Battery display SOC calibration method, device, electronic device and readable medium

Abstract

The present application relates to a calibration method, device, electronic device and readable medium for displaying SOC of a battery, wherein the method comprises: obtaining various performance indicators of the battery when it is detected that the battery is in a charging and discharging state; calling a preset mapping table, and determining the preset SOC corresponding to each performance indicator in the preset mapping table, wherein the preset mapping table is constructed based on the correspondence between different performance indicators and the state of charge; determining various correction coefficients corresponding to each performance indicator through the preset mapping table; calculating the expected SOC according to the preset SOC and each correction coefficient; and calibrating the displayed SOC of the battery using the expected SOC. By calculating the correction coefficients corresponding to the various performance indicators of the battery to perform real-time calibration of the displayed SOC of the battery during the charging and discharging process, the problem that the energy storage system cannot calibrate the displayed SOC of the battery in real time during the charging and discharging process is solved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a calibration method, device, electronic device and readable medium for displaying SOC of a battery. Background Art

[0002] BMS (Battery Management System) is an important part of the energy storage system. SOC (State of Charge) is the main parameter in the battery management system. It is a direct reflection of the battery power. The more mature SOC estimation methods currently include the ampere-hour integration method and the OCV (Open Circuit Voltage) correction method. However, the calculation accuracy of the ampere-hour integration method mainly depends on the accuracy of the instantaneous current. As time goes on, the deviation will continue to accumulate. Although the OCV correction method can make the battery fully static and use the battery OCV to correct the corresponding SOC value, thereby eliminating the error of the ampere-hour integration method, the OCV correction method requires sufficient static time and can only be calibrated at the power-on time, which makes it impossible for the energy storage system to calibrate the displayed SOC of the battery in real time during the charging and discharging process.

[0003] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0004] The present application provides a method, device, electronic device and readable medium for calibrating the displayed SOC of a battery to solve the above-mentioned technical problem that "the energy storage system cannot calibrate the displayed SOC of the battery in real time during the charging and discharging process".

[0005] According to one aspect of an embodiment of the present application, the present application provides a method for calibrating the displayed SOC of a battery, comprising: when it is detected that the battery is in a charging and discharging state, obtaining various performance indicators of the battery, wherein each performance indicator includes a current temperature value, a charging and discharging rate, a number of cycles, and a standing time; calling a preset mapping table, and determining a preset SOC corresponding to each performance indicator in the preset mapping table, wherein the preset mapping table is constructed according to a correspondence between different performance indicators and the state of charge; determining each correction coefficient corresponding to each performance indicator through the preset mapping table; calculating an expected SOC according to the preset SOC and each correction coefficient; and calibrating the displayed SOC of the battery using the expected SOC.

[0006] Optionally, various performance indicators of the battery are obtained, including: obtaining log data of the battery, and reading the number of cycles and standing time of the battery from the log data; detecting the current temperature value of the battery; detecting the current current value of the battery, and calculating the charge and discharge rate of the battery based on the current value, wherein the charge and discharge rate includes the charge rate during charging and the discharge rate during discharging.

[0007] Optionally, each correction coefficient corresponding to each performance indicator is determined by a preset mapping table, including: determining a target indicator value of the target performance indicator, and determining a first indicator value and a second indicator value based on the target indicator value, wherein each performance indicator includes a target performance indicator, the target indicator value is a current value of the target performance indicator of the battery, the first indicator value is less than the target indicator value, and the second indicator value is greater than the target indicator value; using the preset mapping table to determine a first SOC corresponding to the first indicator value and a second SOC corresponding to the second indicator value; calculating a target SOC corresponding to the target indicator value based on the first indicator value, the first SOC, the second indicator value and the second SOC; and determining the ratio of the target SOC to the first SOC as the correction coefficient corresponding to the target performance indicator.

[0008] Optionally, the expected SOC is calculated according to the preset SOC and each correction coefficient, including: determining the numerical range to which the preset SOC belongs, wherein the numerical range includes a first numerical range, a second numerical range and a third numerical range, the maximum value of the first numerical range is less than the minimum value of the second numerical range, and the maximum value of the second numerical range is less than the minimum value of the third numerical range; if the preset SOC falls within the first numerical range, it is determined that the battery is in a discharge terminal state; if the preset SOC falls within the second numerical range, it is determined that the battery is in a normal charge and discharge state; if the preset SOC falls within the third numerical range, it is determined that the battery is in a charge terminal state; when the battery is in a normal charge and discharge state, the preset SOC is multiplied by each correction coefficient to obtain the expected SOC of the battery in the normal charge and discharge state.

[0009] Optionally, if the battery is in a state of terminal discharge, the method further includes: determining a first voltage difference of the battery, wherein the first voltage difference is the difference between an average value of the battery's single cell voltage and a minimum value of the single cell voltage; obtaining a preset discharge voltage difference calibration coefficient; multiplying a preset SOC, each correction coefficient, the first voltage difference, and the discharge voltage difference calibration coefficient to obtain an expected SOC of the battery in the state of terminal discharge.

[0010] Optionally, if the battery is in a charging terminal state, the method further includes: determining a second voltage difference of the battery, wherein the second voltage difference is the difference between the maximum single cell voltage and the average single cell voltage of the battery; obtaining a preset charging voltage difference calibration coefficient; multiplying a preset SOC, each correction coefficient, the second voltage difference and the charging voltage difference calibration coefficient to obtain the expected SOC of the battery in the charging terminal state.

