Battery soc correction method, device and vehicle

Abstract

The application provides a battery SOC correction method and device and a vehicle, and relates to the technical field of battery control. The method comprises the following steps: when an obtained SOC estimation value is not in an OCV detection interval, correcting the SOC estimation value to a boundary value of the OCV detection interval; and when the SOC estimation value is in the OCV detection interval, gradually obtaining a corrected SOC estimation value according to the boundary value, a correction weight and an SOC estimation value at a previous moment, so as to improve the SOC estimation accuracy.

Description

Technical Field

[0001] This invention relates to the field of battery control technology, and more specifically, to a battery SOC correction method, apparatus, and vehicle. Background Technology

[0002] The power battery system is the core of new energy vehicles, and the battery management system (BMS) plays a crucial role. The state of charge (SOC) is the most critical technical parameter in the BMS. SOC directly reflects the remaining battery capacity, providing drivers with a basis for estimating driving range and supporting daily battery management and maintenance. If the SOC is inaccurately estimated, the battery may frequently enter a protection state, thus failing to effectively extend its lifespan.

[0003] In related technologies, the estimation of battery state of charge (SOC) commonly employs a combination of the open-circuit voltage method and the ampere-hour integration method. The ampere-hour integration method, by real-time acquisition of charging and discharging currents and time integration, can continuously track changes in battery charge during operation, making it suitable for dynamic operating conditions. However, over time, the accumulated errors in current measurement and integration gradually increase, affecting the reliability of SOC. To improve SOC accuracy, related technologies typically use open-circuit voltage (OCV) lookup tables to correct the SOC. However, for some battery types, there is a significant open-circuit voltage (OCV) hysteresis during charging and discharging, causing the same voltage value to correspond to different SOC levels under different charging and discharging states. If traditional lookup table correction is still used, it can easily lead to reverse or over-calibration, resulting in large correction errors in certain ranges and affecting the overall accuracy of the estimation. Summary of the Invention

[0004] The problem addressed by this invention is how to improve the accuracy of SOC estimation.

[0005] To address the above problems, the present invention provides a battery SOC correction method, apparatus, and vehicle.

[0006] In a first aspect, the present invention provides a battery SOC correction method, comprising:

[0007] When the obtained SOC estimate is not within the OCV detection range, the SOC estimate is corrected to the boundary value of the OCV detection range;

[0008] When the SOC estimate is within the OCV detection interval, the corrected SOC estimate is obtained step by step based on the boundary value, the correction weight, and the SOC estimate of the previous time step.

[0009] Optionally, when the obtained SOC estimate is not within the OCV detection range, correcting the SOC estimate to the boundary value of the OCV detection range includes:

[0010] Determine the comparison result between the estimated SOC value and the values ​​of the upper and lower boundaries of the OCV detection interval;

[0011] When the SOC estimate is greater than the upper boundary, the SOC estimate is corrected to the upper boundary.

[0012] When the SOC estimate is less than the lower boundary, the SOC estimate is corrected to the lower boundary.

[0013] Optionally, when the SOC estimate is within the OCV detection interval, obtaining the corrected SOC estimate step by step based on the boundary value, the correction weight, and the SOC estimate from the previous time step includes:

[0014] The width center is determined based on the upper and lower boundaries of the OCV detection interval;

[0015] The correction weight is determined based on the upper boundary and the lower boundary, wherein the correction weight is inversely proportional to the width of the OCV detection interval;

[0016] The corrected SOC estimate is obtained based on the corrected weight, the width center, and the SOC estimate from the previous time step.

[0017] Optionally, determining the correction weight based on the upper boundary and the lower boundary includes:

[0018] Determine the reference width and the maximum correction weight under the reference width;

[0019] The larger value between the interval width and the reference width is taken as the effective width;

[0020] Obtain the ratio of the baseline width to the effective width, and obtain the correction weight using the ratio and the maximum correction weight.

[0021] Optionally, when the SOC estimate is within the OCV detection interval, the step of progressively obtaining the corrected SOC estimate based on the boundary value, the correction weight, and the SOC estimate from the previous time step further includes:

[0022] The fusion confidence level is obtained based on at least one of the following: the number of full charge and discharge cycles of the battery, the cumulative time after full charge and discharge, the current integration error after full charge and discharge, and the SOC correction deviation during OCV calibration.

[0023] When the fusion confidence is less than or equal to the confidence threshold, the corrected SOC estimate is obtained step by step based on the boundary value, the correction weight, and the SOC estimate of the previous time step.

