Battery management device and method

Abstract

A battery management device according to one embodiment of the present invention includes a profile acquisition unit that acquires a first profile for each of a plurality of batteries contained in a battery pack, and a diagnostic unit that calculates a target ratio from each of the plurality of first profiles, calculates each target value as a diagnostic factor based on the calculated plurality of target ratios, generates a distribution profile showing the correspondence between the calculated plurality of target values ​​and the number of each of the plurality of target values, determines whether the distribution profile satisfies predetermined conditions, and diagnoses the state of the battery pack according to the result of the determination.

Description

Technical Field

[0001] The present invention relates to a battery management device and method, and more particularly, to a battery management device and method capable of diagnosing the state of a battery pack.

[0002] This application claims priority based on Korean Patent Application No. 10-2024-0005648 filed on January 12, 2024, and all of the contents disclosed in the specification and drawings of the application are incorporated herein.

Background Art

[0003] In recent years, as the demand for portable electronic products such as notebook computers, video cameras, and mobile phones has rapidly increased, and the development of electric vehicles, energy storage batteries, robots, artificial satellites, etc. has become full-scale, research on high-performance rechargeable batteries has been actively conducted.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among these, lithium batteries are in the spotlight because they can be freely charged and discharged with almost no memory effect compared to nickel-based batteries, have a very low self-discharge rate, and have a high energy density.

[0005] Batteries are used in various fields, but in fields where batteries are widely used recently, such as electric vehicles or smart grid systems, a large-capacity battery is often required. To increase the capacity of a battery pack, there is a method of increasing the capacity of a secondary battery, that is, the battery cell itself. However, in this case, the effect of capacity increase is not large, and there are disadvantages that physical limitations occur in expanding the size of the secondary battery and management is inconvenient. Therefore, usually, a battery pack in which a large number of battery cells are connected in series and parallel is widely used.

Summary of the Invention

[0006] The present invention was devised to solve the above-mentioned problems, and aims to provide a battery management device and method that can diagnose the state of degradation imbalance among multiple batteries contained in a battery pack.

[0007] Other objects and advantages of the present invention can be understood from the following description and more clearly from the embodiments of the present invention. Furthermore, the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. [Means for solving the problem]

[0008] A battery management device according to one aspect of the present invention includes a profile acquisition unit configured to acquire a first profile for each of a plurality of batteries contained in a battery pack, and a diagnostic unit configured to calculate a target ratio from each of the plurality of first profiles, calculate each target value as a diagnostic factor based on the calculated plurality of target ratios, generate a distribution profile showing the correspondence between the calculated plurality of target values ​​and the number of each of the plurality of target values, determine whether the distribution profile satisfies predetermined conditions, and diagnose the state of the battery pack according to the result of the determination.

[0009] The first profile is a negative electrode profile, and the target ratio may be a negative electrode change ratio, which is the change ratio of the first profile to a preset reference negative electrode profile.

[0010] If the distribution profile does not satisfy the predetermined conditions, the diagnostic unit may be configured to diagnose the state of the battery pack as being in a state of degradation imbalance.

[0011] If the distribution profile satisfies the predetermined conditions, the diagnostic unit may be configured to compare the characteristic values ​​of the distribution profile with a preset threshold and diagnose the state of the battery pack based on the result of the comparison.

[0012] If the characteristic value exceeds the threshold, the diagnostic unit may be configured to diagnose the state of the battery pack as being in a state of degradation imbalance.

[0013] If the characteristic value is below the threshold, the diagnostic unit may be configured to diagnose the state of the battery pack as being in a state of degradation equilibrium.

[0014] The diagnostic unit may be configured to set the threshold based on the degree of degradation of the battery pack and a preset reference characteristic value.

[0015] The diagnostic unit may be configured to calculate a first value and a second value based on the plurality of target values, and to determine whether the distribution profile satisfies the predetermined conditions according to the ratio of the first value and the second value.

[0016] The diagnostic unit may be configured to determine a minimum value, a maximum value, and a reference value from among the plurality of target values, calculate the difference between the minimum value and the reference value as the first value, and calculate the difference between the reference value and the maximum value as the second value.

[0017] The diagnostic unit may be configured to determine the target value as the reference value, which is the target value with the largest number of corresponding items among the plurality of target values.

[0018] The diagnostic unit may be configured to compare the ratio with a preset critical ratio interval and determine whether the distribution profile satisfies the predetermined conditions based on the results of the comparison.

[0019] If the ratio falls within the critical ratio interval, the diagnostic unit may be configured to determine that the distribution profile satisfies the predetermined conditions.

[0020] When the ratio does not belong to the critical ratio interval, the diagnosis unit may be configured to determine that the distribution profile satisfies the predetermined condition.

[0021] The diagnosis unit may be configured to determine the target ratio as the target value.

[0022] The diagnosis unit may be configured to calculate a negative electrode loss rate based on a ratio between a preset reference ratio and the target ratio for each of the plurality of batteries, and determine the calculated negative electrode loss rate as the target value.

[0023] When it is determined that the state of the battery pack is a deteriorated unbalanced state, the diagnosis unit may be configured to activate a function for eliminating the deteriorated imbalance or output an alarm.

[0024] The function for eliminating the deteriorated imbalance may be a pack balancing function.

[0025] A battery pack according to another aspect of the present invention includes a battery management device according to an aspect of the present invention.

[0026] An automobile according to still another aspect of the present invention includes a battery management device according to an aspect of the present invention.

[0027] According to yet another aspect of the present invention, a battery management method includes a profile acquisition step of acquiring a first profile for each of a plurality of batteries included in a battery pack, a target value calculation step of calculating a target ratio from each of the plurality of first profiles and calculating respective target values as diagnostic factors based on the calculated target ratios, a profile generation step of generating a distribution profile indicating a correspondence relationship between the calculated plurality of target values and the respective numbers of the plurality of target values, a condition determination step of determining whether the distribution profile satisfies a predetermined condition, and a state diagnosis step of diagnosing the state of the battery pack according to the result of the determination.

[0028] When the state of the battery pack is diagnosed as a deteriorated imbalance state in the state diagnosis step, the method may further include a measure step of activating a function for eliminating the deteriorated imbalance or outputting an alarm.

[0029] According to yet another aspect of the present invention, a recording medium is a non-temporary readable recording medium having recorded thereon a program for executing a battery management method including a profile acquisition step of acquiring a first profile for each of a plurality of batteries included in a battery pack, a target value calculation step of calculating a target ratio from each of the plurality of first profiles and calculating respective target values as diagnostic factors based on the calculated plurality of target ratios, a profile generation step of generating a distribution profile indicating a correspondence relationship between the calculated plurality of target values and the respective numbers of the plurality of target values, a condition determination step of determining whether the distribution profile satisfies a predetermined condition, and a state diagnosis step of diagnosing the state of the battery pack according to the result of the determination.

Advantages of the Invention

[0030] According to one aspect of the present invention, a battery management device can diagnose a deteriorated imbalance state among a plurality of batteries included in a battery pack.

[0031] The effects of the present invention are not limited to those described above, and other effects of the present invention not mentioned herein will be clearly understood by those skilled in the art from the claims.

[0032] The drawings accompanying this specification, along with the detailed description of the invention described below, are intended to further facilitate understanding of the technical concept of the present invention, and the present invention is not to be interpreted as being limited only to the matters described in the drawings. [Brief explanation of the drawing]

[0033] [Figure 1] This diagram schematically shows a battery management device according to one embodiment of the present invention. [Figure 2] This figure schematically shows the negative electrode profile NP according to one embodiment of the present invention. [Figure 3] This figure schematically shows the first distribution profile according to one embodiment of the present invention. [Figure 4] This figure schematically shows the second distribution profile according to one embodiment of the present invention. [Figure 5] This figure schematically shows the reference positive electrode profile and reference negative electrode profile according to one embodiment of the present invention. [Figure 6] This figure, by an embodiment of the present invention, is a reference to illustrate an example of a process for generating a comparison profile used for comparison with a battery profile. [Figure 7] This figure, by an embodiment of the present invention, is a reference to illustrate an example of a process for generating a comparison profile used for comparison with a battery profile. [Figure 8] This figure, by an embodiment of the present invention, is a reference to illustrate an example of a process for generating a comparison profile used for comparison with a battery profile. [Figure 9]This figure, by embodiment of the present invention, is a reference to illustrate another example of the process for generating a comparison profile used for comparison with a battery profile. [Figure 10] This figure, by embodiment of the present invention, is a reference to illustrate another example of the process for generating a comparison profile used for comparison with a battery profile. [Figure 11] This figure, by embodiment of the present invention, is a reference to illustrate another example of the process for generating a comparison profile used for comparison with a battery profile. [Figure 12] This figure shows an exemplary configuration of a battery pack according to another embodiment of the present invention. [Figure 13] This figure schematically shows an automobile according to yet another embodiment of the present invention. [Figure 14] This figure schematically illustrates a battery management method according to yet another embodiment of the present invention. [Figure 15] This figure schematically shows the condition determination step and the state diagnosis step of a battery management method according to yet another embodiment of the present invention. [Modes for carrying out the invention]

[0034] The terms and words used in this specification and in the claims are not to be interpreted in a manner limited to their general and dictionary meanings, but rather in a manner corresponding to the technical idea of ​​the present invention, in accordance with the principle that inventors can appropriately define the concepts of terms in order to best describe their invention.

