Battery management device and operating method thereof

Abstract

A battery management device according to an embodiment disclosed in the present document comprises: an interface that acquires a plurality of first voltage profiles respectively indicating changes in the voltages of a plurality of battery cells over time; and a processor that divides the first voltage profiles into a plurality of time sections so as to generate a second voltage profile of each of the plurality of battery cells on the basis of an average change in the respective voltages of the plurality of battery cells that corresponds to each of the plurality of time sections, and calculates, on the basis of the second voltage profile, a first voltage parameter related to a deviation in a second voltage profile value between adjacent time sections from among the plurality of time sections and a second voltage parameter related to a deviation in the second voltage profile value in the same time section from among the plurality of time sections so as to detect whether the plurality of battery cells are abnormal.

Description

Battery management device and its operating method

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2024-0057663, filed April 30, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] One embodiment disclosed in this document relates to a battery management device and a method of operating the same.

[0005] Recently, active research and development has been conducted on secondary batteries. The term "secondary battery" refers to a rechargeable battery, encompassing both conventional Ni / Cd and Ni / MH batteries, as well as more recent lithium-ion batteries. Among secondary batteries, lithium-ion batteries boast a significantly higher energy density than conventional Ni / Cd and Ni / MH batteries. Furthermore, lithium-ion batteries can be manufactured in a compact and lightweight form, making them a popular power source for mobile devices. Recently, their use has expanded to include power sources for electric vehicles, drawing attention as a next-generation energy storage medium.

[0006] Secondary batteries gradually deteriorate through repeated charging and discharging, but accurately predicting and detecting deterioration or defects in secondary batteries remains challenging. To predict abnormal behavior in secondary batteries, methods are used to predict battery characteristics based on the open circuit voltage (OCV) at rest. However, accurately detecting the cause of abnormal behavior in secondary batteries based on the open circuit voltage at rest remains challenging.

[0007] One purpose of the embodiments disclosed in this document is to provide a battery management device and an operating method thereof that diagnose the cause of abnormal behavior of a battery cell based on an open circuit voltage profile of the battery cell in an idle state.

[0008] The technical problems of the embodiments disclosed in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0009] According to an embodiment disclosed in the present document, a battery management device may include an interface for obtaining a plurality of first voltage profiles representing changes in voltage of each of a plurality of battery cells over time; and a processor for dividing the first voltage profiles into a plurality of time periods, generating a second voltage profile of each of the plurality of battery cells based on an average change amount in voltage of each of the plurality of battery cells corresponding to each of the plurality of time periods, and calculating a first voltage parameter related to a deviation of a value of the second voltage profile between adjacent time periods among the plurality of time periods and a second voltage parameter related to a deviation of a value of the second voltage profile in the same time period among the plurality of time periods based on the second voltage profile, thereby detecting whether the plurality of battery cells are abnormal.

[0010] According to one embodiment, the processor may calculate a first sub-voltage parameter representing a deviation of the second voltage profile value in adjacent time intervals among the plurality of time intervals, calculate a second sub-voltage parameter representing a deviation between average values ​​of the plurality of second voltage profile values ​​in the adjacent time intervals, and calculate the first voltage parameter representing a deviation between amplified values ​​of each of the first sub-voltage parameter and the second sub-voltage parameter.

[0011] According to one embodiment, the processor may detect an abnormality in the battery cell based on a comparison result between a product of the first voltage parameter and the second voltage profile value and a preset first reference value, and may detect that the battery cell is abnormal if the product of the first voltage parameter and the second voltage profile value is greater than the first reference value.

[0012] According to one embodiment, the processor may obtain a third sub-voltage parameter corresponding to an nth largest value (n is an integer greater than or equal to 2) among the plurality of second voltage profile values ​​in each of the plurality of time periods, obtain a fourth sub-voltage parameter corresponding to a minimum value among the plurality of second voltage profile values ​​in each of the plurality of time periods, and calculate the second voltage parameter representing a ratio between a difference value between the second voltage profile value and the fourth sub-voltage parameter to a difference value between the third sub-voltage parameter and the fourth sub-voltage parameter.

[0013] According to one embodiment, the second voltage parameter can be calculated based on the following mathematical formula.

[0014] [Mathematical formula]

[0015]

[0016] (Here, corresponds to the second voltage profile value in the time interval T, corresponds to the fourth sub-voltage parameter in the time interval T, corresponds to the third sub-voltage parameter in the time interval T, corresponds to a preset threshold value.)

[0017] According to one embodiment, the processor may detect an abnormality in the battery cell based on a comparison result between the second voltage parameter and a preset second reference value, and may detect that the battery cell is abnormal if the second voltage parameter is greater than the second reference value.

[0018] In one embodiment, the second voltage profile may represent a deviation between average changes in voltage of each of the plurality of battery cells in adjacent time periods among the plurality of time periods.

[0019] An operating method of a battery management device according to an embodiment disclosed in the present document may include the steps of: obtaining a plurality of first voltage profiles representing changes in voltage of each of a plurality of battery cells over time; dividing the first voltage profiles into a plurality of time sections; generating a second voltage profile of each of the plurality of battery cells based on an average change amount of voltage of each of the plurality of battery cells corresponding to each of the plurality of time sections; calculating a first voltage parameter related to a deviation of a value of the second voltage profile between adjacent time sections among the plurality of time sections based on the second voltage profile; calculating a second voltage parameter related to a deviation of a value of the second voltage profile in a same time section among the plurality of time sections; and detecting whether the plurality of battery cells are abnormal based on the first voltage parameter and the second voltage parameter.

[0020] In one embodiment, the second voltage profile may represent a deviation between average changes in voltage of each of the plurality of battery cells in adjacent time periods among the plurality of time periods.

[0021] According to one embodiment, the step of calculating the first voltage parameter may include the step of calculating a first sub-voltage parameter representing a deviation of the second voltage profile value in adjacent time intervals among the plurality of time intervals; the step of calculating a second sub-voltage parameter representing a deviation between average values ​​of the plurality of second voltage profile values ​​in the adjacent time intervals; and the step of calculating the first voltage parameter representing a deviation between amplified values ​​of each of the first sub-voltage parameter and the second sub-voltage parameter.

