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

Abstract

The present application discloses a method, device, equipment and storage medium for obtaining the available capacity of a power battery. The acquisition method includes: obtaining historical charging data of a preset period of time for the power battery, the historical charging data including complete charging data of at least one charge; extracting interval charging data of a pre-acquired SOC interval from each of the complete charging data; for each of the interval charging data, obtaining the ratio of the charged capacity of the interval charging data to the compensation value; the compensation value is the rated capacity compensation value corresponding to the charging depth of the interval charging data; determining the preset quantiles of all the ratios as the available capacity of the power battery. The method for obtaining the available capacity of the power battery of the embodiment of the present application greatly improves the accuracy of the acquisition result of the available capacity of the power battery.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method, device, equipment and storage medium for obtaining the available capacity of a power battery. Background Art

[0002] The available capacity of power batteries is one of the indicators that customers focus on in scenarios such as after-sales of new energy vehicles and second-hand car transactions. During the use of power batteries, the available capacity of power batteries will continue to decrease with the increase in driving mileage, number of charging cycles, etc. At the same time, the available capacity of power batteries is also affected by factors such as the battery management system BMS software strategy. New energy vehicles account for an increasingly high proportion of the automobile market, and more and more electric vehicles are flowing into the second-hand car market. The battery capacity detection technical solution in the relevant technology obtains the battery capacity detection result by recording the fluctuation of the SOC drift value within the SOC drift range every time 1% of the power is charged. The accuracy of the battery available capacity detection result is low, so it is urgent to develop a technical solution for obtaining the available capacity of power batteries with improved accuracy.

[0003] The above statements are only used to provide background information related to the present application and do not necessarily constitute prior art. Summary of the invention

[0004] In view of the problem of low accuracy of detection results of the battery capacity detection technical solutions in the above-mentioned related technologies, the present application provides a method, device, equipment and storage medium for obtaining the available capacity of a power battery to improve the accuracy of the detection results of the battery available capacity detection.

[0005] According to a first aspect of an embodiment of the present application, a method for obtaining available capacity of a power battery is provided, comprising:

[0006] Acquire historical charging data of a power battery for a preset period of time, wherein the historical charging data includes complete charging data of at least one charging;

[0007] Extracting interval charging data of a pre-acquisition SOC interval from each of the complete charging data;

[0008] For each of the interval charging data, a ratio of the charging capacity of the interval charging data to a compensation value is obtained; the compensation value is a rated capacity compensation value corresponding to the charging depth of the interval charging data;

[0009] A preset quantile of all the ratios is determined as the available capacity of the power battery.

[0010] The method for obtaining the available capacity of a power battery in an embodiment of the present application extracts interval charging data of a pre-acquired SOC interval from each complete charging data of historical charging data, obtains the ratio of the charged capacity of the interval charging data to a compensation value, wherein the compensation value is a rated capacity compensation value corresponding to the charging depth of the interval charging data, and determines preset quantiles of all ratios as the available capacity of the power battery, thereby greatly improving the accuracy of the results of obtaining the available capacity of the power battery.

[0011] In some embodiments of the present application, before obtaining the ratio of the charging capacity to the compensation value of the interval charging data, the method further includes:

[0012] Acquire a charging capacity per unit SOC according to the interval charging data of the pre-acquired SOC interval;

[0013] Based on the charging capacity per unit SOC, filtering the interval charging data of the pre-acquired SOC interval to obtain charging data after the first filtering;

[0014] The interval charging data is updated using the charging data after the first filtering.

[0015] The filtering process can eliminate erroneous data in the interval charging data caused by BMS transmission data errors and other reasons, improve the accuracy of the charging data, and help improve the accuracy of the available capacity of the power battery obtained.

[0016] In some embodiments of the present application, before obtaining the ratio of the charging capacity to the compensation value of the interval charging data, the method further includes:

[0017] Acquire a jump charging data frame having a time jump or an SOC jump in the interval charging data;

[0018] Acquire a charging current difference between the jump charging data frame and a previous charging data frame;

[0019] According to the charging current difference and the charging depth corresponding to the jump charging data frame, retain or discard the jump charging data frame to obtain the charging data after the second filtering;

[0020] The interval charging data is updated using the charging data after the second filtering.

[0021] The charging data after the second filtering can further improve the accuracy of the charging data, and help to further improve the accuracy of the acquired available capacity of the power battery.

[0022] In some embodiments of the present application, 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 includes:

[0023] When 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, retaining the jump charging data frame;

[0024] When the charging current difference is not less than a preset current threshold or the charging depth corresponding to the jump charging data frame is not greater than a preset charging depth threshold, the jump charging data frame is discarded.

[0025] When 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 caused by the jump charging data frame to the calculation result of the ampere-hour integration method can be ignored. In this case, retaining the jump charging data frame can keep the interval charging data highly complete, which helps to improve the accuracy of the available capacity obtained. When 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 cause a large error to the calculation result of the ampere-hour integration method, affecting the accuracy of the calculation result. Abandoning the jump charging data frame will help to improve the accuracy of the available capacity obtained.

