Apparatus and method for managing battery

Abstract

A battery management apparatus according to one embodiment of the present invention comprises: a measurement unit configured to measure voltages and currents of a battery bank including a plurality of battery cells during a charging process of the battery bank; and a control unit configured to estimate a first SOH of the battery bank on the basis of a charging capacity obtained by integrating the measured currents, determine a second SOH on the basis of a time during which a circulating current flows through the plurality of battery cells from a charging end time point of the battery bank, and estimate an SOH of the battery bank on the basis of the first SOH and the second SOH.

Description

Battery management device and method

[0001] This application claims priority to Korean Patent Application No. 10-2024-0033300, filed on March 8, 2024, and all contents disclosed in the specification and drawings of the said application are incorporated herein by reference.

[0002] The present invention relates to a battery management device and method, and more particularly, to a battery management device and method capable of more accurately estimating the state of a battery.

[0003] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has rapidly increased, and the development of electric vehicles, energy storage batteries, robots, and satellites has been in full swing, research into high-performance batteries capable of repeated charging and discharging is actively being conducted.

[0004] Currently commercialized batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium batteries. Among these, lithium batteries are receiving attention for their advantages of being able to charge and discharge freely, having a very low self-discharge rate, and having a high energy density, as they have almost no memory effect compared to nickel-based batteries.

[0005] While extensive research is being conducted on these batteries to improve capacity and density, improving lifespan and safety is also crucial. To improve battery safety, technology is required to accurately diagnose the current battery condition.

[0006] The present invention has been devised to solve the above problems, and aims to provide a battery management device and method capable of more accurately estimating the SOH (State of health) and SOC (State of charge) of a battery.

[0007] Other objects and advantages of the present invention can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0008] A battery management device according to one aspect of the present invention may include a measuring unit configured to measure voltage and current of a battery bank including a plurality of battery cells during a charging process of the battery bank; and a control unit configured to estimate a first SOH of the battery bank based on a charging capacity accumulated from the measured current, determine a second SOH based on a time during which a circulating current flows through the plurality of battery cells from a charging termination time of the battery bank, and estimate the SOH of the battery bank based on the first SOH and the second SOH.

[0009] The control unit may be configured to calculate a charge capacity of the battery bank by accumulating the measured current, and estimate a first SOH of the battery bank based on the calculated charge capacity.

[0010] The above control unit may be configured to calculate the time for which the circulating current flows based on the voltage of the battery bank from the time of termination of the charging.

[0011] The above control unit may be configured to determine the second SOH using an SOH table in which an SOH value corresponding to the time during which the circulating current flows is preset.

[0012] The control unit may be configured to determine the voltage of the battery bank at the time of charging termination and the second SOH corresponding to the time by using an SOH table in which the SOH value corresponding to the time at which the circulating current flows and the voltage of the battery bank after the circulating current flows are preset.

[0013] The control unit may be configured to calculate a difference between the first SOH and the second SOH to produce a third SOH, and estimate the produced third SOH as the SOH of the battery bank.

[0014] The control unit may be configured to determine the second SOH when a difference between the first SOH and the previously estimated SOH of the battery bank is greater than or equal to a preset threshold value.

[0015] The above plurality of battery cells may be configured to be connected in parallel with each other.

[0016] A battery pack according to another aspect of the present invention may include a battery management device according to one aspect of the present invention.

[0017] A vehicle according to another aspect of the present invention may include a battery management device according to one aspect of the present invention.

[0018] According to another aspect of the present invention, a battery management method may include a measuring step of measuring voltage and current of a battery bank including a plurality of battery cells during a charging process of the battery bank; a first SOH estimation step of estimating a first SOH of the battery bank based on a charging capacity accumulated from the measured current; a second SOH calculation step of determining a second SOH based on a time during which a circulating current flows through the plurality of battery cells from a charging termination time of the battery bank; and an SOH estimation step of estimating the SOH of the battery bank based on the first SOH and the second SOH.

[0019] According to one aspect of the present invention, there is an advantage in that the SOH of a battery bank can be more accurately estimated by considering the time during which a circulating current flows between a plurality of battery cells.

