Estimation method, electronic device, medium, estimation equipment, battery system and vehicle

Abstract

The invention discloses a health degree estimation method of a battery, an electronic device, a computer readable storage medium, health degree estimation equipment of the battery, a battery system and a vehicle. Under the condition that the voltage of the battery reaches a first preset voltage value, the capacity value of the battery is obtained to determine a first capacity value, and the first preset voltage value is smaller than or equal to the minimum value of the platform voltage of the battery; under the condition that the voltage of the battery reaches a second preset voltage value, the capacity value of the battery is obtained to determine a second capacity value, and the second preset voltage value is larger than or equal to the maximum value of the platform voltage of the battery; and determining a health degree estimated value of the battery according to the first capacity value, the second capacity value and the temperature and current of the current working condition of the battery. The characteristic value is determined according to the actual charging and discharging conditions of the battery. The corresponding characteristic value is extracted in each round of charging and discharging of the battery, the health degree of the battery is determined, the actual application condition of the battery is met, additional training data is not needed, and the method is high in applicability and precision.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and more specifically, to a battery health prediction method, an electronic device, a computer-readable storage medium, a battery health prediction device, a battery system, and a vehicle. Background Art

[0002] In the related art, the state of health (SOH) can be estimated by full charge and discharge method, data-driven method or empirical model method. However, the full charge and discharge method requires the battery to be fully charged or discharged, the data-driven method requires a large amount of training data, and the empirical model method has poor applicability to different types of batteries and low accuracy, which is not conducive to its application in battery management systems (BMS). Summary of the invention

[0003] Embodiments of the present application provide a battery health prediction method, an electronic device, a computer-readable storage medium, a battery health prediction device, a battery system, and a vehicle.

[0004] The health estimation method provided in the embodiment of the present application includes: obtaining the voltage of the battery during the process of charging and discharging the battery; when the voltage of the battery reaches a first preset voltage value, obtaining the capacity value of the battery to determine the first capacity value, and the first preset voltage value is less than or equal to the minimum value of the battery's platform voltage; when the voltage of the battery reaches a second preset voltage value, obtaining the capacity value of the battery to determine the second capacity value, and the second preset voltage value is greater than or equal to the maximum value of the battery's platform voltage; determining the estimated health value of the battery based on the first capacity value, the second capacity value and the temperature and current of the battery's current operating conditions.

[0005] The battery health estimation method provided in the embodiment of the present application can be applied to batteries with a plateau period in charge and discharge (for example, estimating lithium iron phosphate). The characteristic value is determined based on the actual charge and discharge conditions of the battery. To obtain the characteristic value of the estimated battery health, there is no need to fully charge and discharge the battery. The corresponding characteristic value can be extracted for each round of charge and discharge of the battery, and the health of the battery can be determined based on the current working condition of the battery. It conforms to the actual application of the battery and does not require additional training data. It has strong applicability and high accuracy, which is conducive to application in battery management systems (BMS).

[0006] In some embodiments, the method includes: during the charging process of the battery, if the voltage of the battery rises to the first preset voltage value, obtaining the capacity value of the battery to determine the first capacity value, and if the voltage of the battery rises to the second preset voltage value, obtaining the capacity value of the battery to determine the second capacity value; during the discharging process of the battery, if the voltage of the battery drops to the second preset voltage value, obtaining the capacity value of the battery to determine the second capacity value, and if the voltage of the battery drops to the first preset voltage value, obtaining the capacity value of the battery to determine the first capacity value.

[0007] In some embodiments, during the charging process of the battery, the voltage of the battery is sampled according to a specific sampling period, and if the voltage sampled in the mth sampling period is less than the first preset voltage value, and the voltage sampled in the m+1th sampling period is greater than or equal to the first preset voltage value, it is determined that the voltage of the battery rises to the first preset voltage value, and if the voltage sampled in the nth sampling period is less than the second preset voltage value, and the voltage sampled in the n+1th sampling period is greater than or equal to the second preset voltage value, it is determined that the voltage of the battery rises to the second preset voltage value, and m and n are any positive integers. During the discharging process of the battery, if the voltage sampled in the pth sampling period is greater than the first preset voltage value, and the voltage sampled in the p+1th sampling period is less than or equal to the first preset voltage value, it is determined that the voltage of the battery drops to the first preset voltage value, and if the voltage sampled in the qth sampling period is greater than the second preset voltage value, and the voltage sampled in the q+1th sampling period is less than or equal to the second preset voltage value, it is determined that the voltage of the battery drops to the second preset voltage value, and p and q are any positive integers.

