SOC auxiliary correction method, system and equipment based on dynamic voltage interval band

Abstract

The invention discloses an SOC auxiliary correction method, system and device based on a dynamic voltage interval band, and the method comprises the following steps: S1, building a battery basic OCV-SOC curve according to battery characteristic test data, and presetting an initial voltage interval band in a voltage platform region; and S2, based on the collected current data, temperature data and battery health state data, dynamic adjustment factor calculation is carried out through a preset dynamic adjustment factor calculation model, and the invention relates to the technical field of battery management systems. According to the SOC auxiliary correction method based on the dynamic voltage interval band, dynamic adjustment factors composed of current, temperature and aging coefficients are calculated in real time, the effective judgment interval band of a voltage platform area is expanded in a self-adaptive mode, when the voltage deviates from the interval, an OCV method and an ampere-hour integral method are fused to output and correct the SOC, and the SOC auxiliary correction method based on the dynamic voltage interval band is obtained. The problem of error correction caused by a fixed threshold value under a dynamic working condition in a traditional method is solved, and the estimation precision and robustness are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of battery management systems, and more specifically, to a SOC auxiliary correction method, system and device based on a dynamic voltage interval band. Background Art

[0002] In the field of battery management systems, accurately estimating the battery's state of charge (SOC) is crucial for ensuring battery safety, efficient operation, and extending battery life. Common SOC estimation methods include open-circuit voltage, ampere-hour integration, and Kalman filtering. However, ampere-hour integration suffers from cumulative errors, the OCV method requires the battery to rest for a sufficient period of time, and the Kalman filter is computationally complex and relies on model accuracy.

[0003] For batteries such as lithium iron phosphate (LFP), there is a voltage plateau in the middle SOC range (e.g. 30% - 90%). In this region, small voltage fluctuations correspond to large SOC changes (e.g. Figure 3 The OCV method has a significant error.

[0004] To address these issues, several correction methods have been proposed in the prior art, with the fixed voltage threshold correction method being a common one. This method sets fixed voltage thresholds and corrects the SOC estimation when the battery voltage reaches these thresholds. However, under actual dynamic operating conditions, battery performance is affected by various factors, such as temperature and aging. These factors can cause changes in battery characteristics, making the fixed voltage threshold correction method susceptible to failure and unable to guarantee the accuracy and stability of SOC estimation. Summary of the Invention

[0005] 1. Technical problems to be solved In view of the problem in the prior art that under actual dynamic working conditions, the performance of the battery will be affected by multiple factors such as temperature and aging. These factors will cause the characteristics of the battery to change, thereby making the fixed voltage threshold correction method easily fail and unable to guarantee the accuracy and stability of SOC estimation. The purpose of the present invention is to provide an SOC auxiliary correction method based on a dynamic voltage interval band, which can provide an SOC correction method for dynamically adjusting the voltage interval band, solve the problem of voltage-SOC mapping ambiguity in the platform area, and improve the estimation accuracy over the entire life cycle and full temperature range.

[0006] 2. Technical solution To solve the above problems, the present invention adopts the following technical solutions.

[0007] A SOC auxiliary correction method based on a dynamic voltage interval band is characterized in that the method comprises the following steps: S1. Establish a basic OCV-SOC curve for the battery based on the battery characteristic test data, and preset an initial voltage range in the voltage platform area; S2. Determine the dynamic adjustment factor based on the collected current data, temperature data, and battery health status data and the preset dynamic adjustment factor calculation model. ; The dynamic adjustment factor calculation model includes the following formula: ; Among them, I is the absolute value of the real-time current, is the absolute value of the maximum allowable charge and discharge current under the current working conditions, is the real-time temperature, is the reference temperature, is the operating temperature range, SOH is the battery health, 、 、 is the weight coefficient and ; S3, according to the dynamic adjustment factor Dynamically adjusting the initial voltage determination range data to obtain a dynamic voltage interval band, so as to obtain voltage determination range data adjusted in real time; S4. When the battery voltage monitoring data deviates from the voltage determination range data adjusted in real time, a fusion correction process is performed based on the SOC estimation results of the open circuit voltage method and the ampere-hour integration method to output a corrected SOC value.

