Methods, devices, power battery systems and dielectrics for estimating the lifespan of power batteries

Abstract

This application relates to a method, apparatus, power battery system, and medium for estimating the lifespan of a power battery. The method includes: calculating the actual driving range and actual average driving range of a vehicle based on its current operating conditions and the electric vehicle's design life parameters; calculating the number of cycles required under the DOD (Design of Days) and actual usage time of the vehicle's power battery system based on this; obtaining the average charge / discharge temperature and average storage temperature by combining the power battery's temperature rise data; and calculating the first degradation rate of the power battery at the average charge / discharge temperature, the second degradation rate at the average storage temperature, and the third degradation rate consistent across the power battery system based on the power battery degradation curve and calendar life degradation amount, thereby generating a lifespan estimation result for the power battery. This solves the problems of simplistic empirical models and incomplete evaluation results in power battery lifespan estimation methods, improves the accuracy of power battery lifespan assessment, and makes the estimation simpler and more convenient.

Description

Technical Field

[0001] This application relates to the field of power battery technology, and in particular to a method, apparatus, power battery system and medium for estimating the lifespan of a power battery. Background Technology

[0002] The lifespan of new energy electric vehicles is affected by the lifespan of the power battery, so the lifespan assessment of the power battery has become a current research focus.

[0003] In related technologies, the lifespan of a power battery system for electric vehicles can be assessed through testing. This involves collecting data on the actual speed of the electric vehicle over time, converting this data into power over time, and then into current over time. The charging and discharging current data over time is then input into the power battery system using charging and discharging equipment to test the cycle life of the battery system and thus assess whether the power battery can meet the lifespan requirements of the electric vehicle.

[0004] However, while testing methods can assess the lifespan of power batteries, the testing cycle is long, often requiring at least a year, and the energy consumption during the charging and discharging cabinet testing process is high.

[0005] Another related technology involves using simulation software to build a model of the battery system. By utilizing thermo-electric coupling models and electrochemical models, and inputting actual operating conditions, the lifespan of the battery system can be simulated and calculated.

[0006] However, using simulation software requires developing or purchasing specialized simulation software modules, and then using a large number of samples to train and calibrate the model, which is also costly. Summary of the Invention

[0007] This application provides a method, apparatus, power battery system, and medium for estimating the lifespan of a power battery, in order to solve the problems of single empirical models and incomplete evaluation results in related technologies. It improves the accuracy of power battery lifespan estimation, shortens the estimation cycle, reduces computational costs, and makes the estimation process simpler and more convenient.

[0008] The first aspect of this application provides a method for estimating the lifespan of a power battery, comprising the following steps:

[0009] Obtain the current operating parameters of the target vehicle;

[0010] The actual driving range and actual average driving range of the target vehicle are calculated based on the current operating condition parameters. The number of cycles and actual usage time of the target vehicle's power battery system under the required percentage depth of discharge (DOD) are calculated based on the actual average driving range.

[0011] Based on the current operating condition parameters, the number of cycles under DOD, and the actual usage time, the average charging and discharging temperature and the average storage temperature of the power battery to be matched are obtained by combining the temperature rise data of the power battery to be matched.

[0012] Based on the degradation curve of the power battery to be matched and the calendar life degradation amount, calculate the first degradation rate of the power battery to be matched at the average charge and discharge temperature, the second degradation rate at the average storage temperature, and the third degradation rate consistent with the power battery system, and generate the life estimation result of the power battery to be matched based on the first degradation rate, the second degradation rate, and the third degradation rate.

[0013] Optionally, in some embodiments, the current operating condition parameters include at least one of the following: vehicle power consumption, average vehicle power consumption, average daily mileage, average annual operating days, average annual off-duty days, ambient temperature of the operating area, average daily charging frequency, average daily DOD usage, average vehicle charging current, average vehicle discharging current, and battery health exceeding a first preset threshold and average health exceeding a second preset threshold after the vehicle's actual service life reaches a preset service life or after the vehicle has traveled a preset mileage.

[0014] Optionally, in some embodiments, calculating the actual driving range and actual average driving range of the target vehicle based on the current operating condition parameters includes: calculating a first product of the average number of daily charging cycles, the vehicle's required electricity, and the average daily DOD usage; obtaining the actual driving range based on the ratio of the first product to the vehicle's average electricity consumption; and obtaining the actual average driving range based on the product of the actual driving range and the average health status.