[0024] Optionally, obtaining the fusion confidence based on at least one of the following: the number of full-charge and discharge cycles of the battery, the cumulative time after full-charge and discharge, the current integration error after full-charge and discharge, and the SOC correction deviation during OCV calibration:

[0025] The cumulative charging power since the last full charge or full discharge reset is obtained. Based on the cumulative charging power, a normalized cumulative charging amount relative to the target battery capacity is obtained. Based on the normalized cumulative charging amount, a charge / discharge reliability coefficient is obtained by truncating a linear function. The target battery capacity is a first preset multiple of the battery's rated capacity.

[0026] Obtain the cumulative time since the last full charge or full discharge reset, obtain a normalized time relative to a second preset duration based on the cumulative time, and obtain a time reliability coefficient based on the normalized time through the truncated linear function.

[0027] Based on the current measurement error, the current error integral since the reset is accumulated, and the normalized error relative to the preset battery capacity is obtained based on the current error integral. Based on the normalized error, the current reliability coefficient is obtained through the truncated linear function.

[0028] When the SOC correction deviation of the most recent preset number of times is monotonic, the correction deviation confidence coefficient is determined according to the increase in the number of consecutive monotonic points.

[0029] The fusion reliability is obtained by means of at least one of the charge / discharge reliability coefficient, the time reliability coefficient, the current reliability coefficient, and the correction deviation reliability coefficient, through a preset fusion rule.

[0030] Optionally, obtaining the fusion reliability based on at least one of the charge / discharge reliability coefficient, the time reliability coefficient, the current reliability coefficient, and the correction deviation reliability coefficient through a preset fusion rule includes:

[0031] The fusion confidence level is obtained in the form of a product.

[0032] Optionally, when the fusion confidence is less than or equal to the confidence threshold, obtaining the corrected SOC estimate step by step based on the boundary value, the corrected weight, and the SOC estimate from the previous time step includes:

[0033] The fusion unreliability is obtained by subtracting the maximum confidence level from the fusion confidence level.

[0034] The overall correction weight is obtained based on the fusion unreliability and the correction weight;

[0035] The corrected weights are replaced with the overall corrected weights, and the corrected SOC estimate is obtained step by step based on the boundary value, the overall corrected weights, and the SOC estimate of the previous time step.

[0036] Secondly, the present invention also provides a battery SOC correction device, comprising:

[0037] The first correction module is used to correct the SOC estimate to the boundary value of the OCV detection range when the obtained SOC estimate is not within the OCV detection range.

[0038] The second correction module is used to gradually obtain a corrected SOC estimate based on the boundary value, correction weight, and the SOC estimate of the previous time step by step when the SOC estimate is within the OCV detection interval.

[0039] Thirdly, the present invention also provides a vehicle, including a memory and a processor;

[0040] The memory is used to store computer programs;

[0041] The processor is configured to implement the battery SOC correction method as described above when executing the computer program.

[0042] The beneficial effects of the battery SOC correction method of the present invention are:

[0043] When the SOC estimate exceeds the specified range, it is corrected to the nearest boundary value. This ensures the corrected SOC value falls back into the valid range of voltage information, preventing calibration failure due to abnormal initial estimates and providing a reasonable starting point for subsequent OCV-based corrections. In applications where high detection accuracy is not required, this corrected value can be directly used as a usable result, reducing the risk of misjudgment. Within the OCV detection range, a correction weight is introduced to adjust the contribution of voltage information, and the SOC estimate from the previous moment is used for progressive updates. The correction weight is dynamically adjusted based on the reliability of the voltage information: when OCV is insensitive to SOC or exhibits significant hysteresis, the correction weight is reduced; when the voltage response is clear and hysteresis is small, the correction weight is increased. This gradual correction method allows the SOC value to stably return to a reasonable range under voltage guidance, fully utilizing voltage information while considering historical trends. This ensures stable convergence of SOC estimation under different operating conditions, making the estimation results closer to the actual state of charge of the battery, thereby improving SOC estimation accuracy. Attached Figure Description

[0044] Figure 1 This is a schematic flowchart of the battery SOC correction method according to an embodiment of the present invention;

[0045] Figure 2 This is an example diagram of the SOC-OCV curve according to an embodiment of the present invention;

[0046] Figure 3 This is a flowchart of the battery SOC correction method according to an embodiment of the present invention;

[0047] Figure 4 This is a flowchart of a battery SOC correction method according to another embodiment of the present invention;

[0048] Figure 5 This is an example diagram of a vehicle according to an embodiment of the present invention. Detailed Implementation

[0049] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0050] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0051] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0052] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0053] The names of the messages or information exchanged between the multiple devices in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0054] This embodiment provides a battery SOC correction method, apparatus, and vehicle.

