A fast charging current and thermal management collaborative control method

Abstract

This invention discloses a method for coordinated control of fast charging current and thermal management, relating to the field of battery management technology. The method includes: collecting electrochemical and thermal state parameters using cell groups as the smallest unit; calculating lithium plating risk margin, temperature rise margin, and aging sensitivity, and weighted fusion to generate a fast charging safety margin; identifying limiting groups and dominant risk types, and obtaining dual-boundary constraints of the charging pile and thermal management system; aiming to maximize charging current, jointly solving for the optimal charging current and thermal management actuator commands under the safety margin threshold and dual-boundary constraints; and correcting the fusion weights based on the temperature recovery time during the resting period, voltage rebound, and internal resistance increment after fast charging. By treating charging and heat dissipation as a single optimization problem and making simultaneous decisions, with weights adaptively adjusted as the battery ages, this method solves the problems of excessive safety redundancy or localized overheating caused by single-dimensional fixed threshold judgment, independent charging and heating control, and open-loop calibration, thereby improving fast charging efficiency and delaying battery degradation.

Description

Technical Field

[0001] This invention relates to the field of battery management technology, and in particular to a method for coordinated control of fast charging current and thermal management. Background Technology

[0002] With the continuous increase in the capacity of power batteries for new energy vehicles and the demand for vehicle refueling, high-power DC fast charging has become an important technological path to improve user convenience. During fast charging, the power battery typically requires the battery management system to limit the charging current based on the battery's state of charge, voltage, temperature, and other state parameters. A thermal management system is also used to cool, heat, or equalize the battery pack to prevent issues such as cell overheating, lithium plating during low-temperature charging, increased temperature differences, and accelerated cell aging.

[0003] Existing fast charging strategies typically use the highest and lowest temperatures of the entire battery pack, the highest voltage of a single cell, or the overall state of charge (SCC) of the entire pack as the primary basis for derating. When a single cell or a partial module reaches its temperature, voltage, or current limit, the system then triggers a reduction in charging current. This approach is simple to implement, but it has at least the following shortcomings: First, uniform current limiting across the entire pack cannot reflect the differences in thermal state and aging state between different cells or cells located in different cooling channels; Second, charging current control and thermal management control often belong to different control logics, and insufficient cooling or heating capacity of the thermal management system cannot be promptly translated into early constraints on the fast charging current; Third, during low-temperature fast charging, the risk of lithium plating is not only related to temperature but also to SCC, charging rate, and internal resistance, and a single temperature threshold cannot accurately characterize the risk of different cells; Fourth, information such as the temperature recovery time and internal resistance change after fast charging is not fully used for the next fast charging parameter correction, causing the same partial cell or module to repeatedly become a limiting point during continuous fast charging, thereby exacerbating consistency degradation.

[0004] Therefore, a fast-charging collaborative control scheme is needed that can take the battery cell or battery cell group as the control object, comprehensively consider the risk of lithium plating, temperature rise risk, aging sensitivity, the capability of external charging equipment, and the actual capability boundary of the thermal management system, so that the charging current control and thermal management control form a closed loop, and continuously correct the control parameters through feedback after fast charging. Summary of the Invention

[0005] The purpose of this invention is to provide a method for coordinated control of fast charging current and thermal management, which aims to solve or improve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, the present invention provides the following solution: A method for coordinated control of fast charging current and thermal management includes: Using cell groups as the smallest control unit, the electrochemical and thermal state parameters of each cell group are collected in real time. Based on electrochemical state parameters and thermal state parameters, the lithium plating risk margin, temperature rise margin and aging sensitivity of each cell group are calculated respectively, and the fast charging safety margin of each cell group is generated by weighted fusion. Iterate through all fast charging safety margins to identify the current restricted group and the dominant risk type of the restricted group; Obtain the output capacity boundary of the charging pile and the actuator capacity boundary of the thermal management system; With maximizing the charging current as the objective function, under the conditions that the fast charging safety margin of the restricted group is not lower than the preset safety threshold and does not exceed the output capacity boundary of the charging pile and the capacity boundary of the thermal management system actuator, the optimal charging current command and thermal management actuator action command are jointly solved to generate the optimal charging current command and thermal management actuator action command. After fast charging is completed, the weighting coefficients of the weighted fusion are adjusted based on feedback data from the resting period.

