SOC-OCV mapping relationship calibration method and apparatus, and device, medium and product
By receiving the state of charge and cycle number of the battery pack, the OCV is obtained, and the SOC-OCV mapping relationship is calibrated based on experimental data. This solves the problem of low accuracy of the SOC-OCV curve after battery pack aging and achieves higher calibration accuracy.
Patent Information
- Application Number
- PCT/CN2024/100887
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-06-29
- Filing Date
- 2024-06-24
- Publication Date
- 2025-01-02
AI Technical Summary
In existing technologies, the SOC-OCV curves of battery packs do not take into account the effects of battery pack cycle aging during calibration, resulting in low accuracy.
By receiving the state of charge (SOC) and cycle count of the battery pack, the open-circuit volume (OCV) is obtained, and the SOC-OCV mapping relationship is determined based on pre-set experimental data. The SOC-OCV mapping relationship is calibrated using the first calibrated OCV, taking into account the impact of battery pack cycle aging, thus improving accuracy.
It improves the accuracy of the SOC-OCV mapping relationship, especially after the battery pack ages, and can more accurately calibrate the SOC-OCV curve.
Smart Images

Figure CN2024100887_02012025_PF_FP_ABST
Abstract
Description
SOC-OCV mapping relationship calibration method, device, equipment, medium and product
[0001] CROSS-REFERENCE TO RELATED APPLICATIONS
[0002] This application claims priority to Chinese patent application No. 202310791235.6, filed on June 29, 2023, entitled “SOC-OCV mapping relationship calibration method, device, equipment, medium and product,” and the entire contents of that application are incorporated herein by reference. Technical Field
[0003] The present application relates to the field of batteries, and in particular to a method, device, equipment, medium and product for calibrating a SOC-OCV mapping relationship. Background Art
[0004] The state of charge (SOC)-open circuit voltage (OCV) curve is an important performance indicator of a battery pack.
[0005] In the prior art, when calibrating the SOC-OCV curve of a battery pack, the SOC-OCV curve of the battery pack is usually calibrated at different temperatures.
[0006] Summary of the Invention
[0007] The present application provides a SOC-OCV mapping relationship calibration method, device, equipment, medium and product to improve the problem of inaccurate SOC-OCV curve in the prior art.
[0008] In a first aspect, the present application provides a method for calibrating a state-of-charge (SOC)-ocv mapping relationship. The method includes: receiving a first state of charge (SOC) and a first cycle number of a battery pack, and obtaining a first OCV corresponding to the first SOC; determining a first SOC-ocv mapping relationship corresponding to the first cycle number based on pre-set experimental data, where the experimental data is configured as a function of the cycle number, OCV, and SOC; determining a first calibrated OCV corresponding to the first SOC based on the first SOC-ocv mapping relationship; and calibrating the first SOC-ocv mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV.
[0009] The SOC-OCV mapping relationship calibration method provided in an embodiment of the present application can receive a first SOC and a first cycle number of a battery pack, obtain a first OCV corresponding to the first SOC, and then determine a first SOC-OCV mapping relationship corresponding to the first cycle number based on pre-set experimental data. The experimental data is configured as a function of the cycle number, OCV, and SOC. Based on the first SOC-OCV mapping relationship, a first calibrated OCV corresponding to the first SOC can be determined. Then, the first SOC-OCV mapping relationship can be calibrated based on the first SOC, the first OCV, and the first calibrated OCV. Because the first calibrated OCV is determined based on the first SOC-OCV mapping relationship corresponding to the first cycle number, the impact of battery pack cycle aging on the SOC-OCV mapping relationship is taken into account. Therefore, the accuracy of the first calibrated OCV is relatively high. In addition, the present application also calibrates the first SOC-OCV mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV, thereby improving the accuracy of the SOC-OCV mapping relationship.
[0010] In some embodiments, the above-mentioned obtaining of the first OCV corresponding to the first SOC includes: in response to the battery pack satisfying a first condition, collecting the second OCV of the battery pack, the second OCV being configured as the OCV of the battery pack after the battery pack has been stationary for a first time; the first condition being configured as the throughput capacity of the battery pack being less than the nominal capacity of the battery pack within the second time; and using the second OCV as the first OCV; wherein the second time is configured as the time it takes for the battery pack to charge or discharge from the second SOC to the first SOC, and the second time is less than a second time threshold, the throughput capacity of the battery pack is configured as the sum of the cumulative charging capacity and the cumulative discharging capacity of the battery pack within the second time, and the second SOC is configured as the SOC obtained after calibration.
[0011] The SOC-OCV mapping relationship calibration method provided in the embodiment of the present application has a high accuracy of SOC when the time after SOC calibration is short and the throughput is low. The collected second OCV is used as the first OCV corresponding to the first SOC, and the OCV of the battery is more accurate.
[0012] In some embodiments, the second SOC is obtained by calibrating one of the following calibration items: i) in response to the SOC of any cell when the battery pack is charged or discharged reaching the first SOC range, the battery pack is left to stand for a third time, the current OCV of the battery pack is obtained, and the second SOC is calibrated based on the current OCV and experimental data; ii) when the battery pack is charged, the voltage of any cell is greater than the charge cut-off voltage and the charge current is less than the first current threshold, and the duration is T1, the second SOC is calibrated to 100%; iii) when the battery pack is discharged, the voltage of any cell is less than the discharge cut-off voltage and the discharge current is less than the second current threshold, and the duration is T2, the second SOC is calibrated to 0%.
[0013] The SOC-OCV mapping relationship calibration method provided in the embodiment of the present application can accurately calibrate the SOC, so as to more accurately calibrate the SOC-OCV mapping relationship.
[0014] In some embodiments, within the first SOC range, at different cycle times, the difference between different SOCs corresponding to the same OCV is less than a preset threshold.
[0015] The SOC-OCV mapping relationship calibration method provided in the embodiment of the present application is more accurate in calibrating the SOC within a range where the SOC changes slightly.
[0016] In some embodiments, calibrating the first SOC-OCV mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV includes: determining a plurality of target SOCs from the first SOC-OCV mapping relationship, the target SOCs being configured as SOCs set at intervals of x%, where 1≤x≤10, and calibrating the target OCVs corresponding to the target SOCs to obtain calibrated target OCV values. The target OCVs are configured to be OCVs corresponding to the target SOCs based on experimental data.
