Methods and related devices for obtaining the remaining usable energy of lithium batteries

Abstract

The present application provides a method for obtaining the remaining available energy of a lithium battery and a related device, the method comprising: measuring the current voltage and current current of each single cell of a lithium battery pack during the charge and discharge process to obtain the current single cell measured voltage and the current single cell measured current; for any single cell, determining the current static open circuit voltage of the single cell based on the current single cell measured voltage, the current single cell measured current and the DC internal resistance of the single cell; summing the current static open circuit voltages corresponding to each single cell to obtain the current total voltage value of the lithium battery pack; and finally calculating the current remaining available energy of the lithium battery pack based on the current total voltage value of the lithium battery pack. The present application determines the static OCV value of the single cell through the single cell voltage and DCR value, and can use the sum of the static OCV values ​​of the lithium battery pack instead of the total voltage value, thereby ensuring the accuracy of the remaining power estimation result.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method for obtaining the remaining available energy of a lithium battery and a related device. Background Art

[0002] In the fields of pure power battery new energy vehicles, plug-in hybrid vehicles, etc., the remaining power of the power battery is one of the key parameters that are essential for accurately calculating the vehicle's cruising range. The remaining power of the power battery is usually determined by the rated power and SOE (State Of Energy).

[0003] However, there are few algorithms for SOE in the industry at present. Because SOC (State Of Charge) is similar to SOE, the product of SOC value, rated capacity and total voltage value is usually used as SOE. There are usually two methods to obtain the total voltage value: 1. The method of measuring the total voltage value of the battery is adopted. This acquisition method has certain disadvantages. Because in actual use, the battery has a short board effect, and its capacity depends on the lowest cell voltage. When the battery consistency is not good, the remaining power of the battery is determined by the lowest cell. Therefore, if this method is used for calculation, the remaining power of the battery is inaccurate and there will be a large error. 2. The total voltage value is calculated using the OCV (Open circuit voltage) corresponding to the SOC. This acquisition method has certain disadvantages. When the SOC error is large, the OCV reversed by the SOC is also extremely inaccurate, which will lead to calculation errors. Summary of the invention

[0004] The present application provides a method for obtaining the remaining available energy of a lithium battery and a related device to solve the problem of poor accuracy in calculating the remaining available energy of a lithium battery in the prior art.

[0005] In a first aspect, the present application provides a method for obtaining the remaining available energy of a lithium battery, comprising:

[0006] The current voltage and current of each single cell of the lithium battery pack are measured during the charging and discharging process to obtain the current single cell measurement voltage and current single cell measurement current;

[0007] For any single cell, based on the current single cell measured voltage, the current single cell measured current and the DC internal resistance of the single cell, determine the current static open circuit voltage of the single cell;

[0008] Sum the current static open circuit voltages corresponding to the individual cells to obtain the current total voltage value of the lithium battery pack;

[0009] The current remaining available energy of the lithium battery pack is calculated based on the current total voltage value of the lithium battery pack.

[0010] In a possible implementation, calculating the current remaining available energy of the lithium battery pack based on the current total voltage value of the lithium battery pack includes:

[0011] Query the corresponding current SOC value according to the current total voltage value of the lithium battery pack;

[0012] Obtaining the health and total capacity of the lithium battery pack;

[0013] Based on the health, total capacity, current total voltage value and current SOC value of the lithium battery pack, the current remaining available energy of the lithium battery pack is calculated.

[0014] In a possible implementation, calculating the current remaining available energy of the lithium battery pack based on the health, total capacity, current total voltage value, and current SOC value of the lithium battery pack includes:

[0015] calculate Obtaining the current remaining available energy of the lithium battery pack;

[0016] Among them, E REMt The remaining available energy of the lithium battery pack at time t, SOC t represents the current SOC value at time t, U ocvi represents the current static open circuit voltage of single cell i, N represents the number of single cells in the lithium battery pack, SOH represents the health status, and C represents the total capacity of the lithium battery pack.

[0017] In a possible implementation, querying the corresponding current SOC value according to the current total voltage value of the lithium battery pack includes:

[0018] Obtaining the current temperature value of the lithium battery pack;

[0019] The current SOC value corresponding to the lithium battery pack is obtained according to a preset OCV table, the current total voltage value and the current temperature value of the lithium battery.

