Battery cell diagnosis method and electronic device for performing same

Abstract

The present invention comprises an information acquisition interface, a memory, and a processor, wherein the processor acquires a first voltage of each of a plurality of battery cells in an idle state, determines compensation voltage of each of the battery cells on the basis of balancing data, determines a second voltage of each of the battery cells on the basis of the first voltage and the compensation voltage of each of the battery cells, determines a voltage deviation of each of the plurality of battery cells on the basis of a reference voltage and the second voltage of each of the plurality of battery cells, determines the amount of change of the voltage deviation according to a predetermined period with respect to each of the plurality of battery cells, identifies a pattern of the amount of change of the voltage deviation of each of the plurality of battery cells, and diagnoses the state of each of the plurality of battery cells on the basis of a preset diagnosis pattern and the pattern of the amount of change of the voltage deviation of each of the plurality of battery cells.

Description

Battery cell diagnosis method and electronic device performing the same

[0001] The present disclosure relates to a battery cell diagnosis method and an electronic device performing the same.

[0002] Recently, with the rapid increase in demand for portable electronic products such as laptops, video cameras, and mobile phones, and the full-scale development of electric vehicles, energy storage batteries, robots, and satellites, research on high-performance battery cells capable of repeated charging and discharging is actively being conducted. In particular, when charging or discharging multiple batteries, processes such as battery balancing are necessary to minimize the voltage difference between each battery. In order to check for the occurrence of micro-short circuits within the battery, various studies are being conducted to accurately calculate the compensation voltage that takes into account the voltage change due to battery balancing when considering the voltage of the battery cell, and to diagnose micro-short circuits within the battery through battery voltage monitoring.

[0003] The disclosed embodiments aim to increase the accuracy of battery cell diagnosis by identifying the consumed capacity due to balancing of SoC sections of multiple battery cells and determining a compensation voltage considering the consumed capacity when detecting a micro-short circuit inside a battery cell.

[0004] The technical task to be achieved by this embodiment is not limited to the technical task described above, and other technical tasks can be inferred from the following embodiments.

[0005] An electronic device performing a battery cell diagnosis method according to one embodiment includes an information acquisition interface for acquiring voltages of a plurality of battery cells included in a battery pack and balancing data of the plurality of battery cells; a memory for storing one or more instructions; and a processor, wherein the one or more instructions, when executed, cause the processor to acquire a first voltage of each of the plurality of battery cells in an idle state, determine a compensation voltage of each of the plurality of battery cells based on the balancing data of the plurality of battery cells, determine a second voltage of each of the plurality of battery cells based on the first voltage and the compensation voltage of each of the plurality of battery cells, determine a voltage deviation of each of the plurality of battery cells based on a reference voltage and the second voltage of each of the plurality of battery cells, determine an amount of change in the voltage deviation according to a set cycle for each of the plurality of battery cells, confirm a pattern of a voltage deviation variation of each of the plurality of battery cells, and diagnose a state of each of the plurality of battery cells based on the pattern of the voltage deviation variation of each of the plurality of battery cells and a preset diagnosis pattern.

[0006] The above balancing data may include an SoC section in which cell balancing of each of the plurality of battery cells was performed, a time at which cell balancing was performed for each SoC section, a cell balancing current for each SoC section, and a cell balancing capacity for each SoC section.

[0007] The processor may be configured to determine a compensation voltage of each of the plurality of battery cells based on a total capacity of the plurality of battery cells, a time at which cell balancing is performed for each SoC section, a cell balancing current for each SoC section, and a change in OCV voltage according to a change in SoC for each SoC section.

[0008] The second voltage may be a voltage obtained by adding a compensation voltage of each of the plurality of battery cells to the first voltage of each of the plurality of battery cells.

[0009] The above information acquisition interface can acquire the voltage and balancing data of the plurality of battery cells at predefined intervals.

[0010] The above-described preset diagnostic pattern may include a first diagnostic pattern, and the one or more instructions may be configured such that, when executed, the processor determines that the pattern of the voltage deviation change amount of the first battery cell corresponds to the first diagnostic pattern and diagnoses that an internal micro-short circuit has occurred in the first battery cell when all of the voltage deviation change amounts of the first battery cell included in the plurality of battery cells are positive and the sum of the voltage deviation change amounts of the first battery cell is equal to or greater than a first threshold value.

[0011] The above-described preset diagnostic pattern may include a second diagnostic pattern, and the one or more instructions may be configured such that, when executed, the processor determines that the pattern of voltage deviation change amounts of the first battery cell corresponds to the second diagnostic pattern when a plurality of voltage deviation change amounts of the second battery cell included in the plurality of battery cells is equal to or greater than a second threshold value, and diagnoses that an internal micro-short circuit has occurred in the second battery cell.

[0012] The above-described preset diagnostic pattern may include a third diagnostic pattern, and the one or more instructions may be configured such that, when executed, the processor determines that the pattern of the voltage deviation change amount of the third battery cell corresponds to the third diagnostic pattern and diagnoses that an internal micro-short circuit has occurred in the third battery cell when all of the plurality of voltage deviation change amounts of the third battery cell included in the plurality of battery cells are positive and at least one of the plurality of voltage deviation change amounts of the third battery cell is equal to or greater than a third threshold value.

[0013] The above-described preset diagnostic pattern may include a fourth diagnostic pattern, and the one or more instructions may be configured such that, when executed, the processor determines that the pattern of the voltage deviation change amount of the fourth battery cell corresponds to the first diagnostic pattern when all of the plurality of voltage deviation change amounts of the fourth battery cell included in the plurality of battery cells are positive and the plurality of voltage deviation change amounts of the fourth battery cell increase over time, and diagnoses that an internal micro-short circuit has occurred in the fourth battery cell.

[0014] The voltage of the above battery cell may be an OCV voltage according to the SoC change of the plurality of battery cells measured at each predefined cycle.

[0015] The reference voltage may be one of an average value of the second voltages of each of the plurality of battery cells or an average value or a central value of the second voltages of each of the plurality of battery cells.

