WO2023116531A1

WO2023116531A1 - Method and related device for determining initial soc value of battery

Info

Publication number: WO2023116531A1
Application number: PCT/CN2022/139024
Authority: WO
Inventors: 张君伟; 康文蓉
Original assignee: 长城汽车股份有限公司
Priority date: 2021-12-24
Filing date: 2022-12-14
Publication date: 2023-06-29
Also published as: CN115113049A

Abstract

A method and related device for determining an initial SOC value of a battery. The method is applied to a battery, and the battery comprises n battery cells. The method comprises: for each battery cell, reading an SOC value of the battery cell in a preset storage space; determining, according to the SOC value of each battery cell, whether a storage anomaly occurs; if no storage anomaly occurs, for each battery cell, taking the SOC value of the battery cell read in the storage space as an initial SOC value of the current charging and discharging of the battery cell; and if the storage anomaly occurs, correcting, according to the SOC value of a battery cell having no storage error, the SOC value of each battery cell where the storage error occurs, so as to obtain a corrected SOC value of the battery cell, and taking the corrected SOC value of the battery cell as the initial SOC value of the current charging and discharging of the battery cell. According to the method, the precision of the initial SOC value of the battery can be improved.

Description

Method and related device for determining initial value of battery SOC

This patent application claims Chinese Patent Application No.CN filed on December 24, 2021 Priority of 202111604020.6. The disclosure of the prior application is incorporated by reference in its entirety into this application.

technical field

The present application relates to the technical field of battery management, and in particular to a method and a related device for determining an initial value of a battery SOC.

Background technique

With the emergence of global warming and various extreme climates, the issue of greenhouse gas emissions caused by diesel and gasoline vehicles has been paid more and more attention. In order to reduce urban pollution, the development of electric vehicles and hybrid vehicles has received extensive attention.

In order to ensure the operation safety, durability, reliability and efficiency of electric vehicles, and perform necessary management and diagnostic functions, the battery management system (battery management system, BMS) are widely used in electric vehicles. The state of charge (SOC) indicates the percentage value of the remaining charge of the battery pack, which is used to measure the current remaining available power of the battery pack, and is one of the important states that the BMS needs to monitor. Accurate SOC estimation can guarantee the related strategies of the whole vehicle, the safety of the battery and the experience of the driver and passengers.

In the SOC estimation method, the ampere-hour integration method is one of the important algorithms. It is a very important step to estimate the SOC through the ampere-hour integral method and obtain the initial value of the SOC. How to improve the accuracy of the initial value of the SOC is a technical problem that needs to be solved urgently in the prior art.

technical problem

In view of this, the present application provides a method and related device for determining the initial value of battery SOC, which can solve the problem that the initial value of battery SOC is inaccurate when estimating battery SOC through the ampere-hour integration method.

technical solution

In the first aspect, the embodiment of the present application provides a method for determining the initial value of the battery SOC, the method is applied to a battery, the battery includes n battery cells, n is a positive integer greater than or equal to 2; the method include:

For each battery cell, read the SOC value of the battery cell in the preset storage space; wherein, the storage space stores the SOC value of each battery cell when the battery is charged and discharged last time ;

According to the SOC value of each battery cell, it is judged whether a storage abnormality occurs; wherein, the storage abnormality indicates that a storage error occurs in the SOC value of at least one battery cell in the storage space;

When no storage abnormality occurs, for each battery cell, the SOC value of the battery cell read in the storage space is used as the initial SOC value of the battery cell for this charge and discharge; and

When a storage error occurs, the SOC value of each battery cell that has a storage error is corrected according to the SOC value of the battery cell that does not have a storage error to obtain the SOC correction value of the battery cell, and the battery cell The SOC correction value of the battery cell is used as the initial SOC value of the battery cell for this charge and discharge.

In a possible implementation manner, the determining whether a storage abnormality occurs according to the SOC value of each battery cell includes:

When the SOC value of m battery cells is 0, the maximum value is obtained from the SOC values of the n battery cells; wherein, m is a positive integer greater than or equal to 1 and less than n;

When the maximum value is greater than the preset SOC value, it is judged that the SOC values of the m battery cells are stored abnormally; and

When the maximum value is less than or equal to the preset SOC value, it is determined that no storage abnormality occurs.

In a possible implementation manner, the preset SOC value is 10%.