[0008] In certain embodiments, when the battery begins to charge, the voltage of the battery is obtained to determine the charging start voltage; when the charging start voltage is greater than the first preset voltage value, the steps of the battery health estimation method are stopped; when the charging start voltage is less than the first preset voltage value, the voltage of the battery is obtained again until the obtained voltage rises to the first preset voltage value.

[0009] In certain embodiments, the method includes: when the battery stops charging, obtaining the voltage of the battery to determine the charging endpoint voltage; when the charging endpoint voltage is less than the second preset voltage value, stopping the steps of executing the battery health estimation method.

[0010] In certain embodiments, the method includes: when the battery starts to discharge, obtaining the voltage of the battery to determine; when the discharge start voltage is less than the second preset voltage value, stopping the steps of executing the battery health estimation method; when the discharge start voltage is greater than the second preset voltage value, obtaining the voltage of the battery again until the obtained voltage drops to the second preset voltage value.

[0011] In certain embodiments, the method includes: when the battery stops discharging, obtaining the voltage of the battery to determine the discharge endpoint voltage; when the discharge endpoint voltage is greater than the second preset voltage value, stopping the steps of executing the battery health estimation method.

[0012] In some embodiments, estimating the health of the battery based on the first capacity value, the second capacity value, and the temperature and current of the current operating condition of the battery includes: determining a characteristic value based on the first capacity value and the second capacity value; using a table lookup method to obtain a proportional coefficient based on the temperature and current of the current operating condition of the battery; and determining an estimated value of the health of the battery based on the characteristic value and the proportional coefficient.

[0013] In certain embodiments, after determining the estimated health value of the battery based on the first capacity value, the second capacity value, and the temperature and current of the current operating condition of the battery, the method includes: determining the health decay rate of the battery based on the estimated health value of the battery; updating the health of the battery when the health decay rate is within a preset range; and providing identification information to identify that the health decay rate is abnormal when the health decay rate is outside the preset range.

[0014] In certain embodiments, the method includes: determining a health test value of the battery by a full charge and discharge method; and determining the error according to the health test value.

[0015] An embodiment of the present application provides an electronic device, which includes a memory and a processor, wherein the memory is configured to store a computer program, and the processor implements the above-mentioned battery health estimation method when executing the computer program.

[0016] An embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program. When the computer program is executed by one or more processors, the above-mentioned health status estimation method is implemented.

[0017] An embodiment of the present application provides a battery health estimation device, the battery health estimation device includes a first acquisition module, a second acquisition module, a third acquisition module and a determination module. The first acquisition module is configured to acquire the voltage of the battery during the charging and discharging process of the battery. The second acquisition module is configured to acquire the capacity value of the battery to determine the first capacity value when the voltage of the battery is equal to a first preset voltage value, and the first preset voltage value is less than or equal to the minimum value of the platform voltage of the battery. The third acquisition module is configured to acquire the capacity value of the battery to determine the second capacity value when the voltage of the battery is equal to a second preset voltage value, and the second preset voltage value is greater than or equal to the maximum value of the platform voltage of the battery. The determination module is configured to determine the estimated value of the battery health based on the first capacity value, the second capacity value, and the temperature and current of the current operating condition of the battery.

[0018] An embodiment of the present application provides a battery system, comprising the above-mentioned estimation device and a battery, wherein the health estimation device is configured to determine an estimated health value of the battery.

[0019] An embodiment of the present application provides a vehicle, wherein the vehicle includes the above-mentioned battery system.

[0020] The embodiments of the present application disclose a method for estimating the health of a battery, an electronic device, a computer-readable storage medium, a device for estimating the health of a battery, a battery system, and a vehicle. The method for estimating the health of a battery includes: obtaining the voltage of a battery during the process of charging and discharging the battery; when the voltage of the battery reaches a first preset voltage value, obtaining the capacity value of the battery to determine a first capacity value, the first preset voltage value being less than or equal to the minimum value of the platform voltage of the battery; when the voltage of the battery reaches a second preset voltage value, obtaining the capacity value of the battery to determine a second capacity value, the second preset voltage value being greater than or equal to the maximum value of the platform voltage of the battery; determining the estimated value of the health of the battery based on the first capacity value, the second capacity value, and the temperature and current of the current working condition of the battery.