[0055] like Figure 1 and Figure 3 As shown, an embodiment of the present invention provides a battery SOC correction method, comprising:

[0056] Step S100: When the obtained SOC estimate is not within the OCV detection range, correct the SOC estimate to the boundary value of the OCV detection range.

[0057] The SOC estimate represents the current state of charge obtained by the open-circuit voltage method, reflecting the proportion of remaining battery capacity. The OCV detection range refers to the range of battery open-circuit voltage and state of charge that has a clear correspondence; the open-circuit voltage within this range can be used to calibrate the SOC estimate.

[0058] By limiting the SOC estimate beyond the OCV detection range to the boundaries of that range, the corrected SOC value falls within an effective range suitable for open-circuit voltage calibration, thus providing a reasonable initial value for subsequent OCV-based SOC correction. When high detection accuracy is not required, this corrected value can also be used as the final result.

[0059] In one embodiment, the charging OCV curve as a function of SOC is obtained when the battery is stationary and stabilized after charging, and the discharging OCV curve as a function of SOC is obtained when the battery is stationary and stabilized after discharging. After the OCV correction condition is met, the estimated value of the battery's SOC is obtained, and it is determined whether the estimated value falls within the OCV detection interval. If not, it is assigned the value of the nearest interval boundary value, that is, the point of the charging OCV curve or the discharging OCV curve on the OCV.

[0060] Step S200: When the SOC estimate is within the OCV detection interval, the corrected SOC estimate is obtained step by step based on the boundary value, the correction weight and the SOC estimate of the previous time step.

[0061] When the SOC estimate falls within the OCV detection range, the boundary value is used as a reference limit. Combined with preset correction weights and the previous ampere-hour integral SOC estimate, the current SOC estimate is progressively adjusted. The correction weights represent the weight of voltage-provided information. For example, when voltage-provided information is ambiguous and OCV is insensitive to SOC, Ah integration should be trusted more, and the correction weights reduced. Conversely, when voltage-provided information is accurate and the hysteresis effect is not significant, voltage information should be trusted more, and the correction weights increased. The SOC estimate is progressively corrected based on the determined correction weights and the previous ampere-hour integral method. The correction strategy can be automatically adjusted according to the battery's current performance, and voltage can be used to control the SOC within the regression range. The previous ampere-hour integral SOC estimate is the SOC value obtained using this method.

[0062] In one embodiment, when the SOC estimate is within the OCV detection range, the SOC value is adjusted by increasing or decreasing it based on the relative relationship of boundary values, ensuring that the adjustment does not exceed the magnitude of the correction weight. The SOC estimate is updated sequentially with reference to the trend of the previous time step's ampere-hour integral SOC estimate, and the progressively corrected result is output to achieve a smooth adjustment of the state of charge. For example, when the SOC estimate is within the OCV detection range, the range width is obtained based on the boundary values. A smaller range width results in a larger correction weight, and a larger range width results in a smaller correction weight. The current time step's estimate is weighted and used as part of the corrected SOC value, and the previous time step's SOC estimate is weighted and used as another part of the corrected SOC value. This process is repeated sequentially to obtain the corrected SOC estimate.

[0063] In this embodiment, when the SOC estimate exceeds the range, it is corrected to the nearest boundary value. This ensures the corrected SOC value falls back into the valid range of voltage information, avoiding calibration failure due to abnormal initial estimates and providing a reasonable starting point for subsequent OCV-based corrections. In applications where high detection accuracy is not required, this corrected value can be directly used as a usable result, reducing the risk of misjudgment. Within the OCV detection range, a correction weight is introduced to adjust the contribution of voltage information, and a progressive update is performed based on the previous SOC estimate. The correction weight is dynamically adjusted according to the reliability of the voltage information: when OCV is insensitive to SOC or exhibits significant hysteresis, the voltage weight is reduced; when the voltage response is clear and hysteresis is small, the voltage weight is increased. This gradual correction method allows the SOC value to stably return to a reasonable range under voltage guidance, fully utilizing voltage information while considering historical trends. This ensures stable convergence of SOC estimation under different operating conditions, making the estimation results closer to the actual state of charge of the battery, thereby improving SOC estimation accuracy.

