Battery management apparatus and operation method therefor

Abstract

A battery management apparatus according to one embodiment disclosed herein, may comprises: a sensor which obtains the voltage of a battery unit; and a controller which generates a differential profile for a first differential value, which is the amount of change in the voltage with respect to the amount of change in the SOC of the battery unit, on the basis of the SOC of the battery unit and the voltage, detects SOCs respectively corresponding to second differential values included in a threshold range among second differential values obtained by differentiating the differential profile, detects peak values of the differential profile among first differential values, corresponding to the detected SOCs, in the differential profile, and determines the state of the battery unit on the basis of the peak values of the differential profile.

Description

Battery management device and its operating method

[0001] Cross-citation with related applications

[0002] This invention claims the benefit of priority from Korean Patent Application No. 10-2023-0101824, filed August 3, 2023, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The embodiments disclosed in this document relate to a battery management device and a method of operating the same.

[0005] Recently, research and development on secondary batteries has been actively underway. Here, secondary batteries are defined as rechargeable and dischargeable batteries, encompassing both conventional Ni / Cd and Ni / MH batteries, as well as more recent lithium-ion batteries. Recently, their use has expanded to include power sources for electric vehicles, attracting attention as a next-generation energy storage medium.

[0006] Battery cells and modules for electric vehicles undergo internal deformation and transformation through various charging and discharging cycles during production and use, altering their physical and chemical properties. Technology is needed to manage the condition of battery cells and modules due to this degradation and deterioration.

[0007] Charge-discharge tests can be performed on batteries for purposes such as battery condition management. Based on the current and voltage obtained through charge-discharge tests, the open circuit voltage (OCV) profile for the battery's State of Charge (SOC) can be estimated. However, the actual measured OCV profile contains noise and errors, making it difficult to clearly analyze the data for battery condition management. Therefore, a method for accurately analyzing OCV profiles containing noise and errors is needed.

[0008] One purpose of the embodiments disclosed in this document is to provide a battery management device and an operating method thereof capable of managing the state of a battery unit based on the SOC and voltage profile of the battery unit included in a battery pack.

[0009] One object of the embodiments disclosed in this document is to provide a battery management device and a method of operating the same, including a data processing algorithm for reducing the influence of noise included in the SOC and voltage profile of a battery unit.

[0010] 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 from the descriptions below.

[0011] A battery pack according to an embodiment disclosed in the present document may include a sensor for acquiring a voltage of a battery unit; and a controller for generating a differential profile for a first differential value, which is a change amount of the voltage with respect to a change amount of the SOC of the battery unit, based on the SOC of the battery unit and the voltage, detecting an SOC corresponding to each of second differential values ​​included in a critical range among second differential values ​​obtained by differentiating the differential profile, detecting peak values ​​of the differential profile among the first differential values ​​corresponding to the detected SOC, and determining a state of the battery unit based on the peak values ​​of the differential profile.

[0012] According to an embodiment, the voltage may include an open circuit voltage (OCV).

[0013] According to an embodiment, the controller can detect the SOC corresponding to each of the second differential values ​​included in the threshold range by comparing the absolute values ​​of the second differential values ​​with a predetermined threshold value.

[0014] According to an embodiment, the controller can determine the state of the battery unit based on a first peak value and a second peak value, which are peak values ​​included in a region of interest among the peak values ​​of the detected differential profile.

[0015] According to an embodiment, the controller can manage the state of the battery unit based on a deviation between the SOC corresponding to each of the first peak value and the second peak value.

[0016] According to an embodiment, the controller may determine that the degradation of the battery unit is more advanced as the deviation between the SOC corresponding to each of the first peak value and the second peak value is smaller.

[0017] A battery management method according to one embodiment disclosed in the present document may include the steps of: generating a differential profile for a first differential value, which is a change in voltage with respect to a change in SOC of the battery unit, based on the SOC and voltage of the battery unit; detecting an SOC corresponding to each of second differential values ​​included in a critical range among second differential values ​​obtained by differentiating the differential profile; detecting peak values ​​of the differential profile among the first differential values ​​corresponding to the detected SOC in the differential profile; and determining a state of the battery unit based on the peak values ​​of the differential profile.

[0018] According to an embodiment, the voltage may include an open circuit voltage (OCV).

[0019] According to an embodiment, the step of detecting the SOC corresponding to each of the second differential values ​​included in the critical range may include the step of detecting the SOC corresponding to each of the second differential values ​​included in the critical range by comparing the absolute value of the second differential values ​​with a predetermined threshold value.

[0020] According to an embodiment, the step of determining the state of the battery unit may include the step of determining the state of the battery unit based on a first peak value and a second peak value, which are peak values ​​included in a region of interest among the peak values ​​of the detected differential profile.

[0021] According to an embodiment, the step of determining the state of the battery unit may include a step of managing the state of the battery unit based on a deviation between SOCs corresponding to each of the first peak value and the second peak value.

[0022] According to an embodiment, the step of determining the state of the battery unit may include a step of determining that the degradation of the battery unit is more advanced as the deviation between the SOC corresponding to each of the first peak value and the second peak value is smaller.

[0023] A battery management device and its operating method according to an embodiment disclosed in this document can manage the state of a battery unit based on the SOC and voltage profile of the battery unit included in a battery pack.

