Battery pack cell internal resistance detection method and device, electronic equipment and storage medium

Abstract

The invention provides a battery pack cell internal resistance detection method and device, electronic equipment and a storage medium, and relates to the technical field of batteries, and the method comprises the steps: obtaining battery pack operation time sequence data, determining first time sequence data in the battery pack operation time sequence data through employing a preposed working condition judgment condition, whether the first time sequence data meet a first pulse current working condition judgment condition, a second pulse current working condition judgment condition and a third pulse current working condition judgment condition or not is judged, and if yes, the internal resistance of each battery cell in the battery pack is determined according to current time sequence data in the first time sequence data and the voltage time sequence data, the first time sequence data meeting the conditions are the battery operation data corresponding to the effective pulse current working condition, so that the internal resistance of each battery cell in the battery pack determined based on the first time sequence data is prevented from being influenced by a preposed working condition, different temperatures, different charge states, different current magnitudes and current directions; and the calculation precision of the internal resistance of the battery pack cell is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular, to a method, device, electronic device, and storage medium for detecting the internal resistance of battery pack cells. Background Art

[0002] With the rapid growth of the electric vehicle (EVs) and hybrid electric vehicle (HEVs) markets, the importance of the battery management system (BMS) has become increasingly prominent. Among them, accurately measuring the internal resistance of battery cells is one of the key factors to ensure battery safety and improve its efficiency.

[0003] In related technologies, the measurement methods of battery cell internal resistance are generally divided into two categories: AC method and DC method. The AC method measures the impedance of battery cells by applying a high-frequency small-amplitude AC signal. However, additional hardware devices need to be introduced when applying the AC signal, resulting in an increase in cost; the DC method is to instantaneously change the load current of the battery and calculate the internal resistance of the cells according to the change of the voltage of each cell. This method needs to be calculated based on the pulse current condition of the lithium-ion battery itself. However, the determination of the pulse current condition is affected by various factors, such as the temperature of the battery cells, the ambient temperature, the voltage and current conditions of the cells, etc., making it difficult to find an effective pulse current condition, thus affecting the accuracy of the calculation of the battery cell internal resistance. Summary of the Invention

[0004] The problem solved by the present invention is how to improve the detection accuracy of the internal resistance of battery cells.

[0005] To solve the above problems, the present invention provides a method, device, electronic device, and storage medium for detecting the internal resistance of battery pack cells.

[0006] In a first aspect, the present invention provides a method for detecting the internal resistance of battery pack cells, including:

[0007] Obtain the battery pack operation timing data, where the battery pack operation timing data includes: the current timing data of the battery pack, the voltage timing data of each cell in the battery pack, the temperature timing data of each cell in the battery pack, and the ambient temperature timing data of the battery pack;

[0008] Use the precondition judgment condition to determine the timing data in the first preset time range in the battery pack operation timing data to obtain the first timing data;

[0009] Determine whether the current time series data and the voltage time series data in the first time series data meet the first pulsed current condition judgment criteria, and determine whether the temperature time series data and the ambient temperature time series data in the first time series data meet the second pulsed current condition judgment criteria, and determine whether the cross-correlation coefficient of the current time series data and the voltage time series data in the first time series data meets the third pulsed current condition judgment criteria;

[0010] If it is determined that all are satisfied, then determine the internal resistance of each battery cell in the battery pack according to the current time series data and the voltage time series data in the first time series data.

[0011] Optionally, the obtaining the first time series data by using the precondition judgment criteria to determine the time series data within a first preset time range in the battery pack operation time series data includes:

[0012] Determine the time series data that meets the precondition judgment criteria in the battery operation time series data to obtain the time series data corresponding to the precondition;

[0013] Use the last frame of data in the time series data corresponding to the precondition as the starting frame data, and intercept the time series data within a first preset time range in the battery operation time series data to obtain the first time series data.

[0014] Optionally, the precondition judgment criteria are:

[0015] Within a second preset time range, the absolute value of the current time series data of the battery pack in the battery pack operation time series data is less than a first threshold; and,

[0016] Within a second preset time range, the standard deviation of the current time series data of the battery pack in the battery pack operation time series data is less than a second threshold; and,

[0017] Within a second preset time range, the standard deviation of the voltage time series data of each battery cell in the battery pack in the battery pack operation time series data is less than a third threshold.

[0018] Optionally, the first pulsed current condition judgment criteria are:

[0019] The range of the current time series data in the first time series data is greater than a fourth threshold; and,

[0020] The absolute values of the current time series data in the first time series data are all less than a fifth threshold; and,

[0021] The absolute value of the second-frame current data of the current time series data in the first time series data is greater than a sixth threshold; and,

[0022] The range of the maximum set of voltage time series data among the voltage time series data of each battery cell in the first time series data is greater than the seventh threshold; and,

[0023] The range of the minimum set of voltage time series data among the voltage time series data of each battery cell in the first time series data is greater than the eighth threshold;

[0024] And / or, the determination condition for the second pulse current condition is:

[0025] The range between the second frame of temperature data in the temperature time series data of all battery cells in the first time series data and the second frame of temperature data in the ambient temperature time series data is less than the ninth threshold;

[0026] And / or, the determination condition for the third pulse current condition is:

[0027] The lag time corresponding to the maximum value of the cross-correlation coefficient between the current time series data and the voltage time series data in the first time series data is less than the tenth threshold.

[0028] Optionally, determining the internal resistance of each battery cell in the battery pack according to the current time series data and the voltage time series data in the first time series data includes:

[0029] Judging whether the lag time corresponding to the maximum value of the cross-correlation coefficient between the current time series data and the voltage time series data in the first time series data is equal to zero;

[0030] If the lag time corresponding to the maximum value of the cross-correlation coefficient is equal to 0, then determine the internal resistance of each battery cell in the battery pack according to the range of the current time series data in the first time series data and the range of the voltage time series data of each battery cell in the first time series data;

[0031] If the lag time corresponding to the maximum value of the cross-correlation coefficient is not equal to 0, then determine the internal resistance of each battery cell in the battery pack according to the difference between the second frame current data and the first frame current data in the current time series data in the first time series data, and the difference between the pth frame voltage data and the (p - 1)th frame voltage data of the voltage time series data of each battery cell in the first time series data; where p = 2 + max_time_lag, and max_time_lag is the lag time corresponding to the maximum value of the cross-correlation coefficient.

