SOC calculation method, device, equipment and medium for multi-branch battery system

Abstract

A method, device, equipment, and medium for calculating the SOC of a multi-branch battery system, belonging to the field of electric vehicle technology. The method includes: calculating the true SOC value of each branch; combining the true SOC values ​​of all branches to determine the true SOC value of the battery system; subtracting the true SOC value of the battery system from the displayed SOC value of the battery system and taking the absolute value to obtain a difference; determining an SOC catch-up value when the difference is greater than a first threshold; correcting the displayed SOC value of the battery system based on a catch-up rate coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system; and updating the displayed SOC value of the battery system to the corrected displayed SOC value of the battery system, thereby reducing the computational workload and improving the reliability and accuracy of the displayed SOC of the battery system.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicles, and in particular to a method, device, equipment, and computer-readable storage medium for calculating the SOC of a multi-branch battery system. Background Art

[0002] Electric vehicles are rapidly developing due to their low carbon footprint, energy efficiency, and low travel costs. Heavy trucks and buses are also increasingly electrifying these vehicles, requiring high-capacity battery systems. Given that current charging platform voltages do not exceed 1000V, to ensure sufficient power for the battery system, it is necessary to divide the battery system into multiple subsystems and then connect them in parallel to form a multi-branch internal battery system. Determining the displayed SOC value of a multi-branch internal battery system is crucial.

[0003] In the related technology, it is necessary to calculate the actual SOC value and displayed SOC value of each branch, and then distinguish the displayed SOC values ​​of all branches according to the maximum and minimum, determine the maximum and minimum values, and use the maximum value as the displayed SOC value of the battery system under charging conditions, and use the minimum value as the displayed SOC value of the battery system under discharging conditions.

[0004] However, this method of using the displayed SOC value of only one branch to replace the displayed SOC value of the entire battery system requires not only calculating the true SOC value of each branch, but also calculating the displayed SOC value of each branch, which is a large computational workload; and when there is a deviation in the calculation of the branch displayed SOC value, the displayed SOC value of the entire battery system will have low credibility and poor accuracy. Summary of the Invention

[0005] The present application provides a method, device, equipment and computer-readable storage medium for calculating the SOC of a multi-branch battery system, which can solve technical problems existing in the prior art, such as the large computational workload when determining the displayed SOC value of the battery system, and the low reliability and poor accuracy of the displayed SOC value of the battery system.

[0006] In a first aspect, an embodiment of the present application provides a method for calculating the SOC of a multi-branch battery system, the method comprising:

[0007] Calculate the actual SOC value of each branch;

[0008] The actual SOC value of the battery system is determined by integrating the actual SOC values ​​of all branches;

[0009] Subtract the actual SOC value of the battery system from the displayed SOC value of the battery system and take the absolute value to obtain the difference;

[0010] When the difference is greater than a first threshold, determining an SOC catch-up value;

[0011] Correcting the displayed SOC value of the battery system based on the catch-up rate coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system;

[0012] The displayed SOC value of the battery system is updated to the corrected displayed SOC value of the battery system.

[0013] In combination with the first aspect, in one embodiment, the integrating the true SOC values ​​of all branches to determine the true SOC value of the battery system includes:

[0014] In the charging state, when the maximum value of the actual SOC values ​​of all branches is less than the second threshold, the following steps are performed:

[0015] Determine the average value of the actual SOC values ​​of all branches;

[0016] From the actual SOC values ​​of all branches, subtract the two SOC values ​​with larger values ​​and take the absolute value to obtain the first weight coefficient;

[0017] Based on the average value and the first weight coefficient, a true SOC value of the battery system is determined.

[0018] In combination with the first aspect, in one embodiment, the actual SOC value of the battery system is determined based on the average value and the first weight coefficient, and the corresponding formula is:

[0019]

[0020] Wherein, a is the actual SOC value of the battery system, b is the average value, and c is the first weight coefficient.

[0021] In combination with the first aspect, in one embodiment, the integrating the true SOC values ​​of all branches to determine the true SOC value of the battery system includes:

[0022] In the discharging state, when the minimum value of the actual SOC values ​​of all branches is greater than or equal to the third threshold, the following steps are performed:

[0023] Determine the average value of the actual SOC values ​​of all branches;

[0024] From the actual SOC values ​​of all branches, subtract the two smaller SOC values ​​and take the absolute value to obtain the second weight coefficient;

[0025] Based on the average value and the second weight coefficient, a true SOC value of the battery system is determined.