[0022] According to one embodiment, the step of detecting whether the battery cell is abnormal may include the step of multiplying the first voltage parameter and the second voltage profile value; and the step of detecting the abnormality of the battery cell based on a comparison result between a product of the first voltage parameter and the second voltage profile value and a preset first reference value.

[0023] According to one embodiment, the step of calculating the second voltage parameter may include: obtaining a third sub-voltage parameter corresponding to an nth largest value (n is an integer greater than or equal to 2) among the plurality of second voltage profile values ​​in each of the plurality of time periods; obtaining a fourth sub-voltage parameter corresponding to a minimum value among the plurality of second voltage profile values ​​in each of the plurality of time periods; and calculating the second voltage parameter representing a ratio between a difference value between the second voltage profile value and the fourth sub-voltage parameter to a difference value between the third sub-voltage parameter and the fourth sub-voltage parameter.

[0024] According to one embodiment, the second voltage parameter can be calculated based on the following mathematical formula.

[0025] [Mathematical formula]

[0026]

[0027] (Here, corresponds to the second voltage profile value in the time interval T, corresponds to the fourth sub-voltage parameter in the time interval T, corresponds to the third sub-voltage parameter in the time interval T, corresponds to a preset threshold value.)

[0028] According to one embodiment, the step of detecting an abnormality in the battery cell may include the step of detecting an abnormality in the battery cell based on a comparison result between the second voltage parameter and a preset second reference value.

[0029] A battery management device according to an embodiment disclosed in this document can effectively detect a tab disconnection of a battery cell.

[0030] The effects according to the embodiments disclosed in this document are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art according to the disclosure of this document.

[0031] FIG. 1 is a drawing for explaining a battery pack according to one embodiment disclosed in this document.

[0032] FIG. 2 is a drawing for explaining a battery management device according to an embodiment disclosed in this document.

[0033] FIG. 3 is a drawing for explaining a first voltage profile according to an embodiment disclosed in this document.

[0034] FIG. 4 is a diagram illustrating a process for generating a second voltage profile according to an embodiment disclosed in this document.

[0035] FIG. 5 is a drawing for explaining a second voltage profile according to an embodiment disclosed in this document.

[0036] FIG. 6 is a flowchart illustrating the operation of a battery management device according to an embodiment disclosed in this document.

[0037] FIG. 7 is a diagram illustrating a computing system equipped with a battery management device according to an embodiment disclosed in this document.

[0038] Hereinafter, embodiments disclosed in this document will be described in detail with reference to exemplary drawings. When designating components in each drawing, it should be noted that, where possible, identical components are given identical reference numerals, even if they appear in different drawings. Furthermore, when describing embodiments disclosed in this document, detailed descriptions of related known structures or functions will be omitted if they are deemed to hinder understanding of the embodiments disclosed in this document.

[0039] In describing the components of the embodiments disclosed in this document, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components and do not limit the nature, order, or sequence of the components. In addition, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments disclosed in this document belong. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this application.

[0040] FIG. 1 is a drawing for explaining a battery pack according to an embodiment disclosed in this document, and FIG. 2 is a drawing for explaining a battery management device according to an embodiment disclosed in this document.

[0041] First, referring to FIG. 1, a battery pack (1) may include a battery unit (10) and a battery management device (100).

[0042] The battery unit (10) may include a plurality of battery cells (11, 12, 13, 14). In FIG. 1, the battery unit (10) is illustrated as including four battery cells, but is not limited thereto, and the battery unit (10) may be configured to include n battery cells (n is a natural number greater than or equal to 2).

[0043] The plurality of battery cells (11, 12, 13, 14) may be, but are not limited to, lithium ion (Li-ion) batteries, lithium ion polymer (Li-ion Polymer) batteries, nickel cadmium (Ni-Cd) batteries, nickel metal hydride (Ni-MH) batteries, etc., respectively. In addition, although the battery pack (1) in FIG. 1 is illustrated as including one battery unit (10), the battery pack (1000) may be configured to include n (n is a natural number greater than or equal to 2) battery units according to an embodiment. According to one embodiment, the battery unit (10) may be implemented as, but is not limited to, a battery module, a battery pack, and / or a battery rack.

[0044] The battery unit (10) may be configured to be included in the battery pack (1) and supply power to a target device (not shown). For this purpose, the battery pack (1) may be electrically connected to the target device. Here, the target device may include any electrical, electronic, or mechanical device that operates by receiving power from the battery pack (1). For example, the target device may be, but is not limited to, a two-wheeled electric vehicle such as an electric vehicle (EV) or an electric scooter. In addition, when the target device is a two-wheeled electric vehicle such as an electric scooter, the battery pack (1) mounted on the two-wheeled electric vehicle may be replaceable through a battery swapping station (BSS).

[0045] The battery management device (100) can manage and / or control the status and / or operation of the battery unit (10). For example, the battery management device (100) can manage and / or control the status and / or operation of a plurality of battery cells (11, 12, 13, 14) included in the battery unit (10), or manage charging and / or discharging of the battery unit (10).

[0046] The battery management device (100) can monitor the voltage, current, temperature, etc. of the battery unit (10) and each of the plurality of battery cells (11, 12, 13, 14). To this end, sensors or various measuring units not shown in FIG. 1 may be additionally installed at any location within the battery unit (10) or battery pack (1) or in the charging / discharging path.

[0047] The battery management device (100) can calculate parameters indicating the state of the battery unit (10), such as SOC (State of Charge) or SOH (State of Health), based on measured values ​​such as monitored voltage, current, and temperature.

[0048] The battery management device (100) may be configured to diagnose the deterioration of a plurality of battery cells (11, 12, 13, 14) and / or detect a battery cell in which an abnormality has occurred among the plurality of battery cells (11, 12, 13, 14). Details related to this will be described later in the description of FIG. 2.

[0049] Referring to FIG. 2, the battery management device (100) may include an interface (110), a processor (120), and a memory (130).

[0050] The interface (110) can obtain a first voltage profile of each of the plurality of battery cells (11, 12, 13, 14, see FIG. 1). Here, the first voltage profile may include, but is not limited to, a graph showing a change in the voltage of each of the plurality of battery cells (11, 12, 13, 14) over time. The interface (110) can measure and / or predict the voltage of each of the plurality of battery cells (11, 12, 13, 14) based on a current flowing in the battery pack (1, see FIG. 1) and / or an internal resistance.

