CN117074973A - Battery cell SOC estimation method, device, computer equipment and storage medium - Google Patents

Battery cell SOC estimation method, device, computer equipment and storage medium Download PDF

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Publication number
CN117074973A
CN117074973A CN202310890424.9A CN202310890424A CN117074973A CN 117074973 A CN117074973 A CN 117074973A CN 202310890424 A CN202310890424 A CN 202310890424A CN 117074973 A CN117074973 A CN 117074973A
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China
Prior art keywords
battery
calibrated
soc
value
battery cell
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CN202310890424.9A
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Chinese (zh)
Inventor
程海峰
徐良渡
李志飞
杜仑
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Zhejiang Zero Run Technology Co Ltd
Zhejiang Lingxiao Energy Technology Co Ltd
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Zhejiang Zero Run Technology Co Ltd
Zhejiang Lingxiao Energy Technology Co Ltd
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Priority to CN202310890424.9A priority Critical patent/CN117074973A/en
Publication of CN117074973A publication Critical patent/CN117074973A/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/385—Arrangements for measuring battery or accumulator variables
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/396—Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery

Abstract

The application relates to a battery cell SOC estimation method, a battery cell SOC estimation device, computer equipment and a storage medium. The method comprises the following steps: acquiring a first SOC value of a target battery cell and the accumulated charge and discharge quantity of the battery; the target battery cell is any battery cell in the battery; judging whether the first SOC value of the target battery cell needs to be calibrated or not; if the first SOC value needs to be calibrated, acquiring a to-be-calibrated quantity of the first SOC value, and calibrating the first SOC value and the accumulated charge-discharge quantity based on the to-be-calibrated quantity; and updating the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge-discharge quantity. By adopting the method, the SOC values of all the battery cells can be updated according to the calibration results of the SOC values of the single battery cell and the accumulated charge and discharge amount, and the calculated amount required by estimating the SOC values of the battery cells is greatly reduced while the calibration of the to-be-calibrated amount is realized, so that the technical effects of reducing the calculated amount and the occupation condition of hardware resources can be achieved.

Description

Battery cell SOC estimation method, device, computer equipment and storage medium
Technical Field
The present application relates to the field of battery management technologies, and in particular, to a method and apparatus for estimating SOC of a battery cell, a computer device, and a storage medium.
Background
With the development of society, the energy use of society is gradually biased to green energy, and products driven by electric energy also gradually occupy the mainstream market, so that the battery management technology is also getting more and more attention.
Current battery management techniques include SOC estimation, SOC (State of Charge), i.e., the amount of remaining charge, which is the proportion of the available charge in the battery to the nominal capacity. The estimation of the residual electric quantity of the power equipment can be realized by estimating the SOC, so that a user can reasonably plan a use plan of the power equipment based on the residual electric quantity.
The mainstream SOC estimation method includes an ampere-hour integration method, an open-circuit method, and the like. The ampere-hour integration method needs to perform integral calculation on the current variation, however, by the ampere-hour integration method, the SOC values of all the battery cells in the battery pack need to be repeatedly calculated and output for many times, the requirements on the memory and hardware resources are high, and obvious errors exist in the current fluctuation and high-temperature state.
Therefore, the current battery management technology still has the problems of large SOC estimation calculation amount and occupation of hardware resources.
Disclosure of Invention
In view of the foregoing, it is desirable to provide a method, an apparatus, a computer device, and a computer-readable storage medium for estimating a battery SOC, which can reduce the amount of computation and the occupation of hardware resources.
In a first aspect, the present embodiment provides a method for estimating SOC of a battery cell, where the battery includes at least two battery cells, the method includes:
acquiring a first SOC value of a target battery cell and the accumulated charge and discharge quantity of the battery; the target battery cell is any battery cell in the battery;
judging whether the first SOC value of the target battery cell needs to be calibrated or not; if the first SOC value needs to be calibrated, acquiring a to-be-calibrated quantity of the first SOC value, and calibrating the first SOC value and the accumulated charge-discharge quantity based on the to-be-calibrated quantity;
and updating the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge-discharge quantity.
In one embodiment, the acquiring the first SOC value of the target battery cell and the accumulated charge/discharge amount of the battery further includes:
judging whether the target battery cell is balanced or not;
and if equalization is started, acquiring the equalization current and the equalization time length of the target battery cell, and updating the first SOC value based on the equalization current and the equalization time length.
In one embodiment, the determining whether the first SOC value of the target battery cell needs to be calibrated includes:
acquiring a current value of the battery;
and if the current value is not equal to a preset current threshold value, updating the accumulated charge-discharge amount based on the current value.
In one embodiment, the calibrating the first SOC value and the accumulated charge-discharge amount based on the amount to be calibrated includes:
acquiring error information and error adjustment interval duration of a current sensor;
calculating the accumulated error electric quantity of the accumulated charge-discharge quantity based on the accumulated charge-discharge quantity, the error information and the error adjustment interval duration;
and calibrating the first SOC value and the accumulated charge-discharge amount based on the accumulated error electric quantity and the to-be-calibrated amount.
In one embodiment, the calibrating the first SOC value and the accumulated charge-discharge amount based on the accumulated error electric quantity and the amount to be calibrated includes:
determining a cumulative error charge percentage based on the cumulative error charge;
comparing the accumulated error electric quantity percentage with the to-be-calibrated quantity:
if the percentage of the accumulated error electric quantity is larger than or equal to the absolute value of the quantity to be calibrated, updating the accumulated charge-discharge quantity based on the difference between the accumulated charge-discharge quantity and the electric quantity corresponding to the quantity to be calibrated;
if the percentage of the accumulated error electric quantity is smaller than the absolute value of the to-be-calibrated quantity, judging that the to-be-calibrated quantity is positive or negative: if the to-be-calibrated quantity is a positive number, calibrating the first SOC value based on the difference between the to-be-calibrated quantity and the accumulated error electric quantity percentage; calibrating the accumulated charge-discharge amount based on a difference between the accumulated charge-discharge amount and the accumulated error electric amount; if the quantity to be calibrated is a negative number, calibrating the first SOC value based on the sum of the first SOC value, the quantity to be calibrated and the accumulated error electric quantity percentage; and calibrating the accumulated charge-discharge amount based on the sum of the accumulated charge-discharge amount and the accumulated error electric amount.
