Apparatus and method for managing battery

Abstract

An apparatus for managing a battery according to one embodiment of the present invention comprises: a profile processing unit configured to obtain charging / discharging profiles of a cell group in which a plurality of cells are electrically connected; a characteristic point selection unit configured to select characteristic points corresponding to an inflection point from among the charging and discharging profiles; and a diagnosis unit configured to diagnose deterioration imbalance of the cell group by using characteristic information including information on the number of the characteristic points.

Description

Battery management device and method

[0001] This application claims priority to Korean Patent Application No. 10-2023-0126117, filed on September 21, 2023, the entire contents of which are disclosed in the specification and drawings of the said application are incorporated herein by reference.

[0002] The present invention relates to a technology for diagnosing and managing the state of a battery, and more specifically, to a battery management device and method for effectively diagnosing whether a group of cells is degraded or imbalanced.

[0003] As the demand for portable electronic devices such as laptops, video cameras, and mobile phones that use electricity as a power source rapidly increases, and as mobile robots, electric bicycles, electric carts, and electric vehicles become more widely commercialized, research into high-performance secondary batteries capable of repeated charging and discharging is actively being conducted.

[0004] Commercialized secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries have the advantage of being able to charge and discharge freely and have a very low self-discharge rate because they have almost no memory effect compared to nickel-based secondary batteries. In addition, they have the characteristics of high energy density and high operating voltage, so they are being studied more intensively than other types of secondary batteries and are being applied more widely in actual products.

[0005] Recently, secondary batteries are widely used not only in small devices such as portable electronic devices, but also in medium and large devices such as electric vehicles and energy storage systems (ESS).

[0006] In this case, a battery module in which a number of electrically connected secondary batteries are housed together inside a module case is mainly applied, and furthermore, when high power or large capacity is required, a battery pack in which a number of such battery modules are electrically connected is also applied.

[0007] Secondary battery cells, cell assemblies, battery modules, or battery packs (collectively referred to as "batteries") are important factors for power efficiency and safety, so active research is being conducted on BMS (Battery Management System), which monitors the electrical characteristics of the battery and performs feedback control such as charging and discharging using the monitoring results.

[0008] Unlike fossil fuel-based energy generation, secondary cell-based batteries generate energy through electrochemical reactions, so as the charge-discharge cycle continues or is repeated, they cannot maintain the performance they had when they were first manufactured, that is, in the BOL (Beginning Of Life) state, and gradually deteriorate or age.

[0009] In this way, as batteries continue to be used (charged and discharged), their usability decreases due to capacity deterioration, output deterioration, etc., and their safety also becomes a risk factor. Therefore, in order to control limited use, determine replacement timing, objectively determine prices for battery sharing or subscription, and improve the efficiency of battery reuse or recycling, it is necessary to accurately predict the current battery deterioration rate and its remaining lifespan.

[0010] Meanwhile, the electrical characteristic values ​​of the multiple battery cells constituting the battery may be differentiated from each other due to differences in individual dynamic states caused by inherent characteristics such as internal resistance, artificial deviations due to the usage environment, cooling efficiency, capacity, etc., or the degree of aging or deterioration of the inherent driving performance may be different from each other (hereinafter referred to as 'deterioration imbalance').

[0011] Degeneration imbalance can occur not only when the degree of degeneration differs depending on the use of each cell, but also due to defects in the manufacturing process.

[0012] When the degradation levels of each of multiple cells grouped through electrical connection are different in this way, the driving performance of the entire group of grouped cells deteriorates. Therefore, a technology is required to accurately diagnose when a degradation imbalance occurs in a group of cells electrically connected to enable more effective subsequent processing or operation, such as limited use, exclusion of charge and discharge, and determination of replacement timing.

[0013] However, since most of the existing methods or technologies for diagnosing degeneration are methods for predicting the degeneration or remaining life for each individual cell, it is difficult to effectively diagnose degeneration imbalance or degeneration unevenness for an entire cell group in which multiple cells are grouped.

[0014] Furthermore, even if the degeneration imbalance of a cell group is diagnosed using a conventional method, the degeneration calculation for each individual cell must be completed, and then functional processing such as statistical calculation and comparison must be performed again. Therefore, not only is the efficiency of the calculation processing considerably low, but the accuracy of the information may also be reduced.

[0015] The present invention was created to solve the above-described problems in the above background, and the purpose of the present invention is to provide a battery management device and method capable of quickly and accurately diagnosing the presence and / or degree of degeneration imbalance in a cell group through processing that identifies characteristic information of a charge / discharge profile or a differential profile thereof targeting the entire cell group.