[0026] In combination with the first aspect, in one embodiment, the actual SOC value of the battery system is determined based on the average value and the second weight coefficient, and the corresponding formula is:

[0027]

[0028] Wherein, a is the actual SOC value of the battery system, b is the average value, and d is the second weight coefficient.

[0029] In combination with the first aspect, in one embodiment, determining the SOC catch-up value includes:

[0030] Get the maximum pursuit magnification, minimum pursuit magnification and pursuit rate coefficient;

[0031] Based on the maximum catch-up magnification, the catch-up rate coefficient and the difference, the SOC catch-up value is determined, and the corresponding formula is:

[0032]

[0033] beilv=MAX(beilv,MIN_SULV);

[0034] Among them, beilv is the SOC catch-up value, MAX_SULV is the maximum catch-up rate, MIN_SULV is the minimum catch-up rate, deltaSOC_Start is the catch-up rate coefficient, and deltaSOC is the difference.

[0035] In combination with the first aspect, in one embodiment, the displayed SOC value of the battery system is corrected based on the catch-up rate coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system, and the corresponding formula is:

[0036] S0C_Display=SOC_Display+beilv*TIME;

[0037] Among them, SOC_Display' is the displayed SOC value of the battery system after correction, SOC_Display is the displayed SOC value of the battery system, beilv is the SOC catch-up value, and TIME is the catch-up rate coefficient.

[0038] In a second aspect, an embodiment of the present application provides an SOC calculation device for a multi-branch battery system, the SOC calculation device for the multi-branch battery system comprising:

[0039] The first calculation module is used to calculate the real SOC value of each branch;

[0040] The first determination module is used to determine the actual SOC value of the battery system by integrating the actual SOC values ​​of all branches;

[0041] A second calculation module is used to subtract the actual SOC value of the battery system from the displayed SOC value of the battery system and take the absolute value to obtain a difference;

[0042] a second determining module, configured to determine an SOC catching-up value when the difference is greater than a first threshold;

[0043] a correction module, configured to correct a displayed SOC value of the battery system based on a catch-up rate coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system;

[0044] The updating module is used to update the displayed SOC value of the battery system to the corrected displayed SOC value of the battery system.

[0045] In a third aspect, an embodiment of the present application provides an SOC calculation device for a multi-branch battery system, wherein the SOC calculation device for the multi-branch battery system includes a processor, a memory, and an SOC calculation program for the multi-branch battery system stored in the memory and executable by the processor, wherein when the SOC calculation program for the multi-branch battery system is executed by the processor, the steps of the SOC calculation method for the multi-branch battery system as described in any one of the first aspects are implemented.

[0046] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which is stored an SOC calculation program for a multi-branch battery system, wherein when the SOC calculation program for the multi-branch battery system is executed by a processor, the steps of the SOC calculation method for a multi-branch battery system as described in any one of the first aspects are implemented.

[0047] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0048] By calculating the true SOC value of each branch; then combining the true SOC values ​​of all branches to determine the true SOC value of the battery system; subtracting the true SOC value of the battery system from the displayed SOC value of the battery system and taking the absolute value to obtain a difference; further determining the SOC catch-up value when the difference is greater than a first threshold; correcting the displayed SOC value of the battery system based on the catch-up multiplier coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system; then updating the displayed SOC value of the battery system to the corrected displayed SOC value of the battery system, thereby reducing the computational workload and improving the credibility and accuracy of the displayed SOC of the battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a flow chart of a first embodiment of a method for calculating the SOC of a multi-branch battery system of the present application;

[0050] Figure 2 A schematic diagram of SOC fitting for a multi-branch battery system according to one embodiment of the present application;

[0051] Figure 3 A schematic diagram of a battery system display SOC catching up with the actual SOC provided by one embodiment of the present application;

[0052] Figure 4 A schematic diagram of a battery system display SOC catching up with the actual SOC according to one embodiment of the present application;

[0053] Figure 5 This is a functional module diagram of an embodiment of an SOC calculation device for a multi-branch battery system of the present application;

[0054] Figure 6 This is a schematic diagram of the hardware structure of the SOC calculation device of the multi-branch battery system involved in the embodiment of the present application. DETAILED DESCRIPTION

[0055] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0056] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0057] In a first aspect, an embodiment of the present application provides a method for calculating the SOC of a multi-branch battery system.

[0058] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the SOC calculation method for a multi-branch battery system of this application. Figure 1 As shown, the SOC calculation method of the multi-branch battery system includes:

[0059] Step 110: Calculate the actual SOC value of each branch;

[0060] In specific implementation, the current of each branch is obtained from the independent current sensor installed in each branch, and then the current of each branch is integrated by ampere-hour, corrected by OCV and corrected by Kalman filter to obtain the true SOC value of each branch.

