Devices and methods for diagnosing battery status

Abstract

An apparatus for diagnosing battery status according to an embodiment of the present disclosure includes: a measurement unit configured to measure the voltage of each of a plurality of batteries; a graph generation unit configured to receive voltage information of the voltage of each of the plurality of batteries measured by the measurement unit, and generate a distribution graph of the voltage of each of the plurality of batteries based on the received voltage information; and a control unit configured to set a reference voltage for the distribution graph based on a preset standard graph for the plurality of batteries, and diagnose the status of each of the plurality of batteries by comparing the measured voltage of each of the plurality of batteries with the set reference voltage.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2020-0134587, filed in Korea on October 16, 2020, the disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to an apparatus and method for diagnosing battery status, and more specifically, to an apparatus and method for diagnosing battery status that can diagnose battery status according to probability. Background Technology

[0003] In recent years, the demand for portable electronic products such as laptops, cameras, and mobile phones has increased dramatically, leading to serious development in electric vehicles, energy storage batteries, robots, and satellites. Therefore, high-performance batteries that allow for repeated charging and discharging are being actively researched.

[0004] Currently available commercial batteries include nickel-cadmium (NiCd), nickel-metal hydride (NiMH), nickel-zinc (NiZn), and lithium-ion batteries. Among them, lithium-ion batteries have attracted much attention because, compared to nickel-based batteries, they have almost no memory effect and also have a very low self-discharge rate and high energy density.

[0005] Even for batteries of the same specifications, variations in electrochemical characteristics can increase due to changes in the manufacturing process and the actual usage environment after shipment. For example, gaps between batteries can cause behavioral deviations during charge and discharge cycles, thus accelerating heat generation and voltage differences in a non-linear manner.

[0006] Traditionally, fixed thresholds or threshold ranges are set and used to diagnose batteries in abnormal conditions. However, this traditional approach has a problem: it fails to reflect battery degradation over time. Furthermore, the complexity of the numerical determination models used to set thresholds or threshold ranges by reflecting battery degradation makes practical implementation difficult. Summary of the Invention

[0007] Technical issues

[0008] This disclosure is designed to address the problems of the prior art, and therefore aims to provide an apparatus and method for diagnosing battery state that can diagnose battery state according to probability.

[0009] These and other objects and advantages of this disclosure will become apparent from the following detailed description and will be fully apparent from exemplary embodiments thereof. Furthermore, it will be readily understood that the objects and advantages of this disclosure can be achieved by the means shown in the appended claims and combinations thereof.

[0010] Technical solutions

[0011] An apparatus for diagnosing battery status according to one aspect of the present disclosure may include: a measuring unit configured to measure the voltage of each of a plurality of batteries; a graph generation unit configured to receive voltage information of the voltage of each of the plurality of batteries measured by the measuring unit, and generate a distribution graph of the voltage of each of the plurality of batteries based on the received voltage information; and a control unit configured to set a reference voltage for the distribution graph based on a preset standard graph for the plurality of batteries, and diagnose the status of each of the plurality of batteries by comparing the measured voltage of each of the plurality of batteries with the set reference voltage.

[0012] The graph generation unit can be configured to generate a distribution graph representing the normal distribution of the voltage of each of the multiple batteries.

[0013] A standard curve can be a graph that shows the distribution of voltage among multiple cells measured under BOL conditions.

[0014] The control unit can be configured to set the reference voltage of the distribution curve to a standard voltage preset for a standard curve.

[0015] The control unit can be configured to set the reference voltage by applying a standard density corresponding to the average voltage from the standard voltage to the standard curve over the entire voltage range of the standard curve to the distribution curve.

[0016] The control unit can be configured to calculate the voltage corresponding to the standard density in the distribution curve based on the average voltage in the distribution curve, and set the calculated voltage as the reference voltage.

[0017] The control unit can be configured to diagnose an abnormal state in a battery among multiple batteries whose measured voltage is less than a reference voltage.

[0018] The control unit can be configured to diagnose the state of a battery among multiple batteries whose measured voltage is equal to or greater than a reference voltage as normal.

[0019] According to another aspect of this disclosure, a battery pack may include means for diagnosing battery status according to another aspect of this disclosure.

