Battery pack capacity dynamic calibration method and system based on multi-time scale model coupling

Abstract

The invention provides a battery pack capacity dynamic calibration method and system based on multi-time scale model coupling. The method comprises the following steps: collecting data in real time in the charging and discharging process of a battery pack, and identifying the real-time polarization impedance of each single battery on line by using a second-order RC equivalent circuit model; constructing an impedance-capacity coupling model containing a linear attenuation item and an exponential attenuation item taking polarization impedance as an independent variable, and estimating the current maximum available capacity of the single body; the maximum capacity and the impedance voltage drop are comprehensively considered, and the residual discharge time is predicted to lock the short-plate battery; and calculating an inflection point compensation amount according to the impedance change rate of the short-plate battery, and deducting the compensation amount from the theoretical residual capacity of the battery pack to obtain a calibrated actual available capacity. The method can solve the technical problems that the nonlinear capacity diving phenomenon in the later stage of battery aging is difficult to predict in the prior art, and the battery pack is virtually high in electric quantity and suddenly shut down due to the short plate effect caused by single impedance deterioration cannot be effectively handled.

Description

Technical Field

[0001] This invention relates to the field of battery management technology, and more specifically to a method and system for dynamic calibration of battery pack capacity based on multi-timescale model coupling. Background Technology

[0002] With the increasing popularity of new energy vehicles and energy storage systems, the accurate estimation of the remaining capacity (SOC) and state of health (SOH) of lithium-ion battery packs has become a core task of battery management systems, despite existing technological limitations. Current technologies primarily rely on the ampere-hour integration method and the open-circuit voltage method for battery capacity calculation. The ampere-hour integration method calculates the charge by integrating the current over time, but it suffers from estimation drift due to accumulated sensor errors. While the open-circuit voltage method can calibrate errors, it requires the battery to remain stationary for extended periods and cannot be corrected in real-time during dynamic operation.

[0003] Furthermore, the battery degradation process is not entirely linear. Towards the end of the battery's lifespan, a rapid decline in capacity often occurs. Existing SOH (State of Harmony) assessment models typically rely on simple linear fitting based on the number of cycles or time, making it difficult to predict this non-linear inflection point.

[0004] For battery packs composed of multiple individual cells connected in series, the problem is more complex. According to the "weakest link" effect, the actual usable capacity of a battery pack depends on the worst-performing cell. In real-world operating conditions, the internal resistance of a severely aged cell increases significantly. During high-current discharge, the terminal voltage of this cell will prematurely reach its cutoff voltage due to the large impedance voltage drop, causing the battery pack to suddenly shut down even though the BMS indicates there is still remaining charge. Existing capacity estimation methods often ignore the coupling relationship between real-time impedance changes at the microscopic level and nonlinear capacity decay at the macroscopic level, failing to accurately capture the "false" capacity drop caused by the deterioration of polarization impedance in the weakest cell, thus leading to system operational risks. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention proposes a dynamic calibration method and system for battery pack capacity based on multi-timescale model coupling. This addresses the technical problems in existing technologies, such as the inability to accurately predict the nonlinear capacity drop in the later stages of battery aging and the difficulty in dynamically and accurately calibrating the actual usable capacity of the battery pack based on the real-time impedance differences of individual cells.

[0006] The technical solution adopted in this invention is to identify the real-time polarization impedance of a single cell online through a second-order RC equivalent circuit model, and input it as a key variable into an impedance-capacity coupling model containing linear decay terms and exponential decay terms to determine the short-term cell limited by polarization impedance. Based on the impedance change rate of the short-term cell, the inflection point compensation amount is calculated to dynamically deduct and calibrate the theoretical capacity of the battery pack.

[0007] In the first feasible approach, a method for dynamic calibration of battery pack capacity based on multi-timescale model coupling is provided, including: During the charging and discharging process of the battery pack, the terminal voltage, operating current and temperature data of each cell in the battery pack are acquired in real time. Substitute the terminal voltage and operating current into the second-order RC equivalent circuit model, identify the model parameters, and calculate the real-time polarization impedance of each individual cell. An impedance-capacity coupled attenuation model is constructed to estimate the current maximum usable capacity of a single cell based on the real-time polarization impedance. Based on the current maximum available capacity and the real-time polarization impedance, the remaining discharge time of each individual cell to reach the cutoff voltage is predicted, and the cell with the shortest remaining discharge time is determined as the short-term cell. Calculate the inflection point compensation amount of the short-plate battery, and subtract the inflection point compensation amount from the theoretical remaining capacity of the battery pack to obtain the actual usable remaining capacity of the calibrated battery pack.

