Electronic device performing battery cell diagnosis method and control method therefor

Abstract

Disclosed are an electronic device and a control method therefor, the electronic device comprising: an information acquisition interface that acquires voltages of a plurality of battery cells inside a plurality of battery modules included in a battery rack; a memory storing instructions; and a processor connected to the memory, wherein the processor is configured to: estimate SoCs of the plurality of battery cells in an idle state; estimate, on the basis of the SoCs of the plurality of battery cells in the idle state, SoCs of the plurality of battery modules in the idle state; perform first balancing between a plurality of first battery modules to be balanced from among the plurality of battery modules; perform second balancing between a plurality of first battery cells included in the plurality of first battery modules; and diagnose the plurality of first battery cells on which the second balancing has been performed.

Description

Electronic device for performing a method of diagnosing a battery cell and a method of controlling the same

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

[0002] Internal short circuits in battery cells can lead to performance degradation and safety issues, increasing the importance of technologies for early detection of defective battery cells with internal micro-shorts. Recently, with the advancement of battery management systems (BMS) installed in electric vehicles, various research projects are underway to maintain balance among batteries used in electric vehicles, detect internal short circuits early, extend battery life, and reduce potential fire risks.

[0003] The disclosed embodiments aim to provide integrated cell balancing and internal battery diagnostic functions through a method of diagnosing internal micro-short-circuited battery cells based on voltage changes of battery cells after cell balancing of a plurality of battery cells having similar specifications.

[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 according to one embodiment includes an information acquisition interface for acquiring voltages of a plurality of battery cells within a plurality of battery modules included in a battery rack; a memory for storing instructions; and a processor connected to the memory, wherein the processor is configured to estimate SoCs of the plurality of battery cells in an idle state, estimate SoCs of the plurality of battery modules in the idle state based on the SoCs of the plurality of battery cells in the idle state, perform first balancing among a plurality of first battery modules that are targets of balancing among the plurality of battery modules, perform second balancing among a plurality of first battery cells included in the plurality of battery modules, and diagnose the plurality of first battery cells on which the second balancing is performed.

[0006] The above processor may be configured not to perform balancing for a predefined period of time after the second balancing is performed.

[0007] The processor may be configured to measure a voltage change amount of a target battery cell included in the plurality of first battery cells after the predefined time has elapsed, and to diagnose that an internal short circuit has occurred in the target battery cell if the voltage change amount of the target battery cell is greater than or equal to a predefined threshold voltage change amount.

[0008] The processor can determine the predetermined time based on the threshold voltage change amount of the plurality of first battery cells and the voltage change amount of the plurality of first battery cells according to unit time.

[0009] The amount of voltage change of the plurality of first battery cells according to the unit time can be determined based on the internal short-circuit resistance of the plurality of first battery cells.

[0010] The processor determines a reference battery module that serves as a first balancing standard among the plurality of battery modules based on the SoC of the plurality of battery modules,

[0011] A battery module having an SoC higher than the SoC of the reference battery module by a first deviation may be determined as the plurality of first battery modules, and the first balancing may be set to be performed at a first frequency until the difference between the SoC of the plurality of first battery modules and the SoC of the reference battery module becomes within a second deviation.

[0012] The processor may be configured to determine reference battery cells that serve as a basis for second balancing among the battery cells included in each of the plurality of battery modules, determine battery cells having an SoC higher than the SoC of each of the reference battery cells by a third deviation or less as the plurality of first battery cells, and perform the second balancing at a second frequency until the difference between the SoC of each of the plurality of first battery cells and the SoC of the reference battery cells becomes within a fourth deviation.

[0013] The above first frequency may have a value greater than the above second frequency.

[0014] The processor may be configured to estimate the SoC of the plurality of battery modules in the idle state based on an average of the SoCs of the plurality of battery cells in the idle state included in each of the plurality of battery modules in the idle state.