[0026] In some embodiments of the present application, obtaining the charging capacity of the interval charging data includes: obtaining the integral of the current of the interval charging data over time in the pre-acquired SOC interval to obtain the charging capacity of the interval charging data. The charging capacity of the interval charging data obtained by integral calculation is more accurate.

[0027] In some embodiments of the present application, obtaining a rated capacity compensation value corresponding to the charging depth of the interval charging data includes:

[0028] The product of the nameplate capacity of the power battery, the first difference, and the pre-acquired SOC interval is obtained to obtain the rated capacity compensation value corresponding to the charging depth of the interval charging data; the first difference is the difference between the pre-acquired lock power upper limit and the pre-acquired lock power lower limit. The lock power lower limit and the lock power upper limit are used when obtaining the rated capacity compensation value, and the obtained rated capacity compensation value has a high accuracy, which helps to further improve the accuracy of the acquisition result of the available capacity of the power battery.

[0029] In some embodiments of the present application, obtaining the pre-acquisition SOC interval includes:

[0030] Based on the big data of the charging operation of the power battery, the maximum continuous SOC interval that meets the preset stability condition is determined to obtain the pre-acquired SOC interval; the preset stability condition is that the rate of change of the charged capacity relative to the SOC change during the charging process is less than a preset value. The pre-acquired SOC interval obtained through big data has more corresponding charged capacity data, which can improve the accuracy of the available capacity acquisition result.

[0031] In some embodiments of the present application, the method further includes:

[0032] 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;

[0033] According to the attenuation offset and the preset corresponding relationship between the attenuation offset and the score, the score corresponding to the attenuation offset is obtained. The score corresponding to the attenuation offset can more intuitively reflect the available capacity status of the power battery.

[0034] According to a second aspect of an embodiment of the present application, a device for obtaining available capacity of a power battery is provided, comprising:

[0035] A historical charging data acquisition module, used to acquire historical charging data of a power battery for a preset period of time, wherein the historical charging data includes complete charging data of at least one charging;

[0036] An interval charging data extraction module, used to extract interval charging data of a pre-acquired SOC interval from each of the complete charging data;

[0037] A ratio acquisition module, for acquiring, for each of the interval charging data, a ratio of the charging capacity of the interval charging data to a compensation value; the compensation value is a rated capacity compensation value corresponding to the charging depth of the interval charging data;

[0038] The preset quantile determination module is used to determine the preset quantiles of all the ratios as the available capacity of the power battery.

[0039] The second aspect of the embodiment of the present application can achieve the same technical effect as the acquisition method of the first aspect.

[0040] In a third aspect of the embodiments of the present application, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for obtaining the available capacity of a power battery as described in any embodiment of the present application. The third aspect of the embodiments of the present application can achieve the same technical effect as the obtaining method of the first aspect.

[0041] In a fourth aspect of the embodiments of the present application, a computer-readable storage medium is provided, on which a computer program is stored, and the computer program is executed by a processor to implement the method for obtaining the available capacity of a power battery as described in any embodiment of the present application. The fourth aspect of the embodiments of the present application can achieve the same technical effect as the obtaining method of the first aspect.

[0042] The above description is only an overview of the technical solution of the embodiment of the present application. In order to more clearly understand the technical means of the embodiment of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] By reading the detailed description of the following embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used to illustrate the embodiments of the present application and are not to be considered as limitations of the present application. In addition, the same reference numerals are used to represent the same components throughout the drawings.

[0044] Figure 1 is a schematic diagram of the structure of a vehicle according to one or more embodiments.

[0045] Figure 2 The present invention is a flowchart of a method for obtaining the available capacity of a power battery according to one or more embodiments.

[0046] Figure 3 A box plot showing the corresponding relationship between SOC intervals and charging capacity according to one or more embodiments.

[0047] Figure 4 The present invention is a flowchart of a method for obtaining the available capacity of a power battery according to one or more embodiments.

[0048] Figure 5 The present invention is a structural block diagram of a device for acquiring the available capacity of a power battery according to one or more embodiments.

[0049] Figure 6 The present invention is a structural block diagram of a device for acquiring the available capacity of a power battery according to one or more embodiments.

[0050] Figure 7 is a structural block diagram of an electronic device according to one or more embodiments.

[0051] Figure 8 FIG. 1 is a schematic diagram of a computer-readable storage medium according to one or more embodiments. DETAILED DESCRIPTION

[0052] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0054] 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 indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two (including two), unless otherwise clearly and specifically defined.