[0011] Optionally, the displayed SOC of the battery is calibrated using the expected SOC, including: obtaining the displayed SOC of the battery, and determining the difference between the expected SOC and the displayed SOC; when the difference is less than a preset threshold, periodically calibrating the displayed SOC according to a preset step size.

[0012] According to another aspect of an embodiment of the present application, the present application provides a calibration device for displaying SOC of a battery, comprising: an acquisition module, for acquiring various performance indicators of the battery when it is detected that the battery is in a charge and discharge state, wherein each performance indicator includes a current temperature value, a charge and discharge rate, a number of cycles, and a rest time; a calling module, for calling a preset mapping table, and determining a preset SOC corresponding to each performance indicator in the preset mapping table, wherein the preset mapping table is constructed according to a correspondence between different performance indicators and the state of charge; a determination module, for determining each correction coefficient corresponding to each performance indicator through the preset mapping table; a calculation module, for calculating an expected SOC according to the preset SOC and each correction coefficient; and a calibration module, for calibrating the displayed SOC of the battery using the expected SOC.

[0013] According to another aspect of an embodiment of the present application, the present application provides an electronic device, including a memory, a processor, a communication interface and a communication bus, wherein the memory stores a computer program that can be run on the processor, the memory and the processor communicate through the communication bus and the communication interface, and the steps of the above method are implemented when the processor executes the computer program.

[0014] According to another aspect of an embodiment of the present application, the present application also provides a computer-readable medium having a non-volatile program code executable by a processor, and the program code enables the processor to execute the above method.

[0015] The above technical solution provided by the embodiment of the present application has the following advantages compared with the related art:

[0016] The present application provides a calibration method for the displayed SOC of a battery, including: when the battery is detected to be in a charging and discharging state, obtaining various performance indicators of the battery, wherein the various performance indicators include the current temperature value, the charging and discharging rate, the number of cycles, and the rest time; calling a preset mapping table, and determining the preset SOC corresponding to each performance indicator in the preset mapping table, wherein the preset mapping table is constructed based on the correspondence between different performance indicators and the state of charge; determining various correction coefficients corresponding to each performance indicator through the preset mapping table; calculating the expected SOC based on the preset SOC and each correction coefficient; and calibrating the displayed SOC of the battery using the expected SOC. By calculating the correction coefficients corresponding to the various performance indicators of the battery to perform real-time calibration of the displayed SOC of the battery during the charging and discharging process, the problem that the energy storage system cannot calibrate the displayed SOC of the battery in real time during the charging and discharging process is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] Figure 1 A flowchart of an optional battery display SOC calibration method provided according to an embodiment of the present application;

[0020] Figure 2 A logical schematic diagram of an optional cluster of battery structures provided according to an embodiment of the present application;

[0021] Figure 3 A comparison diagram of dynamic voltage-SOC curves of a single cell and a cluster battery during an optional charging process provided according to an embodiment of the present application;

[0022] Figure 4 A comparison diagram of dynamic voltage-SOC curves of a single cell and a cluster battery during an optional discharge process provided according to an embodiment of the present application;

[0023] Figure 5 A schematic diagram of an optional charge-discharge voltage-SOC dynamic curve at different temperatures provided according to an embodiment of the present application;

[0024] Figure 6It is a schematic diagram of a dynamic curve of charge and discharge voltage-SOC at different charge and discharge rates provided according to an optional embodiment of the present application;

[0025] Figure 7 This is a schematic diagram of a charge-discharge voltage-SOC dynamic curve under different cycle numbers provided according to an optional embodiment of the present application;

[0026] Figure 8 It is a schematic diagram of a dynamic curve of charge and discharge voltage-SOC under different resting times provided by an embodiment of the present application;

[0027] Fig. 9 A schematic diagram of an optional charge-discharge voltage-SOC dynamic curve provided according to an embodiment of the present application;

[0028] Fig.10 A block diagram of an optional battery SOC display calibration device provided according to an embodiment of the present application;

[0029] Fig.11 A schematic diagram of an optional electronic device structure provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0031] In the subsequent description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present application and have no specific meaning. Therefore, "module" and "component" can be used interchangeably.

[0032] BMS (Battery Management System) is an important part of the energy storage system. SOC (State of Charge) is the main parameter in the battery management system. It is a direct reflection of the battery power. The more mature SOC estimation methods currently include the ampere-hour integration method and the OCV (Open Circuit Voltage) correction method. However, the calculation accuracy of the ampere-hour integration method mainly depends on the accuracy of the instantaneous current. As time goes on, the deviation will continue to accumulate. Although the OCV correction method can make the battery fully static and use the battery OCV to correct the corresponding SOC value, thereby eliminating the error of the ampere-hour integration method, the OCV correction method requires sufficient static time and can only be calibrated at the power-on time, which makes it impossible for the energy storage system to calibrate the displayed SOC of the battery in real time during the charging and discharging process.

[0033] In order to solve the problem mentioned in the background technology, according to one aspect of an embodiment of the present application, a calibration method for displaying SOC of a battery is provided, such as Figure 1 As shown, including:

[0034] Step 101, when it is detected that the battery is in a charge and discharge state, obtaining various performance indicators of the battery, wherein the various performance indicators include a current temperature value, a charge and discharge rate, a number of cycles, and a rest time;

[0035] Step 103, calling a preset mapping table, and determining a preset SOC corresponding to each performance indicator in the preset mapping table, wherein the preset mapping table is constructed according to the correspondence between different performance indicators and the state of charge;

[0036] Step 105, determining each correction coefficient corresponding to each performance indicator through a preset mapping table;

[0037] Step 107, calculating the expected SOC according to the preset SOC and various correction coefficients;

[0038] Step 109 , calibrate the displayed SOC of the battery using the expected SOC.

