CN117110897A - Lithium battery capacity-division capacity calibration method and system - Google Patents
Lithium battery capacity-division capacity calibration method and system Download PDFInfo
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- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 116
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 116
- 238000000034 method Methods 0.000 title claims abstract description 63
- 238000007599 discharging Methods 0.000 claims abstract description 23
- 230000003044 adaptive effect Effects 0.000 claims description 13
- 238000004590 computer program Methods 0.000 claims description 6
- 238000010606 normalization Methods 0.000 claims description 6
- 238000011835 investigation Methods 0.000 claims description 4
- 230000005856 abnormality Effects 0.000 claims description 3
- 230000010287 polarization Effects 0.000 abstract description 6
- 238000007619 statistical method Methods 0.000 abstract description 3
- 238000004891 communication Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 239000006185 dispersion Substances 0.000 description 3
- 230000002159 abnormal effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 230000001174 ascending effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/374—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC] with means for correcting the measurement for temperature or ageing
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/378—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC] specially adapted for the type of battery or accumulator
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/385—Arrangements for measuring battery or accumulator variables
- G01R31/387—Determining ampere-hour charge capacity or SoC
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/396—Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
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Abstract
The embodiment of the invention provides a method and a system for calibrating capacity of a lithium battery, wherein the method comprises the following steps: performing capacity-division charge and discharge on the target lithium battery; acquiring capacity data and corresponding battery temperature data of a target lithium battery in the charging and discharging process, and determining a median in groups; performing linear fitting on the capacity median and the corresponding battery temperature data, and calculating the goodness of fit; and normalizing capacity-dividing capacity data corresponding to different battery temperature data based on a linear fitting equation, performing capacity compensation on battery temperature data with difference from the normalized temperature, and determining the final capacity of the target lithium battery. The influence of temperature and polarization on capacity calibration can be eliminated within a certain limit, and the real capacity of the lithium battery can be obtained; and the statistical analysis method is used, so that errors in the capacity-temperature fitting process are reduced, more accurate compensation capacity is obtained, accurate calibration of the capacity of the lithium battery is realized, and the consistency of the capacity of the battery in the module is further improved.
Description
Technical Field
The invention relates to the technical field of lithium battery application, in particular to a method and a system for calibrating capacity of a lithium battery.
Background
The lithium battery has the advantages of high specific energy, low self-discharge rate, good high-low temperature performance, long charge-discharge life and the like, is widely applied to industries such as automobiles and the like, and is usually formed by connecting a plurality of battery cells in series or in parallel to form a battery pack for use, so that the requirement on the consistency of the battery is higher, and particularly the consistency of the capacity is higher. Therefore, in the last step of manufacturing the battery cells, the battery cells with consistent capacity are screened out to form the battery pack by fixing the volume of the battery cells.
However, in the conventional constant volume manner, there may be two problems: polarization exists in the battery charging and discharging process, and due to polarization reasons, voltage is high in the charging process, so that cut-off voltage is reached in advance, and the charging capacity is smaller, so that the released capacity is smaller; the battery capacity is greatly affected by temperature, the temperature field of the capacity-dividing equipment is difficult to keep consistent, and meanwhile, heat can be released in the battery charging and discharging process, so that the battery is inaccurate in constant volume.
Disclosure of Invention
Aiming at the problems existing in the prior art, the embodiment of the invention provides a method and a system for calibrating the capacity of a lithium battery.
The embodiment of the invention provides a lithium battery capacity-dividing capacity calibration method, which comprises the following steps:
dividing the capacity of a target lithium battery, and charging and discharging the divided target lithium battery by adopting the use standard based on the use standard of the target lithium battery;
acquiring capacity data of the target lithium battery and corresponding battery temperature data in the charging and discharging process, grouping the capacity data based on the battery temperature data, and acquiring the capacity median of the capacity data in the grouping result;
performing linear fitting on the capacity median and the corresponding battery temperature data, calculating the fitting goodness between capacity data and battery temperature data based on a linear fitting result, and performing adaptive adjustment based on a data result of the fitting goodness to obtain an adjusted linear fitting equation;
and normalizing capacity-division capacity data corresponding to different battery temperature data based on the linear fitting equation, determining a normalized temperature, performing capacity compensation on battery temperature data with difference from the normalized temperature, and determining the final capacity of the target lithium battery.