In one embodiment, updating the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge-discharge amount includes:
sequentially judging whether a plurality of battery cells in the battery need to be calibrated, and if so, calibrating a first SOC value of the battery cells and the accumulated charge-discharge amount based on the to-be-calibrated amount of the battery cells;
updating the SOC values to be updated of all the battery cells based on the accumulated charge and discharge amounts after each battery cell is calibrated respectively;
judging whether the health state of the battery is abnormal or not based on the updated record of the first SOC value of any cell in the battery; and if the battery is abnormal, performing SOH calibration on the battery.
In one embodiment, the SOH calibration of the battery comprises:
controlling the battery to discharge so that the electric quantity is lower than a preset electric quantity percentage threshold value;
after the preset time, acquiring second SOC values of all the battery cells based on an OCV-SOC table;
charging the battery cells to a preset electric quantity by adopting a slow charging or low-current constant-current mode, and recording the charged electric quantity corresponding to all the battery cells;
after the preset time, acquiring third SOC values of all the battery cells based on the OCV-SOC table;
Calculating the SOC difference value corresponding to each battery cell according to the third SOC value and the second SOC value of each battery cell;
and determining the SOH value of each battery cell based on the ratio of the charged electric quantity to the SOC difference value of the battery cell.
In a second aspect, the present embodiment provides a battery cell SOC estimation apparatus, where a battery includes at least two battery cells, the apparatus includes:
the acquisition module is used for acquiring a first SOC value of the target battery core and the accumulated charge and discharge quantity of the battery; the target battery cell is any battery cell in the battery;
the calibration module is used for judging whether the first SOC value of the target battery cell needs to be calibrated or not; if the first SOC value needs to be calibrated, acquiring a to-be-calibrated quantity of the first SOC value, and calibrating the first SOC value and the accumulated charge-discharge quantity based on the to-be-calibrated quantity;
and the updating module is used for updating the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge-discharge quantity.
In a third aspect, the present embodiment provides a computer device comprising a memory storing a computer program and a processor implementing the steps of the method as described above when the processor executes the computer program.
In a fourth aspect, the present embodiment provides a computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of the method as described above.
The battery cell SOC estimation method, the device, the computer equipment and the storage medium are characterized in that a first SOC value of a target battery cell and the accumulated charge and discharge quantity of the battery are obtained; the target battery cell is any battery cell in the battery; judging whether the first SOC value of the target battery cell needs to be calibrated or not; if the first SOC value needs to be calibrated, acquiring a to-be-calibrated quantity of the first SOC value, and calibrating the first SOC value and the accumulated charge-discharge quantity based on the to-be-calibrated quantity; based on the calibrated accumulated charge-discharge quantity, the SOC values to be updated of the remaining battery cells are updated, so that the SOC values of all the battery cells can be updated according to the calibration results of the SOC values of the single battery cell and the accumulated charge-discharge quantity, the calibration of the to-be-calibrated quantity is realized, meanwhile, the calculated quantity required by estimating the SOC values of the battery cells is greatly reduced, and the technical effects of reducing the calculated quantity and the occupation condition of hardware resources can be achieved.
Drawings
FIG. 1 is an application environment diagram of a method for estimating a battery cell SOC in one embodiment;
FIG. 2 is a flow chart of a method for estimating the SOC of a battery cell according to one embodiment;
FIG. 3 is a flowchart of a method for estimating the SOC of the battery cell according to another embodiment;
FIG. 4 is a flowchart of a method for estimating the SOC of a battery cell according to another embodiment;
FIG. 5 is a block diagram of a battery cell SOC estimation device according to one embodiment;
fig. 6 is an internal structural diagram of a computer device in one embodiment.
Detailed Description
The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.
The method for estimating the SOC of the battery cell provided by the embodiment of the application can be applied to a controller or a terminal which is powered by a battery or connected with the battery, wherein the controller of the embodiment can be connected with an automobile energy supply battery and can provide SOC estimation for each battery cell in the automobile energy supply battery, the terminal can be, but is not limited to, various personal computers, notebook computers, smart phones, tablet computers, internet of things equipment and portable wearable equipment, and the Internet of things equipment can be an intelligent sound box, an intelligent television, an intelligent air conditioner, an intelligent vehicle-mounted equipment and the like. The portable wearable device may be a smart watch, smart bracelet, headset, or the like.
In one embodiment, as shown in fig. 2, a method for estimating SOC of a battery cell is provided, where the battery cell includes at least two battery cells, and the method is applied to the terminal as an example for explanation, and includes the following steps:
step S100, a first SOC value of a target battery cell and the accumulated charge and discharge quantity of the battery are obtained. The target cell is any cell in the battery.
The battery comprises at least two battery cells, and the target battery cell can be any one selected from the battery cells or can be determined based on preset selected logic.
The SOC estimation of the battery cell according to this embodiment may be a time when the SOC estimation is determined according to a preset rule, for example, the estimated time may be determined according to a unit time or a designated time point, the estimated time may be determined according to a change of the battery current, or other SOC estimation time determined according to a characteristic of the battery itself or a required time, which is not limited herein.
The first SOC value is an SOC value to be updated of the target battery cell, and may be an SOC value parameter before the current SOC value estimation is performed, and further, may be an initial SOC value of the target battery cell after power-up initialization.
The accumulated charge-discharge amount may be an accumulated charge-discharge amount from the charge time or the discharge time.
Step S200, determining whether the first SOC value of the target battery cell needs to be calibrated. And if the first SOC value needs to be calibrated, acquiring the to-be-calibrated quantity of the first SOC value, and calibrating the first SOC value and the accumulated charge-discharge quantity based on the to-be-calibrated quantity.
