Battery diagnostic apparatus and method of operating same

Abstract

A battery diagnosis apparatus according to an embodiment disclosed in this document may include: an acquisition unit for acquiring open circuit voltage (OCV) data of a battery cell; a calculation unit for calculating, based on the OCV data, an OCV deviation indicating a difference between an average OCV of a plurality of battery cells included in a superior battery cell and an OCV of the plurality of battery cells, and calculating a plurality of OCV deviation change values for at least one time window of the plurality of battery cells; and a configuration unit for configuring a threshold deviation corresponding to the superior battery unit; and a diagnosis unit for diagnosing an abnormality in the superior battery cell based on the plurality of OCV deviation change values of the plurality of battery cells and the threshold deviation.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0023232 filed on February 21, 2023, in the Korean Intellectual Property Office, and Korean Patent Application No. 10-2023-0073410 filed on June 8, 2023, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments disclosed herein relate to battery diagnostic devices and methods of operating the same. Background Art

[0004] Recently, the research and development of secondary batteries are being actively carried out. Here, the secondary batteries as rechargeable / dischargeable batteries can include all conventional nickel (Ni) / cadmium (Cd) batteries, Ni / metal hydride (MH) batteries, etc., and the recent lithium ion batteries. Among the secondary batteries, lithium ion batteries have a much higher energy density than conventional Ni / Cd batteries, Ni / MH batteries, etc. In addition, lithium ion batteries can be made small and lightweight, so that lithium ion batteries have been used as power sources for mobile devices, and recently, their scope of use has been expanded to power sources for electric vehicles, and they have received attention as the next generation of energy storage media.

[0005] In addition, the secondary battery can be used as a battery pack including a battery module in which a plurality of battery cells are connected in series and / or in parallel with each other, or as a battery rack including a plurality of battery modules and a rack frame accommodating the battery modules.

[0006] Battery cells, battery modules, battery packs, or battery racks can be used in a variety of devices. For example, batteries can be used not only in mobile devices such as mobile phones, laptops, smartphones, and tablets, but also in electric vehicles (EVs, HEVs, PHEVs), large-capacity energy storage systems (ESS), and other fields.

[0007] The status and operation of these batteries can be managed and controlled by a battery management system (BMS), which can be included in a device along with the batteries.

[0008] The battery management system can also manage and control the battery while being separated from the device that includes the battery. For example, the battery management system can be implemented as a separate server device. In this case, the battery management system can collect battery data and vehicle data from vehicles, etc., and use the collected data to manage and control the battery. Summary of the Invention

[0009] Technical issues

[0010] When a short circuit or other type of fault occurs inside a battery, the possibility of damage to equipment including the battery (e.g., EV, ESS) increases. Therefore, a solution is needed to reduce the possibility of damage to equipment including the battery by detecting abnormal conditions of the battery.

[0011] Traditionally, battery cell diagnosis has been performed using a comprehensive calculation scheme that utilizes state of charge (SOC), current, capacity, and open-circuit voltage (OCV) information. This diagnostic approach utilizes numerous factors, making diagnosis difficult when specific information is missing. This can be a significant problem in battery management systems implemented using server devices that must collect data from vehicles, and can significantly increase memory usage. Therefore, there is a need to simplify the data required for battery diagnosis.

[0012] According to the embodiments disclosed herein, a battery diagnostic device and an operating method thereof may be provided, by which an abnormality of a battery may be diagnosed using only battery OCV data information.

[0013] The technical problems of the embodiments disclosed herein are not limited to the above-mentioned technical problems, and those skilled in the art will clearly understand other unmentioned technical problems from the following description.

[0014] Technical Solution

[0015] According to an embodiment disclosed herein, a battery diagnostic device includes: an acquisition unit configured to acquire open circuit voltage (OCV) data of a battery cell; a calculation unit configured to calculate an OCV deviation indicating a difference between an average OCV of multiple battery cells included in an upper-level battery cell and the OCV of the multiple battery cells based on the OCV data, and calculate multiple OCV deviation change values ​​of the multiple battery cells within at least one time window; and a diagnosis unit configured to set a threshold deviation corresponding to the upper-level battery cell, and diagnose an abnormality of the upper-level battery cell based on the multiple OCV deviation change values ​​of the multiple battery cells and the threshold deviation.

[0016] The battery diagnostic apparatus according to the embodiment disclosed herein may further include a limiting unit configured to limit a time length of at least one time window to a specified range, wherein the setting unit may be configured to set the threshold deviation based on the specified range.

[0017] In the battery diagnosis apparatus according to the embodiment disclosed herein, the calculation unit may be further configured to limit the time length of the at least one time window to a specified range, and the diagnosis unit may be further configured to set the threshold deviation based on the specified range.

