Control method of embedded lithium battery management system

Abstract

The invention relates to the technical field of lithium battery management systems, in particular to a control method of an embedded lithium battery management system. The control method comprises the following steps: S1, the data acquisition module acquires real-time data of the battery management system, wherein the real-time data comprises real-time voltage, discharge current, short-circuit current, charge current, temperature, corresponding duration, residual capacity, nominal capacity of adopted battery cells, nominal voltage and internal resistance of single battery cells; s2, a parameter configuration module configures voltameter parameters and protection parameters; s3, carrying out capacity learning by a capacity learning module, and judging whether the battery capacity value FCC is updated or not; s4, the calculation module carries out SOC calculation; s5, the system protection module controls charging and discharging of the battery management system and gives an alarm; and S6, data recording. Compared with the prior art, technicians can conveniently adjust corresponding parameters, efficient management and accurate monitoring of the lithium battery are achieved, the safety of the battery in different use stages is ensured, and reliable battery state information is provided.

Description

Technical Field

[0001] This invention relates to the field of lithium battery management system technology, specifically a control method for an embedded lithium battery management system. Background Technology

[0002] With the widespread application of lithium batteries in consumer electronics, electric vehicles, and energy storage systems, the importance of lithium battery management systems (BMS) is becoming increasingly prominent. However, current BMS systems have shortcomings in functionality and accuracy, lacking effective management of the battery charging and discharging process, real-time monitoring of battery status, and accurate calculation of remaining battery capacity. Furthermore, batteries degrade due to aging and environmental factors during use, requiring real-time detection and dynamic updates. Technicians need to be able to adjust corresponding parameters promptly to ensure the system's safety and stability. Summary of the Invention

[0003] To address the problems mentioned in the background art, this invention provides a control method for an embedded lithium battery management system, including an embedded lithium battery management system. The embedded lithium battery management system includes a data acquisition module, a parameter configuration module, a capacity learning module, a calculation module, and a system protection module. The control method includes the following steps: S1, the data acquisition module acquires real-time data from the battery management system, including real-time voltage, discharge current, short-circuit current, charging current, temperature, corresponding duration, remaining capacity, and the nominal capacity, nominal voltage, and internal resistance of the used battery cells; S2, the parameter configuration module configures fuel gauge parameters and protection parameters; S3, the capacity learning module performs capacity learning and determines whether to update the battery capacity value (FCC); S4, the calculation module performs SOC calculation; S5, the system protection module controls the charging and discharging of the battery management system and issues warnings; S6, the data is recorded and saved.

[0004] In step S2, the configured protection parameters include: overvoltage protection threshold, set within the range of 4V-4.25V; overvoltage protection delay time, set within the range of 1-16s; overvoltage protection release threshold, set within the range of 4V-4.2V; undervoltage protection threshold, set within the range of 2.0V-3.2V; undervoltage protection release threshold, set within the range of 3.0V-3.5V; discharge overcurrent threshold and charging overcurrent threshold, set within the range of 1A-60A; and discharge overcurrent delay time and charging overcurrent delay time, set within the range of... The range is set as follows: 100ms-16s; short-circuit current threshold, set to 80A-500A; short-circuit delay time, set to 100us-1ms; charging over-temperature threshold and charging over-temperature release threshold, set to 40℃-60℃; charging under-temperature threshold and charging under-temperature release threshold, set to -10℃-10℃; discharging over-temperature threshold and discharging over-temperature release threshold, set to 50℃-80℃; discharging under-temperature threshold and discharging under-temperature release threshold, set to -10℃-30℃.

[0005] The parameters configured in step S2 include configuring the battery pack design series number S, which is set to a range of 10-16; the battery pack design parallel number P, which is set to a range of 1-16; the battery pack design voltage DV, which is the nominal voltage multiplied by the battery pack design series number S; the battery pack design capacity DC, which is the nominal capacity multiplied by the battery pack design parallel number P; the battery pack full charge capacity FCCmax, cycle count capacity, and capacity learning start capacity CLC, which are set to a range of 1-65555mAh; the battery pack full charge voltage FCVmax, precharge start voltage PRECV, and capacity learning start voltage CLV, which are set to a range of 1-255V; the trickle cutoff current TC, which is set to a range of 0.1A-10A; the trickle cutoff voltage TV, which is set to a range of 1-255V; the trickle time TT, which is set to a range of 0.01-100min; and the low battery alarm threshold, which is set to a range of 0-50%.

