Battery SOC estimation method and related device

Abstract

The present application provides a method for estimating the SOC of a battery and a related device. The method includes: obtaining the current SOC value of the battery; sampling the voltage of the battery to obtain the current measured voltage of the battery; calculating the SOC target value corresponding to the battery at the current measured voltage; obtaining the correction error of the SOC target value, and determining the SOC error range based on the correction error and the SOC target value; and correcting the current SOC value according to the relationship between the SOC error range and the current SOC value. Through the above scheme, the present application can take into account the correction error in the SOC calculation process when correcting the SOC, and expand the uncorrected range of the current SOC value based on the correction error, thereby avoiding the SOC jitter problem caused by frequent repeated corrections and ensuring the estimation accuracy of the SOC.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery SOC estimation method and related devices. Background Art

[0002] In the battery management system, the general correction methods for SOC (state of charge) are static OCV (open circuit voltage) correction and full charge correction. However, if the battery is not static or full charged for a long time, the SOC cannot be corrected for a long time, accumulating a huge error. Therefore, the correction of SOC during the battery charging and discharging operation is particularly important.

[0003] At present, in order to calculate the SOC value of the battery during the charge and discharge operation, the open circuit voltage OCV of the battery during operation can be determined according to the DC resistance of the battery, and then the corresponding SOC target value can be found through the OCV-SOC table. The corresponding SOC target value can also be found through the CCV (closed circuit voltage)-SOC table during the battery charging process. However, there are often various errors in the SOC calculation process, such as sampling errors of measuring devices, table lookup errors, etc. If the SOC target value is used to correct the battery SOC, there will be problems of over-correction and frequent repeated corrections, which will lead to SOC jitter. Summary of the invention

[0004] The present application provides a battery SOC estimation method and related devices to solve the problem of SOC jitter caused by errors in the SOC calculation process in the prior art.

[0005] In a first aspect, the present application provides a method for estimating a battery SOC, comprising:

[0006] Get the current SOC value of the battery;

[0007] Sampling the voltage of the battery to obtain a current measured voltage of the battery;

[0008] Calculating a target SOC value of the battery at the current measured voltage;

[0009] Acquire a correction error of the SOC target value, and determine an SOC error range based on the correction error and the SOC target value;

[0010] The current SOC value is corrected according to the magnitude relationship between the SOC error range and the current SOC value.

[0011] In a possible implementation, the calculating the SOC target value of the battery corresponding to the current measured voltage includes:

[0012] According to the formula U ocv =U c +i*DCR, calculate the open circuit voltage of the battery, where U ocv represents the open circuit voltage, U c represents the current measured voltage, i represents the current measured current of the battery, and DCR represents the DC internal resistance of the battery;

[0013] Based on the OCV-SOC correspondence, an SOC value corresponding to the open circuit voltage is determined, and the SOC value is used as an SOC target value.

[0014] In a possible implementation, the calculating the SOC target value of the battery corresponding to the current measured voltage includes:

[0015] If the battery is in a charging state, the SOC target value corresponding to the current measured voltage is determined according to a preset CCV-SOC table, wherein the preset CCV-SOC table includes a correspondence between the measured voltage and the SOC value.

[0016] In a possible implementation manner, obtaining a correction error of the SOC target value includes:

[0017] Obtaining the real SOC value of the battery at different measurement voltages obtained through offline calibration;

[0018] Obtaining historical SOC target values ​​corresponding to different measurement voltages of the battery in historical charge and discharge cycles;

[0019] For any measured voltage, the difference between the historical SOC target value and the actual SOC value of the battery at the measured voltage is taken as the error value corresponding to the measured voltage;

[0020] The error values ​​corresponding to the various measured voltages are averaged to obtain the corrected error.