[0051] According to one embodiment, the interface (110) may obtain a first voltage profile by applying voltage and / or current to a plurality of battery cells (11, 12, 13, 14). In this case, the interface (110) may include various circuits for applying voltage and / or current to the plurality of battery cells (11, 12, 13, 14) and a processor for calculating and / or processing the obtained first voltage profile.

[0052] According to one embodiment, the interface (110) can indirectly obtain the first voltage profile of each of the plurality of battery cells (11, 12, 13, 14). In this case, the interface (110) may further include a communication module for communicating with the battery pack (1) via wires and / or wirelessly.

[0053] According to one embodiment, the interface (110) may acquire a first voltage profile of the plurality of battery cells (11, 12, 13, 14) whenever the SoC (State of Charge) of each of the plurality of battery cells (11, 12, 13, 14) reaches a preset threshold value. Here, the preset threshold value may be, but is not limited to, 100% or 0%, which are values ​​indicating a state in which charging is completed and / or discharging is completed. The interface (110) may acquire a first voltage profile representing a change in voltage of each of the plurality of battery cells (11, 12, 13, 14) over time from a point in time when each of the plurality of battery cells (11, 12, 13, 14) is charged and / or discharged.

[0054] According to one embodiment, the interface (110) can obtain a first voltage profile of each of the plurality of battery cells (11, 12, 13, 14) until the voltage of each of the plurality of battery cells (11, 12, 13, 14) reaches a rest voltage.

[0055] The processor (120) can control the overall operation of the battery management device (100). Here, the processor can execute software to control the operation of at least one other component (e.g., hardware or software) of the battery management device (100), or perform operations such as processing and / or calculating various data. In addition, referring to FIG. 2, the battery management device (100) is illustrated as including one processor (120), but is not limited thereto, and the battery management device (100) can be configured to include at least one processor.

[0056] The processor (120) may be configured to detect a battery cell in which an abnormality has occurred among the plurality of battery cells (11, 12, 13, 14) based on a first voltage profile of each of the plurality of battery cells (11, 12, 13, 14). The processor (120) may calculate various voltage parameters for detecting an abnormality in the plurality of battery cells (11, 12, 13, 14) based on the first voltage profile of each of the plurality of battery cells (11, 12, 13, 14), and for this purpose, the processor (120) may generate a second voltage profile of each of the plurality of battery cells (11, 12, 13, 14) based on the first voltage profile.

[0057] According to one embodiment, the processor (120) may divide the first voltage profile of each of the plurality of battery cells (11, 12, 13, 14) into a plurality of time periods. Here, the length of each time period may be the same or different from each other, and is not limited to a specific example.

[0058] The processor (120) may generate a second voltage profile of each of the plurality of battery cells (11, 12, 13, 14) based on the first voltage profile of each of the plurality of battery cells (11, 12, 13, 14) in each of the plurality of time periods. According to one embodiment, the second voltage profile may be related to, but is not limited to, an average change in voltage of each of the plurality of battery cells (11, 12, 13, 14) in each of the plurality of time periods.

[0059] According to one embodiment, the processor (120) may calculate an average change in cell voltage of each of the plurality of battery cells (11, 12, 13, 14) in each of the plurality of time periods based on the first voltage profile. The processor (120) may calculate an average change by dividing the change in voltage of each of the plurality of battery cells (11, 12, 13, 14) in each of the plurality of time periods by the length of the time period.

[0060] According to one embodiment, the processor (120) may calculate an average voltage of a plurality of battery cells (11, 12, 13, 14) in each of a plurality of time periods, and may calculate an average change in the average voltage of the plurality of battery cells (11, 12, 13, 14) in each of a plurality of time periods. The processor (120) may calculate an average voltage of a plurality of battery cells (11, 12, 13, 14) and may calculate an average change in the average voltage by dividing the change in the average voltage in each of a plurality of time periods by the length of the time period.

[0061] According to one embodiment, the processor (120) can calculate a deviation between an average change amount of each of the plurality of battery cells (11, 12, 13, 14) and an average change amount of the average voltage of the plurality of battery cells (11, 12, 13, 14) in each of the plurality of time periods. For example, the processor (120) may calculate a deviation between an average change in voltage of a battery cell (11) and an average change in average voltages of a plurality of battery cells (11, 12, 13, 14) in each of a plurality of time periods, calculate a deviation between an average change in voltage of a battery cell (12) and an average change in average voltages of a plurality of battery cells (11, 12, 13, 14), calculate a deviation between an average change in voltage of a battery cell (13) and an average change in average voltages of a plurality of battery cells (11, 12, 13, 14), and calculate a deviation between an average change in voltage of a battery cell (14) and an average change in average voltages of a plurality of battery cells (11, 12, 13, 14).

[0062] The processor (120) can calculate the difference between the average change in voltage of each of the plurality of battery cells (11, 12, 13, 14) in adjacent time periods among the plurality of time periods and the deviation between the average change in the average voltage. Here, the adjacent time period may be any one of the preceding time period and / or the succeeding time period and is not limited to a specific example. For example, if the earliest time period among a plurality of time periods is a first time period and the time period following the first time period is a second time period, the processor (120) can calculate a difference value between a deviation between an average change in voltage of the first battery cell (11) in the second time period and an average change in average voltage of the plurality of battery cells (11, 12, 13, 14) and a deviation between an average change in voltage of the first battery cell (11) in the first time period and an average change in average voltage of the plurality of battery cells (11, 12, 13, 14). The processor (120) can calculate a difference between the average change in voltage of the first battery cell (11) and the average change in average voltage of the plurality of battery cells (11, 12, 13, 14) in a third time period following the second time period and a difference between the average change in voltage of the first battery cell (11) and the average change in average voltage of the plurality of battery cells (11, 12, 13, 14) in the second time period, and this process can be repeated until the difference values ​​for all of the plurality of time periods are calculated and until the difference values ​​for each of the plurality of battery cells (11, 12, 13, 14) are all calculated.