[0015] Optionally, in some embodiments, calculating the number of cycles and actual usage time of the target vehicle's power battery system under the required percentage depth of discharge (DOD) based on the actual average driving range includes: obtaining the number of cycles under DOD based on the ratio of the preset mileage to the actual average driving range; and obtaining the actual usage time based on the ratio of the number of cycles under DOD to the annual average number of operating days.

[0016] Optionally, in some embodiments, generating the lifespan estimation result of the power battery to be matched based on the first decay rate, the second decay rate, and the third decay rate includes: obtaining a total decay rate based on the sum of the first decay rate, the second decay rate, and the third decay rate; calculating the difference between the target value and the total decay rate; and using the product of the difference and the initial capacity of the power battery to be matched as the lifespan estimation result of the power battery to be matched.

[0017] Optionally, in some embodiments, after calculating the difference between the target value and the total attenuation rate, the method further includes: if the difference is greater than or equal to the average health, then it is determined that the power battery to be matched meets the service life of the target vehicle; otherwise, it is determined that the power battery to be matched does not meet the service life of the target vehicle.

[0018] A second aspect of this application provides a power battery life estimation device, comprising:

[0019] The first acquisition module is used to acquire the current operating condition parameters of the target vehicle;

[0020] The calculation module is used to calculate the actual driving range and actual average driving range of the target vehicle based on the current operating condition parameters, and to calculate the number of cycles and actual usage time of the target vehicle's power battery system under the required percentage depth of discharge (DOD) based on the actual average driving range.

[0021] The second acquisition module is used to obtain the average charging and discharging temperature and the average storage temperature of the power battery to be matched based on the current operating condition parameters, the number of cycles under the DOD and the actual usage time, combined with the temperature rise data of the power battery to be matched.

[0022] The estimation module is used to calculate the first degradation rate, the second degradation rate and the third degradation rate of the power battery to be matched at the average charge and discharge temperature, based on the degradation curve and calendar life degradation amount of the power battery to be matched, and the consistency of the power battery system. The module also generates the life estimation result of the power battery to be matched based on the first degradation rate, the second degradation rate and the third degradation rate.

[0023] Optionally, in some embodiments, the current operating condition parameters include at least one of the following: vehicle power consumption, average vehicle power consumption, average daily mileage, average annual operating days, average annual off-duty days, ambient temperature of the operating area, average daily charging frequency, average daily DOD usage, average vehicle charging current, average vehicle discharging current, and battery health exceeding a first preset threshold and average health exceeding a second preset threshold after the vehicle's actual service life reaches a preset service life or after the vehicle has traveled a preset mileage.

[0024] Optionally, in some embodiments, the calculation module is specifically used to: calculate the first product of the average number of daily charging cycles, the vehicle's required electricity, and the average daily DOD usage; obtain the actual driving range based on the ratio of the first product to the vehicle's average electricity consumption; and obtain the actual average driving range based on the product of the actual driving range and the average health status.

[0025] Optionally, in some embodiments, the calculation module is further configured to: determine the number of cycles under DOD based on the ratio of the preset mileage to the actual average driving range; and determine the actual usage time based on the ratio of the number of cycles under DOD to the annual average number of operating days.

[0026] Optionally, in some embodiments, the estimation module is specifically used to: obtain a total attenuation rate based on the sum of the first attenuation rate, the second attenuation rate, and the third attenuation rate; calculate the difference between the target value and the total attenuation rate; and use the product of the difference and the initial capacity of the power battery to be matched as the life estimation result of the power battery to be matched.

[0027] Optionally, in some embodiments, after calculating the difference between the target value and the total attenuation rate, the estimation module is further configured to: determine that the power battery to be matched meets the service life of the target vehicle when the difference is greater than or equal to the average health; otherwise, determine that the power battery to be matched does not meet the service life of the target vehicle.

[0028] A third aspect of this application provides a power battery system, including: 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 power battery life estimation method as described in the above embodiments.

[0029] A fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the life estimation method for a power battery as described in the above embodiments.

[0030] Therefore, this application calculates the actual driving range and actual average driving range of the vehicle based on its current operating parameters, and calculates the number of cycles required under the DOD (Depth of Hour) and actual usage time of the vehicle's power battery system. Combining the power battery's temperature rise data, it obtains the average charge / discharge temperature and average storage temperature. Based on the power battery's degradation curve and calendar life degradation amount, it calculates the first degradation rate at the average charge / discharge temperature, the second degradation rate at the average storage temperature, and the third degradation rate consistent with the power battery system. Based on the first, second, and third degradation rates, it generates a power battery life estimation result. This solves the problems of single empirical models and incomplete evaluation results in related technologies for power battery life estimation methods, improves the accuracy of power battery life estimation, shortens the estimation cycle, reduces computational costs, and makes the estimation process simpler and more convenient.

