Balancing control method and device of lithium iron phosphate battery, electronic equipment and medium

Abstract

The invention relates to a balance control method and device for a lithium iron phosphate battery, electronic equipment and a medium, and the method comprises the steps: detecting whether the lithium iron phosphate battery is in a battery control mode or not according to the single voltage of the lithium iron phosphate battery; determining at least one single residual electric quantity deviation identification strategy when the lithium iron phosphate battery is in a charging working condition, a discharging working condition or a standing working condition; and calculating the residual electric quantity deviation of the single cell of the lithium iron phosphate battery, generating a control action of the equalization state of at least one lithium iron phosphate battery according to the residual electric quantity deviation of the single cell of the lithium iron phosphate battery, and executing the control action of the equalization state of the at least one lithium iron phosphate battery to generate an equalization control result. Therefore, the problems that the SOC difference between the battery cells is difficult to recognize in the related technology, the SOC of each single battery cell is difficult to calculate due to the fact that the voltage plateau period of the lithium iron phosphate battery is very smooth and wide, and the equalization effect is poor are solved.

Description

Technical Field

[0001] The present application relates to the field of battery control technology, and in particular to a method, device, electronic equipment and medium for balancing control of a lithium iron phosphate battery. Background Art

[0002] At present, the self-discharge rates of each single cell in the battery system are inconsistent, resulting in inconsistent remaining power (SOC, State of Charge) of each single cell. If there is no effective balancing control, the difference in the remaining power of each single cell will become larger and larger, eventually resulting in a reduction in the available power of the battery system and a reduction in the vehicle's cruising range.

[0003] In the related art, when the battery voltage is greater than or equal to a preset voltage, the charging energy of the battery cell can be calculated to obtain the target balancing amount of the battery cell, and when the battery voltage is less than the preset voltage, the battery pack is energy balanced according to the target balancing amount.

[0004] However, related technologies have difficulty identifying SOC differences between battery cells, and because the voltage plateau period of lithium iron phosphate batteries is very flat and wide, it is difficult to calculate the SOC of each single battery cell, resulting in poor balancing effect, which urgently needs to be improved. Summary of the invention

[0005] The present application provides a balance control method, device, electronic device and medium for a lithium iron phosphate battery to solve the problems that the related technology is difficult to identify the SOC difference between battery cells, and because the voltage plateau period of the lithium iron phosphate battery is very flat and wide, it is difficult to calculate the SOC of each single battery cell, resulting in poor balance effect.

[0006] In a first aspect, an embodiment of the present application provides a method for controlling a lithium iron phosphate battery in balance, comprising the following steps: detecting whether the lithium iron phosphate battery is in a battery control mode according to the single cell voltage of the lithium iron phosphate battery; determining, when the lithium iron phosphate battery is in the battery control mode, at least one single cell residual power deviation identification strategy when the lithium iron phosphate battery is in a charging condition, a discharging condition or a static condition, respectively; calculating the single cell residual power deviation of the lithium iron phosphate battery according to the at least one single cell residual power deviation identification strategy, generating at least one control action for the balanced state of the lithium iron phosphate battery according to the single cell residual power deviation of the lithium iron phosphate battery, and executing the at least one control action for the balanced state of the lithium iron phosphate battery to generate a balanced control result.

[0007] Optionally, in one embodiment of the present application, the calculation of the single cell remaining power deviation of the lithium iron phosphate battery according to the at least one single cell remaining power deviation identification strategy includes: when the lithium iron phosphate battery is in the charging condition, the single cell remaining power SOC deviation identification strategy based on the capacity increment curve is used to calculate the single cell remaining power deviation according to the correspondence between the peak voltage and the single cell remaining power during the charging process; when the lithium iron phosphate battery is in the charging condition, the single cell SOC deviation identification strategy based on the charging voltage change rate is used to determine the inflection point voltage using the characteristics of the charging terminal voltage, and the single cell remaining power deviation is calculated based on the inflection point voltage.

[0008] Optionally, in one embodiment of the present application, the calculating the single cell remaining power deviation of the lithium iron phosphate battery according to the at least one single cell remaining power deviation identification strategy also includes: when the lithium iron phosphate battery is in the discharge condition, outputting a predicted voltage of a pre-constructed battery equivalent circuit model based on a single cell SOC deviation identification strategy of a battery model; and calculating the single cell remaining power deviation based on an error between the predicted voltage and the real-time collected voltage and a Lumberg gain coefficient.

[0009] Optionally, in one embodiment of the present application, the calculation of the single cell remaining power deviation of the lithium iron phosphate battery according to the at least one single cell remaining power deviation identification strategy also includes: when the lithium iron phosphate battery is in the static working condition, a single cell SOC deviation identification strategy based on the static open circuit voltage OCV is used to calculate the static OCV according to the high-voltage standby time of the whole vehicle, the static OCVSOC that meets the first preset maximum condition, and the static OCVSOC that meets the first preset minimum condition, and the single cell remaining power deviation is calculated according to the static OCV; when the lithium iron phosphate battery is in the static working condition, a single cell SOC deviation identification strategy based on the pseudo-static OCV is used to calculate the pseudo-static OCV according to the power battery charging and discharging current, the pseudo-static OCVSOC that meets the second preset maximum condition, and the pseudo-static OCVSOC that meets the second preset minimum condition, and the single cell remaining power deviation is calculated according to the pseudo-static OCV.

[0010] Optionally, in one embodiment of the present application, the control action of executing the balanced state of at least one lithium iron phosphate battery to generate a balanced control result includes: calculating the triggering cell SOC according to the triggering characteristic cell SOC, the current characteristic cell SOC, the calculated cell SOC deviation and the cell SOC deviation before calculation to determine the final characteristic cell; determining the priority of the at least one cell remaining power deviation identification strategy according to the final characteristic cell to control the lithium iron phosphate battery to be in the balanced state according to the priority of the at least one cell remaining power deviation identification strategy to generate the balanced control result.

