Method and device for correcting state of charge-open circuit voltage curve

Abstract

The invention discloses a state of charge-open circuit voltage curve correction method and device, computer equipment and a computer readable storage medium. The correction method comprises the following steps: acquiring the current internal resistance of the battery; determining a current internal resistance growth rate according to the current internal resistance; and correcting the state of charge-open circuit voltage curve of the battery according to the current internal resistance growth rate. According to the correction method, the current internal resistance of the battery is obtained, the current internal resistance growth rate is determined according to the current internal resistance, and then the current internal resistance growth rate is used for correcting the charge state-open circuit voltage curve, so that the health state of the battery does not need to be determined, and the calibration precision of the charge state-open circuit voltage curve after the battery is aged is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a method and apparatus for correcting the state-of-charge-open-circuit voltage curve. Background Technology

[0002] State of charge (SOC) is a crucial parameter for battery management systems. Accurately estimating SOC maximizes the utilization of the battery's available capacity, ensures battery safety, and improves user experience. Currently, energy storage systems typically use the SOC-OCV curve of new cells to calibrate the SOC throughout the entire battery's lifespan.

[0003] As batteries age, their internal resistance increases, causing the SOC-OCV curve to shift. This results in a significant deviation when using a new cell's OCV to calibrate the SOC of an aged battery. Summary of the Invention

[0004] This application provides a method and apparatus for correcting the state-of-charge-open-circuit voltage curve.

[0005] This application provides a method for correcting the state-of-charge-open-circuit voltage curve, the method comprising:

[0006] Get the current internal resistance of the battery;

[0007] Determine the current internal resistance growth rate based on the current internal resistance;

[0008] The state-of-charge-open-circuit voltage curve of the battery is corrected based on the current internal resistance growth rate.

[0009] Thus, in the calibration method, calibration apparatus, computer device, and computer-readable storage medium of the embodiments of this application, by determining the current internal resistance of the battery and determining the current internal resistance growth rate based on the current internal resistance, and using the current internal resistance growth rate to calibrate the state of charge-open circuit voltage curve, it is possible to update the state of charge-open circuit voltage curve according to the aging state of the battery's internal resistance, without needing to determine the battery's health state, thereby improving the calibration accuracy of the state of charge-open circuit voltage curve after battery aging.

[0010] In some implementations, obtaining the current internal resistance of the battery includes:

[0011] When the state of charge of the battery is within a preset range, the first voltage of the battery is obtained;

[0012] Control the battery discharge;

[0013] Obtain the discharge current during battery discharge and the second voltage after discharge;

[0014] The current internal resistance of the battery is determined based on the discharge current, the first voltage, and the second voltage.

[0015] In this way, the battery is discharged, and the first voltage before discharge, the second voltage after discharge, and the discharge current are collected. The current internal resistance of the battery is determined based on the first voltage, the second voltage, and the discharge current. The current internal resistance can be used to characterize the battery's current internal resistance after use, thus realizing the measurement of the current internal resistance.

[0016] In some embodiments, obtaining the first voltage of the battery when the state of charge of the battery is within a preset range includes:

[0017] Control the charging of the battery so that the state of charge of the battery is within the preset range;

[0018] Let the battery stand still;

[0019] If the resting time is longer than the first duration, the first voltage of the battery is obtained.

[0020] Thus, the first voltage is only collected and acquired after the battery has been fully charged and has been left to stand for a period of time longer than the first duration, so as to ensure that the first voltage is not affected by polarization caused by charging and thus is inaccurate.

[0021] In some embodiments, controlling the battery discharge includes:

[0022] The battery is discharged within a second time period after the first voltage of the battery is obtained.

[0023] In this way, by controlling the battery to charge within the second period after it has been fully charged, the state of charge of the battery can be ensured to remain unaffected by prolonged periods of inactivity.

[0024] In some implementations, the preset range is [70%, 99%].

[0025] Thus, when the battery's state of charge is within the range of [70%, 99%], the impact of sampling voltage error is small, improving the accuracy of the measured internal resistance. Furthermore, there is no need to fully charge and discharge the battery to check its health; the internal resistance can be measured during actual operating conditions, simplifying the detection and control process.

[0026] In some embodiments, obtaining the discharge current during battery discharge and the second voltage after discharge includes:

[0027] Obtain the discharge current of the battery during discharge;

[0028] When the discharge current of the battery during discharge is greater than a preset current, and / or when the temperature of the battery is within a preset temperature range, the discharge duration of the battery is started to be timed.

[0029] When the discharge duration reaches the third duration, the second voltage is obtained.

[0030] Thus, by starting timing only after the discharge current exceeds the preset current, and acquiring the second voltage when the discharge duration reaches the third duration, the acquired second voltage is guaranteed to differ significantly from the first voltage, thereby reducing the impact of voltage acquisition errors. Starting timing when the battery temperature is within the preset range ensures that the battery temperature during discharge will not be too high or too low, thus preventing it from affecting the battery's internal resistance and guaranteeing the accuracy of the calculated internal resistance.

[0031] The step of determining the current internal resistance growth rate based on the current internal resistance includes:

[0032] A first current internal resistance growth rate is determined based on the current internal resistance and the initial internal resistance of the battery;

[0033] The step of correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes:

[0034] If the first current internal resistance growth rate is greater than the first preset parameter, the state-of-charge-open-circuit voltage curve is corrected according to the first current internal resistance growth rate; or,

[0035] The step of determining the current internal resistance growth rate based on the current internal resistance includes:

[0036] The second current internal resistance growth rate is determined based on the current internal resistance and the previous internal resistance of the battery.

[0037] The step of correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes:

[0038] If the second current internal resistance growth rate is greater than the second preset parameter, the state-of-charge-open-circuit voltage curve is corrected according to the second current internal resistance growth rate.

[0039] Thus, the current internal resistance growth rate is determined based on the current internal resistance and the initial internal resistance of the battery, and the second current internal resistance growth rate is determined based on the current internal resistance and the previous internal resistance of the battery. If the first current internal resistance growth rate is greater than the first preset parameter, or the second current internal resistance growth rate is greater than the second preset parameter, the SOC-OCV curve is updated based on the first current internal resistance growth rate or the second current internal resistance growth rate.

[0040] In some implementations, determining the current internal resistance growth rate based on the current internal resistance includes:

[0041] A first current internal resistance growth rate is determined based on the current internal resistance and the initial internal resistance of the battery;

[0042] The second current internal resistance growth rate is determined based on the current internal resistance and the previous internal resistance of the battery.

[0043] The step of correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes:

[0044] If the second current internal resistance growth rate is less than the set state value, and the first current internal resistance growth rate is greater than the first preset parameter, the state of charge-open circuit voltage curve is corrected according to the first current internal resistance growth rate.

[0045] If the second current internal resistance growth rate is greater than or equal to the set state value, and the second current internal resistance growth rate is greater than the second preset parameter, the state of charge-open circuit voltage curve is corrected according to the second current internal resistance growth rate.

[0046] Thus, based on the comparison between the second current internal resistance growth rate and the set state value, it can be determined whether to correct the state-of-charge-open-circuit voltage curve according to the first or second current internal resistance growth rate.

[0047] In some embodiments, correcting the state-of-charge-open-circuit voltage curve based on the first current internal resistance growth rate when the first current internal resistance growth rate is greater than a first preset parameter includes:

[0048] If the first current internal resistance growth rate is greater than the first preset parameter, a first current number is determined. The first current number is used to determine the number of times the first current internal resistance growth rate of the battery is greater than the first preset parameter.

[0049] If the first current count is greater than the first preset count, the state-of-charge-open-circuit voltage curve is corrected according to the first current internal resistance growth rate; and / or,

[0050] The step of correcting the state-of-charge-open-circuit voltage curve based on the second current internal resistance growth rate when the second current internal resistance growth rate is greater than the second preset parameter includes:

[0051] If the second current internal resistance growth rate is greater than the second preset parameter, a second current number is determined. The second current number is used to determine the number of times the second current internal resistance growth rate of the battery is greater than the second preset parameter.