[0035] Therefore, the embodiments described herein and the configurations shown in the drawings represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the invention. It should be understood that there are various equivalents and modifications that can substitute for them at the time of filing this application.

[0036] Furthermore, in describing the present invention, if it is determined that a specific description of a related known configuration or function would obscure the gist of the present invention, such detailed description will be omitted.

[0037] Terms that include ordinal numbers, such as "1st," "2nd," etc., are used to distinguish one of several components from others, and these terms do not limit the components themselves.

[0038] Whenever a part of the specification is described as "including" or "equipping" a component, unless otherwise specified, this does not exclude other components, but rather means that other components may be included.

[0039] Furthermore, when a part of the specification is described as being "connected" to another part, this includes not only "direct connections" but also "indirect connections" mediated by other elements.

[0040] Generally, batteries degrade with use, but repeated charging and discharging of a battery pack or prolonged periods of storage can lead to differences in the degradation state of the multiple batteries contained within the pack. In other words, the degradation state of the multiple batteries contained within a battery pack can be uneven.

[0041] As batteries degrade, their usable capacity decreases. Therefore, if the degradation levels of the multiple batteries in a battery pack are uneven, the usable capacity of each battery may differ. In this case, the usable capacity of the battery pack will be determined based on the smallest usable capacity among the multiple batteries.

[0042] For example, suppose a battery pack contains five batteries connected in series, with four batteries having a usable capacity of 100Ah and one battery having a usable capacity of 90Ah. In this case, the usable capacity of the battery pack is 450Ah, not 490Ah. In this case, there is a problem that 40Ah of capacity is not used because the degradation of the multiple batteries is not uniform.

[0043] This invention provides a technology for diagnosing the state of degradation imbalance among multiple batteries contained in a battery pack.

[0044] Embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0045] Figure 1 is a schematic diagram showing a battery management device 100 according to one embodiment of the present invention.

[0046] Referring to Figure 1, the battery management device 100 includes a profile acquisition unit 110 and a diagnostic unit 120.

[0047] The profile acquisition unit 110 may be configured to acquire a first profile, for example, a negative electrode profile, for each of the multiple batteries included in the battery pack.

[0048] Here, "battery" refers to a single, physically separable, independent cell equipped with a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium-polymer battery may be considered a battery. The type of battery can be cylindrical, prismatic, or pouch-type. Furthermore, "battery" may also refer to a battery bank or battery module in which multiple cells are connected in series and / or parallel. For the sake of explanation, in the following, "battery" will be described as referring to a single, independent cell.

[0049] Figure 2 is a schematic diagram showing the negative electrode profile NP according to one embodiment of the present invention, and Figure 5 is a schematic diagram showing the reference positive electrode profile Rp and reference negative electrode profile Rn according to one embodiment of the present invention.

[0050] In the embodiments shown in Figures 2 and 5, the horizontal axis (X-axis) represents capacitance (Ah), and the vertical axis (Y-axis) represents voltage (V).

[0051] As an example, the profile acquisition unit 110 can acquire a battery profile BP that shows the correspondence between the battery voltage and capacity, and determine a negative electrode profile NP by adjusting a preset reference positive electrode profile Rp and reference negative electrode profile Rn that correspond to the battery profile BP. Then, the profile acquisition unit 110 can acquire a negative electrode change ratio based on the determined negative electrode profile NP.

[0052] Here, the battery profile BP may be a profile showing the correspondence between the voltage (V) and capacity (Q) when the battery is being charged. Alternatively, the battery profile BP may be a profile showing the correspondence between the voltage (V) and capacity (Q) when the battery is being discharged.

[0053] The reference positive electrode profile Rp may be a profile that shows the correspondence between the capacity and voltage of a reference positive electrode cell pre-configured to correspond to the positive electrode of the battery. For example, the reference positive electrode cell may be a positive coin half-cell or the positive electrode of a tri-electrode cell. Similarly, the reference negative electrode profile Rn may be a profile that shows the correspondence between the capacity and voltage of a reference negative electrode cell pre-configured to correspond to the negative electrode of the battery. For example, the reference negative electrode cell may be a negative coin half-cell or the negative electrode of a tri-electrode cell.

[0054] Specifically, the profile acquisition unit 110 can acquire an adjusted positive electrode profile and an adjusted negative electrode profile by adjusting (shifting or scaling) the reference positive electrode profile Rp and the reference negative electrode profile Rn, respectively. The profile acquisition unit 110 can then combine the adjusted positive electrode profile and the adjusted negative electrode profile (summing the capacity values ​​for the same voltage value, or summing the voltage values ​​for the same capacity value) to generate a comparison profile. The profile acquisition unit 110 can generate multiple comparison profiles by repeating the adjustment and combination processes on the reference positive electrode profile Rp and the reference negative electrode profile Rn. The profile acquisition unit 110 can then identify the comparison profile that minimizes the error with the battery profile BP from among the multiple comparison profiles. The profile acquisition unit 110 can then determine the adjusted positive electrode profile and the adjusted negative electrode profile used to generate the identified comparison profile as the battery's positive electrode profile PP and negative electrode profile NP.

[0055] In this regard, a more specific embodiment of how the profile acquisition unit 110 determines the negative electrode profile NP will be described later with reference to Figures 5 to 11.

[0056] As another example, the profile acquisition unit 110 may receive the first profile directly from an external source instead of generating the first profile itself. For example, the profile acquisition unit 110 may receive the first profile by being connected to an external source via wired and / or wireless connection.

[0057] The diagnostic unit 120 may be configured to calculate a target ratio from each of the multiple first profiles and to calculate a target value based on the calculated target ratio.

[0058] Here, the target ratio can be the negative electrode change ratio. The negative electrode change ratio means the percentage change [%] between the negative electrode profile NP and the reference negative electrode profile Rn. Specifically, the negative electrode change ratio can be the contraction or expansion ratio of the negative electrode profile NP relative to the reference negative electrode profile Rn. For example, if the negative electrode profile NP is contracted by 10% from the reference negative electrode profile Rn, the negative electrode change ratio is 90%. Conversely, if the negative electrode profile NP is expanded by 10% from the reference negative electrode profile Rn, the negative electrode change ratio is 110%.

[0059] The diagnostic unit 120 may be configured to calculate the change ratio of the first profile to the reference negative electrode profile Rn as the target ratio. That is, the diagnostic unit 120 may calculate the change ratio of the negative electrode profile NP to the reference negative electrode profile Rn as the target ratio. For example, the diagnostic unit 120 may determine the target ratio as the target value. That is, the diagnostic unit 120 may determine the negative electrode change ratio as the target value.

[0060] The diagnostic unit 120 may be configured to generate a distribution profile that shows the correspondence between the calculated target values ​​and the number of each of the target values.

[0061] Figure 3 is a schematic diagram showing the first distribution profile p1 according to one embodiment of the present invention, and Figure 4 is a schematic diagram showing the second distribution profile p2 according to one embodiment of the present invention.

[0062] In the embodiments shown in Figures 3 and 4, the horizontal axis (X-axis) represents the target value, and the vertical axis (Y-axis) represents the number of each of the multiple target values.

[0063] As mentioned above, since target values ​​can be used as an indicator of battery degradation, a distribution profile showing the distribution of multiple target values ​​can be used as a profile showing the uniformity of degradation across multiple batteries.

[0064] The diagnostic unit 120 may be configured to determine whether the distribution profile meets predetermined conditions and to diagnose the state of the battery pack according to the result of that determination.

[0065] Specifically, the given conditions may be for determining whether the distribution profile follows a Gaussian distribution. In other words, the given conditions may be for determining whether the distribution profile exhibits a form similar to a Gaussian distribution.

[0066] A specific embodiment of how the diagnostic unit 120 determines whether the distribution profile satisfies predetermined conditions will be described later with reference to Figures 3 and 4.

[0067] If the distribution profile does not meet predetermined conditions, the diagnostic unit 120 may be configured to diagnose the state of the battery pack as a state of degradation imbalance.

[0068] Here, a state of degradation imbalance refers to a condition where the degradation state of the multiple batteries contained in a battery pack appears to be uneven. For example, if the degradation state of the multiple batteries in a battery pack is uneven, there may be differences in the maximum usable capacity of each battery.

[0069] Conversely, a state of degradation equilibrium refers to a state where the degradation status of each of the multiple batteries contained in a battery pack appears to be uniform. For example, even if the degradation status of some of the multiple batteries differs slightly, if the degree of difference is small and negligible, the battery pack can be diagnosed as being in a state of degradation equilibrium.

