Power battery cycle life prediction method, device, equipment and medium

Abstract

The invention provides a power battery cycle life prediction method, device, equipment and medium, and the method comprises the steps: formulating a power battery life simulation working condition according to vehicle information and the design life of a power battery of a vehicle, the design life comprising a calendar design life and a mileage design life; according to the power battery life simulation working condition, the storage duration of the power battery design life and the average temperature of the vehicle battery pack are obtained; obtaining the attenuation of the storage life of the power battery according to the storage duration, the average temperature and the calendar life characteristic parameters; subtracting the attenuation of the storage life from the total attenuation index value corresponding to the designed life to obtain an attenuation index value of the cycle life of the power battery; and obtaining a target number of turns corresponding to the cycle life according to the total attenuation index value of the design life, the attenuation index value of the cycle life, the theoretical number of turns of the cycle life and the cycle life characteristic parameters. According to the embodiment of the invention, the influence of storage factors is considered, and the obtained cycle life is more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and in particular to a method, device, equipment and medium for predicting the cycle life of a power battery. Background Art

[0002] The vehicle's power battery life test verification generally has two test verification methods: calendar life and cycle life. Due to the long calendar life storage cycle, most OEMs and battery companies currently only conduct 1-year cell-level storage tests at characteristic temperatures, focusing on cell-level cycle life test verification. System-level life testing is subject to problems such as long test cycles and high test costs. Generally, most OEMs and battery companies currently do not conduct long-cycle storage tests, but only cycle life test verification. Basically, the cycle life test cycle is 1.5 to 2 years.

[0003] However, the current mainstream cycle life test verification method does not take into account the impact of storage factors on the battery, which is quite different from the actual operating conditions of the vehicle. As a result, the cycle life verification results are inaccurate and cannot effectively support the life design reliability. Summary of the invention

[0004] The purpose of the present invention is to provide a method, device, equipment and medium for predicting the cycle life of a power battery, which is used to solve the problem that when the power battery is subjected to a cycle life test, the influence of storage factors on the battery is not considered, resulting in an inaccurate cycle life used for verification and inability to effectively support the reliability of the life design.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a method for predicting the cycle life of a power battery, comprising:

[0006] Formulate a power battery life simulation condition based on vehicle information and the design life of the vehicle's power battery, wherein the design life includes a calendar design life and a mileage design life;

[0007] According to the power battery life simulation working condition, the storage time corresponding to the design life of the power battery and the average temperature of the vehicle battery pack are obtained;

[0008] Obtaining a storage life attenuation amount of the power battery according to the storage time, the average temperature and the calendar life characteristic parameter;

[0009] The attenuation index value corresponding to the cycle life of the power battery is obtained by subtracting the attenuation of the storage life from the total attenuation index value corresponding to the design life;

[0010] According to the total attenuation index value corresponding to the design life, the attenuation index value corresponding to the cycle life, the theoretical number of turns corresponding to the cycle life and the cycle life characteristic parameters, the target number of turns corresponding to the cycle life is obtained.

[0011] Optionally, a power battery life simulation condition is formulated according to the vehicle information and the design life of the power battery, including:

[0012] When the calendar design life and the mileage design life in the design life of the power battery reach their expiration dates at the same time, a power battery life simulation operating condition is formulated according to the vehicle information.

[0013] Optionally, before formulating the power battery life simulation working condition according to the vehicle information and the design life of the power battery, the method further includes:

[0014] Determining a health status index value of a design life of the power battery according to the health status index value of the warranty life of the power battery;

[0015] The mileage design life and the calendar design life in the design life of the power battery are determined according to the health status index value of the warranty life, the health status index value of the design life, the warranty life information of the power battery and the requirement information of the vehicle durability test.

[0016] Optionally, the warranty life information includes warranty mileage life and warranty calendar life;

[0017] The requirement information of the vehicle durability test includes mileage requirement and duration requirement;

[0018] Wherein, determining the mileage design life and calendar design life in the design life of the power battery according to the health status index value of the warranty life, the health status index value of the design life, the warranty life information of the power battery and the requirement information of the vehicle durability test includes:

[0019] determining a first mileage life of the power battery according to the health status index value of the warranty life, the health status index value of the design life, and the warranty mileage life in the warranty life;

[0020] comparing the mileage requirement of the vehicle durability test and the first mileage life, and determining the larger one of the mileage requirement and the first mileage life as the mileage design life in the design life of the power battery;

[0021] Determining a first calendar life of the power battery according to the health status index value of the warranty life, the health status index value of the design life, and the warranty calendar life in the warranty life;

[0022] The duration requirement of the vehicle endurance test and the first calendar life are compared, and the larger one of the duration requirement and the first calendar life is determined as the calendar design life in the design life of the power battery.

[0023] Optionally, the method further comprises:

[0024] According to the health status index value of the design life of the power battery, a total attenuation index value corresponding to the design life is determined.

[0025] Optionally, obtaining the attenuation of the storage life of the power battery according to the storage time, the average temperature and the calendar life characteristic parameter includes:

[0026] According to the storage time, the average temperature and the calendar life characteristic parameters, the attenuation of the storage life of the power battery is obtained through simulation calculation of the Arrhenius equation.

[0027] Optionally, the method further comprises:

[0028] Determining the actual driving range of the vehicle according to the energy consumption coefficient of the vehicle and the target mileage of the vehicle under standard operating conditions;

[0029] The theoretical number of cycles corresponding to the cycle life of the power battery is determined according to the mileage design life, the actual driving range and the health status index value of the design life of the power battery.

