Method, device, equipment and medium for measuring battery impedance

Abstract

The present application discloses a method, device, equipment and medium for measuring battery impedance. The method includes: obtaining first operating condition data of the battery during use, where the first operating condition data is used to reflect the operating state of the battery. When measuring the battery impedance, determining a suitable length range of the sampling time window, and determining a sampling time window that meets the time length range. According to the obtained first operating condition data, determining second operating condition data corresponding to the sampling time window. Then, based on the second operating condition data, determining whether the sampling time window meets a preset condition. If the sampling time window meets the preset condition, the impedance of the battery can be determined based on the second operating condition data. Through the method for measuring battery impedance provided by the present application, the impedance of the battery can be measured in an online application scenario of the battery, and no special current excitation mode needs to be introduced, which is convenient for users to use.

Description

Technical Field

[0001] This application relates to the technical field of power batteries, and particularly to a method, device, equipment, and medium for measuring battery impedance. Background Art

[0002] Currently, the measurement of battery impedance mainly relies on electrochemical means such as electrochemical impedance spectroscopy (EIS). When measuring battery impedance using EIS, it often requires a long measurement time, generally 10 - 20 hours, making it difficult to apply to online measurement scenarios, such as when users are using electric vehicles. Moreover, most online measurement methods require special current excitation modes. For example, a sine wave signal with a specific frequency will also affect the normal use of users. Summary of the Invention

[0003] In view of this, embodiments of this application provide a method, device, equipment, and medium for measuring battery impedance, so as to measure the impedance of the battery online and facilitate user use.

[0004] In a first aspect, embodiments of this application provide a method for measuring battery impedance, the method including:

[0005] Obtain first working condition data during the use of the battery, where the first working condition data is used to reflect the working state of the battery;

[0006] Determine the length range of the sampling time window, and determine the sampling time window based on the length range;

[0007] Determine second working condition data corresponding to the sampling time window based on the first working condition data;

[0008] Judge whether the sampling time window meets a preset condition based on the second working condition data;

[0009] When the sampling time window meets the preset condition, determine the impedance of the battery based on the second working condition data.

[0010] In a possible implementation, the first working condition data includes voltage, current, temperature, and state of charge (SOC);

[0011] The second working condition data includes voltage, current, temperature, and SOC, and the second working condition data is the data in the first working condition data.

[0012] In a possible implementation, the judging whether the sampling time window meets the preset condition based on the second working condition data includes:

[0013] Determine the change interval of the corresponding current within the sampling time window;

[0014] Determine whether the change range of the current satisfies a preset current change range, where the change range of the current represents the current change at different frequencies;

[0015] When the sampling time window meets the preset conditions, determining the impedance of the battery based on the second operating condition data includes:

[0016] When the change range of the current satisfies the preset current change range, determining the impedance of the battery based on the voltage and current in the second operating condition data.

[0017] In a possible implementation manner, determining whether the sampling time window meets the preset conditions based on the second operating condition data includes:

[0018] Determine the change range of the corresponding temperature within the sampling time window;

[0019] Determine whether the change range of the temperature satisfies a preset temperature change range;

[0020] When the sampling time window meets the preset conditions, determining the impedance of the battery based on the second operating condition data includes:

[0021] When the change range of the temperature satisfies the preset temperature change range, determining the impedance of the battery based on the voltage and current in the second operating condition data.

[0022] In a possible implementation manner, determining whether the sampling time window meets the pre-conditions based on the second operating condition data includes:

[0023] Pre-measure the first impedance of the battery based on the electrochemical impedance spectrum EIS;

[0024] Determine the second impedance of the battery based on the voltage and current in the second operating condition data;

[0025] Determine whether the difference between the first impedance and the second impedance satisfies a preset error condition;

[0026] When the sampling time window meets the preset conditions, determining the impedance of the battery based on the second operating condition data includes:

[0027] When the difference between the first impedance and the second impedance satisfies the preset error condition, determine the second impedance as the impedance of the battery.

[0028] In a possible implementation manner, the determining the length range of the sampling time window includes:

[0029] Determine the length range of the sampling time window based on the operating frequency range of the battery.

