Power battery health state assessment method, device and equipment and storage medium
By calibrating the electric-thermal coupling model of the power battery and analyzing its charging habits, the problem of deviation in the power battery SOH assessment was solved, and real-time and accurate SOH assessment was achieved, ensuring battery safety and life.
Patent Information
- Application Number
- CN202511100661.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-07
- Publication Date
- 2025-09-19
AI Technical Summary
Existing power battery state of health (SOH) assessment methods have significant deviations, which may cause the battery to operate beyond the design boundaries, increasing the risk of aging and thermal runaway. The existing correction strategies have harsh conditions and make it difficult to accurately assess in real time.
Based on the battery characteristic parameters of the power battery under different SOH states, the electrothermal coupling model is calibrated. The target constant current voltage segment is determined through charging habit analysis, and the state index is calculated using the calibrated electrothermal coupling model to ultimately determine the SOH evaluation value.
Effectively reduce SOH estimation deviation, avoid power battery operation beyond design boundaries, slow down aging and reduce the risk of thermal runaway, achieve real-time and accurate SOH assessment, and ensure battery safety.
Smart Images
Figure CN120669131A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of power battery management, and in particular to a power battery health status assessment method, apparatus, device, and storage medium. Background Art
[0002] Currently, power battery state of health (SOH) assessment is a key technology for ensuring battery safety and lifespan. However, current SOH assessment methods suffer from significant deviations, with estimated values potentially differing by more than 5% from actual values. This can cause batteries to operate beyond their design boundaries, accelerating aging and increasing the risk of thermal runaway.
[0003] Therefore, it is urgent to provide a technical solution to solve the above problems. Summary of the Invention
[0004] In view of the above problems, the present application provides a power battery health status assessment method, device, equipment and storage medium to solve the problem in the prior art that the power battery SOH cannot be estimated accurately in real time.
[0005] According to one aspect of an embodiment of the present application, a method for evaluating the health status of a power battery is provided, the method comprising: Based on the battery characteristic parameters of the power battery at different SOH states, the electrothermal coupling model is calibrated to obtain a calibrated electrothermal coupling model; performing a charging habit analysis on actual vehicle data of the power battery under various preset operating conditions to determine at least one target constant current voltage segment of the power battery, inputting the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model to obtain a state index of the target constant current voltage segment and determine a comprehensive state index; The SOH evaluation value of the power battery is determined based on the ratio of the current battery capacity to the initial battery capacity under standard operating conditions of the comprehensive state index.
[0006] In an optional manner, the method further includes: An accelerated aging test is performed on the power battery to obtain battery characteristic parameters of the power battery under different SOH states.
[0007] In an optional manner, the battery characteristic parameters include: battery capacity, capacitance energy, and charge and discharge HPPC test data under various preset operating conditions; wherein each preset operating condition includes at least one of the corresponding current value, ambient temperature value, voltage value, charge and discharge rate, and SOC value.
[0008] In an optional manner, the calibrated electrothermal coupling model includes: an equivalent circuit unit and a thermal unit; the equivalent circuit unit includes: an ohmic internal resistance, a polarized capacitor and a polarized internal resistance; the thermal unit establishes an electrothermal association with the equivalent circuit unit through a temperature change equation.
[0009] In an optional manner, the step of inputting the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model, obtaining the state index of the target constant current voltage segment and performing weighted summation to obtain the comprehensive state index further includes: Calculating a first charging capacity of the target constant current voltage segment according to the current value, the average temperature value, and the charging time of the target constant current voltage segment; Inputting the current value and the average temperature value of the target constant current voltage segment into the calibrated electrothermal coupling model to obtain a second charging capacity of the target constant current voltage segment; determining a ratio of the first charging capacity to the second charging capacity of the target constant current voltage segment as a state index of the target constant current voltage segment; When the number of the target constant current voltage segments is one, the state index of the target constant current voltage segment is determined as the comprehensive state index; when the number of the target constant current voltage segments is multiple, the comprehensive state index is obtained by weighted summing the charging capacity ratio and the state index of each target constant current voltage segment.