[0007] Furthermore, electrochemical state parameters include the negative electrode potential. With state of charge Thermal parameters include NTC temperature sensor signals. and coolant inlet temperature sensor signal .

[0008] Furthermore, the lithium plating risk margin is expressed as follows: In the formula, The lithium plating risk margin for the i-th group of cells; Let be the negative electrode potential of the i-th group of cells; This serves as a reference value for lithium deposition potential. This is a preset safety margin.

[0009] Furthermore, the calculation process for the temperature rise margin includes: The cell grouping temperature predicted based on the first-order lumped parameter thermal model is expressed as follows: In the formula, , , These are the thermal resistance, thermal capacity, and time constant of the i-th cell group, respectively; This is the current charging current; For prediction in the time domain; Temperature rise margin, expressed as: In the formula, The temperature rise margin for the i-th cell group; For the predicted cell grouping temperature; This is the upper limit of the temperature range; This is the optimal operating temperature.

[0010] Furthermore, aging sensitivity is expressed as: In the formula, The aging sensitivity of the i-th cell group; Use the SOC point as a reference. This is the attenuation sensitivity coefficient; The health status of the i-th cell group.

[0011] Furthermore, iterate through all fast charging safety margins to identify the current restriction group and the dominant risk type of the restriction group, including: The limiting group index for determining the fast charging safety margin of all cell groups is expressed as: In the formula, To ensure safety margins for fast charging; By comparing the values ​​of lithium plating risk margin, temperature rise margin, and aging sensitivity in the restricted groups, the minimum value is taken as the dominant risk type.

[0012] Furthermore, the output capability boundary of the charging pile and the capability boundary of the thermal management system actuator are obtained, including: The maximum allowable output current is read in real time from the charging pile via a communication protocol. With maximum power ; The maximum heat dissipation power is obtained by reading the electronic water pump speed feedback, compressor frequency feedback, and coolant flow sensor signals via the CAN bus and combining them with a table based on the preset actuator characteristic curve. and the minimum allowable temperature of coolant .

[0013] Furthermore, with maximizing the charging current as the objective function, and under the conditions that the fast charging safety margin of the restricted group is not lower than the preset safety threshold, and simultaneously does not exceed the output capacity boundary of the charging pile and the capability boundary of the thermal management system actuator, the optimal charging current command and thermal management actuator action command are jointly solved, including: The objective function is expressed as: In the formula, To comprehensively optimize the target value, it is a dimensionless scalar; To limit the charging current command value of the group at the current moment; This is the charging efficiency weighting coefficient, and its value range is... It is used to adjust the optimizer's pursuit of charging current intensity; To limit the absolute temperature difference between the grouped surface temperature and the preset uniform temperature target; This is the thermal uniformity penalty weighting coefficient, with a value range of [value range missing]. ; The rate of change of the charging current command, i.e., the period between adjacent control cycles. The first-order difference; The current change rate penalty weighting coefficient; The constraints include: Restricted Grouping In the formula Preset safety threshold; In the formula, This refers to the maximum allowable output current of the charging pile. In the formula, This refers to the real-time total voltage of the battery pack. In the formula, This represents the current heat dissipation power. The minimum heat dissipation power required to keep the group temperature within the limit is calculated from the thermal model. This refers to the rotational speed of the electronic water pump; For compressor frequency; To limit the surface temperature of the group; , In the formula, This is the maximum speed of the electronic water pump; This refers to the compressor's maximum frequency. In the formula, This is the minimum permissible temperature for the coolant; This refers to the coolant outlet temperature. Iterative output of optimal charging current command Target speed of electronic water pump With compressor target frequency .

[0014] Furthermore, after fast charging ends, the weighting coefficients of the weighted fusion are adjusted based on feedback data from the resting period, including: The temperature difference recovery time, static voltage rebound, and internal resistance increment of the data collection and limitation group were measured. If the temperature recovery time, static voltage rebound, and internal resistance increment of the restricted group exceed the corresponding preset thresholds, the weighting coefficients of lithium plating risk margin, temperature rise margin, and aging sensitivity will be corrected.