[0020] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0021] The following drawings attached to this specification serve to further understand the technical idea of ​​the present invention together with the detailed description of the invention described below, and therefore the present invention should not be interpreted as being limited to the matters described in such drawings.

[0022] FIG. 1 is a schematic diagram illustrating a battery management device according to one embodiment of the present invention.

[0023] FIG. 2 is a schematic diagram illustrating a battery bank according to one embodiment of the present invention.

[0024] FIG. 3 is a diagram schematically illustrating an SOH table according to one embodiment of the present invention.

[0025] FIG. 4 is a diagram schematically illustrating an SOH table according to another embodiment of the present invention.

[0026] FIG. 5 is a schematic drawing of a battery pack according to another embodiment of the present invention.

[0027] FIG. 6 is a schematic drawing of a vehicle according to another embodiment of the present invention.

[0028] FIG. 7 is a schematic diagram illustrating an ESS according to another embodiment of the present invention.

[0029] FIG. 8 is a schematic diagram illustrating a battery management method according to another embodiment of the present invention.

[0030] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best possible manner.

[0031] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0032] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0033] Terms that include ordinal numbers, such as first, second, etc., are used to distinguish one of the various components from the rest, and are not used to limit the components by such terms.

[0034] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0035] Additionally, throughout the specification, when we say that a part is "connected" to another part, this includes not only cases where it is "directly connected" but also cases where it is "indirectly connected" with other elements in between.

[0036]

[0037] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0038] FIG. 1 is a schematic diagram illustrating a battery management device (100) according to one embodiment of the present invention.

[0039] Referring to FIG. 1, a battery management device (100) may include a measurement unit (110) and a control unit (120).

[0040] The measuring unit (110) can be configured to measure the voltage and current of the battery bank (BB) during the charging process of the battery bank (BB) including a plurality of battery cells.

[0041] Here, a battery cell refers to a physically separate, independent cell having a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer battery may be considered a battery cell. Furthermore, the battery type may be cylindrical, prismatic, or pouch-type. Furthermore, a battery bank may include multiple battery cells connected in parallel. If it includes multiple battery cells connected in parallel, the battery bank (BB) may also be referred to as a battery module or battery pack.

[0042] FIG. 2 is a schematic diagram illustrating a battery bank (BB) according to one embodiment of the present invention.

[0043] For example, in the embodiment of FIG. 2, the battery bank (BB) may include a first battery cell (B1), a second battery cell (B2), and a third battery cell (B3). In addition, the first battery cell (B1), the second battery cell (B2), and the third battery cell (B3) may be connected in parallel with each other.

[0044] The measuring unit (110) has one end connected to the positive terminal of the battery bank (BB) and can measure the positive potential of the battery bank (BB). Furthermore, the measuring unit (110) has the other end connected to the negative terminal of the battery bank (BB) and can measure the negative potential of the battery bank (BB). Furthermore, the measuring unit (110) can measure the voltage of the battery bank (BB) based on the difference between the positive potential and the negative potential.

[0045] In addition, the measuring unit (110) can be connected to the charge / discharge path of the battery bank (BB) to measure the charge / discharge current of the battery bank (BB). For example, the measuring unit (110) can be connected to a current measuring unit provided in the high current path of the battery bank (BB) to measure the charge current applied to the battery bank (BB) and the discharge current output from the battery bank (BB).

[0046] The control unit (120) may be configured to estimate the first SOH of the battery bank (BB) based on the charging capacity accumulated from the measured current.

[0047] First, the control unit (120) may be configured to calculate the charge capacity of the battery bank (BB) by integrating the measured current. For example, the control unit (120) may calculate the charge capacity of the battery bank (BB) during the charging process by integrating the current measured by the measurement unit (110) from the start time of charging of the battery bank (BB) to the end time of charging. Here, the control unit (120) may calculate the charge capacity of the battery bank (BB) by using a current integration method (Coulomb counting, Ampere counting).

[0048] The control unit (120) may be configured to estimate the first SOH of the battery bank (BB) based on the calculated charge capacity. Specifically, the control unit (120) may estimate the first SOH of the battery bank (BB) by calculating the ratio of the charge capacity to a preset reference capacity. Here, the reference capacity may be preset to correspond to the initial capacity of the battery bank (BB). For example, the reference capacity may be preset to the capacity of the battery bank (BB) in the BOL (Beginning of Life) state.

