Battery management apparatus and battery management method

Abstract

A battery management apparatus according to an embodiment of the present invention comprises: a profile acquisition unit configured to acquire a charge profile and a discharge profile representing charge / discharge characteristics of a battery; and a diagnosis unit configured to calculate a hysteresis characteristic value on the basis of information on voltage difference between the charge profile and the discharge profile in a target section, and diagnose a state of the battery by comparing the hysteresis characteristic value with a diagnostic value.

Description

Battery management device and method

[0001] The present invention relates to a battery management device and method capable of diagnosing the status of a battery.

[0002] This application claims priority to Korean Application No. 10-2024-0015098, filed January 31, 2024, the entire disclosure of which is incorporated herein by reference.

[0003]

[0004] 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.

[0005] 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.

[0006] 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.

[0007] In an ideal charge / discharge cycle of a battery, the charge capacity and discharge capacity may be identical. However, in an actual charge / discharge cycle, the charge capacity and discharge capacity may differ due to factors such as internal resistance. In other words, batteries exhibit hysteresis, which causes the charge and discharge characteristics to differ during an actual charge / discharge cycle. The hysteresis characteristic arises from the difference between the phase transition voltage that occurs when the battery is charged and the phase transition voltage that occurs when the battery is discharged. The hysteresis phenomenon may become more pronounced as the battery deteriorates or the charge / discharge rate (C-rate) increases. Therefore, there is a need to develop a technology that can determine the parameters that represent the hysteresis characteristics of a battery and diagnose the battery deterioration status based on the determined parameters.

[0008] Furthermore, if charge / discharge characteristics across the 0% to 100% SOC range are essential for diagnosing a battery's deterioration status, the diagnosis can be unnecessarily time-consuming. Therefore, to shorten the diagnostic time, the development of technology capable of diagnosing deterioration status using only charge / discharge characteristics across a specific capacity range (or SOC range) is needed.

[0009]

[0010] The present invention has been devised to solve the above problems, and its purpose is to provide a battery management device and method capable of diagnosing the deterioration state of a battery based on a hysteresis characteristic value, which is a parameter indicating the hysteresis characteristic of a battery.

[0011] In addition, the present invention aims to provide a battery management device and method capable of diagnosing the state of a battery using only the charge / discharge characteristics for a portion of the battery's capacity (or SOC) range.

[0012] 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.

[0013]

[0014] A battery management device according to one aspect of the present invention may include a profile acquisition unit configured to acquire a charge profile and a discharge profile representing charge and discharge characteristics of a battery; and a diagnosis unit configured to calculate a hysteresis characteristic value based on voltage difference information between the charge profile and the discharge profile in a target section, and to compare the hysteresis characteristic value with a diagnosis value to diagnose a state of the battery.

[0015] The above diagnostic unit may be configured to determine the target section by comparing the capacity range of the charging profile with the capacity range of the discharge profile.

[0016] The above diagnostic unit may be configured to determine all or part of a capacity section common to the charge profile and the discharge profile as the target section.

[0017] The above target range may be predetermined.

[0018] The above diagnostic unit may be configured to calculate the hysteresis characteristic value based on a value obtained by integrating the voltage difference between the voltage of the charging profile and the voltage of the discharging profile with respect to the target section.

[0019] The above battery management device may further include a storage unit.

[0020] The above storage unit may store a lookup table in which multiple reference capacity sections and multiple diagnostic values ​​are mapped one-to-one with each other.

[0021] The above diagnostic unit may be configured to determine a reference value mapped to one of the plurality of reference capacity intervals corresponding to the target interval as the diagnostic value.

[0022] The above diagnostic unit may be configured to calculate the diagnostic value based on a preset reference charge profile and reference discharge profile.

[0023] The above diagnostic unit may be configured to determine the diagnostic value based on an integrated value of the voltage difference between the voltage of the reference charging profile and the voltage of the discharge profile with respect to the target section.