[0030] In a possible implementation, the method further includes:

[0031] Obtaining a plurality of the sampling time windows within a target preset time period;

[0032] Determining the similarity between the working condition data corresponding to the plurality of sampling time windows;

[0033] Performing weighted averaging on the impedances of the sampling time windows corresponding to the similarities that meet the preset similarity conditions to obtain a target impedance, where the target impedance is the impedance of the battery within the target preset time period.

[0034] In a second aspect, an embodiment of the present application provides a device for measuring battery impedance, and the device includes: an acquisition module, a first determination module, a second determination module, a judgment module, and a third determination module;

[0035] The acquisition module is configured to acquire first working condition data during the use of the battery, and the first working condition data is used to reflect the working state of the battery;

[0036] The first determination module is configured to determine the length range of the sampling time window and determine the sampling time window based on the length range;

[0037] The second determination module is configured to determine second working condition data corresponding to the sampling time window based on the first working condition data;

[0038] The judgment module is configured to judge whether the sampling time window meets the preset conditions based on the second working condition data;

[0039] The third determination module is configured to determine the impedance of the battery based on the second working condition data when the sampling time window meets the preset conditions.

[0040] In a third aspect, an embodiment of the present application provides a device for measuring battery impedance, and the device includes: a memory and a processor;

[0041] The memory is used to store relevant program codes;

[0042] The processor is used to call the program codes to execute the method for measuring battery impedance according to any one of the implementations in the first aspect above.

[0043] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, and the computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method for measuring battery impedance according to any one of the implementations in the first aspect above.

[0044] As can be seen, the embodiments of the present application have the following beneficial effects:

[0045] In the above implementation manner of the embodiments of the present application, when measuring the impedance of a battery online, first obtain the first operating condition data of the battery during use, and the first operating condition data is used to reflect the working state of the battery. For example, the voltage, current, temperature, and SOC of the battery, etc. When measuring the battery impedance, the operating condition data during the discharge process of the battery can be sampled for a certain period of time, that is, determine the length range of a suitable sampling time window and determine the sampling time window that meets the time length range. According to the obtained first operating condition data of the battery, determine the second operating condition data corresponding to the sampling time window, that is, the second operating condition data is part of the first operating condition data. Then, based on the second operating condition data, determine whether the sampling time window meets the preset conditions, that is, whether the operating condition data within the sampling time window can be used to measure the impedance of the battery. If the sampling time window meets the preset conditions, the impedance of the battery can be determined based on the second operating condition data. Through the battery impedance measurement method provided by the present application, the impedance of the battery can be measured in the online application scenario of the battery, and no special current excitation mode needs to be introduced, which is convenient for users to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments provided in the present application. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings.

[0047] Figure 1 is a flowchart of a method for measuring the impedance of a battery provided by an embodiment of the present application;

[0048] Figure 2 is a schematic diagram of a device for measuring the impedance of a battery provided by an embodiment of the present application;

[0049] Figure 3 is a schematic diagram of a device for measuring the impedance of a battery provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. The described embodiments are only exemplary embodiments of the present application and not all implementation manners. Those skilled in the art can obtain other embodiments without creative work based on the embodiments of the present application, and these embodiments are also within the protection scope of the present application.

[0051] Currently, the measurement of battery impedance mainly relies on technical means such as Electrochemical Impedance Spectroscopy (EIS). That is, a small-amplitude alternating potential wave with different frequencies is applied to the electrochemical system, and the ratio of the alternating potential to the current signal (this ratio is the impedance of the system) is measured as a function of the sine wave frequency ω. When measuring battery impedance using EIS, it often requires a long measurement time, generally 10 to 20 hours, making it difficult to apply in on-line measurement scenarios, such as when users are using electric vehicles. Moreover, most on-line measurement methods require special current excitation modes. For example, a sine wave signal with a specific frequency will also affect the normal use of users.

