A dynamic reconfigurable energy storage battery system soc calibration method

Abstract

The application belongs to the technical field of new energy power system energy storage, and particularly relates to a dynamic reconfigurable energy storage battery system SOC calibration method, which comprises the following steps: acquiring the voltage of single batteries in each battery module, the current of each battery module and the total current of the battery energy storage system; presetting calibration points, wherein the calibration points comprise voltage calibration points and SOC calibration points; determining the SOC state flag of the battery module according to the voltage and SOC value of the single batteries in the current battery module and in combination with the preset calibration points; judging whether the battery module enters a calibration mode according to the SOC state flag of the battery module; if the calibration mode is entered, the battery module starts calibration and judges whether the calibration is completed in real time. The calibration mode can provide more accurate system SOC information, so that the battery management system can make reasonable charging and discharging control, equalization management and safety protection decisions according to the accurate SOC information, and errors caused by inaccurate SOC can be avoided.

Description

Technical Field

[0001] This invention belongs to the field of energy storage technology for new energy power systems, and specifically relates to a SOC calibration method for a dynamically reconfigurable energy storage battery system. Background Technology

[0002] To meet the diverse needs for battery capacity and power in different scenarios, parallel connection of battery modules is widely adopted in actual battery system design. By connecting multiple battery modules in parallel, the total capacity and output power of the entire battery system can be effectively increased, thereby better adapting to various complex working conditions and providing reliable power support for the stable operation of equipment.

[0003] However, accurate calculation and calibration of the State of Charge (SOC) has become a critical issue that urgently needs to be addressed in the use of parallel battery modules. Currently, the calculation of SOC for parallel battery modules mainly relies on the current information of each module itself. However, in practical applications, due to the influence of various factors, there is a certain error in the module current measurement. Among them, the accuracy of the current acquisition sensor is one of the main factors causing the error. Limited by the current technology and manufacturing cost, the current acquisition sensor cannot achieve absolute accuracy in the measurement process, and there is often a certain deviation between its measured value and the actual current value. This deviation may stem from defects in the sensor's manufacturing process, the influence of environmental factors (such as temperature, electromagnetic interference, etc.) on the sensor's performance, and aging of the sensor during long-term use. Since the calculation of the module SOC is highly dependent on the current measurement data, the current measurement error will inevitably be transmitted to the SOC estimate, resulting in a large error in the module SOC estimate.

[0004] Significant errors in module SOC not only pose a serious challenge to calculating the system SOC but also negatively impact the overall performance of the battery system. Inaccurate system SOC can affect battery system performance, such as allowing continued discharge when the battery's actual charge is low or stopping charging before it is fully charged. This not only shortens battery life but may also create safety hazards. Therefore, improving the accuracy of SOC estimation for parallel battery modules is of significant practical importance. Summary of the Invention

[0005] To overcome the problems in the prior art, this invention proposes a SOC calibration method for a dynamically reconfigurable energy storage battery system.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] This invention provides a method for SOC calibration of a dynamically reconfigurable energy storage battery system, comprising the following steps:

[0008] Step 100: Obtain the voltage of each individual cell in each battery module, the current of each battery module, and the total current of the battery energy storage system;

[0009] Step 200: Preset calibration points, including voltage calibration points and SOC calibration points;

[0010] Step 300: Based on the voltage and SOC value of the individual cells in the current battery module, and in conjunction with the preset calibration points, determine the SOC status flag of the battery module.

[0011] Step 400: Determine whether the battery module has entered calibration mode based on the SOC status flag of the battery module;

[0012] Step 500: If the calibration mode is entered, the battery module will begin calibration and will determine in real time whether the calibration is complete.

[0013] Furthermore, step 100 also includes: determining whether the sum of the currents of the parallel battery modules is equal to the total current of the battery energy storage system; if not, calibrating the currents of the parallel battery modules.

[0014] Furthermore, the current calibration of the parallel battery module includes:

[0015] ;

[0016] In the formula, i For the first i One parallel battery module; N This refers to the total number of parallel battery modules; It is the first i Original current values ​​for each battery module; It is the first i Individual battery module current calibration values; It is the total current of the battery energy storage system; k It is the first k That moment.

[0017] Furthermore, there is a mapping relationship between the voltage calibration point and the SOC calibration point. When the voltage of a single cell in the battery module reaches the preset voltage calibration point value, the SOC of the single cell at this time is the corresponding SOC calibration point value.