[0024] The above diagnostic unit may be configured to diagnose the state of the battery as normal if the difference between the hysteresis characteristic value and the diagnostic value is less than a preset first threshold value.

[0025] The above diagnostic unit may be configured to diagnose the state of the battery as abnormal if the difference between the hysteresis characteristic value and the diagnostic value is greater than or equal to the first threshold value.

[0026] The above diagnostic unit may be configured to diagnose the state of the battery as normal if the ratio of the hysteresis characteristic value to the diagnostic value is less than a preset second threshold value.

[0027] The above diagnostic unit may be configured to diagnose the state of the battery as abnormal if the ratio of the hysteresis characteristic value to the diagnostic value is greater than or equal to a preset second threshold value.

[0028] The above battery management device may further include a control unit.

[0029] The above control unit may be configured to set usage conditions for the battery based on the diagnosis results.

[0030] 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.

[0031] A vehicle according to another aspect of the present invention may include a battery management device according to one aspect of the present invention.

[0032] A battery management method according to another aspect of the present invention may include the steps of: obtaining a charge profile and a discharge profile representing charge and discharge characteristics of a battery; calculating a hysteresis characteristic value based on voltage difference information between the charge profile and the discharge profile in a target section; and diagnosing the state of the battery by comparing the hysteresis characteristic value with a diagnostic value.

[0033]

[0034] According to at least one of the embodiments of the present invention, the degradation state of a battery can be diagnosed based on a hysteresis characteristic value, which is a parameter indicating the hysteresis characteristic of the battery.

[0035] In addition, according to at least one of the embodiments of the present invention, the time required for diagnosis can be shortened by diagnosing the state of the battery only with the charge / discharge characteristics for a portion of the capacity section (or SOC section) of the battery.

[0036] In addition, according to at least one of the embodiments of the present invention, by appropriately setting the usage conditions of the battery based on the results of the status diagnosis of the battery, it is possible to prevent degradation or accelerated degradation of the battery.

[0037] 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.

[0038]

[0039] 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.

[0040] FIG. 1 is a schematic diagram illustrating a battery management device according to one embodiment of the present invention.

[0041] Figure 2 is a schematic diagram illustrating an example of a charge profile and a discharge profile.

[0042] FIG. 3 is a drawing illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention.

[0043] FIG. 4 is a schematic drawing of a vehicle according to another embodiment of the present invention.

[0044] FIG. 5 is a schematic diagram illustrating a battery management method according to another embodiment of the present invention.

[0045] FIG. 6 is a schematic diagram illustrating a battery management method according to another embodiment of the present invention.

[0046]

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0054] FIG. 1 is a schematic diagram illustrating a battery management device (100) according to one embodiment of the present invention.

[0055] Referring to FIG. 1, the battery management device (100) includes a profile acquisition unit (110) and a diagnostic unit (120), and may further include a control unit (130). The battery management device (100) may further include a storage unit (140).

[0056] A battery management device (100) is provided to diagnose the status of a battery (see reference numeral 11 in FIG. 3). Depending on the embodiment, the battery management device (100) may be configured to organically link with other components or modules / devices to generate and output diagnostic data for the battery.

[0057] Here, a battery 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. Furthermore, the battery may be of a cylindrical type, a prismatic type, or a pouch type. Furthermore, a battery may also refer to a battery bank, a battery module, or a battery pack in which multiple cells are connected in series and / or parallel. For convenience of explanation, the term "battery" will be described herein below as referring to a single, independent cell.

[0058] Figure 2 is a schematic diagram illustrating an example of a charge profile (CP) and a discharge profile (DP).

[0059] In the embodiment of FIG. 2, the horizontal axis (X-axis) represents capacity (mAh), and the vertical axis (Y-axis) represents voltage (V).

[0060] The profile acquisition unit (110) can be configured to acquire a charge profile (CP) and a discharge profile (DP) representing the charge and discharge characteristics of the battery.