[0032] Optionally, determine the average internal resistance of all battery cells in the battery pack and the standard deviation of the internal resistances of all battery cells according to the internal resistance of each battery cell in the battery pack;

[0033] Determine the internal resistance consistency coefficient of the battery pack according to the average internal resistance of all battery cells in the battery pack and the standard deviation of the internal resistances of all battery cells;

[0034] Determine whether the internal resistance consistency coefficient of the battery pack is greater than a preset internal resistance consistency coefficient threshold;

[0035] If it is determined that it is greater than the preset internal resistance consistency coefficient threshold, output a first abnormal reminder message for characterizing abnormal internal resistance consistency.

[0036] Optionally, the battery pack cell internal resistance detection method further includes:

[0037] According to the internal resistance of each cell in the battery pack, determine the average internal resistance of each cell in the battery pack within a continuous plurality of unit statistical time periods;

[0038] Determine whether the change value of the average internal resistance of each cell in the battery pack within two consecutive unit statistical time periods is greater than a preset change threshold;

[0039] If it is determined that it is greater than the preset change threshold, output a second abnormal reminder message for characterizing abnormal internal resistance growth.

[0040] In a second aspect, the present invention provides a battery pack cell internal resistance detection device, including:

[0041] A data acquisition module, configured to acquire battery pack operation timing data, where the battery pack operation timing data includes: battery pack current timing data, voltage timing data of each cell in the battery pack, temperature timing data of each cell in the battery pack, and ambient temperature timing data of the battery pack;

[0042] A pulse condition data determination module, configured to determine timing data within a first preset time range in the battery pack operation timing data according to the sampling time sequence of the battery pack operation timing data, using a precondition judgment condition, to obtain first timing data;

[0043] A pulse condition validity judgment module, configured to judge whether the current timing data and the voltage timing data in the first timing data satisfy a first pulse current condition judgment condition, and judge whether the temperature timing data and the ambient temperature timing data in the first timing data satisfy a second pulse current condition judgment condition, and judge whether the cross-correlation coefficient of the current timing data and the voltage timing data in the first timing data satisfies a third pulse current condition judgment condition;

[0044] A cell internal resistance determination module, configured to, in the case where it is determined that all are satisfied, determine the internal resistance of each cell in the battery pack according to the current timing data and the voltage timing data in the first timing data.

[0045] In a third aspect, the present invention provides an electronic device, including a memory and a processor;

[0046] The memory is used to store a computer program;

[0047] The processor is configured to implement the battery pack cell internal resistance detection method as described in the first aspect when executing the computer program.

[0048] In a fourth aspect, the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the battery pack cell internal resistance detection method as described in the first aspect is implemented.

[0049] The beneficial effects of the battery pack cell internal resistance detection method, device, electronic device, and storage medium of the present invention are as follows: Obtain the battery pack operation timing data, and use the precondition judgment condition to determine the timing data within the first preset time range in the battery pack operation timing data to obtain the first timing data. Since the pulsed current condition in the battery follows the precondition, determining the timing data corresponding to the preliminary pulsed current condition through the precondition judgment condition can avoid the influence of inaccurate determination of the precondition on the accurate determination of the pulsed current condition. Determine whether the current timing data and voltage timing data in the first timing data satisfy the first pulsed current condition judgment condition, whether the temperature timing data and ambient temperature timing data in the first timing data satisfy the second pulsed current condition judgment condition, and whether the cross-correlation coefficient of the current timing data and voltage timing data in the first timing data satisfies the third pulsed current condition judgment condition. Use the first pulsed current condition judgment condition, the second pulsed current condition judgment condition, and the third pulsed current condition judgment condition to determine whether the first timing data can be used as the data of the effective pulsed current condition, so as to avoid the influence of different temperatures, different state of charge, different current magnitudes, and current directions on the accurate determination of the pulsed current condition. If all the judgments are satisfied, then determine the internal resistance of each cell in the battery pack according to the current timing data and the voltage timing data in the first timing data. The first timing data that meets the above conditions is the battery operation data corresponding to the effective pulsed current condition. Therefore, the internal resistance of each cell in the battery pack determined based on the first timing data avoids the influence of the precondition, different temperatures, different state of charge, different current magnitudes, and current directions, and effectively improves the calculation accuracy of the battery pack cell internal resistance. Description of the Drawings

[0050] Figure 1 It is a flowchart of a battery pack cell internal resistance detection method according to an embodiment of the present invention;

[0051] Figure 2 It is a schematic diagram corresponding to three examples of the precondition and the pulsed current condition;

[0052] Figure 3Flow chart for determining the first timing data using the precondition judgment conditions in one embodiment;

[0053] Figure 4 Flow chart for determining the internal resistance of each battery cell in the battery pack based on the current timing data and voltage timing data in the first timing data;

[0054] Figure 5 Flow chart for judging the internal resistance consistency of the battery pack in one embodiment;

[0055] Figure 6 Flow chart for judging the change situation of each battery cell in the battery pack within the unit statistical time period in one embodiment;

[0056] Figure 7 Schematic structural diagram of a battery pack cell internal resistance detection device according to an embodiment of the present invention;

[0057] Figure 8 Schematic structural diagram of an electronic device according to an embodiment of the present invention. Detailed implementation manners

[0058] To make the above objects, features and advantages of the present invention more obvious and understandable, the following will describe the specific embodiments of the present invention in detail with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments described herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not used to limit the protection scope of the present invention.

[0059] It should be understood that the various steps described in the method embodiments of the present invention can be executed in different orders and / or executed in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this regard.

[0060] The term "including" and its variants used herein are open-ended, that is, "including but not limited to"; the term "based on" is "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependent relationships.

[0061] It should be noted that the modifiers "one" and "multiple" mentioned in the present invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise clearly specified in the context, it should be understood as "one or more".

[0062] The names of the messages or information exchanged between multiple devices in the embodiments of the present invention are only for illustrative purposes and are not used to limit the scope of these messages or information.

[0063] As Figure 1 shown, an internal resistance detection method for battery pack cells provided by an embodiment of the present invention can be applied to the local processor of an electric vehicle and a hybrid vehicle, and can also be applied to a cloud server. This embodiment does not make specific limitations in this regard. Among them, the internal resistance detection method for battery pack cells includes:

[0064] S100: Obtain the battery pack operation timing data. Among them, the battery pack operation timing data includes: the current timing data of the battery pack, the voltage timing data of each cell in the battery pack, the temperature timing data of each cell in the battery pack, and the ambient temperature timing data of the battery pack.