[0055] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0056] With the rapid development of new energy technology, the application of power batteries has become more and more extensive. Power batteries have the advantages of high energy density, rechargeable, safe and environmentally friendly, and are widely used in new energy vehicles, consumer electronics, energy storage systems and other fields. Power batteries are not only used in energy storage power systems such as hydropower, thermal, wind and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric vehicles, as well as military equipment and aerospace and other fields. The market demand for electric vehicles powered by power batteries is also constantly expanding. Power battery performance is one of the important indicators for measuring the performance of electric vehicles, especially in scenarios such as new energy vehicle after-sales and second-hand car transactions. The performance of the available capacity of power batteries is one of the important indicators that customers focus on. During the use of power batteries, the available capacity of power batteries will continue to decrease with the increase of driving mileage, number of charging cycles, etc. At the same time, the available capacity of power batteries is also affected by factors such as the battery management system BMS software strategy. Therefore, the detection of the available capacity of power batteries is an important operation.

[0057] In the related art, the SOC interval used to detect the available capacity of the power battery is usually set manually based on experience, so the accuracy of the available capacity result obtained based on the charging data of the SOC interval is not high.

[0058] In response to the technical problems existing in the related art, an embodiment of the present application provides a method for obtaining the available capacity of a power battery. First, historical charging data of a preset period of the power battery is obtained, and the historical charging data includes complete charging data of at least one charging. Interval charging data of a pre-acquired SOC interval is extracted from each complete charging data. For each interval charging data, a ratio of a charged capacity of the interval charging data to a compensation value is obtained. The compensation value is a rated capacity compensation value corresponding to a charging depth of the interval charging data. Preset quantiles of all ratios are determined as the available capacity of the power battery. The obtained available capacity result has high accuracy and high coverage of the applicable range.

[0059] The method for obtaining the available capacity of a power battery provided in the embodiment of the present application can be used to obtain the available capacity of a power battery of a vehicle using a power battery as energy. Figure 1 As shown, Figure 1 A schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A power battery 100 is provided inside the vehicle 1000, and the power battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The power battery 100 may be used to power the vehicle 1000, for example, the power battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the power battery 100 to power the motor 300, for example, for the starting, navigation and driving power requirements of the vehicle 1000. The power battery 100 may be used not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000. The method for obtaining the available capacity of the power battery provided in the embodiment of the present application may be used to obtain the available capacity of the power battery 100. The power battery in the embodiment of the present application can be a lithium-ion battery, a lithium metal battery, a lead-acid battery, a nickel-cathode battery, a nickel-hydrogen battery, a lithium-sulfur battery, a lithium-air battery or a sodium-ion battery, etc., which is not limited here.

[0060] A method for obtaining the available capacity of a power battery according to an embodiment of the present application is described below in conjunction with the accompanying drawings.

[0061] refer to Figure 2As shown, an embodiment of the present application provides a method for obtaining the available capacity of a power battery, which may include steps S10 to S40:

[0062] S10. Obtain historical charging data of the power battery during a preset period of time.

[0063] The preset time period can be, for example, the last 30 days, the last 20 days, etc., and can be set according to actual needs. The historical charging data includes the complete charging data of the power battery at least once. The power battery is used in electric vehicles to provide power for the electric vehicles. The historical charging data of the power battery can be obtained through the battery management system BMS. For the power battery, the BMS can obtain charging data once every preset time period (the preset time period can be, for example, 10s, 5s, etc.), and the charging data obtained each time can be a data frame, and the charging data obtained each time can include but is not limited to timestamp, SOC, charging current and voltage and other information. SOC is the abbreviation of State of Charge, which refers to the state of charge of the battery, that is, the remaining power.

[0064] Exemplarily, the initial data can be cleaned (for example, outliers are eliminated) and converted to unit formats. The data can be merged, deleted, and other operations can be performed based on the current characteristics of the charging process, taking into account short-term charging, data missing, charging interruptions, excessive voltage differences, and braking recharging, to extract complete charging segment data, that is, historical charging data for a preset time period.

[0065] S20 , extracting interval charging data of a pre-acquired SOC interval from each complete charging data.

[0066] The pre-acquired SOC interval is obtained based on the big data of the charging operation of the power battery (such as cloud big data). Specifically, based on the big data of the charging operation of the power battery, the maximum continuous SOC interval that meets the preset stability condition is determined to obtain the pre-acquired SOC interval; the preset stability condition is that the change rate of the charged capacity relative to the SOC change during the charging process is less than a preset value.

[0067] For example, a box plot can be made based on the charging capacity corresponding to each 5% SOC for the data of all charging segments of vehicles using the target power battery as energy source in the current market in the past year. Figure 3 The figure shows a box plot of the charging capacity corresponding to each 5% SOC for all charging stages of a vehicle using the target power battery as energy source in the past year. Figure 3It can be determined that the charging capacity of every 5% SOC of the vehicle using the target power battery as energy is relatively stable in the SOC charging range of 10%-90%, that is, the difference in the charging capacity of every 5% SOC in the SOC charging range of 10%-90% is less than the preset threshold. After verifying different battery cell materials and different BMS software strategies, an SOC upper threshold and a SOC lower threshold can be determined. In the SOC charging range with the SOC upper threshold and the SOC lower threshold as endpoints, the charging capacity corresponding to each unit SOC is relatively stable, and the SOC charging range also has good generalization. Therefore, it is determined to use this SOC charging range as the pre-acquired SOC range, and the pre-acquired SOC range can be, for example, [20%, 90%] or [10%, 90%], etc.

