Combined time-frequency domain battery parameter identification method and apparatus

Abstract

The present invention relates to the technical field of new energy tests, and discloses a time domain-frequency domain combined battery parameter identification method and device.SOLUTION: Charging the battery to be tested to a fully charged state, and performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the battery to be tested to obtain an electrical characteristic parameter value of the battery to be tested at 100% SOC; and performing a constant current discharge on the battery to be tested at a preset SOC interval, and performing the electrochemical impedance spectrum test and the hybrid power pulse characteristic test on the battery to be tested when the battery to be tested is discharged to the preset SOC, to obtain all electrical characteristic parameter values of the battery to be tested in a (0% SOC, 100% SOC) interval.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the technical field of new energy testing, and particularly to a method and apparatus for identifying battery parameters by combining time domain and frequency domain. [Background technology]

[0002] With the development of new power systems and the widespread use of new energy vehicles, the demand for batteries is rapidly increasing. Since battery impedance and capacitance parameters are the basis for estimating the state of charge (SOC), analyzing the state of health (SOH), and managing safety of battery systems, it is extremely important to accurately obtain these electrical characteristic parameters.

[0003] The second-order RC equivalent circuit model is one of the most commonly used equivalent circuit models in battery simulation research. The battery parameters that need to be identified and acquired in this model include the ohmic internal resistance R0, the first polarization resistance R1, the first polarization capacitance C1, the second polarization resistance R2, and the second polarization capacitance C2. Here, the ohmic internal resistance R0 is the solid contact resistance due to physical elements such as the battery material, electrolyte, and separator. The first polarization resistance R1 and the first polarization capacitance C1 reflect the electrochemical polarization characteristics of the battery and have short relaxation times (small time scales). The second polarization resistance R2 and the second polarization capacitance C2 are due to the ionic diffusion effect and reflect the concentration polarization characteristics of the battery. The relaxation times of R2 and C2 are long (large time scales).

[0004] Battery parameters can be identified and obtained by analyzing time-domain or frequency-domain features. The time-domain feature acquisition method typically involves performing a hybrid power pulse characteristic (HPPC) test on a battery. This method applies a short-term pulse charge or discharge stimulus to the battery and then analyzes the voltage-time curve during the rest period after the pulse stimulus to obtain battery parameters. However, if the rest period is short, the large-time-scale second polarization resistance R2 and second polarization capacity C2 cannot be accurately identified. If the rest period is long, R2 and C2 can be accurately identified, but the data volume becomes large, resulting in data oversaturation problems. The frequency-domain feature acquisition method typically involves electrochemical impedance spectroscopy (EIS). This method is highly sensitive to the battery's small-time-scale parameters (first polarization resistance R1 and first polarization capacity C1) but has a large identification error for the large-time-scale parameters (second polarization resistance R2 and second polarization capacity C2).

[0005] In summary, all of the prior art techniques identify and acquire battery electrical characteristic parameters from a single time domain characteristic or frequency domain characteristic. Due to the long time span of the battery electrochemical process, methods for identifying battery parameters from a single time domain feature or frequency domain feature have problems such as data saturation or inaccurate identification of parameters over a long time scale. Currently, there is a need for a battery parameter identification technique that can acquire parameters with a small amount of data, accurately, and meet the actual electrochemical situation. Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above circumstances, the present invention provides a method and apparatus for identifying battery parameters that combines time domain and frequency domain to solve the problems of data saturation or inaccurate identification of parameters on a large time scale in current methods for identifying battery parameters from a single time domain feature or frequency domain feature. [Means for solving the problem]

[0007] In a first aspect, the present invention provides a method for producing a composition comprising: Charging a test battery to a fully charged state, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test battery, and obtaining electrical characteristic parameter values ​​of the test battery at 100% SOC; performing a constant current discharge on the test target battery at predetermined SOC intervals, and when the test target battery is discharged to a predetermined SOC, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristics test on the test target battery, and acquiring all electrical characteristic parameter values ​​in the (0% SOC, 100% SOC) interval of the test target battery.