[0011] A second aspect of the present application provides a balancing control device for a lithium iron phosphate battery, comprising: a detection module, used to detect whether the lithium iron phosphate battery is in a battery control mode according to the single cell voltage of the lithium iron phosphate battery; a determination module, used to determine, when the lithium iron phosphate battery is in the battery control mode, at least one single cell remaining power deviation identification strategy when the lithium iron phosphate battery is in a charging condition, a discharging condition or a static condition respectively; a control module, used to calculate the single cell remaining power deviation of the lithium iron phosphate battery according to the at least one single cell remaining power deviation identification strategy, generate at least one control action for the balancing state of the lithium iron phosphate battery according to the single cell remaining power deviation of the lithium iron phosphate battery, and execute the at least one control action for the balancing state of the lithium iron phosphate battery to generate a balancing control result.

[0012] Optionally, in one embodiment of the present application, the control module includes: a first calculation unit, which is used to, when the lithium iron phosphate battery is in the charging condition, identify the single cell remaining power SOC deviation based on the capacity increment curve, and calculate the single cell remaining power deviation according to the correspondence between the peak voltage and the single cell remaining power during the charging process; a first determination unit, which is used to, when the lithium iron phosphate battery is in the charging condition, identify the single cell remaining power SOC deviation based on the charging voltage change rate, determine the inflection point voltage using the characteristics of the charging terminal voltage, and calculate the single cell remaining power deviation according to the inflection point voltage.

[0013] Optionally, in one embodiment of the present application, the control module also includes: an output unit, used to output a predicted voltage of a pre-constructed battery equivalent circuit model based on a single cell SOC deviation identification strategy of a battery model when the lithium iron phosphate battery is in the discharge condition; and a second calculation unit, used to calculate the remaining power deviation of the single cell based on the error between the predicted voltage and the real-time collected voltage and the Romberg gain coefficient.

[0014] Optionally, in one embodiment of the present application, the control module also includes: a third calculation unit, which is used to, when the lithium iron phosphate battery is in the static condition, calculate the static OCV based on the single cell SOC deviation identification strategy of the static open circuit voltage OCV, according to the high-voltage standby time of the whole vehicle, the static OCVSOC that meets the first preset maximum condition, and the static OCVSOC that meets the first preset minimum condition, and calculate the remaining power deviation of the single cell according to the static OCV; a fourth calculation unit, which is used to, when the lithium iron phosphate battery is in the static condition, calculate the pseudo-static OCV based on the single cell SOC deviation identification strategy of the pseudo-static OCV, according to the power battery charging and discharging current, the pseudo-static OCVSOC that meets the second preset maximum condition, and the pseudo-static OCVSOC that meets the second preset minimum condition, and calculate the remaining power deviation of the single cell according to the pseudo-static OCV.

[0015] Optionally, in one embodiment of the present application, the control module includes: a second determination unit, used to calculate the triggering cell SOC based on the triggering characteristic cell SOC, the current characteristic cell SOC, the calculated cell SOC deviation and the cell SOC deviation before calculation, so as to determine the final characteristic cell; a generation unit, used to determine the priority of the at least one cell remaining power deviation identification strategy based on the final characteristic cell, so as to control the lithium iron phosphate battery to be in the balanced state according to the priority of the at least one cell remaining power deviation identification strategy, and generate the balanced control result.

[0016] A third aspect of 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 the processor executes the program to implement the balancing control method for a lithium iron phosphate battery as described in the above embodiment.

[0017] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned balancing control method for a lithium iron phosphate battery.

[0018] The embodiment of the present application designs a single-cell SOC deviation identification strategy based on the capacity increment curve and a single-cell SOC deviation identification strategy based on the charging voltage change rate for charging conditions, a single-cell SOC deviation identification strategy based on the battery model for discharging conditions, and a single-cell SOC deviation identification strategy based on static OCV and a single-cell SOC deviation identification strategy based on pseudo-static OCV for static conditions. According to the application priority between different single-cell SOC calculation strategies, the accuracy of calculating the single-cell SOC deviation is improved, and the control balancing effect is improved. Thus, the problems that the related technology is difficult to identify the SOC difference between the cells, and because the voltage platform period of the lithium iron phosphate battery is very gentle and wide, it is difficult to calculate the SOC of each single cell, resulting in poor balancing effect.

[0019] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0021] Figure 1 A flowchart of a method for controlling a balance of a lithium iron phosphate battery provided according to an embodiment of the present application;

[0022] Figure 2 This is a flow chart of a method for controlling a balance of a lithium iron phosphate battery according to an embodiment of the present application;

[0023] Figure 3 A schematic diagram of a single cell SOC deviation identification strategy based on a battery model according to an embodiment of the present application;

[0024] Figure 4 A schematic diagram of the structure of a balancing control device for a lithium iron phosphate battery provided according to an embodiment of the present application;

[0025] Figure 5 It is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0027] The following describes the equalization control method, device, electronic device and medium of the lithium iron phosphate battery of the embodiment of the present application with reference to the accompanying drawings. In view of the problem that the related technology mentioned in the above background technology is difficult to identify the SOC difference between the cells, and because the voltage plateau period of the lithium iron phosphate battery is very gentle and wide, it is difficult to calculate the SOC of each single cell, resulting in poor equalization effect, the present application provides a equalization control method for a lithium iron phosphate battery, in which a single cell SOC deviation identification strategy based on a capacity increment curve and a single cell SOC deviation identification strategy based on a charging voltage change rate are designed for charging conditions, a single cell SOC deviation identification strategy based on a battery model for discharging conditions, and a single cell SOC deviation identification strategy based on a static OCV and a single cell SOC deviation identification strategy based on a pseudo-static OCV for static conditions. According to the application priority between different single cell SOC calculation strategies, the accuracy of calculating the single cell SOC deviation is improved, and the equalization effect of control is improved. This solves the problem that the related technology is difficult to identify the SOC difference between battery cells, and because the voltage plateau period of the lithium iron phosphate battery is very flat and wide, it is difficult to calculate the SOC of each single battery cell, resulting in poor balancing effect.

[0028] Specifically, Figure 1 A schematic flow chart of a method for controlling a balance of a lithium iron phosphate battery provided in an embodiment of the present application.

[0029] like Figure 1 As shown, the equalization control method of the lithium iron phosphate battery includes the following steps:

[0030] In step S101 , it is detected whether the lithium iron phosphate battery is in a battery control mode according to the cell voltage of the lithium iron phosphate battery.

