Battery capacity correction method, system, device, and program product

Abstract

This application relates to the field of battery management technology and provides a battery capacity correction method, system, device, and program product. The method includes: obtaining an estimated state of charge (SOC) value before correction and a reference SOC value after correction at a preset SOC correction anchor point; calculating a SOC correction difference based on the estimated SOC value and the reference value; determining the battery capacity corresponding to the current battery temperature; and correcting the remaining battery capacity before correction according to the SOC correction anchor point, the SOC correction difference, and the battery capacity to obtain the corrected remaining battery capacity. This application can correct the remaining battery capacity according to different anchor points and operating conditions, making the correction of the remaining battery capacity more accurate and improving the estimation accuracy of SOC across the entire operating range.

Description

Technical Field

[0001] This application belongs to the field of battery management technology, and in particular relates to a battery capacity correction method, system, device and program product. Background Technology

[0002] The state of charge (SOC) of a battery is a key parameter characterizing its remaining capacity, but it cannot be directly measured and usually needs to be estimated using algorithms. The ampere-hour integration method is one of the most commonly used SOC estimation methods. Its basic principle is to calculate the change in capacity by integrating the current flowing through the battery over time, thereby estimating the change in SOC.

[0003] Traditional ampere-hour integration methods typically use the battery's factory-specified rated capacity as the basis for calculations. However, the actual usable capacity of a battery is not a fixed value; it is dynamically affected by various factors such as operating temperature, charge / discharge rate, and aging. Therefore, using a fixed rated capacity for calculations inevitably introduces estimation errors, and these errors accumulate over time.

[0004] To improve this, existing technologies propose using real-time updated battery remaining capacity as the core parameter of the ampere-hour integration method. Theoretically, this method can more accurately reflect the current state of the battery. However, its key drawback is that the actual remaining battery capacity is difficult to accurately correct online under certain operating conditions (especially in low-temperature environments). When the battery operates under such conditions for an extended period, the estimation error of the remaining capacity accumulates, leading to a growing deviation between the SOC value calculated by the ampere-hour integration method and the actual value, thus affecting the accuracy of the SOC estimation. Summary of the Invention

[0005] This application provides a battery capacity correction method, system, device, and program product, aiming to solve the technical problem in the prior art where the accuracy of SOC estimation is low due to the inaccuracy of the remaining capacity, which is the core parameter, when using the ampere-hour integration method to estimate the battery state of charge.

[0006] In a first aspect, embodiments of this application provide a battery capacity correction method, the battery capacity correction method comprising: At the preset State of Charge (SOC) correction anchor point, obtain the estimated SOC value before correction and the baseline SOC value after correction. Based on the estimated SOC value and the baseline SOC value, the SOC correction difference ΔSoc is calculated. Determine the battery capacity Qtab corresponding to the current battery temperature; Based on the SOC correction anchor point, the SOC correction difference ΔSoc, and the battery capacity Qtab, the remaining battery capacity Qrem1 before correction is corrected to obtain the remaining battery capacity Qrem2 after correction.

[0007] In one possible implementation of the first aspect, the SOC correction anchor point includes at least one of: the moment when the battery reaches a fully charged state, the moment when the battery reaches a fully discharged state, and the moment when the SOC is statically corrected based on the open-circuit voltage.

[0008] In one possible implementation of the first aspect, determining the battery capacity Qtab corresponding to the current battery temperature includes: Get the current battery temperature; By consulting the preset table of battery temperature and battery capacity, the battery capacity Qtab corresponding to the current battery temperature can be obtained. Alternatively, the battery capacity Qtab corresponding to the current battery temperature can be calculated by substituting the current battery temperature into a preset temperature-capacity function model.

[0009] In one possible implementation of the first aspect, the step of correcting the uncorrected remaining battery capacity Qrem1 based on the SOC correction anchor point, the SOC correction difference ΔSoc, and the battery capacity Qtab to obtain the corrected remaining battery capacity Qrem2 includes: Based on the SOC correction difference ΔSoc and the battery capacity Qtab, the correction amount for the remaining battery capacity Qrem1 before correction is calculated. Based on the SOC correction anchor point and the correction amount, the remaining battery capacity Qrem1 before correction is corrected to obtain the remaining battery capacity Qrem2 after correction.

[0010] In one possible implementation of the first aspect, the step of correcting the uncorrected battery remaining capacity Qrem1 based on the SOC correction anchor point and the correction amount to obtain the corrected battery remaining capacity Qrem2 includes: When the SOC correction anchor point is when the battery reaches a fully charged state, and the estimated SOC value is less than the SOC benchmark value, the difference between the remaining battery capacity Qrem1 before correction and the correction amount is taken as the remaining battery capacity Qrem2 after correction. When the SOC correction anchor point is that the battery reaches a fully discharged state, and the estimated SOC value is greater than the SOC benchmark value, the sum of the remaining battery capacity Qrem1 before correction and the correction amount is used as the remaining battery capacity Qrem2 after correction. When the SOC correction anchor point is a static correction of SOC based on open-circuit voltage, the remaining battery capacity Qrem1 before correction is corrected according to the battery condition before correction, the SOC correction anchor point and the correction amount, so as to obtain the remaining battery capacity Qrem2 after correction.