[0039] The present application provides an implementation example of SOC dynamic calibration for a battery in a charging and discharging state, which can be applied to, but not limited to, batteries in an energy storage system. The solution can be executed by a battery management system.

[0040] Figure 2A logical schematic diagram of a battery cluster structure of the energy storage system provided for this application. The battery cluster in the figure contains multiple battery modules (n), each battery module contains dozens of cells, and each battery module is controlled by a BMS slave control module for voltage and temperature acquisition and active balancing. Each slave control module is connected to the same CAN (Controller Area Network) bus. In addition to uploading voltage and temperature data information to the master control module, it also accepts the balancing scheduling of the master control module.

[0041] The real-time dynamic voltage-SOC curve of a single cell under charge and discharge conditions has the same trend as the voltage-SOC curve of a clustered battery. The difference in the battery's equalized voltage is due to the DC internal resistance of the battery, which causes the curve to shift upward or downward as a whole (mainly within the range of 10% SOC-90% SOC). During the battery's charge and discharge process, the obstacles encountered by electrons and ions are collectively referred to as DC internal resistance, which are divided into ohmic internal resistance, electrochemical reaction internal resistance, and diffusion internal resistance. Among them, ohmic internal resistance is the obstacle encountered during electron transmission, electrochemical reaction internal resistance is the obstacle caused by the electrochemical reaction rate being lower than the electron transmission rate, and diffusion internal resistance is the obstacle caused by the solid-phase diffusion process of lithium ions being slower than the electrochemical reaction rate. Regardless of ohmic internal resistance, reaction internal resistance or diffusion internal resistance, corresponding polarization will be generated, namely ohmic polarization, electrochemical reaction polarization, and concentration polarization, which will lead to certain significant differences in charge and discharge compared to the open circuit voltage.

[0042] During the charging process, as the number of cycles increases, each unit of current provided externally needs to do more work per unit time to achieve the migration of Li ions. Because part of the work will be used to overcome the internal resistance, it is reflected as an increase in the charging platform, that is, the polarization internal resistance increases. At this time, the overall charging dynamic voltage-SOC curve shifts upward. Figure 3 A comparison diagram of the dynamic voltage-SOC curves of a single cell and a cluster battery during the charging process provided in the present application. As shown in the figure, the real-time dynamic voltage-SOC curve of the charging of the single cell and the dynamic voltage-SOC curve of the cluster battery formed by connecting 256 strings in series are almost identical (within the SOC range of 10% to 90%), and the curve trends are consistent. The curve corresponding to the cluster battery is slightly higher than the curve corresponding to the single cell. This is due to the differences in the single cells after the series connection to form a cluster (factors such as the consistency of the single cells and the consistency of the temperature).

[0043] During the discharge process, a unit of current provided inside the lithium-ion battery requires a portion of the work done per unit time to overcome the internal resistance, and the external work will be reduced, which is reflected as a decrease in the discharge platform, that is, an increase in the polarization internal resistance, so it is manifested as a downward shift of the overall discharge dynamic voltage-SOC curve. Figure 4A comparison diagram of the dynamic voltage-SOC curves of a single cell and a cluster battery during the discharge process provided in the present application is shown in the figure. As shown in the figure, the real-time dynamic voltage-SOC curve of the charging of the single cell and the dynamic voltage-SOC curve of the cluster battery formed by connecting 256 strings in series have the same trend (in the SOC range of 10% to 90%). The curve corresponding to the cluster battery will move downward as a whole compared to the curve of the single cell. This is due to the differences in the single cells after the series-connected batteries are clustered (factors such as the consistency of the single cells and the consistency of the temperature).

[0044] This application first obtains a preset SOC that matches the current performance index of the battery (which can be understood as the estimated value that best matches the current battery performance index value), then calculates the correction coefficient corresponding to each performance index of the battery and multiplies it with the preset SOC to obtain the expected SOC (which can be understood as an expected target value), and then calibrates the current displayed SOC of the battery (that is, the SOC displayed to the user) through the expected SOC.

[0045] Generally, the displayed SOC is equal to the expected SOC. When there is a difference between the two SOC values, the change in the displayed SOC is multiplied by a certain coefficient to speed up or slow down the change in the displayed SOC so that the displayed SOC is close to the expected SOC, thereby achieving the purpose of dynamic calibration.

[0046] The main factors affecting the DC internal resistance of the battery are: SOC, temperature, standing time, number of cycles, and charge and discharge current (rate), and each influencing factor has its own unique rules.

[0047] The various performance indicators of the battery used in this application include the current temperature value, charge and discharge rate, number of cycles and standing time. Next, how to obtain the current value of each performance indicator of the battery is explained.

[0048] As an optional embodiment, various performance indicators of the battery are obtained, including: obtaining the battery log data and reading the battery cycle times and standing time from the log data; detecting the current temperature value of the battery; detecting the current current value of the battery, and calculating the battery charge and discharge rate based on the current value, wherein the charge and discharge rate includes the charge rate during charging and the discharge rate during discharging.