[0065] Specifically, for both electric vehicles and hybrid vehicles, a battery management system is configured. After the battery pack is powered on, the battery management system starts to automatically obtain the battery pack operation timing data of the vehicle, and the battery pack operation timing data obtained by the battery management system can also be transmitted to the cloud server.

[0066] Specifically, each cell in the battery pack is connected in series, and each cell is equipped with a current detection sensor, a voltage detection sensor, and a temperature sensor for detecting the current data, voltage data, and temperature data of each cell. Since each cell in the battery pack is connected in series, each cell in the battery pack has the same current data, which is the current data of the battery pack. In addition, an ambient temperature sensor is also configured to detect the ambient temperature data of the battery pack. The battery management system samples the data detected by each sensor at a certain sampling rate to obtain the battery pack operation timing data.

[0067] Specifically, the current timing data is current time series data arranged in the order of sampling time, the voltage timing data is voltage time series data arranged in the order of sampling time, and the temperature timing data is temperature time series data arranged in the order of sampling time.

[0068] In some embodiments, obtaining the battery pack operation timing data can be the battery pack operation timing data collected in real time after the battery pack is powered on. In other embodiments, obtaining the battery pack operation timing data can also be the offline battery pack operation timing data stored in advance.

[0069] S200: Determine the time-series data within the first preset time range from the time-series data of the battery pack's operation sequence using the precondition judgment condition to obtain the first time-series data.

[0070] Specifically, based on the operating conditions of the battery pack, it is known that the pulsed current condition usually follows the precondition. As Figure 2 shown, Figure 2 (a), (b), and (c) in it are examples of three preconditions and the pulsed current condition respectively, where the A curve is the time-series data of the total vehicle current, and a set of B curves are the time-series data of each battery cell in the vehicle's battery pack. S1 is the precondition, and S2 is the pulsed current condition. It can be seen that the pulsed current condition is connected to the precondition in the time series, and in the time series, the pulsed current condition follows the precondition.

[0071] In one embodiment, judge the data in the time-series data of the battery pack's operation sequence in the order of the sampling time of the time-series data of the battery pack's operation sequence one by one to find a section of time-series data in the time-series data of the battery pack's operation sequence that meets the precondition judgment condition, that is, determine the time-series data corresponding to the precondition. After determining the time-series data corresponding to the precondition, the time-series data within the first preset time range after the time-series data corresponding to the precondition is the first time-series data, and this first time-series data is the preliminarily determined time-series data corresponding to the pulsed current condition.

[0072] Specifically, the first preset time range is related to the sampling rate of the time-series data of the battery pack's operation sequence and the first preset data volume. In one embodiment, the first preset data volume corresponding to the pulsed current condition can be 5 - 10 frames. Taking the first preset data volume as 6 frames as an example, for example, when the sampling rate is 1 frame / second, the first preset time range is 6s. Another example, when the sampling rate is 1 frame / millisecond, the first preset time is 6ms.

[0073] S300: Judge whether the current time-series data and voltage time-series data in the first time-series data meet the first pulsed current condition judgment condition, and judge whether the temperature time-series data and ambient temperature time-series data in the first time-series data meet the second pulsed current condition judgment condition, and judge whether the cross-correlation coefficient of the current time-series data and voltage time-series data in the first time-series data meets the third pulsed current condition judgment condition.

[0074] Specifically, taking the data volume corresponding to the first preset time range as 6 frames as an example, the current time series data in the first time series data is [I_1, I_2, I_3, I_4, I_5, I_6], and the voltage time series data of each battery cell in the first time series data is [V_1_i, V_2_i, V_3_i, V_4_i, V_5_i, V_6_i], where i is the serial number of the battery cell; the temperature time series data of each battery cell in the first time series data is [Temp_1_i, Temp_2_i, Temp_3_i, Temp_4_i, Temp_5_i, Temp_6_i], and the ambient temperature time series data in the first time series data is [Temp_ambient_1, Temp_ambient_2, Temp_ambient_3, Temp_ambient_4, Temp_ambient_5, Temp_ambient_6]; among them, I_1, V_1_i, and Temp_ambient_1 are the current data, voltage data, and temperature data respectively corresponding to the last frame of data in the precondition.

[0075] S400: If it is determined that all are satisfied, then determine the internal resistance of each battery cell in the battery pack according to the current time series data and voltage time series data in the first time series data.

[0076] Specifically, when the first time series data all satisfy the above first pulsed current condition judgment condition, second pulsed current condition judgment condition, and third pulsed current condition judgment condition, it indicates that the first time series data is the data corresponding to the effective pulsed current condition; when the first time series data does not satisfy any of the above first pulsed current condition judgment condition, second pulsed current condition judgment condition, and third pulsed current condition judgment condition, return to step S200 to continue the precondition judgment to obtain new first time series data, and then continue the judgment of S300 based on the new first time series data.

[0077] In this embodiment, first determine the first time series data corresponding to the preliminary pulsed current condition through the precondition judgment condition, which can avoid the influence of inaccurate determination of the precondition on the accurate determination of the pulsed current condition, and then perform validity judgment on the first time series data corresponding to the preliminary pulsed current condition through the first pulsed current condition judgment condition, second pulsed current condition judgment condition, and third pulsed current condition. If the above conditions are satisfied, calculate the internal resistance of each battery cell in the battery pack based on the first time series data to avoid the influence of different temperatures, different state of charge, different current magnitudes, and current directions on the accurate determination of the pulsed current condition.

[0078] Optionally, as Figure 3As shown, in S200, the timing data within the first preset time range is determined from the battery pack operation timing data using the precondition judgment condition, and the obtained first timing data includes:

[0079] S210: Determine the timing data that meets the precondition judgment condition from the battery operation timing data to obtain the timing data corresponding to the precondition.

[0080] S220: Use the last frame of data in the timing data corresponding to the precondition as the starting frame data, and intercept the timing data within the first preset time range from the battery operation timing data to obtain the first timing data.

[0081] Specifically, when determining the timing data that meets the precondition judgment condition from the battery operation timing data, the data in the battery operation timing data is judged in the order of the acquisition time of the battery operation timing data to determine whether it meets the precondition judgment condition, and a section of timing data that meets the precondition judgment condition is extracted as the timing data corresponding to the precondition.