It will be appreciated that the amount of charge in the battery cells varies during charging or discharging, and thus calibration to the target SOC value is required. The determining whether the first SOC value of the target battery cell needs to be calibrated may be based on an ampere-hour integration method, an open-circuit voltage calibration method, a kalman filtering algorithm, a neural network method, or other existing calibration methods, determining whether the first SOC value of the target battery cell needs to be calibrated, and acquiring a to-be-calibrated amount of the first SOC value when the determination is made that the calibration is needed. The amount to be calibrated may be an adjustment amount required to calibrate the first SOC value to the target SOC.
The first SOC value and the accumulated charge/discharge amount may be calibrated based on the amount to be calibrated, and the preset error value may be set based on actual requirements, may be obtained based on an accumulated error of the accumulated charge/discharge amount, or may be calculated based on other SOC calibration methods, which is not limited herein. Further, the first SOC value and the accumulated charge/discharge amount may be calibrated by only the accumulated charge/discharge amount based on the comparison result, or the first SOC value and the accumulated charge/discharge amount may be calibrated together based on the comparison result.
And step S300, updating the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge-discharge quantity.
The remaining cells may be cells other than the target cell in the battery.
And updating the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge-discharge quantity, wherein the SOC value to be updated can be updated according to the ratio of the accumulated charge-discharge quantity to the rated capacity of the battery, so as to obtain the current SOC value.
According to the battery cell SOC estimation method, a first SOC value of a target battery cell and the accumulated charge and discharge quantity of the battery are obtained; the target battery cell is any battery cell in the battery; judging whether the first SOC value of the target battery cell needs to be calibrated or not; if the first SOC value needs to be calibrated, acquiring a to-be-calibrated quantity of the first SOC value, and calibrating the first SOC value and the accumulated charge-discharge quantity based on the to-be-calibrated quantity; based on the calibrated accumulated charge-discharge quantity, the SOC values to be updated of the remaining battery cells are updated, so that the SOC values of all the battery cells can be updated according to the calibration results of the SOC values of the single battery cell and the accumulated charge-discharge quantity, the calibration of the to-be-calibrated quantity is realized, meanwhile, the calculated quantity required by estimating the SOC values of the battery cells is greatly reduced, and the technical effects of reducing the calculated quantity and the occupation condition of hardware resources can be achieved.
In one embodiment, the acquiring the first SOC value of the target battery cell and the accumulated charge/discharge amount of the battery further includes:
judging whether the target battery cell is balanced or not;
and if equalization is started, acquiring the equalization current and the equalization time length of the target battery cell, and updating the first SOC value based on the equalization current and the equalization time length.
The battery equalization is to actively equalize the difference of each battery cell in the battery pack in the charging or discharging process. The battery equalization may be performed by using a switched capacitor equalization method, a buck converter method, an average voltage equalization method, or the like, which is not limited in this embodiment.
The equalization current can be the current charged or discharged by the target battery cell in the process of starting the battery equalization, and the equalization time can be the time from the time of starting the equalization to the current time.
And updating the first SOC value based on the equalization current and the equalization time length, namely multiplying the equalization current and the equalization time length to obtain the equalization electric quantity, calculating the ratio of the equalization electric quantity to the available capacity of the battery core to obtain the equalization electric quantity percentage, and taking the difference value between the first SOC value and the equalization electric quantity percentage as the updated first SOC value. The available capacity of the battery cell can be obtained based on the product of the rated capacity of the battery cell and the health of the battery cell.
According to the battery cell SOC estimation method provided by the embodiment, whether the target battery cells are balanced or not is judged in advance, so that the influence of updating the SOC values of the to-be-calibrated quantity and all the remaining battery cells caused by the balanced starting of the target battery cells can be eliminated, and the effect of improving the SOC estimation accuracy can be achieved.
In one embodiment, the determining whether the first SOC value of the target battery cell needs to be calibrated includes:
acquiring a current value of the battery;
and if the current value is not equal to a preset current threshold value, updating the accumulated charge-discharge amount based on the current value.
It will be appreciated that the accumulated charge/discharge amount should be updated accordingly during the charge or discharge of the battery. The current value of the current battery may be obtained by determining whether the current battery has charge or discharge, and the preset current threshold may be 0A. If the current value is not equal to the preset current value, the accumulated charge-discharge amount is updated based on the current value, and the accumulated charge-discharge amount may be updated according to the charge-discharge current value and the charge-discharge time.
Further, the charging and discharging time may be represented by a scheduling step, the accumulated charging and discharging amount is updated based on the current value, or may be calculated by multiplying the current value by the scheduling step, and the product is added to the accumulated charging and discharging amount to obtain the updated accumulated charging and discharging amount.
According to the battery cell SOC estimation method, whether the battery is in a charge-discharge state is judged based on the current value of the current battery, and the accumulated charge-discharge quantity is updated based on the current value, so that the accumulated charge-discharge quantity can be updated, and the effect of improving the battery cell SOC estimation accuracy is achieved.
In one embodiment, the calibrating the first SOC value and the accumulated charge-discharge amount based on the amount to be calibrated includes:
acquiring error information and error adjustment interval duration of a current sensor;
calculating the accumulated error electric quantity of the accumulated charge-discharge quantity based on the accumulated charge-discharge quantity, the error information and the error adjustment interval duration;
and calibrating the first SOC value and the accumulated charge-discharge amount based on the accumulated error electric quantity and the to-be-calibrated amount.
The error information of the current sensor may include a linear error of the current sensor and an offset error, where the linear error may be a maximum deviation between an actual measurement value and an ideal value of the current sensor in a range, and the offset error may be a value where the output signal is not zero when the input signal is zero. The error adjustment interval time may be an operation time since the last calibration of the accumulated charge/discharge amount.
And calculating the accumulated error electric quantity of the accumulated charge-discharge quantity based on the accumulated charge-discharge quantity, the error information and the error adjustment interval time length, wherein the accumulated error electric quantity of the accumulated charge-discharge quantity can be obtained by taking the product of the accumulated charge-discharge quantity and the linear error as a first error electric quantity, taking the product of the error adjustment interval time length and the offset error as a second error electric quantity, and calculating the sum of the first error electric quantity and the second error electric quantity to obtain the accumulated error electric quantity of the accumulated charge-discharge quantity.