[0010] In an optional manner, the step of determining the SOH evaluation value of the power battery based on the ratio of the current battery capacity to the initial battery capacity of the comprehensive state index under standard operating conditions further includes: The comprehensive state index is used as the SOC value under the standard operating condition and input into the calibrated electrothermal coupling model to obtain the current battery capacity; The ratio of the current battery capacity to the initial battery capacity is determined as the SOH evaluation value of the power battery.
[0011] According to another aspect of an embodiment of the present application, a power battery health status assessment device is provided, comprising: A calibration module is used to calibrate the electrothermal coupling model based on the battery characteristic parameters of the power battery at different SOH states to obtain a calibrated electrothermal coupling model; a processing module, configured to analyze charging habits of actual vehicle data of the power battery under various preset operating conditions, determine at least one target constant current voltage segment of the power battery, input the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model, obtain a state index of the target constant current voltage segment, and determine a comprehensive state index; An evaluation module is used to determine an SOH evaluation value of the power battery based on a ratio of a current battery capacity to an initial battery capacity of the comprehensive state index under standard operating conditions.
[0012] In an optional manner, the device further includes: The test module is used to perform an accelerated aging test on the power battery to obtain battery characteristic parameters of the power battery under different SOH states.
[0013] According to another aspect of an embodiment of the present application, a power battery health status assessment device is provided, comprising: Controller; The memory is used to store one or more programs. When the one or more programs are executed by the controller, the controller implements the power battery health status assessment method of the present application.
[0014] According to another aspect of an embodiment of the present application, a computer-readable storage medium is provided, which stores at least one executable instruction. When the executable instruction is executed on a power battery health status assessment device / equipment, the power battery health status assessment device / equipment performs the operation of the power battery health status assessment method of the present application.
[0015] The embodiment of the present application calibrates the electrothermal coupling model based on the battery characteristic parameters of the power battery under different SOH states to obtain a calibrated electrothermal coupling model; performs charging habit analysis on the actual vehicle data of the power battery under various preset operating conditions to determine at least one target constant current voltage segment of the power battery, and inputs the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model to obtain the state index of the target constant current voltage segment and determine the comprehensive state index; determines the SOH evaluation value of the power battery based on the ratio of the current battery capacity to the initial battery capacity under standard operating conditions of the comprehensive state index, which can effectively reduce the SOH estimation deviation, avoid the power battery from operating beyond the design boundary, slow down aging and reduce the risk of thermal runaway, and overcome the harsh conditions and limitations of the existing correction strategy, realize real-time and accurate evaluation of SOH, and ensure the safety of the power battery.
[0016] The above description is only an overview of the technical solutions of the embodiments of the present application. In order to more clearly understand the technical means of the embodiments of the present application, they can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and it is clear that a person of ordinary skill in the art can derive other drawings based on these drawings without inventive effort.
[0018] Figure 1 A flow chart of a first embodiment of a method for evaluating the health status of a power battery provided in this application is shown.
[0019] Figure 2 A schematic diagram of the HPPC test of a power battery is shown.
[0020] Figure 3 A schematic diagram of the equivalent circuit is shown.
[0021] Figure 4 A flow chart of a second embodiment of the method for evaluating the health status of a power battery provided in this application is shown.
[0022] Figure 5 A schematic structural diagram of an embodiment of a power battery health status assessment device provided in the present application is shown.
[0023] Figure 6 A structural schematic diagram of an embodiment of a power battery health status assessment device provided in this application is shown. DETAILED DESCRIPTION
[0024] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. When the following description refers to the drawings, identical numerals in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.
[0025] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically separate entities. That is, these functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.
[0026] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.
[0027] In this application, "plurality" refers to two or more. "And / or" describes the relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally indicates that the related objects are in an "or" relationship.
[0028] Currently, assessing the State of Health (SOH) of power batteries is a key technology for ensuring battery safety and lifespan. However, current SOH assessment methods exhibit significant deviations, with estimated values potentially differing by more than 5% from actual values. This can cause batteries to operate beyond their design boundaries, accelerating aging and increasing the risk of thermal runaway. Furthermore, existing SOH correction strategies are difficult to implement accurately and in real time due to demanding conditions, resulting in periodic deviations between displayed SOH and actual SOH. Based on this: Figure 1 The flowchart of the first embodiment of the power battery health status assessment method provided by the present application is shown. The method is executed by the power battery health status assessment device. Figure 1 As shown, the method includes the following steps: Step S110: calibrating the electrothermal coupling model based on the battery characteristic parameters of the power battery at different SOH states to obtain a calibrated electrothermal coupling model.