[0024] A battery management device and its operating method according to an embodiment disclosed in this document may include a data processing algorithm for reducing the influence of noise included in the SOC and voltage profile of a battery unit.

[0025] In addition, various effects may be provided, either directly or indirectly, through this document.

[0026] FIG. 1 is a drawing showing a battery pack according to one embodiment disclosed in this document.

[0027] FIG. 2 is a block diagram showing a battery management device according to one embodiment disclosed in this document.

[0028] FIG. 3a is a drawing illustrating a profile according to one embodiment disclosed in this document.

[0029] FIG. 3b is a diagram illustrating a first-order differential profile according to one embodiment disclosed in this document.

[0030] FIG. 3c is a diagram illustrating a second-order differential profile according to one embodiment disclosed in this document.

[0031] FIG. 3d is a diagram illustrating a second-order differential profile according to another embodiment disclosed in this document.

[0032] FIG. 3e is a diagram illustrating a first-order differential profile according to another embodiment disclosed in this document.

[0033] FIG. 3f is a diagram illustrating a first-order differential profile according to another embodiment disclosed in the present document.

[0034] FIG. 4 is an operation flowchart of a battery management device according to one embodiment disclosed in this document.

[0035] FIG. 5 is a flowchart illustrating the operation of a battery management device according to another embodiment disclosed in this document.

[0036] FIG. 6 is a block diagram showing the hardware configuration of a computing system for performing an operating method of a battery management device according to one embodiment disclosed in this document.

[0037] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that the present invention encompasses various modifications, equivalents, and / or alternatives of the embodiments.

[0038] The various embodiments and terminology used in this document are not intended to limit the technical features described in this document to specific embodiments, but should be understood to encompass various modifications, equivalents, or alternatives of the embodiments. In connection with the description of the drawings, similar reference numerals may be used to refer to similar or related components. The singular form of a noun corresponding to an item may include one or more of the items, unless the context clearly indicates otherwise.

[0039] In this document, the phrases "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" can each include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as "first", "second", "first", "second", "A", "B", "(a)", or "(b)" may be used merely to distinguish the corresponding element from other corresponding elements, and do not limit the corresponding elements in any other respect (e.g., importance or order) unless specifically stated otherwise.

[0040] In this document, whenever a component (e.g., a first component) is referred to as being “connected,” “coupled,” or “connected,” with or without the terms “functionally” or “communicatively,” or “coupled” or “connected,” it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or via a third component.

[0041] According to one embodiment, the method according to various embodiments disclosed in this document may be provided as a computer program product. The computer program product may be traded as a commodity between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) through an application store or directly between two user devices. In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0042] According to various embodiments, each component (e.g., a module or a program) of the above-described components may include one or more entities, and some of the entities may be separated and placed in other components. According to various embodiments, one or more components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. According to various embodiments, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0043] FIG. 1 is a drawing showing a battery pack according to one embodiment disclosed in this document.

[0044] Referring to FIG. 1, a battery pack (1000) may include an upper battery unit (100) and a battery management device (200). The upper battery unit (100) may include a plurality of battery units (110, 120, ..., 130). According to an embodiment, the upper battery unit (100) may be a battery module included in a battery pack mounted inside an electric vehicle to provide power to the electric vehicle. When the upper battery unit (100) is a battery module, the plurality of battery units (110, 120, ..., 130) may be a plurality of battery cells. Although FIG. 1 illustrates one upper battery unit (100), the present invention is not limited thereto, and the battery pack (1000) may be configured to include n (n is a natural number greater than or equal to 2) upper battery units. Additionally, some configurations may be excluded from the battery pack (1000) or other universal configurations may be further included in the battery pack (1000).

[0045] The upper battery unit (100) can supply power to a target device (not shown). To this end, the upper battery unit (100) can be electrically connected to the target device. Here, the target device can include an electrical, electronic, or mechanical device that operates by receiving power from a battery pack (1000) including the upper battery unit (100). For example, the target device can be, but is not limited to, an electric vehicle (EV) or an energy storage system (ESS).

[0046] The upper battery unit (100) may include a plurality of battery units (110, 120, …, 130). According to an embodiment, the plurality of battery units (110, 120, …, 130) may be basic units of battery cells that can charge and discharge electric energy. For example, the plurality of battery units may be lithium-ion (Li-ion) batteries, lithium-ion polymer (Li-ion polymer) batteries, nickel-cadmium (Ni-Cd) batteries, nickel-metal hydride (Ni-MH) batteries, etc., but are not limited thereto. In FIG. 1, the plurality of battery units (110, 120, …, 130) are illustrated as three, but are not limited thereto, and the upper battery unit (100) may be configured to include n (n is a natural number greater than or equal to 2) battery units. Additionally, some configurations may be excluded from the upper battery unit (100) and / or the plurality of battery units (110, 120, …, 130) or other universal configurations may be further included in the upper battery unit (100) and / or the plurality of battery units (110, 120, …, 130).