[0020] A method for diagnosing battery status according to another aspect of this disclosure may include: a measurement step of measuring the voltage of each of a plurality of batteries; a graph generation step of generating a distribution graph for the voltage of each of the plurality of batteries measured in the measurement step; a reference voltage setting step of setting a reference voltage for the distribution graph based on a standard graph preset for the plurality of batteries; and a status diagnosis step of diagnosing the status of each of the plurality of batteries by comparing the measured voltage of each of the plurality of batteries with the set reference voltage.

[0021] Beneficial effects

[0022] According to one aspect of this disclosure, when considering the BOL (Start of Life) state and current degradation state of multiple batteries, there is an advantage that the state of each of the multiple batteries can be diagnosed.

[0023] The effects of this disclosure are not limited to those described above, and those skilled in the art will clearly understand, based on the appended claims, other effects not mentioned herein. Attached Figure Description

[0024] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are intended to provide a further understanding of the technical features of the present disclosure; therefore, the present disclosure should not be construed as limited to the drawings.

[0025] Figure 1 This is a schematic diagram illustrating an apparatus for diagnosing battery status according to an embodiment of the present disclosure.

[0026] Figure 2 This is a schematic diagram illustrating an example of a distribution curve generated by a device for diagnosing battery state according to an embodiment of the present disclosure.

[0027] Figure 3 This is a schematic diagram illustrating an example of a standard graph according to an embodiment of the present disclosure.

[0028] Figure 4 This is an example schematically illustrating a distribution curve generated by a device for diagnosing battery state according to an embodiment of the present disclosure, and a schematic diagram of a reference voltage set therefrom.

[0029] Figure 5 This is a schematic diagram illustrating an exemplary configuration of a battery pack including a device for diagnosing battery status according to embodiments of this disclosure.

[0030] Figure 6 This is a schematic diagram illustrating a method for diagnosing battery status according to another embodiment of the present disclosure. Detailed Implementation

[0031] It should be understood that the terms used in the specification and appended claims should not be construed as limited to their general or dictionary meaning, but rather are interpreted based on their meanings and concepts corresponding to the technical aspects of this disclosure, on the basis of allowing the inventors to appropriately define the terms for the best interpretation.

[0032] Therefore, the description given herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of this disclosure. It should be understood that other equivalents and modifications may be conceived thereto without departing from the scope of this disclosure.

[0033] Furthermore, in describing this disclosure, detailed descriptions of relevant known elements or functions are omitted here where such descriptions would obscure the key subject matter of the disclosure.

[0034] Terms including ordinal numbers such as “first” and “second” can be used to distinguish one element from another among various elements, and are not intended to limit elements by terms.

[0035] Throughout the specification, when a section is referred to as “comprising” or “including” any element, it means that the section may further include other elements without excluding other elements, unless otherwise expressly stated.

[0036] Furthermore, terms such as "control unit" as described in this specification refer to a unit that processes at least one function or operation, which may be implemented as hardware or software or a combination of hardware and software.

[0037] Furthermore, throughout the specification, when a part is referred to as being "connected" to another part, this is not limited to the case where they are "directly connected," but also includes the case where they are "indirectly connected" when another element is inserted between them.

[0038] Preferred embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings.

[0039] Figure 1 This is a schematic diagram illustrating an apparatus 100 for diagnosing battery status according to an embodiment of the present disclosure.

[0040] refer to Figure 1 The device 100 for diagnosing battery status may include a measurement unit 110, a graph generation unit 120, and a control unit 130.

[0041] The measuring unit 110 can be configured to measure the voltage of each of a plurality of batteries.

[0042] Here, a battery refers to a physically separable, independent unit having a negative terminal and a positive terminal. For example, a pouch-type lithium polymer cell can be considered a battery. Furthermore, a battery can be a battery module in which one or more battery cells are connected in series and / or parallel. For ease of explanation, a battery will be described below as a battery cell.

[0043] Specifically, the measurement unit 110 can measure the voltage of each of the multiple batteries and output voltage information of the measured voltage of each of the multiple batteries.

[0044] The graph generation unit 120 can be configured to receive voltage information of the voltage of each of a plurality of batteries measured by the measurement unit 110.

[0045] For example, the measurement unit 110 and the graph generation unit 120 can be connected to communicate with each other. Therefore, the voltage information output from the measurement unit 110 can be received by the graph generation unit 120.

[0046] Furthermore, the curve generation unit 120 can be configured to generate a voltage distribution curve P1 for each of the multiple batteries based on the received voltage information.

[0047] Here, the distribution curve P1 can be a curve representing the distribution of voltage of each of the multiple batteries. For example, the curve generation unit 120 can be configured to generate a distribution curve P1 representing the normal distribution of voltage of each of the multiple batteries.