[0016] The technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0017] A battery management device according to one aspect of the present invention may include a profile processing unit configured to obtain a charge / discharge profile of a cell group in which a plurality of cells are electrically connected; a characteristic point selection unit configured to select a characteristic point corresponding to an inflection point among the charge / discharge profiles; and a diagnosis unit configured to diagnose a degradation imbalance of the cell group using characteristic information including information on the number of characteristic points.

[0018] If the number of the above characteristic points is a single number, the diagnostic unit may be configured to diagnose that the degenerative imbalance has not occurred in the cell group.

[0019] If the number of the above characteristic points is plural, the diagnostic unit may be configured to diagnose that the degenerative imbalance has occurred in the cell group.

[0020] The above charge / discharge profile may be a profile indicating a correspondence between the voltage and capacity of the cell group.

[0021] The above characteristic point selection unit may include a function processing unit configured to generate a differential profile, which is a profile indicating a correspondence between the capacity and differential voltage of the cell group or a correspondence between the voltage and differential capacity of the cell group, based on the charge / discharge profile; and a point selection unit configured to select the characteristic point from the differential profile.

[0022] The above point selection unit may be configured to determine a capacity having the smallest corresponding differential voltage in the generated differential profile when a differential profile representing a correspondence between the capacity and the differential voltage is generated, and to select the characteristic point from among a plurality of peaks included in a capacity range greater than the determined capacity.

[0023] The above point selection unit may be configured to determine a voltage having the largest corresponding differential capacity in the generated differential profile when a differential profile representing a correspondence between the voltage and the differential capacity is generated, and to select the characteristic point from among a plurality of peaks included in a voltage range greater than the determined voltage.

[0024] The above point selection unit may be configured to select a peak among the above peaks in which the SOC of the above cell group is located in a range of 40% or more and 70% or less as the characteristic point.

[0025] A battery management device according to another aspect of the present invention may further include a management control unit configured to change the usage conditions of the cell group so as to limit charging and discharging of the cell group when the degradation imbalance is diagnosed to have occurred in the cell group.

[0026] The above characteristic information may further include information on the spacing between the characteristic points when there are multiple characteristic points.

[0027] The above diagnostic unit may be configured to generate diagnostic data including information on the degree of the degenerative imbalance, the greater the degree of the deviation information, the greater the severity information.

[0028] According to another aspect of the present invention, a battery management device may further include a management control unit configured to change the usage conditions of the cell group so that the charge / discharge range of the cell group is differentially limited according to the size of the gap information when the degradation imbalance is diagnosed to have occurred in the cell group.

[0029] A battery pack according to another aspect of the present invention may include a battery management device according to one aspect of the present invention.

[0030] A vehicle according to another aspect of the present invention may include a battery management device according to one aspect of the present invention.

[0031] A battery management method according to another aspect of the present invention may include a profile processing step of acquiring a charge / discharge profile of a cell group in which a plurality of cells are electrically connected; a characteristic point selection step of selecting a characteristic point corresponding to an inflection point among the charge / discharge profiles; and a diagnosis step of diagnosing a degradation imbalance of the cell group using characteristic information of the characteristic point.

[0032] According to the present invention, rather than from a microscopic perspective of individual cells, it is possible to accurately diagnose degradation imbalance at the cell group level applied to actual application devices such as banks, modules, and battery packs, thereby improving the effectiveness of battery control and management.

[0033] According to one aspect of the present invention, it is possible to simply and accurately diagnose whether or not a cell group is degenerated or not, or to what extent, through software processing targeting the charge / discharge profile of the cell group or its differential profile.

[0034] In this respect, the diagnostic method according to the present invention can be implemented through software that can be installed in a BMS or a module that implements the same, thereby providing higher expandability.

[0035] In addition, according to the present invention, the information on the severity of degeneration imbalance can be effectively combined with processing that differentially applies the usage restriction range of the corresponding cell group, thereby further increasing the efficiency of battery management processing.

[0036] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0037] The following drawings attached to this specification serve to further understand the technical idea of ​​the present invention together with the detailed description of the invention described below, and therefore the present invention should not be interpreted as being limited to the matters described in such drawings.

[0038] FIG. 1 is a block diagram illustrating a detailed configuration of a battery management device according to one embodiment of the present invention.

[0039] Figure 2 is a block diagram showing the detailed configuration of the characteristic point selection unit illustrated in Figure 1.

[0040] Figure 3 is a flowchart explaining a processing process according to one embodiment of the present invention.