[0061] A charge profile (CP) can represent the correspondence between voltage and capacity (or SOC: State of Charge, resistance) during the charging process of a battery. For example, the charging process may proceed according to a CC-CV (Constant Current - Constant Voltage) charging protocol. The magnitude of the charging current used for CC charging and the magnitude of the charging voltage used for CV charging during the charging process may be predetermined. The charging protocol used to periodically or aperiodically acquire the charge profile (CP) throughout the life of the battery may be the same as the charging protocol used to acquire the reference charge profile described below. As long as the capacity-voltage characteristics during battery charging can be acquired, the type of charging protocol is not limited to the CC-CV charging protocol.

[0062] In addition, the discharge profile (DP) can represent the correspondence between the voltage and capacity (or SOC, resistance) during the discharge process of the battery. For example, the discharge process can proceed according to the CC (Constant Current) discharge protocol. The size of the discharge current used for the CC discharge during the discharge process can be predetermined. The discharge protocol used to periodically or aperiodically obtain the discharge profile (DP) throughout the entire life of the battery can be the same as the discharge protocol used to obtain the reference discharge profile described below. As long as the capacity-voltage characteristics during the discharge of the battery can be obtained, the type of discharge protocol is not limited to the CC discharge protocol.

[0063] In this specification, acquisition of any data or information should be understood to mean reception from an external device through a communication means, input from a user through an input means, or creation through execution of a program, etc.

[0064] For example, the profile acquisition unit (110) can be connected to the outside world via wired and / or wireless connections to directly receive a charging profile (CP) and a discharging profile (DP). Wired communication may be, for example, CAN (controller area network) communication or CAN-FD (CAN with Flexible Data Rate) communication. Wireless communication may be, for example, Zigbee or Bluetooth communication. Of course, as long as it supports communication between the profile acquisition unit (110) and the outside world, the type of communication protocol is not particularly limited.

[0065] As another example, the profile acquisition unit (110) can receive measurement information indicating the voltage and current of the battery. Then, the profile acquisition unit (110) can generate a charge profile (CP) and a discharge profile (DP) based on the received measurement information.

[0066] For example, the profile acquisition unit (110) can generate a charge profile (CP) and a discharge profile (DP) by executing a process of mutually mapping the voltage time series and capacity time series (or SOC time series, resistance time series) of the battery based on a time index. The charge profile (CP) and the discharge profile (DP) may be a set or polynomial of data points representing the correspondence between the voltage and capacity (or SOC, resistance) of the battery. Each data point of the charge profile (CP) and the discharge profile (DP) may be a pair of a voltage value and a capacity value (or SOC, resistance value) indexed at the same time (same measurement timing).

[0067] A voltage time series can represent the history of battery voltage changes over time. A current time series can represent the history of battery current changes over time. A capacity time series (or SOC time series) can be determined by applying ampere counting to the current time series. A resistance time series can be determined by applying Ohm's law to the battery's voltage and current.

[0068] SOC is a parameter that represents the current capacity relative to the maximum capacity, from 0% to 100%, and can be calculated using various techniques such as current integration, equivalent circuit modeling, and Kalman filtering. Depending on the embodiment, the battery management device (100) may be configured to generate information on SOC by further reflecting environmental information such as temperature information.

[0069] The profile acquisition unit (110) may be connected to the diagnosis unit (120) so as to be able to communicate with it. For example, the profile acquisition unit (110) may be connected to the diagnosis unit (120) by wire and / or wirelessly. The profile acquisition unit (110) may transmit the acquired charge profile (CP) and discharge profile (DP) to the diagnosis unit (120).