[0030] Optionally, obtaining a target number of cycles corresponding to the cycle life according to the total attenuation index value corresponding to the design life, the attenuation index value corresponding to the cycle life, the theoretical number of cycles corresponding to the cycle life, and a cycle life characteristic parameter includes:

[0031] according to Obtaining a target number of cycles corresponding to the cycle life;

[0032] Among them, PACK cyc_t Indicates the target number of cycles corresponding to the cycle life, PACK cyc Indicates the theoretical number of cycles corresponding to the cycle life, 1-SOH d Indicates the total attenuation index value corresponding to the design life, SOH d Indicates the health status index value corresponding to the design life, ΔSOH cyc It represents the attenuation index value corresponding to the cycle life, and Z represents the battery pack cycle life aging factor in the cycle life characteristic parameters.

[0033] Optionally, the vehicle information includes one or more of the following:

[0034] Weekly mileage, weekly fast charging and slow charging ratio, weekly total number of fast charging and slow charging, driving time, battery status of the charging terminal corresponding to the power battery, and weekly charging and discharging depth corresponding to the power battery.

[0035] Optionally, before formulating the power battery life simulation working condition according to the vehicle information and the design life of the power battery, the method further includes:

[0036] According to the calendar design life and the mileage design life, obtaining the weekly mileage in the vehicle information;

[0037] Obtaining a target energy consumption of the vehicle according to a target mileage and a target power of the vehicle under standard operating conditions;

[0038] Determining the actual energy consumption of the vehicle according to the energy consumption coefficient of the vehicle and the target energy consumption;

[0039] According to the weekly mileage, the actual energy consumption and the target power, a weekly charge and discharge depth corresponding to the power battery in the vehicle information is obtained.

[0040] The embodiment of the present invention further provides a power battery cycle life prediction device, comprising:

[0041] A first formulation module is used to formulate a power battery life simulation condition according to vehicle information and a design life of the vehicle's power battery; wherein the design life includes a calendar design life and a mileage design life;

[0042] A first calculation module, used for obtaining the storage time corresponding to the design life of the power battery and the average temperature of the vehicle battery pack according to the power battery life simulation working condition;

[0043] A second calculation module, used to obtain the attenuation of the storage life of the power battery according to the storage time, the average temperature and the calendar life characteristic parameter;

[0044] A third calculation module is used to obtain a decay index value corresponding to the cycle life of the power battery by subtracting the decay amount of the storage life from the total decay index value corresponding to the design life;

[0045] The fourth calculation module is used to obtain the target number of cycles corresponding to the cycle life according to the total attenuation index value corresponding to the design life, the attenuation index value corresponding to the cycle life, the theoretical number of cycles corresponding to the cycle life and the cycle life characteristic parameters.

[0046] An embodiment of the present invention further provides a network device, comprising: a processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the power battery cycle life prediction method as described in any one of the above items.

[0047] An embodiment of the present invention further provides a readable storage medium, comprising: a program is stored on the readable storage medium, and when the program is executed by a processor, the steps of the power battery cycle life prediction method as described in any one of the above items are implemented.

[0048] An embodiment of the present invention further provides a computer program product, comprising computer instructions, which, when executed by a processor, implement the steps of the power battery cycle life prediction method as described in any one of the above items.

[0049] At least one of the above technical solutions of the present invention has the following beneficial effects:

[0050] In the above scheme, first, simulation is performed according to the vehicle information and the design life of the power battery of the vehicle, and a power battery life simulation condition is formulated. Then, based on the power battery life simulation condition, the storage time corresponding to the design life of the power battery and the average temperature of the vehicle battery pack are obtained. According to the storage time, average temperature and calendar life characteristic parameters, the attenuation of the storage life of the power battery is obtained. Finally, according to the total attenuation index value corresponding to the design life and the attenuation of the storage life, the attenuation index value corresponding to the cycle life of the power battery is obtained. According to the total attenuation index value corresponding to the design life, the attenuation index value corresponding to the cycle life, the theoretical number of cycles corresponding to the cycle life and the cycle life characteristic parameters, the target number of cycles corresponding to the cycle life is obtained. According to the target number of cycles corresponding to the cycle life obtained by the above prediction method, the life verification test of the power battery of the vehicle is performed. Compared with the prior art, when determining the cycle life of the vehicle, the present invention also takes into account the influence of storage factors. The calculation is based on the attenuation of the storage life of the power battery, which is more in line with the actual vehicle use behavior of the user. The target number of cycles corresponding to the cycle life obtained in the end is more accurate, which effectively supports the reliability of the life design. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A schematic diagram of a flow chart of a method for predicting cycle life of a power battery according to an embodiment of the present invention;

[0052] Figure 2 Schematic diagram of the structure of a power battery cycle life prediction device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] like Figure 1 As shown, an embodiment of the present invention provides a method for predicting cycle life of a power battery, comprising:

[0055] Step S101, formulating a power battery life simulation condition according to vehicle information and the design life of the power battery of the vehicle, wherein the design life includes a calendar design life and a mileage design life;

[0056] In step S101, a vehicle battery life simulation condition is formulated based on vehicle information and a pre-configured design life of the vehicle's power battery. Furthermore, for better application, it is also necessary to determine the proportion of the vehicle's state of charge (SOC) time in the power battery life simulation condition. When the vehicle's SOC time proportion meets the preset conditions, the vehicle battery life simulation condition is determined as the required power battery life simulation condition.