[0015] Furthermore, if the temperature recovery time, resting voltage rebound, and internal resistance increment of the restricted groups exceed the corresponding preset thresholds, the weighting coefficients of lithium plating risk margin, temperature rise margin, and aging sensitivity will be modified, including: When the increase in internal resistance exceeds a preset threshold, the weight of aging sensitivity is adjusted, as expressed by: In the formula, For new aging sensitivity; Original aging sensitivity; This is the aging weight correction factor; This represents the increase in internal resistance. Incremental threshold; When the temperature difference recovery time exceeds the preset recovery time threshold, a weighted adjustment for the temperature rise margin is performed, expressed as: In the formula, For new temperature rise margin; This is the original temperature rise margin; This is the temperature rise weighting correction factor; This refers to the temperature recovery time. The recovery time threshold; If the resting voltage rebound exceeds a preset rebound threshold, a lithium plating weight correction is performed, expressed as follows: In the formula, New lithium deposition weights; The original lithium plating weight; This is the lithium plating weight correction coefficient; This refers to the static voltage rebound. The rebound threshold; After correction, all weight coefficients are normalized and used as the initial weights for the next fast charging.

[0016] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: This invention discloses a collaborative control method for fast charging current and thermal management. The method employs multi-dimensional safety margin weighted fusion and joint solution of charging and thermal management, treating charging current and thermal management actions as the same optimization variable for synchronous decision-making. This effectively avoids the conservative current limiting or localized overheating problems caused by traditional independent control. The weighting coefficients are dynamically corrected based on feedback data after fast charging and resting, allowing the control strategy to adaptively evolve throughout the battery's lifespan without manual recalibration. This solution significantly improves the average fast charging power, shortens charging time, and slows battery degradation while ensuring safety in areas such as lithium plating, temperature rise, and aging, thus balancing user experience and battery lifespan. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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.

[0018] Figure 1 This is a flowchart illustrating the method of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The purpose of this invention is to provide a method for coordinated control of fast charging current and thermal management, which aims to solve or improve at least one of the above-mentioned technical problems.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 As shown, the present invention provides a method for coordinated control of fast charging current and thermal management, including: This embodiment uses a ternary lithium-ion battery pack installed in a pure electric passenger vehicle as the implementation object. The battery pack contains 96 cell groups, each group consisting of 4 series and 3 parallel cells, with a rated capacity of 75kWh, and is compatible with a 250kW liquid-cooled supercharging pile. The method described in this embodiment is executed by the vehicle domain controller, and the hardware platform is a multi-core microcontroller, with each functional module allocated to an independent core for parallel operation.

[0023] Step 1: Using cell groups as the smallest control unit, collect the electrochemical and thermal state parameters of each cell group in real time. Before fast charging is initiated and during the charging process, parameter data is collected at 10ms intervals, including: Using a pre-defined polarity equivalent circuit model and an extended Kalman filter observer, the negative electrode potential of each cell group is estimated in real time based on the terminal voltage, current, and historical data of each cell group. With state of charge ,in .

[0024] The process noise covariance matrix of the extended Kalman filter observer is adaptively adjusted based on the residual of the previous cycle to ensure that the negative electrode potential estimation error does not exceed 5mV.

[0025] Simultaneously, the signals from the NTC temperature sensors arranged on the surface of each cell group are directly read. and coolant inlet temperature sensor signal The sampling frequency is 100ms, and a moving average filter is applied.

[0026] If the estimated negative electrode potential of a certain cell group exceeds the reasonable range of [-0.2V, 0.5V] for three consecutive cycles, or the surface temperature change rate exceeds 10℃ / s, the data of that cell group will be marked as abnormal, and the system will automatically switch to conservative safety mode and record the fault code.

[0027] Step 2: Based on electrochemical and thermal state parameters, calculate the lithium plating risk margin, temperature rise margin, and aging sensitivity for each cell group, and generate the fast-charging safety margin for each cell group through weighted fusion, including: The lithium plating risk margin is expressed as: In the formula, The lithium plating risk margin for the i-th group of cells; Let be the negative electrode potential of the i-th group of cells; This serves as a reference value for lithium deposition potential. This is a preset safety margin.

[0028] when hour, The value is 0; when hour, The value is 1.