[0015] A method for diagnosing a battery cell performed by an electronic device according to one embodiment comprises: a step of estimating SoCs of the plurality of battery cells in an idle state; a step of estimating SoCs of the plurality of battery modules in an idle state based on the SoCs of the plurality of battery cells in the idle state; a step of performing first balancing among a plurality of first battery modules to be balanced among the plurality of battery modules;

[0016] The method may include: performing a second balancing between a plurality of first battery cells included in the plurality of battery modules; and diagnosing the plurality of first battery cells on which the second balancing has been performed.

[0017] Specific details of other embodiments are included in the detailed description and drawings.

[0018] According to the proposed embodiment, one or more of the following effects can be expected.

[0019] According to an embodiment of the present specification, the SoC between battery modules existing within a battery rack and the SoC between battery cells within a battery module can be maintained equally.

[0020] In addition, according to the embodiment of the present specification, after balancing the battery cells in the battery module, it is possible to diagnose whether there is an internal micro-short circuit defect in the battery cell based only on the voltage change of the battery cell over a certain period of time without a separate additional device.

[0021] 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.

[0022] FIG. 1 illustrates the interlocking relationships of electronic devices performing a method for diagnosing a battery cell according to one embodiment.

[0023] FIG. 2 is a drawing for explaining the relationship between a battery rack, a battery module, and a battery cell according to one embodiment.

[0024] Figure 3 is a block diagram showing the configuration of an electronic device according to one embodiment.

[0025] FIG. 4 is a diagram for explaining the concept of a battery cell diagnosis method according to battery balancing according to one embodiment.

[0026] FIG. 5 is a flowchart illustrating a method for diagnosing a battery cell according to one embodiment.

[0027] The terms used in the embodiments have been selected from widely used, current 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 their meanings and the overall content of the present disclosure.

[0028] When a part of a specification is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0029] 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'.

[0030] The "terminal" mentioned below may be implemented as a computer or portable terminal that can connect to a server or other terminal via a network. Here, the computer includes, for example, a notebook, desktop, laptop, etc. equipped with a web browser, and the portable terminal may include, for example, a wireless communication device that guarantees portability and mobility, and may include all types of handheld-based wireless communication devices such as communication-based terminals such as IMT (International Mobile Telecommunication), CDMA (Code Division Multiple Access), W-CDMA (W-Code Division Multiple Access), LTE (Long Term Evolution), smartphones, tablet PCs, etc.

[0031] 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.

[0032] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0033] FIG. 1 illustrates the interlocking relationships of electronic devices performing a method for diagnosing a battery cell according to one embodiment.

[0034] Referring to FIG. 1, an electronic device (100) may operate in conjunction with a battery management device (200) that manages a battery (300). At this time, the battery (300) may include a battery module in which a plurality of battery cells, which are the smallest battery units that store and release electrical energy through chemical reactions, are assembled to provide a higher voltage and capacity than a single cell, and a battery rack in which a plurality of battery modules are assembled to form a complete battery system. Meanwhile, FIG. 1 only illustrates components related to the present embodiment. Therefore, those skilled 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.

[0035] The electronic device (100) is a device that configures and provides various information. The electronic device (100) can obtain information related to battery cells included in the battery (300). The electronic device (100) can provide a balancing function between battery modules and a balancing function for battery cells within a battery module. Battery balancing can include first balancing, which equalizes charge and discharge capacities between battery modules, and second balancing, which equalizes charge and discharge capacities between individual battery cells within a battery module to ensure optimal performance, lifespan, and safety. The electronic device (100) can provide a passive balancing function to prevent overcharging and overdischarging of battery cells due to changes in the capacity and voltage of battery cells that occur due to differences in manufacturing properties, aging, or operating conditions of battery cells that constitute battery modules included in a battery rack. Passive balancing can correspond to a process of dissipating excess energy as heat by connecting a resistor to each battery cell. In one embodiment, the electronic device (100) may correspond to a server, an analysis device, or a charging device that receives parameters related to a battery (300) from a battery management device (200) present inside a vehicle and instructs the battery management device (200) to perform a method for diagnosing a battery cell according to the present disclosure. The electronic device (100) may receive parameters related to the battery (300) from the battery management device (200) and measure voltages of a plurality of battery cells inside a plurality of battery modules included in the battery (300) in an idle state. The electronic device (100) may be configured to estimate SoCs of the plurality of battery cells in an idle state based on the voltages, determine first battery modules to be the target of first balancing among the plurality of battery modules, and then perform first balancing between the first battery modules through the battery management device (200).The electronic device (100) may be configured to additionally perform a second balancing on a plurality of battery cells within a plurality of battery modules through a battery management device (200) and then diagnose each battery cell. The entire process of performing battery cell diagnosis after performing the first balancing and the second balancing will be described in detail below.