[0068] In the related art, in order to obtain a relatively stable SOC interval for the charging capacity per unit SOC, the adopted SOC interval is often relatively small, such as 40%-80%, which results in less corresponding charging capacity data and affects the accuracy of the available capacity detection result. The present technical solution uses the pre-acquired SOC interval obtained through big data. The charging capacity per unit SOC in the pre-acquired SOC interval is relatively stable, and the interval is relatively large, so the corresponding charging capacity data is relatively large, which can improve the accuracy of the available capacity acquisition result.

[0069] In addition, in the related art, the corresponding charging capacity data is less due to the small SOC interval used. In actual applications, after the charging capacity data of some power batteries are filtered and cleaned, there is not enough normal data to calculate the available capacity, resulting in a low coverage rate of the applicable scope. For example, the technical solution of the related art may cause the proportion of power batteries that cannot obtain available capacity to reach more than 50% in actual applications, that is, the coverage rate of the applicable scope is less than 50%. Compared with the related art, the charging capacity data corresponding to the pre-acquired SOC interval obtained through big data in this technical solution is more, and after data filtering and cleaning, there is usually still enough data that can be used to calculate the available capacity, and the coverage rate of the applicable scope is higher. Compared with the related art, the coverage rate of the applicable scope is greatly improved.

[0070] S30 . For each interval of charging data, obtain a ratio of the charging capacity of the interval of charging data to the compensation value.

[0071] The compensation value is the rated capacity compensation value corresponding to the charging depth of the interval charging data.

[0072] For example, the integral of the current of the interval charging data in the pre-acquired SOC interval over the time may be obtained to obtain the charging capacity of the interval charging data. The charging capacity of the interval charging data obtained by the integral calculation is relatively accurate.

[0073] The power battery is provided with a nameplate, on which a variety of parameters are marked, 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 lock power upper limit and the pre-acquired lock power lower limit. The lock power lower limit and the lock power upper limit can be obtained by matching the frame number (i.e., the vehicle identification code VIN). The lock power lower limit and the lock power upper limit are used when obtaining the rated capacity compensation value, and the obtained rated capacity compensation value has a high accuracy, which helps to further improve the accuracy of the acquisition result of the available capacity of the power battery.

[0074] Exemplarily, the upper and lower limit lock power boundaries can be obtained by taking the median of the starting voltage from full discharge to full charge and looking up the corresponding OCV (open circuit voltage) table, and establishing a capacity lock power information library to store the upper and lower limit lock power boundary data.

[0075] In a specific example, the pre-acquired SOC interval is [SOC1, SOC2], SOC1<SOC2, and the ratio of the charging capacity of the charging data in the interval to the compensation value is obtained. The ratio is the available capacity of the charging data in the interval, and the calculation formula is:

[0076]

[0077] in, , , , I represents the current, represents the time difference, Represents the nameplate capacity, Represents the lower limit of lock power. Represents the upper limit of the lock power. is the charging capacity calculated by the ampere-hour integration method within [SOC1, SOC2];

[0078] [SOC1, SOC2] is the rated capacity compensation value of the depth of charge DOD corresponding to [SOC1, SOC2].

[0079] S40: Determine preset quantiles of all ratios as available capacity of the power battery.

[0080] The preset quantiles include but are not limited to the 75% quantile, which can be set according to actual needs. Quantile refers to the numerical point that divides the probability distribution range of a random variable into several equal parts. The 75th quantile is the third quartile (Q3), also known as the "larger quartile", which is equal to the 75th percentile of all the values ​​in the sample after arranging them from small to large.

[0081] The method of the embodiment of the present application can realize online real-time calculation of the available capacity of the power battery, and is particularly suitable for application scenarios such as new energy vehicle after-sales and second-hand car transactions.

[0082] In some embodiments, before obtaining the ratio of the charging capacity to the compensation value of the interval charging data, the method may further include: obtaining the charging capacity per unit SOC based on the pre-acquired interval charging data of the SOC interval; filtering the pre-acquired interval charging data of the SOC interval based on the charging capacity per unit SOC to obtain the charging data after the first filtering; and updating the interval charging data using the charging data after the first filtering.

[0083] For example, in the pre-acquired interval charging data of the 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 for each 1% SOC. The filtering process can use sliding window filtering to obtain the charging data after the first filtering. The filtering process can eliminate the erroneous data in the interval charging data caused by BMS transmission data errors and other reasons, improve the accuracy of the charging data, and help improve the accuracy of the available capacity of the acquired power battery.