[0008] In one alternative embodiment, the step of charging a battery under test to a fully charged state, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the battery under test, and obtaining electrical characteristic parameter values ​​of the battery under test at 100% SOC includes: charging the battery under test to a full charge state at a predetermined rate; performing an electrochemical impedance spectrum test on the battery under test to obtain frequency domain characteristics at 100% SOC of the battery under test; and performing parameter identification on the frequency domain characteristics to obtain an ohmic internal resistance, a first polarization resistance, and a first polarization capacity; performing a hybrid power pulse characteristic test on the battery under test to obtain time domain characteristics at 100% SOC of the battery under test; and performing parameter identification on the time domain characteristics to obtain a second polarization resistance and a second polarization capacity.

[0009] In one alternative embodiment, the step of performing a constant current discharge on the battery under test at a predetermined SOC interval, discharging the battery under test to the predetermined SOC, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the battery under test, and acquiring all electrical characteristic parameter values ​​in the interval (0% SOC, 100% SOC) of the battery under test, comprises: constant current discharging the battery under test to a first predetermined SOC, the positive difference between the first predetermined SOC and 100% SOC being a predetermined SOC interval; performing an electrochemical impedance spectrum test on the battery under test to obtain frequency domain characteristics of the battery under test at the first predetermined SOC; and performing parameter identification on the frequency domain characteristics to obtain an ohmic internal resistance, a first polarization resistance, and a first polarization capacity; performing a hybrid power pulse characteristic test on the battery under test to obtain time domain characteristics of the battery under test at the first predetermined SOC; and performing parameter identification on the time domain characteristics to obtain a second polarization resistance and a second polarization capacity.

[0010] In one alternative embodiment, the step of performing a constant current discharge on the battery under test at a predetermined SOC interval, discharging the battery under test to the predetermined SOC, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the battery under test, and acquiring all electrical characteristic parameter values ​​in the interval (0% SOC, 100% SOC) of the battery under test, comprises: determining whether the current SOC of the battery under test is greater than 0; If the current SOC is greater than 0, continuously discharge the battery under test at a constant current at a predetermined SOC interval until the current SOC is equal to 0, and obtain the ohmic internal resistance, the first polarization resistance, the first polarization capacity, the second polarization resistance and the second polarization capacity of the battery under test at the next predetermined SOC; If the first predetermined SOC is equal to 0, stopping the constant current discharge of the battery under test.

[0011] In one alternative embodiment, the formula for parameter identification of the frequency domain features is: TIFF2026031416000002.tif18125In the formula, j is the imaginary unit, R0 is the ohmic internal resistance of the battery, R1 is the first polarization resistance, C1 is the first polarization capacitance, and τ1 is the first relaxation time. TIFF2026031416000003.tif721, where ω is the angular frequency and ω=2πf.

[0012] In one alternative embodiment, the second polarization resistance and the second polarization capacity are obtained by identifying the voltage-time curve during the rest phase of the hybrid power pulse characterization test.

[0013] In one alternative embodiment, the voltage-time curve during the resting phase is represented by the formula: TIFF2026031416000004.tif1494, U d (t) is the terminal voltage of the battery at time t, U OC is the open circuit voltage of the battery at that SOC, TIFF2026031416000005.tif723, where τ2 is the second relaxation time, R2 is the second polarization resistance, and C2 is the second polarization capacitance.

[0014] In a second aspect, the present invention provides a method for producing a pharmaceutical composition comprising: a first identification module for charging a test battery to a fully charged state, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test battery, and obtaining electrical characteristic parameter values ​​of the test battery at 100% SOC; and a second identification module for performing a constant current discharge on the test target battery at predetermined SOC intervals, and when the test target battery is discharged to a predetermined SOC, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test target battery, and obtaining all electrical characteristic parameter values ​​in the (0% SOC, 100% SOC) interval of the test target battery.

[0015] In a third aspect, the present invention provides a computer device including a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, the processor executing the computer instructions to perform the method for combined time domain-frequency domain battery parameter identification of the first aspect or any one of the corresponding embodiments.

[0016] In a fourth aspect, the present invention provides a computer-readable storage medium having stored thereon computer instructions for causing a computer to execute the method for identifying battery parameters using a combined time domain and frequency domain according to the first aspect or any one of the embodiments corresponding thereto.