[0008] Furthermore, the model parameters are identified using a recursive least squares method with a forgetting factor, including: A forgetting factor is introduced to exponentially decay the weights of historical data, the identification matrix is ​​updated in real time, and the model parameters are calculated. The historical data represents the sequence of operating current and terminal voltage collected before the current sampling time.

[0009] Furthermore, the terminal voltage and operating current are substituted into a second-order RC equivalent circuit model to identify the model parameters and calculate the real-time polarization impedance of each individual cell, including: Using the operating current as the system excitation input and the terminal voltage as the system observation output, a second-order RC equivalent circuit model is constructed. Based on the second-order RC equivalent circuit model, identify the model parameters in the terminal voltage of each battery, including the ohmic internal resistance, the first polarization voltage, and the second polarization voltage. The real-time polarization impedance is calculated based on the first polarization voltage and the second polarization voltage. The specific calculation formula is as follows: in, Indicates real-time polarization impedance. Indicates the first polarization voltage. Indicates the second polarization voltage. It represents electric current.

[0010] Furthermore, the impedance-capacity coupling attenuation model is expressed as: in, Indicates the current maximum available capacity. Indicates the design capacity. Indicates accumulated energy throughput. Indicates real-time polarization impedance. Indicates the reference impedance. , , Represents the model coefficients.

[0011] Furthermore, the battery temperature is collected in real time, and the model coefficients are dynamically adjusted according to a preset Arrhenius temperature relationship function. , , and reference impedance .

[0012] Furthermore, the formula for calculating the cumulative energy throughput is as follows: in, Indicates accumulated energy throughput. Indicates time The current, Indicates time The voltage.

[0013] Furthermore, based on the current maximum available capacity and the real-time polarization impedance, the remaining discharge time of each battery before reaching the cutoff voltage is predicted, and the battery with the shortest remaining discharge time is determined as the weakest link battery, including: For each cell in the battery pack, obtain the current remaining capacity of each cell; The current remaining capacity is calculated based on the ampere-hour integral method combined with the maximum available capacity; Based on the following voltage prediction equation, the remaining discharge time for each battery to reach the preset cutoff voltage is calculated according to the maximum available capacity and current remaining capacity of each battery: in, Indicates the preset cutoff voltage. This represents the preset mapping function between the battery open-circuit voltage and the state of charge. Indicates the current remaining capacity. This represents the load current at the current moment. Indicates the remaining discharge time. Indicates the current maximum available capacity. This indicates the ohmic internal resistance included in the model parameters. Indicates real-time polarization impedance; The battery with the shortest remaining discharge time is identified as the short-term battery.

[0014] Preferably, the inflection point compensation amount of the short-plate battery is calculated, and the inflection point compensation amount is subtracted from the theoretical remaining capacity of the battery pack to obtain the calibrated actual usable remaining capacity of the battery pack, including: The inflection point compensation amount of the short-plate battery is calculated based on the current maximum available capacity of the short-plate battery and the rate of change of real-time polarization impedance. When the first-order partial derivative of the rate of change of the current maximum available capacity and the real-time polarization impedance of the short-plate battery is greater than the preset decay acceleration threshold, it is determined that the short-plate battery has entered the nonlinear drop zone, and the inflection point compensation amount is deducted from the theoretical remaining capacity of the battery pack. When the first-order partial derivative of the rate of change of the current maximum available capacity and the real-time polarization impedance of the short-plate battery is less than or equal to the preset decay acceleration threshold, the inflection point compensation is set to zero.

[0015] Furthermore, the inflection point compensation amount of the short-plate battery is calculated based on the current maximum usable capacity and the rate of change of real-time polarization impedance. The calculation formula is as follows: in, Indicates the inflection point compensation amount. This represents the compensation weighting coefficient. This indicates the current maximum usable capacity of the short-plate battery. This represents the real-time polarization impedance of the short-plate battery. This represents the impedance change trend within a preset time window.