[0021] In a possible implementation manner, obtaining a correction error of the SOC target value includes:

[0022] Obtaining sampling error of a voltage measuring device;

[0023] Determine a voltage error range of a target measurement voltage based on the sampling error; the target measurement voltage is a measurement voltage corresponding to a preset SOC value;

[0024] Determining an error range corresponding to the preset SOC value based on the voltage error range;

[0025] A correction error of the SOC target value is determined according to the error range of the preset SOC value and the preset SOC value.

[0026] In a possible implementation manner, obtaining a correction error of the SOC target value includes:

[0027] Obtaining the real SOC value of the battery at different measurement voltages obtained through offline calibration;

[0028] Obtaining historical SOC target values ​​corresponding to different measurement voltages of the battery in historical charge and discharge cycles;

[0029] For any measured voltage, the difference between the historical SOC target value and the actual SOC value of the battery at the measured voltage is taken as the error value corresponding to the measured voltage;

[0030] Averaging the error values ​​corresponding to the various measured voltages to obtain a first corrected error;

[0031] Obtaining sampling error of a voltage measuring device;

[0032] Determine a voltage error range of a target measurement voltage based on the sampling error; the target measurement voltage is a measurement voltage corresponding to a preset SOC value;

[0033] Determining an error range corresponding to the preset SOC value based on the voltage error range;

[0034] determining a second correction error according to the error range of the preset SOC value and the preset SOC value;

[0035] A larger value between the first correction error and the second correction error is selected, and the larger value is used as the correction error of the SOC target value.

[0036] In a possible implementation, the SOC error range includes an upper error limit value and a lower error limit value;

[0037] The correcting the current SOC value according to the magnitude relationship between the SOC error range and the current SOC value includes:

[0038] If the current SOC value exceeds the SOC error range and the current SOC value is less than the lower error limit, correcting the current SOC value to the lower error limit;

[0039] If the current SOC value exceeds the SOC error range and the current SOC value is greater than the upper error limit value, correcting the current SOC value to the upper error limit value;

[0040] If the current SOC value is within the SOC error range, the current SOC value is not corrected.

[0041] In a second aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method described in any possible implementation of the first aspect are implemented.

[0042] In a third aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in any possible implementation of the first aspect above are implemented.

[0043] In a fourth aspect, the present application provides a car, which includes the electronic device as described in the second aspect above.

[0044] The embodiment of the present application provides a method for estimating the SOC of a battery, which first obtains the current SOC value of the battery; then samples the voltage of the battery to obtain the current measured voltage of the battery; calculates the SOC target value corresponding to the battery at the current measured voltage; then obtains the correction error of the SOC target value, and determines the SOC error range based on the correction error and the SOC target value; finally, according to the size relationship between the SOC error range and the current SOC value, the current SOC value is corrected. Through the above scheme, the present application can take into account the correction error in the SOC calculation process when correcting the SOC, and expand the uncorrected range of the current SOC value based on the correction error, thereby avoiding the SOC jitter problem caused by frequent repeated corrections and ensuring the estimation accuracy of the SOC. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0046] Figure 1 is a flow chart of an implementation of a battery SOC estimation method provided in an embodiment of the present application;

[0047] Figure 2 It is a curve diagram of the charging current, charging voltage and SOC real value obtained by offline calibration of the battery provided in the embodiment of the present application;

[0048] Figure 3It is a schematic diagram of demarcating the SOC error range provided in an embodiment of the present application;

[0049] Figure 4 is a schematic diagram of the structure of a battery SOC estimation device provided in an embodiment of the present application;

[0050] Figure 5 It is a schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0052] In order to make the purpose, technical solutions and advantages of the present application clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0053] See also Figure 1 , which shows a flow chart of the implementation of the battery SOC estimation method provided in the embodiment of the present application, which is described in detail as follows:

[0054] S101: Obtain the current SOC value of the battery.

[0055] The execution subject (electronic device) of this embodiment may be a battery management system.

[0056] S102: Sampling the voltage of the battery to obtain a current measured voltage of the battery.