[0041] Figure 4 is a flowchart illustrating a processing process according to another embodiment of the present invention.

[0042] Figure 5 is a flowchart illustrating a processing process according to another embodiment of the present invention.

[0043] Figure 6 is a diagram illustrating a differential profile of a reference cell group.

[0044] Figure 7 is a diagram illustrating a differential profile of a target cell group.

[0045] Figure 8 is a drawing explaining the characteristic points of the differential profile.

[0046] Figures 9 and 10 are drawings explaining the spacing of multiple characteristic points (peaks).

[0047] FIG. 11 is a schematic drawing of a vehicle according to another embodiment of the present invention.

[0048] FIG. 12 is a diagram schematically illustrating a battery management method according to another embodiment of the present invention.

[0049] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best possible manner.

[0050] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0051] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0052] Terms that include ordinal numbers, such as first, second, etc., are used to distinguish one of the various components from the rest, and are not used to limit the components by such terms.

[0053] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0054] Additionally, throughout the specification, when a part is said to be "connected" to another part, this includes not only cases where it is "directly connected" but also cases where it is "indirectly connected" with other elements in between.

[0055]

[0056] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0057] FIG. 1 is a block diagram illustrating a detailed configuration of a battery management device (100) according to one embodiment of the present invention. FIG. 2 is a block diagram illustrating a detailed configuration of a characteristic point selection unit illustrated in FIG. 1. FIG. 3 is a flowchart illustrating a processing process according to one embodiment of the present invention.

[0058] First, with reference to FIG. 1 and related drawings, etc., the detailed configuration of the battery management device (100) according to the present invention and the processing performed by these configurations will be described in detail, and the detailed contents of the characteristic point selection unit (130) will be described later.

[0059] Referring to FIG. 1, a battery management device (100) may include a measurement unit (110), a profile processing unit (120), a characteristic point selection unit (130), a diagnosis unit (140), a management control unit (150), and a reference data storage unit (160).

[0060] Specifically, the characteristic point selection unit (130) may be configured to include an information storage unit (131), a function processing unit (133), and a point selection unit (135), as illustrated in FIG. 2, depending on the embodiment.

[0061] Before going into a detailed description of the present invention, it should be understood that the battery management device (100) according to the present invention can be implemented through various combinational applications of electronic devices, parts, etc., such as storage means, operation processing means, input / output means, etc. Therefore, each component of the battery management device (100) illustrated in FIG. 1 should be understood as a functionally or logically distinct component rather than a physically distinct component. The same applies to each component of the characteristic point selection unit (130) illustrated in FIG. 2.

[0062] That is, since each component illustrated in the above drawing corresponds to a logical configuration for effectively explaining the technical idea of ​​the present invention, even if each component is configured integrated or separated, if the function performed by the logical configuration of the present invention can be realized, it should be interpreted as being within the scope of the present invention, and of course, if it is a component that performs the same or similar function, it should be interpreted as being within the scope of the present invention regardless of whether or not the name is consistent.

[0063] In addition, the battery management method according to the present invention can be implemented as a set or algorithm of processing related to data processing, handling, control, operation, input / output, etc., and thus, it can be implemented by a combination of logical configurations shown in FIG. 1, etc., as well as in the form of software installed and operated in a system, device, computer (or a device equivalent thereto), BMS, module, or sub-component thereof.

[0064] The battery management device (100) of the present invention is configured to diagnose whether a degradation imbalance has occurred or / and the degree of degradation imbalance (hereinafter referred to as “severity”) in a cell group (50) in which a plurality of cells (51) are electrically connected, and may be configured to generate and output diagnostic data for the corresponding cell group (50) for organic linkage with other configurations or modules / devices, depending on the embodiment.

[0065] As illustrated in FIG. 1, it goes without saying that a plurality of cell groups (50) diagnosed and managed by the battery management device (100) according to the present invention can be provided in the target battery (10), which is an upper assembly (50-1, 50-2, 50-3, 50-N).

[0066] In addition, although FIG. 1 shows a plurality of cells (51) constituting a cell group (50) connected in parallel, this is only an example, and it is to be understood that, depending on the embodiment, each cell (51) connected in parallel may be a plurality of unit cells connected in series.

[0067] The profile processing unit (120) of the present invention is configured to acquire a charge / discharge profile of a cell group (50) in which a plurality of cells are electrically connected. Here, the charge / discharge profile refers to a profile indicating a correspondence between the voltage and capacity of the cell group (50). Meanwhile, the capacity may be replaced with the State of Charge (SOC). That is, depending on the embodiment, the charge / discharge profile may also refer to a profile indicating a correspondence between the voltage and SOC.