[0016] The above voltage deviation may be the difference between the second voltage of each of the plurality of battery cells and the reference voltage.

[0017] The above-determined cycle may correspond to a charge and discharge cycle of the plurality of battery cells.

[0018] According to one embodiment, a method for diagnosing a battery cell state may include: acquiring a first voltage of each of a plurality of battery cells in an idle state; determining a compensation voltage of each of the plurality of battery cells based on balancing data of the plurality of battery cells; determining a second voltage of each of the plurality of battery cells based on the first voltage and the compensation voltage of each of the plurality of battery cells; determining a voltage deviation of each of the plurality of battery cells based on a reference voltage and the second voltage of each of the plurality of battery cells; determining an amount of change in voltage deviation according to a set cycle for each of the plurality of battery cells; confirming a pattern of a voltage deviation change amount of each of the plurality of battery cells; and diagnosing a state of each of the plurality of battery cells based on the pattern of the voltage deviation change amount of each of the plurality of battery cells and a preset diagnosis pattern.

[0019] According to the proposed embodiment, one or more of the following effects can be expected.

[0020] According to an embodiment of the present specification, when determining a voltage for determining an internal micro-short circuit, the compensation voltage can be performed based on the voltage in the idle state and the compensation voltage according to the voltage change rate according to the battery cell capacity change rate by considering the charging time and charging current for each SoC section, so that an accurate compensation voltage can be determined even when the voltage change rate according to the battery cell capacity change rate is not constant.

[0021] In addition, according to the embodiment of the present specification, it is possible to identify the trend of the voltage deviation change amount of the battery cell based on the determined compensation voltage value, thereby diagnosing the status of each battery cell.

[0022] The effects of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0023] FIG. 1 illustrates the interlocking relationship of electronic devices performing a battery cell diagnosis method according to one embodiment.

[0024] Figure 2 is a block diagram illustrating the configuration of an electronic device according to one embodiment.

[0025] FIGS. 3 and 4 are drawings for explaining a compensation voltage determination process performed by an electronic device according to one embodiment.

[0026] FIG. 5 is a drawing for explaining a first diagnostic pattern according to one embodiment.

[0027] FIG. 6 is a drawing for explaining a second diagnostic pattern according to one embodiment.

[0028] FIG. 7 is a drawing for explaining a third diagnostic pattern according to one embodiment.

[0029] FIG. 8 is a drawing for explaining a fourth diagnostic pattern according to one embodiment.

[0030] FIG. 9 is a flowchart illustrating a battery cell diagnosis method according to one embodiment.

[0031] The terms used in the embodiments have been selected from widely used and common terms, taking into account the functions of the present disclosure. However, these terms may vary depending on the intentions of those skilled in the art, precedents, the emergence of new technologies, etc. Furthermore, in certain cases, terms may be arbitrarily selected by the applicant, in which case their meanings will be described in detail in the relevant description. Therefore, the terms used in this disclosure should not be defined simply as names of terms, but rather based on the meanings of the terms and the overall content of the present disclosure.

[0032] When a part of the specification is said to "include" a component, this does not exclude other components, but rather implies the inclusion of other components, unless otherwise specifically stated. Furthermore, terms such as "part" and "module" used in the specification mean a unit that processes at least one function or operation, which may be implemented in hardware, software, or a combination of hardware and software.

[0033] The expression “at least one of a, b, and c” described throughout the specification may encompass ‘a alone’, ‘b alone’, ‘c alone’, ‘a and b’, ‘a and c’, ‘b and c’, or ‘all of a, b, and c’.

[0034] Below, embodiments of the present disclosure are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein.

[0035] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0036] In describing the embodiments, descriptions of technical details that are well-known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to avoid obscuring the gist of the present invention by omitting unnecessary explanations and to convey it more clearly.

[0037] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0038] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0039] At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0040] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0041] FIG. 1 illustrates the interlocking relationship of electronic devices performing a battery cell diagnosis method according to one embodiment.

[0042] Referring to FIG. 1, the electronic device (100) may operate in conjunction with a battery management device (200) that manages a battery cell (300). At this time, the battery cell (300) may correspond to a battery cell (300) included in a battery pack, and may include a plurality of battery cells (300) that are the subject of diagnosis regarding whether they correspond to internal micro-short-circuit battery cells. Meanwhile, FIG. 1 only illustrates components related to the present embodiment. Therefore, a person having ordinary skill in the art related to the present embodiment will understand that other general-purpose components may be further included in addition to the components illustrated in FIG. 1. The battery cell (300) according to one embodiment may include a first battery cell, a second battery cell, a third battery cell, and a fourth battery cell, which will be discussed below. For example, the first battery cell, the second battery cell, the third battery cell, and the fourth battery cell may be connected in series, and the first to fourth battery cells may be connected to the battery management device (200) through a sensing line.

[0043] An electronic device (100) according to an embodiment is a device that configures and provides various information. In an embodiment, the electronic device (100) may correspond to a server, an analysis device, or a charging device that receives parameters related to battery cells (300) from a battery management device (200) present inside a vehicle and instructs the battery management device (200) to perform a balancing method of battery cells (300) according to the present disclosure. The electronic device (100) may receive parameters related to battery cells (300) from the battery management device (200) to obtain voltages of a plurality of battery cells (300) included in a battery pack and balancing data of the plurality of battery cells (300). The electronic device (100) may obtain a first voltage of each of the plurality of battery cells (300) in an idle state. The voltages of the plurality of battery cells obtained by the electronic device (100) may correspond to OCV voltages according to SoC changes of the plurality of battery cells measured at predefined intervals. The voltage of the plurality of battery cells may refer to the voltage of the plurality of battery cells in a resting state after a certain period of time (e.g., 10 days) has elapsed since the balancing was performed. The predefined cycle may refer to one cycle in which charging and discharging of the battery cells are performed over the entire SoC section. The electronic device (100) may determine the compensation voltage of each of the plurality of battery cells based on the balancing data of the plurality of battery cells. The balancing data may include the SoC section in which cell balancing was performed for each of the plurality of battery cells, the time at which cell balancing was performed for each SoC section, the cell balancing current for each SoC section, and the cell balancing capacity for each SoC section. The electronic device (100) can determine the compensation voltage of each of the plurality of battery cells based on the total capacity of the plurality of battery cells, the time at which cell balancing was performed for each SoC section, the cell balancing current for each SoC section, and the amount of change in OCV voltage according to SoC change for each SoC section, which will be specifically discussed in FIGS. 2 and 3 below.