[0049] The battery management system can be used to obtain battery log data, which includes the battery's historical usage records.

[0050] Specifically, the number of battery cycles can be read from the log data. The number of cycles refers to the number of complete processes from full charge to full discharge (or vice versa) of the battery.

[0051] Specifically, the battery rest time can be read from the log data, and the rest time refers to a period of time during which the battery is not charged or discharged.

[0052] Specifically, detecting the current temperature value of the battery includes: installing a temperature sensor on the battery pack or at a key position to monitor the temperature of the battery in real time.

[0053] Specifically, the current value of the battery is detected and the charge and discharge rate is calculated, including: installing a current sensor at the output or input end of the battery to measure the current value in real time; reading the data of the current sensor in real time through a data collection system; and calculating the charge and discharge rate according to the current value.

[0054] Calculating the charge and discharge rate includes calculating the charge rate and the discharge rate. To calculate the charge rate, when the current value is positive (i.e. the battery is charging), divide the current current value by the rated capacity (Ah) of the battery to get the charge rate (C-rate); to calculate the discharge rate, when the current value is negative (i.e. the battery is discharging), divide the absolute value of the current current value by the rated capacity of the battery to get the discharge rate.

[0055] By obtaining the current performance indicators of the battery, it is helpful to evaluate the performance of the battery under the current circumstances and to accurately predict the battery SOC in real time.

[0056] As an optional embodiment, each correction coefficient corresponding to each performance indicator is determined by a preset mapping table, including: determining a target indicator value of the target performance indicator, and determining a first indicator value and a second indicator value based on the target indicator value, wherein each performance indicator includes a target performance indicator, the target indicator value is a current value of the target performance indicator of the battery, the first indicator value is less than the target indicator value, and the second indicator value is greater than the target indicator value; using the preset mapping table to determine a first SOC corresponding to the first indicator value and a second SOC corresponding to the second indicator value; calculating a target SOC corresponding to the target indicator value based on the first indicator value, the first SOC, the second indicator value and the second SOC; and determining the ratio of the target SOC to the first SOC as the correction coefficient corresponding to the target performance indicator.

[0057] The present application introduces a preset mapping table to predict an initial preset SOC, and then transforms the preset SOC through a correction coefficient to obtain a desired SOC.

[0058] Specifically, it is necessary to establish the corresponding relationship between the battery's SOC and various performance indicators in advance, so as to construct a preset mapping table. For example, pre-test a single cell at different temperatures (such as 5℃ / 10℃ / 15℃ / 20℃ / 25℃ / 30℃ / 35℃ / 40℃ / 45℃ / 50℃, etc.), different charge and discharge rates (such as 0.5C / 1C / 1.5C / 2C / 2.5C / 3C / 3.5C / 4C, etc.), different number of cycles (such as 100T / 200T / 300T / 400T / 500T, etc.), different standing times (such as 3 days / 7 days / 14 days / 21 days / 28 days, etc.) charge and discharge dynamic voltage-SOC curves or test DCIR (Direct Current Internal Resistance) under different working conditions, extract specific element points to form the corresponding dynamic voltage-SOC mapping table.

[0059] To calculate the correction coefficient corresponding to each performance indicator, it is necessary to first determine a first indicator value that is smaller than the current indicator value (of the performance indicator whose modification coefficient is to be calculated), and a second indicator value that is larger than the current indicator value, and then determine the first SOC corresponding to the first indicator value and the second SOC corresponding to the second indicator value through a preset mapping table, and then calculate the first indicator value, the second indicator value, the first SOC and the second SOC to obtain the target SOC corresponding to the current indicator value, and finally determine the ratio of the target SOC to the first SOC as the correction coefficient to be determined.

[0060] Figure 5 This is a schematic diagram of the charge and discharge voltage-SOC dynamic curve at different temperatures. Figure 5 Describes how to calculate the correction factor for the current temperature value.

[0061] For example, if the target performance indicator is the current temperature value, then the correction coefficient (denoted as K) corresponding to the current temperature value is calculated. T ) is:

[0062] ,

[0063] ,

[0064] Among them, T represents the current indicator value (temperature value), T1 represents the first indicator value (temperature value), T2 represents the second indicator value (temperature value), SOC T1 Indicates the first SOC corresponding to T1, SOC T2 Indicates the second SOC corresponding to T2, SOC T-cluster Indicates the target SOC corresponding to T.

[0065] Figure 6This is a schematic diagram of the charge and discharge voltage-SOC dynamic curve under different charge and discharge rates. Figure 6 How to calculate the correction factor of the charge and discharge rate is explained.

[0066] For example, if the target performance indicator is the charge and discharge rate, then the correction coefficient corresponding to the charge and discharge rate (denoted as K RC ) is:

[0067] ,

[0068] ,

[0069] Among them, RC represents the current index value (charge and discharge rate), RC1 represents the first index value (charge and discharge rate), RC2 represents the second index value (charge and discharge rate), SOC RC1 represents the first SOC corresponding to the first index value, SOC RC2 represents the second SOC corresponding to the second index value, SOC RC-cluster Indicates the target SOC corresponding to the current indicator value.

[0070] Figure 7 This is a schematic diagram of the charge and discharge voltage-SOC dynamic curve under different cycle numbers. Figure 7 How to calculate the correction factor for the number of cycles is explained below.