[0084] In some embodiments, before obtaining the ratio of the charging capacity to the compensation value of the interval charging data, the method also includes: obtaining a jump charging data frame in which there is a time jump or an 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 the charging depth corresponding to the jump charging data frame to obtain the charging data after the second filtering; and using the charging data after the second filtering to update the interval charging data.

[0085] A time-hopping charging data frame refers to a charging data frame whose time interval with the previous charging data frame exceeds a first preset threshold value. Each charging data frame contains timestamp information, and the time interval between a charging data frame and the previous charging data frame can be determined based on the timestamp information. A SOC-hopping charging data frame refers to a charging data frame whose absolute value of the SOC difference with the previous charging data frame exceeds a second preset threshold value. Each charging data frame contains SOC information. For a charging data frame, the absolute value of the difference between the SOC of the charging data frame and the SOC of the previous charging data frame can be calculated. By comparing the absolute value of the difference with the second preset threshold value, it can be determined whether the charging data frame is a SOC-hopping charging data frame.

[0086] The second filtering includes but is not limited to box filtering. The charging data after the second filtering can further improve the accuracy of the charging data, which helps to further improve the accuracy of the available capacity of the power battery obtained.

[0087] Exemplarily, 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 may include: retaining the jump charging data frame when 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 the preset charging depth threshold; discarding the jump charging data frame when 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.

[0088] When 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 caused by the jump charging data frame to the calculation result of the ampere-hour integration method can be ignored. In this case, retaining the jump charging data frame can maintain a high degree of integrity of the interval charging data, which helps to improve the accuracy of the obtained available capacity.

[0089] When 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 calculation result of the ampere-hour integration method, affecting the accuracy of the calculation result. Abandoning the jump charging data frame will help improve the accuracy of the obtained available capacity.

[0090] refer to Figure 4 As shown, in some embodiments, the method may further include steps S50 and S60:

[0091] S50: Obtain a difference between the 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.

[0092] The factory default capacity of the power battery includes but is not limited to 100%.

[0093] S60: Obtain a score corresponding to the attenuation offset according to the attenuation offset and a preset corresponding relationship between the attenuation offset and the score.

[0094] The preset corresponding relationship between the attenuation offset and the score may be, for example, a pre-established scoring model, and the scoring rule of the scoring model is:

[0095] SCORE = 5, ;

[0096] SCORE = 4.5, ;

[0097] SCORE = 4, ;

[0098] SCORE = 3.5, ;

[0099] represents the available capacity attenuation offset, SCORE represents the score, C swift =1-available capacity of the power battery.

[0100] The score corresponding to the attenuation offset can more intuitively reflect the available capacity status of the power battery.

[0101] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0102] A specific example of a method for obtaining the available capacity of a power battery is as follows: first, for the current market, all charging segment data for the vehicle that uses a power battery of a certain project as energy in the past year, a box plot is made based on the data of each 5% SOC and its corresponding charging capacity, and the pre-acquisition SOC interval is determined based on the box plot. In this pre-acquisition SOC interval, the charging capacity corresponding to each unit SOC is relatively stable, and the SOC charging interval also has good generalization. In this example, the pre-acquisition SOC interval is [20%, 90%]. The SOC upper limit threshold of the pre-acquisition SOC interval is 90%, and the SOC lower limit threshold is 20%.

[0103] By taking the median of the starting voltage from fully discharged to fully charged and looking up the corresponding OCV table, the upper and lower lock limits of the power battery of the project are obtained, and a capacity lock information database is established to store the upper and lower lock limits.

[0104] Then, an available capacity calculation model is set. The available capacity calculation model calculates the charging capacity by executing the 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 to the rated capacity compensation value, and obtains the available capacity of the power battery. The calculation formula is:

[0105]

[0106] in, , , , I represents the current, represents the time difference, Represents the nameplate capacity, Represents the lower limit of lock power. Represents the upper limit of the lock power.

[0107] In addition, a scoring model is established, and the scoring model rules are as follows:

[0108] SCORE = 5, ; SCORE = 4.5, ; SCORE = 4, ; SCORE = 3.5, ; It is the available capacity attenuation offset.

[0109] This example uses big data to quantify the endpoint values ​​of the stable SOC range, and combines the lock power upper limit, lock power lower limit and rated capacity compensation to obtain the available capacity of the power battery. It can simplify the input parameters of the available capacity calculation model and improve the transparency of the model while achieving the preset applicable range coverage and the preset available capacity acquisition result accuracy.

[0110] The pre-acquisition SOC interval and the available capacity calculation model are both acquired in advance.