[0008] Furthermore, the initial voltage interval range is ,in, ; ; in is the initial offset, obtained through experimental calibration, Indicates that the corresponding open circuit voltage value is obtained by looking up the SOC table.

[0009] Furthermore, the bandwidth of the dynamic voltage interval band Calculated by the following formula: ; in, is the initial offset, is the expansion coefficient, which is used to control the bandwidth It expands linearly with the increase of .

[0010] Furthermore, the upper and lower limits of the dynamic voltage range satisfy: ; ; in, is the internal resistance of the battery, which can be obtained by looking up the Res(SOC, T, SOH) table.

[0011] Furthermore, the method further includes: setting a trigger condition for SOC correction based on the dynamic voltage range band, and determining whether the battery voltage monitoring data meets the trigger condition, including the following steps: When the real-time voltage The modification is triggered when the following conditions are met: or , get correction ; according to exist and SOC reverse check is performed on the curve; when correcting, the SOC reverse check strategy is selected according to the charge and discharge status: the charging status adopts Check back, the discharge status is Reverse check; Get corrections based on the current charge and discharge status If it is in charging state, , if in discharge state, .

[0012] Furthermore, the formula for the fusion correction is: ; in, The SOC value retrieved by the OCV method is: is the SOC value estimated by the ampere-hour integration method, is the weight factor and Negative correlation.

[0013] Furthermore, in the initial voltage interval, ; ; in is the initial offset, obtained through experimental calibration.

[0014] Furthermore, the The absolute value of the maximum allowable charge and discharge current of the battery in its current state; ; in: : Current temperature and battery health The results of the table lookup; : Current temperature and battery health The results of the table lookup; : The effective range of the battery operating temperature range (unit: °C or K); ; in: : The maximum temperature allowed for the battery to operate; : The minimum temperature at which the battery is allowed to operate.

[0015] A dynamic voltage interval-based SOC auxiliary correction system, used in the above-mentioned dynamic voltage interval-based SOC auxiliary correction method, the system comprising: An initial voltage interval band preset unit is used to establish a basic OCV-SOC curve of a battery according to battery characteristic test data, and preset an initial voltage interval band in the voltage platform area; Dynamic adjustment factor calculation unit, used to determine the dynamic adjustment factor based on the collected current data, temperature data and battery health status data, combined with the preset dynamic adjustment factor calculation model ; The dynamic adjustment factor calculation model includes the following formula: ; Among them, I is the absolute value of the real-time current, is the absolute value of the maximum allowable charge and discharge current under the current working conditions, is the real-time temperature, is the reference temperature, is the operating temperature range, SOH is the battery health, 、 、 is the weight coefficient and ; Dynamic voltage range adjustment unit, used to adjust the factor according to the dynamic Dynamically adjusting the initial voltage determination range data to obtain a dynamic voltage interval band, so as to obtain voltage determination range data adjusted in real time; The SOC estimation fusion correction unit is used to perform fusion correction processing based on the SOC estimation results of the open circuit voltage method and the ampere-hour integration method when the battery voltage monitoring data deviates from the voltage judgment range data adjusted in real time, so as to output the corrected SOC value.

[0016] An electronic device, comprising: a processor; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the above-mentioned SOC auxiliary correction method based on the dynamic voltage interval band.

[0017] 3. Beneficial effects Compared with the prior art, the advantages of the present invention are: 1. By establishing a basic battery OCV-SOC curve and defining an initial voltage range, a dynamic adjustment factor is calculated based on real-time current, temperature, and health status, and the voltage determination range is adjusted in real time to form a dynamic voltage range. This dynamic adjustment mechanism fully considers the changing characteristics of the battery under different operating conditions. Compared with the traditional fixed voltage range method, it can more accurately reflect the actual battery state, effectively reducing SOC estimation errors caused by changes in battery operating conditions, thereby improving the accuracy of SOC estimation.

