Battery management method, device and apparatus, and computer readable storage medium

Abstract

Embodiments of the present application provide a battery management method, device and equipment and a computer readable storage medium, the method comprising: determining the power of a to-be-tested battery and the temperature of a test environment; calculating the power and the temperature by a preset health degree determination model to determine the health degree of the to-be-tested battery; the preset health degree determination model represents the influence degree of the battery power and the temperature on the health degree of the battery. In the above scheme, the power of the battery and the temperature of the test environment will affect the health degree of the battery. After determining the power of the to-be-tested battery and the temperature of the test environment, the health degree of the to-be-tested battery is determined according to the power of the to-be-tested battery and the temperature of the test environment by the preset health degree determination model. Since the preset health degree determination model represents the influence degree of the battery power and the temperature on the health degree of the battery, the application range of the preset health degree determination model is wider and the accuracy is higher. The battery management is performed by the preset health degree determination model, thereby improving the battery management performance.

Description

Technical Field

[0001] This application relates to the field of battery management, and more particularly to a battery management method, apparatus, device, and computer-readable storage medium. Background Technology

[0002] Lithium-ion batteries are a crucial power source for consumer devices, and their charging and discharging processes are highly complex, significantly impacting device performance. Therefore, better battery management and control are needed to study real-time battery status, such as charge level, temperature, capacity health, charging / discharging speed, and power prediction, to better utilize the battery system. Battery management systems (BMS) are generally based on battery models, and the accuracy of these models greatly influences the system's performance. Due to limitations in storage space and processor speed within the BMS, a more accurate battery model is a prerequisite for the effective operation of the BMS.

[0003] Because remote control models are relatively simple and have low accuracy at lower orders, their accuracy gradually increases with the increase in order, but so does the computational load. Therefore, they are widely used in battery management systems.

[0004] Existing battery models are used within a fixed temperature value or range, or within a specific capacity range. This can lead to a limited application range and low accuracy, thereby reducing battery management performance. Summary of the Invention

[0005] This application aims to provide a battery management method, apparatus, device, and computer-readable storage medium that can improve battery management performance.

[0006] The technical solution of this application is implemented as follows:

[0007] In a first aspect, embodiments of this application provide a battery management method, comprising: determining the charge level of a battery under test and the temperature of the test environment; calculating the charge level and the temperature using a preset health determination model to determine the health level of the battery under test; wherein the preset health determination model characterizes the degree of influence of battery charge level and temperature on the health level of the battery.

[0008] Secondly, embodiments of this application provide a battery management device, the battery management device comprising: a determining unit, wherein,

[0009] The determining unit is used to determine the charge level of the battery under test and the temperature of the test environment; it calculates the charge level and the temperature using a preset health determination model to determine the health level of the battery under test; the preset health determination model characterizes the degree of influence of battery charge level and temperature on the health level of the battery.

[0010] Thirdly, embodiments of this application provide a battery management device, the battery management device comprising: a processor and a memory; wherein,

[0011] The memory is used to store computer programs;

[0012] The processor is configured to call and run the computer program from the memory to perform the method as described in the first aspect.

[0013] Fourthly, embodiments of this application provide a computer-readable storage medium storing executable instructions for causing a processor to perform the method described in the first aspect.

[0014] This application provides a battery management method, apparatus, device, and computer-readable storage medium. The method includes: determining the charge level of a battery under test and the temperature of the test environment; calculating the health level of the battery under test based on the charge level and the temperature using a preset health level determination model; the preset health level determination model characterizes the degree of influence of battery charge level and temperature on battery health level. In the above solution, since the battery charge level and the temperature of the test environment affect battery health level, after determining the charge level of the battery under test and the temperature of the test environment, the preset health level determination model is used to determine the health level of the battery under test based on the charge level of the battery under test and the temperature of the test environment, making the health level of the battery under test determined by the preset health level determination model more accurate. At the same time, since the preset health level determination model characterizes the degree of influence of battery charge level and temperature on battery health level, the preset health level determination model has a wider range of applications and higher accuracy. Battery management using the preset health level determination model improves battery management performance. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the technical solutions of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0016] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0017] Figure 1 This application provides an optional flowchart of a battery management method. Figure 1 ;

[0018] Figure 2 This application provides an optional flowchart of a battery management method. Figure 2 ;

[0019] Figure 3 This application provides an optional flowchart of a battery management method. Figure 3 ;

[0020] Figure 4 This application provides an optional flowchart of a battery management method. Figure 4 ;

[0021] Figure 5 This application provides an optional flowchart of a battery management method. Figure 5 ;

[0022] Figure 6 An optional current diagram is provided for an embodiment of the battery management method in this application;

[0023] Figure 7 An optional voltage diagram is provided for an embodiment of the battery management method in this application;

[0024] Figure 8 This is a schematic diagram illustrating an optional preset relationship between health and impedance in a battery management method provided in this application embodiment.

[0025] Figure 9 This application provides a schematic diagram of the structure of a battery management device according to an embodiment of the present application;

[0026] Figure 10 This is a schematic diagram of the structure of a battery management device provided in an embodiment of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the specific technical solutions of this application will be further described in detail below with reference to the accompanying drawings of the embodiments of this application. The following embodiments are used to illustrate this application, but are not intended to limit the scope of this application.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0029] In the following description, references to "some embodiments," "this embodiment," "this application embodiment," and examples, etc., describe a subset of all possible embodiments. However, it is understood that "some embodiments" may be the same subset or different subset of all possible embodiments and may be combined with each other without conflict.

[0030] If the application documents contain similar descriptions such as "first / second", the following explanation shall be added: In the following description, the terms "first / second / third" are used only to distinguish similar objects and do not represent a specific order of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0031] This application provides a battery management method. Figure 1 This is an optional flowchart illustrating a battery management method provided in this application embodiment. Figure 1 , will combine Figure 1 The steps shown are explained.