[0111] When obtaining the available capacity of the power battery, the initial historical charging data of the preset time period of the power battery can be cleaned (outliers can be eliminated) and the unit format can be converted. According to the current characteristics during the charging process, and taking into account short-term gun withdrawal and stillness, data missing, charging interruption, excessive voltage difference and braking recharging during the charging process, the data can be merged, deleted, etc. to extract the complete charging segment data, that is, the historical charging data of the preset time period.

[0112] Extract the interval charging data of the pre-acquired SOC interval from each complete charging data. The pre-acquired SOC interval is obtained based on the big data of the charging operation of the power battery (such as cloud big data). Specifically, based on the big data of the charging operation of the power battery, determine the maximum continuous SOC interval that meets the preset stability condition, and obtain the pre-acquired SOC interval; the preset stability condition is that the rate of change of the charged capacity relative to the SOC change during the charging process is less than a preset value.

[0113] According to the interval charging data of the pre-acquired SOC interval, the 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 the charging data after the first filtering; and the interval charging data is updated using the charging data after the first filtering.

[0114] Acquire a jump charging data frame in which there is a time jump or an SOC jump in the interval charging data; acquire a charging current difference between the jump charging data frame and a previous charging data frame; when 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 the preset charging depth threshold, retain the jump charging data frame to obtain the charging data after the second filtering; when 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, discard the jump charging data frame to obtain the charging data after the second filtering; and use the charging data after the second filtering to update the interval charging data.

[0115] For each interval charging data, the integral of the current over time of the interval charging data in the pre-acquired SOC interval is 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.

[0116] The power battery is provided with a nameplate, on which are marked various parameters, including the battery capacity of the power battery. The nameplate capacity is the battery capacity marked on the nameplate. The product of the nameplate capacity of the power battery, the first difference, and the pre-acquired SOC interval is 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 lock power upper limit and the pre-acquired lock power lower limit.

[0117] The lock power lower limit and lock power upper limit can be obtained by matching the vehicle frame number (i.e., vehicle identification code VIN). The lock power lower limit and lock power upper limit are used when obtaining the rated capacity compensation value. The obtained rated capacity compensation value has a high accuracy, which helps to further improve the accuracy of the results of obtaining the available capacity of the power battery.

[0118] For each interval charging data, a ratio of the charging capacity of the interval charging data to the compensation value is obtained. The compensation value is a rated capacity compensation value corresponding to the charging depth of the interval charging data.

[0119] The difference between the factory default capacity of the power battery and the available capacity of the power battery is obtained to obtain the available capacity attenuation offset of the power battery; according to the attenuation offset and the preset correspondence between the attenuation offset and the score, the score corresponding to the attenuation offset is obtained. The preset correspondence between the attenuation offset and the score is a pre-established scoring model, and the scoring rules of the scoring model are:

[0120] SCORE = 5, ;

[0121] SCORE = 4.5, ;

[0122] SCORE = 4, ;

[0123] SCORE = 3.5, ;

[0124] represents the available capacity attenuation offset, SCORE represents the score, C swift =1-the available capacity of the power battery. The score corresponding to the attenuation offset can more intuitively reflect the available capacity of the power battery.

[0125] The method of this example extracts the interval charging data of the pre-acquired SOC interval from each complete charging data of the historical charging data, obtains the ratio of the charging capacity of the interval charging data to the compensation value, the compensation value is the rated capacity compensation value corresponding to the charging depth of the interval charging data, and determines the preset quantiles of all ratios as the available capacity of the power battery, which greatly improves the accuracy of the results of obtaining the available capacity of the power battery and overcomes the defect of low accuracy of the power battery available capacity detection results obtained in the related art by recording the fluctuation of the SOC drift value within the SOC drift range when 1% of the power is charged.

[0126] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0127] refer to Figure 5 As shown, another embodiment of the present application provides a device for obtaining the available capacity of a power battery, which may include:

[0128] A historical charging data acquisition module, used to acquire historical charging data of a power battery for a preset period of time, the historical charging data including complete charging data of at least one charging;

[0129] An interval charging data extraction module, used to extract interval charging data of a pre-acquired SOC interval from each complete charging data;

[0130] A ratio acquisition module, for acquiring, for each of the aforementioned interval charging data, a ratio of the charging capacity of the aforementioned interval charging data to a compensation value; the compensation value is a rated capacity compensation value corresponding to the charging depth of the interval charging data;

[0131] The preset quantile determination module is used to determine the preset quantiles of all the aforementioned ratios as the available capacity of the power battery.

[0132] Exemplarily, the device may further include:

[0133] A charging capacity acquisition module, used to acquire the charging capacity per unit SOC according to the interval charging data of the pre-acquired SOC interval before the ratio acquisition module acquires the ratio of the charging capacity to the compensation value of the aforementioned interval charging data;

[0134] A first filtering module, configured to filter the interval charging data of the pre-acquired SOC interval based on the charging capacity per unit SOC to obtain charging data after the first filtering;

[0135] The first updating module is used to update the interval charging data using the charging data after the first filtering.