[0071] For example, if the target performance indicator is the number of cycles, then the correction factor corresponding to the number of cycles (denoted as K C ) is:

[0072] ,

[0073] ,

[0074] Among them, C represents the current index value (number of cycles), C1 represents the first index value (number of cycles), C2 represents the second index value (number of cycles), SOC C1 represents the first SOC corresponding to the first index value, SOC C2 represents the second SOC corresponding to the second index value, SOC C-cluster Indicates the target SOC corresponding to the current indicator value.

[0075] Figure 8 This is a schematic diagram of the charge and discharge voltage-SOC dynamic curve under different static times. Figure 8 How to calculate the correction factor for the rest time is explained.

[0076] For example, if the target performance indicator is the rest time, then the correction factor corresponding to the rest time (denoted as K ST ) is:

[0077] ,

[0078] ,

[0079] Among them, ST represents the current indicator value (stationary time), ST1 represents the first indicator value (stationary time), ST2 represents the second indicator value (stationary time), SOC ST1 represents the first SOC corresponding to the first index value, SOC ST2 represents the second SOC corresponding to the second index value, SOC ST-cluster Indicates the target SOC corresponding to the current indicator value.

[0080] Calculating the correction coefficients corresponding to different performance indicators to correct the predicted SOC can improve data accuracy.

[0081] As an optional embodiment, the expected SOC is calculated according to the preset SOC and various correction coefficients, including: determining the numerical range to which the preset SOC belongs, wherein the numerical range includes a first numerical range, a second numerical range and a third numerical range, the maximum value of the first numerical range is less than the minimum value of the second numerical range, and the maximum value of the second numerical range is less than the minimum value of the third numerical range; if the preset SOC falls within the first numerical range, it is determined that the battery is in a discharge terminal state; if the preset SOC falls within the second numerical range, it is determined that the battery is in a normal charge and discharge state; if the preset SOC falls within the third numerical range, it is determined that the battery is in a charge terminal state; when the battery is in a normal charge and discharge state, the preset SOC is multiplied by each correction coefficient to obtain the expected SOC of the battery in the normal charge and discharge state.

[0082] SOC is a parameter used to indicate the remaining power of the battery. The value range of SOC is [0, 1], or expressed as a percentage of 0% to 100%. Within this range, an SOC of 0% indicates that the battery has been fully discharged, and an SOC of 100% indicates that the battery is fully charged.

[0083] The present application determines whether the battery is in the terminal state of charge and discharge by setting a first numerical range, a second numerical range, and a third numerical range.

[0084] For example, if the preset SOC falls within a first numerical range (e.g., preset SOC∈[0, 10%)), the battery is determined to be in a terminal state of discharge; if the preset SOC falls within a second numerical range (e.g., preset SOC∈[10%, 90%)), the battery is determined to be in a normal charge and discharge state; if the preset SOC falls within a third numerical range (e.g., preset SOC∈[90, 100%]), the battery is determined to be in a terminal state of charge. The specific values ​​of each numerical range can also be adjusted according to actual conditions, and this application only gives a preferred example.

[0085] When SOC is in the range of 0% to 10%, the remaining power of the battery is small and the discharge capacity is weakened, so the battery can be considered to be in the terminal state of discharge. When SOC reaches more than 90%, the battery is close to being fully charged, so the battery can be considered to be in the terminal state of charge. When SOC is between the terminal state of discharge and the terminal state of charge, it is defined as being in the normal charge and discharge state.

[0086] When the battery is in a normal charge and discharge state, the preset SOC is multiplied by each correction factor to obtain the expected SOC of the battery in a normal charge and discharge state. The formula is as follows:

[0087] ,

[0088] Among them, SOC C / T / RC / ST Indicates the preset SOC corresponding to the current performance indicator value queried from the preset mapping table, Represents the calculated expected SOC under normal charge and discharge conditions.

[0089] Fig. 9 The schematic diagram of the charge and discharge voltage-SOC dynamic curve provided in this application is shown in the figure. At the end of the charge and discharge state, the charge and discharge voltage-SOC dynamic curve will change, where ΔV D Represents the voltage difference at the end of discharge, ΔV C Represents the voltage difference at the charging end, ΔV C1 <ΔV C <ΔV C2 , ΔV D1 <ΔV D <ΔV D2 .

[0090] Because the terminal state of charge and the terminal state of discharge have a special impact on the performance, life and safety of the battery, it is necessary to separately calculate the voltage difference and calibration coefficient to calculate the expected SOC when the battery is in the terminal state of charge and discharge (which will be explained below).

[0091] As an optional embodiment, if the battery is in a state of terminal discharge, the method further includes: determining a first voltage difference of the battery, wherein the first voltage difference is the difference between an average value of the battery's single cell voltage and a minimum value of the single cell voltage; obtaining a preset discharge voltage difference calibration coefficient; multiplying a preset SOC, each correction coefficient, the first voltage difference, and the discharge voltage difference calibration coefficient to obtain an expected SOC of the battery in the state of terminal discharge.

[0092] Get the battery voltage data, including the lowest voltage V of the battery MIN (i.e. the minimum value of the single cell voltage) and the average single cell voltage V AVE (i.e., the average voltage of each cell), based on which the first voltage difference can be calculated, i.e., the voltage difference between the average voltage of each cell and the lowest voltage of each cell (V AVE-MIN ).

[0093] The discharge voltage difference calibration coefficient is a preset value.

[0094] The formula for calculating the expected SOC of the battery at the end of discharge is:

[0095] ,

[0096] in, represents the first voltage difference, Indicates the discharge voltage difference calibration coefficient, Represents the calculated expected SOC at the end of discharge.