[0029] A power battery refers to the power source that provides power for electric vehicles (such as electric cars, electric trains, and electric bicycles). The SOH value ranges from 0 to 100%. In this embodiment, the SOH value is divided into different 5% intervals by default. For example, an SOH value of 100% is considered an SOH state, an SOH value of 95% is considered an SOH state, and so on. Battery characteristic parameters include battery capacity, capacitance energy, and charge and discharge HPPC (Hybrid Pulse Power Characteristic) test data under various preset operating conditions. Each preset operating condition corresponds to at least one of the current value, ambient temperature, voltage value, charge and discharge rate, and SOC (State of Charge) value. Ambient temperatures are categorized as high (45°C), normal (25°C), and low (-10°C). The charge and discharge rate depends on the battery cell design and charging strategy, such as 1C or fast charge rate. The SOC value can be determined according to a specific percentage, and can also be divided into high SOC (80%-100%), medium SOC (30%-70%) and low SOC (0%-20%), with no restrictions set here. Figure 2 A schematic diagram of the HPPC test of a battery is shown. The charge and discharge HPPC test data includes capacitance parameters such as ohmic internal resistance and projected internal resistance.
[0030] The calibrated electrothermal coupling model includes equivalent circuit units and thermal units. The equivalent circuit units include ohmic internal resistance, polarized capacitance, and polarized internal resistance. The thermal unit establishes an electrothermal relationship with the equivalent circuit unit through a temperature change equation.
[0031] It should be noted that the construction process of the equivalent circuit unit is as follows: Figure 3 As shown, the power battery is equivalent to a circuit diagram consisting of resistors and capacitors that can characterize the internal reaction of the battery. By calibrating the parameters of each component in the circuit diagram, the corresponding output can be obtained by modifying the input. This embodiment uses the battery characteristic parameters of the power battery at different SOH states to calibrate the parameters of each component in the equivalent circuit. Figure 3 middle, is the ohmic internal resistance, is the polarized capacitance, is the polarization internal resistance, is the open circuit voltage, is the terminal voltage, is the voltage across the polarization internal resistance.
[0032] Since the performance of power batteries is directly related to temperature, the thermal unit is coupled with the equivalent circuit unit to establish the mutual connection between electricity and heat, thereby improving the accuracy of the electric-thermal coupling model. The temperature change equation is: ;in, is the specific heat capacity, For battery quality, is the charge and discharge time, is the battery temperature change, is the charge and discharge current, is the battery temperature, is the heat dissipation coefficient, is the battery heat dissipation area, is the ambient temperature; all parameters in the temperature change equation can be obtained through simple charge and discharge tests and literature research.
[0033] by Figure 2 Taking the battery HPPC test schematic shown in the figure as an example, the calibration process of the electrothermal coupling model is as follows: ; Time constant ; ; .in, is the time constant, Indicates the first moment (the moment when the pulse discharge ends), Indicates the second moment (the moment when the pulse discharge starts), Indicates the third moment, represents the fourth moment, for The voltage value, express The corresponding voltage value, express The corresponding voltage value, express The equivalent circuit unit calibrates the electrothermal coupling model using parameters under multiple preset operating conditions. For other operating conditions not covered, data processing and supplementation can be performed through polynomial fitting. The purpose of building and calibrating the electrothermal coupling model is to correct the data collected from subsequent actual vehicles so that it better reflects the battery SOH value of the power battery under the same test conditions.
[0034] Step S120: Analyze the charging habits of the actual vehicle data of the power battery under various preset operating conditions, determine at least one target constant current voltage segment of the power battery, and input the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model to obtain the state index of the target constant current voltage segment and determine the comprehensive state index.