[0018] In the battery diagnostic device according to the embodiment disclosed herein, the diagnostic unit may be further configured to: set the threshold deviation to a first threshold deviation when the specified range is less than or equal to a first time length; and set the threshold deviation to a second threshold deviation greater than the first threshold deviation when the specified range is at least the second time length but not more than a third time length greater than the second time length.

[0019] The battery diagnostic device according to the embodiment disclosed herein may further include an identification unit configured to identify the presence of a low voltage period in the plurality of battery cells based on the OCV deviation of the plurality of battery cells, wherein the diagnostic unit is further configured to set the threshold deviation based on the presence of the low voltage period.

[0020] In the battery diagnostic apparatus of the embodiment disclosed herein, the identification unit may be further configured to identify the presence of the low voltage period when a battery cell having an OCV deviation greater than or equal to a specified value exists among the plurality of battery cells.

[0021] In the battery diagnostic device according to the embodiment disclosed herein, the diagnostic unit may be further configured to, when the presence of the low voltage period is identified, set the threshold deviation to a third threshold deviation; and, when the absence of the low voltage period is identified, set the threshold deviation to a fourth threshold deviation greater than the third threshold deviation.

[0022] In the battery diagnostic apparatus according to the embodiment disclosed herein, the diagnostic unit may be further configured to compare a maximum value among the plurality of OCV deviation change values ​​of the plurality of battery cells with the threshold deviation to diagnose abnormality of the upper-level battery cell.

[0023] In the battery diagnostic apparatus according to the embodiment disclosed herein, the diagnosis unit may be configured to diagnose that the upper-level battery cell is abnormal when the maximum value is greater than or equal to the threshold deviation.

[0024] In the battery diagnostic apparatus according to an embodiment, the calculation unit may be further configured to: extract OCV data within a specified voltage range from the OCV data; and calculate the OCV deviations of the plurality of battery cells based on the extracted OCV data within the specified voltage range.

[0025] According to a battery diagnostic method of an embodiment disclosed herein, the battery diagnostic method includes the following steps: obtaining open circuit voltage (OCV) data of a battery cell; calculating an OCV deviation based on the OCV data, wherein the OCV deviation indicates a difference between an average OCV of a plurality of battery cells included in an upper-level battery cell and the OCV of the plurality of battery cells; calculating a plurality of OCV deviation change values ​​of the plurality of battery cells within at least one time window; setting a threshold deviation corresponding to the upper-level battery cell; and diagnosing an abnormality of the upper-level battery cell based on the plurality of OCV deviation change values ​​of the plurality of battery cells and the threshold deviation.

[0026] The battery diagnosis method according to the embodiment disclosed herein further includes the step of limiting the time length of the at least one time window to a specified range, wherein the step of setting the threshold deviation includes setting the threshold deviation based on the specified range.

[0027] In the battery diagnosis method according to the embodiment disclosed herein, the step of setting the threshold deviation may include: when the specified range is less than or equal to the first time length, setting the threshold deviation to a first threshold deviation; and when the specified range is at least the second time length but not more than a third time length greater than the second time length, setting the threshold deviation to a second threshold deviation greater than the first threshold deviation.

[0028] The battery diagnosis method according to the embodiment disclosed herein includes the following steps: identifying the presence of a low voltage period in the plurality of battery cells based on the OCV deviation of the plurality of battery cells, wherein the step of setting the threshold deviation includes setting the threshold deviation based on the presence of the low voltage period.

[0029] In the battery diagnosis method according to the embodiment disclosed herein, the step of setting the threshold deviation may include: when it is identified that the low voltage period exists, setting the threshold deviation to a third threshold deviation; and when it is identified that the low voltage period does not exist, setting the threshold deviation to a fourth threshold deviation greater than the third threshold deviation.

[0030] In the battery diagnosis method according to the embodiment disclosed herein, the step of diagnosing the abnormality of the upper-level battery cell may include: comparing the maximum value of the multiple OCV deviation change values ​​of the multiple battery cells with the threshold deviation to diagnose the abnormality of the upper-level battery cell.

[0031] Beneficial effects

[0032] According to the embodiments disclosed herein, data used for abnormality diagnosis of a battery can be simplified.

[0033] According to the embodiments disclosed herein, the accuracy of battery abnormality diagnosis can be improved by setting a threshold deviation used in diagnosis according to the time length of a time window calculated based on an OCV deviation change value and / or a low voltage period in the battery.

[0034] Furthermore, various effects directly or indirectly recognized from the present disclosure can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a block diagram of a battery diagnostic apparatus according to an embodiment.

