Method and apparatus for acquiring available capacity of power battery, device, and storage medium

Abstract

A method and apparatus for acquiring an available capacity of a power battery, a device, and a storage medium. The acquisition method comprises: acquiring historical charging data of a power battery in a preset time period (S10), the historical charging data comprising complete charging data of at least one charging cycle; extracting interval charging data of a pre-acquired SOC interval from each piece of complete charging data (S20); for each piece of interval charging data, acquiring a ratio of the charged capacity of the interval charging data to a compensation value (S30), the compensation value being a rated capacity compensation value corresponding to a charging depth of the interval charging data; and determining a preset quantile of all the ratios as an available capacity of the power battery (S40). The method for acquiring an available capacity of a power battery greatly improves the accuracy of a result of acquiring the available capacity of the power battery.

Description

Method, device and equipment for obtaining available capacity of power battery and storage medium

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of the following patent applications, the contents of which are incorporated herein by reference in their entirety:

[0003] Chinese Patent Application No. 202411352945.X, filed on September 26, 2024, with the China National Intellectual Property Administration, and entitled “Method, device and equipment for obtaining available capacity of power battery and storage medium”. TECHNICAL FIELD

[0004] The present application relates to the technical field of batteries, in particular to a method, device and equipment for obtaining available capacity of a power battery and a storage medium. BACKGROUND

[0005] The available capacity of a power battery is one of the indicators that customers focus on in scenarios such as after-sales of new energy vehicles and trading of second-hand vehicles. During the use of the power battery, the available capacity of the power battery will continuously decrease with the increase of the driving mileage and the number of charging cycles, and the available capacity of the power battery is also affected by factors such as the software strategy of the battery management system (BMS). The proportion of new energy vehicles in the automobile market is increasing, and the number of electric vehicles flowing into the second-hand vehicle market is also increasing. The battery capacity detection technical solution in the related art obtains the battery capacity detection result by recording the fluctuation of the SOC drift value within the SOC drift range when 1% of the power is charged. The accuracy of the available capacity detection result of the battery is low, and therefore there is an urgent need to develop a technical solution for obtaining the available capacity of the power battery that improves the accuracy.

[0006] The above statements are only used to provide background technical information related to the present application, and do not necessarily constitute the prior art. SUMMARY

[0007] In view of the problem of low accuracy of the detection result of the battery capacity detection technical solution in the related art, the present application provides a method, device and equipment for obtaining the available capacity of a power battery and a storage medium to improve the accuracy of the detection result of the battery capacity detection.

[0008] In a first aspect of the embodiments of the present application, a method for obtaining the available capacity of a power battery is provided, comprising:

[0009] obtaining historical charging data of a preset time period of the power battery, the historical charging data comprising complete charging data of at least one charging;

[0010] extracting interval charging data of a pre-acquired SOC interval from each of the complete charging data.

[0011] For each of the interval charging data, a ratio of a compensation value and a charging capacity of the interval charging data is obtained; the compensation value is a rated capacity compensation value corresponding to a charging depth of the interval charging data;

[0012] A preset quantile of all the ratios is determined as the available capacity of the power battery.

[0013] The method for obtaining the available capacity of the power battery according to the embodiments of the present application extracts interval charging data of a pre-obtained SOC interval from each complete charging data of historical charging data, obtains a ratio of a compensation value and a charging capacity of the interval charging data, the compensation value is a rated capacity compensation value corresponding to a charging depth of the interval charging data, and determines a preset quantile of all the ratios as the available capacity of the power battery, thereby greatly improving the accuracy of the obtained result of the available capacity of the power battery.

[0014] In some embodiments of the present application, before the ratio of the compensation value and the charging capacity of the interval charging data is obtained, the method further comprises:

[0015] According to the interval charging data of the pre-obtained SOC interval, a charging capacity per unit SOC is obtained;

[0016] Based on the charging capacity per unit SOC, the interval charging data of the pre-obtained SOC interval is filtered to obtain first filtered charging data;

[0017] The interval charging data is updated by using the first filtered charging data.

[0018] The filtering processing can eliminate error data existing in the interval charging data due to BMS transmission data errors and the like, thereby improving the accuracy of the charging data and helping to improve the accuracy of the obtained available capacity of the power battery.

[0019] In some embodiments of the present application, before the ratio of the compensation value and the charging capacity of the interval charging data is obtained, the method further comprises:

[0020] Obtaining a jump charging data frame existing in the interval charging data, the jump charging data frame having a time jump or a SOC jump;

[0021] Obtaining a charging current difference between the jump charging data frame and a previous charging data frame;

[0022] According to the charging current difference and a charging depth corresponding to the jump charging data frame, the jump charging data frame is retained or discarded to obtain second filtered charging data;

[0023] Update the interval charging data by using the second filtered charging data.

[0024] The second filtered charging data can further improve the accuracy of the charging data, and help to further improve the accuracy of the available capacity of the obtained power battery.

[0025] In some embodiments of the present application, the retaining or discarding of the jump charging data frame according to the charging current difference and the charging depth corresponding to the jump charging data frame comprises:

[0026] In the case that the charging current difference is less than the preset current threshold and the charging depth corresponding to the jump charging data frame is greater than the preset charging depth threshold, the jump charging data frame is retained.

[0027] In the case that the charging current difference is not less than the preset current threshold or the charging depth corresponding to the jump charging data frame is not greater than the preset charging depth threshold, the jump charging data frame is discarded.

[0028] In the case that the charging current difference is less than the preset current threshold and the charging depth corresponding to the jump charging data frame is greater than the preset charging depth threshold, the error brought by the ampere-hour integration method calculation result can be ignored, the jump charging data frame is retained in this case, which can make the interval charging data maintain high integrity and help to improve the accuracy of the obtained available capacity. In the case that the charging current difference is not less than the preset current threshold or the charging depth corresponding to the jump charging data frame is not greater than the preset charging depth threshold, the jump charging data frame will bring a large error to the ampere-hour integration method calculation result, which will affect the accuracy of the calculation result, and discarding the jump charging data frame helps to improve the accuracy of the obtained available capacity.