[0048] Figure 2 This is a schematic diagram illustrating an example of a distribution curve P1 generated by a device 100 for diagnosing battery state according to an embodiment of the present disclosure.

[0049] For example, refer to Figure 2 The distribution curve P1 can be generated by the curve generation unit 120. Specifically, it can generate a distribution curve P1 based on a normal distribution with an average voltage E1 of 3.0V.

[0050] The control unit 130 can be configured to set the reference voltage V1 of the distribution curve P1 based on a standard curve P2 preset for multiple batteries.

[0051] Preferably, the curve generation unit 120 and the control unit 130 can be connected to communicate with each other. That is, the curve generation unit 120 can output the generated distribution curve P1, and the control unit 130 can receive the distribution curve P1 output from the curve generation unit 120.

[0052] Specifically, the standard curve P2 can be a graph representing the distribution of voltage among multiple batteries measured at BOL (Bearing Open to Life). For example, voltages can be measured when multiple batteries are at BOL, and the standard curve P2 can be pre-generated based on the measured voltages.

[0053] In other words, the standard curve P2 can be a curve representing the normal distribution of the voltage of multiple batteries in the BOL state, and the distribution curve P1 can be a curve representing the normal distribution of the voltage of multiple batteries in the current state.

[0054] Figure 3 This is a schematic diagram illustrating an example of a standard graph P2 according to an embodiment of the present disclosure. For example, refer to... Figure 3 The standard curve P2 can be a curve based on a normal distribution with an average voltage E2 of 3.4V.

[0055] Specifically, the control unit 130 can set the reference voltage V1 in the distribution curve P1 to correspond to the standard voltage V2 in the standard curve P2. That is, the reference voltage V1 can be set not based on a preset lower limit voltage value, but rather to correspond to the standard voltage V2 in the standard curve P2. Therefore, the control unit 130 can set the reference voltage V1 for the current state of the multiple batteries based on the standard curve P2 and the standard voltage V2 reflecting the BOL state of the multiple batteries.

[0056] Figure 4 This is a schematic diagram illustrating an example of a distribution curve P1 generated by a device 100 for diagnosing battery state according to an embodiment of the present disclosure, and a reference voltage V1 set therefrom.

[0057] For example, in Figure 4 In this embodiment, the average voltage E2 of the standard curve P2 can be 3.4V, and the standard voltage V2 can be 3.25V. Furthermore, the average voltage of the distribution curve P1 can be 3.0V, and the reference voltage V1 can be 2.4V.

[0058] Furthermore, the control unit 130 can be configured to diagnose the state of each of the multiple batteries by comparing the measured voltage of each of the multiple batteries with a set reference voltage V1.

[0059] For example, control unit 130 can be configured to diagnose an abnormal state in a battery among multiple batteries whose measured voltage is less than the reference voltage V1. Furthermore, control unit 130 can be configured to diagnose a normal state in a battery among multiple batteries whose measured voltage is equal to or greater than the reference voltage V1.

[0060] For example, in Figure 4 In one embodiment, when the voltage measured by the measuring unit 110 among the multiple batteries is less than 2.4V, the control unit 130 can be configured to diagnose the battery state as abnormal. Conversely, when the voltage measured by the measuring unit 110 among the multiple batteries is equal to or greater than 2.4V, the control unit 130 can be configured to diagnose the battery state as normal.

[0061] In other words, the device 100 for diagnosing battery state according to embodiments of this disclosure can diagnose the battery state not uniformly based on a preset voltage value, but by considering the entirety of the standard curve P2 of the battery in the BOL state and the distribution curve P1 of the battery in the current state. That is, because the device 100 for diagnosing battery state can consider battery degradation to diagnose the state of each of the multiple batteries, it can diagnose the state of each of the multiple batteries more accurately.

[0062] More specifically, a standard curve P2 is generated based on the voltages measured when multiple batteries are in the BOL state, and the standard voltage V2 can be set to detect the voltage of batteries in the BOL state but in an abnormal state. Even if multiple batteries deteriorate, the deterioration of the multiple batteries can follow a normal distribution to correspond to the standard curve P2. Therefore, the device 100 for diagnosing battery state can set a reference voltage V1 for the distribution curve P1 by taking into account the standard voltage V2 of the standard curve P2, and diagnose the state of the batteries based on the set reference voltage V1, thereby diagnosing the state of each of the multiple batteries while taking into account the deterioration of the multiple batteries.