[0097] As an optional embodiment, if the battery is in a charging terminal state, the method further includes: determining a second voltage difference of the battery, wherein the second voltage difference is the difference between the maximum single cell voltage and the average single cell voltage of the battery; obtaining a preset charging voltage difference calibration coefficient; multiplying the preset SOC, each correction coefficient, the second voltage difference and the charging voltage difference calibration coefficient to obtain the expected SOC of the battery in the charging terminal state.

[0098] Get the voltage data of the battery, including the highest voltage V of the single cell MAX (i.e. the maximum value of the single cell voltage) and the average single cell voltage V AVE (i.e., the average voltage of each cell), based on which the second voltage difference can be calculated, i.e., the voltage difference V between the highest voltage of each cell and the average voltage of each cell MAX-AVE .

[0099] The charging voltage difference calibration coefficient is a preset value.

[0100] The formula for calculating the expected SOC of the battery at the end of charging is:

[0101] ,

[0102] in, represents the second voltage difference, Indicates the charging voltage difference calibration coefficient, Represents the calculated expected SOC at the end of charging state.

[0103] This application starts from the influencing factors of the battery's DC internal resistance, and corrects the charging and discharging dynamic voltage-SOC curve of the original single battery cell with different influencing factors. On the premise of retaining the trend of the original charging and discharging curve, the curve is made closer to the charging and discharging characteristics of the battery. At the same time, the voltage difference and the voltage difference calibration coefficient are introduced to perform different operations on the SOC calibration in the terminal state of charging / discharging, so that the battery characteristics are met within the entire SOC range.

[0104] As an optional embodiment, the displayed SOC of the battery is calibrated using the expected SOC, including: obtaining the displayed SOC of the battery and determining the difference between the expected SOC and the displayed SOC; when the difference is less than a preset threshold, periodically calibrating the displayed SOC according to a preset step size.

[0105] The preset threshold represents the critical value of the relative difference between the displayed SOC and the expected SOC, which can be set to 5% and can also be changed by the BMS configuration.

[0106] If the relative difference between the displayed SOC and the expected SOC is less than the preset threshold, the displayed SOC does not need to be calibrated. If the relative difference between the displayed SOC and the expected SOC is greater than or equal to the preset threshold, the displayed SOC needs to be periodically calibrated according to the preset step size. In each calibration cycle, the BMS adjusts the displayed SOC according to the preset step size and the current charge and discharge status of the battery.

[0107] Preferably, the preset step size can be set to 0.01%, which can be configured and changed by the BMS.

[0108] Optionally, for a battery at the end of discharge, the calibration process includes: discharging until the lowest voltage limit threshold of the single cell is reached (which can be set by the BMS configuration) according to the characteristics of the single cell, and forcibly calibrating the expected SOC and the displayed SOC to 0%. After calibration, the displayed SOC will immediately become 0%, and the user will intuitively see that the battery power has been exhausted.

[0109] The minimum limit threshold is set to prevent the battery cell from over-discharging, so as to avoid permanent damage to the battery cell or safety hazards.

[0110] Optionally, for batteries in the terminal state of charging, the calibration process includes: according to the characteristics of the single cell, until the single cell voltage reaches the maximum limit threshold, which means that the cell is close to or reaches the fully charged state, the BMS will force the expected SOC and displayed SOC to be calibrated to 100%. After calibration, the displayed SOC will become 100%, and the user will intuitively see that the battery is fully charged. This ensures that users can accurately understand the power status of the battery system and avoid safety issues caused by overcharging.

[0111] The maximum limit threshold is set to prevent the battery cell from overcharging, so as to avoid permanent damage to the battery cell or safety hazards.

[0112] The present application provides a calibration method for the displayed SOC of a battery, including: when the battery is detected to be in a charging and discharging state, obtaining various performance indicators of the battery, wherein the various performance indicators include the current temperature value, the charging and discharging rate, the number of cycles, and the rest time; calling a preset mapping table, and determining the preset SOC corresponding to each performance indicator in the preset mapping table, wherein the preset mapping table is constructed based on the correspondence between different performance indicators and the state of charge; determining various correction coefficients corresponding to each performance indicator through the preset mapping table; calculating the expected SOC based on the preset SOC and each correction coefficient; and calibrating the displayed SOC of the battery using the expected SOC. By calculating the correction coefficients corresponding to the various performance indicators of the battery to perform real-time calibration of the displayed SOC of the battery during the charging and discharging process, the problem that the energy storage system cannot calibrate the displayed SOC of the battery in real time during the charging and discharging process is solved.

[0113] According to another aspect of the embodiment of the present application, the present application provides a calibration device for displaying SOC of a battery, such as Fig.10 As shown, including:

[0114] The acquisition module 1002 is used to acquire various performance indicators of the battery when it is detected that the battery is in a charging and discharging state, wherein each performance indicator includes a current temperature value, a charging and discharging rate, a number of cycles, and a rest time;

[0115] A calling module 1004 is used to call a preset mapping table and determine a preset SOC corresponding to each performance indicator in the preset mapping table, wherein the preset mapping table is constructed according to the correspondence between different performance indicators and the state of charge;

[0116] A determination module 1006, configured to determine each correction coefficient corresponding to each performance indicator through a preset mapping table;

[0117] A calculation module 1008, configured to calculate a desired SOC according to a preset SOC and various correction coefficients;

[0118] The calibration module 1010 is used to calibrate the displayed SOC of the battery using the expected SOC.