[0021] The battery health estimation method provided in the embodiment of the present application can be applied to batteries with a plateau period in charge and discharge (for example, estimating lithium iron phosphate). The characteristic value is determined based on the actual charge and discharge conditions of the battery. To obtain the characteristic value of the estimated battery health, there is no need to fully charge and discharge the battery. The corresponding characteristic value can be extracted for each round of charge and discharge of the battery, and the health of the battery can be determined based on the current working condition of the battery. It conforms to the actual application of the battery and does not require additional training data. It has strong applicability and high accuracy, which is conducive to application in battery management systems (BMS). BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 is a flowchart of a health estimation method of certain implementation modes of the present application;

[0024] Figure 2 is a schematic diagram of a vehicle and a battery system according to an embodiment of the present application;

[0025] Figure 3 It is a schematic diagram of the charging voltage curve of the battery;

[0026] Figure 4 It is a schematic diagram of the relationship between the battery health and the characteristic value;

[0027] Figure 5 is a flowchart of a health prediction method of certain implementation methods of the present application;

[0028] Figure 6 is a flowchart of a health estimation method of certain implementation modes of the present application;

[0029] Figure 7 is a schematic diagram showing the relationship between the characteristic ratio parameter value and temperature. DETAILED DESCRIPTION

[0030] The 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 represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are optional and are only used to explain the embodiments of the present application, and cannot be understood as limiting the embodiments of the present application.

[0031] In the related art, the state of health (SOH) can be estimated by full charge and discharge method, data-driven method or empirical model method. However, the full charge and discharge method requires the battery to be fully charged or discharged, the data-driven method requires a large amount of training data, and the empirical model method has poor applicability to different types of batteries and low accuracy, which is not conducive to its application in battery management systems (BMS).

[0032] Specifically, the full charge and discharge method requires the battery to be fully charged or discharged, which requires special experiments. It is difficult for the battery to reach the empty or full condition during actual use. The data-driven method is dependent on the training data and requires a large amount of training data. If there are different types of battery data, retraining is required, and the storage and computing power requirements are high, which is not conducive to application in BMS. The empirical model method has poor applicability to different types of batteries and low accuracy.

[0033] In order to solve the above technical problems, an embodiment of the present application provides a method for estimating the health of a battery.

[0034] Reference Figure 1 Compared with the above-mentioned technology, the battery health estimation method provided in the embodiment of the present application can be applied to batteries with a plateau period in charging and discharging (for example, estimating lithium iron phosphate). The characteristic value is determined according to the actual charging and discharging conditions of the battery. To obtain the characteristic value of estimating the health of the battery, there is no need to fully charge and discharge the battery. The corresponding characteristic value can be extracted for each round of charging and discharging of the battery, and the health of the battery can be determined according to the current working condition of the battery. It conforms to the actual application of the battery and does not require additional training data. It has strong applicability and high accuracy, which is conducive to application in battery management systems (BMS).

[0035] An embodiment of the present application also provides an electronic device, which includes a memory and a processor. The memory is configured to store a computer program. When the processor executes the computer program, it implements the battery health estimation method provided in the embodiment of the present application.

[0036] Reference Figure 2 The embodiment of the present application also provides a health prediction device 20, a battery system 100 and a vehicle 1000. The battery system 100 may include the health prediction device 20 and the battery 10 provided in the embodiment of the present application. The vehicle 1000 may include the battery system 100 provided in the embodiment of the present application.

[0037] The health prediction device 20 includes a first acquisition module, a second acquisition module, a third acquisition module and a determination module. Among them, the first acquisition module is configured to obtain the voltage of the battery during the charging and discharging process of the battery. The second acquisition module is configured to obtain the capacity value of the battery to determine the first capacity value when the voltage of the battery is equal to the first preset voltage value, and the first preset voltage value is less than or equal to the minimum value of the platform voltage of the battery. The third acquisition module is configured to obtain the capacity value of the battery to determine the second capacity value when the voltage of the battery is equal to the second preset voltage value, and the second preset voltage value is greater than or equal to the maximum value of the platform voltage of the battery. The determination module is configured to determine the health estimation value of the battery based on the first capacity value, the second capacity value and the temperature and current of the current operating condition of the battery.

[0038] In some embodiments, the health prediction device 20 may include an electronic device provided in an embodiment of the present application to implement a battery health prediction method provided in an embodiment of the present application.

[0039] Specifically, during the charge and discharge process of the battery 10 , there is a stage in which the voltage of the battery 10 remains relatively stable. During this stage, the voltage of the battery 10 does not change significantly and is considered to be the platform voltage of the battery 10 .

[0040] During the charging process of the battery 10, the platform voltage reflects the voltage level of the battery 10 that remains relatively stable after the voltage rises to a certain level during the charging process. During the discharging process of the battery 10, the platform voltage reflects the voltage level of the battery 10 that remains relatively stable after the voltage drops to a certain level during the charging process.