[0061] It should be noted that only the actual SOC value of the branch that is normally connected to high voltage is calculated, and the branch that is not connected to high voltage is not included in the calculation. Among them, the branch that is not connected to high voltage refers to the fault branch that cannot participate in charging or discharging due to the MSD being unplugged or the high voltage circuit of the branch being broken.

[0062] Step 120: Determine the actual SOC value of the battery system by integrating the actual SOC values ​​of all branches;

[0063] After the actual SOC value of each branch is updated, the actual SOC value of the battery system must be updated simultaneously. The calculation of the actual SOC value of the battery system is divided into charging and discharging conditions. In charging conditions, the actual SOC value of the battery system is calculated by combining the actual SOC values ​​of all branches; in discharging conditions, the actual SOC value of the battery system is calculated by combining the actual SOC values ​​of all branches. The charging condition refers to the plug-in state, and the discharging condition refers to the driving state.

[0064] Step 130: Subtract the actual SOC value of the battery system from the displayed SOC value of the battery system and take the absolute value to obtain a difference;

[0065] In specific implementation, the actual SOC value of the battery system and the displayed SOC value of the battery system are subtracted and the absolute value is taken to obtain the difference, so as to judge whether the displayed SOC value of the battery system needs to catch up with the actual SOC value of the battery system through the difference.

[0066] Step 140: When the difference is greater than a first threshold, determine an SOC catch-up value;

[0067] It should be noted that the actual SOC value of the battery system needs to be updated during each power-on cycle. When the actual SOC value of the battery system is updated and the difference is greater than a first threshold, an SOC catch-up value needs to be determined. The displayed SOC of the battery system will catch up with the actual SOC of the battery system, gradually approaching the actual SOC. During this process, the actual SOC of the battery system is allowed to jump, but the displayed SOC of the battery system is not allowed to jump. The SOC is stored between intervals and before powering down and sleeping, and can be read again after powering up again.

[0068] It can be understood that when the difference is less than or equal to the first threshold, it means that the gap between the displayed SOC value and the actual SOC value of the battery system can be ignored. It can be understood that the SOC catch-up value determined at this time is 1, that is, no catching-up is required.

[0069] When the difference is greater than a first threshold, a pre-defined catch-up strategy is used to calculate based on a first parameter to determine the SOC catch-up value. The first parameter includes, but is not limited to, a maximum catch-up ratio, a minimum catch-up ratio, and a catch-up rate coefficient. The value of the first parameter in this application is flexibly calibrated based on actual conditions and is not specifically limited in this application.

[0070] Step 150: Correcting the displayed SOC value of the battery system based on the catch-up rate coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system;

[0071] In a specific implementation, after determining the SOC catch-up value, the displayed SOC value of the battery system is corrected based on the catch-up rate coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system. It should be noted that in the present application, the displayed SOC value of the battery system is corrected by only calculating the true SOC of each branch, and it is not necessary to calculate the displayed SOC of each branch, thereby reducing the computational workload.

[0072] The process of determining the displayed SOC value of the battery system in this application integrates all branches and is not based on only one branch, which can improve the credibility and accuracy of the displayed SOC of the entire battery system.

[0073] Furthermore, in one embodiment, the displayed SOC value of the battery system is corrected based on the catch-up rate coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system, and the corresponding formula is:

[0074] S0C_Display=SOC__Display+beil*TIME;

[0075] Among them, SOC_Display' is the displayed SOC value of the battery system after correction, SOC_Display is the displayed SOC value of the battery system, beilv is the SOC catch-up value, and TIME is the catch-up rate coefficient.

[0076] The catch-up multiplier is also pre-calibrated in the program and can be re-calibrated by the host computer. For example, TIME=0.95.

[0077] In specific implementation, during each power-on cycle, the actual SOC value of the battery system is updated according to step 230 or step 330; the currently stored displayed SOC value of the battery system is read; then, the value of the relevant first parameter is obtained, and the SOC catch-up value is determined using the formula described above. It will be understood that the currently stored displayed SOC value of the battery system is the value recorded during the previous power-on cycle.

[0078] Furthermore, in each power-on cycle, the displayed SOC value of the battery system is corrected using the above formula, so that the gap between the displayed SOC value of the battery system and the actual SOC value of the battery system is continuously reduced, thereby achieving efficient catching up with the actual SOC value of the battery system.