[0052] If the second current number is greater than the second preset number, the state-of-charge-open-circuit voltage curve is corrected according to the second current internal resistance growth rate.

[0053] Thus, if the current number of cycles exceeds the preset number of cycles, the state-of-charge-open-circuit voltage curve can be updated based on the current internal resistance growth rate, even while the battery continues to age rapidly.

[0054] In some embodiments, correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes:

[0055] The state-of-charge-open-circuit voltage curve is corrected according to the first preset correction function and the current internal resistance growth rate. The first preset correction function is used to characterize the correspondence between the internal resistance growth rate and the state-of-charge-open-circuit voltage curve.

[0056] Thus, the state-of-charge-open-circuit voltage curve can be corrected based on the first preset correction function and the current internal resistance growth rate, thereby achieving the correction of the state-of-charge-open-circuit voltage curve.

[0057] In some embodiments, correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes:

[0058] The correction coefficient is determined based on the second preset correction function and the current internal resistance growth rate. The second preset correction function is used to characterize the correspondence between the internal resistance growth rate and the correction coefficient.

[0059] The state-of-charge-open-circuit voltage curve is corrected according to the correction coefficient.

[0060] Thus, the correction coefficient can be determined based on the second preset correction function and the current internal resistance growth rate. The correction coefficient can be used to correct the state-of-charge-open-circuit voltage curve to achieve the correction of the state-of-charge-open-circuit voltage curve.

[0061] In some embodiments, correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes:

[0062] The state-of-charge-open-circuit voltage curve is corrected according to a preset correction table and the current internal resistance growth rate. In the preset correction table, the current internal resistance growth rate and the state-of-charge-open-circuit voltage curve correspond one-to-one.

[0063] Thus, the calculation of the state-of-charge-open-circuit voltage curve is relatively simple, based on the preset correction table and the current internal resistance growth rate.

[0064] In some implementations, correcting the state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate includes:

[0065] The state-of-charge-open-circuit voltage curve is corrected based on a preset electrochemical mechanism model and the current internal resistance growth rate. The preset electrochemical mechanism model is configured to simulate and output the state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate.

[0066] Thus, by correcting the state-of-charge-open-circuit voltage curve based on the preset electrochemical mechanism model and the current internal resistance growth rate, a highly accurate SOC-OCV curve can be obtained.

[0067] This application provides a device for correcting the state-of-charge-open-circuit voltage curve, the device comprising:

[0068] A first determining module is configured to obtain the current internal resistance of the battery;

[0069] The second determining module is configured to determine the current internal resistance growth rate based on the current internal resistance.

[0070] A curve correction module is configured to correct the state-of-charge-open-circuit voltage curve of the battery based on the internal resistance growth rate.

[0071] In some implementations, the first determining module includes:

[0072] The first acquisition submodule is configured to acquire the first voltage of the battery when the state of charge of the battery is within a preset range;

[0073] The first control submodule is configured to control the discharge of the battery;

[0074] The second acquisition submodule is configured to acquire the discharge current during battery discharge and the second voltage after discharge.

[0075] The first determining submodule is configured to determine the current internal resistance based on the first voltage, the second voltage, and the discharge current.

[0076] In some implementations, the first acquisition submodule includes:

[0077] A first control unit is configured to control the charging of the battery so that the state of charge of the battery is within the preset range;

[0078] A resting unit, configured to rest the battery;

[0079] The first acquisition unit is configured to acquire the first voltage of the battery when the resting time is longer than a first duration.

[0080] In some implementations, the first control submodule includes:

[0081] The second control unit is configured to discharge the battery within a second time period after acquiring the first voltage of the battery.

[0082] In some implementations, the second acquisition submodule includes:

[0083] The second acquisition unit is configured to acquire the discharge current of the battery during discharge.

[0084] The timing unit is configured to start timing the discharge duration of the battery when the discharge current during battery discharge is greater than a preset current, and / or when the temperature of the battery is within a preset temperature range.

[0085] The third acquisition unit is configured to acquire the second voltage when the discharge duration reaches the third duration.

[0086] In some embodiments, the curve correction module includes:

[0087] The second determining submodule is configured to determine a first current internal resistance growth rate based on the current internal resistance and the initial internal resistance of the battery.

[0088] The first correction submodule is configured to correct the state-of-charge-open-circuit voltage curve according to the first current internal resistance growth rate when the first current internal resistance growth rate is greater than the first preset parameter.

[0089] The third determining submodule determines the second current internal resistance growth rate based on the current internal resistance and the previous internal resistance of the battery;

[0090] The second correction submodule is configured to correct the state-of-charge-open-circuit voltage curve.

[0091] In some embodiments, the curve correction module includes:

[0092] The fourth determining submodule is configured to determine a first current internal resistance growth rate based on the current internal resistance and the initial internal resistance of the battery;

[0093] The fifth determining submodule is configured to determine the second current internal resistance growth rate based on the current internal resistance and the previous internal resistance of the battery;

[0094] The third correction submodule is configured to correct the state of charge-open circuit voltage curve according to the first current internal resistance growth rate if the second current internal resistance growth rate is less than a set state value and the first current internal resistance growth rate is greater than a first preset parameter.

[0095] The fourth correction submodule is configured to correct the state-of-charge-open-circuit voltage curve based on the second current internal resistance growth rate if the second current internal resistance growth rate is greater than or equal to a set state value, and if the second current internal resistance growth rate is greater than a second preset parameter.

[0096] This application provides a computer device that includes one or more processors and a memory. The memory stores a computer program that, when executed by the processor, implements the steps of the correction method as described in any of the above embodiments.

[0097] This application provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the correction method as described in any of the above embodiments.

[0098] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0099] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0100] Figure 1 This is one of the flowcharts illustrating the correction method of the embodiments of this application;

[0101] Figure 2 This is a second schematic flowchart of the correction method according to the embodiments of this application;

[0102] Figure 3 This is the third flowchart illustrating the correction method of the embodiments of this application;

[0103] Figure 4 This is the fourth flowchart illustrating the correction method of the embodiments of this application;

[0104] Figure 5 This is the fifth flowchart illustrating the correction method of the embodiments of this application;

[0105] Figure 6 This is the sixth flowchart illustrating the correction method of the embodiments of this application;

[0106] Figure 7 This is the seventh flowchart illustrating the correction method according to the embodiments of this application;

[0107] Figure 8 This is the eighth flowchart illustrating the correction method according to the embodiments of this application;

[0108] Figure 9This is the ninth flowchart illustrating the correction method of the embodiments of this application;

[0109] Figure 10 This is the tenth flowchart illustrating the correction method according to the embodiments of this application;

[0110] Figure 11 This is eleventh of the flowcharts illustrating the correction method of the embodiments of this application;

[0111] Figure 12 This is the twelfth flowchart of the correction method according to the embodiments of this application;

[0112] Figure 13 This is the thirteenth flowchart illustrating the correction method of the embodiments of this application;

[0113] Figure 14 This is the fourteenth flowchart illustrating the correction method according to the embodiments of this application;

[0114] Figure 15 This is the fifteenth flowchart illustrating the correction method of the embodiments of this application. Detailed Implementation

[0115] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0116] State of charge (SOC) is a crucial parameter for battery management systems. Accurately estimating SOC maximizes the utilization of the battery's available capacity, ensures battery safety, and improves user experience. Currently, energy storage systems typically use the SOC-OCV curve of new cells to calibrate the SOC throughout the entire battery's lifespan.

[0117] As batteries age, their internal resistance increases, causing the SOC-OCV curve to shift. This results in significant deviations when using the OCV calibration of new cells to adjust the SOC of aged batteries. Related technologies adjust the SOC-OCV curve by detecting and estimating the battery's health state; however, errors in health state estimation can lead to incorrect SOC-OCV curve selection.

[0118] Based on the above-mentioned issues that need to be resolved, please refer to Figure 1 This application provides a method for correcting the state-of-charge-open-circuit voltage curve, the method comprising:

[0119] Step 01: Obtain the current internal resistance of the battery;

[0120] Step 02: Determine the current internal resistance growth rate based on the current internal resistance;

[0121] Step 03: Correct the battery's state of charge-open circuit voltage curve based on the current internal resistance growth rate.