[0031] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0032] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0033] Figure 1 This is a flowchart of a power battery life estimation method provided according to an embodiment of this application;

[0034] Figure 2 A flowchart illustrating the lifespan estimation of a power battery according to a specific embodiment of this application;

[0035] Figure 3 This is a block diagram of a power battery life estimation device provided according to an embodiment of this application;

[0036] Figure 4 This is a block diagram of a power battery system provided according to an embodiment of this application. Detailed Implementation

[0037] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0038] The following description, with reference to the accompanying drawings, illustrates a method, apparatus, power battery system, and dielectric for estimating the lifespan of a power battery according to embodiments of this application. Addressing the issues of limited empirical models and incomplete evaluation results in the power battery lifespan estimation methods mentioned in the background section, this application provides a method for estimating the lifespan of a power battery. In this method, the current operating condition parameters of the target vehicle are obtained; the actual driving range and actual average driving range of the target vehicle are calculated based on the current operating condition parameters; the number of cycles and actual usage time at the required percentage depth of discharge (DOD) of the power battery system of the target vehicle are calculated based on the actual average driving range; the average charge / discharge temperature and average storage temperature of the power battery to be matched are obtained based on the current operating condition parameters, the number of cycles at DOD, and the actual usage time, combined with the temperature rise data of the power battery to be matched; the first degradation rate, the second degradation rate, and the third degradation rate consistent with the power battery system are calculated based on the degradation curve and calendar lifespan degradation amount of the power battery to be matched; and the lifespan estimation result of the power battery to be matched is generated based on the first degradation rate, the second degradation rate, and the third degradation rate. This solves the problems of single empirical models and incomplete evaluation results in power battery life estimation methods, improves the accuracy of power battery life estimation, shortens the estimation cycle, reduces calculation costs, and makes the estimation process simpler and more convenient.

[0039] Before introducing the embodiments of this application, a brief description of the relevant technologies involved in the background technology of this application will be given.

[0040] Regarding the lifespan of power batteries for electric vehicles, current battery manufacturers' requirements and test methods for cycle life of power batteries for electric vehicles are as follows: the battery is fully charged at 1C at room temperature, left to rest for 30 minutes, and then discharged at 1C to the termination condition. The number of battery cycles tested under these conditions is the cycle life of the power battery. However, the above test process does not take into account the actual usage conditions of electric vehicle users, and there is no test data available during the design and selection phase. Therefore, the coverage of the above test results is relatively small, and the accuracy of the test results is questionable.

[0041] Related patents propose a method for assessing the driving life of vehicle batteries. This method inputs the current charging method, current temperature, and current energy throughput into a pre-built aging model to obtain the capacity degradation rate of the battery to be evaluated. However, this method requires training the model across multiple target regions and a large number of target vehicles based on their charging habits, necessitating a large number of samples and thus consuming a significant amount of time. Furthermore, it does not consider the vehicle's operating conditions and calendar life degradation, resulting in an incomplete assessment.

[0042] Another related patent discloses a battery management system with the function of estimating the lifespan of electric vehicle power batteries, including five steps: parameter acquisition, charging, calculation, lifespan comparison, and notification. The battery pack's lifespan is determined by calculating lifespan evaluation indicators. However, this method estimates the remaining battery lifespan and provides it to the owner by querying pre-stored power battery lifespan data in the memory during the electric vehicle's usage phase.

[0043] In summary, the life estimation methods for power batteries in related technologies suffer from problems such as incomplete and inaccurate assessments, complex assessment processes, and limited empirical models.

[0044] To address the aforementioned issues, this application provides a method for estimating the lifespan of a power battery. This method is applicable to the selection and design phase of power batteries for electric vehicles. By combining power battery test data, it estimates whether the lifespan of the power battery system meets the requirements of the entire vehicle, enabling rapid matching of the power battery and its cells. This method offers a simpler and more convenient estimation process, significantly improving the accuracy of power battery lifespan estimation and reducing computational costs. The power battery lifespan estimation method of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] Specifically, Figure 1 This is a flowchart illustrating a method for estimating the lifespan of a power battery, as provided in an embodiment of this application.