[0032] S101. Determine the charge level of the battery under test and the temperature of the test environment.

[0033] In this embodiment, batteries experience aging during daily use, leading to a decrease in battery performance. The degree of battery aging can be measured by testing the battery's health. Typically, battery health is tested by measuring a target specific physical quantity of the battery, which refers to a target value during actual use.

[0034] In some embodiments of this application, the physical quantities of the battery include the remaining capacity, thickness, temperature, and charge level. Differences in battery charge level and ambient temperature during battery testing can affect battery impedance, thus impacting battery health.

[0035] In some embodiments of this application, the battery management method is applicable to scenarios where the health status of a battery is managed.

[0036] In some embodiments of this application, when the battery management device tests the health of the battery under test, the battery charge and the temperature of the test environment will affect the test results. Therefore, the battery charge and the temperature of the test environment are obtained.

[0037] It should be noted that the battery charge level is expressed as a percentage.

[0038] For example, the preferred method for calculating battery capacity is the rated capacity measurement method, such as the capacity at 0.2C discharge at 25°C. Alternatively, it can be the capacity measurement at other rates, such as 1C, 0.5C, 2C, etc.

[0039] It should be noted that the battery management device can be a terminal.

[0040] S102. By using a preset health determination model, the battery capacity and temperature are calculated to determine the health of the battery under test; the preset health determination model characterizes the degree of influence of battery capacity and temperature on the battery health.

[0041] In this embodiment, the preset health determination model characterizes the degree of influence of battery charge and temperature on battery health; the preset health determination model includes: a preset impedance fitting relationship and a preset health and impedance correspondence relationship.

[0042] In some embodiments of this application, the preset health determination model is the relationship between temperature, electrical charge, impedance and health obtained by fitting multiple test data.

[0043] In some embodiments of this application, the battery management device can calculate the impedance of the battery under test by using a preset impedance fitting relationship to calculate the charge and temperature; and calculate the impedance of the battery under test by using a preset correspondence between health and impedance to determine the health of the battery under test.

[0044] In some embodiments of this application, the battery management device can calculate the impedance of the battery under test based on the charge level when the temperature of the test environment is determined, by using a preset impedance fitting relationship; or, when the charge level of the battery under test is determined, the impedance of the battery under test can be calculated based on the temperature of the test environment.

[0045] In some embodiments of this application, after determining the impedance of the battery under test, the impedance of the battery under test can be substituted into a preset correspondence between health and impedance to calculate the health of the battery under test.

[0046] Understandably, battery management devices determine the battery's charge level and the ambient temperature. Using a preset health determination model, they calculate the battery's health level based on these parameters. This preset health determination model characterizes the degree to which battery charge and temperature affect battery health. Since battery charge and ambient temperature influence battery health, determining the battery's health level using the preset health determination model after establishing these parameters makes the determined health level more accurate. Furthermore, because the preset health determination model characterizes the degree to which battery charge and temperature affect battery health, it has a wider applicability and higher accuracy. Using this preset health determination model for battery management improves battery management performance.

[0047] In the embodiments of this application, Figure 2 This application provides an optional flowchart of a battery management method. Figure 2 ,like Figure 2 As shown, S102 can be implemented through S1021 and S1022, as follows:

[0048] S1021. The impedance of the battery under test is determined by calculating the charge and temperature through a preset impedance fitting relationship. The preset impedance fitting relationship characterizes the relationship between impedance and charge and temperature.

[0049] In this embodiment, the preset impedance fitting relationship includes: a preset temperature impedance fitting relationship and a preset electrical impedance fitting relationship.

[0050] In some embodiments of this application, the preset temperature impedance fitting relationship is obtained by fitting the temperature and impedance together, with a fixed amount of charge, changing the temperature, recording the impedance after the temperature change, and determining the law of impedance change caused by temperature change. The preset temperature impedance fitting relationship is different for different amounts of charge.

[0051] In some embodiments of this application, the preset charge-resistance fitting relationship is obtained by fitting the charge and impedance together, where the temperature is constant, the temperature is changed, the impedance is recorded after the charge level is changed, and the law of impedance change caused by charge change is obtained. The preset charge-resistance fitting relationship is different at different temperatures.

[0052] In some embodiments of this application, under the condition of electric charge, a standard temperature and a first impedance corresponding to a preset temperature impedance fitting relationship are determined; based on the standard temperature, the first impedance, the preset temperature impedance fitting relationship and the temperature, calculations are performed to determine the impedance of the battery under test.

[0053] In some embodiments of this application, when determining the preset temperature impedance fitting relationship, the impedance at a certain temperature is calculated, and that temperature is used as the standard temperature, and the impedance at that temperature is used as the first impedance.

[0054] It should be noted that the battery health status is calculated as: current battery capacity / initial battery capacity.

[0055] Understandably, the battery management device determines the standard temperature and first impedance corresponding to the preset temperature impedance fitting relationship under power conditions. Based on the standard temperature, first impedance, preset temperature impedance fitting relationship, and temperature, it performs calculations to determine the impedance of the battery under test. Since the preset temperature impedance fitting relationship is a rule for impedance change caused by temperature change obtained by fitting temperature and impedance, determining the impedance of the battery under test through the preset temperature impedance fitting relationship can improve the accuracy of determining the impedance of the battery under test.

[0056] In some embodiments of this application, at a certain temperature, a standard charge and a second impedance corresponding to a preset charge-to-impedance fitting relationship are determined; based on the standard charge, the second impedance, the preset charge-to-impedance fitting relationship, and the charge, calculations are performed to determine the impedance of the battery under test.