[0079] For example, if SOC_Display = 10, SOC_Real = 20, TIME = 0.95, and beil = 11.11, the correction formula above yields SOC_Display' = 10 + 11.11 * 0.95 = 20.55. This shows that the initial difference between the battery system's displayed SOC value of 10 and its actual SOC value of 20 was 10. After correction, the difference between the battery system's displayed SOC value of 20.55 and its actual SOC value of 20 is reduced to 0.55, a significantly narrowed difference.

[0080] In this embodiment, a formula for correcting the displayed SOC value of the battery system based on the catch-up rate coefficient and the SOC catch-up value is described, and the catch-up efficiency can be improved by obtaining the corrected displayed SOC value of the battery system.

[0081] Step 160: Update the displayed SOC value of the battery system to the corrected displayed SOC value of the battery system.

[0082] Furthermore, after obtaining the corrected displayed SOC value of the battery system, since the displayed SOC of the battery system is not allowed to jump during the calibration process, the displayed SOC value of the battery system is updated to the corrected displayed SOC value of the battery system during the interval period and before powering off and sleeping, and stored. The displayed SOC value of the battery system read after powering on again is the corrected displayed SOC value of the battery system.

[0083] In this embodiment, the real SOC value of each branch is calculated; then the real SOC value of all branches is combined to determine the real SOC value of the battery system; the real SOC value of the battery system and the displayed SOC value of the battery system are subtracted and the absolute value is taken to obtain a difference; further, when the difference is greater than a first threshold, the SOC catch-up value is determined; the displayed SOC value of the battery system is corrected based on the catch-up multiplier coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system; then the displayed SOC value of the battery system is updated to the corrected displayed SOC value of the battery system, thereby reducing the calculation workload and improving the credibility and accuracy of the displayed SOC of the battery system.

[0084] Furthermore, in one embodiment, the integrating the actual SOC values ​​of all branches to determine the actual SOC value of the battery system includes:

[0085] In the charging state, when the maximum value of the actual SOC values ​​of all branches is greater than or equal to a second threshold, the actual SOC value of the battery system is equal to the maximum value. Exemplarily, the second threshold is 90%.

[0086] In the charging state, when the maximum value of the actual SOC values ​​of all branches is less than the second threshold, the following steps are performed:

[0087] Step 210: Determine the average value of the actual SOC values ​​of all branches;

[0088] The actual SOC values ​​of all branches are averaged to obtain the average value.

[0089] Step 220: From the actual SOC values ​​of all branches, subtract the two SOC values ​​with larger values ​​and take the absolute value to obtain a first weight coefficient;

[0090] In specific implementation, the actual SOC values ​​of all branches can be sorted according to numerical values, and then two SOC values ​​with larger numerical values ​​are selected. The two selected SOC values ​​are subtracted and the absolute value is taken to obtain the first weight coefficient.

[0091] Step 230: Determine a true SOC value of the battery system based on the average value and the first weight coefficient.

[0092] Under charging conditions, because the actual SOC value of the battery system will tend to the branch with a higher SOC value, the actual SOC value of the battery system is determined based on the average value and the first weight coefficient. In this way, the jump amplitude when reaching the full charge calibration point during the charging process is relatively low, which provides a better visual experience for the entire charging process.

[0093] It is understood that during full charge calibration, at the end of charging, when one of the branches reaches the full charge condition, the SOC of all branches is calibrated to 100%. The battery system's actual SOC and displayed SOC are simultaneously calibrated to 100% and stored before the BMS is powered off. The full charge condition refers to the cell voltage reaching the cutoff voltage or the total voltage exceeding the cell voltage multiplied by the number of battery strings.

[0094] Furthermore, in one embodiment, the actual SOC value of the battery system is determined based on the average value and the first weight coefficient, and the corresponding formula is:

[0095]

[0096] Wherein, a is the actual SOC value of the battery system, b is the average value, and c is the first weight coefficient.

[0097] In this embodiment, in the charging state, when the maximum value of the real SOC values ​​of all branches is less than the second threshold value, the following steps are performed: determining the average value of the real SOC values ​​of all branches; subtracting the two SOC values ​​with larger values ​​from the real SOC values ​​of all branches and taking the absolute value to obtain a first weight coefficient; based on the average value and the first weight coefficient, determining the real SOC value of the battery system, so that the jump amplitude when reaching the full charge calibration point during the charging process is relatively low, thereby improving the visual experience of the entire charging process.