[0122] This application provides a computer device, which includes one or more processors and a memory. The memory stores a computer program that can be executed by the processor. The processor can be used to obtain the current internal resistance of a battery; to determine the current internal resistance growth rate based on the current internal resistance; and to correct the battery's state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate.

[0123] This application provides a calibration device for the state-of-charge-open-circuit voltage curve. The calibration device includes a first determining module, a second determining module, and a curve calibration module. The first determining module is configured to obtain the current internal resistance of the battery. The second determining module is configured to determine the current internal resistance growth rate based on the current internal resistance. The curve calibration module is configured to calibrate the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate.

[0124] Specifically, batteries include energy storage batteries, power batteries, and portable batteries. Energy storage batteries include lithium iron phosphate batteries, ternary lithium batteries, and lithium cobalt oxide batteries; this application uses lithium iron phosphate batteries as an example. A battery comprises multiple cells.

[0125] The current internal resistance can be used to characterize the battery's internal resistance after aging. Determining the current internal resistance growth rate based on the current internal resistance reveals the aging state of the battery. Adjusting the state-of-charge-open-circuit voltage (SOC-OCV) curve based on the current internal resistance allows for the determination of a new SOC-OCV curve corresponding to the battery's aging state. This ensures that the SOC-OCV curve matches the battery's aging state, making the state of charge obtained from the open-circuit voltage (OCV) adjustment accurate.

[0126] The methods for obtaining the current internal resistance may include: discharging the battery to determine the current internal resistance based on the voltage and current, using an internal resistance measuring instrument to detect a more accurate internal resistance, or monitoring the battery internal resistance in real time.

[0127] In one embodiment, the current internal resistance growth rate is calculated based on the obtained current internal resistance and the initial internal resistance of the battery to determine the change in the battery's internal resistance, and the current internal resistance growth rate is substituted into a preset correction function to determine the SOC-OCV curve corresponding to the current internal resistance growth rate.

[0128] Thus, in the calibration method, calibration apparatus, computer device, and computer-readable storage medium of the embodiments of this application, by determining the current internal resistance of the battery and determining the internal resistance growth rate based on the current internal resistance, and using the internal resistance growth rate to correct the state of charge-open circuit voltage curve, it is possible to update the state of charge-open circuit voltage curve according to the aging state of the battery's internal resistance, without needing to determine the health state of the battery, thereby improving the calibration accuracy of the state of charge-open circuit voltage curve after battery aging.

[0129] Please see Figure 2 In some implementations, step 01, obtaining the current internal resistance of the battery, includes:

[0130] Step 011: When the battery's state of charge is within a preset range, obtain the battery's first voltage;

[0131] Step 012: Control battery discharge;

[0132] Step 013: Obtain the discharge current during battery discharge and the second voltage after discharge;

[0133] Step 014: Determine the current internal resistance of the battery based on the discharge current, the first voltage, and the second voltage.

[0134] In some implementations, the processor can be used to acquire a first voltage of the battery when the battery's state of charge is within a preset range; to control the battery discharge; to acquire the discharge current during battery discharge and the second voltage after discharge; and to determine the current internal resistance of the battery based on the discharge current, the first voltage, and the second voltage.

[0135] In some embodiments, the first determining module includes a first acquiring submodule, a first controlling submodule, a second acquiring submodule, and a first determining submodule. The first acquiring submodule is configured to acquire a first voltage of the battery when the battery's state of charge is within a preset range; the first controlling submodule is configured to control the battery to discharge; the second acquiring submodule is configured to acquire the discharge current during battery discharge and the second voltage after discharge; and the first determining submodule is configured to determine the current internal resistance based on the first voltage, the second voltage, and the discharge current.

[0136] In this way, the battery is discharged, and the first voltage before discharge, the second voltage after discharge, and the discharge current are collected. The current internal resistance of the battery is determined based on the first voltage, the second voltage, and the discharge current. The current internal resistance can be used to characterize the battery's current internal resistance after use, thus realizing the measurement of the current internal resistance.

[0137] Specifically, the preset range is a pre-defined range of values ​​for the state of charge (SOC), which can be set according to actual needs. Since the voltage change during battery discharge is larger when the SOC is higher, the impact of voltage acquisition errors is smaller. Therefore, the preset range can be set within the range of higher SOC.

[0138] When the battery's state of charge (SOC) is within a preset range, the voltage of the cell with the highest voltage among multiple cells is acquired as a first voltage, which can be used to characterize the battery's voltage before discharge. The battery is controlled to discharge, and the discharge current during discharge and the voltage of the cell with the highest voltage among multiple cells after a specific discharge time are acquired as a second voltage, which can be used to characterize the battery's voltage after discharge.

[0139] The specific duration can be a pre-set time value; in this embodiment, a specific duration of 30 seconds is used for illustration. That is, after the battery has discharged for 30 seconds, the voltage of the cell with the highest voltage among multiple cells is obtained.

[0140] The battery's internal resistance is determined based on the first voltage, the second voltage, and the discharge current. In one embodiment, the current internal resistance is determined by the discharge current over 30 seconds and the highest cell voltage before and after discharge. The formula for determining the current internal resistance is:

[0141]

[0142] Among them, R 30s Let V be the current internal resistance, V' be the first voltage, V' be the second voltage, and I be the discharge current. That is, the current internal resistance is the quotient of the difference between the first voltage and the second voltage and the discharge current.

[0143] In this way, the battery is discharged, and the first voltage before discharge, the second voltage after discharge, and the discharge current are collected. The current internal resistance of the battery is determined based on the first voltage, the second voltage, and the discharge current. The current internal resistance can be used to characterize the battery's current internal resistance after use, thus realizing the measurement of the current internal resistance.

[0144] Please see Figure 3 In some embodiments, step 011, obtaining the first voltage of the battery when the battery's state of charge is within a preset range, includes:

[0145] Step 0111: Control the battery charging to keep the battery's state of charge within a preset range;

[0146] Step 0112: Let the battery stand still;

[0147] Step 0113: If the resting time is longer than the first duration, obtain the first voltage of the battery. The first voltage is the voltage of the cell with the highest voltage among the multiple cells of the battery.

[0148] In some implementations, the processor can be used to charge the battery to bring the battery's state of charge to a preset range; and to allow the battery to rest; if the resting time is longer than a first duration, it can also be used to obtain a first voltage of the battery, the first voltage being the voltage of the cell with the highest voltage among the battery's multiple cells.

[0149] In some embodiments, the first determining module includes a first acquiring submodule, a first controlling submodule, a second acquiring submodule, and a first determining submodule. The first acquiring submodule is configured to acquire a first voltage of the battery when the battery's state of charge is within a preset range; the first controlling submodule is configured to control the battery to discharge; the second acquiring submodule is configured to acquire the discharge current during battery discharge and the second voltage after discharge; and the first determining submodule is configured to determine the current internal resistance of the battery based on the discharge current, the first voltage, and the second voltage.

[0150] Specifically, polarization occurs during battery charging. If the voltage is measured directly after the battery has finished charging, the measured voltage may be inaccurate due to the influence of polarization.

[0151] Therefore, in this embodiment, after controlling battery charging and reaching a state of charge within a preset range, the battery is left to rest. If the battery resting time is longer than a first duration, and the battery's state of charge is within the preset range, a first voltage of the battery is obtained to eliminate the influence of polarization on the battery voltage.

[0152] The first duration can be a preset duration value. The first duration can be set according to actual needs so that when the battery resting time is longer than the first duration, the battery can eliminate the effect of polarization on voltage.

[0153] In one embodiment, the first duration is 1 hour, and the first duration is a preset interval of (90%, 99%). If the battery is fully charged and has been idle for more than 1 hour, and the battery's state of charge is within (90%, 99%), the voltage of the cell with the highest voltage among the multiple cells of the battery is obtained to obtain the first voltage.

[0154] In addition, if the battery has been fully charged and the resting time is less than or equal to the first duration, the battery should continue to be left to rest.