[0044] An electronic device (100) according to an embodiment may determine a second voltage of each of the plurality of battery cells based on a first voltage and a compensation voltage of each of the plurality of battery cells. The second voltage may correspond to a voltage obtained by adding a compensation voltage of each of the plurality of battery cells to the first voltage of each of the plurality of battery cells. An electronic device (100) according to an embodiment may determine a second voltage of each of the plurality of battery cells by adding the compensation voltages of each of the plurality of battery cells in a plurality of sections in which cell balancing of the battery cells (300) is performed to the first voltage of each of the plurality of battery cells (300) in an idle state.

[0045] An electronic device (100) according to an embodiment may determine a voltage deviation of each of the plurality of battery cells based on a reference voltage and a second voltage of each of the plurality of battery cells. The reference voltage may be an average value of the second voltages of each of the plurality of battery cells or one of an average value or a median value of the second voltages of each of the plurality of battery cells. The voltage deviation may correspond to a difference between the second voltage of each of the plurality of battery cells and the reference voltage. An electronic device (100) according to an embodiment may determine an amount of change in voltage deviation for each of the plurality of battery cells according to a set cycle, check a pattern of the amount of change in voltage deviation of each of the plurality of battery cells, and diagnose a state of each of the plurality of battery cells based on a preset diagnostic pattern that will be described below with reference to FIGS. 5 to 8.

[0046] The battery management device (200) may include one or more sensors for measuring parameters such as current, voltage, initial SoC, internal resistance, and internal temperature of the battery cell (300), and may include a memory and a processor (not shown) for various operations. That is, the battery management device (200) operates based on the memory and processor similarly to the electronic device (100), but additionally includes a sensor to measure and calculate the parameters of the battery cell (300). In addition, the battery management device (200) may similarly perform the overall calculations and simulations performed by the electronic device (100), as briefly described above.

[0047] Here, the electronic device (100) and the battery management device (200) may be completely separate and independent objects, but may exist only conceptually separated within a single device or system. That is, the electronic device (100) may exist in combination with the battery management device (200) within a single vehicle system according to an embodiment, and may acquire balancing data of the battery cells (300) included in the battery within the vehicle, and may diagnose the status of each battery cell (300) by considering the compensation voltage of each battery cell (300) according to the matters described below. That is, a single computing device having a control function for battery cells may perform all of the functions of the electronic device (100) and the battery management device (200) described below, and therefore, such an embodiment is also considered to fall within the scope of the present disclosure.

[0048] Figure 2 is a block diagram illustrating the configuration of an electronic device according to one embodiment.

[0049] Referring to FIG. 2, an electronic device (100) according to an embodiment may include an information acquisition interface (110), a memory (120), and a processor (130). The electronic device (100) illustrated in FIG. 2 only illustrates components related to the present embodiment. Therefore, it will be understood by those skilled in the art related to the present embodiment that other general-purpose components may be included in addition to the components illustrated in FIG. 2.

[0050] An information acquisition interface (110) according to an embodiment can acquire time-series data on the voltage of each of a plurality of battery cells included in a battery cell (300). For example, the information acquisition interface (110) can acquire the voltage value of each battery cell at specific time intervals and acquire time-series data on the voltage values. That is, the time-series data can be a set of voltage values ​​acquired at multiple points in time. In addition to the voltage of the battery cell, the information acquisition interface (110) can also acquire data such as current, temperature, and SOC (State-Of-Charge). When the electronic device (100) that performs the battery cell diagnosis method is a battery management system (BMS) of the battery cell (300), the information acquisition interface (110) can be a component that directly measures the voltage of the battery cell (300), for example, a voltage sensor. In addition, the information acquisition interface (110) may be a communication interface that receives voltage information measured from a component that measures the voltage of a battery pack (e.g., a voltage sensor of a battery cell (300)) when the electronic device (100) corresponds to a vehicle OBD (on-board diagnostics device), a server, a cloud BMS, or a charger / discharger. The processor (130) may analyze time-series data acquired from the information acquisition interface (110) to diagnose the status of each battery cell. Unless there are special circumstances, the processor (130) in the present disclosure may mean a set of one or more processors.

[0051] According to one embodiment, the memory (120) is hardware that stores various data processed within the electronic device (100), and the memory (120) can store one or more instructions, and store data processed and data to be processed through the processor (130) when executing one or more instructions. In addition, the memory (120) can store basic programming and data structures that can provide functions of at least one embodiment of the present disclosure, as well as applications (programs, code modules, instructions), drivers, etc. that can provide functions of the embodiments of the present disclosure. The memory may include random access memory (RAM) such as dynamic random access memory (DRAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), CD-ROM, Blu-ray or other optical disk storage, hard disk drive (HDD), solid state drive (SSD), or flash memory, but is not limited to the specific cases mentioned in the embodiments according to the present disclosure.

[0052] In one embodiment, the processor (130) may control the overall operation of the electronic device (100) and process data and signals. The processor (130) may be composed of at least one hardware unit. In addition, the processor (130) may operate by one or more software modules generated by executing one or more instructions stored in the memory (120).

[0053] Methods implemented as software modules or algorithms may be stored on a computer-readable recording medium as computer-readable codes or program instructions executable on the processor. Here, the computer-readable recording medium includes a magnetic storage medium (e.g., read-only memory (ROM), random-access memory (RAM), floppy disks, hard disks, etc.) and an optical reading medium (e.g., CD-ROM, DVD: Digital Versatile Disc)). The computer-readable recording medium may be distributed across network-connected computer systems, so that the computer-readable codes may be stored and executed in a distributed manner. The medium may be readable by a computer, stored in a memory, and executed by a processor.