[0035] Among them, the power battery can be divided into at least one constant current voltage segment according to the user's charging habits, and each constant current voltage segment corresponds to a constant current charging stage. Different constant current charging stages correspond to different currents, voltages, temperatures, etc. The actual vehicle data is the charging and discharging data of different mileages, different ambient temperatures, different battery states and types downloaded through the big data platform. The data signals include current, temperature, voltage, SOC and other signals. The process of charging habit analysis is: based on health indicators that reflect battery attenuation, such as charging time, voltage standard deviation skewness, and voltage-time integral, etc., determine the target constant current voltage segment. Each target constant current voltage segment corresponds to a state index, which is used to characterize the battery health status of the voltage segment. The comprehensive state index represents the battery health status of the power battery in the overall stage.
[0036] Step S130: Determine the SOH evaluation value of the power battery based on the ratio of the current battery capacity to the initial battery capacity of the comprehensive state index under standard operating conditions.
[0037] The default standard operating conditions are: 25°C temperature and 1C charge / discharge rate. The standard operating conditions are used to ignore the effects of temperature on the power battery, thereby correcting the SOH value. The SOH evaluation value is the SOH value obtained after correction in this embodiment.
[0038] The technical solution of this embodiment can effectively reduce the SOH estimation deviation, avoid the power battery from operating beyond the design boundary, slow down aging and reduce the risk of thermal runaway. It also overcomes the harsh conditions and limitations of existing correction strategies, realizes real-time and accurate SOH assessment, and ensures the safety of the power battery.
[0039] Figure 4The flowchart of the second embodiment of the power battery health status assessment method provided by the present application is shown. The method is executed by the power battery health status assessment device. Figure 4 As shown, the method includes the following steps: Step S210: performing an accelerated aging test on the power battery to obtain battery characteristic parameters of the power battery under different SOH states.
[0040] Among them, the methods of accelerated aging testing include but are not limited to increasing the temperature of battery cycle conditions, increasing the battery discharge rate, adjusting the battery charge and discharge strategy, etc. The purpose of conducting accelerated aging tests on power batteries is to obtain battery characteristic parameters under different SOH states, which are used to calibrate various parameters in the electrothermal coupling model, such as ohmic internal resistance, projected internal resistance and other capacitance parameters.
[0041] Step S220: calibrating the electrothermal coupling model based on the battery characteristic parameters of the power battery at different SOH states to obtain a calibrated electrothermal coupling model.
[0042] Step S230: Analyze the charging habits of the actual vehicle data of the power battery under various preset operating conditions, determine at least one target constant current voltage segment of the power battery, and input the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model to obtain the state index of the target constant current voltage segment and determine the comprehensive state index.
[0043] Step S240: Determine the SOH evaluation value of the power battery based on the ratio of the current battery capacity to the initial battery capacity of the comprehensive state index under standard operating conditions.
[0044] The technical solution of this embodiment further conducts accelerated aging tests on the power battery and calibrates the electrothermal coupling model, and dynamically estimates and corrects the SOH value in combination with the battery's power usage habits. This can effectively reduce the SOH estimation deviation, avoid the power battery from operating beyond its design boundaries, slow down aging and reduce the risk of thermal runaway. It also overcomes the harsh conditions and limitations of existing correction strategies, realizes real-time and accurate SOH assessment, and ensures the safety of the power battery.
[0045] Based on any of the above embodiments, the step of inputting the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model to obtain the state index of the target constant current voltage segment and determine the comprehensive state index further includes: Calculating a first charging capacity of the target constant current voltage segment according to the current value, the average temperature value, and the charging time of the target constant current voltage segment; Inputting the current value and the average temperature value of the target constant current voltage segment into the calibrated electrothermal coupling model to obtain a second charging capacity of the target constant current voltage segment; determining a ratio of the first charging capacity to the second charging capacity of the target constant current voltage segment as a state index of the target constant current voltage segment; When the number of the target constant current voltage segments is one, the state index of the target constant current voltage segment is determined as the comprehensive state index; when the number of the target constant current voltage segments is multiple, the comprehensive state index is obtained by weighted summing the charging capacity ratio and the state index of each target constant current voltage segment.