[0017] The SOC-OCV mapping relationship calibration method provided in the embodiment of the present application can determine the target OCV calibration values corresponding to the multiple target SOCs by calibrating the target OCVs corresponding to the pre-set multiple target SOCs, and then determine the calibrated first SOC-OCV mapping relationship based on the target OCV calibration values corresponding to the multiple target SOCs. In this way, the calibrated first SOC-OCV mapping relationship can be made more accurate.
[0018] In some embodiments, there are multiple first SOCs; the calibration of the target OCV corresponding to the target SOC to obtain the target OCV calibration value includes: determining, from the multiple first SOCs, a first SOC having a minimum absolute difference from the target SOC, and a first calibrated OCV corresponding to the first SOC; calculating a first OCV difference, where the first OCV difference is the difference between the first calibrated OCV and the first OCV; calculating a target first OCV calibration value based on the first OCV difference; and calculating the target OCV calibration value based on the target OCV corresponding to the target SOC and the first OCV calibration value.
[0019] The SOC-OCV mapping relationship calibration method provided in the embodiment of the present application can determine the first OCV difference corresponding to the target SOC based on the first calibrated OCV corresponding to the first SOC closest to the target SOC and the first OCV, and then gradually calculate the target OCV calibration value corresponding to the target SOC, thereby accurately calibrating the OCV corresponding to the target SOC.
[0020] In some embodiments, the above-mentioned calculation of the target first OCV calibration value based on the first OCV difference includes: calculating the target first OCV calibration value based on the first OCV difference, a voltage sampling error coefficient, a current sampling error coefficient, and a rest time error coefficient; wherein the voltage sampling error coefficient is configured to be associated with an error of the voltage sampling chip; the current sampling error coefficient is configured to be a function associated with the error of the current sampling chip, the second time, the second time threshold, the nominal capacity of the battery pack, and the throughput capacity of the battery pack; the rest time error coefficient is configured to be associated with the first time and the first time threshold, and the first time threshold is a function of the maximum time that the battery pack is resting to meet the first condition.
[0021] The SOC-OCV mapping relationship calibration method provided in the embodiment of the present application can more accurately determine the target first OCV calibration value corresponding to the target SOC through the first OCV difference, the voltage sampling error coefficient, the current sampling error coefficient, and the static time error coefficient, thereby more accurately calibrating the SOC-OCV mapping relationship.
[0022] In some embodiments, the target OCV calibration value is the OCV obtained after calibration of the battery pack in a first state. The method further includes calibrating the SOC-OCV mapping relationship of the battery pack in a second state based on the target OCV calibration value. The first state is one of a charging state and a discharging state of the battery pack, and the second state is the other of the charging state and the discharging state of the battery pack.
[0023] The SOC-OCV mapping relationship calibration method provided in the embodiment of the present application can improve calibration efficiency because the SOC-OCV mapping relationship in the discharge state can be calibrated based on the target OCV calibration value in the charge state, or the SOC-OCV mapping relationship in the charge state can be calibrated based on the target OCV calibration value in the discharge state.
[0024] In some embodiments, the above-mentioned calibration of the OSC-OCV mapping relationship of the battery pack in the second state based on the target OCV calibration value also includes: determining a third SOC of the battery pack in the second state, the third SOC corresponding to the target SOC of the battery pack in the first state; determining a third OCV corresponding to the third SOC based on experimental data; calculating the difference between the OCV calibration value of the battery pack in the first state and the third OCV to obtain N differences, and calculating the average of the N differences to obtain a deviation; based on the deviation and the third OCV, calibrating the SOC-OCV mapping relationship of the battery pack in the second state.
[0025] The SOC-OCV mapping relationship calibration method provided in the embodiment of the present application calibrates the SOC-OCV mapping relationship based on the difference relationship between the charging OCV and the discharging OCV, which can improve the accuracy of calibrating the SOC-OCV mapping relationship in the discharging state based on the target OCV calibration value in the charging state, or calibrating the SOC-OCV mapping relationship in the charging state based on the target OCV calibration value in the discharge state.
[0026] In a second aspect, the present application provides an SOC-OCV mapping relationship calibration device, including: a receiving module for receiving a first state of charge SOC and a first cycle number of a battery pack; an acquisition module for acquiring a first OCV corresponding to the first SOC; a first determination module for determining a first SOC-OCV mapping relationship corresponding to the first cycle number based on pre-set experimental data; the experimental data is configured as a function between the cycle number, OCV and SOC; a second determination module for determining a first calibrated OCV corresponding to the first SOC based on the first SOC-OCV mapping relationship; a first calibration module for calibrating the first SOC-OCV mapping relationship based on the first SOC, the first OCV and the first calibrated OCV.
[0027] The SOC-OCV mapping relationship calibration device provided in an embodiment of the present application can receive a first SOC and a first cycle number of a battery pack, obtain a first OCV corresponding to the first SOC, and then determine a first SOC-OCV mapping relationship corresponding to the first cycle number based on pre-set experimental data. The experimental data is configured as a function of the cycle number, OCV, and SOC. Based on the first SOC-OCV mapping relationship, a first calibrated OCV corresponding to the first SOC can be determined. Then, the first SOC-OCV mapping relationship can be calibrated based on the first SOC, the first OCV, and the first calibrated OCV. Because the first calibrated OCV is determined based on the first SOC-OCV mapping relationship corresponding to the first cycle number, the impact of battery pack cycle aging on the SOC-OCV mapping relationship is taken into account. Therefore, the accuracy of the first calibrated OCV is relatively high. In addition, the present application also calibrates the first SOC-OCV mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV, thereby improving the accuracy of the SOC-OCV mapping relationship.
[0028] In a third aspect, the present application provides an electronic device, the device comprising: a processor and a memory storing computer program instructions;
[0029] When the processor executes the computer program instructions, the SOC-OCV mapping relationship calibration method as shown in any one of the embodiments of the first aspect is implemented.
[0030] In a fourth aspect, the present application provides a computer storage medium having computer program instructions stored thereon, and when the computer program instructions are executed by a processor, the SOC-OCV mapping relationship calibration method shown in any one of the embodiments of the first aspect is implemented.
[0031] In a fifth aspect, an embodiment of the present application provides a computer program product. When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the SOC-OCV mapping relationship calibration method shown in any one of the embodiments of the first aspect.