[0098] Furthermore, in one embodiment, the integrating the actual SOC values ​​of all branches to determine the actual SOC value of the battery system includes:

[0099] In the discharge state, when the minimum value of the actual SOC values ​​of all branches is less than a third threshold, it is determined that the actual SOC value of the battery system is equal to the minimum value. Exemplarily, the third threshold is 20%.

[0100] In the discharging state, when the minimum value of the actual SOC values ​​of all branches is greater than or equal to the third threshold, the following steps are performed:

[0101] Step 310: Determine the average value of the actual SOC values ​​of all branches;

[0102] The actual SOC values ​​of all branches are averaged to obtain the average value.

[0103] Step 320: From the actual SOC values ​​of all branches, subtract the two smaller SOC values ​​and take the absolute value to obtain a second weight coefficient;

[0104] In specific implementation, the real SOC values ​​of all branches can be sorted according to numerical values, and then two SOC values ​​with smaller numerical values ​​are selected. The two selected SOC values ​​are subtracted and the absolute value is taken to obtain the second weight coefficient.

[0105] Step 330: Determine a true SOC value of the battery system based on the average value and the second weight coefficient.

[0106] During discharge conditions, because the SOC value of the battery system tends to favor the branch with a lower SOC value, the actual SOC value of the battery system is determined based on the average value and the second weight coefficient. This better matches the available power during actual use. When the SOC value reaches below the third threshold, the fault alarm value can be triggered more quickly to prevent over-discharge.

[0107] Furthermore, in one embodiment, the actual SOC value of the battery system is determined based on the average value and the second weight coefficient, and the corresponding formula is:

[0108]

[0109] Wherein, a is the actual SOC value of the battery system, b is the average value, and d is the second weight coefficient.

[0110] In this embodiment, in the discharge state, when the minimum value of the true SOC values ​​of all branches is greater than or equal to the third threshold value, the following steps are performed: determining the average value of the true SOC values ​​of all branches; subtracting the two SOC values ​​with smaller values ​​from the true SOC values ​​of all branches and taking the absolute value to obtain a second weight coefficient; based on the average value and the second weight coefficient, determining the true SOC value of the battery system, so that the true SOC value of the battery system is more closely matched with the available power during actual use. When it reaches below the third threshold value, the fault alarm value can be triggered more quickly to prevent over-discharge.

[0111] Furthermore, in one embodiment, determining the SOC catch-up value includes:

[0112] Step 410: Obtain the maximum pursuit magnification, the minimum pursuit magnification, and the pursuit rate coefficient;

[0113] Among them, the values ​​of the maximum pursuit ratio, minimum pursuit ratio and pursuit rate coefficient are all pre-calibrated in the program and can also be recalibrated by the host computer.

[0114] Step 420: Determine an SOC catch-up value based on the maximum catch-up magnification, the catch-up rate coefficient, and the difference. The corresponding formula is:

[0115]

[0116] beilv=MAX(beilv,MIN_SULV);

[0117] Among them, beilv is the SOC catch-up value, MAX_SULV is the maximum catch-up rate, MIN_SULV is the minimum catch-up rate, deltaSOC_Start is the catch-up rate coefficient, and deltaSOC is the difference.

[0118] Setting beilv to the maximum value of beilv and MIN_SULV is to improve the catching-up efficiency, otherwise there is a risk of not being able to catch up.

[0119] For example, the displayed SOC value of the battery system is 10, that is, SOC_Display=10; the actual SOC value of the battery system is 20, that is, SOC_Real=20; the maximum catch-up ratio is 10, that is, MAX_SULV=10; the minimum catch-up ratio is 2, that is, MIN_SULV=2; the catch-up rate coefficient is 9, that is, deltaSOC_Start=9, 1≤deltaSOC_Start<10; the difference deltaSOC is equal to 10, then the SOC catch-up value determined by the above formula is 10*10 / 9=11.11.

[0120] In this embodiment, the maximum catch-up ratio, the minimum catch-up ratio and the catch-up rate coefficient are obtained, and then the SOC catch-up value is determined based on the maximum catch-up ratio, the catch-up rate coefficient and the difference. This describes how to determine the SOC catch-up value. The SOC catch-up value can be obtained through simple numerical calculations, which can improve calculation efficiency.

[0121] In order to verify the effectiveness of the SOC calculation method of the multi-branch battery system provided by this application, an experiment was conducted in the simulation test software MATLAB. Figure 2 This is a schematic diagram of SOC fitting of a multi-branch battery system provided by one embodiment of the present application, where the horizontal axis is time and the vertical axis is SOC value; Figure 3 A schematic diagram of the battery system display SOC catching up with the actual SOC provided in one embodiment of the present application, wherein the horizontal axis is time and the vertical axis is SOC value. Figure 3 It can be seen that the battery system displayed SOC and the battery system real SOC eventually reach synchronous changes; Figure 4 A schematic diagram of a battery system displaying a SOC catching up with the actual SOC according to an embodiment of the present application is provided. Figure 4 It can be seen that the catching-up rate gradually decreases as the SOC difference decreases until it stabilizes.