[0017] The present invention provides a method for identifying battery parameters by combining the time and frequency domains, including the steps of: charging a battery under test to a fully charged state, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the battery under test to obtain electrical characteristic parameter values ​​at 100% SOC of the battery under test; and performing a constant current discharge on the battery under test at a predetermined SOC interval. After discharging the battery under test to the predetermined SOC, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the battery under test to obtain all electrical characteristic parameter values ​​in the interval (0% SOC, 100% SOC) of the battery under test. By combining the time and frequency domain characteristics of the battery and identifying the frequency domain characteristics of the battery, the battery's small-time scale electrical characteristic parameters are obtained, avoiding the problem of inaccurate identification of large-time scale parameters. By identifying the time domain characteristics of the battery, the battery's large-time scale electrical characteristic parameters are obtained. Since the purpose of this process is to obtain the battery's parameters over large time scales, the interval between data collection points does not need to be too small, thereby reducing the amount of test data and avoiding the phenomenon of data oversaturation.

[0018] The present invention provides a battery parameter identification device that combines time and frequency domains, including a first identification module that charges a test battery to a fully charged state, performs an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test battery, and obtains electrical characteristic parameter values ​​of the test battery at 100% SOC, and a second identification module that performs constant current discharge on the test battery at predetermined SOC intervals, and when the test battery is discharged to the predetermined SOC, performs an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test battery to obtain all electrical characteristic parameter values ​​of the test battery in the (0% SOC, 100% SOC) interval. By combining the time domain characteristics and frequency domain characteristics of the battery, the amount of data required for offline parameter identification of the battery can be reduced and the accuracy of the identification results can be improved.

[0019] In order to more clearly describe the specific embodiments of the present invention or the technical solutions of the prior art, the drawings that need to be used to describe the specific embodiments or the prior art will be briefly described below. It is obvious that the drawings described below are some embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without any creative work. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a flowchart of a method for identifying battery parameters by combining time domain and frequency domain according to an embodiment of the present invention; [Figure 2] 1 shows an EIS test model and EIS test curves according to an embodiment of the present invention. [Figure 3] 1 is a diagram illustrating an HPPC test model and voltage-time curves according to an embodiment of the present invention. [Figure 4] 1 is a structural block diagram of a battery parameter identification device that combines time domain and frequency domain according to an embodiment of the present invention; [Figure 5]1 is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0021] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present invention, the technical solutions of the embodiments of the present invention will be described below clearly and completely with reference to the drawings of the embodiments of the present invention, and it is obvious that the described embodiments are only some of the embodiments of the present invention, and not all of the embodiments. All other embodiments that can be obtained by those skilled in the art based on the embodiments of the present invention without any creative work fall within the scope of protection of the present invention.

[0022] The present invention provides a battery parameter identification method that combines time domain and frequency domain, which combines the time domain characteristics and frequency domain characteristics of the battery and determines parameter values ​​of different time scales in the time domain and frequency domain respectively, thereby improving the accuracy of battery electrical characteristic parameter identification and reducing the amount of test data.

[0023] According to an embodiment of the present invention, an embodiment of a combined time domain-frequency domain battery parameter identification method is provided, wherein the steps shown in the flowcharts of the drawings can be performed, for example, by a computer system having a set of computer-executable instructions, and although a logical order is shown in the flowcharts, in some cases the steps shown or described can be performed in an order different from that shown here.

[0024] In this embodiment, a battery parameter identification method combining time domain and frequency domain is provided. FIG. 1 is a flowchart of the battery parameter identification method combining time domain and frequency domain according to an embodiment of the present invention. As shown in FIG. 1, the flow includes the following steps:

[0025] Step S11: Charge the test battery to a fully charged state, and perform an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test battery to obtain the electrical characteristic parameter values ​​of the test battery at 100% SOC.

[0026] Specifically, the test battery is first charged to 100% SOC and subjected to an electrochemical impedance spectroscopy (EIS) test. The frequency domain characteristics obtained from the EIS test are analyzed to obtain electrical characteristic parameters, such as the ohmic internal resistance (R0), first polarization resistance (R1), and first polarization capacity (C1), of the test battery at 100% SOC. Next, a hybrid power pulse characteristic (HPPC) test is performed on the test battery. The time domain characteristics obtained from the HPPC test are analyzed to obtain electrical characteristic parameters, such as the second polarization resistance (R2) and second polarization capacity (C2). All electrical characteristic parameters at 100% SOC are identified. Because the EIS test is nondestructive and does not cause damage or capacity change to the battery, it is possible to ensure that the characteristic parameters obtained from the two tests are the same for the battery at the same SOC point.