In a possible implementation manner, the storage space is a non-volatile memory.

In a possible implementation manner, the non-volatile memory is a Flash memory.

In a possible implementation manner, the battery is a lithium ion battery.

In a possible implementation manner, when the storage abnormality occurs, the SOC value of each battery cell with a storage error is corrected according to the SOC value of the battery cell without a storage error to obtain the battery cell The SOC correction value of the battery cell, and the SOC correction value of the battery cell as the SOC initial value of the battery cell charge and discharge this time includes:

Acquiring the minimum value among all the SOC values of the n battery cells that are not 0; and

For each battery cell whose SOC value is 0, the minimum value is used as the SOC correction value of the battery cell.

When the SOC value of each battery cell read from the storage space is 0, it is determined that a storage abnormality occurs;

In this embodiment, the method also includes:

Obtain the minimum open circuit voltage among the open circuit voltages of the n battery cells, and according to the minimum open circuit voltage, look up an OCV (Open Circuit Voltage, open circuit voltage) table to determine an SOC value, and use this SOC value as the The initial SOC value of the battery for this charge and discharge.

In a possible implementation, the method further includes:

The SOC value of each battery cell is stored in the storage space when the current charging and discharging of the battery ends.

In a second aspect, the present application provides a device for determining the initial value of the battery SOC, the device is applied to a battery, the battery includes n battery cells, n is a positive integer greater than or equal to 2; the device includes: Reading module, judging module and initial value determining module;

The reading module is used to read the SOC value of the battery cell in the preset storage space for each battery cell; wherein, the storage space stores the time when the last charge and discharge of the battery is completed SOC value of each battery cell;

The judging module is configured to judge whether a storage abnormality occurs according to the SOC value of each battery cell; wherein, the storage abnormality indicates that a storage error occurs in the SOC value of at least one battery cell in the storage space;

The initial value determination module is configured to, for each battery cell, use the SOC value of the battery cell read in the storage space as the current charge of the battery cell when no storage abnormality occurs. SOC initial value of discharge;

The initial value determination module is further configured to correct the SOC value of each battery cell with a storage error according to the SOC value of the battery cell without a storage error when a storage abnormality occurs, to obtain the battery cell The SOC correction value of the battery cell is used as the SOC initial value of the battery cell for this charging and discharging.

In a possible implementation, the judging module is used to:

In a possible implementation manner, the initial value determination module is used for:

In a third aspect, the present application provides a vehicle, the vehicle includes a control device, the control device includes a memory, a processor, and a computer program stored in the memory and operable on the processor, the When the processor executes the computer program, the steps of the method described in the above first aspect or any possible implementation manner of the first aspect are implemented.

In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements any of the above first aspect or the first aspect. A possible implementation manner is the steps of the described method.

Beneficial effect

Compared with the prior art, the method for determining the initial value of battery SOC provided by this application has the following beneficial effects:

The method provided by this application judges whether there is a wrong SOC value in the SOC value of each battery cell stored in the storage space; The SOC value is corrected; by using the corrected SOC value as the initial SOC value of the battery cell, the accuracy of the initial battery SOC value in the ampere-hour integration method is improved, thereby improving the estimation accuracy of the battery SOC value.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the accompanying drawings that need to be used in the descriptions of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings in the following description are only for the present application For some embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings without paying creative efforts.

FIG. 1 is an implementation flowchart of a method for determining an initial value of battery SOC provided in an embodiment of the present application;

Fig. 2 is a schematic structural diagram of a device for determining the initial value of battery SOC provided by an embodiment of the present application;

Fig. 3 is a schematic diagram of a control device provided in an embodiment of the present application.

Embodiments of the present invention

In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

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

Lithium-ion batteries are highly complex nonlinear systems, and the SOC cannot be directly measured. It can only be estimated by parameters such as battery terminal voltage, charge and discharge current, and internal resistance. The ampere-hour integration method, also known as the current integration method, is one of the most widely used SOC estimation methods for lithium-ion batteries. The main idea is to measure the discharge current of the battery and integrate the current over time to calculate the amount of electricity discharged over a period of time, thereby estimating the SOC of the battery. The calculation formula of the ampere-hour integral method is:

In the formula, SOC ₀ is the initial value of SOC of the battery, C _N is the rated capacity of the battery, and I is the charging and discharging current of the battery, where I is negative for charging and positive for discharging.