[0036] The battery management device (200) may include one or more information acquisition interfaces for estimating or measuring parameters such as current, voltage, initial SoC, internal resistance, and internal temperature of the battery (300), and may include a memory and a processor (not shown) for various operations. That is, the battery management device (200) operates based on a memory and a processor similar to the electronic device (100), but additionally includes a sensor to measure and calculate the parameters of the battery (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.

[0037] Here, the electronic device (100) and the battery management device (200) may be completely separate and independent entities, but may also 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) according to an embodiment, and may control the balancing between battery modules within the battery rack included in the vehicle's internal battery (300), control the balancing between battery cells within the battery module, and then diagnose whether there is an internal micro-short circuit defect in the battery cells. That is, a single computing device having a control function for a battery 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.

[0038] FIG. 2 is a drawing for explaining the relationship between a battery rack, a battery module, and a battery cell according to one embodiment.

[0039] Referring to FIG. 2, a connection relationship between a battery rack (210), a plurality of battery modules (220), and a plurality of battery cells (230) according to an embodiment can be confirmed. The battery rack (210) according to an embodiment may include a plurality of battery modules (220). In an embodiment, each of the plurality of battery modules (220) included in the battery rack (210) may be connected in series, and each of the plurality of battery cells (230) included in the plurality of battery modules (220) may be connected in series. In other words, the battery (300) examined in FIG. 1 may be hierarchically configured starting from battery cells, which are basic units for storing and releasing electrical energy. The plurality of battery cells (230) may be grouped together to form a plurality of battery modules (220) that provide a higher voltage and capacity than a single battery cell can store and release on its own. A plurality of battery modules (220) can be assembled into a battery rack (210), and the battery rack (210) can serve as a framework that accommodates and configures the plurality of battery modules (220) to provide appropriate electrical connections and structural support. The following description of the battery module (220) is equally applicable to a battery pack formed by connecting a plurality of battery cells.

[0040] The electronic device (100) and the battery management device (200) illustrated in FIG. 1 can communicate with each of the plurality of battery cells (230), monitor the current, voltage, and temperature of the plurality of battery cells (230), and estimate the SoC (status of charge) of the plurality of battery cells (230) and control charging and discharging based on the monitoring results. The electronic device (100) and the battery management device (200) can perform a first balancing function corresponding to a passive balancing method that consumes energy of other battery modules based on a battery module having the lowest SoC among the plurality of battery modules (220) included in the battery rack (210). The electronic device (100) and the battery management device (200) can perform a second balancing function corresponding to a passive balancing method that consumes energy of other battery cells in other identical battery modules based on a battery cell having the lowest SoC among the plurality of battery cells (230) included in each of the plurality of battery modules (220). Thereafter, the electronic device (100) can diagnose whether there is an internal micro-short circuit defect in the battery cell (230) based on the voltage change amount after a predetermined time of the plurality of battery cells (230) in which the second balancing was performed.

[0041] Figure 3 is a block diagram showing the configuration of an electronic device according to one embodiment.

[0042] Referring to FIG. 3, an electronic device (100) according to an embodiment may include an information acquisition interface (101), a memory (102), and a processor (103). The electronic device (100) illustrated in FIG. 3 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. 3.

[0043] An information acquisition interface (101) according to an embodiment can acquire time-series data on the voltages of each of a plurality of battery modules and a plurality of battery cells included in a battery (300). For example, the information acquisition interface (101) can acquire voltage values ​​of each battery module or 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 module or battery cell, the information acquisition interface (101) can also acquire data such as current, temperature, and SOC (State-Of-Charge). When the electronic device (100) that performs a method for diagnosing a battery cell is a battery management system (BMS) of the battery (300), the information acquisition interface (101) can be a component that directly measures the voltage of the battery (300), for example, a voltage sensor. In addition, the information acquisition interface (101) may be a communication interface that receives voltage information measured from a component (e.g., a voltage sensor of the battery (300)) that measures the voltage of the battery pack 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 (103) may analyze time-series data acquired from the information acquisition interface (101) to diagnose the status of each battery cell. Unless there are special circumstances, the processor (103) in the present disclosure may mean a set of one or more processors.