[0018] 2. The current size affects the battery's charge and discharge rate, the temperature has a significant impact on the battery's chemical reaction and internal resistance, and the health status reflects the battery's aging. By incorporating these factors into the calculation of the adjustment factor, the method can adapt to different current, temperature, and battery aging conditions, ensuring accurate SOC estimation in various complex environments, thereby enhancing the system's adaptability to different usage scenarios.

[0019] 3. Lightweight calculation, only simple formula calculation is required, suitable for embedded BMS. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 The SOC correction logic block diagram of the present invention; Figure 2 Generate a flow chart for the dynamic voltage interval band of the present invention; Figure 3 The OCV-SOC curve and voltage platform area of ​​the LFP battery are shown; Figure 4 This is a comparison chart of the dynamic voltage range changes at a current rate of 0.1C; Figure 5 This is a comparison chart of the dynamic voltage band changes at a current rate of 0.2C; Figure 6 This is a comparison chart of the dynamic voltage band changes at a current rate of 0.33C; Figure 7 This is a comparison chart of the dynamic voltage range changes at a current rate of 0.5C. DETAILED DESCRIPTION

[0021] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0022] Example 1: See also Figure 1-3 The present invention provides a technical solution: a SOC auxiliary correction method based on a dynamic voltage interval band, the method comprising the following steps: S1. Establish a basic OCV-SOC curve for the battery based on the battery characteristic test data, and preset an initial voltage range in the voltage platform area; OCV is the open-circuit voltage, or the battery's voltage when there's no load or external current. It forms the basis for the relationship between battery SOC (state of charge) and voltage and is often used to estimate a battery's SOC. A battery's state of charge represents the percentage of energy currently stored in the battery relative to its maximum capacity. SOC describes the remaining charge in the battery, indicating whether it's fully charged or low on power. The voltage plateau region, where the battery's voltage changes relatively little within a certain SOC range, is a crucial reference area for SOC estimation because the battery voltage in this region is less sensitive to SOC changes.

[0023] S2. Determine the dynamic adjustment factor based on the collected current data, temperature data, and battery health status data and the preset dynamic adjustment factor calculation model. ; The dynamic adjustment factor calculation model includes the following formula: ; Among them, I is the absolute value of the real-time current, is the absolute value of the maximum allowable charge and discharge current under the current working conditions, is the real-time temperature, is the reference temperature, is the operating temperature range, SOH is the battery health, 、 、 is the weight coefficient and ; The dynamic adjustment factor is a factor used to adjust the battery SOC estimation in real time, taking into account the battery's real-time operating conditions. It is calculated based on parameters such as battery current, temperature, and health status, and is used to adjust the battery's voltage range. S3, according to the dynamic adjustment factor Dynamically adjusting the initial voltage determination range data to obtain a dynamic voltage interval band, so as to obtain voltage determination range data adjusted in real time; The dynamic voltage band refers to the range within which the battery voltage may vary based on real-time conditions. The dynamic voltage band is adjusted based on real-time current, temperature, and health status to ensure more accurate SOC estimation. S4. When the battery voltage monitoring data deviates from the voltage determination range data adjusted in real time, a fusion correction process is performed based on the SOC estimation results of the open circuit voltage method and the ampere-hour integration method to output a corrected SOC value; Among them, the open circuit voltage method is a commonly used method to estimate SOC by measuring the open circuit voltage of the battery. This method relies on the established OCV-SOC curve relationship; the ampere-hour integration method is a method to estimate SOC by real-time current (usually charging current or discharging current). It is based on the charging and discharging process of the battery and obtains the battery's SOC by integrating the current. The SOC estimation correction is achieved by integrating the SOC estimation results of the open circuit voltage method and the ampere-hour integration method, which can improve the accuracy of the SOC estimation. When the battery voltage deviates from the dynamic voltage range, the estimation results of the two methods are combined for correction to ensure the accuracy of the SOC.