The calibration of the first SOC value and the accumulated charge/discharge amount based on the accumulated error electric quantity and the to-be-calibrated amount may be performed by comparing the accumulated error electric quantity with the to-be-calibrated amount, determining whether the to-be-calibrated amount of the target battery cell is affected by the accumulated error electric quantity, adjusting the to-be-calibrated amount based on the accumulated error electric quantity, and calibrating the first SOC value and the accumulated charge/discharge amount.
According to the battery cell SOC estimation method, the accumulated error electric quantity of the accumulated charge and discharge quantity is calculated through the error information and the error adjustment interval time of the current sensor, and is further calibrated based on the accumulated error electric quantity, so that the influence of the current sensor on the calculation of the battery cell SOC value can be eliminated, and the effect of improving the accuracy of battery cell SOC estimation can be achieved.
In one embodiment, the calibrating the first SOC value and the accumulated charge-discharge amount based on the accumulated error electric quantity and the amount to be calibrated includes:
determining a cumulative error charge percentage based on the cumulative error charge;
comparing the accumulated error electric quantity percentage with the to-be-calibrated quantity:
if the percentage of the accumulated error electric quantity is larger than or equal to the absolute value of the quantity to be calibrated, updating the accumulated charge-discharge quantity based on the difference between the accumulated charge-discharge quantity and the electric quantity corresponding to the quantity to be calibrated;
if the percentage of the accumulated error electric quantity is smaller than the absolute value of the to-be-calibrated quantity, judging that the to-be-calibrated quantity is positive or negative: if the to-be-calibrated quantity is a positive number, calibrating the first SOC value based on the difference between the to-be-calibrated quantity and the accumulated error electric quantity percentage; calibrating the accumulated charge-discharge amount based on a difference between the accumulated charge-discharge amount and the accumulated error electric amount; if the quantity to be calibrated is a negative number, calibrating the first SOC value based on the sum of the first SOC value, the quantity to be calibrated and the accumulated error electric quantity percentage; and calibrating the accumulated charge-discharge amount based on the sum of the accumulated charge-discharge amount and the accumulated error electric amount.
The integrated error percentage is determined based on the integrated error electric quantity, and may be determined based on a ratio of the integrated error electric quantity to the available battery cell capacity, and the available battery cell capacity may be obtained based on a product of the rated battery cell capacity and the health of the battery cell.
The comparison of the accumulated error electric quantity percentage and the quantity to be calibrated can be that the accumulated error electric quantity percentage and the value of the quantity to be calibrated are compared.
If the percentage of the accumulated error electric quantity is greater than or equal to the absolute value of the to-be-calibrated quantity, the to-be-calibrated quantity representing the calculated first SOC value may be caused by the error of the current sensor, so that the first SOC value does not need to be calibrated at this time, but the accumulated charge-discharge quantity needs to be updated according to the difference between the accumulated charge-discharge quantity and the electric quantity corresponding to the to-be-calibrated quantity.
If the accumulated error electric quantity percentage is smaller than the absolute value of the quantity to be calibrated, the accumulated error electric quantity percentage has a certain influence on the quantity to be calibrated, the influence of the accumulated error electric quantity is required to be eliminated in the quantity to be calibrated, and meanwhile the accumulated charge and discharge quantity is calibrated.
Judging whether the quantity to be calibrated is positive or negative, if the quantity to be calibrated is positive, calibrating the first SOC value based on the difference between the quantity to be calibrated and the accumulated error electric quantity percentage, and further, adding the difference between the quantity to be calibrated and the accumulated error electric quantity percentage to the first SOC value to obtain an updated SOC value; and calibrating the accumulated charge-discharge amount based on the difference between the accumulated charge-discharge amount and the accumulated error electric amount, wherein the accumulated charge-discharge amount can be obtained by subtracting the accumulated error electric amount from the accumulated charge-discharge amount and setting the accumulated error electric amount to zero.
If the amount to be calibrated is a negative number, calibrating the first SOC value based on the sum of the amount to be calibrated and the percentage of the accumulated error electric quantity, and further, adding the sum of the amount to be calibrated and the percentage of the accumulated error electric quantity to the first SOC value to obtain an updated SOC value; and calibrating the accumulated charge-discharge amount based on the sum of the accumulated charge-discharge amount and the accumulated error amount, wherein the accumulated charge-discharge amount and the accumulated error amount can be added, and the accumulated error amount is set to zero.
According to the battery cell SOC estimation method, the accumulated error electric quantity and the first SOC value are updated according to the comparison result of the accumulated error electric quantity percentage and the to-be-calibrated quantity, so that accurate calibration based on errors can be achieved, and the effect of improving the accuracy of SOC estimation is achieved.
In one embodiment, updating the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge-discharge amount includes:
sequentially judging whether a plurality of battery cells in the battery need to be calibrated, and if so, calibrating a first SOC value of the battery cells and the accumulated charge-discharge amount based on the to-be-calibrated amount of the battery cells;
Updating the SOC values to be updated of all the battery cells based on the accumulated charge and discharge amounts after each battery cell is calibrated respectively;
judging whether the health state of the battery is abnormal or not based on the updated record of the first SOC value of any cell in the battery; and if the battery is abnormal, performing SOH calibration on the battery.
The SOH (State of Health) is the battery health, i.e. the percentage of the current capacity of the battery to the rated capacity of the factory, and represents the current available condition of the battery.
The determining whether the plurality of electric cores in the battery need to be calibrated sequentially may be determining whether the electric cores which have not undergone SOC estimation in a preset time need to be calibrated, and obtaining the amount to be calibrated may be implemented based on an existing SOC calibration method, which is not described herein. Based on the to-be-calibrated amount of the battery cell, the first SOC value and the accumulated charge-discharge amount of the battery cell may be calibrated, specifically, may be implemented by using the same calibration method as the error correction method for the to-be-calibrated amount.
And updating the SOC values to be updated of all the battery cells based on the accumulated charge and discharge amounts after the calibration of each battery cell, wherein all the battery cells can be all the remaining battery cells except the battery cell after the calibration of each battery cell.