[0011] In one possible implementation of the first aspect, the step of correcting the remaining battery capacity Qrem1 before correction based on the battery condition before correction, the SOC correction anchor point, and the correction amount to obtain the corrected remaining battery capacity Qrem2 includes: If the battery was in a charging state before the correction and the estimated SOC value was greater than the SOC benchmark value, then the difference between the remaining battery capacity Qrem1 before the correction and the correction amount will be used as the remaining battery capacity Qrem2 after the correction. If the battery was in a charging state before the correction and the estimated SOC value was less than the SOC benchmark value, then the sum of the remaining battery capacity Qrem1 before the correction and the correction amount is taken as the remaining battery capacity Qrem2 after the correction. If the battery was in a discharged state before correction and the estimated SOC value was greater than the SOC benchmark value, then the difference between the remaining battery capacity Qrem1 before correction and the correction amount would be taken as the remaining battery capacity Qrem2 after correction. If the battery was in a discharged state before correction and the estimated SOC value was less than the SOC benchmark value, then the sum of the remaining battery capacity Qrem1 before correction and the correction amount is taken as the remaining battery capacity Qrem2 after correction.

[0012] In one possible implementation of the first aspect, the method further includes: The SOC of the battery is calculated based on the corrected remaining battery capacity Qrem2.

[0013] Secondly, embodiments of this application provide a battery capacity correction system, including: The acquisition module is used to obtain the estimated SOC value before correction and the reference SOC value after correction at a preset SOC correction anchor point. The calculation module is used to calculate the SOC correction difference ΔSoc based on the estimated SOC value and the benchmark SOC value. The matching module is used to determine the battery capacity Qtab corresponding to the current battery temperature; The correction module is used to correct the remaining battery capacity Qrem1 before correction based on the SOC correction anchor point, the SOC correction difference ΔSoc, and the battery capacity Qtab, so as to obtain the corrected remaining battery capacity Qrem2.

[0014] Thirdly, embodiments of this application provide a computer 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 battery capacity correction method described in any one of the first aspects above.

[0015] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the battery capacity correction method described in any one of the first aspects.

[0016] Fifthly, embodiments of this application provide a computer program product that, when run on a computer device, causes the computer device to execute the battery capacity correction method described in any one of the first aspects.

[0017] In this embodiment, at a preset State of Charge (SOC) correction anchor point, the estimated SOC value before correction and the benchmark SOC value after correction are obtained. Based on the estimated SOC value and the benchmark SOC value, the SOC correction difference ΔSoc is calculated. The battery capacity Qtab corresponding to the current battery temperature is determined. According to the SOC correction anchor point, the SOC correction difference ΔSoc, and the battery capacity Qtab, the remaining battery capacity Qrem1 before correction is corrected to obtain the remaining battery capacity Qrem2 after correction. By correcting the root cause of the error, namely the remaining battery capacity on which the ampere-hour integration method relies, the continuous accumulation of error can be effectively suppressed, and the estimation accuracy of SOC across the entire operating range can be improved. In addition, by introducing temperature-related capacity as a correction benchmark and making corresponding corrections to the remaining battery capacity according to different anchor points and operating conditions, the correction of the remaining battery capacity is made more accurate.

[0018] It is understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic flowchart of a battery capacity correction method provided in an embodiment of this application; Figure 2This is a schematic diagram of the battery capacity correction system provided in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the computer device provided in the embodiments of this application. Detailed Implementation

[0021] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0022] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0023] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0024] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0025] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0027] Figure 1 A schematic flowchart of a battery capacity correction method provided in an embodiment of this application is shown.

[0028] S101, at the preset State of Charge (SOC) correction anchor point, obtain the estimated SOC value before correction and the reference SOC value after correction.

[0029] In this context, the State of Charge (SOC) correction anchor point refers to a pre-defined specific moment or event where the SOC value has a clear reference benchmark. This SOC correction anchor point may include, but is not limited to: the moment the battery reaches a fully charged state, the moment the battery reaches a fully discharged state, or the moment when the SOC is statically corrected based on the open-circuit voltage. These anchor points provide a benchmark for calibrating SOC estimation errors.

[0030] The uncorrected SOC estimate refers to the uncorrected SOC value calculated using conventional methods such as the ampere-hour integration method when the SOC correction anchor point is triggered.

[0031] The revised SOC baseline value refers to the standard value that SOC should theoretically possess or is forcibly set at the SOC revision anchor point. The specific magnitude of this baseline value depends on the type of revision anchor point. When the correction anchor point is in a fully charged state, the SOC reference value is usually set to a value close to that of a fully charged state, such as 95%~100% or 100%. When the correction anchor point is in a fully discharged state, the SOC reference value is usually set to a value close to that of an empty state, such as 0%~5% or 0%. When the correction anchor point is a static correction based on open-circuit voltage, the SOC reference value is obtained by measuring the current stable open-circuit voltage (OCV) of the battery and dynamically looking up the value according to a preset OCV-SOC relationship table or model. This value changes with the actual state of the battery.

[0032] The aforementioned SOC baseline value can be a specific value (such as 100% or 0%), or it can be a range (such as 95%~100% or 0%~5%) to accommodate different battery characteristics and system design requirements, thereby obtaining a wider protection range.