[0018] Further, step 300 specifically includes:

[0019] If the voltage of a single cell in the battery module does not reach the preset voltage calibration point value, and the estimated SOC value of the battery module also does not reach the preset SOC calibration point value, the SOC status flag SOC_state of the battery module is set to 0.

[0020] If the voltage of a single cell in the battery module has not reached the preset voltage calibration point value, but the SOC of the battery module has reached the preset SOC calibration point value, the SOC status flag SOC_state of the battery module is set to 1.

[0021] If the voltage of a single cell in the battery module reaches the preset voltage calibration point value, regardless of whether the SOC of the battery module has reached the preset SOC calibration point value, the SOC status flag SOC_state of the battery module will be set to 2.

[0022] Furthermore, in step 400, the conditions for determining whether a battery module has entered calibration mode include: the number of battery modules corresponding to the SOC status flag SOC_state < 2 is not zero; and the sum of the SOC status flags of the corresponding battery modules is not zero.

[0023] Further, in step 500, the battery module begins calibration, including:

[0024] The SOC status flag SOC_state=1 corresponds to a battery module SOC that is limited to the SOC calibration point range.

[0025] The current integral value of the battery module corresponding to the SOC status flag SOC_state=1 is transferred to the battery module corresponding to the SOC status flag SOC_state=0.

[0026] Furthermore, the current integral value corresponding to the battery module with SOC status flag SOC_state=1 is transferred to the battery module with SOC status flag SOC_state=0, including:

[0027] If the number of parallel battery modules is n, the number of modules corresponding to SOC status flag SOC_state=1 is i, and the number of modules corresponding to SOC_state=0 is j;

[0028] Real-time calculation of the integral current value corresponding to the battery module with SOC state flag SOC_state=1 at each moment. And evenly distribute them to the battery modules corresponding to the SOC status flag SOC_state=0. ;

[0029] When SOC_state=0 corresponds to the battery module performing SOC calculation, an additional step is added to the original ampere-hour integral. .

[0030] Furthermore, in step 500, determining in real time whether calibration is complete includes: continuously and in real time judging the SOC status flag of the battery module; when the conditions for entering the calibration mode are no longer met, the battery module will exit the calibration mode, and the calibration process will end.

[0031] Furthermore, one or more voltage calibration points and SOC calibration points are set.

[0032] Compared with the prior art, the present invention has the following technical effects:

[0033] (1) This invention determines the SOC status flag of the battery module by presetting voltage calibration points and SOC calibration points, and combining the voltage and SOC value of individual cells, thereby determining whether the battery module has entered calibration mode. During the calibration process, the SOC of the battery module with SOC status flag 1 is limited, and its current integral value is reasonably transferred to the battery module with SOC status flag 0, effectively reducing the SOC estimation deviation caused by current measurement error. This calibration method can provide more accurate system SOC information, enabling the battery management system (BMS) to make reasonable decisions on charge and discharge control, equalization management, and safety protection based on accurate SOC data, avoiding erroneous control caused by inaccurate SOC, such as continuing to discharge when the actual battery capacity is low or stopping charging before it is fully charged, thereby ensuring the stable operation of the battery system, extending battery life, and reducing safety hazards.

[0034] (2) In the process of acquiring battery module data, this invention adds a step to determine whether the sum of the currents of the parallel battery modules is equal to the total current of the battery energy storage system. If they are not equal, the currents of the parallel battery modules are calibrated. Using a calibration formula, the calibration value of the current for each module is calculated based on information such as the total current of the battery energy storage system, the number of parallel battery modules, and the original current values ​​of each module. This process effectively solves the current measurement errors caused by current acquisition sensor accuracy issues, manufacturing defects, environmental factors, and sensor aging, thus improving the accuracy of the current data for the parallel battery modules.