[0016] In conjunction with the first feasible approach, the second feasible approach provides a battery pack capacity dynamic calibration management system 21 based on multi-timescale model coupling, including: Sensor module 22 is used to acquire the terminal voltage, operating current and temperature data of each cell in the battery pack in real time during the charging and discharging process of the battery pack. The model building module 23 is used to substitute the terminal voltage and operating current into the second-order RC equivalent circuit model, identify the model parameters, and calculate the real-time polarization impedance of each individual cell. The capacity estimation module 24 is used to construct an impedance-capacity coupling attenuation model and estimate the current maximum usable capacity of a single cell based on the real-time polarization impedance. The short-board battery positioning module 25 is used to predict the remaining discharge time of each individual battery to reach the cutoff voltage based on the current maximum available capacity and the real-time polarization impedance, and to determine the battery with the shortest remaining discharge time as the short-board battery. The capacity calibration module 26 is used to calculate the inflection point compensation amount of the short-board battery and subtract the inflection point compensation amount from the theoretical remaining capacity of the battery pack to obtain the actual usable remaining capacity of the calibrated battery pack.

[0017] As can be seen from the above technical solution, the beneficial technical effects of the present invention are as follows: 1. This invention constructs an impedance-capacity coupled degradation model driven by real-time polarization impedance, which not only describes the linear degradation in the early stage of battery aging but also accurately captures the nonlinear inflection point caused by the loss of active lithium in the later stage of battery aging. This allows for precise capacity calibration when the battery is about to enter a rapid degradation period, effectively preventing sudden system shutdown caused by poor consistency among individual cells within the battery pack.

[0018] 2. By comprehensively considering the maximum usable capacity and real-time impedance voltage drop, this invention can accurately pinpoint the shortest-capacity battery that limits the overall discharge capacity of the battery pack. It uses derivative methods to calculate the inflection point compensation and dynamically deducts from the theoretical capacity, eliminating artificially high charge levels caused by the deterioration of the short-capacity cell's internal resistance. This ensures that the remaining capacity displayed by the system is truly usable, thus improving system safety.

[0019] 3. By using a second-order RC equivalent circuit model in conjunction with a recursive least squares method with a forgetting factor, the ohmic internal resistance and polarization impedance can be separated in real time. Combined with the Arrhenius temperature compensation mechanism, the capacity calibration algorithm can maintain high robustness and real-time performance under different temperatures, different aging stages and dynamic operating conditions. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0021] Figure 1 This is a flowchart of the method in Embodiment 1 of the present invention; Figure 2 This is a system structure diagram of Embodiment 2 of the present invention; Figure label: 21- Battery pack capacity dynamic calibration management system based on multi-timescale model coupling; 22- Sensor module; 23- Model building module; 24- Capacity estimation module; 25- Short-board battery location module; 26- Capacity calibration module. Detailed Implementation

[0022] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0023] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0024] Example 1 This embodiment provides a dynamic calibration method for battery pack capacity based on multi-timescale model coupling. The working principle of Embodiment 1 is explained in detail below: The method flowchart of this embodiment is as follows: Figure 1 As shown, this includes: real-time acquisition of terminal voltage, operating current, and temperature data of each series-connected cell in the battery pack during the charging and discharging process; Substitute the terminal voltage and operating current into the discretized state equation of the second-order RC equivalent circuit model, identify the model parameters, and calculate the real-time polarization impedance of each individual cell. An impedance-capacity coupled attenuation model is constructed to estimate the current maximum usable capacity of a single cell based on the real-time polarization impedance. Based on the current maximum available capacity and the real-time polarization impedance, the remaining discharge time of each individual cell to reach the cutoff voltage is predicted, and the cell with the shortest remaining discharge time is determined as the short-term cell. Calculate the inflection point compensation amount of the short-plate battery, and subtract the inflection point compensation amount from the theoretical remaining capacity of the battery pack to obtain the actual usable remaining capacity of the calibrated battery pack.