[0033] The battery capacity correction method proposed in this application, in a conventional process of estimating SOC using the ampere-hour integration method, involves the battery capacity correction system simultaneously detecting whether a preset SOC correction anchor point has been triggered. If not triggered, the conventional SOC estimation continues. If a trigger is detected, the battery capacity parameters are corrected. The first step of the correction process requires obtaining the estimated SOC value before correction and the baseline SOC value after correction. Specifically, when any preset SOC correction anchor point is triggered, the current SOC value calculated by the ampere-hour integration method is recorded as the estimated SOC value before correction, and the theoretical SOC value corresponding to that anchor point is simultaneously determined as the baseline SOC value after correction.

[0034] S102, based on the above SOC estimate and the above SOC benchmark, the SOC correction difference ΔSoc is calculated.

[0035] Among them, the SOC correction difference ΔSoc is a key indicator for quantifying the SOC estimation error, directly reflecting the magnitude of the current cumulative error in ampere-hour integration. Optionally, the absolute magnitude of the error can be calculated using the following formula: ΔSoc = |SOC baseline value - SOC estimated value|; Where ΔSoc represents the SOC correction difference, the SOC baseline value represents the corrected SOC baseline value, and the SOC estimate value represents the SOC estimate value before correction.

[0036] S103, determine the battery capacity Qtab corresponding to the current battery temperature.

[0037] The battery capacity Qtab is a key coefficient used to convert the dimensionless SOC percentage error (ΔSoc) into actual capacity error (in ampere-hours). This value is typically related to the battery's current temperature and aging condition.

[0038] S104. Based on the above SOC correction anchor point, the above SOC correction difference ΔSoc, and the above battery capacity Qtab, the remaining battery capacity Qrem1 before correction is corrected to obtain the remaining battery capacity Qrem2 after correction.

[0039] Among them, the remaining battery capacity before correction, Qrem1, refers to the remaining battery capacity value stored in the battery capacity correction system and used for ampere-hour integration calculation before this correction was performed. This value is the root cause of the error in SOC estimation.

[0040] The corrected remaining battery capacity Qrem2 is the core result of the final output of this application. It is a calibrated remaining capacity value that is closer to the actual state of the battery.

[0041] Optionally, S104 corrects the remaining battery capacity Qrem1 before correction based on the above-mentioned SOC correction anchor point, the above-mentioned SOC correction difference ΔSoc, and the above-mentioned battery capacity Qtab, to obtain the corrected remaining battery capacity Qrem2, including: The first step is to calculate the correction amount ΔQ for the uncorrected remaining battery capacity Qrem1 based on the SOC correction difference ΔSoc and the battery capacity Qtab.

[0042] The formula for calculating the correction amount ΔQ is: ΔQ=Qtab*ΔSoc, where ΔQ represents the power correction amount, Qtab represents the battery capacity corresponding to the current battery temperature, and ΔSoc represents the SOC correction difference.

[0043] The second step is to correct the remaining battery capacity Qrem1 before correction based on the SOC correction anchor point and the above correction amount ΔQ, so as to obtain the corrected remaining battery capacity Qrem2.

[0044] Subsequently, the correction direction (i.e., increasing or decreasing Qrem1) is determined based on the specific type of the SOC correction anchor point (e.g., full charge, full discharge, etc.), and the correction calculation is performed to obtain the corrected remaining battery capacity Qrem2. Optionally, the obtained corrected remaining battery capacity Qrem2 can be updated in memory for subsequent more accurate SOC estimation. In this way, the correction difference of SOC at the anchor point is used as the capacity parameter in the denominator of the ampere-hour integral, forming a closed-loop feedback, thereby suppressing error accumulation and preventing jumps in the SOC estimation value.

[0045] In this embodiment, at a preset State of Charge (SOC) correction anchor point, the estimated SOC value before correction and the benchmark SOC value after correction are obtained. Based on the estimated SOC value and the benchmark SOC value, the SOC correction difference ΔSoc is calculated. The battery capacity Qtab corresponding to the current battery temperature is determined. According to the SOC correction anchor point, the SOC correction difference ΔSoc, and the battery capacity Qtab, the remaining battery capacity Qrem1 before correction is corrected to obtain the remaining battery capacity Qrem2 after correction. By correcting the root cause of the error, namely the remaining battery capacity on which the ampere-hour integration method relies, the continuous accumulation of error can be effectively suppressed, and the estimation accuracy of SOC across the entire operating range can be improved. In addition, by introducing temperature-related capacity as a correction benchmark and correcting the remaining battery capacity accordingly based on different anchor points and operating conditions, the correction of the remaining battery capacity is made more accurate.

[0046] In one optional embodiment, the determination of the battery capacity Qtab in the above embodiments can be carried out in a variety of ways.

[0047] The first method involves obtaining the current battery temperature and then consulting a preset table showing the relationship between battery temperature and battery capacity to obtain the battery capacity Qtab corresponding to the current battery temperature.