[0057] Step S102, obtaining the storage time corresponding to the design life of the power battery and the average temperature of the vehicle battery pack according to the power battery life simulation working condition;

[0058] In step S102, the storage life decay of the power battery system is mainly affected by factors such as the standing time, standing temperature, and standing SOC. Therefore, it is necessary to combine the vehicle operation mode and user operation characteristics to finally determine the standing time at different SOCs and different characteristic temperatures, and then deduce the storage time corresponding to the design life of the power battery. Specifically, first, according to the power battery life simulation working conditions formulated in step S101, the storage time of the vehicle's power battery per week (that is, the time when the battery charging and discharging current is 0A) is obtained, and then, according to the storage time of the power battery per week, the cumulative storage time corresponding to the design life of the power battery is obtained.

[0059] The average temperature of the vehicle battery pack is the average of the maximum temperatures of the battery cells at different times, and the temperature of the battery cells is affected by the vehicle operating conditions, thermal management strategy, and urban environment. Therefore, the power battery life simulation conditions, thermal management strategy, and different urban environment temperature curves formulated in step S101 are imported into the life simulation model to simulate the average temperature of the battery pack (PACK) under different urban environments.

[0060] Step S103, obtaining the attenuation of the storage life of the power battery according to the storage time, the average temperature and the calendar life characteristic parameter;

[0061] In step S103, the storage life evaluation of the power battery mainly relies on the calendar life specification and calendar life test of the battery cell, and generally the storage life of the battery cell level is related to the temperature and SOC dimensions. Therefore, according to the calendar life characteristic parameter E a , A, Z, the storage time corresponding to the design life obtained in step S102, and the average temperature of the battery pack (PACK) are calculated to obtain the attenuation ΔSOH of the storage life of the power battery cal ; Among them, E a It represents the activation energy of capacity decay, the unit is J / mol, A represents the pre-exponential factor of capacity decay, and Z represents the aging factor.

[0062] It should be noted that the average temperature of the battery pack (PACK) corresponding to different urban environments is different, and the average temperature is selected for calculation based on actual conditions.

[0063] It should also be noted that in step S103, the attenuation of the storage life of the power battery ΔSOH is obtained. cal After that, it is necessary to verify ΔSOH cal The accuracy of the cal Determine the desired ΔSOH cal The specific verification method is to verify at multiple different temperature points (for example: 25°C, 45°C and 60°C), and at multiple different SOC test points (for example: 100%, 80% and 50%). In addition, since the 25°C calendar life test cycle is very long, the battery cell calendar life specification verification is generally achieved through temperature acceleration, thereby effectively verifying the accuracy of the storage life attenuation.

[0064] Step S104, subtracting the attenuation of the storage life from the total attenuation index value corresponding to the design life to obtain an attenuation index value corresponding to the cycle life of the power battery;

[0065] In step S104, the design life corresponds to a total attenuation index value ΔSOH d , based on the storage life attenuation ΔSOH cal , for the total attenuation index value △SOH d Decompose and obtain the attenuation index value ΔSOH corresponding to the cycle life of the power battery cyc , specifically: ΔSOH cyc ≤△SOH d -ΔSOH cal .

[0066] It should be noted that the average temperature of the battery pack (PACK) corresponding to different urban environments is different, that is, △SOH d The higher the temperature, the faster the calendar life decays. In order to improve the success rate of life design, in actual application, cities with higher average temperatures throughout the year are generally selected for decomposition, but the present invention is not limited to this.

[0067] Step S105, obtaining a target number of cycles corresponding to the cycle life according to the total attenuation index value corresponding to the design life, the attenuation index value corresponding to the cycle life, the theoretical number of cycles corresponding to the cycle life and the cycle life characteristic parameter.

[0068] In step S105, theoretically, the capacity attenuation of the power battery during cycle life can also be calculated by simulation of the Arrhenius equation, and the formula is as follows:

[0069]

[0070] Among them, △SOH represents the capacity decay caused by the comparison between the battery cycle life and the beginning of life (BOL) state; A represents the capacity decay pre-exponential factor; E a It represents the activation energy of capacity decay, in J / mol; R represents the Boltzmann constant (8.314); T represents temperature, corresponding to degrees Fahrenheit, in K; n represents the number of cycles, in circles; and Z represents the aging factor of the battery cell cycle life.

[0071] According to the above Arrhenius equation and the attenuation index value ΔSOH corresponding to the cycle life of the power battery cyc Expression: ΔSOH cyc ≤△SOH d -ΔSOH cal , under the premise that the average temperature of the battery cell remains unchanged, the calculation formula for the target number of cycles corresponding to the cycle life is derived as follows:

[0072]

[0073] Among them, PACK cyc_t Indicates the target number of cycles corresponding to the cycle life, PACK cyc Indicates the theoretical number of cycles corresponding to the cycle life, 1-SOH d Indicates the total attenuation index value △SOH corresponding to the design life d , SOH d Indicates the health status index value corresponding to the design life, ΔSOH cyc It represents the attenuation index value corresponding to the cycle life, and Z represents the cell cycle life aging factor in the cycle life characteristic parameters.