[0029] In some embodiments of the present application, the charging-in capacity of the interval charging data is obtained by integrating the current with respect to time of the interval charging data in the pre-acquired SOC interval.

[0030] In some embodiments of the present application, the rated capacity compensation value corresponding to the charging depth of the interval charging data is obtained by:

[0031] The rated capacity compensation value corresponding to the charging depth of the interval charging data is obtained by multiplying the nameplate capacity of the power battery, a first difference value, and the pre-acquired SOC interval. The first difference value is the difference between the pre-acquired upper limit of the lock-in and the pre-acquired lower limit of the lock-in. The rated capacity compensation value is obtained by using the lower limit of the lock-in and the upper limit of the lock-in, and the accuracy of the obtained rated capacity compensation value is high, which helps to further improve the accuracy of the obtained available capacity of the power battery.

[0032] In some embodiments of the present application, the pre-acquired SOC interval is acquired, including:

[0033] Based on the big data of the charging operation of the power battery, the maximum continuous SOC interval reaching a preset stable condition is determined to obtain the pre-acquired SOC interval; the preset stable condition is that the change rate of the charging capacity relative to the SOC change amount in the charging process is less than a preset value. The pre-acquired SOC interval obtained by the big data has more corresponding charging capacity data, which can improve the accuracy of the available capacity acquisition result.

[0034] In some embodiments of the present application, the method further includes:

[0035] The difference between the factory default capacity of the power battery and the available capacity of the power battery is acquired to obtain the available capacity attenuation offset of the power battery;

[0036] According to the attenuation offset and a preset corresponding relationship between the attenuation offset and the score, the score corresponding to the attenuation offset is acquired. The score corresponding to the attenuation offset can more intuitively reflect the available capacity condition of the power battery.

[0037] The second aspect of the embodiments of the present application provides a power battery available capacity acquisition device, including:

[0038] A historical charging data acquisition module is configured to acquire historical charging data of a preset time period of a power battery, wherein the historical charging data includes complete charging data of at least one charging;

[0039] An interval charging data extraction module is configured to extract interval charging data of a pre-acquired SOC interval from each of the complete charging data;

[0040] A ratio acquisition module is configured to acquire, for each of the interval charging data, a ratio of a charging capacity of the interval charging data to a compensation value; the compensation value is a rated capacity compensation value corresponding to a charging depth of the interval charging data;

[0041] A preset quantile determination module is configured to determine a preset quantile of all the ratios as the available capacity of the power battery.

[0042] The second aspect of the embodiments of the present application can achieve the same technical effects as the first aspect of the acquisition method.

[0043] In a third aspect, an electronic device is provided, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the computer program to implement the method for obtaining the available capacity of the power battery according to any of the embodiments of the present application. The third aspect of the embodiments of the present application can achieve the same technical effects as the method for obtaining according to the first aspect.

[0044] In a fourth aspect, a computer readable storage medium is provided, which stores a computer program. The computer program is executed by a processor to implement the method for obtaining the available capacity of the power battery according to any of the embodiments of the present application. The fourth aspect of the embodiments of the present application can achieve the same technical effects as the method for obtaining according to the first aspect.

[0045] The above description is only a summary of the technical solutions of the embodiments of the present application. In order to enable one of ordinary skill in the art to better understand the technical means of the embodiments of the present application, the embodiments of the present application can be implemented according to the content of the description, and in order to make the above and other purposes, characteristics and advantages of the embodiments of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0046] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the embodiments. The accompanying drawings are intended to depict only a few embodiments of the present application and therefore should not be considered to limit the scope of the present application in any way. Furthermore, the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the embodiments of the present application.

[0047] FIG. 1 is a structural schematic diagram of a vehicle according to one or more embodiments.

[0048] FIG. 2 is a flowchart of a method for obtaining the available capacity of a power battery according to one or more embodiments.

[0049] FIG. 3 is a box plot of the correspondence between the SOC interval and the charging capacity according to one or more embodiments.

[0050] FIG. 4 is a flowchart of a method for obtaining the available capacity of a power battery according to one or more embodiments.

[0051] FIG. 5 is a structural block diagram of an apparatus for obtaining the available capacity of a power battery according to one or more embodiments.

[0052] FIG. 6 is a structural block diagram of an apparatus for obtaining the available capacity of a power battery according to one or more embodiments.

[0053] FIG. 7 is a structural block diagram of an electronic device according to one or more embodiments.

[0054] FIG. 8 is a schematic diagram of a computer readable storage medium according to one or more embodiments. DETAILED DESCRIPTION

[0055] The embodiments of the present application will be described in detail with reference to the drawings. The following examples are only used to more clearly illustrate the technical scheme of the present application, and therefore only serve as examples, but cannot be used to limit the protection scope of the present application.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for describing particular embodiments only and is not intended to be limiting of the application; the use of the terms "including," "comprising," "having" and variations thereof herein is intended to be broad and encompass the terms "consisting of" and "consisting essentially of" and variations thereof. The terms "comprise," "comprising," "include," "including," and "includes" used in the specification and the appended claims, including the use of these terms in the claims, are intended to be inclusive or open-ended and not exclusive or limiting.

[0057] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more (including two), unless otherwise explicitly and specifically limited.

[0058] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments to one another. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined.

[0059] With the rapid development of new energy technology, the application of power battery is more and more extensive. Power battery has the advantages of high energy density, cyclic charging, safety and environmental protection, and is widely used in new energy vehicles, consumer electronics, energy storage systems and other fields. Power battery is not only applied to energy storage power supply systems such as hydraulic, thermal, wind and solar power stations, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. The market demand for electric vehicles powered by power batteries is also expanding, and the performance of power batteries is one of the important indicators to measure the performance of electric vehicles, especially in the scenarios of new energy vehicle after-sales and second-hand vehicle trading, the performance of power battery available capacity is one of the important indicators that customers focus on. During the use of power battery, the available capacity of power battery will decrease with the increase of driving mileage, charging cycle number, etc., and the available capacity of power battery is also affected by factors such as battery management system (BMS) software strategy. Therefore, the detection of the available capacity of power battery is an important operation.