[0057] In this embodiment, the battery management system uses a voltage measuring device to measure the voltage of the battery to obtain the current measured voltage; the battery management system may also use a current measuring device to measure the current of the battery to obtain the current measured current.

[0058] S103: Calculate the SOC target value of the battery corresponding to the current measured voltage.

[0059] The battery management system will calculate and update the current SOC value of the battery in real time during the operation of the battery. The SOC value has errors, and the battery management system needs to correct the SOC value from time to time. Since the conventional static OCV correction method requires the open circuit voltage to be detected when the battery is static, lithium batteries that are in working state for a long time will accumulate large errors.

[0060] In order to solve the above problems, this embodiment can adopt two SOC calculation methods during battery operation, which are detailed as follows:

[0061] In a possible embodiment, a first implementation process of S103 includes:

[0062] According to the formula U ocv =U c +i*DCR, calculate the open circuit voltage of the battery, where U ocv Indicates the open circuit voltage, U c represents the current measured voltage, i represents the current measured current, and DCR represents the DC internal resistance of the battery;

[0063] Based on the OCV-SOC correspondence relationship, the SOC value corresponding to the open circuit voltage is determined, and the SOC value is used as the SOC target value.

[0064] Specifically, when the battery is in operation, the battery management system can use the DC internal resistance DCR to calculate the open circuit voltage U corresponding to the current measured current and the current measured voltage. ocv , and then determine the current open circuit voltage U by looking up the table ocv The corresponding SOC value can be used to realize SOC correction during battery operation.

[0065] In this embodiment, the OCV-SOC correspondence relationship can be that the horizontal axis is the SOC value and the vertical axis is U ocv A two-dimensional curve diagram can also be a two-dimensional curve diagram including SOC value, U ocv And a table showing the corresponding relationship between the two.

[0066] Specifically, the OCV-SOC table includes the correspondence between the open circuit voltage and the SOC value at a certain temperature. Before looking up the table, the battery management system can first obtain the current temperature of the battery, then lock the OCV-SOC table corresponding to the battery at the current temperature, and determine the SOC target value corresponding to the current open circuit voltage by querying the OCV-SOC table.

[0067] In a possible embodiment, the second implementation process of S103 includes:

[0068] If the battery is in a charging state, the SOC target value corresponding to the current measured voltage is determined according to a preset CCV-SOC table, wherein the preset CCV-SOC table includes a correspondence between the measured voltage and the SOC value.

[0069] Specifically, the preset CCV-SOC table includes the correspondence between the measured voltage and the SOC value at a certain temperature and a certain current rate. Before looking up the table, the battery management system can first obtain the current temperature of the battery, then lock the CCV-SOC table corresponding to the battery at the current temperature, and determine the SOC target value corresponding to the current measured voltage by querying the CCV-SOC table.

[0070] Preferably, since the battery cell factory can only provide CCV-SOC tables with several current ratios, the present embodiment can select the CCV-SOC table corresponding to the current ratio of 0.1C with the best accuracy for table lookup operation.

[0071] S104: Obtain a correction error of the SOC target value, and determine an SOC error range based on the correction error and the SOC target value.

[0072] Specifically, this embodiment can determine the SOC error range by obtaining a correction error between the SOC target value and the SOC actual value.

[0073] In a possible implementation manner, the specific implementation process of obtaining the correction error of the SOC target value in S104 includes:

[0074] Obtain the actual SOC value of the battery at different measurement voltages obtained through offline calibration;

[0075] Obtain the historical SOC target value corresponding to different measured voltages of the battery in historical charge and discharge cycles;

[0076] For any measured voltage, the difference between the historical SOC target value and the actual SOC value of the battery at the measured voltage is taken as the error value corresponding to the measured voltage;

[0077] The error values ​​corresponding to each measured voltage are averaged to obtain the corrected error.

[0078] Specifically, during the SOC calculation process, errors may exist in multiple links, one of which is the DCR error. Since the DC internal resistance DCR of the battery is a value provided by the battery cell manufacturer, this value often has a certain error in actual application. Therefore, if the SOC target value calculated by using the DCR provided by the battery cell manufacturer is used to correct the current SOC value, there may be SOC jitter problems caused by over-correction or frequent corrections.