[0119] It should be noted that the acquisition module 1002 in this embodiment can be used to execute step 101 in the embodiment of the present application, the calling module 1004 in this embodiment can be used to execute step 103 in the embodiment of the present application, the determination module 1006 in this embodiment can be used to execute step 105 in the embodiment of the present application, the calculation module 1008 in this embodiment can be used to execute step 107 in the embodiment of the present application, and the calibration module 1010 in this embodiment can be used to execute step 109 in the embodiment of the present application.

[0120] Optionally, the acquisition module 1002 is also used to obtain the battery's log data and read the battery's cycle times and rest time from the log data; detect the battery's current temperature value; detect the battery's current current value, and calculate the battery's charge and discharge rate based on the current value, wherein the charge and discharge rate includes the charge rate during charging and the discharge rate during discharging.

[0121] Optionally, the determination module 1006 is also used to determine a target indicator value of the target performance indicator, and determine a first indicator value and a second indicator value based on the target indicator value, wherein each performance indicator includes a target performance indicator, the target indicator value is the current value of the target performance indicator of the battery, the first indicator value is less than the target indicator value, and the second indicator value is greater than the target indicator value; a first SOC corresponding to the first indicator value and a second SOC corresponding to the second indicator value are determined using a preset mapping table; a target SOC corresponding to the target indicator value is calculated based on the first indicator value, the first SOC, the second indicator value and the second SOC; and a ratio of the target SOC to the first SOC is determined as a correction coefficient corresponding to the target performance indicator.

[0122] Optionally, the calculation module 1008 is also used to determine the numerical range to which the preset SOC belongs, wherein the numerical range includes a first numerical range, a second numerical range and a third numerical range, the maximum value of the first numerical range is less than the minimum value of the second numerical range, and the maximum value of the second numerical range is less than the minimum value of the third numerical range; if the preset SOC falls within the first numerical range, it is determined that the battery is in a discharge terminal state; if the preset SOC falls within the second numerical range, it is determined that the battery is in a normal charge and discharge state; if the preset SOC falls within the third numerical range, it is determined that the battery is in a charge terminal state; when the battery is in a normal charge and discharge state, the preset SOC is multiplied by each correction coefficient to obtain the expected SOC of the battery in the normal charge and discharge state.

[0123] Optionally, the calculation module 1008 is also used to determine a first voltage difference of the battery if the battery is in a terminal discharge state, wherein the first voltage difference is the difference between an average value of the battery's single cell voltage and a minimum value of the single cell voltage; obtain a preset discharge voltage difference calibration coefficient; multiply a preset SOC, each correction coefficient, the first voltage difference, and the discharge voltage difference calibration coefficient to obtain an expected SOC of the battery in the terminal discharge state.

[0124] Optionally, the calculation module 1008 is also used to determine a second voltage difference of the battery if the battery is in a terminal state of charging, wherein the second voltage difference is the difference between the maximum single cell voltage and the average single cell voltage of the battery; obtain a preset charging voltage difference calibration coefficient; multiply the preset SOC, each correction coefficient, the second voltage difference and the charging voltage difference calibration coefficient to obtain the expected SOC of the battery in the terminal state of charging.

[0125] Optionally, the calibration module 1010 is further configured to obtain the displayed SOC of the battery and determine the difference between the expected SOC and the displayed SOC; when the difference is smaller than a preset threshold, the displayed SOC is periodically calibrated according to a preset step size.

[0126] It should be noted here that the examples and application scenarios implemented by the above modules and corresponding steps are the same, but are not limited to the contents disclosed in the above embodiments.

[0127] According to another aspect of the embodiments of the present application, the present application provides an electronic device, such as Fig.11 As shown, it includes a memory 1101, a processor 1103, a communication interface 1105 and a communication bus 1107. The memory 1101 stores a computer program that can be run on the processor 1103. The memory 1101 and the processor 1103 communicate through the communication interface 1105 and the communication bus 1107. When the processor 1103 executes the computer program, the steps of the above method are implemented.

[0128] The memory and processor in the above electronic device communicate via a communication bus and a communication interface. The communication bus may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus may be divided into an address bus, a data bus, a control bus, etc.

[0129] The memory may include a random access memory (RAM) or a non-volatile memory, such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0130] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0131] According to another aspect of the embodiments of the present application, a computer-readable medium having a non-volatile program code executable by a processor is provided.

[0132] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0133] When the embodiments of the present application are specifically implemented, reference may be made to the above-mentioned embodiments, which have corresponding technical effects.

[0134] It is understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit may be implemented in one or more application specific integrated circuits (ASIC), digital signal processors (DSP), digital signal processing devices (DSPD), programmable logic devices (PLD), field programmable gate arrays (FPGA), general purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described in the present application, or a combination thereof.

[0135] For software implementation, the technology described herein can be implemented by a unit that performs the functions described herein. The software code can be stored in a memory and executed by a processor. The memory can be implemented in the processor or outside the processor.

[0136] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0137] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0138] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0139] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0140] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0141] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium, including several instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk or an optical disk. It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "include" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such a process, method, article or device. Without more constraints, an element defined by the phrase "comprising a..." does not exclude the existence of other identical elements in the process, method, article or apparatus comprising the element.