[0074] In the embodiment of the present invention, first, simulation is performed according to vehicle information and the design life of the power battery of the vehicle, and a power battery life simulation condition is formulated. Then, based on the power battery life simulation condition, the storage time corresponding to the design life of the power battery and the average temperature of the vehicle battery pack are obtained. According to the storage time, the average temperature and the calendar life characteristic parameters, the attenuation of the storage life of the power battery is obtained. Finally, according to the total attenuation index value corresponding to the design life and the attenuation of the storage life, the attenuation index value corresponding to the cycle life of the power battery is obtained. According to the total attenuation index value corresponding to the design life, the attenuation index value corresponding to the cycle life, the theoretical number of cycles corresponding to the cycle life and the cycle life characteristic parameters, the target number of cycles corresponding to the cycle life is obtained. When determining the cycle life of the vehicle, the influence of the storage factor is taken into account. The attenuation index value corresponding to the cycle life is obtained based on the attenuation of the storage life of the power battery, and then the target number of cycles corresponding to the cycle life is predicted, which is more in line with the actual vehicle use behavior of the user. The target number of cycles corresponding to the cycle life obtained in the end is more accurate. The subsequent life verification test of the power battery of the vehicle based on the target number of cycles corresponding to the cycle life is more accurate, which effectively supports the reliability of the life design.

[0075] In addition, the embodiment of the present invention decomposes the power battery system into the module level and the battery cell level in the process of predicting the cycle life, so that the method has wide applicability and is applicable to the decomposition of the power battery system, battery cell, and module cycle life indicators corresponding to the three guarantees validity period, warranty period, power battery warranty period, and design life of the whole vehicle. The method provided by the present invention is also applicable to pure electric vehicles, plug-in hybrid electric vehicles (PHEV), hybrid electric vehicles (HEV) and other models.

[0076] Optionally, a power battery life simulation condition is formulated according to the vehicle information and the design life of the power battery, including:

[0077] When the calendar design life and the mileage design life in the design life of the power battery reach their expiration dates at the same time, a power battery life simulation operating condition is formulated according to the vehicle information.

[0078] In the embodiment of the present invention, the life index of the power battery system is defined as the calendar life and mileage life reaching the deadline at the same time, rather than whichever arrives first. Therefore, based on the principle that the calendar design life and mileage design life in the design life of the power battery reach the deadline at the same time, the vehicle information is input to formulate the power battery life simulation condition. The life index definition of the embodiment of the present invention is very strict, which can ensure the success rate and reliability of the life design, and the accuracy of the cycle life verification is higher.

[0079] Optionally, before formulating the power battery life simulation working condition according to the vehicle information and the design life of the power battery, the method further includes:

[0080] Determining a health status index value of a design life of the power battery according to the health status index value of the warranty life of the power battery;

[0081] The mileage design life and the calendar design life in the design life of the power battery are determined according to the health status index value of the warranty life, the health status index value of the design life, the warranty life information of the power battery and the requirement information of the vehicle durability test.

[0082] In an embodiment of the present invention, a method for confirming the design life is provided. When the warranty life information of the power battery and the health state (SOH) index value of the warranty life are known, the design life confirmation method is provided. w In this case, the design life is obtained.

[0083] First, under the same mileage and service life, determine the SOH index value of the design life of the power battery d For: SOH d =SOH w + first threshold; generally, the first threshold is 0.05, but the present invention is not limited to this. Then, based on SOH w and SOH d , the mileage design life and calendar design life of the power battery in its design life are derived based on the warranty life information of the power battery. Finally, the derived mileage design life and calendar design life are compared with the requirement information of the vehicle durability test in the vehicle technical specification (VTS) to determine the final mileage design life and calendar design life.

[0084] Optionally, the warranty life information includes warranty mileage life and warranty calendar life;

[0085] The requirement information of the vehicle durability test includes mileage requirement and duration requirement;

[0086] Wherein, determining the mileage design life and calendar design life in the design life of the power battery according to the health status index value of the warranty life, the health status index value of the design life, the warranty life information of the power battery and the requirement information of the vehicle durability test includes:

[0087] determining a first mileage life of the power battery according to the health status index value of the warranty life, the health status index value of the design life, and the warranty mileage life in the warranty life;

[0088] comparing the mileage requirement of the vehicle durability test and the first mileage life, and determining the larger one of the mileage requirement and the first mileage life as the mileage design life in the design life of the power battery;

[0089] Determining a first calendar life of the power battery according to the health status index value of the warranty life, the health status index value of the design life, and the warranty calendar life in the warranty life;

[0090] The duration requirement of the vehicle endurance test and the first calendar life are compared, and the larger one of the duration requirement and the first calendar life is determined as the calendar design life in the design life of the power battery.

[0091] In the embodiment of the present invention, the health state SOH index value corresponding to the design life is required to be consistent with the health state SOH index corresponding to the warranty life, and the final mileage design life and calendar design life are determined respectively. The method for determining the mileage design life is:

[0092] Step 1: According to Determine the first mileage life of the power battery;

[0093] Among them, ODO d For the first mileage life of the power battery, ODO w SOH is the guaranteed mileage life of the power battery in the guaranteed life. d SOH is the index value of the design life of the power battery. w SOH is the indicator value of the warranty life of the power battery w ;

[0094] It should be noted that if ODO d If it is not an integer, it is rounded up.

[0095] Step 2: Determine ODO d The larger of the mileage requirement and the mileage requirement of the vehicle durability test will be determined as the mileage design life in the final design life of the power battery.