[0031] It can be understood that the battery control mode in the embodiment of the present application includes but is not limited to a balancing mode, a charging mode, a discharging mode, a static mode, and the like.

[0032] During the actual implementation process, the embodiment of the present application can detect whether the lithium iron phosphate battery is in the battery control mode based on the single cell voltage of the lithium iron phosphate battery, and perform targeted control when the lithium iron phosphate battery is in the battery control mode, thereby ensuring the stability and efficiency of the entire battery system, thereby improving the accuracy of calculating the single cell SOC deviation and improving the balancing effect of the control.

[0033] In step S102, when the lithium iron phosphate battery is in the battery control mode, at least one single cell remaining power deviation identification strategy is determined when the lithium iron phosphate battery is in a charging condition, a discharging condition or a stationary condition.

[0034] It can be understood that the strategy for identifying the deviation of the remaining power state of a single cell of the lithium iron phosphate battery under different working conditions (charging, discharging or standing) in the embodiment of the present application is the key to ensuring the safe and efficient operation of the battery system.

[0035] Specifically, the embodiment of the present application can determine the single cell remaining power deviation identification strategy when the lithium iron phosphate battery is in a charging condition, a discharging condition or a static condition, respectively, when the lithium iron phosphate battery is in a battery control mode, thereby achieving more accurate battery management and improving the corresponding overall performance and safety.

[0036] In step S103, the single cell remaining power deviation of the lithium iron phosphate battery is calculated according to at least one single cell remaining power deviation identification strategy, at least one lithium iron phosphate battery balancing state control action is generated according to the single cell remaining power deviation of the lithium iron phosphate battery, and at least one lithium iron phosphate battery balancing state control action is executed to generate a balancing control result.

[0037] It is understandable that the embodiments of the present application can design corresponding methods to identify the SOC deviation of single cells based on the voltage characteristics of the lithium iron phosphate battery in different usage scenarios for balanced control.

[0038] During the actual implementation process, the embodiment of the present application can calculate the single cell remaining power deviation of the lithium iron phosphate battery according to the single cell remaining power deviation identification strategy of the charging condition, the discharging condition or the static condition, generate the control action of the lithium iron phosphate battery balance state according to the single cell remaining power deviation of the lithium iron phosphate battery, and execute the control action of the lithium iron phosphate battery balance state to generate a balance control result, so as to select the most appropriate single cell SOC deviation identification strategy according to the current working condition of the battery (charging, discharging or static) to improve the balance effect.

[0039] Optionally, in one embodiment of the present application, the single cell remaining power deviation of the lithium iron phosphate battery is calculated according to at least one single cell remaining power deviation identification strategy, including: when the lithium iron phosphate battery is in a charging condition, a single cell remaining power SOC deviation identification strategy based on the capacity increment curve is used to calculate the single cell remaining power deviation according to the correspondence between the peak voltage and the single cell remaining power during the charging process; when the lithium iron phosphate battery is in a charging condition, a single cell SOC deviation identification strategy based on the charging voltage change rate is used to determine the inflection point voltage using the characteristics of the charging terminal voltage, and calculate the single cell remaining power deviation based on the inflection point voltage.

[0040] It can be understood that the two main single cell remaining power deviation identification strategies in the embodiments of the present application - the method based on the capacity increment curve (ICA, Incremental Capacity Analysis) and the method based on the charging voltage change rate, respectively calculate the SOC deviation of the single cell in different ways.

[0041] In the actual implementation process, the embodiment of the present application can identify the single cell SOC deviation based on the capacity increment curve when the lithium iron phosphate battery is in a charging condition, adopt the capacity increment curve analysis, and identify the single cell SOC deviation according to the corresponding relationship between the ΔQ / ΔV peak voltage and the single cell SOC during the charging process, and calculate the single cell remaining power deviation, such as Figure 2 If all monomer SOCs are obtained through the above calculation, the calculated monomer SOC is output and the characteristic monomer SOC is set equal to 107.

[0042] It should be noted that the characteristic cell SOC is the n+1th cell, where n is the number of battery packs in series.

[0043] Furthermore, in the embodiment of the present application, when the lithium iron phosphate battery is in a charging condition, a single-cell SOC deviation identification strategy based on the charging voltage change rate is used to find the inflection point voltage of the plateau period according to the characteristics of the rapid growth of the charging terminal voltage, and the single-cell SOC reaching the inflection point is calculated according to the SOCref corresponding to the inflection point voltage. The specific calculation process is as follows:

[0044] 1) The rate of change of the cell voltage (dV / dt) is greater than or equal to 0.0002V (calibrated value); (dV = V10-V1, V10 is the average value of the highest cell voltage within 200ms recorded from the n+10th second, and V1 is the average value of the cell voltage within 200ms recorded from the nsth second). After dV / dt is turned on, the current charging will not be exited;

[0045] 2) The voltage of the single cell is greater than the value (calibrated value) of the temperature of the single cell in Table 1;

[0046] 3) The power battery charging current is less than the single cell temperature lookup table 2 value (calibrated value);

[0047] When the above conditions are met, the inflection point voltage is identified, and the single cell SOC is calculated as SOCref (calibrated value: 98%). After the inflection point, each single cell SOC = SOCref + ∫Idt; when charging is completed, the single cell SOC that has not reached the inflection point is assigned SOCref.

[0048] Since temperature has a significant impact on charging voltage polarization and the temperature of each single cell cannot be accurately obtained, it is necessary to limit the deviation between the maximum temperature of the single cell and the minimum temperature of the single cell to be less than or equal to 5°C. Once this condition is met, the above single cell SOC calculation is considered valid and output.

[0049] If all monomer SOCs reach the inflection point, the characteristic monomer SOC is set equal to 108; otherwise, the characteristic monomer SOC is set equal to 118.

[0050] Table 1

[0051] Temperature ℃ -20 -10 -5 0 10 15 25 30 40 Voltage V 3.57 3.51 3.46 3.46 3.41 3.41 3.41 3.41 3.4

[0052] Table 2

[0053] Temperature ℃ -10 -5 0 5 10 15 20 25 30 35 40 Current A -6 -13 -19 -20 -24 -27 -35 -56 -56 -56 -56

[0054] Optionally, in one embodiment of the present application, the single cell remaining power deviation of the lithium iron phosphate battery is calculated according to at least one single cell remaining power deviation identification strategy, and also includes: when the lithium iron phosphate battery is in a discharge condition, based on the single cell SOC deviation identification strategy of the battery model, outputting the predicted voltage of the pre-constructed battery equivalent circuit model; calculating the single cell remaining power deviation according to the error between the predicted voltage and the real-time collected voltage and the Romberg gain coefficient.