[0136] Exemplarily, the device further comprises:

[0137] A data frame acquisition module, used for acquiring a jump charging data frame with a time jump or an SOC jump in the aforementioned interval charging data before the ratio acquisition module acquires the ratio of the charging capacity to the compensation value of the aforementioned interval charging data;

[0138] A current difference acquisition module, used to acquire a charging current difference between a jump charging data frame and a previous charging data frame;

[0139] A second filtering module is used to retain or discard the jump charging data frame according to the charging current difference and the charging depth corresponding to the jump charging data frame to obtain charging data after the second filtering;

[0140] The second updating module is used to update the interval charging data using the charging data after the second filtering.

[0141] Exemplarily, the second filtering module includes:

[0142] A first filtering unit, configured to retain the jump charging data frame when 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;

[0143] The second filtering unit is configured to discard the jump charging data frame when the charging current difference is not less than a preset current threshold or the charging depth corresponding to the jump charging data frame is not greater than a preset charging depth threshold.

[0144] Exemplarily, the ratio acquisition module includes:

[0145] A charging capacity acquisition unit for interval charging data, used to acquire the charging capacity of the aforementioned interval charging data;

[0146] A compensation value acquisition unit, used to acquire a compensation value, where the compensation value is a rated capacity compensation value corresponding to the charging depth of the charging data in the aforementioned interval;

[0147] The ratio calculation unit is used to calculate the ratio of the charging capacity of the charging data in the above interval to the compensation value.

[0148] The charging capacity acquisition unit of the interval charging data is further specifically used to acquire the integral of the current of the aforementioned interval charging data over time within the pre-acquired SOC interval to obtain the charging capacity of the interval charging data.

[0149] Exemplarily, the compensation value acquisition unit is further specifically used to obtain the product of the nameplate capacity of the power battery, the first difference, and the pre-acquired SOC interval to obtain the rated capacity compensation value corresponding to the charging depth of the interval charging data; the first difference is the difference between the pre-acquired lock power upper limit and the pre-acquired lock power lower limit.

[0150] Exemplarily, the device also includes a pre-acquisition SOC interval acquisition module, which is used to obtain a pre-acquisition SOC interval; the pre-acquisition SOC interval acquisition module is further specifically used to determine the maximum continuous SOC interval that meets the preset stability condition based on the big data of the charging operation of the power battery, and obtain the pre-acquisition SOC interval; the preset stability condition is that the rate of change of the charged capacity relative to the SOC change during the charging process is less than a preset value.

[0151] refer to Figure 6 As shown, in some embodiments, the device may further include a scoring module, which is used to: obtain the difference between the factory default capacity of the power battery and the available capacity of the power battery to obtain the available capacity attenuation offset of the power battery; and obtain the score corresponding to the attenuation offset according to the attenuation offset and the preset corresponding relationship between the attenuation offset and the score.

[0152] The device for acquiring the available capacity of a power battery in an embodiment of the present application extracts interval charging data of a pre-acquired SOC interval from each complete charging data of historical charging data, acquires the ratio of the charged capacity of the interval charging data to a compensation value, wherein the compensation value is a rated capacity compensation value corresponding to the charging depth of the interval charging data, and determines preset quantiles of all ratios as the available capacity of the power battery, thereby greatly improving the accuracy of the acquisition result of the available capacity of the power battery.

[0153] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0154] Another embodiment of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for obtaining the available capacity of a power battery according to any of the above embodiments.

[0155] refer to Figure 7As shown, the electronic device 10 may include: a processor 100, a memory 101, a bus 102 and a communication interface 103, and the processor 100, the communication interface 103 and the memory 101 are connected via the bus 102; the memory 101 stores a computer program that can be run on the processor 100, and when the processor 100 runs the computer program, it executes the method for obtaining the available capacity of the power battery provided in any of the aforementioned embodiments of the present application.

[0156] The memory 101 may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk storage. The communication connection between the device network element and at least one other network element is realized through at least one communication interface 103 (which may be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. may be used.

[0157] The bus 102 may be an ISA bus, a PCI bus, or an EISA bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. 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 implementation of the aforementioned embodiment of the present application may be applied to the processor 100, or implemented by the processor 100.

[0158] The processor 100 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in the processor 100 or an instruction in the form of software. The above processor 100 may be a general-purpose processor, which may include a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application can be directly embodied as a hardware decoding processor for execution, or a combination of hardware and software modules in the decoding processor for execution. The software module may be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 101, and the processor 100 reads the information in the memory 101 and completes the steps of the above method in combination with its hardware.

[0159] The electronic device provided in the embodiment of the present application and the method provided in the embodiment of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, operated or implemented by them.

[0160] Another embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored, and the computer program is executed by a processor to implement the method for obtaining the available capacity of a power battery in any of the above embodiments. Figure 8 As shown, the computer-readable storage medium shown is a CD 20 on which a computer program (ie, a program product) is stored. When the computer program is executed by a processor, the method for obtaining the available capacity of a power battery provided in any of the aforementioned embodiments will be executed.

