Lithium battery pack health state analysis management and control method and related device

Abstract

The invention discloses a lithium battery pack health state analysis management and control method and a related device, and relates to the technical field of data analysis, and the method comprises the steps: collecting the monitoring data of a lithium battery pack in different modes based on a data verification method; preprocessing the monitoring data; safety state analysis of the lithium battery pack in different modes is carried out based on the monitoring data, and safety state analysis results are obtained; calculating the calibration actual capacity of the lithium battery pack based on the monitoring data, and calculating the target residual capacity of the lithium battery pack in different modes based on an open-circuit voltage-ampere-hour integral method; based on the safety state analysis results of the lithium battery pack in different modes, calibrating the actual capacity and the target residual capacity, and combining the monitoring data to determine a corresponding management and control strategy; and performing equalization and protection processing on the lithium battery pack in different modes based on the management and control strategy. The health state of the lithium battery pack can be effectively managed, so that the service life of the lithium battery pack is prolonged, and the energy utilization rate is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of data analysis, and in particular, to a method and related device for analyzing and controlling the health state of a lithium battery pack. Background Art

[0002] Nowadays, with the developed social transportation, electric vehicles have become a means of transportation commonly used by people in daily life. It not only has zero pollution emissions, but also has fast power improvement and low power consumption cost. At the same time, due to the advantages of high energy density, low self-discharge rate, small pollution, long cycle life, etc. of lithium batteries, and with the gradual reduction of manufacturing process costs in recent years, lithium batteries are widely used in electric vehicles. In order to meet the voltage and power requirements of electric vehicles, multiple single lithium batteries are usually connected in series and in parallel. In order to ensure the healthy use of the lithium battery pack of the electric vehicle, it is necessary to control the health state of the lithium battery pack. In the current control of the health state of the lithium battery pack, usually only the data collection, analysis and health state control of the lithium battery pack in the charging mode are carried out, and it is impossible to comprehensively control the health state of the lithium battery pack in various modes, resulting in difficulty in realizing multi-faceted protection of the lithium battery pack. The calculation of the remaining battery capacity is also an important part of the health state control. At present, usually only the open circuit voltage method or the ampere-hour integration method is used to calculate the remaining battery capacity. The remaining battery capacity calculated only by the open circuit voltage method or the ampere-hour integration method will have a large deviation from the actual situation, and the error cannot be corrected separately. At the same time, how to analyze the control strategy of the lithium battery pack based on the obtained data is also an important link in the health control of the lithium battery pack. If this link is ignored, it will seriously affect the performance and service life of the lithium battery pack. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art. The present invention provides a method and related device for analyzing and controlling the health state of a lithium battery pack, which can effectively manage the health state of the lithium battery pack, thereby improving the service life and energy utilization rate of the lithium battery pack.

[0004] To solve the above technical problems, the present invention provides a method for analyzing and controlling the health state of a lithium battery pack, which is applied to the lithium battery pack and the battery management system of an electric vehicle; the method includes:

[0005] The battery management system collects the monitoring data of the lithium battery pack in different modes based on the data verification method;

[0006] Preprocess the monitoring data to obtain the preprocessed monitoring data;

[0007] Based on the preprocessed monitoring data, perform a safety state analysis of the lithium battery pack in different modes to obtain a safety state analysis result;

[0008] Calculate the calibrated actual capacity of the lithium battery pack using the temperature capacity coefficient based on the preprocessed monitoring data, and calculate the target remaining capacity of the lithium battery pack in different modes based on the open-circuit voltage-Ah integration method;

[0009] Determine the corresponding control strategy based on the safety state analysis results, calibrated actual capacity, and target remaining capacity of the lithium battery pack in different modes, combined with the preprocessed monitoring data;

[0010] Perform balancing and protection processing on the lithium battery pack in different modes based on the control strategy.

[0011] Optionally, the acquisition of the monitoring data of the lithium battery pack in different modes based on the data verification method includes:

[0012] The battery management system configures the reading and writing of the voltage acquisition register based on the device address verification;

[0013] Based on the reading and writing configuration, issue a single-cell battery voltage acquisition instruction using analog-to-digital conversion and data verification to obtain the single-cell battery voltage of the lithium battery pack in different modes, and generate the corresponding lithium battery pack voltage based on the single-cell battery voltage. The different modes include the standby mode, charging mode, and discharging mode;

[0014] Perform data sampling and conversion on the analog quantity generated by the sampling resistor to obtain the lithium battery pack current in different modes;

[0015] Compare the current temperature of the lithium battery pack in different modes read with the temperature at the previous moment, determine the target temperature based on the comparison result, and calibrate the target temperature based on the proportional coefficient to obtain the calibrated target temperature. The monitoring data of the lithium battery pack consists of the single-cell battery voltage, lithium battery pack voltage, lithium battery pack current, and calibrated target temperature.

[0016] Optionally, the preprocessing of the monitoring data to obtain the preprocessed monitoring data includes:

[0017] Perform standardization processing and data integration processing on the monitoring data to obtain the preprocessed monitoring data.

[0018] Optionally, the safety state analysis of the lithium battery pack in different modes based on the preprocessed monitoring data to obtain the safety state analysis result includes:

[0019] In the discharging mode / charging mode, compare the lithium battery pack current in the preprocessed monitoring data with the preset overcurrent protection threshold to obtain a comparison result, and perform overcurrent analysis of the lithium battery based on the comparison result to obtain the overcurrent analysis result;

[0020] In the discharge mode / charging mode, the calibrated target temperature in the preprocessed monitoring data is compared with the preset over-temperature threshold and the preset low-temperature threshold respectively to obtain the corresponding comparison results, and over-temperature analysis and low-temperature analysis of the lithium battery are performed based on the corresponding comparison results to obtain the over-temperature analysis result and the low-temperature analysis result. The safety status analysis result is composed of the over-current analysis result, the over-temperature analysis result and the low-temperature analysis result.

[0021] Optionally, calculating the calibrated actual capacity of the lithium battery pack using the temperature capacity coefficient based on the preprocessed monitoring data includes:

[0022] Calculating the calibrated actual capacity of the lithium battery pack using the temperature capacity coefficient based on the calibrated target temperature in the preprocessed monitoring data. The calculation expression of the calibrated actual capacity is:

[0023]

[0024] Wherein, RL is the calibrated actual capacity, BL is the nominal capacity of the lithium battery pack, σ is the temperature capacity coefficient, and T is the calibrated target temperature.