[0122] Furthermore, the present application also provides a treatment measure for the presence of a circulation in the branch. After full charge calibration, when a circulation is detected in the branch and the circulating current is greater than the fourth threshold, the BMS does not sleep, and the branch continues to calculate and update the true SOC of the branch, and updates the true SOC of the battery system according to step 230 or step 330. The displayed SOC of the battery system remains at 100%. When the total current is greater than the fourth threshold and lasts for a preset period of time, the SOC catch-up value is determined according to the above-mentioned catch-up method, and the displayed SOC of the battery system is corrected to continuously catch up with the true SOC of the battery system, thereby preventing the displayed SOC of the battery system from being corrected from 100% downward after full charge, affecting the vehicle instrument display. Exemplarily, the fourth threshold is 5A.

[0123] When there is a circulation in the branch under other static working conditions, the actual SOC of the branch changes. According to step 230 or step 330, the actual SOC of the battery system is updated. According to the above-mentioned catch-up method, the SOC catch-up value is determined, and the displayed SOC of the battery system is corrected. When the BMS receives a power-off sleep request, if there is still a circulation, the sleep is delayed and the SOC correction is continued until the circulation is less than the fifth threshold and the sleep is entered. For example, the fifth threshold is 2A. It should be noted that the thresholds in this application can be flexibly set according to actual needs, and this application does not make specific restrictions on this.

[0124] Furthermore, according to electrical principles, when the branch cell consistency is good, when there is a pressure difference between the branches, it means that the real SOC difference between the branches is large, and there must be a circulation between the branches. On the contrary, if the real SOC difference between the branches is large, and there is no pressure difference between the branches to generate circulation, it means that there is a problem with the cell consistency. In one embodiment, when the real SOC difference between multiple branches of the battery system is too large (for example, more than 15%), and under static working conditions, there is no circulation between the branches, it is determined that the cell consistency difference between the branches is too large, and a maintenance warning reminder is triggered to prompt relevant personnel to perform battery maintenance.

[0125] In a second aspect, an embodiment of the present application further provides an SOC calculation device for a multi-branch battery system.

[0126] In one embodiment, referring to Figure 5 , Figure 5 This is a functional module diagram of an embodiment of the SOC calculation device for a multi-branch battery system of the present application. Figure 5 As shown, the SOC calculation device 500 of the multi-branch battery system includes:

[0127] A first calculation module 510 is used to calculate the actual SOC value of each branch;

[0128] A first determination module 520 is configured to determine a true SOC value of the battery system by integrating the true SOC values ​​of all branches;

[0129] A second calculation module 530 is configured to subtract the actual SOC value of the battery system from the displayed SOC value of the battery system and take the absolute value to obtain a difference;

[0130] a second determining module 540 , configured to determine an SOC catching-up value when the difference is greater than a first threshold;

[0131] a correction module 550, configured to correct the displayed SOC value of the battery system based on the catch-up rate coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system;

[0132] The updating module 560 is configured to update the displayed SOC value of the battery system to a corrected displayed SOC value of the battery system.

[0133] Furthermore, in one embodiment, the first determining module is specifically configured to:

[0134] In the charging state, when the maximum value of the actual SOC values ​​of all branches is less than the second threshold, the following steps are performed:

[0135] Determine the average value of the actual SOC values ​​of all branches;

[0136] From the actual SOC values ​​of all branches, subtract the two SOC values ​​with larger values ​​and take the absolute value to obtain the first weight coefficient;

[0137] Based on the average value and the first weight coefficient, a true SOC value of the battery system is determined.

[0138] Furthermore, in one embodiment, the first determination module is specifically configured to determine the actual SOC value of the battery system according to the following formula:

[0139]

[0140] Wherein, a is the actual SOC value of the battery system, b is the average value, and c is the first weight coefficient.

[0141] Furthermore, in one embodiment, the first determining module is specifically configured to:

[0142] In the discharging state, when the minimum value of the actual SOC values ​​of all branches is greater than or equal to the third threshold, the following steps are performed:

[0143] Determine the average value of the actual SOC values ​​of all branches;

[0144] From the actual SOC values ​​of all branches, subtract the two smaller SOC values ​​and take the absolute value to obtain the second weight coefficient;

[0145] Based on the average value and the second weight coefficient, a true SOC value of the battery system is determined.