[0020] In a possible implementation, determining the current static open circuit voltage of the single cell based on the current single cell measured voltage, the current single cell measured current and the DC internal resistance of the single cell includes:

[0021] By formula U ocvi =U d +I*DCR, calculate the current static open circuit voltage of the single cell;

[0022] Among them, U drepresents the current single-cell measured voltage, I represents the current single-cell measured current, and the measured current sign when the lithium battery is charged is negative, and the measured current sign when the lithium battery is discharged is positive; DCR (DC internal resistance) represents the DC internal resistance, U ocvi Indicates the current static open circuit voltage of single cell i.

[0023] In a second aspect, the present application provides a device for obtaining the remaining available energy of a lithium battery, comprising:

[0024] The data measurement module is used to measure the current voltage and current of each single cell of the lithium battery pack during the charging and discharging process to obtain the current single cell measurement voltage and current single cell measurement current;

[0025] A static open circuit voltage calculation module is used to determine the current static open circuit voltage of any single cell based on the current single cell measured voltage, current single cell measured current and DC internal resistance of the single cell;

[0026] A total voltage value calculation module is used to sum the current static open circuit voltages corresponding to each single cell to obtain the current total voltage value of the lithium battery pack;

[0027] The remaining available energy calculation module is used to calculate the current remaining available energy of the lithium battery pack based on the current total voltage value of the lithium battery pack.

[0028] In a possible implementation, the remaining available energy calculation module includes:

[0029] An SOC query unit, used to query the corresponding current SOC value according to the current total voltage value of the lithium battery pack;

[0030] A parameter acquisition unit, used to acquire the health and total capacity of the lithium battery pack;

[0031] The remaining available energy calculation unit is used to calculate the current remaining available energy of the lithium battery pack based on the health, total capacity, current total voltage value and current SOC value of the lithium battery pack.

[0032] In a possible implementation, the remaining available energy calculation unit is specifically used to:

[0033] calculate Obtaining the current remaining available energy of the lithium battery pack;

[0034] Among them, E REMt The remaining available energy of the lithium battery pack at time t, SOC t represents the current SOC value at time t, U ocvirepresents the current static open circuit voltage of single cell i, N represents the number of single cells in the lithium battery pack, SOH represents the health status, and C represents the total capacity of the lithium battery pack.

[0035] In a possible implementation, the SOC query unit includes:

[0036] Obtaining the current temperature value of the lithium battery pack;

[0037] The current SOC value corresponding to the lithium battery pack is obtained according to a preset OCV table, the current total voltage value and the current temperature value of the lithium battery.

[0038] In a possible implementation, the static open circuit voltage calculation module includes:

[0039] By formula U ocvi =U d +I*DCR, calculate the current static open circuit voltage of the single cell;

[0040] Among them, U d represents the current single-cell measurement voltage, I represents the current single-cell measurement current, and the measurement current sign when the lithium battery is charged is negative, and the measurement current sign when the lithium battery is discharged is positive; DCR represents the DC internal resistance, U ocvi Indicates the current static open circuit voltage of single cell i.

[0041] In a third aspect, the present application provides a terminal comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method described in the first aspect or any possible implementation of the first aspect are implemented.

[0042] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in any possible implementation of the first aspect above are implemented.

[0043] In a fifth aspect, an embodiment of the present application provides a car, comprising the terminal as described above.

[0044] The embodiment of the present application provides a method for obtaining the remaining available energy of a lithium battery, which first measures the current voltage and current current of each single cell of a lithium battery pack during the charge and discharge process to obtain the current single cell measured voltage and current single cell measured current; then, for any single cell, based on the current single cell measured voltage, current single cell measured current and DC internal resistance of the single cell, determines the current static open circuit voltage of the single cell; sums the current static open circuit voltages corresponding to each single cell to obtain the current total voltage value of the lithium battery pack; finally, calculates the current remaining available energy of the lithium battery pack based on the current total voltage value of the lithium battery pack. This embodiment determines the static OCV value of the single cell through the single cell voltage and DCR value, and can use the sum of the static OCV values ​​of the lithium battery pack instead of the total voltage value, thereby avoiding the problem of large remaining power estimation error caused by the method of measuring the total voltage value when the battery consistency is not good, and avoiding the problem of inaccurate remaining power estimation result caused by directly checking OCV through inaccurate SOC, thereby ensuring the accuracy of the remaining power estimation result. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0046] Figure 1 is a flow chart of a method for obtaining the remaining available energy of a lithium battery provided in an embodiment of the present application;