[0046] Among them, the first charging capacity is the charging capacity calculated by the ampere-hour integration method, and the second charging capacity is the charging capacity output and determined by the calibrated electrothermal coupling model. Specifically, assuming that the number of target constant current voltage segments is two, the first target constant current voltage segment is [ , ], then the current value of the constant current charging stage corresponding to the target constant current voltage segment is The average temperature is , charging time is , then the first charging capacity of the power battery in this constant current charging stage is obtained by the ampere-hour integration method: The current value of the constant current charging stage is The average temperature is Input into the calibrated electrothermal coupling model to obtain the charging capacity of the full voltage segment under the corresponding conditions, and through the target constant current voltage segment [ , ] Extract the corresponding second charging capacity The first charging capacity of the constant current charging stage is With the second charging capacity The ratio of the first target constant current voltage segment is obtained. Similarly, the second target constant current voltage segment is [ , ], then the state index of the second target constant current voltage segment is .
[0047] The charging capacity ratio is the ratio of the charging capacity of a certain target constant current voltage segment to the sum of the charging capacities of all target constant current voltage segments. For example, the charging capacity ratio of the first target constant current voltage segment is , the charging capacity ratio of the second target constant current voltage segment is , then the comprehensive state index .
[0048] It should be noted that the above calculation process is only illustrated by taking two target constant current voltage segments as an example. If there is only one target constant current voltage segment in the actual process, the state index of the target constant current voltage segment is directly determined as the comprehensive state index; if there are multiple target constant current voltage segments in the actual process, the weighted summation can be performed according to the specific number of target constant current voltage segments, and there is no restriction here.
[0049] The above technical solution further refines the complex battery status assessment into quantifiable operations, making the calculation of the status index more scientific and operational, further improving the accuracy of the comprehensive status index, ensuring that subsequent SOH assessment is more accurate, and effectively reducing assessment deviations.
[0050] Based on any of the above embodiments, the step of determining the SOH evaluation value of the power battery based on the ratio of the current battery capacity to the initial battery capacity of the comprehensive state index under standard operating conditions further includes: The comprehensive state index is used as the SOC value under the standard operating condition and input into the calibrated electrothermal coupling model to obtain the current battery capacity.
[0051] Among them, the comprehensive state index is determined as the SOC value, and the SOC value under the standard working condition is input into the calibrated electrothermal coupling model. According to the simulation results of the model, the corresponding battery capacity, that is, the current battery capacity, is extracted.
[0052] The ratio of the current battery capacity to the initial battery capacity is determined as the SOH evaluation value of the power battery.
[0053] The initial battery capacity is the capacity corresponding to a 100% SOH value under standard operating conditions. The ratio of the current battery capacity to the initial battery capacity is the SOH assessment value of the power battery.
[0054] The above technical solution further inputs the comprehensive state index as the SOC value into the model to obtain the current battery capacity, and then calculates the ratio to obtain the SOH evaluation value. It fully utilizes the comprehensive state index and the electrothermal coupling model to improve the accuracy of the SOH evaluation value, so that the evaluation result can more realistically reflect the battery health status and ensure that the battery is used within a safe range.
[0055] Figure 5 The schematic diagram of the structure of the embodiment of the power battery health status assessment device provided by the present application is shown. Figure 5 As shown, the device 300 includes: a calibration module 310 , a processing module 320 and an evaluation module 330 .
[0056] A calibration module 310 is configured to calibrate the electrothermal coupling model based on battery characteristic parameters of the power battery at different SOH states to obtain a calibrated electrothermal coupling model; a processing module 320 configured to analyze charging habits of the power battery under various preset operating conditions based on actual vehicle data, determine at least one target constant current voltage segment for the power battery, and input the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model to obtain a state index for the target constant current voltage segment and determine a comprehensive state index; The evaluation module 330 is configured to determine an SOH evaluation value of the power battery based on a ratio of a current battery capacity to an initial battery capacity of the comprehensive state index under standard operating conditions.
[0057] In an optional manner, the device further includes: The test module is used to perform an accelerated aging test on the power battery to obtain battery characteristic parameters of the power battery under different SOH states.
[0058] In an optional manner, the battery characteristic parameters include: battery capacity, capacitance energy, and charge and discharge HPPC test data under various preset operating conditions; wherein each preset operating condition includes at least one of the corresponding current value, ambient temperature value, voltage value, charge and discharge rate, and SOC value.