[0068] The charge / discharge profile can be stored and utilized in the profile processing unit (120) of the present invention by receiving input from a separately provided device or module, etc.

[0069] In addition, according to the embodiment, the measuring unit (110) can measure the voltage, current, etc. of the cell group (50) during the charging or discharging process to generate electrical characteristic values ​​of the cell group (50) (S300, see FIG. 3). Of course, the profile processing unit (120) can also generate a charge / discharge profile based on the generated electrical characteristic values ​​(S310). According to the embodiment, the charge / discharge profile can be a data set in which voltage values ​​and capacity values ​​measured at the same time are mapped.

[0070] SOC is a parameter that represents the current capacity relative to the maximum capacity as 0 to 1 or 0% to 100%, and various techniques and technologies such as ampere counting, equivalent circuit model (ECM), Kalman filter, etc. can be applied, and depending on the embodiment, temperature information can be further reflected to generate information on SOC.

[0071] When a charge / discharge profile is created in this way (S310), the characteristic point selection unit (130) selects a characteristic point corresponding to an inflection point among the charge / discharge profiles (S320).

[0072] An inflection point can be a point where the slope trend changes based on the graph shape or curve shape of the charge / discharge profile. In other words, an inflection point means a point where the sign of the slope increase rate changes (from positive to negative or from negative to positive), and means a point where a change in the shape of the irregularities in the graph of the charge / discharge profile, i.e., a change from convex (upward convex) to concave (downward convex), occurs.

[0073] An inflection point is a point where a change occurs due to the intrinsic characteristics of a cell (51) or a cell group (50) which is a collection of multiple cells, and can function as an important parameter point that can define the intrinsic state or characteristics of a cell (51), etc.

[0074] The identification or selection of such inflection points can be accomplished using tools or algorithms that parse graph structures. Furthermore, the differential profile of the charge / discharge profile can be utilized to enable more precise and clear identification of inflection points through numerical analysis, etc. The detailed description of the present invention will be described later.

[0075] In this way, when a characteristic point corresponding to an inflection point of the charge / discharge profile is selected, the diagnostic unit (140) is configured to diagnose the degeneration imbalance of the corresponding cell group (50) using the characteristic information of the characteristic point.

[0076] Specifically, the characteristic information may include information on the number of characteristic points.

[0077] For example, if the number of characteristic points is a single number, the diagnosis unit (140) may be configured to diagnose that no degenerate imbalance has occurred in the cell group. Conversely, if the number of characteristic points is plural, the diagnosis unit (140) may diagnose that a degenerate imbalance has occurred in the cell group (S330).

[0078] For example, in the case of a cell group (50) (hereinafter referred to as a 'reference cell group') consisting only of cells in a BOL (Beginning Of Life) state (excluding cases where defective cells are mixed in during the manufacturing process, etc.), the electrochemical behavior characteristics of individual cells constituting the reference cell group are substantially the same, so that the characteristic points selected from the charge / discharge profile of the reference cell group may be a single number. This is because the states of the multiple cells included in the reference cell group are substantially the same.

[0079] In addition, even if the degree of degradation according to the use (charge / discharge) of each of the plurality of cells (51) belonging to the cell group (50) is substantially the same, the number of characteristic points selected from the charge / discharge profile of the cell group (50) may be a single number. This is because the degradation of the plurality of cells (51) included in the cell group (50) is uniform.

[0080] In contrast, when a degradation imbalance occurs between a plurality of cells (51) belonging to a cell group (50), a plurality of characteristic points may be selected from the charge / discharge profile of the cell group (50). This is because the characteristics of the plurality of cells (51) with a degradation imbalance are comprehensively reflected in the charge / discharge profile of the cell group (50).

[0081] The battery management device (100) of the present invention can simply and accurately diagnose the degeneration imbalance of a cell group (50) by utilizing the characteristic change in the charge / discharge profile deformation, i.e., the phenomenon of differentiation or separation of characteristic points (inflection points) confirmed in the charge / discharge profile.

[0082] Depending on the embodiment, for subsequent control processing or organic linkage with other configurations as described above, the diagnostic unit (140) may be configured to generate diagnostic data containing the diagnostic results (S340).

[0083]

[0084] FIG. 2 is a block diagram showing a detailed configuration of the characteristic point selection unit (130) shown in FIG. 1, and FIG. 4 is a flowchart explaining a processing process according to another embodiment of the present invention.