[0041] The first preset voltage value can be set to Vleft, and the second preset voltage value can be set to Vright. The minimum and maximum values of the platform voltage can be determined according to the charge-discharge voltage curve of the battery 10, and then Vleft and Vright can be set.

[0042] Refer to Figure 3 , taking the charging voltage curve of the lithium iron phosphate battery 10 as an example, the voltage of the battery 10 has an obvious plateau period. The platform voltage range corresponding to the plateau period is Vbegin~Vend. The maximum value of the platform voltage is Vend, and the minimum value of the platform voltage is Vbegin. The first preset voltage value can be set to Vleft, and the second preset voltage value can be set to Vright. Vleft is set to a value less than or equal to Vbegin, and Vright is set to a value greater than or equal to Vend. The range of Vleft~Vright at least covers the range of Vbegin~Vend to ensure the accuracy of the estimated battery 10 health.

[0043] Refer to Figure 3 , according to the charging voltage curve of the lithium iron phosphate battery 10, the starting voltage of the battery 10 can also be determined as Vstart, and the termination voltage is Vend. The values of Vleft and Vright should satisfy: Vstart <= Vleft <= Vbegin; Vend <= Vright <= Vend. Since Vend < Vbegin, so Vleft < Vright. According to the test data of the lithium iron phosphate battery 10, the charging voltage curve of the lithium iron phosphate battery 10 can be determined, and then the values of Vleft and Vright can be set.

[0044] During the charge-discharge process of the battery 10, the voltage value V0 of the battery 10 is obtained in real time. When the voltage value V0 of the battery 10 reaches Vleft, the capacity value of the battery 10 at this time is recorded as the first capacity value Cvleft. When the voltage value V0 of the battery 10 reaches Vright, the capacity value of the battery 10 at this time is recorded as the first capacity value Cvright.

[0045] Refer to Figure 4The characteristic value Feature has a strong correlation with the health of the battery 10. According to the temperature and current of the current working condition of the battery 10, the correlation coefficient between the characteristic value Feature and the health of the battery 10 can be determined, and then the health of the battery 10 can be estimated.

[0046] In this way, each time the battery 10 is charged and discharged, the health status of the battery 10 can be determined by using the health status prediction method provided in the embodiment of the present application. This method is in line with the actual application of the battery 10 and does not require additional training data. It has strong applicability and high accuracy, and is conducive to application in battery management systems.

[0047] In some embodiments, during the charging process of the battery 10, if the voltage of the battery 10 rises to a first preset voltage value, the capacity value of the battery 10 is obtained to determine the first capacity value; if the voltage of the battery 10 rises to a second preset voltage value, the capacity value of the battery 10 is obtained to determine the second capacity value.

[0048] Specifically, during the process of charging and discharging the battery 10 , the voltage value of the battery 10 is acquired in real time according to a specific sampling frequency, so the voltage value obtained by sampling is a discrete value.

[0049] During the charging process of the battery 10, it can be determined that the voltage value of the battery 10 continues to rise, and the sampled voltage value also shows an increasing trend. If a voltage greater than or equal to the first preset voltage value and a voltage less than the first preset voltage value are sampled at two adjacent sampling moments, it can be determined that the battery 10 rises to the first preset voltage value, and the corresponding first capacity value is determined.

[0050] In some embodiments, during the charging process of the battery 10, the voltage sampled in the mth sampling cycle is less than the first preset voltage value, and the voltage sampled in the m+1th sampling cycle is greater than or equal to the first preset voltage value. At this time, it can be determined that the voltage of the battery 10 has risen to the first preset voltage value, and the capacity value of the battery 10 is obtained to determine the first capacity value.

[0051] Similarly, during the charging process of the battery 10, the voltage sampled in the nth sampling cycle is less than the second preset voltage value, and the voltage sampled in the n+1th sampling cycle is greater than or equal to the second preset voltage value. At this time, it can be determined that the voltage of the battery 10 has risen to the second preset voltage value, and the capacity value of the battery 10 is obtained to determine the second capacity value.

[0052] During the discharge process of the battery 10, if the voltage of the battery 10 drops to a second preset voltage value, the capacity value of the battery 10 is obtained to determine the second capacity value; if the voltage of the battery 10 drops to a first preset voltage value, the capacity value of the battery 10 is obtained to determine the first capacity value.

[0053] During the discharge process of the battery 10, it can be determined that the voltage value of the battery 10 continues to decrease, and the sampled voltage value also shows a decreasing trend. During the discharge process of the battery 10, if the voltage sampled in the pth sampling period is greater than the first preset voltage value, and the voltage sampled in the p+1th sampling period is less than or equal to the first preset voltage value, it can be determined that the voltage of the battery 10 drops to the first preset voltage value, and the capacity value of the battery 10 is obtained to determine the first capacity value.