[0060] In the related art, the SOC interval used for detecting the available capacity of the power battery is usually set artificially according to experience, and therefore the accuracy of the available capacity result obtained based on the charging data of the SOC interval is not high.

[0061] The depth of charge refers to the ratio of the amount of electricity accepted by the battery from the external circuit during the charging process to the amount of electricity in the fully charged state.

[0062] The upper limit of the lock-in electricity corresponds to the SOC of the upper limit cut-off voltage during the charging and discharging process of the battery pack; and the lower limit of the lock-in electricity corresponds to the SOC of the lower limit cut-off voltage during the charging and discharging process of the battery pack.

[0063] The rated capacity compensation value is the sum of the upper limit of the lock-in electricity and the lower limit of the lock-in electricity.

[0064] The jump charging data frame refers to the charging data frame whose time interval from the previous charging data frame exceeds a first preset threshold. Each charging data frame includes timestamp information, and the time interval between a charging data frame and the previous charging data frame can be determined according to the timestamp information.

[0065] In view of the technical problems in the related art, the embodiments of the present application provide a method for obtaining the available capacity of a power battery. First, the historical charging data of a preset period of the power battery is obtained, the historical charging data including complete charging data of at least one charging. The interval charging data of a preset SOC interval is extracted from each complete charging data. For each interval charging data, the ratio of the charging capacity of the interval charging data to a compensation value is obtained. The compensation value is the rated capacity compensation value corresponding to the depth of charge of the interval charging data. A preset quantile of all the ratios is determined as the available capacity of the power battery. The obtained available capacity result has high accuracy, and the coverage of the applicable range is high.

[0066] The method for obtaining available capacity of a power battery provided in the embodiments of the present application can be used to obtain the available capacity of a power battery serving as the energy source of a vehicle. Referring to FIG. 1, FIG. 1 is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile or a range extended automobile, etc. The vehicle 1000 is internally provided with a power battery 100, which can be arranged at the bottom, the head or the tail of the vehicle 1000. The power battery 100 can be used to supply power to the vehicle 1000, for example, the power battery 100 can serve as the operating power source of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300, and the controller 200 is used to control the power battery 100 to supply power to the motor 300, for example, to meet the power demand of the vehicle 1000 during starting, navigation and driving. The power battery 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000. The method for obtaining available capacity of a power battery provided in the embodiments of the present application can be used to obtain the available capacity of the power battery 100. The power battery in the embodiments of the present application can be a lithium ion battery, a lithium metal battery, a lead-acid battery, a nickel-separation battery, a nickel-hydrogen battery, a lithium-sulfur battery, a lithium-air battery or a sodium ion battery, etc., which is not limited herein.

[0067] A method for obtaining available capacity of a power battery is described below in combination with the accompanying drawings according to the embodiments of the present application.

[0068] Referring to FIG. 2, one embodiment of the present application provides a method for obtaining available capacity of a power battery, which can include steps S10 to S40:

[0069] S10, obtain historical charging data of the power battery in a preset time period.

[0070] The preset time period can be, for example, the last 30 days, the last 20 days, etc., which can be set according to actual needs. The historical charging data includes complete charging data of at least one charging of the power battery. The complete charging data refers to the charging data of the charging process from the start of charging with SOC 0 to the end of charging with SOC 100%. The power battery is applied to an electric vehicle to provide power for the electric vehicle. The historical charging data of the power battery can be obtained by a battery management system (BMS). For the power battery, the BMS can obtain charging data every preset time interval (the preset time interval can be, for example, 10 s, 5 s, etc.), and each obtained charging data can be a data frame, which can include but is not limited to time stamp, SOC, charging current and voltage, etc. SOC is the abbreviation of State of Charge, which refers to the remaining capacity of the battery.

[0071] Exemplarily, the initial data can be subjected to data cleaning (e.g., removing outliers, etc.), unit format conversion, etc. The data can be subjected to merging, deleting, etc. according to the current characteristics during the charging process, and considering the short-time gun pulling and standing during the charging process, data loss, charging interruption, excessively large voltage difference, and brake recharging, etc. The complete charging segment data, i.e., the historical charging data of the preset time period, can be extracted.

[0072] S20, extracting interval charging data of a pre-acquired SOC interval from each complete charging data.

[0073] The pre-acquired SOC interval is acquired based on big data (e.g., cloud big data) of the charging operation of the power battery. The big data is historical data of multiple charging operations of the power battery. Specifically, based on the big data of the charging operation of the power battery, the maximum continuous SOC interval reaching a preset stable condition is determined, and the pre-acquired SOC interval is obtained. The preset stable condition is that the change rate of the charging capacity relative to the SOC change amount during the charging process is less than a preset value. The preset value is, for example, 1%, 2%, or 3%, etc.

[0074] For example, a box plot can be made for the charging capacity corresponding to every 5% SOC of all charging segments of a vehicle with the target power battery as the energy source in the past year on the current market. As shown in FIG. 3, a box plot is made for the charging capacity corresponding to every 5% SOC of all charging segments of a vehicle with the target power battery as the energy source in the past year. From FIG. 3, it can be determined that the charging capacity corresponding to every 5% SOC of the vehicle with the target power battery as the energy source in the SOC charging interval of 10%-90% is relatively stable, i.e., the charging capacity corresponding to every 5% SOC in the SOC charging interval of 10%-90% is less than a preset threshold. After verifying different cell materials and different BMS software strategies, an upper SOC threshold and a lower SOC threshold can be determined. In the SOC charging interval with the upper SOC threshold and the lower SOC threshold as endpoints, the charging capacity corresponding to every unit SOC is relatively stable, and the SOC charging interval also has good generalization. Therefore, the SOC charging interval is determined as the pre-acquired SOC interval. The pre-acquired SOC interval can be, for example, [20%, 90%] or [10%, 90%], etc.