[0096] The method for determining the calendar design life is:

[0097] Step 1: According to Determine the first calendar life of the power battery;

[0098] Among them, Timed is the first calendar life of the power battery, Time w SOH is the guaranteed calendar life of the power battery. d SOH is the index value of the design life of the power battery. w SOH is the indicator value of the warranty life of the power battery w ;

[0099] It should be noted that if Time d If it is not an integer, it is rounded up.

[0100] Step 2: Determine Time d The larger of the two, whichever is greater, will be determined as the calendar design life in the final design life of the power battery.

[0101] The mileage design life and calendar design life together constitute the design life. For example, the vehicle warranty life requirement is 8 years and 150,000 kilometers @ 70% SOH, which is the health status indicator value SOH of the warranty life. w 70% warranty mileage life ODO w The warranty calendar life is 150,000 kilometers. w is 8 years. According to the above formula, the first mileage life ODO can be obtained. d The first calendar life is 180,000 km. d It is 10 years; according to the demand information of VTS vehicle durability test (for example: the mileage requirement is 240,000 kilometers, and the duration requirement is 8 years), the final mileage design life is 240,000 kilometers, and the calendar design life is 10 years, that is, the design life of the power battery is: 10 years and 240,000 kilometers @70% SOH.

[0102] Optionally, the method further comprises:

[0103] According to the health status index value of the design life of the power battery, a total attenuation index value corresponding to the design life is determined.

[0104] In the embodiment of the present invention, the total attenuation index value △SOH corresponding to the design life d for:

[0105] △SOH d =1-SOH d .

[0106] Among them, SOH d It is the indicator value of the state of health (SOH) of the design life of the power battery.

[0107] Optionally, obtaining the attenuation of the storage life of the power battery according to the storage time, the average temperature and the calendar life characteristic parameter includes:

[0108] According to the storage time, the average temperature and the calendar life characteristic parameters, the attenuation of the storage life of the power battery is obtained through simulation calculation of the Arrhenius equation.

[0109] In the embodiment of the present invention, the calculation method of step S103 is specifically described. According to the Arrhenius equation Obtain the capacity attenuation ΔSOH generated by comparing the storage life of the power battery with the BOL state cal ;

[0110] Among them, calendar life characteristic parameters include A, E a , Z, A represents the capacity attenuation pre-exponential factor, E a It represents the activation energy of capacity decay in J / mol, Z represents the aging factor, t represents the storage time corresponding to the design life of the power battery, T represents the average temperature of the battery pack, and R is the Boltzmann constant (8.314).

[0111] Optionally, the method further comprises:

[0112] Determining the actual driving range of the vehicle according to the energy consumption coefficient of the vehicle and the target mileage of the vehicle under standard operating conditions;

[0113] The theoretical number of cycles corresponding to the cycle life of the power battery is determined according to the mileage design life, the actual driving range and the health status index value of the design life of the power battery.

[0114] In the embodiment of the present invention, the theoretical number of cycles PACK corresponding to the cycle life of the power battery in step S105 is cyc The calculation method is explained as follows:

[0115] The first step is to use the formula Get the actual driving range of the vehicle D t , unit is km;

[0116] Wherein, D is the target mileage of the vehicle under the normal temperature standard working condition in VTS, namely the China Light-duty Vehicle Test Cycle (CLTC), and η is the energy consumption coefficient. It should be noted that the energy consumption coefficient η in the embodiment of the present invention is mainly determined by the ratio of the actual energy consumption average of operating vehicles and non-operating vehicles and the project design energy consumption based on big data statistics, but the present invention is not limited to this.

[0117] The second step is to use the formula Get the theoretical number of cycles PACK corresponding to the cycle life of the power battery cyc ;

[0118] Among them, ODO d Design life for mileage, SOH d is the indicator value of the health state SOH of the design life of the power battery, D t The actual driving mileage of the vehicle.

[0119] Optionally, the vehicle information includes one or more of the following:

[0120] Weekly mileage, weekly fast charging and slow charging ratio, weekly total number of fast charging and slow charging, driving time, battery status of the charging terminal corresponding to the power battery, and weekly charging and discharging depth corresponding to the power battery.

[0121] In the embodiment of the present invention, the vehicle information includes but is not limited to one or more of the following: weekly mileage, weekly fast charge and slow charge ratio, weekly total number of fast charge and slow charge, driving time, battery status of the charging terminal corresponding to the power battery, and weekly charge and discharge depth corresponding to the power battery. Specifically:

[0122] The user's charging behavior and driving behavior of the vehicle are statistically analyzed based on big data working conditions, including the weekly fast charging and slow charging ratio, the total number of fast charging and slow charging per week, the battery status SOC distribution of the charging terminal corresponding to the power battery, and the driving time. The driving working condition adopts the standard working condition cycle in VTS.

[0123] In addition, the weekly mileage is derived from the mileage design life and calendar design life in the power battery design life;

[0124] The weekly charge and discharge depth of the power battery is derived based on the power consumption of the weekly mileage and the available power at room temperature in the VTS.

[0125] Optionally, before formulating the power battery life simulation working condition according to the vehicle information and the design life of the power battery, the method further includes:

[0126] According to the calendar design life and the mileage design life, obtaining the weekly mileage in the vehicle information;

[0127] Obtaining a target energy consumption of the vehicle according to a target mileage and a target power of the vehicle under standard operating conditions;

[0128] Determining the actual energy consumption of the vehicle according to the energy consumption coefficient of the vehicle and the target energy consumption;

[0129] According to the weekly mileage, the actual energy consumption and the target power, a weekly charge and discharge depth corresponding to the power battery in the vehicle information is obtained.