[0059] In an optional manner, the calibrated electrothermal coupling model includes: an equivalent circuit unit and a thermal unit; the equivalent circuit unit includes: an ohmic internal resistance, a polarized capacitor and a polarized internal resistance; the thermal unit establishes an electrothermal association with the equivalent circuit unit through a temperature change equation.
[0060] In an optional manner, the processing module 320 is specifically configured to: Calculating a first charging capacity of the target constant current voltage segment according to the current value, the average temperature value, and the charging time of the target constant current voltage segment; Inputting the current value and the average temperature value of the target constant current voltage segment into the calibrated electrothermal coupling model to obtain a second charging capacity of the target constant current voltage segment; determining a ratio of the first charging capacity to the second charging capacity of the target constant current voltage segment as a state index of the target constant current voltage segment; When the number of the target constant current voltage segments is one, the state index of the target constant current voltage segment is determined as the comprehensive state index; when the number of the target constant current voltage segments is multiple, the comprehensive state index is obtained by weighted summing the charging capacity ratio and the state index of each target constant current voltage segment.
[0061] In an optional manner, the evaluation module 330 is specifically configured to: The comprehensive state index is used as the SOC value under the standard operating condition and input into the calibrated electrothermal coupling model to obtain the current battery capacity; The ratio of the current battery capacity to the initial battery capacity is determined as the SOH evaluation value of the power battery.
[0062] The technical solution of this embodiment can effectively reduce the SOH estimation deviation, avoid the power battery from operating beyond the design boundary, slow down aging and reduce the risk of thermal runaway. It also overcomes the harsh conditions and limitations of existing correction strategies, realizes real-time and accurate SOH assessment, and ensures the safety of the power battery.
[0063] It should be noted that the power battery health status assessment device provided in the above embodiment and the power battery health status assessment method provided in the above embodiment belong to the same concept, and the specific manner in which each module and unit performs operations has been described in detail in the method embodiment and will not be repeated here.
[0064] Figure 6 A structural schematic diagram of an embodiment of the power battery health status assessment device provided in the present application is shown, which shows a structural schematic diagram of a computer system suitable for implementing the power battery health status assessment device of the embodiment of the present application. The specific embodiment of the present application does not limit the specific implementation of the power battery health status assessment device.
[0065] See also Figure 6 As shown, the power battery health status assessment device includes: a controller; a memory for storing one or more programs, and when the one or more programs are executed by the controller, the above-mentioned power battery health status assessment method is executed.
[0066] Please continue reading Figure 6 As shown, the computer system 500 of the power battery health status assessment device includes a central processing unit (CPU) 501, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 502 or the program loaded from the storage part 508 to the random access memory (RAM) 503, such as executing the method in the above embodiment. Various programs and data required for system operation are also stored in RAM 503. CPU 501, ROM 502 and RAM 503 are connected to each other via a bus 504. Input / output (I / O) interface 505 is also connected to bus 504.
[0067] The following components are connected to the I / O interface 505: an input section 506 including a keyboard, a mouse, and the like; an output section 507 including devices such as a cathode ray tube (CRT), a liquid crystal display (LCD), and a speaker; a storage section 508 including a hard disk and the like; and a communication section 509 including a network interface card such as a LAN (Local Area Network) card or a modem. The communication section 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to the I / O interface 505 as needed. Removable media 511, such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, is installed in the drive 510 as needed, so that computer programs read therefrom can be installed into the storage section 508 as needed.
[0068] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a computer program for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via the communication section 509, and / or installed from a removable medium 511. When the computer program is executed by the central processing unit (CPU) 501, the various functions defined in the system of the present application are executed.
[0069] Another aspect of the present application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the power battery health status assessment method described above. The computer-readable storage medium may be included in the power battery health status assessment device described in the above embodiments, or may exist independently and not be incorporated into the electronic device.
[0070] Another aspect of the present application also provides a computer program product or computer program, which includes at least one executable instruction. When the executable instruction is run on a power battery health status assessment device / equipment, the power battery health status assessment device / equipment executes the power battery health status assessment method as described above.