[0054] During the discharge process of the battery 10, the voltage sampled in the qth sampling period is greater than the second preset voltage value, and the voltage sampled in the q+1th sampling period is less than or equal to the second preset voltage value. At this time, it can be determined that the voltage of the battery 10 drops to the second preset voltage value, and the capacity value of the battery 10 is obtained to determine the second capacity value.

[0055] Reference Figure 5 In some embodiments, the method includes: when the battery 10 starts to be charged, obtaining the voltage of the battery 10 to determine the charging start voltage; when the charging start voltage is greater than a first preset voltage value, stopping the steps of the battery 10 health estimation method; when the charging start voltage is less than the first preset voltage value, obtaining the voltage of the battery 10 again until the obtained voltage rises to the first preset voltage value.

[0056] Specifically, during the charging process of the battery 10, it can be determined that the voltage value of the battery 10 continues to rise, and the charging start voltage of the battery 10 at the beginning of charging is the minimum voltage value of the battery 10. If the charging start voltage of the battery 10 at the beginning of charging is greater than Vleft, it can be determined that during the charging process, the voltage value of the battery 10 is greater than Vleft, that is, the first capacity value Cvleft cannot be determined, and the steps of the battery 10 health estimation method can be stopped.

[0057] If the charging start voltage of the battery 10 is lower than Vleft, the voltage of the battery 10 may be acquired again until the acquired voltage rises to Vleft, and then the capacity value of the battery 10 is acquired to determine the corresponding first capacity value Cvleft.

[0058] In some embodiments, the method includes: when the battery 10 stops charging, obtaining the voltage of the battery 10 to determine the charging endpoint voltage; when the charging endpoint voltage is less than a second preset voltage value, stopping executing the steps of the battery 10 health estimation method.

[0059] Specifically, during the charging process of the battery 10 , it can be determined that the voltage value of the battery 10 continues to rise, and the charging termination voltage at which the battery 10 stops charging is the maximum voltage value of the battery 10 .

[0060] Since the charging start voltage of the battery 10 is set to be less than or equal to Vleft, the charging start voltage of the battery 10 is also less than Vright. The voltage of the battery 10 can be obtained again until the obtained voltage rises to Vright, and the capacity value of the battery 10 is obtained to determine the corresponding second capacity value Cvright.

[0061] If the charging termination voltage of the battery 10 is still less than Vright, it can be determined that during the charging process, the voltage value of the battery 10 is less than Vright, that is, the second capacity value Cvright cannot be determined, and the steps of the battery 10 health prediction method can be stopped.

[0062] In certain embodiments, the method includes: when the battery 10 starts to discharge, obtaining the voltage of the battery 10 for determination; when the discharge start voltage is less than a second preset voltage value, stopping the steps of the method for estimating the health of the battery 10; when the discharge start voltage is greater than the second preset voltage value, obtaining the voltage of the battery 10 again until the obtained voltage drops to the second preset voltage value.

[0063] During the discharge process of the battery 10, it can be determined that the voltage value of the battery 10 continues to decrease, and the discharge start voltage at which the battery 10 starts to discharge is the maximum voltage value of the battery 10. If the discharge start voltage at which the battery 10 starts to discharge is less than Vright, it can be determined that during the discharge process, the voltage value of the battery 10 is less than Vright, that is, the first capacity value Cvright cannot be determined, and the steps of the method for estimating the health of the battery 10 can be stopped.

[0064] If the discharge start voltage of the battery 10 is greater than Vright, the voltage of the battery 10 may be acquired again until the acquired voltage drops to Vright, and then the capacity value of the battery 10 is acquired to determine the corresponding second capacity value Cvright.

[0065] In some embodiments, the method includes: when the battery 10 stops discharging, obtaining the voltage of the battery 10 to determine the discharge endpoint voltage; when the discharge endpoint voltage is greater than a second preset voltage value, stopping executing the steps of the battery 10 health estimation method.

[0066] During the discharge process of the battery 10 , it can be determined that the voltage value of the battery 10 continues to decrease, and the discharge termination voltage at which the battery 10 stops discharging is the minimum voltage value of the battery 10 .

[0067] Since the discharge starting voltage of the battery 10 is set to be greater than or equal to Vright, the discharge starting voltage of the battery 10 is also greater than Vleft. The voltage of the battery 10 can be obtained again until the obtained voltage drops to Vleft, and the capacity value of the battery 10 is obtained to determine the corresponding first capacity value Cvleft.