[0027] Step S12: A constant current discharge is performed on the battery under test at a predetermined SOC interval. When the battery under test is discharged to a predetermined SOC, an electrochemical impedance spectrum test and a hybrid power pulse characteristic test are performed on the battery under test, and all electrical characteristic parameter values ​​in the (0% SOC, 100% SOC) interval of the battery under test are obtained.

[0028] Specifically, the battery is discharged at a constant current to the next SOC point (e.g., 95% SOC), and the process of step S11 is repeated to obtain all electrical characteristic parameters at the 95% SOC point. The process of step S12 is repeated to obtain all electrical characteristic parameter values ​​in the interval (0% SOC, 100% SOC). Steps S11 and S12 can be combined to obtain all electrical characteristic parameter values ​​in the interval (0% SOC, 100% SOC). In this embodiment of the present invention, the SOC interval is 5%, but this is merely an example and is not limiting.

[0029] The present invention provides a method for identifying battery parameters by combining the time and frequency domains, including the steps of: charging a battery under test to a fully charged state, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the battery under test to obtain electrical characteristic parameter values ​​at 100% SOC of the battery under test; and performing a constant current discharge on the battery under test at a predetermined SOC interval. After discharging the battery under test to the predetermined SOC, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the battery under test to obtain all electrical characteristic parameter values ​​in the interval (0% SOC, 100% SOC) of the battery under test. By combining the time and frequency domain characteristics of the battery and identifying the frequency domain characteristics of the battery, the battery's small-time scale electrical characteristic parameters are obtained, avoiding the problem of inaccurate identification of large-time scale parameters. By identifying the time domain characteristics of the battery, the battery's large-time scale electrical characteristic parameters are obtained. Since the purpose of this process is to obtain the battery's parameters over large time scales, the interval between data collection points does not need to be too small, thereby reducing the amount of test data and avoiding the phenomenon of data oversaturation.

[0030] In one alternative embodiment, step S11 includes the following steps:

[0031] Step S111: The battery under test is charged to a full charge state at a predetermined rate.

[0032] Specifically, this example uses a lithium iron phosphate cell as an example, and the upper and lower voltage limits during the cell's charge and discharge process are 2.5 to 3.65 V. During charging, the battery is first charged at a rate of 0.2 C until the voltage reaches 3.65 V, then constant voltage charged at 3.65 V until the current becomes less than 0.02 C, and then left to stand for 1 hour. At this time, the battery is in a fully charged state.

[0033] Step S112: Perform an electrochemical impedance spectrum test on the battery under test to obtain frequency domain characteristics at 100% SOC of the battery under test, and perform parameter identification on the frequency domain characteristics to obtain the ohmic internal resistance R0, the first polarization resistance R1, and the first polarization capacity C1.

[0034] Specifically, the frequency domain characteristics of the battery are obtained using electrochemical impedance spectroscopy (EIS) testing, with the frequency (f) range of 100 kHz to 100 Hz and the voltage amplitude of 10 mV. TIFF2026031416000006.tif5150 The ohmic internal resistance R0, first polarization resistance R1, and first polarization capacity C1 of the battery at SOC=100% are obtained. The electrochemical impedance spectrum test of the lithium iron phosphate cell is carried out at a constant temperature of 25°C.

[0035] Step S113: A hybrid power pulse characteristic test is performed on the battery under test, the time domain characteristics of the battery under test at 100% SOC are obtained, and parameter identification is performed on the time domain characteristics to obtain the second polarization resistance R2 and the second polarization capacity C2.

[0036] Specifically, the HPPC test is used to obtain the time-domain characteristics of the battery at 100% SOC. As shown in Figure 3, the HPPC test steps include two sequential steps: a 30-second discharge step with a 1C current pulse and a 60-second rest step, with a 10-second interval between data collection points. By identifying the voltage-time curve during the resting step, the second polarization resistance R2 and second polarization capacity C2 of the battery at 100% SOC are obtained. The hybrid power pulse characteristic test of the lithium iron phosphate cell is performed at a constant temperature of 25°C. Since the purpose of this process is to obtain battery parameters over a long time scale, the interval between data collection points does not need to be too short, thereby reducing the amount of test data and avoiding data oversaturation.

[0037] In this embodiment, the present invention is temperature-versatile, and similar EIS and HPPC test methods can be used to obtain electrical characteristic parameters of a battery at different temperatures. The frequency range and voltage amplitude of the EIS test can be changed depending on the battery type and test temperature. The magnitude of the pulse discharge current, pulse discharge time, and rest time of the HPPC test can be determined depending on the battery type and test temperature.