[0044] According to an embodiment, the memory (102) is hardware that stores various data processed within the electronic device (100). The memory (102) is located within the processor (103) of the electronic device (100) and can store data processed and data to be processed through the processor (103). In addition, the memory 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.

[0045] In one embodiment, the processor (103) may control the overall operation of the electronic device (100) and process data and signals. The processor (103) may be composed of at least one hardware unit. In addition, the processor (103) may operate by one or more software modules generated by executing program codes stored in the memory (102). The processor (103) may include the memory (102), and the processor (103) may control the overall operation of the electronic device (100) and process data and signals by executing the program codes stored in the memory (102). That is, the processor (103) according to one embodiment may be configured to estimate SoCs of a plurality of battery cells in an idle state, estimate SoCs of a plurality of battery modules in an idle state based on the SoCs of the plurality of battery cells in an idle state, perform first balancing among a plurality of first battery modules that are targets of balancing among the plurality of battery modules, perform second balancing among a plurality of first battery cells included in the plurality of battery modules, and diagnose a plurality of first battery cells on which the second balancing has been performed, which will be described in detail with reference to FIGS. 4 and 5 below.

[0046] The electronic device (100) according to the above-described embodiments may include a processor, a memory for storing and executing program data, permanent storage such as a disk drive, a communication port for communicating with an external device, a user interface device such as a touch panel, a key, a button, etc. Methods implemented as software modules or algorithms may be stored on a computer-readable recording medium as computer-readable codes or program commands 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 disk, hard disk, etc.) and an optical reading medium (e.g., CD-ROM, DVD: Digital Versatile Disc)). The computer-readable recording medium may be distributed to computer systems connected to a network, so that the computer-readable code 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.

[0047] FIG. 4 is a diagram for explaining the concept of a battery cell diagnosis method according to battery balancing according to one embodiment.

[0048] Referring to FIG. 4, an electronic device (100) according to one embodiment can measure voltages of a plurality of battery cells within a plurality of battery modules included in a battery rack in an idle state in step S410. The electronic device (100) can measure open circuit voltages (OCVs) of a plurality of battery cells included in each of the plurality of battery modules in an idle state.

[0049] In one embodiment, the electronic device (100) may estimate the SoC of a plurality of battery cells in an idle state in step S420, and may estimate the SoC of a plurality of battery modules in an idle state based on the SoC of the plurality of battery cells in the idle state. For example, the electronic device (100) may estimate the SoC of each of the plurality of battery modules in an idle state based on the average of the SoCs of the plurality of battery cells in an idle state included in each of the plurality of battery modules in the idle state.

[0050] According to an embodiment, the electronic device (100) may determine whether first balancing between battery modules is necessary in step S425. Based on this, the electronic device (100) may determine whether to perform first balancing between battery modules. For example, if at least one battery module among the plurality of battery modules has been replaced since the most recent first balancing was performed at the time of determining whether first balancing between battery modules is necessary in step S425, the electronic device (100) may determine that first balancing between battery modules is necessary and determine to perform first balancing between battery modules. For example, if the SoCs of each of the plurality of battery modules differ within a specific deviation and thus the SoCs of the plurality of battery modules are all equal, the electronic device (100) may determine that first balancing between battery modules is not necessary and determine not to perform first balancing between battery modules.

[0051] According to an embodiment, if the electronic device (100) determines to perform the first balancing between battery modules in step S425, the electronic device may determine a balancing reference battery module and first battery modules to be subjected to the first balancing among a plurality of battery modules in step S430. The reference battery module may correspond to a battery module having a minimum SoC among a plurality of battery modules in the battery rack. The first battery modules may correspond to battery modules having an SoC higher than the SoC of the reference battery module by a first deviation. For example, the first deviation may be defined as a % value based on the SoC of the reference battery module. In other words, if the SoC of the reference battery module is a% and the first deviation is b%, the SoC of the first battery module higher than the SoC of the reference battery module by a first deviation that is predefined can be defined as in the following mathematical expression 1.