[0055] It is understandable that the embodiment of the present application can construct an equivalent circuit model that can accurately describe the behavior of the lithium iron phosphate battery based on the physical and chemical properties of the lithium iron phosphate battery.

[0056] In the actual implementation process, the embodiment of the present application can establish a battery equivalent circuit model based on the single-cell SOC deviation identification strategy of the battery model when the lithium iron phosphate battery is in a discharge condition, use the forgetting factor recursive least squares method to identify the model parameters in real time online, and calculate the SOC of each single cell online through the Luenberger observer based on the error between the model predicted voltage and the real-time collected voltage, thereby realizing effective estimation of the SOC deviation of the single cell.

[0057] like Figure 3 As shown, based on the error between the predicted voltage of the battery model and the actual collected voltage, combined with the Lumberg gain coefficient K (calibrated value), the current SOC of each cell is calculated online in real time. The expression for calculating the SOC of each cell using the Lumberg observer is as follows:

[0058] SOC k =SOC 0 +∫I*dt / C a

[0059] SOC k+1 =SOC k+K*(Vestm-Vmeas)

[0060] Vestm=U oc -U 1 -I*R 0

[0061] The battery model calculates the maximum and minimum SOC deviation: △SOC = battery model maximum SOC - battery model minimum SOC.

[0062] Sum_△SOC(k)=Sum_△SOC(k-1)+△SOC(k)

[0063] Avrg_△SOC(k)=Sum_△SOC(k) / k

[0064] k: accumulates every 1 second.

[0065] When the vehicle switches from the driving state to other states, if any of the following conditions are met, the single cell SOC calculated by the battery model is output and the characteristic single cell SOC is set equal to 109.

[0066] ① When the maximum SOC of the battery model is ≤20%, and Avrg_△SOC(k)≥the value in Table 3 of the lowest temperature of the single cell, then the single cell SOC = the single cell SOC calculated by the battery model - the value in Table 3.

[0067] ② When 20%<battery model maximum SOC≤30%, and Avrg_△SOC(k)≥the value in Table 4 of the lowest temperature of the single cell, then the single cell SOC=battery model calculated single cell SOC-the value in Table 4.

[0068] ③ When 30%<the maximum SOC of the battery model≤40%, and Avrg_△SOC(k)≥the value in Table 5 of the lowest temperature of the single cell, then the single cell SOC=the single cell SOC calculated by the battery model-the value in Table 5.

[0069] ④ When 40%<battery model maximum SOC≤50%, and Avrg_△SOC(k)≥the value in Table 6 of the lowest temperature of the single cell, then the single cell SOC=battery model calculated single cell SOC-the value in Table 6.

[0070] ⑤ When the maximum SOC of the battery model is greater than 50%, and Avrg_△SOC(k)≥the value in Table 7 of the lowest temperature of the single cell, then the single cell SOC=the single cell SOC calculated by the battery model-the value in Table 7.

[0071] Table 3

[0072] Temperature(℃) 0 15 20 25 40 SOC(pct) 5 8 7 6 6

[0073] Table 4

[0074] Temperature(℃) 0 15 20 25 40 SOC(pct) 20 5 10 8 8

[0075] Table 5

[0076] Temperature(℃) 0 15 20 25 40 SOC(pct) 25 15 5 10 10

[0077] Table 6

[0078] Temperature(℃) 0 15 20 25 40 SOC(pct) 30 20 18 15 15

[0079] Table 7

[0080] Temperature(℃) 0 15 20 25 40 SOC(pct) 40 25 20 15 15

[0081] Optionally, in one embodiment of the present application, the single cell remaining power deviation of the lithium iron phosphate battery is calculated according to at least one single cell remaining power deviation identification strategy, and also includes: when the lithium iron phosphate battery is in a static condition, a single cell SOC deviation identification strategy based on the static open circuit voltage OCV is used to calculate the static OCV according to the high-voltage standby time of the whole vehicle, the static OCVSOC that meets the first preset maximum condition, and the static OCVSOC that meets the first preset minimum condition, and the single cell remaining power deviation is calculated according to the static OCV; when the lithium iron phosphate battery is in a static condition, a single cell SOC deviation identification strategy based on pseudo-static OCV is used to calculate the pseudo-static OCV according to the power battery charging and discharging current, the pseudo-static OCVSOC that meets the second preset maximum condition, and the pseudo-static OCVSOC that meets the second preset minimum condition, and the single cell remaining power deviation is calculated according to the pseudo-static OCV.

[0082] It is understandable that, because strategies in different scenarios have different degrees of accuracy in identifying single-cell SOC deviations, the embodiments of the present application design the priority of application between different strategies to make single-cell SOC deviations more accurate, thereby further improving the balancing effect.

[0083] During the actual implementation process, the embodiment of the present application can, when the lithium iron phosphate battery is in a static condition, use a single cell SOC deviation identification strategy based on the static open circuit voltage OCV, calculate the static OCV according to the vehicle's high-voltage idle time, the static OCVSOC that meets the first preset maximum condition (i.e., static OCVSOCmax), and the static OCVSOC that meets the first preset minimum condition (i.e., static OCVSOCmin), and calculate the single cell remaining power deviation based on the static OCV.

[0084] Because the plateau of the OCV-SOC curve of lithium iron phosphate battery is very gentle, the strategy of calculating SOC by static OCV can only use the area with large slope at both ends of the OCV-SOC curve. The strategy of designing static OCV to calculate the SOC of a single cell is as follows:

[0085] (1) If (the vehicle is disconnected from high voltage and is at rest for a period of greater than or equal to 3 hours) and ((static OCVSOCmax is greater than 98.3%) and (static OCVSOCmin is greater than 98.3%)), the static OCV calculation is triggered, the characteristic single cell SOC is equal to 102, and the single cell SOC is calculated to the single cell voltage lookup table 8 value.