[0025] Optionally, calculating the target remaining capacity of the lithium battery pack in different modes based on the open-circuit voltage - ampere-hour integration method includes:

[0026] Calculating the initial state of charge based on the open-circuit voltage method. The calculation expression of the initial state of charge is:

[0027] OCV SOC =index*10+((SocOcvTab[index]-voltage)*10) /

[0028] (SocOcvTab[index]-SocOcvTab[index+1]),

[0029] BMSCAP OCV-SOC =MR*OCV SOC ,

[0030] Wherein, OCV SOC is the percentage of the state of charge, SocOcvTab[] is the voltage table corresponding to the state of charge of the lithium battery pack, index is the initial point, voltage is the open-circuit voltage, BMSCAP OCV-SOC is the initial state of charge, and MR is the full charge capacity of the lithium battery pack;

[0031] Calculating the first target remaining capacity of the lithium battery pack in the charging mode using the ampere-hour integration method based on the initial state of charge. The calculation expression of the first target remaining capacity is:

[0032]

[0033] Among them, BMSCAP AHOCV-SOC-C1 is the first target remaining capacity, and BMSCAP OCV-SOC is the initial state of charge, and A cur is the current value from time period t 0 to time period t in the charging mode;

[0034] Based on the initial state of charge, the second target remaining capacity of the lithium battery pack in the discharging mode is calculated by the ampere-hour integration method, and the calculation expression of the second target remaining capacity is:

[0035]

[0036] Among them, BMSCAP AHOCV-SOC-C2 is the second target remaining capacity, and BMSCAP OCV-SOC is the initial state of charge, and A cur is the current value from time period t 0 to time period t in the discharging mode.

[0037] Optionally, the corresponding control strategy is determined based on the analysis results of the safety state of the lithium battery pack in different modes, the calibrated actual capacity and the target remaining capacity, and the preprocessed monitoring data, including:

[0038] Determine the battery safety control strategy based on the overcurrent analysis result, over-temperature analysis result and low-temperature analysis result of the lithium battery in the discharging mode / charging mode;

[0039] Determine the battery charge and discharge management strategy based on the calibrated actual capacity and the target remaining capacity of the lithium battery pack in different modes;

[0040] Determine the battery balancing strategy based on the voltage of the single battery of the lithium battery pack in different modes in combination with the preset equalization voltage difference, and determine the control strategy based on the battery safety control strategy, charge and discharge management strategy and battery balancing strategy.

[0041] Optionally, the equalization and protection processing of the lithium battery pack in different modes is performed based on the control strategy, including:

[0042] Perform overcurrent protection during charging, over-temperature protection during charging, low-temperature protection during charging, low-temperature protection during discharging, high-temperature protection during discharging and overcurrent protection during discharging on the lithium battery pack in different modes based on the battery safety control strategy in the control strategy;

[0043] Perform overcharge and over-discharge protection on the lithium battery pack in different modes based on the charge and discharge management strategy in the control strategy;

[0044] Perform equalization control on the lithium battery pack in different modes based on the battery balancing strategy in the control strategy using the discharge flag bit.

[0045] In addition, the present invention also provides a device for analyzing and controlling the health state of a lithium battery pack, which is applied to the lithium battery pack and the battery management system of an electric vehicle; the device includes:

[0046] A data acquisition module: used for the battery management system to acquire the monitoring data of the lithium battery pack in different modes based on the data verification method;

[0047] A preprocessing module: used for preprocessing the monitoring data to obtain the preprocessed monitoring data;

[0048] A safety state analysis module: used for analyzing the safety state of the lithium battery pack in different modes based on the preprocessed monitoring data to obtain the safety state analysis result;

[0049] A capacity calculation module: used for calculating the calibrated actual capacity of the lithium battery pack based on the temperature capacity coefficient of the preprocessed monitoring data, and calculating the target remaining capacity of the lithium battery pack in different modes based on the open circuit voltage - ampere - hour integration method;

[0050] A strategy determination module: used for determining the corresponding control strategy based on the safety state analysis result, calibrated actual capacity, and target remaining capacity of the lithium battery pack in different modes in combination with the preprocessed monitoring data;

[0051] An equalization and protection module: used for equalizing and protecting the lithium battery pack in different modes based on the control strategy.

[0052] In addition, the present invention also provides a computer - readable storage medium, which stores computer instructions. When the computer instructions run on an electronic device, the electronic device is enabled to execute the above - mentioned method for analyzing and controlling the health state of the lithium battery pack.

[0053] In the embodiments of the present invention, monitoring data of a lithium battery pack in standby mode, charging mode, and discharging mode is collected based on a data verification method, which can comprehensively collect data of the lithium battery pack in different modes and facilitate subsequent data analysis of the lithium battery pack in different modes. Overcurrent analysis, overtemperature analysis, and low-temperature analysis of the lithium battery pack in discharging mode / charging mode are performed based on the preprocessed monitoring data, so as to achieve multi-faceted safety analysis of the lithium battery pack. The target remaining capacity of the lithium battery pack in different modes is calculated based on the open-circuit voltage-Ah integration method, which can not only make up for the defect that the open-circuit voltage method has inaccurate estimation of the remaining capacity during battery charging and discharging, but also solve the problem that the Ah integration method cannot determine the initial value, making the obtained target remaining capacity more reliable. Based on the safety state analysis results of the lithium battery pack in different modes, calibrating the actual capacity and the target remaining capacity, and combining the preprocessed monitoring data to determine the corresponding control strategy to perform balancing and protection processing on the lithium battery pack in different modes, it can effectively manage the differences of the single cells in the lithium battery pack, greatly avoid the occurrence of phenomena such as overcharging, over-discharging, and overcurrent of the lithium battery pack, thereby improving the service life and energy utilization rate of the lithium battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for description in the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0055] Figure 1 is a flowchart of a method for analyzing and controlling the health state of a lithium battery pack in an embodiment of the present invention;

[0056] Figure 2 is a flowchart of a method for analyzing and controlling the health state of a lithium battery pack in another embodiment of the present invention;

[0057] Figure 3 is a detailed flowchart of step S208 in an embodiment of the present invention;

[0058] Figure 4 is a schematic structural diagram of a device for analyzing and controlling the health state of a lithium battery pack in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0059] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0060] Embodiment 1