It can be seen that the ampere-hour integration method depends on SOC ₀ , and only by ensuring accurate SOC ₀ can an accurate SOC value be obtained. If there is a deviation in SOC ₀ , the error of the SOC value will become larger and larger due to accumulation, resulting in low estimation accuracy.

There are two existing SOC initial value acquisition methods, that is, SOC ₀ , one is the open circuit voltage method, and the other is the NVM (Non-Volatile Memory, non-volatile storage) reading method.

Among them, the open circuit voltage (open circuit voltage, OCV) refers to the static open circuit voltage of the battery cell. The battery cell will be polarized after being charged or discharged. At this time, the external characteristic voltage of the battery cell is inconsistent with the open circuit resting voltage of the battery cell. Therefore, in order to obtain the open-circuit voltage, the battery cells need to be left for a certain period of time to eliminate polarization. On the one hand, due to the hysteresis phenomenon generated by the internal ohmic resistance, polarization resistance, electrochemical polarization and concentration polarization of the battery, it is necessary to uniformly distribute the electrolyte inside the battery to obtain a stable terminal voltage; therefore, the OCV method It is more dependent on the standing time. On the other hand, since the OCV of the battery is numerically close to the electromotive force of the battery, and there is a certain mapping relationship with the internal lithium ion concentration; therefore, the OCV-SOC lookup table is established through a large number of intensive experiments. When the battery is in the working state, by measuring the OCV of the battery, the SOC of the battery is determined according to the mapping relationship between OCV and SOC (the mapping relationship is obtained from the above OCV-SOC lookup table). However, since the OCV-SOC lookup table is established through experiments, it is only applicable to battery SOC estimation under the same experimental conditions. When the target battery is at different temperatures and different life cycles, using the previously established lookup table to estimate the SOC will lead to large errors.

The NVM reading method is to store the SOC value of the battery when the last charge and discharge is completed in the storage space as the initial value of the SOC for this charge and discharge. NVM storage relies on flash storage. During the storage process, due to factors such as chip reasons, flashing problems, large data volumes, or refreshing software to erase stored values, storage failures may occur. Once the storage fails, forcibly using the SOC value obtained by the OCV look-up table method as the initial SOC value of the ampere-hour integration method may cause greater errors.

In view of the above problems, the present application provides a method for determining the initial value of the SOC of a battery pack. Referring to FIG. 1 , in one implementation manner, the method provided in this application includes four steps from S101 to S104. A detailed description of these four steps follows.

S101: For each battery cell, read the SOC value of the battery cell in the preset storage space; wherein, the storage space stores the SOC of each battery cell when the last charge and discharge of the battery is completed value.

In this step, the preset storage space may be NVM memory. Each time the charging and discharging of the battery ends, the SOC at the end is stored in the storage space as the initial value of the SOC for the next charging and discharging of the battery.

The method provided in this application can be applied to a battery, and the battery includes n battery cells. At the end of charging and discharging of the battery, the SOC value of each battery cell is stored in the storage space as the initial value of the SOC of each battery cell when the battery starts to charge and discharge next time.

When the current charge and discharge of the battery starts, a set of data SOC _S1 , SOC _S2 , SOC _S3 ..., SOC _SX , ..., SOC _S _n is obtained by reading data in the storage space; among them, SOC _SX is the The SOC value of the xth battery cell read in the space.

S102: According to the SOC value of each battery cell, determine whether a storage abnormality occurs; wherein, the storage abnormality indicates that a storage error occurs in the SOC value of at least one battery cell in the storage space.

In a possible implementation, when the SOC values of m battery cells are 0, the maximum value is obtained from the SOC values of the n battery cells; wherein, m is greater than or equal to 1 and less than n positive integer. When the above maximum value is greater than the preset SOC value, it is judged that the SOC values of the m battery cells are stored abnormally. When the above maximum value is less than or equal to the preset SOC value, it is determined that no storage abnormality occurs.

For ease of understanding, an example is given below:

A battery includes five battery cells, namely battery cell 1 , battery cell 2 , battery cell 3 , battery cell 4 and battery cell 5 .