In one embodiment, the method further comprises:
determining the charge-discharge multiplying power of the target lithium battery based on the use standard, and setting charge-discharge parameters according to the charge-discharge multiplying power;
and carrying out constant-current constant-voltage charge and constant-current discharge or constant-power charge and constant-power discharge on the target lithium battery subjected to capacity division through the charge and discharge parameters.
In one embodiment, the battery temperature data includes:
and the battery temperature data at the end of discharge are acquired in the charge and discharge process.
In one embodiment, the method further comprises:
dividing the corresponding capacity data of the battery when the temperature data of the battery are the same into a group, and detecting the discrete degree of the capacity data of each group in the grouping result;
when the discrete degree of the capacity data in the grouping result is larger than a preset threshold value, removing the capacity data with the discrete degree larger than the preset threshold value, and obtaining the capacity median of the capacity data.
In one embodiment, the method further comprises:
when the goodness of fit is smaller than 0.8, carrying out temperature field fluctuation investigation on capacity-dividing equipment of the target lithium battery, or detecting the target lithium battery to carry out abnormality investigation;
when the goodness of fit is greater than 0.8 and less than 0.9, adjusting a temperature data range corresponding to battery temperature data in the linear fit;
and when the goodness of fit is greater than 0.9, obtaining a linear fitting equation based on the data result of the goodness of fit.
In one embodiment, the method further comprises:
acquiring temperature points in the linear fitting method, and calculating a predicted capacity value corresponding to each temperature point based on the temperature points and in combination with a linear fitting equation;
and calculating the relative value of the capacity data and the predicted capacity value to obtain normalized data, and comparing the normalized data at different temperature points to determine the normalized temperature.
The embodiment of the invention provides a lithium battery capacity-dividing capacity calibration system, which comprises the following components:
the capacity-dividing module is used for dividing the capacity of the target lithium battery and charging and discharging the divided target lithium battery by adopting the use standard based on the use standard of the target lithium battery;
the grouping module is used for acquiring capacity data of the target lithium battery and corresponding battery temperature data in the charging and discharging process, grouping the capacity data based on the battery temperature data and acquiring the capacity median of the capacity data in the grouping result;
the linear fitting module is used for carrying out linear fitting on the capacity median and the corresponding battery temperature data, calculating the fitting goodness between the capacity data and the battery temperature data based on the linear fitting result, and carrying out adaptive adjustment based on the data result of the fitting goodness to obtain an adjusted linear fitting equation;
and the normalization module is used for normalizing the capacity-division capacity data corresponding to different battery temperature data based on the linear fitting equation, determining the normalized temperature, performing capacity compensation on the battery temperature data with the difference from the normalized temperature, and determining the final capacity of the target lithium battery.
In one embodiment, the system further comprises:
the setting module is used for determining the charge-discharge multiplying power of the target lithium battery based on the use standard and setting charge-discharge parameters according to the charge-discharge multiplying power;
and the charge-discharge module is used for carrying out constant-current constant-voltage charge and constant-current discharge or constant-power charge and constant-power discharge on the target lithium battery after capacity division through the charge-discharge parameters.
The embodiment of the invention provides an electronic device, which comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein the processor realizes the steps of the lithium battery capacity division capacity calibration method when executing the program.
The embodiment of the invention provides a non-transitory computer readable storage medium, on which a computer program is stored, which when executed by a processor, implements the steps of the lithium battery capacity division capacity calibration method.