[0068] If the discharge termination voltage of the battery 10 is still greater than Vleft, it can be determined that during the discharge process, the voltage value of the battery 10 is greater than Vleft, that is, the first capacity value Cvleft cannot be determined, and the steps of the battery 10 health prediction method can be stopped.

[0069] Reference Figure 5 as well as Figure 6 In some embodiments, the health of the battery 10 is estimated based on the first capacity value, the second capacity value, and the temperature and current of the current operating condition of the battery 10, including: determining a characteristic value based on the first capacity value and the second capacity value; using a table lookup method to obtain a proportionality coefficient based on the temperature and current of the current operating condition of the battery 10; and determining an estimated health value of the battery 10 based on the characteristic value and the proportionality coefficient.

[0070] Specifically, after determining the first capacity value Cvleft and the first capacity value Cvright, the feature value Feature=CVright-Cvleft is calculated.

[0071] The characteristic ratio parameter F, the temperature coefficient Kt, and the current coefficient Ki can be determined according to the current and temperature of the actual working condition of the battery 10, and the proportional coefficient Kt*Ki*F can be further determined. The estimated health status of the battery 10 is SOHestimate=Feature / (Kt*Ki*F)*100%.

[0072] Reference Figure 4 The characteristic value Feature has a strong correlation with the health of the battery 10. The characteristic ratio parameter value F of the characteristic value can be determined according to the characteristic value. The characteristic ratio parameter value F can be calculated by the actual SOH / characteristic value Feature. By continuously performing testing and calibration, a definite value is finally obtained.

[0073] Based on the data relationship between the characteristic ratio parameter value F obtained under different working conditions and the temperature and current of the current working conditions, linear interpolation, polynomial fitting, least squares method and other methods can be used for fitting.

[0074] In some embodiments, the battery 10 can be charged and discharged at a constant current of 0.37C at temperatures of -10°C, 0°C, 10°C, 25°C, and 45°C, and a linear interpolation is selected to fit the relationship between the characteristic ratio parameter value F and the temperature. The relationship between the characteristic ratio parameter value F and the temperature is as follows: Figure 7 shown.

[0075] The charge and discharge rate is constant at 0.37C, and the current coefficient Ki can be 1. The linear interpolation fitting results are as follows:

[0076] -10℃~0℃: F(-10℃)=180; Ki=1; YF=F(-10℃)+3*(T+10);

[0077] 0℃~10℃: F(0℃)=210; Ki=1; YF=F(0℃)+2*T;

[0078] 10℃~25℃: F(10℃)=230; Ki=1; YF=F(10℃)+0.933*(T-10);

[0079] 25℃~45℃: F(25℃)=244; Ki=1; YF=F(25℃)+0.3*(T-25);

[0080] Where F(i) is the characteristic ratio parameter value determined at temperature i. YF is the characteristic ratio parameter value obtained by linear interpolation fitting, and T is the temperature in °C.

[0081] After conversion, the YF formula is:

[0082] -10℃~0℃: YF=F(-10℃)*(1+3*(T+10) / F(-10℃))*Ki;

[0083] 0℃~10℃: YF=F(0℃)*(1+2*T / F(0℃))*Ki;

[0084] 10℃~25℃: YF=F(10℃)*(1+0.933*(T-10) / F(10℃))*Ki;

[0085] 25℃~45℃: YF=F(25℃)*(1+0.3*(T-25) / F(25℃))*Ki;

[0086] In this way, it can be determined that under the constant current 0.37C charge and discharge conditions, the characteristic ratio parameter value F, current coefficient Ki, and temperature coefficient Kt are as follows:

[0087] -10℃~0℃: F=180; Ki=1; Kt=1+3*(T+10) / 180;

[0088] 0℃~10℃: F=210; Ki=1; Kt=1+2*T / 210;

[0089] 10℃~25℃: F=230; Ki=1; Kt=1+0.933*(T-10) / 230;

[0090] 25℃~45℃: F=244; Ki=1; Kt=1+0.3*(T-25) / 244.

[0091] In some embodiments, the battery 10 may also use different currents and charge and discharge at the same temperature, and select linear interpolation to fit the relationship between the characteristic ratio parameter value F and the charge and discharge current. The process of fitting the relationship between the characteristic ratio parameter value F and the charge and discharge current can refer to the relationship between the characteristic ratio parameter value F and the temperature, which is not repeated here.

[0092] The characteristic ratio parameter F, temperature coefficient Ki and current coefficient Kt are stored in the table for subsequent table lookup.

