (RAM).

[0103] Memory 1102 can be used to store computer programs and / or modules. Processor 1101 implements various functions of vehicle 100 by running or executing the computer programs and / or modules stored in memory 1102 and accessing data stored in memory 1102. Memory 1102 may primarily include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function (such as audio playback or image playback); the data storage area may store data generated based on vehicle usage. Memory 1102 may include both non-volatile and volatile memory, such as a hard drive, internal memory, a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, at least one disk storage device, a flash memory device, or other storage devices.

[0104] For example, the computer program may be divided into one or more modules / units, one or more of which are stored in memory 1102 and executed by processor 1101 to implement the present application. One or more modules / units may be a series of computer program segments capable of performing specific functions, and the computer program segments are used to describe the execution process of the computer program in vehicle 100. For example, the computer program may be divided into a screening unit 110, a determination unit 111, a replacement unit 112, and an identification unit 113.

[0105] For details about the functions of each module / unit, please refer to the above Figure 2 The detailed description is not repeated here.

[0106] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of modules is merely a logical function division, and other division methods may be used in actual implementation.

[0107] Modules described as separate components may or may not be physically separate, and components shown as modules may or may not be physical units, that is, they may be located in one place or distributed across multiple network elements. Some or all of these modules may be selected to achieve the purpose of this embodiment based on actual needs.

[0108] In addition, the functional modules in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0109] Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present application is defined by the appended claims rather than the foregoing description, and all changes that come within the meaning and range of equivalents of the claims are intended to be embraced therein. Any reference to a figure in a claim should not be construed as limiting the claim to which it relates.

[0110] Furthermore, it is clear that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units or devices may also be implemented by a single unit or device through software or hardware. The words "first", "second", etc. are used to indicate names and do not indicate any particular order.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for identifying abnormal battery cells, characterized in that: The method comprises: Filtering second voltage data of each battery cell in the battery cell group from first voltage data of each battery cell at multiple moments; Determining a first internal resistance of each battery cell based on the second voltage data of each battery cell and the internal resistance of the battery cell group; replacing abnormal values ​​in the first internal resistance of each battery cell to obtain a second internal resistance of each battery cell; Determining a first outlier degree and a second outlier degree of each battery cell based on the second internal resistance of each battery cell; Based on the first outlier degree and the second outlier degree, abnormal cells are identified from a plurality of cells in the cell group.

2. The abnormal cell identification method according to claim 1, characterized in that: The step of filtering the second voltage data of each battery cell in the battery cell group from the first voltage data of each battery cell at multiple moments includes: Calculating a first voltage change of each battery cell between adjacent moments based on the first voltage data of each battery cell at the multiple moments; determining a first variation characteristic value of the battery cell group based on the first voltage variation value of each battery cell; The second voltage data of each battery cell is selected from the first voltage data of each battery cell based on the absolute value of the first change characteristic value, the time difference between the adjacent moments, and the temperature of the battery in which the battery cell group is located.

3. The abnormal cell identification method according to claim 1, characterized in that: The determining the first internal resistance of each battery cell based on the second voltage data of each battery cell and the internal resistance of the battery cell group includes: Calculating a second voltage change of each battery cell between adjacent moments based on the second voltage data of each battery cell; determining a second variation characteristic value of the battery cell group based on the second voltage variation value of each battery cell; Determining a voltage difference index for each battery cell based on the second voltage change amount of each battery cell and the second change characteristic amount of the battery cell group; The first internal resistance of each battery cell is calculated according to the voltage difference index of each battery cell and the internal resistance of the battery cell group.

4. The abnormal cell identification method according to claim 1, characterized in that: The replacing the abnormal value in the first internal resistance of each battery cell to obtain the second internal resistance of each battery cell includes: Dividing the first internal resistance of each battery cell according to a time sequence to obtain a plurality of first windows; Determine the low quantile internal resistance, the median internal resistance, and the high quantile internal resistance of each first window; calculating a first difference between a plurality of first internal resistances in each first window and the median internal resistance, a second difference between the high quantile internal resistance and the median internal resistance, and a third difference between the low quantile internal resistance and the median internal resistance; determining a first internal resistance corresponding to a first difference greater than a first threshold, or a first internal resistance corresponding to a first difference less than a second threshold, as the abnormal value, where the first threshold is determined based on the second difference, and the second threshold is determined based on the third difference; The abnormal value is replaced by the median internal resistance, and the first internal resistance after the replacement is determined as the second internal resistance of each battery cell.

5. The abnormal cell identification method according to claim 1, characterized in that: The process of determining the first outlier degree of each battery cell includes: Dividing the second internal resistance of each battery cell according to a time sequence to obtain a plurality of second windows; Determining a first internal resistance characteristic value of each battery cell in the plurality of second windows based on the second internal resistance of each battery cell; Calculating second internal resistance characteristic values ​​of the battery cell group in the plurality of second windows based on the first internal resistance characteristic value; A first outlier degree of each battery cell in the plurality of second windows is determined based on the first internal resistance characteristic value and the second internal resistance characteristic value.

6. The abnormal cell identification method according to claim 5, characterized in that: The determining, based on the first internal resistance characteristic value and the second internal resistance characteristic value, a first outlier degree of each battery cell in the plurality of second windows includes: Selecting the largest first internal resistance characteristic value in each second window from among the first internal resistance characteristic values; A change value between the maximum first internal resistance characteristic value and the second internal resistance characteristic value in each second window is determined as a first outlier degree of each battery cell in each second window.

7. The abnormal cell identification method according to claim 5, characterized in that: The process of determining the second outlier degree of each battery cell includes: determining a third internal resistance characteristic value of the battery cell group in the plurality of second windows based on a change in the first internal resistance characteristic value and the second internal resistance characteristic value; The second outlier degree of each battery cell in the second windows is determined based on the first outlier degree of each battery cell in the second windows and the third internal resistance characteristic value of the battery cell group in the second windows.

8. The abnormal cell identification method according to claim 1, characterized in that: The step of identifying abnormal cells from the plurality of cells in the cell group based on the first outlier degree and the second outlier degree includes: A battery cell corresponding to a first outlier degree that meets a first preset requirement and a second dispersion degree that meets a second preset requirement is determined as the abnormal battery cell.

9. A vehicle, characterized in that: include: A memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the abnormal battery cell identification method according to any one of claims 1 to 8 is implemented.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-readable instructions, and when the computer-readable instructions are executed by a processor of a vehicle, the abnormal battery cell identification method according to any one of claims 1 to 8 is implemented.

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