[0071] The executable instructions may be used to cause the power battery health status assessment device / apparatus to perform the following operations: Based on the battery characteristic parameters of the power battery at different SOH states, the electrothermal coupling model is calibrated to obtain a calibrated electrothermal coupling model; performing a charging habit analysis on actual vehicle data of the power battery under various preset operating conditions to determine at least one target constant current voltage segment of the power battery, inputting the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model to obtain a state index of the target constant current voltage segment and determine a comprehensive state index; The SOH evaluation value of the power battery is determined based on the ratio of the current battery capacity to the initial battery capacity under standard operating conditions of the comprehensive state index.
[0072] In an optional manner, the method further includes: An accelerated aging test is performed on the power battery to obtain battery characteristic parameters of the power battery under different SOH states.
[0073] In an optional manner, the battery characteristic parameters include: battery capacity, capacitance energy, and charge and discharge HPPC test data under various preset operating conditions; wherein each preset operating condition includes at least one of the corresponding current value, ambient temperature value, voltage value, charge and discharge rate, and SOC value.
[0074] In an optional manner, the calibrated electrothermal coupling model includes: an equivalent circuit unit and a thermal unit; the equivalent circuit unit includes: an ohmic internal resistance, a polarized capacitor and a polarized internal resistance; the thermal unit establishes an electrothermal association with the equivalent circuit unit through a temperature change equation.
[0075] In an optional manner, the step of inputting the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model to obtain the state index of the target constant current voltage segment and determine the comprehensive state index further includes: Calculating a first charging capacity of the target constant current voltage segment according to the current value, the average temperature value, and the charging time of the target constant current voltage segment; Inputting the current value and the average temperature value of the target constant current voltage segment into the calibrated electrothermal coupling model to obtain a second charging capacity of the target constant current voltage segment; determining a ratio of the first charging capacity to the second charging capacity of the target constant current voltage segment as a state index of the target constant current voltage segment; When the number of the target constant current voltage segments is one, the state index of the target constant current voltage segment is determined as the comprehensive state index; when the number of the target constant current voltage segments is multiple, the comprehensive state index is obtained by weighted summing the charging capacity ratio and the state index of each target constant current voltage segment.
[0076] In an optional manner, the step of determining the SOH evaluation value of the power battery based on the ratio of the current battery capacity to the initial battery capacity of the comprehensive state index under standard operating conditions further includes: The comprehensive state index is used as the SOC value under the standard operating condition and input into the calibrated electrothermal coupling model to obtain the current battery capacity; The ratio of the current battery capacity to the initial battery capacity is determined as the SOH evaluation value of the power battery.
[0077] The technical solution of this embodiment can effectively reduce the SOH estimation deviation, avoid the power battery from operating beyond the design boundary, slow down aging and reduce the risk of thermal runaway. It also overcomes the harsh conditions and limitations of existing correction strategies, realizes real-time and accurate SOH assessment, and ensures the safety of the power battery.
[0078] It should be noted that the computer-readable medium shown in the embodiments of the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media can include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In the present application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable computer program. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. A computer program embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, or any suitable combination thereof.
[0079] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. Among them, each box in the flowchart or block diagram can represent a module, program segment, or part of the code, and the above-mentioned module, program segment, or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.
[0080] The units involved in the embodiments described in this application may be implemented by software or hardware, and the units described may also be set in a processor. In some cases, the names of these units do not constitute limitations on the units themselves.
[0081] According to one aspect of an embodiment of the present application, a computer system is further provided, including a central processing unit (CPU), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) or a program loaded from a storage portion into a random access memory (RAM), such as executing the method in the above embodiment. Various programs and data required for system operation are also stored in the RAM. The CPU, ROM, and RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.
[0082] The following components are connected to the I / O interface: an input section including a keyboard, mouse, etc.; an output section including a cathode ray tube (CRT), liquid crystal display (LCD), and speakers; a storage section including a hard disk; and a communication section including a network interface card such as a LAN (Local Area Network) card and a modem. The communication section performs communication processing via a network such as the Internet. A drive is also connected to the I / O interface as needed. Removable media such as magnetic disks, optical disks, magneto-optical disks, semiconductor memories, etc. are installed in the drive as needed so that computer programs read from them can be installed into the storage section as needed.
[0083] The above content is only a preferred exemplary embodiment of the present application and is not intended to limit the implementation scheme of the present application. Ordinary technicians in this field can easily make corresponding changes or modifications based on the main ideas and spirit of the present application. Therefore, the scope of protection of the present application shall be based on the scope of protection required by the claims.