[0061] Please refer to Figure 1 , Figure 1 , which is a schematic flowchart of the method for analyzing and controlling the health state of the lithium battery pack in the embodiments of the present invention. The method is applied to the lithium battery pack and the battery management system of an electric vehicle; the method includes:

[0062] S11: The battery management system collects the monitoring data of the lithium battery pack in different modes based on the data verification method;

[0063] In the specific implementation process of the present invention, the collection of the monitoring data of the lithium battery pack in different modes based on the data verification method includes: The battery management system performs read and write configuration of the voltage acquisition register based on the device address verification; issues a single-cell battery voltage acquisition instruction by using analog-to-digital conversion and data verification based on the read and write configuration, obtains the single-cell battery voltage of the lithium battery pack in different modes, and generates the corresponding lithium battery pack voltage based on the single-cell battery voltage. The different modes include the standby mode, the charging mode, and the discharging mode; performs data sampling and conversion on the analog quantity generated by the sampling resistor to obtain the lithium battery pack current in different modes; compares the current temperature of the lithium battery pack in different modes read with the temperature at the previous moment, determines the target temperature based on the comparison result, and calibrates the target temperature based on the proportional coefficient to obtain the calibrated target temperature. The monitoring data of the lithium battery pack is composed of the single-cell battery voltage, the lithium battery pack voltage, the lithium battery pack current, and the calibrated target temperature.

[0064] Specifically, the battery management system performs read and write configuration of the voltage acquisition register based on device address verification. The battery management system executes the voltage acquisition subroutine, checks whether the address of the battery management integrated chip is correct through the communication serial bus interface. If the address verification of the battery management integrated chip is correct, the read and write configuration of the voltage acquisition register is performed. Based on the read and write configuration, an individual battery voltage acquisition instruction is issued by using analog-to-digital conversion and data verification. According to the read and write configuration of the voltage acquisition register, analog-to-digital conversion and data verification are carried out. After the analog-to-digital conversion and data verification are completed, an individual battery voltage acquisition instruction is issued to collect the voltages of the individual batteries in the lithium battery pack, obtain the voltages of the individual batteries in the lithium battery pack in different modes, and generate the corresponding lithium battery pack voltage based on the individual battery voltages, that is, calculate the total voltage of the lithium battery pack according to the voltages of the individual batteries. The different modes of the lithium battery pack include the standby mode, the charging mode, and the discharging mode. The standby mode can also be called the stationary mode. Thus, regardless of the mode of the lithium battery pack, reliable state control can be performed on it. Data sampling and conversion are performed on the analog quantity generated by the sampling resistor. The analog quantity is collected through the sampling resistor of the coulomb meter and input into the analog-to-digital conversion channel for data sampling and conversion to obtain the current of the lithium battery pack cells in each mode, that is, obtain the current of the lithium battery pack in different modes. The current temperature of the lithium battery pack in different modes read is compared with the temperature at the previous moment. The current temperature of the lithium battery pack in each mode is read through the temperature sensor, and it is judged whether the current temperature is within the effective range. If it is within the effective range, the current temperature is compared with the temperature at the previous moment. If it is not within the effective range, the temperature acquisition operation is returned to continue collecting the temperature. Based on the comparison result, the target temperature is determined. It is calculated whether the difference between the current temperature and the temperature at the previous moment exceeds the preset difference. If the difference exceeds the preset difference, the temperature is updated, and the current temperature is used as the target temperature. If it does not exceed the preset difference, the acquisition operation is returned to continue collecting the temperature, and the temperature at the previous moment is still used as the target temperature. The target temperature is calibrated based on the proportionality coefficient to obtain the calibrated target temperature. The monitoring data of the lithium battery pack consists of the individual battery voltages, the lithium battery pack voltage, the lithium battery pack current, and the calibrated target temperature.

[0065] S12: Preprocess the monitoring data to obtain the preprocessed monitoring data;

[0066] In the specific implementation process of the present invention, the preprocessing of the monitoring data to obtain the preprocessed monitoring data includes: performing standardization processing and data integration processing on the monitoring data to obtain the preprocessed monitoring data.

[0067] Specifically, perform standardization processing and data integration processing on the monitoring data. Perform format standardization processing on the monitoring data for subsequent data analysis. Classify and integrate the monitoring data in the standby mode, discharge mode, and charging mode to facilitate the distinction of the monitoring data in different modes and obtain the preprocessed monitoring data.

[0068] S13: Based on the preprocessed monitoring data, perform safety status analysis of the lithium battery pack in different modes to obtain the safety status analysis result.

[0069] In the specific implementation process of the present invention, the performing safety status analysis of the lithium battery pack in different modes based on the preprocessed monitoring data to obtain the safety status analysis result includes: in the discharge mode / charging mode, compare the current of the lithium battery pack in the preprocessed monitoring data with the preset overcurrent protection threshold to obtain the comparison result, and perform overcurrent analysis of the lithium battery based on the comparison result to obtain the overcurrent analysis result; in the discharge mode / charging mode, compare the calibrated target temperature in the preprocessed monitoring data with the preset over-temperature threshold and the preset low-temperature threshold respectively to obtain the corresponding comparison results, and perform over-temperature analysis and low-temperature analysis of the lithium battery based on the corresponding comparison results to obtain the over-temperature analysis result and the low-temperature analysis result. The overcurrent analysis result, the over-temperature analysis result, and the low-temperature analysis result constitute the safety status analysis result.

[0070] Specifically, the safety protection of the lithium battery pack focuses on its discharge mode and charging mode. In the discharge mode / charging mode, compare the current of the lithium battery pack in the preprocessed monitoring data with the preset overcurrent protection threshold to obtain the comparison result, and perform overcurrent analysis of the lithium battery based on the comparison result to obtain the overcurrent analysis result, that is, compare the current of the lithium battery pack with the preset overcurrent threshold. If the current of the lithium battery pack is greater than the preset overcurrent threshold, the state of the lithium battery pack is the overcurrent state. In the discharge mode / charging mode, compare the calibrated target temperature in the preprocessed monitoring data with the preset over-temperature threshold and the preset low-temperature threshold respectively to obtain the corresponding comparison results, and perform over-temperature analysis and low-temperature analysis of the lithium battery based on the corresponding comparison results to obtain the over-temperature analysis result and the low-temperature analysis result, that is, compare the calibrated target temperature with the preset over-temperature threshold. If the calibrated target temperature is greater than the preset over-temperature threshold, the state of the lithium battery pack is the over-temperature state. Compare the calibrated target temperature with the preset low-temperature threshold. If the calibrated target temperature is less than the preset low-temperature threshold, the state of the lithium battery pack is the low-temperature state. The overcurrent analysis result, the over-temperature analysis result, and the low-temperature analysis result constitute the safety status analysis result, and analyze the safety status of the lithium battery pack from multiple aspects of overcurrent, over-temperature, and low-temperature to achieve a more comprehensive health status analysis.