[0082] In some embodiments, the precondition judgment condition is:

[0083] Within the second preset time range, the absolute value of the current timing data of the battery pack in the battery pack operation timing data is less than the first threshold; and,

[0084] Within the second preset time range, the standard deviation of the current timing data of the battery pack in the battery pack operation timing data is less than the second threshold; and,

[0085] Within the second preset time range, the standard deviation of the voltage timing data of each battery cell in the battery pack in the battery pack operation timing data is less than the third threshold.

[0086] Specifically, the current timing data is a series of consecutive current values, and the voltage timing data is a series of consecutive voltage values. In one embodiment, the second preset time range can be 10 min, the first threshold can be 5 A, the second threshold can be 0.1 A, and the third threshold can be 5 mV. In other embodiments, the first threshold, the second threshold, and the third threshold can also be other values, not limited to the above examples, and this embodiment does not make specific limitations thereto.

[0087] Specifically, after determining the timing data corresponding to the precondition, since the pulsed current condition of the battery pack follows the precondition immediately, the last frame of data in the timing data corresponding to the precondition is used as the starting frame data, and in the order of the sampling time, continuous data within the first preset time range is intercepted from the starting frame data in the battery pack operation data as the first timing data.

[0088] In this optional embodiment, since the pulse current condition of the battery pack follows immediately after the previous condition, the previous condition corresponding to the pulse current condition of the battery pack is accurately judged according to the previous condition judgment condition, so as to obtain the battery pack operation data corresponding to the previous condition, and then based on the battery pack operation data corresponding to the previous condition, the battery pack operation data corresponding to the preliminary pulse current condition is accurately intercepted from the battery pack operation data.

[0089] After the battery pack operation data (the first time series data) corresponding to the preliminary pulse current condition is extracted, the validity of the first time series data is judged according to the first pulse current condition judgment condition, the second pulse current condition judgment condition, and the third pulse current condition judgment condition.

[0090] Optionally, the first pulse current condition judgment condition is:

[0091] The range of the current time series data in the first time series data is greater than the fourth threshold; and, the absolute values of the current time series data in the first time series data are all less than the fifth threshold; and, the absolute value of the second frame current data in the current time series data in the first time series data is greater than the sixth threshold; and, the range of the largest group of voltage time series data in the voltage time series data of each battery cell in the first time series data is greater than the seventh threshold; and, the range of the smallest group of voltage time series data in the voltage time series data of each battery cell in the first time series data is greater than the eighth threshold.

[0092] Specifically, the range of the current time series data in the first time series data is the difference between the maximum current value and the minimum current value in the current time series data. The maximum set of voltage time series data among the voltage time series data of each battery cell in the first time series data is a set of data corresponding to the maximum voltage value of each battery cell in each sampling frame. The minimum set of voltage time series data among the voltage time series data of each battery cell in the first time series data is a set of data corresponding to the minimum voltage value of each battery cell in each sampling frame. For example, taking the first preset time as 6s and the sampling rate as 1 frame / s as an example, the current time series data for 6s is [I_1, I_2, I_3, I_4, I_5, I_6], then the range of the current time series data is: max[I_1, I_2, I_3, I_4, I_5, I_6] - min[I_1, I_2, I_3, I_4, I_5, I_6]. The maximum set of voltage time series data among the voltage time series data of each battery cell in the first time series data is [maxv_1, maxv_2, maxv_3, maxv_4, maxv_5, maxv_6], and the minimum set of voltage time series data among the voltage time series data of each battery cell in the first time series data is [minv_1, minv_2, minv_3, minv_4, minv_5, minv_6]. Among them, maxv_1 is the maximum value of the voltage data of the first frame of all battery cells, and so on, maxv_6 is the maximum value of the voltage data of the sixth frame of all battery cells. minv_1 is the minimum value of the voltage data of the first frame of all battery cells, and so on, maxv_6 is the minimum value of the voltage data of the sixth frame of all battery cells.

[0093] Specifically, the selection of the threshold can be set according to experience or determined based on the results of multiple tests. This embodiment provides a set of threshold examples: the fourth threshold can be 30A, the fifth threshold can be 200A, the sixth threshold can be 5A, the seventh threshold can be 10mV, and the eighth threshold can be the same as the seventh threshold, that is, also 10mV. It should be noted that the above thresholds can also be other values, not limited to the above examples, and this embodiment does not make specific limitations on this.

[0094] Optionally, the second pulse current condition judgment condition is: the range between the starting frame temperature data in the temperature time series data of all battery cells in the first time series data and the starting frame temperature data in the ambient temperature time series data is less than the ninth threshold.

[0095] Specifically, the cell temperature data and the ambient temperature data corresponding to the starting moment of the pulsed current condition are respectively the second frame data of the cell temperature data and the second frame data of the ambient temperature data. Then, at the starting moment of the pulsed current condition, for example, the temperature data of n cells is Temp = [Temp_1, Temp_2, Temp_3,..., Temp_n], the ambient temperature data is Temp_ambient, and the range between the two is: Temp_range = max(Temp, Temp_ambient) - min(Temp, Temp_ambient).

[0096] In one embodiment, the ninth threshold is 5°C; in other embodiments, the ninth threshold can also be other values, not limited to the above examples.

[0097] Optionally, the third pulsed current condition determination condition is: the lag time corresponding to the maximum value of the cross-correlation coefficient of the current time series data and the voltage time series data in the first time series data is less than the tenth threshold.

[0098] Specifically, taking the first preset time as 6s and the sampling rate as 1 frame / s as an example, the calculation of the cross-correlation coefficient of the current time series data and the voltage time series data in the first time series data is described below:

[0099] (1) When the voltage time series data of each cell is synchronized, each frame of current data in the current time series data is respectively subjected to cross-correlation calculation with each frame of voltage data in the voltage time series data of any cell to obtain cross-correlation coefficients with the same number of frames as the current time series data or the voltage time series data. For example, the first frame of current data in the current time series data is subjected to cross-correlation calculation with the second frame of voltage data in the voltage time series data to obtain the first cross-correlation coefficient, the second frame of current data in the current time series data is subjected to cross-correlation calculation with the third frame of voltage data in the voltage time series data to obtain the second cross-correlation coefficient, and so on. The sixth frame of current data in the current time series data is subjected to cross-correlation calculation with the first frame of voltage data in the voltage time series data to obtain the sixth cross-correlation coefficient, that is, 6 cross-correlation coefficients are obtained. The largest one of the 6 cross-correlation coefficients is found, and then the lag time is obtained.