[0063] In another embodiment, the control unit 130 can receive a target voltage from an external source. Here, the target voltage can be a voltage value set for diagnosing the state of multiple batteries in a BOL (Best in Least) state. For example, the batteries can be used in various products such as vehicles, energy storage systems (ESS), and household appliances. To appropriately change the standard voltage V2, which is considered a standard value for diagnosing battery state, according to battery usage, the control unit 130 can set the target voltage to the standard voltage V2 when receiving the target voltage from an external source. Furthermore, the control unit 130 can set a reference voltage V1 in the distribution curve P1 based on the standard voltage V2 set according to the target voltage, and diagnose the battery state based on the set reference voltage V1. That is, because the standard voltage V2 can be appropriately set according to the battery usage environment, there is an advantage that the battery state can be appropriately diagnosed based on the battery usage environment.

[0064] Furthermore, the control unit 130 provided to the device 100 for diagnosing battery status may optionally include application-specific integrated circuits (ASICs), another chipset, logic circuits, registers, communication modems, and data processing devices, etc., known in the art, to execute various control logics disclosed below. Additionally, when the control logic is implemented in software, the control unit 130 can be implemented as a collection of program modules. In this case, the program modules can be stored in memory and executed by the control unit 130. The memory can be located within or outside the control unit 130 and can be connected to the control unit 130 in various known ways.

[0065] Furthermore, the device 100 for diagnosing battery status may also include a storage unit 140. The storage unit 140 may store programs, data, etc., required for diagnosing battery status according to this disclosure. That is, the storage unit 140 may store data necessary for the operation and function of each component of the device 100 for diagnosing battery status, data generated during the execution of operations or functions, etc. There are no particular limitations on the type of storage unit 140, as long as it is a known information storage device capable of recording, erasing, updating, and retrieving data. As examples, the information storage device may include RAM, flash memory, ROM, EEPROM, registers, etc. Furthermore, the storage unit 140 may store program code that defines the processes executable by the control unit 130.

[0066] For example, information about the standard curve P2 and standard voltage V2 of multiple batteries, information about the standard ratio, and the distribution curve P1 can be stored in the storage unit 140. Furthermore, the control unit 130 can access the storage unit 140 to obtain information about the standard curve P2 and standard voltage V2 of multiple batteries, as well as information about the standard ratio.

[0067] Simultaneously, the curve generation unit 120 can generate a distribution curve P1 at a predetermined diagnostic cycle or when a diagnostic command is input. Furthermore, whenever the control unit 130 receives the distribution curve P1 from the curve generation unit 120, the control unit 130 can use the standard curve P2 and the received distribution curve P1 to diagnose the current state of multiple batteries. In other words, the current state of multiple batteries can be diagnosed based on the distribution curve P1 generated at the current time point.

[0068] The control unit 130 can be configured to set the reference voltage V1 of the distribution curve P1 to the standard voltage V2 corresponding to the standard curve P2. Furthermore, the control unit 130 can also be configured to set the calculated voltage as the reference voltage V1.

[0069] Specifically, the control unit 130 can be configured to set the reference voltage V1 by applying the standard density D, which corresponds to the average voltage E2 from the standard voltage V2 to the standard voltage P2 over the entire voltage range of the standard curve P2, to the distribution curve P1.

[0070] exist Figure 4 In one embodiment, the standard density corresponding to the standard voltage V2 to the average voltage E2 across the entire voltage range of the standard curve P2 can be D. The control unit 130 can apply the standard density D to the distribution curve P1.

[0071] Specifically, the control unit 130 can calculate the voltage corresponding to the standard density D in the distribution curve P1 based on the average voltage E1 of the distribution curve P1. Here, the calculated voltage can be the reference voltage V1.

[0072] For example, in Figure 4 In this embodiment, when the standard density D of the standard curve P2 is applied to the distribution curve P1, the voltage corresponding to the standard density D can be calculated as 2.4V based on the average voltage E1 of the distribution curve P1. That is, the standard voltage V2 corresponding to the standard density D in the standard curve P2 can be 3.25V, but the voltage corresponding to the standard density D in the distribution curve P1 can be 2.4V. Furthermore, the control unit 130 can set the calculated voltage 2.4V as the reference voltage V1. Thereafter, the control unit 120 can diagnose batteries with a measured voltage less than 2.4V as abnormal and batteries with a measured voltage equal to or greater than 2.4V as normal.