When the battery is charged and discharged this time, read the SOC values of battery cell 1 to battery cell 5 from the storage space, which are SOC _S1 =0, SOC _S2 =a, SOC _S3 =b, SOC _S4 =0, SOC _S5 =c, where a, b, and c are constants greater than zero.

In this implementation manner, in order to determine whether a storage abnormality occurs, first obtain the maximum value of the SOC values of the above five battery cells, assuming that c is the maximum value. Then, it is judged whether c is greater than a preset SOC value. For example, the preset SOC value is set to 10% (both the SOC and the preset SOC here are percentages). Since the initial SOC values of multiple battery cells of the same battery do not differ too much, if c is greater than 10%, it is judged that the SOC value of battery cell 1 and the SOC value of battery cell 4 have been stored incorrectly. Taking battery cell 1 as an example, the storage error process may be: after the last charge and discharge of the battery, the SOC value of battery cell 1 is a constant d greater than zero, but due to storage reasons, d is set to 0, That is, a storage error occurs in the SOC value of the battery cell 1 . If c is less than or equal to 10%, it is judged that the SOC values of the battery cell 1 and the battery cell 4 have no storage error, that is, no storage abnormality has occurred.

In a possible implementation manner, when the SOC values of each battery cell read from the storage space are all 0, it is determined that a storage exception occurs. At this time, the method provided by the present application also includes: obtaining the minimum open circuit voltage among the open circuit voltages of n battery cells; according to the above minimum open circuit voltage, looking up the OCV table to determine a SOC value, and using the SOC value as the minimum open circuit voltage of each battery cell The initial SOC value of the battery for this charge and discharge.

For a storage space, when the current charge and discharge of the battery is the first charge and discharge of the battery, there is no SOC value of the battery at the end of the last charge and discharge in the storage space. That is, the SOC value of each battery cell stored in the storage space is a preset initial value of 0. Or, the SOC value of each battery cell in the storage space is stored incorrectly, causing the original data to be overwritten with 0, so that the SOC value of each battery cell read from the storage space is 0.

Regardless of which of the above situations causes the SOC value of each battery cell in the storage space to be 0, the initial SOC value for each battery cell can be assigned to each battery cell through the following two steps: the first step, in n battery cells The minimum open circuit voltage is obtained from the open circuit voltage of the battery; the second step, according to the minimum open circuit voltage, look up the OCV table to determine a SOC, assuming it is SOC1, then the initial value of the SOC of each battery cell is SOC1 during the charge and discharge of the battery.

In an example of this embodiment, the method provided by this application further includes: storing the SOC value of each battery cell in the storage space when the current charge and discharge of the battery ends, as the next charge of the battery. Initial SOC value of discharge.

S103: When there is no storage abnormality, for each battery cell, use the SOC value of the battery cell read in the storage space as the initial SOC value of the battery cell for this charging and discharging.

In this step, if c is less than or equal to 10%, it is judged that the SOC values of the battery cell 1 and the battery cell 4 do not have a storage error, that is, there is no storage abnormality. At this time, SOC _S1 =0, SOC _S2 =a, SOC _S3 =b, SOC _S4 =0, SOC _S5 =c are the initial SOC values of each battery cell during the charging and discharging of the battery. That is, the initial SOC value of battery cell 1 is 0, the initial SOC value of battery cell 2 is a, the initial SOC value of battery cell 3 is b, the initial SOC value of battery cell 4 is 0, and the initial SOC value of battery cell 5 is The initial value of SOC of is c.

S104: When a storage error occurs, correct the SOC value of each battery cell with a storage error according to the SOC value of the battery cell without a storage error to obtain the SOC correction value of the battery cell, and convert the The SOC correction value of the battery cell is used as the initial SOC value of the battery cell for charging and discharging this time.

In this step, the minimum value may be obtained among all the non-zero SOC values of the n battery cells. Then, for each battery cell whose SOC value is 0, the above minimum value is used as the SOC correction value of the battery cell.

The minimum value is selected as the SOC correction value of the battery cell whose SOC value is 0, in order to avoid the situation that the battery is not fully charged or the battery is over-discharged.