[0064] Optionally, when the obtained SOC estimate is not within the OCV detection range, correcting the SOC estimate to the boundary value of the OCV detection range includes:

[0065] The SOC estimate is compared with the values ​​of the upper and lower boundaries of the OCV detection interval.

[0066] When the SOC estimate is greater than the upper boundary, the SOC estimate is corrected to the upper boundary.

[0067] When the SOC estimate is less than the lower boundary, the SOC estimate is corrected to the lower boundary.

[0068] In one embodiment, such as Figure 2 As shown, by judging the numerical relationship between the estimated SOC value (SOC_Ah) and its upper and lower boundaries (OCV-SOC_High and OCV-SOC_Low), it is determined whether the estimated value exceeds the OCV detection range. If the estimated SOC value is higher than the upper boundary, it indicates that it is in a high-charge region where the voltage cannot effectively reflect the SOC. In this case, the estimated value is adjusted to the upper boundary to limit it from exceeding the range. If the estimated SOC value is lower than the lower boundary, it indicates that it is in a low-charge region where the voltage response is insufficient. In this case, the estimated value is adjusted to the lower boundary to bring it back to the effective detection range.

[0069] Specifically, the current SOC estimate is obtained and compared with the upper and lower boundaries of the OCV detection range. If the current SOC estimate exceeds the upper boundary, the upper boundary value is output as the corrected SOC estimate. If the current SOC estimate is lower than the lower boundary, the lower boundary value is output as the corrected SOC estimate, thereby ensuring that the corrected SOC value is within the effective range that can be used for voltage calibration.

[0070] Optionally, when the SOC estimate is within the OCV detection interval, obtaining the corrected SOC estimate step by step based on the boundary value, the correction weight, and the SOC estimate from the previous time step includes:

[0071] The width center is determined based on the upper and lower boundaries of the OCV detection interval.

[0072] The correction weight is determined based on the upper boundary and the lower boundary, wherein the correction weight is inversely proportional to the width of the OCV detection interval.

[0073] The corrected SOC estimate is obtained based on the corrected weight, the width center, and the SOC estimate from the previous time step.

[0074] In one embodiment, the OCV detection interval represents the range of states of charge (SOC) where there is a clear correspondence between the battery's open-circuit voltage and its SOC, defined by an upper and lower boundary. The width center represents the midpoint between the upper and lower boundaries, characterizing the center position of the OCV detection interval. The correction weight is used to adjust the influence of voltage information on SOC correction; its magnitude affects the adjustment range of each correction. When the estimated SOC is within the OCV detection interval, progressive correction is performed using the boundary information of that interval. The width center is calculated based on the values ​​of the upper and lower boundaries, serving as a reference benchmark during the correction process. The correction weight is set based on the interval width determined by the difference between the upper and lower boundaries; a larger interval width results in a smaller correction weight, and vice versa, meaning the correction weight is inversely proportional to the interval width. This avoids over-reliance on voltage information in wide intervals where the voltage response to SOC changes is weak and the correspondence is dispersed, while increasing the correction range in narrow intervals where the correspondence is concentrated. Using the SOC estimate from the previous moment as a reference, the corrected SOC estimate is output progressively based on the determined correction weight and width center.

[0075] The corrected SOC estimate is expressed as follows:

[0076] SOC_Ah(k)=alpha_adaptive*SOC_center +(1-alpha_adaptive)* SOC_ah(k-1),

[0077] SOC_center=(OCV-SOC_High-OCV-SOC_Low) / 2,

[0078] Where SOC_Ah(k) represents the corrected SOC estimate, SOC_ah(k-1) represents the ampere-hour integral SOC estimate of the previous time step, alpha_adaptive represents the corrected weight, SOC_center represents the width center, OCV-SOC_High represents the upper boundary, and OCV-SOC_Low represents the lower boundary.

[0079] In one embodiment, a possible SOC range is obtained by looking up the OCV-SOC table with the current measured voltage. The most likely SOC value in this range is estimated by taking the midpoint of the voltage range to obtain the width center SOC_center. Using the width center as a correction reference, the SOC estimate of the ampere-hour integral at the previous moment is combined with the correction weight to slowly obtain the fused SOC value, that is, the corrected SOC estimate SOC_Ah(k).