[0155] Thus, the first voltage is only collected and acquired after the battery has been fully charged and has been left to stand for a period of time longer than the first duration, so as to ensure that the first voltage is not affected by polarization caused by charging and thus is inaccurate.

[0156] Please see Figure 4 In some embodiments, step 012 controls battery discharge, including:

[0157] Step 0121: Discharge the battery within a second time period after obtaining the first voltage of the battery.

[0158] In some implementations, the processor may be used to discharge the battery within a second time period after acquiring the first voltage of the battery.

[0159] In some implementations, the first control submodule further includes a second control unit. The second control unit can be used to discharge the battery within a second time period after acquiring the first voltage of the battery.

[0160] Specifically, the second duration can be a pre-set value, which can be determined according to actual needs. For example, the second duration can be 18h, 20h, 24h, 26h, 28h, etc. The second duration can be used to determine whether the battery has been in an unused state for too long. If the battery has not been discharged within the second duration, the state of charge of the battery may drop outside the preset range due to the long period of inactivity. In this case, discharging the battery to measure the internal resistance will result in inaccurate internal resistance measurements.

[0161] Therefore, the battery is controlled to discharge during the second period after it has finished charging.

[0162] In one embodiment, the second duration includes 24 hours, i.e., within 24 hours after the battery has been fully charged, the battery is controlled to discharge in order to calculate and determine the current internal resistance of the battery.

[0163] In this way, by controlling the battery to charge within the second period after it has been fully charged, the state of charge of the battery can be ensured to remain unaffected by prolonged periods of inactivity.

[0164] In some implementations, the preset range is [70%, 99%].

[0165] Specifically, when the battery's state of charge (SOC) is greater than or equal to 70% and less than 99%, if the controlled battery is discharged, the battery voltage will change significantly, resulting in a large difference between the measured first and second voltages. This leads to a relatively small error in the voltage acquisition and a minimal impact on the accuracy of the calculated internal resistance. For example, the SOC can be 70%, 72%, 76%, 80%, 85%, 88%, 91%, 95%, 99%, etc.

[0166] Thus, when the battery's state of charge is within the range of [70%, 99%], the impact of sampling voltage error is small, improving the accuracy of the measured internal resistance. Furthermore, there is no need to fully charge and discharge the battery to check its health; the internal resistance can be measured during actual operating conditions, simplifying the detection and control process.

[0167] In some implementations, the preset range is [90%, 99%].

[0168] Specifically, setting the preset range to [90%, 99%] ensures that the battery's state of charge (SOC) is limited to [90%, 99%] before multiple discharges, minimizing the difference in SOC before each discharge and thus reducing the impact of different SOCs on internal resistance. In some implementations, when the SOC is within [90%, 99%], the BMS triggers SOC calibration, which calibrates the SOC based on open-circuit voltage and dynamic voltage. This results in higher accuracy of the SOC, avoiding the inaccurate SOC issue during the plateau phase of lithium iron phosphate batteries. This ensures that the current internal resistance is determined within a reliable SOC range and compared with the initial or previous internal resistance to obtain the current internal resistance growth rate.

[0169] Therefore, setting the preset range to [90%, 99%] can reduce the impact of different charging states before discharge on the internal resistance.

[0170] Please see Figure 5 In some embodiments, step 013, obtaining the discharge current during battery discharge and the second voltage after discharge, includes:

[0171] Step 0131: Obtain the discharge current during battery discharge;

[0172] Step 0132: When the discharge current of the battery is greater than the preset current, and / or when the battery temperature is within the preset temperature range, start timing the battery discharge time.

[0173] Step 0133: When the discharge duration reaches the third duration, obtain the second voltage.

[0174] In some implementations, the processor can be used to acquire the discharge current during battery discharge; can be used to start timing the battery discharge duration when the discharge current during battery discharge is greater than a preset current, and / or when the battery temperature is within a preset temperature range; and can also be used to acquire a second voltage when the discharge duration reaches a third duration.

[0175] In some embodiments, the acquisition control module includes a second acquisition unit, a timing unit, and a third unit. The second acquisition unit can be used to acquire the discharge current during battery discharge; the timing unit can be used to start timing the battery discharge duration when the discharge current during battery discharge is greater than a preset current, and / or when the battery temperature is within a preset temperature range; the third acquisition unit can also be used to acquire a second voltage when the discharge duration reaches a third duration.

[0176] Specifically, in the initial stage of battery discharge, the discharge current is small, and the voltage change is also small. If timing starts from this point, the voltage change before and after discharge will be small after the third duration, leading to a relatively large error in the voltage acquisition and causing a significant impact. Therefore, timing begins when the discharge current exceeds the preset current. After the discharge current exceeds the preset current for three consecutive durations, the voltage of the cell with the highest voltage in the battery is obtained as the second voltage.

[0177] The preset current is a pre-set current value used to determine if the discharge current is large enough, and it can be set according to actual needs.

[0178] It is worth noting that after the discharge current exceeds the preset current, the increase in discharge current decreases and remains basically around the preset current without significant changes. Therefore, the discharge current used to calculate and determine the current internal resistance can be the preset current, the discharge current collected at any time within the third time period, or the average value of the discharge current within the third time period.

[0179] Furthermore, since the overall discharge current is relatively small, the voltage change is negligible during the period from when the battery starts discharging until the discharge current exceeds the preset current. Therefore, the current internal resistance of the battery can be calculated based on the first voltage detected before the battery starts discharging, the second voltage detected after the discharge current exceeds the preset current for a third period of time, and the discharge current.

[0180] In one embodiment, the battery's SOC is 95%. The highest voltage of the battery cell at this time is collected to obtain a first voltage. The battery is controlled to discharge, and the discharge current is collected. When the discharge current exceeds a preset current, timing begins. After the discharge current exceeds the preset current for 30 seconds, the highest voltage of the battery cell at this time is collected to obtain a second voltage. The current internal resistance of the battery is calculated based on the first voltage, the second voltage, and the discharge current collected within 30 seconds.

[0181] Furthermore, since battery temperature affects its internal resistance, excessively high or low temperatures during discharge can lead to inaccurate internal resistance measurements. Therefore, a preset temperature range can be set according to actual needs to ensure accurate internal resistance calculations when the battery temperature exceeds this range.

[0182] Therefore, timing can begin once the battery temperature is within the preset temperature range during discharge, to ensure that the battery temperature does not become too high and affect the internal resistance, thus preventing the determined internal resistance from being inaccurate.

[0183] Furthermore, the discharge time can be started when the discharge current is greater than the preset current and the battery temperature is within the preset temperature range. This ensures that the discharge current is large enough to cause a significant change in the voltage collected before and after discharge, and that the battery temperature does not affect the internal resistance, thereby further improving the accuracy of the determined current internal resistance.

[0184] In addition, if the discharge current during battery discharge is consistently less than the preset current within a preset time period, or if the battery temperature is outside the preset temperature range, the discharge of the battery is stopped, and step 011 is executed to re-determine the battery's state of charge.

[0185] Thus, by starting timing only after the discharge current exceeds the preset current, and acquiring the second voltage when the discharge duration reaches the third duration, it can be ensured that the acquired second voltage differs significantly from the first voltage, thereby reducing the impact of voltage acquisition errors. Starting timing when the battery temperature is within the preset range ensures that the battery temperature during discharge will not be too high or too low, thus preventing it from affecting the battery's internal resistance and guaranteeing the accuracy of the calculated internal resistance.

[0186] Please see Figure 6 In some embodiments, step 0133 involves acquiring a second voltage when the discharge duration reaches a third duration, including...

[0187] Step 01331: If the battery temperature is within the preset temperature range, obtain the second voltage when the discharge time reaches the third duration.

[0188] In some implementations, the processor can be used to acquire a second voltage when the discharge duration reaches a third duration, provided that the battery temperature is within a preset temperature range.

[0189] In some embodiments, the third acquisition unit includes an acquisition subunit. The acquisition subunit can be used to acquire a second voltage when the battery temperature is within a preset temperature range and the discharge duration reaches a third duration.

[0190] Specifically, since the battery temperature affects the internal resistance, the battery temperature can also be judged when the discharge time reaches the third duration to determine whether the temperature is too high or too low.