[0057] In some embodiments of this application, when determining the preset electrical quantity impedance fitting relationship, the impedance at a certain electrical quantity is calculated, and the certain electrical quantity is used as the standard electrical quantity, and the impedance at the certain electrical quantity is used as the second impedance.

[0058] Understandably, the battery management device determines the standard charge and second impedance corresponding to the preset charge-to-impedance fitting relationship under temperature. Based on the standard charge, second impedance, preset charge-to-impedance fitting relationship, and charge, it performs calculations to determine the impedance of the battery under test. Since the preset charge-to-impedance fitting relationship is a rule for impedance change caused by charge change obtained by fitting charge and impedance, determining the impedance of the battery under test through the preset charge-to-impedance fitting relationship can improve the accuracy of determining the impedance of the battery under test.

[0059] In some embodiments of this application, the battery management device can determine the temperature difference based on the standard temperature and the temperature; perform calculations based on the preset temperature impedance fitting relationship and the temperature difference to determine the impedance change value; and perform calculations based on the first impedance and the impedance change value to determine the impedance of the battery under test.

[0060] For example, the preset temperature impedance fitting relationship is: y = 2.0246x + 132.87, where x is temperature and y is impedance. The preset temperature impedance fitting relationship means that for every degree increase in temperature, the impedance value decreases by 2.0246mΩ. In the use of the whole machine, at 50% SOC (i.e., the battery capacity is 50%), the impedance value at 36℃ (i.e., the standard temperature) is 65mΩ (i.e., the first impedance). Then, the impedance at 25℃ (i.e., the temperature) is 65 + 11 * 2.0246 = 87.2706mΩ, which means that the impedance of the battery under test is 87.2706mΩ.

[0061] S1022. By using the preset correspondence between health and impedance, the impedance of the battery under test is calculated to determine the health of the battery under test; the preset correspondence between health and impedance characterizes the change law of battery health with impedance change.

[0062] In this embodiment, the preset relationship between health and impedance characterizes the change pattern of battery health as impedance changes.

[0063] In some embodiments of this application, the battery management device can calculate the health status of the battery under test by substituting the impedance of the battery under test into a preset correspondence between health status and impedance.

[0064] For example, the preset relationship between health level and impedance is: m = -0.0024n + 1.1478; where n is the impedance value and m is the health level. When the impedance is 87.2706mΩ, the health level of the battery under test is m = -0.0024 * 87.2706 + 1.1478 = 0.938, which means the health level of the battery under test is 93.8%.

[0065] Understandably, battery management devices calculate the impedance of the battery under test based on the charge and temperature using a preset impedance fitting relationship; they also calculate the battery's health based on the preset health-to-impedance correlation. Since the preset impedance fitting relationship characterizes the relationship between impedance and charge / temperature, determining the battery's impedance using this relationship improves the accuracy of impedance determination. Furthermore, since the preset health-to-impedance correlation characterizes the relationship between impedance and battery health, determining the battery's health using this correlation results in even higher accuracy in determining the battery's health.

[0066] In this embodiment of the application, based on Figure 1 , Figure 3 This application provides an optional flowchart of an electric vehicle anti-shake method. Figure 3 ,like Figure 3As shown, S103-S106 are executed before S102, as follows:

[0067] S103. Perform an aging process on at least one battery to obtain batteries under different aging conditions; and determine the health status of the batteries under different aging conditions.

[0068] In this embodiment of the application, the battery management device can perform an aging process on at least one battery to obtain batteries in different aging states, and take out the batteries in different aging states and place them in a specific ambient temperature to test the health of the batteries in that state.

[0069] In some embodiments of this application, the battery management device selects several batteries that have not been newly manufactured, ages them according to a specific aging path, and then takes out batteries in different aging states (i.e., different health levels of the batteries) and places them in a specific ambient temperature to test the target specific physical quantity of the battery in that state. The target specific physical quantity of the battery is the health level of the battery.

[0070] It should be noted that the target physical quantity of the battery refers to the target value in actual use, such as the remaining capacity of the battery, the thickness of the battery, the temperature of the battery, and the charge of the battery.

[0071] In some embodiments of this application, several batteries that have not been newly manufactured can be lithium-ion batteries, with the number of lithium-ion batteries being ≥2, and generally 3.

[0072] It should be noted that the specific aging path can be a conventional battery aging process, such as a 0.5C charge and then a 0.5C discharge cycle test at 25°C, or an accelerated aging path, such as a high-temperature aging process, a 50°C high-temperature cycle test, a 1C charge and a 0.5C discharge. The battery aging path in this application is not limited.

[0073] It should be noted that the specific ambient temperature refers to a specific standard definition of the battery during actual use, such as the remaining capacity standard of 25°C, which is consistent before and after; different aging states generally refer to different health levels of the battery, such as 100%, 95%, 90%, etc.

[0074] S104. Under the target temperature and target capacity, current disturbance signals are superimposed on batteries under different aging conditions according to a preset time period to determine the preset health status and impedance correspondence of batteries under different aging conditions.

[0075] In this embodiment, the battery management device superimposes current disturbance signals onto batteries in different aging states at target temperature and target charge, and continuously performs the signal for a preset time period to determine the correspondence between the preset health level and impedance of batteries in different aging states.

[0076] In some embodiments of this application, the battery management device superimposes current disturbance signals onto batteries in different aging states at a target temperature and target charge level, according to a preset time period, and samples them at a preset acquisition frequency to obtain voltage and current signals; performs time-frequency conversion analysis on the voltage and current signals to obtain the impedance corresponding to the characteristic frequency; and fits the health status of the batteries in different aging states with the impedance value at a specific frequency to determine the preset health status and impedance correspondence of the batteries in different aging states.