Based on the updated record of the first SOC value of any cell in the battery, whether the health state of the battery is abnormal or not is judged, and whether the updated SOC value is within a preset allowable error range or not can be judged according to the calibration results of different cells on other cells. It can be understood that the SOC value to be updated of other cells is updated based on different cells, and the calculated SOC value will be different due to different battery health of different cells. Therefore, when the difference between the SOC values of the same cell updated by different cells is greater than the preset range, it indicates that there is an abnormality in the health of at least one cell, and SOH calibration is required for the battery.
According to the battery cell SOC estimation method, through the updating results of the to-be-updated SOC values of the rest battery cells based on the different battery cells, judgment of the battery health degree in the SOC calibration process can be achieved, and the effects of reducing the calculated amount and the occupation condition of hardware resources in the aspect of battery health degree calculation are achieved.
In one embodiment, the SOH calibration of the battery comprises:
controlling the battery to discharge so that the electric quantity is lower than a preset electric quantity percentage threshold value;
After the preset time, acquiring second SOC values of all the battery cells based on an OCV-SOC table;
charging the battery cells to a preset electric quantity by adopting a slow charging or low-current constant-current mode, and recording the charged electric quantity corresponding to all the battery cells;
after the preset time, acquiring third SOC values of all the battery cells based on the OCV-SOC table;
calculating the SOC difference value corresponding to each battery cell according to the third SOC value and the second SOC value of each battery cell;
and determining the SOH value of each battery cell based on the ratio of the charged electric quantity to the SOC difference value of the battery cell.
The SOH value calculation in this embodiment can be applied to a ternary battery. The battery is controlled to discharge so that the electric quantity is lower than a preset electric quantity percentage threshold, and specifically, the preset electric quantity percentage threshold may be 5%, that is, the battery is controlled to discharge so that the electric quantity is lower than 5%.
The preset time in this embodiment may be a rest time of the battery, and the rest time may be a rest time for sufficiently contacting the electrolyte inside the battery cell with the electrode material, which is not limited herein. In one embodiment, the preset time may be three hours. And acquiring second SOC values of all the electric cores based on the OCV-SOC table, namely acquiring open-circuit voltages of all the electric cores, and inquiring the OCV-SOC table according to the open-circuit voltages to acquire the corresponding SOC values of all the electric cores as the second SOC values.
The battery core is charged to the preset electric quantity by adopting a slow charging or low-current constant-current mode, and the highest single voltage of the battery system can be charged to the charging cut-off voltage. The recording of the charged electric quantity corresponding to all the battery cells can be recording of the electric quantity of the battery cells charged by the charging power supply.
After the preset time, acquiring the third SOC values of all the battery cells based on the OCV-SOC table, where the preset time and the method for acquiring the third SOC values may refer to the above preset time and the method for acquiring the second SOC values, which are not described herein.
And calculating the SOC difference value corresponding to each battery cell according to the third SOC value and the second SOC value of each battery cell, wherein the difference value between the third SOC value and the second SOC value can be calculated.
And determining the SOH value of each battery cell based on the ratio of the charged electric quantity to the SOC difference value of each battery cell, namely calculating the ratio of the actual charged electric quantity to the ideal charged electric quantity as the SOH value of the corresponding battery cell.
The SOH calculation of this embodiment may also be applicable to a lithium iron phosphate battery, and further, when the executed battery cell is a lithium iron phosphate battery, after the battery cell is charged, the battery cell may record the electric quantity charged by the battery cell through the inflection point of the lithium iron phosphate battery platform to replace the third SOC value, and calculate the difference between the inflection point SOC value of the lithium iron phosphate battery platform and the second SOC value to determine the SOC difference.
Further, the SOH calculation in this example may be to control the battery temperature to the [20 ℃,30 ℃) interval.
According to the battery cell SOC estimation method, the battery cell is charged after being discharged and placed still, the difference value between the SOC value of the battery cell under the low electric quantity and the SOC value of the battery cell under the full state is obtained based on the open circuit voltage method, the SOH value of the single battery cell is obtained through calculation based on the difference value and the charged electric quantity, and calculation of the SOH value of the single battery cell can be achieved.
The application further provides a detailed embodiment for more clearly explaining the technical scheme of the application.
As shown in fig. 2, the battery cell SOC estimation method of the present embodiment includes the following steps:
the initial SOC values of all the battery cells and the accumulated charge and discharge capacity are initialized by power-on, wherein the initial SOC values of the battery cells are recorded as SOC1_Ini, SOC2_Ini … SOCn_Ini, n is the number of a single battery cell, and the accumulated charge and discharge capacity is AccQPack_mAs.
And judging whether the battery cell X starts equalization, and if the equalization is started, updating the SOC value of the battery cell X according to the equalization current and the time length, namely SOCx_Ini (updated value) =SOCx_Ini (latest historical value) -equalization current is equal to the time length/SOHx/fresh battery cell capacity is equal to 100%.
And if the flow rate of the battery pack is not equal to 0A, updating the accumulated charge and discharge quantity AccQPack_mAs based on ampere-hour integration, namely AccQPack_mAs (updated value) =AccQPack_mAs (recent historical value) +the current of the battery pack to be equal to the scheduling step.
Judging whether the SOC value of the battery cell X needs to be calibrated, and if so, calibrating the accumulated charge-discharge quantity and the SOC value of the battery cell X based on the quantity to be calibrated of the battery cell X.
Judging whether the zero clearing condition of the accumulated charge and discharge amount is met currently, if the zero clearing condition of the AccQPack_mAs is met, if the highest SOC of the battery pack is 100% or the lowest SOC is 0%, the accumulated charge and discharge amount is cleared and the initial SOC values of all the battery cells are updated, namely SOCn_Ini (updated value) =SOCn_Ini (recent historical value) -AccQPack_mAs/fresh battery cell capacity/SOHn is 100%.
And updating the current SOC values of all the battery cells based on the accumulated charge and discharge amounts, namely SOCn=SOCn_Ini-AccQPack_mAs/fresh battery cell capacity/SOHn being 100%.