[0032] The SOC-OCV mapping relationship calibration method, apparatus, device, medium, and product provided in the embodiments of the present application can receive a first SOC and a first cycle number of a battery pack, obtain a first OCV corresponding to the first SOC, and then determine a first SOC-OCV mapping relationship corresponding to the first cycle number based on pre-set experimental data. The experimental data is configured as a function of the cycle number, OCV, and SOC. Based on the first SOC-OCV mapping relationship, a first calibrated OCV corresponding to the first SOC can be determined. Then, the first SOC-OCV mapping relationship can be calibrated based on the first SOC, the first OCV, and the first calibrated OCV. Because the first calibrated OCV is determined based on the first SOC-OCV mapping relationship corresponding to the first cycle number, the impact of battery pack cycle aging on the SOC-OCV mapping relationship is taken into account. Therefore, the accuracy of the first calibrated OCV is relatively high. In addition, the present application also calibrates the first SOC-OCV mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV, thereby improving the accuracy of the SOC-OCV mapping relationship. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.
[0034] FIG1 is a schematic flow chart of a method for calibrating an SOC-OCV mapping relationship according to an embodiment of the present application;
[0035] FIG2 is a schematic diagram of an SOC-OCV curve according to an embodiment of the present application;
[0036] FIG3 is a schematic structural diagram of a SOC-OCV mapping relationship calibration device according to an embodiment of the present application;
[0037] FIG4 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
[0038] In the accompanying drawings, the drawings are not necessarily drawn to scale. DETAILED DESCRIPTION
[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.
[0040] It should be noted that, in this document, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.
[0041] As mentioned in the background art, the state of charge (SOC)-open circuit voltage (OCV) curve is an important performance indicator of a battery pack.
[0042] When calibrating the SOC-OCV curve of the battery pack, the SOC-OCV curve of the battery pack can be calibrated at different temperatures.
[0043] However, the actual SOC-OCV curve of the battery pack will change after cycle aging, and the existing technology does not take into account the impact of battery pack cycle aging on the SOC-OCV curve. Therefore, the accuracy of the SOC-OCV curve calibrated in the existing technology is low.
[0044] The SOC-OCV mapping relationship calibration method, apparatus, device, medium, and product provided in the embodiments of the present application can receive a first SOC and a first cycle number of a battery pack, obtain a first OCV corresponding to the first SOC, and then determine a first SOC-OCV mapping relationship corresponding to the first cycle number based on pre-set experimental data. The experimental data is configured as a function of the cycle number, OCV, and SOC. Based on the first SOC-OCV mapping relationship, a first calibrated OCV corresponding to the first SOC can be determined. Then, the first SOC-OCV mapping relationship can be calibrated based on the first SOC, the first OCV, and the first calibrated OCV. Because the first calibrated OCV is determined based on the first SOC-OCV mapping relationship corresponding to the first cycle number, the impact of battery pack cycle aging on the SOC-OCV mapping relationship is taken into account. Therefore, the accuracy of the first calibrated OCV is relatively high. In addition, the present application also calibrates the first SOC-OCV mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV, thereby improving the accuracy of the SOC-OCV mapping relationship.
[0045] First, the SOC-OCV mapping relationship calibration method provided in an embodiment of the present application is described in detail with reference to FIG1 .
[0046] Figure 1 shows a flow chart of a SOC-OCV mapping relationship calibration method provided by one embodiment of the present application. It should be noted that the SOC-OCV mapping relationship calibration method can be applied to a SOC-OCV mapping relationship calibration device, such as a battery management system (BMS). In some specific implementations of the present application, the battery management system can be embodied in the form of a printed circuit board, and a variety of electronic components can be set on the battery management system to implement the calibration method of the present application, wherein the electronic components can include a microcontroller, an analog front end, a charging switch, a discharging switch, a fuse, a capacitor, a resistor, etc.
[0047] As shown in FIG1 , the SOC-OCV mapping relationship calibration method may include the following steps:
[0048] S110, receiving a first state of charge (SOC) and a first cycle number of a battery pack;
[0049] S120, obtaining a first OCV corresponding to the first SOC;
[0050] S130, determining a first SOC-OCV mapping relationship corresponding to a first cycle number based on preset experimental data;
[0051] S140 , determining a first calibrated OCV corresponding to the first SOC based on a first SOC-OCV mapping relationship;
[0052] S150 , calibrating a first SOC-OCV mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV.
[0053] Thus, a first SOC and a first cycle number of the battery pack can be received, and a first OCV corresponding to the first SOC can be obtained. Then, based on pre-set experimental data, a first SOC-OCV mapping relationship corresponding to the first cycle number can be determined. The experimental data is configured as a function of the cycle number, OCV, and SOC. Based on the first SOC-OCV mapping relationship, a first calibrated OCV corresponding to the first SOC can be determined. Then, the first SOC-OCV mapping relationship can be calibrated based on the first SOC, the first OCV, and the first calibrated OCV. Since the first calibrated OCV is determined based on the first SOC-OCV mapping relationship corresponding to the first cycle number, the impact of battery pack cycle aging on the SOC-OCV mapping relationship is taken into account. Therefore, the accuracy of the first calibrated OCV is relatively high. In addition, the present application also calibrates the first SOC-OCV mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV, thereby improving the accuracy of the SOC-OCV mapping relationship.
[0054] Regarding S110 , calibrating the SOC-OCV mapping relationship may involve separately calibrating the OCVs corresponding to multiple SOCs. Considering the impact of battery pack aging on the SOC-OCV mapping relationship, the SOC-OCV mapping relationships at multiple different cycle numbers may be pre-calibrated, and then the SOC-OCV mapping relationships at the multiple different cycle numbers may be separately calibrated.
[0055] For example, the number of different cycles can be 10, 200, 300, 500, 700, 1000, etc., or can be selected according to y=100*x+10, where y is the number of cycles and x is 1, 2, ... n. This application does not impose any specific restrictions on the number of cycles.
[0056] Battery cycle number = (accumulated charge capacity + accumulated discharge capacity) / (2*Capstd), where Capstd is the nominal capacity of the battery pack.
[0057] Here, the first cycle number may be a cycle number corresponding to the SOC-OCV mapping relationship to be calibrated.
[0058] Regarding S120 , the first OCV may be an OCV test value corresponding to the first SOC, which may be used to calibrate a calibrated OCV corresponding to the first SOC. In one specific implementation, the OCV of the battery pack in a non-operating state (i.e., a static state) may be acquired by an analog front end on the BMS.
[0059] In some embodiments, to obtain a more accurate first OCV, S120 may include:
[0060] In response to the battery pack meeting the first condition, collecting a second OCV of the battery pack;
[0061] The second OCV is used as the first OCV.