[0080] Optionally, determining the correction weight based on the upper boundary and the lower boundary includes:

[0081] Determine the baseline width and the maximum correction weight under the baseline width.

[0082] The larger value between the interval width and the reference width is taken as the effective width.

[0083] Obtain the ratio of the baseline width to the effective width, and obtain the correction weight using the ratio and the maximum correction weight.

[0084] Set the base width (base_width) and the maximum correction weight (alpha_max). Determine the relationship between the base width and the interval width, and use the larger value as the effective width. A larger width indicates that the OCV is less sensitive to the SOC, exhibits a severe hysteresis effect, and provides ambiguous information from the voltage, resulting in a large error in OCV SOC estimation. In this case, the ampere-hour integral should be trusted more, and the correction weight (alpha_adaptive) should be reduced. Conversely, a smaller width indicates that the OCV is more sensitive to the SOC, exhibits less hysteresis, and provides very accurate information from the voltage, resulting in accurate OCV estimation. In this case, voltage information can be referenced more, and the correction weight (alpha_adaptive) can be increased.

[0085] The larger of the interval width and the baseline width is taken as the effective width. The ratio of the baseline width to the effective width is assigned the maximum correction weight, and the correction weight is obtained as follows:

[0086] alpha_adaptive=alpha_max*(base_width / max(base_width, width)),

[0087] width= OCV-SOC_High-OOCV-SOC_Low,

[0088] Where alpha_adaptive represents the adjusted weight, alpha_max represents the maximum adjusted weight, base_width represents the base width, and width represents the interval width.

[0089] In one embodiment, alpha_max=3% and base_width=6%, meaning the weighting is adjusted to no more than 3% and the minimum width is 6%.

[0090] Optionally, when the SOC estimate is within the OCV detection interval, the step of progressively obtaining the corrected SOC estimate based on the boundary value, the correction weight, and the SOC estimate from the previous time step further includes:

[0091] The fusion confidence level is obtained based on at least one of the following: the number of full charge and discharge cycles of the battery, the cumulative time after full charge and discharge, the current integration error after full charge and discharge, and the SOC correction deviation during OCV calibration.

[0092] When the fusion confidence is less than or equal to the confidence threshold, the corrected SOC estimate is obtained step by step based on the boundary value, the correction weight, and the SOC estimate of the previous time step.

[0093] Fusion reliability is a comprehensive index calculated based on at least one of the following: number of charge-discharge cycles, cumulative running time, error generated by current integration, and correction deviation of SOC during open-circuit voltage (OCV) calibration. It is used to reflect the reliability of the current SOC estimate.

[0094] The charge / discharge cycle count represents the total number of full charge / discharge cycles the battery has completed; the cumulative time represents the duration of continuous operation after a full charge / discharge cycle; the current integration error represents the deviation caused by measurement or cumulative factors when calculating the charge capacity by integrating current over time; the SOC correction deviation during OCV calibration represents the correction direction between the SOC determined using open-circuit voltage and the original estimate. The credibility threshold represents a preset judgment benchmark used to determine whether the credibility of the current SOC estimate is within an acceptable range. When the fused credibility is less than or equal to the credibility threshold, it indicates that the current SOC estimate has significant uncertainty and needs correction. When the fused credibility is greater than the credibility threshold, it indicates that the current SOC estimate is relatively accurate and no correction is needed, or voltage error correction can be further reduced.

[0095] In one embodiment, the corrected SOC estimate is obtained by: when the fusion confidence does not meet the requirements, constraining the correction amount by combining boundary values, and using correction weights to adjust the SOC estimate of the previous time step by step through iterative updates.

[0096] Optionally, obtaining the fusion confidence based on at least one of the following: the number of full-charge and discharge cycles of the battery, the cumulative time after full-charge and discharge, the current integration error after full-charge and discharge, and the SOC correction deviation during OCV calibration:

[0097] The cumulative charging amount since the last full charge or full discharge reset is obtained. Based on the cumulative charging amount, a normalized cumulative charging amount relative to the battery target capacity is obtained. Based on the normalized cumulative charging amount, a charge / discharge reliability coefficient is obtained by truncating a linear function. The battery target capacity is a first preset multiple of the battery rated capacity.