[0070] As batteries degrade, their usable capacity decreases. Therefore, if the degradation levels of the batteries within a battery pack are uneven, the usable capacity of each battery may differ. More specifically, if the degradation levels of the batteries within a battery pack are uneven, the usable capacities of all the batteries will not be the same. In this case, the usable capacity of the battery pack will be determined based on the smallest usable capacity among the multiple batteries.

[0071] For example, suppose a battery pack contains five batteries connected in series, with four batteries having a usable capacity of 100Ah and one battery having a usable capacity of 90Ah. In this case, the usable capacity of the battery pack is 450Ah, not 490Ah. That is, because the degradation of the multiple batteries is not uniform, there is a problem in that 40Ah of capacity is not used.

[0072] The second distribution profile p2 shown in Figure 4 is an example of a distribution profile that does not meet the predetermined conditions. The diagnostic unit 120 can diagnose the state of the battery pack corresponding to the second distribution profile p2 as a state of degradation imbalance.

[0073] If the distribution profile satisfies predetermined conditions, the diagnostic unit 120 may be configured to compare the characteristic values ​​of the distribution profile with a preset threshold and diagnose the state of the battery pack based on the results of the comparison.

[0074] The first distribution profile p1 shown in Figure 3 is an example of a distribution profile that satisfies the given conditions.

[0075] In the embodiment shown in Figure 3, the diagnostic unit 120 compares the characteristic values ​​of the first distribution profile p1 with a preset threshold and can diagnose the state of the battery pack based on the comparison result.

[0076] Here, the feature value represents the difference between two target values ​​that have the same number of corresponding occurrences on the distribution profile. The number of occurrences (Y-axis value) used to determine the feature value can be predetermined. For example, the feature value may represent the full width at half maximum (FWHM). In this case, the number of occurrences used to determine the feature value can be predetermined to half the maximum number of occurrences on the distribution profile. As another example, the feature value may represent the maximum difference between two target values ​​that have the same number of corresponding occurrences on the distribution profile. Referring to Figure 3, the feature value of the first distribution profile p1 may be the difference (x2-x1) between two target values ​​(x1, x2) that have the same number of corresponding occurrences as k.

[0077] Thresholds can be pre-set based on the battery pack's BOL (Beginning of Life) state, the battery pack's current state (e.g., degradation level), a reference value derived from a corresponding reference pack, or a theoretically derived distribution profile. BOL refers to the battery's initial state, which is the point of first use after manufacturing and represents the state in which the battery can achieve its maximum capacity and performance.

[0078] Specifically, if the feature value exceeds a threshold, the diagnostic unit 120 may be configured to diagnose the battery pack as being in a state of degradation imbalance. Conversely, if the feature value is below the threshold, the diagnostic unit 120 may be configured to diagnose the battery pack as being in a state of degradation equilibrium.

[0079] A battery management device 100 according to one embodiment of the present invention can diagnose whether a battery pack is in a state of degradation imbalance by looking at the distribution of target values ​​that indicate the degradation state of multiple batteries contained in the battery pack.

[0080] On the other hand, the profile acquisition unit 110 and diagnostic unit 120 provided in the battery management device 100 may selectively include processors, ASICs (Application-Specific Integrated Circuits), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the industry, in order to execute the various control logics performed in the present invention. Furthermore, when the control logic is implemented as software, the profile acquisition unit 110 and diagnostic unit 120 may be implemented as a collection of program modules. In this case, the program modules are recorded in memory and can be executed by the profile acquisition unit 110 and diagnostic unit 120. The memory may be provided inside or outside the battery management device 100 and can be connected to the profile acquisition unit 110 and diagnostic unit 120 by various well-known means.

[0081] The battery management device 100 may further include a recording unit 130. The recording unit 130 may store data and programs necessary for each component of the battery management device 100 to operate and function, or data generated during the process of operation and functioning. The recording unit 130 is not particularly limited in type, as long as it is a known information recording means that is known to be able to record, erase, update, and read data. For example, information recording means may include RAM (Random Access Memory), flash memory, ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), registers, etc. The recording unit 130 may also store program code in which the process that can be executed by the profile acquisition unit 110 and the diagnostic unit 120 is defined.

[0082] Specifically, the recording unit 130 can store information necessary for the profile acquisition unit 110 to acquire a battery profile. The recording unit 130 can also store information necessary for the diagnostic unit 120 to diagnose the state of the battery pack. For example, the recording unit 130 can store a reference positive electrode profile, a reference negative electrode profile, a reference ratio, etc. In addition, the profile acquisition unit 110 and the diagnostic unit 120 can access the recording unit 130 to acquire necessary information. For example, target ratios for multiple batteries acquired by the profile acquisition unit 110 are recorded in the recording unit 130, and the diagnostic unit 120 can access the recording unit 130 to acquire the multiple target ratios that have been recorded.

[0083] According to one embodiment, the diagnostic unit 120 can set a threshold based on the degree of battery pack degradation and a preset reference characteristic value. For example, any value that the diagnostic unit 120 can calculate by relating the degree of battery pack degradation and the preset reference characteristic value can be applied as a threshold without limitation.

[0084] Preferably, the diagnostic unit 120 can set a threshold by multiplying the degree of battery pack degradation by a preset reference characteristic value.

[0085] The battery pack degradation level indicates the degree to which the battery pack has deteriorated. In other words, the battery pack degradation level indicates the rate of deterioration of the battery pack. That is, the battery pack degradation level is the opposite concept of SOH (State of Health), which indicates the health status of the battery pack, and can be expressed by the formula "(100-SOH)%". Here, SOH is estimated according to the ratio obtained by comparing the current value of the battery pack (e.g., capacity or resistance) with the initial value, and conventional SOH estimation methods can be applied.

[0086] The reference feature values ​​can be pre-set considering the battery pack's BOL status, distribution profile feature values, or battery pack specifications.

[0087] For example, the reference feature value can be pre-set to a specific value considering the specifications of the battery pack. That is, a general value considering the specifications of the battery pack to be diagnosed can be pre-set as the reference feature value. On the other hand, a general value considering the specifications of the battery pack can be pre-set to correspond to the feature value of the battery pack.

[0088] As another example, reference feature values ​​may be pre-set as feature values ​​of a baseline distribution profile. Here, the baseline distribution profile may mean the distribution profile obtained from a reference pack corresponding to the battery pack. Alternatively, the baseline distribution profile may mean the distribution profile generated when the battery pack is in a BOL state. The feature values ​​of the baseline distribution profile mean the difference between two target values ​​that have the same number of corresponding elements on the baseline distribution profile. Preferably, the criteria for determining the feature values ​​of the baseline distribution profile may be the same as the criteria for determining the feature values ​​of the distribution profile. Therefore, the feature values ​​of the baseline distribution profile and the feature values ​​of the distribution profile determined by the same criteria may be corresponding values.

[0089] In other words, the threshold can be set taking into account the current degree of degradation of the battery pack. Therefore, the battery management device 100 can more accurately diagnose the state of the battery pack based on a standard (threshold) for the current state of the battery pack.

[0090] The following describes a specific embodiment in which the diagnostic unit 120 determines whether or not the distribution profile satisfies predetermined conditions.

[0091] The diagnostic unit 120 may be configured to calculate a first value and a second value based on a plurality of target values, and to determine whether the distribution profile satisfies predetermined conditions according to the ratio of the first value and the second value.

[0092] For example, the diagnostic unit 120 can calculate a first value and a second value based on the minimum, maximum, and reference values ​​of a plurality of target values. Specifically, the diagnostic unit 120 can determine the minimum, maximum, and reference values ​​from among the plurality of target values. The diagnostic unit 120 can determine the target value with the largest corresponding number from among the plurality of target values ​​as the reference value. The diagnostic unit 120 may then be configured to calculate the difference between the minimum value and the reference value as the first value, and the difference between the reference value and the maximum value as the second value. Finally, the diagnostic unit 120 can determine whether the distribution profile satisfies predetermined conditions based on the ratio of the first value and the second value.

[0093] In the embodiment shown in Figure 3, the diagnostic unit 120 may determine a1 as the minimum value and a3 as the maximum value from among a plurality of target values. The diagnostic unit 120 may then determine a2, which has the largest corresponding number from among the plurality of target values, as the reference value. The diagnostic unit 120 may then calculate the difference between a1 and a2 (a2-a1) as the first value and the difference between a2 and a3 (a3-a2) as the second value. The diagnostic unit 120 may calculate the ratio of the first value (a2-a1) to the second value (a3-a2), which is "(a2-a1)÷(a3-a2)" or "(a3-a2)÷(a2-a1)", and determine whether the distribution profile satisfies predetermined conditions based on the calculation result.

[0094] For example, if a1 is 11.1%, a2 is 12.1%, and a3 is 13.1%, then the first value is 1%(12.1-11.1) and the second value is 1%(13.1-12.1). The ratio of the first value to the second value is 1.