[0086] (2) If (the vehicle is disconnected from high voltage and is stationary for a period of greater than or equal to 3 hours) and ((static OCVSOCmax is less than 25%) and (static OCVSOCmin is less than 25%)), the static OCV calculation is triggered, the characteristic single cell SOC is equal to 102, and the single cell SOC is calculated to the single cell voltage lookup table 8 value.

[0087] (3) If (the vehicle is disconnected from high voltage and is stationary for a period of greater than or equal to 3 hours) and ((static OCVSOCmax is greater than 98.3%) and (static OCVSOCmin is less than 25%)), the static OCV calculation is triggered, the characteristic cell SOC is equal to 102, the cell SOC in the plateau period is calculated to 25%, and the cell SOC in the non-plateau period is calculated to the cell voltage lookup table 8 value.

[0088] (4) If (the vehicle is disconnected from high voltage and is stationary for a period of greater than or equal to 3 hours) and ((static OCVSOCmax is less than or equal to 98.3% and greater than or equal to 25%) and (static OCVSOCmin is less than 25%)), the static OCV calculation is triggered, the characteristic cell SOC is equal to 52, the cell SOC in the plateau period is calculated to 25%, and the cell SOC in the non-plateau period is calculated to the cell voltage lookup table 8 value.

[0089] (5) If (the vehicle is disconnected from high voltage and is stationary for a period of greater than or equal to 3 hours) and ((static OCVSOCmax is greater than 98.3%) and (static OCVSOCmin is less than or equal to 98.3% and greater than or equal to 25%)), the static OCV calculation is triggered, the characteristic cell SOC is equal to 15, the cell SOC in the plateau period is calculated to 98.3%, and the cell SOC in the non-plateau period is calculated to the cell voltage lookup table 8 value.

[0090] It should be noted that the static OCVSOCmax is equal to the maximum voltage of the single cell as shown in Table 8, and the static OCVSOCmin is equal to the minimum voltage of the single cell as shown in Table 8.

[0091] Table 8

[0092] Voltage V 2.769 3.155 3.205 3.225 3.25 3.265 ... 3.3334 3.3335 3.352 3.482 SOC% 0 5 10 15 20 25 ... 97 98 99 100

[0093] Furthermore, in the embodiment of the present application, when the lithium iron phosphate battery is in a static condition, a single cell SOC deviation identification strategy based on pseudo-static OCV is used to calculate the pseudo-static OCV according to the power battery charge and discharge current, the pseudo-static OCVSOC that meets the second preset maximum condition (i.e., pseudo-static OCVSOCmax), and the pseudo-static OCVSOC that meets the second preset minimum condition (i.e., pseudo-static OCVSOCmin), and the single cell remaining power deviation is calculated based on the pseudo-static OCV.

[0094] Similar to the strategy of calculating the single SOC of static OCV, the difference between pseudo-static OCV and static OCV lies in the OCV acquisition conditions. Therefore, the strategy of calculating the single SOC of pseudo-static OCV is designed as follows:

[0095] (1) If (the power battery charge and discharge current is ≤ the value in Table 9 of the lowest cell temperature and the duration is greater than or equal to 3h) and ((pseudo-static OCVSOCmax is greater than 98.3%) and (pseudo-static OCVSOCmin is greater than 98.3%)), then the pseudo-static OCV calculation is triggered, the characteristic cell SOC is equal to 103, and the cell SOC is calculated to the value in Table 8 of the cell voltage.

[0096] (2) If (the power battery charging and discharging current is ≤ the value in Table 9 of the lowest cell temperature and the duration is greater than or equal to 3h) and ((pseudo-static OCVSOCmax is less than 25%) and (pseudo-static OCVSOCmin is less than 25%)), the pseudo-static OCV calculation is triggered, the characteristic cell SOC is equal to 103, and the cell SOC is calculated to the value in Table 8 of the cell voltage.

[0097] (3) If (the power battery charge and discharge current is ≤ the value in Table 9 of the lowest cell temperature and the duration is greater than or equal to 3h) and ((pseudo-static OCVSOCmax is greater than 98.3%) and (pseudo-static OCVSOCmin is less than 25%)), then the pseudo-static OCV calculation is triggered, the characteristic cell SOC is equal to 103, the cell SOC in the plateau period is calculated to 25%, and the cell SOC in the non-plateau period is calculated to the cell voltage in Table 8.

[0098] (4) If (the power battery charge and discharge current is ≤ the value in Table 9 of the lowest cell temperature and the duration is greater than or equal to 3h) and ((the pseudo-static OCVSOCmax is less than or equal to 98.3% and greater than or equal to 25%) and (the pseudo-static OCVSOCmin is less than 25%)), the pseudo-static OCV calculation is triggered, the characteristic cell SOC is equal to 53, the cell SOC in the plateau period is calculated to 25%, and the cell SOC in the non-plateau period is calculated to the cell voltage in Table 8.

[0099] It should be noted that the pseudo-static OCVSOCmax is equal to the maximum voltage of the single cell as shown in Table 8, and the pseudo-static OCVSOCmin is equal to the minimum voltage of the single cell as shown in Table 8.

[0100] Table 9

[0101] Temperature(℃) -20 -10 -5 5 10 15 25 45 Current (A) 0 0 0 0 1 1 2 2

[0102] It should be noted that the first preset maximum condition, the first preset minimum condition, the second preset maximum condition and the second preset minimum condition can be set by those skilled in the art according to actual conditions and are not specifically limited here.

[0103] Optionally, in one embodiment of the present application, at least one control action of the balanced state of a lithium iron phosphate battery is performed to generate a balanced control result, including: calculating the triggering cell SOC according to the triggering characteristic cell SOC, the current characteristic cell SOC, the calculated cell SOC deviation, and the cell SOC deviation before calculation to determine the final characteristic cell; determining the priority of at least one cell remaining power deviation identification strategy according to the final characteristic cell, so as to control the lithium iron phosphate battery to be in a balanced state according to the priority of at least one cell remaining power deviation identification strategy, and generate a balanced control result.

[0104] It can be understood that the priority of application between different strategies in the embodiment of the present application makes the single-cell SOC deviation more accurate, thereby improving the balancing effect.