Still using the example in S102 for illustration, if c is greater than 10%, it is determined that the SOC value of the battery cell 1 and the SOC value of the battery cell 4 have a storage error. Then according to S104 , the minimum value can be obtained among a, b, and c, assuming that the minimum value is a, then a is used as the SOC correction value of the battery cell 1 and the battery cell 4 . The corrected SOC values are respectively SOC _S1 = a, SOC _S2 = a, SOC _S3 = b, SOC _S4 = a, SOC _S5 = c. That is, at the beginning of charging and discharging of the battery, the initial SOC value of battery cell 1 is a, the initial SOC value of battery cell 2 is a, the initial SOC value of battery cell 3 is b, and the SOC of battery cell 4 is b. The initial value is a, and the initial value of the SOC of the battery cell 5 is c.

In S104, the method provided by the present application judges whether there is an SOC value with a storage error in the SOC value of each battery cell stored in the storage space; when there is a storage error, use the SOC value of other battery cells that do not have a storage error The wrong SOC value is corrected; by using the corrected SOC value as the initial SOC value of the battery cell, the accuracy of the initial battery SOC value in the ampere-hour integration method is improved, thereby improving the estimation accuracy of the battery SOC value.

It should be understood that the sequence numbers of the steps in the above description do not mean the sequence of execution, and the execution sequence of each process should be determined by its function and internal logic, rather than the implementation process of each implementation mode or embodiment of the present application. constitute any limitation.

The following are various implementations of the device for determining the initial value of the SOC of the battery provided in the present application. For details that are not described in detail, reference may be made to the above corresponding implementations of the method.

Fig. 2 shows a schematic structural diagram of an apparatus for determining an initial value of a battery SOC provided by an implementation manner of the present application. For ease of description, FIG. 2 only shows the parts related to the present application.

As shown in FIG. 2 , the device 2 for determining the initial value of the battery SOC includes: a reading module 21 , a judging module 22 , and an initial value determining module 23 .

The reading module 21 is used to: for each battery cell, read the SOC value of the battery cell in the preset storage space; The SOC value of the battery cell.

The judging module 22 is configured to: judge whether a storage abnormality occurs according to the SOC value of each battery cell; wherein, the storage abnormality indicates that a storage error occurs in the SOC value of at least one battery cell in the storage space.

The initial value determination module 23 is used for: when there is no storage abnormality, for each battery cell, the SOC value of the battery cell read in the storage space is used as the SOC of the battery cell this time. initial value.

The initial value determination module 23 is also used for: when a storage abnormality occurs, correct the SOC value of each battery cell that has a storage error according to the SOC value of the battery cell that does not have a storage error, and obtain the SOC value of the battery cell. SOC correction value, and use the SOC correction value of the battery cell as the SOC initial value of the battery cell for this charge and discharge.

The device provided by the present application can judge whether there is a wrong SOC value in the SOC value of each battery cell stored in the storage space; Correct the SOC value of the battery; by using the corrected SOC value as the initial SOC value of the battery cell, the accuracy of the initial battery SOC value in the ampere-hour integration method is improved, thereby improving the estimation accuracy of the battery SOC value.

In a possible implementation, the judging module 22 is used to:

When the SOC value of m battery cells is 0, the maximum value is obtained from the SOC values of n battery cells; wherein, m is a positive integer greater than or equal to 1 and less than n;

When the above maximum value is greater than the preset SOC value, it is judged that the SOC values of the above m battery cells are stored abnormally;

When the above maximum value is less than or equal to the preset SOC value, it is determined that no storage abnormality occurs.

In a possible implementation, the initial value determination module 23 is used to:

Obtain the minimum value among all SOC values of n battery cells that are not 0;

For each battery cell whose SOC value is 0, the above minimum value is used as the SOC correction value of the battery cell.

In a possible implementation, the initial value determination module 23 is also used to:

When the SOC value of each battery cell read from the storage space is 0, the minimum open circuit voltage is obtained from the open circuit voltages of n battery cells;

According to the above minimum open circuit voltage, look up the OCV table to determine a SOC value, and use this SOC value as the initial SOC value of each battery cell for this charge and discharge.

In a possible implementation, the device provided by this application is also used for:

Store the SOC value of each battery cell in the storage space at the end of the current charge and discharge of the battery.

The devices for determining the initial value of the battery SOC provided by the above implementations can be used to implement the implementations of the methods for determining the initial value of the battery SOC provided in this application. Their implementation principles and technical effects are similar and will not be described again.