[0047] A battery management system (BMS) (200) can manage and / or control the status and / or operation of each of an upper battery unit (100) and / or a plurality of battery units (110, 120, …, 130). According to an embodiment, the battery management device (200) can determine the status of the upper battery unit (100) and / or a plurality of battery units (110, 120, …, 130) and manage the status of the upper battery unit (100) and / or a plurality of battery units (110, 120, …, 130) based on the status. According to an embodiment, the battery management device (200) can control the operation of the upper battery unit (100) and / or a plurality of battery units (110, 120, …, 130) and manage the operation of the upper battery unit (100) and / or a plurality of battery units (110, 120, …, 130) based on the status.

[0048] In addition, the battery management device (200) can monitor the voltage, current, and / or temperature of each of the upper battery unit (100) and / or the plurality of battery units (110, 120, …, 130). In addition, for monitoring by the battery management device (200), unillustrated sensors or various measurement modules can be additionally installed at any location, such as the upper battery unit (100), the charge / discharge path, or the plurality of battery units (110, 120, …, 130) included in the upper battery unit (100).

[0049] The battery management device (200) can calculate parameters, such as SOC (State of Charge) or SOH (State of Health), representing the status of each of the upper battery unit (100) and / or the plurality of battery units (110, 120, …, 130) based on measured values ​​such as monitored voltage, current, and temperature. According to an embodiment, the battery management device (200) can diagnose or determine the status of the upper battery unit (100) and / or the plurality of battery units (110, 120, …, 130) based on measured values ​​and / or calculated values ​​obtained from the upper battery unit (100) and / or the plurality of battery units (110, 120, …, 130).

[0050] The operation of the battery management device (200) below can be performed in various devices such as a server, cloud, charger, or charger / discharger connected to the battery management device (200) or a vehicle equipped with the battery management device (200).

[0051] FIG. 2 is a block diagram showing a battery management device according to one embodiment disclosed in this document.

[0052] Referring to FIG. 2, the battery management device (200) may include a sensor (210) and a controller (220). However, the present invention is not limited thereto, and some components may be omitted from the battery management device (200), and other general-purpose components may be further included in the battery management device (200).

[0053] The sensor (210) can obtain information about the upper battery unit (100) and / or each of the plurality of battery units (110, 120, …, 130). The sensor (210) can obtain voltage, current, and / or temperature of the upper battery unit (100) and / or each of the plurality of battery units (110, 120, …, 130) during the charging and / or discharging process.

[0054] For convenience of explanation, the following description assumes that the upper battery unit (100) is a battery module and each of the plurality of battery units (110, 120, …, 130) is a battery cell. In addition, for convenience of explanation, the battery unit (110) among the plurality of battery units (110, 120, …, 130) is described as an example, but the same can be applied substantially to other battery units (120, …, 140).

[0055] According to an embodiment, the sensor (210) can obtain the voltage across the battery unit (110) during charging and discharging of the battery unit (110). In addition, the sensor (210) can obtain the current applied to the battery unit (110) and the charging time during charging and discharging of the battery unit (110).

[0056] According to an embodiment, the sensor (210) can obtain the open circuit voltage (OCV) of the battery unit (110). OCV may mean a voltage obtained by subtracting a voltage drop due to the internal resistance of the battery unit (110) from the output voltage of the battery unit (110) and excluding the influence of the battery current, i.e., a no-load voltage (OCV).

[0057] The controller (220) can manage and / or control the operation of the battery unit (110). The controller (220) can manage the operation of the battery unit (110) based on information obtained through the sensor (210).

[0058] According to an embodiment, the controller (220) may process algebraic and / or statistical operations based on information acquired through the sensor (210). For example, the controller (220) may calculate the capacity and / or SOC (State of Charge) of the battery unit (110) based on the current and charging time of the battery unit (110) acquired from the sensor (210). In addition, the controller (220) may generate a function and / or profile (hereinafter, OCV profile) related to the open circuit voltage (OCV) of the battery unit (110) corresponding to the SOC of the battery unit (110) based on the voltage of the battery unit (110) acquired through the sensor (210).

[0059] According to an embodiment, the controller (220) can process algebraic and / or statistical operations on the generated OCV profile. For example, the controller (220) can process various operations such as differentiating or integrating the OCV profile, clustering the values ​​of the OCV profile, calculating the deviation, etc. The operations that the controller (220) can process are not limited thereto, and the controller (220) can process data using various data processing methods and / or algorithms.

[0060] The controller (220) can determine or manage the status of the battery unit (110) based on the processed information.

[0061] According to an embodiment, the internal resistance of the battery unit (110) may increase as the battery unit (110) is used, which may result in a decrease in output and a decrease in charging capacity. In addition, electrochemical changes may occur within the battery unit (110) during the charging and discharging process of the battery unit (110).

[0062] For example, when the battery unit (110) is a Li-ion battery cell, the active material present in the electrode of the battery cell may decrease as the battery cell is used. The active material may be a material that reacts with Li ions. For example, the active material may include materials such as LFP, NCM, LMO, and combinations thereof. When the active material of the battery unit (110) decreases, the open circuit voltage (OCV) may change during the charging and discharging process of the battery unit (110). Therefore, as the battery unit (110) is used, the characteristics of the OCV profile of the battery unit (110) may change due to such changes in the active material.