[0071] S14: Calculate the calibrated actual capacity of the lithium battery pack using the temperature capacity coefficient based on the preprocessed monitoring data, and calculate the target remaining capacity of the lithium battery pack in different modes based on the open circuit voltage - ampere - hour integration method;

[0072] In the specific implementation process of the present invention, the calculation of the calibrated actual capacity of the lithium battery pack using the temperature capacity coefficient based on the preprocessed monitoring data includes: calculating the calibrated actual capacity of the lithium battery pack using the temperature capacity coefficient based on the calibrated target temperature in the preprocessed monitoring data, and the calculation expression of the calibrated actual capacity is:

[0073]

[0074] Wherein, RL is the calibrated actual capacity, BL is the nominal capacity of the lithium battery pack, σ is the temperature capacity coefficient, and T is the calibrated target temperature.

[0075] Furthermore, the calculation of the target remaining capacity of the lithium battery pack in different modes based on the open circuit voltage - ampere - hour integration method includes: calculating the initial state of charge based on the open circuit voltage method, and the calculation expression of the initial state of charge is:

[0076] OCV SOC =index*10+((SocOcvTab[index]-voltage)*10) /

[0077] (SocOcvTab[index]-SocOcvTab[index+1]),

[0078] BMSCAP OCV-SOC =MR*OCV SOC ,

[0079] Wherein, OCV SOC is the percentage of the state of charge, SocOcvTab[] is the voltage table corresponding to the state of charge of the lithium battery pack, index is the initial point, voltage is the open circuit voltage, BMSCAP OCV-SOC is the initial state of charge, and MR is the full charge capacity of the lithium battery pack;

[0080] Calculate the first target remaining capacity of the lithium battery pack in the charging mode based on the initial state of charge using the ampere - hour integration method, and the calculation expression of the first target remaining capacity is:

[0081]

[0082] Wherein, BMSCAP AHOCV-SOC-C1 is the first target remaining capacity, BMSCAP OCV-SOC is the initial state of charge, A cur is from t in the charging mode0 The current value from time period t to time period t;

[0083] Based on the initial state of charge, use the ampere-hour integration method to calculate the second target remaining capacity of the lithium battery pack in the discharge mode. The calculation expression of the second target remaining capacity is:

[0084]

[0085] Where, BMSCAP AHOCV-SOC-C2 is the second target remaining capacity, BMSCAP OCV-SOC is the initial state of charge, A cur is the current value from time period t 0 to time period t in the discharge mode.

[0086] Specifically, based on the calibrated target temperature in the preprocessed monitoring data, use the temperature capacity coefficient to calculate the calibrated actual capacity of the lithium battery pack. Since the internal chemical reaction rate of the battery and the electrolyte conductivity will increase with the increase of temperature, high temperature will accelerate the internal chemical reaction rate of the battery. On the contrary, low temperature will reduce the reaction rate, resulting in a decrease in the battery discharge performance and thus a reduction in the available capacity. Especially for lithium battery packs, low temperature will cause the reaction rate between the electrode material and the electrolyte to slow down, and the charge transfer will be blocked, resulting in a significant reduction in the actual available capacity of the battery. Therefore, the actual capacity of the battery will change with temperature. Therefore, the actual capacity of the battery is affected by temperature. In this regard, adding the temperature capacity coefficient in the calculation of the actual capacity can make the obtained actual capacity more accurate. The calculation expression of the calibrated actual capacity is:

[0087]

[0088] Where, RL is the calibrated actual capacity, BL is the nominal capacity of the lithium battery pack, σ is the temperature capacity coefficient, and T is the calibrated target temperature. The value of the temperature capacity coefficient is as follows:

[0089]

[0090] Battery remaining power estimation is an important part of the battery health monitoring system. To avoid the situation that the battery life is shortened due to overcharging and over-discharging of the battery, it is of great significance to accurately estimate the available power of the lithium battery. Based on the open-circuit voltage method, calculate the initial state of charge. The calculation expression of the initial state of charge is:

[0091] OCV SOC = index * 10 + ((SocOcvTab[index] - voltage) * 10) /

[0092] (SocOcvTab[index] - SocOcvTab[index + 1]),

[0093] BMSCAP OCV-SOC = MR * OCV SOC ,

[0094] where OCV SOC is the percentage of state of charge, SocOcvTab[] is the voltage table corresponding to the state of charge of the lithium battery pack, index is the initial point, voltage is the open circuit voltage, BMSCAP OCV-SOC is the initial state of charge, and MR is the full charge capacity of the lithium battery pack. Thus, the decimal point of the percentage of state of charge can be accurately calculated, making the calculated initial state of charge more accurate.

[0095] Based on the initial state of charge, the first target remaining capacity of the lithium battery pack in the charging mode is calculated using the ampere-hour integration method. The calculation expression of the first target remaining capacity is:

[0096]

[0097] where BMSCAP AHOCV-SOC-C1 is the first target remaining capacity, BMSCAP OCV-SOC is the initial state of charge, and A cur is the current value from time t 0 to time t during the charging mode.

[0098] Based on the initial state of charge, the second target remaining capacity of the lithium battery pack in the discharging mode is calculated using the ampere-hour integration method. The calculation expression of the second target remaining capacity is:

[0099]

[0100] where BMSCAP AHOCV-SOC-C2 is the second target remaining capacity, BMSCAP OCV-SOC is the initial state of charge, and A cur is the current value from time t 0 to time t during the discharging mode. The remaining capacity calculated by this method can not only compensate for the defect that the open circuit voltage method is inaccurate in estimating the state of charge during the charge and discharge of the battery, but also solve the problem that the ampere-hour integration method cannot determine the initial value.