[0079] Another error in the SOC calculation process is the CCV-SOC table / OCV-SOC table error. The CCV-SOC table or OCV-SOC table is data provided by the battery cell factory. During application, it may cause certain errors due to differences in the actual battery temperature and actual current rate.

[0080] In order to avoid the above errors, the staff can regularly perform offline calibration on the battery to determine the relationship between the voltage, current and SOC of the battery during the entire charging cycle. Figure 2 As shown, Figure 2 The comparison curves of charging current, charging voltage and actual SOC value are shown. Figure 2 The top curve is the curve corresponding to the charging current, with the horizontal axis being time and the vertical axis being the charging current; the middle curve is the curve corresponding to the charging voltage, with the horizontal axis being time and the vertical axis being the charging voltage; the bottom curve is the curve corresponding to the actual SOC value, with the horizontal axis being time and the vertical axis being the actual SOC value. Figure 2 It can be seen that offline calibration can determine the actual SOC value of the battery at each charging voltage.

[0081] The battery management system is also used to store the SOC target values ​​corresponding to different measurement voltages in the previous N charge and discharge cycles at the current moment. Then, the SOC target value corresponding to different measurement voltages in a charge and discharge cycle can be arbitrarily selected. By finding the SOC true value and the SOC target value under the same measurement voltage, the error value between the SOC true value and the SOC target value corresponding to each measurement voltage can be determined, and then all error values ​​are averaged to obtain the corrected error.

[0082] In a possible implementation manner, another implementation process of obtaining the correction error of the SOC target value in S104 includes:

[0083] Obtaining sampling error of a voltage measuring device;

[0084] Determine a voltage error range of a target measurement voltage based on the sampling error; the target measurement voltage is a measurement voltage corresponding to a preset SOC value;

[0085] Determining an error range corresponding to the preset SOC value based on the voltage error range;

[0086] A correction error of the SOC target value is determined according to the error range of the preset SOC value and the preset SOC value.

[0087] In this embodiment, during the SOC calculation process, the sampling error of the measuring device is also an important factor causing the SOC correction error. Therefore, this embodiment can determine the correction error to be considered based on the sampling error of the measuring device. The process is described in detail as follows:

[0088] First, the battery management system can take any SOC value as a reference, and use the correction error of the SOC as the correction error of all SOCs. After determining the preset SOC value and its corresponding target measurement voltage, the battery management system subtracts the sampling error from the target measurement voltage to obtain the lower limit of the voltage error in the voltage error range, and adds the sampling error to the target measurement voltage to obtain the upper limit of the voltage error in the voltage error range, and then obtains the SOC upper limit value corresponding to the upper limit of the voltage error and the SOC lower limit value corresponding to the lower limit of the voltage error by looking up the CCV-SOC table, thereby determining the error range of the preset SOC value. Finally, the preset SOC value is subtracted from the SOC upper limit value to obtain the first SOC error, and the preset SOC value is subtracted from the SOC lower limit value to obtain the second SOC error. The larger value of the first SOC error and the second SOC error is taken as the correction error corresponding to the SOC target value.

[0089] Specifically, since the current of the battery in different SOC sections is different during the charging process, as shown in Table 1, Table 1 shows the current multiples of different SOC intervals. It can be seen from Table 1 that when the SOC is in the range of 95%-100%, the current is 0.1C. Since the CCV lookup table method usually uses the CCV-SOC table corresponding to 0.1C, the embodiment of the present application selects any SOC value in the range of 95%-100% as the preset SOC value.