[0062] The second OCV can be configured as the OCV of the battery pack after the battery pack has been at rest for a first time. The first condition can be configured as the battery pack's throughput capacity being less than the battery pack's nominal capacity within a second time. The second time can be configured as the time it takes for the battery pack to charge or discharge from the second SOC to the first SOC, with the second time being less than a second time threshold. The battery pack's throughput capacity can be configured as the sum of the battery pack's cumulative charge capacity and cumulative discharge capacity within the second time. The second SOC can be configured as the SOC obtained after calibration.
[0063] Here, the battery pack meeting the first condition indicates that the time since the last SOC calibration is short, and the SOC at this time, that is, the first SOC, is also considered accurate. Therefore, the second OCV can be acquired through the analog front-end.
[0064] For example, if the battery pack is a lithium iron battery, the first time can be any time greater than 20 minutes and less than 60 minutes; if the battery pack is a ternary battery, the first time can be any time greater than 10 minutes and less than 30 minutes. The second time can be 48 hours.
[0065] In this way, when the time after the SOC calibration is short and the throughput is low, the accuracy of the SOC is still high, and it is more accurate to use the collected second OCV as the first OCV corresponding to the first SOC.
[0066] In some embodiments, to improve the accuracy of the SOC-OCV mapping relationship, the second SOC can be calibrated through one of the following calibration items:
[0067] i) In response to the SOC of any cell in the battery pack reaching the first SOC range during charging or discharging of the battery pack, the battery pack is left standing for a third time, the current OCV of the battery pack is obtained, and based on the current OCV and experimental data, the second SOC is calibrated;
[0068] ii) When the voltage of any cell in the battery pack during charging is greater than the charging cut-off voltage and the charging current is less than the first current threshold, and this lasts for a time T1, the second SOC is calibrated to 100%;
[0069] iii) When the voltage of any cell in the battery pack during discharging is less than the discharging cut-off voltage and the discharging current is less than the second current threshold, and this lasts for a time T2, the second SOC is calibrated to 0%.
[0070] Here, the second SOC can be the calibrated SOC. The SOC of the battery pack in the first SOC range, the full charge point during charging, and the cut-off point during discharging can be selected as the SOC calibration points.
[0071] In some embodiments, to more accurately calibrate the SOC, within the first SOC range, at different numbers of cycles, the difference between different SOCs corresponding to the same OCV is less than a preset threshold.
[0072] That is to say, the first SOC range can be a range where the SOC corresponding to the same OCV changes little at different numbers of cycles. Calibrating the SOC within a range where the SOC changes little is more accurate.
[0073] Exemplarily, the first SOC range can be SOC < X1% and SOC > X2%, where X1% can be 14% and X2% can be 96%. The positions of X1% and X2% can be as shown in Figure 2.
[0074] Exemplarily, the third time can be 20 minutes. If the positive electrode material of the cell is lithium iron phosphate, the charging cut-off voltage can be 3.6V or 3.65V, and the discharging cut-off voltage can be set between 2.0V and 2.5V; if the positive electrode material of the cell is nickel cobalt manganese (i.e., a ternary cell), the charging cut-off voltage can be 4.2V or 4.25V, and the discharging cut-off voltage can be set between 2.5V and 3.2V. Both the first current threshold and the second current threshold can be 0.1C. Both the T1 time and the T2 time can be any time greater than 3s and less than 10s.
[0075] For example, when the SOC of any cell in the battery pack is less than 14% or greater than 96% when charging or discharging and the battery pack is left to stand for 20 minutes, the current OCV can be collected and the current OCV can be used to check the OCV-SOC curve calibrated in the laboratory, and the queried SOC can be used as the second SOC. When the voltage of any cell in the battery pack is greater than 3.6V and the charging current is less than 0.1C, and it lasts for 5s when the battery pack is charging, the second SOC can be calibrated to 100%. When the voltage of any cell in the battery pack is less than 2V and the discharge current is less than 0.1C, and it lasts for 5s when the battery pack is discharging, the second SOC can be calibrated to 0%.
[0076] In this way, the SOC can be accurately calibrated, so that the SOC-OCV mapping relationship can be calibrated more accurately.
[0077] In relation to S130 , the experimental data may be configured as a function between the cycle number, OCV, and SOC.
[0078] For example, the SOC-OCV mapping relationship at different cycle numbers can be pre-calibrated in the laboratory to obtain experimental data. The SOC-OCV curves at different cycle numbers can be stored in a register of the BMS at every X% SOC. For example, when X is 5, the SOC is 0%, 5%, 10%, ..., 95%, and 100%. Alternatively, a polynomial can be used to fit the SOC-OCV curves at different cycle numbers, and the fitting coefficients can be stored in a table.
[0079] For example, under a certain number of cycles, the battery pack can be controlled to discharge from a full charge, and after each 5% SOC discharge, the battery pack is allowed to rest for 120 minutes. The OCV corresponding to the SOC is collected until the OCV is less than 2.0V (discharge cut-off voltage), and multiple SOCs and their corresponding OCVs are obtained. The battery pack can also be controlled to charge from a full discharge, and after each 5% SOC charge, the battery pack is allowed to rest for 120 minutes. The OCV corresponding to the SOC is collected until the OCV is greater than 3.6V (charge cut-off voltage), and multiple SOCs and their corresponding OCVs are obtained.
[0080] Specifically, the experimental data may include SOC-OCV mapping relationships corresponding to a plurality of cycle numbers, from which a first SOC-OCV mapping relationship corresponding to a first cycle number may be searched.
[0081] If the pre-calibrated experimental data does not include the SOC-OCV mapping relationship corresponding to the first cycle number, the SOC-OCV mapping relationship corresponding to the first cycle number can be interpolated based on the SOC-OCV mapping relationships under different cycle numbers.
[0082] Regarding S140 , the OCV corresponding to the first SOC in the first SOC-OCV mapping relationship may be used as the first calibrated OCV.
[0083] Regarding S150 , the OCVs corresponding to the plurality of SOCs may be calibrated respectively based on the first SOC, the first OCV, and the first calibrated OCV, thereby calibrating the first SOC-OCV mapping relationship.
[0084] In some embodiments, to more accurately calibrate the SOC-OCV mapping relationship, S150 may include:
[0085] Determining a plurality of target SOCs from the first SOC-OCV mapping relationship, the target SOCs may be configured as SOCs set at intervals of x%, 1≤x≤10, and calibrating the target OCVs corresponding to the target SOCs to obtain target OCV calibration values;
[0086] The target OCV may be configured as an OCV corresponding to a target SOC based on experimental data.