[0191] If the battery temperature remains within the preset temperature range, when the discharge time reaches the third duration, the voltage of the cell with the highest voltage among the multiple cells of the battery is collected as the second voltage. The internal resistance of the battery is then calculated based on the first voltage, the second voltage, and the discharge current.

[0192] Furthermore, if the battery temperature is outside the preset temperature range, the discharge will stop. Even if the discharge duration reaches the third duration, the second voltage will not be collected, and step 011 will be executed to re-determine the battery's state of charge.

[0193] Thus, by comparing the battery temperature with the preset temperature range and determining whether the discharge time has reached the third duration, it is possible to determine whether to obtain the second voltage, ensuring that the internal resistance calculated based on the obtained second voltage is relatively accurate.

[0194] Please see Figure 7 and Figure 8 In some implementations, step 02, determining the internal resistance growth rate based on the current internal resistance, includes:

[0195] Step 021: Determine the first current internal resistance growth rate based on the current internal resistance and the initial internal resistance of the battery;

[0196] Step 03: Correct the battery's state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate, including:

[0197] Step 031: If the rate of increase of the first current internal resistance is greater than the first preset parameter, correct the state-of-charge-open-circuit voltage curve according to the rate of increase of the first current internal resistance; or,

[0198] Step 02, determine the internal resistance growth rate based on the current internal resistance, including:

[0199] Step 022: Determine the second current internal resistance growth rate based on the current internal resistance and the previous internal resistance of the battery;

[0200] Step 03: Correct the battery's state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate, including:

[0201] Step 032: If the second current internal resistance growth rate is greater than the second preset parameter, correct the state of charge-open circuit voltage curve according to the second current internal resistance growth rate.

[0202] In some implementations, the processor can be used to determine a first current internal resistance growth rate based on the current internal resistance and the initial internal resistance of the battery; can be used to correct the state-of-charge-open-circuit voltage curve based on the first current internal resistance growth rate when the first current internal resistance growth rate is greater than a first preset parameter; can also be used to determine a second current internal resistance growth rate based on the current internal resistance and the previous internal resistance of the battery; and can be used to correct the state-of-charge-open-circuit voltage curve based on the second current internal resistance growth rate when the second current internal resistance growth rate is greater than a second preset parameter.

[0203] In some embodiments, the curve correction module comprises a second determining submodule, a first correction submodule, a third determining submodule, and a second correction submodule. The second determining submodule is configured to determine a first current internal resistance growth rate based on the current internal resistance and the battery's initial internal resistance; the first correction submodule is configured to correct the state-of-charge-open-circuit voltage curve based on the first current internal resistance growth rate if the first current internal resistance growth rate is greater than a first preset parameter; the third determining submodule determines a second current internal resistance growth rate based on the current internal resistance and the battery's previous internal resistance; and the second correction submodule is configured to correct the state-of-charge-open-circuit voltage curve.

[0204] Specifically, the initial internal resistance is the internal resistance value when the battery is unused or first put into use, and it is also determined based on the first voltage, second voltage, and discharge current before and after the third discharge duration. The initial internal resistance can be used to characterize the actual internal resistance of the battery when it is put into use. The aging state of the battery can be determined based on the current internal resistance and the initial internal resistance. The first current internal resistance growth rate is determined based on the current internal resistance and the battery's initial internal resistance. The first current internal resistance growth rate can be used to characterize the aging state of the battery; the higher the current internal resistance growth rate, the higher the degree of battery aging.

[0205] The previous internal resistance is determined based on the first voltage, second voltage, and discharge current measured around the third duration of the previous discharge. It can be used to characterize the actual internal resistance of the battery during the previous discharge. The aging rate of the battery can be determined based on the current internal resistance and the previous internal resistance, and the second rate of increase of the current internal resistance can be determined based on the current internal resistance and the previous internal resistance.

[0206] After calculating the second current internal resistance growth rate, it is determined whether to correct the SOC-OCV curve based on the current internal resistance growth rate. The determination scheme includes a first scheme and a second scheme. Either the first scheme or the second scheme can be selected to correct the SOC-OCV curve, or it can be done in a progressive manner. For example, if the first scheme is satisfied, and the second scheme is satisfied, then the SOC-OCV curve is corrected.

[0207] The first scheme includes step 031, which is: when the current internal resistance growth rate is greater than a first preset parameter, the state-of-charge-open-circuit voltage curve is corrected according to the current internal resistance growth rate. The second scheme includes step 032, which is: when the current internal resistance growth rate is greater than a second preset parameter, the state-of-charge-open-circuit voltage curve is corrected according to the second current internal resistance growth rate.

[0208] The first and second preset parameters can be pre-set parameters, and can be set according to actual needs.

[0209] When the current internal resistance growth rate exceeds a first preset parameter, the battery is aging significantly. In this case, determining the SOC based on the initial or previous SOC-OCV curve would result in an inaccurate SOC. Therefore, when the current internal resistance growth rate exceeds the first preset parameter, the SOC-OCV curve is updated based on the current internal resistance growth rate.

[0210] If the current internal resistance growth rate is greater than the second preset parameter, it is determined that the current battery is aging faster. The accurate SOC value may not be determined based on the initial or previous SOC-OCV curve. Therefore, the SOC-OCV curve is corrected based on the current internal resistance growth rate.

[0211] In one embodiment, the initial internal resistance is R0, the current internal resistance is Ri, and the first current internal resistance growth rate ΔR1 = (Ri - R0) / R0.

[0212] In another embodiment, the previous internal resistance is Ri-1, the current internal resistance is Ri, and the second current internal resistance growth rate is ΔR2 = (Ri-Ri-1) / Ri-1.

[0213] Furthermore, if the first current internal resistance growth rate is less than or equal to the first preset parameter, there is no need to correct the SOC-OCV curve.

[0214] Thus, the current internal resistance growth rate is determined based on the current internal resistance and the initial internal resistance of the battery, and the second current internal resistance growth rate is determined based on the current internal resistance and the previous internal resistance of the battery. If the first current internal resistance growth rate is greater than the first preset parameter, or the second current internal resistance growth rate is greater than the second preset parameter, the SOC-OCV curve is updated based on the first current internal resistance growth rate or the second current internal resistance growth rate.

[0215] Please see Figure 9 In some implementations, step 02, determining the internal resistance growth rate based on the current internal resistance, includes:

[0216] Step 023: Determine the first current internal resistance growth rate based on the current internal resistance and the initial internal resistance of the battery;

[0217] Step 024: Determine the second current internal resistance growth rate based on the current internal resistance and the previous internal resistance of the battery;

[0218] Step 03: Correct the battery's state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate, including:

[0219] Step 033: If the second current internal resistance growth rate is less than the set state value, and the first current internal resistance growth rate is greater than the first preset parameter, the state of charge-open circuit voltage curve is corrected according to the first current internal resistance growth rate.

[0220] Step 034: If the second current internal resistance growth rate is greater than or equal to the set state value, and the second current internal resistance growth rate is greater than the second preset parameter, the state of charge-open circuit voltage curve is corrected according to the second current internal resistance growth rate.

[0221] In some implementations, the processor can be used to determine a first current internal resistance growth rate based on the current internal resistance and the initial internal resistance of the battery; can be used to determine a second current internal resistance growth rate based on the current internal resistance and the previous internal resistance of the battery; can be used to correct the state-of-charge-open-circuit voltage curve based on the first current internal resistance growth rate if the second current internal resistance growth rate is less than a set state value and the first current internal resistance growth rate is greater than a first preset parameter; and can be used to correct the state-of-charge-open-circuit voltage curve based on the second current internal resistance growth rate if the second current internal resistance growth rate is greater than or equal to a set state value and the second current internal resistance growth rate is greater than a second preset parameter.