[0095] In the embodiment shown in Figure 4, the diagnostic unit 120 may determine b1 as the minimum value and b3 as the maximum value from among a plurality of target values. The diagnostic unit 120 may then determine b2, which has the largest corresponding number from among the plurality of target values, as the reference value. The diagnostic unit 120 may then calculate the difference between b1 and b2 (b2-b1) as the first value and the difference between b2 and b3 (b3-b2) as the second value. The diagnostic unit 120 may calculate the ratio of the first value (b2-b1) to the second value (b3-b2), which is "(b2-b1)÷(b3-b2)" or "(b3-b2)÷(b2-b1)", and determine whether the distribution profile satisfies predetermined conditions based on the calculation result.

[0096] For example, if b1 is 10.1%, b2 is 11.9%, and b3 is 29.2%, then the first value is 1.8% (11.9 - 10.1) and the second value is 17.3% (29.2 - 11.9). The ratio of the first value to the second value is 9.61 (17.3 ÷ 1.8) or 0.10 (1.8 ÷ 17.3).

[0097] The diagnostic unit 120 may be configured to compare the ratio with a preset critical ratio interval and determine whether the distribution profile satisfies predetermined conditions based on the results of the comparison.

[0098] Specifically, if the calculated ratio falls within the critical ratio interval, the diagnostic unit 120 may determine that the distribution profile satisfies predetermined conditions. Conversely, if the calculated ratio does not fall within the critical ratio interval, the diagnostic unit 120 may be configured to determine that the distribution profile satisfies predetermined conditions.

[0099] If the ratio of the first value to the second value is greater than or equal to the lower limit and less than or equal to the upper limit of the critical ratio interval, the diagnostic unit 120 may determine that the calculated ratio belongs to the critical ratio interval. The diagnostic unit 120 may then determine that the distribution profile satisfies predetermined conditions. Conversely, if the ratio of the first value to the second value is less than the lower limit or greater than the upper limit, the diagnostic unit 120 may determine that the ratio does not belong to the critical ratio interval. The diagnostic unit 120 may then determine that the distribution profile does not satisfy predetermined conditions.

[0100] For example, the lower limit of the critical ratio interval may be set to "3÷7" and the upper limit to "7÷3". In other words, the critical ratio interval may be a predetermined interval used to check whether the ratio of the first value to the second value falls within the range of "3:7 to 7:3". In the following explanation, the lower limit of the critical ratio interval will be described as "3÷7" and the upper limit as "7÷3", but please note that the specific numerical values ​​are not limited by one embodiment of the present invention.

[0101] Similar to the embodiment described above, it is assumed that the lower limit of the critical ratio interval is set to "3÷7" and the upper limit is predetermined to "7÷3". In this case, in the embodiment of Figure 3, the ratio of the first value to the second value (first value (1%) ÷ second value (1%) = 1) is between "3÷7" and "7÷3", so the diagnostic unit 120 can determine that the ratio belongs to the critical ratio interval. The diagnostic unit 120 can then determine that the first distribution profile p1 satisfies predetermined conditions.

[0102] Similar to the embodiment described above, assume that the lower limit of the critical ratio interval is set to "3÷7" and the upper limit is set to "7÷3". In this case, in the embodiment of Figure 4, if the critical ratio interval is set to be between "3÷7" and "7÷3", then the ratio of the first value to the second value (first value (17.3%) ÷ second value (1.8%) = 9.61 or first value (1.8%) ÷ second value (17.3%) = 0.10) is either less than "3÷7" or greater than "7÷3", so the diagnostic unit 120 can determine that the ratio does not belong to the critical ratio interval. The diagnostic unit 120 can then determine that the second distribution profile p2 does not satisfy the predetermined conditions.

[0103] The following describes a specific embodiment in which the diagnostic unit 120 calculates the negative electrode loss rate based on the reference ratio and the target ratio, and determines the negative electrode loss rate as the target value.

[0104] The diagnostic unit 120 can calculate the negative electrode loss rate for each of the multiple batteries based on the ratio between a preset reference ratio and a target ratio, and determine the calculated negative electrode loss rate as the target value.

[0105] Here, the reference ratio is the negative electrode change ratio corresponding to a battery in a BOL (Body-Only) state. Specifically, the reference ratio is the ratio by which the negative electrode profile corresponding to the battery profile for a battery in a BOL state is changed compared to the reference negative electrode profile Rn. Furthermore, the negative electrode loss rate refers to the negative electrode reaction area of ​​the battery at the time of diagnosis relative to the negative electrode reaction area of ​​the battery in a BOL state.

[0106] Specifically, the diagnostic unit 120 can calculate the negative electrode loss rate through the following calculation process. The diagnostic unit 120 can calculate the negative electrode loss rate based on the value obtained by dividing the target ratio by the reference ratio.

[0107] For example, the diagnostic unit 120 can calculate the negative electrode loss rate using the following formula 1.

[0108] [Formula 1]

number

[0109] Here, L n is the negative electrode loss rate, ns MOL This is the target ratio, ns BOL This indicates the reference ratio. MOL (Middle of Life) refers to the stage where the battery has been used to some extent, and although its performance has decreased compared to its initial (BOL) state, it still operates normally.

[0110] On the other hand, as a battery degrades, the negative electrode reaction area decreases, and therefore the negative electrode capacity involved in the reaction during charging or discharging decreases. Consequently, the negative electrode loss rate, which represents the negative electrode reaction area of ​​the battery at the time of diagnosis compared to the negative electrode reaction area of ​​the battery in a BOL (Battery-on-Liquid) state, can be used as an indicator of battery degradation. Furthermore, the negative electrode loss rate has a one-to-one correspondence with the negative electrode change ratio. This can be confirmed through the calculation process of the negative electrode loss rate described above. Therefore, the negative electrode change ratio can also be used as an indicator of battery degradation. In other words, the target value can be used as an indicator of battery degradation.

[0111] A battery management device 100 according to one embodiment of the present invention can diagnose battery pack degradation imbalances from the perspective of the degree of negative electrode loss by calculating the negative electrode loss rate, which indicates the degradation state of the battery, as a target value.

[0112] The following describes an embodiment in which the profile acquisition unit 110 acquires the negative electrode change ratio.

[0113] Figure 5 is a schematic diagram showing the reference positive electrode profile Rp and reference negative electrode profile Rn according to one embodiment of the present invention. In the embodiment of Figure 5, the horizontal axis (X axis) represents capacitance (Ah), and the vertical axis (Y axis) represents voltage (V).

[0114] Figures 6 to 8 are diagrams that illustrate an example of the process for generating a comparison profile S used for comparison with a battery profile BP according to one embodiment of the present invention.

[0115] The process for generating the comparison profile S, as described with reference to Figures 6 to 8, is performed in the following order: a first routine (see Figure 6) to set four points (positive electrode involvement start point (pi), positive electrode involvement end point (pf), negative electrode involvement start point (ni), negative electrode involvement end point (nf)) corresponding to the voltage range of interest; a second routine (see Figure 7) to perform profile shifting; and a third routine (see Figure 8) to perform capacitance scaling. The process for generating the comparison profile S according to one embodiment of the present invention includes the first to third routines.

[0116] Here, the positive electrode involvement start point (pi) refers to the point on the positive electrode where the reaction begins during the charging process or where the reaction ends during the discharging process. The positive electrode involvement end point (pf) refers to the point on the positive electrode where the reaction ends during the charging process or where the reaction begins during the discharging process. Similarly, the negative electrode involvement start point (ni) refers to the point on the negative electrode where the reaction begins during the charging process or where the reaction ends during the discharging process. The negative electrode involvement end point (nf) refers to the point on the negative electrode where the reaction ends during the charging process or where the reaction begins during the discharging process.

[0117] First, referring to Figure 6, the reference positive electrode profile Rp and the reference negative electrode profile Rn are the same as those shown in Figure 5.

[0118] The profile acquisition unit 110 determines the positive electrode involvement start point (pi), positive electrode involvement end point (pf), negative electrode involvement start point (ni), and negative electrode involvement end point (nf) on the reference positive electrode profile Rp and reference negative electrode profile Rn.

[0119] Either the positive electrode involvement start point (pi) or the negative electrode involvement start point (ni) depends on the other.

[0120] Preferably, the difference between the voltage at the positive electrode engagement start point (pi) and the voltage at the negative electrode engagement start point (ni) can be set to be equal to the starting voltage (minimum voltage) of the battery profile BP.

[0121] As an example, the profile acquisition unit 110 can divide the positive electrode voltage range from the start point to the end point of the reference positive electrode profile Rp into a plurality of minute voltage intervals, and then set the boundary point between two adjacent minute voltage intervals as the positive electrode involvement start point (pi). Each minute voltage interval may have a predetermined size (e.g., 0.01V). Subsequently, the profile acquisition unit 110 can set a point on the reference negative electrode profile Rn that is smaller than the voltage of the positive electrode involvement start point (pi) by a first set voltage (e.g., 3V) as the negative electrode involvement start point (ni).