[0049] In the embodiment of FIG. 2, the control unit (120) can calculate the charging capacity based on the current of the battery bank (BB) measured by the measurement unit (110). In addition, the control unit (120) can estimate the first SOH of the battery bank (BB) by calculating the ratio between the calculated charging capacity and a preset reference capacity corresponding to the battery bank (BB). For example, the control unit (120) can estimate the first SOH of the battery bank (BB) by calculating the formula “calculated charging capacity ÷ preset reference capacity.”

[0050] The control unit (120) may be configured to determine the second SOH based on the time during which circulating current flows through the plurality of battery cells from the time of termination of charging of the battery bank (BB).

[0051] Specifically, the control unit (120) can be configured to calculate the time for which the circulating current flows based on the voltage of the battery bank (BB) from the time of charging termination.

[0052] More specifically, the measuring unit (110) can measure the voltage of the battery bank (BB) according to the measurement cycle even after the charging of the battery bank (BB) is terminated. In addition, the control unit (120) can calculate the time for which the circulating current flows through the plurality of battery cells based on the voltage of the battery bank (BB) at the time of termination of charging and the voltage of the battery bank (BB) measured by the measuring unit (110) after the termination of charging.

[0053] Typically, if the degradation rates of battery cells connected in parallel differ, the capacities of the multiple battery cells may differ immediately after charging the battery bank (BB). In this case, a circulating current flows between the multiple battery cells, balancing their capacities and voltages. This phenomenon is called self-balancing or self-energy balancing.

[0054] Since this circulating current is generated by the voltage difference between the plurality of battery cells, the voltage of the battery bank (BB) may change while the circulating current flows even after charging has been completed. That is, the circulating current may flow between the plurality of battery cells during the time from the time when charging of the battery bank (BB) is completed to the time when the voltage of the battery bank (BB) changes. Accordingly, the control unit (120) may calculate the time from the time when charging of the battery bank (BB) is completed to the time when the voltage change of the battery bank (BB) is completed as the time during which the circulating current flows through the plurality of battery cells.

[0055] Here, since the circulating current is the current that flows directly between the multiple battery cells, it should be noted that the time for the circulating current to flow between the multiple battery cells and the time for the multiple battery cells to reach a resting state (e.g., a state where the OCV (Open circuit voltage) can be measured) are different times.

[0056] The control unit (120) can be configured to determine the second SOH using an SOH table in which an SOH value corresponding to the time at which the circulating current flows is preset.

[0057] FIG. 3 is a schematic diagram illustrating an SOH table according to one embodiment of the present invention. For example, the SOH table may be preset with corresponding SOH values ​​for each time period during which circulating current flows. In the embodiment of FIG. 3, when the time period is 0 seconds, no circulating current flows between the plurality of battery cells, and therefore the SOH value is 0%.

[0058] Specifically, the control unit (120) can determine an SOH value corresponding to the calculated time using the SOH table. Then, the control unit (120) can determine the determined SOH value as a second SOH for the battery bank (BB). Here, the second SOH may be a correction value used to correct the estimated first SOH for the battery bank (BB). In other words, the second SOH is a value that converts the difference in deterioration between multiple battery cells into SOH. In other words, the second SOH is an internal error value for correcting the SOH of the battery bank (BB).

[0059] Preferably, the second SOH may be proportional to the time over which the circulating current flows. For example, as the difference in degradation between the multiple battery cells increases, the time over which the circulating current flows between the multiple battery cells may increase. Accordingly, as the time over which the circulating current flows increases, the second SOH value for the battery bank (BB) may increase.

[0060] For example, in the embodiment of FIG. 2, it is assumed that a circulating current has flowed in the battery bank (BB) for t seconds. The control unit (120) can determine an SOH value corresponding to t seconds from the SOH table and determine the determined SOH value as the second SOH for the battery bank (BB).

[0061] The control unit (120) may be configured to estimate the SOH of the battery bank (BB) based on the first SOH and the second SOH.