[0098] The charge / discharge reliability coefficient C_TotAh decreases as the ampere-hour integral Ah increases. After exceeding the rated capacity of the battery at the first preset rate, it begins to decrease linearly. Assuming the rated capacity of the battery at the first preset rate is 10 times the capacity, the charge / discharge reliability coefficient is expressed as:

[0099] C_TotAh=min(1,2-(total_ah_since_reset / (10ah_capacity))),

[0100] Where C_TotAh represents the charge / discharge reliability coefficient, total_ah_since_reset represents the cumulative charge amount since the last full charge or full discharge reset, and ah_capacity represents the battery's rated capacity.

[0101] Obtain the cumulative time since the last full charge or full discharge reset, obtain a normalized time relative to a second preset duration based on the cumulative time, and obtain a time reliability coefficient based on the normalized time using the truncated linear function.

[0102] The time reliability coefficient C_Time decreases as time increases, and decreases linearly after exceeding a second preset duration. If the second preset duration is 7 days, then the time reliability coefficient is expressed as:

[0103] C_Time=min(1,2-(time_since_reset / (7*24*3600))),

[0104] Where C_Time represents the time reliability coefficient, and time_since_reset represents the cumulative time since the last full charge or full discharge reset.

[0105] Based on the current measurement error, the current error integral since the reset is accumulated, and the normalized error relative to the preset battery capacity is obtained based on the current error integral. Based on the normalized error, the current reliability coefficient is obtained through the truncated linear function.

[0106] The current reliability coefficient C_Curr represents the linear decrease that begins after the cumulative current error exceeds a preset capacity, based on a small current integral error. Assuming the preset capacity is 3%, the current reliability coefficient is expressed as:

[0107] C_Curr=min(1,2-(CurrentError_since_reset / 3)),

[0108] Where C_Curr represents the current reliability coefficient, and CurrentError_since_reset represents the cumulative integral of the current error since the reset.

[0109] When the SOC correction deviation of the most recent preset number of times is monotonic, the confidence coefficient of the correction deviation is determined according to the increase in the number of consecutive monotonic points.

[0110] Record the correction deviation SOC_ah-soc_center for the first preset number of times in the past. If the correction deviation shows a monotonically changing trend, decrease the current correction coefficient C_HistoryDeviation. For example, if the correction deviation for the second consecutive preset number of times in the past has been monotonically increasing or decreasing, then decrease the correction deviation reliability coefficient for each additional correction deviation with the same monotonicity.

[0111] In one embodiment, the first preset number of times is set to 20, the second preset number of times is set to 5, and the coefficient is reduced by 0.1 for each consecutive 5 times. The calculation process of the correction deviation confidence coefficient is as follows: record the correction deviation of the past 20 times. When the correction deviation of the past 5 consecutive times is monotonically increasing (for example, each time it is corrected in the direction of increasing SOC), then when the correction deviation of the 6th time is still in the direction of increasing SOC, the correction deviation confidence coefficient is reduced by 0.1.

[0112] The fusion reliability is obtained by means of at least one of the charge / discharge reliability coefficient, the time reliability coefficient, the current reliability coefficient, and the correction deviation reliability coefficient, through a preset fusion rule.

[0113] At least one coefficient is involved in the calculation of fusion credibility. For example, if a battery is sensitive to the number of charge-discharge cycles and time, the charge-discharge credibility coefficient and the time credibility coefficient are used as coefficients, and the fusion credibility is obtained through preset fusion rules.

[0114] Optionally, obtaining the fusion reliability based on at least one of the charge / discharge reliability coefficient, the time reliability coefficient, the current reliability coefficient, and the correction deviation reliability coefficient through a preset fusion rule includes:

[0115] The fusion confidence level is obtained in the form of a product.

[0116] If all coefficients participate in the fusion credibility calculation, then the fusion credibility is expressed as:

[0117] C_Ah=C_TotAh*C_Time*C_Curr*C_HistoryDeviation.

[0118] Optionally, such as Figure 4 As shown, when the fusion confidence is less than or equal to the confidence threshold, the stepwise acquisition of the corrected SOC estimate based on the boundary value, the corrected weight, and the SOC estimate from the previous time step includes:

[0119] The fusion unreliability is obtained by subtracting the maximum confidence level from the fusion confidence level.

[0120] The overall correction weight is obtained based on the fusion unreliability and the correction weight.

[0121] The corrected weights are replaced with the overall corrected weights, and the corrected SOC estimate is obtained step by step based on the boundary value, the overall corrected weights, and the SOC estimate of the previous time step.