As shown in fig. 3, determining whether the SOC value of the battery cell X needs to be calibrated, if so, calibrating the accumulated charge-discharge amount and the SOC value of the battery cell X based on the amount to be calibrated of the battery cell X includes:
updating the accumulated charge and discharge quantity AccQPack_mAs in real time, and calculating an ampere-hour integral accumulated error, namely an accumulated error electric quantity AhERr_mAs, namely AhERr_mAs=uncalibrated AccQPack_mAs current sensor advance error+uncalibrated operation time length; the SOC value corresponding to the aherr_mas is the cumulative error charge percentage Δaherrsoc=aherr_mas/fresh cell capacity/SOHn 100%.
Judging whether the cell X needs to be calibrated, if so, acquiring the quantity delta SOCx_Calib to be calibrated of the cell X, and if not, ending the calibration flow.
When the accumulated error electric quantity percentage delta AhERRCOS is more than or equal to the absolute value of the quantity to be calibrated delta SOCx_Calib, the SOCx_Ini does not need to be updated, and the accumulated charge-discharge quantity and the ampere-hour integral accumulated error are updated: aherr_mas (updated value) =aherr_mas (recent history value) -ABS (Δsocx_calib) ×sohn×fresh cell capacity; accqpack_mas (updated value) =accqpack_mas (recent history value) - Δsocx_calib) ×sohn×fresh cell capacity.
When the quantity to be calibrated delta SOCx_Calib > is the accumulated error electric quantity percentage delta AhERrSOC, the SOC value and the accumulated charge and discharge quantity of the battery cell X are updated, and the ampere-hour integral accumulated error is set to zero: socx_ini (updated value) =socx_ini (recent history value) + (Δsocx_calib-aherr_mas/fresh cell capacity/SOHx); accqpack_mas (updated value) =accqpack_mas (recent history value) -aherr_mas; and zeroes the Aherr_mAs.
Otherwise, the SOC value and the accumulated charge and discharge amount of the battery cell X are updated, and the ampere integral accumulated error is set to zero, wherein the absolute value of the to-be-calibrated amount Δsocx_calib is equal to the accumulated error electric quantity percentage Δaherrsoc and the accumulated error electric quantity percentage Δaherrsoc is equal to the to-be-calibrated amount Δsocx_calib: socx_ini (updated value) =socx_ini (recent history value) + (Δsocx_calib+aherr_mas/fresh cell capacity/SOHx); accqpack_mas (updated value) =accqpack_mas (recent history value) +aherr_mas; and zeroes the Aherr_mAs.
As shown in fig. 4, this embodiment further includes determining whether an SOH calibration procedure is required, which specifically includes:
judging the percentage of the accumulated error electric quantity to be less than 10%, if yes, requesting to execute an SOH calibration flow;
if ΔAhERrSOC is more than or equal to 10%, and at the same time, the battery cell X meets the SOC calibration condition, the SOC calibration quantity of the calibrated battery cell n is more than 5%, and the accumulated error electric quantity percentage ΔAhERrSOC is more than 0%, requesting to execute an SOH calibration flow.
The SOH calibration procedure includes: discharging the battery system to an electric quantity of less than 5%; after standing for 3 hours, acquiring the SOC of each single cell in the battery system by using an OCV-SOC table to look up a table: SOCn_S;
the highest single voltage of the battery system is charged to a charging cut-off voltage by slow charge or low current constant current, the charged charge quantity can be 0.05C, the charged charge quantity in the whole process is recorded as delta Qall, and if the measured battery is a lithium iron phosphate battery, the charge quantity delta Qn_knee of all the battery cells passing through the inflection point of the lithium iron phosphate battery platform is recorded;
after standing for 3 hours, if the battery is a ternary battery, acquiring the SOC of each single cell of the battery system by using an OCV-SOC lookup table: SOCn_E;
calculating single-cell SOHn: if the measured battery is a ternary battery, sohn=Δqall/(socn_e-socn_s), otherwise, if the measured battery is a lithium iron phosphate battery, sohn=Δqn_knee/(lithium iron phosphate battery platform inflection point SOC-socn_s).
According to the battery cell SOC estimation method, the SOC values of all battery cells are updated according to the calibration results of the SOC values of the single battery cells and the accumulated charge and discharge amounts, so that the calculation amount required by battery cell SOC value estimation is greatly reduced while the calibration of the to-be-calibrated amount is realized, and the technical effects of reducing the calculation amount and the occupation condition of hardware resources can be achieved; by judging whether the target battery cells are balanced or not, the influence caused by updating the SOC values of the quantity to be calibrated and all the remaining battery cells due to the balanced starting of the target battery cells can be eliminated, and the effect of improving the accuracy of SOC estimation can be achieved; the method has the advantages that whether the battery is in a charging and discharging state is judged based on the current value of the current battery, and the accumulated charging and discharging amount is updated based on the current value, so that the accumulated charging and discharging amount can be updated, and the effect of improving the estimation accuracy of the SOC of the battery cell is achieved; the accumulated error electric quantity of the accumulated charge and discharge quantity is calculated through the error information of the current sensor and the error adjustment interval time, and is further calibrated based on the accumulated error electric quantity, so that the influence of the current sensor on the calculation of the SOC value of the battery cell can be eliminated, and the effect of improving the estimation accuracy of the SOC of the battery cell can be achieved; the accumulated error electric quantity and the first SOC value are updated according to the comparison result of the accumulated error electric quantity percentage and the to-be-calibrated quantity, so that accurate calibration based on errors can be realized, and the effect of improving the accuracy of SOC estimation is achieved; based on the updating results of the SOC values to be updated of the rest cells of the different cells, the judgment of the battery health degree in the SOC calibration process can be realized, and the effects of reducing the calculated amount and the occupation condition of hardware resources in the aspect of battery health degree calculation are achieved.
It should be understood that, although the steps in the flowcharts related to the embodiments described above are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in the flowcharts described in the above embodiments may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily performed sequentially, but may be performed alternately or alternately with at least some of the other steps or stages.
Based on the same inventive concept, the embodiment of the application also provides a battery cell SOC estimation device for realizing the battery cell SOC estimation method. The implementation of the solution provided by the device is similar to that described in the above method, so the specific limitation in the embodiments of the device for estimating a battery cell SOC provided below may be referred to the limitation of the method for estimating a battery cell SOC hereinabove, and will not be described herein.