[0025] In this embodiment, further, during battery operation, the microcontroller first constructs a second-order RC equivalent circuit model, which includes an ohmic internal resistance, a first RC parallel circuit, and a second RC parallel circuit. To obtain accurate battery internal states in real time, this embodiment employs recursive least squares with a forgetting factor (FF-RLS) for online identification. The specific operation is as follows: Define the input vector at the current sampling time k: in, This represents the input vector at the current sampling time k. In this embodiment, the forgetting factor ranges from (0.95, 0.99). The forgetting factor is set accordingly. This forgetting factor is used for historical data (i.e., time points). The weights of previous current / voltage sequences are exponentially decayed. Since the internal chemical state of the battery (such as temperature and SOC) changes dynamically over time, the current and voltage data collected too early reflect the battery's past state (e.g., high internal resistance at low temperatures) and cannot accurately characterize the current features. By introducing a forgetting factor, earlier current / voltage data are assigned exponentially decreasing weights, rapidly reducing their contribution to parameter identification and ensuring that the model can quickly track the battery's current true impedance changes.

[0026] By iteratively updating the gain matrix and covariance matrix, the current ohmic internal resistance and the voltage response of the polarization element are output in real time.

[0027] The real-time polarization impedance is calculated based on the identified first and second polarization voltages, using the following formula: in, Indicates real-time polarization impedance. Indicates the first polarization voltage. Indicates the second polarization voltage. It represents electric current.

[0028] In this embodiment, an impedance-capacity coupling degradation model is further introduced to estimate the current maximum usable capacity of a single cell. The impedance-capacity coupling degradation model is expressed as follows: in, Indicates the current maximum available capacity. Indicates the design capacity. Indicates accumulated energy throughput. Indicates real-time polarization impedance. Indicates the reference impedance. , , Represents the model coefficients.

[0029] In this embodiment, the microcontroller reads the battery temperature in real time and dynamically adjusts the model coefficients according to a preset Arrhenius temperature relationship function. , , and reference impedance For example, at low temperatures, the reference impedance will increase to prevent the impedance increase caused by the low temperature itself from falsely triggering the aging judgment.

[0030] In this embodiment, further, The historical cumulative energy throughput is obtained by integrating the product of current and voltage. The formula for calculating the cumulative energy throughput is as follows: in, Indicates accumulated energy throughput. Indicates time The current, Indicates time The voltage. The linear term ( This term is used to represent the linear capacity loss of a battery in the early stages of aging caused by the thickening of the solid electrolyte interphase (SEI) film.

[0031] In a battery pack, the system's range is often determined not by the battery with the smallest capacity, but by the battery that reaches its cutoff voltage first. In this embodiment, based on the current maximum available capacity and the real-time polarization impedance, the remaining discharge time of each battery before reaching its cutoff voltage is predicted, and the battery with the shortest remaining discharge time is identified as the bottleneck battery, including: Obtain the load current at the current moment; For each cell in the battery pack, obtain the current remaining capacity of each cell; The current remaining capacity is calculated based on the ampere-hour integral method combined with the maximum available capacity; Based on the following voltage prediction equation, the remaining discharge time for each battery to reach the preset cutoff voltage is calculated according to the maximum available capacity and current remaining capacity of each battery: in, Indicates the preset cutoff voltage. This represents the preset mapping function between the battery open-circuit voltage and the state of charge. Indicates the current remaining capacity. This represents the load current at the current moment. Indicates the remaining discharge time. Indicates the current maximum available capacity. This indicates the ohmic internal resistance included in the model parameters. Indicates real-time polarization impedance; Furthermore, the battery with the shortest remaining discharge time is identified as the weakest link battery. This step considers both the battery's capacity limitation and impedance, avoiding misjudgments caused by simply comparing capacity.

[0032] In this embodiment, the system further adjusts the total capacity based on the state of the short-pole battery, and the specific steps include: The inflection point compensation amount of the short-plate battery is calculated based on the current maximum available capacity and the rate of change of real-time polarization impedance. The calculation formula is as follows: in, Indicates the inflection point compensation amount. This represents the compensation weighting coefficient. This indicates the current maximum usable capacity of the short-plate battery. This represents the real-time polarization impedance of the short-plate battery. This represents the impedance change trend within a preset time window.