[0038] This application is also versatile for various battery types. By adjusting the frequency range of the EIS test, the voltage amplitude, and the pulse current magnitude and rest time of the HPPC test, it can be applied to various battery types (e.g., lithium-ion batteries, sodium-ion batteries, and supercapacitor units) and battery models (e.g., rectangular, pouch, and cylindrical).

[0039] In one alternative embodiment, step S12 includes the following steps:

[0040] Step S121: Constant current discharge the battery under test to a first predetermined SOC, and the positive difference between the first predetermined SOC and 100% SOC is the predetermined SOC interval.

[0041] Step S122: Perform an electrochemical impedance spectrum test on the battery under test to obtain frequency domain characteristics at a first predetermined SOC of the battery under test, and perform parameter identification on the frequency domain characteristics to obtain an ohmic internal resistance R0, a first polarization resistance R1, and a first polarization capacity C1.

[0042] Step S123: Perform a hybrid power pulse characteristic test on the battery under test, obtain time domain characteristics at a first predetermined SOC of the battery under test, and perform parameter identification on the time domain characteristics to obtain a second polarization resistance R2 and a second polarization capacity C2.

[0043] Specifically, the battery is discharged at a constant current of 1C, and the battery SOC is adjusted to the next SOC point (e.g., 95% SOC). An electrochemical impedance spectrum test and a hybrid power pulse characteristic test are sequentially performed on the battery under test to obtain frequency and time domain characteristics of the battery under test at 95% SOC. Parameters are then identified for the frequency and time domain characteristics to obtain the ohmic internal resistance R0, first polarization resistance R1, first polarization capacity C1, second polarization resistance R2, and second polarization capacity C2 at 95% SOC. In this embodiment of the present invention, the first predetermined SOC is 95% SOC. The predetermined SOC interval is 5%.

[0044] In one alternative embodiment, step S12 further includes the following steps:

[0045] Step S124: Determine whether the current SOC of the battery under test is greater than 0.

[0046] Step S125: If the current SOC is greater than 0, continuously discharge the battery under test at a constant current at a predetermined SOC interval until the current SOC is equal to 0, and obtain the ohmic internal resistance, the first polarization resistance, the first polarization capacity, the second polarization resistance and the second polarization capacity of the battery under test at the next predetermined SOC.

[0047] Step S127: If the first predetermined SOC is equal to 0, stop the constant current discharge of the battery under test.

[0048] Specifically, if it is determined that the current SOC is greater than 0, the process of steps S122 to S123 is repeated until the current SOC is equal to 0, and all electrical characteristic parameter values ​​in the (0% SOC, 100% SOC) interval are obtained.

[0049] In one alternative embodiment, the formula for parameter identification of frequency domain features is: TIFF2026031416000007.tif18136In the formula, j is the imaginary unit, R0 is the ohmic internal resistance of the battery, R1 is the first polarization resistance, C1 is the first polarization capacitance, and τ1 is the first relaxation time. TIFF2026031416000008.tif721, where ω is the angular frequency and ω=2πf.

[0050] Specifically, the real and imaginary parts of the model are expressed by the relation TIFF2026031416000009.tif12107

[0051] In this embodiment, one of several software programs such as Zview and ZSimpWin is used to perform parameter identification in the frequency domain to obtain the small-time scale parameter values ​​of the battery, including the ohmic internal resistance R0, the first polarization resistance R1, and the first polarization capacitance C1.

[0052] In one alternative embodiment, the second polarization resistance and the second polarization capacity are obtained by identifying the voltage-time curve during the rest phase of the hybrid power pulse characterization test.

[0053] Specifically, the voltage-time curve in the resting stage of the HPPC test is expressed by the formula TIFF2026031416000010.tif14105, U d (t) is the terminal voltage of the battery at time t, U OC is the open circuit voltage of the battery at that SOC, TIFF2026031416000011.tif723, where τ2 is the second relaxation time, R2 is the second polarization resistance, and C2 is the second polarization capacitance.