[0035] (3) The method of the present invention can be adjusted in real time according to different battery module states and working scenarios. By judging the SOC status flag of the battery module in real time, it dynamically determines whether to enter the calibration mode and when to end the calibration process. When the SOC status of the battery module no longer meets the conditions for entering the calibration mode, it automatically exits the calibration mode, ensuring the efficiency and timeliness of the calibration process. This flexible calibration mechanism enables the battery energy storage system to better adapt to various complex working conditions, improving the overall applicability and reliability of the system. Attached Figure Description

[0036] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the process of the present invention;

[0038] Figure 2 It is a dynamically reconfigurable energy storage battery system;

[0039] Figure 3 The voltage and SOC variation curves of the battery cell during discharge;

[0040] Figure 4 This is a schematic diagram showing the SOC changes of the three battery modules;

[0041] Figure 5 A schematic diagram showing the SOC status indicators for the three battery modules;

[0042] Figure 6 A schematic diagram showing the increase in Ah during calibration of modules 1-1 and 1-2;

[0043] Figure 7 for Figure 6 Enlarged image;

[0044] Figure 8 This is a schematic diagram showing the comparison of SOC joint calibration before and after for module 1-1;

[0045] Figure 9 This is a schematic diagram showing the comparison of SOC joint calibration before and after for modules 1-2. Detailed Implementation

[0046] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the specific implementation methods, structures, features, and effects of the technical solutions proposed according to the present invention are described in detail below with reference to the accompanying drawings and preferred embodiments. Specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0047] Reference Figure 2 The dynamically reconfigurable energy storage battery system includes multiple battery packs connected in series, each battery pack includes N battery modules connected in parallel, and the battery pack also includes energy storage elements and a switching module. The switching module can switch the series and parallel connection modes of the energy storage elements and the battery modules.

[0048] In this embodiment, refer to Figure 1 This paper provides a method for SOC calibration of a dynamically reconfigurable energy storage battery system, including the following steps:

[0049] Step 100: Obtain the voltage of each individual cell in each battery module, the current of each battery module, and the total current of the battery energy storage system;

[0050] Step 200: Preset calibration points, including voltage calibration points and SOC calibration points;

[0051] Step 300: Based on the voltage and SOC value of the individual cells in the current battery module, and in conjunction with the preset calibration points, determine the SOC status flag of the battery module.

[0052] Step 400: Determine whether the battery module has entered calibration mode based on the SOC status flag of the battery module;

[0053] Step 500: If the calibration mode is entered, the battery module will begin calibration and will determine in real time whether the calibration is complete.

[0054] The following is a detailed explanation of each of the above steps:

[0055] Step 100: Obtain the voltage of individual cells in each battery module, the current of each battery module, and the total current of the battery energy storage system.

[0056] The system acquires the voltage of individual cells in each battery module, the current of each battery module, and the total current of the battery energy storage system. The voltage data of individual cells reflects the health status and charging / discharging status of each cell and is an important indicator for evaluating the performance of the battery module. The current information of each battery module is used to analyze the charging / discharging power and energy flow of each battery module. The total current of the battery energy storage system represents the energy exchange between the entire battery system and external loads or charging equipment.

[0057] A crucial prerequisite for obtaining these parameters is ensuring that the sum of the currents of the parallel battery modules equals the total current of the battery energy storage system. This is based on fundamental circuit principles; ideally, the sum of the currents in each branch of a parallel circuit should equal the current in the main circuit. However, in practical applications, factors such as accuracy errors in current acquisition sensors and interference from the measurement environment may cause the measured sum of the currents of the individual battery modules to differ from the total current of the battery energy storage system.

[0058] If the above conditions are not met, the current of the parallel battery module needs to be calibrated. The specific calibration formula is as follows:

[0059] ;

[0060] In the formula, i For the first i One parallel battery module; N This refers to the total number of parallel battery modules; It is the first i Original current values ​​for each battery module; It is the first i Individual battery module current calibration values; It is the total current of the battery energy storage system; k It is the first k That moment.

[0061] Step 200: Preset calibration points, including voltage calibration points and SOC calibration points.

[0062] The preset voltage calibration point CaliVol_value and SOC calibration point CaliSOC_value are calibrated using offline test data.

[0063] Offline testing involves conducting comprehensive charge-discharge tests on a battery under specific experimental conditions, recording the battery's voltage and state of charge (SOC) data under different states. By analyzing and fitting this large amount of test data, corresponding voltage and SOC calibration points are determined. Specifically, offline testing requires charging and discharging the battery at different temperatures and rates. One or more voltage points within the range of large voltage variations are selected as voltage calibration points, and the corresponding SOC values ​​are obtained as SOC calibration points. Figure 3 It is the discharge curve of the battery cell, such as Figure 3 As shown, the cell is discharged at a rate of 0.5C, and 3.0V is selected as the voltage calibration point. The corresponding SOC value is 5.23%, meaning the SOC calibration point is 5.23%. This correspondence reflects the inherent relationship between the voltage of a single battery cell and its SOC. That is, during the discharge process, when the voltage of a single battery cell in the battery module reaches CaliVol_value, its theoretical corresponding SOC should be CaliSOC_value.