[0101] S15: Determine the corresponding control strategy based on the safety state analysis results of the lithium battery pack in different modes, calibrate the actual capacity and the target remaining capacity, and combine the preprocessed monitoring data;

[0102] In the specific implementation process of the present invention, the control strategy corresponding to the preprocessed monitoring data is determined by combining the analysis results of the safety state, the calibrated actual capacity, and the target remaining capacity of the lithium battery pack in different modes, including: determining the battery safety control strategy based on the overcurrent analysis result, over-temperature analysis result, and low-temperature analysis result of the lithium battery in the discharge mode / charging mode; determining the battery charge and discharge management strategy based on the calibrated actual capacity and the target remaining capacity of the lithium battery pack in different modes; determining the battery equalization strategy based on the single-cell voltages of the lithium battery pack in different modes in combination with a preset equalization voltage difference, and determining the control strategy based on the battery safety control strategy, the charge and discharge management strategy, and the battery equalization strategy.

[0103] Specifically, the battery safety control strategy is determined based on the overcurrent analysis result, over-temperature analysis result, and low-temperature analysis result of the lithium battery in the discharge mode / charging mode. The disable time corresponding to the charge / discharge state is determined according to the overcurrent analysis result, over-temperature analysis result, and low-temperature analysis result of the lithium battery in the discharge mode / charging mode. The disable times corresponding to the overcurrent state, over-temperature state, and low-temperature state are different, and a timer is set according to the disable time. The battery charge and discharge management strategy is determined based on the calibrated actual capacity and the target remaining capacity of the lithium battery pack in different modes, that is, the charging time, charging power, and discharge power limits of the lithium battery pack are determined according to the calibrated actual capacity and the target remaining capacity. The battery equalization strategy is determined based on the single-cell voltages of the lithium battery pack in different modes in combination with a preset equalization voltage difference, that is, the comparison result of the difference between the minimum single-cell voltage and the voltages of the other single cells and the preset equalization voltage difference determines the conditions for turning on and off the discharge flag bit, and the control strategy is determined based on the battery safety control strategy, the charge and discharge management strategy, and the battery equalization strategy, that is, the three jointly constitute the final control strategy.

[0104] S16: Perform equalization and protection processing on the lithium battery pack in different modes based on the control strategy.

[0105] In the specific implementation process of the present invention, the equalization and protection processing of the lithium battery pack in different modes based on the control strategy includes: performing charging overcurrent protection, charging over-temperature protection, charging low-temperature protection, discharging low-temperature protection, discharging high-temperature protection, and discharging overcurrent protection on the lithium battery pack in different modes based on the battery safety control strategy in the control strategy; performing overcharge and over-discharge protection on the lithium battery pack in different modes based on the charge and discharge management strategy in the control strategy; using the discharge flag bit to perform equalization control on the lithium battery pack in different modes based on the battery equalization strategy in the control strategy.

[0106] Specifically, based on the battery safety control strategy in the control policy, over-current protection, over-temperature protection, low-temperature protection during charging, low-temperature protection during discharging, high-temperature protection during discharging, and over-current protection during discharging are performed on the lithium battery pack in different modes. When it is determined that the lithium battery pack in the discharging / charging mode has over-current during charging, over-temperature during charging, low-temperature during charging, low-temperature during discharging, high-temperature during discharging, or over-current during discharging, the charging mode / discharging mode of the lithium battery pack is turned off according to the battery safety control strategy, and the timer starts to count until the disabling time in the battery safety control strategy is reached, and then the charging mode / discharging mode is restored. Based on the charge and discharge management strategy in the control policy, over-charge and over-discharge protection are performed on the lithium battery pack in different modes. When the lithium battery pack is in the discharging mode, the discharging power of the lithium battery pack is controlled according to the charge and discharge management strategy. When the discharging power reaches the discharging power limit in the charge and discharge management strategy, the discharging of the lithium battery pack is stopped. When the lithium battery is in the charging mode, the charging time of the lithium battery pack is controlled according to the charge and discharge management strategy. When the charging time of the lithium battery reaches the limit time of the charge and discharge management strategy, the charging of the lithium battery pack is stopped. Based on the battery balancing strategy in the control policy, the lithium battery pack in different modes is balanced and controlled using the discharge flag bit. In the discharging mode, since the battery itself needs to provide energy to the load, it is not suitable for balancing. In the standby state, the voltage of the battery cells can be accurately measured, so it is easy to find the cells that meet the balancing conditions for balancing. In the charging mode, the system can determine whether the voltage difference between the highest voltage cell and the lowest voltage cell reaches the balancing condition. If the condition is met, balancing is enabled to inhibit the charging speed of the highest voltage cell. Therefore, when the battery is in the discharging mode, balancing is turned off; when the battery is in the standby mode, balancing is turned on; when the battery is in the charging mode, balancing is not turned off. The minimum cell voltage is found among the monitored voltages of each individual cell in the preprocessed monitoring data, and the difference between the minimum cell voltage and the maximum cell voltage is calculated to obtain the target difference. The target difference is compared with the preset balancing voltage difference in the battery balancing strategy. If the difference between the target difference and the preset balancing voltage difference is greater than the preset balancing difference, the charging switch of the individual cell is turned off and the discharge flag bit of the individual cell is turned on. If the difference is less than or equal to the preset balancing difference, no balancing process is required temporarily, and the monitoring data is continuously collected. After excluding this individual cell, the calculation of the difference between the next minimum cell voltage and the balancing difference is continued, and the above process is repeated. It is judged whether the number of individual cells that need to be balanced is greater than three. If it is greater than three, the three cells with the largest voltage difference from the minimum voltage cell are balanced first. After the balancing of these three cells is completed, the balancing of other cells is performed, that is, the discharge flag bit of the corresponding individual cell is turned on for discharging until the difference between the recalculated target difference and the preset balancing voltage difference is less than the preset balancing difference, the discharge flag bit of the individual cell is turned off, and the charging mode is turned on. The above process is repeated until all the battery cells of the lithium battery pack are fully charged.

[0107] In the embodiment of the present invention, monitoring data of the lithium battery pack in standby mode, charging mode, and discharging mode is collected based on the data verification method, which can comprehensively collect data of the lithium battery pack in different modes and facilitate subsequent data analysis of the lithium battery pack in different modes. Based on the preprocessed monitoring data, overcurrent analysis, overtemperature analysis, and low-temperature analysis of the lithium battery pack in discharging mode / charging mode are carried out, so as to achieve multi-faceted safety analysis of the lithium battery pack. The target remaining capacity of the lithium battery pack in different modes is calculated based on the open-circuit voltage-Ah integration method, which can not only make up for the defect that the open-circuit voltage method has inaccurate estimation of the remaining capacity during battery charging and discharging, but also solve the problem that the Ah integration method cannot determine the initial value, making the obtained target remaining capacity more reliable. Based on the safety state analysis results of the lithium battery pack in different modes, calibrating the actual capacity and the target remaining capacity, and combining the preprocessed monitoring data to determine the corresponding control strategy to balance and protect the lithium battery pack in different modes can effectively manage the differences of the single cells in the lithium battery pack, greatly avoiding the occurrence of phenomena such as overcharging, over-discharging, and overcurrent of the lithium battery pack, thereby improving the service life and energy utilization rate of the lithium battery pack.