[0077] In some embodiments of this application, after performing time-frequency conversion analysis on the voltage signal and the current signal, the impedance Z = [Z1, Z2, Z3, ... Zn] corresponding to the characteristic frequency f = [f1, f2, f3, ... fn] can be obtained.

[0078] S105. Under different preset temperatures or different preset charge levels, current disturbance signals are superimposed on batteries in different aging states according to preset time periods to determine the preset impedance fitting relationship.

[0079] In this embodiment, when the battery charge is determined, the battery management device superimposes current disturbance signals onto batteries in different aging states at different preset temperatures and according to preset time periods to determine a preset temperature impedance fitting relationship; when the temperature of the battery's test environment is determined, under different preset charge levels, current disturbance signals are superimposed onto batteries in different aging states at different preset time periods to determine a preset charge impedance fitting relationship; the preset temperature impedance fitting relationship and the preset charge impedance fitting relationship are used as the preset impedance fitting relationship.

[0080] S106. The correspondence between the preset health level and impedance and the fitting relationship of the preset impedance are determined as the preset health level determination model.

[0081] In this embodiment, the battery management device determines the preset health determination model by using the preset health degree and impedance correspondence and the preset impedance fitting relationship.

[0082] Understandably, the battery management device ages at least one battery to obtain batteries in different aging states; determines the corresponding health level of the batteries in different aging states; under target temperature and target capacity, current perturbation signals are superimposed on the batteries in different aging states according to a preset time period to determine the preset health level and impedance correspondence of the batteries in different aging states; under different preset temperatures or different preset capacity, current perturbation signals are superimposed on the batteries in different aging states according to a preset time period to determine the preset impedance fitting relationship; the preset health level and impedance correspondence and the preset impedance fitting relationship are defined as the preset health level determination model; since the preset health level determination model characterizes the degree of influence of battery capacity and temperature on battery health, the preset health level determination model has a wider range of applications and higher accuracy. Battery management through the preset health level determination model can improve battery management performance.

[0083] In the embodiments of this application, Figure 4 This application provides an optional flowchart of a battery management method. Figure 4 ,like Figure 4 As shown, S104 can be implemented through S1041, S1042, and S1043, as follows:

[0084] S1041. Under the target temperature and target charge, current disturbance signals are superimposed on batteries under different aging states according to a preset time period, and sampled at a preset acquisition frequency to obtain voltage and current signals.

[0085] In this embodiment, the battery management device superimposes current disturbance signals onto batteries in different aging states at target temperature and target charge, and continues for a preset time period. Then, it samples the batteries at a preset sampling frequency to obtain voltage and current signals.

[0086] In some embodiments of this application, during the charging process, batteries in different aging states are placed at a set temperature and a specific SOC (i.e., battery capacity), and a specific current disturbance signal is superimposed for a duration of t (i.e., a preset time period), while simultaneously recording the voltage and current values ​​of the batteries.

[0087] It should be noted that the target temperature is the set temperature value, which is consistent with the test target physical quantity temperature in S103. The specific SOC is calculated using a fixed SOC value, meaning that this SOC value is used under different aging conditions.

[0088] For example, the superimposed specific current disturbance signal includes square wave signals and sinusoidal signals. If it is a sinusoidal signal, it is preferably generated by superimposing sinusoidal waves of multiple frequencies, and its mean is 0. It can also be a square wave signal, with a current step size ΔI ≥ 500mA, that is, for example, charging t / 2 with 1000mA and then charging t / 2 with 500mA. If the current signal is a square wave signal, the current does not need to be continuously constant, and slight fluctuations in the current are acceptable. The fluctuation value is less than or equal to 500mA, preferably less than or equal to 200mA. For example, when charging with 1000mA, it can be between 900mA and 1100mA.

[0089] It should be noted that the duration t must be greater than or equal to twice the reciprocal of the frequency in the selected specific frequency impedance, i.e., t ≥ 2 / fn, preferably t ≥ 10 / fn; the battery current acquisition frequency fs (i.e., the preset acquisition frequency) under the current disturbance signal must be greater than or equal to twice the frequency in the selected specific frequency impedance, i.e., fs ≥ 2fn, generally fs ≥ 10fn is chosen. The disturbance signal is calculated during battery charging, but it is also applicable to calculations during discharging.

[0090] S1042. Perform time-frequency conversion analysis on the voltage and current signals to obtain the impedance corresponding to the characteristic frequency.

[0091] In this embodiment, the battery management device performs time-frequency conversion analysis on the collected voltage and current signals to obtain the impedance corresponding to the characteristic frequency.

[0092] In some embodiments of this application, the time-frequency conversion analysis method used by the battery management device includes wavelet transform or windowed Fourier transform.

[0093] It should be noted that the characteristic frequency is preferably 0.01Hz to 60Hz, and more specifically, 0.1Hz to 5Hz is generally selected.

[0094] S1043. Based on the battery health under different aging conditions and the impedance value at a specific frequency, fit the data to determine the preset health and impedance relationship of the battery under different aging conditions; the impedance value at a specific frequency is the impedance value at any frequency in the characteristic frequency range.

[0095] In this embodiment, the impedance value at a specific frequency is the impedance value at any frequency among the characteristic frequencies.

[0096] In some embodiments of this application, the battery management device fits the health status of batteries under different aging states with the impedance value at a specific frequency to obtain a fitting function, that is, the correspondence between the preset health status and impedance of batteries under different aging states.

[0097] For example, the fitting function is m = f'(Zn); where Zn is the impedance value and m is the health status.