[0064] During actual operation, the battery management system's sensors monitor the voltage and estimated state of charge (SOC) of individual cells within the battery module in real time. If the voltage of a single cell reaches the preset CaliVol_value, but the estimated SOC value is not CaliSOC_value, this indicates an error in the current SOC estimation. In this case, the system will automatically calibrate the SOC to CaliSOC_value to ensure the accuracy of the SOC value.

[0065] To accommodate the calibration requirements of batteries under different operating conditions, voltage calibration points (CaliVol_value) and state-of-the-art (SOC) calibration points (CaliSOC_value) can be set during both the charging and discharging processes. Furthermore, considering the complex changes in battery performance at different stages, the system allows for the setting of multiple sets of calibration points. Setting multiple sets of calibration points can more accurately cover the entire operating range of the battery, improving the accuracy and effectiveness of calibration. For example, the battery's voltage-SOC characteristics may differ between the shallow charge / discharge phase and the deep charge / discharge phase. By setting multiple sets of calibration points, more accurate calibration can be performed for different phases, thereby improving the overall performance of the battery management system.

[0066] Step 300: Based on the voltage and SOC value of the individual cells in the current battery module, and in conjunction with the preset calibration points, determine the SOC status flag of the battery module.

[0067] The value of the SOC status flag SOC_state is determined based on a combination of the voltage, SOC value, and preset calibration points of the individual cells in the current battery module.

[0068] The SOC status flag SOC_state = 0 is set to 0 when: the voltage of a single cell in the battery module has not reached the preset voltage calibration point CaliVol_value, and the estimated SOC value of the battery module has also not reached the preset SOC calibration point CaliSOC_value. This situation typically indicates that the battery module is in a relatively normal operating state, having neither reached the voltage calibration threshold nor the specific SOC level required for calibration.

[0069] The SOC status flag SOC_state = 1 is determined as follows: If the voltage of a single cell in the battery module has not reached the preset voltage calibration point CaliVol_value, but the SOC of the battery module has reached the preset SOC calibration point CaliSOC_value, then the SOC status flag SOC_state is set to 1. This may indicate certain special circumstances in the SOC estimation of the battery module, such as changes in the battery's voltage-SOC characteristics, or deviations in the SOC estimation algorithm under certain circumstances, requiring further attention and analysis.

[0070] The condition for setting the SOC status flag SOC_state = 2 is as follows: Once the voltage of a single cell in the battery module reaches the preset voltage calibration point CaliVol_value, the SOC status flag SOC_state will be set to 2, regardless of whether the battery module's SOC has reached the preset SOC calibration point CaliSOC_value. This condition reflects the emphasis on voltage thresholds, because a single cell's voltage reaching the calibration point often means that the battery module is approaching or has reached a specific operating boundary, such as near the charging cutoff voltage or discharging cutoff voltage, requiring corresponding measures to prevent overcharging or over-discharging of the battery.

[0071] Step 400: Determine whether the battery module has entered calibration mode based on the SOC status flag of the battery module.

[0072] A comprehensive analysis of the battery modules was performed, calculating all battery modules with SOC_state < 2 and their corresponding SOC_state values. Parallel battery modules will only enter calibration mode when both of the following conditions are met:

[0073] (1) First condition: The number of battery modules corresponding to the SOC state flag SOC_state < 2 is not zero;

[0074] (2) The second condition: the sum of the SOC status flags of the corresponding battery modules is not zero.

[0075] The first condition indicates that a certain number of battery modules are not fully charged (SOC_state = 2 is considered close to full charge), necessitating calibration. The second condition further ensures that valid SOC status information is available for calibration, preventing accidental entry into calibration mode when there is no actual state difference. If the above conditions are met, the parallel battery modules enter calibration mode; otherwise, they remain in non-calibration mode.

[0076] Step 500: If the calibration mode is entered, the battery module will begin calibration and will determine in real time whether the calibration is complete.

[0077] Once in calibration mode, the system will operate according to the following rules:

[0078] SOC Limitation and Current Integration Transfer: The SOC of the battery module corresponding to SOC_state=1 will be limited to CaliSOC_value, while the current integration value of the battery module corresponding to SOC_state=1 will be transferred to the module corresponding to SOC_state=0.