[0054] FIGS. 3 and 4 are drawings for explaining a compensation voltage determination process performed by an electronic device according to one embodiment.

[0055] Referring to FIG. 3, an electronic device (100) according to an embodiment can acquire voltages of a plurality of battery cells included in a battery pack and balancing data of the plurality of battery cells through the information acquisition interface (110) discussed above. The balancing data can include an SoC section in which cell balancing was performed for each of the plurality of battery cells, a time at which cell balancing was performed for each SoC section, a cell balancing current for each SoC section, and a cell balancing capacity for each SoC section. The balancing-related information can include, for example, a chart (301) including a graph regarding a change in voltage according to the SoC of the battery cells of FIG. 3. An electronic device (100) according to an embodiment may determine a compensation voltage of a battery cell based on the total capacity of the battery cell, the time for which cell balancing was performed in the SoC section (210), the cell balancing current in the SoC section (210), and the amount of change in OCV voltage according to the SoC change in the SoC section (210). For example, when the total capacity of the battery cell is 100 Ah, the balancing performance time in the SoC section (210) is 80 hours, and the cell balancing current value in the SoC section (210) is 25 mA, when the measured voltage is 4.0 V when measuring the first voltage in the resting state after performing balancing, and the SoC is 90%, the compensation voltage determined by the electronic device (100) may be determined based on the following mathematical expression 1.

[0056]

[0057]

[0058] In this case, Bcap may represent the cell balancing consumption capacity (Ah) in the SoC section, Bt may represent the time (h) for which cell balancing was performed, and Bc may represent the cell balancing current (A). In addition, Comv may represent the second voltage determined based on the first voltage and the compensation voltage, SoC (Cv) may represent the SoC corresponding to the voltage in the resting state, and Ccap may represent the total capacity of the battery cell.

[0059] The second voltage according to an embodiment may correspond to a voltage obtained by adding a compensation voltage to the first voltage. For example, in the case above, since the balancing consumption capacity is 2 Ah, the second voltage may correspond to 4.01 V, which is the voltage when the battery cell SoC is 92%, by adding a compensation voltage of 0.01 V to the first voltage of 4.0 V. Accordingly, the electronic device (100) may determine the voltage deviation of the battery cell based on the second voltage of 4.01 V on which voltage compensation is performed. Although the description is based on one battery cell with reference to FIG. 3, the electronic device (100) according to an embodiment may determine the amount of change in voltage deviation of each of a plurality of battery cells at predetermined intervals through the above method, and compare the pattern of the amount of change in voltage deviation of each of the plurality of battery cells with a preset diagnosis pattern to diagnose the state of each of the plurality of battery cells.

[0060] Referring to FIG. 4, the balancing-related information acquired by the electronic device (100) according to one embodiment may include, for example, a chart (401) including a graph regarding the amount of change in voltage according to the SoC of the battery cell of FIG. 4. Just as the amount of change in battery cell voltage (420, 440, 460) in the SoC change sections (410, 430, 450) of the battery cell is different depending on the material composition ratio during the manufacturing of the battery cell, the degree of the amount of change in voltage according to the SoC change of the battery cell may be different for each SoC section, and for example, in a specific SoC section (470), the degree of the amount of change in voltage according to the SoC change of the battery cell may be greater than a critical level. In this case, the electronic device (100) according to one embodiment may determine a compensation voltage by considering the amount of change in battery cell voltage (420, 440, 460) in each SoC change section (410, 430, 450), and may determine a second voltage based on the first voltage of the battery cell in the resting state and the compensation voltage in each SoC change section.

[0061] The battery cell balancing execution time for each SoC section of the battery cell included in the battery cell balancing data acquired by the electronic device (100) according to one embodiment may include, for example, Table 1 below.

[0062] SoC(%)Balancing Time(h)0 - 10%010 - 20%020 - 30%030 - 40%040 - 50%4050 - 60%2060 - 70%2070 - 80%080 - 90%090 - 100%0

[0063] For example, when the electronic device (100) according to one embodiment measures the voltage of a battery cell in a resting state and the measured first voltage is 4.0 V and the SoC at this time is 97%, the electronic device can determine the second voltage based on the compensation voltage in each SoC change section based on the first voltage of 4.0 V.

[0064] For example, if cell balancing is performed for 40 hours at a cell balancing current of 25 mA in the SoC 40-50% range of the battery cell as shown in Table 1, a cell balancing capacity of 1 Ah may be consumed. If balancing is performed for 20 hours at a cell balancing current of 25 mA in the SoC 50-60% range of the battery cell, a balancing capacity of 0.5 Ah may be consumed. If cell balancing is performed for 20 hours at a cell balancing current of 25 mA in the SoC 60-70% range of the battery cell, a balancing capacity of 0.5 Ah may be consumed.

[0065] As shown in the chart (401) of FIG. 5, since the battery cell voltage changes (420, 440, 460) in each SoC change section (410, 430, 450) may be different from each other, the electronic device (100) according to one embodiment may determine a compensation voltage for each section in each SoC change section and add all of the compensation voltages for each section in each SoC change section to the first voltage of the battery cell in an idle state to determine a second voltage. The electronic device (100) according to one embodiment may determine the compensation voltage for each section in each SoC change section, for example, based on the following mathematical expression 2.

[0066]

[0067] In mathematical expression 2, Vci may denote a compensation voltage in a specific SoC section i, dvi may denote a voltage change amount in a specific SoC section i, dSoC may denote a SoC change amount in a specific SoC section i, Bcap may denote a cell balancing consumption capacity (Ah), and Ccap may denote the total capacity of the battery cell. For example, the voltage change amount in a specific SoC section i with respect to the SoC change amount in a specific SoC section i may correspond to the slope of the graph in each SoC change section (410, 430, 450).

[0068] An electronic device (100) according to one embodiment can determine a second voltage of a battery cell by adding the sum of the compensation voltages for each section in each SoC change section to the first voltage of the battery cell in the resting state.