Claims
1. A method for evaluating the health status of a power battery, characterized in that: The method comprises: Based on the battery characteristic parameters of the power battery at different SOH states, the electrothermal coupling model is calibrated to obtain a calibrated electrothermal coupling model; performing a charging habit analysis on actual vehicle data of the power battery under various preset operating conditions to determine at least one target constant current voltage segment of the power battery, inputting the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model to obtain a state index of the target constant current voltage segment and determine a comprehensive state index; The SOH evaluation value of the power battery is determined based on the ratio of the current battery capacity to the initial battery capacity under standard operating conditions of the comprehensive state index.
2. The power battery health status assessment method according to claim 1, characterized in that: The method further comprises: An accelerated aging test is performed on the power battery to obtain battery characteristic parameters of the power battery under different SOH states.
3. The power battery health status assessment method according to claim 1, characterized in that: The battery characteristic parameters include: battery capacity, capacitance energy and charge and discharge HPPC test data under various preset operating conditions; wherein each preset operating condition includes at least one of a corresponding current value, ambient temperature value, voltage value, charge and discharge rate and SOC value.
4. The power battery health status assessment method according to claim 1, characterized in that: The calibrated electrothermal coupling model includes: an equivalent circuit unit and a thermal unit; the equivalent circuit unit includes: an ohmic internal resistance, a polarized capacitor and a polarized internal resistance; the thermal unit establishes an electrothermal association with the equivalent circuit unit through a temperature change equation.
5. The method for evaluating the health status of a power battery according to claim 3, wherein: The step of inputting the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model to obtain the state index of the target constant current voltage segment and determine the comprehensive state index further includes: Calculating a first charging capacity of any target constant current voltage segment according to the current value, average temperature value, and charging time of the target constant current voltage segment; Inputting the current value and the average temperature value of the target constant current voltage segment into the calibrated electrothermal coupling model to obtain a second charging capacity of the target constant current voltage segment; determining a ratio of the first charging capacity to the second charging capacity of the target constant current voltage segment as a state index of the target constant current voltage segment; When the number of the target constant current voltage segments is one, the state index of the target constant current voltage segment is determined as the comprehensive state index; when the number of the target constant current voltage segments is multiple, the comprehensive state index is obtained by weighted summing the charging capacity ratio and the state index of each target constant current voltage segment.
6. The method for evaluating the health status of a power battery according to claim 3, characterized in that: The step of determining the SOH evaluation value of the power battery based on the ratio of the current battery capacity to the initial battery capacity of the comprehensive state index under standard operating conditions further includes: The comprehensive state index is used as the SOC value under the standard operating condition and input into the calibrated electrothermal coupling model to obtain the current battery capacity; The ratio of the current battery capacity to the initial battery capacity is determined as the SOH evaluation value of the power battery.
7. A power battery health status assessment device, characterized in that: The device comprises: A calibration module is used to calibrate the electrothermal coupling model based on the battery characteristic parameters of the power battery at different SOH states to obtain a calibrated electrothermal coupling model; a processing module, configured to analyze charging habits of actual vehicle data of the power battery under various preset operating conditions, determine at least one target constant current voltage segment of the power battery, input the actual vehicle data corresponding to the target constant current voltage segment into the calibrated electrothermal coupling model, obtain a state index of the target constant current voltage segment, and determine a comprehensive state index; An evaluation module is used to determine an SOH evaluation value of the power battery based on a ratio of a current battery capacity to an initial battery capacity of the comprehensive state index under standard operating conditions.
8. The power battery health status assessment device according to claim 7, characterized in that: The device further comprises: The test module is used to perform an accelerated aging test on the power battery to obtain battery characteristic parameters of the power battery under different SOH states.
9. A power battery health status assessment device, characterized in that: include: Controller; A memory for storing one or more programs, which, when executed by a controller, enables the controller to implement the power battery health status assessment method according to any one of claims 1 to 6.
10. A computer-readable storage medium, characterized in that The storage medium stores at least one executable instruction. When the executable instruction is executed on the power battery health status assessment device / equipment, the power battery health status assessment device / equipment performs the operation of the power battery health status assessment method according to any one of claims 1 to 6.
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