[0105] Among them, the embodiment of the present application can calculate the triggering cell SOC according to the triggering characteristic cell SOC, the current characteristic cell SOC, the calculated cell SOC deviation and the cell SOC deviation before calculation to determine the final characteristic cell, and determine the priority of the above-mentioned cell remaining power deviation identification strategy according to the final characteristic cell, so as to control the lithium iron phosphate battery to be in a balanced state according to the priority of the above-mentioned cell remaining power deviation identification strategy, and generate a balanced control result.

[0106] In principle, the application priority of the single SOC deviation identification strategy is determined by the accuracy of the strategy in calculating the single SOC. Considering that different strategies can accurately identify different single SOC deviations in different application scenarios, the following priorities are designed to give full play to the advantages of each strategy, improve the accuracy of single SOC deviation identification, and further improve the balancing effect.

[0107] If (the trigger characteristic monomer SOC is equal to 102), then the trigger monomer SOC calculation is performed and the characteristic monomer is equal to 102.

[0108] If (the trigger characteristic single-cell SOC is equal to 52) and (the single-cell SOC deviation after calculation is greater than the single-cell SOC deviation before calculation), the single-cell SOC calculation is triggered and the characteristic single-cell SOC is equal to 52.

[0109] If (the trigger characteristic single cell SOC is equal to 52) and (the current characteristic single cell SOC is equal to 118 or 108), and the calculated single cell SOC deviation is greater than the calculated single cell SOC deviation + 3%, then the single cell SOC calculation is triggered and the characteristic single cell SOC is equal to 52.

[0110] If (the trigger characteristic single-cell SOC is equal to 102 or 51 or 52 or 15) and ((maximum single-cell SOC value - minimum single-cell SOC value) < 0.05%), then the single-cell SOC calculation is triggered and the characteristic single-cell SOC is equal to 102 or 51 or 52 or 15.

[0111] If (the trigger characteristic single cell SOC is equal to 103) and (the current characteristic single cell SOC is equal to 102 or 51 or 52) and (the single cell SOC deviation after calculation is greater than the single cell SOC deviation before calculation + 2%), then the single cell SOC calculation is triggered and the characteristic single cell SOC is equal to 103.

[0112] If (the triggered characteristic monomer SOC is equal to 103) and (the current characteristic monomer SOC is not equal to 102 and not equal to 51 and not equal to 52), then the monomer SOC calculation is triggered and the characteristic monomer SOC is equal to 103.

[0113] If (the trigger characteristic single cell SOC is equal to 53) and (the current characteristic single cell SOC is equal to 102 or 51 or 52) and (the single cell SOC deviation after calculation is greater than the single cell SOC deviation before calculation + 2%), then the single cell SOC calculation is triggered and the characteristic single cell SOC is equal to 53.

[0114] If (the trigger characteristic single cell SOC is equal to 53) and (the current characteristic single cell SOC is equal to 103 or 53 or 109 or 108 or 107) and (the single cell SOC deviation after calculation is greater than the single cell SOC deviation before calculation), then the single cell SOC calculation is triggered and the characteristic single cell SOC is equal to 53.

[0115] If (the trigger characteristic single cell SOC is equal to 53) and (the current characteristic single cell SOC is equal to 15 or 118) and (the calculated single cell SOC deviation is greater than the calculated single cell SOC deviation + 2%), then the single cell SOC calculation is triggered and the characteristic single cell SOC is equal to 53.

[0116] If (the trigger characteristic single-cell SOC is equal to 103 or 53) and ((the maximum single-cell SOC value - the minimum single-cell SOC value) < 0.05%), then the single-cell SOC calculation is triggered and the characteristic single-cell SOC is equal to 103 or 53.

[0117] If (the trigger characteristic monomer SOC is equal to 109) and (the current characteristic monomer SOC is equal to 102 or 103 or 108) and (the monomer SOC deviation after calculation is greater than the monomer SOC deviation before calculation + 3%), then the monomer SOC calculation is triggered and the characteristic monomer is equal to 109.

[0118] If (the trigger characteristic monomer SOC is equal to 109) and (the current characteristic monomer SOC is equal to 51 or 52 or 53 or 15 or 118) and (the monomer SOC deviation after calculation is greater than the monomer SOC deviation before calculation + 3%), then the monomer SOC calculation is triggered and the characteristic monomer is equal to 109.

[0119] If (the trigger characteristic monomer SOC is equal to 109) and (the current characteristic monomer SOC is equal to 109) and (the calculated monomer SOC deviation is less than the calculated monomer SOC deviation and (the calculated monomer SOC deviation is greater than or equal to 5%), then the monomer SOC calculation is triggered and the characteristic monomer is equal to 109.

[0120] If (the triggered characteristic monomer SOC is equal to 109) and (the current characteristic monomer SOC is equal to 109) and (the calculated monomer SOC deviation is less than 5%), then the monomer SOC calculation is triggered and the characteristic monomer is equal to 109.

[0121] If (the triggered characteristic monomer SOC is equal to 109) and (the current characteristic monomer SOC is equal to 107), then the monomer SOC calculation is triggered and the characteristic monomer is equal to 109.

[0122] If (the triggered characteristic cell SOC is equal to 108) and (the current characteristic cell SOC is equal to 108 or 109 or 107 or 118), then the cell SOC calculation is triggered and the characteristic cell SOC is equal to 108.

[0123] If (the triggered characteristic cell SOC is equal to 118) and (the current characteristic cell SOC is equal to 108 or 118), then the cell SOC calculation is triggered and the characteristic cell SOC is equal to 118.

[0124] If (the trigger characteristic single-cell SOC is equal to 108) and (the single-cell SOC deviation before calculation is ≤ 0.05%), the single-cell SOC calculation is triggered and the characteristic single-cell SOC is equal to 108.

[0125] If (the trigger characteristic single-cell SOC is equal to 118) and (the single-cell SOC deviation before calculation is ≤ 0.05%), the single-cell SOC calculation is triggered and the characteristic single-cell SOC is equal to 118.

[0126] If (the triggered characteristic monomer SOC is equal to 107) and (the current characteristic monomer SOC is equal to 107 or 118) and (ICA calculated monomer SOCmax-ICA calculated monomer SOCmin≥8%), then the monomer SOC calculation is triggered and the characteristic monomer SOC is equal to 107.