[0047] Figure 2 is a schematic diagram of an OCV-SOC curve provided in an embodiment of the present application;

[0048] Figure 3 It is a structural schematic diagram of a device for obtaining the remaining available energy of a lithium battery provided in an embodiment of the present application;

[0049] Figure 4 It is a schematic diagram of a terminal provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0051] In order to make the purpose, technical solutions and advantages of the present application clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0052] Figure 1 The implementation process of the method for obtaining the remaining available energy of a lithium battery provided in the embodiment of the present application is described in detail as follows:

[0053] S101: measuring the current voltage and current of each single cell of the lithium battery pack during the charge and discharge process to obtain the current single cell measured voltage and the current single cell measured current.

[0054] S102: for any single cell, determine the current static open circuit voltage of the single cell based on the current single cell measured voltage, the current single cell measured current and the DC internal resistance of the single cell.

[0055] In the prior art, since the static open circuit voltage can only be detected after the lithium battery is at rest or fully charged, a lithium battery that is in working condition for a long time will accumulate a large error. In order to solve the above problem, this embodiment uses DC internal resistance to calculate the static open circuit voltage corresponding to the dynamic measurement voltage during the charging and discharging process, thereby realizing the static open circuit voltage estimation during the charging and discharging process.

[0056] In a possible embodiment, the specific implementation process of S102 includes:

[0057] By formula U ocvi =U d +I*DCR, calculate the current static open circuit voltage of the single cell;

[0058] Among them, U d represents the current single-cell measurement voltage, I represents the current single-cell measurement current, and the measurement current sign when the lithium battery is charged is negative, and the measurement current sign when the lithium battery is discharged is positive; DCR represents the DC internal resistance, U ocvi Indicates the current static open circuit voltage of single cell i.

[0059] Specifically, the DC internal resistance DCR of lithium-ion batteries is an important indicator for measuring battery performance, which is mainly composed of ohmic internal resistance and polarization internal resistance. The static OCV of the battery is approximately equal to the difference between the measured voltage and the measured current * DCR. Therefore, OCV can be calculated using DCR to avoid the problem of large OCV errors caused by directly using SOC to check OCV.

[0060] Specifically, the DC internal resistance DCR of a lithium battery is a value provided by a battery cell manufacturer.

[0061] S103: summing the current static open circuit voltages corresponding to the individual cells to obtain the current total voltage value of the lithium battery pack.

[0062] This embodiment obtains the current total voltage value by respectively calculating the static open circuit voltages corresponding to the single cells and then summing them up, which can avoid the problem of large remaining power estimation errors caused by directly measuring the total voltage value of the lithium battery pack when the battery consistency is poor.

[0063] S104: Calculate the current remaining available energy of the lithium battery pack based on the current total voltage value of the lithium battery pack.

[0064] In one embodiment, the specific implementation process of S104 includes:

[0065] S201: Query the corresponding current SOC value according to the current total voltage value of the lithium battery pack.

[0066] In a possible embodiment, the specific implementation process of S201 includes:

[0067] Obtaining the current temperature value of the lithium battery pack;

[0068] The current SOC value corresponding to the lithium battery pack is obtained according to a preset OCV table, the current total voltage value and the current temperature value of the lithium battery.

[0069] In one possible implementation, after obtaining the current single-cell measurement current of the single-cell battery, it is also necessary to determine whether the current single-cell measurement current meets the preset correction condition. If so, the step of "obtaining the current SOC value corresponding to the lithium battery pack according to the preset OCV table, the current total voltage value of the lithium battery and the current temperature value" is executed; if not, the SOC value of the lithium battery pack is not corrected.

[0070] Specifically, the preset correction conditions are:

[0071] During the discharge process of the lithium battery, the measured current is greater than a first preset current threshold and the duration of the monotonically increasing current is greater than a first preset time;

[0072] Or, during the charging process of the lithium battery, the measured current is less than a second preset current threshold and lasts longer than a second preset time.