[0222] In some embodiments, the curve correction module further includes a fourth determining submodule, a fifth determining submodule, a third correction submodule, and a fourth correction submodule. Specifically, the fourth determining submodule can be used to determine a first current internal resistance growth rate based on the current internal resistance and the battery's initial internal resistance; the fifth determining submodule can be used to determine a second current internal resistance growth rate based on the current internal resistance and the battery's previous internal resistance; the third correction submodule can be used to correct the state-of-charge-open-circuit voltage curve based on the first current internal resistance growth rate if the second current internal resistance growth rate is less than a set state value and the first current internal resistance growth rate is greater than a first preset parameter; and the fourth correction submodule can be used to correct the state-of-charge-open-circuit voltage curve based on the second current internal resistance growth rate if the second current internal resistance growth rate is greater than or equal to a set state value and the second current internal resistance growth rate is greater than a second preset parameter.

[0223] Specifically, when the battery is in good health, the battery degrades linearly, the aging process is basically the same, and the internal resistance increases linearly. Therefore, the same correction method can be used to correct the SOC-OCV curve. Thus, when the battery is in good health, the first approach can be used to determine whether correction is necessary: ​​if the current internal resistance growth rate is greater than a first preset parameter, the SOC-OCV curve is corrected based on the current internal resistance growth rate.

[0224] When a battery's health is low, its capacity may plummet, lithium plating may occur, and battery degradation may accelerate, leading to a rapid increase in internal resistance. At this point, the battery's aging pattern changes, differing from that observed when the battery is in higher health. Therefore, the SOC-OCV curve correction scheme needs to be adjusted to align with the current aging pattern. Thus, when the battery's health is low, a second approach can be used to determine whether correction is necessary: ​​if the current internal resistance growth rate exceeds a second preset parameter, the state-of-charge (SOC)-open-circuit voltage (OCV) curve is corrected based on this second SOC growth rate. Adjusting the SOC-OCV curve based on the battery's health allows for full-lifecycle correction of the battery.

[0225] The second current internal resistance growth rate can be used to characterize the aging state and aging rate of the battery. Therefore, the battery's health status can be determined based on the second current internal resistance growth rate. A preset state value is established. If the second current internal resistance growth rate is less than the preset state value, the current battery's health status is determined to be relatively high; if the second current internal resistance growth rate is greater than or equal to the preset state value, the current battery's health status is determined to be relatively low.

[0226] In one embodiment, if the second current internal resistance growth rate is less than a set state value, the current battery health state SOH < 80% is determined, and it is determined whether to correct the SOC-OCV curve based on the first current internal resistance growth rate using the first scheme; if the second current internal resistance growth rate is greater than or equal to the set state value, the current battery health state SOH ≥ 80% is determined, and it is determined whether to correct the SOC-OCV curve based on the second current internal resistance growth rate using the second scheme.

[0227] Thus, based on the comparison between the second current internal resistance growth rate and the set state value, it is possible to determine whether to select the first or second scheme to correct the state-of-charge-open-circuit voltage curve, thereby achieving full life cycle correction of the battery.

[0228] Please see Figure 10 and Figure 11 In some embodiments, step 033, when the first current internal resistance growth rate is greater than a first preset parameter, corrects the state-of-charge-open-circuit voltage curve according to the first current internal resistance growth rate, including:

[0229] Step 0331: If the first current internal resistance growth rate is greater than the first preset parameter, determine the first current number of times. The first current number of times is used to determine the number of times the battery's first current internal resistance growth rate is greater than the first preset parameter.

[0230] Step 0332: If the first current count is greater than the first preset count, correct the state-of-charge-open-circuit voltage curve according to the first current internal resistance growth rate; and / or,

[0231] Step 034, when the growth parameter is greater than the second preset parameter, correct the state-of-charge-open-circuit voltage curve according to the current internal resistance growth rate, including:

[0232] Step 0341: If the second current internal resistance growth rate is greater than the second preset parameter, determine the second current number of times. The second current number of times is used to determine the number of times the battery's second current internal resistance growth rate is greater than the second preset parameter.

[0233] Step 0342: If the second current number is greater than the second preset number, correct the state of charge-open circuit voltage curve according to the second current internal resistance growth rate.

[0234] In some embodiments, the processor can be used to determine a first current count when the first current internal resistance growth rate is greater than a first preset parameter, the first current count being used to determine the number of times the first current internal resistance growth rate of the battery is greater than the first preset parameter; and to correct the state-of-charge-open-circuit voltage curve based on the first current internal resistance growth rate when the first current count is greater than the first preset count; further, to determine a second current count when the second current internal resistance growth rate is greater than a second preset parameter, the second current count being used to determine the number of times the second current internal resistance growth rate of the battery is greater than the second preset parameter; and to correct the state-of-charge-open-circuit voltage curve based on the second current internal resistance growth rate when the second current count is greater than the second preset count.

[0235] In some embodiments, the third correction submodule includes a first determining unit and a first correction unit, and the fourth correction submodule includes a second determining unit and a second correction unit. The first determining unit can be used to determine a first current count when the first current internal resistance growth rate is greater than a first preset parameter; the first current count is used to determine the number of times the battery's first current internal resistance growth rate is greater than the first preset parameter. The first correction unit can be used to correct the state-of-charge-open-circuit voltage curve based on the first current internal resistance growth rate when the first current count is greater than the first preset count. The second determining unit can be used to determine a second current count when the second current internal resistance growth rate is greater than a second preset parameter; the second current count is used to determine the number of times the battery's second current internal resistance growth rate is greater than the second preset parameter. The second correction unit can be used to correct the state-of-charge-open-circuit voltage curve based on the second current internal resistance growth rate when the second current count is greater than the second preset count.

[0236] Specifically, if the battery ages rapidly, updating the SOC-OCV curve when the first current internal resistance growth rate exceeds a first preset parameter or when the second current internal resistance growth rate exceeds a second preset parameter may result in frequent SOC-OCV curve updates. Therefore, the number of times the first current internal resistance growth rate exceeds the first preset parameter is counted to obtain the first current count; and the number of times the second current internal resistance growth rate exceeds the second preset parameter is counted to obtain the second current count.

[0237] If the first current number of discharges is greater than the first preset number of discharges, the first current internal resistance growth rate of the battery in multiple discharge tests is greater than the first preset parameter, which indicates that the battery is aging continuously. In this case, the SOC-OCV curve is corrected according to the first current internal resistance growth rate.

[0238] If the second current count is greater than the second preset count, then the second current internal resistance growth rate of the battery during multiple discharge tests is greater than the second preset parameter, indicating that the battery is aging at a relatively rapid rate. In this case, the SOC-OCV curve is corrected based on the second current internal resistance growth rate. In some embodiments, if the first current count is greater than the first preset count, or the second current count is greater than the second preset count, the first current count or the second current count is set to zero. The current count restarts when the first current internal resistance growth rate is greater than the first preset parameter, or the second current internal resistance growth rate is greater than the second preset parameter.

[0239] Furthermore, the consideration of the number of cycles can be introduced into either the first or the second scheme; alternatively, when calibrating the SOC-OCV curve of the battery, the consideration of the number of cycles can be introduced into both the first and the second schemes to further simplify the control and avoid the SOC-OCV curve being updated too frequently.

[0240] In one embodiment, the processor has a built-in electrochemical mechanism model, with a first current count of 4 and a first preset count of 3. If the first current count is greater than the preset count, the first current internal resistance growth rate is input into the electrochemical mechanism model, and the electrochemical mechanism model simulates and outputs the corresponding SOC-OCV curve based on the first current internal resistance growth rate.

[0241] Thus, if the current number of cycles exceeds the preset number of cycles, the state-of-charge-open-circuit voltage curve can be updated based on the current internal resistance growth rate, even while the battery continues to age rapidly.

[0242] Please see Figure 12 In some implementations, step 03 corrects the battery's state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate, including:

[0243] Step 035: Correct the state-of-charge-open-circuit voltage curve according to the first preset correction function and the current internal resistance growth rate. The first preset correction function is used to characterize the correspondence between the internal resistance growth rate and the state-of-charge-open-circuit voltage curve.

[0244] In some implementations, the processor can be used to correct the state-of-charge-open-circuit voltage curve according to a first preset correction function and the current internal resistance growth rate, wherein the first preset correction function is used to characterize the correspondence between the internal resistance growth rate and the state-of-charge-open-circuit voltage curve.