[0046] like Figure 1 As shown, the method for estimating the lifespan of this power battery includes the following steps:

[0047] In step S101, the current operating condition parameters of the target vehicle are obtained.

[0048] It should be noted that, in order to improve the accuracy of the power battery life estimation and make the estimation results more comprehensive, this application fully considers the vehicle's operating condition parameters, takes the actual use conditions and scenario parameters of the target vehicle as input conditions, and obtains the actual mileage data of the target vehicle, thereby evaluating the life of the power battery under actual use conditions.

[0049] Optionally, in some embodiments, the current operating condition parameters include at least one of the following: vehicle power consumption, vehicle average power consumption, average daily mileage, average annual operating days, average annual off-duty days, ambient temperature of the operating area, average daily charging frequency, average daily DOD usage, average vehicle charging current, average vehicle discharging current, and battery health exceeding a first preset threshold and average health exceeding a second preset threshold after the vehicle's actual service life reaches a preset service life or the vehicle has traveled a preset mileage.

[0050] It is understandable that many factors affect the lifespan of a power battery. In addition to considering parameters such as the vehicle's required power, average power consumption, and ambient temperature of the operating area, this application also needs to consider the vehicle's State of Health (SOH). In this embodiment, the battery health can be the battery health after the vehicle has reached a preset service life, or the battery health after the vehicle has traveled a preset mileage. Both the battery health and the average health need to be greater than preset thresholds. Furthermore, this application does not specifically limit the first and second preset thresholds for battery health in this embodiment; those skilled in the art can set them according to actual conditions. In this embodiment, the methods for obtaining data such as average daily mileage and average daily DOD usage are similar to those in related technologies, and will not be elaborated upon here to avoid redundancy.

[0051] In step S102, the actual driving range and actual average driving range of the target vehicle are calculated based on the current operating condition parameters, and the number of cycles and actual usage time of the target vehicle's power battery system under the required percentage depth of discharge (DOD) are calculated based on the actual average driving range.

[0052] It should be noted that after obtaining the current operating condition parameters of the target vehicle, this application needs to decompose the operating condition parameters in the above embodiments to convert them into the required parameters of the power battery cells.

[0053] Optionally, in some embodiments, the actual driving range and actual average driving range of the target vehicle are calculated based on the current operating condition parameters, including: calculating the first product of the average number of daily charging times, the vehicle's required electricity, and the average daily DOD usage; obtaining the actual driving range based on the ratio of the first product to the vehicle's average electricity consumption; and obtaining the actual average driving range based on the product of the actual driving range and the average health status.

[0054] Specifically, in this embodiment, the average number of daily charging cycles, the vehicle's required electricity E, and the average daily DOD are multiplied together, and the ratio of this product to the vehicle's average energy consumption is used as the actual driving range L. 实际 L 实际 = Average number of charging sessions per day × Vehicle's required energy E × Average daily DOD / Average vehicle energy consumption. Then, based on the actual driving range L... 实际 and average health status (SOH) 平均 Obtain the actual average driving range L 实际平 L 实际平 =L 实际 ×SOH 平均 .

[0055] Furthermore, in some embodiments, the number of cycles and actual usage time of the target vehicle's power battery system under the required percentage depth of discharge (DOD) are calculated based on the actual average driving range, including: obtaining the number of cycles under DOD based on the ratio of a preset mileage to the actual average driving range; and obtaining the actual usage time based on the ratio of the number of cycles under DOD to the annual average number of operating days.

[0056] It should be noted that, based on the above embodiments, this application obtained the actual driving range L. 实际 And actual average driving range L 实际平 Therefore, this application can calculate and convert these parameters into the required parameters for power battery cells, namely the number of cycles and actual usage time required by the power battery system under the DOD.

[0057] Specifically, in this embodiment, the preset mileage is M, then the required number of cycles under DOD for the power battery system is Cyc = M / L. 实际平 If the average number of operating days per year is n, then the actual usage time = Cyc / n.

[0058] In step S103, based on the current operating condition parameters, the number of cycles under DOD and the actual usage time, the average charging and discharging temperature and the average storage temperature of the power battery to be matched are obtained in combination with the temperature rise data of the power battery to be matched.

[0059] It should be noted that, through steps S101 and S102, this application uses the actual operating condition data and scenario parameters of the target vehicle as input conditions, and then decomposes the parameters for the power battery, transforming the parameters into the required parameters for the power battery cells, namely the number of cycles and actual usage time required by the power battery system under the DOD. Furthermore, this application needs to collect the temperature rise data of the matched power battery cells, and under preset operating conditions, calculate the average charging and discharging temperature and the average storage temperature of the power battery to be matched.