[0108] Embodiment 2

[0109] Please refer to Figure 2 , Figure 2 which is a schematic flowchart of the method for analyzing and controlling the health state of the lithium battery pack in another embodiment of the present invention. The method is applied to the lithium battery pack and the battery management system of an electric vehicle; the method includes:

[0110] S201: The battery management system collects monitoring data of the lithium battery pack in different modes based on the data verification method;

[0111] In the specific implementation process of the present invention, the battery management system performs read and write configuration of the voltage acquisition register based on device address verification; based on the read and write configuration, a single-cell battery voltage acquisition instruction is issued by using analog-to-digital conversion and data verification to obtain the single-cell battery voltage of the lithium battery pack in different modes, and a corresponding lithium battery pack voltage is generated based on the single-cell battery voltage. The different modes include standby mode, charging mode, and discharging mode; data sampling and conversion are performed on the analog quantity generated by the sampling resistor to obtain the lithium battery pack current in different modes; the current temperature of the lithium battery pack in different modes read is compared with the temperature at the previous moment, the target temperature is determined based on the comparison result, and the target temperature is calibrated based on the proportional coefficient to obtain the calibrated target temperature. The monitoring data of the lithium battery pack is composed of the single-cell battery voltage, the lithium battery pack voltage, the lithium battery pack current, and the calibrated target temperature.

[0112] S202: Preprocess the monitoring data to obtain preprocessed monitoring data;

[0113] S203: Analyze the safety state of the lithium battery pack in different modes based on the preprocessed monitoring data to obtain the safety state analysis result;

[0114] In the specific implementation process of the present invention, the step of analyzing the safety state of the lithium battery pack in different modes based on the preprocessed monitoring data to obtain the safety state analysis result includes: in the discharge mode / charging mode, compare the current of the lithium battery pack in the preprocessed monitoring data with the preset overcurrent protection threshold to obtain a comparison result, and perform overcurrent analysis on the lithium battery based on the comparison result to obtain the overcurrent analysis result; in the discharge mode / charging mode, compare the calibrated target temperature in the preprocessed monitoring data with the preset over-temperature threshold and the preset low-temperature threshold respectively to obtain the corresponding comparison results, and perform over-temperature analysis and low-temperature analysis on the lithium battery based on the corresponding comparison results to obtain the over-temperature analysis result and the low-temperature analysis result. The safety state analysis result is composed of the overcurrent analysis result, the over-temperature analysis result, and the low-temperature analysis result.

[0115] S204: Calculate the calibrated actual capacity of the lithium battery pack using the temperature capacity coefficient based on the preprocessed monitoring data, and calculate the target remaining capacity of the lithium battery pack in different modes based on the open-circuit voltage-Ah integration method;

[0116] S205: Determine the corresponding control strategy based on the safety state analysis result, the calibrated actual capacity, and the target remaining capacity of the lithium battery pack in different modes in combination with the preprocessed monitoring data;

[0117] S206: Perform overcurrent protection for charging, over-temperature protection for charging, low-temperature protection for charging, low-temperature protection for discharging, high-temperature protection for discharging, and overcurrent protection for discharging on the lithium battery pack in different modes based on the battery safety control strategy in the control strategy;

[0118] S207: Perform overcharge and overdischarge protection on the lithium battery pack in different modes based on the charge and discharge management strategy in the control strategy;

[0119] S208: Perform equalization control on the lithium battery pack in different modes using the discharge flag bit based on the battery equalization strategy in the control strategy.

[0120] In the specific implementation process of the present invention, the detailed steps for performing equalization control on the lithium battery pack in different modes can refer to Figure 3 , Figure 3 which is the detailed schematic diagram of step S208 in the embodiment of the present invention, as shown in Figure 3 shown:

[0121] S2081: Continuously collect the voltage of each single battery in the lithium battery pack in the charging mode / standby mode, calculate the difference between the minimum single-battery voltage and the maximum single-battery voltage to obtain the target difference;

[0122] In the specific implementation process of the present invention, in the discharge mode, since the battery itself needs to provide energy to the load, it is not suitable for balancing. In the standby state, the voltage of the battery cells can be accurately measured, so it is easy to find the cells that meet the balancing conditions for balancing. In the charging mode, the system can determine whether the difference between the highest cell voltage and the lowest cell voltage reaches the balancing condition. If the condition is met, balancing is enabled to inhibit the charging speed of the highest voltage cell. In this regard, when the battery is in the discharge mode, balancing is turned off; when the battery is in the standby mode, balancing is turned on; in the charging mode, balancing is not turned off. Among the monitored data of each single cell voltage after preprocessing, find the minimum single cell voltage, calculate the difference between the minimum single cell voltage and the maximum single cell voltage to obtain the target difference.

[0123] S2082: Determine whether the difference between the target difference and the preset balancing voltage difference is greater than the preset balancing difference;

[0124] In the specific implementation process of the present invention, compare the target difference with the preset balancing voltage difference in the battery balancing strategy. If the difference between the target difference and the preset balancing voltage difference is greater than the preset balancing difference, go to step S2083; if the difference between the target difference and the preset balancing voltage difference is less than or equal to the preset balancing difference, go to step S2081.

[0125] S2083: Take the single cells corresponding to the difference between the target difference and the preset balancing voltage difference being greater than the preset balancing difference as the single cells that need to be balanced;

[0126] S2084: Determine whether the number of single cells that need to be balanced is greater than three;

[0127] In the specific implementation process of the present invention, determine whether the single cells that need to be balanced are greater than three. If greater than three, go to step S2085; if not greater than three, directly go to step S2086.

[0128] S2085: First take the three cells with the largest difference among the single cells that need to be balanced;

[0129] S2086: Turn on the discharge flag bit of the single cells that need to be balanced;

[0130] S2087: Discharge the single cells;

[0131] S2088: Determine whether the difference between the recalculated target difference and the preset balancing voltage difference is less than the preset balancing difference;

[0132] S2089: Turn off the discharge flag bit and restart the charging state of the corresponding single cells.