Fig. 3 is a schematic diagram of the control device provided by the present application. As shown in FIG. 3 , the control device 3 provided by the present application includes: a processor 30 , a memory 31 , and a computer program 32 stored in the memory 31 and operable on the processor 30 . When the processor 30 executes the computer program 32 , the above-mentioned steps in the method for determining the initial value of the battery SOC are implemented, such as S101 to S104 shown in FIG. 1 . Alternatively, when the processor 30 executes the computer program 32, the functions of the modules/units in the above-mentioned device implementation manners are implemented, for example, the functions of the units 21 to 23 shown in FIG. 2 .

Exemplarily, the computer program 32 can be divided into one or more modules/units, and these modules/units can be stored in the memory 31 and executed by the processor 30 to complete the technical solutions provided by the implementation modes of the present application. These modules/units may be a series of computer program instruction segments capable of accomplishing specific functions, and these instruction segments can describe the execution process of the computer program 32 in the control device 3 .

The control device 3 may be a control device, a module, a chip, etc. corresponding to the battery management system. The control device 3 may also be a control device, a module, a chip, etc. independent of the battery management system, and solely used to implement various method implementations of the present application. The control device 3 may include, but not limited to, a processor 30 and a memory 31 . Those skilled in the art can understand that FIG. 3 is only an example of the control device 3 and does not constitute a limitation to the control device 3 . The control device 3 may comprise more or fewer components than shown, or combine certain components, or different components. For example, the control device 3 may also include an input and output device, a network access device, a bus, and the like.

The processor 30 can be a central processing unit (Central Processing Unit, CPU), and can also be other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), Application Specific Integrated Circuit (Application Specific Integrated Circuit, ASIC), Field-Programmable Gate Array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The above-mentioned general-purpose processor may be a microprocessor or any other conventional processor.

The memory 31 may be an internal storage unit of the control device 3 , such as a hard disk or a memory of the control device 3 . The memory 31 can also be an external storage device of the control device 3, such as a plug-in hard disk equipped on the control device 3, a smart memory card (Smart Media Card, SMC), Secure Digital (Secure Digital, SD) card, Flash Card (Flash Card), etc. Further, the memory 31 may also include both an internal storage unit of the control device 3 and an external storage device. The memory 31 is used to store a computer program 32 and other programs and data required by the control device 3 . The memory 31 can also be used to temporarily store data that has been output or will be output.

Those skilled in the art can clearly understand that, for convenience and brevity of description, only the division of the above functional units and modules is used as an example for illustration. In practical applications, the above function allocation can be completed by different functional units or modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the implementation manner may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units 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 protection scope of the present application. For the specific working process of the units and modules in the above device, reference may be made to the corresponding process in the implementation of the aforementioned method, which will not be repeated here.

In the above implementation manners, descriptions of each implementation manner have their own emphases, and for parts not described or recorded in detail in a certain implementation manner, please refer to relevant descriptions of other implementation manners.

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in the various implementations disclosed in the present application can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but these implementation methods should not be regarded as exceeding the scope of the present application.

It should be understood that the disclosed device/control device and method may be implemented in other ways. For example, the device/control device implementations described above are merely illustrative. For example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation. For example, several units or components may be combined or integrated into another system, or some features may be omitted, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described above 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, the above components and units may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of each implementation.

If the integrated module/unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, all or part of the procedures in the implementation manners of the above-mentioned methods in this application may be completed by controlling related hardware through computer programs. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can realize the steps of the above-mentioned method for determining the initial value of the SOC of the battery. Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, 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, removable hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), Random Access Memory (RAM, Random Access Memory), electrical 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 practice in the jurisdiction. For example, in some jurisdictions, computer readable media exclude electrical carrier signals and telecommunication signals under legislative and patent practice.

The above-described embodiments 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 foregoing embodiments, those of ordinary skill in the art should understand that: it can still implement the foregoing embodiments Modifications to the technical solutions described in the examples, or equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the application, and should be included in the Within the protection scope of this application.