[0127] If (the trigger characteristic monomer SOC is equal to 107) and (the current characteristic monomer SOC is equal to 107) and (the monomer SOC deviation before calculation - the monomer SOC deviation after calculation ≥ 3%), then the monomer SOC calculation is triggered and the characteristic monomer SOC is equal to 107.

[0128] According to the balanced control method of lithium iron phosphate battery proposed in the embodiment of the present application, based on the voltage characteristics of lithium iron phosphate battery in different usage scenarios, a corresponding method is designed to identify the SOC deviation of single battery cells, and the accuracy difference of single battery SOC is calculated by combining different strategy methods, and the priority of application between different strategies is designed, which gives full play to the advantages of each strategy, improves the accuracy of single battery SOC deviation identification, and thus improves the balanced effect. Thus, it solves the problem that the related technology is difficult to identify the SOC difference between batteries, and because the voltage platform period of lithium iron phosphate battery is very flat and wide, it is difficult to calculate the SOC of each single battery cell, resulting in poor balanced effect.

[0129] Next, the equalization control device for a lithium iron phosphate battery proposed in an embodiment of the present application is described with reference to the accompanying drawings.

[0130] Figure 4 It is a structural schematic diagram of a balancing control device for a lithium iron phosphate battery according to an embodiment of the present application.

[0131] like Figure 4 As shown, the equalization control device 10 for the lithium iron phosphate battery includes: a detection module 100 , a determination module 200 and a control module 300 .

[0132] Specifically, the detection module 100 is used to detect whether the lithium iron phosphate battery is in the battery control mode according to the single cell voltage of the lithium iron phosphate battery.

[0133] The determination module 200 is used to determine at least one single cell remaining power deviation identification strategy when the lithium iron phosphate battery is in a charging condition, a discharging condition or a static condition, respectively, when the lithium iron phosphate battery is in a battery control mode.

[0134] The control module 300 is used to calculate the single cell remaining power deviation of the lithium iron phosphate battery according to at least one single cell remaining power deviation identification strategy, generate at least one lithium iron phosphate battery balancing state control action according to the single cell remaining power deviation of the lithium iron phosphate battery, and execute at least one lithium iron phosphate battery balancing state control action to generate a balancing control result.

[0135] Optionally, in one embodiment of the present application, the control module 300 includes: a first calculation unit and a first determination unit.

[0136] Among them, the first calculation unit is used to calculate the single cell remaining power deviation based on the single cell remaining power SOC deviation identification strategy of the capacity increment curve when the lithium iron phosphate battery is in a charging condition, according to the corresponding relationship between the peak voltage and the single cell remaining power during the charging process.

[0137] The first determination unit is used to determine the inflection point voltage based on the single cell SOC deviation identification strategy of the charging voltage change rate when the lithium iron phosphate battery is in a charging condition, and calculate the single cell remaining power deviation according to the inflection point voltage.

[0138] Optionally, in one embodiment of the present application, the control module 300 further includes: an output unit and a second calculation unit.

[0139] Among them, the output unit is used to output the predicted voltage of the pre-built battery equivalent circuit model based on the single cell SOC deviation identification strategy of the battery model when the lithium iron phosphate battery is in a discharge condition.

[0140] The second calculation unit is used to calculate the remaining power deviation of the single cell according to the error between the predicted voltage and the real-time collected voltage and the Romberg gain coefficient.

[0141] Optionally, in one embodiment of the present application, the control module 300 further includes: a third calculation unit and a fourth calculation unit.

[0142] Among them, the third calculation unit is used to, when the lithium iron phosphate battery is in a static condition, calculate the static OCV based on the single cell SOC deviation identification strategy of the static open circuit voltage OCV according to the high-voltage static time of the whole vehicle, the static OCVSOC that meets the first preset maximum condition, and the static OCVSOC that meets the first preset minimum condition, and calculate the remaining power deviation of the single cell based on the static OCV.

[0143] The fourth calculation unit is used to calculate the pseudo-static OCV according to the single-cell SOC deviation identification strategy based on the pseudo-static OCV when the lithium iron phosphate battery is in a static condition, according to the power battery charging and discharging current, the pseudo-static OCVSOC that meets the second preset maximum condition, and the pseudo-static OCVSOC that meets the second preset minimum condition, and calculate the single-cell remaining power deviation according to the pseudo-static OCV.

[0144] Optionally, in one embodiment of the present application, the control module 300 includes: a second determining unit and a generating unit.

[0145] The second determination unit is used to calculate the triggering cell SOC according to the triggering characteristic cell SOC, the current characteristic cell SOC, the calculated cell SOC deviation and the cell SOC deviation before calculation, so as to determine the final characteristic cell.

[0146] A generating unit is used to determine the priority of at least one single cell remaining power deviation identification strategy according to the final characteristic single cell, so as to control the lithium iron phosphate battery to be in a balanced state according to the priority of at least one single cell remaining power deviation identification strategy, and generate a balanced control result.

[0147] It should be noted that the above explanation of the embodiment of the equalization control method for lithium iron phosphate battery is also applicable to the equalization control device for lithium iron phosphate battery of this embodiment, which will not be described in detail here.

[0148] According to the equalization control device of the lithium iron phosphate battery proposed in the embodiment of the present application, a single SOC deviation identification strategy based on the capacity increment curve and a single SOC deviation identification strategy based on the charging voltage change rate are designed for charging conditions, a single SOC deviation identification strategy based on the battery model for discharging conditions, and a single SOC deviation identification strategy based on static OCV and a single SOC deviation identification strategy based on pseudo-static OCV for static conditions are designed. According to the application priority between different single SOC calculation strategies, the accuracy of calculating the single SOC deviation is improved, and the equalization effect of the control is improved. Thus, the problem that the related technology is difficult to identify the SOC difference between the cells, and because the voltage platform period of the lithium iron phosphate battery is very gentle and wide, it is difficult to calculate the SOC of each single cell, resulting in poor equalization effect.

[0149] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0150] A memory 501 , a processor 502 , and a computer program stored in the memory 501 and executable on the processor 502 .