[0093] After determining the characteristic value according to the first capacity value and the second capacity value, a table lookup method can be used to obtain the characteristic ratio parameter F, the temperature coefficient Ki and the current coefficient Kt according to the temperature and current of the current operating condition of the battery 10, and determine the proportional coefficient Kt*Ki*F, and then determine the health estimate value of the battery 10 SOHestimate=Feature / (Kt*Ki*F)*100%.

[0094] Reference Figure 5 In some embodiments, after determining an estimated health value of the battery 10 based on the first capacity value, the second capacity value, and the temperature and current of the current operating condition of the battery 10, the method includes: determining a health decay rate of the battery 10 based on the estimated health value of the battery 10; when the health decay rate is within a preset range, updating the health of the battery 10; when the health decay rate is outside the preset range, providing identification information to identify an abnormal health decay rate.

[0095] Specifically, the decay rate R of the estimated SOH value is calculated as (SOH-SOHestimate) / SOH, where Rmax is the maximum health decay rate of the battery 10 under normal conditions. SOH can be the standard health of the battery 10 when it leaves the factory. If the SOH decay rate R is within the normal health decay range of the battery 10, the SOH of the battery 10 is updated; if the SOH decay rate exceeds the normal health decay range of the battery 10, it indicates that the health decay of the battery 10 is abnormal, and an abnormal health decay warning and processing of the battery 10 are performed.

[0096] In some embodiments, the method includes: determining a health test value of the battery 10 by a full charge and discharge method; and determining an error of a health estimate value based on the health test value.

[0097] Specifically, the battery 10 is fully charged or fully discharged once in the early period of its entire life, and the charged or discharged capacity is calculated.

[0098] The battery 10 may be charged until the voltage of the battery 10 is substantially consistent with the charging cut-off voltage of the battery 10. When the voltage of the battery 10 is substantially consistent with the charging cut-off voltage of the battery 10, the capacity value charged into the battery 10 during the full charging process is obtained, and the SOH value of the battery 10 is determined according to the charged capacity value, and recorded as the health test value of the battery 10.

[0099] The battery 10 may be discharged until the voltage of the battery 10 is substantially consistent with the discharge cut-off voltage of the battery 10. When the voltage of the battery 10 is substantially consistent with the discharge cut-off voltage of the battery 10, the capacity value discharged by the battery 10 during the full discharge process is obtained, and the SOH value of the battery 10 is determined according to the discharged capacity value, and recorded as the health test value of the battery 10.

[0100] The health test value of the battery 10 can be combined with the health estimate to obtain an error rate, so that the health estimate can be calibrated later to reduce the estimated error rate.

[0101] The health status estimation method provided by the embodiment of the present application includes at least the following technical effects:

[0102] (1) The current health status of the lithium iron phosphate battery 10 can be estimated efficiently and accurately.

[0103] (2) By determining the characteristic ratio parameter value and extracting the data characteristics based on the charging and discharging voltage plateau period, the current SOH of the battery 10 can be estimated without fully charging and discharging, which is in line with the actual application of the battery 10 and is conducive to its application in the BMS.

[0104] (3) The estimated error of SOH is stable, which is convenient for error calibration in the later stage.

[0105] (4) The abnormal health degradation of the battery 10 can be identified in a timely manner based on the SOH estimation result.

[0106] In the description of this specification, the descriptions with reference to the terms "certain embodiments", "in an example", "exemplarily", etc., mean that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples 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 more 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, unless they are contradictory.

[0107] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific 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 the 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.

[0108] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are optional and cannot be understood as limitations to the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for estimating battery health, characterized in that: The method comprises: During the process of charging and discharging the battery, obtaining the voltage of the battery; When the voltage of the battery reaches a first preset voltage value, obtaining a capacity value of the battery to determine a first capacity value, wherein the first preset voltage value is less than or equal to a minimum value of a platform voltage of the battery; When the voltage of the battery reaches a second preset voltage value, obtaining a capacity value of the battery to determine a second capacity value, wherein the second preset voltage value is greater than or equal to a maximum value of a platform voltage of the battery; The estimated health value of the battery is determined according to the first capacity value, the second capacity value, and the temperature and current of the current operating condition of the battery.

2. The health status estimation method according to claim 1, characterized in that: The method comprises: During the charging process of the battery, if the voltage of the battery rises to the first preset voltage value, the capacity value of the battery is obtained to determine the first capacity value; if the voltage of the battery rises to the second preset voltage value, the capacity value of the battery is obtained to determine the second capacity value; During the discharge of the battery, if the voltage of the battery drops to the second preset voltage value, the capacity value of the battery is obtained to determine the second capacity value; if the voltage of the battery drops to the first preset voltage value, the capacity value of the battery is obtained to determine the first capacity value.