[0146] Furthermore, in one embodiment, the first determination module is specifically configured to determine the actual SOC value of the battery system according to the following formula:

[0147]

[0148] Wherein, a is the actual SOC value of the battery system, b is the average value, and d is the second weight coefficient.

[0149] Furthermore, in one embodiment, the second determining module is specifically configured to:

[0150] Get the maximum pursuit magnification, minimum pursuit magnification and pursuit rate coefficient;

[0151] Based on the maximum catch-up magnification, the catch-up rate coefficient and the difference, the SOC catch-up value is determined, and the corresponding formula is:

[0152]

[0153] beilv=MAX(beilv,MIN_SULV);

[0154] Among them, beilv is the SOC catch-up value, MAX_SULV is the maximum catch-up rate, MIN_SULV is the minimum catch-up rate, deltaSOC_Start is the catch-up rate coefficient, and deltaSOC is the difference.

[0155] Furthermore, in one embodiment, the correction module is used to correct the displayed SOC value of the battery system according to the following formula:

[0156] S0C_Display=SOC_Display+beil*TIME;

[0157] Among them, SOC_Display' is the displayed SOC value of the battery system after correction, SOC_Display is the displayed SOC value of the battery system, beilv is the SOC catch-up value, and TIME is the catch-up rate coefficient.

[0158] Among them, the functional implementation of each module in the above-mentioned SOC calculation device for a multi-branch battery system corresponds to the various steps in the above-mentioned SOC calculation method embodiment for a multi-branch battery system, and their functions and implementation processes are not repeated here one by one.

[0159] In a third aspect, an embodiment of the present application provides a SOC calculation device for a multi-branch battery system. The SOC calculation device for the multi-branch battery system may be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0160] Reference Figure 6 , Figure 6 Schematic diagram of the hardware structure of the SOC calculation device of the multi-branch battery system involved in the embodiment of the present application. In the embodiment of the present application, the SOC calculation device of the multi-branch battery system may include a processor, a memory, a communication interface and a communication bus.

[0161] The communication bus may be of any type and is used to interconnect the processor, memory, and communication interface.

[0162] Communication interfaces include input / output (I / O) interfaces, physical interfaces, and logical interfaces, used to interconnect components within the SOC computing device of a multi-branch battery system, as well as interfaces used to interconnect the SOC computing device of a multi-branch battery system with other devices (e.g., other computing devices or user devices). Physical interfaces can include Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user devices can include displays, keyboards, etc.

[0163] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0164] The processor may be a general-purpose processor that can call the SOC calculation program for the multi-branch battery system stored in the memory and execute the SOC calculation method for the multi-branch battery system provided in the embodiment of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the SOC calculation program for the multi-branch battery system is called can refer to the various embodiments of the SOC calculation method for the multi-branch battery system of the present application, and will not be repeated here.

[0165] Those skilled in the art will understand that Figure 6 The hardware structure shown in the figure does not constitute a limitation to the present application and may include more or fewer components than shown in the figure, or a combination of certain components, or a different arrangement of components.

[0166] In a fourth aspect, an embodiment of the present application also provides a computer-readable storage medium.

[0167] The computer-readable storage medium of the present application stores an SOC calculation program for a multi-branch battery system, wherein when the SOC calculation program for the multi-branch battery system is executed by a processor, the steps of the SOC calculation method for the multi-branch battery system as described above are implemented.

[0168] Among them, the method implemented when the SOC calculation program of the multi-branch battery system is executed can refer to the various embodiments of the SOC calculation method of the multi-branch battery system of the present application, and will not be repeated here.

[0169] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0170] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0171] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0172] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0173] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0174] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0175] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for calculating the SOC of a multi-branch battery system, characterized in that: The SOC method of the multi-branch battery system includes: Calculate the actual SOC value of each branch; The actual SOC value of the battery system is determined by integrating the actual SOC values ​​of all branches; Subtract the actual SOC value of the battery system from the displayed SOC value of the battery system and take the absolute value to obtain the difference; When the difference is greater than a first threshold, determining an SOC catch-up value; Correcting the displayed SOC value of the battery system based on the catch-up rate coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system; Updating the displayed SOC value of the battery system to the corrected displayed SOC value of the battery system; The determining of the SOC catch-up value includes: Get the maximum pursuit magnification, minimum pursuit magnification and pursuit rate coefficient; Based on the maximum catch-up magnification, the catch-up rate coefficient and the difference, the SOC catch-up value is determined, and the corresponding formula is: ; ; Where, beilv is the SOC catch-up value, MAX_SULV is the maximum catch-up rate, MIN_SULV is the minimum catch-up rate, deltaSOC_Start is the catch-up rate coefficient, and deltaSOC is the difference value; The displayed SOC value of the battery system is corrected based on the catch-up rate coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system. The corresponding formula is: ; Among them, SOC_Display' is the displayed SOC value of the battery system after correction, SOC_Display is the displayed SOC value of the battery system, beilv is the SOC catch-up value, and TIME is the catch-up rate coefficient.