[0036] Figure 2 1 is a diagram for explaining an example of calculation of a determination value by a battery diagnostic device.

[0037] Figure 3 1 is a diagram for explaining an example of calculating an OCV deviation change value in a determination value by a battery diagnosis device.

[0038] Figure 4 1 is a diagram for explaining an example of calculating an OCV deviation change value in a determination value by a battery diagnosis device.

[0039] Figure 5 is an operation flow chart of a battery diagnostic apparatus according to an embodiment.

[0040] Figure 6 is an operation flow chart of a battery diagnostic apparatus according to an embodiment.

[0041] Figure 7 is an operation flow chart of a battery diagnostic apparatus according to an embodiment. DETAILED DESCRIPTION

[0042] Hereinafter, various embodiments of the present disclosure will be disclosed with reference to the accompanying drawings. However, this description is not intended to limit the present disclosure to a specific embodiment, and should be construed as including various modifications, equivalents and / or alternatives according to the embodiments of the present disclosure.

[0043] It should be understood that the various embodiments of this document and the terms used therein are not intended to limit the technical features set forth herein to specific embodiments, and include various changes, equivalents, or replacements of the corresponding embodiments. With respect to the description of the drawings, the same reference numerals may be used to refer to the same or related elements. It should be understood that, unless the relevant context clearly indicates otherwise, the singular form of a noun corresponding to an item may include one or more of the things.

[0044] As used herein, each of phrases such as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B or C,” “at least one of A, B and C,” and “at least one of A, B or C” may include any or all possible combinations of items listed together in the corresponding one of the phrases. Unless otherwise specified, terms such as “first,” “second,” “first,” “second,” “A,” “B,” “(a),” or “(b)” may be used to simply distinguish a corresponding component from another component and do not limit the components in other respects (e.g., importance or order).

[0045] Herein, it should be understood that when an element (e.g., a first element) is referred to as being “connected,” “coupled,” or “linked,” or “coupled to” or “connected to” another element (e.g., a second element), with or without the term “operably” or “communicatively,” this means that the element can be connected to the other element directly (e.g., by wire), wirelessly, or via a third element.

[0046] According to various embodiments, each component (e.g., module or program) of the above-mentioned components may include a single entity or multiple entities, and some of the multiple entities may be individually arranged in different components. According to various embodiments, one or more of the above-mentioned components may be omitted, or one or more other components may be added. Alternatively or additionally, multiple components (e.g., modules or programs) may be integrated into a single component. In this case, according to various embodiments, the integrated component may still perform one or more functions of each of the multiple components in the same or similar manner as performed by the corresponding components in the multiple components before integration. According to various embodiments, the operations performed by a module, program or another component may be performed sequentially, in parallel, repeatedly or heuristically, or one or more of the operations may be performed in a different order or omitted, or one or more other operations may be added.

[0047] Figure 1 is a block diagram of a battery diagnostic apparatus according to an embodiment.

[0048] Reference Figure 1, the upper battery unit 110 may include a plurality of battery cells 111, 112, and 113. According to an embodiment, the upper battery unit 110 may be a battery pack installed inside an electric vehicle to supply power to the electric vehicle, or a battery module included in the battery pack. When the upper battery unit 110 is a battery pack, the plurality of battery cells 111, 112, and 113 may be a plurality of battery modules or a plurality of battery cells. When the upper battery unit 110 is a battery module, the plurality of battery cells 111, 112, and 113 may be a plurality of battery cells.

[0049] According to an embodiment, the battery diagnostic device 120 may diagnose abnormality of the upper-level battery cell 110 based on OCV data obtained from the upper-level battery cell 110 and / or the battery cells 111 , 112 , and / or 113 .

[0050] According to an embodiment, the battery diagnostic device 120 may be integrally formed with the upper-level battery unit 110. In this case, the battery diagnostic device 120 may be included in a battery management system (BMS) of the higher-level battery unit 110.

[0051] According to an embodiment, battery diagnostic apparatus 120 may be formed separately from upper-level battery unit 110. In this case, battery diagnostic apparatus 120 may be implemented using an external server connected to upper-level battery unit 110 and / or battery units 111, 112, and / or 113 via a wireless network.

[0052] According to an embodiment, the battery diagnostic apparatus 120 may include an obtaining unit 121 , a calculating unit 122 , an identifying unit 123 , and / or a diagnosing unit 124 . According to an embodiment, the identifying unit 123 may not be included in the battery diagnostic apparatus 120 .