[0054] By substituting the values ​​of τ and R in the parameter identification formula for the frequency domain features into Equation (3) and fitting the voltage-time curve during the resting stage of the HPPC test using the least squares method, the values ​​of τ, R, and C at the SOC can be calculated. The parameters of the time domain features can be identified and obtained using MATLAB software. In an embodiment of the present invention, the maximum likelihood estimation method and the sequential estimation method can be replaced with the least squares method.

[0055] By analyzing and identifying the EIS and HPPC test curves at all SOC points in the (0% SOC, 100% SOC) interval, all electrical characteristic parameter values ​​in the (0% SOC, 100% SOC) interval can be obtained. As shown in Table 1, the time constants (τ1 and τ2) obtained by this method show an order of magnitude difference and meet the actual electrochemical conditions of the battery.

[0056] [Table 1] TIFF2026031416000013.tif199157

[0057] In one alternative embodiment, before step S11, the method further includes the following steps:

[0058] Step S101: A standard capacity calibration test is performed under a predetermined temperature to determine the standard capacity of the battery under test.

[0059] Specifically, the lithium-ion battery under test is placed in an incubator at 25°C, and a standard capacity calibration test (static - constant current and constant voltage charge - static - constant current discharge) is performed three times, and the average value C of the three discharge capacities is used as the battery capacity.

[0060] Step S102: The battery under test is charged to a fully charged state, and the open circuit voltage of the battery under test is measured.

[0061] Specifically, the battery is charged at a rate of 0.2 C until the voltage reaches 3.65 V, then constant-voltage charged at 3.65 V until the current falls below 0.02 C, and then allowed to rest for 1 hour. At this point, the battery is fully charged, and its open-circuit voltage (OCV) (corresponding to the open-circuit voltage at 100% SOC) is measured. In this embodiment of the present invention, the magnitude of the charging current, the end-of-charge voltage, and the constant-voltage charging current threshold can all be determined according to the battery type and temperature.

[0062] This embodiment further provides a battery parameter identification device that combines the time domain and the frequency domain, which can be applied to realizing the above-described embodiments and preferred embodiments, and redundant explanations of parts that have already been explained will be omitted. As used below, the term "module" can realize a software and / or hardware combination of pre-configured functions. The device described in the following embodiment is preferably realized by software, but it is also possible and envisioned to realize it by hardware or a combination of software and hardware.

[0063] This embodiment provides a battery parameter identification device that combines time domain and frequency domain, which includes a first identification module 41 and a second identification module 42, as shown in FIG.

[0064] The first identification module 41 is used to charge the test battery to a fully charged state, perform an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test battery, and obtain the electrical characteristic parameter values ​​of the test battery at 100% SOC.

[0065] The second identification module 42 performs constant current discharge on the battery under test at a predetermined SOC interval, and after discharging the battery under test to a predetermined SOC, performs an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the battery under test to obtain all electrical characteristic parameter values ​​of the battery under test in the (0% SOC, 100% SOC) interval.

[0066] Further functional explanations of the above modules and units are the same as those of the corresponding embodiments, so duplicate explanations will be omitted here.

[0067] The battery parameter identification device combining time domain and frequency domain in this embodiment is presented in the form of a functional unit, where unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory executing one or more software or fixed programs, and / or other device capable of providing the above functionality.

[0068] The present invention provides a battery parameter identification device that combines the time domain and frequency domain, and includes: a first identification module for charging a test battery to a fully charged state, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test battery, and obtaining electrical characteristic parameter values ​​of the test battery at 100% SOC; and a second identification module for performing a constant current discharge on the test battery at a predetermined SOC interval, and, when the test battery is discharged to the predetermined SOC, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test battery, and obtaining all electrical characteristic parameter values ​​of the test battery in the (0% SOC, 100% SOC) interval. By combining the time domain characteristics and frequency domain characteristics of the battery, the amount of data required for offline parameter identification of the battery can be reduced and the accuracy of the identification results can be improved.

[0069] An embodiment of the present invention further provides a computer device, which includes the time domain-frequency domain combined battery parameter identification device shown in FIG.

[0070] Referring to FIG. 5, FIG. 5 is a structural diagram of a computer device according to an alternative embodiment of the present invention. As shown in FIG. 5, the computer device includes one or more processors 10, memory 20, and interfaces, including high-speed and low-speed interfaces, for connecting each component. The components are communicatively connected to each other via different buses and may be mounted on a common motherboard or otherwise attached as needed. The processor can process instructions executed within the computer device, including instructions stored in or on memory for displaying GUI graphic information on an external input / output device (e.g., a display device coupled to the interface). In some alternative embodiments, multiple processors and / or multiple buses may be used along with multiple memories and multiple memories as needed. Similarly, multiple computer devices may be connected, each providing a portion of the required operations (e.g., functioning as a server array, a set of blade servers, or a multiprocessor system). FIG. 5 illustrates one processor 10 as an example.