[0029] The calculation process for temperature rise margin includes: Based on a first-order lumped-parameter thermal model, the cell group temperature is predicted for the next 60 seconds. The expression is: In the formula, , , The thermal resistance, thermal capacity, and time constant of the i-th cell group are respectively obtained from offline calibration; This is the current charging current; For prediction in the time domain; Temperature rise margin, expressed as: In the formula, The temperature rise margin for the i-th cell group; For the predicted cell grouping temperature; This is the upper limit of the temperature range; This is the optimal operating temperature.

[0030] when hour, ;when hour, .

[0031] Aging sensitivity, expressed as: In the formula, The aging sensitivity of the i-th cell group; Use the SOC point as a reference. This is the attenuation sensitivity coefficient; The health status of the i-th cell group is initially 1.0, which decays with each cycle.

[0032] Fast charging safety margin, expressed as: In the formula, To ensure safety margins for fast charging; , and These are the weighting coefficients for lithium plating risk margin, temperature rise margin, and aging sensitivity, respectively.

[0033] In this embodiment, the initial weight is set to , , And satisfy .

[0034] Step 3: Traverse all fast charging safety margins, identify the current restricted group and the dominant risk type of the restricted group, including: The limiting group index for determining the fast charging safety margin of all cell groups is expressed as: By comparing the values ​​of lithium plating risk margin, temperature rise margin, and aging sensitivity in the restricted groups, the minimum value is taken as the dominant risk type.

[0035] In this embodiment, during the fast charging test, when the SOC reaches 68%, group number 42 is identified as the restricted group. ,and If the value is the minimum among the three sub-margins, the system determines that the dominant risk is the risk of temperature rise.

[0036] Step 4: Obtain the charging pile output capacity boundary and the thermal management system actuator capacity boundary, including: The maximum allowable output current is read in real time from the charging pile via a communication protocol. With maximum power ; In this embodiment, the 250kW supercharging pile feedback... , ; The maximum heat dissipation power is obtained by reading the electronic water pump speed feedback, compressor frequency feedback, and coolant flow sensor signals via the CAN bus and combining them with a table based on the preset actuator characteristic curve. and the minimum allowable temperature of coolant .

[0037] In this embodiment, the compressor's highest frequency corresponds to a maximum heat dissipation power of 18kW.

[0038] Step 5: Using maximizing the charging current as the objective function, and under the conditions that the fast charging safety margin of the restricted group is not lower than the preset safety threshold, and simultaneously does not exceed the output capacity boundary of the charging pile and the capability boundary of the thermal management system actuator, jointly solve to generate the optimal charging current command and thermal management actuator action command, including: The objective function is expressed as: In the formula, To comprehensively optimize the target value, it is a dimensionless scalar; To limit the charging current command value of the group at the current moment; This is the charging efficiency weighting coefficient, and its value range is... It is used to adjust the optimizer's pursuit of charging current intensity; To limit the absolute temperature difference between the grouped surface temperature and the preset uniform temperature target; This is the thermal uniformity penalty weighting coefficient, with a value range of [value range missing]. ; The rate of change of the charging current command, i.e., the period between adjacent control cycles. The first-order difference; The current change rate penalty weighting coefficient; The constraints include: Restricted Grouping In the formula Preset safety threshold; In the formula, This refers to the maximum allowable output current of the charging pile. In the formula, This refers to the real-time total voltage of the battery pack. In the formula, This represents the current heat dissipation power. The minimum heat dissipation power required to keep the group temperature within the limit is calculated from the thermal model. This refers to the rotational speed of the electronic water pump; For compressor frequency; To limit the surface temperature of the group; , In the formula, This is the maximum speed of the electronic water pump; This refers to the compressor's maximum frequency. In the formula, This is the minimum permissible temperature for the coolant; This refers to the coolant outlet temperature.

[0039] The solver iterates every 100ms and synchronously outputs the optimal charging current command. Target speed of electronic water pump With compressor target frequency .

[0040] In this embodiment, at the aforementioned SOC=68%, the solution result is: (10.9% lower than the 320A without synergy) , This ensures that the temperature rise margin of cell group No. 42 is maintained above the safe threshold.