According to the capacity-dividing capacity calibration method and system for the lithium battery, provided by the embodiment of the invention, the capacity of the target lithium battery is divided, and the divided target lithium battery is charged and discharged by adopting the use standard based on the use standard of the target lithium battery; acquiring capacity data of a target lithium battery and corresponding battery temperature data in the charging and discharging process, grouping the capacity data based on the battery temperature data, and acquiring the capacity median of the capacity data in the grouping result; performing linear fitting on the capacity median and corresponding battery temperature data, calculating the fitting goodness between capacity data and battery temperature data based on the linear fitting result, and performing adaptive adjustment based on the data result of the fitting goodness to obtain an adjusted linear fitting equation; and normalizing capacity-dividing capacity data corresponding to different battery temperature data based on a linear fitting equation, determining a normalized temperature, performing capacity compensation on battery temperature data with difference from the normalized temperature, and determining the final capacity of the target lithium battery. The influence of temperature and polarization on capacity calibration can be eliminated within a certain limit, and the real capacity of the lithium battery can be obtained; and the statistical analysis method is used, so that errors in the capacity-temperature fitting process are reduced, more accurate compensation capacity is obtained, accurate calibration of the capacity of the lithium battery is realized, and the consistency of the capacity of the battery in the module is further improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of a method for calibrating capacity of a lithium battery according to an embodiment of the invention;
FIG. 2 is a block diagram of a lithium battery capacity-division capacity calibration system according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of an electronic device according to an embodiment of the invention.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Fig. 1 is a flow chart of a method for calibrating capacity of a lithium battery according to an embodiment of the present invention, and as shown in fig. 1, the embodiment of the present invention provides a method for calibrating capacity of a lithium battery:
and step S101, capacity division is carried out on the target lithium battery, and based on the use standard of the target lithium battery, the capacity-divided target lithium battery is charged and discharged by adopting the use standard.
In particular, the capacity division is to divide one battery pack into a plurality of battery cells in order to better manage and control the performance and service life of the battery system. By balancing the charge and discharge between the cells, a relative balance of performance and life of each cell is ensured. If there is a difference between the battery cells, some battery cells may fail too early, thereby reducing the performance and lifetime of the whole battery pack, wherein the target lithium battery may be a high-capacity battery pack, after capacity division, a subsequent charge and discharge standard is determined based on a usage standard of the target lithium battery, and the usage standard may be a charge and discharge rate of the lithium battery, a battery capacity, and the like, for example, the charge and discharge power is 0.5C/0.5C, and then a series of charge and discharge cycles are performed on the divided lithium battery through the charge and discharge rate, so as to measure the capacity and performance of the battery. In this case, 0.5C means that the current of both charge and discharge is 0.5 times the capacity of the battery, and constant-current constant-voltage charge and constant-current discharge, or constant-power charge and constant-power discharge, is performed on the divided target lithium battery by the charge and discharge parameters during the charge and discharge, and the battery polarization is eliminated by increasing the constant-voltage step.
Step S102, capacity data of the target lithium battery and corresponding battery temperature data in the charge and discharge process are obtained, the capacity data are grouped based on the battery temperature data, and the capacity median of the capacity data in the grouping result is obtained.
Specifically, the capacity-dividing capacity data of the target lithium battery and the corresponding battery temperature data are acquired in the charging and discharging process, the capacity-dividing capacity data refer to capacity data of each battery cell after one battery pack is divided into a plurality of battery cells, in a series of charging and discharging cycles of the lithium battery after capacity division, the battery temperature data can acquire battery temperature data at the end of discharging and capacity-dividing capacity data at a corresponding time point, and under the condition that the battery temperature data are the same, the corresponding capacity-dividing capacity data are divided into the same group of data, and the capacity median of the capacity-dividing capacity data is acquired in the grouping result.
In addition, after the grouping is determined, the discrete degree of the grouping data can be tested, the discrete value in the grouping data can be screened in advance, and the discrete degree of the data can be measured by using a standard deviation or a variation coefficient in statistics. The larger the degree of dispersion is, the wider the variation range of the data is, and in the grouping result, whether the capacity data with the degree of dispersion larger than a preset threshold exists or not is checked. The preset threshold value can be set according to specific requirements. If data having a degree of dispersion greater than a preset threshold exists, these data are excluded, and the median of their capacity is calculated for the remaining capacity-divided capacity data. The median represents the numerical value at the middle position after the data are arranged in an ascending order, and the influence of the abnormal value on the partial capacity data can be reduced by excluding the partial capacity data with the discrete degree larger than the preset threshold value, so that the capacity median can be calculated more accurately.
And step S103, performing linear fitting on the capacity median and the corresponding battery temperature data, calculating the fitting goodness between the capacity data and the battery temperature data based on the linear fitting result, and performing adaptive adjustment based on the data result of the fitting goodness to obtain an adjusted linear fitting equation.