In one embodiment, as shown in fig. 5, there is provided a battery cell SOC estimation apparatus, the battery including at least two battery cells, the apparatus including: an acquisition module 100, a calibration module 200, and an update module 300, wherein:
the acquisition module 100 is configured to acquire a first SOC value of a target battery cell and an accumulated charge/discharge amount of the battery; the target battery cell is any battery cell in the battery;
the calibration module 200 is configured to determine whether the first SOC value of the target battery cell needs to be calibrated; if the first SOC value needs to be calibrated, acquiring a to-be-calibrated quantity of the first SOC value, and calibrating the first SOC value and the accumulated charge-discharge quantity based on the to-be-calibrated quantity;
and the updating module 300 is configured to update the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge/discharge amount.
In one embodiment, the apparatus further includes an equalization determination module configured to: judging whether the target battery cell is balanced or not; and if equalization is started, acquiring the equalization current and the equalization time length of the target battery cell, and updating the first SOC value based on the equalization current and the equalization time length.
In one embodiment, the apparatus includes a current determination module configured to: acquiring a current value of the battery; and if the current value is not equal to a preset current threshold value, updating the accumulated charge-discharge amount based on the current value.
In one embodiment, the calibration module 200 is further configured to:
acquiring error information and error adjustment interval duration of a current sensor; calculating the accumulated error electric quantity of the accumulated charge-discharge quantity based on the accumulated charge-discharge quantity, the error information and the error adjustment interval duration; and calibrating the first SOC value and the accumulated charge-discharge amount based on the accumulated error electric quantity and the to-be-calibrated amount.
In one embodiment, the calibration module 200 is further configured to: determining a cumulative error charge percentage based on the cumulative error charge; comparing the accumulated error electric quantity percentage with the to-be-calibrated quantity: if the percentage of the accumulated error electric quantity is larger than or equal to the absolute value of the quantity to be calibrated, updating the accumulated charge-discharge quantity based on the difference between the accumulated charge-discharge quantity and the electric quantity corresponding to the quantity to be calibrated; if the percentage of the accumulated error electric quantity is smaller than the absolute value of the to-be-calibrated quantity, judging that the to-be-calibrated quantity is positive or negative: if the to-be-calibrated quantity is a positive number, calibrating the first SOC value based on the difference between the to-be-calibrated quantity and the accumulated error electric quantity percentage; calibrating the accumulated charge-discharge amount based on a difference between the accumulated charge-discharge amount and the accumulated error electric amount; if the quantity to be calibrated is a negative number, calibrating the first SOC value based on the sum of the first SOC value, the quantity to be calibrated and the accumulated error electric quantity percentage; and calibrating the accumulated charge-discharge amount based on the sum of the accumulated charge-discharge amount and the accumulated error electric amount.
In one embodiment, the apparatus further comprises a battery health calibration module for: sequentially judging whether a plurality of battery cells in the battery need to be calibrated, and if so, calibrating a first SOC value of the battery cells and the accumulated charge-discharge amount based on the to-be-calibrated amount of the battery cells; updating the SOC values to be updated of all the battery cells based on the accumulated charge and discharge amounts after each battery cell is calibrated respectively; judging whether the health state of the battery is abnormal or not based on the updated record of the first SOC value of any cell in the battery; and if the battery is abnormal, performing SOH calibration on the battery.
In one embodiment, the battery health calibration module is further configured to: controlling the battery to discharge so that the electric quantity is lower than a preset electric quantity percentage threshold value; after the preset time, acquiring second SOC values of all the battery cells based on an OCV-SOC table; charging the battery cells to a preset electric quantity by adopting a slow charging or low-current constant-current mode, and recording the charged electric quantity corresponding to all the battery cells; after the preset time, acquiring third SOC values of all the battery cells based on the OCV-SOC table; calculating the SOC difference value corresponding to each battery cell according to the third SOC value and the second SOC value of each battery cell; and determining the SOH value of each battery cell based on the ratio of the charged electric quantity to the SOC difference value of the battery cell.
The above-described respective modules in the battery SOC estimation apparatus may be implemented in whole or in part by software, hardware, and a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.
In one embodiment, a computer device is provided, which may be a terminal, and the internal structure of which may be as shown in fig. 6. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The communication interface of the computer device is used for carrying out wired or wireless communication with an external terminal, and the wireless mode can be realized through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. The computer program when executed by a processor implements a method of estimating a battery cell SOC. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, can also be keys, a track ball or a touch pad arranged on the shell of the computer equipment, and can also be an external keyboard, a touch pad or a mouse and the like.
It will be appreciated by those skilled in the art that the structure shown in FIG. 6 is merely a block diagram of some of the structures associated with the present inventive arrangements and is not limiting of the computer device to which the present inventive arrangements may be applied, and that a particular computer device may include more or fewer components than shown, or may combine some of the components, or have a different arrangement of components.
In one embodiment, a computer device is provided comprising a memory and a processor, the memory having stored therein a computer program, the processor when executing the computer program performing the steps of:
acquiring a first SOC value of a target battery cell and the accumulated charge and discharge quantity of the battery; the target battery cell is any battery cell in the battery;
judging whether the first SOC value of the target battery cell needs to be calibrated or not; if the first SOC value needs to be calibrated, acquiring a to-be-calibrated quantity of the first SOC value, and calibrating the first SOC value and the accumulated charge-discharge quantity based on the to-be-calibrated quantity;
and updating the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge-discharge quantity.
In one embodiment, a computer readable storage medium is provided having a computer program stored thereon, which when executed by a processor, performs the steps of:
Acquiring a first SOC value of a target battery cell and the accumulated charge and discharge quantity of the battery; the target battery cell is any battery cell in the battery;
judging whether the first SOC value of the target battery cell needs to be calibrated or not; if the first SOC value needs to be calibrated, acquiring a to-be-calibrated quantity of the first SOC value, and calibrating the first SOC value and the accumulated charge-discharge quantity based on the to-be-calibrated quantity;
and updating the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge-discharge quantity.