[0063] Accordingly, the controller (220) can determine the current state of the battery unit (110) by comparing the OCV profile of the changed charge / discharge process of the battery unit (110) with the OCV profile at the initial stage of production of the battery unit (110). According to an embodiment, the controller (220) can determine the deterioration state of the battery unit (110) by analyzing the OCV data for the SOC of the battery unit (110). The controller (220) can determine the deterioration state of the battery unit (110) in a non-destructive manner that does not physically destroy the battery unit (110) through the analysis of the OCV profile for the SOC.

[0064] Hereinafter, an embodiment in which a controller (220) analyzes an OCV profile and determines the status of a battery unit (110) will be described with reference to FIGS. 3a to 3e.

[0065] According to an embodiment, FIGS. 3A to 3E may be drawings according to the operation sequence of the controller (220). However, some operations may be excluded from FIGS. 3A to 3E, or other general operations may be further included in the middle of FIGS. 3A to 3E.

[0066] FIG. 3A is a diagram illustrating a profile according to one embodiment disclosed in the present document. FIG. 3B is a diagram illustrating a first-order differential profile according to one embodiment disclosed in the present document. FIG. 3C is a diagram illustrating a second-order differential profile according to one embodiment disclosed in the present document. FIG. 3D is a diagram illustrating a second-order differential profile according to another embodiment disclosed in the present document. FIG. 3E is a diagram illustrating a first-order differential profile according to another embodiment disclosed in the present document. FIG. 3F is a diagram illustrating a first-order differential profile according to another embodiment disclosed in the present document.

[0067] First, referring to FIG. 3A, the controller (220) can generate a profile (P0) based on information of the battery unit (110) acquired from the sensor (210) during charging and discharging of the battery unit (110). According to an embodiment, the controller (220) can generate a profile (P0) regarding a voltage (V, unit: V) of the battery unit (110) corresponding to a capacity (Q, unit: Ah) of the battery unit (110). According to an embodiment, the controller (220) can also generate a profile (P0) based on a voltage of the battery unit (100) corresponding to the SOC of the battery unit (110) based on a State of Charge (SOC, unit: %) instead of the capacity (Q). Here, the SOC can be a value obtained by dividing the capacity (Q) of the battery unit (110) by a maximum capacity (QMAX), which is a constant value. In the following, for convenience of explanation, the independent variable of the profile (P0) is illustrated as SOC (unit: %), and the dependent variable is illustrated as voltage (unit: V).

[0068] According to an embodiment, the voltage of the battery unit (110) in the profile (P0) may be an open circuit voltage (OCV). According to an embodiment, the no-load voltage (OCV) of the battery unit (110) may be data that better reflects the state of the battery unit (110). Therefore, the controller (220) can accurately analyze the state of the battery unit (110) by analyzing the profile (P0) generated based on the OCV.

[0069] According to an embodiment, the OCV profile (P0) may be an XY graph in which SOC is set as an independent variable X and OCV is set as a dependent variable Y. That is, the OCV profile (P0) may be defined as a graph that depicts OCV and SOC in a one-to-one relationship in the form of a function. According to an embodiment, the entire range of SOC of the OCV profile (P0) may be from 0% to 100%.

[0070] The controller (220) can detect an inflection point of the OCV profile (P0). In addition, the state of the battery unit (110) can be determined based on the detected inflection point. According to an embodiment, the inflection point may be a point where the instantaneous rate of change of the second differential function is 0 and the sign of the instantaneous rate of change of the second differential function changes. The point where the sign of the instantaneous rate of change of the second differential function changes may mean a point where the concavity and / or convexity of the original function changes. For example, the inflection point may mean a point where the graph of the function changes from a convex upward state to a convex downward state, or from a convex downward state to a convex upward state.

[0071] According to an embodiment, the controller (220) can set the OCV profile (P0) representing the correspondence between SOC and OCV as a function f(x), and differentiate the function f(x) twice to produce a second derivative function f"(x) (i.e., a second derivative profile (P2)) of the OCV profile (P0). Here, it can be assumed that the function f(x) is continuous and a function that can be differentiated twice. In addition, the controller (220) can determine a point where the sign of f"(x) changes from positive to negative or from negative to positive based on f"(SOC) while f"(SOC) = 0 in the second derivative function f"(x), as an inflection point.

[0072] In another aspect, the controller (220) can detect an inflection point of the OCV profile (P0) through a local extreme point of a function f'(x) (i.e., the first derivative profile (P1)) that is differentiated once with the OCV profile (P0). The local extreme point may be a point where the instantaneous rate of change of the first derivative function is 0. The local extreme point may mean a maximum point and a minimum point. A maximum point may be a point having the largest function value in an arbitrary section, and a minimum point may be a point having the smallest function value in an arbitrary section. The controller (220) can determine a point where the sign of f"(x) changes from positive to negative while f'(SOC)=0 in the first derivative f'(x) (i.e., the first derivative profile (P1)) as a maximum point, and a point where the sign of f"(x) changes from negative to positive while f'(SOC)=0 in the first derivative f'(x) as a minimum point.

[0073] The inflection point of the OCV profile (P0) may include information about various state changes of the battery unit (110). According to an embodiment, the inflection point of the OCV profile (P0) corresponding to a specific SOC section may include information about a chemical reaction occurring during charging and discharging of the battery unit (110). Therefore, the controller (220) may detect an inflection point located in a specific SOC section among the inflection points of the OCV profile (P0) to determine the state of the battery unit (110).