[0130] In the embodiment of the present invention, the derivation method of the weekly driving mileage and the weekly charging and discharging depth corresponding to the power battery is specifically described:

[0131] According to the formula Get weekly mileage DR week ;

[0132] According to the formula Get the weekly charge and discharge depth DOD corresponding to the power battery week ;

[0133] Among them, DR weer represents weekly mileage, C t Represents the actual energy consumption of the vehicle, then DR weer ×C t It represents the power consumption of weekly mileage; E represents the power demand at normal temperature in the VTS of the whole vehicle, in kWh.

[0134] The actual energy consumption C t According to formula C t =η×C d Calculated, where C d is the design energy consumption, and η is the energy consumption coefficient. It should be noted that the energy consumption coefficient η in the embodiment of the present invention is mainly determined by the ratio of the actual energy consumption average of operating vehicles and non-operating vehicles based on big data statistics to the project design energy consumption, but the present invention is not limited to this.

[0135] Design energy consumption C d According to the formula Calculated, where E represents the target power, i.e., the power required at normal temperature in the vehicle VTS, in kWh;

[0136] D represents the target mileage, that is, the design mileage of the normal temperature standard operating conditions (CLTC conditions) in the vehicle VTS, in km.

[0137] The following is a specific example 1 to illustrate the cycle life prediction and verification process of a power battery:

[0138] Step 1: Determine the design life of the power battery based on the warranty life and the demand information of the vehicle durability test, where the design life includes the mileage design life and the calendar design life;

[0139] Step 2: obtaining vehicle information based on the design life and big data, the vehicle information including but not limited to one or more of weekly mileage, weekly fast charge and slow charge ratio, weekly total number of fast charge and slow charge, driving time, battery status of the charging terminal corresponding to the power battery, and weekly charge and discharge depth corresponding to the power battery;

[0140] Step 3: Based on the principle that the mileage design life and the calendar design life reach their deadlines at the same time, input vehicle information and formulate power battery life simulation conditions;

[0141] Step 4: Based on the power battery life simulation working condition, the storage time corresponding to the design life of the power battery and the average temperature of the vehicle battery pack are obtained. The specific process is shown in step S102;

[0142] Step 5: According to the storage time corresponding to the design life of the power battery, the average temperature of the vehicle battery pack and the calendar life characteristic parameters, the attenuation of the storage life of the power battery ΔSOH is obtained through the Arrhenius equation simulation calculation. cal ;

[0143] Step 6: Determine the theoretical number of cycles PACK corresponding to the cycle life of the power battery according to the actual driving mileage of the vehicle, the mileage design life in the design life, and the health status index value of the design life cyc .

[0144] Step 7: Use the total attenuation index value △SOH corresponding to the design life d Subtract the storage life attenuation ΔSOH cal , obtain the attenuation index value ΔSOH corresponding to the cycle life of the power battery cyc , where △SOH d =1-SOH d , SOH d It is the indicator value of the state of health (SOH) of the design life of the power battery.

[0145] Step 8: Calculate the total attenuation index value △SOH corresponding to the design life d , attenuation index value ΔSOH corresponding to cycle life cyc 、Theoretical number of cycles corresponding to cycle life PACK cyc and cycle life characteristic parameters to obtain the target number of cycles PACK corresponding to the cycle life cyc_t ;

[0146] Step 9: PACK according to the target number of laps cyc_t Perform cycle life verification on vehicles.

[0147] like Figure 2As shown, an embodiment of the present invention further provides a power battery cycle life prediction device, comprising:

[0148] The first formulation module 201 is used to formulate a power battery life simulation condition according to vehicle information and the design life of the vehicle's power battery; wherein the design life includes a calendar design life and a mileage design life;

[0149] A first calculation module 202, configured to obtain a storage time corresponding to the design life of the power battery and an average temperature of a vehicle battery pack according to the power battery life simulation working condition;

[0150] A second calculation module 203, configured to obtain a storage life attenuation of the power battery according to the storage duration, the average temperature and a calendar life characteristic parameter;

[0151] A third calculation module 204 is used to obtain a decay index value corresponding to the cycle life of the power battery by subtracting the decay amount of the storage life from the total decay index value corresponding to the design life;

[0152] The fourth calculation module 205 is used to obtain the target number of cycles corresponding to the cycle life according to the total attenuation index value corresponding to the design life, the attenuation index value corresponding to the cycle life, the theoretical number of cycles corresponding to the cycle life and the cycle life characteristic parameter.

[0153] Optionally, the first formulation module 201 includes:

[0154] The first formulation unit is used to formulate a power battery life simulation condition according to the vehicle information when the calendar design life and the mileage design life in the design life of the power battery reach their expiration dates at the same time.

[0155] Optionally, the device further comprises:

[0156] A first determining module, configured to determine a health status index value of a design life of the power battery according to a health status index value of a warranty life of the power battery;

[0157] The second determination module is used to determine the mileage design life and the calendar design life in the design life of the power battery according to the health status index value of the warranty life, the health status index value of the design life, the warranty life information of the power battery and the requirement information of the vehicle durability test.