[0087] Here, the target SOC may be pre-set. For example, the target SOC may be 0%, 5%, 10%, ..., 95%, 100%. It is understood that the target SOC may also be set in 4% intervals, i.e., 4%, 8%, 12%, 16%, ..., 96%, 100%. This application does not limit the specific method for setting the target SOC.
[0088] Specifically, based on a plurality of target SOCs and their corresponding target OCV calibration values, a calibrated first SOC-OCV mapping relationship may be determined.
[0089] In this way, by calibrating the target OCVs corresponding to multiple target SOCs, the target OCV calibration value can be determined, and then the calibrated first SOC-OCV mapping relationship can be determined based on the multiple target SOCs and the target OCV calibration value. In this way, the calibrated first SOC-OCV mapping relationship can be made more accurate.
[0090] In some embodiments, there may be multiple first SOCs. To accurately calibrate the OCV corresponding to the target SOC, calibrating the target OCV corresponding to the target SOC to obtain a target OCV calibration value may include:
[0091] Determining, from a plurality of first SOCs, a first SOC having a minimum absolute difference from a target SOC and a first calibrated OCV corresponding to the first SOC;
[0092] Calculating a first OCV difference, where the first OCV difference is a difference between the first calibrated OCV and the first OCV;
[0093] Calculating a target first OCV calibration value based on the first OCV difference;
[0094] The target OCV calibration value is calculated based on the target OCV corresponding to the target SOC and the first OCV calibration value.
[0095] Specifically, a target OCV corresponding to the target SOC may be determined based on experimental data.
[0096] For example, if the target SOC is 5%, then based on the first SOC-OCV mapping relationship, the OCV corresponding to the SOC of 5% may be determined as the target OCV.
[0097] Then, a difference between the first calibrated OCV and the first OCV is calculated to obtain a first OCV difference value. A target first OCV calibration value is calculated based on the first OCV difference value. A target OCV calibration value corresponding to the target SOC is calculated based on the target OCV corresponding to the target SOC and the first OCV calibration value.
[0098] For example, the calculation formula of the first OCV difference may be: DeltaOCV(SOC)=OCVTable(SOC)-OCVTest(SOC)
[0099] Among them, DeltaOCV(SOC) is the first OCV difference, OCVTable(SOC) is the first calibrated OCV corresponding to the target SOC, and OCVTest(SOC) is the first OCV.
[0100] The target OCV calibration value can be calculated as: NewOCV(SOC)=OCVTable(SOC)+OCVcorrect(SOC)
[0101] Wherein, NewOCV(SOC) is the target OCV calibration value, OCVTable(SOC) is the first calibrated OCV corresponding to the target SOC, and OCVcorrect(SOC) is the first OCV calibration value.
[0102] In this way, a first OCV difference can be calculated based on the first calibrated OCV corresponding to the first SOC closest to the target SOC and the first OCV, and then the target OCV calibration value corresponding to the target SOC can be gradually calculated, thereby accurately calibrating the OCV corresponding to the target SOC.
[0103] As an example, the battery pack is charged or discharged from a second SOC to a first SOC. The first SOC may be multiple, for example, 3.2%, 5.9%, 8.5%, 12.6%, etc. When calibrating the target OCV of 5% to achieve a target SOC, the first SOC with the smallest absolute difference from the target SOC is first taken. In this case, the first SOC that can be used for calibration is 5.9%. Then, based on experimental data, the first calibrated OCV corresponding to the SOC of 5.9% is obtained. DeltaOCV(SOC) is the difference between this first calibrated OCV and the first OCV obtained when the battery pack meets the first condition.
[0104] In some embodiments, to more accurately calibrate the SOC-OCV mapping relationship, the calculation of the target first OCV calibration value based on the first OCV difference may include:
[0105] Calculating a target first OCV calibration value based on the first OCV difference, the voltage sampling error coefficient, the current sampling error coefficient, and the static time error coefficient;
[0106] Wherein, the voltage sampling error coefficient is configured to be associated with the error of the voltage sampling chip;
[0107] The current sampling error coefficient is configured as a function associated with an error of the current sampling chip, the second time, the second time threshold, the nominal capacity of the battery pack, and the throughput capacity of the battery pack;
[0108] The rest time error coefficient is configured to be associated with the first time and a first time threshold, where the first time threshold is a function of a maximum rest time of the battery pack that meets the first condition.
[0109] For example, the calculation formula of the target first OCV calibration value may be: OCVcorrect(SOC)=Alpha_correct*DeltaOCV(SOC)
[0110] Where OCVcorrect(SOC) is the target first OCV calibration value, Alpha_correct is the calibration coefficient, and DeltaOCV(SOC) is the first OCV difference.
[0111] Alpha_correct = voltage sampling error coefficient * current sampling error coefficient * static time error coefficient.
[0112] The voltage sampling error coefficient = (DeltaOCV(SOC) - sampling error of the voltage sampling chip) / sampling error of the voltage sampling chip. The current sampling error coefficient = current sampling error coefficient 1 * current sampling error coefficient 2. The static time error coefficient = |first time - first time threshold| / first time threshold.
[0113] Current sampling error coefficient 1 = (1-current sampling accuracy) * (72-t1) / 72. Current sampling error coefficient 2 = (2*Capstd-Q) / 2*Capstd.
[0114] Wherein, t1 is the time from SOC calibration to the first OCV calibration, that is, the sum of the time the battery pack charges or discharges from the second SOC to the first SOC and the first static time of the battery pack, and Q is the discharge throughput from SOC calibration to the first OCV calibration.
[0115] In this way, the target first OCV calibration value corresponding to the target SOC can be more accurately determined by the first OCV difference, the voltage sampling error coefficient, the current sampling error coefficient, and the static time error coefficient, so that the SOC-OCV mapping relationship can be calibrated more accurately.
[0116] The target OCV calibration value is calculated based on the target OCV corresponding to the target SOC and the first OCV calibration value: target OCV calibration value=target OCV+OCVcorrect(SOC).
[0117] In some embodiments, in order to more efficiently calibrate the SOC-OCV mapping relationship, the target OCV calibration value may be the OCV obtained after calibration of the battery pack in the first state. The method may further include:
[0118] calibrating the SOC-OCV mapping relationship of the battery pack in the second state based on the target OCV calibration value;
[0119] The first state is one of a charging state and a discharging state of the battery pack, and the second state is the other of a charging state and a discharging state of the battery pack.