[0052]

[0053] In other words, the electronic device (100) according to one embodiment may determine a battery module having a high SoC that exceeds the SoC of a reference battery module and is within a first deviation of the SoC of the reference battery module as the first battery module. For example, based on mathematical expression 1, if the SoC of the battery module having the minimum SoC among the plurality of battery modules is 80% and the first deviation is 10%, the electronic device (100) may determine battery modules having an SoC of 80% or more and 88% or less among the plurality of battery modules in the battery rack as the first battery modules.

[0054] According to an embodiment, the electronic device (100) may perform a first balancing between the first battery modules in step S430. In this case, the first balancing may include the entire process of reducing the SoC of the first battery module through manual balancing of all the plurality of battery cells included in the first battery module. According to an embodiment, the electronic device (100) may perform the first balancing between the battery modules at a first frequency in step S540 until the SoC difference between the reference battery module and the first battery modules becomes within a second deviation. For example, the second deviation may correspond to a value smaller than the first deviation. The second deviation may be defined as a % value based on the SoC of the reference battery module. In other words, if the SoC of the reference battery module is a% and the second deviation is c%, the SoC of the first battery module after the balancing, which serves as a criterion for terminating the first balancing, may be defined as in the following mathematical expression 2.

[0055]

[0056] For example, as previously discussed, if the first-first deviation is 10%, the electronic device (100) may determine battery modules having an SoC of 80% or more and 88% or less among the plurality of battery modules in the battery rack as the first battery modules. If the second deviation, which is a condition for terminating the first balancing, is 5%, the electronic device (100) may perform manual balancing for all of the plurality of battery cells included in the first battery module until the SoC difference between the first battery module and the reference battery module becomes within the second deviation. For example, assuming that there is a battery module among the first battery modules whose SoC is 85% before performing the first balancing, the SoC within the second deviation corresponds to an SoC of 80% or more and 84% or less, so the electronic device (100) can perform the first balancing until the SoC of the battery module whose SoC is 85% before performing the first balancing becomes 84%, and can terminate the first balancing when all the first battery modules satisfy the condition. In this case, the first frequency can be defined as the number of times the first balancing is performed over time.

[0057] According to an embodiment, the electronic device (100) may determine whether a second balancing is required between battery cells within a battery module in step S435. Based on this, the electronic device (100) may determine whether to perform a first balancing between battery cells within the battery module. For example, the electronic device (100) may determine that it is necessary to compensate for natural SoC deviations between battery cells that occur due to manufacturing property differences, aging, or operating conditions of battery cells within the battery module after performing the first balancing, and may thus determine to perform a second balancing between battery cells. For example, if the electronic device (100) determines that the SoCs of each of a plurality of battery cells differ within a specific deviation and thus the SoCs of the battery cells within the plurality of battery modules are all equal, the electronic device (100) may determine that a second balancing between battery cells is not required, and may thus determine not to perform the second balancing between battery cells.

[0058] In an embodiment, when the electronic device (100) determines to perform the second balancing in step S435, the electronic device (100) may determine a reference battery cell and first battery cells to be subject to the second balancing among the battery cells of each of the plurality of battery modules in step S440. The reference battery cell may correspond to a battery cell having a minimum SoC among the plurality of battery cells in the battery module. The first battery cells may correspond to battery cells having an SoC higher than the SoC of the reference battery cell by a third deviation. For example, when the SoC of the battery cell having the minimum SoC among a specific battery module is 90% and the third deviation is 5%, the electronic device (100) may determine battery cells having an SoC of 90% or more and 94.5% or less among the plurality of battery cells in the battery module as the first battery cells.