[0073] For example, multiple batteries may deteriorate depending on usage, and the degree of deterioration may vary among them. Therefore, in Figure 4 In the embodiments, even if the same standard density D is applied to the standard curve P2 and the distribution curve P1, the voltage difference (0.15V) between the average voltage E2 and the standard voltage V2 of the standard curve P2 and the voltage difference (0.6V) between the average voltage E1 and the reference voltage V1 of the distribution curve P1 can be different from each other.

[0074] In other words, the device 100 for diagnosing battery state according to embodiments of this disclosure can calculate the reference voltage V1 by applying the standard density D of the standard curve P2 to the distribution curve P1, and set the reference voltage V1 while taking into account the degradation of multiple batteries. Therefore, the device 100 for diagnosing battery state has the advantage of diagnosing the current state of the battery by comprehensively considering the normal distribution of the battery in the BOL state and the degradation of the battery.

[0075] The device 100 for diagnosing battery state according to this disclosure can be applied to a BMS (Battery Management System). That is, a BMS according to this disclosure may include the aforementioned device 100 for diagnosing battery state. In this configuration, at least some components of the device 100 for diagnosing battery state can be implemented by supplementing or adding functions included in a conventional BMS. For example, the measurement unit 110, graph generation unit 120, control unit 130, and storage unit 140 of the device 100 for diagnosing battery state can be implemented as components of a BMS.

[0076] Furthermore, the device 100 for diagnosing battery status according to this disclosure can be provided to the battery pack 1. For example, the battery pack 1 according to this disclosure may include the device 100 for diagnosing battery status as described above and the battery cell B. In addition, the battery pack 1 may also include electrical equipment (relays, fuses, etc.), a casing, etc.

[0077] Figure 5 This is a schematic diagram illustrating an exemplary configuration of a battery pack including a device 100 for diagnosing battery status according to an embodiment of this disclosure.

[0078] exist Figure 5 In this embodiment, there may be multiple batteries B. The measurement unit 110 can measure the voltage of each of the multiple batteries B, and the graph generation unit 120 can generate a distribution curve P1 based on the voltages of the multiple batteries B measured by the measurement unit 110. The control unit 130 can diagnose the state of each of the batteries B based on the distribution curve P1 generated by the graph generation unit 120 and a preset standard curve P2 for the batteries B.

[0079] Meanwhile, the measuring unit 110 can be connected to the current measuring unit A, which is located on the charging and discharging path of the battery B, to measure the current of the battery B.

[0080] Figure 6 This is a schematic diagram illustrating a method for diagnosing battery status according to another embodiment of the present disclosure.

[0081] Here, each step of the method for diagnosing battery status can be performed by the device 100 for diagnosing battery status. For ease of explanation, content that is repeated above will be omitted or briefly described below.

[0082] refer to Figure 6 The method for diagnosing battery status may include a measurement step (S100), a graph generation step (S200), a reference voltage setting step (S300), and a status diagnosis step (S400).

[0083] The measurement step (S100) is the step of measuring the voltage of each of the multiple batteries, and can be performed by the measurement unit 110.

[0084] The curve generation step (S200) is a step of generating a distribution curve P1 for the voltage of each of the multiple batteries measured in the measurement step (S100), and can be executed by the curve generation unit 120.

[0085] Specifically, the graph generation unit 120 can receive voltage information of the voltage of each of the multiple batteries measured by the measurement unit 110. Furthermore, the graph generation unit 120 can generate a distribution curve P1 for the voltage of each of the multiple batteries based on the received voltage information.

[0086] For example, in Figure 2 In one embodiment, the graph generation unit 120 can generate a distribution curve P1 that follows a normal distribution with an average voltage E1 of 3.0V.

[0087] The reference voltage setting step (S300) is a step of setting the reference voltage V1 of the distribution curve P1 based on the standard curve P2 preset for multiple batteries, and can be executed by the control unit 130.

[0088] For example, in Figure 4 In one embodiment, the control unit 130 can apply the standard density D of the standard curve P2 to the distribution curve P1 to calculate the voltage corresponding to the standard density D in the distribution curve P1 as 2.4V. Furthermore, the control unit 120 can set the reference voltage V1 to the calculated 2.4V.

[0089] The status diagnosis step (S400) is a step of diagnosing the status of each of the multiple batteries by comparing the measured voltage of each of the multiple batteries with a set reference voltage V1, and can be executed by the control unit 130.