[0098] Understandably, the battery management device, under target temperature and target charge, superimposes current disturbance signals onto batteries in different aging states according to a preset time period, and samples them at a preset acquisition frequency to obtain voltage and current signals. Time-frequency conversion analysis is performed on the voltage and current signals to obtain the impedance corresponding to the characteristic frequency. Based on the battery health under different aging states and the impedance value at a specific frequency, a fitting is performed to determine the preset health and impedance correspondence of the battery under different aging states. This facilitates subsequent determination of the battery's health based on the preset health and impedance correspondence under different aging states. Furthermore, since the preset health and impedance correspondence of the battery under different aging states fully considers the influence of charge and temperature on battery health, the accuracy of the preset health and impedance correspondence is improved.

[0099] In the embodiments of this application, Figure 5 This application provides an optional flowchart of a battery management method. Figure 5 ,like Figure 5 As shown, S105 can be implemented through S1051, S1052, and S1053, as follows:

[0100] S1051. Given a fixed battery capacity, at different preset temperatures, current disturbance signals are superimposed on batteries under different aging states for different time periods to determine the preset temperature impedance fitting relationship.

[0101] In this embodiment, after obtaining the preset health status and impedance correspondence of batteries under different aging states, the battery management device adjusts the temperature under a given battery capacity, and superimposes current disturbance signals onto batteries under different aging states at different preset temperatures to determine the preset temperature impedance fitting relationship.

[0102] In some embodiments of this application, the battery management device superimposes current disturbance signals onto batteries under different aging conditions and continues this process for a preset time period to obtain a first test voltage signal and a first test current signal. Time-frequency conversion analysis is performed on the first test voltage signal and the first test current signal to obtain a first test impedance at a characteristic frequency. The temperature corresponding to the battery under different aging conditions is then fitted with the first test impedance to determine a preset temperature-impedance fitting relationship.

[0103] For example, the impedance at temperatures of 25, 30, 35, and 40°C is calculated, and a temperature-fitted relationship is established. The corresponding trend relationship is y = 2.0246x + 132.87, meaning that for every degree Celsius increase in temperature, the impedance decreases by 2.0246 mΩ. y = 2.0246x + 132.87 represents the preset temperature-impedance fitting relationship.

[0104] It should be noted that, given a fixed battery capacity, the preset temperature impedance fitting relationship will differ depending on the battery capacity.

[0105] S1052. Under the condition that the temperature of the battery test environment is determined, under different preset charge levels, current disturbance signals are superimposed on batteries under different aging states according to preset time periods to determine the preset charge impedance fitting relationship.

[0106] In this embodiment, after obtaining the preset health status and impedance correspondence of batteries under different aging states, the battery management device adjusts the power level under a fixed temperature in the battery testing environment. Under different preset power levels, current disturbance signals are superimposed on batteries under different aging states to determine the preset power impedance fitting relationship.

[0107] In some embodiments of this application, the battery management device superimposes current disturbance signals onto batteries in different aging states for a preset time period to obtain a second test voltage signal and a second test current signal. Time-frequency conversion analysis is performed on the second test voltage signal and the second test current signal to obtain a second test impedance at a characteristic frequency. The battery capacity corresponding to different aging states and the second test impedance are fitted to determine a preset capacity-impedance fitting relationship.

[0108] For example, when calculating the impedance Zn, the batteries at different states of charge (SOC) are placed at the same temperature, such as 30% SOC and 35% SOC, and the impedance Zn' (i.e., the second impedance) at the corresponding SOC is calculated. The battery capacity corresponding to different aging states is fitted with Zn' to determine the preset capacity impedance fitting relationship.

[0109] S1053. The preset temperature impedance fitting relationship and the preset electrical impedance fitting relationship are used as the preset impedance fitting relationship.

[0110] In this embodiment of the application, the battery management device can use a preset temperature impedance fitting relationship and a preset charge impedance fitting relationship as the preset impedance fitting relationship.

[0111] Understandably, given a fixed battery capacity, current disturbance signals are superimposed on batteries under different aging states at different preset temperatures and for different time periods to determine a preset temperature impedance fitting relationship. Similarly, given a fixed battery test environment temperature, current disturbance signals are superimposed on batteries under different aging states at different preset battery capacities and for different time periods to determine a preset charge impedance fitting relationship. The preset temperature impedance fitting relationship and the preset charge impedance fitting relationship are then used as the preset impedance fitting relationship. Determining the preset impedance fitting relationship facilitates subsequent determination of the impedance of the battery under test.

[0112] In some embodiments of this application, the correspondence between preset health level and impedance, preset temperature impedance fitting relationship, and preset electrical impedance fitting relationship can be determined in the following ways:

[0113] (1) Select several lithium-ion batteries that have not been newly manufactured and age them according to the set aging path (conventional battery aging, such as charging at 0.5C and then discharging at 0.5C at 25°C). Then take out the batteries under different aging states (different health levels of the batteries) and place them under a specific ambient temperature (fixed temperature) to test the target specific physical quantity (i.e., health level) of the batteries under that state.

[0114] It should be noted that the number of battery samples should be ≥2, preferably 3; the specific aging path can be a conventional battery aging process, such as a 0.5C charge followed by a 0.5C discharge cycle test at 25°C, or an accelerated aging path, such as a high-temperature aging process, a 50°C high-temperature cycle test, a 1C charge followed by a 0.5C discharge. This application does not limit the battery aging path. The specific physical quantity of the battery target refers to the target value during actual use, such as the battery's remaining capacity, battery thickness, battery temperature, and battery charge. The battery capacity calculation method is preferably the battery's rated capacity measurement method, such as the capacity at 0.2C discharge at 25°C, but it can also be the capacity measurement at other rates, such as 1C, 0.5C, 2C, etc. The specific ambient temperature refers to a specific standard definition of the battery during actual use, such as a remaining capacity standard of 25°C, which should be consistent before and after. Different aging states generally refer to different battery health levels, such as 100%, 95%, 90%, etc.