[0100] (2) When the voltage timing data of each battery cell is asynchronous, the cross-correlation calculation is respectively performed on each frame of current data in the current timing data and each frame of voltage data in the voltage timing data of n battery cells, so as to obtain n cross-correlation coefficients with the same number of frames as the current timing data or the voltage timing data. For example, assuming that the battery pack includes n battery cells, the cross-correlation calculation is performed on the first frame of current data in the current timing data and the second frame of voltage data in the voltage timing data of each battery cell, and n cross-correlation coefficients are obtained. Similarly, 6n cross-correlation coefficients are finally obtained. Find the largest cross-correlation coefficient among the 6n cross-correlation coefficients, and then obtain the lag time.

[0101] Specifically, the tenth threshold is 3s; in other embodiments, the ninth threshold may also take other values, not limited to the above examples.

[0102] In this alternative embodiment, the current and voltage conditions in the first timing data are judged through the first pulsed current condition judgment condition, so as to avoid the influence of the current and voltage distribution conditions on the determination of the effective pulsed current condition. The temperature data in the first timing data is judged through the second pulsed current condition judgment condition, so as to avoid the influence of temperature detection errors on the determination of the effective pulsed current condition. The cross-correlation of the current and voltage data in the first timing data is judged through the third pulsed current condition judgment condition, so as to avoid the influence of the cross-correlation of the current and voltage data on the determination of the effective pulsed current condition, so as to accurately find the effective pulsed current condition and improve the accuracy of determining the internal resistance of each battery cell in the battery pack according to the effective pulsed current condition.

[0103] Optionally, when the above conditions are met, S400 can determine the internal resistance of each battery cell in the battery pack according to the current timing data and the voltage timing data in the first timing data, which can be determined according to the range of the current timing data and the range of the voltage timing data of each battery cell in the voltage timing data. As Figure 4 shown, it may specifically include:

[0104] S410: Judge whether the lag time corresponding to the maximum value of the cross-correlation coefficient of the current timing data and the voltage timing data in the first timing data is equal to zero.

[0105] S420: If the lag time corresponding to the maximum value of the cross-correlation coefficient is equal to 0, then determine the internal resistance of each battery cell in the battery pack according to the range of the current timing data in the first timing data and the range of the voltage timing data of each battery cell in the first timing data.

[0106] S430: If the lag time corresponding to the maximum value of the cross-correlation coefficient is not equal to 0, then determine the internal resistance of each cell in the battery pack according to the difference between the second-frame current data and the first-frame current data in the current time series data of the first time series data, and the difference between the p-th frame voltage data and the (p - 1)-th frame voltage data of the voltage time series data of each cell in the first time series data; where p = max_time_lag + 2, and max_time_lag is the lag time corresponding to the maximum value of the cross-correlation coefficient.

[0107] Specifically, in the case where the lag time max_time_lag corresponding to the maximum value of the cross-correlation coefficient is equal to 0, taking the first preset time as 6s and the sampling rate as 1 frame / s as an example, the maximum value of the current time series data in the first time series data is I_max = max(I_1, I_2, I_3, I_4, I_5, I_6), the minimum value of the current time series data in the first time series data is I_min = min(I_1, I_2, I_3, I_4, I_5, I_6), and the range of the current time series data in the first time series data is I_range1 = I_max - I_min. The maximum value of the voltage time series data of each cell in the first time series data is V_max_i = max(V_1_i, V_2_i, V_3_i, V_4_i, V_5_i, V_6_i), the minimum value of the voltage time series data of each cell in the first time series data is V_min_i = min(V_1_i, V_2_i, V_3_i, V_4_i, V_5_i, V_6_i), and the range of the voltage time series data of each cell in the first time series data is V_range1_i = V_max_i - V_min_i, where i is the serial number of the cell; the internal resistance of each cell in the battery pack is the absolute value of the ratio of the range of the voltage time series data of the corresponding cell to the range of the current time series data, and the expression can be R(i) = abs(V_range1_i / I_range1), and abs() represents taking the absolute value.

[0108] Specifically, when the lag time max_time_lag corresponding to the maximum value of the cross-correlation coefficient is not equal to 0, the difference I_range2 = I_2 - I_1 between the second-frame current data and the first-frame current data of the current time-series data in the first time-series data, where I_1 is the first-frame current data of the current time-series data and I_2 is the second-frame current data of the current time-series data. The difference V_range2_i = V_max_i_(2 + max_time_lag) - V_min_i_(1 + max_time_lag) between the (2 + max_time_lag)-th frame voltage data and the (1 + max_time_lag)-th frame voltage data of the voltage time-series data of each battery cell in the first time-series data, where i is the serial number of the battery cell, V_max_i_(2 + max_time_lag) is the maximum value of the (2 + max_time_lag)-th frame voltage data, and V_min_i_(1 + max_time_lag) is the minimum value of the (1 + max_time_lag)-th frame voltage data. The internal resistance of each battery cell in the battery pack is the absolute value of the ratio of the difference between the (2 + max_time_lag)-th frame voltage data and the (1 + max_time_lag)-th frame voltage data of the corresponding battery cell to the difference between the second-frame current data and the first-frame current data of the current time-series data. The expression can be R(i) = abs(V_range2_i / I_range2), and abs() represents taking the absolute value.

[0109] In this alternative embodiment, based on the difference in the maximum lag time between the current time-series data and the voltage time-series data in the first time-series data, the range of the current time-series data and the range of the voltage time-series data corresponding to the pulse current condition are extracted in different ways to calculate the internal resistance of each battery cell in the battery pack, solving the problem of the synchronization of current data and voltage data in the battery cell.

[0110] Optionally, after detecting the internal resistance of each battery cell in the battery pack, it is necessary to judge the consistency of the internal resistance of the battery pack, such as Figure 5 , the battery cell internal resistance detection method of the battery pack further includes the following steps:

[0111] S500: Determine the average internal resistance of all battery cells in the battery pack and the standard deviation of the internal resistance of all battery cells according to the internal resistance of each battery cell in the battery pack.