Specifically, determining the capacity median of each battery temperature data, forming a corresponding data set, performing linear fitting on the data set, wherein the specific linear fitting process can be realized by taking the capacity median as a vertical axis and the temperature as a horizontal axis, drawing a scatter diagram, and the scatter diagram can intuitively show the relation between the capacity median and the temperature; finding out the best fitting straight line through a least square method, so that the error square sum of the fitting straight line and scattered point data is minimum; the result of the least squares method is to obtain the slope and intercept of the fitted line, and the equation of the fitted line is: capacity = slope x temperature + intercept. The slope represents the rate of change of capacity with temperature, the intercept represents the initial capacity at zero temperature, and finally, a fitting straight line is drawn by using the obtained slope and intercept, the fitting straight line can be used for representing the linear relation between the median of capacity and the temperature, and then, the fitting goodness is calculated based on the linear relation in the linear fitting result, wherein the fitting goodness can be the conditions of average value of observed values (the average value of the median of capacity and the temperature), total square sum, regression square sum, residual square sum, correlation coefficient, root mean square error and the like. The goodness of fit between the capacity data and the battery temperature data is represented, for example, by a correlation coefficient. After the fitting goodness is determined, carrying out adaptive adjustment based on the data result of the fitting goodness to obtain an adjusted linear fitting equation, wherein the adjusted linear fitting equation can describe the relationship between the capacity median and the temperature more accurately. For example, when the correlation coefficient is low in the goodness of fit, it is indicated that the linear relationship between the fitted line and the observed data is weak, in which case higher order polynomial fitting may be attempted, or other nonlinear fitting methods may be considered. When the root mean square error is high, the difference between the predicted value and the observed value of the fitting straight line is large, in this case, the elimination of abnormal values or outliers can be considered, linear fitting can be carried out again, different weights can be given to data at different temperatures by using a weighted least square method, so that the fitting error is reduced, and the like, after adaptation and adjustment, the data set after adjustment is subjected to linear fitting again, a new linear fitting result is detected, and the improved fitting result after adjustment is ensured. Therefore, through the adaptive adjustment, the accuracy and the adaptability of the linear fitting equation can be improved, and the relationship between the capacity median and the temperature can be better described.
In addition, the adaptive adjustment is performed based on the data result of the goodness of fit, and the obtained adjusted linear fitting equation may be specifically: when the goodness-of-fit correlation coefficient is less than 0.8, it may be necessary to further check whether the temperature field fluctuation of the capacity-division apparatus is too large or whether there is an abnormality in the battery production process by adjusting the temperature data range corresponding to the battery temperature data in the linear fitting, which may be a cause of poor fitting results. When the fitting goodness-of-measure correlation coefficient is larger than 0.8 and smaller than 0.9, the fitting temperature selection range can be properly reduced, and a section with larger linear correlation is selected for linear fitting, so that the fitting accuracy and reliability can be improved by focusing on the data in the temperature range. When the correlation coefficient of the goodness of fit is larger than 0.9, the fitting result is good, and a linear fitting equation is obtained based on the data result of the goodness of fit.
Step S104, normalizing capacity-dividing capacity data corresponding to different battery temperature data based on the linear fitting equation, determining a normalized temperature, performing capacity compensation on battery temperature data with difference from the normalized temperature, and determining the final capacity of the target lithium battery.
Specifically, after determining the linear fit equation, the battery capacities at different discharge temperatures are normalized. The step of normalization may divide the capacity value at each temperature by the slope in the fitting equation to obtain a normalized capacity value, or may obtain temperature points in the linear fitting method through a specific step, calculate a predicted capacity value corresponding to each temperature point based on the temperature points in combination with the linear fitting equation, calculate a relative value between the capacity data and the predicted capacity value to obtain normalized data, and convert the battery capacity data at different temperatures into relative values through normalization to eliminate the influence of temperature on capacity. This allows a better comparison of the battery performance at different temperatures, and then calculates a compensation value for the temperature fluctuation versus the capacity. The predicted capacity at different temperatures can be calculated by fitting an equation and then compared with the actual capacity to obtain a compensation value. The compensation value may be the difference between the predicted capacity and the actual capacity or a value derived from other compensation algorithms to compensate for the normalized capacity value. And adding the normalized capacity value with the compensation value at the corresponding temperature to obtain a compensated capacity value, and converting the compensated capacity value into an actual capacity value. The compensated capacity value can be multiplied by the slope in the fitting equation to obtain the final constant volume capacity, and in addition, the final constant volume capacity can be the constant volume capacity at a certain temperature, wherein the certain temperature can be a temperature value least influenced by temperature fluctuation, and can also be a preset temperature value, namely the final capacity corresponding to the normalized temperature.