[0115] (2) During the charging process, the batteries under different aging states in step (1) are placed at a set temperature (25 degrees) and a specific SOC (50% charge). A specific current disturbance signal is superimposed and the duration is t (t≥2 / fn). At the same time, the voltage and current values ​​of the battery are recorded to obtain the voltage and current signals. The acquisition frequency is (fs≥2fn).

[0116] It should be noted that the set temperature value should be consistent with the temperature of the target physical quantity tested in step (1); the specific SOC is calculated using a fixed SOC value, that is, the SOC value is used under different aging conditions. The superimposed specific current disturbance signal includes square wave signal and sine wave signal. If it is a sine wave signal, the preferred feature is that it is generated by superimposing sine waves of multiple frequencies and its mean is 0; it can also be a square wave signal, with a current step size ΔI ≥ 500mA, that is, for example, charging t / 2 with 1000mA and then charging t / 2 with 500mA. If the current signal is a square wave signal, the current does not need to be constant, and slight fluctuations in the current are acceptable. The fluctuation value is less than or equal to 500mA, preferably less than or equal to 200mA. For example, when charging with 1000mA, it can be between 1100 and 900mA. The charging duration t should be greater than or equal to twice the reciprocal of the frequency in the specific frequency impedance selected in step (4), i.e., t≥2 / fn, preferably t≥10 / fn; the battery current frequency fs collected under the current disturbance signal should be greater than or equal to twice the frequency in the specific frequency impedance selected in step (4), i.e., fs≥2fn, preferably fs≥10fn.

[0117] (3) Perform time-frequency conversion analysis (wavelet transform or windowed Fourier transform) on the current and voltage signals acquired in step (2) and obtain the impedance Z = [Z1, Z2, Z3, ... Zn] at the characteristic frequency f = [f1, f2, f3, ... fn].

[0118] It should be noted that the time-frequency conversion analysis method includes wavelet transform or windowed Fourier transform. The characteristic frequency is preferably 0.01Hz to 60Hz, and more particularly, preferably 0.1Hz to 5Hz.

[0119] (4) Fit the target specific physical quantity of the battery recorded in step (1) with the impedance value Zn at a specific frequency (one of the characteristic frequencies) in step (3) to obtain the fitting function y = f'(Zn), thereby obtaining the correspondence between the target specific physical quantity value and the impedance of the battery under different aging states.

[0120] It should be noted that the correspondence between the target specific physical quantity value and the impedance is the same as the correspondence between the preset health level and the impedance.

[0121] (5) Repeat steps (2)-(3), and adjust the temperature and SOC in step (2), and record the corresponding impedance value Zn' obtained by calculation.

[0122] (6) Fit the relationship between Zn and Zn' in step (4) under different temperatures and SOC values ​​to obtain the function Zn=f'(Zn'), that is, the relationship between impedance and temperature, and the relationship between impedance and SOC.

[0123] It should be noted that the impedance-temperature relationship is the preset temperature impedance fitting relationship; the impedance-state-of-charge (SOC) relationship is the preset charge impedance fitting relationship. The fitting relationships can be achieved using linear fitting, piecewise difference fitting, or other methods.

[0124] (7) Output model, namely the correspondence between the target specific physical quantity of the battery and the impedance under different aging states, and the relationship between impedance and temperature and SOC (i.e., the relationship between impedance and temperature and the relationship between impedance and SOC in step 6).

[0125] For example, battery health can be calculated in the following way:

[0126] 1) Two batteries were selected and aged for 100 cycles at 45°C with 0.5C charge and 1C discharge. Then, the batteries were placed at 25°C and tested with 1C discharge to obtain the battery capacity Qmax. The battery health was found to be 94%.

[0127] 2) Discharge the battery to 50% capacity and place it in an environment at 25℃. The applied current disturbance signal is a square wave signal, such as... Figure 6 As shown, the battery is first charged at 2A for 10 seconds, then at 1A for 10 seconds, with a sampling frequency of 1 second and a sampling duration of 20 seconds. The collected voltage signal is as follows. Figure 7 As shown, the voltage variation range before 10s is 4.24V-4.25V, and the voltage variation range from 10s to 20s is 4.25V-4.18V.

[0128] 3) The impedance Zn at a frequency of 0.05Hz is obtained by using Fourier transform.

[0129] 4) Then, repeat the test on batteries under different aging conditions to obtain the corresponding health value and the relationship between Zn, such as... Figure 8 As shown, m = -0.0024n + 1.1478; n is the impedance value, and m is the health status.

[0130] 5) When calculating the impedance Zn, the battery in the same state is placed at different temperatures, such as 30℃ and 35℃, and the impedance Zn' at the corresponding temperature is calculated.

[0131] 6) As shown in Table 1, the impedances at 25, 30, 35, and 40℃ were calculated to be 82.65459mΩ, 71.43848mΩ, 62.1718mΩ, and 52mΩ, respectively. A fitting relationship was made with the temperature, and the corresponding trend relationship was y = 2.0246x + 132.87, which means that for every degree increase in temperature, the impedance value decreases by 2.0246mΩ; x is the temperature, and y is the impedance.

[0132] Table 1

[0133] Temperature / degree 25 30 35 40 Impedance / mΩ 82.65459 71.43848 62.1718 52

[0134] 7) For example, in the use of the whole machine, the calculated impedance value at 36℃ under 50% SOC is 65mΩ, then the impedance at 25℃ in the model is 65+11*2.0246=87.2706mΩ.

[0135] 8) Then, substitute the impedance into the relationship model between health and impedance in 4), and calculate the current health metric of the battery as m = -0.0024 * 87.2706 + 1.1478 = 0.938.