[0053] According to an embodiment, the obtaining unit 121 may obtain OCV data of the battery cells 111, 112, and / or 113. For example, the obtaining unit 121 may measure the voltage, current, and / or temperature of the battery cells 111, 112, and / or 113, and configure the OCV data based on the measured information. In this case, the obtaining unit 121 may include a sensor for measuring the voltage, current, and / or temperature and a processor for configuring the OCV data based on the measured information. In another example, the obtaining unit 121 may receive the OCV data of the battery cells 111, 112, and / or 113 obtained by the upper-level battery cell 110 or the battery cells 111, 112, and / or 113. In this case, the obtaining unit 121 may include a communication circuit capable of performing wired and / or wireless network communication.

[0054] According to an embodiment, the calculation unit 122 may calculate a determination value (e.g., an OCV deviation and / or an OCV deviation change value) based on the OCV data obtained by the obtaining unit 121. According to an embodiment, the calculation unit 122 may extract OCV data within a specified voltage range (e.g., a voltage range of 3.9 V or greater) from the OCV data. The calculation unit 122 may calculate the determination value based on the extracted OCV data within the specified voltage range.

[0055] In the following, reference will be made to Figures 2 to 4 Various embodiments in which the calculation unit 122 calculates the determination value will be described.

[0056] Figure 2 1 is a diagram for explaining an example of calculation of a determination value by a battery diagnostic device. Figure 3 1 is a diagram for explaining an example of calculating an OCV deviation change value by a battery diagnostic device. Figure 4 1 is a diagram for explaining an example of calculating an OCV deviation change value by a battery diagnostic device.

[0057] Reference Figure 2 , the computing unit 122 may include a first computing unit 210 and a second computing unit 220 .

[0058] According to an embodiment, the obtaining unit 121 may transmit the OCV data OCV1 , OCV2 , and OCV3 of the plurality of battery cells 111 , 112 , and 113 to the first calculating unit 210 .

[0059] According to an embodiment, the first calculation unit 210 may calculate the OCV deviation OCV based on the OCV data OCV1, OCV2, and OCV3. D1 、OCV D2 and OCV D3 , the OCV deviation OCV D1 、OCV D2 and OCV D3 Indicates a difference between an average value between the OCVs of the plurality of battery cells 111, 112, and 113 included in the upper-level battery unit 110 and the OCVs of the plurality of battery cells 111, 112, and 113. For example, the first calculation unit 210 may calculate OCV deviations 310 and 320 of the plurality of battery cells 111, 112, and 113, as shown in FIG. Figure 3 and Figure 4 Graph of the curve.

[0060] According to an embodiment, the first calculation unit 210 may calculate the OCV deviation OCV D1 、OCV D2 and OCV D3 Send to the second computing unit 210.

[0061] According to an embodiment, the second calculation unit 220 may calculate a plurality of OCV deviation values ​​dOCV of the plurality of battery cells 111, 112, and 113 in at least one time window. D1 dOCV D2 and dOCV D3 Here, the OCV deviation value dOCV D1 dOCV D2 and dOCV D3 Each of the OCV deviation values ​​dOCV may correspond to each of the plurality of battery cells 111, 112, and 113. D1 dOCV D2 and dOCV D3 Each of the first OCV deviation values ​​dOCV may include at least one OCV deviation value of each of the plurality of battery cells 111, 112, and 113 in at least one time window. For example, the first OCV deviation value dOCV D1 At least one OCV deviation value in at least one time window of the battery cell 111 may be included.

[0062] Depending on the embodiment, the calculation unit 122 may limit the duration of at least one time window to within a specified range. For example, the calculation unit 122 may limit at least one time window to a first duration or less. In another example, the calculation unit 122 may limit at least one time window to at least a second duration but not more than a third duration, where the third duration is greater than the second duration. Here, the second duration may be greater than the first duration. However, this is merely an example, and the specified range may be set differently.

[0063] According to an embodiment, the second calculation unit 220 may calculate a plurality of OCV deviation change values ​​in at least one time window W1, W2, W3, W4, and W5 limited to a first time length (e.g., 10 days) or shorter, such as Figure 3 As shown. For example, the second calculation unit 220 can calculate at least one OCV deviation change value in at least one time window W1, W2, W3, W4, and W5 based on the OCV deviation 310 data of the battery cell 111. Similarly, the second calculation unit 220 can also calculate at least one OCV deviation change value in at least one time window W1, W2, W3, W4, and W5 based on the OCV deviation 320 data of the other battery cells 112 and 113. Although Figure 3 Five time windows W1 , W2 , W3 , W4 , and W5 are shown in FIG, but this is merely an example, and the number of time windows and the range of the time windows are not limited.