[0122] As another example, the profile acquisition unit 110 may divide the negative electrode voltage range from the start point to the end point of the reference negative electrode profile Rn into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point between two adjacent minute voltage intervals as the negative electrode involvement start point (ni). Subsequently, the profile acquisition unit 110 may set a point on the reference positive electrode profile Rp that is greater than the voltage of the negative electrode involvement start point (ni) by a first set voltage as the positive electrode involvement start point (pi).

[0123] Either the positive electrode-involved termination point (pf) or the negative electrode-involved termination point (nf) depends on the other.

[0124] Preferably, the difference between the voltage at the positive electrode termination point (pf) and the voltage at the negative electrode termination point (nf) can be set to be equal to the termination voltage (maximum voltage) of the battery profile BP.

[0125] As an example, the profile acquisition unit 110 can divide the positive electrode voltage range from the second set voltage to the end point of the reference positive electrode profile Rp into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point between two adjacent minute voltage intervals as the positive electrode involvement termination point (pf). Subsequently, the profile acquisition unit 110 can set a point on the reference negative electrode profile Rn that is smaller than the voltage of the positive electrode involvement termination point (pf) by the second set voltage (for example, 4V) as the negative electrode involvement termination point (nf).

[0126] As another example, the profile acquisition unit 110 may divide the negative voltage range from the start point to the end point of the reference negative electrode profile Rn into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point between two adjacent minute voltage intervals as the negative electrode involvement termination point (nf). Subsequently, the profile acquisition unit 110 may set a point on the reference positive electrode profile Rp that is greater than the negative electrode involvement termination point (nf) by a second set voltage as the positive electrode involvement termination point (pf).

[0127] Once the determination of the positive electrode involvement start point (pi), positive electrode involvement end point (pf), negative electrode involvement start point (ni), and negative electrode involvement end point (nf) is complete, the profile acquisition unit 110 shifts at least one of the reference positive electrode profile Rp and reference negative electrode profile Rn to the left or right along the horizontal axis.

[0128] Preferably, the difference between the capacity value at the positive electrode engagement start point (pi) and the capacity value at the positive electrode engagement end point (pf), the difference between the capacity value at the negative electrode engagement start point (ni) and the capacity value at the negative electrode engagement end point (nf), and the difference between the starting capacity of battery profile BP and the ending capacity of battery profile BP can be set to be equal.

[0129] Referring to Figure 7, for example, the profile acquisition unit 110 can shift the reference positive electrode profile Rp to the left (towards the lower capacitance side), or shift the reference negative electrode profile Rn to the right (towards the higher capacitance side), or both, so that the capacitance value at the positive electrode involvement start point (pi) matches the capacitance value at the negative electrode involvement start point (ni).

[0130] As another example, the profile acquisition unit 110 may shift the reference positive electrode profile Rp to the left, or the reference negative electrode profile Rn to the right, or both, so that the capacitance value of the positive electrode termination point (pf) matches the capacitance value of the negative electrode termination point (nf).

[0131] Figure 7 shows the result of generating the adjusted positive electrode profile Rp' by shifting only the reference positive electrode profile Rp to the left, illustrating a situation where the capacitance value at the positive electrode involvement start point (pi') matches the capacitance value at the negative electrode involvement start point (ni). The adjusted positive electrode profile Rp' is the result of applying an adjustment process to the reference positive electrode profile Rp that shifts it to the left by the difference between the capacitance value at the positive electrode involvement start point (pi) and the capacitance value at the negative electrode involvement start point (ni). Therefore, the two points (pi, pi') differ only in capacitance value, but have the same voltage. The two points (pf, pf') differ only in capacitance value, but have the same voltage.

[0132] Once an adjusted profile (Rp', Rn) is obtained in which at least one of the reference positive electrode profile Rp and the reference negative electrode profile Rn is shifted, the profile acquisition unit 110 scales at least one of the capacitance ranges of the adjusted profile (Rp', Rn).

[0133] Preferably, capacity scaling can be performed so that the capacity range between the positive electrode involvement start point and the positive electrode involvement end point of the adjusted positive electrode profile Rp', the capacity range between the negative electrode involvement start point and the negative electrode involvement end point of the reference negative electrode profile Rn, and the capacity range of the battery profile BP coincide.

[0134] As shown in the example in Figure 8, the profile acquisition unit 110 performs an additional adjustment process (capacitance scaling) that contracts or expands at least one of the adjusted positive electrode profile Rp' and the reference negative electrode profile Rn along the horizontal axis. That is, the capacitance range of the adjusted positive electrode profile Rp' can be contracted or expanded while maintaining a constant voltage range. Alternatively, the capacitance range of the reference negative electrode profile Rn can be contracted or expanded while maintaining a constant voltage range.

[0135] Referring to Figure 8, the profile acquisition unit 110 can generate an adjusted positive electrode profile Rp'' by contracting or expanding the adjusted positive electrode profile Rp' so that the capacity range between the two points (pi', pf') of the adjusted positive electrode profile Rp' matches the capacity range of the battery profile BP. In this case, one of the two points (pi', pf') (pi') can be fixed. As a result, the capacity range between the two points (pi', pf) of the adjusted positive electrode profile Rp'' matches the capacity range of the battery profile BP.

[0136] Furthermore, the profile acquisition unit 110 can generate an adjusted negative electrode profile Rn' by contracting or expanding the reference negative electrode profile Rn so that the capacity range between the two points (ni, nf) of the reference negative electrode profile Rn also matches the capacity range of the battery profile BP. In this case, one of the two points (ni, nf) (ni) can be fixed. As a result, the capacity range between the two points (ni, nf') of the adjusted negative electrode profile Rn' will match the capacity range of the battery profile BP.

[0137] In Figure 8, the adjusted positive electrode profile Rp'' is the result of the adjusted positive electrode profile Rp' shown in Figure 7 being contracted along the capacitance axis, and the adjusted negative electrode profile Rn' is the result of the reference negative electrode profile Rn shown in Figure 6 being expanded along the capacitance axis.

[0138] The positive electrode involvement endpoint (pf) on the adjusted positive electrode profile Rp'' corresponds to the positive electrode involvement endpoint (pf') on the adjusted positive electrode profile Rp'. The negative electrode involvement endpoint (nf') on the adjusted negative electrode profile Rn' corresponds to the negative electrode involvement endpoint (nf) on the reference negative electrode profile Rn.

[0139] The capacity range between the positive electrode involvement start point (pi') and the positive electrode involvement end point (pf) of the tuned positive electrode profile Rp'' matches the capacity range of the battery profile BP. Similarly, the capacity range between the negative electrode involvement start point (ni) and the negative electrode involvement end point (nf') of the tuned negative electrode profile Rn' matches the capacity range of the battery profile BP.

[0140] Furthermore, the capacitance range between two points (pi', pf) of the tuned positive electrode profile Rp'' coincides with the capacitance range between two points (ni, nf') of the tuned negative electrode profile Rn'. The profile acquisition unit 110 can generate a comparison profile S by subtracting the profile between two points (pi', pf) of the tuned positive electrode profile Rp'' from the profile between two points (ni, nf') of the tuned negative electrode profile Rn'.

[0141] The profile acquisition unit 110 can calculate the error (profile error) between the comparison profile S and the battery profile BP.

[0142] In this regard, various methods known at the time of filing of the present invention can be used to determine the error between two profiles that can each be represented in a two-dimensional coordinate system. For example, the integral of the absolute value over the region between the two profiles or the RMSE (Root Mean Square Error) can be used as the error between the two profiles.

[0143] The profile acquisition unit 110 can map at least two of the following to each other and record them in the recording unit 130: the adjusted positive electrode profile Rp'', the adjusted negative electrode profile Rn', the positive electrode involvement start point (pi'), the positive electrode involvement end point (pf''), the negative electrode involvement start point (ni), the negative electrode involvement end point (nf'), the first scale factor, the second scale factor, the comparison profile S, and the profile error. The first scale factor may represent the ratio of the capacitance difference between two points (pi', pf'') to the capacitance difference between two points (pi0, pf0). The second scale factor may represent the ratio of the capacitance difference between two points (ni, nf') to the capacitance difference between two points (ni0, nf0).

[0144] The profile acquisition unit 110 can calculate the positive electrode change ratio (ps) based on the reference positive electrode profile Rp and the adjusted positive electrode profile Rp''. Here, the positive electrode change ratio (ps) means the ratio to which the adjusted positive electrode profile is changed relative to the reference positive electrode profile. The profile acquisition unit 110 can also calculate the negative electrode change ratio (ns) based on the reference negative electrode profile Rn and the adjusted negative electrode profile Rn'. Here, the negative electrode change ratio (ns) means the ratio to which the adjusted negative electrode profile is changed relative to the reference negative electrode profile.

[0145] For example, the profile acquisition unit 110 may determine the first scale factor as the positive electrode change ratio (ps) and the second scale factor as the negative electrode change ratio (ns).