[0090] Table 1

[0091]

[0092] In a possible implementation manner, another implementation process of obtaining the correction error of the SOC target value in S104 includes:

[0093] Obtaining the real SOC value of the battery at different measurement voltages obtained through offline calibration;

[0094] Obtaining historical SOC target values ​​corresponding to different measurement voltages of the battery in historical charge and discharge cycles;

[0095] For any measured voltage, the difference between the historical SOC target value and the actual SOC value of the battery at the measured voltage is taken as the error value corresponding to the measured voltage;

[0096] Averaging the error values ​​corresponding to the various measured voltages to obtain a first corrected error;

[0097] Obtaining sampling error of a voltage measuring device;

[0098] Determine a voltage error range of a target measurement voltage based on the sampling error; the target measurement voltage is a measurement voltage corresponding to a preset SOC value;

[0099] Determining an error range corresponding to the preset SOC value based on the voltage error range;

[0100] determining a second correction error according to the error range of the preset SOC value and the preset SOC value;

[0101] A larger value between the first correction error and the second correction error is selected, and the larger value is used as the correction error of the SOC target value.

[0102] Specifically, this embodiment can obtain the maximum error value in the SOC calculation process through the above method, thereby further expanding the uncorrected range of the current SOC value through the maximum error value, avoiding the SOC jitter problem caused by frequent repeated corrections, and ensuring the estimation accuracy of the SOC.

[0103] In a possible implementation manner, the specific implementation process of S104 further includes:

[0104] Subtract the correction error from the SOC target value to obtain the lower limit of the SOC error range;

[0105] The SOC target value is added to the correction error to obtain the upper error limit of the SOC error range.

[0106] In this embodiment, Figure 3 FIG. 4 shows a schematic diagram of dividing the SOC error range provided by this embodiment, such as Figure 3 As shown, the SOC target value is taken as the center of the circle and the correction error is taken as the radius to define the SOC error range of the SOC target value. If the current SOC value is within the SOC error range, it means that the current SOC value is calculated correctly and does not need to be corrected, otherwise it needs to be corrected.

[0107] S105: Correct the current SOC value according to the relationship between the SOC error range and the current SOC value.

[0108] In a possible implementation, the SOC error range includes an upper error limit value and a lower error limit value; the specific implementation process of S105 includes:

[0109] If the current SOC value exceeds the SOC error range and the current SOC value is less than the lower error limit, the current SOC value is corrected to the lower error limit;

[0110] If the current SOC value exceeds the SOC error range and the current SOC value is greater than the upper error limit, the current SOC value is corrected to the upper error limit;

[0111] If the current SOC value is within the SOC error range, the current SOC value is not corrected.

[0112] In this embodiment, if the current SOC value exceeds the SOC error range, and the current SOC value is greater than the SOC error upper limit, and the difference between the current SOC value and the error upper limit is greater than the preset error difference, that is, the difference between the current SOC estimation value and the SOC error upper limit is large, the correction force of forcibly correcting the current SOC value to the SOC error upper limit is large, and the SOC value may jump. Therefore, the average value of the current SOC value and the error upper limit can be calculated, and the current SOC value can be corrected using the average value.

[0113] Correspondingly, if the current SOC value exceeds the SOC error range, and the current SOC value is less than the lower error limit, and the difference between the current SOC value and the lower error limit is greater than the preset error difference, that is, the difference between the current SOC value and the lower error limit is large, and the correction force of forcibly correcting the current SOC value to the lower error limit is large, the SOC value may jump. Therefore, the average value of the current SOC value and the lower error limit may be calculated, and the current SOC value may be corrected using the average value.

[0114] In this embodiment, if the difference between the current SOC value and the lower limit of the error is greater than the preset error difference, or the difference between the current SOC value and the upper limit of the error is greater than the preset error difference, the duration of the next N sampling cycles of the current sampling cycle is shortened, so as to increase the number of corrections to smoothly correct the SOC value to within the SOC target range, thereby avoiding jumps and jitters in the SOC value.