[0052] Based on this, the embodiments of the present application provide a method for measuring battery impedance, so that the impedance of the battery can be measured in the on-line application scenario of the battery without affecting the use of the user. Specifically, when measuring the impedance of the battery on-line, first obtain the first operating condition data of the battery during use, and this first operating condition data is used to reflect the working state of the battery. For example, the voltage, current, temperature, and SOC of the battery, etc. When measuring the battery impedance, the operating condition data during the discharge process of the battery for a certain period of time can be sampled, that is, determine the length range of the appropriate sampling time window and determine the sampling time window that meets the time length range. According to the obtained first operating condition data of the battery, determine the second operating condition data corresponding to the sampling time window, that is, this second operating condition data is part of the first operating condition data. Then, based on the second operating condition data, determine whether the sampling time window meets the preset conditions, that is, whether the operating condition data within the sampling time window can be used to measure the impedance of the battery. If the sampling time window meets the preset conditions, the impedance of the battery can be determined based on the second operating condition data. Through the method for measuring battery impedance provided by the present application, the impedance of the battery can be measured in the on-line application scenario of the battery, and there is no need to introduce a special current excitation mode, which is convenient for users to use.

[0053] Next, the method for measuring battery impedance provided by the embodiments of the present application will be described with reference to the accompanying drawings.

[0054] See Figure 1 , Figure 1 which is a flowchart of a method for measuring battery impedance provided by an embodiment of the present application.

[0055] The method mainly includes the following steps:

[0056] S101: Obtain the first operating condition data of the battery during use, and this first operating condition data is used to reflect the working state of the battery.

[0057] The battery provided by the embodiments of the present application can be a power battery for an electric vehicle. When the user is using the electric vehicle, it means that the battery is in an online application scenario. To measure the impedance of the battery, it is necessary to obtain the first operating condition data of the battery during use, where the first operating condition data is used to reflect the operating state of the battery. For example, the first operating condition data may include: the voltage, current, temperature, and state of charge (SOC) of the battery, etc., where SOC represents the percentage of the remaining capacity of the battery to the fully charged capacity of the battery. As the battery discharges and is used, the voltage, current, temperature, and SOC of the battery will all change, affecting the impedance of the battery.

[0058] In a possible implementation, the battery pack in the electric vehicle contains sensors that can collect the battery voltage, current, and temperature, which can collect the battery voltage, current, and temperature, and then estimate the SOC of the battery based on the current. For example, the ampere-hour integration method, that is, by integrating time and current to calculate the discharge amount of the battery, so as to obtain the SOC of the battery. During the use of the electric vehicle, the battery management system (BMS) can periodically send control signals to the sensors to control each sensor to collect the battery voltage, current, and temperature. Among them, the main function of the BMS is to intelligently manage and maintain each battery unit, prevent the battery from overcharging and over-discharging, extend the service life of the battery, and monitor the state of the battery.

[0059] S102: Determine the length range of the sampling time window, and determine the sampling time window based on this length range.

[0060] When calculating the impedance of the battery, since the impedance will change during the use of the battery, in order to avoid the large change in battery power from affecting the impedance state of the battery as much as possible, the operating condition data of the battery within a period of time can be sampled to measure the impedance of the battery during this sampling time. A possible implementation is that the length range of the sampling time window can be determined according to the operating frequency range of the battery. Usually, the battery of the electric vehicle operates in a low-frequency region, such as the operating frequency is between 0.001 Hz and 1 Hz, and the length range of the sampling time window can be determined according to the operating frequency range of the battery. For example, the sampling time window T can be selected between 200 - 600 s. After determining the length range that the sampling time window needs to meet, a specific sampling time window T is determined within this length range.

[0061] It should be noted that the sampling time window described in the above embodiments is only an exemplary description, and the embodiments of the present application do not limit the specific value of the sampling time window. In actual applications, the sampling time window can be determined according to specific scenario requirements.

[0062] S103: Determine the second operating condition data corresponding to the sampling time window based on the first operating condition data.

[0063] After determining the sampling time window, since the first operating condition data of the battery during use has been obtained, the second operating condition data corresponding to the sampling time window can be determined based on the first operating condition data. That is, the second operating condition data is a part of the data sampled and selected from the first operating condition data. Among them, the second operating condition data includes voltage, current, temperature, and SOC, etc.

[0064] S104: Determine whether the sampling time window meets the preset conditions based on the second operating condition data.