[0122] Since a higher fusion confidence level indicates a more reliable ampere-hour integral result, the difference between the maximum confidence level and the fusion confidence level yields the degree of unreliability. The overall correction strength, using the fusion unreliability level as a correction weight, influences the global correction capability. This overall correction strength is then substituted into the correction scheme.

[0123] SOC_Ah(k)=alpha_final*SOC_center +(1-alpha_final)* SOC_ah(k-1),

[0124] Slowly adjust the SOC.

[0125] The overall adjusted weight is expressed as:

[0126] alpha_final=alpha_adaptive(1-C_Ah),

[0127] Where alpha_final represents the overall corrected weight, alpha_adaptive represents the corrected weight, and 1-C_Ah represents the fusion unconfidence, with the maximum fusion confidence being 1.

[0128] When the obtained SOC estimate is not within the OCV detection range, the reliability of the current ampere-hour integral, i.e. the fusion reliability C_Ah, is calculated. When the reliability is less than or equal to the reliability threshold, the overall correction weight alpha_final replaces the original correction weight alpha_adaptive. Using the width center as the correction reference, the ampere-hour integral SOC estimate from the previous moment is combined with the overall correction weight to slowly obtain the fused SOC value, i.e. the corrected SOC estimate SOC_Ah(k).

[0129] An embodiment of the present invention provides a battery SOC correction device, comprising:

[0130] The first correction module is used to correct the SOC estimate to the boundary value of the OCV detection range when the obtained SOC estimate is not within the OCV detection range.

[0131] The second correction module is used to gradually obtain a corrected SOC estimate based on the boundary value, correction weight, and the SOC estimate of the previous time step by step when the SOC estimate is within the OCV detection interval.

[0132] like Figure 5 As shown, an embodiment of the present invention provides a vehicle 500, including a memory 510 and a processor 520; the memory 510 is used to store a computer program; the processor 520 is used to implement the battery SOC correction method as described above when the computer program is executed.

[0133] Alternatively, a vehicle 500 includes a memory 510 and a processor 520 coupled to the memory 510; the memory 510 is configured to store a computer program; the processor 520 is configured to perform the following operations when the computer program is executed:

[0134] When the obtained SOC estimate is not within the OCV detection range, the SOC estimate is corrected to the boundary value of the OCV detection range;

[0135] When the SOC estimate is within the OCV detection interval, the corrected SOC estimate is obtained step by step based on the boundary value, the correction weight, and the SOC estimate of the previous time step.

[0136] This invention provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the battery SOC correction method described above.

[0137] Alternatively, a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the following operations:

[0138] When the obtained SOC estimate is not within the OCV detection range, the SOC estimate is corrected to the boundary value of the OCV detection range;

[0139] When the SOC estimate is within the OCV detection interval, the corrected SOC estimate is obtained step by step based on the boundary value, the correction weight, and the SOC estimate of the previous time step.

[0140] Vehicle 500, which can serve as a server or client of the present invention, is now described as an example of a hardware device that can be applied to various aspects of the present invention. Vehicle 500 includes various forms of digital electronic computer devices, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Vehicle 500 also includes various forms of mobile devices, such as personal digital assistants, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0141] Vehicle 500 includes a computing unit that can perform various appropriate actions and processes based on a computer program stored in read-only memory (ROM) or a computer program loaded from a storage unit into random access memory (RAM). The RAM can also store various programs and data required for device operation. The computing unit, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0142] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc. In this application, 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 the embodiments of the present invention according to actual needs. Furthermore, the functional units in the various embodiments of the present invention 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 units can be implemented in hardware or as software functional units.

[0143] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A battery SOC correction method characterized by, The method comprises the steps of: when the obtained SOC estimation value is not in the OCV detection interval, correcting the SOC estimation value to the boundary value of the OCV detection interval; when the SOC estimation value is in the OCV detection interval, gradually obtaining a corrected SOC estimation value according to the boundary value, a correction weight and a SOC estimation value at a previous time, comprising: determining a width center according to an upper boundary and a lower boundary of the OCV detection interval; determining the correction weight according to the upper boundary and the lower boundary, wherein the correction weight is inversely proportional to the interval width of the OCV detection interval; and obtaining the corrected SOC estimation value according to the correction weight, the width center and the SOC estimation value at the previous time.

2. The battery SOC correction method according to claim 1, characterized by, The step of correcting the SOC estimation value to the boundary value of the OCV detection interval when the obtained SOC estimation value is not in the OCV detection interval comprises the steps of: judging the numerical comparison result of the SOC estimation value and the upper boundary and the lower boundary of the OCV detection interval; when the SOC estimation value is greater than the upper boundary, correcting the SOC estimation value to the upper boundary; when the SOC estimation value is less than the lower boundary, correcting the SOC estimation value to the lower boundary.