[0112] S600: Determine the internal resistance consistency coefficient of the battery pack according to the average internal resistance of all battery cells in the battery pack and the standard deviation of the internal resistance of all battery cells.

[0113] S700: Judge whether the internal resistance consistency coefficient of the battery pack is greater than the preset internal resistance consistency coefficient threshold.

[0114] S800: If it is determined that it is greater than the preset internal resistance consistency coefficient threshold, output a first abnormal reminder message for characterizing the abnormal internal resistance consistency.

[0115] Specifically, the internal resistance consistency coefficient R_consis_coefficient of the battery pack = R_std / R_mean, where R_std is the standard deviation of the internal resistances of all the battery cells in the battery pack, and R_mean is the average internal resistance of all the battery cells in the battery pack.

[0116] Specifically, for a normal battery pack, its internal resistance consistency coefficient should be very small. If the internal resistance consistency coefficient is large, it indicates that there is an abnormal internal resistance consistency in the battery pack. In one embodiment, the preset internal resistance consistency coefficient threshold can be 0.4 - 0.6. In this embodiment, the value is 0.5. When the internal resistance consistency coefficient of the battery pack is greater than 0.5, it characterizes the abnormal internal resistance consistency, and a first abnormal reminder message is output to the user. In one embodiment, the first abnormal reminder message can be prompted on the local display screen of the vehicle, or can be prompted through a user terminal, such as a mobile phone, a tablet computer, etc.

[0117] In this optional embodiment, normalizing the internal resistances of each battery cell in the battery pack to obtain the internal resistance consistency coefficient of the battery pack can eliminate the influence of factors such as different temperatures, states of charge (SOC), current intensities and directions on the internal resistance measurement. Furthermore, by calculating the internal resistance consistency coefficient, the degree of difference in internal resistance between each battery cell can be quantified, which is of great significance for maintaining the consistency of the overall performance of the battery pack and extending its service life.

[0118] Optionally, as Figure 6 , the battery cell internal resistance detection method of the battery pack further includes the following steps:

[0119] S900: Determine the average internal resistance of each battery cell in the battery pack within a continuous plurality of unit statistical time periods according to the internal resistances of each battery cell in the battery pack.

[0120] S1000: Judge whether the change value of the average internal resistance of each battery cell in the battery pack within two consecutive unit statistical time periods is greater than the preset change threshold.

[0121] S1100: If it is determined that it is greater than the preset change threshold, output a second abnormal reminder message for characterizing the abnormal internal resistance growth.

[0122] Specifically, the unit statistical time period can be a month, or a statistical time period such as a quarter or a half year. For a normal battery cell, its internal resistance should be relatively constant over a long period of time. If the internal resistance of a certain battery cell shows a significant change, it indicates that the internal resistance is abnormal. In one embodiment, taking the unit statistical time period as a month as an example, let R_normal(i, t) represent the average value of the internal resistances corresponding to all pulse current conditions of the i-th battery cell within the time range t, where t can be a month. Compare the change in internal resistance between the t-th month and the (t - 1)-th month. If the average internal resistance in the t-th month increases by more than a preset change threshold compared to the average internal resistance in the (t - 1)-th month, it is considered that the battery cell may have an abnormal increase in internal resistance, that is, output a second abnormal reminder message to remind the user. Specifically, the preset change threshold is 0.5.

[0123] In this alternative embodiment, as time goes by, by comparing and analyzing the internal resistances of each battery cell obtained in each unit statistical time period, battery cells showing abnormal behavior can be detected in a timely manner, which not only helps to identify potential faults early, but also provides a basis for formulating preventive maintenance plans, thereby reducing unexpected downtime and maintenance costs.

[0124] As Figure 7 shown, a battery pack battery cell internal resistance detection device 700 provided by an embodiment of the present invention includes:

[0125] A data acquisition module 710, configured to acquire battery pack operation timing data, where the battery pack operation timing data includes: current timing data of the battery pack, voltage timing data of each battery cell in the battery pack, temperature timing data of each battery cell in the battery pack, and ambient temperature timing data of the battery pack;

[0126] A pulse condition data determination module 720, configured to determine, according to the sampling time sequence of the battery pack operation timing data, timing data within a first preset time range in the battery pack operation timing data by using a precondition for judging a condition, to obtain first timing data;

[0127] A pulse condition validity judgment module 730, configured to judge whether the current timing data and the voltage timing data in the first timing data meet a first pulse current condition judgment condition, and judge whether the temperature timing data and the ambient temperature timing data in the first timing data meet a second pulse current condition judgment condition, and judge whether the cross-correlation coefficient between the current timing data and the voltage timing data in the first timing data meets a third pulse current condition judgment condition;

[0128] A battery cell internal resistance determination module 740, configured to, in the case where all judgments are satisfied, determine the internal resistances of each battery cell in the battery pack according to the current timing data and the voltage timing data in the first timing data.

[0129] Optionally, the timing data within the first preset time range is determined from the battery pack operation timing data by using the precondition judgment condition, and the obtained first timing data includes:

[0130] The timing data that meets the precondition judgment condition is determined from the battery operation timing data, and the timing data corresponding to the precondition is obtained;

[0131] Using the last frame of data in the timing data corresponding to the precondition as the starting frame data, the timing data within the first preset time range is intercepted from the battery operation timing data to obtain the first timing data.

[0132] Optionally, the precondition judgment condition is:

[0133] Within the second preset time range, the absolute value of the current timing data of the battery pack in the battery pack operation timing data is less than the first threshold; and,

[0134] Within the second preset time range, the standard deviation of the current timing data of the battery pack in the battery pack operation timing data is less than the second threshold; and,

[0135] Within the second preset time range, the standard deviation of the voltage timing data of each battery cell in the battery pack in the battery pack operation timing data is less than the third threshold.

[0136] Optionally, the first pulse current condition judgment condition is:

[0137] The range of the current timing data in the first timing data is greater than the fourth threshold; and,

[0138] The absolute value of the current timing data in the first timing data is less than the fifth threshold; and,

[0139] The absolute value of the second frame of current data in the current timing data in the first timing data is greater than the sixth threshold; and,

[0140] The range of the largest set of voltage timing data among the voltage timing data of each battery cell in the first timing data is greater than the seventh threshold; and,

[0141] The range of the smallest set of voltage timing data among the voltage timing data of each battery cell in the first timing data is greater than the eighth threshold;

[0142] And / or, the second pulse current condition judgment condition is:

[0143] The range between the second frame of temperature data in the temperature timing data of all battery cells in the first timing data and the second frame of temperature data in the ambient temperature timing data is less than the ninth threshold;

[0144] And / or, the determination condition of the third pulse current working condition is:

[0145] The lag time corresponding to the maximum value of the cross-correlation coefficient between the current time series data and the voltage time series data in the first time series data is less than the tenth threshold.