[0064] According to an embodiment, the second calculation unit 220 may calculate a plurality of OCV deviation change values ​​in at least one time window W6, W7, W8, and W9, wherein the time windows W6, W7, W8, and W9 are limited to at least a second time length (e.g., 80 days) but not more than a third time length (e.g., 120 days), wherein the third time length is greater than the second time length, such as Figure 4 As shown. For example, the second calculation unit 220 can calculate at least one deviation change value in at least one time window W6, W7, W8, and W9 based on the OCV deviation 310 data of the battery cell 111. Similarly, the second calculation unit 220 can calculate at least one OCV deviation change value in at least one time window W6, W7, W8, and W9 based on the OCV deviation 320 data of the other battery cells 112 and 113. Although Figure 4 Four time windows W6, W7, W8, and W9 are shown in FIG, but this is merely an example, and the number of time windows and the range of the time windows are not limited.

[0065] According to an embodiment, the second calculation unit 220 may calculate a plurality of OCV deviation values ​​dOCV D1 dOCV D2 and dOCV D3 Sent to the diagnostic unit 124 .

[0066] Return Reference Figure 1 , the recognition unit 123 may recognize the presence of a low voltage period in the plurality of battery cells 111, 112, and 113 based on the OCV deviations of the plurality of battery cells 111, 112, and 113 calculated by the calculation unit 122. For example, when a battery cell having an OCV deviation of a specified value or greater (e.g., 0.015 mV) exists among the plurality of battery cells 111, 112, and 113, the recognition unit 123 may recognize the presence of a low voltage period.

[0067] According to an embodiment, the diagnosis unit 124 may set a threshold deviation corresponding to the upper battery cell 110. More specifically, the diagnosis unit 124 may set a threshold deviation used in abnormality diagnosis of the upper battery cell 110.

[0068] According to an embodiment, the diagnostic unit 124 may set a threshold deviation based on a specified range defined by the calculation unit 122. For example, when the specified range is less than or equal to a first time length, the diagnostic unit 124 may set the threshold deviation to a first threshold deviation. When the specified range is at least a second time length but not more than a third time length (where the third time length is greater than the second time length), the diagnostic unit 124 may set the threshold deviation to a second threshold deviation greater than the first threshold deviation. Thus, the battery diagnostic device 120 may set different threshold deviations for use in diagnosis based on OCV deviation change values ​​calculated based on shorter time windows and OCV deviation change values ​​calculated based on longer time windows (more specifically, setting a larger threshold deviation for longer time windows), thereby improving diagnostic accuracy.

[0069] According to an embodiment, the diagnostic unit 124 may set a threshold deviation based on the presence of a low voltage period in the plurality of battery cells 111, 112, and 113 identified by the identification unit 123. For example, when it is identified that there is a low voltage period, the diagnostic unit 124 may set the threshold deviation to a third threshold deviation. When it is identified that there is no low voltage period, the diagnostic unit 124 may set the threshold deviation to a fourth threshold deviation that is greater than the third threshold deviation. This is because, when there is a low voltage battery cell among the plurality of battery cells 111, 112, and 113, the upper-level battery unit 110 may perform voltage balancing of the plurality of battery cells 111, 112, and 113, thereby increasing the OCV deviation. That is, when there is a low voltage period, the battery diagnostic device 120 can prevent misdiagnosis due to voltage balancing by setting the threshold deviation to a larger value.

[0070] According to an embodiment, the diagnosis unit 124 may set the threshold deviation based on the specified range and the presence of the low voltage period. That is, the diagnosis unit 124 may set the threshold deviation based on both the specified range and the presence of the low voltage period.

[0071] According to an embodiment, when the specified range is less than or equal to the first time length, the diagnostic unit 124 may set the threshold deviation to the fifth threshold deviation or the sixth threshold deviation. The sixth threshold deviation may be greater than the fifth threshold deviation. For example, the diagnostic unit 124 may set the threshold deviation to the fifth threshold deviation when there is a low voltage period, and set the threshold deviation to the sixth threshold deviation when there is no low voltage period.

[0072] According to an embodiment, when the specified range is the second time length or longer and the third time length or shorter, the diagnostic unit 124 may set the threshold deviation to the seventh threshold deviation or the eighth threshold deviation. Here, the sixth and eighth threshold deviations may be greater than the fifth and sixth threshold deviations. The eighth threshold deviation may be greater than the seventh threshold deviation. For example, the diagnostic unit 124 may set the threshold deviation to the seventh threshold deviation when a low voltage period exists, and to the eighth threshold deviation when a low voltage period does not exist.