3. The battery SOC correction method according to claim 1, characterized by, The step of determining the correction weight according to the upper boundary and the lower boundary comprises the steps of: determining a reference width and a maximum correction weight under the reference width; taking the larger value of the interval width and the reference width as an effective width; obtaining the ratio of the reference width to the effective width, and obtaining the correction weight through the ratio and the maximum correction weight.

4. The battery SOC correction method according to any one of claims 1 to 3, characterized by, The step of gradually obtaining the corrected SOC estimation value according to the boundary value, the correction weight and the SOC estimation value at the previous time when the SOC estimation value is in the OCV detection interval further comprises the steps of: obtaining a fusion confidence level according to at least one of the number of charge-discharge times of full charge and full discharge of the battery, the cumulative time after full charge and full discharge, the current integral error after full charge and full discharge, and the SOC correction deviation at the OCV calibration time; when the fusion confidence level is less than or equal to a confidence level threshold, gradually obtaining the corrected SOC estimation value according to the boundary value, the correction weight and the SOC estimation value at the previous time.

5. The battery SOC correction method according to claim 4, characterized by, The step of obtaining the fusion confidence level according to at least one of the number of charge-discharge times of full charge and full discharge of the battery, the cumulative time after full charge and full discharge, the current integral error after full charge and full discharge, and the SOC correction deviation at the OCV calibration time comprises the steps of: obtaining the cumulative charging capacity since the last full charge or full discharge reset, obtaining a normalized cumulative charging capacity relative to the target capacity of the battery according to the cumulative charging capacity, and obtaining a charge-discharge confidence coefficient through a truncated linear function according to the normalized cumulative charging capacity, wherein the target capacity of the battery is a first preset multiple of the rated capacity of the battery; obtaining the cumulative time since the last full charge or full discharge reset, obtaining a normalized time relative to a second preset time length according to the cumulative time, and obtaining a time confidence coefficient through the truncated linear function according to the normalized time; accumulate a current error integral from a reset according to a current measurement error, obtain a normalized error relative to a preset battery capacity according to the current error integral, obtain a current credibility coefficient by the truncated linear function according to the normalized error; when the SOC correction deviation has monotonicity for a preset number of times, then determine a correction deviation credibility coefficient according to an increasing number of continuous monotonic points; obtain the fusion credibility by a preset fusion rule based on at least one of the charge-discharge credibility coefficient, the time credibility coefficient, the current credibility coefficient and the correction deviation credibility coefficient.

6. The battery SOC correction method according to claim 5, characterized by, obtaining the fusion credibility by a preset fusion rule based on at least one of the charge-discharge credibility coefficient, the time credibility coefficient, the current credibility coefficient and the correction deviation credibility coefficient includes: obtaining the fusion credibility in the form of a product.

7. The battery SOC correction method according to claim 4, characterized by, when the fusion credibility is less than or equal to a credibility threshold, gradually obtaining the corrected SOC estimation value according to the boundary value, the correction weight and the SOC estimation value at the last time includes: obtaining a fusion uncredibility according to a difference between a maximum credibility and the fusion credibility; obtaining an overall correction weight according to the fusion uncredibility and the correction weight; replacing the correction weight with the overall correction weight, and gradually obtaining the corrected SOC estimation value according to the boundary value, the overall correction weight and the SOC estimation value at the last time.

8. A battery SOC correction device characterized by comprising: including: a first correction module configured to correct the SOC estimation value to a boundary value of an OCV detection interval when the obtained SOC estimation value is not in the OCV detection interval; a second correction module configured to gradually obtain a corrected SOC estimation value according to the boundary value, a correction weight and a SOC estimation value at the last time when the SOC estimation value is in the OCV detection interval, including: determining a width center according to an upper boundary and a lower boundary of the OCV detection interval; determining the correction weight according to the upper boundary and the lower boundary, wherein the correction weight is inversely proportional to an interval width of the OCV detection interval; and obtaining the corrected SOC estimation value according to the correction weight, the width center and the SOC estimation value at the last time.

9. A vehicle characterized by comprising: including a memory and a processor; the memory is configured to store a computer program; the processor is configured to implement the battery SOC correction method of any one of claims 1-7 when executing the computer program.

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