[0063] The processor (120) may generate a second voltage profile of each of the plurality of battery cells (11, 12, 13, 14) based on the difference between the deviation between the average change in voltage of each of the plurality of battery cells (11, 12, 13, 14) calculated in adjacent time periods among the plurality of time periods and the average change in the average voltage of the plurality of battery cells (11, 12, 13, 14). Here, the second voltage profile may include, but is not limited to, a graph representing the difference between the deviation between the average change in voltage of each of the plurality of battery cells (11, 12, 13, 14) and the average change in the average voltage of the plurality of battery cells (11, 12, 13, 14) over time.

[0064] The processor (120) may calculate a first voltage parameter and a second voltage parameter for detecting an abnormality of the plurality of battery cells (11, 12, 13, 14) based on the second voltage profiles of each of the plurality of battery cells (11, 12, 13, 14). According to one embodiment, the first voltage parameter may be related to a difference in the second voltage profile values ​​of each of the plurality of battery cells (11, 12, 13, 14) in adjacent time periods among the plurality of time periods, and the second voltage parameter may be related to a deviation in the second voltage profile values ​​of each of the plurality of battery cells (11, 12, 13, 14) in the same time period among the plurality of time periods, but is not limited thereto.

[0065] Specifically, the processor (120) may calculate a first sub-voltage parameter and a second sub-voltage parameter for calculating a first voltage parameter. Here, the first sub-voltage parameter may include data related to a deviation of a second voltage profile value of each of the plurality of battery cells (11, 12, 13, 14) in an adjacent time period among a plurality of time periods. For example, when the earliest time period is a first time period and a time period following the first time period is a second time period, the processor (120) may calculate the deviation between the second voltage profile value of the first battery cell (11) in the second time period and the second voltage profile value of the first battery cell (11) in the first time period to calculate the first sub-voltage parameter. Similarly, the processor (120) may calculate the first sub-voltage parameter by calculating the deviation between the second voltage profile value of the first battery cell (11) in the third time period following the second time period and the second voltage profile value of the first battery cell (11) in the second time period, and this process may be repeated until the first sub-voltage parameter is calculated for all of the multiple time periods. In addition, the processor (120) may calculate the first sub-voltage parameter based on the second voltage profile of each of the second battery cell (12), the third battery cell (13), and the fourth battery cell (14) as well as the first battery cell (11).

[0066] Additionally, the processor (120) can generate a second average voltage profile representing an average of the second voltage profile values ​​of each of the plurality of battery cells (11, 12, 13, 14).

[0067] The processor (120) may calculate a second sub-voltage parameter based on the generated second average voltage profile. Here, the second sub-voltage parameter may include, but is not limited to, data related to a difference between a second average voltage profile value in adjacent time intervals among a plurality of time intervals. For example, the processor (120) may calculate the second sub-voltage parameter by calculating a deviation between the second average voltage profile value in the second time interval and the second average voltage profile value in the first time interval, and may calculate the second sub-voltage parameter by calculating a deviation between the second average voltage profile value in the third time interval and the second average voltage profile value in the second time interval. This process may be repeated until the second sub-voltage parameter is calculated for all of the plurality of time intervals.

[0068] The processor (120) may calculate the first voltage parameter based on the calculated first sub-voltage parameter and the second sub-voltage parameter. According to one embodiment, the first voltage parameter may include, but is not limited to, data related to a difference value between a value obtained by amplifying the first sub-voltage parameter by an amplification factor and a value obtained by amplifying the second sub-voltage parameter by an amplification factor in a corresponding time period among a plurality of time periods.

[0069] According to one embodiment, the amplification factor multiplied to each of the first sub-voltage parameter and the second sub-voltage parameter may correspond to the same value or may correspond to different values, and is not limited to a specific example. The amplification factor may be a value multiplied so that each of the first sub-voltage parameter and the second sub-voltage parameter is included in a preset range, and for example, the amplification factor may be a coefficient that makes each of the first sub-voltage parameter and the second sub-voltage parameter a positive integer, but is not limited thereto.

[0070] The processor (120) can detect whether there is an abnormality in each of the plurality of battery cells (11, 12, 13, 14) based on the first voltage parameter calculated. According to one embodiment, the processor (120) can detect an abnormality in each of the plurality of battery cells (11, 12, 13, 14) based on a comparison result between a value obtained by multiplying the first voltage parameter calculated in each of the plurality of time periods by the second voltage profile value of each of the plurality of battery cells (11, 12, 13, 14) in the corresponding time period and a preset first reference value.

[0071] According to one embodiment, the processor (120) may diagnose that a tab break has occurred in the battery cell when the product of the second voltage profile value of each of the plurality of battery cells (11, 12, 13, 14) and the first voltage parameter in each of the plurality of time periods is greater than the first reference value, and may diagnose that an abnormal behavior due to polarization has occurred in the battery cell when the product of the second voltage profile value of each of the plurality of battery cells (11, 12, 13, 14) and the first voltage parameter in each of the plurality of time periods is less than the first reference value, but is not limited thereto.

[0072] In addition, the processor (120) may calculate a third sub-voltage parameter and a fourth sub-voltage parameter for calculating the second voltage parameter. Here, the third sub-voltage parameter may include data corresponding to the nth largest value (n is an integer greater than or equal to 2) among the plurality of second voltage profile values ​​in each of the plurality of time periods, and the fourth sub-voltage parameter may include data corresponding to the smallest value among the plurality of second voltage profile values ​​in each of the plurality of time periods, but is not limited thereto. Hereinafter, for convenience of explanation, it is assumed that n is 2.

[0073] For example, if the second voltage profile value of the first battery cell (11) has the second largest value in a first time period among a plurality of time periods and the second voltage profile value of the fourth battery cell (11) has the minimum value, the processor (120) may determine the second voltage profile value of the first battery cell (11) in the first time period as the third sub-voltage parameter and may determine the second voltage profile value of the fourth battery cell (11) in the first time period as the fourth sub-voltage parameter. This process may be repeatedly performed until the third sub-voltage parameter and the fourth sub-voltage parameter corresponding to each of the plurality of time periods are determined.

[0074] The processor (120) may calculate the second voltage parameter based on the acquired third sub-voltage parameter and the fourth sub-voltage parameter. According to one embodiment, the second sub-voltage parameter may include data related to a ratio of a difference value between the second voltage profile value and the fourth sub-voltage parameter of each of the plurality of battery cells (11, 12, 13, 14) for a difference value between the third sub-voltage parameter and the fourth sub-voltage parameter in each of the plurality of time periods.