[0073] According to an embodiment, the diagnostic unit 124 may diagnose an abnormality in the upper-level battery cell 110 based on the multiple OCV deviation change values ​​of the multiple battery cells 111, 112, and 113 calculated by the calculation unit 122 and a set threshold deviation. According to an embodiment, the diagnostic unit 124 may compare the maximum value among the multiple OCV deviation change values ​​with the threshold deviation to diagnose an abnormality in the upper-level battery cell 110. For example, when the maximum value among the multiple OCV deviation change values ​​is greater than or equal to the threshold deviation, the diagnostic unit 124 may diagnose the upper-level battery cell 110 as abnormal.

[0074] The calculation unit 122, the identification unit 123, and the diagnosis unit 124 may be implemented as a single processor or separate processors. Here, the processor may execute software to control at least one other component (e.g., a hardware component or a software component) of the battery diagnostic device 120 connected to the processor, and may process or calculate various data.

[0075] Depending on the embodiment, the battery diagnostic device 120 may transmit the battery diagnostic results to an external source (e.g., a cloud server or a user terminal). Here, the cloud server may provide a service for providing battery diagnostic results to each of a plurality of users. In addition, the user terminal may include a terminal such as a personal computer (PC), a smartphone, etc.

[0076] Figure 5 is an operation flow chart of a battery diagnostic device according to an embodiment. Figure 1 Description Figure 5 To describe Figure 1 The operation of the battery diagnostic device 120.

[0077] Figure 5 The embodiment shown in the may be an example, and the order of operations according to various embodiments of the present disclosure may be different from Figure 5 is different from that shown in Figure 5 Some of the operations shown in , change the order of operations, or combine operations.

[0078] refer to Figure 5In operation 505, the battery diagnostic device 120 may obtain OCV data of the battery cells 111, 112, and / or 113. For example, the battery diagnostic device 120 may measure the voltage, current, and / or temperature of the battery cells 111, 112, and / or 113 and configure the OCV data based on the measured information. In another example, the battery diagnostic device 120 may receive the OCV data of the battery cells 111, 112, and / or 113 obtained by the upper-level battery unit 110 or the battery cells 111, 112, and / or 113.

[0079] In operation 510, the battery diagnostic device 120 may calculate an OCV deviation based on the OCV data obtained in operation 505, the OCV deviation indicating a difference between an average OCV of the plurality of battery cells 111, 112, and 113 included in the upper-level battery unit 110 and the OCVs of the plurality of battery cells 111, 112, and 113. According to an embodiment, the battery diagnostic device 120 may extract OCV data within a specified voltage range (e.g., a voltage range of 3.9V or greater) from the OCV data. The battery diagnostic device 120 may calculate the OCV deviation based on the OCV data extracted within the specified voltage range.

[0080] In operation 515, the battery diagnostic device 120 may calculate a plurality of OCV deviation values ​​for the plurality of battery cells 111, 112, and 113 in at least one time window. Here, each of the OCV deviation values ​​may correspond to each of the plurality of battery cells 111, 112, and 113. Each of the OCV deviation values ​​may include at least one OCV deviation value for each of the plurality of battery cells 111, 112, and 113 in at least one time window.

[0081] In operation 520, the battery diagnostic device 120 may set a threshold deviation corresponding to the upper battery cell 110. More specifically, the battery diagnostic device 120 may set a threshold deviation used in abnormality diagnosis of the upper battery cell 110. Figure 6 and Figure 7 The operation of setting the threshold deviation performed by the battery diagnostic apparatus 120 is described in detail.

[0082] In operation 525, the battery diagnostic device 120 may diagnose an abnormality in the upper-level battery cell 110. According to an embodiment, the battery diagnostic device 120 may diagnose an abnormality in the upper-level battery cell 110 based on the multiple OCV deviation change values ​​of the multiple battery cells 111, 112, and 113 calculated in operation 515 and the threshold deviation set in operation 520. According to an embodiment, the battery diagnostic device 120 may compare the maximum value of the multiple OCV deviation change values ​​with the threshold deviation to diagnose an abnormality in the upper-level battery cell 110. For example, when the maximum value of the multiple OCV deviation change values ​​is greater than or equal to the threshold deviation, the battery diagnostic device 120 may diagnose the upper-level battery cell 110 as abnormal.

[0083] Figure 6 is an operation flow chart of a battery diagnostic device according to an embodiment. Figure 1 Component description Figure 6 To describe Figure 1 The operation of the battery diagnostic device 120.

[0084] Figure 6 The embodiment shown in the may be an example, and the order of operations according to various embodiments of the present disclosure may be different from Figure 6 is different from that shown in Figure 6 Some of the operations shown in , change the order of operations, or combine operations.