[0146] As described above, when the positive electrode voltage range of the reference positive electrode profile Rp is divided into multiple minute voltage intervals, the boundary point between two adjacent minute voltage intervals can be set as the positive electrode engagement start point (pi).

[0147] For example, if the positive electrode voltage range of the reference positive electrode profile Rp is divided into 100 minute voltage ranges, there may be 100 boundary points that can be set as the positive electrode involvement start point (pi). Also, if the voltage range of the reference positive electrode profile Rp above the second set voltage is divided into 40 minute voltage ranges, there may be 40 boundary points that can be set as the positive electrode involvement end point (pf). In this case, up to 4000 different comparison profiles can be generated.

[0148] Of course, it is easy for those skilled in the art to understand that the number of comparison profiles that can be generated increases as the size of the minute voltage interval decreases, and conversely, the number of comparison profiles that can be generated decreases as the size of the minute voltage interval increases.

[0149] The profile acquisition unit 110 identifies the minimum value from among the multiple comparison profiles generated as described above, and then acquires information mapped to the minimum profile error (for example, at least one of the following: positive electrode involvement start point, positive electrode involvement end point, negative electrode involvement start point, negative electrode involvement end point, first scale factor, second scale factor) from the recording unit 130.

[0150] If the comparative full cell profile S shown in Figure 8 has the minimum profile error in the battery profile BP, then the adjusted reference negative electrode profile (adjusted negative electrode profile Rn') can be used as the negative electrode profile NP.

[0151] Figures 9 to 11 are diagrams that illustrate another example of the process for generating a comparison profile U, used for comparison with the battery profile BP, according to one embodiment of the present invention. For reference, the embodiments in Figures 9 to 11 are independent of the embodiments in Figures 6 to 8. Therefore, terms and reference numerals that are common to the embodiments in Figures 6 to 8 and Figures 9 to 11 should be understood to be limited to the respective embodiments.

[0152] The process for generating the comparative profile U, as described with reference to Figures 9 to 11, is performed in the following order: a fourth routine for capacity scaling (see Figure 9), a fifth routine for setting four points (positive electrode involvement start point, positive electrode involvement end point, negative electrode involvement start point, negative electrode involvement end point) (see Figure 10), and a sixth routine for profile shifting (see Figure 11). That is, the process for generating the comparative profile U according to other embodiments of the present invention includes the fourth to sixth routines.

[0153] Referring to Figure 9, the reference positive electrode profile Rp and the reference negative electrode profile Rn are the same as those shown in Figure 5.

[0154] The profile acquisition unit 110 applies the first scale factor and the second scale factor selected from the scaling numerical range to the reference positive electrode profile Rp and the reference negative electrode profile Rn, respectively, to generate the adjusted positive electrode profile Rp' and the adjusted negative electrode profile Rn'.

[0155] The scaling numerical range may be predetermined or vary depending on the ratio of the capacity range size of the battery profile BP to the capacity range size of the reference profile R. For example, if the first and second scale factors can be selected from values ​​spaced 0.1% apart within the scaling numerical range (e.g., 90% to 99%) (i.e., 90%, 90.1%, 90.2%, ..., 98.9%, 99%), then 91 values ​​can be selected as the first and second scale factors, respectively. In this case, 91 × 91 = 8,281 adjustment levels (combinations of the first and second scale factors) can generate up to 8,281 pairs of adjusted profiles. A pair of adjusted profiles represents a combination of an adjusted positive electrode profile and an adjusted negative electrode profile.

[0156] The modified positive electrode profile Rp' and modified negative electrode profile Rn' shown in Figure 9 illustrate the results of applying a first scale factor and a second scale factor of less than 100%, respectively, to the reference positive electrode profile Rp and the reference negative electrode profile Rn.

[0157] Since the first and second scale factors are less than 100%, the adjusted positive electrode profile Rp' is the reference positive electrode profile Rp contracted along the horizontal axis, and the adjusted negative electrode profile Rn' is the reference negative electrode profile Rn contracted along the horizontal axis. For ease of understanding, the starting points of the reference positive electrode profile Rp and the reference negative electrode profile Rn are fixed, and only the remaining parts are shown as a schematic representation contracted to the left along the horizontal axis.

[0158] Referring to Figure 10, the profile acquisition unit 110 determines the positive electrode involvement start point (pi'), positive electrode involvement end point (pf'), negative electrode involvement start point (ni'), and negative electrode involvement end point (nf') on the adjusted positive electrode profile Rp' and adjusted negative electrode profile Rn'.

[0159] Either the positive electrode involvement start point (pi') or the negative electrode involvement start point (ni') may depend on the other. Similarly, either the positive electrode involvement end point (pf') or the negative electrode involvement end point (nf') may depend on the other. Furthermore, either the positive electrode involvement start point (pi') or the positive electrode involvement end point (pf') may be set based on the other.

[0160] In other words, if any one of the positive electrode involvement start point (pi'), positive electrode involvement end point (pf'), negative electrode involvement start point (ni'), and negative electrode involvement end point (nf') is set, the remaining three points can be automatically set by the first set voltage, the second set voltage, and / or the size of the capacity range of the battery profile BP (e.g., the charge capacity from SOC 0 to 100%).

[0161] As an example, the profile acquisition unit 110 can divide the positive electrode voltage range from the start point to the end point (or second set voltage) of the adjusted positive electrode profile Rp' into a plurality of minute voltage intervals, and then set the boundary point between two adjacent minute voltage intervals as the positive electrode involvement start point (pi'). Subsequently, the profile acquisition unit 110 can set the negative electrode involvement start point (ni') as a point on the adjusted negative electrode profile Rn' that is smaller than the voltage of the positive electrode involvement start point (pi') by a first set voltage (e.g., 3V).

[0162] As another example, the profile acquisition unit 110 may divide the negative electrode voltage range from the start point to the end point of the adjusted negative electrode profile Rn' into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point between two adjacent minute voltage intervals as the negative electrode involvement start point (ni'). Subsequently, the profile acquisition unit 110 may set a point on the adjusted positive electrode profile Rp' that is greater than the negative electrode involvement start point (ni') by a first set voltage as the positive electrode involvement start point (pi').

[0163] As yet another example, the profile acquisition unit 110 may divide the voltage range from the second set voltage to the end point of the adjusted positive electrode profile Rp' into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point between two adjacent minute voltage intervals as the positive electrode involvement termination point (pf'). Subsequently, the profile acquisition unit 110 may set the negative electrode involvement termination point (nf') as a point on the adjusted negative electrode profile Rn' that is smaller than the voltage of the positive electrode involvement termination point (pf') by the second set voltage (e.g., 4V).

[0164] As yet another example, the profile acquisition unit 110 may divide the negative electrode voltage range from the start point to the end point of the adjusted negative electrode profile Rn' into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point between two adjacent minute voltage intervals as the negative electrode involvement termination point (nf'). Subsequently, the profile acquisition unit 110 may set a point on the adjusted positive electrode profile Rp' that is greater than the voltage of the negative electrode involvement termination point (nf') by a second set voltage as the positive electrode involvement termination point (pf').

[0165] If any one of the positive electrode involvement start point (pi'), positive electrode involvement end point (pf'), negative electrode involvement start point (ni'), and negative electrode involvement end point (nf') is determined, the profile acquisition unit 110 can additionally determine the remaining three points based on the determined point.

[0166] As an example, once the positive electrode involvement start point (pi') is determined, the profile acquisition unit 110 may set a point on the tuned positive electrode profile Rp' having a capacity value that is larger by the size of the capacity range of the battery profile BP than the capacity value of the positive electrode involvement start point (pi') as the positive electrode involvement end point (pf'). The profile acquisition unit 110 may also search for a point in the tuned negative electrode profile Rn' that is lower by a first set voltage than the voltage of the positive electrode involvement start point (pi') and set the found point as the negative electrode involvement start point (ni'). The profile acquisition unit 110 may also set a point on the tuned negative electrode profile Rn' having a capacity value that is larger by the size of the capacity range of the battery profile BP than the capacity value of the negative electrode involvement start point (ni') as the negative electrode involvement end point (nf').

[0167] As another example, once the positive electrode involvement termination point (pf') is determined, the profile acquisition unit 110 may set a point on the tuned positive electrode profile Rp' having a capacity value smaller by the size of the capacity range of the battery profile BP than the capacity value of the positive electrode involvement termination point (pf') as the positive electrode involvement start point (pi'). Alternatively, the profile acquisition unit 110 may search for a point on the tuned negative electrode profile Rn' that is lower by a second set voltage than the voltage of the positive electrode involvement termination point (pf') and set the found point as the negative electrode involvement termination point (nf'). Furthermore, the profile acquisition unit 110 may set a point on the tuned negative electrode profile Rn' having a capacity value smaller by the size of the capacity range of the battery profile BP than the capacity value of the negative electrode involvement termination point (nf') as the negative electrode involvement start point (ni').