The user information (including but not limited to user equipment information, user personal information, etc.) and the data (including but not limited to data for analysis, stored data, presented data, etc.) related to the present application are information and data authorized by the user or sufficiently authorized by each party.
Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, database, or other medium used in embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, high density embedded nonvolatile Memory, resistive random access Memory (ReRAM), magnetic random access Memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric Memory (Ferroelectric Random Access Memory, FRAM), phase change Memory (Phase Change Memory, PCM), graphene Memory, and the like. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, and the like. By way of illustration, and not limitation, RAM can be in the form of a variety of forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), and the like. The databases referred to in the embodiments provided herein may include at least one of a relational database and a non-relational database. The non-relational database may include, but is not limited to, a blockchain-based distributed database, and the like. The processor referred to in the embodiments provided in the present application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, or the like, but is not limited thereto.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The foregoing examples illustrate only a few embodiments of the application and are described in detail herein without thereby limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of the application should be assessed as that of the appended claims.

Claims (10)

1. A method of cell SOC estimation, wherein a battery includes at least two cells, the method comprising:
acquiring a first SOC value of a target battery cell and the accumulated charge and discharge quantity of the battery; the target battery cell is any battery cell in the battery;
judging whether the first SOC value of the target battery cell needs to be calibrated or not; if the first SOC value needs to be calibrated, acquiring a to-be-calibrated quantity of the first SOC value, and calibrating the first SOC value and the accumulated charge-discharge quantity based on the to-be-calibrated quantity;
And updating the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge-discharge quantity.
2. The method of estimating SOC of a battery according to claim 1, further comprising, after the obtaining the first SOC value of the target battery and the accumulated charge-discharge amount of the battery:
judging whether the target battery cell is balanced or not;
and if equalization is started, acquiring the equalization current and the equalization time length of the target battery cell, and updating the first SOC value based on the equalization current and the equalization time length.
3. The method of claim 1, wherein the determining whether the first SOC value of the target cell needs to be calibrated comprises:
acquiring a current value of the battery;
and if the current value is not equal to a preset current threshold value, updating the accumulated charge-discharge amount based on the current value.
4. The battery cell SOC estimation method of claim 1, wherein calibrating the first SOC value and the accumulated charge-discharge amount based on the amount to be calibrated comprises:
acquiring error information and error adjustment interval duration of a current sensor;
calculating the accumulated error electric quantity of the accumulated charge-discharge quantity based on the accumulated charge-discharge quantity, the error information and the error adjustment interval duration;
And calibrating the first SOC value and the accumulated charge-discharge amount based on the accumulated error electric quantity and the to-be-calibrated amount.
5. The battery cell SOC estimation method of claim 4, wherein calibrating the first SOC value and the accumulated charge-discharge amount based on the accumulated error charge and the amount to be calibrated comprises:
determining a cumulative error charge percentage based on the cumulative error charge;
comparing the accumulated error electric quantity percentage with the to-be-calibrated quantity:
if the percentage of the accumulated error electric quantity is larger than or equal to the absolute value of the quantity to be calibrated, updating the accumulated charge-discharge quantity based on the difference between the accumulated charge-discharge quantity and the electric quantity corresponding to the quantity to be calibrated;
if the percentage of the accumulated error electric quantity is smaller than the absolute value of the to-be-calibrated quantity, judging that the to-be-calibrated quantity is positive or negative: if the to-be-calibrated quantity is a positive number, calibrating the first SOC value based on the difference between the to-be-calibrated quantity and the accumulated error electric quantity percentage; calibrating the accumulated charge-discharge amount based on a difference between the accumulated charge-discharge amount and the accumulated error electric amount; if the quantity to be calibrated is a negative number, calibrating the first SOC value based on the sum of the first SOC value, the quantity to be calibrated and the accumulated error electric quantity percentage; and calibrating the accumulated charge-discharge amount based on the sum of the accumulated charge-discharge amount and the accumulated error electric amount.
6. The method according to claim 1, wherein updating the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge-discharge amount comprises:
sequentially judging whether a plurality of battery cells in the battery need to be calibrated, and if so, calibrating a first SOC value of the battery cells and the accumulated charge-discharge amount based on the to-be-calibrated amount of the battery cells;
updating the SOC values to be updated of all the battery cells based on the accumulated charge and discharge amounts after each battery cell is calibrated respectively;
judging whether the health state of the battery is abnormal or not based on the updated record of the first SOC value of any cell in the battery; and if the battery is abnormal, performing SOH calibration on the battery.
7. The method of claim 1, wherein SOH calibrating the battery comprises:
controlling the battery to discharge so that the electric quantity is lower than a preset electric quantity percentage threshold value;
after the preset time, acquiring second SOC values of all the battery cells based on an OCV-SOC table;
charging the battery cells to a preset electric quantity by adopting a slow charging or low-current constant-current mode, and recording the charged electric quantity corresponding to all the battery cells;
After the preset time, acquiring third SOC values of all the battery cells based on the OCV-SOC table;
calculating the SOC difference value corresponding to each battery cell according to the third SOC value and the second SOC value of each battery cell;
and determining the SOH value of each battery cell based on the ratio of the charged electric quantity to the SOC difference value of the battery cell.
8. A battery cell SOC estimation apparatus, wherein a battery includes at least two battery cells, the apparatus comprising:
the acquisition module is used for acquiring a first SOC value of the target battery core and the accumulated charge and discharge quantity of the battery; the target battery cell is any battery cell in the battery;
the calibration module is used for judging whether the first SOC value of the target battery cell needs to be calibrated or not; if the first SOC value needs to be calibrated, acquiring a to-be-calibrated quantity of the first SOC value, and calibrating the first SOC value and the accumulated charge-discharge quantity based on the to-be-calibrated quantity;
and the updating module is used for updating the SOC value to be updated of the remaining battery cells based on the calibrated accumulated charge-discharge quantity.
9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any one of claims 1 to 7 when the computer program is executed.
10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any one of claims 1 to 7.
CN202310890424.9A 2023-07-19 2023-07-19 Battery cell SOC estimation method, device, computer equipment and storage medium Pending CN117074973A (en)

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