[0062] Specifically, the control unit (120) may be configured to calculate the difference between the first SOH and the second SOH to produce a third SOH, and estimate the produced third SOH as the SOH of the battery bank (BB).

[0063] For example, the control unit (120) can calculate the formula of “first SOH - second SOH” to produce a third SOH, and estimate the produced third SOH as the SOH of the battery bank (BB).

[0064] In the embodiment of FIG. 2, the control unit (120) can estimate the first SOH of the battery bank (BB) by calculating the charge capacity of the battery bank (BB), and determine the second SOH based on the time for which the circulating current flows between the plurality of battery cells (B1, B2, B3). In addition, the control unit (120) can estimate the SOH of the battery bank (BB) by calculating the difference between the first SOH and the second SOH.

[0065] A battery management device (100) according to one embodiment of the present invention can estimate the SOH of the battery bank (BB) more accurately by correcting the SOH of the battery bank (BB) by taking into account an internal error of the battery bank (BB) (difference in deterioration between multiple battery cells).

[0066] That is, the first SOH estimated by integrating the charging current may not reflect the state difference between the plurality of battery cells included in the battery bank (BB). Therefore, the battery management device (100) can estimate the SOH of the battery bank (BB) more accurately by correcting the first SOH of the battery bank (BB) using the second SOH based on the difference between the plurality of battery cells.

[0067]

[0068] Meanwhile, the control unit (120) provided in the battery management device (100) may optionally include a processor, an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a register, a communication modem, a data processing device, etc. known in the art to execute various control logics performed in the present invention. In addition, when the control logic is implemented in software, the control unit (120) may be implemented as a set of program modules. In this case, the program modules may be stored in a memory and executed by the control unit (120). The memory may be located inside or outside the control unit (120) and may be connected to the control unit (120) by various well-known means.

[0069] In addition, the battery management device (100) may further include a storage unit (130). The storage unit (130) may store data or programs required for each component of the battery management device (100) to perform operations and functions, or data generated in the process of performing operations and functions. The storage unit (130) is not particularly limited in type as long as it is a known information storage means known to be capable of recording, erasing, updating, and reading data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, etc. In addition, the storage unit (130) may store program codes defining processes executable by the control unit (120).

[0070] For example, the storage unit (130) can store the voltage and current of the battery bank (BB) measured by the SOH measurement unit (110). In addition, an SOH table can be stored in the storage unit (130). The control unit (120) can access the storage unit (130) to secure the SOH table. In addition, the storage unit (130) can store information estimated or determined by the control unit (120).

[0071]

[0072] The control unit (120) may be configured to determine a second SOH corresponding to the voltage and time of the battery bank (BB) at the end of charging by using an SOH table in which the SOH value corresponding to the time at which the circulating current flows and the voltage of the battery bank (BB) after the circulating current flows is preset.

[0073] FIG. 4 is a schematic diagram illustrating an SOH table according to another embodiment of the present invention. For example, the SOH table may be preset with SOH values ​​corresponding to the time during which a circulating current flows and the voltage of a battery bank (BB).

[0074] As in the embodiment of FIG. 3, in the embodiment of FIG. 4, when the time is 0 seconds, no circulating current flows between the plurality of battery cells, and therefore the SOH value is 0%. For example, in the embodiment of FIG. 4, when the time for which the circulating current flows is 10 seconds and the voltage of the battery bank (BB) is 4.163 [V], the second SOH may be 2%.

[0075] Preferably, to more accurately estimate the SOH of a battery bank (BB), a second SOH that compensates for the first SOH should be determined more accurately. Furthermore, since the second SOH reflects the state difference between multiple battery cells, the SOH table can be established by taking into account not only the time during which the circulating current flows but also the voltage of the battery bank (BB) after the circulating current flows.

[0076] The control unit (120) can determine a more accurate second SOH by inputting the time during which the circulating current flows and the voltage of the battery bank (BB) into the SOH table. In addition, since the first SOH is corrected by the determined second SOH, the control unit (120) can estimate the SOH of the battery bank (BB) more accurately.

[0077]

[0078] Preferably, the control unit (120) estimates the first SOH of the battery bank (BB) each time the battery bank (BB) is charged, determines the second SOH based on the difference between the plurality of battery cells, and estimates the SOH of the battery bank (BB) based on the first SOH and the second SOH.