[0133] In the embodiments of the present invention, by collecting the monitoring data of the lithium battery pack in the standby mode, charging mode, and discharging mode based on the data verification method, it is possible to comprehensively collect the data of the lithium battery pack in different modes, which is convenient for subsequent data analysis of the lithium battery pack in different modes. Based on the preprocessed monitoring data, overcurrent analysis, overtemperature analysis, and low-temperature analysis of the lithium battery pack in the discharging mode / charging mode are carried out, so as to achieve multi-faceted safety analysis of the lithium battery pack. Based on the open-circuit voltage-Ah integration method, the target remaining capacity of the lithium battery pack in different modes is calculated. This can not only make up for the defect that the open-circuit voltage method has inaccurate estimation of the remaining capacity during the charging and discharging of the battery, but also solve the problem that the Ah integration method cannot determine the initial value, making the obtained target remaining capacity more reliable. Based on the safety state analysis results of the lithium battery pack in different modes, the calibrated actual capacity and the target remaining capacity, combined with the preprocessed monitoring data, the corresponding control strategies are determined to perform balancing and protection processing on the lithium battery pack in different modes, which can effectively manage the differences of the single cells in the lithium battery pack, greatly avoid the occurrence of phenomena such as overcharging, over-discharging, and overcurrent of the lithium battery pack, and thus improve the service life and energy utilization rate of the lithium battery pack.

[0134] Embodiment III

[0135] Please refer to Figure 4 , Figure 4 which is a schematic structural diagram of the health state analysis and control device for the lithium battery pack in the embodiments of the present invention. The device is applied to the lithium battery pack and the battery management system of an electric vehicle; the device includes:

[0136] Data acquisition module 31: used for the battery management system to collect the monitoring data of the lithium battery pack in different modes based on the data verification method;

[0137] Pretreatment module 32: used for preprocessing the monitoring data to obtain the preprocessed monitoring data;

[0138] Safety state analysis module 33: used for performing safety state analysis of the lithium battery pack in different modes based on the preprocessed monitoring data to obtain the safety state analysis results;

[0139] Capacity calculation module 34: used for calculating the calibrated actual capacity of the lithium battery pack based on the preprocessed monitoring data using the temperature capacity coefficient, and calculating the target remaining capacity of the lithium battery pack in different modes based on the open-circuit voltage-Ah integration method;

[0140] Strategy determination module 35: used for determining the corresponding control strategies based on the safety state analysis results, calibrated actual capacity, and target remaining capacity of the lithium battery pack in different modes, combined with the preprocessed monitoring data;

[0141] Balanced protection module 36: used to perform balancing and protection processing on the lithium battery pack in different modes based on the control strategy.

[0142] In the specific implementation process of the present invention, the specific implementation manner of the device item can refer to the implementation manner of the above method item, which will not be elaborated here.

[0143] In the embodiment of the present invention, monitoring data of the lithium battery pack in the standby mode, charging mode, and discharging mode is collected based on the data verification method, which can comprehensively collect the data of the lithium battery pack in different modes and facilitate subsequent data analysis of the lithium battery pack in different modes. Based on the preprocessed monitoring data, overcurrent analysis, overtemperature analysis, and low-temperature analysis of the lithium battery pack in the discharging mode / charging mode are carried out, so as to achieve multi-faceted safety analysis of the lithium battery pack. The target remaining capacity of the lithium battery pack in different modes is calculated based on the open-circuit voltage-Ah integration method, which can not only make up for the defect that the open-circuit voltage method has inaccurate estimation of the remaining capacity during the charge and discharge of the battery, but also solve the problem that the Ah integration method cannot determine the initial value, making the obtained target remaining capacity more reliable. Based on the safety state analysis results of the lithium battery pack in different modes, the calibrated actual capacity and the target remaining capacity, combined with the preprocessed monitoring data, determine the corresponding control strategy to perform balancing and protection processing on the lithium battery pack in different modes, which can effectively manage the differences of the single cells in the lithium battery pack and greatly avoid the occurrence of phenomena such as overcharging, over-discharging, and overcurrent of the lithium battery pack, thereby improving the service life and energy utilization rate of the lithium battery pack.

[0144] A computer-readable storage medium provided by an embodiment of the present invention, on which a computer program is stored, and when the program is executed by a processor, it implements the method for analyzing and controlling the health state of the lithium battery pack in any one of the above embodiments. Among them, the computer-readable storage medium includes but is not limited to any type of disk (including floppy disk, hard disk, optical disk, CD-ROM, and magneto-optical disk), ROM (Read-Only Memory), RAM (Random Access Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory, magnetic card or optical card. That is, the storage device includes any medium that can store or transmit information in a readable form by a device (such as a computer, mobile phone), and can be a read-only memory, a magnetic disk or an optical disk, etc.

[0145] In addition, the above has introduced in detail a method and related device for analyzing and controlling the health state of a lithium battery pack provided by an embodiment of the present invention. In this article, specific examples should have been used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A method for analyzing and controlling the health status of a lithium battery pack, characterized in that: A lithium battery pack and a battery management system applied to electric vehicles; the method comprises: The battery management system collects monitoring data of lithium battery packs in different modes based on the data verification method; Preprocessing the monitoring data to obtain preprocessed monitoring data; Based on the pre-processed monitoring data, the safety status of the lithium battery pack in different modes is analyzed to obtain the safety status analysis results; The calibrated actual capacity of the lithium battery pack is calculated based on the preprocessed monitoring data using the temperature capacity coefficient, and the target remaining capacity of the lithium battery pack in different modes is calculated based on the open circuit voltage-ampere-hour integration method; Determine the corresponding control strategy based on the safety status analysis results of the lithium battery pack in different modes, the calibrated actual capacity and the target remaining capacity combined with the pre-processed monitoring data; Based on the control strategy, the lithium battery packs in different modes are balanced and protected.