[0120] Here, the SOC-OCV mapping relationship in the discharge state may be calibrated based on the target OCV calibration value in the charge state, or the SOC-OCV mapping relationship in the charge state may be calibrated based on the target OCV calibration value in the discharge state.
[0121] In this way, since the SOC-OCV mapping relationship in the discharge state can be calibrated based on the target OCV calibration value in the charge state, or the SOC-OCV mapping relationship in the charge state can be calibrated based on the target OCV calibration value in the discharge state, the calibration efficiency can be improved.
[0122] In some embodiments, to further improve the accuracy of the SOC-OCV mapping relationship, calibrating the OSC-OCV mapping relationship of the battery pack in the second state based on the target OCV calibration value may include:
[0123] determining a third SOC of the battery pack in the second state, the third SOC corresponding to a target SOC of the battery pack in the first state;
[0124] Determining a third OCV corresponding to a third SOC based on experimental data;
[0125] Calculating a difference between an OCV calibration value of the battery pack in the first state and a third OCV to obtain N differences, and calculating an average of the N differences to obtain a deviation;
[0126] Based on the deviation and the third OCV, the SOC-OCV mapping relationship of the battery pack in the second state is calibrated.
[0127] Here, the third SOC is equal to the target SOC. The number of the third SOC and the target SOC can both be N, where N is a positive integer.
[0128] For example, if the target SOC is 5%, 10% and 15%, the target OCV calibration values corresponding to the target SOC are NewOCV(5%), NewOCV(10%) and NewOCV(15%) respectively, and the third SOC is 5%, 10% and 15%, based on experimental data, the third OCV corresponding to the third SOC is OCVTable(5%), OCVTable(10%) and OCVTable(15%) respectively, then the three differences are NewOCV(5%)-OCVTable(5%), NewOCV(10%)-OCVTable(10%) and NewOCV(15%)-OCVTable(15%), and the deviation is the average of the above three differences.
[0129] Calibrating the SOC-OCV mapping relationship of the battery pack in the second state may be calibrating the third SOCs corresponding to the plurality of third SOCs. Specifically, the sum of the third OCV and the deviation may be determined as the calibrated OCV corresponding to the third SOC.
[0130] In this way, calibrating the SOC-OCV mapping relationship based on the difference between the charging OCV and the discharging OCV can improve the accuracy of calibrating the SOC-OCV mapping relationship in the discharging state based on the target OCV calibration value in the charging state, or calibrating the SOC-OCV mapping relationship in the charging state based on the target OCV calibration value in the discharge state.
[0131] Based on the same inventive concept, the embodiment of the present application further provides a SOC-OCV mapping relationship calibration device. The SOC-OCV mapping relationship calibration device provided in the embodiment of the present application is described in detail below with reference to FIG3 .
[0132] FIG3 shows a schematic structural diagram of a SOC-OCV mapping relationship calibration device provided by an embodiment of the present application.
[0133] As shown in FIG3 , the SOC-OCV mapping relationship calibration device may include:
[0134] A receiving module 301 is configured to receive a first state of charge (SOC) and a first cycle number of a battery pack;
[0135] An acquisition module 302 is configured to acquire a first open circuit voltage OCV corresponding to a first SOC;
[0136] A first determining module 303 is configured to determine a first SOC-OCV mapping relationship corresponding to a first cycle number based on preset experimental data; the experimental data is configured as a function of the cycle number, OCV, and SOC;
[0137] A second determining module 304 is configured to determine a first calibrated OCV corresponding to the first SOC based on the first SOC-OCV mapping relationship;
[0138] The first calibration module 305 is configured to calibrate a first SOC-OCV mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV.
[0139] Thus, a first SOC and a first cycle number of the battery pack can be received, and a first OCV corresponding to the first SOC can be obtained. Then, based on pre-set experimental data, a first SOC-OCV mapping relationship corresponding to the first cycle number can be determined. The experimental data is configured as a function of the cycle number, OCV, and SOC. Based on the first SOC-OCV mapping relationship, a first calibrated OCV corresponding to the first SOC can be determined. Then, the first SOC-OCV mapping relationship can be calibrated based on the first SOC, the first OCV, and the first calibrated OCV. Since the first calibrated OCV is determined based on the first SOC-OCV mapping relationship corresponding to the first cycle number, the impact of battery pack cycle aging on the SOC-OCV mapping relationship is taken into account. Therefore, the accuracy of the first calibrated OCV is relatively high. In addition, the present application also calibrates the first SOC-OCV mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV, thereby improving the accuracy of the SOC-OCV mapping relationship.
[0140] In some embodiments, to obtain a more accurate first OCV, the acquisition module 302 may include:
[0141] a collection submodule, configured to collect a second OCV of the battery pack in response to the battery pack meeting a first condition;
[0142] The second OCV is configured as the OCV of the battery pack after the battery pack has been stationary for a first time;
[0143] The first condition is configured as follows: within a second time, the throughput capacity of the battery pack is less than the nominal capacity of the battery pack;
[0144] a processing submodule, configured to use the second OCV as the first OCV;
[0145] The second time is configured as the time it takes for the battery pack to charge or discharge from the second SOC to the first SOC, and the second time is less than a second time threshold;
[0146] The throughput capacity of the battery pack is configured as the sum of the cumulative charging capacity and the cumulative discharging capacity of the battery pack within the second time;
[0147] The second SOC is configured as an SOC obtained after calibration.
[0148] In some embodiments, to improve the accuracy of the SOC-OCV mapping relationship, the second SOC is calibrated by one of the following calibration items:
[0149] i) in response to any cell in the battery pack being charged or discharged to a first SOC range, the battery pack is left to rest for a third time, obtaining a current OCV of the battery pack, and calibrating the second SOC based on the current OCV and the experimental data;
[0150] ii) when the battery pack is charged, if the voltage of any cell is greater than the charge cut-off voltage and the charging current is less than the first current threshold value and this lasts for a time T1, the second SOC is calibrated to 100%;
[0151] iii) When the battery pack is discharged, the voltage of any cell is less than the discharge cut-off voltage and the discharge current is less than the second current threshold, and this lasts for a time T2, and the second SOC is calibrated to 0%.
[0152] In some embodiments, in order to calibrate the SOC more accurately, within the first SOC range, the difference between different SOCs corresponding to the same OCV at different cycle numbers is less than a preset threshold.