[0075] In the related art, in order to obtain an SOC interval with relatively stable charging capacity per unit SOC, the SOC interval used is usually small, for example, 40%-80%, which will result in less corresponding charging capacity data and affect the accuracy of the available capacity detection result. The pre-acquired SOC interval obtained by big data in the technical solution has relatively stable charging capacity per unit SOC, and the interval is large, and the corresponding charging capacity data is more, which can improve the accuracy of the available capacity acquisition result.

[0076] In addition, in the related art, the small SOC interval used results in less corresponding charging capacity data, and in actual application, after the abnormal data is removed through data filtering and data cleaning, etc., some power batteries may not have enough normal data to calculate the available capacity, resulting in a low application range coverage rate. For example, the technical solution of the related art may result in that the proportion of power batteries that cannot obtain the available capacity in actual application is more than 50%, i.e., the application range coverage rate is less than 50%. Compared with the related art, the pre-acquired SOC interval obtained by big data in the technical solution has more corresponding charging capacity data, and after the data filtering and cleaning, etc., there are usually still enough data that can be used to calculate the available capacity, and the application range coverage rate is high, which greatly improves the application range coverage rate compared with the related art.

[0077] S30, for each interval charging data, obtaining the ratio of the charging capacity of the interval charging data to the compensation value.

[0078] The compensation value is a rated capacity compensation value corresponding to the charging depth of the interval charging data.

[0079] Exemplarily, the integral of the current with respect to time of the interval charging data in the pre-acquired SOC interval can be obtained to obtain the charging capacity of the interval charging data. The charging capacity of the interval charging data obtained by integral calculation is relatively accurate.

[0080] The power battery is provided with a nameplate, and the nameplate is marked with a plurality of parameters, including the battery capacity of the power battery. The nameplate capacity is the battery capacity marked on the nameplate. Exemplarily, the product of the nameplate capacity of the power battery, the first difference, and the pre-acquired SOC interval can be obtained to obtain the rated capacity compensation value corresponding to the charging depth of the interval charging data; wherein the first difference is the difference between the pre-acquired upper limit of the lock-up and the pre-acquired lower limit of the lock-up. The lower limit of the lock-up and the upper limit of the lock-up can be obtained by matching the vehicle identification code (VIN). The lower limit of the lock-up and the upper limit of the lock-up are used to obtain the rated capacity compensation value, and the accuracy of the obtained rated capacity compensation value is high, which is helpful to further improve the accuracy of the available capacity acquisition result of the power battery.

[0081] Exemplarily, the upper and lower lock voltage boundaries can be obtained by taking the median of the starting voltage from full discharge static to full charge static and looking up the OCV (open circuit voltage) table, and a capacity lock voltage information library is established to store the upper and lower lock voltage boundary data.

[0082] In one specific example, the pre-acquired SOC interval is [SOC1, SOC2], SOC1 < SOC2, and the ratio of the charge-in capacity of the interval charge data to the compensation value is the available capacity of the interval charge data, and the calculation formula is:

[0083] wherein SOC1 ≥ 20, SOC2 ≤ 90, SOC2-SOC1 ≥ 40, I represents the current, Δt represents the time difference, C R represents the nameplate capacity, SOC LOWER represents the lower lock voltage, SOC UPPER represents the upper lock voltage. is the charge-in capacity calculated by the ampere-hour integration method in [SOC1, SOC2];

[0084] C R *(SOC UPPER -SOC LOWER )*(SOC2-SOC1) is the rated capacity compensation value corresponding to the charge depth DOD of [SOC1, SOC2].

[0085] S40, determine a preset quantile of all the ratios as the available capacity of the power battery.

[0086] The preset quantile includes but is not limited to the 75th quantile, and can be set according to actual needs. The quantile refers to the numerical point obtained by dividing the probability distribution range of a random variable into several equal parts. The 75th quantile, also known as the third quartile (Q3), is equal to the 75th number in the sample arranged in ascending order.

[0087] The method of the embodiments of the application can realize online real-time calculation of the available capacity of the power battery, and is especially suitable for application scenarios such as new energy vehicle after-sales and second-hand vehicle transaction.

[0088] In some embodiments, before obtaining the ratio of the charge-in capacity of the interval charge data to the compensation value, the method can further include: obtaining the charge-in capacity per unit SOC according to the interval charge data of the pre-acquired SOC interval; performing filtering processing on the interval charge data of the pre-acquired SOC interval based on the charge-in capacity per unit SOC to obtain the first filtered charge data; and updating the interval charge data by using the first filtered charge data.

[0089] For example, in the interval charging data of the pre-acquired SOC interval [SOC1, SOC2], the ratio of the total charging capacity corresponding to [SOC1, SOC2] to (SOC2-SOC1) can be calculated to obtain the charging capacity per 1% SOC. The filtering process can use a sliding window filter to obtain the first filtered charging data. The filtering process can eliminate error data existing in the interval charging data due to BMS transmission data errors and the like, improve the accuracy of the charging data, and help improve the accuracy of the available capacity of the acquired power battery.

[0090] In some embodiments, before obtaining the ratio of the charging capacity of the interval charging data to the compensation value, the method further comprises: acquiring a jump charging data frame with a time jump or a SOC jump in the interval charging data; acquiring a charging current difference between the jump charging data frame and a previous charging data frame; retaining or discarding the jump charging data frame according to the charging current difference and the charging depth corresponding to the jump charging data frame to obtain second filtered charging data; and updating the interval charging data using the second filtered charging data.

[0091] The jump charging data frame with a time jump refers to a charging data frame with a time interval exceeding a first preset threshold from a previous charging data frame. Each charging data frame contains timestamp information, and the time interval between a charging data frame and a previous charging data frame can be determined according to the timestamp information. The first preset threshold is, for example, 30s, 60s, or 180s, etc. The jump charging data frame with a SOC jump refers to a charging data frame with an absolute value of a SOC difference exceeding a second preset threshold from a previous charging data frame. The second preset threshold is, for example, 1%, 2%, or 3%, etc. Each charging data frame contains SOC information, and for a charging data frame, the absolute value of the difference between the SOC of the charging data frame and the SOC of a previous charging data frame can be calculated. Comparing the absolute value with the second preset threshold can determine whether the charging data frame is a jump charging data frame with a SOC jump.