[0065] After obtaining the second operating condition data corresponding to the sampling time window, it can be determined whether the sampling time window meets the preset conditions based on the second operating condition data. For example, since the current of the battery changes during discharge, the impedance of the battery is different under different frequencies of current. If the frequency of the current covered within the obtained sampling time window hardly changes, the distribution characteristics of the impedance with frequency cannot be well reflected. Therefore, this sampling time window does not meet the preset conditions.

[0066] S105: When the sampling time window meets the preset conditions, determine the impedance of the battery based on the second operating condition data.

[0067] When it is determined based on the second operating condition data that the sampling time window meets the preset conditions, the impedance of the battery under this operating condition can be determined.

[0068] The principle of using the second operating condition data to judge the sampling time window will be specifically introduced below.

[0069] In a possible implementation, the sampling time window can be judged according to the current in the second operating condition data. Specifically, the change interval corresponding to the current within the sampling time window can be determined, and it can be judged whether the change interval of the current meets the preset current change interval. When the change interval of the current meets the preset current change interval, it indicates that the sampling time window meets the preset conditions, and the impedance of the battery can be determined according to the voltage and current in the second operating condition data. Specifically, during the discharge process of the battery, the current fluctuates with the discharge frequency of the battery. In order to make the current within the sampling time window cover a wider frequency range and better reflect the characteristics of the battery impedance, the range, standard deviation, etc. of the current within the sampling time window can be used to determine the change interval of the current. Only when the change interval of the current with frequency exceeds the preset change interval can it be determined that the fluctuation of the current with frequency meets the conditions, that is, the sampling time window meets the preset conditions. Then, the impedance of the battery can be determined according to the voltage and current in the second operating condition data. For example, perform Fourier transform on the voltage and current to calculate the impedance within this time window.

[0070] It should be noted that, since the frequency of the battery discharge current will also change within the sampling time window, the impedance obtained based on the voltage and current is actually the impedance distribution with frequency, that is, the battery impedance at different frequencies can be obtained.

[0071] In addition, the principle of judging whether the sampling time window meets the preset condition according to the voltage is the same as the principle of judging whether the sampling time window meets the preset condition according to the current in the above embodiment, and will not be repeated here.

[0072] In another possible implementation, the sampling time window can be judged according to the temperature in the second operating condition data. Specifically, the temperature variation interval in the sampling time window can be determined to determine whether the temperature variation interval meets the preset temperature variation interval. When the temperature variation interval meets the preset temperature variation interval, it indicates that the sampling time window meets the preset conditions, and the impedance of the battery can be determined according to the voltage and current in the second operating condition data. Specifically, since the temperature changes during the use of the battery, the temperature will affect the impedance of the battery. Therefore, in order to eliminate the influence of temperature changes on the battery impedance as much as possible, the temperature variation interval in the sampling time window can be first determined. When the temperature variation interval is less than the preset temperature variation interval, it indicates that the temperature change in the sampling time window does not have a significant effect on the impedance of the battery, and meets the requirements, so the sampling time window meets the preset conditions, and the impedance of the battery can be calculated according to the voltage and current in the second operating condition data.

[0073] In the above embodiments, the sampling time window is screened in advance by using voltage, current or temperature, and the impedance of the battery is calculated when the sampling time window that meets the preset conditions is obtained. In another possible implementation manner, after obtaining the working condition data corresponding to the sampling time window, the impedance under the sampling time window can be calculated first, and then compared with the pre-determined battery impedance to determine whether the error between the two impedances meets the preset error condition, so as to screen the sampling time window. Specifically, the first impedance of the battery can be obtained by using EIS in advance, and then the second impedance of the battery can be determined by using the voltage and current in the second working condition data. Compare the first impedance and the second impedance to obtain the difference in impedance, and determine whether the difference meets the preset error condition. If the difference meets the preset error condition, it indicates that the impedance corresponding to the sampling time window meets the requirements, that is, the sampling time window meets the preset conditions, and the second impedance calculated by using the second working condition data can be used as the impedance of the battery. When judging the difference between the first impedance and the second impedance, a possible implementation manner is to judge whether the difference between the first impedance and the second impedance is less than the preset error. If it is less, it indicates that the second impedance meets the requirements, that is, the sampling time window meets the preset conditions. In addition, the preset error of the impedance can be determined in advance through experiments, and a classification model is established by using the error of the impedance. When the difference between the actually measured impedance and the pre-determined impedance is less than the preset error, it is classified as a qualified impedance model; when the difference between the actually measured impedance and the pre-determined impedance is greater than or equal to the preset error, it is classified as an unqualified impedance model.