[0115] It can be seen from the above embodiments that the embodiments of the present application first obtain the current SOC value of the battery; then sample the voltage of the battery to obtain the current measured voltage of the battery; calculate the SOC target value corresponding to the battery at the current measured voltage; then obtain the correction error of the SOC target value, and determine the SOC error range based on the correction error and the SOC target value; finally, correct the current SOC value based on the size relationship between the SOC error range and the current SOC value. Through the above scheme, the present application can consider the correction error in the SOC calculation process when correcting the SOC, and expand the uncorrected range of the current SOC value based on the correction error, thereby avoiding the SOC jitter problem caused by frequent repeated corrections and ensuring the estimation accuracy of the SOC.

[0116] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0117] The following is an embodiment of the device of the present application. For details not described in detail, please refer to the corresponding method embodiment described above.

[0118] Figure 4The structure diagram of the battery SOC estimation device 100 provided in the embodiment of the present application is shown. For the convenience of explanation, only the part related to the embodiment of the present application is shown, which is described in detail as follows:

[0119] like Figure 4 As shown, the battery SOC estimation device 100 includes:

[0120] A current SOC value acquisition module is used to obtain the current SOC value of the battery;

[0121] A measurement voltage acquisition module, used to sample the voltage of the battery to obtain the current measurement voltage of the battery;

[0122] An SOC target value calculation module, used to calculate the SOC target value corresponding to the battery at the current measured voltage;

[0123] An SOC error range determination module, configured to obtain a correction error of the SOC target value, and determine an SOC error range based on the correction error and the SOC target value;

[0124] The SOC correction module is used to correct the current SOC value according to the size relationship between the SOC error range and the current SOC value.

[0125] In a possible embodiment, the SOC target value calculation module includes:

[0126] According to the formula U ocv =U c +i*DCR, calculate the open circuit voltage of the battery, where U ocv represents the open circuit voltage, U c represents the current measured voltage, i represents the current measured current of the battery, and DCR represents the DC internal resistance of the battery;

[0127] Based on the OCV-SOC correspondence, an SOC value corresponding to the open circuit voltage is determined, and the SOC value is used as an SOC target value.

[0128] In a possible embodiment, the SOC target value calculation module includes:

[0129] If the battery is in a charging state, the SOC target value corresponding to the current measured voltage is determined according to a preset CCV-SOC table, wherein the preset CCV-SOC table includes a correspondence between the measured voltage and the SOC value.

[0130] In a possible embodiment, the SOC error range determination module includes a first corrected error acquisition unit, which is used to:

[0131] Obtaining the real SOC value of the battery at different measurement voltages obtained through offline calibration;

[0132] Obtaining historical SOC target values ​​corresponding to different measurement voltages of the battery in historical charge and discharge cycles;

[0133] For any measured voltage, the difference between the historical SOC target value and the actual SOC value of the battery at the measured voltage is taken as the error value corresponding to the measured voltage;

[0134] The error values ​​corresponding to the various measured voltages are averaged to obtain the corrected error.

[0135] In a possible embodiment, the SOC error range determination module includes a second corrected error acquisition unit, which is used to:

[0136] Obtaining sampling error of a voltage measuring device;

[0137] Determine a voltage error range of a target measurement voltage based on the sampling error; the target measurement voltage is a measurement voltage corresponding to a preset SOC value;

[0138] Determining an error range corresponding to the preset SOC value based on the voltage error range;

[0139] A correction error of the SOC target value is determined according to the error range of the preset SOC value and the preset SOC value.

[0140] In a possible embodiment, the SOC error range determination module includes a third corrected error acquisition unit, which is used to:

[0141] Obtaining the real SOC value of the battery at different measurement voltages obtained through offline calibration;

[0142] Obtaining historical SOC target values ​​corresponding to different measurement voltages of the battery in historical charge and discharge cycles;

[0143] For any measured voltage, the difference between the historical SOC target value and the actual SOC value of the battery at the measured voltage is taken as the error value corresponding to the measured voltage;

[0144] Averaging the error values ​​corresponding to the various measured voltages to obtain a first corrected error;

[0145] Obtaining sampling error of a voltage measuring device;

[0146] Determine a voltage error range of a target measurement voltage based on the sampling error; the target measurement voltage is a measurement voltage corresponding to a preset SOC value;

[0147] Determining an error range corresponding to the preset SOC value based on the voltage error range;

[0148] determining a second correction error according to the error range of the preset SOC value and the preset SOC value;

[0149] A larger value between the first correction error and the second correction error is selected, and the larger value is used as the correction error of the SOC target value.