[0153] In some embodiments, to more accurately calibrate the SOC-OCV mapping relationship, the first calibration module 305 may include:
[0154] A first calibration submodule is configured to determine a plurality of target SOCs from a first SOC-OCV mapping relationship, wherein the target SOCs are configured as SOCs set at intervals of x%, 1≤x≤10, and calibrate target OCVs corresponding to the target SOCs to obtain target OCV calibration values;
[0155] The target OCV is configured as an OCV corresponding to the target SOC based on the experimental data.
[0156] In some embodiments, there are multiple first SOCs; in order to accurately calibrate the OCV corresponding to the target SOC, the first calibration submodule may include:
[0157] a determining unit configured to determine, from among the plurality of first SOCs, a first SOC having a minimum absolute value of difference from the target SOC, and a first calibrated OCV corresponding to the first SOC;
[0158] a first calculation unit, configured to calculate a first OCV difference, where the first OCV difference is a difference between the first calibrated OCV and the first OCV;
[0159] a second calculation unit, configured to calculate a target first OCV calibration value based on the first OCV difference;
[0160] The third calculation unit is configured to calculate the target OCV calibration value based on a target OCV corresponding to the target SOC and the first OCV calibration value.
[0161] In some embodiments, in order to more accurately calibrate the SOC-OCV mapping relationship, the second calculation unit may include:
[0162] a calculation subunit, configured to calculate a target first OCV calibration value based on the first OCV difference, a voltage sampling error coefficient, a current sampling error coefficient, and a static time error coefficient;
[0163] Wherein, the voltage sampling error coefficient is configured to be associated with the error of the voltage sampling chip;
[0164] The current sampling error coefficient is configured as a function associated with an error of a current sampling chip, the second time, the second time threshold, the nominal capacity of the battery pack, and the throughput capacity of the battery pack;
[0165] The rest time error coefficient is configured to be associated with the first time and a first time threshold, where the first time threshold is a function of a maximum rest time of the battery pack that meets a first condition.
[0166] In some embodiments, the target OCV calibration value is the OCV obtained after calibration of the battery pack in the first state. In order to more efficiently calibrate the SOC-OCV mapping relationship, the apparatus may further include:
[0167] a second calibration module, configured to calibrate the SOC-OCV mapping relationship of the battery pack in a second state based on the target OCV calibration value;
[0168] The first state is one of a charging state and a discharging state of the battery pack, and the second state is the other of a charging state and a discharging state of the battery pack.
[0169] In some embodiments, to further improve the accuracy of the SOC-OCV mapping relationship, the second calibration module may include:
[0170] a first determining submodule, configured to determine a third SOC of the battery pack in the second state, the third SOC corresponding to the target SOC of the battery pack in the first state;
[0171] a second determining submodule, configured to determine a third OCV corresponding to the third SOC based on the experimental data;
[0172] a calculation submodule, configured to calculate a difference between the OCV calibration value of the battery pack in the first state and the third OCV to obtain N differences, and calculate an average of the N differences to obtain a deviation;
[0173] The second calibration submodule is configured to calibrate the SOC-OCV mapping relationship of the battery pack in a second state based on the deviation and the third OCV.
[0174] FIG4 shows a schematic structural diagram of an electronic device provided by an embodiment of the present application.
[0175] As shown in Figure 4, the electronic device 4 is a block diagram of an exemplary hardware architecture of an electronic device capable of implementing the SOC-OCV mapping relationship calibration method and SOC-OCV mapping relationship calibration apparatus according to the embodiments of the present application. The electronic device may refer to the electronic device in the embodiments of the present application.
[0176] The electronic device 4 may include a processor 401 and a memory 402 storing computer program instructions.
[0177] Specifically, the processor 401 may include a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.
[0178] Memory 402 may include a large-capacity memory for data or instructions. By way of example and not limitation, memory 402 may include a hard disk drive (HDD), a floppy disk drive, flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 402 may include removable or non-removable (or fixed) media. Where appropriate, memory 402 may be internal or external to the integrated gateway disaster recovery device. In certain embodiments, memory 402 is non-volatile solid-state memory. In certain embodiments, memory 402 may include read-only memory (ROM), random access memory (RAM), a magnetic disk storage media device, an optical storage media device, a flash memory device, an electrical, optical, or other physical / tangible memory storage device. Therefore, generally, memory 402 includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to one aspect of the present application.
[0179] The processor 401 reads and executes computer program instructions stored in the memory 402 to implement any one of the SOC-OCV mapping relationship calibration methods in the above embodiments.
[0180] In one example, the electronic device may further include a communication interface 403 and a bus 404. As shown in FIG4, the processor 401, the memory 402, and the communication interface 403 are connected via the bus 404 and communicate with each other.
[0181] The communication interface 403 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.
[0182] Bus 404 comprises hardware, software or both, couples the parts of electronic equipment to each other.For example, and not limitation, bus can comprise accelerated graphics port (AGP) or other graphics bus, enhanced industry standard architecture (EISA) bus, front side bus (FSB), hypertransport (HT) interconnection, industry standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations.In suitable cases, bus 404 can comprise one or more buses.Although the present application embodiment describes and shows specific bus, the application considers any suitable bus or interconnection.
[0183] The electronic device can execute the SOC-OCV mapping relationship calibration method in the embodiment of the present application, thereby realizing the SOC-OCV mapping relationship calibration method and device described in conjunction with Figures 1 to 3.
[0184] In addition, in conjunction with the SOC-OCV mapping relationship calibration method in the above embodiments, embodiments of the present application may provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when executed by a processor, the computer program instructions implement any of the SOC-OCV mapping relationship calibration methods in the above embodiments.
[0185] It should be understood that the present application is not limited to the specific configurations and processes described above and illustrated in the figures. For the sake of brevity, a detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and illustrated as examples. However, the method process of the present application is not limited to the specific steps described and illustrated. Those skilled in the art can make various changes, modifications, and additions, or change the order of the steps after understanding the spirit of the present application.
[0186] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium that can store or transmit information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memories, erasable ROMs (EROMs), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.
[0187] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps. In other words, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.
[0188] Aspects of the present application have been described above with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present application. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine so that these instructions executed via the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. This processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor or a field programmable logic circuit. It is also understood that each box in the block diagram and / or the flowchart and the combination of the boxes in the block diagram and / or the flowchart can also be implemented by the dedicated hardware that performs the specified function or action, or can be implemented by the combination of dedicated hardware and computer instructions.
[0189] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims.