[0071] The processor 10 may be a central processing unit, a network processor, or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be an application specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable logic gate array, a generic array logic, or any combination thereof.

[0072] The memory 20 stores instructions executable by at least one processor 10, causing the at least one processor 10 to execute and implement the methods illustrated in the above embodiments.

[0073] The memory 20 may include a program storage area capable of storing an operating system and / or application programs required for at least one function, and a data storage area capable of storing data generated in response to use of the computing device. The memory 20 may also include high-speed random access memory and may further include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory located remotely from the processor 10, and such remote memory may be connected to the computing device via a network. Examples of such networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0074] Memory 20 may include volatile memory, such as random access memory, or may include non-volatile memory, such as flash memory, a hard disk, or a solid state drive, or memory 20 may include a combination of the above types of memory.

[0075] The computing device further includes a communications interface 30 that allows the computing device to communicate with other devices or communications networks.

[0076] An embodiment of the present invention further provides a computer-readable storage medium, and the methods according to the above-described embodiment of the present invention may be implemented in hardware, firmware, recordable on a storage medium, or as computer code downloaded over a network, originally stored on a remote storage medium or a non-transitory machine-readable storage medium, but stored on a local storage medium, whereby the methods described herein may be processed by software stored on a storage medium using a general-purpose computer, a special-purpose processor, or programmable or special-purpose hardware. The storage medium may be a magnetic disk, optical disk, read-only memory, random-access memory, flash memory, hard disk, solid-state drive, etc., and optionally, the storage medium may include a combination of the above types of memory. It will be understood that a computer, processor, microprocessor controller, or programmable hardware may include a storage component capable of storing or receiving software or computer code, and when the software or computer code is accessed and executed by the computer, processor, or hardware, it implements the methods described in the above-described embodiment.

[0077] Although the embodiments of the present invention have been described with reference to the drawings, those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications fall within the scope defined by the appended claims.

Claims

1. A method for identifying battery parameters using a combined time domain-frequency domain method, comprising: Charging a test battery to a fully charged state, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test battery, and obtaining electrical characteristic parameter values ​​of the test battery at 100% SOC; performing a constant current discharge on the test target battery at predetermined SOC intervals, and when the test target battery is discharged to the predetermined SOC, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristics test on the test target battery, and acquiring all electrical characteristic parameter values ​​in the (0% SOC, 100% SOC) interval of the test target battery; The step of charging a test target battery to a fully charged state, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test target battery, and obtaining electrical characteristic parameter values ​​of the test target battery at 100% SOC includes: charging the battery under test to a full charge state at a predetermined rate; performing an electrochemical impedance spectrum test on the battery under test to obtain frequency domain characteristics at 100% SOC of the battery under test; and performing parameter identification on the frequency domain characteristics to obtain an ohmic internal resistance, a first polarization resistance, and a first polarization capacity; performing a hybrid power pulse characteristic test on the battery under test to obtain time domain characteristics at 100% SOC of the battery under test; and performing parameter identification on the time domain characteristics to obtain a second polarization resistance and a second polarization capacity; the step of performing a constant current discharge on the test target battery at a predetermined SOC interval, discharging the test target battery to a predetermined SOC, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test target battery, and acquiring all electrical characteristic parameter values ​​in the (0% SOC, 100% SOC) interval of the test target battery; constant current discharging the battery under test to a first predetermined SOC, the positive difference between the first predetermined SOC and 100% SOC being a predetermined SOC interval; performing an electrochemical impedance spectrum test on the battery under test to obtain frequency domain characteristics of the battery under test at the first predetermined SOC; and performing parameter identification on the frequency domain characteristics to obtain an ohmic internal resistance, a first polarization resistance, and a first polarization capacity; performing a hybrid power pulse characteristics test on the battery under test to obtain time domain characteristics at the first predetermined SOC of the battery under test; and performing parameter identification on the time domain characteristics to obtain a second polarization resistance and a second polarization capacity.