[0074] In the above embodiments of the present application, in the online application scenario of the battery, the impedance of the battery can be measured by appropriately sampling the working condition data of the battery without introducing a special current excitation mode, which is convenient for users to use.

[0075] Since the above embodiments can determine the battery impedance under a specific time window, based on the above method embodiments, the present application also provides a possible implementation manner, that is, the impedance of the battery can be measured over a relatively long period of time. Specifically, when implementing, multiple sampling time windows are obtained within the target preset time period, and according to the method provided by the above embodiments, the working condition data and impedance corresponding to each sampling time window are obtained, and then the similarity between the working condition data corresponding to different sampling time windows is determined. When the similarity meets the preset similarity condition, the multiple sampling time windows corresponding to the similarity are determined. The impedances corresponding to the multiple sampling time windows are weighted and averaged to obtain the target impedance, and the target impedance is the impedance of the battery within the target preset time period. Among them, the weight corresponding to each sampling time window can be set according to the actual scenario, and the embodiments of the present application do not limit this. In addition, the multiple sampling time windows within the target preset time period can be screened sampling time windows, that is, all meet the preset conditions.

[0076] In specific implementation, the sampling time windows with similar operating conditions can be determined according to the temperature or SOC in each sampling time window, that is, when the similarity of the temperatures corresponding to different sampling time windows is greater than the preset similarity, it indicates that the sampling time windows meeting the preset similarity conditions have similar operating conditions, and the impedances corresponding to the above sampling time windows can be weighted and averaged to obtain the target impedance. For example, the sampling time windows obtained within the target preset time period are T1, T2, T3, T4, and T5 respectively. The temperature corresponding to the sampling time window T1 is t1, the impedance is z1, and the weight is w1. The temperature corresponding to the sampling time window T2 is t2, the impedance is z2, and the weight is w2, and so on. The temperature corresponding to the sampling time window T5 is t5, the impedance is z5, and the weight is w5. Then, the similarities between t1, t2, t3, t4, and t5 are calculated pairwise. In this embodiment, the similarity can be represented by the difference between two temperatures, and the smaller the difference, the higher the similarity. In this application scenario, if the temperatures with a similarity greater than the preset similarity are determined to be t1, t3, and t4, then the target impedance z = (z1 * w1 + z3 * w3 + z4 * w4) / (w1 + w2 + w3 + w4) can be determined.

[0077] It should be noted that the implementation method for obtaining the target impedance in the above embodiment is only an exemplary illustration and does not impose any formal limitation on this application. For the principle of determining the sampling time windows with similar operating conditions according to the SOC of the battery, refer to the above embodiment and will not be elaborated here.

[0078] In another possible implementation, the operating condition data (temperature, SOC) of multiple sampling time windows within the target preset time period can also be used to establish a model based on the influence of temperature and SOC on impedance, fit the correlation relationship between temperature, SOC, and impedance, and determine the multiple impedances corresponding to the temperature and SOC within the target preset time period based on the established model, and then perform weighted averaging on the above multiple impedances to obtain the target impedance.

[0079] After obtaining the impedance of the battery, an equivalent circuit model of the battery can be composed of elements such as resistors, capacitors, and inductors, which can be used for subsequent battery aging analysis, abnormal detection analysis, etc. For example, first obtain the voltage, current, and impedance during the actual application process of the battery, and then determine the theoretical impedance corresponding to the equivalent circuit model according to the voltage and current, and compare the actual impedance with the theoretical impedance for battery aging analysis or abnormal detection.

[0080] Based on the above method embodiments, an embodiment of this application also provides a measuring device for battery impedance. Refer to Figure 2 , Figure 2 which is a schematic diagram of a measuring device for battery impedance provided by an embodiment of this application.