Claims
1. A SOC-OCV mapping relationship calibration method, comprising: Receiving a first state of charge SOC and a first cycle number of a battery pack; Acquire a first open circuit voltage OCV corresponding to the first SOC; Determine a first SOC-OCV mapping relationship corresponding to the first cycle number based on preset experimental data; the experimental data is configured as a function between the cycle number, OCV and SOC; Determining a first calibrated OCV corresponding to the first SOC based on the first SOC-OCV mapping relationship; The first SOC-OCV mapping relationship is calibrated based on the first SOC, the first OCV and the first calibrated OCV.
2. The method according to claim 1, wherein: The acquiring a first OCV corresponding to the first SOC includes: In response to the battery pack satisfying a first condition, collecting a second OCV of the battery pack; The second OCV is configured as the OCV of the battery pack after the battery pack has been stationary for a first time; The first condition is configured as that the throughput capacity of the battery pack is less than the nominal capacity of the battery pack within the second time; using the second OCV as the first OCV; The second time is configured as the time taken for the battery pack to charge or discharge from the second SOC to the first SOC, and the second time is less than a second time threshold; The throughput capacity of the battery pack is configured as the sum of the cumulative charging capacity and the cumulative discharging capacity of the battery pack within the second time; The second SOC is configured as a SOC obtained after calibration.
3. The method according to claim 2, wherein: The second SOC is obtained by calibration through one of the following calibration items: i) in response to any battery cell in the battery pack being charged or discharged to a first SOC range, standing for a third time, obtaining a current OCV of the battery pack, and calibrating the second SOC based on the current OCV and the experimental data; ii) when the battery pack is charged, the voltage of any cell is greater than the charge cut-off voltage and the charging current is less than the first current threshold value, and this lasts for a period of time T1, and the second SOC is calibrated to 100%; iii) When the voltage of any cell of the battery pack is less than the discharge cut-off voltage and the discharge current is less than the second current threshold value and the duration is T2, the second SOC is calibrated to 0%.
4. The method according to claim 3, wherein: Within the first SOC range, at different cycle times, the difference between different SOCs corresponding to the same OCV is less than a preset threshold.
5. The method according to any one of claims 1 to 4, wherein: The calibrating the first SOC-OCV mapping relationship based on the first SOC, the first OCV, and the first calibrated OCV includes: Determine a plurality of target SOCs from a first SOC-OCV mapping relationship, wherein the target SOCs are configured as SOCs set at intervals of x%, 1≤x≤10, and calibrate target OCVs corresponding to the target SOCs to obtain target OCV calibration values; The target OCV is configured to obtain an OCV corresponding to the target SOC based on the experimental data.
6. The method according to claim 5, wherein: The first SOC is multiple; The calibrating a target OCV corresponding to the target SOC to obtain a target OCV calibration value includes: Determine, from among the plurality of first SOCs, a first SOC having a smallest absolute value of difference from the target SOC, and a first calibrated OCV corresponding to the first SOC; Calculating a first OCV difference, where the first OCV difference is a difference between the first calibrated OCV and the first OCV; Based on the first OCV difference, a target first OCV calibration value is calculated; The target OCV calibration value is calculated based on a target OCV corresponding to the target SOC and the first OCV calibration value.
7. The method according to claim 6, wherein: The calculating a target first OCV calibration value based on the first OCV difference value includes: Calculate a target first OCV calibration value based on the first OCV difference, the voltage sampling error coefficient, the current sampling error coefficient, and the static time error coefficient; Wherein, the voltage sampling error coefficient is configured to be associated with the error of the voltage sampling chip; The current sampling error coefficient is configured as a function associated with an error of a current sampling chip, the second time, the second time threshold, a nominal capacity of the battery pack, and a throughput capacity of the battery pack; The rest time error coefficient is configured to be associated with the first time and a first time threshold, where the first time threshold is a function of a maximum rest time of the battery pack that satisfies a first condition.
8. The method according to claim 6 or 7, wherein: The target OCV calibration value is the OCV obtained after the battery pack is calibrated in the first state; The method further comprises: calibrating the SOC-OCV mapping relationship of the battery pack in the second state based on the target OCV calibration value; The first state is one of a charging state or a discharging state of the battery pack, and the second state is the other of a charging state or a discharging state of the battery pack.
9. The method according to claim 8, wherein: The calibrating the OSC-OCV mapping relationship of the battery pack in the second state based on the target OCV calibration value includes: determining a third SOC of the battery pack in the second state, the third SOC corresponding to the target SOC of the battery pack in the first state; determining a third OCV corresponding to the third SOC based on the experimental data; Calculating a difference between the OCV calibration value of the battery pack in the first state and the third OCV to obtain N differences, and calculating an average value of the N differences to obtain a deviation; Based on the deviation and the third OCV, a SOC-OCV mapping relationship of the battery pack in the second state is calibrated.
10. A SOC-OCV mapping relationship calibration device, the device comprising: A receiving module, used for receiving a first state of charge SOC and a first cycle number of the battery pack; An acquisition module, configured to acquire a first open circuit voltage OCV corresponding to the first SOC; A first determining module is used to determine the first cycle number corresponding to the first cycle number based on the preset experimental data. A first SOC-OCV mapping relationship; the experimental data is configured as a function between the number of cycles, OCV and SOC; A second determination module, configured to determine a first calibrated OCV corresponding to the first SOC based on the first SOC-OCV mapping relationship; The first calibration module is configured to calibrate the first SOC-OCV mapping relationship based on the first SOC, the first OCV and the first calibrated OCV.
11. An electronic device, comprising: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the SOC-OCV mapping relationship calibration method according to any one of claims 1 to 9 is implemented.
12. A computer storage medium having computer program instructions stored thereon, wherein the computer program instructions, when executed by a processor, implement the SOC-OCV mapping relationship calibration method according to any one of claims 1 to 9.
13. A computer program product, wherein when instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the SOC-OCV mapping relationship calibration method according to any one of claims 1 to 9.
Citation Information
Patent Citations
Lithium-battery-pack equalization control method and system based on dynamic correction SOC
CN107839500A
Method for solving open circuit voltage and state of health of battery pack based on constant-current charging and discharging voltage curve
CN108896916A
Battery SOC estimation algorithm
CN109001639A
Method for real-time correction of SOC-OCV curve of lithium battery
CN109239608A
Battery cell OCV-SOC curve correction method and device, and storage medium
CN112415399A
Cited By
Automobile battery full capacitance updating method, device and equipment and storage medium
CN116160914A
Method, device, equipment and storage medium for updating full-charge capacity of automobile batteries
CN116160914B
Dynamic calibration method and system for aircraft lithium batteries
CN122671926A