[0074] According to an embodiment, some of the maximum points (peak points) of the first differential profile (P1) may include information related to the degradation state of the battery unit (110). Accordingly, the controller (220) may detect the peak points of the first differential profile (P1) of the OCV profile (P0) to determine at which SOC value of the battery unit (110) a chemical reaction related to the degradation state of the battery unit (110) occurred. Meanwhile, the contents related to the peak points may be explained with reference to FIGS. 3b to 3f, which will be described later.

[0075] According to an embodiment, the OCV profile (P0) acquired during the charge / discharge time of the battery unit (110) may include noise. For example, the OCV profile (P0) may include noise measured at the positive terminal or the negative terminal of the battery unit (110) and / or noise measured at various components connected to the battery unit (110). In addition, the OCV profile (P0) may include noise according to the driving state of the vehicle including the battery unit (110). For example, the OCV profile (P0) may include noise according to the driving state, such as sudden braking, sudden starting, or regenerative braking of the vehicle. Due to this, the controller (220) may not be able to accurately determine the state of the battery unit (110) when analyzing the OCV profile (P0) including noise.

[0076] Accordingly, the controller (220) can cluster the second differential profile (P2) obtained by differentiating the OCV profile (P0) twice, and detect a peak value in the first differential profile (P1) obtained by differentiating the OCV profile (P0) once based on the clustered data. Through this, the controller (220) can determine the state of the battery unit (110) without interference from noise during actual driving and / or charging / discharging. In addition, the controller (220) can detect the inflection point of the OCV profile (P0) (i.e., the peak point of the first differential profile (P1)) without smoothing data of the OCV profile (P0) containing noise. And, the controller (220) can accurately determine the degradation state of the battery unit (110) based on the inflection point of the detected OCV profile (P0) (i.e., the peak point of the first differential profile (P1)).

[0077] Referring to FIG. 3b, the controller (220) can generate a profile (i.e., a first differentiation profile (P1)) that differentiates the OCV profile (P0) of the battery unit (110) once. The first differentiation profile (P1) can be a function of the amount of change in the voltage of the battery unit (110) with respect to the amount of change in the SOC of the battery unit (110).

[0078] According to an embodiment, the first differential profile (P1) may be an XY graph in which SOC is set to a variable X and the OCV change amount for the change amount of SOC is set to a variable Y. According to an embodiment, the entire range of SOC of the first differential profile (P1) may be from 0% to 100%. According to an embodiment, the function value of the first differential profile (P1) may be a first differential value.

[0079] According to an embodiment, the first differential profile (P1) may include a plurality of extrema. The plurality of extrema may be points where the instantaneous rate of change of the first differential profile (P1) is 0.

[0080] The controller (220) can detect an inflection point of the OCV profile (P0) through the peak point of the function f'(x) (i.e., the first differential profile (P1)) that differentiates the OCV profile (P0) once. The controller (220) can determine the peak where the instantaneous rate of change of the first differential profile (P1) is 0 and the differential voltage is the largest as the peak point.

[0081] As described above, some of the peaks of the first derivative profile (P1) may include information related to the degradation state of the battery unit (110). According to an embodiment, the controller (220) may determine and manage the state of the battery unit (110) based on the peaks in the region of interest associated with the degradation state of the battery unit. According to an embodiment, the controller (220) may detect a first peak value (PK1) and a second peak value (PK2) located in the region of interest on the first derivative profile (P1).

[0082] In an embodiment, the region of interest may include a specific SOC range associated with a degradation state of the battery unit (110). For example, the region of interest may be a range where a chemical reaction occurs within the battery unit (110) during charging and discharging of the battery unit (110). The chemical reaction occurring within the battery unit (110) may occur within a specific SOC range. Such a chemical reaction may occur due to, but is not limited to, a change in an active material present in an electrode within the battery unit (110).

[0083] According to an embodiment, the region of interest may be a portion where the SOC of the battery unit (110) is greater than or equal to 10% and less than or equal to 90% of the entire section. According to an embodiment, the region of interest may be a portion where the SOC of the battery unit (110) is greater than or equal to 15% and less than or equal to 80% of the entire section.

[0084] According to an embodiment, the controller (220) may determine a region of interest including a first SOC section and a second SOC section. The first SOC section is a capacity section in which a first peak (PK1) is expected to be included, and may be set to a specific section considering the capacity of the battery unit (110). Similarly, the second SOC section is a capacity section in which a second peak (PK2) is expected to be included, and may be set to a certain section considering the capacity of the battery unit (110). The first peak (PK1) and / or the second peak (PK2) may be related to a staging phenomenon in which lithium ions are desorbed during a charge / discharge process of the battery unit (110).

[0085] According to the embodiment of FIGS. 3A to 3F, the first SOC range may be set to an SOC range of 10% to 30% of the total SOC range of the battery unit (110). Additionally, the second SOC range may be set to an SOC range of 60% to 80% of the total SOC range of the battery unit (110). According to the embodiment, the controller (220) may detect a peak point of the SOC of the battery unit (110) at around 20% and / or around 75% of the total SOC range.