[0245] In some implementations, the curve correction module includes a third correction submodule. The third correction submodule can be used to correct the state-of-charge-open-circuit voltage curve according to a first preset correction function and the current internal resistance growth rate. The first preset correction function is used to characterize the correspondence between the internal resistance growth rate and the state-of-charge-open-circuit voltage curve.

[0246] Specifically, the first preset correction function can be a pre-set SOC-OCV curve correction function with the internal resistance growth rate as a parameter. By inputting the current internal resistance growth rate into the SOC-OCV curve correction function, a SOC-OCV curve determined according to the current internal resistance growth rate can be obtained. The newly determined SOC-OCV curve is used to replace the original SOC-OCV curve to achieve the correction of the SOC-OCV curve.

[0247] In one embodiment, the second preset parameter is 10%, and the processor has a built-in SOC-OCV curve correction function that includes the internal resistance growth rate. If the internal resistance parameter determined based on the current internal resistance growth rate and the previous internal resistance growth rate is greater than 10%, then the SOC-OCV curve corresponding to the current internal resistance growth rate can be calculated by substituting the current internal resistance growth rate into the function relationship.

[0248] Thus, the state-of-charge-open-circuit voltage curve can be corrected based on the first preset correction function and the current internal resistance growth rate, thereby achieving the correction of the state-of-charge-open-circuit voltage curve.

[0249] Please see Figure 13 In some implementations, step 03 corrects the battery's state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate, including:

[0250] Step 036: Determine the correction coefficient based on the second preset correction function and the current internal resistance growth rate. The second preset correction function is used to characterize the correspondence between the internal resistance growth rate and the correction coefficient.

[0251] Step 037: Correct the state-of-charge-open-circuit voltage curve according to the correction factor.

[0252] In some implementations, the processor can be used to determine a correction coefficient based on a second preset correction function and the current internal resistance growth rate, wherein the second preset correction function is used to characterize the correspondence between the internal resistance growth rate and the correction coefficient; and can be used to correct the state-of-charge-open-circuit voltage curve based on the correction coefficient.

[0253] In some implementations, the curve correction module includes a fifth determining submodule and a fourth correction submodule. The fifth determining submodule can be used to determine the correction coefficient based on a second preset correction function and the current internal resistance growth rate, wherein the second preset correction function is used to characterize the correspondence between the internal resistance growth rate and the correction coefficient; the fourth correction submodule can be used to correct the state-of-charge-open-circuit voltage curve based on the correction coefficient.

[0254] Specifically, the second preset correction function can be a pre-set SOC-OCV curve correction function that uses the internal resistance growth rate as a parameter. By inputting the current internal resistance growth rate into the SOC-OCV curve correction function, a correction coefficient determined based on the current internal resistance growth rate can be obtained. This correction coefficient can then be used to correct the original SOC-OCV curve, resulting in a new SOC-OCV curve. The newly determined SOC-OCV curve then replaces the original SOC-OCV curve, thus achieving the correction of the SOC-OCV curve.

[0255] In one embodiment, if the current internal resistance growth rate is greater than the first preset parameter, the current internal resistance growth rate is input into the second preset correction function to obtain the corresponding correction coefficient, and the SOC-OCV curve can be corrected according to the correction coefficient.

[0256] Thus, the correction coefficient can be determined based on the second preset correction function and the current internal resistance growth rate. The correction coefficient can be used to correct the state-of-charge-open-circuit voltage curve to achieve the correction of the state-of-charge-open-circuit voltage curve.

[0257] Please see Figure 14 In some implementations, step 03 corrects the battery's state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate, including:

[0258] Step 038: Correct the state-of-charge-open-circuit voltage curve according to the preset correction table and the current internal resistance growth rate. In the preset correction table, the current internal resistance growth rate and the state-of-charge-open-circuit voltage curve correspond one-to-one.

[0259] In some implementations, the processor can be used to correct the state-of-charge-open-circuit voltage curve according to a preset correction table and the current internal resistance growth rate, in which the current internal resistance growth rate and the state-of-charge-open-circuit voltage curve correspond one-to-one.

[0260] In some implementations, the curve correction module includes a fifth correction submodule. The fifth correction submodule can be used to correct the state-of-charge-open-circuit voltage curve according to a preset correction table and the current internal resistance growth rate, in which the current internal resistance growth rate and the state-of-charge-open-circuit voltage curve correspond one-to-one.

[0261] Specifically, the preset calibration table is a pre-defined table corresponding to the internal resistance growth rate and the SOC-OCV curve. Within the preset calibration table, one internal resistance growth rate corresponds to one state-of-charge-open-circuit voltage curve. Therefore, when it is necessary to correct the SOC-OCV curve based on the current internal resistance growth rate, the corresponding SOC-OCV curve can be found in the preset calibration table to achieve the correction. Calculating the SOC-OCV curve based on the preset calibration table is relatively simple and the correction speed is fast.

[0262] In another embodiment, if the first current internal resistance growth rate is greater than the first preset parameter, the SOC-OCV curve corresponding to the current internal resistance growth rate is searched in the preset correction table to serve as the current SOC-OCV curve, thereby updating the SOC-OCV curve.

[0263] Thus, the calculation of the state-of-charge-open-circuit voltage curve is relatively simple, based on the preset correction table and the current internal resistance growth rate.

[0264] Please see Figure 15 In some implementations, step 03 corrects the battery's state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate, including:

[0265] Step 039: Correct the state-of-charge-open-circuit voltage curve according to the preset electrochemical mechanism model and the current internal resistance growth rate. The preset electrochemical mechanism model is configured to simulate and output the state-of-charge-open-circuit voltage curve according to the current internal resistance growth rate.

[0266] In some implementations, the processor can be used to correct the state-of-charge-open-circuit voltage curve based on a preset electrochemical mechanism model and the current internal resistance growth rate. The preset electrochemical mechanism model is configured to simulate and output the state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate.

[0267] In some implementations, the curve correction module includes a sixth correction submodule. This sixth correction submodule can be used to correct the state-of-charge-open-circuit voltage curve based on a preset electrochemical mechanism model and the current internal resistance growth rate. The preset electrochemical mechanism model is configured to simulate and output the state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate.

[0268] Specifically, the electrochemical mechanism model can be used to simulate the state of the battery based on the internal resistance growth rate to obtain the corresponding state-of-charge (SOC-OCV) curve. When it is necessary to correct the SOC-OCV curve based on the current internal resistance growth rate, the current internal resistance growth rate is input into the electrochemical mechanism model. The model then performs simulation calculations based on the internal resistance growth rate and outputs the SOC-OCV curve corresponding to the current internal resistance growth rate, thus achieving SOC-OCV curve correction. The SOC-OCV curve obtained using the electrochemical mechanism model has higher accuracy and better matches the actual SOC-OCV curve corresponding to the current internal resistance growth rate.

[0269] Thus, by correcting the state-of-charge-open-circuit voltage curve based on the preset electrochemical mechanism model and the current internal resistance growth rate, a highly accurate SOC-OCV curve can be obtained.

[0270] This application provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the correction method as described in any of the above embodiments.

[0271] It is understood that a computer program includes computer program code. Computer program code can be in the form of source code, object code, executable files, or some intermediate form. Computer-readable storage media can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, external hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), and software distribution media, etc.

[0272] In the description of this specification, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with an embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, without contradiction, those skilled in the art can combine and integrate different embodiments or examples described in this specification, as well as features of different embodiments or examples.

[0273] Furthermore, the term "connection" should be interpreted broadly. For example, it can include fixed connections, detachable connections, or integral connections; it can include direct connections or indirect connections through an intermediate medium; and it can also include internal communication between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0274] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0275] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order according to the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0276] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for correcting the state-of-charge-open-circuit voltage curve, characterized in that, The correction method includes: Get the current internal resistance of the battery; Determine the current internal resistance growth rate based on the current internal resistance; The state-of-charge-open-circuit voltage curve of the battery is corrected based on the current internal resistance growth rate.