2. The method for analyzing and controlling the health status of a lithium battery pack according to claim 1, characterized in that: The data verification method is used to collect monitoring data of the lithium battery pack in different modes, including: The battery management system performs read and write configuration of the voltage acquisition register based on device address verification; Based on the read-write configuration, analog-to-digital conversion and data verification are used to issue a single cell voltage acquisition instruction to obtain the single cell voltage of the lithium battery pack in different modes, and the corresponding lithium battery pack voltage is generated based on the single cell voltage, and the different modes include standby mode, charging mode and discharging mode; Perform data sampling and conversion on the analog quantity generated by the sampling resistor to obtain the lithium battery pack current in different modes; The current temperature of the lithium battery pack read in different modes is compared with the temperature at the previous moment, the target temperature is determined based on the comparison result, and the target temperature is calibrated based on the proportional coefficient to obtain the calibrated target temperature. The monitoring data of the lithium battery pack is composed of the single cell voltage, lithium battery pack voltage, lithium battery pack current and calibrated target temperature.

3. The method for analyzing and controlling the health status of a lithium battery pack according to claim 1, characterized in that: The preprocessing of the monitoring data to obtain the preprocessed monitoring data includes: The monitoring data are subjected to standardization processing and data integration processing to obtain pre-processed monitoring data.

4. The method for analyzing and controlling the health status of a lithium battery pack according to claim 1, characterized in that: The safety status analysis of the lithium battery pack in different modes is performed based on the pre-processed monitoring data to obtain the safety status analysis results, including: In the discharge mode / charge mode, the lithium battery pack current in the preprocessed monitoring data is compared with the preset overcurrent protection threshold to obtain a comparison result, and an overcurrent analysis of the lithium battery is performed based on the comparison result to obtain an overcurrent analysis result; In the discharge mode / charge mode, the calibrated target temperature in the preprocessed monitoring data is compared with the preset over-temperature threshold and the preset low-temperature threshold, respectively, to obtain corresponding comparison results, and over-temperature analysis and low-temperature analysis of the lithium battery are performed based on the corresponding comparison results to obtain over-temperature analysis results and low-temperature analysis results. The over-current analysis results, over-temperature analysis results and low-temperature analysis results constitute the safety status analysis results.

5. The method for analyzing and controlling the health status of a lithium battery pack according to claim 1, characterized in that: The method of calculating the calibrated actual capacity of the lithium battery pack based on the preprocessed monitoring data using the temperature capacity coefficient includes: The calibrated actual capacity of the lithium battery pack is calculated based on the calibration target temperature in the preprocessed monitoring data using the temperature capacity coefficient. The calculation expression of the calibrated actual capacity is: Among them, RL is the actual capacity of calibration, BL is the nominal capacity of the lithium battery pack, σ is the temperature capacity coefficient, and T is the calibration target temperature.

6. The method for analyzing and controlling the health status of a lithium battery pack according to claim 1, characterized in that: The calculation of the target remaining capacity of the lithium battery pack in different modes based on the open circuit voltage-ampere-hour integration method includes: The initial state of charge is calculated based on the open circuit voltage method. The calculation expression of the initial state of charge is: OCV SOC =index*10+((SocOcvTab[index]-voltage)*10) / (SocOcvTab[index]-SocOcvTab[index+1]), BMSCAP OCV-SOC =MR*OCV SOC , Among them, OCV SOC is the percentage of state of charge, SocOcvTab[] is the voltage table corresponding to the state of charge of the lithium battery pack, index is the initial point, voltage is the open circuit voltage, BMSCAP OCV-SOC is the initial state of charge, MR is the full capacity of the lithium battery pack; Based on the initial state of charge, the first target remaining capacity of the lithium battery pack in the charging mode is calculated using the ampere-hour integration method. The calculation expression of the first target remaining capacity is: Among them, BMSCAP AHOCV-SOC-C1 The first target remaining capacity, BMSCAP OCV-SOC is the initial state of charge, A cur is the current value from time period t0 to time period t in charging mode; Based on the initial state of charge, the second target remaining capacity of the lithium battery pack in the discharge mode is calculated using the ampere-hour integration method. The calculation expression of the second target remaining capacity is: Among them, BMSCAP AHOCV-SOC-C2 The second target remaining capacity, BMSCAP OCV-SOC is the initial state of charge, A cur is the current value from time period t0 to time period t in the discharge mode.

7. The method for analyzing and controlling the health status of a lithium battery pack according to claim 1, characterized in that: The corresponding control strategy is determined based on the safety status analysis results of the lithium battery pack in different modes, the calibrated actual capacity and the target remaining capacity combined with the pre-processed monitoring data, including: Determine the battery safety control strategy based on the overcurrent analysis results, overtemperature analysis results and low temperature analysis results of the lithium battery in the discharge mode / charge mode; Determine the battery charge and discharge management strategy based on the calibrated actual capacity and target remaining capacity of the lithium battery pack in different modes; A battery balancing strategy is determined based on the single cell voltage of the lithium battery pack in different modes combined with a preset balancing voltage difference, and a management and control strategy is determined based on the battery safety control strategy, the charge and discharge management strategy and the battery balancing strategy.

8. The method for analyzing and controlling the health status of a lithium battery pack according to claim 1, characterized in that: The balancing and protecting the lithium battery packs in different modes based on the control strategy includes: Based on the battery safety control strategy in the management and control strategy, the lithium battery pack in different modes is protected against charging overcurrent, charging overtemperature, charging low temperature, discharging low temperature, discharging high temperature and discharging overcurrent; Based on the charge and discharge management strategy in the control strategy, the lithium battery pack in different modes is protected from overcharge and overdischarge; Based on the battery balancing strategy in the management and control strategy, the discharge flag is used to balance and control the lithium battery pack in different modes.

9. A health status analysis and control device for a lithium battery pack, characterized in that: A lithium battery pack and a battery management system used in electric vehicles; the device comprises: Data acquisition module: used by the battery management system to collect monitoring data of lithium battery packs in different modes based on data verification method; Preprocessing module: used to preprocess the monitoring data to obtain preprocessed monitoring data; Safety status analysis module: used to analyze the safety status of lithium battery packs in different modes based on pre-processed monitoring data to obtain safety status analysis results; Capacity calculation module: used to calculate the calibrated actual capacity of the lithium battery pack based on the pre-processed monitoring data using the temperature capacity coefficient, and calculate the target remaining capacity of the lithium battery pack in different modes based on the open circuit voltage-ampere-hour integration method; Strategy determination module: used to determine the corresponding control strategy based on the safety status analysis results of the lithium battery pack in different modes, the calibration actual capacity and the target remaining capacity combined with the pre-processed monitoring data; Balance protection module: used to balance and protect lithium battery packs in different modes based on the management and control strategy.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and when the computer instructions are executed on an electronic device, the electronic device executes the health status analysis and control method of a lithium battery pack as described in any one of claims 1 to 8.

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