[0041] Step 6: After fast charging is completed, adjust the weighted fusion coefficients based on feedback data from the resting period, including: The temperature difference recovery time, static voltage rebound, and internal resistance increment of the data collection and limitation group were measured. Among them, the temperature recovery time is the time required for the surface temperature to drop from its peak to a temperature difference of ≤5℃ with the environment; the static voltage rebound is the magnitude of the open circuit voltage rebound during the static period; and the internal resistance increment is the increment of the DC internal resistance obtained from the pulse test at the end of the static period compared with the last fast charge.

[0042] In this embodiment, the temperature difference recovery time is 420s, the static voltage rebound is 12mV, and the internal resistance increment is 0.8mΩ; If the temperature recovery time, static voltage rebound, and internal resistance increment of the restricted groups exceed the corresponding preset thresholds, the weighting coefficients of lithium plating risk margin, temperature rise margin, and aging sensitivity will be adjusted, including: When the increase in internal resistance exceeds a preset threshold, the weight of aging sensitivity is adjusted, as expressed by: In the formula, For new aging sensitivity; Original aging sensitivity; This is the aging weight correction factor; This represents the increase in internal resistance. The incremental threshold is 0.5mΩ in this embodiment; When the temperature difference recovery time exceeds the preset recovery time threshold, a weighted adjustment for the temperature rise margin is performed, expressed as: In the formula, For new temperature rise margin; This is the original temperature rise margin; This is the temperature rise weighting correction factor; This refers to the temperature recovery time. The recovery time threshold is 300 seconds in this embodiment; If the resting voltage rebound exceeds a preset rebound threshold, a lithium plating weight correction is performed, expressed as follows: In the formula, New lithium deposition weights; The original lithium plating weight; This is the lithium plating weight correction coefficient; This refers to the static voltage rebound. The rebound threshold; After correction, all weight coefficients are normalized and used as the initial weights for the next fast charge, forming a closed-loop adaptive data flow across charging cycles.

[0043] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0044] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for coordinated control of fast charging current and thermal management, characterized in that, include: Using cell groups as the smallest control unit, the electrochemical and thermal state parameters of each cell group are collected in real time. Based on electrochemical state parameters and thermal state parameters, the lithium plating risk margin, temperature rise margin and aging sensitivity of each cell group are calculated respectively, and the fast charging safety margin of each cell group is generated by weighted fusion. Iterate through all fast charging safety margins to identify the current restricted group and the dominant risk type of the restricted group; Obtain the output capacity boundary of the charging pile and the actuator capacity boundary of the thermal management system; With maximizing the charging current as the objective function, under the conditions that the fast charging safety margin of the restricted group is not lower than the preset safety threshold and does not exceed the output capacity boundary of the charging pile and the capacity boundary of the thermal management system actuator, the optimal charging current command and thermal management actuator action command are jointly solved to generate the optimal charging current command and thermal management actuator action command. After fast charging is completed, the weighting coefficients of the weighted fusion are adjusted based on feedback data from the resting period.

2. The fast charging current and thermal management coordinated control method according to claim 1, characterized in that, The electrochemical state parameters include the negative electrode potential. With state of charge The thermal state parameters include NTC temperature sensor signals. and coolant inlet temperature sensor signal .

3. The fast charging current and thermal management coordinated control method according to claim 1, characterized in that, The lithium plating risk margin is expressed as follows: In the formula, The lithium plating risk margin for the i-th group of cells; Let be the negative electrode potential of the i-th group of cells; This serves as a reference value for lithium deposition potential. This is a preset safety margin.

4. The fast charging current and thermal management coordinated control method according to claim 1, characterized in that, The calculation process for the temperature rise margin includes: The cell grouping temperature predicted based on the first-order lumped parameter thermal model is expressed as follows: In the formula, , , These are the thermal resistance, thermal capacity, and time constant of the i-th cell group, respectively; This is the current charging current; For prediction in the time domain; Temperature rise margin, expressed as: In the formula, This represents the temperature rise margin for the i-th cell group; For the predicted cell grouping temperature; This is the upper limit of the temperature range; This is the optimal operating temperature.

5. The fast charging current and thermal management coordinated control method according to claim 1, characterized in that, The aging sensitivity is expressed as: In the formula, The aging sensitivity of the i-th cell group; Use the SOC point as a reference. This is the attenuation sensitivity coefficient; The health status of the i-th cell group.