[0136] It is understandable that the accuracy of the battery model is affected by external environmental factors such as battery temperature and charge level under the operating conditions of the terminal, thus making the battery model more accurate and more suitable for the actual use of the terminal.

[0137] Based on the battery management method described in the above embodiments, this application also provides a battery management device, such as... Figure 9 As shown, Figure 9 This is a schematic diagram of a battery management system provided in an embodiment of this application. The battery management device 9 includes: a determination unit 901, wherein...

[0138] The determining unit 901 is used to determine the charge level of the battery under test and the temperature of the test environment; and to calculate the health level of the battery under test by using a preset health level determination model; the preset health level determination model characterizes the degree of influence of battery charge level and temperature on the health level of the battery.

[0139] In some embodiments of this application, the preset health determination model includes: a preset impedance fitting relationship and a preset health degree and impedance correspondence relationship;

[0140] The determining unit 901 is further configured to calculate the impedance of the battery under test by using the preset impedance fitting relationship to calculate the charge and the temperature; the preset impedance fitting relationship characterizes the relationship between impedance and charge and temperature; the battery under test is calculated by using the preset health status and impedance correspondence to determine the health status of the battery under test; the preset health status and impedance correspondence characterizes the change law of battery health status with impedance change.

[0141] In some embodiments of this application, the preset impedance fitting relationship includes: a preset temperature impedance fitting relationship;

[0142] The determining unit 901 is further configured to determine, under the specified charge level, the standard temperature and the first impedance corresponding to the preset temperature impedance fitting relationship; and to perform calculations based on the standard temperature, the first impedance, the preset temperature impedance fitting relationship and the temperature to determine the impedance of the battery under test.

[0143] In some embodiments of this application, the preset impedance fitting relationship includes: a preset electrical impedance fitting relationship;

[0144] The determining unit 901 is further configured to determine, at the temperature, the standard charge and the second impedance corresponding to the preset charge-impedance fitting relationship; and to perform calculations based on the standard charge, the second impedance, the preset charge-impedance fitting relationship and the charge to determine the impedance of the battery under test.

[0145] In some embodiments of this application, the determining unit 901 is further configured to: determine a temperature difference based on the standard temperature and the temperature; perform calculations based on the preset temperature impedance fitting relationship and the temperature difference to determine an impedance change value; and perform calculations based on the first impedance and the impedance change value to determine the impedance of the battery under test.

[0146] In some embodiments of this application, the battery management device 9 further includes: an acquisition unit 902;

[0147] The acquisition unit 902 is used to perform an aging process on at least one battery before calculating the power and temperature using a preset health determination model to determine the health of the battery under test, thereby obtaining batteries in different aging states.

[0148] The determining unit 901 is further configured to determine the health level of batteries under different aging states; at target temperature and target capacity, superimpose current disturbance signals onto batteries under different aging states according to a preset time period to determine the preset health level and impedance correspondence of batteries under different aging states; at different preset temperatures or different preset capacity, superimpose current disturbance signals onto batteries under different aging states according to the preset time period to determine the preset impedance fitting relationship; and determine the preset health level and impedance correspondence and the preset impedance fitting relationship as the preset health level determination model.

[0149] In some embodiments of this application, the acquisition unit 902 is used to superimpose current disturbance signals on batteries under different aging states at a preset time period under target temperature and target charge, and sample them at a preset acquisition frequency to obtain voltage signals and current signals; and perform time-frequency conversion analysis on the voltage signals and current signals to obtain the impedance corresponding to the characteristic frequency;

[0150] The determining unit 901 is further configured to fit the health value of the battery under different aging conditions and the impedance value at a specific frequency to determine the preset health value and impedance correspondence of the battery under different aging conditions; the impedance value at the specific frequency is the impedance value at any frequency among the characteristic frequencies.

[0151] In some embodiments of this application, the determining unit 901 is further configured to, when the battery charge is determined, superimpose current disturbance signals onto batteries in different aging states at different preset temperatures and according to the preset time period to determine a preset temperature impedance fitting relationship; when the temperature of the battery test environment is determined, superimpose current disturbance signals onto batteries in different aging states at different preset charge levels and according to the preset time period to determine a preset charge impedance fitting relationship; and use the preset temperature impedance fitting relationship and the preset charge impedance fitting relationship as the preset impedance fitting relationship.

[0152] Based on the battery management method described in the above embodiments, this application also provides a battery management device, such as... Figure 10 As shown, Figure 10 This is a schematic diagram of a battery management device provided in an embodiment of this application. The battery management device 10 includes a processor 1001 and a memory 1002. The memory 1002 is used to store computer programs; the processor 1001 is used to call and run the computer programs from the memory to execute the battery management method as described in the above embodiment.

[0153] In the embodiments of this application, the processor 1001 described above can be at least one of the following: Application-Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), Central Processing Unit (CPU), Controller, Microcontroller, and Microprocessor. It is understood that for different devices, the electronic device used to implement the above processor function can also be other types, and the embodiments of this application do not specifically limit it.

[0154] This application provides a computer-readable storage medium storing a computer program for implementing the battery management method described in any of the above embodiments when executed by a processor.

[0155] For example, the program instructions corresponding to a battery management method in this embodiment can be stored on a storage medium such as an optical disc, hard disk, or USB flash drive. When the program instructions corresponding to a battery management method in the storage medium are read or executed by an electronic device, the battery management method described in any of the above embodiments can be implemented.

[0156] Furthermore, in the embodiments of this application, the functional modules can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional module.

[0157] If the integrated unit is implemented as a software functional module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the method of this embodiment. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0158] It should be understood that the phrases "one embodiment," "an embodiment," or "some embodiments" mentioned throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment," "in one embodiment," or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. The descriptions of the various embodiments above tend to emphasize the differences between the various embodiments; their similarities or commonalities can be referred to mutually, and for the sake of brevity, they will not be repeated here.