[0081] The device 200 includes: an acquisition module 201, a first determination module 202, a second determination module 203, a judgment module 204, and a third determination module 205;

[0082] The acquisition module 201 is configured to acquire first operating condition data during the use of the battery, and the first operating condition data is used to reflect the working state of the battery;

[0083] The first determination module 202 is configured to determine the length range of the sampling time window and determine the sampling time window based on the length range;

[0084] The second determination module 203 is configured to determine second operating condition data corresponding to the sampling time window based on the first operating condition data;

[0085] The judgment module 204 is configured to judge whether the sampling time window meets a preset condition based on the second operating condition data;

[0086] The third determination module 205 is configured to determine the impedance of the battery based on the second operating condition data when the sampling time window meets the preset condition.

[0087] In a possible implementation manner, the first operating condition data includes voltage, current, temperature, and state of charge SOC; the second operating condition data includes voltage, current, temperature, and SOC, and the second operating condition data is the data in the first operating condition data.

[0088] In a possible implementation manner, the judgment module 204 is specifically configured to determine the change interval of the corresponding current within the sampling time window; judge whether the change interval of the current meets the preset current change interval, and the change interval of the current represents the current change at different frequencies;

[0089] The third determination module 205 is specifically configured to determine the impedance of the battery based on the voltage and current in the second operating condition data when the change interval of the current meets the preset current change interval.

[0090] In a possible implementation manner, the judgment module 204 is specifically configured to determine the change interval of the corresponding temperature within the sampling time window; judge whether the change interval of the temperature meets the preset temperature change interval;

[0091] The third determination module 205 is specifically configured to determine the impedance of the battery based on the voltage and current in the second operating condition data when the change interval of the temperature meets the preset temperature change interval.

[0092] In a possible implementation, the determination module 204 is specifically configured to pre-measure a first impedance of the battery based on an Electrochemical Impedance Spectroscopy (EIS); determine a second impedance of the battery based on the voltage and current in the second operating condition data; and determine whether a difference between the first impedance and the second impedance meets a preset error condition.

[0093] The third determination module 205 is specifically configured to, when the difference between the first impedance and the second impedance meets the preset error condition, determine the second impedance as the impedance of the battery.

[0094] In a possible implementation, the first determination module 202 is specifically configured to determine a length range of the sampling time window based on an operating frequency range of the battery.

[0095] In a possible implementation, the apparatus 200 is further configured to obtain a plurality of the sampling time windows within a target preset time period; determine a similarity between the operating condition data corresponding to the plurality of the sampling time windows; and perform weighted averaging on the impedances of the sampling time windows corresponding to the similarities that meet a preset similarity condition to obtain a target impedance, where the target impedance is the impedance of the battery within the target preset time period.

[0096] Based on the above method embodiments and apparatus embodiments, an embodiment of the present application further provides a measurement device for battery impedance. Refer to Figure 3 , Figure 3 which is a schematic diagram of a measurement device for battery impedance provided by an embodiment of the present application.

[0097] The device 300 includes: a memory 301 and a processor 302;

[0098] The memory 301 is used to store relevant program codes;

[0099] The processor 302 is used to call the program codes to execute the method for measuring battery impedance described in the above method embodiments.

[0100] In addition, an embodiment of the present application further provides a computer-readable storage medium, where the computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method for measuring battery impedance described in the above method embodiments.

[0101] It should be noted that the embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. In particular, for the system or device embodiments, since they are basically similar to the method embodiments, they are described relatively simply. For the relevant parts, reference can be made to the descriptions in the method embodiments. The device embodiments described above are merely illustrative. The units or modules described as separate components may or may not be physically separated. The components shown as units or modules may or may not be physical modules, that is, they may be located in one place or distributed to multiple network units. Some or all of the units or modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without creative efforts.

[0102] It should be understood that in this application, "at least one (item)" means one or more, and "a plurality" means two or more. "And / or" is used to describe the association relationship of associated objects and indicates that three relationships can exist. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist at the same time. Here, A and B can be singular or plural. The character " / " generally means that the associated objects before and after are in an "or" relationship. "At least one (one) of the following" or its similar expression means any combination of these items, including any combination of single items (ones) or plural items (ones). For example, at least one (one) of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0103] It should also be noted that in this article, relative terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