[0085] As described above, the characteristic point selection unit (130) can select a characteristic point corresponding to an inflection point in the charge / discharge profile.

[0086] Specifically, the characteristic point selection unit (130) may include an information storage unit (131), a function processing unit (133), and a point selection unit (135) as illustrated in FIG. 2. As previously discussed, the components illustrated in FIG. 2 correspond to a logical configuration.

[0087] The information storage unit (131) can store information on the charge / discharge profile of the cell group (50), identification information, specification information of the included cells (51), usage period, and usage history (S400).

[0088] The function processing unit (133) can perform function processing, etc. on the charge / discharge profile of the cell group (50) stored in the information storage unit (131) to generate a differential profile (S410).

[0089] For example, the function processing unit (133) can generate a differential profile indicating a correspondence between the capacity and differential voltage of the cell group (50). As another example, the function processing unit (133) can also generate a differential profile indicating a correspondence between the voltage and differential capacity of the cell group (50).

[0090] Here, the differential voltage is the voltage differentiated with respect to the capacity, and can be expressed as "dV / dQ" and the unit can be [V / Ah]. If the charge / discharge profile that is the basis of the differential profile is a profile generated during the charging process, if the X-axis of the two-dimensional coordinate is set to SOC (or capacity) and the Y-axis is set to the differential voltage, the differential profile (differential voltage profile) can be expressed as a graph exemplified in Fig. 6.

[0091] In addition, the differential capacity is the capacity differentiated with respect to the voltage, and can be expressed as "dQ / dV" and the unit can be [Ah / V]. Of course, the differential profile (differential capacity profile) can be expressed as a two-dimensional graph by setting the X-axis of the two-dimensional coordinates to voltage and the Y-axis to differential capacity.

[0092] Hereinafter, as illustrated in FIG. 6, the differential profile is explained assuming that it is a differential voltage profile generated during the charging process of the cell group (50). However, it is to be understood that the technical idea of ​​the present invention can be applied not only to cases where the differential profile is generated based on the charge / discharge profile generated during the discharging process by applying simple transformations such as symmetry movement and variable conversion, but also to cases where a differential profile (differential capacity profile) representing the correspondence between the voltage and differential capacity of the cell group (50) is used.

[0093] When a differential profile is generated as described above, the point selection unit (135) can select a peak of the differential profile as a characteristic point (S420).

[0094] As described above, the characteristic point is a point corresponding to an inflection point of the charge / discharge profile of the cell group (50). Specifically, the peak of the differential profile is a point where the sign of the slope changes in the differential profile, and is a point where the slope is 0. For example, the point corresponding to the maximum point of the differential profile is the peak of the differential profile. That is, since the characteristic point (inflection point) appears as a vertex (peak) of an upward convex shape in the differential profile, the characteristic point can be selected more accurately and clearly by selecting a peak having a corresponding shape characteristic.

[0095] For example, when a differential profile representing a correspondence between a capacity and a differential voltage is generated, the point selection unit (135) can determine a capacity having the smallest corresponding differential voltage in the generated differential profile. In addition, the point selection unit (135) can be configured to select a characteristic point from among a plurality of peaks included in a capacity range greater than the determined capacity.

[0096] As another example, if a differential profile representing a correspondence between voltage and differential capacitance is generated, the point selection unit (135) can determine a voltage having the largest corresponding differential capacitance in the generated differential profile. In addition, the point selection unit (135) can be configured to select a characteristic point from among a plurality of peaks included in a voltage range greater than the determined voltage.

[0097] Hereinafter, with further reference to FIGS. 6 to 10, the specific technical contents of this invention for selecting characteristic points using peaks and diagnosing degenerative imbalance will be described.

[0098] Figure 6 is a diagram illustrating a differential profile of a reference cell group. As previously defined, the reference cell group refers to a group of cells comprised of cells in a BOL state, and therefore, the differential profile illustrated in Figure 6 serves as a criterion for determining whether or not there is a degenerate imbalance.

[0099] As illustrated in Fig. 6, there may be multiple points that geometrically correspond to peaks in the differential profile of the reference cell group.

[0100] In the case of a secondary battery-based cell (51) or a cell group (50) that is a collection of these, since the intrinsic characteristic change of the negative electrode is concentrated in the middle region of the SOC, a peak (Peak1) corresponding to a maximum point may be included in the middle region of the SOC of the differential profile. For example, in the embodiment of FIG. 6, a peak (Peak1) may be included in the range of 40% to 70% of the SOC of the differential profile.