[0086] The controller (220) can detect a first peak value (PK1) and a second peak value (PK2) located in a region of interest on the first differential profile (P1). According to an embodiment, the controller (220) can detect the first peak value (PK1) in the vicinity of where the SOC of the battery unit (110) is 20 (%) of the entire section, and the second peak value (PK2) in the vicinity of where the SOC is 80 (%) of the entire section. According to an embodiment, the controller (220) can detect the first peak value (PK1) in the vicinity of where the SOC of the battery unit (110) is 15 (%) of the entire section, and the second peak value (PK2) in the vicinity of where the SOC is 75 (%) of the entire section.

[0087] The controller (220) may not be able to accurately detect peak values ​​in the region of interest due to noise included in the first derivative profile (P1). Therefore, a method for more accurately detecting peak values ​​in the region of interest is described with reference to FIGS. 3C to 3F.

[0088] Referring to FIG. 3c, the controller (220) can generate a second derivative profile (P2), which is a profile obtained by differentiating the first derivative profile (P1). The second derivative profile (P2) can be a function of the change in the first derivative value with respect to the change in the SOC of the battery unit (110). The controller (220) can detect an inflection point of the OCV profile (P0) using the second derivative profile (P2).

[0089] According to an embodiment, the second derivative profile (P2) may be an XY graph in which SOC is set to a variable X and a change in the first derivative with respect to the change in SOC is set to a variable Y. According to an embodiment, the entire range of SOC of the second derivative profile (P2) may be from 0% to 100%. According to an embodiment, the function value of the second derivative profile (P2) may be a second derivative.

[0090] The controller (220) can detect an inflection point of the OCV profile (P0) by detecting a point where the second derivative of the second derivative profile (P2) is within a critical range. In an embodiment, the critical range may be a predetermined range that includes a point where the second derivative becomes 0. In an embodiment, the critical range may include a range where the absolute value of the second derivative is around 0.

[0091] According to an embodiment, the controller (220) can detect an inflection point of the OCV profile (P0) by comparing the absolute value of the second derivatives with a predetermined threshold value. For example, the predetermined threshold value can be a constant that is a microsecond greater than 0.

[0092] The first derivative profile (P1), like the OCV profile (P0), may include noise during actual driving and / or charging / discharging. Therefore, a number of points unrelated to the chemical reaction occurring within the battery unit (110) may be detected as inflection points of the OCV profile (P0). The controller (220) may detect points that may become inflection points in the OCV profile containing noise by detecting the second derivative values ​​within the critical range, i.e., the inflection points of the OCV profile.

[0093] Referring to FIG. 3d, the controller (220) can perform clustering in the second differential profile (P2).

[0094] In an embodiment, clustering may be an algorithm that classifies distributed data into specific groups. For example, the clustering algorithm may include a known clustering algorithm such as k-means clustering, density-based clustering, Gaussian clustering, etc.

[0095] The controller (220) can cluster the second derivative values ​​within the critical range detected in the second derivative profile (P2). According to an embodiment, the controller (220) can cluster the second derivative values ​​within the critical range based on the SOC of the battery unit (110).

[0096] The second derivative profile (P2), like the OCV profile (P0) and the first derivative profile (P1), may include noise during actual driving and / or charging / discharging. Therefore, a number of points unrelated to the chemical reaction occurring within the battery unit (110) may be detected as inflection points of the OCV profile (P0). The controller (220) may detect points that may be inflection points of the OCV profile (P0) through a clustering algorithm and reduce the influence of such noise. In addition, the controller (220) may detect inflection points of the OCV profile (P0) (i.e., peak points of the first derivative profile (P1)) without smoothing the OCV data of the battery unit (110).

[0097] According to an embodiment, the controller (220) can detect a representative value representing each clustered SOC group. For example, the representative value may be the SOC average value of the clustered SOC group. The controller (220) can classify the clustered SOC groups based on the detected representative value.

[0098] Referring to FIG. 3e, the controller (220) can detect the function value of the first differential profile (P1) corresponding to the clustered SOC groups.

[0099] The controller (220) can detect the first differential values ​​on the first differential profile (P1) corresponding to each of the clustered SOC groups. According to an embodiment, since the second differential values ​​corresponding to each of the clustered SOC groups are values ​​near 0, it may be difficult for the controller (220) to detect the peak value of the first differential profile (P1) only by detecting the second differential values ​​on the second differential profile (P2). Therefore, the controller (220) can detect the corresponding first differential values ​​on the first differential profile (P1) based on the clustered SOC groups on the second differential profile (P2). Through this, the controller (220) can accurately determine the state of the battery unit (110).

[0100] Referring to FIG. 3F, the controller (220) can detect peak values ​​based on the detected first differential values. According to an embodiment, the controller (220) can detect peak values ​​among the detected first differential values.

[0101] According to an embodiment, the controller (220) can detect a first peak value (PK1) and a second peak value (PK2) included in the region of interest based on the detected peak values. The process of detecting the peak values ​​included in the region of interest is the same as described in FIG. 3b and is therefore not described again herein.

[0102] The controller (220) can accurately detect peak values ​​in the first differential profile (P1) containing noise by detecting peak values ​​of the first differential profile (P1) through clustering. The controller (220) can accurately detect the first peak value (PK1) and the second peak value (PK2) located in the region of interest through clustering. Therefore, the controller (220) can detect the first peak value (PK1) and the second peak value (PK2) related to the chemical reaction occurring within the battery unit (110) without smoothing the data.