[0069] For example, since 1 Ah of balancing capacity is consumed in the SoC 40-50% section of the battery cell, which corresponds to a SoC change of 1% of the total capacity of 100 Ah of the battery cell, the electronic device (100) can determine 0.007 (V), which corresponds to a voltage change amount for 1% of the SoC change amount in the SoC 40-50% section, as the first compensation voltage in the SoC 40-50% section of the battery cell. For example, since 0.5 Ah of balancing capacity is consumed in the SoC 50-60% section of the battery cell, which corresponds to a SoC change of 0.5% of the total capacity of 100 Ah of the battery cell, the electronic device (100) can determine 0.004 (V), which corresponds to a voltage change amount for 0.5% of the SoC change amount in the SoC 50-60% section, as the second compensation voltage in the SoC 40-50% section of the battery cell. For example, since 0.5 Ah of balancing capacity is consumed in the SoC 60-70% section of the battery cell, which corresponds to a SoC change of 0.5% of the total capacity of 100 Ah of the battery cell, the electronic device (100) can determine 0.003 (V), which corresponds to the voltage change amount for the SoC change amount in the SoC 60-70% section, as the third compensation voltage in the SoC 40-50% section of the battery cell.

[0070] According to one embodiment, the electronic device (100) may determine the second voltage as 4.014 (V) by adding 0.014 (V), which is the sum of the first compensation voltage to the third voltage compensation degree, to the first voltage, which is 4.0 V, measured when measuring the voltage of the battery cell in a resting state.

[0071] In this way, the electronic device (100) can perform voltage compensation by considering the voltage change amount according to the SoC change in each SoC change section, and can accurately perform voltage compensation according to the balancing of a plurality of battery cells. Through this, the electronic device (100) determines a second voltage by determining a compensation voltage that is higher than the required compensation voltage, for example, different from the actual required compensation voltage, and in the process of comparing the pattern of the voltage deviation change amount with the preset diagnosis pattern, the case where a specific battery cell is incorrectly detected as an internal micro-short battery cell when it is not actually an internal micro-short battery cell can be reduced. Hereinafter, an embodiment of the preset diagnosis pattern will be described in detail with reference to FIGS. 5 to 8.

[0072] FIG. 5 is a drawing for explaining a first diagnostic pattern according to one embodiment.

[0073] In order to diagnose the status of each of a plurality of battery cells based on a preset diagnostic pattern to be described below, it is assumed that an electronic device (100) according to an embodiment is equipped with a first battery cell, a second battery cell, a third battery cell, and a fourth battery cell as a plurality of battery cells that determine a second voltage.

[0074] According to an embodiment, an electronic device (100) may measure a first voltage in an idle state after performing balancing of a plurality of battery cells, and obtain a second voltage of each battery cell based on the first voltage and the compensation voltage examined in FIGS. 3 and 4 above. The electronic device (100) may obtain the second voltage of the first battery cell as Va, the second voltage of the second battery cell as Vb, the second voltage of the third battery cell as Vc, and the second voltage of the fourth battery cell as Vd. The electronic device (100) may determine a voltage deviation for a second voltage for which voltage compensation is performed based on balancing-related information with respect to the first voltage in an idle state after performing balancing of a plurality of battery cells. Specifically, the electronic device (100) receives voltage information of a plurality of battery cells in a resting state after performing balancing, and determines a voltage deviation of the plurality of battery cells based on a compensation voltage for which voltage compensation is performed according to a degree of voltage compensation for the voltage in the resting state.

[0075] An electronic device (100) according to an embodiment may determine a reference voltage of a plurality of battery cells. In the embodiments of FIGS. 5 to 8, the electronic device (100) may determine a reference voltage for a compensation voltage of the first to fourth battery cells. The reference voltage may be one of an average value of the second voltages of each of the plurality of battery cells or an average value or a median value of the second voltages of each of the plurality of battery cells. For example, the electronic device (100) may determine the reference voltage as Vavg by calculating the formula “(Va+Vb+Vc+Vd)χ4”. The electronic device (100) may determine the reference voltage (Vavg) at each predetermined cycle to be described below. The reference voltage (Vavg) corresponding to a time point t1 may be determined based on a plurality of second voltages for the plurality of battery cells obtained at a time point t1. Similarly, the reference voltage (Vavg) corresponding to a time point t2 may be determined based on a plurality of second voltages for the plurality of battery cells obtained at a time point t2. Therefore, the reference voltage (Vavg) corresponding to each point in time may be different.

[0076] According to an embodiment, the electronic device (100) may determine a voltage deviation of each of the plurality of battery cells by calculating a difference between a determined reference voltage and a second voltage of each of the plurality of battery cells. In other words, the voltage deviation may correspond to a difference between the second voltage of each of the plurality of battery cells and the reference voltage. In the embodiments of FIGS. 5 to 8, the electronic device (100) may determine the voltage deviation of the first to fourth batteries by calculating a difference between the second voltages of the first to fourth batteries and the reference voltage. For example, the electronic device (100) may determine the voltage deviation of the first battery cell as dVa by calculating the formula “|Va-Vavg|”, and may determine the voltage deviation of the second battery cell as dVb by calculating the formula “|Vb-Vavg|”. And, the electronic device (100) can determine the voltage deviation of the third battery cell as dVc by calculating the formula “|Vc-Vavg|”, and can determine the voltage deviation of the fourth battery cell as dVd by calculating the formula “|Vd-Vavg|”. Here, “||” is an absolute value symbol, and the determined voltage deviation can be expressed as the absolute value of the difference between the compensation voltage of the battery cell and the reference voltage.

[0077] An electronic device (100) according to an embodiment may determine a voltage deviation change amount of each of a plurality of battery cells at a predetermined cycle. For example, the predetermined cycle may correspond to a charge and discharge cycle of the plurality of battery cells. Specifically, the electronic device (100) may determine a voltage deviation for each of the plurality of batteries at a predetermined cycle. Here, the voltage deviation may be a voltage deviation of the plurality of battery cells measured at a corresponding cycle (i.e., a compensation voltage measurement point in time of the corresponding cycle). In addition, the electronic device (100) may determine a voltage deviation change amount between a voltage deviation determined at a previous cycle and a compensation voltage deviation determined at a current cycle. That is, the electronic device (100) may determine a voltage deviation change amount of each of the plurality of battery cells at a predetermined cycle.