[0161] It should be noted that examples of computer-readable storage media may also include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical or magnetic storage media, which are not listed here one by one.

[0162] The computer-readable storage medium provided in the above-mentioned embodiments of the present application and the method provided in the embodiments of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, run or implemented by the application program stored therein.

[0163] It should be noted that:

[0164] The term "module" is not intended to be limited to a specific 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 may or may not be clear boundaries between different modules.

[0165] The algorithm and display provided herein are not inherently related to any specific computer, virtual device or other equipment. Various general devices can also be used together with examples based on this. According to the above description, it is obvious to construct the structure required for this type of device. In addition, the application is not directed to any specific programming language yet. It should be understood that various programming languages ​​can be utilized to realize the content of the application described herein, and the description made to specific languages ​​above is for the purpose of disclosing the best mode of implementation of the application.

[0166] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0167] The above embodiments only express the implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for obtaining the available capacity of a power battery, characterized in that: include: Acquire historical charging data of a power battery for a preset period of time, wherein the historical charging data includes complete charging data of at least one charging; Extracting interval charging data of a pre-acquisition SOC interval from each of the complete charging data; For each of the interval charging data, a ratio of the charging capacity of the interval charging data to a compensation value is obtained; the compensation value is a rated capacity compensation value corresponding to the charging depth of the interval charging data; Determining preset quantiles of all the ratios as the available capacity of the power battery; Acquiring the pre-acquisition SOC interval includes: Based on the big data of the charging operation of the power battery, determining a maximum continuous SOC interval that meets a preset stability condition, and obtaining the pre-acquired SOC interval; The preset stability condition is that the rate of change of the charged capacity relative to the SOC change during the charging process is less than a preset value.

2. The method according to claim 1, characterized in that Before obtaining the ratio of the charging capacity to the compensation value of the interval charging data, the method further includes: Acquire a charging capacity per unit SOC according to the interval charging data of the pre-acquired SOC interval; Based on the charging capacity per unit SOC, filtering the interval charging data of the pre-acquired SOC interval to obtain charging data after the first filtering; The interval charging data is updated using the charging data after the first filtering.

3. The method according to claim 1 or 2, characterized in that: Before obtaining the ratio of the charging capacity to the compensation value of the interval charging data, the method further includes: Acquire a jump charging data frame having a time jump or an SOC jump in the interval charging data; Acquire a charging current difference between the jump charging data frame and a previous charging data frame; According to the charging current difference and the charging depth corresponding to the jump charging data frame, retain or discard the jump charging data frame to obtain the charging data after the second filtering; The interval charging data is updated using the charging data after the second filtering.

4. The method according to claim 3, characterized in that The 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 includes: When 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, retaining the jump charging data frame; When the charging current difference is not less than a preset current threshold or the charging depth corresponding to the jump charging data frame is not greater than a preset charging depth threshold, the jump charging data frame is discarded.

5. The method according to claim 3, characterized in that: Acquiring the charging capacity of the interval charging data includes: acquiring the integral of the current of the interval charging data over time in the pre-acquired SOC interval to obtain the charging capacity of the interval charging data.

6. The method according to claim 3, characterized in that Obtaining a rated capacity compensation value corresponding to the charging depth of the interval charging data, including: Obtain the product of the nameplate capacity of the power battery, the first difference, and the pre-acquired SOC interval to obtain a rated capacity compensation value corresponding to the charging depth of the interval charging data; the first difference is the difference between the pre-acquired lock power upper limit and the pre-acquired lock power lower limit.

7. The method according to claim 1 or 2, characterized in that: 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; 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 obtained.

8. A device for obtaining the available capacity of a power battery, characterized in that: include: A historical charging data acquisition module, used to acquire historical charging data of a power battery for a preset period of time, wherein the historical charging data includes complete charging data of at least one charging; An interval charging data extraction module, used to extract interval charging data of a pre-acquired SOC interval from each of the complete charging data; A ratio acquisition module, for acquiring, for each of the interval charging data, a ratio of the charging capacity of the interval charging data to a compensation value; the compensation value is a rated capacity compensation value corresponding to the charging depth of the interval charging data; A preset quantile determination module, used to determine the preset quantiles of all the ratios as the available capacity of the power battery; A pre-acquisition SOC interval acquisition module, used to determine a maximum continuous SOC interval that meets a preset stability condition based on the big data of the charging operation of the power battery, and obtain the pre-acquisition SOC interval; The preset stability condition is that the rate of change of the charged capacity relative to the SOC change during the charging process is less than a preset value.

9. An electronic device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for obtaining the available capacity of a power battery as claimed in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The computer program is executed by a processor to implement the method for obtaining the available capacity of a power battery as described in any one of claims 1 to 7.

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