[0059] According to an embodiment, the electronic device (100) may perform second balancing between battery cells at a second frequency until the SoC difference between the reference battery cell and the first battery cells becomes within a fourth deviation in step S440. For example, the fourth deviation may correspond to a value smaller than the third deviation. For example, as discussed above, when the third deviation is 5%, the electronic device (100) may determine battery cells having an SoC of 90% or more and 94.5% or less among the plurality of battery cells in the battery module as first battery cells. When the fourth deviation, which is a condition for terminating the second balancing, is 1%, the electronic device (100) may perform manual balancing targeting the first battery cell among the plurality of battery cells included in the battery module. For example, assuming that there is a battery module among the first battery cells whose SoC is 92% before performing the second balancing, since the SoC within the fourth deviation corresponds to an SoC of 90% or more and 90.9% or less, the electronic device (100) can perform the second balancing until the SoC of the battery cell whose SoC is 92% before performing the second balancing becomes 90.9%, and can terminate the second balancing when all the first battery cells satisfy the condition. In this case, the second frequency can be defined as the number of times the second balancing is performed over time. As confirmed throughout steps S430 to S440, the electronic device (100) can sequentially perform the first balancing corresponding to balancing between battery modules and the second balancing corresponding to balancing between battery cells within the battery module. In this case, the first deviation in the first balancing and the third deviation in the second balancing may be different from each other, and the second deviation in the first balancing and the fourth deviation in the second balancing may be different from each other. The electronic device (100) according to one embodiment may perform the first balancing between battery modules more frequently than the second balancing between battery cells within the battery module, taking into account the replacement cycle of the battery modules.That is, the electronic device (100) according to one embodiment can perform the first balancing and the second balancing by making the first frequency for performing the first balancing have a value greater than the second frequency for performing the second balancing.

[0060] According to an embodiment, the electronic device (100) may perform battery cell diagnosis on the first battery cell for which the second balancing was performed in step S450. For example, the electronic device (100) may not perform balancing for a predetermined period of time after the second balancing is performed. For example, the electronic device (100) may perform balancing between battery cells for a predetermined period of time or may leave the battery cells unattended so that the capacity of the battery cells is not consumed by use of the battery cells. After the predetermined period of time has elapsed, the electronic device (100) may measure the voltage change amount of a target battery cell included in the plurality of first battery cells, and if the voltage change amount of the target battery cell is greater than or equal to a predetermined threshold voltage change amount, it may diagnose that an internal short circuit has occurred in the target battery cell. The electronic device (100) measures the voltage change amount of a target battery cell included in a plurality of first battery cells after a predefined period of time has elapsed, and if the voltage change amount of the target battery cell is less than a predefined threshold voltage change amount, it can be diagnosed that no internal short circuit has occurred in the target battery cell. For example, if an internal micro-short circuit occurs in a battery cell, an internal short circuit resistance of the battery cell occurs, and the internal short circuit resistance can be determined, for example, as in Mathematical Expression 3 below.

[0061]

[0062] In mathematical expression 3, R represents the internal short-circuit resistance, dV represents the voltage change amount of the battery cell over a unit time due to the internal short-circuit of the battery cell, dC represents the leakage capacity over a unit time due to the internal short-circuit of the battery cell, and T represents the duration of the internal short-circuit of the battery cell. In other words, the voltage change amount of the battery cell over a unit time can be determined based on the internal short-circuit resistance of the plurality of first battery cells.

[0063] For example, the leakage capacity due to an internal short circuit of a battery cell can be determined as shown in the following mathematical expression 4.

[0064]

[0065] R in Equation 4 ISC corresponds to the internal short-circuit resistance, and V nominal is the nominal voltage of the battery cell, Capacity ISC may represent the leakage capacity due to the internal short circuit of the battery cell, and t may represent the duration of the internal short circuit of the battery cell. That is, the electronic device (100) can confirm the leakage capacity due to the internal short circuit of the battery cell when the nominal voltage, internal short circuit resistance, and internal short circuit duration of the battery cell are confirmed, and can determine a predefined time satisfying a specific leakage capacity due to the internal short circuit based on the above mathematical expression 4 and confirm the voltage change amount of the corresponding battery cell.