[0078] Referring to FIG. 5, an electronic device (100) according to an embodiment can diagnose the status of each of a plurality of battery cells based on a pattern of voltage deviation change amounts of each of a plurality of battery cells and a preset diagnostic pattern. The preset diagnostic pattern may include a first diagnostic pattern to a fourth diagnostic pattern. For example, when all of a plurality of voltage deviation change amounts (521, 522, 523) for voltage deviations (510, 511, 512, 513) of a specific battery cell at each point in time are positive and the sum of the plurality of voltage deviation change amounts (521, 522, 523) is equal to or greater than a preset first threshold value, the electronic device (100) determines that the pattern of voltage deviation change amounts corresponds to the first diagnostic pattern and can diagnose that an internal micro-short circuit has occurred in the specific battery cell. For example, in the embodiment of FIG. 5, the first voltage deviation change amount (521), the second voltage deviation change amount (522), and the third voltage deviation change amount (523) may all be positive. In addition, the sum of the first voltage deviation change amount (521), the second voltage deviation change amount (522), and the third voltage deviation change amount (523) may be equal to or greater than a first threshold value, for example, 10 mV. In the embodiment of FIG. 5, since the determined sum is equal to or greater than the first threshold value, the electronic device (100) may diagnose that an internal micro-short circuit has occurred in a specific battery cell.

[0079] FIG. 6 is a drawing for explaining a second diagnostic pattern according to one embodiment.

[0080] Referring to FIG. 6, an electronic device (100) according to an embodiment may diagnose the status of each of a plurality of battery cells based on a pattern of voltage deviation change amounts of each of a plurality of battery cells and a second diagnostic pattern. For example, when a plurality of voltage deviation change amounts (621, 622, 623) for voltage deviations (610, 611, 612, 613) of a specific battery cell at each point in time is equal to or greater than a preset second threshold value, the electronic device (100) may determine that the pattern of voltage deviation change amounts corresponds to the second diagnostic pattern and may diagnose that an internal micro-short circuit has occurred in the specific battery cell. For example, in the embodiment of FIG. 6, the first voltage deviation change amount (621), the second voltage deviation change amount (622), and the third voltage deviation change amount (623) may be positive numbers. And, the magnitudes of the first voltage deviation change amount (621), the second voltage deviation change amount (622), and the third voltage deviation change amount (623) may be greater than or equal to a second threshold value. In one embodiment, the second threshold value may be set to a value less than the first threshold value. For example, the first threshold value (R1) may be set to 10 mV, and the second threshold value may be set to 2 mV. The electronic device (100) may compare each of the first voltage deviation change amount (621), the second voltage deviation change amount (622), and the third voltage deviation change amount (623) with the second threshold value. In the embodiment of FIG. 6, since the first voltage deviation change amount (621), the second voltage deviation change amount (622), and the third voltage deviation change amount (623) are all greater than or equal to the second threshold value, the electronic device (100) may diagnose that an internal micro-short circuit has occurred in the specific battery cell.

[0081] FIG. 7 is a drawing for explaining a third diagnostic pattern according to one embodiment.

[0082] Referring to FIG. 7, an electronic device (100) according to an embodiment may diagnose the status of each of a plurality of battery cells based on a pattern of voltage deviation change amounts of each of a plurality of battery cells and a third diagnostic pattern. For example, if a plurality of voltage deviation change amounts (721, 722, 723) for voltage deviations (710, 711, 712, 713) of a specific battery cell at each point in time are all positive and at least one of the plurality of voltage deviation change amounts is equal to or greater than a preset third threshold value, the electronic device (100) may determine that the pattern of voltage deviation change amounts corresponds to the third diagnostic pattern and may diagnose that an internal micro-short circuit has occurred in the specific battery cell. For example, in the embodiment of FIG. 7, the first voltage deviation change amount (621), the second voltage deviation change amount (622), and the third voltage deviation change amount (623) may be positive numbers. Among the first voltage deviation change amount (621), the second voltage deviation change amount (622), and the third voltage deviation change amount (623), the magnitude of the second voltage deviation change amount (623) may be greater than or equal to a third threshold value. That is, the maximum magnitudes of the first voltage deviation change amount (621), the second voltage deviation change amount (622), and the third voltage deviation change amount (623) may be greater than or equal to the third threshold value. In one embodiment, the third threshold value may be less than a first threshold value preset to correspond to the first diagnostic pattern and may exceed a second threshold value preset to correspond to the second diagnostic pattern. For example, the first threshold value may be set to 10 mV, the second threshold value may be set to 2 mV, and the third threshold value may be set to 6 mV. The electronic device (100) may compare the maximum magnitudes of the first voltage deviation change amount (621), the second voltage deviation change amount (622), and the third voltage deviation change amount (623) with the third threshold value. In the embodiment of FIG. 7, since the second voltage deviation change amount (622) is greater than or equal to the third threshold value, the electronic device (100) can diagnose that an internal micro-short circuit has occurred in the specific battery cell.

[0083] FIG. 8 is a drawing for explaining a fourth diagnostic pattern according to one embodiment.