[0085] refer to Figure 6 In operation 605, the battery diagnosis device 120 may Figure 5 The time length of at least one time window described in operation 520 is limited to a specified range. For example, the battery diagnostic device 120 may limit the at least one time window to a first time length or less. In another example, the battery diagnostic device 120 may limit the at least one time window to at least a second time length but not more than a third time length, the third time length being greater than the second time length. Here, the second time length may be greater than the first time length. However, this is merely an example, and the specified range may be set differently.

[0086] In operation 610, the battery diagnostic device 120 may set a threshold deviation based on the specified range limited in operation 605. For example, when the specified range is less than or equal to the first time period, the battery diagnostic device 120 may set the threshold deviation to the first threshold deviation. When the specified range is at least the second time period but not more than a third time period that is greater than the second time period, the battery diagnostic device 120 may set the threshold deviation to a second threshold deviation that is greater than the first threshold deviation. Thus, the battery diagnostic device 120 may set different threshold deviations used in diagnosis based on the OCV deviation change value calculated based on a shorter time window and the OCV deviation change value calculated based on a longer time window, thereby improving diagnostic accuracy.

[0087] Figure 7 is an operation flow chart of a battery diagnostic device according to an embodiment. Figure 1 Component description Figure 7 To describe Figure 1 The operation of the battery diagnostic device 120.

[0088] Figure 7 The embodiment shown in the may be an example, and the order of operations according to various embodiments of the present disclosure may be different from Figure 7 is different from that shown in Figure 7 Some of the operations shown in , change the order of operations, or combine operations.

[0089] refer to Figure 7 In operation 705, the battery diagnosis device 120 may identify a low voltage period in the plurality of battery cells 111, 112, and 113. According to an embodiment, the battery diagnosis device 120 may be based on the Figure 5 The battery diagnosis apparatus 120 identifies the presence of a low voltage period in the plurality of battery cells 111, 112, and 113 based on the OCV deviations of the plurality of battery cells 111, 112, and 113 calculated in operation 510. For example, when a battery cell having an OCV deviation of a specified value or greater (e.g., 0.015 mV) exists among the plurality of battery cells 111, 112, and 113, the battery diagnosis apparatus 120 may identify the presence of a low voltage period.

[0090] In operation 710, the battery diagnostic device 120 may set a threshold deviation based on the identification of the presence of a low voltage period in the plurality of battery cells 111, 112, and 113 in operation 705. For example, when the presence of a low voltage period is identified, the battery diagnostic device 120 may set the threshold deviation to a third threshold deviation. When the absence of a low voltage period is identified, the battery diagnostic device 120 may set the threshold deviation to a fourth threshold deviation that is greater than the third threshold deviation. This is because, when a low voltage battery cell is present in the plurality of battery cells 111, 112, and 113, the upper-level battery unit 110 may perform voltage balancing of the plurality of battery cells 111, 112, and 113, thereby increasing the OCV deviation. In other words, when a low voltage period is present, the battery diagnostic device 120 can prevent misdiagnosis due to voltage balancing by setting the threshold deviation to a larger value.

[0091] According to an embodiment, the battery diagnostic apparatus 120 may set the threshold deviation based on the specified range and the existence of the low voltage period. That is, the battery diagnostic apparatus 120 may set the threshold deviation based on both the specified range and the existence of the low voltage period.

[0092] According to an embodiment, when the specified range is less than or equal to the first time length, the battery diagnostic device 120 may set the threshold deviation to the fifth threshold deviation or the sixth threshold deviation. The sixth threshold deviation may be greater than the fifth threshold deviation. For example, the battery diagnostic device 120 may set the threshold deviation to the fifth threshold deviation when a low voltage period occurs, and set the threshold deviation to the sixth threshold deviation when no low voltage period occurs.

[0093] According to an embodiment, when the specified range is the second time length or longer and the third time length or shorter, the battery diagnostic device 120 may set the threshold deviation to the seventh or eighth threshold deviation. Here, the sixth and eighth threshold deviations may be greater than the fifth and sixth threshold deviations. The eighth threshold deviation may be greater than the seventh threshold deviation. For example, the diagnostic unit 120 may set the threshold deviation to the seventh threshold deviation when a low voltage period occurs, and set the threshold deviation to the eighth threshold deviation when a low voltage period does not occur.

[0094] Unless otherwise specified, the terms "including," "consisting of," or "having" as described above may mean that the corresponding components may be inherent and should therefore be interpreted as further including other components rather than excluding other components. Unless otherwise defined, all terms, including technical or scientific terms, have the same meaning as commonly understood by those skilled in the art to which the embodiments disclosed herein belong. Common terms such as terms defined in dictionaries should be interpreted as having the same meaning as the contextual meaning of the relevant technology and should not be interpreted as having an ideal or overly formal meaning unless they are clearly defined herein.