[0070] The diagnostic unit (120) may be configured to calculate a hysteresis characteristic value based on voltage difference information between a charge profile (CP) and a discharge profile (DP) in a target section. The time interval between the end time of one of the charging process and the discharge process performed to obtain the charge profile (CP) and the discharge profile (DP) used to calculate the hysteresis characteristic value and the start time of the other may be less than a predetermined threshold time. For example, the time interval between the end time of the charging process from which the charge profile (CP) was obtained and the start time of the discharging process from which the discharge profile (DP) was obtained may be less than the threshold time. In this case, the corresponding discharge process may have been performed after the corresponding charging process. As another example, the time interval between the end time of the discharging process from which the discharge profile (DP) was obtained and the start time of the charging process from which the charge profile (CP) was obtained may be less than the threshold time. In this case, the corresponding charging process may have been performed after the corresponding discharge process.

[0071] In addition or separately, the charge / discharge capacity of the battery during the time between the end of one of the charging and discharging processes and the start of the other may be less than the critical capacity.

[0072] In one embodiment, the diagnostic unit (120) may be configured to determine a target period (TS) by comparing a capacity range (or SOC range, resistance range) of a charge profile (CP) with a capacity range (or SOC range, resistance range) of a discharge profile (DP).

[0073] The target section (TS) may be all or part of a capacity section common to the charge profile (CP) and the discharge profile (DP). For example, the diagnostic unit (120) may determine a larger value between the minimum capacity of the charge profile (CP) and the minimum capacity of the discharge profile (DP) as the lower limit of the target section (TS). If the minimum capacity of the charge profile (CP) and the minimum capacity of the discharge profile (DP) are the same, the diagnostic unit (120) may determine the minimum capacity of the charge profile (CP) or the minimum capacity of the discharge profile (DP) as the lower limit of the target section (TS).

[0074] In addition, the diagnostic unit (120) can determine a smaller value between the maximum capacity of the charging profile (CP) and the maximum capacity of the discharge profile (DP) as the upper limit of the target section (TS). If the maximum capacity of the charging profile (CP) and the maximum capacity of the discharge profile (DP) are the same, the diagnostic unit (120) can determine the maximum capacity of the charging profile (CP) or the maximum capacity of the discharge profile (DP) as the upper limit of the target section (TS).

[0075] In the embodiment of FIG. 2, the diagnostic unit (120) determines the minimum capacity (Q) of the charging profile (CP). C_min ) and maximum capacity (Q C_max ) and determine the minimum capacity (Q) of the discharge profile (DP). D_min ) and maximum capacity (Q D_max) can be determined. And, the diagnostic unit (120) determines the minimum capacity (Q) of the charging profile (CP). C_min ) and the minimum capacity (Q) of the discharge profile (DP) D_min ) among the maximum values ​​(Q D_min ) can be determined as the lower limit of the target section (TS). The diagnostic unit (120) determines the maximum capacity (Q) of the charging profile (CP). C_max ) and the maximum capacity (Q) of the discharge profile (DP) D_max ) among the minimum values ​​(Q C_max ) can be determined as the upper limit of the target section (TS). That is, the diagnostic unit (120) can determine Q D_min Inland Q C_max The capacity section can be determined as the target section (TS).

[0076] Likewise, the diagnostic unit (120) may be configured to determine a target interval (TS) identical to the common SOC range of the charge profile (CP) and the discharge profile (DP). In this case, the target interval (TS) may represent an SOC interval.

[0077] If the charge profile (CP) and the discharge profile (DP) represent a correspondence between the voltage and resistance of the battery, the diagnostic unit (120) may be configured to determine the target section (TS) to be identical to the common resistance range of the charge profile (CP) and the discharge profile (DP). In this case, the target section (TS) may represent a resistance section.

[0078] In other embodiments, the target range (TS) may be predetermined. Specifically, the target range (TS) may be a predetermined capacity range, SOC range, or resistance range. For example, the target range (TS) may be a SOC range (e.g., 40% to 60%) where the hysteresis characteristics significantly change beyond a certain level as the battery degrades, a range confirmed through numerous prior experiments.