[0084] Referring to FIG. 8, an electronic device (100) according to an embodiment may diagnose the status of each of a plurality of battery cells based on a pattern of voltage deviation change amounts of each of a plurality of battery cells and a fourth diagnostic pattern. For example, if the plurality of voltage deviation change amounts (821, 822, 823) for the voltage deviations (810, 811, 812, 813) of the second battery cell at each point in time are all positive and the plurality of voltage deviation change amounts (821, 822, 823) increase over time, the electronic device (100) may determine that the pattern of the voltage deviation change amounts (821, 822, 823) corresponds to the fourth diagnostic pattern, and may diagnose that an internal micro-short circuit has occurred in a specific battery cell. For example, in the embodiment of FIG. 8, the first voltage deviation change amount (821), the second voltage deviation change amount (822), and the third voltage deviation change amount (823) may be an increasing pattern. That is, the first voltage deviation change amount (821), the second voltage deviation change amount (822), and the third voltage deviation change amount (823) may gradually increase as time passes (i.e., as time passes from time points t1, t2, and t3). For example, the first voltage deviation change amount (821) may be less than the second compensation voltage deviation change amount (822), and the second voltage deviation change amount (822) may be less than the third voltage deviation change amount (823). The electronic device (100) may compare the magnitudes of the first voltage deviation change amount (821), the second voltage deviation change amount (822), and the third voltage deviation change amount (823) with each other to determine the pattern of the voltage deviation change amount of the battery cell as an increasing pattern. In the embodiment of FIG. 8, the first voltage deviation change amount (821), the second voltage deviation change amount (822), and the third voltage deviation change amount (823) are increasing patterns, so the electronic device (100) can diagnose that an internal micro-short circuit has occurred in the specific battery cell.

[0085] FIG. 9 is a flowchart illustrating a battery diagnosis method based on compensation voltage according to one embodiment.

[0086] Referring to FIG. 9, an electronic device (100) according to an embodiment can obtain a first voltage of each of a plurality of battery cells in an idle state in step S910. The electronic device (100) can obtain the first voltage of each of the plurality of battery cells in an idle state after balancing of the battery cells is performed through an information acquisition interface that obtains voltages of the plurality of battery cells included in a battery pack and balancing data of the plurality of battery cells at each predefined cycle.

[0087] According to an embodiment, the electronic device (100) may determine a compensation voltage of each of the plurality of battery cells based on balancing data of the plurality of battery cells in step S920. The balancing data may include an SoC section in which cell balancing was performed for each of the plurality of battery cells, a time at which cell balancing was performed for each SoC section, a cell balancing current for each SoC section, and a cell balancing capacity for each SoC section. According to an embodiment, the electronic device (100) may determine a compensation voltage of each of the plurality of battery cells based on a total capacity of the plurality of battery cells, a time at which cell balancing was performed for each SoC section, a cell balancing current for each SoC section, and a change in OCV voltage according to a SoC change for each SoC section in step S920.

[0088] According to an embodiment, the electronic device (100) may determine a second voltage of each of the plurality of battery cells based on the first voltage and the compensation voltage of each of the plurality of battery cells in step S930. The second voltage may be a voltage obtained by adding the compensation voltage of each of the plurality of battery cells to the first voltage of each of the plurality of battery cells. The electronic device (100) may determine the compensation voltage by considering the amount of change in the battery cell voltage in each SoC change section through the process described above with reference to FIGS. 3 and 4, for example, and may determine the second voltage based on the first voltage of the battery cell in the idle state and the compensation voltage in each SoC change section.

[0089] According to an embodiment, the electronic device (100) may determine a voltage deviation of each of the plurality of battery cells based on a reference voltage and a second voltage of each of the plurality of battery cells in step S940. The reference voltage may be an average value of the second voltages of each of the plurality of battery cells or an average value or a median value of the second voltages of each of the plurality of battery cells, and the voltage deviation of each of the plurality of battery cells may be a difference between the second voltage of each of the plurality of battery cells and the reference voltage.

[0090] An electronic device (100) according to an embodiment may determine, in step S950, the amount of change in voltage deviation according to a set cycle for each of a plurality of battery cells. The amount of change in voltage deviation may correspond to the difference between voltage deviations at adjacent times, as previously discussed in FIGS. 5 to 8 .

[0091] An electronic device (100) according to an embodiment can check a pattern of change in voltage deviation of each of a plurality of battery cells in step S960. The electronic device (100) can check a change pattern of the pattern of change in voltage deviation according to a set cycle corresponding to a charge and discharge cycle of the plurality of battery cells.

[0092] In step S970, the electronic device (100) according to an embodiment may diagnose the status of each of the plurality of battery cells based on the pattern of the voltage deviation change amount of each of the plurality of battery cells and the preset diagnostic pattern. As discussed above with reference to FIGS. 5 to 8, the electronic device (100) compares the pattern of the voltage deviation change amount of each of the plurality of battery cells with the preset first to fourth diagnostic patterns, and if it determines that a specific battery cell corresponds to a specific diagnostic pattern, it may diagnose that an internal micro-short has occurred in the specific battery cell. Since the first and fourth diagnostic patterns correspond to different patterns of voltage deviation change amount, the electronic device (100) according to an embodiment may diagnose that an internal micro-short has occurred in the specific battery cell if the pattern of the voltage deviation change amount of the specific battery cell corresponds to any one of the first to fourth diagnostic patterns, and if it determines that the pattern of the voltage deviation change amount of the specific battery cell does not correspond to any other diagnostic pattern among the first to fourth diagnostic patterns. The first to fourth diagnostic patterns may be based on the assumption that multiple voltage deviation variations are positive. For example, all of the multiple voltage deviation variations may be positive. That is, a battery in which an internal micro-short circuit has occurred may have an increasing compensation voltage deviation from other batteries over time. Therefore, in order to efficiently utilize system resources, the electronic device (100) may compare the patterns of multiple voltage deviation variations with a preset diagnostic pattern only for battery cells in which all of the multiple voltage deviation variations are positive.

[0093] Meanwhile, the present specification and drawings disclose preferred embodiments of the present invention. Although specific terms have been used, they are used in a general sense only to easily explain the technical contents of the present invention and to assist in understanding the invention, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modified examples based on the technical concept of the present invention are possible in addition to the embodiments disclosed herein.