[0146] Optionally, determining the internal resistance of each battery cell in the battery pack according to the current time series data and the voltage time series data in the first time series data includes:

[0147] Judging whether the lag time corresponding to the maximum value of the cross-correlation coefficient between the current time series data and the voltage time series data in the first time series data is equal to zero;

[0148] If the lag time corresponding to the maximum value of the cross-correlation coefficient is equal to 0, determine the internal resistance of each battery cell in the battery pack according to the range of the current time series data in the first time series data and the range of the voltage time series data of each battery cell in the first time series data;

[0149] If the lag time corresponding to the maximum value of the cross-correlation coefficient is not equal to 0, determine the internal resistance of each battery cell in the battery pack according to the difference between the second-frame current data and the first-frame current data of the current time series data in the first time series data, and the difference between the p-frame voltage data and the (p - 1)-frame voltage data of the voltage time series data of each battery cell in the first time series data; where p = 2 + max_time_lag, and max_time_lag is the lag time corresponding to the maximum value of the cross-correlation coefficient.

[0150] Optionally, it further includes:

[0151] Determine the average internal resistance of all battery cells in the battery pack and the standard deviation of the internal resistances of all battery cells according to the internal resistances of each battery cell in the battery pack;

[0152] Determine the internal resistance consistency coefficient of the battery pack according to the average internal resistance of all battery cells in the battery pack and the standard deviation of the internal resistances of all battery cells;

[0153] Judge whether the internal resistance consistency coefficient of the battery pack is greater than the preset internal resistance consistency coefficient threshold;

[0154] If it is judged to be greater than the preset internal resistance consistency coefficient threshold, output the first abnormal reminder information for characterizing abnormal internal resistance consistency.

[0155] Optionally, it further includes:

[0156] Determine the average internal resistance of each battery cell in the battery pack within a plurality of consecutive unit statistical time periods according to the internal resistance of each battery cell in the battery pack;

[0157] Judge whether the change value of the average internal resistance of each battery cell in the battery pack within two consecutive unit statistical time periods is greater than a preset change threshold;

[0158] If it is judged that it is greater than the preset change threshold, output a second abnormal reminder message for characterizing abnormal internal resistance growth.

[0159] As Figure 8 As shown, an electronic device 800 provided by an embodiment of the present invention includes a memory 810 and a processor 820; the memory 810 is used to store a computer program; the processor 820 is used to implement the battery cell internal resistance detection method as described above when executing the computer program.

[0160] Or, an electronic device 800 includes a memory 810 and a processor 820 coupled to the memory 810; the memory 810 is configured to store a computer program; the processor 820 is configured to perform the following operations when executing the computer program:

[0161] Obtain battery pack operation timing data, where the battery pack operation timing data includes: current timing data of the battery pack, voltage timing data of each battery cell in the battery pack, temperature timing data of each battery cell in the battery pack, and ambient temperature timing data of the battery pack;

[0162] Use the precondition judgment conditions to determine the timing data within the first preset time range in the battery pack operation timing data to obtain first timing data;

[0163] Judge whether the current timing data and the voltage timing data in the first timing data meet the first pulsed current condition judgment conditions, and judge whether the temperature timing data and the ambient temperature timing data in the first timing data meet the second pulsed current condition judgment conditions, and judge whether the cross-correlation coefficient of the current timing data and the voltage timing data in the first timing data meets the third pulsed current condition judgment conditions;

[0164] If it is judged that all are satisfied, determine the internal resistance of each battery cell in the battery pack according to the current timing data and the voltage timing data in the first timing data.

[0165] A computer-readable storage medium provided by an embodiment of the present invention stores a computer program thereon, and when the computer program is executed by a processor, the battery cell internal resistance detection method as described above is implemented.

[0166] Alternatively, a non - volatile computer - readable storage medium stores a computer program thereon. When the computer program is executed by a processor, the processor performs the following operations:

[0167] Obtain the battery pack operation timing data, where the battery pack operation timing data includes: the current timing data of the battery pack, the voltage timing data of each battery cell in the battery pack, the temperature timing data of each battery cell in the battery pack, and the ambient temperature timing data of the battery pack;

[0168] Use the pre - condition judgment conditions to determine the timing data within the first preset time range in the battery pack operation timing data, and obtain the first timing data;

[0169] Judge whether the current timing data and the voltage timing data in the first timing data satisfy the first pulsed - current condition judgment conditions, and judge whether the temperature timing data and the ambient temperature timing data in the first timing data satisfy the second pulsed - current condition judgment conditions, and judge whether the cross - correlation coefficient of the current timing data and the voltage timing data in the first timing data satisfies the third pulsed - current condition judgment conditions;

[0170] If all the judgments are satisfied, determine the internal resistance of each battery cell in the battery pack according to the current timing data and the voltage timing data in the first timing data.

[0171] Now, an electronic device 800 that can be a server or a client of the present invention will be described. It is an example of a hardware device that can be applied to various aspects of the present invention. The electronic device 800 is intended to represent various forms of digital - electronic computer devices, such as, a laptop computer, a desktop computer, a workbench, a personal digital assistant, a server, a blade server, a mainframe computer, and other suitable computers. The electronic device 800 can also represent various forms of mobile devices, such as, a personal digital processor, a cellular phone, a smart phone, a wearable device, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0172] The electronic device 800 includes a computing unit that can perform various appropriate actions and processes according to a computer program stored in a read - only memory (ROM) or a computer program loaded from a storage unit into a random - access memory (RAM). In the RAM, various programs and data required for device operation can also be stored. The computing unit, the ROM, and the RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.

[0173] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above methods. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM), etc. In this application, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present invention. In addition, the functional units in each embodiment of the present invention can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0174] Although the present invention is disclosed as above, the scope of protection of the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will all fall within the scope of protection of the present invention.