[0033] The system continuously monitors the sensitivity of the capacity of the short-circuit battery to impedance, i.e., the first-order partial derivative. When the first-order partial derivative of the current maximum usable capacity and the rate of change of real-time polarization impedance of the short-plate battery is greater than the preset decay acceleration threshold, it is determined that the short-plate battery has entered the nonlinear drop zone. A small increase in internal resistance will cause the capacity to drop sharply, and the inflection point compensation amount is deducted from the theoretical remaining capacity of the battery pack. When the first-order partial derivative of the rate of change of the current maximum available capacity and the real-time polarization impedance of the short-plate battery is less than or equal to the preset decay acceleration threshold, it indicates that the battery is in a stable decay period and no additional compensation is required. The inflection point compensation amount is set to zero.

[0034] Example 2 In conjunction with the method provided in Example 1, Example 2 provides a battery pack capacity dynamic calibration management system based on multi-timescale model coupling, the system structure diagram of which is shown below. Figure 2 As shown, it includes: The sensor module is used to acquire the terminal voltage, operating current, and temperature data of each cell in the battery pack in real time during the charging and discharging process.

[0035] The model building module is used to substitute the terminal voltage and operating current into the second-order RC equivalent circuit model, identify the model parameters, and calculate the real-time polarization impedance of each individual cell.

[0036] The capacity estimation module is used to construct an impedance-capacity coupling attenuation model and estimate the current maximum usable capacity of a single cell based on the real-time polarization impedance.

[0037] The short-board battery positioning module is used to predict the remaining discharge time of each individual battery to reach the cutoff voltage based on the current maximum available capacity and the real-time polarization impedance, and to determine the battery with the shortest remaining discharge time as the short-board battery.

[0038] The capacity calibration module is used to calculate the inflection point compensation amount of the short-board battery and subtract the inflection point compensation amount from the theoretical remaining capacity of the battery pack to obtain the actual usable remaining capacity of the calibrated battery pack.

[0039] This invention can solve the technical problems of existing technologies, such as the difficulty in predicting the nonlinear capacity drop in the later stages of battery aging, and the inability to effectively deal with the short-board effect caused by the deterioration of individual cell impedance, which leads to the battery pack having an inflated capacity and sudden shutdown.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for dynamic calibration of battery pack capacity based on multi-timescale model coupling, characterized in that, include: During the charging and discharging process of the battery pack, the terminal voltage, operating current and temperature data of each cell in the battery pack are acquired in real time. Substitute the terminal voltage and operating current into the second-order RC equivalent circuit model, identify the model parameters, and calculate the real-time polarization impedance of each individual cell. An impedance-capacity coupled attenuation model is constructed to estimate the current maximum usable capacity of a single cell based on the real-time polarization impedance. Based on the current maximum available capacity and the real-time polarization impedance, the remaining discharge time of each individual cell to reach the cutoff voltage is predicted, and the cell with the shortest remaining discharge time is determined as the short-term cell. Calculate the inflection point compensation amount of the short-plate battery, and subtract the inflection point compensation amount from the theoretical remaining capacity of the battery pack to obtain the actual usable remaining capacity of the calibrated battery pack.

2. The battery pack capacity dynamic calibration method based on multi-timescale model coupling according to claim 1, characterized in that, The model parameters are identified using a recursive least squares method with a forgetting factor, including: A forgetting factor is introduced to exponentially decay the weights of historical data, the identification matrix is ​​updated in real time, and the model parameters are calculated. The historical data represents the sequence of operating current and terminal voltage collected before the current sampling time.

3. The battery pack capacity dynamic calibration method based on multi-timescale model coupling according to claim 1, characterized in that, Substituting the terminal voltage and operating current into a second-order RC equivalent circuit model, the model parameters are identified and the real-time polarization impedance of each individual cell is calculated, including: Using the operating current as the system excitation input and the terminal voltage as the system observation output, a second-order RC equivalent circuit model is constructed. Based on the second-order RC equivalent circuit model, identify the model parameters in the terminal voltage of each battery, including the ohmic internal resistance, the first polarization voltage, and the second polarization voltage. The real-time polarization impedance is calculated based on the first polarization voltage and the second polarization voltage. The specific calculation formula is as follows: in, Indicates real-time polarization impedance. Indicates the first polarization voltage. Indicates the second polarization voltage. It represents electric current.