[0079] The diagnostic unit (120) may be configured to calculate a hysteresis characteristic value based on the integrated value of the voltage difference between the voltage of the charge profile (CP) and the voltage of the discharge profile (DP) with respect to the target section (TS). In this case, the hysteresis characteristic value represents the area of ​​a closed curve defined by the charge profile (CP), the discharge profile (DP), and the target section (TS), and may be defined as one of the degradation parameters used to evaluate the degradation state of the battery.

[0080] For example, the diagnostic unit (120) can calculate the voltage difference between the voltage value of the charge profile (CP) and the voltage value of the discharge profile (DP), which correspond to the same capacity within the target section (TS). In addition, the diagnostic unit (120) can determine the integrated value for the voltage difference within the target section (TS) as the hysteresis characteristic value.

[0081] In the embodiment of FIG. 2, the diagnostic unit (120) detects any capacity (Q) within the target section (TS). x ) corresponding to the voltage value (V) of the charge profile (CP) C (Q x )) and the voltage value (V) of the discharge profile (DP) D (Q x )) voltage difference between them (i.e. V C (Q x ) - V D (Q x )) can be produced. And, the diagnostic unit (120) can determine the integrated value for the voltage difference in the target section (TS) as the hysteresis characteristic value.

[0082] For example, the diagnostic unit (120) can determine the hysteresis characteristic value using Equation 1.

[0083] [Formula 1]

[0084]

[0085] Here, H represents the hysteresis characteristic value, and V C(Q) represents the corresponding voltage value when the capacity is Q in the charge profile (CP), and V D (Q) represents the corresponding voltage value when the capacity is Q in the discharge profile (DP).

[0086] The diagnostic unit (120) can be configured to diagnose the state of the battery by comparing the hysteresis characteristic value with the diagnostic value.

[0087] The diagnostic value is a parameter that is compared with the hysteresis characteristic value of the battery, and may be determined from among a plurality of preset reference values ​​or based on preset reference charge profiles and reference discharge profiles. A specific embodiment of how the diagnostic unit (120) determines the diagnostic value will be described below.

[0088] The diagnostic unit (120) can diagnose the state of the battery as a normal state or an abnormal state. Here, the abnormal state may mean a state in which the hysteresis characteristic value determined based on the charge profile (CP) and the discharge profile (DP) becomes larger than a predetermined value as the battery deteriorates. As the battery deteriorates, the internal resistance increases, and the hysteresis characteristic value and the internal resistance of the battery have a strong positive correlation. Therefore, the abnormal state may mean a state in which the internal resistance of the battery becomes larger than a predetermined value. In other words, the abnormal state may be understood as a state in which the battery is excessively deteriorated and appropriate control is required to use the battery safely and for a long period of time thereafter.

[0089] In one embodiment, the diagnostic unit (120) can diagnose the condition of the battery based on the difference between the hysteresis characteristic value and the diagnostic value. For example, if the difference between the hysteresis characteristic value and the diagnostic value is less than a first preset threshold value, the diagnostic unit (120) can be configured to diagnose the condition of the battery as a normal state. In another example, if the difference between the hysteresis characteristic value and the diagnostic value is greater than or equal to the first threshold value, the diagnostic unit (120) can be configured to diagnose the condition of the battery as an abnormal state. The difference between the hysteresis characteristic value and the diagnostic value tends to increase as the battery deteriorates. Therefore, the difference between the hysteresis characteristic value and the diagnostic value can be viewed as an indicator of the degree of battery deterioration, which indicates the degree of battery deterioration.

[0090] In another embodiment, the diagnostic unit (120) can diagnose the condition of the battery based on the ratio between the hysteresis characteristic value and the diagnostic value. For example, if the ratio of the hysteresis characteristic value to the diagnostic value is less than a preset second threshold value, the diagnostic unit (120) can be configured to diagnose the condition of the battery as a normal state. In another example, if the ratio of the hysteresis characteristic value to the diagnostic value is greater than or equal to the second threshold value, the diagnostic unit (120) can be configured to diagnose the condition of the battery as an abnormal state. The ratio of the hysteresis characteristic value to the diagnostic value tends to increase as the battery deteriorates. Therefore, the ratio of the hysteresis characteristic value to the diagnostic value can be viewed as an indicator of the degree of battery deterioration, which indicates the degree of battery deterioration.