[0075] Specifically, the second voltage parameter can be calculated based on the following mathematical expression 1.

[0076]

[0077] (Here, corresponds to the second voltage profile value in the time interval T, corresponds to the fourth sub-voltage parameter in the time interval T, corresponds to the third sub-voltage parameter in the time interval T, corresponds to a preset threshold value.)

[0078] According to one embodiment, the max(a, b) function may be a function that outputs the larger value of a and b that are substituted into the function. Accordingly, the second voltage parameter is a preset threshold value M and It could be a function that outputs the larger value among the values. This is because, when the value becomes relatively small, the second voltage parameter itself can diverge infinitely. The preset threshold value may be a threshold value that prevents the second voltage parameter from diverging and enables detection of abnormalities in multiple battery cells (11, 12, 13, 14). Here, the value of M is not limited to a specific value and may be set to have various values ​​depending on the design.

[0079] The processor (120) can detect whether there is an abnormality in each of the plurality of battery cells (11, 12, 13, 14) based on the calculated second voltage parameter. According to one embodiment, the processor (120) can detect an abnormality in each of the plurality of battery cells (11, 12, 13, 14) based on the comparison result between the calculated second voltage parameter and the preset second reference value in each of the plurality of time periods.

[0080] According to one embodiment, the processor (120) may diagnose that a tab break has occurred in the battery cell when the second voltage parameter value of each of the plurality of battery cells (11, 12, 13, 14) is greater than a preset second reference value in each of the plurality of time periods, and may diagnose that an abnormal behavior due to polarization has occurred in the battery cell when the second voltage parameter value of each of the plurality of battery cells (11, 12, 13, 14) is less than the second reference value in each of the plurality of time periods, but is not limited thereto. Here, the above-described first reference value and second reference value are not limited to a specific example and may be set and changed to have various values.

[0081] According to one embodiment, the processor (120) may consider at least one of the first voltage parameter and the second voltage parameter to detect an abnormality of a plurality of battery cells (11, 12, 13, 14). For example, the processor (120) may diagnose that a tap disconnection has occurred in the battery cell (11, 12, 13, 14) when a product of the first voltage parameter and the second voltage profile value is equal to or greater than a preset first reference value, or may diagnose that a tap disconnection has occurred in the battery cell (11, 12, 13, 14) when the second voltage parameter is equal to or greater than a preset second reference value, and / or may diagnose that a tap disconnection has occurred in the battery cell (11, 12, 13, 14) when a product of the first voltage parameter and the second voltage profile value is equal to or greater than a preset first reference value and the second voltage parameter is equal to or greater than a preset second reference value.

[0082] The memory (130) can store various data (e.g., commands, data related to mathematical formulas, voltage profiles of a plurality of battery cells, data related to reference values) for the operation of the battery management device (100). According to one embodiment, the memory (130) can include, but is not limited to, a volatile memory device such as a static random access memory (SRAM) or a dynamic random access memory (DRAM), or a non-volatile memory device such as a read only memory (ROM), a programmable ROM (PROM), or a flash memory.

[0083] According to one embodiment, the battery management device (100) may be formed integrally with a battery pack (1, see FIG. 1). In this case, the battery management device (100) may be implemented as a module BMS (Battery Management System; BMS) that controls the overall operation of the battery module (10, see FIG. 1) or a pack BMS that controls the overall operation of the battery pack (1), but is not limited thereto.

[0084] According to one embodiment, the battery management device (100) may be formed separately from the battery pack (1). In this case, the battery management device (100) may be connected to the battery module (10) and / or the battery pack (1) including the same via a wired and / or wireless network, and the battery management device (100) may be implemented through various devices such as a cloud server, a charger, or a charger / discharger.

[0085] According to one embodiment, the battery management device (100) can transmit the degradation level (e.g., SOH, etc.), diagnosis results, etc. of each of the plurality of battery cells (11, 12, 13, 14) to an external source (e.g., a cloud server or a user terminal). The cloud server can be configured to provide the degradation level and / or diagnosis results, etc. of each of the plurality of battery cells (11, 12, 13, 14) to a plurality of users, and the user terminal may include, but is not limited to, a terminal such as a personal computer (PC) or a smartphone.

[0086] According to one embodiment, the battery management device (100) may be implemented through a BSS (Battery Swapping Station; BSS). Here, the BSS may be a system having a slot into which a battery pack (1) can be inserted and capable of charging the inserted battery pack (1).

[0087] FIG. 3 is a drawing for explaining a first voltage profile according to an embodiment disclosed in this document, and FIG. 4 is a drawing for explaining a process for generating a second voltage profile according to an embodiment disclosed in this document.

[0088] First, referring to FIG. 3, multiple voltage profiles are shown relating to changes in voltage over time for each of multiple battery cells (11, 12, 13, 14, see FIG. 1).

[0089] According to one embodiment, the horizontal axis of the graph illustrated in FIG. 3 may represent time (t, sec), and the vertical axis may represent voltage (V). For convenience of explanation, the plurality of battery cells (11, 12, 13, 14) are assumed to be in a charging state, but the present invention is not limited thereto, and the same may be applied to battery cells in a discharged state.

[0090] After the charging of the plurality of battery cells (11, 12, 13, 14) is completed, each of the plurality of battery cells (11, 12, 13, 14) enters a resting state. The voltage of each of the plurality of battery cells (11, 12, 13, 14) gradually decreases as it enters the resting state, and after about 4000 s has elapsed, the voltage of each of the plurality of battery cells (11, 12, 13, 14) gradually converges to a resting voltage with a small amount of change.

[0091] The processor (120, see FIG. 2) can divide the voltage profile of each of the plurality of battery cells (11, 12, 13, 14) into a plurality of time periods. According to one embodiment, the processor (120) can divide the time periods from the time at which each of the plurality of battery cells (11, 12, 13, 14) enters an idle state into n (n is a positive integer) time periods. As illustrated in FIG. 3, the earliest time period may be the first time period, T1 period, and the latest time period may be the last time period, Tn period.

[0092] According to one embodiment, the length of each of the plurality of time intervals (T1 to Tn) may be equal to and / or different from each other.