According to the capacity-dividing capacity calibration method for the lithium battery, provided by the embodiment of the invention, the capacity of the target lithium battery is divided, and the divided target lithium battery is charged and discharged by adopting the use standard based on the use standard of the target lithium battery; acquiring capacity data of a target lithium battery and corresponding battery temperature data in the charging and discharging process, grouping the capacity data based on the battery temperature data, and acquiring the capacity median of the capacity data in the grouping result; performing linear fitting on the capacity median and corresponding battery temperature data, calculating the fitting goodness between capacity data and battery temperature data based on the linear fitting result, and performing adaptive adjustment based on the data result of the fitting goodness to obtain an adjusted linear fitting equation; and normalizing capacity-dividing capacity data corresponding to different battery temperature data based on a linear fitting equation, determining a normalized temperature, performing capacity compensation on battery temperature data with difference from the normalized temperature, and determining the final capacity of the target lithium battery. The influence of temperature and polarization on capacity calibration can be eliminated within a certain limit, and the real capacity of the lithium battery can be obtained; and the statistical analysis method is used, so that errors in the capacity-temperature fitting process are reduced, more accurate compensation capacity is obtained, accurate calibration of the capacity of the lithium battery is realized, and the consistency of the capacity of the battery in the module is further improved.
In another embodiment, the method for calibrating the capacity of the lithium battery includes:
s1, carrying out 0.5C/0.5C capacity division on the batch A batteries;
s2, selecting the capacity-dividing discharge capacity C of the batch A batteries A And the corresponding single battery temperature data are used for grouping the partial capacity data by taking the discharge end temperature as a grouping standard, and the median of the capacity at each temperature is calculated in sequence;
s3, performing linear fitting on the volume median and the temperature at each discharge end temperature to obtain a volume-dividing volume C A Correspondence with temperature T: c=a×t+b, fit relationship of the batch battery capacity to temperature: a=1.303, b= 278.762,
calculating and determining the fitting goodness-of-fit correlation coefficient R 2 >0.99, showing that the fitting result is good;
and S4, normalizing the battery capacity at different discharge temperatures through a linear fitting equation, and compensating the capacity influenced by temperature fluctuation to obtain the compensation capacity at a certain specific temperature, wherein the compensation capacity is used as the final capacity of the constant volume lithium battery. Selecting 31 ℃ as the normalized temperature, then C Compensation ＝C-a×(T-31)，C Compensation The final capacity of the lithium battery is fixed.
Fig. 2 is a schematic diagram of a system for calibrating capacity of a lithium battery according to an embodiment of the present invention, including: a capacity division module S201, a grouping module S202, a linear fitting module S203 and a normalization module S204, wherein:
and the capacity division module S201 is used for dividing the capacity of the target lithium battery and charging and discharging the divided target lithium battery by adopting the use standard based on the use standard of the target lithium battery.
The grouping module S202 is configured to obtain capacity data of the target lithium battery and corresponding battery temperature data in a charging and discharging process, and group the capacity data based on the battery temperature data, so as to obtain a capacity median of the capacity data in the grouping result.
And the linear fitting module S203 is used for performing linear fitting on the capacity median and the corresponding battery temperature data, calculating the fitting goodness between the capacity data and the battery temperature data based on the linear fitting result, and performing adaptive adjustment based on the data result of the fitting goodness to obtain an adjusted linear fitting equation.
And the normalization module S204 is used for normalizing the capacity-division capacity data corresponding to different battery temperature data based on the linear fitting equation, determining the normalized temperature, performing capacity compensation on the battery temperature data with the difference from the normalized temperature, and determining the final capacity of the target lithium battery.
In one embodiment, the system further comprises:
and the setting module is used for determining the charge-discharge multiplying power of the target lithium battery based on the use standard and setting charge-discharge parameters according to the charge-discharge multiplying power.