[0048] In this embodiment, the method pre-calibrates and stores a relationship table between battery temperature and battery capacity, which reflects the actual usable capacity of the battery at different temperatures. The specific steps are as follows: First, obtain the current battery temperature T; then, find the entry in the preset relationship table closest to temperature T and obtain the corresponding battery capacity Qtab value. If temperature T is between two calibration points, it can be calculated using methods such as linear interpolation. For example, the preset Qtab relationship table may contain data points such as (25℃, 100 AH), (0℃, 92 AH), (-10℃, 85 AH), and (-20℃, 75 AH). When a correction event occurs, the system reads the current average temperature of the battery pack as -10℃, and then looks up the Qtab value in the table to obtain 85 AH, which will be used for subsequent correction calculations.

[0049] The second method involves substituting the current battery temperature into a preset temperature-capacity function model to calculate the battery capacity Qtab corresponding to the current battery temperature.

[0050] In this embodiment, the method pre-defines a function model describing the relationship between temperature and capacity. The specific steps are as follows: First, obtain the current battery temperature T; then, substitute the temperature T into the pre-define function model Qtab=f(T) to calculate the current battery capacity Qtab. For example, the pre-define function model can be a polynomial function, such as: Qtab=aT²+bT+c. Here, Qtab represents the battery capacity, T represents the current battery temperature, and a, b, and c are coefficients pre-fitted from experimental data. Once the current temperature T is obtained, Qtab is directly calculated using this formula. By employing the above method of dynamically determining Qtab, the capacity correction can better match the physical characteristics of the battery under specific operating conditions (such as low temperature), thereby achieving a more accurate correction effect than using a fixed Qtab.

[0051] In an optional embodiment, the battery's SOC is calculated based on the corrected remaining battery capacity Qrem2.

[0052] In this embodiment, after correcting the remaining battery capacity Qrem1 to obtain Qrem2, the battery's SOC can be recalculated based on the corrected remaining battery capacity Qrem2. The corrected remaining battery capacity Qrem2 is then used for subsequent SOC calculations using the ampere-hour integration method, thereby improving the accuracy of SOC estimation.

[0053] In one optional embodiment, the specific correction rules for correcting the uncorrected battery remaining capacity Qrem1 based on the SOC correction anchor point and correction amount to obtain the corrected battery remaining capacity Qrem2 are described in detail. These include the following cases: The first method is to use the difference between the battery remaining capacity Qrem1 before correction and the correction amount when the battery reaches full charge and the estimated SOC value is less than the SOC baseline value.

[0054] In this embodiment, when the SOC correction anchor point is the battery reaching full charge, and the estimated SOC before correction is less than the corrected SOC baseline value (e.g., close to 100%, such as 95%~100%), this indicates an underestimation of the battery's capacity. To correct this deviation, the remaining battery capacity Qrem1 before correction should be subtracted during full charge. Therefore, the difference between the remaining battery capacity Qrem1 before correction and the correction amount ΔQ is taken as the corrected remaining battery capacity Qrem2. That is: Qrem2 = Qrem1 - ΔQ. For example, if the SOC jumps from 97% to 100% during full charge, ΔSoc is 3%, and ΔQ is calculated to be 1.5Ah, then the new Qrem2 is 1.5Ah less than the old Qrem1.

[0055] The second approach is to use the SOC correction anchor point as the battery reaching full discharge and the estimated SOC value as greater than the SOC baseline value. In this case, the sum of the original battery remaining capacity Qrem1 and the correction amount is used as the corrected battery remaining capacity Qrem2.

[0056] In this embodiment, when the SOC correction anchor point is the battery reaching a fully discharged state, and the estimated SOC before correction is greater than the corrected SOC baseline value (e.g., close to 0%, such as 0%~5%), this indicates that the system has overestimated the remaining battery capacity. This means that the capacity base upon which the ampere-hour integration depends is too large. To correct this deviation, the remaining battery capacity Qrem1 before correction should be additively corrected when fully discharged. Therefore, the sum of the remaining battery capacity Qrem1 before correction and the aforementioned correction amount ΔQ is taken as the corrected remaining battery capacity Qrem2. That is: Qrem2 = Qrem1 + ΔQ. For example, if the SOC jumps from 3% to 0% when fully discharged, ΔSoc is 3%, and ΔQ is calculated to be 1.5Ah, then the new Qrem2 is 1.5Ah larger than the old Qrem1.

[0057] The third method involves adjusting the SOC based on the open-circuit voltage. In this case, the remaining battery capacity Qrem1 before the adjustment is adjusted according to the battery condition before the adjustment, the SOC adjustment anchor point, and the adjustment amount, to obtain the remaining battery capacity Qrem2 after the adjustment.

[0058] In this embodiment, when the SOC correction anchor is based on the open-circuit voltage for static correction of SOC, the correction logic becomes more complex, requiring additional consideration of the battery condition (charging or discharging) before correction. In this case, the correction method for Qrem1 is determined based on the battery condition before correction, the relative magnitude of the estimated SOC value and the reference value, and the calculated correction amount ΔQ.

[0059] In the embodiments of this application, the aforementioned explicit correction rules provide deterministic guidance for correction operations under different anchor points, enabling corrections to proceed in the direction of reducing future estimation errors, which helps to achieve algorithm convergence and stability.

[0060] To further elaborate on the specific correction logic in the static OCV correction scenario, this application also provides a more detailed implementation method. This method specifies in detail the Qrem correction rules under different operating conditions and different correction directions, including four cases: The first scenario: If the battery was in a charging state before the correction and the estimated SOC value was greater than the baseline SOC value, then the difference between the remaining battery capacity Qrem1 before the correction and the correction amount will be used as the remaining battery capacity Qrem2 after the correction.