[0060] Specifically, this application needs to calculate the average ambient temperature of the target vehicle's operating area based on the ambient temperature obtained in step S101, and then calculate the average charging current I of the vehicle obtained in step S101. 充 and vehicle average discharge current I 放 The ratio, combined with the temperature rise data of the power battery to be matched, in the average ambient temperature and I in the operating area of ​​the target vehicle. 充 / I 放 Under the operating conditions, the average charging and discharging temperature and the average storage temperature of the power battery are calculated.

[0061] In step S104, based on the degradation curve of the power battery to be matched and the calendar life degradation amount, the first degradation rate of the power battery to be matched at the average charging and discharging temperature, the second degradation rate at the average storage temperature, and the third degradation rate of the power battery system consistency are calculated, and the life estimation result of the power battery to be matched is generated according to the first degradation rate, the second degradation rate, and the third degradation rate.

[0062] Specifically, this application requires testing the battery cells of the power battery to be matched under different ambient temperatures, the capacity retention rate decay curve of the power battery with the number of cycles, and the calendar life decay amount under different ambient temperatures, i.e., the capacity decay amount with the number of storage days. Therefore, this application can calculate the power battery degradation rate after multiple cycles at the average charge / discharge temperature, i.e., the first degradation rate in this embodiment, and the actual usage time (i.e., calendar life) degradation rate at the average storage temperature, i.e., the second degradation rate in this embodiment. In addition, this application also needs to obtain the consistent degradation rate of the power battery system, i.e., the third degradation rate in this embodiment.

[0063] Furthermore, this application can calculate the total degradation rate of the power battery based on the obtained first degradation rate, second degradation rate and third degradation rate to generate a life estimation result of the power battery to be matched.

[0064] Optionally, in some embodiments, generating a lifespan estimation result for the power battery to be matched based on a first decay rate, a second decay rate, and a third decay rate includes: obtaining a total decay rate based on the sum of the first decay rate, the second decay rate, and the third decay rate; calculating the difference between the target value and the total decay rate; and using the product of the difference and the initial capacity of the power battery to be matched as the lifespan estimation result for the power battery to be matched.

[0065] Specifically, in this embodiment, the total degradation rate S% of the power battery to be matched 总 S% is the sum of the first attenuation rate S1%, the second attenuation rate S2%, and the third attenuation rate S3% mentioned above. 总 =S1% + S2% + S3%. Therefore, this application needs to calculate the target value and the total attenuation rate S%. 总 The difference, preferably, in the embodiment of this application, the target value is 1, then the difference is 1-S%. 总 The product of this difference and the initial capacity of the power battery to be matched is calculated, and the product of the two is used as the estimated life of the power battery of the target vehicle under the preset service life or preset mileage.

[0066] Optionally, in some embodiments, after calculating the difference between the target value and the total attenuation rate, the method further includes: if the difference is greater than or equal to the average health, then it is determined that the power battery to be matched meets the service life of the target vehicle; otherwise, it is determined that the power battery to be matched does not meet the service life of the target vehicle.

[0067] It should be noted that after calculating the difference between the target value and the total degradation rate, this application needs to compare the difference with the average health of the power battery. If the difference between the target value and the total degradation rate is greater than or equal to the average health, it is determined that the currently matched power battery can meet the life requirements of the vehicle design; otherwise, it is not met, and the lifespan of the current power battery is estimated.

[0068] Based on the above embodiments, it can be understood that this application fully considers the actual operating conditions of the vehicle, including parameters such as average vehicle power consumption, average daily mileage, and ambient temperature of the operating area. It also combines the cyclic test data of the power battery cells under different temperature environments, calendar life data under different ambient temperatures, and the consistent degradation rate of the power battery system to establish a more accurate and comprehensive estimation model for the life of the power battery. This greatly improves the accuracy of the power battery life estimation. Only by inputting the relevant parameters can the current life of the power battery system be estimated to determine whether it meets the requirements of the vehicle. The estimation method is simple and easy to implement.

[0069] To enable those skilled in the art to further understand the life estimation method for power batteries of this application, the following examples illustrate the implementation steps of the method.