[0073] In this embodiment, the DC internal resistance DCR value is obtained by HPPC testing, using a fixed rate current to discharge for 10s or 30s, and dividing the voltage change difference by the current value. However, in actual operating conditions, the current often cannot meet the constant current condition. When the sign phase of the current changes suddenly or monotonically, the polarization internal resistance partial pressure of the battery will change. At this time, using the battery DCR to correct the SOC will lead to serious miscorrection results. Therefore, it is necessary to perform difference analysis on the estimated results through actual vehicle data, and analyze and identify the current characteristics in the section that meets the accuracy requirements, so as to avoid miscorrection problems under all operating conditions and improve SOC accuracy.

[0074] Exemplarily, in the preset correction condition, the first preset current threshold value may be 5A, and the first preset time may be 1s, that is, during the discharge process, if the measured current is greater than 5A and the duration of the monotonically increasing period is greater than 1s, then it is determined that the measured current meets the preset correction condition. The second preset current threshold value may be -5A, and the second preset time may be 120s, that is, during the charging process, if the measured current is less than -5A and the duration is greater than 120s, then it is determined that the measured current meets the preset correction condition.

[0075] S202: Obtain the health and total capacity of the lithium battery pack.

[0076] S203: Calculate the current remaining available energy of the lithium battery pack based on the health, total capacity, current total voltage value and current SOC value of the lithium battery pack.

[0077] In one embodiment, the specific implementation process of S203 includes:

[0078] calculate Obtaining the current remaining available energy of the lithium battery pack;

[0079] Among them, E REMt The remaining available energy of the lithium battery pack at time t, SOC t represents the current SOC value at time t, U ocvi represents the current static open circuit voltage of single cell i, N represents the number of single cells in the lithium battery pack, SOH represents the health status, and C represents the total capacity of the lithium battery pack.

[0080] In an embodiment, Figure 2 As shown, Figure 2 The OCV-SOC curve is shown in the figure. Figure 2 By calculating the shaded area in the figure, we can get the remaining available energy of the lithium battery pack at time t.

[0081] From the above embodiments, it can be seen that the technical solution not only avoids the error caused by the total voltage measurement method when the battery has a short board effect, but also avoids the error caused by the SOC reverse check OCV method when the SOC is inaccurate. The accurate static open circuit voltage value of the battery is obtained based on the results of the single cell measurement voltage and DCR calculation, ensuring the accuracy of the estimation of the remaining available energy of the battery.

[0082] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the 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 the present application.

[0083] The following is an embodiment of the device of the present application. For details not described in detail, please refer to the corresponding method embodiment described above.

[0084] Figure 3 The schematic diagram of the structure of the device for obtaining the remaining available energy of a lithium battery provided in an embodiment of the present application is shown. For the convenience of explanation, only the part related to the embodiment of the present application is shown, which is described in detail as follows:

[0085] like Figure 3 As shown, the device 100 for obtaining the remaining available energy of a lithium battery provided in the present application includes:

[0086] The data measurement module 110 is used to measure the current voltage and current of each single cell of the lithium battery pack during the charging and discharging process to obtain the current single cell measurement voltage and current single cell measurement current;

[0087] The static open circuit voltage calculation module 120 is used to determine the current static open circuit voltage of any single cell based on the current single cell measured voltage, current single cell measured current and DC internal resistance of the single cell;

[0088] The total voltage value calculation module 130 is used to sum the current static open circuit voltages corresponding to the individual cells to obtain the current total voltage value of the lithium battery pack;

[0089] The remaining available energy calculation module 140 is used to calculate the current remaining available energy of the lithium battery pack based on the current total voltage value of the lithium battery pack.

[0090] In a possible implementation, the remaining available energy calculation module 140 includes:

[0091] An SOC query unit, used to query the corresponding current SOC value according to the current total voltage value of the lithium battery pack;

[0092] A parameter acquisition unit, used to acquire the health and total capacity of the lithium battery pack;

[0093] The remaining available energy calculation unit is used to calculate the current remaining available energy of the lithium battery pack based on the health, total capacity, current total voltage value and current SOC value of the lithium battery pack.

[0094] In a possible implementation, the remaining available energy calculation unit is specifically used to:

[0095] calculate Obtaining the current remaining available energy of the lithium battery pack;

[0096] Among them, E REMt The remaining available energy of the lithium battery pack at time t, SOC t represents the current SOC value at time t, U ocvi represents the current static open circuit voltage of single cell i, N represents the number of single cells in the lithium battery pack, SOH represents the health status, and C represents the total capacity of the lithium battery pack.