[0079] In another embodiment, the control unit (120) may determine the second SOH based on the difference between the first SOH estimated in the current charging process (hereinafter, referred to as “current first SOH”) and the SOH estimated in the previous charging process (hereinafter, referred to as “past SOH”).

[0080] Specifically, the control unit (120) may be configured to determine the second SOH when the difference between the first SOH and the previously estimated SOH of the battery bank (BB) is greater than or equal to a preset threshold value.

[0081] By estimating the SOH of the battery bank (BB) by correcting the first SOH each time the battery bank (BB) is charged, the SOH of the battery bank (BB) can be estimated more accurately. However, since the SOH correction using the second SOH is performed every time, the SOH estimation takes more time and may excessively use system resources. Therefore, the control unit (120) can determine the second SOH if the difference between the current first SOH and the past SOH is greater than a threshold value.

[0082] Here, the threshold value serves as a criterion for determining that the battery bank (BB) has deteriorated to the point where correction of the first SOH by the second SOH is necessary, and can be set theoretically or experimentally. For example, the threshold value can be set to a value below 10% SOH. Preferably, the threshold value can be set to a value below 5% SOH. More preferably, the threshold value can be set to a value below 1% SOH.

[0083] For example, it is assumed that the threshold value is set to SOH 1%. If the difference between the current first SOH and the past SOH is 1% or more, the battery bank (BB) has deteriorated more than the time at which the past SOH was estimated, and thus the control unit (120) can determine the second SOH to compensate for the current first SOH.

[0084] Specifically, if the difference between the current first SOH and the past SOH is greater than or equal to a threshold value, the control unit (120) can determine a second SOH and estimate the SOH of the battery bank (BB) by calculating the difference between the current first SOH and the determined second SOH. As another example, if the difference between the current first SOH and the past SOH is less than a threshold value, the control unit (120) can estimate the current first SOH as the SOH of the battery bank (BB).

[0085]

[0086] The control unit (120) may be configured to update the OCV table indicating the correspondence between the voltage and SOC of multiple battery cells so as to correspond to the SOH of the battery bank (BB).

[0087] Specifically, multiple OCV tables corresponding to multiple SOHs can be stored in advance. Then, the control unit (120) can select an OCV table corresponding to the SOH of the battery bank (BB) from among the multiple OCV tables and use the selected OCV table to estimate the states of multiple battery cells.

[0088] That is, since the OCV table is updated to correspond to the SOH of the compensated battery bank (BB), the status of multiple battery cells can be estimated more accurately according to the updated OCV table.

[0089]

[0090] The battery management device (100) according to the present invention can be applied to a BMS (Battery Management System). That is, the BMS according to the present invention can include the battery management device (100) described above. In this configuration, at least some of the components of the battery management device (100) can be implemented by supplementing or adding to the functions of the components included in a conventional BMS. For example, the measurement unit (110), control unit (120), and storage unit (130) of the battery management device (100) can be implemented as components of the BMS.

[0091] In addition, the battery management device (100) according to the present invention may be installed in a battery bank (BB). That is, the battery bank (BB) according to the present invention may include the battery management device (100) described above and one or more battery cells. In addition, the battery bank (BB) may further include electrical components (relays, fuses, etc.) and a case, etc.

[0092] FIG. 5 is a schematic drawing of a battery pack (1) according to another embodiment of the present invention.

[0093] The battery module (10) may include a plurality of battery banks (11, 12, 13) connected in series with each other. Here, the plurality of battery banks (11, 12, 13) may each include a plurality of battery cells connected in parallel. That is, the battery module (10) may include a plurality of battery cells connected in series and parallel.

[0094] The measuring unit (110) can be connected to the first to fourth sensing lines (SL1, SL2, SL3, SL4). Specifically, the measuring unit (110) can measure the voltage of the first battery bank (11) through the first sensing line (SL1) and the second sensing line (SL2). In addition, the measuring unit (110) can measure the voltage of the second battery bank (12) through the second sensing line (SL2) and the third sensing line (SL3), and can measure the voltage of the third battery bank (13) through the third sensing line (SL3) and the fourth sensing line (SL4). Finally, the measuring unit (110) can measure the voltage of the battery module (10) through the first sensing line (SL1) and the fourth sensing line (SL4).