[0024] Specifically, the initial voltage interval range is ,in, ; ; in is the initial offset, obtained through experimental calibration, Indicates that the corresponding open circuit voltage value is obtained by looking up the SOC table.

[0025] The bandwidth of the dynamic voltage interval band is Calculated by the following formula: ; in, is the initial offset, is the expansion coefficient, which is used to control the bandwidth It expands linearly with the increase of .

[0026] The upper and lower limits of the dynamic voltage range satisfy: ; ; in, is the internal resistance of the battery, which can be obtained by looking up the Res(SOC, T, SOH) table.

[0027] Furthermore, based on the dynamic voltage range, setting a trigger condition for SOC correction and determining whether the battery voltage monitoring data meets the trigger condition includes the following steps: When the real-time voltage The modification is triggered when the following conditions are met: or , get correction ; according to exist and SOC reverse check is performed on the curve; when correcting, the SOC reverse check strategy is selected according to the charge and discharge status: the charging status adopts Check back, the discharge status is Reverse check; Get corrections based on the current charge and discharge status If it is in charging state, , if in discharge state, .

[0028] The formula for the fusion correction is: ; in, The SOC value retrieved by the OCV method is: is the SOC value estimated by the ampere-hour integration method, is the weight factor and Negative correlation.

[0029] Among them, the The absolute value of the maximum allowable charge and discharge current of the battery in its current state; ; in: : Current temperature and battery health The results of the table lookup; : Current temperature and battery health The results of the table lookup; : The effective range of the battery operating temperature range (unit: °C or K); ; in: : The maximum temperature allowed for the battery to operate; : The minimum temperature at which the battery is allowed to operate.

[0030] Example 2 A dynamic voltage band-based SOC auxiliary correction system is used to execute the above-mentioned dynamic voltage band-based SOC auxiliary correction method. The system includes: An initial voltage interval band preset unit is used to establish a basic OCV-SOC curve of a battery according to battery characteristic test data, and preset an initial voltage interval band in the voltage platform area; Dynamic adjustment factor calculation unit, used to determine the dynamic adjustment factor based on the collected current data, temperature data and battery health status data, combined with the preset dynamic adjustment factor calculation model ; The dynamic adjustment factor calculation model includes the following formula: ; Among them, I is the absolute value of the real-time current, is the absolute value of the maximum allowable charge and discharge current under the current working conditions, is the real-time temperature, is the reference temperature, is the operating temperature range, SOH is the battery health, 、 、 is the weight coefficient and ; Dynamic voltage range adjustment unit, used to adjust the factor according to the dynamic Dynamically adjusting the initial voltage determination range data to obtain a dynamic voltage interval band, so as to obtain voltage determination range data adjusted in real time; The SOC estimation fusion correction unit is used to perform fusion correction processing based on the SOC estimation results of the open circuit voltage method and the ampere-hour integration method when the battery voltage monitoring data deviates from the voltage judgment range data adjusted in real time, so as to output the corrected SOC value.

[0031] Example 3 An electronic device, comprising: a processor; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the above-mentioned SOC auxiliary correction method based on the dynamic voltage interval band.

[0032] The electronic device proposed in this invention can be embodied as a battery management system terminal or intelligent battery monitoring device. This device integrates a current sensor, a temperature sensor, and a battery health monitoring module, enabling real-time acquisition of current, temperature, and battery health data during battery operation. The device's built-in processor executes a dynamic voltage band-based SOC correction method based on pre-defined algorithms and models.