[0092] The second filtering includes but is not limited to box filtering. The second filtered charging data can further improve the accuracy of the charging data, and help further improve the accuracy of the available capacity of the acquired power battery.

[0093] For example, according to the charging current difference and the charging depth corresponding to the jump charging data frame, retaining or discarding the jump charging data frame can include: in a case where the charging current difference is less than a preset current threshold and the charging depth corresponding to the jump charging data frame is greater than a preset charging depth threshold, retaining the jump charging data frame; in a case where the charging current difference is not less than the preset current threshold or the charging depth corresponding to the jump charging data frame is not greater than the preset charging depth threshold, discarding the jump charging data frame. The preset current threshold is, for example, 5A, 10A, or 15A, etc. The preset charging depth threshold is, for example, 3SOC or 5SOC, etc.

[0094] In a case where the charging current difference is less than the preset current threshold and the charging depth corresponding to the jump charging data frame is greater than the preset charging depth threshold, the error brought by the jump charging data frame to the calculation result of the ampere-hour integration method can be negligible, and in this case, retaining the jump charging data frame can make the interval charging data maintain higher integrity, which is helpful to improve the accuracy of the obtained available capacity.

[0095] In a case where the charging current difference is not less than the preset current threshold or the charging depth corresponding to the jump charging data frame is not greater than the preset charging depth threshold, the jump charging data frame will bring a larger error to the calculation result of the ampere-hour integration method, which will affect the accuracy of the calculation result, and discarding the jump charging data frame is helpful to improve the accuracy of the obtained available capacity.

[0096] Referring to FIG. 4, in some embodiments, the method can further include steps S50 and S60:

[0097] S50, obtaining a difference between a factory default capacity of the power battery and the available capacity of the power battery to obtain an available capacity attenuation offset of the power battery.

[0098] The factory default capacity of the power battery includes but is not limited to 100%.

[0099] S60, according to the attenuation offset and a preset corresponding relationship between the attenuation offset and the score, obtaining a score corresponding to the attenuation offset.

[0100] The preset corresponding relationship between the attenuation offset and the score can be, for example, a pre-established score model, and the score rule of the score model is:

[0101] SCORE = 5, C swift <5%;

[0102] SCORE = 4.5, C swift <10%;

[0103] SCORE = 4, C swift <15%;

[0104] SCORE = 3.5, C swift ≥ 20%;

[0105] C swift represents the available capacity attenuation offset, SCORE represents the score, C swift = 1 - the available capacity of the power battery. The preset correspondence between the attenuation offset and the score is represented by the scoring rules of the scoring model.

[0106] The score corresponding to the attenuation offset can more intuitively reflect the available capacity condition of the power battery.

[0107] The above description of various embodiments tends to emphasize the differences between various embodiments, and the same or similar parts can be referred to each other, and for the sake of brevity, will not be repeated here.

[0108] One specific example of a method for obtaining the available capacity of a power battery, first, the total charging section data of a vehicle using a certain project power battery as energy in the past year on the current market, based on every 5% SOC and its corresponding charging capacity data, make a box plot, and determine the pre-acquired SOC interval according to the box plot. In the pre-acquired SOC interval, the charging capacity corresponding to each unit SOC is relatively stable, and the SOC charging interval also has good generalization, and in this example, the pre-acquired SOC interval is [20%, 90%]. The upper threshold of the SOC of the pre-acquired SOC interval is 90%, and the lower threshold of the SOC is 20%.

[0109] The upper and lower limits of the power battery lock are obtained by taking the median of the starting voltage from full discharge to full charge and looking up the OCV table, and a capacity lock information library is established to store the upper and lower limits of the lock.

[0110] Then, set up an available capacity calculation model, which calculates the charging capacity by performing ampere-hour integration method in the pre-acquired SOC interval, calculates the rated capacity compensation value in the charging depth DOD corresponding to the pre-acquired SOC interval, calculates the ratio of the charging capacity and the rated capacity compensation value, and obtains the available capacity of the power battery, and the calculation formula is:

[0111] Wherein, SOC1≥20, SOC2≤90, SOC2-SOC1≥40, I represents the current, Δt represents the time difference, C R represents the nameplate capacity, SOC LOWER represents the lower limit of the lock, SOC UPPER represents the upper limit of the lock.

[0112] In addition, a scoring model is established, and the scoring model rules are as follows:

[0113] SCORE = 5, C swift <5%; SCORE = 4.5, C swift <10%; SCORE = 4, C swift <15%; SCORE = 3.5, C awift ≥ 20%; C swift is the available capacity fade offset.

[0114] The example adopts a manner of quantifying end values of a stable SOC interval by a large amount of data, and combines a lock-in upper limit and a lock-in lower limit and a rated capacity compensation to obtain the available capacity of the power battery. The available capacity calculation model can simplify input parameters of the available capacity calculation model and improve transparency of the model in a case that a preset applicable range coverage rate and a preset available capacity obtaining result accuracy are reached.

[0115] The pre-acquired SOC interval and the available capacity calculation model are pre-acquired.

[0116] In obtaining the available capacity of the power battery, initial historical charging data of a preset period of the power battery can be cleaned (abnormal values are removed) and unit format conversion is performed. According to current characteristics in the charging process, and considering short-time gun pulling and standing, data missing, charging interruption, voltage difference being too large, and brake recharging in the charging process, the data are respectively processed by merging and deleting, and complete charging section data, that is, historical charging data of the preset period, are extracted.

[0117] Interval charging data of the pre-acquired SOC interval are extracted from each complete charging data. The pre-acquired SOC interval is acquired based on a large amount of data (for example, cloud big data) of the charging operation of the power battery. Specifically, based on the large amount of data of the charging operation of the power battery, a maximum continuous SOC interval reaching a preset stable condition is determined to obtain the pre-acquired SOC interval; the preset stable condition is that a change rate of a charging capacity relative to a SOC change amount in the charging process is less than a preset value.