Claims

A method for determining an initial value of a battery SOC, wherein the method is applied to a battery, the battery includes n battery cells, and n is a positive integer greater than or equal to 2, and the method includes:

Reading step: For each battery cell, read the SOC value of the battery cell in the preset storage space; wherein, the storage space stores the SOC value of each battery cell when the battery is charged and discharged last time. Body SOC value;

Judging step: judging whether a storage abnormality occurs according to the SOC value of each battery cell; wherein, the storage abnormality indicates that in the storage space, at least one SOC value of a battery cell has a storage error;

The first branch step: when there is no storage abnormality, for each battery cell, the SOC value of the battery cell read in the storage space is used as the SOC initial value of the charge and discharge of the battery cell value; and

The second branch step: when a storage abnormality occurs, correct the SOC value of each battery cell with a storage error according to the SOC value of the battery cell without a storage error to obtain the SOC correction value of the battery cell, And the SOC correction value of the battery cell is used as the initial SOC value of the battery cell for charging and discharging this time.
The method according to claim 1, wherein the judging step comprises:

When the SOC value of m battery cells is 0, the maximum value is obtained from the SOC values of the n battery cells; wherein, m is a positive integer greater than or equal to 1 and less than n;

When the maximum value is greater than the preset SOC value, it is judged that the SOC values of the m battery cells are stored abnormally; and

When the maximum value is less than or equal to the preset SOC value, it is determined that no storage abnormality occurs.
The method according to claim 1, wherein the preset SOC value is 10%.
The method according to claim 1, wherein the storage space is a non-volatile memory.
The method according to claim 4, wherein the non-volatile memory is a Flash memory.
The method according to claim 1, wherein the battery is a lithium ion battery.
The method according to claim 1 or 2, wherein the second branching step comprises:

Acquiring the minimum value among all the SOC values of the n battery cells that are not 0; and

For each battery cell whose SOC value is 0, the minimum value is used as the SOC correction value of the battery cell.
The method according to claim 1 or 2, wherein the judging step comprises:

When the SOC value of each battery cell read from the storage space is 0, it is determined that a storage abnormality occurs;

The method for determining the initial value of battery SOC also includes:

Obtain the minimum open circuit voltage among the open circuit voltages of the n battery cells, and according to the minimum open circuit voltage, look up an OCV (Open Circuit Voltage, open circuit voltage) table to determine an SOC value, and use this SOC value as the The initial SOC value of the battery for this charge and discharge.
The method according to claim 8, wherein the method for determining the initial value of the battery SOC further comprises:

The SOC value of each battery cell is stored in the storage space when the current charging and discharging of the battery ends.
A device for determining the initial value of battery SOC, characterized in that the device is applied to a battery, the battery includes n battery cells, n is a positive integer greater than or equal to 2, and the device includes: a reading module, Judgment module and initial value determination module;

The reading module is used to read the SOC value of the battery cell in the preset storage space for each battery cell; wherein, the storage space stores the time when the last charge and discharge of the battery is completed SOC value of each battery cell;

The judging module is configured to judge whether a storage abnormality occurs according to the SOC value of each battery cell; wherein, the storage abnormality indicates that a storage error occurs in the SOC value of at least one battery cell in the storage space;

The initial value determination module is configured to, for each battery cell, use the SOC value of the battery cell read in the storage space as the current charge of the battery cell when no storage abnormality occurs. SOC initial value of discharge;

The initial value determination module is further configured to correct the SOC value of each battery cell with a storage error according to the SOC value of the battery cell without a storage error when a storage abnormality occurs, to obtain the battery cell The SOC correction value of the battery cell is used as the SOC initial value of the battery cell for this charging and discharging.
The device according to claim 10, wherein the judging module is used for:

When the SOC value of m battery cells is 0, the maximum value is obtained from the SOC values of the n battery cells; wherein, m is a positive integer greater than or equal to 1 and less than n;

When the maximum value is greater than the preset SOC value, it is judged that the SOC values of the m battery cells are stored abnormally; and

When the maximum value is less than or equal to the preset SOC value, it is determined that no storage abnormality occurs.
The device according to claim 10 or 11, wherein the initial value determination module is used for:

Acquiring the minimum value among all the SOC values of the n battery cells that are not 0; and

For each battery cell whose SOC value is 0, the minimum value is used as the SOC correction value of the battery cell.
A vehicle includes a control device, the control device includes a memory, a processor, and a computer program stored in the memory and operable on the processor, wherein the processor executes the The computer program implements the steps of the method as claimed in any one of claims 1 to 9 above.
A computer-readable storage medium, the computer-readable storage medium stores a computer program, characterized in that, when the computer program is executed by a processor, the steps of the method described in any one of claims 1 to 9 above are realized .