[0101] As can be seen in Fig. 6, in the case of the reference cell group, i.e., the cell group (50) in which no degeneration imbalance has occurred, the characteristic point of the charge / discharge profile is a single number. In contrast, as can be seen in Figs. 7 and 8, in the case of the degeneration imbalance cell group (50) in which the degeneration degrees of the individual cells (51) are different from each other, a phenomenon of peak separation or differentiation (split) occurs, and thus multiple characteristic points (Peak2) can be detected.

[0102] For example, in the embodiment of FIG. 7, the point selection unit (135) can determine the lowest differential voltage in the differential profile. For example, the differential voltage may be lowest around about 30% of SOC. The point selection unit (135) can detect the characteristic point (Peak2) in the SOC section after the SOC corresponding to the lowest differential voltage. For example, the point selection unit (135) can detect the characteristic point (Peak2) in the range of 40% or more and 70% or less of SOC.

[0103] In this way, when multiple characteristic points are detected or selected (S430, FIG. 4), the diagnostic unit (140) of the present invention can diagnose that a degenerative imbalance has occurred in the corresponding cell group (50) (S450).

[0104] In contrast, if the characteristic points of the corresponding cell group (50) are detected as a single number, it can be considered that the degree of degeneration or aging of the cells (51) belonging to the corresponding cell group (50) is at an equivalent level within the error range, and therefore the diagnosis unit (140) of the present invention can diagnose that no degeneration imbalance has occurred in the corresponding cell group (50) (S440). Of course, depending on the embodiment, even if a plurality of characteristic points are detected within a range that does not exceed the reference error, it can be configured so that the characteristic points are considered to have been detected as a single number.

[0105] Specifically, the intrinsic characteristic change of the cathode may be concentrated in the target SOC section included in a predetermined SOC range from the SOC corresponding to the lowest differential voltage in the differential profile. That is, if unbalanced degradation occurs in a plurality of cells (51), the cathode states of the plurality of cells (51) may become different. Therefore, the diagnosis unit (140) may diagnose whether or not a degradation imbalance occurs in the cell group (50) based on information on the number of characteristic points in the target SOC section.

[0106] As the cell (51) is used for a long time, the driving performance deteriorates and the possibility of occurrence of peculiar behavioral characteristics increases, so the reference error is configured to be set variably, but it is preferable to set it so that the longer the period of use of the cell group (50), the smaller it becomes, that is, so that the judgment of deterioration imbalance becomes stricter.

[0107] The diagnostic unit (140) can be configured to generate and output diagnostic data representing a diagnosis of a degenerative imbalance of a cell group (50) as described above (S460).

[0108] The management control unit (150) may be configured to change the usage conditions of the cell group (50) so that charging and discharging of the cell group (50) is limited when a degeneration imbalance occurs in the cell group (50) based on the diagnostic data input from the diagnostic unit (140) (S470).

[0109] For example, the management control unit (150) may change the upper limit SOC and / or the lower limit SOC of the cell group (50) to prevent the degradation of the cell group (50) in which the degradation imbalance has occurred from becoming more unbalanced. Specifically, the management control unit (150) may decrease the upper limit SOC or increase the lower limit SOC. In addition, the management control unit (150) may decrease the upper limit SOC and increase the lower limit SOC.

[0110] According to an embodiment, it is preferable that the diagnostic unit (140) or management control unit (150) of the present invention be configured to output information (identification information, degradation severity information, etc.) about a cell group (50) in which a degradation imbalance has occurred to a user terminal or a vehicle's info system.

[0111]

[0112] Hereinafter, another embodiment of the present invention will be described in detail with reference to FIG. 5, etc.

[0113] As described above, the characteristic information may include information on the number of characteristic points, but for implementation of a more preferred embodiment, the characteristic information may further include information on the spacing between characteristic points when a plurality of characteristic points are detected (S500).

[0114] Specifically, the diagnostic unit (140) of the present invention can generate information on the degree of separation of a plurality of characteristic points when data on characteristic points is input from the characteristic point selection unit (130) (S510). In addition, the diagnostic unit (140) can be configured to generate information on the degree of degeneration imbalance, which increases as the degree of separation information increases (S520).

[0115] The distance information can be generated by calculating the distance (based on SOC) (D1, D2) between multiple characteristic points or by statistically processing it (variance, weighted average, etc.).

[0116] Based on the example of Fig. 9, in case 1, D1 ((a) of Fig. 9) serves as the reference for the separation information, and in case 2, D2 ((b) of Fig. 9) serves as the reference for the separation information. For reference, case 1 and case 2 represent the differential profiles of each group of degenerate imbalanced cells (50) having different degenerate characteristics.