[0118] According to the interval charging data of the pre-acquired SOC interval, a charging capacity per unit SOC is obtained; based on the charging capacity per unit SOC, the interval charging data of the pre-acquired SOC interval is filtered to obtain first filtered charging data; and the interval charging data is updated by using the first filtered charging data.

[0119] The jump charging data frame is obtained from the interval charging data in which time jump or SOC jump exists; a charging current difference between the jump charging data frame and a previous charging data frame is obtained; in a case that the charging current difference is less than a preset current threshold and a charging depth corresponding to the jump charging data frame is greater than a preset charging depth threshold, the jump charging data frame is reserved to obtain second filtered charging data; in a case that the charging current difference is not less than the preset current threshold or the charging depth corresponding to the jump charging data frame is not greater than the preset charging depth threshold, the jump charging data frame is discarded to obtain the second filtered charging data; and the interval charging data is updated by using the second filtered charging data.

[0120] For each interval charging data, an integral of current with respect to time of the interval charging data in a pre-obtained SOC interval is obtained to obtain a charging capacity of the interval charging data. The charging capacity of the interval charging data obtained by the integral calculation is relatively accurate.

[0121] The power battery is provided with a nameplate, and a plurality of parameters are marked on the nameplate, including a battery capacity of the power battery. The nameplate capacity is the battery capacity marked on the nameplate. A product of the nameplate capacity of the power battery, a first difference and the pre-obtained SOC interval is obtained to obtain a rated capacity compensation value corresponding to a charging depth of the interval charging data; wherein the first difference is a difference between a pre-obtained upper limit of lock-up and a pre-obtained lower limit of lock-up.

[0122] Lock-up refers to protection of a battery pack by a system by controlling charging and discharging voltages of the vehicle, prolonging a service life of the battery pack, and preventing overcharging and overdischarging. When the battery pack is charged, if a voltage of a single cell reaches a preset upper limit value, charging is then controlled to stop to achieve protection of the battery pack; when the battery pack is discharged, if the voltage of the single cell reaches a preset lower limit value, discharging is then controlled to stop to achieve protection of the battery pack.

[0123] The preset upper limit value of the ternary lithium battery may be, for example, 4.15V, 4.20V or 4.30V, etc., and the preset lower limit value of the ternary lithium battery may be, for example, 2.80V, 2.60V or 2.50V, etc. The preset upper limit value of the lithium iron phosphate battery may be, for example, 3.70V, 3.65V or 3.60V, etc., and the preset lower limit value of the lithium iron phosphate battery may be, for example, 2.55V, 2.50V or 2.45V, etc.

[0124] For example, when the ternary lithium battery is charged to stop at a preset upper limit value of 4.15V, and when the ternary lithium battery is discharged to stop at a preset lower limit value of 2.5V; when the lithium iron phosphate battery is charged to stop at a preset upper limit value of 3.65V, and when the lithium iron phosphate battery is charged to stop at a preset lower limit value of 2.45V.

[0125] The lower lock power limit and the upper lock power limit can be obtained by matching the vehicle frame number (i.e., the vehicle identification number, VIN). The lower lock power limit and the upper lock power limit are used to obtain the rated capacity compensation value, and the obtained rated capacity compensation value has high accuracy, which helps to further improve the accuracy of the obtained available capacity of the power battery.

[0126] For each interval charging data, a ratio of the compensation value to the charging capacity of the interval charging data is obtained. The compensation value is the rated capacity compensation value corresponding to the charging depth of the interval charging data.

[0127] A difference between the factory default capacity of the power battery and the available capacity of the power battery is obtained to obtain an available capacity attenuation offset of the power battery. According to the attenuation offset and a preset corresponding relationship between the attenuation offset and the score, a score corresponding to the attenuation offset is obtained. The preset corresponding relationship between the attenuation offset and the score is a pre-established score model, and a score rule of the score model is:

[0128] SCORE = 5, C swift <5%;

[0129] SCORE = 4.5, C swift <10%;

[0130] SCORE = 4, C swift <15%;

[0131] SCORE = 3.5, C swift ≥20%;

[0132] C swift represents the available capacity attenuation offset, SCORE represents the score, and C swift = 1 - the available capacity of the power battery. The score corresponding to the attenuation offset can more intuitively reflect the available capacity condition of the power battery.

[0133] The method of the present example extracts interval charging data of a pre-acquired SOC interval from each complete charging data of historical charging data, obtains a ratio of the compensation value to the charging capacity of the interval charging data, the compensation value is the rated capacity compensation value corresponding to the charging depth of the interval charging data, determines a preset quantile of all ratios as the available capacity of the power battery, and greatly improves the accuracy of the obtained available capacity of the power battery, thereby overcoming the defect that the accuracy of the obtained available capacity of the power battery is low in the related art by recording the fluctuation of the SOC drift value within the SOC drift range when 1% of the charging capacity is charged.

[0134] The above description of each embodiment tends to emphasize the differences between each embodiment, and the same or similar parts can be referred to each other. For brevity, the same or similar parts are not described again.

[0135] Referring to FIG. 5, another embodiment of the present application provides a device for obtaining available capacity of a power battery, which can include:

[0136] a historical charging data obtaining module configured to obtain historical charging data of a preset time period of the power battery, the historical charging data comprising complete charging data of at least one charging;

[0137] an interval charging data extracting module configured to extract interval charging data of a pre-obtained SOC interval from each of the complete charging data;

[0138] a ratio obtaining module configured to obtain, for each of the interval charging data, a ratio of a charging-in capacity of the interval charging data to a compensation value, the compensation value being a rated capacity compensation value corresponding to a charging depth of the interval charging data;

[0139] a preset quantile determining module configured to determine a preset quantile of all the ratios as the available capacity of the power battery.

[0140] Exemplarily, the device can further include:

[0141] a charging-in capacity obtaining module configured to obtain, before the ratio obtaining module obtains the ratio of the charging-in capacity of the interval charging data to the compensation value, a charging-in capacity per unit SOC according to the interval charging data of the pre-obtained SOC interval;

[0142] a first filtering module configured to perform filtering processing on the interval charging data of the pre-obtained SOC interval based on the charging-in capacity per unit SOC to obtain first filtered charging data;

[0143] a first updating module configured to update the interval charging data by using the first filtered charging data.