[0142] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for calibrating the displayed SOC of a battery, characterized in that: include: When it is detected that the battery is in a charge and discharge state, obtaining various performance indicators of the battery, wherein the various performance indicators include a current temperature value, a charge and discharge rate, a number of cycles, and a rest time; Calling a preset mapping table, and determining a preset SOC corresponding to each performance indicator in the preset mapping table, wherein the preset mapping table is constructed according to a correspondence between different performance indicators and states of charge; Determine each correction coefficient corresponding to each performance indicator through the preset mapping table; Calculating the expected SOC according to the preset SOC and the correction coefficients; calibrating a displayed SOC of the battery using the expected SOC; The determining, by means of the preset mapping table, each correction coefficient corresponding to each performance indicator comprises: Determine a target indicator value of a target performance indicator, and determine a first indicator value and a second indicator value according to the target indicator value, wherein each performance indicator includes the target performance indicator, the target indicator value is a current value of the target performance indicator of the battery, the first indicator value is less than the target indicator value, and the second indicator value is greater than the target indicator value; Determine a first SOC corresponding to the first indicator value and a second SOC corresponding to the second indicator value by using the preset mapping table; Calculating a target SOC corresponding to the target index value according to the first index value, the first SOC, the second index value, and the second SOC; A ratio of the target SOC to the first SOC is determined as the correction coefficient corresponding to the target performance indicator.

2. The method according to claim 1, characterized in that The obtaining of various performance indicators of the battery includes: Acquire log data of the battery, and read the number of cycles and the rest time of the battery from the log data; Detecting the current temperature value of the battery; The current value of the battery is detected, and the charge and discharge rate of the battery is calculated according to the current value, wherein the charge and discharge rate includes the charge rate during charging and the discharge rate during discharging.

3. The method according to claim 1, characterized in that The step of calculating the expected SOC according to the preset SOC and the correction coefficients includes: Determine a numerical range to which the preset SOC belongs, wherein the numerical range includes a first numerical range, a second numerical range, and a third numerical range, the maximum value of the first numerical range is less than the minimum value of the second numerical range, and the maximum value of the second numerical range is less than the minimum value of the third numerical range; If the preset SOC falls within the first value range, it is determined that the battery is in a discharge terminal state; if the preset SOC falls within the second value range, it is determined that the battery is in a normal charge and discharge state; if the preset SOC falls within the third value range, it is determined that the battery is in a charge terminal state; When the battery is in the normal charge and discharge state, the preset SOC is multiplied by each correction coefficient to obtain the expected SOC of the battery in the normal charge and discharge state.

4. The method according to claim 3, characterized in that If the battery is in the end-of-discharge state, the method further includes: Determine a first voltage difference of the battery, wherein the first voltage difference is a difference between an average value of the single cell voltage of the battery and a minimum value of the single cell voltage; Obtaining a preset discharge voltage difference calibration coefficient; The preset SOC, the correction coefficients, the first voltage difference value, and the discharge voltage difference calibration coefficient are multiplied together to obtain the expected SOC of the battery at the end-of-discharge state.

5. The method according to claim 3, characterized in that: If the battery is in the charging terminal state, the method further includes: Determine a second voltage difference of the battery, wherein the second voltage difference is a difference between a maximum single cell voltage of the battery and an average single cell voltage; Obtaining a preset charging voltage difference calibration coefficient; The preset SOC, the correction coefficients, the second voltage difference, and the charging voltage difference calibration coefficient are multiplied together to obtain the expected SOC of the battery in the charging terminal state.

6. The method according to claim 1, characterized in that The step of calibrating the displayed SOC of the battery by using the expected SOC includes: Acquiring the displayed SOC of the battery, and determining a difference between the expected SOC and the displayed SOC; When the difference is smaller than a preset threshold, the displayed SOC is periodically calibrated according to a preset step size.

7. A battery SOC display calibration device, characterized in that: include: An acquisition module, configured to acquire various performance indicators of the battery when detecting that the battery is in a charge and discharge state, wherein the various performance indicators include a current temperature value, a charge and discharge rate, a number of cycles, and a rest time; A calling module, used to call a preset mapping table and determine a preset SOC corresponding to each performance indicator in the preset mapping table, wherein the preset mapping table is constructed according to the correspondence between different performance indicators and the state of charge; A determination module, used to determine each correction coefficient corresponding to each performance indicator through the preset mapping table; A calculation module, used for calculating the expected SOC according to the preset SOC and the correction coefficients; A calibration module, configured to calibrate the displayed SOC of the battery using the expected SOC; The determination module is also used to determine a target indicator value of a target performance indicator, and determine a first indicator value and a second indicator value based on the target indicator value, wherein the various performance indicators include the target performance indicator, the target indicator value is the current value of the target performance indicator of the battery, the first indicator value is less than the target indicator value, and the second indicator value is greater than the target indicator value; using the preset mapping table to determine a first SOC corresponding to the first indicator value and a second SOC corresponding to the second indicator value; calculating the target SOC corresponding to the target indicator value based on the first indicator value, the first SOC, the second indicator value and the second SOC; and determining the ratio of the target SOC to the first SOC as the correction coefficient corresponding to the target performance indicator.

8. An electronic device, comprising a memory, a processor, a communication interface and a communication bus, wherein the memory stores a computer program that can be run on the processor, and the memory and the processor communicate through the communication bus and the communication interface, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable medium having a non-volatile program code executable by a processor, characterized in that: The program code enables the processor to execute the method according to any one of claims 1 to 6.

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