[0095] And, the measuring unit (110) can be connected to the current measuring unit (A) through the fifth sensing line (SL5). For example, the current measuring unit (A) can be an ammeter or a shunt resistor capable of measuring the charging current and discharging current of the battery module (10). The measuring unit (110) can measure the charging current of the battery module (10) through the fifth sensing line (SL5) to calculate the charging amount. In addition, the measuring unit (110) can measure the discharging current of the battery module (10) through the fifth sensing line (SL5) to calculate the discharging amount.

[0096] An external device can be connected to the positive terminal (P+) and negative terminal (P-) of the battery pack (1). For example, the external device can be a charging device or a load. In addition, the positive terminal of the battery module (10), the positive terminal (P+) of the battery pack (1), the external device, the negative terminal (P-) of the battery pack (1), and the negative terminal of the battery module (10) can be electrically connected.

[0097]

[0098] FIG. 6 is a schematic drawing of a vehicle (600) according to another embodiment of the present invention.

[0099] Referring to FIG. 6, a battery pack (610) according to an embodiment of the present invention may be included in a vehicle (600), such as an electric vehicle (EV) or a hybrid vehicle (HV). Furthermore, the battery pack (610) may drive the vehicle (600) by supplying power to a motor through an inverter provided in the vehicle (600). Here, the battery pack (610) may include a battery management device (100). That is, the vehicle (600) may include a battery management device (100). In this case, the battery management device (100) may be an onboard device included in the vehicle (600).

[0100] For example, a battery pack (610) includes a plurality of battery banks (BB), and the battery management device (100) can estimate the SOH of each of the plurality of battery banks (BB). Here, a plurality of battery banks (BB) connected in series with each other are included in a battery module, and a plurality of battery modules can be included in the battery pack (610).

[0101]

[0102] FIG. 7 is a schematic diagram illustrating an ESS (Energy storage system) according to another embodiment of the present invention.

[0103] Referring to FIG. 7, the ESS (700) includes a plurality of battery modules (720) and a rack case (710). The plurality of battery modules (720) may be configured to be accommodated in the rack case (710) in a vertically arranged manner. Here, a battery management device (100) according to an embodiment of the present invention may be attached to the battery module (720).

[0104] For example, the battery module (720) includes a plurality of battery banks (BB), and the battery management device (100) can estimate the SOH of each of the plurality of battery banks (BB).

[0105]

[0106] FIG. 8 is a schematic diagram illustrating a battery management method according to another embodiment of the present invention.

[0107] Referring to FIG. 8, the battery management method may include a measurement step (S100), a first SOH estimation step (S200), a second SOH calculation step, and an SOH estimation step.

[0108] Preferably, each step of the battery management method can be performed by a battery management device (100). In the following, for convenience of explanation, any content that overlaps with the previously described content will be omitted or briefly described.

[0109] The measurement step (S100) is a step of measuring the voltage and current of the battery bank (BB) during a charging process of the battery bank (BB) including a plurality of battery cells, and can be performed by the measurement unit (110).

[0110] The first SOH estimation step (S200) is a step of estimating the first SOH of the battery bank (BB) based on the charging capacity accumulated from the measured current, and can be performed by the control unit (120).

[0111] First, the control unit (120) may be configured to calculate the charge capacity of the battery bank (BB) by integrating the measured current. For example, the control unit (120) may calculate the charge capacity of the battery bank (BB) during the charging process by integrating the current measured by the measurement unit (110) from the start time of charging of the battery bank (BB) to the end time of charging.

[0112] In addition, the control unit (120) may be configured to estimate the first SOH of the battery bank (BB) based on the calculated charge capacity. For example, the control unit (120) may estimate the first SOH of the battery bank (BB) by calculating the ratio of the charge capacity to a preset reference capacity.

[0113] The second SOH determination step (S300) is a step of determining the second SOH based on the time during which circulating current flows through multiple battery cells from the time of end of charging of the battery bank (BB), and can be performed by the control unit (120).