[0168] As another example, once the negative electrode involvement start point (ni') is determined, the profile acquisition unit 110 may set a point on the adjusted negative electrode profile Rn' having a capacity value that is larger by the size of the capacity range of the battery profile BP than the capacity value of the negative electrode involvement start point (ni') as the negative electrode involvement end point (nf'). The profile acquisition unit 110 may also search for a point on the adjusted positive electrode profile Rp' that is higher by a first set voltage than the voltage of the negative electrode involvement start point (ni') and set the found point as the positive electrode involvement start point (pi'). Furthermore, the profile acquisition unit 110 may set a point on the adjusted positive electrode profile Rp' having a capacity value that is larger by the size of the capacity range of the battery profile BP than the capacity value of the positive electrode involvement start point (pi') as the positive electrode involvement end point (pf').

[0169] As yet another example, once the negative electrode involvement termination point (nf') is determined, the profile acquisition unit 110 may set a point on the adjusted negative electrode profile Rn' having a capacity value smaller by the size of the capacity range of the battery profile BP than the capacity value of the negative electrode involvement termination point (nf') as the negative electrode involvement start point (ni'). The profile acquisition unit 110 may also search for a point on the adjusted positive electrode profile Rp' that is higher by a second set voltage than the voltage of the negative electrode involvement termination point (nf') and set the found point as the positive electrode involvement termination point (pf'). Furthermore, the profile acquisition unit 110 may set a point on the adjusted positive electrode profile Rp' having a capacity value smaller by the size of the capacity range of the battery profile BP than the capacity value of the positive electrode involvement termination point (pf') as the positive electrode involvement start point (pi').

[0170] Once the determination of the positive electrode involvement start point (pi'), positive electrode involvement end point (pf'), negative electrode involvement start point (ni'), and negative electrode involvement end point (nf') is complete based on the pair of the first scale factor and the second scale factor, the profile acquisition unit 110 may shift at least one of the adjusted positive electrode profile Rp' and adjusted negative electrode profile Rn' to the left or right along the horizontal axis so that the capacity value of the positive electrode involvement start point (pi') matches the capacity value of the negative electrode involvement start point (ni'), or so that the capacity value of the positive electrode involvement end point (pf') matches the capacity value of the negative electrode involvement end point (nf').

[0171] The adjusted negative electrode profile Rn'' shown in Figure 11 is obtained by shifting only the adjusted negative electrode profile Rn' shown in Figure 10 to the right. As a result, the capacitance value at the positive electrode engagement start point (pi') matches the capacitance value at the negative electrode engagement start point (ni''). In relation to this, since the capacitance difference between the positive electrode engagement start point (pi') and the positive electrode engagement end point (pf') is equal to the capacitance difference between the negative electrode engagement start point (ni') and the negative electrode engagement end point (nf'), if the capacitance value at the positive electrode engagement start point (pi') matches the capacitance value at the negative electrode engagement start point (ni''), then the capacitance value at the positive electrode engagement end point (pf') and the negative electrode engagement end point (nf'') will also match.

[0172] Referring to Figure 11, the profile acquisition unit 110 can generate a comparison profile U by subtracting the partial profile between two points (pi', pf') of the tuned positive electrode profile Rp' from the partial profile between two points (ni'', nf'') of the tuned negative electrode profile Rn''.

[0173] The profile acquisition unit 110 can calculate the error (profile error) between the comparison profile U and the battery profile BP.

[0174] The profile acquisition unit 110 can map at least two of the following to each other and record them in the recording unit 130: the adjusted positive electrode profile Rp', the adjusted negative electrode profile Rn'', the positive electrode involvement start point (pi'), the positive electrode involvement end point (pf'), the negative electrode involvement start point (ni"), the negative electrode involvement end point (nf"), the first scale factor, the second scale factor, the comparison profile U, and the profile error.

[0175] The profile acquisition unit 110 can calculate the positive electrode change ratio (ps) based on the reference positive electrode profile Rp and the adjusted positive electrode profile Rp'. Here, the positive electrode change ratio (ps) means the ratio to which the adjusted positive electrode profile is changed relative to the reference positive electrode profile. The profile acquisition unit 110 can also calculate the negative electrode change ratio (ns) based on the reference negative electrode profile Rn and the adjusted negative electrode profile Rn''. Here, the negative electrode change ratio (ns) means the ratio to which the adjusted negative electrode profile is changed relative to the reference negative electrode profile.

[0176] For example, the profile acquisition unit 110 may determine the first scale factor as the positive electrode change ratio (ps) and the second scale factor as the negative electrode change ratio (ns).

[0177] As described above, the profile acquisition unit 110 can generate a corresponding comparison profile for each pair of first and second scale factors selected from the scaling numerical range. Since there are multiple pairs of first and second scale factors, it is obvious that multiple comparison profiles will be generated. After identifying the minimum value from among the profile errors of the multiple comparison profiles, the profile acquisition unit 110 can acquire information mapped to the minimum profile error from the recording unit 130.

[0178] If the comparative full cell profile U shown in Figure 11 has the minimum profile error in the battery profile BP, then the adjusted reference negative electrode profile (adjusted negative electrode profile Rn") can be used as the negative electrode profile NP.

[0179] A battery management device 100 according to one embodiment of the present invention can be applied to a battery management system (BMS). That is, the BMS according to the present invention may include the battery management device 100 described above. In such a configuration, at least some of the components of the battery management device 100 can be implemented by complementing or adding to the functions of components included in a conventional BMS. For example, the profile acquisition unit 110, the diagnostic unit 120, and the recording unit 130 of the battery management device 100 can be implemented as components of a BMS.

[0180] Furthermore, a battery management device 100 according to one embodiment of the present invention may be provided in a battery pack. That is, a battery pack according to the present invention may include the above-described battery management device 100 and one or more batteries. The battery pack may further include electrical components (relays, fuses, etc.) and a case, etc.

[0181] Figure 12 shows an exemplary configuration of a battery pack 10 according to another embodiment of the present invention.

[0182] The positive terminal of battery 11 may be connected to the positive terminal P+ of battery pack 10, and the negative terminal of battery 11 may be connected to the negative terminal P- of battery pack 10.

[0183] The measuring unit 12 can be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3. Specifically, the measuring unit 12 can be connected to the positive terminal of the battery 11 through the first sensing line SL1 and to the negative terminal of the battery 11 through the second sensing line SL2. The measuring unit 12 can measure the voltage of the battery 11 based on the voltages measured in the first sensing line SL1 and the second sensing line SL2, respectively.

[0184] Furthermore, the measurement unit 12 can be connected to the current measurement unit A via the third sensing line SL3. For example, the current measurement unit A may be an ammeter or shunt resistor capable of measuring the charging current and discharging current of the battery 11. The measurement unit 12 can measure the charging current of the battery 11 via the third sensing line SL3 and calculate the charge amount. The measurement unit 12 can also measure the discharging current of the battery 11 via the third sensing line SL3 and calculate the discharge amount.

[0185] An external device (not shown) may have one end connected to the positive terminal P+ of the battery pack 10 and the other end connected to the negative terminal P- of the battery pack 10. Therefore, the positive terminal of the battery 11, the positive terminal P+ of the battery pack 10, the external device, the negative terminal P- of the battery pack 10, and the negative terminal of the battery 11 can be electrically connected.

[0186] For example, the external device may be a charger, or it may be a load such as a motor of an electric vehicle that receives power from the battery 11.

[0187] Figure 13 is a schematic diagram showing an automobile 1 according to yet another embodiment of the present invention.

[0188] Referring to Figure 13, the battery pack 10 according to an embodiment of the present invention can be installed in an automobile 1 such as an electric vehicle (EV) or a hybrid vehicle (HV). Here, the battery pack 10 may be the same as the battery pack 10 described above. The battery pack 10 can also drive the automobile 1 by supplying power to the motor through an inverter provided in the automobile 1. Here, the battery pack 10 may include a battery management device 100 according to an embodiment of the present invention. That is, the automobile 1 may include a battery management device 100. In this case, the battery management device 100 may be an onboard device included in the automobile 1.

[0189] Figure 14 is a schematic diagram showing a battery management method according to yet another embodiment of the present invention, and Figure 15 is a schematic diagram showing the condition determination step and the state diagnosis step of the battery management method according to yet another embodiment of the present invention.

[0190] Referring to Figure 14, the battery management method includes a profile acquisition step S100, a target value calculation step S200, a profile generation step S300, a condition determination step S400, and a state diagnosis step S500.

[0191] Preferably, each step of the battery management method can be performed by the battery management device 100. For the sake of clarity, the following will either omit or briefly explain any content that overlaps with the above.

[0192] The profile acquisition step S100 is a step of acquiring a first profile for each of the multiple batteries included in the battery pack, and may be performed by the profile acquisition unit 110.

[0193] The target value calculation step S200 is a step of calculating a target ratio from each of the plurality of first profiles and calculating a target value based on the calculated target ratio, and can be performed by the diagnostic unit 120.