[0158] Optionally, the warranty life information in the second determination module includes warranty mileage life and warranty calendar life;

[0159] The requirement information of the vehicle durability test in the second determination module includes mileage requirement and duration requirement;

[0160] Wherein, the second determining module includes:

[0161] A first determining unit, configured to determine a first mileage life of the power battery according to the health status index value of the warranty life, the health status index value of the design life, and the warranty mileage life in the warranty life;

[0162] a second determining unit, configured to compare the mileage requirement of the vehicle durability test with the first mileage life, and determine the larger one of the mileage requirement and the first mileage life as the mileage design life in the design life of the power battery;

[0163] a third determining unit, configured to determine a first calendar life of the power battery according to the health status index value of the warranty life, the health status index value of the design life, and the warranty calendar life in the warranty life;

[0164] The fourth determination unit is used to compare the duration requirement of the vehicle endurance test with the first calendar life, and determine the larger one of the duration requirement and the first calendar life as the calendar design life in the design life of the power battery.

[0165] Optionally, the device further comprises:

[0166] The third determination module is used to determine the total attenuation index value corresponding to the design life according to the health status index value of the design life of the power battery.

[0167] Optionally, the second calculation module 203 includes:

[0168] The first calculation unit is used to obtain the attenuation of the storage life of the power battery through Arrhenius equation simulation calculation according to the storage time, the average temperature and the calendar life characteristic parameter.

[0169] Optionally, the device further comprises:

[0170] a fifth calculation module, configured to determine an actual driving range of the vehicle according to an energy consumption coefficient of the vehicle and a target mileage of the vehicle under standard operating conditions;

[0171] The sixth calculation module is used to determine the theoretical number of cycles corresponding to the cycle life of the power battery according to the mileage design life, the actual driving range and the health status index value of the design life of the power battery.

[0172] Optionally, the fourth calculation module 205 includes:

[0173] The second computing unit is used to Obtaining a target number of cycles corresponding to the cycle life;

[0174] Among them, PACK cyc_t Indicates the target number of cycles corresponding to the cycle life, PACK cyc Indicates the theoretical number of cycles corresponding to the cycle life, 1-SOH d Indicates the total attenuation index value corresponding to the design life, SOH d Indicates the health status index value corresponding to the design life, ΔSOH cyc It represents the attenuation index value corresponding to the cycle life, and Z represents the cell cycle life aging factor in the cycle life characteristic parameters.

[0175] Optionally, the vehicle information in the first formulation module 201 includes one or more of the following:

[0176] Weekly mileage, weekly fast charging and slow charging ratio, weekly total number of fast charging and slow charging, driving time, battery status of the charging terminal corresponding to the power battery, and weekly charging and discharging depth corresponding to the power battery.

[0177] Optionally, the device further comprises:

[0178] a seventh calculation module, configured to obtain the weekly mileage in the vehicle information according to the calendar design life and the mileage design life;

[0179] an eighth calculation module, configured to obtain a target energy consumption of the vehicle according to a target mileage and a target power of the vehicle under standard operating conditions;

[0180] a ninth calculation module, configured to determine the actual energy consumption of the vehicle according to the energy consumption coefficient of the vehicle and the target energy consumption;

[0181] The tenth calculation module is used to obtain the weekly charge and discharge depth corresponding to the power battery in the vehicle information according to the weekly mileage, the actual energy consumption and the target power.

[0182] It should be noted that the embodiment of the device is a device corresponding to the embodiment of the above method, and all implementation methods in the embodiment of the above method are applicable to the embodiment of the device and can achieve the same technical effect.

[0183] An embodiment of the present invention also provides a network device, comprising: a processor, a memory, and a program stored in the memory and executable on the processor. When the program is executed by the processor, the program implements the power battery cycle life prediction method as described in any one of the above items, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0184] The embodiment of the present invention further provides a readable storage medium, including: a program is stored on the readable storage medium, and when the program is executed by the processor, the steps of the power battery cycle life prediction method as described in any one of the above items are implemented, and the same technical effect can be achieved. To avoid repetition, it is not repeated here. Among them, the computer-readable storage medium is such as a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, etc.

[0185] An embodiment of the present invention further provides a computer program product, including computer instructions. When the computer instructions are executed by a processor, the steps of the power battery cycle life prediction method as described in any of the above items are implemented, and the same technical effect can be achieved. To avoid repetition, they are not repeated here.

[0186] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0187] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for predicting the cycle life of a power battery, characterized in that: include: Formulate a power battery life simulation condition based on vehicle information and the design life of the vehicle's power battery, wherein the design life includes a calendar design life and a mileage design life; According to the power battery life simulation working condition, the storage time corresponding to the design life of the power battery and the average temperature of the vehicle battery pack are obtained; Obtaining a storage life attenuation amount of the power battery according to the storage time, the average temperature and the calendar life characteristic parameter; The attenuation index value corresponding to the cycle life of the power battery is obtained by subtracting the attenuation of the storage life from the total attenuation index value corresponding to the design life; According to the total attenuation index value corresponding to the design life, the attenuation index value corresponding to the cycle life, the theoretical number of cycles corresponding to the cycle life and the cycle life characteristic parameters, the target number of cycles corresponding to the cycle life is obtained.

2. The method for predicting the cycle life of a power battery according to claim 1, characterized in that: According to the vehicle information and the design life of the power battery, formulate the power battery life simulation conditions, including: When the calendar design life and the mileage design life in the design life of the power battery reach their expiration dates at the same time, a power battery life simulation operating condition is formulated according to the vehicle information.