[0079] Real-time calculation and allocation of current integral value: If the number of parallel battery modules is n, n≤N, the number of modules corresponding to SOC status flag SOC_state=1 is i, and the number of modules corresponding to SOC_state=0 is j. The current integral value corresponding to the battery module with SOC status flag SOC_state=1 at each moment is calculated in real time. And evenly distribute them to the battery modules corresponding to the SOC status flag SOC_state=0. When SOC_state=0, the battery module will add an additional ampere-hour to its original integral value during SOC calculation. .

[0080] The battery module's SOC status flag is continuously monitored in real time. When the two conditions for entering calibration mode are no longer met (i.e., the number of modules corresponding to SOC_state < 2 is zero, or the sum of the corresponding SOC_states is zero), the battery module will exit calibration mode, and the calibration process will end. Afterward, the battery module will resume normal operation and SOC estimation.

[0081] Reference Figure 2 This embodiment uses battery module 1-1, battery module 1-2, and battery module 1-3 as examples to illustrate the above-mentioned invention.

[0082] Preset calibration points include a voltage calibration point CaliVol_value=3.1V and a SOC calibration point CaliSOC_value6.1%.

[0083] That is, when discharging, when the voltage of the lowest single cell reaches 3.1V, the corresponding SOC should be 6.1%. If the SOC is greater than 6.1%, it should be calibrated to 6.1%. If the voltage does not reach 3.1V, the SOC should not be less than 6.1%. Only when the voltage of the lowest single cell is less than 3.1V is the SOC allowed to continue to decrease from 6.1%.

[0084] When the voltage of a single cell in the battery module does not reach CaliVol_value and the SOC of the battery module does not reach CaliSOC_value, the SOC status flag of the battery module is SOC_state=0.

[0085] When the voltage of a single cell in the battery module does not reach CaliVol_value, but the SOC of the battery module reaches CaliSOC_value, the SOC status flag of the battery module is SOC_state=1.

[0086] When the voltage of a single cell in the battery module reaches CaliVol_value, regardless of whether the SOC of the battery module has reached CaliSOC_value, the SOC status flag of the battery module is SOC_state=2.

[0087] like Figure 4 These are the SOC curves for the three battery modules. Figure 5 These are the SOC_state values ​​of the three battery modules. It can be seen that battery modules 1-3 have an underestimated SOC, while battery modules 1-1 and 1-2 have overestimated SOC. When the voltage of the lowest single cell in battery module 1-3 does not reach 3.1V, its SOC drops to 6.1%, which should remain at 6.1% and should not continue to decrease. At this point, the SOC_state flag for battery modules 1-3 is set to 2, and joint calibration begins.

[0088] Calculate the battery modules corresponding to SOC_state < 2 and their corresponding SOC_state values. Parallel battery modules enter calibration mode if and only if the number of battery modules corresponding to SOC_state < 2 is not zero and the sum of their corresponding SOC_state values ​​is not zero; otherwise, they enter non-calibration mode.

[0089] At the start of the joint calibration, the SOC_state of battery module 1-1, battery module 1-2 and battery module 1-3 are 0, 0 and 1 respectively. That is, the number of modules corresponding to SOC_state < 2 is not zero, and the sum of the corresponding SOC_state is not zero. Then the calibration mode is entered.

[0090] When entering calibration mode, the SOC of the battery module corresponding to SOC_state=1 will be limited to CaliSOC_value, while the current integral value of the battery module corresponding to SOC_state=1 will be transferred to the battery module corresponding to SOC_state=0; the number of parallel battery modules is n, the number of modules corresponding to SOC_state=1 is i, and the number of modules corresponding to SOC_state=0 is j.

[0091] Integrate the current of battery modules 1-3 in ampere-hours. And divide the points equally. . It is through the current of battery modules 1-3. This is the time interval between two current samplings.

[0092] Battery module 1-1 and battery module 1-2, based on their original current integrals, further increase... This causes battery modules 1-1 and 1-2 to drop more rapidly, thereby achieving the purpose of SOC calibration. Figure 6 and Figure 7 Battery module 1-1 and battery module 1-2 are shown. .