[0104] The steps of the methods or algorithms described in connection with the embodiments disclosed herein may be implemented directly in hardware, in a software module executed by a processor, or in a combination thereof. The software module may be placed in a random access memory (RAM), memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0105] The foregoing description of the disclosed embodiments enables those skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for measuring battery impedance, characterized in that, The method includes: Obtaining first operating condition data during battery use, where the first operating condition data is used to reflect the operating state of the battery; Determining the length range of the sampling time window, and determining the sampling time window based on the length range; Determining second operating condition data corresponding to the sampling time window based on the first operating condition data; the second operating condition data is data in the first operating condition data; Judging whether the sampling time window meets a preset condition based on the second operating condition data; When the sampling time window meets the preset condition, determining the impedance of the battery based on the second operating condition data; Obtaining a plurality of the sampling time windows within a target preset time period; the plurality of sampling time windows are sampling time windows that meet the preset condition; Determining the similarity between the operating condition data corresponding to the plurality of sampling time windows; Performing weighted averaging on the impedances of the sampling time windows corresponding to the similarities that meet the preset similarity condition to obtain a target impedance, where the target impedance is the impedance of the battery within the target preset time period.

2. The method according to claim 1, wherein The first operating condition data includes voltage, current, temperature, and state of charge (SOC); The second operating condition data includes voltage, current, temperature, and SOC, and the second operating condition data is data in the first operating condition data.

3. The method according to claim 2, wherein The judging whether the sampling time window meets the preset condition based on the second operating condition data includes: Determining the change interval of the corresponding current within the sampling time window; Judging whether the change interval of the current meets a preset current change interval, where the change interval of the current represents the current change at different frequencies; The determining the impedance of the battery based on the second operating condition data when the sampling time window meets the preset condition includes: When the change interval of the current meets the preset current change interval, determining the impedance of the battery based on the voltage and current in the second operating condition data.

4. The method according to claim 2, wherein The judging whether the sampling time window meets the preset condition based on the second operating condition data includes: Determining the change interval of the corresponding temperature within the sampling time window; Judging whether the change interval of the temperature meets a preset temperature change interval; The determining the impedance of the battery based on the second operating condition data when the sampling time window meets the preset condition includes: When the change interval of the temperature meets the preset temperature change interval, determining the impedance of the battery based on the voltage and current in the second operating condition data.

5. The method according to claim 2, wherein The judging whether the sampling time window meets the preset condition based on the second operating condition data includes: Pre-measuring a first impedance of the battery based on electrochemical impedance spectroscopy (EIS); Determining a second impedance of the battery based on the voltage and current in the second operating condition data; Judging whether the difference between the first impedance and the second impedance meets a preset error condition; The determining the impedance of the battery based on the second operating condition data when the sampling time window meets the preset condition includes: When the difference between the first impedance and the second impedance meets the preset error condition, determining the second impedance as the impedance of the battery.

6. The method according to claim 1, wherein The determining the length range of the sampling time window includes: Determine the length range of the sampling time window based on the operating frequency range of the battery.

7. A measuring device for battery impedance, characterized in that, The device includes: an acquisition module, a first determination module, a second determination module, a judgment module, and a third determination module; The acquisition module is configured to acquire first operating condition data during the use of the battery, and the first operating condition data is used to reflect the operating state of the battery; The first determination module is configured to determine the length range of the sampling time window, and determine the sampling time window based on the length range; The second determination module is configured to determine second operating condition data corresponding to the sampling time window based on the first operating condition data; the second operating condition data is data in the first operating condition data; The judgment module is configured to judge whether the sampling time window meets a preset condition based on the second operating condition data; The third determination module is configured to determine the impedance of the battery based on the second operating condition data when the sampling time window meets the preset condition; The device is further configured to acquire a plurality of the sampling time windows within a target preset time period; the plurality of sampling time windows are sampling time windows that meet the preset condition; determine the similarity between the operating condition data corresponding to the plurality of sampling time windows; perform weighted averaging on the impedances of the sampling time windows corresponding to the similarities that meet the preset similarity condition to obtain a target impedance, and the target impedance is the impedance of the battery within the target preset time period.

8. A measuring device for battery impedance, characterized in that, The device includes: a memory and a processor; The memory is used to store relevant program codes; The processor is used to call the program codes to execute the method for measuring the impedance of the battery according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method for measuring the impedance of the battery according to any one of claims 1 to 6.

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