[0117] According to an embodiment, as illustrated in FIG. 10, the distance between the characteristic points of the reference cell group and each characteristic point of the degenerate imbalance cell group (50) can be used to generate the distance information. In the case of FIG. 10(a), "d11+d12" becomes the standard for the distance information, and in the case of FIG. 10(b), "d21+d22" becomes the standard for the distance information.

[0118] The charge / discharge profile, differential profile, characteristic point information, etc. of the reference cell group can be stored and utilized in a reference data storage unit (160) that is communicatively connected to the diagnostic unit (140) of the present invention.

[0119] When the diagnostic unit (140) generates diagnostic data including the depth information and outputs it to the management control unit (150) (S530), the management control unit (150) controls the charging and discharging of the corresponding cell group (50) to be limited depending on whether a degeneration imbalance occurs.

[0120] In addition, the management control unit (150) can control the charging / discharging range of the cell group (50) to be differentially limited according to the size of the depth information, such as by making the limit of the charging / discharging range relatively large for a cell group (50) with relatively large depth information (S540).

[0121] For example, in the embodiment of FIG. 10, since the depth information of case 2 is greater than the depth information of case 1, the management control unit (150) can further restrict the charge / discharge range of the cell group of case 2 than the charge / discharge range of the cell group of case 1. For example, the management control unit (150) can reduce the upper limit SOC of the cell group of case 1 by 10% and increase the lower limit SOC by 10%. In addition, the management control unit (150) can reduce the upper limit SOC of the cell group of case 2 by 15% and increase the lower limit SOC by 15%.

[0122] That is, the battery management device (100) can diagnose not only whether a degeneration imbalance has occurred for each of the plurality of cell groups (50) constituting the target battery (10), but also the degree of degeneration imbalance worsening using accurately quantified values, so that the replacement time for a specific cell group (50), setting of a usage restriction range, and charge / discharge control can be implemented more precisely.

[0123]

[0124] Meanwhile, the battery management device (100) according to the present invention can be applied to a BMS (Battery Management System). That is, the BMS according to the present invention can include the battery management device (100) described above. In this configuration, at least some of the components of the battery management device (100) can be implemented by supplementing or adding to the functions of the components included in a conventional BMS.

[0125] In addition, the battery management device (100) according to the present invention may be provided in a battery pack. That is, the battery pack according to the present invention may include the battery management device (100) described above and one or more cell groups (50).

[0126]

[0127] FIG. 11 is a schematic drawing of a vehicle (1100) according to another embodiment of the present invention.

[0128] Referring to FIG. 11, a battery pack according to an embodiment of the present invention may be included in a vehicle (1100), such as an electric vehicle (EV) or a hybrid vehicle (HV). Furthermore, the battery pack (1110) may drive the vehicle (1100) by supplying power to a motor through an inverter provided in the vehicle (1100). Here, the battery pack (1110) may include a battery management device (100). That is, the vehicle (1100) may include a battery management device (100). In this case, the battery management device (100) may be an onboard diagnostic device included in the vehicle (1100).

[0129]

[0130] FIG. 12 is a diagram schematically illustrating a battery management method according to another embodiment of the present invention.

[0131] Referring to FIG. 12, the battery management method may include a profile processing step (S110), a characteristic point selection step (S120), and a diagnosis step (S130).

[0132] Preferably, each step of the battery management method can be performed by a battery management device (100). In the following, any content that overlaps with the previously described content will be omitted or briefly described.

[0133] The profile processing step (S110) is a step of obtaining a charge / discharge profile of a cell group in which multiple cells are electrically connected, and can be performed by a profile processing unit (120).

[0134] The characteristic point selection step (S120) is a step of selecting a characteristic point corresponding to an inflection point in the charge / discharge profile, and can be performed by the characteristic point selection unit (130).

[0135] For example, the characteristic point selection unit (130) may specify an inflection point in the charge / discharge profile and select a characteristic point corresponding to the specified inflection point. As another example, the characteristic point selection unit (130) may specify a peak in the differential profile and select a characteristic point corresponding to the specified peak.

[0136] Preferably, the characteristic point selection unit (130) can select characteristic points in the SOC middle region (e.g., SOC 40% to 70% region) among the entire SOC range of the cell group (50).

[0137] The diagnosis step (S130) is a step for diagnosing the degeneration imbalance of a cell group using characteristic information of characteristic points, and can be performed by the diagnosis unit (140).