6. The fast charging current and thermal management coordinated control method according to claim 1, characterized in that, The process of traversing all fast-charging safety margins and identifying the current restricted group and the dominant risk type of the restricted group includes: The limiting group index for determining the fast charging safety margin of all cell groups is expressed as: In the formula, To ensure safety margins for fast charging; By comparing the values ​​of lithium plating risk margin, temperature rise margin, and aging sensitivity in the restricted groups, the minimum value is taken as the dominant risk type.

7. The fast charging current and thermal management coordinated control method according to claim 1, characterized in that, The process of obtaining the charging pile output capability boundary and the thermal management system actuator capability boundary includes: The maximum allowable output current is read in real time from the charging pile via a communication protocol. With maximum power ; The maximum heat dissipation power is obtained by reading the electronic water pump speed feedback, compressor frequency feedback, and coolant flow sensor signals via the CAN bus and combining them with a table based on the preset actuator characteristic curve. and the minimum allowable temperature of coolant .

8. The fast charging current and thermal management coordinated control method according to claim 1, characterized in that, The process, with maximizing the charging current as the objective function, and under the conditions that the fast charging safety margin of the restricted group is not lower than a preset safety threshold, and simultaneously does not exceed the output capacity boundary of the charging pile and the capability boundary of the thermal management system actuator, jointly solves to generate the optimal charging current command and thermal management actuator action command, including: The objective function is expressed as: In the formula, To comprehensively optimize the target value; To limit the charging current command value of the group at the current moment; This is a weighting coefficient for charging efficiency; To limit the absolute temperature difference between the grouped surface temperature and the preset uniform temperature target; This is the weighting coefficient for thermal uniformity penalty; The rate of change of the charging current command; The current change rate penalty weighting coefficient; The constraints include: Restricted Grouping In the formula Preset safety threshold; In the formula, This refers to the maximum allowable output current of the charging pile. In the formula, This refers to the real-time total voltage of the battery pack. In the formula, This represents the current heat dissipation power. The minimum heat dissipation power required to keep the group temperature within the limit is calculated from the thermal model. This refers to the rotational speed of the electronic water pump; For compressor frequency; To limit the surface temperature of the group; , In the formula, This is the maximum speed of the electronic water pump; This refers to the compressor's maximum frequency. In the formula, This is the minimum permissible temperature for the coolant; This refers to the coolant outlet temperature. Iterative output of optimal charging current command Target speed of electronic water pump With compressor target frequency .

9. The fast charging current and thermal management coordinated control method according to claim 1, characterized in that, After the fast charging is completed, the weighting coefficients of the weighted fusion are adjusted based on the feedback data during the rest period, including: The temperature difference recovery time, static voltage rebound, and internal resistance increment of the data collection and limitation group were measured. If the temperature recovery time, static voltage rebound, and internal resistance increment of the restricted group exceed the corresponding preset thresholds, the weighting coefficients of lithium plating risk margin, temperature rise margin, and aging sensitivity will be corrected.

10. The fast charging current and thermal management coordinated control method according to claim 9, characterized in that, If the temperature recovery time, static voltage rebound, and internal resistance increment of the restricted group exceed the corresponding preset thresholds, the weighting coefficients of lithium plating risk margin, temperature rise margin, and aging sensitivity will be corrected, including: When the increase in internal resistance exceeds a preset threshold, the weight of aging sensitivity is adjusted, as expressed by: In the formula, For new aging sensitivity; Original aging sensitivity; This is the aging weight correction factor; This represents the increase in internal resistance. Incremental threshold; When the temperature difference recovery time exceeds the preset recovery time threshold, a weighted adjustment for the temperature rise margin is performed, expressed as: In the formula, For new temperature rise margin; This is the original temperature rise margin; This is the temperature rise weighting correction factor; This refers to the temperature recovery time. The recovery time threshold; If the resting voltage rebound exceeds a preset rebound threshold, a lithium plating weight correction is performed, expressed as follows: In the formula, New lithium deposition weights; The original lithium plating weight; This is the lithium plating weight correction coefficient; This refers to the static voltage rebound. The rebound threshold; After correction, all weight coefficients are normalized and used as the initial weights for the next fast charging.

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