2. The SOC calculation method of a multi-branch battery system according to claim 1, wherein: The method of integrating the actual SOC values ​​of all branches to determine the actual SOC value of the battery system includes: In the charging state, when the maximum value of the actual SOC values ​​of all branches is less than the second threshold, the following steps are performed: Determine the average value of the actual SOC values ​​of all branches; From the actual SOC values ​​of all branches, subtract the two SOC values ​​with larger values ​​and take the absolute value to obtain the first weight coefficient; Based on the average value and the first weight coefficient, a true SOC value of the battery system is determined.

3. The SOC calculation method of a multi-branch battery system according to claim 2, wherein: The actual SOC value of the battery system is determined based on the average value and the first weight coefficient, and the corresponding formula is: ； Wherein, a is the actual SOC value of the battery system, b is the average value, and c is the first weight coefficient.

4. The SOC calculation method of a multi-branch battery system according to claim 1, wherein: The method of integrating the actual SOC values ​​of all branches to determine the actual SOC value of the battery system includes: In the discharging state, when the minimum value of the actual SOC values ​​of all branches is greater than or equal to the third threshold, the following steps are performed: Determine the average value of the actual SOC values ​​of all branches; From the actual SOC values ​​of all branches, subtract the two smaller SOC values ​​and take the absolute value to obtain the second weight coefficient; Based on the average value and the second weight coefficient, a true SOC value of the battery system is determined.

5. The SOC calculation method of a multi-branch battery system according to claim 4, wherein: The actual SOC value of the battery system is determined based on the average value and the second weight coefficient, and the corresponding formula is: ； Wherein, a is the actual SOC value of the battery system, b is the average value, and d is the second weight coefficient.

6. A SOC calculation device for a multi-branch battery system, characterized in that: The SOC calculation device of the multi-branch battery system includes: The first calculation module is used to calculate the real SOC value of each branch; The first determination module is used to determine the actual SOC value of the battery system by integrating the actual SOC values ​​of all branches; A second calculation module is used to subtract the actual SOC value of the battery system from the displayed SOC value of the battery system and take the absolute value to obtain a difference; a second determining module, configured to determine an SOC catching-up value when the difference is greater than a first threshold; a correction module, configured to correct a displayed SOC value of the battery system based on a catch-up rate coefficient and the SOC catch-up value to obtain a corrected displayed SOC value of the battery system; An updating module, configured to update a displayed SOC value of the battery system to a corrected displayed SOC value of the battery system; The second determining module is specifically configured to: Get the maximum pursuit magnification, minimum pursuit magnification and pursuit rate coefficient; Based on the maximum catch-up magnification, the catch-up rate coefficient and the difference, the SOC catch-up value is determined, and the corresponding formula is: ; ; Where, beilv is the SOC catch-up value, MAX_SULV is the maximum catch-up rate, MIN_SULV is the minimum catch-up rate, deltaSOC_Start is the catch-up rate coefficient, and deltaSOC is the difference value; The correction module is used to correct the displayed SOC value of the battery system according to the formula, and the corresponding formula is: ; Among them, SOC_Display' is the displayed SOC value of the battery system after correction, SOC_Display is the displayed SOC value of the battery system, beilv is the SOC catch-up value, and TIME is the catch-up rate coefficient.

7. A SOC calculation device for a multi-branch battery system, characterized in that: The SOC calculation device of the multi-branch battery system includes a processor, a memory, and an SOC calculation program for the multi-branch battery system stored on the memory and executable by the processor, wherein when the SOC calculation program for the multi-branch battery system is executed by the processor, the steps of the SOC calculation method for the multi-branch battery system as described in any one of claims 1 to 5 are implemented.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium stores an SOC calculation program for a multi-branch battery system, wherein when the SOC calculation program for the multi-branch battery system is executed by a processor, the steps of the SOC calculation method for a multi-branch battery system according to any one of claims 1 to 5 are implemented.

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