[0070] Specifically, Figure 2 This is a flowchart illustrating a method for estimating the lifespan of a power battery according to a specific embodiment of this application. In this embodiment, the electric vehicle's design lifespan is N years, the driving mileage is M tens of thousands of kilometers, the number of power battery cycle tests is Cyc, the actual usage time is n, and the vehicle's average charging current is denoted as I. 充 The average discharge current of a vehicle is denoted as I. 放 The average charging and discharging temperature of the power battery is T1, and the average storage temperature is T2. For example... Figure 2 As shown, the method for estimating the lifespan of this power battery specifically includes the following steps:

[0071] Step 201: Input the actual operating conditions of the vehicle, including: the vehicle's required electricity E, the vehicle's average energy consumption, the vehicle's average daily DOD, the average number of charging times per day, the vehicle's operating area, the vehicle's annual operating days n, and the average charging current I. 充 Average discharge current I 放 Electric vehicles with a design life of N years or M kilometers must meet the State of Health (SOH) standard. 需求 And meet a certain design average health (SOH) 平均 );

[0072] Step S202: Decompose parameters and calculate the vehicle's actual driving range L. 实际= Average number of charging sessions per day × Energy consumption (E) × Average daily usage (DOD) / Vehicle energy consumption, to calculate the average driving range (L). 实际平 =L 实际 ×SOH 平均 The number of cycles required to convert to 100% DOD for an electric vehicle battery system is Cyc = M / L. 实际平 Actual usage time = Cyc / n;

[0073] Step S203: Combining the temperature rise data of the target power battery cell, and based on the average ambient temperature and average charge / discharge current I in the vehicle's operating area... 充 / I 放 Under operating conditions, calculate the average charging and discharging temperature T1 and the average storage temperature T2 of the power battery;

[0074] Step S204 requires testing the capacity retention rate decay curve of the target power battery cell under different ambient temperatures with the number of cycles, the calendar life decay amount under different ambient temperatures (capacity decay amount with storage days), and then calculating the cycle decay rate S1% of the battery at the number of cycles at temperature T1, the actual usage time (i.e., calendar life) decay rate S2% at the average storage temperature T2, and the battery system consistency decay S3%.

[0075] Step S205, calculate the attenuation S%. 总 =S1% + S2% + S3%, if 1 - S% 总 ≥SOH 需求 If the matched battery cells meet the vehicle's design life requirements, then they do not; otherwise, they do not. The output estimate is: the battery's design life for N years or M kilomiles is (1-S%) of the initial capacity. 总 ).

[0076] Therefore, the power battery life estimation method of this application does not require assembling the power battery in an electric vehicle and using data from a period of actual vehicle operation to assess the remaining lifespan of the power battery, nor does it require battery bench testing or simulation software simulation, effectively reducing computational costs.

[0077] The method for estimating the lifespan of a power battery proposed in this application involves calculating the vehicle's actual driving range and actual average driving range based on the vehicle's current operating parameters. Based on this, the required number of cycles and actual usage time under the DOD (Depth of Hour) of the vehicle's power battery system are calculated. Combined with the power battery's temperature rise data, the average charge / discharge temperature and average storage temperature are obtained. Based on the power battery's degradation curve and calendar lifespan degradation amount, a first degradation rate at the average charge / discharge temperature, a second degradation rate at the average storage temperature, and a third degradation rate consistent with the power battery system are calculated. The lifespan estimation result of the power battery is then generated based on the first, second, and third degradation rates. This method solves the problems of single empirical models and incomplete evaluation results in related technologies, improving the accuracy of power battery lifespan estimation, shortening the estimation cycle, reducing computational costs, and making the estimation process simpler and more convenient.

[0078] Next, the life estimation device for a power battery according to an embodiment of this application is described with reference to the accompanying drawings.

[0079] Figure 3 This is a block diagram of a power battery life estimation device according to an embodiment of this application.

[0080] like Figure 3 As shown, the power battery life estimation device 10 includes: a first acquisition module 100, a calculation module 200, a second acquisition module 300, and an estimation module 400.

[0081] The system comprises the following modules: a first acquisition module 100, used to acquire the current operating condition parameters of the target vehicle; a calculation module 200, used to calculate the actual driving range and actual average driving range of the target vehicle based on the current operating condition parameters, and to calculate the number of cycles and actual usage time of the target vehicle's power battery system under the required percentage depth of discharge (DOD) based on the actual average driving range; a second acquisition module 300, used to obtain the average charge / discharge temperature and average storage temperature of the power battery to be matched based on the current operating condition parameters, the number of cycles under DOD, and the actual usage time, combined with the temperature rise data of the power battery to be matched; and an estimation module 400, used to calculate the first degradation rate of the power battery to be matched at the average charge / discharge temperature, the second degradation rate at the average storage temperature, and the third degradation rate consistent with the power battery system based on the degradation curve and calendar life degradation amount of the power battery to be matched, and to generate the life estimation result of the power battery to be matched based on the first degradation rate, the second degradation rate, and the third degradation rate.