[0061] In this embodiment, if the battery was in a charging state before correction, and the estimated SOC before correction was greater than the baseline SOC after correction (i.e., the SOC was corrected downward), then the difference between the remaining battery capacity Qrem1 before correction and the aforementioned correction amount ΔQ is taken as the remaining battery capacity Qrem2 after correction. For example, if the vehicle is paused during charging, the estimated SOC is 70%, while the baseline value obtained from the OCV lookup table is 68%. In this case, the system overestimates the battery capacity, and Qrem should be reduced, i.e., Qrem2 = Qrem1 - ΔQ.

[0062] The second scenario: If the battery was in a charging state before the correction and the estimated SOC value was less than the benchmark SOC value, then the sum of the remaining battery capacity Qrem1 before the correction and the correction amount will be used as the remaining battery capacity Qrem2 after the correction.

[0063] In this embodiment, if the battery was in a charging state before correction, and the estimated SOC before correction was less than the corrected SOC baseline value (i.e., the SOC was corrected upwards), then the sum of the remaining battery capacity Qrem1 before correction and the aforementioned correction amount ΔQ is taken as the corrected remaining battery capacity Qrem2. For example, when charging is paused, the estimated SOC is 60%, and the OCV baseline value is 62%. The system underestimates the battery capacity, and Qrem should be increased, i.e., Qrem2 = Qrem1 + ΔQ.

[0064] The third scenario: If the battery was in a discharged state before the correction and the estimated SOC value was greater than the benchmark SOC value, then the difference between the remaining battery capacity Qrem1 before the correction and the correction amount will be used as the remaining battery capacity Qrem2 after the correction.

[0065] In this embodiment, if the battery was in a discharged state before correction, and the estimated SOC before correction was greater than the corrected SOC baseline value (i.e., the SOC was corrected downward), then the difference between the remaining battery capacity Qrem1 before correction and the aforementioned correction amount ΔQ is taken as the corrected remaining battery capacity Qrem2. For example, if the vehicle is stationary after driving, the estimated SOC is 50%, and the OCV baseline value is 48%, the system has overestimated the battery capacity, and Qrem should be reduced, i.e., Qrem2 = Qrem1 - ΔQ.

[0066] The fourth scenario: If the battery was in a discharged state before the correction and the estimated SOC value was less than the SOC baseline value, then the sum of the remaining battery capacity Qrem1 before the correction and the correction amount will be used as the remaining battery capacity Qrem2 after the correction.

[0067] In this embodiment, if the battery was in a discharged state before correction, and the estimated SOC before correction was less than the corrected SOC baseline value (i.e., the SOC was corrected upwards), then the sum of the remaining battery capacity Qrem1 before correction and the correction amount ΔQ is taken as the corrected remaining battery capacity Qrem2. For example, if the vehicle is stationary after driving, the estimated SOC is 45%, and the OCV baseline value is 48%. The system underestimated the battery capacity, so Qrem should be increased, i.e., Qrem2 = Qrem1 + ΔQ.

[0068] By defining four possibilities in the OCV correction scenario, the adjustment direction of Qrem conforms to the preset physical logic when performing static correction under different states, thereby improving the correction accuracy of the algorithm under complex working conditions.

[0069] To facilitate understanding of the correction logic under typical operating conditions, the battery capacity correction process is described in detail here, taking the SOC correction anchor point as the moment when the battery reaches a fully discharged state as an example: First, the battery is determined to be in a fully discharged state, and the estimated SOC value before correction is recorded at this moment. Simultaneously, the corrected SOC baseline value is set to a value close to the empty state (e.g., 0% or 0%~5%). For example, if the estimated SOC value is 2%, the baseline value is set to 0%. In this embodiment, the battery status can be detected by the battery management system. When the battery meets the preset fully discharged conditions, it is determined that the SOC correction anchor point has been reached. Next, the SOC correction difference ΔSoc is calculated: ΔSoc = |0%| The original SOC estimate is then determined. Next, the battery capacity Qtab corresponding to the current battery temperature is determined. Subsequently, the original remaining battery capacity Qrem1 is corrected, specifically by calculating the capacity correction ΔQ based on the SOC correction difference ΔSoc and the battery capacity Qtab: ΔQ = Qtab × ΔSoc. In this embodiment, since the SOC correction anchor point is when the battery reaches full discharge, the original SOC estimate is usually larger than the corrected SOC baseline value (e.g., the SOC estimate is 2%, and the baseline value is 0%). This phenomenon indicates that the remaining battery capacity Qrem used for ampere-hour integration calculation during discharge is too large (according to the principle of ampere-hour integration, SOC change = ΔQ / Qrem; under the same discharge amount ΔQ, the larger Qrem is, the smaller the SOC decrease), resulting in a slower SOC decrease rate. Therefore, the remaining battery capacity needs to be reduced, and the correction formula is: Qrem2 = Qrem1. ΔQ. Finally, the corrected remaining battery capacity Qrem2 is used for subsequent SOC calculations using the ampere-hour integration method, thereby improving the accuracy of SOC estimation.