[0194] Here, the target ratio could be the negative electrode change ratio.

[0195] The diagnostic unit 120 can determine the target ratio by calculating the change ratio of the negative electrode profile to the reference negative electrode profile.

[0196] For example, the diagnostic unit 120 may determine the target ratio as the target value.

[0197] As another example, the diagnostic unit 120 may calculate the negative electrode loss rate for each of the multiple batteries based on the ratio of a preset reference ratio to a target ratio, and determine the calculated negative electrode loss rate as the target value.

[0198] The profile generation step S300 is a step that generates a distribution profile showing the correspondence between the calculated target values ​​and the number of each of the target values, and can be performed by the diagnostic unit 120.

[0199] The condition determination step S400 is a step in which it is determined whether or not the distribution profile satisfies predetermined conditions, and can be performed by the diagnostic unit 120.

[0200] The status diagnosis step S500 is a step of diagnosing the status of the battery pack according to the result of the determination, and can be performed by the diagnosis unit 120.

[0201] Step S600 is a step in which various measures are taken if the battery diagnosis determines that the battery is in a state of degradation imbalance, and can be performed by the diagnostic unit 120 or a separate control unit (not shown). For example, the battery may be charged at a low rate, or the pack balancing function may be activated. Alternatively, the user may be prompted to visit an inspection service through an appropriate alarm to undergo pack balancing, or, if necessary, the battery pack may be replaced. According to one embodiment, the output of such an alarm may be received by an external device that manages the battery pack, such as a BMS, server, or user terminal, or by an external device, display, or sound device that diagnoses the status of the battery pack.

[0202] Referring to Figure 15, in step S410, the diagnostic unit 120 may determine whether the distribution profile satisfies predetermined conditions. Specifically, the predetermined conditions may be conditions for determining whether the distribution profile follows a Gaussian distribution. That is, the predetermined conditions may be conditions for determining whether the distribution profile exhibits a form similar to a Gaussian distribution. If the value in step S410 is "yes", step S420 may be performed. If the value in step S410 is "no", step S520 may be performed.

[0203] In step S420, the diagnostic unit 120 may determine whether the characteristic value of the distribution profile is below a threshold. The threshold may be set in advance based on the BOL status of the battery pack, the current state of the battery pack (e.g., degree of degradation), a reference value derived from a reference pack corresponding to the battery pack, or a theoretically derived distribution profile. If the value in step S420 is "yes", step S510 may be performed. If the value in step S420 is "no", step S520 may be performed.

[0204] Referring to Figure 15, in step S510, the diagnostic unit 120 may diagnose the state of the battery pack as being in a state of degradation equilibrium. In step S520, the diagnostic unit 120 may diagnose the state of the battery pack as being in a state of degradation imbalance.

[0205] Here, a state of degradation equilibrium refers to a state in which the degradation state of each of the multiple batteries contained in the battery pack is considered to be uniform. Conversely, a state of degradation disequilibrium refers to a state in which the degradation state of each of the multiple batteries contained in the battery pack is considered to be non-uniform.

[0206] The embodiments of the present invention described above are not limited to apparatus and methods, but can also be implemented through a program that realizes the functions corresponding to the configuration of the embodiments of the present invention, or through a recording medium on which such program is recorded. The program or recording medium can be easily implemented by those skilled in the art based on the description of the embodiments described above.

[0207] As described above, the present invention has been explained with limited embodiments and drawings, but it goes without saying that the present invention is not limited thereto, and that various modifications and variations are possible within the equivalent scope of the technical idea and claims of the present invention by persons with ordinary skill in the art to which the present invention pertains.

[0208] Furthermore, the present invention described above can be substituted, modified, and altered in various ways by a person with ordinary skill in the art to which the present invention pertains, without departing from the technical spirit of the invention, and is not limited by the embodiments described above and the accompanying drawings. For diverse modifications, all or part of each embodiment may be selectively combined to form the present invention. [Explanation of Symbols]

[0209] 1: Automobile 10: Battery Pack 11: Battery 12: Measuring part 100: Battery management device 110: Profile acquisition unit 120: Diagnostic Department 130: Records Department

Claims

1. A profile acquisition unit configured to acquire a first profile for each of the multiple batteries included in the battery pack, A battery management device comprising: a diagnostic unit configured to calculate a target ratio from each of a plurality of first profiles, calculate each target value as a diagnostic factor based on the calculated plurality of target ratios, generate a distribution profile showing the correspondence between the calculated plurality of target values ​​and the number of each of the plurality of target values, determine whether the distribution profile satisfies predetermined conditions, and diagnose the state of the battery pack according to the result of the determination.

2. The first profile is a negative electrode profile, The battery management device according to claim 1, wherein the target ratio is a negative electrode change ratio which is the change ratio of the first profile with respect to a preset reference negative electrode profile.

3. The battery management device according to claim 1, wherein the diagnostic unit is configured to diagnose the state of the battery pack as a state of degradation imbalance if the distribution profile does not satisfy the predetermined conditions.

4. The battery management device according to claim 1, wherein the diagnostic unit is configured to compare the characteristic values ​​of the distribution profile with a preset threshold when the distribution profile satisfies the predetermined conditions, and to diagnose the state of the battery pack based on the result of the comparison.

5. The aforementioned diagnostic unit, If the aforementioned characteristic value exceeds the aforementioned threshold, the state of the battery pack is diagnosed as being in a state of degradation imbalance. The battery management device according to claim 4, which is configured to diagnose the state of the battery pack as being in a degradation equilibrium state if the characteristic value is less than or equal to the threshold.

6. The battery management device according to claim 4, wherein the diagnostic unit is configured to set the threshold based on the degree of degradation of the battery pack and a preset reference characteristic value.

7. The battery management device according to claim 1, wherein the diagnostic unit is configured to calculate a first value and a second value based on the plurality of target values, and to determine whether the distribution profile satisfies the predetermined conditions according to the ratio of the first value and the second value.

8. The battery management device according to claim 7, wherein the diagnostic unit is configured to determine a minimum value, a maximum value, and a reference value from among the plurality of target values, calculate the difference between the minimum value and the reference value as the first value, and calculate the difference between the reference value and the maximum value as the second value.

9. The battery management device according to claim 8, wherein the diagnostic unit is configured to determine the target value from among the plurality of target values ​​that has the largest corresponding number as the reference value.

10. The battery management device according to claim 7, wherein the diagnostic unit is configured to compare the ratio with a preset critical ratio interval and determine whether the distribution profile satisfies the predetermined conditions according to the result of the comparison.

11. The aforementioned diagnostic unit, If the ratio falls within the critical ratio interval, it is determined that the distribution profile satisfies the predetermined conditions. The battery management device according to claim 10, wherein if the ratio does not fall within the critical ratio interval, it is determined that the distribution profile satisfies the predetermined conditions.

12. The battery management device according to claim 1, wherein the diagnostic unit is configured to determine the target ratio as the target value.

13. The battery management device according to claim 1, wherein the diagnostic unit is configured to calculate the negative electrode loss rate for each of the plurality of batteries based on the ratio of a preset reference ratio to the target ratio, and to determine the calculated negative electrode loss rate as the target value.

14. The battery management device according to claim 1, wherein the diagnostic unit is configured to activate a function to resolve the degradation imbalance or output an alarm when it diagnoses that the state of the battery pack is in a state of degradation imbalance.

15. The battery management device according to claim 14, wherein the function for resolving the aforementioned degradation imbalance is a pack balancing function.

16. A battery pack including a battery management device according to any one of claims 1 to 15.

17. An automobile comprising a battery management device according to any one of claims 1 to 15.

18. A profile acquisition step to obtain a first profile for each of the multiple batteries included in the battery pack, A target value calculation step involves calculating target ratios from each of several first profiles, and then calculating each target value as a diagnostic factor based on the calculated target ratios. A profile generation step that generates a distribution profile showing the correspondence between a plurality of calculated target values ​​and the number of each of the plurality of target values, A condition determination step for determining whether the distribution profile satisfies predetermined conditions, A battery management method comprising a condition diagnosis step of diagnosing the state of the battery pack according to the result of the judgment.

19. The battery management method according to claim 18, further comprising a step of activating a function to resolve degradation imbalance or outputting an alarm if the state of the battery pack is diagnosed as being in a state of degradation imbalance in the state diagnosis step.

20. A profile acquisition step to obtain a first profile for each of the multiple batteries included in the battery pack, A target value calculation step involves calculating target ratios from each of several first profiles, and then calculating each target value as a diagnostic factor based on the calculated target ratios. A profile generation step that generates a distribution profile showing the correspondence between a plurality of calculated target values ​​and the number of each of the plurality of target values, A condition determination step for determining whether the distribution profile satisfies predetermined conditions, A non-temporary, readable recording medium on which a program for performing a battery management method, including a state diagnosis step for diagnosing the state of the battery pack according to the result of a determination, is recorded.

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