[0093] Figure 8 The comparison of SOC before and after joint calibration of battery module 1-1 is shown. It can be seen that without joint calibration, the SOC of this module will have a large jump when the voltage of a single cell drops to 3.1V, while after using the joint calibration algorithm, the SOC decreases smoothly without jump.

[0094] Figure 9 The comparison of SOC before and after joint calibration of battery modules 1-2 is shown. It can be seen that without joint calibration, the SOC of this module will have a large jump when the voltage of a single cell drops to 3.1V, while after using the joint calibration algorithm, the SOC decreases smoothly without any jump.

[0095] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention 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 the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for SOC calibration of a dynamically reconfigurable energy storage battery system, characterized in that, Includes the following steps: Step 100: Obtain the voltage of each individual cell in each battery module, the current of each battery module, and the total current of the battery energy storage system; Step 200: Preset calibration points, including voltage calibration points and SOC calibration points; Step 300: Based on the voltage and SOC value of the individual cells in the current battery module, and in conjunction with the preset calibration points, determine the SOC status flag of the battery module. If the voltage of a single cell in the battery module does not reach the preset voltage calibration point value, and the estimated SOC value of the battery module also does not reach the preset SOC calibration point value, the SOC status flag SOC_state of the battery module is set to 0. If the voltage of a single cell in the battery module has not reached the preset voltage calibration point value, but the SOC of the battery module has reached the preset SOC calibration point value, the SOC status flag SOC_state of the battery module is set to 1. If the voltage of a single cell in the battery module reaches the preset voltage calibration point value, regardless of whether the SOC of the battery module reaches the preset SOC calibration point value, the SOC status flag SOC_state of the battery module is set to 2. Step 400: Determine whether the battery module has entered calibration mode based on the SOC status flag of the battery module, including: if and only if the number of battery modules corresponding to the SOC status flag SOC_state < 2 is not zero; and the sum of the SOC status flags of the corresponding battery modules is not zero; Step 500: If the calibration mode is entered, the battery module will begin calibration and will determine in real time whether the calibration is complete. The battery module begins calibration, including: the current integral value corresponding to the battery module with SOC status flag SOC_state=1 is transferred to the battery module with SOC status flag SOC_state=0, specifically including: If the number of parallel battery modules is n, the number of modules corresponding to SOC status flag SOC_state=1 is i, and the number of modules corresponding to SOC_state=0 is j; Real-time calculation of the integral current value corresponding to the battery module with SOC state flag SOC_state=1 at each moment. And evenly distribute them to the battery modules corresponding to the SOC status flag SOC_state=0. ; When SOC_state=0 corresponds to the battery module performing SOC calculation, an additional step is added to the original ampere-hour integral. .

2. The SOC calibration method for a dynamically reconfigurable energy storage battery system according to claim 1, characterized in that, Step 100 further includes: determining whether the sum of the currents of the parallel battery modules is equal to the total current of the battery energy storage system; if not, calibrating the currents of the parallel battery modules.

3. The SOC calibration method for a dynamically reconfigurable energy storage battery system according to claim 2, characterized in that, Calibrling the current of the parallel battery module includes: ； In the formula, i For the first i One parallel battery module; N This refers to the total number of parallel battery modules; It is the first i Original current values ​​for each battery module; It is the first i Individual battery module current calibration values; It is the total current of the battery energy storage system; k It is the first k That moment.

4. The SOC calibration method for a dynamically reconfigurable energy storage battery system according to claim 1, characterized in that, There is a mapping relationship between the voltage calibration point and the SOC calibration point. When the voltage of a single cell in the battery module reaches the preset voltage calibration point value, the SOC of the single cell at this time is the corresponding SOC calibration point value.

5. The SOC calibration method for a dynamically reconfigurable energy storage battery system according to claim 1, characterized in that, In step 500, the battery module begins calibration, which further includes: The SOC status flag SOC_state=1 indicates that the SOC of the battery module is limited to the SOC calibration point range.

6. The SOC calibration method for a dynamically reconfigurable energy storage battery system according to claim 1, characterized in that, In step 500, determining in real time whether calibration is complete includes: continuously and in real time judging the SOC status flag of the battery module; when the conditions for entering the calibration mode are no longer met, the battery module will exit the calibration mode, and the calibration process will end.

7. The SOC calibration method for a dynamically reconfigurable energy storage battery system according to claim 1, characterized in that, One or more voltage calibration points and SOC calibration points can be set.

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