[0090] For example, if the measured voltage is less than the reference voltage V1, the control unit 130 can diagnose the battery as being in an abnormal state. Conversely, if the measured voltage is equal to or greater than the reference voltage V1, the control unit 130 can diagnose the battery as being in a normal state.

[0091] Therefore, the method for diagnosing battery status does not uniformly use preset thresholds to determine the status of multiple batteries, but has the following advantages: it diagnoses the current status of each of the multiple batteries based on a standard curve P2 reflecting the BOL status of multiple batteries and a distribution curve P1 reflecting the current status.

[0092] The embodiments of this disclosure described above are not necessarily implemented by apparatus and methods, but may also be implemented by a program for implementing functions corresponding to the configuration of this disclosure, or by a recording medium on which the program is recorded. Based on the description of the above embodiments, those skilled in the art can readily perform such implementations.

[0093] This disclosure has been described in detail. However, it should be understood that while indicating preferred embodiments of this disclosure, the detailed description and specific examples are given by way of example only, as various variations and modifications falling within the scope of this disclosure will become apparent to those skilled in the art based on this detailed description.

[0094] Furthermore, those skilled in the art can make many substitutions, modifications and variations to the above-described concepts without departing from the technical aspects of this disclosure, and this disclosure is not limited to the above embodiments and drawings. Each embodiment may be selectively combined in part or in whole to allow for various modifications.

[0095] (See attached image labels)

[0096] 1: Battery pack

[0097] 100: Device for diagnosing battery status

[0098] 110: Measurement Unit

[0099] 120: Curve Graph Generation Unit

[0100] 130: Control Unit

[0101] 140: Storage unit.

Claims

1.An apparatus for diagnosing a state of a battery, comprising: a measurement unit configured to measure a voltage of each of a plurality of batteries; a profile generation unit configured to receive voltage information of the voltage of each of the plurality of batteries measured by the measurement unit, and generate a profile of a distribution for the voltage of each of the plurality of batteries based on the received voltage information; and a control unit configured to set a reference voltage for the profile of the distribution based on a standard profile preset for the plurality of batteries in a BOL state, and diagnose a state of each of the plurality of batteries by comparing the measured voltage of each of the plurality of batteries with the set reference voltage. 2.The apparatus for diagnosing a state of a battery according to claim 1, wherein, the profile generation unit is configured to generate the profile of the distribution representing a normal distribution of the voltage of each of the plurality of batteries. 3.The apparatus for diagnosing a state of a battery according to claim 1, wherein the standard profile is a profile representing a distribution of the voltage of each of the plurality of batteries measured in the BOL state. 4.The apparatus for diagnosing a state of a battery according to claim 3, wherein, the control unit is configured to set the reference voltage of the profile of the distribution to correspond to a standard voltage preset for the standard profile. 5.The apparatus for diagnosing a state of a battery according to claim 4, wherein the control unit is configured to set the reference voltage by applying a standard density corresponding to the standard voltage to an average voltage of the standard profile to the profile of the distribution over an entire voltage range of the standard profile. 6.The apparatus for diagnosing a state of a battery according to claim 5, wherein the control unit is configured to calculate a voltage corresponding to the standard density in the profile of the distribution based on an average voltage of the profile of the distribution, and set the calculated voltage as the reference voltage. 7.The apparatus for diagnosing a state of a battery according to claim 1, wherein, the control unit is configured to diagnose a state of a battery having a measured voltage less than the reference voltage among the plurality of batteries as an abnormal state. 8.The apparatus for diagnosing a state of a battery according to claim 7, wherein the control unit is configured to diagnose a state of a battery having a measured voltage equal to or greater than the reference voltage among the plurality of batteries as a normal state. 9.A battery pack including the apparatus for diagnosing a state of a battery according to any one of claims 1 to 8. 10.A method for diagnosing a state of a battery, comprising: a measurement step of measuring a voltage of each of a plurality of batteries; a profile generation step of generating a profile of a distribution for the voltage of each of the plurality of batteries measured in the measurement step; a reference voltage setting step of setting a reference voltage for the profile of the distribution based on a standard profile preset for the plurality of batteries in a BOL state; and a diagnosis step of diagnosing a state of each of the plurality of batteries by comparing the measured voltage of each of the plurality of batteries with the set reference voltage. a state diagnosing step of diagnosing a state of each of the plurality of batteries by comparing the measured voltage of each of the plurality of batteries with a set reference voltage.

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