[0150] In a possible embodiment, the SOC error range includes an upper error limit value and a lower error limit value; the SOC correction module specifically includes:

[0151] If the current SOC value exceeds the SOC error range and the current SOC value is less than the lower error limit, correcting the current SOC value to the lower error limit;

[0152] If the current SOC value exceeds the SOC error range and the current SOC value is greater than the upper error limit value, correcting the current SOC value to the upper error limit value;

[0153] If the current SOC value is within the SOC error range, the current SOC value is not corrected.

[0154] It can be seen from the above embodiments that the embodiments of the present application first obtain the current SOC value of the battery; then sample the voltage of the battery to obtain the current measured voltage of the battery; calculate the SOC target value corresponding to the battery at the current measured voltage; then obtain the correction error of the SOC target value, and determine the SOC error range based on the correction error and the SOC target value; finally, correct the current SOC value based on the size relationship between the SOC error range and the current SOC value. Through the above scheme, the present application can consider the correction error in the SOC calculation process when correcting the SOC, and expand the uncorrected range of the current SOC value based on the correction error, thereby avoiding the SOC jitter problem caused by frequent repeated corrections and ensuring the estimation accuracy of the SOC.

[0155] The present application also provides a computer program product having a program code, which executes the steps of any of the above-mentioned battery SOC estimation method embodiments when the program code is run in a corresponding processor, controller, computing device or electronic device, such as Figure 1Steps 101 to 105 shown. Those skilled in the art will appreciate that the method and the device of the present application embodiment can be implemented in various forms of hardware, software, firmware, a dedicated processor or a combination thereof. The dedicated processor may include an application specific integrated circuit (ASIC), a reduced instruction set computer (RISC) and / or a field programmable gate array (FPGA). The proposed method and device are preferably implemented as a combination of hardware and software. The software is preferably installed on a program storage device as an application. It is typically based on a machine with a computer platform having hardware, such as one or more central processing units (CPUs), random access memories (RAMs) and one or more input / output (I / O) interfaces. An operating system is typically also installed on the computer platform. The various processes and functions described herein may be part of an application, or a part thereof may be executed by an operating system.

[0156] Figure 5 Schematic diagram of an electronic device provided in an embodiment of the present application. Figure 5 As shown, the electronic device 5 of this embodiment includes: a processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the processor 50. When the processor 50 executes the computer program 52, the steps in the above-mentioned various battery SOC estimation method embodiments are implemented, such as Figure 1 Alternatively, when the processor 50 executes the computer program 52, the functions of each module / unit in the above-mentioned device embodiments are realized, for example, Figure 4 The functions of the modules 110 to 150 are shown.

[0157] Exemplarily, the computer program 52 may be divided into one or more modules / units, which are stored in the memory 51 and executed by the processor 50 to complete / implement the solution provided by the present application. The one or more modules / units may be a series of computer program instruction segments that can complete specific functions, and the instruction segments are used to describe the execution process of the computer program 52 in the electronic device 5. For example, the computer program 52 may be divided into Figure 4 Modules 110 to 150 are shown.

[0158] The electronic device 5 may include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art will appreciate that Figure 5 It is only an example of the electronic device 5 and does not constitute a limitation of the electronic device 5. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0159] The processor 50 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0160] The memory 51 may be an internal storage unit of the electronic device 5, such as a hard disk or memory of the electronic device 5. The memory 51 may also be an external storage device of the electronic device 5, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 5. Further, the memory 51 may also include both an internal storage unit of the electronic device 5 and an external storage device. The memory 51 is used to store the computer program and other programs and data required by the electronic device. The memory 51 may also be used to temporarily store data that has been output or is to be output.