[0033] During use, the electronic device first establishes the battery's basic OCV-SOC curve based on the battery characteristic test data and presets the initial voltage range band in the voltage platform area. Then, based on the various types of collected data, combined with a preset dynamic adjustment factor calculation model, the dynamic adjustment factor is determined. This model comprehensively considers factors such as the real-time current absolute value, the maximum allowable charge and discharge current absolute value under the current operating conditions, the real-time temperature, the reference temperature, the operating temperature range, and the battery health, and calculates the dynamic adjustment factor through a specific formula. Subsequently, the initial voltage judgment range data is dynamically adjusted according to the dynamic adjustment factor to obtain the dynamic voltage range band and the real-time adjusted voltage judgment range data.

[0034] During battery operation, electronic equipment continuously monitors battery voltage data. When the battery voltage monitoring data deviates from the voltage determination range data adjusted in real time, the device triggers the SOC correction mechanism. At this time, a fusion correction process is performed based on the SOC estimation results of the open circuit voltage method and the ampere-hour integration method. During the fusion correction process, the trigger conditions for the SOC correction are set based on the dynamic range, and it is determined whether the battery voltage monitoring data meets the trigger conditions. The corresponding SOC reverse query strategy is selected according to different charge and discharge states, and finally the corrected SOC value is output according to the fusion correction formula. The fusion correction formula comprehensively considers the SOC value reversed by the OCV method, the SOC value estimated by the ampere-hour integration method, and the negatively correlated weighting factor.

[0035] This electronic device is particularly suitable for applications requiring high accuracy in battery SOC estimation, such as electric vehicles and energy storage systems. By providing real-time, precise SOC correction, it effectively improves the accuracy and reliability of battery management, extends battery life, and ensures stable device operation. The device can synchronize battery status data and corrected SOC values ​​to the cloud or other monitoring platforms via wired interfaces (such as USB, CAN) or wireless transmission methods (such as Bluetooth, Wi-Fi), supporting remote battery monitoring and data analysis, and providing a data basis for optimized battery use and maintenance.

[0036] In order to more clearly illustrate the present invention and its advantages, the method provided by the present invention will be further explained below in combination with specific experimental data.

[0037] Figure 3This is the experimental data of a battery cell used in a certain project. It is used here to show the relationship between the voltage platform and SOC. The original data is as follows (SOC: 1%, voltage: mv): Table 1 Cell experimental data ; This data is obtained by full static test when SOH is 100%. Figure 3 The calculation data of the Central and African plateau period is based on 0-30%, and the calculation data of the plateau period is based on 30-98%). As the battery life decays and the charge and discharge current values ​​change, Figure 4-7 The dynamic voltage curve will be updated with the internal resistance and real-time current of SOH decay.

[0038] Figure 4-7 , is based on Figure 3 And the battery internal resistance corresponding to different current rates (0.1C, 0.2C, 0.33C, 0.5C) and SOC ranges (mΩ) dynamic voltage interval construction (Table 1 data is Figure 4-7 The data in Table 2 are the battery internal resistance corresponding to the SOC range), which aims to reflect the dynamic change characteristics of the voltage range band between different rates (here the constant current only controls the SOC change drawing, in actual use both the current and SOC will change).

[0039] Table 2 Battery internal resistance corresponding to SOC range ; Those skilled in the art will appreciate that all or part of the steps in the above-mentioned embodiment methods can be accomplished by instructing the relevant hardware through a program. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0040] The above embodiments provide a detailed introduction to the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A SOC auxiliary correction method based on dynamic voltage interval band, characterized in that: The method comprises the following steps: S1. Establish a basic OCV-SOC curve for the battery based on the battery characteristic test data, and preset an initial voltage range in the voltage platform area; S2. Determine the dynamic adjustment factor based on the collected current data, temperature data, and battery health status data and the preset dynamic adjustment factor calculation model. ; The dynamic adjustment factor calculation model includes the following formula: ； Among them, I is the absolute value of the real-time current, is the absolute value of the maximum allowable charge and discharge current under the current working conditions, is the real-time temperature, is the reference temperature, is the operating temperature range, SOH is the battery health, 、 、 is the weight coefficient and ; S3, according to the dynamic adjustment factor Dynamically adjusting the initial voltage determination range data to obtain a dynamic voltage interval band, so as to obtain voltage determination range data adjusted in real time; S4. When the battery voltage monitoring data deviates from the voltage determination range data adjusted in real time, a fusion correction process is performed based on the SOC estimation results of the open circuit voltage method and the ampere-hour integration method to output a corrected SOC value.