And the charge-discharge module is used for carrying out constant-current constant-voltage charge and constant-current discharge or constant-power charge and constant-power discharge on the target lithium battery after capacity division through the charge-discharge parameters.
For specific limitation of the lithium battery capacity division and calibration system, reference may be made to the limitation of the lithium battery capacity division and calibration method hereinabove, and no further description is given here. All or part of each module in the lithium battery capacity-division capacity calibration system can be realized by software, hardware and a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.
Fig. 3 illustrates a physical schematic diagram of an electronic device, as shown in fig. 3, where the electronic device may include: a processor (processor) 301, a memory (memory) 302, a communication interface (Communications Interface) 303 and a communication bus 304, wherein the processor 301, the memory 302 and the communication interface 303 perform communication with each other through the communication bus 304. The processor 301 may call logic instructions in the memory 302 to perform the following method: dividing the capacity of the target lithium battery, and charging and discharging the divided target lithium battery by adopting the use standard based on the use standard of the target lithium battery; acquiring capacity data of a target lithium battery and corresponding battery temperature data in the charging and discharging process, grouping the capacity data based on the battery temperature data, and acquiring the capacity median of the capacity data in the grouping result; performing linear fitting on the capacity median and corresponding battery temperature data, calculating the fitting goodness between capacity data and battery temperature data based on the linear fitting result, and performing adaptive adjustment based on the data result of the fitting goodness to obtain an adjusted linear fitting equation; and normalizing capacity-dividing capacity data corresponding to different battery temperature data based on a linear fitting equation, determining a normalized temperature, performing capacity compensation on battery temperature data with difference from the normalized temperature, and determining the final capacity of the target lithium battery.
Further, the logic instructions in memory 302 described above may be implemented in the form of software functional units and stored in a computer readable storage medium when sold or used as a stand alone product. Based on this understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
In another aspect, embodiments of the present invention further provide a non-transitory computer readable storage medium having stored thereon a computer program, which when executed by a processor is implemented to perform the transmission method provided in the above embodiments, for example, including: dividing the capacity of the target lithium battery, and charging and discharging the divided target lithium battery by adopting the use standard based on the use standard of the target lithium battery; acquiring capacity data of a target lithium battery and corresponding battery temperature data in the charging and discharging process, grouping the capacity data based on the battery temperature data, and acquiring the capacity median of the capacity data in the grouping result; performing linear fitting on the capacity median and corresponding battery temperature data, calculating the fitting goodness between capacity data and battery temperature data based on the linear fitting result, and performing adaptive adjustment based on the data result of the fitting goodness to obtain an adjusted linear fitting equation; and normalizing capacity-dividing capacity data corresponding to different battery temperature data based on a linear fitting equation, determining a normalized temperature, performing capacity compensation on battery temperature data with difference from the normalized temperature, and determining the final capacity of the target lithium battery.
The system embodiments described above are merely illustrative, wherein the elements illustrated as separate elements may or may not be physically separate, and the elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art will understand and implement the present invention without undue burden.
From the above description of the embodiments, it will be apparent to those skilled in the art that the embodiments may be implemented by means of software plus necessary general hardware platforms, or of course may be implemented by means of hardware. Based on this understanding, the foregoing technical solution may be embodied essentially or in a part contributing to the prior art in the form of a software product, which may be stored in a computer readable storage medium, such as ROM/RAM, a magnetic disk, an optical disk, etc., including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method described in the respective embodiments or some parts of the embodiments.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. The method for calibrating the capacity of the lithium battery is characterized by comprising the following steps of:
dividing the capacity of a target lithium battery, and charging and discharging the divided target lithium battery by adopting the use standard based on the use standard of the target lithium battery;
acquiring capacity data of the target lithium battery and corresponding battery temperature data in the charging and discharging process, grouping the capacity data based on the battery temperature data, and acquiring the capacity median of the capacity data in the grouping result;
performing linear fitting on the capacity median and the corresponding battery temperature data, calculating the fitting goodness between capacity data and battery temperature data based on a linear fitting result, and performing adaptive adjustment based on a data result of the fitting goodness to obtain an adjusted linear fitting equation;
and normalizing capacity-division capacity data corresponding to different battery temperature data based on the linear fitting equation, determining a normalized temperature, performing capacity compensation on battery temperature data with difference from the normalized temperature, and determining the final capacity of the target lithium battery.