[0006] The capacity learning in step S3 includes the following steps: S31, obtaining the real-time current value CUR and the real-time voltage value VOL; S32, calculating FCC, the calculation formula is as follows: Where FCC is the full charge capacity, I(t) is the current at time t, t0 is the start time of integration, and t is the end time of integration; S33, when the remaining capacity in the real-time data is less than the capacity learning start capacity, and the real-time voltage is less than the capacity learning start voltage, the capacity learning function is enabled, and FCC starts updating; S34, the current remaining capacity is recorded as the starting reference capacity FCCstart; S35, the system begins to prepare for the next charge, and the next charge begins to perform integration calculation on FCC, the formula of which is as follows: Among them, CUR is the current value sampled in real time by the battery system. When calculating the energy loss and integrating the current, multiply the current integration coefficient by the current. S36: Determine whether the FCC is updated. When the charging enters the trickle charging stage, determine that the voltage is greater than the trickle cut-off voltage, the current is less than the trickle cut-off current, and the trickle time is greater than or equal to the trickle time threshold, and record the FCCupd at this time. When VOL>FCVmax and FCCupd <= FCCmax, update FCCupd to FCC. When VOL>FCVmax and FCCupd>FCCmax, update FCCmax to FCC. If VOL<FCVmax, FCC is not updated;

[0007] The SOC calculation in step S4 described above includes the following steps: S41: Calculate the total battery voltage, and the formula is as follows: where n is the number of battery packs in series S; calculate the total battery capacity, and the formula is as follows: where n is the number of battery packs in parallel P; S42: Calculate SOC, and the formula is as follows: SOC = RMC / FCC * 100%, where RMC is the remaining capacity of the current integration.

[0008] The control of the charge and discharge of the battery management system and the issuance of warnings in step S5 described above specifically includes the following steps: S51: Determine that the real-time voltage is higher than the overvoltage protection threshold and the duration exceeds the overvoltage protection delay time, and the battery management system closes the charging. When the real-time voltage is lower than the overvoltage protection release threshold, the battery management system reopens the charging. When the real-time voltage is lower than the undervoltage protection threshold and the duration exceeds the undervoltage protection delay time, the battery management system closes the discharge. When the real-time voltage is higher than the undervoltage protection release threshold, the battery management system reopens the discharge; S52: Determine that the discharge current is higher than the discharge overcurrent threshold and the duration exceeds the discharge overcurrent delay time, and the battery management system closes the discharge; S53: Determine that the short-circuit current is higher than the short-circuit current threshold and the duration exceeds the short-circuit delay time, and the battery management system closes the discharge; S54: Determine that the charging current is higher than the charging overcurrent threshold and the duration exceeds the charging overcurrent delay time, and the battery management system closes the charging. When the charging current is lower than the trickle cut-off current and the voltage is higher than the trickle cut-off voltage and the duration exceeds the trickle time, it is determined that the battery is full, and the battery management system stops charging; S55: When the temperature is higher than the charging over-temperature threshold or the discharge over-temperature threshold, the battery management system closes the charging. When the temperature is lower than the charging over-temperature release threshold or the discharge over-temperature release threshold, the battery management system reopens the charging. When the temperature is lower than the charging under-temperature threshold or the discharge under-temperature threshold, the battery management system closes the charging. When the temperature is higher than the charging under-temperature release threshold or the discharge under-temperature release threshold, the battery management system reopens the charging; S56: Determine that the SOC is lower than the low battery warning threshold, and the battery management system issues a low battery warning.

[0009] Compared with existing technologies, this invention enables technicians to adjust corresponding parameters through the collaborative work of multiple modules, achieving efficient management and precise monitoring of lithium batteries, dynamically updating battery capacity values, ensuring the safety and performance of batteries at different stages of use, and providing reliable battery status information. Attached Figure Description

[0010] Figure 1 This is a flowchart of the method of the present invention;

[0011] Figure 2 Here is a flowchart of the capacity learning module.

[0012] Figure 3 This is a flowchart of the system protection module. Detailed Implementation

[0013] The present invention will now be further described with reference to the accompanying drawings.