[0144] Exemplarily, the device further includes:

[0145] a data frame obtaining module configured to obtain, before the ratio obtaining module obtains the ratio of the charging-in capacity of the interval charging data to the compensation value, a jump charging data frame with time jump or SOC jump in the interval charging data;

[0146] a current difference obtaining module configured to obtain a charging current difference between the jump charging data frame and a previous charging data frame;

[0147] a second filtering module configured to retain or discard the jump charging data frame according to the charging current difference and a charging depth corresponding to the jump charging data frame to obtain second filtered charging data;

[0148] a second updating module, configured to update the interval charging data by using the second filtered charging data.

[0149] The second filtering module includes, for example:

[0150] The first filtering unit is configured to retain the jump charging data frame in a case that the charging current difference is less than the preset current threshold and the charging depth corresponding to the jump charging data frame is greater than the preset charging depth threshold.

[0151] The second filtering unit is configured to discard the jump charging data frame in a case that the charging current difference is not less than the preset current threshold or the charging depth corresponding to the jump charging data frame is not greater than the preset charging depth threshold.

[0152] The ratio obtaining module includes, for example:

[0153] The interval charging data capacity obtaining unit is configured to obtain the capacity of the interval charging data.

[0154] The compensation value obtaining unit is configured to obtain a compensation value, which is a rated capacity compensation value corresponding to the charging depth of the interval charging data.

[0155] The ratio calculating unit is configured to calculate a ratio of the capacity of the interval charging data and the compensation value.

[0156] The interval charging data capacity obtaining unit is further configured to obtain an integral of the current with respect to time of the interval charging data in a pre-obtained SOC interval, to obtain the capacity of the interval charging data.

[0157] The compensation value obtaining unit is further configured to obtain a product of a nameplate capacity of the power battery, a first difference value, and the pre-obtained SOC interval, to obtain the rated capacity compensation value corresponding to the charging depth of the interval charging data; the first difference value is a difference between a pre-obtained upper limit of the locked power and a pre-obtained lower limit of the locked power.

[0158] The device further includes a pre-obtained SOC interval obtaining module configured to obtain a pre-obtained SOC interval; the pre-obtained SOC interval obtaining module is further configured to determine a maximum continuous SOC interval that meets a preset stability condition based on big data of a charging operation of the power battery, to obtain the pre-obtained SOC interval; the preset stability condition is that a change rate of the capacity of the charging operation with respect to a SOC change amount is less than a preset value.

[0159] Referring to FIG. 6, in some embodiments, the apparatus can further include a scoring module configured to: obtain a difference between a factory default capacity of the power battery and an available capacity of the power battery, to obtain an available capacity attenuation offset of the power battery; and obtain a score corresponding to the attenuation offset according to the attenuation offset and a preset correspondence between the attenuation offset and the score.

[0160] The apparatus for obtaining the available capacity of the power battery according to the embodiments of the present application extracts the interval charging data of the pre-obtained SOC interval from each complete charging data of the historical charging data, obtains a ratio of the charging capacity of the interval charging data to the compensation value, the compensation value being a rated capacity compensation value corresponding to the charging depth of the interval charging data, and determines a preset quantile of all the ratios as the available capacity of the power battery, thereby greatly improving the accuracy of the obtained result of the available capacity of the power battery.

[0161] The above description of the various embodiments tends to emphasize the differences between the various embodiments, and the same or similar parts can be referred to each other, and for brevity, will not be described herein.

[0162] Another embodiment of the present application provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to implement the method for obtaining the available capacity of the power battery according to any of the above embodiments.

[0163] Referring to FIG. 7, the electronic device 10 can include a processor 100, a memory 101, a bus 102, and a communication interface 103, the processor 100, the communication interface 103, and the memory 101 being connected through the bus 102; the memory 101 stores a computer program executable on the processor 100, and the processor 100 executes the computer program to implement the method for obtaining the available capacity of the power battery according to any of the above embodiments.

[0164] The memory 101 can include a high-speed random access memory (RAM) and can also include a non-volatile memory such as at least one disk memory. The communication interface 103 can be wired or wireless, and can be used to implement the communication connection between the apparatus and at least one other network element, and can use the Internet, a wide area network, a local area network, a metropolitan area network, etc.

[0165] The bus 102 can be an ISA bus, a PCI bus, an EISA bus, or the like. The bus can be divided into an address bus, a data bus, a control bus, and the like. Among them, the memory 101 is used to store a program, and the processor 100 executes the program after receiving an execution instruction. The method disclosed in any of the embodiments of the present application can be applied to the processor 100 or implemented by the processor 100.

[0166] The processor 100 can be an integrated circuit chip with signal processing capability. In the implementation process, each step of the above method can be completed by the integrated logic circuit of hardware in the processor 100 or the instruction in the form of software. The processor 100 described above can be a general processor, which can include a central processing unit (CPU), a network processor (NP), and the like; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a ready programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component. Each method, step and logic block disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or any conventional processor. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as a hardware code processor for execution, or a combination of hardware and software modules in the code processor for execution. The software module can be located in a random access memory, a flash memory, a read only memory, a programmable read only memory, an electrically erasable programmable memory, a register, or other mature storage medium in the art. The storage medium is located in the memory 101, and the processor 100 reads the information in the memory 101 and combines the hardware to complete the steps of the above method.

[0167] The electronic device provided by the embodiments of the present application and the method provided by the embodiments of the present application have the same beneficial effects as the method they adopt, run or implement.

[0168] Another embodiment of the present application provides a computer readable storage medium having a computer program stored thereon, which is executed by a processor to implement the power battery available capacity acquisition method of any of the above embodiments. Referring to FIG. 8, the computer readable storage medium shown is an optical disc 20, which stores a computer program (i.e. program product), and when the computer program is run by the processor, the power battery available capacity acquisition method provided by any of the above embodiments is executed.