Claims

1. A method for detecting the internal resistance of battery pack cells, characterized in that Including: Obtaining the battery pack operation timing data, where the battery pack operation timing data includes: the current timing data of the battery pack, the voltage timing data of each battery cell in the battery pack, the temperature timing data of each battery cell in the battery pack, and the ambient temperature timing data of the battery pack; Determining the timing data within a first preset time range in the battery pack operation timing data using the precondition judgment conditions to obtain first timing data; Judging whether the current timing data and the voltage timing data in the first timing data meet the first pulsed current condition judgment conditions, and judging whether the temperature timing data and the ambient temperature timing data in the first timing data meet the second pulsed current condition judgment conditions, and judging whether the cross-correlation coefficient of the current timing data and the voltage timing data in the first timing data meets the third pulsed current condition judgment conditions; If it is judged that all are satisfied, then determine the internal resistance of each battery cell in the battery pack according to the current timing data and the voltage timing data in the first timing data.

2. The method for detecting the internal resistance of the battery pack cell according to claim 1, wherein The step of determining the timing data within a first preset time range in the battery pack operation timing data using the precondition judgment conditions to obtain first timing data includes: Determining the timing data that meets the precondition judgment conditions in the battery operation timing data to obtain the timing data corresponding to the precondition; Using the last frame of data in the timing data corresponding to the precondition as the starting frame data, and intercepting the timing data within the first preset time range in the battery operation timing data to obtain the first timing data.

3. The method for detecting the internal resistance of the battery pack cell according to claim 2, wherein The precondition judgment conditions include: Within a second preset time range, the absolute value of the current timing data of the battery pack in the battery pack operation timing data is less than a first threshold; and, Within the second preset time range, the standard deviation of the current timing data of the battery pack in the battery pack operation timing data is less than a second threshold; and, Within the second preset time range, the standard deviation of the voltage timing data of each battery cell in the battery pack in the battery pack operation timing data is less than a third threshold.

4. The method for detecting the internal resistance of battery cells in a battery pack according to claim 1, wherein The first pulsed current condition judgment conditions include: The range of the current timing data in the first timing data is greater than a fourth threshold; and, The absolute value of the current timing data in the first timing data is less than a fifth threshold; and, The absolute value of the second-frame current data of the current timing data in the first timing data is greater than a sixth threshold; and, The range of the largest set of voltage timing data among the voltage timing data of each battery cell in the first timing data is greater than a seventh threshold; and, The range of the smallest set of voltage timing data among the voltage timing data of each battery cell in the first timing data is greater than an eighth threshold; And / or, the second pulsed current condition judgment conditions include: The range between the second-frame temperature data of the temperature timing data of all battery cells in the first timing data and the second-frame temperature data of the ambient temperature timing data is less than a ninth threshold; And / or, the third pulse current condition determination condition includes: The lag time corresponding to the maximum value of the cross-correlation coefficient between the current time series data and the voltage time series data in the first time series data is less than the tenth threshold.

5. The method for detecting the internal resistance of a battery pack cell according to claim 1, characterized in that, Determining the internal resistance of each cell in the battery pack according to the current time series data and the voltage time series data in the first time series data includes: Judging whether the lag time corresponding to the maximum value of the cross-correlation coefficient between the current time series data and the voltage time series data in the first time series data is equal to zero; If the lag time corresponding to the maximum value of the cross-correlation coefficient is equal to 0, determine the internal resistance of each cell in the battery pack according to the range of the current time series data in the first time series data and the range of the voltage time series data of each cell in the first time series data; If the lag time corresponding to the maximum value of the cross-correlation coefficient is not equal to 0, determine the internal resistance of each cell in the battery pack according to the difference between the second frame current data and the first frame current data of the current time series data in the first time series data, and the difference between the p-th frame voltage data and the (p-1)-th frame voltage data of the voltage time series data of each cell in the first time series data; where p = 2 + max_time_lag, and max_time_lag is the lag time corresponding to the maximum value of the cross-correlation coefficient.

6. The battery cell internal resistance detection method according to any one of claims 1 to 5, characterized in that, It further includes: Determine the average internal resistance of all cells in the battery pack and the standard deviation of the internal resistances of all cells according to the internal resistance of each cell in the battery pack; Determine the internal resistance consistency coefficient of the battery pack according to the average internal resistance of all cells in the battery pack and the standard deviation of the internal resistances of all cells; Judge whether the internal resistance consistency coefficient of the battery pack is greater than a preset internal resistance consistency coefficient threshold; If it is judged to be greater than the preset internal resistance consistency coefficient threshold, output a first abnormal reminder message for characterizing abnormal internal resistance consistency.

7. The battery cell internal resistance detection method according to any one of claims 1 to 5, characterized in that, It further includes: Respectively determine the average internal resistance of each cell in the battery pack within a continuous plurality of unit statistical time periods according to the internal resistance of each cell in the battery pack; Judge whether the change value of the average internal resistance of a single cell in the battery pack within two consecutive unit statistical time periods is greater than a preset change threshold; If it is judged to be greater than the preset change threshold, output a second abnormal reminder message for characterizing abnormal growth of the internal resistance of the cell.

8. A battery pack cell internal resistance detection device, characterized in that It includes: A data acquisition module for acquiring battery pack operation time series data, where the battery pack operation time series data includes: the current time series data of the battery pack, the voltage time series data of each cell in the battery pack, the temperature time series data of each cell in the battery pack, and the ambient temperature time series data of the battery pack; A pulse condition data determination module for determining the time series data within a first preset time range in the battery pack operation time series data according to the sampling time sequence of the battery pack operation time series data, and obtaining first time series data; The pulse condition effectiveness judgment module is used to judge whether the current time series data and the voltage time series data in the first time series data meet the first pulse current condition judgment condition, and judge whether the temperature time series data and the ambient temperature time series data in the first time series data meet the second pulse current condition judgment condition, and judge whether the cross-correlation coefficient of the current time series data and the voltage time series data in the first time series data meets the third pulse current condition judgment condition; The cell internal resistance determination module is used to, when all the judgments are satisfied, determine the internal resistance of each cell in the battery pack according to the current time series data and the voltage time series data in the first time series data.

9. An electronic device, characterized in that, It includes a memory and a processor; The memory is used to store computer programs; The processor is used to, when executing the computer program, implement the battery pack cell internal resistance detection method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, A computer program is stored on the storage medium, and when the computer program is executed by the processor, the battery pack cell internal resistance detection method according to any one of claims 1 to 7 is implemented.

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