[0103] According to an embodiment, the controller (220) can manage the state of the battery unit (110) based on the first peak value (PK1) and the second peak value (PK2). The controller (220) can determine the degree of aging and / or deterioration of the battery unit (110) through the deviation between the SOC corresponding to each of the first peak value (PK1) and the second peak value (PK2).

[0104] The controller (220) can determine that the degradation of the battery unit (110) is more advanced as the SOC deviation between the SOC corresponding to the first peak value (PK1) and the SOC corresponding to the second peak value (PK2) narrows. According to an embodiment, the active material capable of reacting with Li ions may decrease during the repeated charging and discharging of the battery unit (110). For example, the decrease in the reactive active material may appear as a decrease in the interval between inflection points in the OCV profile (P0) of the battery unit (110). Therefore, the controller (220) can non-destructively determine the degradation state of the battery unit (110) through the SOC deviation of the peak values ​​on the first derivative profile (P1) of the OCV profile (P0).

[0105] The controller (220) described with reference to FIGS. 2 and 3A to 3F is not limited to the above-described configuration, and general configurations necessary for operating the battery management device (200) may be added or omitted in the controller (220). According to an embodiment, the controller (220) may provide information about the battery unit (110) to a user terminal through a communication unit (not shown), and may also provide information about the battery unit (110) through a display equipped in a vehicle or a charger, etc.

[0106] FIG. 4 is an operation flowchart of a battery management device according to one embodiment disclosed in this document.

[0107] The operations illustrated in FIG. 4 can be performed through the battery management device (200) of FIG. 2.

[0108] In operation S101, the controller (220) can generate a profile (P0) based on the SOC and voltage of the battery unit (110). The generated profile (P0) may be an OCV profile (P0) for the SOC of the battery unit (110).

[0109] In operation S102, the controller (220) may generate a first derivative profile (P1). In an embodiment, the controller (220) may differentiate the OCV profile (P0) to generate the first derivative profile (P1). For example, the first derivative profile (P1) may be a derivative profile for a first derivative value, which is a change in voltage with respect to a change in SOC of the battery unit (110).

[0110] In operation S103, the controller (220) may generate a second differentiation profile (P2). In an embodiment, the controller (220) may differentiate the first differentiation profile (P1) to generate a second differentiation profile (P2). For example, the second differentiation profile (P2) may be a differentiation profile for a second differentiation value, which is a change amount of a first differentiation value for a change amount of the SOC of the battery unit (110).

[0111] In operation S104, the controller (220) can cluster SOC values ​​included in the critical range in the second differential profile (P2). According to an embodiment, the controller (220) can detect an SOC corresponding to each of the second differential values ​​included in the critical range among the second differential values. The controller (220) can cluster the second differential values ​​based on the detected SOC. The controller (220) can detect a representative value of the clustered SOC groups.

[0112] In operation S105, the controller (220) can detect peak values ​​in the first differential profile (P1) based on the clustered SOC. According to an embodiment, the controller (220) can detect peak values ​​of the first differential profile (P1) among the first differential values ​​corresponding to the detected SOC in the first differential profile (P1). In another aspect, the controller (220) can detect peak values ​​of the first differential profile (P1) among the first differential values ​​corresponding to the detected representative value in the first differential profile (P1).

[0113] FIG. 5 is a flowchart illustrating the operation of a battery management device according to another embodiment disclosed in this document.

[0114] The operations illustrated in FIG. 5 can be performed through the battery management device (200) of FIG. 2.

[0115] In operation S201, the controller (220) can determine a first peak value (PK1) and a second peak value (PK2) among the peak values ​​of the first differential profile (P1). According to an embodiment, the controller (220) can determine peak values ​​included in the region of interest among the peak values ​​of the detected first differential profile (P1) as the first peak value (PK1) and the second peak value (PK2).

[0116] In operation S202, the controller (220) can determine a deviation between the SOC corresponding to each of the first peak value (PK1) and the second peak value (PK2). According to an embodiment, the controller (220) can calculate the deviation based on the difference between the SOC corresponding to the first peak value (PK1) and the SOC corresponding to the second peak value (PK2).

[0117] In operation S203, the controller (220) can manage the state of the battery unit (110) based on the SOC deviation. According to an embodiment, the controller (220) can determine that the degradation of the battery unit (110) is more advanced as the SOC deviation between the first peak value (PK1) and the second peak value (PK2) is smaller.

[0118] FIG. 6 is a block diagram showing the hardware configuration of a computing system for performing an operating method of a battery management device (200) according to one embodiment disclosed in this document.

[0119] Referring to FIG. 6, a computing system (2000) according to one embodiment disclosed in the present document may include an MCU (2010), a memory (2020), an input / output I / F (2030), and a communication I / F (2040).

[0120] The MCU (2010) may be a processor that executes various programs (e.g., a battery cell characteristic data collection program, a latent variable extraction program, a distribution generation program, a battery cell diagnosis program, etc.) stored in the memory (2020), processes various information including battery cell characteristic data and latent variables through these programs, and performs the functions of the controller (220) included in the battery management device (200) shown in the above-described FIGS. 1 to 5.