[0014] like Figure 1 A control method for an embedded lithium battery management system includes an embedded lithium battery management system, which comprises a data acquisition module, a parameter configuration module, a capacity learning module, a calculation module, and a system protection module. The control method includes the following steps: S1, the data acquisition module acquires real-time data from the battery management system, including real-time voltage, discharge current, short-circuit current, charging current, temperature, remaining capacity, and the nominal capacity, nominal voltage, and single-cell internal resistance of the battery cells used; S2, the parameter configuration module configures fuel gauge parameters and protection parameters; S3, the capacity learning module performs capacity learning and determines whether to update the battery capacity value (FCC).

[0015] S4. The calculation module performs SOC calculation; S5. The system protection module controls the battery management system to charge and discharge and issues warnings; S6. Data is recorded and saved.

[0016] In step S2, the protection parameters are configured, including: overvoltage protection threshold (set to a range of 4V-4.25V); overvoltage protection delay time (set to a range of 1-16s); overvoltage protection release threshold (set to a range of 4V-4.2V); undervoltage protection threshold (set to a range of 2.0V-3.2V); undervoltage protection release threshold (set to a range of 3.0V-3.5V); discharge overcurrent threshold and charging overcurrent threshold (set to a range of 1A-60A); and discharge overcurrent delay time and charging overcurrent delay time (set to a range of...). The ranges are as follows: 100ms-16s; short-circuit current threshold, set to 80A-500A; short-circuit delay time, set to 100us-1ms; charging over-temperature threshold and charging over-temperature release threshold, set to 40℃-60℃; charging under-temperature threshold and charging under-temperature release threshold, set to -10℃-10℃; discharging over-temperature threshold and discharging over-temperature release threshold, set to 50℃-80℃; discharging under-temperature threshold and discharging under-temperature release threshold, set to -10℃-30℃.

[0017] In step S2, the parameters configured for the battery pack include: the number of series batteries S (set to a range of 10-16); the number of parallel batteries P (set to a range of 1-16); the battery pack design voltage DV (the nominal voltage multiplied by the number of series batteries S); the battery pack design capacity DC (the nominal capacity multiplied by the number of parallel batteries P); the battery pack full charge capacity FCCmax, cycle count capacity, and capacity learning start capacity CLC (set to a range of 1-65555mAh); the battery pack full charge voltage FCVmax, precharge start voltage PRECV, and capacity learning start voltage CLV (set to a range of 1-255V); the trickle cutoff current TC (set to a range of 0.1A-10A); the trickle cutoff voltage TV (set to a range of 1-255V); the trickle time TT (set to a range of 0.01-100min); and the low battery alarm threshold (set to a range of 0-50%).

[0018] The capacity learning in step S3 includes the following steps: S31, obtaining the real-time current value CUR and the real-time voltage value VOL; S32, calculating FCC, the calculation formula is as follows: Where FCC is the full charge capacity, I(t) is the current at time t, t0 is the start time of integration, and t is the end time of integration; S33, when the remaining capacity in the real-time data is less than the capacity learning start capacity, and the real-time voltage is less than the capacity learning start voltage, the capacity learning function is enabled, and FCC starts updating; S34, the current remaining capacity is recorded as the starting reference capacity FCCstart; S35, the system begins to prepare for the next charge, and the next charge begins to perform integration calculation on FCC, the formula of which is as follows: Among them, CUR is the current value sampled in real time by the battery system. When calculating the energy loss and integrating the current, multiply the current integration coefficient by the current. S36: Determine whether the FCC is updated. When the charging enters the trickle charging stage, determine that the voltage is greater than the trickle cut-off voltage, the current is less than the trickle cut-off current, and the trickle time is greater than or equal to the trickle time threshold, and record the FCCupd at this time. When VOL>FCVmax and FCCupd <= FCCmax, update FCCupd to FCC. When VOL>FCVmax and FCCupd>FCCmax, update FCCmax to FCC. If VOL<FCVmax, the FCC is not updated.

[0019] The SOC calculation in step S4 includes the following steps: S41: Calculate the total battery voltage, and the formula is as follows: where n is the number of battery pack strings S; calculate the total battery capacity, and the formula is as follows: where n is the number of battery pack parallel connections P;

[0020] S42: Calculate the SOC, and the formula is as follows: SOC = RMC / FCC * 100%, where RMC is the remaining capacity of the current integration.