[0082] Optionally, in some embodiments, the current operating condition parameters include at least one of the following: vehicle power consumption, vehicle average power consumption, average daily mileage, average annual operating days, average annual off-duty days, ambient temperature of the operating area, average daily charging frequency, average daily DOD usage, average vehicle charging current, average vehicle discharging current, and battery health exceeding a first preset threshold and average health exceeding a second preset threshold after the vehicle's actual service life reaches a preset service life or the vehicle has traveled a preset mileage.

[0083] Optionally, in some embodiments, the calculation module 200 is specifically used to: calculate the first product of the average number of daily charging times, the vehicle's required electricity, and the average daily DOD usage; obtain the actual driving range based on the ratio of the first product to the vehicle's average electricity consumption; and obtain the actual average driving range based on the product of the actual driving range and the average health status.

[0084] Optionally, in some embodiments, the calculation module 200 is further configured to: obtain the number of cycles under DOD based on the ratio of the preset mileage to the actual average driving range; and obtain the actual usage time based on the ratio of the number of cycles under DOD to the annual average number of operating days.

[0085] Optionally, in some embodiments, the estimation module 400 is specifically used to: obtain the total attenuation rate based on the sum of the first attenuation rate, the second attenuation rate, and the third attenuation rate; calculate the difference between the target value and the total attenuation rate; and use the product of the difference and the initial capacity of the power battery to be matched as the life estimation result of the power battery to be matched.

[0086] Optionally, in some embodiments, after calculating the difference between the target value and the total attenuation rate, the estimation module 400 is further configured to: determine that the power battery to be matched meets the service life of the target vehicle when the difference is greater than or equal to the average health level; otherwise, determine that the power battery to be matched does not meet the service life of the target vehicle.

[0087] It should be noted that the foregoing explanation of the embodiment of the power battery life estimation method also applies to the power battery life estimation device of this embodiment, and will not be repeated here.

[0088] The power battery life estimation device proposed in this application calculates the actual driving range and actual average driving range of the vehicle based on the vehicle's current operating parameters. Based on this, it calculates the number of cycles required under the DOD (Depth of Hour) of the vehicle's power battery system and the actual usage time. Combining the power battery's temperature rise data, it obtains the average charge / discharge temperature and the average storage temperature. Based on the power battery's degradation curve and calendar life degradation amount, it calculates the first degradation rate at the average charge / discharge temperature, the second degradation rate at the average storage temperature, and the third degradation rate consistent with the power battery system. The power battery life estimation result is generated based on the first, second, and third degradation rates. This solves the problems of single empirical models and incomplete evaluation results in related technologies, improving the accuracy of power battery life estimation, shortening the estimation cycle, reducing computational costs, and making the estimation process simpler and more convenient.

[0089] Figure 4 This is a schematic diagram of a power battery system provided in an embodiment of this application. The power battery system may include:

[0090] The memory 401, the processor 402, and the computer program stored on the memory 401 and capable of running on the processor 402.

[0091] When the processor 402 executes the program, it implements the power battery life estimation method provided in the above embodiments.

[0092] Furthermore, the power battery system also includes:

[0093] Communication interface 403 is used for communication between memory 401 and processor 402.

[0094] The memory 401 is used to store computer programs that can run on the processor 402.

[0095] The memory 401 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.

[0096] If the memory 401, processor 402, and communication interface 403 are implemented independently, then the communication interface 403, memory 401, and processor 402 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 4 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0097] Optionally, in a specific implementation, if the memory 401, processor 402, and communication interface 403 are integrated on a single chip, then the memory 401, processor 402, and communication interface 403 can communicate with each other through an internal interface.

[0098] Processor 402 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement embodiments of this application.

[0099] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for estimating the lifespan of a power battery.