3. The power battery cycle life prediction method according to claim 1 or 2, characterized in that: Before formulating the power battery life simulation working condition according to the vehicle information and the design life of the power battery, the method further includes: Determining a health status index value of a design life of the power battery according to the health status index value of the warranty life of the power battery; The mileage design life and the calendar design life in the design life of the power battery are determined according to the health status index value of the warranty life, the health status index value of the design life, the warranty life information of the power battery and the requirement information of the vehicle durability test.

4. The method for predicting the cycle life of a power battery according to claim 3, characterized in that: The warranty life information includes warranty mileage life and warranty calendar life; The requirement information of the vehicle durability test includes mileage requirement and duration requirement; Wherein, determining the mileage design life and calendar design life in the design life of the power battery according to the health status index value of the warranty life, the health status index value of the design life, the warranty life information of the power battery and the requirement information of the vehicle durability test includes: determining a first mileage life of the power battery according to the health status index value of the warranty life, the health status index value of the design life, and the warranty mileage life in the warranty life; comparing the mileage requirement of the vehicle endurance test and the first mileage life, and determining the larger of the mileage requirement and the first mileage life as the mileage design life in the design life of the power battery; Determining a first calendar life of the power battery according to the health status index value of the warranty life, the health status index value of the design life, and the warranty calendar life in the warranty life; The duration requirement of the vehicle endurance test and the first calendar life are compared, and the larger one of the duration requirement and the first calendar life is determined as the calendar design life in the design life of the power battery.

5. The method for predicting the cycle life of a power battery according to claim 3, characterized in that: The method further comprises: According to the health status index value of the design life of the power battery, a total attenuation index value corresponding to the design life is determined.

6. The method for predicting the cycle life of a power battery according to claim 1, characterized in that: Obtaining the attenuation of the storage life of the power battery according to the storage time, the average temperature and the calendar life characteristic parameter, including: According to the storage time, the average temperature and the calendar life characteristic parameters, the attenuation of the storage life of the power battery is obtained through simulation calculation of the Arrhenius equation.

7. The method for predicting the cycle life of a power battery according to claim 1, characterized in that: The method further comprises: Determining the actual driving range of the vehicle according to the energy consumption coefficient of the vehicle and the target mileage of the vehicle under standard operating conditions; The theoretical number of cycles corresponding to the cycle life of the power battery is determined according to the mileage design life, the actual driving range and the health status index value of the design life of the power battery.

8. The method for predicting cycle life of a power battery according to claim 1, characterized in that: Obtaining a target number of cycles corresponding to the cycle life according to the total attenuation index value corresponding to the design life, the attenuation index value corresponding to the cycle life, the theoretical number of cycles corresponding to the cycle life, and a cycle life characteristic parameter, comprising: according to Obtaining a target number of cycles corresponding to the cycle life; Among them, PACK cyc_t Indicates the target number of cycles corresponding to the cycle life, PACK cyc Indicates the theoretical number of cycles corresponding to the cycle life, 1-SOH d Indicates the total attenuation index value corresponding to the design life, SOH d Indicates the health status index value corresponding to the design life, ΔSOH cyc It represents the attenuation index value corresponding to the cycle life, and Z represents the cell cycle life aging factor in the cycle life characteristic parameters.

9. The method for predicting the cycle life of a power battery according to claim 1 or 2, characterized in that: The vehicle information includes one or more of the following: Weekly mileage, weekly fast charging and slow charging ratio, weekly total number of fast charging and slow charging, driving time, battery status of the charging terminal corresponding to the power battery, and weekly charging and discharging depth corresponding to the power battery.

10. The method for predicting the cycle life of a power battery according to claim 9, characterized in that: Before formulating a power battery life simulation operating condition based on vehicle information and the design life of the power battery, the method further includes: According to the calendar design life and the mileage design life, obtaining the weekly mileage in the vehicle information; Obtaining a target energy consumption of the vehicle according to a target mileage and a target power of the vehicle under standard operating conditions; Determining the actual energy consumption of the vehicle according to the energy consumption coefficient of the vehicle and the target energy consumption; According to the weekly mileage, the actual energy consumption and the target power, a weekly charge and discharge depth corresponding to the power battery in the vehicle information is obtained.

11. A power battery cycle life prediction device, characterized in that: include: A first formulation module is used to formulate a power battery life simulation condition according to vehicle information and a design life of the vehicle's power battery; wherein the design life includes a calendar design life and a mileage design life; A first calculation module, used for obtaining the storage time corresponding to the design life of the power battery and the average temperature of the vehicle battery pack according to the power battery life simulation working condition; A second calculation module, used to obtain the attenuation of the storage life of the power battery according to the storage time, the average temperature and the calendar life characteristic parameter; A third calculation module is used to obtain a decay index value corresponding to the cycle life of the power battery by subtracting the decay amount of the storage life from the total decay index value corresponding to the design life; The fourth calculation module is used to obtain the target number of cycles corresponding to the cycle life according to the total attenuation index value corresponding to the design life, the attenuation index value corresponding to the cycle life, the theoretical number of cycles corresponding to the cycle life and the cycle life characteristic parameters.

12. A network device, characterized in that: include: A processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the power battery cycle life prediction method as claimed in any one of claims 1 to 10.

13. A readable storage medium, characterized in that: include: The readable storage medium stores a program, and when the program is executed by the processor, the steps of the power battery cycle life prediction method according to any one of claims 1 to 10 are implemented.

14. A computer program product, characterized in that The method comprises computer instructions, which, when executed by a processor, implement the steps of the power battery cycle life prediction method as described in any one of claims 1 to 10.

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