3. The health status estimation method according to claim 2, characterized in that: The method comprises: During the charging process of the battery, the voltage of the battery is sampled according to a specific sampling period, if the voltage sampled in the mth sampling period is less than the first preset voltage value, and the voltage sampled in the m+1th sampling period is greater than or equal to the first preset voltage value, it is determined that the voltage of the battery rises to the first preset voltage value, if the voltage sampled in the nth sampling period is less than the second preset voltage value, and the voltage sampled in the n+1th sampling period is greater than or equal to the second preset voltage value, it is determined that the voltage of the battery rises to the second preset voltage value, and m and n are any positive integers; During the discharge of the battery, if the voltage sampled in the p-th sampling period is greater than the first preset voltage value, and the voltage sampled in the p+1-th sampling period is less than or equal to the first preset voltage value, it is determined that the voltage of the battery drops to the first preset voltage value; if the voltage sampled in the q-th sampling period is greater than the second preset voltage value, and the voltage sampled in the q+1-th sampling period is less than or equal to the second preset voltage value, it is determined that the voltage of the battery drops to the second preset voltage value, and p and q are any positive integers.

4. The health status estimation method according to claim 2, characterized in that: The method comprises: When the battery starts to be charged, obtaining the voltage of the battery to determine the charging start voltage; When the charging start voltage is greater than the first preset voltage value, stop executing the steps of the battery health estimation method; when the charging start voltage is less than the first preset voltage value, obtain the battery voltage again until the obtained voltage rises to the first preset voltage value.

5. The health status estimation method according to claim 2, characterized in that: The method comprises: When the battery stops charging, obtaining the voltage of the battery to determine the charging end point voltage; When the charging endpoint voltage is less than the second preset voltage value, the steps of executing the battery health estimation method are stopped.

6. The health status estimation method according to claim 2, characterized in that: The method comprises: When the battery starts to discharge, obtaining the voltage of the battery to determine; When the discharge start voltage is less than the second preset voltage value, stop executing the steps of the battery health estimation method; when the discharge start voltage is greater than the second preset voltage value, obtain the battery voltage again until the obtained voltage drops to the second preset voltage value.

7. The health status estimation method according to claim 2, characterized in that: The method comprises: When the battery stops discharging, obtaining the voltage of the battery to determine the discharge end point voltage; When the discharge endpoint voltage is greater than the second preset voltage value, the steps of executing the battery health prediction method are stopped.

8. The health status estimation method according to claim 1, characterized in that: The estimating the health of the battery according to the first capacity value, the second capacity value, and the temperature and current of the current working condition of the battery includes: determining a characteristic value according to the first capacity value and the second capacity value; Using a table lookup method, the proportionality coefficient is obtained according to the temperature and current of the current working condition of the battery; An estimated health value of the battery is determined according to the characteristic value and the proportionality coefficient.

9. The health status estimation method according to claim 1, characterized in that: After determining the estimated health value of the battery according to the first capacity value, the second capacity value, and the temperature and current of the current working condition of the battery, the method includes: Determining a health decay rate of the battery according to the estimated health value of the battery; When the health decay rate is within a preset range, updating the health of the battery; In the case where the health decay rate is outside a preset range, identification information is provided to identify that the health decay rate is abnormal.

10. The health status estimation method according to claim 1, characterized in that: The method comprises: Determine the health test value of the battery by full charge and discharge method; An error of the health estimate is determined according to the health test value.

11. An electronic device, characterized in that: The electronic device includes a memory and a processor, the memory is configured to store a computer program, and the processor implements the battery health prediction method according to any one of claims 1 to 10 when executing the computer program.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by one or more processors, the health status prediction method according to any one of claims 1 to 10 is implemented.

13. A battery health prediction device, characterized in that: The battery health estimation device comprises: A first acquisition module is configured to acquire the voltage of the battery during the process of charging and discharging the battery; a second acquisition module, configured to acquire the capacity value of the battery to determine a first capacity value when the voltage of the battery is equal to a first preset voltage value, and the first preset voltage value is less than or equal to a minimum value of the platform voltage of the battery; a third acquisition module, configured to acquire the capacity value of the battery to determine a second capacity value when the voltage of the battery is equal to a second preset voltage value, and the second preset voltage value is greater than or equal to the maximum value of the platform voltage of the battery; The determination module is configured to determine the estimated health value of the battery according to the first capacity value, the second capacity value, and the temperature and current of the current working condition of the battery.

14. A battery system, characterized in that: The battery system comprises the health prediction device of claim 13 and a battery, wherein the health prediction device is configured to determine an estimated health value of the battery.

15. A vehicle, characterized in that: The vehicle includes the battery system of claim 14.

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