[0100] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0101] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0102] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0103] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0104] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0105] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for estimating the lifetime of a power battery, characterized in that, Includes the following steps: Obtain the current operating parameters of the target vehicle; The actual driving range and actual average driving range of the target vehicle are calculated based on the current operating condition parameters, and the number of cycles and actual usage time of the target vehicle's power battery system under the required percentage depth of discharge (DOD) are calculated based on the actual average driving range. Based on the current operating condition parameters, the number of cycles under DOD, and the actual usage time, the average charging and discharging temperature and the average storage temperature of the power battery to be matched are obtained by combining the temperature rise data of the power battery to be matched. as well as Based on the degradation curve and calendar life degradation of the power battery to be matched, the first degradation rate, the second degradation rate and the third degradation rate of the power battery to be matched at the average charge and discharge temperature, the second degradation rate and the third degradation rate of the power battery system consistency are calculated, and the life estimation result of the power battery to be matched is generated according to the first degradation rate, the second degradation rate and the third degradation rate. The step of generating the life estimation result of the power battery to be matched based on the first decay rate, the second decay rate and the third decay rate includes: obtaining the total decay rate based on the sum of the first decay rate, the second decay rate and the third decay rate; Calculate the difference between the target value and the total degradation rate, and multiply the difference by the initial capacity of the power battery to be matched as the life estimation result of the power battery to be matched.

2. The method of claim 1, wherein, The current operating condition parameters include at least one of the following: vehicle power requirement, vehicle average power consumption, average daily mileage, average annual operating days, average annual off-duty days, ambient temperature of the operating area, average daily charging frequency, average daily DOD usage, average vehicle charging current, average vehicle discharging current, and battery health exceeding a first preset threshold and average health exceeding a second preset threshold after the vehicle's actual service life reaches a preset service life or after the vehicle has traveled a preset mileage.

3. The method of claim 2, wherein, The step of calculating the actual driving range and actual average driving range of the target vehicle based on the current operating condition parameters includes: Calculate the first product of the average number of daily charging cycles, the vehicle's required electricity, and the average daily DOD usage; The actual driving range is obtained by the ratio of the first product to the average energy consumption of the vehicle. The actual average driving range is obtained by multiplying the actual driving range and the average health status.

4. The method of claim 3, wherein, The calculation of the required number of cycles and actual usage time under the percentage depth of discharge (DOD) of the target vehicle's power battery system based on the actual average driving range includes: The number of cycles under DOD is obtained based on the ratio of the preset mileage to the actual average driving range; The actual usage time is obtained by the ratio of the number of cycles under the DOD to the average number of operating days per year.

5. The method of claim 1, wherein, After calculating the difference between the target value and the total attenuation rate, the method further includes: If the difference is greater than or equal to the average health level, it is determined that the power battery to be matched meets the service life of the target vehicle; otherwise, it is determined that the power battery to be matched does not meet the service life of the target vehicle.

6. A lifetime estimation device for a power battery, characterized by comprising: include: The first acquisition module is used to acquire the current operating condition parameters of the target vehicle; The calculation module is used to calculate the actual driving range and actual average driving range of the target vehicle based on the current operating condition parameters, and to calculate the number of cycles and actual usage time of the target vehicle's power battery system under the required percentage depth of discharge (DOD) based on the actual average driving range. The second acquisition module is used to obtain the average charging and discharging temperature and the average storage temperature of the power battery to be matched based on the current operating condition parameters, the number of cycles under the DOD and the actual usage time, combined with the temperature rise data of the power battery to be matched. as well as The estimation module is used to calculate the first degradation rate, the second degradation rate and the third degradation rate of the power battery under the average charge and discharge temperature, based on the degradation curve and calendar life degradation amount of the power battery to be matched, and the consistency of the power battery system. The module also generates the life estimation result of the power battery to be matched based on the first degradation rate, the second degradation rate and the third degradation rate. The estimation module is further configured to: obtain a total attenuation rate based on the sum of the first attenuation rate, the second attenuation rate, and the third attenuation rate; calculate the difference between the target value and the total attenuation rate; and use the product of the difference and the initial capacity of the power battery to be matched as the life estimation result of the power battery to be matched.

7. The apparatus of claim 6, wherein, The current operating condition parameters include at least one of the following: vehicle power requirement, vehicle average power consumption, average daily mileage, average annual operating days, average annual off-duty days, ambient temperature of the operating area, average daily charging frequency, average daily DOD usage, average vehicle charging current, average vehicle discharging current, and battery health exceeding a first preset threshold and average health exceeding a second preset threshold after the vehicle's actual service life reaches a preset service life or after the vehicle has traveled a preset mileage.

8. A power battery system, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the life estimation method for a power battery as described in any one of claims 1-5.

9. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the life estimation method for the power battery as described in any one of claims 1-5.

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