[0161] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0162] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0163] This embodiment also provides a car, which includes the electronic device as described above.

[0164] 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.

[0165] In the embodiments provided in the present application, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units 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 through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0166] 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.

[0167] 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. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0168] If the integrated module / unit 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 this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned battery SOC estimation method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practices, computer-readable media does not include electrical carrier signals and telecommunication signals.

[0169] In addition, the embodiments shown in the drawings of the present application or the features of the various embodiments mentioned in this specification are not necessarily understood as independent embodiments. Instead, each feature described in one example of an embodiment can be combined with one or more other desired features from other embodiments to produce other embodiments not described in words or with reference to the drawings.

[0170] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for estimating battery SOC, characterized in that: include: Get the current SOC value of the battery; Sampling the voltage of the battery to obtain a current measured voltage of the battery; Calculating a target SOC value of the battery at the current measured voltage; Acquire a correction error of the SOC target value, and determine an SOC error range based on the correction error and the SOC target value; Correcting the current SOC value according to the relationship between the SOC error range and the current SOC value; The obtaining of the correction error of the SOC target value includes: Obtaining the real SOC value of the battery at different measurement voltages obtained through offline calibration; Obtaining historical SOC target values ​​corresponding to different measurement voltages of the battery in historical charge and discharge cycles; For any measured voltage, the difference between the historical SOC target value and the actual SOC value of the battery at the measured voltage is taken as the error value corresponding to the measured voltage; Averaging the error values ​​corresponding to the various measured voltages to obtain a first corrected error; Obtaining sampling error of a voltage measuring device; Determine a voltage error range of a target measurement voltage based on the sampling error; the target measurement voltage is a measurement voltage corresponding to a preset SOC value; the preset SOC value is any SOC value within a range of 95%-100%; Determining an error range corresponding to the preset SOC value based on the voltage error range; determining a second correction error according to the error range of the preset SOC value and the preset SOC value; Selecting a larger value between the first correction error and the second correction error, and using the larger value as the correction error of the SOC target value; The correcting the current SOC value according to the magnitude relationship between the SOC error range and the current SOC value includes: If the current SOC value is within the SOC error range, the current SOC value is not corrected.

2. The method for estimating battery SOC according to claim 1, characterized in that: The calculating the SOC target value corresponding to the battery at the current measured voltage includes: According to the formula , calculate the open circuit voltage of the battery, where, represents the open circuit voltage, represents the current measured voltage, i represents the current measurement current of the battery, DCR represents the DC internal resistance of the battery; Based on the OCV-SOC correspondence relationship, the SOC value corresponding to the open circuit voltage is determined, and the SOC value is used as the SOC target value.

3. The method for estimating battery SOC according to claim 1, characterized in that: The calculating the SOC target value corresponding to the battery at the current measured voltage includes: If the battery is in a charging state, the SOC target value corresponding to the current measured voltage is determined according to a preset closed-circuit voltage-SOC table, wherein the preset closed-circuit voltage-SOC table includes a correspondence between the measured voltage and the SOC value.

4. The method for estimating battery SOC according to claim 1, characterized in that: The SOC error range includes an upper error limit value and a lower error limit value; The correcting the current SOC value according to the magnitude relationship between the SOC error range and the current SOC value further includes: If the current SOC value exceeds the SOC error range and the current SOC value is less than the lower error limit, correcting the current SOC value to the lower error limit; If the current SOC value exceeds the SOC error range and the current SOC value is greater than the upper error limit, the current SOC value is corrected to the upper error limit.

5. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the battery SOC estimation method as described in any one of claims 1 to 4 are implemented.

6. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the battery SOC estimation method as described in any one of claims 1 to 4 are implemented.

7. A car, characterized in that: Comprising the electronic device as claimed in claim 5.

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