[0151] When the processor 502 executes the program, the equalization control method for the lithium iron phosphate battery provided in the above embodiment is implemented.

[0152] Furthermore, the electronic device further comprises:

[0153] The communication interface 503 is used for communication between the memory 501 and the processor 502 .

[0154] The memory 501 is used to store computer programs that can be executed on the processor 502 .

[0155] The memory 501 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0156] If the memory 501, the processor 502 and the communication interface 503 are implemented independently, the communication interface 503, the memory 501 and the processor 502 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0157] Optionally, in a specific implementation, if the memory 501, the processor 502 and the communication interface 503 are integrated on a chip, the memory 501, the processor 502 and the communication interface 503 can communicate with each other through an internal interface.

[0158] The processor 502 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0159] This embodiment also provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the above-mentioned balancing control method for lithium iron phosphate batteries is implemented.

[0160] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0161] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0162] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0163] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0164] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0165] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0166] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0167] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for controlling the balance of a lithium iron phosphate battery, characterized in that: The following steps are involved: Detecting whether the lithium iron phosphate battery is in a battery control mode according to the single cell voltage of the lithium iron phosphate battery; When the lithium iron phosphate battery is in the battery control mode, determining at least one single cell remaining power deviation identification strategy when the lithium iron phosphate battery is in a charging condition, a discharging condition or a static condition respectively; The residual power deviation of the single cell of the lithium iron phosphate battery is calculated according to the at least one single cell residual power deviation identification strategy, at least one control action for the balanced state of the lithium iron phosphate battery is generated according to the residual power deviation of the single cell of the lithium iron phosphate battery, and the at least one control action for the balanced state of the lithium iron phosphate battery is executed to generate a balanced control result.

2. The method according to claim 1, characterized in that The calculating the single cell remaining power deviation of the lithium iron phosphate battery according to the at least one single cell remaining power deviation identification strategy includes: When the lithium iron phosphate battery is in the charging condition, the single cell SOC deviation identification strategy based on the capacity increment curve is used to calculate the single cell SOC deviation according to the corresponding relationship between the peak voltage and the single cell SOC during the charging process; When the lithium iron phosphate battery is in the charging condition, a single cell SOC deviation identification strategy based on the charging voltage change rate is used to determine the inflection point voltage using the characteristics of the charging terminal voltage, and the single cell remaining power deviation is calculated based on the inflection point voltage.

3. The method according to claim 2, characterized in that The calculating the single cell remaining power deviation of the lithium iron phosphate battery according to the at least one single cell remaining power deviation identification strategy also includes: When the lithium iron phosphate battery is in the discharge condition, outputting a predicted voltage of a pre-built battery equivalent circuit model based on a single cell SOC deviation identification strategy of a battery model; The remaining power deviation of the single cell is calculated according to the error between the predicted voltage and the real-time collected voltage and the Romberg gain coefficient.

4. The method according to claim 3, characterized in that The calculating the single cell remaining power deviation of the lithium iron phosphate battery according to the at least one single cell remaining power deviation identification strategy also includes: When the lithium iron phosphate battery is in the static working condition, a single cell SOC deviation identification strategy based on static open circuit voltage OCV is used to calculate the static OCV according to the high voltage disconnection static time of the whole vehicle, the static OCVSOC that meets the first preset maximum condition and the static OCVSOC that meets the first preset minimum condition, and the single cell remaining power deviation is calculated according to the static OCV; When the lithium iron phosphate battery is in the static working condition, the single cell SOC deviation identification strategy based on pseudo-static OCV is used to calculate the pseudo-static OCV according to the power battery charging and discharging current, the pseudo-static OCVSOC that meets the second preset maximum condition, and the pseudo-static OCVSOC that meets the second preset minimum condition, and the single cell remaining power deviation is calculated according to the pseudo-static OCV.

5. The method according to claim 1, characterized in that The performing of the control action of the balanced state of the at least one lithium iron phosphate battery to generate a balanced control result includes: Calculate the triggering monomer SOC according to the triggering characteristic monomer SOC, the current characteristic monomer SOC, the calculated monomer SOC deviation and the monomer SOC deviation before calculation to determine the final characteristic monomer; The priority of the at least one single cell remaining power deviation identification strategy is determined according to the final characteristic single cell, so as to control the lithium iron phosphate battery to be in the balanced state according to the priority of the at least one single cell remaining power deviation identification strategy, and generate the balanced control result.

6. A balance control device for a lithium iron phosphate battery, characterized in that: include: A detection module, used for detecting whether the lithium iron phosphate battery is in a battery control mode according to the single cell voltage of the lithium iron phosphate battery; A determination module, used for determining, when the lithium iron phosphate battery is in the battery control mode, at least one single cell remaining power deviation identification strategy when the lithium iron phosphate battery is in a charging condition, a discharging condition or a static condition respectively; A control module is used to calculate the single cell remaining power deviation of the lithium iron phosphate battery according to the at least one single cell remaining power deviation identification strategy, generate at least one lithium iron phosphate battery balance state control action according to the single cell remaining power deviation of the lithium iron phosphate battery, and execute the at least one lithium iron phosphate battery balance state control action to generate a balance control result.

7. The device according to claim 6, characterized in that The control module comprises: A first calculation unit is used to calculate the single cell SOC deviation according to the corresponding relationship between the peak voltage and the single cell SOC during the charging process based on the single cell SOC deviation identification strategy of the capacity increment curve when the lithium iron phosphate battery is in the charging condition; The determination unit is used to determine the inflection point voltage based on the single cell SOC deviation identification strategy of the charging voltage change rate when the lithium iron phosphate battery is in the charging condition, and calculate the single cell remaining power deviation according to the inflection point voltage.

8. The device according to claim 7, characterized in that The control module also includes: An output unit, configured to output a predicted voltage of a pre-built battery equivalent circuit model based on a single cell SOC deviation identification strategy of a battery model when the lithium iron phosphate battery is in the discharge condition; The second calculation unit is used to calculate the remaining power deviation of the single battery cell according to the error between the predicted voltage and the real-time collected voltage and the Romberg gain coefficient.

9. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the equalization control method for a lithium iron phosphate battery as described in any one of claims 1 to 5.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the equalization control method for a lithium iron phosphate battery as described in any one of claims 1 to 5.

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