[0021] The control of the charge and discharge of the battery management system and the issuance of warnings in step S5 specifically includes the following steps: S51: Determine that the real-time voltage is higher than the overvoltage protection threshold and the duration exceeds the overvoltage protection delay time, and the battery management system closes the charging. When the real-time voltage is lower than the overvoltage protection release threshold, the battery management system re-opens the charging. When the real-time voltage is lower than the undervoltage protection threshold and the duration exceeds the undervoltage protection delay time, the battery management system closes the discharge. When the real-time voltage is higher than the undervoltage protection release threshold, the battery management system re-opens the discharge; S52: Determine that the discharge current is higher than the discharge overcurrent threshold and the duration exceeds the discharge overcurrent delay time, and the battery management system closes the discharge; S53: Determine that the short-circuit current is higher than the short-circuit current threshold and the duration exceeds the short-circuit delay time, and the battery management system closes the discharge; S54: Determine that the charging current is higher than the charging overcurrent threshold and the duration exceeds the charging overcurrent delay time, and the battery management system closes the charging. When the charging current is lower than the trickle cut-off current and the voltage is higher than the trickle cut-off voltage, and the duration exceeds the trickle time, it is determined that the battery is full, and the battery management system stops charging; S55: When the temperature is higher than the charging over-temperature threshold or the discharge over-temperature threshold, the battery management system closes the charging. When the temperature is lower than the charging over-temperature release release over-temperature release threshold or the discharge over-temperature release threshold, the battery management system re-opens the charging. When the temperature is lower than the charging under-temperature threshold or the discharge under-temperature threshold, the battery management system closes the charging. When the temperature is higher than the charging under-temperature release threshold or the discharge under-temperature release threshold, the battery management system re-opens the charging; S56: Determine that the SOC is lower than the low battery warning threshold, and the battery management system issues a low battery warning.

Claims

1. A control method for an embedded lithium battery management system, comprising an embedded lithium battery management system, the embedded lithium battery management system including a data acquisition module, a parameter configuration module, a capacity learning module, a calculation module, and a system protection module, characterized in that: The control method includes the following steps: S1, the data acquisition module acquires real-time data from the battery management system, including real-time voltage, discharge current, short-circuit current, charging current, temperature, corresponding duration, remaining capacity, and the nominal capacity, nominal voltage, and internal resistance of the used battery cells; S2, the parameter configuration module configures the fuel gauge parameters and protection parameters; S3, the capacity learning module performs capacity learning and determines whether to update the battery capacity value (FCC); S4, the calculation module performs SOC calculation; S5, the system protection module controls the charging and discharging of the battery management system and issues warnings; S6, the data is recorded and saved.

2. The control method for an embedded lithium battery management system according to claim 1, characterized in that: In step S2, the configured protection parameters include: overvoltage protection threshold, set within the range of 4V-4.25V; overvoltage protection delay time, set within the range of 1-16s; overvoltage protection release threshold, set within the range of 4V-4.2V; undervoltage protection threshold, set within the range of 2.0V-3.2V; undervoltage protection release threshold, set within the range of 3.0V-3.5V; discharge overcurrent threshold and charging overcurrent threshold, set within the range of 1A-60A; and discharge overcurrent delay time and charging overcurrent delay time, set within the range of... The range is set as follows: 100ms-16s; short-circuit current threshold, set to 80A-500A; short-circuit delay time, set to 100us-1ms; charging over-temperature threshold and charging over-temperature release threshold, set to 40℃-60℃; charging under-temperature threshold and charging under-temperature release threshold, set to -10℃-10℃; discharging over-temperature threshold and discharging over-temperature release threshold, set to 50℃-80℃; discharging under-temperature threshold and discharging under-temperature release threshold, set to -10℃-30℃.