2. The method for calibrating capacity of a lithium battery according to claim 1, wherein the charging and discharging the target lithium battery after capacity division by using the usage standard based on the usage standard of the target lithium battery comprises:
determining the charge-discharge multiplying power of the target lithium battery based on the use standard, and setting charge-discharge parameters according to the charge-discharge multiplying power;
and carrying out constant-current constant-voltage charge and constant-current discharge or constant-power charge and constant-power discharge on the target lithium battery subjected to capacity division through the charge and discharge parameters.
3. The method for calibrating capacity of a lithium battery according to claim 1, wherein the battery temperature data comprises:
and the battery temperature data at the end of discharge are acquired in the charge and discharge process.
4. The method for calibrating capacity of a lithium battery according to claim 1, wherein the grouping the capacity data based on the battery temperature data to obtain a median of capacities of the capacity data in the grouping result comprises:
dividing the corresponding capacity data of the battery when the temperature data of the battery are the same into a group, and detecting the discrete degree of the capacity data of each group in the grouping result;
when the discrete degree of the capacity data in the grouping result is larger than a preset threshold value, removing the capacity data with the discrete degree larger than the preset threshold value, and obtaining the capacity median of the capacity data.
5. The method for calibrating capacity of a lithium battery according to claim 1, wherein the adaptively adjusting based on the data result of the goodness of fit to obtain an adjusted linear fitting equation comprises:
when the goodness of fit is smaller than 0.8, carrying out temperature field fluctuation investigation on capacity-dividing equipment of the target lithium battery, or detecting the target lithium battery to carry out abnormality investigation;
when the goodness of fit is greater than 0.8 and less than 0.9, adjusting a temperature data range corresponding to battery temperature data in the linear fit;
and when the goodness of fit is greater than 0.9, obtaining a linear fitting equation based on the data result of the goodness of fit.
6. The method for calibrating capacity of a lithium battery according to claim 1, wherein normalizing capacity data corresponding to different battery temperature data based on the linear fitting equation, and determining a normalized temperature, comprises:
acquiring temperature points in the linear fitting method, and calculating a predicted capacity value corresponding to each temperature point based on the temperature points and in combination with a linear fitting equation;
and calculating the relative value of the capacity data and the predicted capacity value to obtain normalized data, and comparing the normalized data at different temperature points to determine the normalized temperature.
7. A lithium battery capacity-division capacity calibration system, the system comprising:
the capacity-dividing module is used for dividing the capacity of the target lithium battery and charging and discharging the divided target lithium battery by adopting the use standard based on the use standard of the target lithium battery;
the grouping module is used for acquiring capacity data of the target lithium battery and corresponding battery temperature data in the charging and discharging process, grouping the capacity data based on the battery temperature data and acquiring the capacity median of the capacity data in the grouping result;
the linear fitting module is used for carrying out linear fitting on the capacity median and the corresponding battery temperature data, calculating the fitting goodness between the capacity data and the battery temperature data based on the linear fitting result, and carrying out adaptive adjustment based on the data result of the fitting goodness to obtain an adjusted linear fitting equation;
and the normalization module is used for normalizing the capacity-division capacity data corresponding to different battery temperature data based on the linear fitting equation, determining the normalized temperature, performing capacity compensation on the battery temperature data with the difference from the normalized temperature, and determining the final capacity of the target lithium battery.
8. The lithium battery capacity-division capacity calibration system of claim 7, further comprising:
the setting module is used for determining the charge-discharge multiplying power of the target lithium battery based on the use standard and setting charge-discharge parameters according to the charge-discharge multiplying power;
and the charge-discharge module is used for carrying out constant-current constant-voltage charge and constant-current discharge or constant-power charge and constant-power discharge on the target lithium battery after capacity division through the charge-discharge parameters.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the steps of the lithium battery capacity-division capacity calibration method according to any one of claims 1 to 6 when executing the program.
10. A non-transitory computer readable storage medium having stored thereon a computer program, characterized in that the computer program when executed by a processor realizes the steps of the lithium battery capacity allocation method according to any one of claims 1 to 6.
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