[0066] For example, if an internal micro-short circuit occurs in a battery cell and an internal short circuit resistance of 1 kΩ occurs in the battery cell, the voltage of 0.22 mV may decrease due to the internal short circuit in a day (24 h), and the voltage change amount of the battery cell per 24 hours may occur by 0.22 mV, and a threshold voltage change amount of 11 mV may need to be checked to diagnose the internal short circuit of the battery cell. The electronic device (100) according to one embodiment may determine a predefined time of about 50 days, and if the voltage change amount of a specific battery cell measured at a time point of 50 predefined times after the second balancing is performed is 11 mV or more, it may be diagnosed that an internal short circuit has occurred in the specific battery cell. The electronic device (100) according to one embodiment may diagnose whether an internal short circuit has occurred in the battery cell based on an average value of a difference between the voltage after the second balancing is performed on a plurality of battery cells on which the second balancing is performed and the voltage at a time point after the predefined time has elapsed. For example, if the difference between the voltage of a specific battery cell after the second balancing is performed and the voltage at a point in time when a predetermined time has elapsed is greater than a threshold value compared to the average value of the differences between the voltages of multiple battery cells after the second balancing is performed and the voltages at a point in time when a predetermined time has elapsed, the electronic device (100) may diagnose that an internal short circuit has occurred in the specific battery cell. In this way, the electronic device (100) may diagnose a specific battery cell in which a large voltage decrease has occurred compared to other battery cells during the same time as a battery cell in which an internal micro-short circuit has occurred, based on the assumption that the voltage change amount in a situation in which the battery is left for the same predetermined time without charging or discharging is similar, based on the fact that battery cells within the same battery module have similar physical properties.

[0067] FIG. 5 is a flowchart illustrating a method for diagnosing a battery cell according to one embodiment.

[0068] Referring to FIG. 5, an electronic device (100) according to one embodiment can measure the voltage of a plurality of battery cells inside a plurality of battery modules included in a battery rack in a resting state in step S510.

[0069] According to an embodiment, the electronic device (100) may estimate the SoC of a plurality of battery cells in an idle state in step S520, and may estimate the SoC of a plurality of battery modules in an idle state based on the SoC of the plurality of battery cells in an idle state. As described above, the electronic device (100) may estimate the SoC of each of the plurality of battery modules in an idle state based on the average of the SoCs of the plurality of battery cells in an idle state included in each of the plurality of battery modules in an idle state.

[0070] According to an embodiment, the electronic device (100) may perform first balancing among a plurality of first battery modules to be balanced among a plurality of battery modules in step S530. For example, if at least one battery module among the plurality of battery modules is replaced after the first balancing among the battery modules has been previously performed as described above, the electronic device (100) may perform the first balancing among the battery modules, determine a reference battery module corresponding to a battery module having a minimum SoC among the plurality of battery modules in the battery rack, and perform the first balancing at a first frequency until the SoC of the first battery modules corresponding to battery modules having an SoC higher than the SoC of the reference battery module by a first deviation or less becomes higher than the SoC of the reference battery module by a second deviation or less.

[0071] An electronic device (100) according to an embodiment may perform second balancing between a plurality of first battery cells included in a plurality of battery modules in step S540. The electronic device (100) according to an embodiment may perform second balancing between a plurality of first battery cells within a first battery module in which the first balancing has been performed, and may also perform second balancing between a plurality of first battery cells included in a battery module other than the first battery module in which the first balancing has been performed among the plurality of battery modules. For example, the electronic device (100) may perform second balancing between battery cells within a battery module to compensate for natural SoC deviations between battery cells as described above, determine reference battery cells corresponding to a battery module having a minimum SoC among a plurality of battery cells within each battery module, and perform second balancing at a second frequency until the SoC of the first battery cells corresponding to battery cells having a SoC higher than the SoC of the reference battery cell within a third deviation becomes higher than the SoC of the reference battery module within a fourth deviation. The electronic device (100) may perform the first balancing and the second balancing by making the second frequency at which the second balancing is performed lower than the first frequency at which the first balancing is performed.