2. the step of performing a constant current discharge on the test target battery at a predetermined SOC interval, discharging the test target battery to a predetermined SOC, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test target battery, and acquiring all electrical characteristic parameter values ​​in the (0% SOC, 100% SOC) interval of the test target battery; determining whether the current SOC of the battery under test is greater than 0; If the current SOC is greater than 0, continuously discharge the battery under test at a constant current at predetermined SOC intervals until the current SOC is equal to 0, and obtain the ohmic internal resistance, the first polarization resistance, the first polarization capacity, the second polarization resistance, and the second polarization capacity of the battery under test at the next predetermined SOC; 2. The method of claim 1, further comprising: stopping the constant current discharge of the battery under test when the first predetermined SOC is equal to 0.

3. The calculation formula for parameter identification of the frequency domain feature is: In the formula, j is the imaginary unit, R 0 is the internal resistance of the battery in ohms, R 1 is the first polarization resistance, C 1 is the first polarization capacity, τ 1 is the first relaxation time, 2. The combined time domain-frequency domain battery parameter identification method of claim 1, wherein ω is the angular frequency, and ω=2πf.

4. The method for identifying battery parameters by combining the time domain and frequency domain as claimed in claim 1, further comprising: obtaining the second polarization resistance and the second polarization capacity by identifying a voltage-time curve during a resting stage of a hybrid power pulse characteristics test.

5. The voltage-time curve during the resting stage is given by the formula In the ceremony, U d (t) is the terminal voltage of the battery at time t, U OC is the open circuit voltage of the battery at that SOC, and τ 2 is the second relaxation time, R 2 is the second polarization resistance, C 2 The method for identifying battery parameters using a combined time domain and frequency domain as claimed in claim 4, wherein: is the second polarization capacity.

6. A battery parameter identification device combining time domain and frequency domain, comprising: a first identification module for charging a test battery to a fully charged state, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test battery, and obtaining electrical characteristic parameter values ​​of the test battery at 100% SOC; a second identification module for performing a constant current discharge on the test target battery at predetermined SOC intervals, and when the test target battery is discharged to the predetermined SOC, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test target battery, and obtaining all electrical characteristic parameter values ​​in the (0% SOC, 100% SOC) interval of the test target battery; The steps of charging a test target battery to a fully charged state, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test target battery, and obtaining electrical characteristic parameter values ​​of the test target battery at 100% SOC include: charging the battery under test to a full charge state at a predetermined rate; performing an electrochemical impedance spectrum test on the battery under test to obtain frequency domain characteristics at 100% SOC of the battery under test; and performing parameter identification on the frequency domain characteristics to obtain an ohmic internal resistance, a first polarization resistance, and a first polarization capacity; performing a hybrid power pulse characteristic test on the battery under test to obtain time domain characteristics at 100% SOC of the battery under test; and performing parameter identification on the time domain characteristics to obtain a second polarization resistance and a second polarization capacity; a step of performing a constant current discharge on the test target battery at a predetermined SOC interval, discharging the test target battery to a predetermined SOC, performing an electrochemical impedance spectrum test and a hybrid power pulse characteristic test on the test target battery, and acquiring all electrical characteristic parameter values ​​in the (0% SOC, 100% SOC) interval of the test target battery, constant current discharging the battery under test to a first predetermined SOC, the positive difference between the first predetermined SOC and 100% SOC being a predetermined SOC interval; performing an electrochemical impedance spectrum test on the battery under test to obtain frequency domain characteristics of the battery under test at the first predetermined SOC; and performing parameter identification on the frequency domain characteristics to obtain an ohmic internal resistance, a first polarization resistance, and a first polarization capacity; performing a hybrid power pulse characteristics test on the battery under test, acquiring time domain characteristics at the first predetermined SOC of the battery under test, and performing parameter identification on the time domain characteristics to obtain a second polarization resistance and a second polarization capacity.

7. A computer device comprising: A computer device comprising: a memory; and a processor, the memory and the processor being communicatively connected to each other; computer instructions stored in the memory; and the processor executing the computer instructions to perform the method for identifying battery parameters by combining the time domain and the frequency domain according to any one of claims 1 to 5.

8. A computer-readable storage medium having stored thereon computer instructions for causing a computer to execute the method for identifying battery parameters using a combination of time domain and frequency domain according to any one of claims 1 to 5.

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