[0094] The present embodiment may be represented by functional block configurations and various processing steps. These functional blocks may be implemented by various hardware and / or software configurations that perform specific functions. For example, the embodiment may employ integrated circuit configurations such as memory, processing, logic, look-up tables, etc., which may perform various functions under the control of one or more microprocessors or other control devices. Similarly, the present embodiment may be implemented in a programming or scripting language such as C, C++, Java, assembler, Python, etc., including various algorithms implemented as a combination of data structures, processes, routines, or other programming configurations. Functional aspects may be implemented as algorithms that execute on one or more processors. Furthermore, the present embodiment may employ conventional techniques for electronic configuration, signal processing, and / or data processing. Terms such as "mechanism," "element," "means," and "composition" can be used broadly and are not limited to mechanical or physical structures. These terms can also encompass a series of software routines, such as those associated with a processor.

[0095] The above-described embodiments are merely examples, and other embodiments may be implemented within the scope of the claims set forth below.

Claims

1. In electronic devices, An information acquisition interface for acquiring voltage data of a plurality of battery cells included in a battery pack and balancing data of the plurality of battery cells; Memory that stores one or more instructions; and Contains a processor, The one or more instructions, when executed, cause the processor to: Obtaining the first voltage of each of the plurality of battery cells in a resting state, Based on the balancing data of the plurality of battery cells, a compensation voltage of each of the plurality of battery cells is determined, Based on the first voltage and compensation voltage of each of the plurality of battery cells, a second voltage of each of the plurality of battery cells is determined, Based on the reference voltage and the second voltage of each of the plurality of battery cells, a voltage deviation of each of the plurality of battery cells is determined, For each of the plurality of battery cells, the amount of change in voltage deviation according to a set cycle is determined, Check the pattern of voltage deviation change amount of each of the above multiple battery cells, An electronic device configured to diagnose the status of each of the plurality of battery cells based on a pattern of change in voltage deviation of each of the plurality of battery cells and a preset diagnostic pattern.

2. In paragraph 1, The above balancing data is, Including the SoC section in which cell balancing of each of the plurality of battery cells is performed, the time at which cell balancing is performed for each SoC section, the cell balancing current for each SoC section, and the cell balancing capacity for each SoC section. Electronic devices.

3. In paragraph 1, The above processor, Set to determine the compensation voltage of each of the plurality of battery cells based on the total capacity of the plurality of battery cells, the time at which cell balancing was performed for each SoC section, the cell balancing current for each SoC section, and the amount of change in OCV voltage according to SoC change for each SoC section. Electronic devices.

4. In paragraph 1, The above second voltage is, A voltage that is the first voltage of each of the plurality of battery cells plus the compensation voltage of each of the plurality of battery cells, Electronic devices.

5. In paragraph 1, The above information acquisition interface is, Obtaining the voltage and balancing data of the plurality of battery cells at each predefined cycle, Electronic devices.

6. In paragraph 1, The above preset diagnostic pattern is: Includes the first diagnostic pattern, The one or more instructions, when executed, cause the processor to: If all of the plurality of voltage deviation changes of the first battery cell included in the plurality of battery cells are positive and the sum of the plurality of voltage deviation changes of the first battery cell is equal to or greater than a first threshold value, it is determined that the pattern of the voltage deviation change of the first battery cell corresponds to the first diagnosis pattern, and it is set to diagnose that an internal micro short circuit has occurred in the first battery cell. Electronic devices.

7. In paragraph 1, The above preset diagnostic pattern is: Includes a second diagnostic pattern, The one or more instructions, when executed, cause the processor to: When the voltage deviation change amount of the plurality of second battery cells included in the plurality of battery cells is greater than or equal to the second threshold value, it is determined that the pattern of the voltage deviation change amount of the first battery cell corresponds to the second diagnostic pattern, which is set to diagnose that an internal micro short circuit has occurred in the second battery cell, Electronic devices.

8. In paragraph 1, The above preset diagnostic pattern is: Includes a third diagnostic pattern, The one or more instructions, when executed, cause the processor to: If all of the plurality of voltage deviation changes of the third battery cell included in the plurality of battery cells are positive, and at least one of the plurality of voltage deviation changes of the third battery cell is greater than or equal to a third threshold value, it is determined that the pattern of the voltage deviation change of the third battery cell corresponds to the third diagnostic pattern, which is set to diagnose that an internal micro short circuit has occurred in the third battery cell. Electronic devices.

9. In paragraph 1, The above preset diagnostic pattern is: Includes the fourth diagnostic pattern, The one or more instructions, when executed, cause the processor to: When the plurality of voltage deviation changes of the fourth battery cell included in the plurality of battery cells are all positive and the plurality of voltage deviation changes of the fourth battery cell increase over time, it is determined that the pattern of the voltage deviation change of the fourth battery cell corresponds to the first diagnostic pattern, It is set to diagnose that an internal micro short circuit has occurred in the fourth battery cell. Electronic devices.

10. In paragraph 1, The voltage of the above battery cell is, The OCV voltage according to the SoC change of the plurality of battery cells measured at predefined intervals, Electronic devices.

11. In paragraph 1, The above reference voltage is, One of the average value of the second voltage of each of the plurality of battery cells or the average value or the median value of the second voltage of each of the plurality of battery cells, Electronic devices.

12. In paragraph 1, The above voltage deviation is, The difference between the second voltage of each of the plurality of battery cells and the reference voltage, Electronic devices.

13. In paragraph 1, The above stated cycle is, Corresponding to the charge and discharge cycles of the above plurality of battery cells, Electronic devices.

14. A non-transitory computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 1 to 13 on an electronic device.

15. In a method for diagnosing the status of a battery cell, A step of obtaining a first voltage of each of a plurality of battery cells in a resting state; A step of determining a compensation voltage of each of the plurality of battery cells based on balancing data of the plurality of battery cells; A step of determining a second voltage of each of the plurality of battery cells based on the first voltage and compensation voltage of each of the plurality of battery cells; A step of determining a voltage deviation of each of the plurality of battery cells based on a reference voltage and a second voltage of each of the plurality of battery cells; A step of determining the amount of change in voltage deviation according to a set cycle for each of the plurality of battery cells; A step of checking the pattern of change in voltage deviation of each of the plurality of battery cells; and A step of diagnosing the status of each of the plurality of battery cells based on a pattern of change in voltage deviation of each of the plurality of battery cells and a preset diagnostic pattern, How to diagnose.

Images