[0072] According to an embodiment, the electronic device (100) may diagnose a plurality of first battery cells on which second balancing has been performed in step S540. For example, after the second balancing has been performed, the electronic device (100) may not perform both the first balancing and the second balancing for a predetermined period of time, and may monitor a voltage deviation between a normal battery cell and a battery cell in which an internal short circuit has occurred to diagnose whether an internal short circuit has occurred in the battery cell. The electronic device (100) may measure a voltage change amount of a target battery cell included in the plurality of first battery cells, and if the voltage change amount of the target battery cell is greater than or equal to a predetermined threshold voltage change amount, it may diagnose that an internal short circuit has occurred in the target battery cell. The electronic device (100) may determine a predetermined time based on the threshold voltage change amount of the plurality of first battery cells and the voltage change amount of the plurality of first battery cells according to a unit time. The voltage change amount of the plurality of first battery cells according to a unit time may be determined based on the internal short circuit resistance of the plurality of first battery cells.

[0073] 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.

[0074] 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.

[0075] 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 voltages of multiple battery cells within multiple battery modules included in a battery rack; memory for storing instructions; and comprising a processor connected to the above memory, The above processor, Estimate the SoC of the plurality of battery cells in the resting state, Based on the SoC of the plurality of battery cells in the resting state, the SoC of the plurality of battery modules in the resting state is estimated, Performing first balancing between a plurality of first battery modules that are the target of balancing among the plurality of battery modules, Performing a second balancing between a plurality of first battery cells included in the plurality of battery modules, Set to diagnose the plurality of first battery cells on which the second balancing has been performed, Electronic devices.

2. In paragraph 1, The above processor, After the above second balancing is performed, balancing is set not to be performed for a predefined period of time. Electronic devices.

3. In paragraph 2, The above processor, After the above-described time has elapsed, the voltage change amount of the target battery cell included in the plurality of first battery cells is measured, If the voltage change amount of the target battery cell is greater than or equal to a predefined threshold voltage change amount, it is set to diagnose that an internal short circuit has occurred in the target battery cell. Electronic devices.

4. In paragraph 2, The above processor, Based on the threshold voltage change amount of the plurality of first battery cells and the voltage change amount of the plurality of first battery cells according to unit time, the predetermined time is determined. Electronic devices.

5. In paragraph 3, The voltage change amount of the plurality of first battery cells according to the unit time is, Determined based on the internal short-circuit resistance of the plurality of first battery cells, Electronic devices.

6. In paragraph 1, The above processor, Based on the SoC of the plurality of battery modules, a reference battery module that serves as a first balancing standard among the plurality of battery modules is determined, A battery module having an SoC higher than the SoC of the above-mentioned reference battery module by a first deviation is determined as the plurality of first battery modules, An electronic device configured to perform the first balancing at a first frequency until the difference between the SoC of the plurality of first battery modules and the SoC of the reference battery module becomes within a second deviation.

7. In paragraph 6, The above processor, Determine each of the reference battery cells that serve as the basis for the second balancing among the battery cells included in each of the plurality of battery modules, Battery cells having an SoC higher than the SoC of each of the above reference battery cells by a third deviation are determined as the plurality of first battery cells, The second balancing is set to be performed at a second frequency until the difference between the SoC of each of the plurality of first battery cells and the SoC of the reference battery cells becomes within a fourth deviation. Electronic devices.

8. In paragraph 7, The above first frequency is, having a value greater than the second frequency, Electronic devices.

9. In paragraph 1, The above processor, Set to estimate the SoC of the plurality of battery modules in the resting state based on the average of the SoC of the plurality of battery cells included in each of the plurality of battery modules in the resting state, Electronic devices.

10. A non-transitory computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 1 to 9 on an electronic device.

11. In a method for diagnosing a battery cell performed by an electronic device, A step of estimating the SoC of the plurality of battery cells in a resting state; A step of estimating the SoC of the plurality of battery modules in the resting state based on the SoC of the plurality of battery cells in the resting state; A step of performing first balancing between a plurality of first battery modules to be balanced among the plurality of battery modules; A step of performing a second balancing between a plurality of first battery cells included in the plurality of battery modules; and A step of diagnosing the plurality of first battery cells on which the second balancing has been performed, How to diagnose battery cells.

Images