4. The battery pack capacity dynamic calibration method based on multi-timescale model coupling according to claim 1, characterized in that, The impedance-capacitance coupling attenuation model is expressed as follows: in, Indicates the current maximum available capacity. Indicates the design capacity. Indicates accumulated energy throughput. Indicates real-time polarization impedance. Indicates the reference impedance. , , Represents the model coefficients.

5. The battery pack capacity dynamic calibration method based on multi-timescale model coupling according to claim 4, characterized in that, The battery temperature is collected in real time, and the model coefficients are dynamically adjusted according to a preset Arrhenius temperature relationship function. , , and reference impedance .

6. The battery pack capacity dynamic calibration method based on multi-timescale model coupling according to claim 4, characterized in that, The formula for calculating the cumulative energy throughput is: in, Indicates accumulated energy throughput. Indicates time The current, Indicates time The voltage.

7. The battery pack capacity dynamic calibration method based on multi-timescale model coupling according to claim 1, characterized in that, Based on the current maximum available capacity and the real-time polarization impedance, predict the remaining discharge time of each battery to reach the cutoff voltage, and determine the battery with the shortest remaining discharge time as the weakest battery, including: For each cell in the battery pack, obtain the current remaining capacity of each cell; The current remaining capacity is calculated based on the ampere-hour integral method combined with the maximum available capacity; Based on the following voltage prediction equation, the remaining discharge time for each battery to reach the preset cutoff voltage is calculated according to the maximum available capacity and current remaining capacity of each battery: in, Indicates the preset cutoff voltage. This represents the preset mapping function between the battery open-circuit voltage and the state of charge. Indicates the current remaining capacity. This represents the load current at the current moment. Indicates the remaining discharge time. Indicates the current maximum available capacity. This indicates the ohmic internal resistance included in the model parameters. Indicates real-time polarization impedance; The battery with the shortest remaining discharge time is identified as the short-term battery.

8. The battery pack capacity dynamic calibration method based on multi-timescale model coupling according to claim 1, characterized in that, Calculate the inflection point compensation amount for the short-pole battery, and subtract the inflection point compensation amount from the theoretical remaining capacity of the battery pack to obtain the calibrated actual usable remaining capacity of the battery pack, including: The inflection point compensation amount of the short-plate battery is calculated based on the current maximum available capacity of the short-plate battery and the rate of change of real-time polarization impedance. When the first-order partial derivative of the rate of change of the current maximum available capacity and the real-time polarization impedance of the short-plate battery is greater than the preset decay acceleration threshold, it is determined that the short-plate battery has entered the nonlinear drop zone, and the inflection point compensation amount is deducted from the theoretical remaining capacity of the battery pack. When the first-order partial derivative of the rate of change of the current maximum available capacity and the real-time polarization impedance of the short-plate battery is less than or equal to the preset decay acceleration threshold, the inflection point compensation is set to zero.

9. The battery pack capacity dynamic calibration method based on multi-timescale model coupling according to claim 8, characterized in that, The inflection point compensation amount of the short-plate battery is calculated based on the current maximum available capacity and the rate of change of real-time polarization impedance. The calculation formula is as follows: in, Indicates the inflection point compensation amount. This represents the compensation weighting coefficient. This indicates the current maximum usable capacity of the short-plate battery. This represents the real-time polarization impedance of the short-plate battery. This represents the impedance change trend within a preset time window.

10. A battery pack capacity dynamic calibration management system based on multi-timescale model coupling, characterized in that, include: The sensor module is used to acquire the terminal voltage, operating current and temperature data of each cell in the battery pack in real time during the charging and discharging process. The model building module is used to substitute the terminal voltage and operating current into the second-order RC equivalent circuit model, identify the model parameters, and calculate the real-time polarization impedance of each individual cell. The capacity estimation module is used to construct an impedance-capacity coupling attenuation model and estimate the current maximum usable capacity of a single cell based on the real-time polarization impedance. The short-board battery positioning module is used to predict the remaining discharge time of each individual battery to reach the cutoff voltage based on the current maximum available capacity and the real-time polarization impedance, and to determine the battery with the shortest remaining discharge time as the short-board battery. The capacity calibration module is used to calculate the inflection point compensation amount of the short-board battery and subtract the inflection point compensation amount from the theoretical remaining capacity of the battery pack to obtain the actual usable remaining capacity of the calibrated battery pack.

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