[0070] As an example: Suppose the vehicle discharges until the Battery Management System (BMS) determines it to be fully discharged, and the internally recorded pre-correction SOC estimate is 2%. At this point, the BMS triggers a full-discharge anchor point correction and sets the SOC baseline value to 0%. The calculation yields: ΔSoc = |0% 2% = 2%. If the battery capacity Qtab corresponding to the current temperature is 100Ah, then the capacity correction is: ΔQ = 100Ah × 2% = 2Ah. If the remaining battery capacity Qrem1 before correction is 78Ah, then the remaining battery capacity Qrem2 after correction is: Qrem2 = 78Ah. 2Ah = 76Ah. This correction compensates for the problem of excessively slow SOC decline caused by an overestimation of the remaining battery capacity, making the corrected remaining battery capacity Qrem2 more closely match the actual usable battery capacity and improving the accuracy of SOC estimation.

[0071] To facilitate understanding of the correction logic in the static storage scenario of this application, the battery capacity correction process is described in detail here, taking the moment when the SOC correction anchor point is based on the open-circuit voltage OCV for static correction of SOC as an example: First, at the SOC correction anchor point, the estimated SOC value before correction and the baseline SOC value after correction are obtained, and the battery operating conditions before correction are recorded. In this embodiment, when the battery meets the preset resting conditions, such as the current remaining within ±50mA for more than 2 hours, it can be determined that the static correction anchor point has been reached. The battery operating conditions before correction refer to the last effective operating state before entering the resting state, i.e., the charging state or the discharging state. The baseline SOC value after correction is obtained by measuring the current stable open-circuit voltage (OCV) of the battery and looking it up in the preset OCV-SOC lookup table. This value varies with the actual state of the battery and is not a fixed value. Next, the SOC correction difference is calculated: ΔSoc = |corrected SOC baseline value| The original SOC estimate is used. Then, the battery capacity Qtab corresponding to the current battery temperature is determined. Subsequently, the original remaining battery capacity Qrem1 is corrected. This process first calculates the correction amount: ΔQ = Qtab × ΔSoc. Then, based on the battery condition before correction, the relationship between the original SOC estimate and the corrected SOC baseline value, the corresponding correction logic is executed: If the battery was in a charging state before correction, and the estimated SOC before correction was greater than the baseline SOC after correction, it indicates that the SOC increased too quickly during charging, and the estimated remaining battery capacity Qrem was too large. In this case, the correction formula is used: Qrem2 = Qrem1 ΔQ.

[0072] If the battery was in a charging state before the correction, and the estimated SOC value before the correction was less than the baseline SOC value after the correction, it indicates that the SOC growth during charging was too slow and the estimated remaining battery capacity Qrem was too small. In this case, the correction formula is used: Qrem2=Qrem1+ΔQ.

[0073] If the battery was in a discharge state before correction, and the estimated SOC before correction was greater than the baseline SOC after correction, it indicates that the SOC decreased too slowly during discharge, and the estimated remaining battery capacity Qrem was too large. In this case, the correction formula is used: Qrem2 = Qrem1 ΔQ.

[0074] If the battery was in a discharge state before correction, and the estimated SOC value before correction was less than the benchmark SOC value after correction, it indicates that the SOC dropped too quickly during discharge and the estimated remaining battery capacity Qrem was too small. In this case, the correction formula is used: Qrem2=Qrem1+ΔQ.

[0075] Finally, the corrected remaining battery capacity Qrem2 is used for subsequent SOC calculations using the ampere-hour integration method.

[0076] As an example: After a long-distance drive and while in a discharged state, the vehicle is parked and stationary. At the time of parking, the BMS's pre-correction SOC estimate based on ampere-hour integration is 55%. After the vehicle has been stationary for a period meeting preset conditions, the BMS triggers OCV static correction, obtaining a baseline SOC value of 52% by looking up the stable open-circuit voltage. At this point, the SOC correction difference is: ΔSoc = |52%| 55% = 3%. Since the operating condition before correction was discharge, and the estimated SOC before correction was greater than the baseline value after correction, it was determined that the remaining battery capacity needed to be reduced. If the battery capacity Qtab corresponding to the current temperature is 100Ah, then the correction amount is: ΔQ = 100Ah × 3% = 3Ah. If the remaining battery capacity Qrem1 before correction was 85Ah, then after correction: Qrem2 = 85Ah. 3Ah = 82Ah. The above correction can compensate for the SOC error caused by deviations in the remaining battery capacity estimation, thus improving the accuracy of subsequent SOC estimations.

[0077] In another specific application scenario, taking the correction process when the battery reaches full charge as an example, the interaction flow of this method in the hardware system is demonstrated: The charger sends charging status information to the BMS via a communication interface. After receiving the information, the BMS continuously estimates the SOC using the ampere-hour integration method on its internal processor. When the charging process ends, the charger sends a charging completion signal to the BMS. Upon receiving this signal, the BMS triggers the full charge correction anchor point and executes the capacity correction logic, calculating the SOC correction difference ΔSoc and the capacity correction amount ΔQ. The BMS processor writes instructions to the memory, storing the calculated updated Qrem2, completing one correction cycle.