[0093] According to one embodiment, when the lengths of each of the plurality of time sections (T1 to Tn) are different from each other, the processor (120) may set the length of the T1 section, which is the earliest time section, to be shorter than the lengths of the other time sections (T2 to Tn). This is because the voltage change of the battery cells (11, 12, 13, 14) that have entered the rest state is relatively large in the earlier time sections. In order to effectively detect such voltage change, the processor (120) may set the length of the T1 section, which is the earliest time section, to be shorter than the lengths of the other time sections. However, this is exemplary, and the processor (120) may set the lengths of the time sections in various ways, such as setting the lengths of the plurality of earliest time sections to be shorter than the lengths of the other time sections, depending on the design.

[0094] According to one embodiment, as described above in the detailed description of FIG. 2, the processor (120) can calculate the deviation between the average change amount of the voltage of each of the plurality of battery cells (11, 12, 13, 14) and the average change rate of the average voltage of the plurality of battery cells (11, 12, 13, 14) in each of the plurality of time periods (T1 to Tn), and overlapping content is omitted.

[0095] Specifically, referring to FIG. 4, a graph for generating a second voltage profile according to an embodiment disclosed in the present document is illustrated. As illustrated in FIG. 3, the horizontal axis of the graph illustrated in FIG. 4 may represent time (t), and the vertical axis may represent voltage (V).

[0096] According to one embodiment, the second time period (T2) may be a time period between time points t1 and t2. The processor (120, see FIG. 2) may calculate a deviation between an average change in voltage of each of the plurality of battery cells (11, 12, 13, 14) and an average change in average voltage of the plurality of battery cells (11, 12, 13, 14) in each of the second time period (T2) and the first time period (T1), which is a time period preceding the second time period (T2).

[0097] According to one embodiment, the processor (120) may calculate a difference (V2(t2)) between a deviation (V1(t2)) calculated in a second time interval (T2) and a deviation (V1(t1)) calculated in a first time interval (T1) preceding the second time interval (T2). This process may be repeated until differences for all of the multiple time intervals are calculated.

[0098] The processor (120) can generate a second voltage profile based on the difference (V2(t)) in each of the plurality of time intervals.

[0099] FIG. 5 is a drawing for explaining a second voltage profile according to an embodiment disclosed in this document.

[0100] According to one embodiment, the horizontal axis of the graph illustrated in FIG. 5 may represent time (t, sec) and the vertical axis may represent voltage (V).

[0101] The processor (120, see FIG. 2) may generate a second voltage profile of each of the plurality of battery cells (11, 12, 13, 14) based on the differences calculated in each of the plurality of time periods (T1, T2, T3, T4) described with reference to FIG. 4. According to one embodiment, dVsig[t] may represent a difference value between the average change in voltage of the plurality of battery cells (11, 12, 13, 14) in each of the plurality of time periods (T1, T2, T3, T4) and the average change in the average voltage of the plurality of battery cells (11, 12, 13, 14) and the difference value between the average change in voltage of the first battery cell (11) in the first time period and the average change in the average voltage of the plurality of battery cells (11, 12, 13, 14).

[0102] According to one embodiment, the processor (120) can calculate a first voltage parameter for detecting whether a plurality of battery cells (11, 12, 13, 14) are abnormal based on a second voltage profile of each of the plurality of battery cells (11, 12, 13, 14), and a redundant description is omitted.

[0103] According to one embodiment, the processor (120) may calculate a second voltage parameter for detecting whether a plurality of battery cells (11, 12, 13, 14) are abnormal based on the second voltage profile of each of the plurality of battery cells (11, 12, 13, 14). To this end, the processor (120) may calculate a third sub-voltage parameter and a fourth sub-voltage parameter based on the second voltage profile of each of the plurality of battery cells (11, 12, 13, 14).

[0104] As described above in the description of FIG. 2, the processor (120) may obtain data corresponding to the nth largest value and the smallest value among the plurality of second voltage profile values ​​(n is an integer greater than or equal to 2) in each of the plurality of time periods (T1, T2, T3, T4, T5) in order to calculate the fourth sub-voltage parameter. In the following description, for convenience of explanation, it is assumed that n is 2, but the present invention is not limited thereto.

[0105] For example, if the second voltage profile value of the first battery cell (11) has the second largest value (2nd[t]) and the second voltage profile value of the fourth battery cell (11) has the minimum value (Min[t]) in the fifth time period (T5) including the time point Ta, the processor (120, see FIG. 2) may determine the second voltage profile value of the first battery cell (11) in the fifth time period (T5) as the third sub-voltage parameter and determine the second voltage profile value of the fourth battery cell (11) in the first time period as the fourth sub-voltage parameter.

[0106] In addition, the processor (120) may calculate the second voltage parameter based on the acquired third sub-voltage parameter and the fourth sub-voltage parameter. According to one embodiment, the second sub-voltage parameter may include data related to a ratio of a difference value between the second voltage profile value and the fourth sub-voltage parameter of each of the plurality of battery cells (11, 12, 13, 14) for a difference value between the third sub-voltage parameter and the fourth sub-voltage parameter in each of the plurality of time periods, and the second voltage parameter may be calculated based on the above-described mathematical expression 1.

[0107] The voltage profile of a battery cell until it enters a resting period after a charge / discharge operation of the battery cell exhibits various behaviors depending on the state of the battery cell. A battery management device (100, see FIG. 1) according to an embodiment disclosed in the present document can detect abnormal voltage behavior due to a tab open defect of a battery cell and abnormal voltage behavior due to a polarization difference. The voltage change due to voltage inflection tends to rise momentarily at the beginning of the resting period, whereas the voltage change due to polarization tends to fall continuously during the resting period. The battery management device (100) can effectively detect momentary voltage changes due to polarization by appropriately dividing the time period in the period where a momentary voltage increase appears and calculating the deviation of the voltage parameter between adjacent time periods.

[0108] In addition, according to one embodiment disclosed in this document, the battery management device (100) can detect abnormal voltage behavior of a battery cell due to a minute voltage fluctuation of the battery cell by amplifying the minute voltage fluctuation.

[0109] FIG. 6 is a flowchart illustrating the operation of a battery management device according to an embodiment disclosed in this document.

[0110] In step S101, the battery management device (100) can obtain a plurality of first voltage profiles representing changes in the voltage of each of a plurality of battery cells (11, 12, 13, 14, see FIG. 1) over time.