[0159] The modules described above as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules. They may be located in one place or distributed across multiple network units. Some or all of the modules may be selected to achieve the purpose of this embodiment according to actual needs.

[0160] In addition, each functional module in the various embodiments of this application can be integrated into one processing unit, or each module can be a separate unit, or two or more modules can be integrated into one unit; the integrated modules can be implemented in hardware or in the form of hardware plus software functional units.

[0161] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0162] The methods disclosed in the several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0163] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0164] The features disclosed in the several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method or device embodiments.

[0165] The above description is merely an embodiment of this application, but the protection scope of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A battery management method, characterized by, The method comprises: determining the power of the battery to be tested and the temperature of the test environment; calculating the power and the temperature by a preset health degree determination model to determine the health degree of the battery to be tested; the preset health degree determination model represents the influence degree of the battery power and the temperature on the health degree of the battery, and the preset health degree determination model comprises a preset impedance fitting relationship and a preset health degree and impedance corresponding relationship; wherein the method further comprises: based on the power, calculating the impedance of the battery to be tested under the condition that the temperature is determined by the preset impedance fitting relationship; or based on the temperature, calculating the impedance of the battery to be tested under the condition that the power is determined by the preset impedance fitting relationship; the impedance of the battery to be tested is brought into the preset health degree and impedance corresponding relationship to calculate the health degree of the battery to be tested.

2. The method of claim 1, wherein, The method comprises: calculating the impedance of the battery to be tested by the preset impedance fitting relationship based on the power and the temperature; the preset impedance fitting relationship represents the relationship between impedance and power and temperature; calculating the health degree of the battery to be tested by the preset health degree and impedance corresponding relationship based on the impedance of the battery to be tested; the preset health degree and impedance corresponding relationship represents the change rule of the health degree of the battery with the change of the impedance.

3. The method of claim 2, wherein, The preset impedance fitting relationship comprises a preset temperature impedance fitting relationship. The method comprises: under the power, determining the standard temperature and the first impedance corresponding to the preset temperature impedance fitting relationship; based on the standard temperature, the first impedance, the preset temperature impedance fitting relationship and the temperature, performing operation to determine the impedance of the battery to be tested.

4. The method of claim 2, wherein, The preset impedance fitting relationship comprises a preset power impedance fitting relationship. The method comprises: under the temperature, determining the standard power and the second impedance corresponding to the preset power impedance fitting relationship; based on the standard power, the second impedance, the preset power impedance fitting relationship and the power, performing operation to determine the impedance of the battery to be tested.

5. The method of claim 3, wherein, The method comprises: based on the standard temperature and the temperature, determining the temperature difference value; based on the preset temperature impedance fitting relationship and the temperature difference value, performing operation to determine the impedance change value; based on the first impedance and the impedance change value, performing operation to determine the impedance of the battery to be tested.

6. The method according to any one of claims 1 to 5, characterized in that, Before the method of calculating the health degree of the battery to be tested by the preset health degree determination model based on the power and the temperature, the method further comprises: aging at least one battery to obtain batteries in different aging states; and determining a health degree corresponding to the batteries in the different aging states; superimposing a current disturbance signal on the batteries in the different aging states according to a preset time period at a target temperature and a target electric quantity, to determine a preset health degree and impedance corresponding relationship of the batteries in the different aging states; superimposing a current disturbance signal on the batteries in the different aging states according to the preset time period at different preset temperatures or different preset electric quantities, to determine a preset impedance fitting relationship; determining the preset health degree and impedance corresponding relationship and the preset impedance fitting relationship as a preset health degree determination model.

7. The method of claim 6, wherein, The superimposing a current disturbance signal on the batteries in the different aging states according to a preset time period at a target temperature and a target electric quantity, to determine a preset health degree and impedance corresponding relationship of the batteries in the different aging states, comprises: superimposing a current disturbance signal on the batteries in the different aging states according to a preset time period at a target temperature and a target electric quantity, and sampling at a preset sampling frequency to obtain a voltage signal and a current signal; performing time-frequency conversion analysis on the voltage signal and the current signal to obtain an impedance corresponding to a characteristic frequency; fitting the health degree corresponding to the batteries in the different aging states and an impedance value at the characteristic frequency to determine the preset health degree and impedance corresponding relationship of the batteries in the different aging states; the impedance value at the characteristic frequency is an impedance value at any frequency in the characteristic frequency.

8. The method of claim 6, wherein, The superimposing a current disturbance signal on the batteries in the different aging states according to the preset time period at different preset temperatures or different preset electric quantities, to determine a preset impedance fitting relationship, comprises: in a case where an electric quantity of the battery is determined, superimposing a current disturbance signal on the batteries in the different aging states according to the preset time period at different preset temperatures to determine a preset temperature impedance fitting relationship; in a case where a temperature of a test environment of the battery is determined, superimposing a current disturbance signal on the batteries in the different aging states according to the preset time period at different preset electric quantities to determine a preset electric quantity impedance fitting relationship; taking the preset temperature impedance fitting relationship and the preset electric quantity impedance fitting relationship as the preset impedance fitting relationship.

9. A battery management device, characterized by, The battery management device is used to implement the method in any one of claims 1 to 8.

10. A battery management device, characterized by, comprises: a processor and a memory, wherein the memory is used to store a computer program; the processor is used to call and run the computer program from the memory to execute the method in any one of claims 1 to 8.

11. A computer readable storage medium, characterized in that, executable instructions are stored, which are used to cause the processor to implement the method in any one of claims 1 to 8 when executed.

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