[0078] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0079] Corresponding to the battery capacity correction method described in the above embodiments, Figure 2 A structural block diagram of the battery capacity correction system provided in the embodiments of this application is shown. For ease of explanation, only the parts related to the embodiments of this application are shown.

[0080] Reference Figure 2 The battery capacity correction system includes: The acquisition module is used to obtain the estimated SOC value before correction and the reference SOC value after correction at a preset SOC correction anchor point. The calculation module is used to calculate the SOC correction difference ΔSoc based on the above SOC estimate and the above SOC benchmark value. The matching module is used to determine the battery capacity Qtab corresponding to the current battery temperature; The correction module is used to correct the remaining battery capacity Qrem1 before correction based on the above-mentioned SOC correction anchor point, the above-mentioned SOC correction difference ΔSoc, and the above-mentioned battery capacity Qtab, so as to obtain the corrected remaining battery capacity Qrem2.

[0081] In one possible implementation, the aforementioned SOC correction anchor point includes at least one of the following: the moment when the battery reaches a fully charged state, the moment when the battery reaches a fully discharged state, and the moment when the SOC is statically corrected based on the open-circuit voltage.

[0082] In one possible implementation, the matching module is used for: Get the current battery temperature; By consulting the preset table of battery temperature and battery capacity, the battery capacity Qtab corresponding to the current battery temperature can be obtained. Alternatively, the battery capacity Qtab corresponding to the current battery temperature can be calculated by substituting the current battery temperature into a preset temperature-capacity function model.

[0083] In one possible implementation, the correction module is used for: Based on the above SOC correction difference ΔSoc and the above battery capacity Qtab, the correction amount for the remaining battery capacity Qrem1 before correction is calculated. Based on the above SOC correction anchor point and the above correction amount, the remaining battery capacity Qrem1 before correction is corrected to obtain the corrected remaining battery capacity Qrem2.

[0084] In one possible implementation, the correction module is used for: When the above SOC correction anchor point is the battery reaching full charge, and the above SOC estimated value is less than the above SOC benchmark value, the difference between the battery remaining capacity Qrem1 before correction and the above correction amount is taken as the battery remaining capacity Qrem2 after correction. When the above SOC correction anchor point is that the battery reaches a fully discharged state, and the above SOC estimated value is greater than the above SOC benchmark value, the sum of the battery remaining capacity Qrem1 before correction and the above correction amount is taken as the battery remaining capacity Qrem2 after correction. When the above SOC correction anchor point is a static correction of SOC based on open-circuit voltage, the remaining battery capacity Qrem1 before correction is corrected according to the battery condition before correction, the above SOC correction anchor point and the above correction amount, so as to obtain the remaining battery capacity Qrem2 after correction.

[0085] In one possible implementation, the correction module is used for: If the battery was in a charging state before the correction and the above SOC estimate was greater than the above SOC baseline value, then the difference between the battery remaining capacity Qrem1 before the correction and the above correction amount will be used as the corrected battery remaining capacity Qrem2. If the battery was in a charging state before the correction and the estimated SOC value was less than the SOC baseline value, then the sum of the remaining battery capacity Qrem1 before the correction and the correction amount will be used as the remaining battery capacity Qrem2 after the correction. If the battery was in a discharged state before correction and the estimated SOC value was greater than the SOC baseline value, then the difference between the remaining battery capacity Qrem1 before correction and the correction amount was taken as the remaining battery capacity Qrem2 after correction. If the battery was in a discharged state before the correction and the estimated SOC value was less than the benchmark SOC value, then the sum of the remaining battery capacity Qrem1 before the correction and the correction amount will be used as the remaining battery capacity Qrem2 after the correction.

[0086] It should be noted that the information interaction and execution process between the above modules are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, which will not be repeated here.

[0087] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the system can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0088] This application also provides a computer device, which includes: at least one processor, a memory, and a computer program stored in the memory and executable on the at least one processor, wherein the processor executes the computer program to implement the steps in any of the above method embodiments.

[0089] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0090] This application provides a computer program product that, when run on a computer device, enables the computer device to execute the steps described in the various method embodiments above.

[0091] Figure 3 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Figure 3 As shown, the computer device of this embodiment includes: at least one processor 30 ( Figure 3 (Only one is shown in the diagram), memory 31, and computer program 32 stored in said memory 31 and executable on said at least one processor 30, wherein said processor 30 executes said computer program 32 to implement the steps in any of the above-described battery capacity correction method embodiments.

[0092] The computer device may include, but is not limited to, a processor 30 and a memory 31. Those skilled in the art will understand that... Figure 3 The examples of computer devices are merely examples and do not constitute a limitation on computer devices. They may include more or fewer components than shown in the illustration, or combinations of certain components, or different components. For example, they may also include input / output devices, network access devices, etc.

[0093] The processor 30 may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0094] In some embodiments, the memory 31 may be an internal storage unit of the computer device, such as a hard drive or memory. In other embodiments, the memory 31 may be an external storage device of the computer device, such as a plug-in hard drive, smart media card (SMC), secure digital card (SD), flash card, etc. Furthermore, the memory 31 may include both internal and external storage units of the computer device. The memory 31 is used to store the operating system, applications, bootloader, data, and other programs, such as the program code of the computer program. The memory 31 can also be used to temporarily store data that has been output or will be output.