2. The SOC auxiliary correction method based on dynamic voltage interval band according to claim 1, characterized in that: The initial voltage interval range is , in, ； ； in is the initial offset, obtained through experimental calibration, Indicates that the corresponding open circuit voltage value is obtained by looking up the SOC table.

3. The SOC auxiliary correction method based on dynamic voltage interval band according to claim 2, characterized in that: The bandwidth of the dynamic voltage interval band Calculated by the following formula: ； in, is the initial offset, is the expansion coefficient, which is used to control the bandwidth It expands linearly with the increase of .

4. The SOC auxiliary correction method based on dynamic voltage interval band according to claim 3, characterized in that: The upper and lower limits of the dynamic voltage range satisfy: ； ； in, is the internal resistance of the battery, which can be obtained by looking up the Res(SOC, T, SOH) table.

5. The SOC auxiliary correction method based on a dynamic voltage range according to claim 4, before step S4, the method further comprises: Setting a trigger condition for SOC correction based on the dynamic voltage range and determining whether the battery voltage monitoring data meets the trigger condition includes the following steps: When the real-time voltage The modification is triggered when the following conditions are met: or , get correction ; according to exist and SOC reverse check is performed on the curve; when correcting, the SOC reverse check strategy is selected according to the charge and discharge status: the charging status adopts Check back, the discharge status is Reverse check; Get corrections based on the current charge and discharge status If it is in charging state, , if in discharge state, .

6. The SOC auxiliary correction method based on dynamic voltage interval band according to claim 5, characterized in that: The formula for the fusion correction is: ； in, The SOC value retrieved by the OCV method is: is the SOC value estimated by the ampere-hour integration method, is the weight factor and Negative correlation.

7. The SOC auxiliary correction method based on dynamic voltage interval band according to claim 2, characterized in that: described The absolute value of the maximum allowable charge and discharge current of the battery in its current state; ； in: : Current temperature and battery health The results of the table lookup; : Current temperature and battery health The results of the table lookup; : The effective range of the battery operating temperature range (unit: °C or K); ； in: : The maximum temperature allowed for the battery to operate; : The minimum temperature at which the battery is allowed to operate.

8. A dynamic voltage interval-based SOC auxiliary correction system, configured to execute the dynamic voltage interval-based SOC auxiliary correction method according to any one of claims 1 to 7, characterized in that: The system comprises: An initial voltage interval band preset unit is used to establish a basic OCV-SOC curve of a battery according to battery characteristic test data, and preset an initial voltage interval band in the voltage platform area; Dynamic adjustment factor calculation unit, used to determine the dynamic adjustment factor based on the collected current data, temperature data and battery health status data, combined with the preset dynamic adjustment factor calculation model ; The dynamic adjustment factor calculation model includes the following formula: ； Among them, I is the absolute value of the real-time current, is the absolute value of the maximum allowable charge and discharge current under the current working conditions, is the real-time temperature, is the reference temperature, is the operating temperature range, SOH is the battery health, 、 、 is the weight coefficient and ; Dynamic voltage range adjustment unit, used to adjust the factor according to the dynamic Dynamically adjusting the initial voltage determination range data to obtain a dynamic voltage interval band, so as to obtain voltage determination range data adjusted in real time; The SOC estimation fusion correction unit is used to perform fusion correction processing based on the SOC estimation results of the open circuit voltage method and the ampere-hour integration method when the battery voltage monitoring data deviates from the voltage judgment range data adjusted in real time, so as to output the corrected SOC value.

9. An electronic device, characterized in that: include: processor; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the SOC auxiliary correction method based on a dynamic voltage interval band according to any one of claims 1 to 7.

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