[0111] In step S102, the battery management device (100) may divide the plurality of first voltage profiles into a plurality of time periods. According to one embodiment, the length of each of the plurality of time periods may be equal to and / or different from each other.

[0112] In step S103, the battery management device (100) can generate a second voltage profile of each of the plurality of battery cells (11, 12, 13, 14) based on the average change amount of the voltage of each of the plurality of battery cells (11, 12, 13, 14) corresponding to each of the plurality of time periods.

[0113] According to one embodiment, the second voltage profile may include, but is not limited to, data relating to a deviation between the average amount of change in voltage of each of the plurality of battery cells (11, 12, 13, 14) in adjacent time intervals among the plurality of time intervals.

[0114] In step S104, the battery management device (100) can calculate a first voltage parameter related to a deviation of a second voltage profile value between adjacent time periods among a plurality of time periods based on the second voltage profile.

[0115] According to one embodiment, the step of calculating the first voltage parameter may include the step of calculating a first sub-voltage parameter representing a deviation of a second voltage profile value in adjacent time intervals among the plurality of time intervals.

[0116] In one embodiment, the step of computing the first voltage parameter may include the step of computing a second sub-voltage parameter representing a deviation between average values ​​of a plurality of second voltage profile values ​​in adjacent time intervals.

[0117] According to one embodiment, the step of calculating the first voltage parameter may include the step of calculating the first voltage parameter representing a deviation between the amplified values ​​of each of the calculated first sub-voltage parameter and the second sub-voltage parameter.

[0118] In step S105, the battery management device (100) can calculate a second voltage parameter related to a deviation of a second voltage profile value in the same time period among multiple time periods.

[0119] According to one embodiment, the step of calculating the second voltage parameter may include the step of obtaining a third sub-voltage parameter corresponding to an nth largest value (where n is an integer greater than or equal to 2) among the plurality of second voltage profile values ​​in each of the plurality of time intervals.

[0120] According to one embodiment, the step of calculating the second voltage parameter may include the step of obtaining a fourth sub-voltage parameter corresponding to a minimum value among a plurality of second voltage profile values ​​in each of the plurality of time intervals.

[0121] According to one embodiment, the step of calculating the second voltage parameter may include calculating the second voltage parameter representing a ratio between a difference value between the second voltage profile value and the fourth sub-voltage parameter to a difference value between the third sub-voltage parameter and the fourth sub-voltage parameter.

[0122] According to one embodiment, the second voltage parameter can be calculated based on the mathematical expression 1 described above.

[0123] At step S106, the battery management device (100) can detect whether a plurality of battery cells (11, 12, 13, 14) are abnormal based on the first voltage parameter and the second voltage parameter.

[0124] According to one embodiment, the step of detecting whether a battery cell is abnormal may include the step of multiplying a first voltage parameter and a second voltage profile value, and the step of detecting the abnormality of the battery cell based on a comparison result between a product of the first voltage parameter and the second voltage profile value and a preset first reference value.

[0125] According to one embodiment, the step of detecting whether a battery cell is abnormal may include the step of detecting the abnormality of the battery cell based on a comparison result between a second voltage parameter and a preset second reference value.

[0126] According to one embodiment, the step of detecting whether a battery cell is abnormal may take into consideration at least one of a first voltage parameter and a second voltage parameter. For example, the step of detecting whether a battery cell is abnormal may include any one of: a step of diagnosing that a tap disconnection has occurred in a battery cell (11, 12, 13, 14) when a product of the first voltage parameter and the second voltage profile value is greater than or equal to a first preset reference value; a step of diagnosing that a tap disconnection has occurred in a battery cell (11, 12, 13, 14) when a second voltage parameter is greater than or equal to a second preset reference value; and / or a step of diagnosing that a tap disconnection has occurred in a battery cell (11, 12, 13, 14) when a product of the first voltage parameter and the second voltage profile value is greater than or equal to a first preset reference value and the second voltage parameter is greater than or equal to a second preset reference value.

[0127] FIG. 7 is a diagram illustrating a computing system equipped with a battery management device according to an embodiment disclosed in this document.

[0128] Referring to FIG. 7, the computing system (700) may include an MCU (710), a memory (720), an input / output I / F (730), and a communication I / F (740).

[0129] The MCU (710) may be a processor that executes various programs (e.g., battery cell diagnostic programs, etc.) stored in the memory (720), processes various data for detecting abnormalities in multiple battery cells (11, 12, 13, 14, see FIG. 1) through these programs, and performs the functions of the battery management device (100) described with reference to FIG. 2.

[0130] The memory (720) can store various programs for detecting abnormalities in battery cells. Furthermore, the memory (720) can store various data generated during the process of detecting abnormalities in battery cells, such as information on time interval length, deviation, first and second voltage parameters, etc.

[0131] Such memories (720) may be provided in multiples as needed. The memories (720) may be volatile memories or non-volatile memories. As volatile memories (720), RAM, DRAM, SRAM, etc. may be used. As non-volatile memories (720), ROM, PROM, EAROM, EPROM, EEPROM, flash memories, etc. may be used. The examples of the memories (720) listed above are merely examples and are not limited to these examples.

[0132] The input / output I / F (730) can provide an interface that enables data transmission and reception between an input device (not shown) such as a keyboard, mouse, or touch panel, and an output device (not shown) such as a display and the MCU (710).

[0133] The communication I / F (740) is a component capable of transmitting and receiving various data with a server, and may be any device capable of supporting wired or wireless communication. For example, a program for predicting battery cell deterioration or various data may be transmitted and received from a separately provided external server via the communication I / F (740).

[0134] In this way, the battery cell abnormality detection method according to one embodiment disclosed in this document can be recorded in the memory (720) and executed by the MCU (710).

[0135] In the above, all components constituting the embodiments have been described as being combined or operating in combination as one. However, this is not necessarily limited to such embodiments, and within the scope of the purpose, all components may be selectively combined and operated in one or more combinations. Furthermore, terms such as "include," "comprise," or "have" described above, unless specifically stated to the contrary, imply that the corresponding component may be inherent, and therefore should be interpreted to include other components rather than excluding other components.

[0136] The above description is merely an example of the technical idea disclosed in this document, and those skilled in the art to which the embodiments disclosed in this document pertain may make various modifications and variations without departing from the essential characteristics of the embodiments disclosed in this document.