[0095] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or system capable of carrying computer program code to a system / computer device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, such as a USB flash drive, a portable hard drive, a magnetic disk, or an optical disk.

[0096] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0097] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0098] In the embodiments provided in this application, it should be understood that the disclosed systems / computer devices and methods can be implemented in other ways. For example, the system / computer device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0099] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0100] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A battery capacity correction method, characterized in that, The battery capacity correction method includes: At the preset State of Charge (SOC) correction anchor point, obtain the estimated SOC value before correction and the baseline SOC value after correction. Based on the estimated SOC value and the baseline SOC value, the SOC correction difference ΔSoc is calculated. Determine the battery capacity Qtab corresponding to the current battery temperature; Based on the SOC correction anchor point, the SOC correction difference ΔSoc, and the battery capacity Qtab, the remaining battery capacity Qrem1 before correction is corrected to obtain the remaining battery capacity Qrem2 after correction.

2. The battery capacity correction method according to claim 1, characterized in that, The SOC correction anchor point includes at least one of the following: the moment when the battery reaches a fully charged state, the moment when the battery reaches a fully discharged state, and the moment when the SOC is statically corrected based on the open-circuit voltage.

3. The battery capacity correction method according to claim 1, characterized in that, Determining the battery capacity Qtab corresponding to the current battery temperature includes: Get the current battery temperature; By consulting the preset table of battery temperature and battery capacity, the battery capacity Qtab corresponding to the current battery temperature can be obtained. Alternatively, the battery capacity Qtab corresponding to the current battery temperature can be calculated by substituting the current battery temperature into a preset temperature-capacity function model.

4. The battery capacity correction method according to claim 2, characterized in that, The step of correcting the remaining battery capacity Qrem1 before correction based on the SOC correction anchor point, the SOC correction difference ΔSoc, and the battery capacity Qtab to obtain the corrected remaining battery capacity Qrem2 includes: Based on the SOC correction difference ΔSoc and the battery capacity Qtab, the correction amount for the remaining battery capacity Qrem1 before correction is calculated. Based on the SOC correction anchor point and the correction amount, the remaining battery capacity Qrem1 before correction is corrected to obtain the remaining battery capacity Qrem2 after correction.

5. The battery capacity correction method according to claim 4, characterized in that, The step of correcting the remaining battery capacity Qrem1 before correction based on the SOC correction anchor point and the correction amount to obtain the corrected remaining battery capacity Qrem2 includes: When the SOC correction anchor point is when the battery reaches a fully charged state, and the estimated SOC value is less than the SOC benchmark value, the difference between the remaining battery capacity Qrem1 before correction and the correction amount is taken as the remaining battery capacity Qrem2 after correction. When the SOC correction anchor point is that the battery reaches a fully discharged state, and the estimated SOC value is greater than the SOC benchmark value, the sum of the remaining battery capacity Qrem1 before correction and the correction amount is used as the remaining battery capacity Qrem2 after correction. When the SOC correction anchor point is a static correction of SOC based on open-circuit voltage, the remaining battery capacity Qrem1 before correction is corrected according to the battery condition before correction, the SOC correction anchor point and the correction amount, so as to obtain the remaining battery capacity Qrem2 after correction.

6. The battery capacity correction method according to claim 5, characterized in that, The step of correcting the remaining battery capacity Qrem1 before correction based on the battery operating condition before correction, the SOC correction anchor point, and the correction amount to obtain the corrected remaining battery capacity Qrem2 includes: If the battery was in a charging state before the correction and the estimated SOC value was greater than the SOC benchmark value, then the difference between the remaining battery capacity Qrem1 before the correction and the correction amount will be used as the remaining battery capacity Qrem2 after the correction. If the battery was in a charging state before the correction and the estimated SOC value was less than the SOC benchmark value, then the sum of the remaining battery capacity Qrem1 before the correction and the correction amount is taken as the remaining battery capacity Qrem2 after the correction. If the battery was in a discharged state before correction and the estimated SOC value was greater than the SOC benchmark value, then the difference between the remaining battery capacity Qrem1 before correction and the correction amount would be taken as the remaining battery capacity Qrem2 after correction. If the battery was in a discharged state before correction and the estimated SOC value was less than the SOC benchmark value, then the sum of the remaining battery capacity Qrem1 before correction and the correction amount is taken as the remaining battery capacity Qrem2 after correction.

7. The battery capacity correction method according to any one of claims 1 to 6, characterized in that, The method further includes: The SOC of the battery is calculated based on the corrected remaining battery capacity Qrem2.

8. A battery capacity correction system, characterized in that, include: The acquisition module is used to obtain the estimated SOC value before correction and the reference SOC value after correction at a preset SOC correction anchor point. The calculation module is used to calculate the SOC correction difference ΔSoc based on the estimated SOC value and the benchmark SOC value. The matching module is used to determine the battery capacity Qtab corresponding to the current battery temperature; The correction module is used to correct the remaining battery capacity Qrem1 before correction based on the SOC correction anchor point, the SOC correction difference ΔSoc, and the battery capacity Qtab, so as to obtain the corrected remaining battery capacity Qrem2.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method as described in any one of claims 1 to 7.

10. A computer program product, characterized in that, Includes a computer program that, when run, implements the method as described in any one of claims 1 to 7.

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