[0114] First, the control unit (120) may be configured to calculate the time for which circulating current flows based on the voltage of the battery bank (BB) from the time of charging completion. For example, the control unit (120) may calculate the time for which circulating current flows in the plurality of battery cells as the time for which the voltage of the battery bank (BB) changes from the time of charging completion.

[0115] In addition, the control unit (120) can determine an SOH value corresponding to the calculated time using the SOH table. In addition, the control unit (120) can determine the determined SOH value as the second SOH for the battery bank (BB).

[0116] The SOH estimation step (S400) is a step of estimating the SOH of the battery bank (BB) based on the first SOH and the second SOH, and can be performed by the control unit (120).

[0117] Specifically, the control unit (120) may be configured to calculate the difference between the first SOH and the second SOH to produce a third SOH, and estimate the produced third SOH as the SOH of the battery bank (BB).

[0118]

[0119] The embodiments of the present invention described above are not implemented only through devices and methods, but may also be implemented through a program that realizes a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation can be easily implemented by an expert in the technical field to which the present invention belongs based on the description of the embodiments described above.

[0120] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0121] In addition, the present invention described above is not limited to the above-described embodiments and the attached drawings, and all or part of each embodiment may be selectively combined and configured so that various modifications can be made, as those skilled in the art can make various substitutions, modifications, and changes within the scope of the technical idea of ​​the present invention.

[0122]

[0123] (Explanation of symbols)

[0124] 1: Battery pack

[0125] 10: Battery module

[0126] 11: 1st Battery Bank

[0127] 12: Second battery bank

[0128] 13: Third Battery Bank

[0129] 100: Battery management device

[0130] 110: Measurement section

[0131] 120: Control unit

[0132] 130: Storage

[0133] 600: Car

[0134] 610: Battery Pack

[0135] 700: ESS

[0136] 710: Battery Rack

[0137] 720: Battery module

Claims

1. A measuring unit configured to measure voltage and current of a battery bank during a charging process of a battery bank including a plurality of battery cells; and A battery management device including a control unit configured to estimate a first SOH of the battery bank based on a charge capacity accumulated from the measured current, determine a second SOH based on a time during which a circulating current flows through the plurality of battery cells from a charging end point of the battery bank, and estimate the SOH of the battery bank based on the first SOH and the second SOH.

2. In paragraph 1, The above control unit, A battery management device configured to calculate a charge capacity of the battery bank by accumulating the measured current, and to estimate a first SOH of the battery bank based on the calculated charge capacity.

3. In paragraph 1, The above control unit, A battery management device configured to calculate the time for which the circulating current flows based on the voltage of the battery bank from the end of the charging time.

4. In paragraph 1, The above control unit, A battery management device configured to determine the second SOH corresponding to the time using an SOH table in which an SOH value corresponding to the time at which the circulating current flows is preset.

5. In paragraph 1, The above control unit, A battery management device configured to determine the voltage of the battery bank at the time of charging termination and the second SOH corresponding to the time by using an SOH table in which the SOH value corresponding to the time during which the circulating current flows and the voltage of the battery bank after the circulating current flows is preset.

6. In paragraph 1, The above control unit, A battery management device configured to calculate a difference between the first SOH and the second SOH to produce a third SOH, and to estimate the produced third SOH as the SOH of the battery bank.

7. In paragraph 1, The above control unit, A battery management device configured to determine the second SOH when a difference between the first SOH and the previously estimated SOH of the battery bank is greater than or equal to a preset threshold.

8. In paragraph 1, A battery management device in which the above plurality of battery cells are configured to be connected in parallel with each other.

9. A battery pack comprising a battery management device according to any one of claims 1 to 8.

10. A vehicle including a battery management device according to any one of paragraphs 1 to 8.

11. A measuring step of measuring the voltage and current of a battery bank during a charging process of a battery bank including a plurality of battery cells; A first SOH estimation step for estimating a first SOH of the battery bank based on a charging capacity calculated by accumulating the measured current; A second SOH determination step for determining a second SOH based on the time for which a circulating current flows through the plurality of battery cells from the time of termination of charging of the battery bank; and A battery management method comprising an SOH estimation step of estimating the SOH of the battery bank based on the first SOH and the second SOH.

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