[0097] In a possible implementation, the SOC query unit includes:

[0098] Obtaining the current temperature value of the lithium battery pack;

[0099] The current SOC value corresponding to the lithium battery pack is obtained according to a preset OCV table, the current total voltage value and the current temperature value of the lithium battery.

[0100] In a possible implementation, the static open circuit voltage calculation module 120 is specifically used for:

[0101] By formula U ocvi =U d +I*DCR, calculate the current static open circuit voltage of the single cell;

[0102] Among them, U d represents the current single-cell measurement voltage, I represents the current single-cell measurement current, and the measurement current sign when the lithium battery is charged is negative, and the measurement current sign when the lithium battery is discharged is positive; DCR represents the DC internal resistance, U ocvi Indicates the current static open circuit voltage of single cell i.

[0103] The present application also provides a computer program product having a program code, which, when executed in a corresponding processor, controller, computing device or terminal, executes the steps in any of the above-mentioned methods for calculating the remaining available energy of a lithium battery, for example: Figure 1Steps 101 to 104 shown. It will be appreciated by those skilled in the art that the method and the device proposed in the embodiment of the present application can be implemented in various forms of hardware, software, firmware, a dedicated processor or a combination thereof. The dedicated processor may include an application specific integrated circuit (ASIC), a reduced instruction set computer (RISC) and / or a field programmable gate array (FPGA). The proposed method and device are preferably implemented as a combination of hardware and software. The software is preferably installed on a program storage device as an application. It is typically based on a machine with a computer platform having hardware, such as one or more central processing units (CPUs), random access memories (RAMs) and one or more input / output (I / O) interfaces. An operating system is also typically installed on the computer platform. The various processes and functions described here may be part of an application, or a part thereof may be executed by an operating system.

[0104] Figure 4 is a schematic diagram of a terminal provided in an embodiment of the present application. Figure 4 As shown, the terminal 4 of this embodiment includes: a processor 40, a memory 41, and a computer program 42 stored in the memory 41 and executable on the processor 40. When the processor 40 executes the computer program 42, the steps in the above-mentioned method for obtaining the remaining available energy of the lithium battery are implemented, for example Figure 1 Alternatively, when the processor 40 executes the computer program 42, the functions of each module / unit in the above-mentioned device embodiments are realized, for example Figure 3 Functionality of modules / units 110 to 140 is shown.

[0105] Exemplarily, the computer program 42 may be divided into one or more modules / units, which are stored in the memory 41 and executed by the processor 40 to complete / implement the solution provided by the present application. The one or more modules / units may be a series of computer program instruction segments that can complete specific functions, and the instruction segments are used to describe the execution process of the computer program 42 in the terminal 4. For example, the computer program 42 may be divided into Figure 3 Modules / units 110 to 140 are shown.

[0106] The terminal 4 may be a battery management system (BMS) on a car. The terminal 4 may include, but is not limited to, a processor 40 and a memory 41. Those skilled in the art may understand that Figure 4It is only an example of terminal 4 and does not constitute a limitation on terminal 4. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal may also include input and output devices, network access devices, buses, etc.

[0107] The processor 40 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0108] The memory 41 may be an internal storage unit of the terminal 4, such as a hard disk or memory of the terminal 4. The memory 41 may also be an external storage device of the terminal 4, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal 4. Further, the memory 41 may also include both an internal storage unit and an external storage device of the terminal 4. The memory 41 is used to store the computer program and other programs and data required by the terminal. The memory 41 may also be used to temporarily store data that has been output or is to be output.

[0109] This embodiment provides a car, including the terminal as described above.

[0110] Specifically, the above-mentioned automobile can be a new energy power automobile with pure power battery, or a plug-in hybrid automobile.

[0111] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0112] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0113] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0114] In the embodiments provided in the present application, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0115] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0116] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0117] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned lithium battery remaining available energy acquisition method embodiment can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practices, computer-readable media does not include electrical carrier signals and telecommunication signals.

[0118] In addition, the embodiments shown in the drawings of the present application or the features of the various embodiments mentioned in this specification are not necessarily understood as independent embodiments. Instead, each feature described in one example of an embodiment can be combined with one or more other desired features from other embodiments to produce other embodiments not described in words or with reference to the drawings.