Claims

1. A battery diagnostic device, comprising: an acquisition unit, configured to acquire open circuit voltage (OCV) data of a battery cell; a calculation unit configured to calculate an OCV deviation indicating a difference between an average OCV of a plurality of battery cells included in an upper-level battery unit and the OCVs of the plurality of battery cells based on the OCV data, and calculate a plurality of OCV deviation change values ​​of the plurality of battery cells within at least one time window; and A diagnosis unit is configured to set a threshold deviation corresponding to the upper-level battery cell and diagnose an abnormality of the upper-level battery cell based on the plurality of OCV deviation change values ​​of the plurality of battery cells and the threshold deviation.

2. The battery diagnostic device according to claim 1, wherein: The computing unit is further configured to limit the time length of the at least one time window to a specified range, and The diagnosis unit is further configured to set the threshold deviation based on the specified range.

3. The battery diagnostic device according to claim 2, wherein: The diagnostic unit is further configured to: When the designated range is less than or equal to a first time length, setting the threshold deviation to a first threshold deviation; and When the designated range is at least a second time length greater than the first time length but not more than a third time length greater than the second time length, the threshold deviation is set to a second threshold deviation greater than the first threshold deviation.

4. The battery diagnostic device according to claim 1 , further comprising an identification unit configured to identify the presence of a low voltage period in the plurality of battery cells based on the OCV deviations of the plurality of battery cells. in, The diagnostic unit is further configured to set the threshold deviation based on the presence of the low voltage period.

5. The battery diagnostic device according to claim 4, wherein: The recognition unit is further configured to recognize that the low voltage period exists when a battery cell having an OCV deviation greater than or equal to a specified value exists among the plurality of battery cells.

6. The battery diagnostic device according to claim 4, wherein: The diagnostic unit is further configured to: When the low voltage period is identified, setting the threshold deviation to a third threshold deviation; and When it is recognized that the low voltage period does not exist, the threshold deviation is set to a fourth threshold deviation that is greater than the third threshold deviation.

7. The battery diagnostic device according to claim 1, wherein: The diagnosis unit is further configured to compare a maximum value among the plurality of OCV deviation change values ​​of the plurality of battery cells with the threshold deviation to diagnose abnormality of the upper-level battery cell.

8. The battery diagnostic device according to claim 7, wherein: The diagnosis unit is further configured to diagnose that the upper-level battery cell is abnormal when the maximum value is greater than or equal to the threshold deviation.

9. The battery diagnostic device according to claim 1, wherein: The computing unit is further configured to: extracting OCV data within a specified voltage range from the OCV data; and The OCV deviations of the plurality of battery cells are calculated based on the extracted OCV data within the specified voltage range.

10. A battery diagnosis method, comprising the following steps: Obtain the open circuit voltage (OCV) data of the battery cell; calculating an OCV deviation based on the OCV data, the OCV deviation indicating a difference between an average OCV of a plurality of battery cells included in an upper-level battery cell and the OCVs of the plurality of battery cells; calculating a plurality of OCV deviation change values ​​of the plurality of battery cells within at least one time window; Setting a threshold deviation corresponding to the parent battery cell; and An abnormality of the upper-level battery cell is diagnosed based on the plurality of OCV deviation change values ​​of the plurality of battery cells and the threshold deviation.

11. The battery diagnosis method according to claim 10, further comprising the following steps: limiting the time length of the at least one time window to a specified range, The step of setting the threshold deviation includes setting the threshold deviation based on the specified range.

12. The battery diagnosis method according to claim 11, wherein: The step of setting the threshold deviation comprises: When the designated range is less than or equal to a first time length, setting the threshold deviation to a first threshold deviation; and When the designated range is at least a second time length greater than the first time length but not more than a third time length greater than the second time length, the threshold deviation is set to a second threshold deviation greater than the first threshold deviation.

13. The battery diagnosis method according to claim 10, further comprising the following steps: identifying the presence of a low voltage period in the plurality of battery cells based on the OCV deviations of the plurality of battery cells, The step of setting the threshold deviation includes setting the threshold deviation based on the existence of the low voltage period.

14. The battery diagnosis method according to claim 13, wherein: The step of setting the threshold deviation comprises: When the presence of the low voltage period is identified, setting the threshold deviation to a third threshold deviation; and When it is recognized that the low voltage period does not exist, the threshold deviation is set to a fourth threshold deviation that is greater than the third threshold deviation.

15. The battery diagnosis method according to claim 10, wherein: The step of diagnosing the abnormality of the upper battery cell includes comparing a maximum value among the plurality of OCV deviation change values ​​of the plurality of battery cells with the threshold deviation to diagnose the abnormality of the upper battery cell.

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