[0138] For example, the diagnostic unit (140) can diagnose that a degenerate imbalance has not occurred in the cell group (50) if the number of characteristic points is a single number. As another example, the diagnostic unit (140) can diagnose that a degenerate imbalance has occurred in the cell group (50) if the number of characteristic points is a plurality.

[0139]

[0140] The embodiments of the present invention described above are not implemented only through devices and methods, but may also be implemented through a program that realizes a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation can be easily implemented by an expert in the technical field to which the present invention belongs based on the description of the embodiments described above.

[0141] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0142] In addition, the present invention described above is not limited to the above-described embodiments and the attached drawings, and all or part of each embodiment may be selectively combined and configured so that various modifications can be made, as those skilled in the art can make various substitutions, modifications, and changes within the scope of the technical idea of ​​the present invention.

[0143] [Explanation of symbols]

[0144] 10: Target Battery

[0145] 50: Cell Group

[0146] 51: Cell

[0147] 100: Battery management device

[0148] 110: Measurement section

[0149] 120: Profile Processing Unit

[0150] 130: Characteristic Point Selection Section

[0151] 131: Information storage unit

[0152] 133: Function processing unit

[0153] 135: Point Selection Department

[0154] 140: Diagnostic Department

[0155] 150: Management Control Unit

[0156] 160: Reference data storage

[0157] 1100: Car

[0158] 1110: Battery Pack

Claims

1. A profile processing unit configured to obtain a charge / discharge profile of a group of cells in which a plurality of cells are electrically connected; A characteristic point selection unit configured to select a characteristic point corresponding to an inflection point among the above charge / discharge profiles; and A battery management device characterized by including a diagnostic unit configured to diagnose a degradation imbalance of the cell group using characteristic information including information on the number of characteristic points.

2. In paragraph 1, The above diagnostic section, If the number of the above characteristic points is a single number, it is diagnosed that the degenerative imbalance has not occurred in the above cell group, A battery management device characterized in that it is configured to diagnose that the degeneration imbalance has occurred in the cell group when the number of the above characteristic points is plural.

3. In paragraph 1, The above charge / discharge profile is, A profile showing the correspondence between the voltage and capacity of the above cell group, The above characteristic point selection section, A function processing unit configured to generate a differential profile, which is a profile representing a correspondence between the capacity and differential voltage of the cell group or a correspondence between the voltage and differential capacity of the cell group, based on the charge / discharge profile; and A battery management device characterized by including a point selection unit configured to select the characteristic point from the differential profile.

4. In paragraph 3, The above point selection section, A battery management device characterized in that, when a differential profile representing a correspondence between the capacity and the differential voltage is generated, a capacity having the smallest corresponding differential voltage in the generated differential profile is determined, and the characteristic point is selected from among a plurality of peaks included in a capacity range greater than the determined capacity.

5. In paragraph 3, The above point selection section, A battery management device characterized in that, when a differential profile representing a correspondence between the voltage and the differential capacity is generated, a voltage having the largest corresponding differential capacity in the generated differential profile is determined, and the characteristic point is selected from among a plurality of peaks included in a voltage range greater than the determined voltage.

6. In paragraph 3, The above point selection section, A battery management device characterized in that it is configured to select a peak in which the SOC of the cell group among the above peaks is located in a range of 40% or more and 70% or less as the characteristic point.

7. In paragraph 1, A battery management device further comprising a management control unit configured to change the usage conditions of the cell group so that charging and discharging of the cell group is limited when the degradation imbalance is diagnosed to have occurred in the cell group.

8. In paragraph 1, The above characteristic information is, If there are multiple characteristic points, the distance information between the characteristic points is further included. The above diagnostic section, A battery management device characterized in that it is configured to generate diagnostic data including information on the degree of the above-mentioned degradation imbalance, the greater the degree of the above-mentioned degeneration imbalance information, the greater the degree of the above-mentioned degeneration imbalance information.

9. In paragraph 8, A battery management device characterized in that it further includes a management control unit configured to change the usage conditions of the cell group so that the charge / discharge range of the cell group is differentially limited according to the size of the separation information when the degradation imbalance is diagnosed to have occurred in the cell group.

10. A battery pack comprising a battery management device according to any one of claims 1 to 9.

11. A vehicle including a battery management device according to any one of claims 1 to 9.

12. A profile processing step for obtaining a charge / discharge profile of a group of cells in which multiple cells are electrically connected; A characteristic point selection step for selecting a characteristic point corresponding to an inflection point among the above charge / discharge profiles; and A battery management method characterized by including a diagnosis step of diagnosing a degeneration imbalance of the cell group using characteristic information of the characteristic point.

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