[0119] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for obtaining the remaining available energy of a lithium battery, characterized in that: include: The current voltage and current of each single cell of the lithium battery pack are measured during the charging and discharging process to obtain the current single cell measurement voltage and current single cell measurement current; For any single cell, based on the current single cell measured voltage, the current single cell measured current and the DC internal resistance of the single cell, determine the current static open circuit voltage of the single cell; Sum the current static open circuit voltages corresponding to the individual cells to obtain the current total voltage value of the lithium battery pack; Calculating the current remaining available energy of the lithium battery pack based on the current total voltage value of the lithium battery pack; The calculating the current remaining available energy of the lithium battery pack based on the current total voltage value of the lithium battery pack includes: Query the corresponding current SOC value according to the current total voltage value of the lithium battery pack; Obtaining the health and total capacity of the lithium battery pack; Calculate the current remaining available energy of the lithium battery pack based on the health, total capacity, current total voltage value and current SOC value of the lithium battery pack; The calculating the current remaining available energy of the lithium battery pack based on the health, total capacity, current total voltage value and current SOC value of the lithium battery pack includes: calculate Obtaining the current remaining available energy of the lithium battery pack; Among them, E REMt The remaining available energy of the lithium battery pack at time t, SOC t represents the current SOC value at time t, U ocvi represents the current static open circuit voltage of single cell i, N represents the number of single cells in the lithium battery pack, SOH represents the health status, and C represents the total capacity of the lithium battery pack; The method of determining the current static open circuit voltage of the single cell based on the current single cell measured voltage, the current single cell measured current and the DC internal resistance of the single cell comprises: By formula U ocvi =U d +I*DCR, calculate the current static open circuit voltage of the single cell; Among them, U d represents the current single-cell measurement voltage, I represents the current single-cell measurement current, and the measurement current sign when the lithium battery is charged is negative, and the measurement current sign when the lithium battery is discharged is positive; DCR represents the DC internal resistance, U ocvi Indicates the current static open circuit voltage of single cell i.

2. The method for obtaining the remaining available energy of a lithium battery according to claim 1, characterized in that: The querying of the corresponding current SOC value according to the current total voltage value of the lithium battery pack includes: Obtaining the current temperature value of the lithium battery pack; The current SOC value corresponding to the lithium battery pack is obtained according to a preset OCV table, the current total voltage value and the current temperature value of the lithium battery.

3. A device for obtaining the remaining available energy of a lithium battery, characterized in that: include: The data measurement module is used to measure the current voltage and current of each single cell of the lithium battery pack during the charging and discharging process to obtain the current single cell measurement voltage and current single cell measurement current; A static open circuit voltage calculation module is used to determine the current static open circuit voltage of any single cell based on the current single cell measured voltage, current single cell measured current and DC internal resistance of the single cell; A total voltage value calculation module is used to sum the current static open circuit voltages corresponding to each single cell to obtain the current total voltage value of the lithium battery pack; A remaining available energy calculation module, used to calculate the current remaining available energy of the lithium battery pack based on the current total voltage value of the lithium battery pack; The remaining available energy calculation module comprises: An SOC query unit, used to query the corresponding current SOC value according to the current total voltage value of the lithium battery pack; A parameter acquisition unit, used to acquire the health and total capacity of the lithium battery pack; A remaining available energy calculation unit, used to calculate the current remaining available energy of the lithium battery pack based on the health, total capacity, current total voltage value and current SOC value of the lithium battery pack; The remaining available energy calculation unit comprises: calculate Obtaining the current remaining available energy of the lithium battery pack; Among them, E REMt The remaining available energy of the lithium battery pack at time t, SOC t represents the current SOC value at time t, U ocvi represents the current static open circuit voltage of single cell i, N represents the number of single cells in the lithium battery pack, SOH represents the health status, and C represents the total capacity of the lithium battery pack; The static open circuit voltage calculation module comprises: By formula U ocvi =U d +I*DCR, calculate the current static open circuit voltage of the single cell; Among them, U d represents the current single-cell measurement voltage, I represents the current single-cell measurement current, and the measurement current sign when the lithium battery is charged is negative, and the measurement current sign when the lithium battery is discharged is positive; DCR represents the DC internal resistance, U ocvi Indicates the current static open circuit voltage of single cell i.

4. A terminal comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for obtaining the remaining available energy of a lithium battery as described in any one of claims 1 to 2 are implemented.

5. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for obtaining the remaining available energy of a lithium battery as described in any one of claims 1 to 2 are implemented.

6. A car, characterized in that: Comprising the terminal as claimed in claim 4.

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