2. The correction method according to claim 1, characterized in that, The step of obtaining the current internal resistance of the battery includes: When the state of charge of the battery is within a preset range, the first voltage of the battery is obtained; Control the battery discharge; Obtain the discharge current during battery discharge and the second voltage after discharge; The current internal resistance of the battery is determined based on the discharge current, the first voltage, and the second voltage.

3. The correction method according to claim 2, characterized in that, When the state of charge of the battery is within a preset range, obtaining the first voltage of the battery includes: Control the charging of the battery so that the state of charge of the battery is within the preset range; Let the battery stand still; If the resting time is longer than the first duration, the first voltage of the battery is obtained.

4. The correction method according to claim 2, characterized in that, The control of the battery discharge includes: The battery is discharged within a second time period after the first voltage of the battery is obtained.

5. The correction method according to claim 2, characterized in that, The preset range is [70%, 99%].

6. The correction method according to claim 2, characterized in that, The step of obtaining the discharge current during battery discharge and the second voltage after discharge includes: Obtain the discharge current of the battery during discharge; When the discharge current of the battery during discharge is greater than a preset current, and / or when the temperature of the battery is within a preset temperature range, the discharge duration of the battery is started to be timed; When the discharge duration reaches the third duration, the second voltage is obtained.

7. The correction method according to claim 1, characterized in that, The step of determining the current internal resistance growth rate based on the current internal resistance includes: A first current internal resistance growth rate is determined based on the current internal resistance and the initial internal resistance of the battery; The step of correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes: If the first current internal resistance growth rate is greater than the first preset parameter, the state-of-charge-open-circuit voltage curve is corrected according to the first current internal resistance growth rate; or, The step of determining the current internal resistance growth rate based on the current internal resistance includes: The second current internal resistance growth rate is determined based on the current internal resistance and the previous internal resistance of the battery. The step of correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes: If the second current internal resistance growth rate is greater than the second preset parameter, the state-of-charge-open-circuit voltage curve is corrected according to the second current internal resistance growth rate.

8. The correction method according to claim 1, characterized in that, The step of determining the current internal resistance growth rate based on the current internal resistance includes: A first current internal resistance growth rate is determined based on the current internal resistance and the initial internal resistance of the battery; The second current internal resistance growth rate is determined based on the current internal resistance and the previous internal resistance of the battery. The step of correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes: If the second current internal resistance growth rate is less than the set state value, and the first current internal resistance growth rate is greater than the first preset parameter, the state of charge-open circuit voltage curve is corrected according to the first current internal resistance growth rate. If the second current internal resistance growth rate is greater than or equal to the set state value, and the second current internal resistance growth rate is greater than the second preset parameter, the state of charge-open circuit voltage curve is corrected according to the second current internal resistance growth rate.

9. The correction method according to claim 7 or 8, characterized in that, The step of correcting the state-of-charge-open-circuit voltage curve based on the first current internal resistance growth rate when the first current internal resistance growth rate is greater than the first preset parameter includes: If the first current internal resistance growth rate is greater than the first preset parameter, a first current number is determined. The first current number is used to determine the number of times the first current internal resistance growth rate of the battery is greater than the first preset parameter. If the first current count is greater than the first preset count, the state-of-charge-open-circuit voltage curve is corrected according to the first current internal resistance growth rate; and / or, The step of correcting the state-of-charge-open-circuit voltage curve based on the second current internal resistance growth rate when the second current internal resistance growth rate is greater than the second preset parameter includes: If the second current internal resistance growth rate is greater than the second preset parameter, a second current number is determined. The second current number is used to determine the number of times the second current internal resistance growth rate of the battery is greater than the second preset parameter. If the second current number is greater than the second preset number, the state-of-charge-open-circuit voltage curve is corrected according to the second current internal resistance growth rate.

10. The correction method according to claim 1, characterized in that, The step of correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes: The state-of-charge-open-circuit voltage curve is corrected according to the first preset correction function and the current internal resistance growth rate. The first preset correction function is used to characterize the correspondence between the internal resistance growth rate and the state-of-charge-open-circuit voltage curve.

11. The correction method according to claim 1, characterized in that, The step of correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes: The correction coefficient is determined based on the second preset correction function and the current internal resistance growth rate. The second preset correction function is used to characterize the correspondence between the internal resistance growth rate and the correction coefficient. The state-of-charge-open-circuit voltage curve is corrected according to the correction coefficient.

12. The correction method according to claim 1, characterized in that, The step of correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes: The state-of-charge-open-circuit voltage curve is corrected according to a preset correction table and the current internal resistance growth rate. In the preset correction table, the current internal resistance growth rate and the state-of-charge-open-circuit voltage curve correspond one-to-one.

13. The correction method according to claim 1, characterized in that, The step of correcting the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate includes: The state-of-charge-open-circuit voltage curve is corrected based on a preset electrochemical mechanism model and the current internal resistance growth rate. The preset electrochemical mechanism model is configured to simulate and output the state-of-charge-open-circuit voltage curve based on the current internal resistance growth rate.

14. A device for correcting the state-of-charge-open-circuit voltage curve, characterized in that, The device includes: A first determining module is configured to obtain the current internal resistance of the battery; The second determining module is configured to determine the current internal resistance growth rate based on the current internal resistance. A curve correction module is configured to correct the state-of-charge-open-circuit voltage curve of the battery based on the current internal resistance growth rate.

15. The calibration device according to claim 14, characterized in that, The first determining module includes: The first acquisition submodule is configured to acquire the first voltage of the battery when the state of charge of the battery is within a preset range; The first control submodule is configured to control the discharge of the battery; The second acquisition submodule is configured to acquire the discharge current during battery discharge and the second voltage after discharge. The first determining submodule is configured to determine the current internal resistance of the battery based on the discharge current, the first voltage, and the second voltage.

16. The calibration device according to claim 15, characterized in that, The first acquisition submodule includes: A first control unit is configured to control the charging of the battery so that the state of charge of the battery is within the preset range; A resting unit, configured to rest the battery; The first acquisition unit is configured to acquire the first voltage of the battery when the resting time is longer than a first duration.

17. The calibration device according to claim 15, characterized in that, The first control submodule includes: The second control unit is configured to discharge the battery within a second time period after acquiring the first voltage of the battery.

18. The calibration device according to claim 15, characterized in that, The second acquisition submodule includes: The second acquisition unit is configured to acquire the discharge current of the battery during discharge. The timing unit is configured to start timing the discharge duration of the battery when the discharge current during battery discharge is greater than a preset current, and / or when the temperature of the battery is within a preset temperature range. The third acquisition unit is configured to acquire the second voltage when the discharge duration reaches the third duration.

19. The calibration device according to claim 14, characterized in that, The curve correction module includes: The second determining submodule is configured to determine a first current internal resistance growth rate based on the current internal resistance and the initial internal resistance of the battery. The first correction submodule is configured to correct the state-of-charge-open-circuit voltage curve according to the first current internal resistance growth rate when the first current internal resistance growth rate is greater than the first preset parameter. The third determining submodule determines the second current internal resistance growth rate based on the current internal resistance and the previous internal resistance of the battery; The second correction submodule is configured to correct the state-of-charge-open-circuit voltage curve.

20. The calibration device according to claim 14, characterized in that, The curve correction module includes: The fourth determining submodule is configured to determine a first current internal resistance growth rate based on the current internal resistance and the initial internal resistance of the battery; The fifth determining submodule is configured to determine the second current internal resistance growth rate based on the current internal resistance and the previous internal resistance of the battery; The third correction submodule is configured to correct the state of charge-open circuit voltage curve according to the first current internal resistance growth rate if the second current internal resistance growth rate is less than a set state value and the first current internal resistance growth rate is greater than a first preset parameter. The fourth correction submodule is configured to correct the state-of-charge-open-circuit voltage curve based on the second current internal resistance growth rate if the second current internal resistance growth rate is greater than or equal to a set state value, and if the second current internal resistance growth rate is greater than a second preset parameter.

21. A computer device, characterized in that, The computer device includes one or more processors and a memory, the memory storing a computer program that, when executed by the processor, implements the steps of the correction method as described in any one of claims 1 to 13.

22. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by a processor, it implements the steps of the correction method as described in any one of claims 1 to 13.

Images