[0121] The memory (2020) can store various programs, such as a battery cell characteristic data collection program, a latent variable extraction program, a distribution map generation program, and a battery cell diagnosis program. In addition, the memory (2020) can store various information, including battery cell characteristic data and latent variables.

[0122] Such memories (2020) may be provided in multiples as needed. The memories (2020) may be volatile or non-volatile memories. As volatile memories (2020), RAM, DRAM, SRAM, etc. may be used. As non-volatile memories (2020), ROM, PROM, EAROM, EPROM, EEPROM, flash memory, etc. may be used. The examples of the memories (2020) listed above are merely examples and are not limited to these examples.

[0123] The input / output I / F (2030) 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 (2010).

[0124] The communication I / F (2040) is a component capable of transmitting and receiving various data with the server, and may be any device capable of supporting wired or wireless communication. For example, the battery management device (200) can transmit and receive various information, including the SOC, OCV, and parameters of the battery cell, from a separately provided external server via the communication I / F (2040).

[0125] In this way, a computer program according to an embodiment disclosed in this document may be implemented as a module that is recorded in a memory (2020) and processed by an MCU (2010) to perform each function illustrated in FIG. 2, for example.

[0126] Although all components constituting the embodiments disclosed in this document have been described as being combined or operating in combination as one, the embodiments disclosed in this document are not necessarily limited to such embodiments. That is, within the scope of the purpose of the embodiments disclosed in this document, all of the components may be selectively combined and operated one or more times.

[0127] In addition, terms such as "include," "comprise," or "have" described above, unless specifically stated otherwise, mean that the corresponding component can be included, and therefore should be interpreted to include other components rather than excluding other components. All terms, 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, unless otherwise defined. Commonly used terms, such as terms defined in a dictionary, should be interpreted to be consistent with the contextual meaning of the relevant technology, and shall not be interpreted in an idealized or overly formal sense, unless explicitly defined in this document.

[0128] The foregoing disclosure outlines features of several embodiments to enable those skilled in the art to better understand the aspects of the present disclosure. Those skilled in the art will readily appreciate that the present disclosure can be readily used as a basis for designing or modifying other structures to achieve the same purposes or advantages of the embodiments introduced herein. Furthermore, those skilled in the art will recognize that such equivalent structures do not depart from the scope of the present disclosure, and that various changes, substitutions, and modifications can be made herein without departing from the scope of the present disclosure.

Claims

1. A sensor that obtains the voltage of the battery unit; and Generate a differential profile for a first differential value, which is a change in the voltage with respect to a change in the SOC of the battery unit, based on the SOC and the voltage of the battery unit, Detecting the SOC corresponding to each of the second differential values ​​included in the critical range among the second differential values ​​obtained by differentiating the above differential profile, In the above differential profile, peak values ​​of the differential profile are detected among the first differential values ​​corresponding to the detected SOC, A battery management device including a controller that determines the state of the battery unit based on peak values ​​of the differential profile.

2. In claim 1, The above voltage is a battery management device including an open circuit voltage (OCV).

3. In claim 1, The above controller, A battery management device that compares the absolute values ​​of the second differential values ​​with a predetermined threshold value and detects the SOC corresponding to each of the second differential values ​​included in the threshold range.

4. In claim 1, The above controller, A battery management device that determines the status of the battery unit based on a first peak value and a second peak value, which are peak values ​​included in a region of interest among the peak values ​​of the detected differential profile.

5. In claim 4, The above controller, A battery management device that manages the state of the battery unit based on the deviation between the SOC corresponding to each of the first peak value and the second peak value.

6. In claim 5, The above controller, A battery management device that determines that the smaller the deviation between the SOC corresponding to each of the first peak value and the second peak value, the more advanced the degradation of the battery unit is.

7. A step of generating a differential profile for a first differential value, which is a change in the voltage with respect to a change in the SOC of the battery unit, based on the SOC and voltage of the battery unit; A step of detecting SOC corresponding to each of the second differential values ​​included in the critical range among the second differential values ​​obtained by differentiating the above differential profile; In the above differential profile, a step of detecting peak values ​​of the differential profile among the first differential values ​​corresponding to the detected SOC; and A battery management method comprising a step of determining the state of the battery unit based on peak values ​​of the differential profile.

8. In claim 7, The above voltage is a battery management method including open circuit voltage (OCV).

9. In claim 7, The step of detecting the SOC corresponding to each of the second differential values ​​included in the above critical range is: A battery management method comprising a step of comparing the absolute values ​​of the second differential values ​​with a predetermined threshold value and detecting the SOC corresponding to each of the second differential values ​​included in the threshold range.

10. In claim 7, The step of judging the status of the above battery unit is: A battery management method comprising a step of determining the state of the battery unit based on a first peak value and a second peak value, which are peak values ​​included in a region of interest among peak values ​​of the detected differential profile.

11. In claim 10, The step of judging the status of the above battery unit is: A battery management method comprising a step of managing the state of the battery unit based on a deviation between the SOC corresponding to each of the first peak value and the second peak value.

12. In claim 11, The step of judging the status of the above battery unit is: A battery management method including a step of determining that the degradation of the battery unit is more advanced as the deviation between the SOC corresponding to each of the first peak value and the second peak value is smaller.

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