[0169] It should be noted that examples of computer-readable storage media can include but are not limited to phase-change RAM (PRAM), static RAM (SRAM), dynamic RAM (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory or other optical, magnetic, or solid-state storage media. Examples of computer-readable storage media do not pertain to modulated data signals or carrier waves.

[0170] The computer-readable storage medium provided by the above embodiments of the present application has the same beneficial effects as the method adopted, run or implemented by the application program stored therein, based on the same inventive concept.

[0171] It should be noted that:

[0172] The term "module" is not intended to be limited to a particular physical form. Depending on the specific application, a module can be implemented as hardware, firmware, software, and / or a combination thereof. In addition, different modules can share common components or even be implemented by the same components. There can or can not be a clear boundary between different modules.

[0173] The algorithms and displays presented herein are not inherently related to any particular computer, virtual apparatus, or other device. Various general purpose devices can be used with these examples based on the teachings herein. The structure required to construct such devices will be apparent to those skilled in the art from the description above. In addition, the present application is not intended to be limited to any particular programming language. It will be appreciated that there are many programming languages that can be used to implement the teachings herein, and that the examples given above are merely examples of the best mode of the application.

[0174] It should be understood that, although the steps in the flowcharts of the drawings are shown in a sequential order, these steps are not necessarily performed in the order shown by the arrows. Unless otherwise explicitly stated herein, the steps are not necessarily performed in the order shown, and can be performed in other orders. Moreover, at least some of the steps in the flowcharts of the drawings can include multiple sub-steps or multiple stages, which are not necessarily performed at the same time, but can be performed at different times, and the order of their execution is not necessarily sequential, but can be performed alternately or alternately with at least part of other steps or sub-steps or stages of other steps.

[0175] The above embodiments only express the implementation ways of the present application, and the description is specific and detailed, but it should not be understood as a limitation to the patent scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for obtaining the available capacity of a power battery, wherein, The method comprises: obtaining historical charging data of a preset time period of a power battery, the historical charging data comprising complete charging data of at least one charging; extracting interval charging data of a pre-obtained SOC interval from each of the complete charging data; for each of the interval charging data, obtaining a ratio of a charging capacity of the interval charging data to a compensation value, the compensation value being a rated capacity compensation value corresponding to a charging depth of the interval charging data; determining a preset quantile of all the ratios as an available capacity of the power battery.

2. The method of claim 1, wherein, Before the obtaining of the ratio of the charging capacity of the interval charging data to the compensation value, the method further comprises: obtaining a charging capacity per unit of SOC according to the interval charging data of the pre-obtained SOC interval; performing filtering processing on the interval charging data of the pre-obtained SOC interval based on the charging capacity per unit of SOC to obtain first filtered charging data; updating the interval charging data by using the first filtered charging data.

3. The method of claim 1 or 2, wherein, Before the obtaining of the ratio of the charging capacity of the interval charging data to the compensation value, the method further comprises: obtaining a jump charging data frame with time jump or SOC jump in the interval charging data; obtaining a charging current difference between the jump charging data frame and a previous charging data frame; retaining or discarding the jump charging data frame according to the charging current difference and a charging depth corresponding to the jump charging data frame to obtain second filtered charging data; updating the interval charging data by using the second filtered charging data.

4. The method of claim 3, wherein, The retaining or discarding of the jump charging data frame according to the charging current difference and the charging depth corresponding to the jump charging data frame comprises: in a case where the charging current difference is less than a preset current threshold and the charging depth corresponding to the jump charging data frame is greater than a preset charging depth threshold, retaining the jump charging data frame; in a case where the charging current difference is not less than the preset current threshold or the charging depth corresponding to the jump charging data frame is not greater than the preset charging depth threshold, discarding the jump charging data frame.

5. The method of any one of claims 3-4, wherein, The obtaining of the charging capacity of the interval charging data comprises: obtaining an integral of current with respect to time of the interval charging data in the pre-obtained SOC interval to obtain the charging capacity of the interval charging data.

6. The method of any one of claims 3-5, wherein, The obtaining of the rated capacity compensation value corresponding to the charging depth of the interval charging data comprises: obtaining a product of a nameplate capacity of the power battery, a first difference and the pre-obtained SOC interval to obtain the rated capacity compensation value corresponding to the charging depth of the interval charging data, the first difference being a difference between a pre-obtained upper lock-in limit and a pre-obtained lower lock-in limit.

7. The method of any one of claims 1-6, wherein, The obtaining of the pre-obtained SOC interval comprises: determining a maximum continuous SOC interval reaching a preset stability condition based on big data of a charging operation of the power battery to obtain the pre-obtained SOC interval, the preset stability condition being that a change rate of charging capacity with respect to a SOC change amount in a charging process is less than a preset value.

8. The method of any one of claims 1-7, wherein, The method further comprises: obtaining a difference between a factory default capacity of the power battery and an available capacity of the power battery, to obtain an available capacity attenuation offset of the power battery; obtaining a score corresponding to the attenuation offset according to the attenuation offset and a preset corresponding relationship between attenuation offsets and scores.

9. An apparatus for acquiring available capacity of a power battery, wherein, The method comprises: a historical charging data obtaining module configured to obtain historical charging data of a preset time period of the power battery, the historical charging data comprising complete charging data of at least one charging; an interval charging data extracting module configured to extract interval charging data of a preset SOC interval from each of the complete charging data; a ratio obtaining module configured to obtain, for each of the interval charging data, a ratio of a charging capacity of the interval charging data to a compensation value, the compensation value being a rated capacity compensation value corresponding to a charging depth of the interval charging data; a preset quantile determining module configured to determine a preset quantile of all the ratios as the available capacity of the power battery.

10. An electronic device, comprising: The computer program is executed by the processor to implement the method for obtaining the available capacity of the power battery according to any one of claims 1-8.

11. A computer readable storage medium having stored thereon a computer program, wherein, The computer program is executed by the processor to implement the method for obtaining the available capacity of the power battery according to any one of claims 1-8.

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