[0137] Accordingly, the embodiments disclosed in this document are intended to illustrate, rather than limit, the technical concepts disclosed in this document, and the scope of the technical concepts disclosed in this document is not limited by these embodiments. The scope of protection of the technical concepts disclosed in this document should be interpreted by the claims below, and all technical concepts within the equivalent scope should be interpreted as being included within the scope of the rights of this document.

[0138] [Explanation of symbols]

[0139] 10: Battery unit 11, 12, 13, 14: Battery cells

[0140] 100: Battery management device 110: Interface

[0141] 120: Processor 130: Memory

Claims

1. An interface for obtaining a plurality of first voltage profiles representing changes in the voltage of each of a plurality of battery cells over time; and Dividing the first voltage profile into a plurality of time periods, and generating a second voltage profile of each of the plurality of battery cells based on the average change amount of the voltage of each of the plurality of battery cells corresponding to each of the plurality of time periods, A battery management device comprising a processor that detects whether the plurality of battery cells are abnormal by calculating a first voltage parameter related to a deviation of the second voltage profile value between adjacent time periods among the plurality of time periods based on the second voltage profile and a second voltage parameter related to a deviation of the second voltage profile value in the same time period among the plurality of time periods.

2. In the first paragraph, the processor, Compute a first sub-voltage parameter representing a deviation of the second voltage profile value in adjacent time intervals among the plurality of time intervals, Compute a second sub-voltage parameter representing a deviation between the average values ​​of the plurality of second voltage profile values ​​in the adjacent time intervals, A battery management device that calculates the first voltage parameter representing a deviation between the amplified values ​​of the first sub-voltage parameter and the second sub-voltage parameter, respectively.

3. In the second paragraph, the processor, Detecting an abnormality of the battery cell based on a comparison result between a product of the first voltage parameter and the second voltage profile value and a preset first reference value, A battery management device that detects that there is an abnormality in the battery cell when the product of the first voltage parameter and the second voltage profile value is greater than the first reference value.

4. In the first paragraph, the processor, Obtain a third sub-voltage parameter corresponding to the nth largest value (n is an integer greater than or equal to 2) among the plurality of second voltage profile values ​​in each of the plurality of time intervals, Obtain a fourth sub-voltage parameter corresponding to the minimum value among the plurality of second voltage profile values ​​in each of the plurality of time intervals, A battery management device that calculates the second voltage parameter representing a ratio between the second voltage profile value and the difference value between the third sub-voltage parameter and the fourth sub-voltage parameter.

5. In the fourth paragraph, the second voltage parameter is A battery management device that operates based on the following mathematical formula. [Mathematical formula] (Here, corresponds to the second voltage profile value in the time interval T, corresponds to the fourth sub-voltage parameter in the time interval T, corresponds to the third sub-voltage parameter in the time interval T, corresponds to a preset threshold value.) 6. In the fifth paragraph, the processor, Detecting an abnormality in the battery cell based on a comparison result between the second voltage parameter and a preset second reference value, A battery management device that detects that there is an abnormality in the battery cell when the second voltage parameter is greater than the second reference value.

7. In the first paragraph, the second voltage profile is: A battery management device that indicates a deviation between the average changes in voltage of each of the plurality of battery cells in adjacent time periods among the plurality of time periods.

8. A step of obtaining a plurality of first voltage profiles representing changes in voltage of each of a plurality of battery cells over time; A step of dividing the first voltage profile into a plurality of time intervals; A step of generating a second voltage profile of each of the plurality of battery cells based on an average change amount of voltage of each of the plurality of battery cells corresponding to each of the plurality of time periods; A step of calculating a first voltage parameter related to a deviation of the second voltage profile value between adjacent time intervals among the plurality of time intervals based on the second voltage profile; A step of calculating a second voltage parameter related to the deviation of the second voltage profile value in the same time period among the plurality of time periods; and A method for operating a battery management device, comprising: a step of detecting whether the plurality of battery cells are abnormal based on the first voltage parameter and the second voltage parameter.

9. In the 8th paragraph, the second voltage profile is: An operating method of a battery management device that indicates a deviation between the average change amount of the voltage of each of the plurality of battery cells in adjacent time periods among the plurality of time periods.

10. In the 8th paragraph, the step of calculating the first voltage parameter is: A step of calculating a first sub-voltage parameter representing a deviation of the second voltage profile value in adjacent time intervals among the plurality of time intervals; A step of calculating a second sub-voltage parameter representing a deviation between the average values ​​of the plurality of second voltage profile values ​​in the adjacent time intervals; and A method of operating a battery management device, comprising: calculating the first voltage parameter representing a deviation between the amplified values ​​of the first sub-voltage parameter and the second sub-voltage parameter, respectively; 11. In the 10th paragraph, the step of detecting whether the battery cell is abnormal is as follows: a step of multiplying the first voltage parameter and the second voltage profile value; and A method for operating a battery management device, comprising: a step of detecting an abnormality of the battery cell based on a comparison result between a product of the first voltage parameter and the second voltage profile value and a preset first reference value.

12. In the 8th paragraph, the step of calculating the second voltage parameter is: A step of obtaining a third sub-voltage parameter corresponding to the nth largest value (n is an integer greater than or equal to 2) among the plurality of second voltage profile values ​​in each of the plurality of time periods; A step of obtaining a fourth sub-voltage parameter corresponding to a minimum value among the plurality of second voltage profile values ​​in each of the plurality of time intervals; and A method of operating a battery management device, comprising: calculating a second voltage parameter representing a ratio between a difference value between the second voltage profile value and the fourth sub-voltage parameter with respect to a difference value between the third sub-voltage parameter and the fourth sub-voltage parameter; 13. In paragraph 12, The above second voltage parameter is an operating method of a battery management device calculated based on the following mathematical formula. [Mathematical formula] (Here, corresponds to the second voltage profile value in the time interval T, corresponds to the fourth sub-voltage parameter in the time interval T, corresponds to the third sub-voltage parameter in the time interval T, corresponds to a preset threshold value.) 14. In the 13th paragraph, the step of detecting an abnormality in the battery cell is: A method of operating a battery management device, comprising: a step of detecting an abnormality in the battery cell based on a comparison result between the second voltage parameter and a preset second reference value.

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