3. The control method for an embedded lithium battery management system according to claim 1, characterized in that: The parameters configured in step S2 include configuring the battery pack design series number S, which is set to a range of 10-16; the battery pack design parallel number P, which is set to a range of 1-16; the battery pack design voltage DV, which is the nominal voltage multiplied by the battery pack design series number S; the battery pack design capacity DC, which is the nominal capacity multiplied by the battery pack design parallel number P; the battery pack full charge capacity FCCmax, cycle count capacity, and capacity learning start capacity CLC, which are set to a range of 1-65555mAh; the battery pack full charge voltage FCVmax, precharge start voltage PRECV, and capacity learning start voltage CLV, which are set to a range of 1-255V; the trickle cutoff current TC, which is set to a range of 0.1A-10A; the trickle cutoff voltage TV, which is set to a range of 1-255V; the trickle time TT, which is set to a range of 0.01-100min; and the low battery alarm threshold, which is set to a range of 0-50%.

4. The control method for an embedded lithium battery management system according to claim 1, characterized in that: The capacity learning in step S3 includes the following steps: S31, obtaining the real-time current value CUR and the real-time voltage value VOL; S32, calculating FCC, the calculation formula is as follows: Where FCC is the full charge capacity, I(t) is the current at time t, t0 is the start time of integration, and t is the end time of integration; S33, when the remaining capacity in the real-time data is less than the capacity learning start capacity, and the real-time voltage is less than the capacity learning start voltage, the capacity learning function is enabled, and FCC starts updating; S34, the current remaining capacity is recorded as the starting reference capacity FCCstart; S35, the system starts preparing for the next charge, and the next charge begins to perform integration calculation on FCC, the formula of which is as follows: Where CUR is the current value sampled in real time by the battery system. When calculating energy loss, the current integration coefficient is multiplied by the current during current integration. S36. Determine whether FCC should be updated. When charging enters the trickle stage, determine whether the voltage is greater than the trickle cutoff voltage, the current is less than the trickle cutoff current, and the slippage time is greater than or equal to the slippage time threshold. Record FCCupd at this time. If VOL>FCVmax and FCCupd<=FCCmax, then update FCCupd to FCC. If VOL>FCVmax and FCCupd>FCCmax, then update FCCmax to FCC. If VOL<FCVmax, then FCC is not updated.

5. The control method for an embedded lithium battery management system according to claim 1, characterized in that: The SOC calculation in step S4 includes the following steps: S41, Calculate the total battery voltage, using the following formula: Where n is the number of battery pack strings S; the formula for calculating the total battery capacity is as follows: , where n is the number of parallel batteries P; S42, calculate SOC, the formula is as follows: SOC = RMC / FCC*100%, where RMC is the remaining capacity of the current integral.

6. The control method for an embedded lithium battery management system according to claim 1, characterized in that: The step S5, which controls the charging and discharging of the battery management system and issues warnings, specifically includes the following steps: S51, if the real-time voltage is higher than the overvoltage protection threshold and the duration exceeds the overvoltage protection delay time, the battery management system shuts down charging; if the real-time voltage is lower than the overvoltage protection release threshold, the battery management system restarts charging; if the real-time voltage is lower than the undervoltage protection threshold and the duration exceeds the undervoltage protection delay time, the battery management system shuts down discharging; if the real-time voltage is higher than the undervoltage protection release threshold, the battery management system restarts discharging; S52, if the discharge current is higher than the discharge overcurrent threshold and the duration exceeds the discharge overcurrent delay time, the battery management system shuts down discharging; S53, if the short-circuit current is higher than the short-circuit current threshold and the duration exceeds the short-circuit delay time, the battery management system shuts down discharging; 54. If the charging current is higher than the charging overcurrent threshold and the duration exceeds the charging overcurrent delay time, the battery management system shuts down charging. If the charging current is lower than the trickle cutoff current and the voltage is higher than the trickle cutoff voltage and the duration exceeds the trickle time, the battery is considered fully charged, and the battery management system stops charging. S55. If the temperature is higher than the charging overtemperature threshold or the discharging overtemperature threshold, the battery management system shuts down charging. If the temperature is lower than the charging overtemperature release threshold or the discharging overtemperature release threshold, the battery management system restarts charging. If the temperature is lower than the charging undertemperature threshold or the discharging undertemperature threshold, the battery management system shuts down charging. If the temperature is higher than the charging undertemperature release threshold or the discharging undertemperature release threshold, the battery management system restarts charging. S56. If the SOC is lower than the low battery warning threshold, the battery management system issues a low battery warning.

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