[0091] The battery management device (100) diagnoses the state of the battery based on the hysteresis characteristic value in the target section (TS), so that charging and discharging for the entire section (e.g., SOC 0% to 100% section) does not necessarily need to be performed for the state diagnosis. In other words, the state of the battery can be diagnosed using only the charging and discharging characteristics for a portion of the battery's capacity section (or SOC section), thereby shortening the time required for diagnosis.

[0092]

[0093] Meanwhile, the profile acquisition unit (110), the diagnosis unit (120), and the control unit (130) 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 profile acquisition unit (110) and the diagnosis unit (120) may be implemented as a set of program modules. At this time, the program modules may be stored in a memory and executed by the profile acquisition unit (110), the diagnosis unit (120), and the control unit (130). The memory may be located inside or outside the battery management device (100), and may be connected to the profile acquisition unit (110), the diagnosis unit (120), and the control unit (130) by various well-known means.

[0094]

[0095] In addition, the battery management device (100) may further include a storage unit (140). The storage unit (140) 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 (140) 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 deriving data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, etc. In addition, the storage unit (140) may store program codes defining processes executable by the profile acquisition unit (110), the diagnosis unit (120), and the control unit (130).

[0096] Specifically, the storage unit (140) can store information required for the profile acquisition unit (110) to acquire a charge profile (CP) and a discharge profile (DP). The storage unit (140) can store information required for the diagnosis unit (120) to calculate a hysteresis characteristic value. In addition, the storage unit (140) can store information required for the diagnosis unit (120) to compare the hysteresis characteristic value with a diagnosis value to diagnose the state of the battery. For example, the storage unit (140) can store a charge profile (CP), a discharge profile (DP), a hysteresis characteristic value, a diagnosis value, a target section (TS), a lookup table, a reference charge profile, a reference discharge profile, a first threshold value, a second threshold value, and the like. In addition, the profile acquisition unit (110), the diagnosis unit (120), and the control unit (130) can access the storage unit (140) to acquire required information.

[0097]

[0098] Below, a specific embodiment in which the diagnostic unit (120) determines a diagnostic value is described.

[0099] For example, the storage unit (140) may store a lookup table in which a plurality of reference capacity sections and a plurality of reference values ​​are mapped one-to-one with each other. The diagnostic unit (120) may be configured to determine a reference value mapped to one of the plurality of reference capacity sections corresponding to the target section (TS) as a diagnostic value.

[0100] In the embodiment of FIG. 2, the diagnostic unit (120) selects a target section (TS, Q) from among multiple reference capacity sections of the lookup table. D_min Inland Q C_max ) can determine a reference capacity interval corresponding to Q. For example, the lower bound of the reference capacity interval is Q D_min , and the upper limit is Q C_max It can be. The diagnostic unit (120) may be configured to detect one reference capacity section (Q) corresponding to the target section (TS). D_min Inland Q C_max) can be determined as a diagnostic value. That is, the diagnostic unit (120) determines the determined reference capacity interval (Q) in the lookup table. D_min Inland Q C_max ) can be determined as a diagnostic value.

[0101] As another example, the diagnostic unit (120) may be configured to produce diagnostic values ​​based on a reference charge profile and a reference discharge profile.

[0102] Specifically, the diagnostic unit (120) may be configured to determine a diagnostic value based on an integrated value of the voltage difference between the voltage of the reference charge profile and the voltage of the discharge profile (DP) with respect to the target section (TS).

[0103] A reference charge profile may be a profile that represents the relationship between the voltage and capacity (or SOC, resistance) obtained during charging when a reference battery preset to correspond to the battery to be diagnosed is in the BOL (Beginning of Life) state.

[0104] A reference discharge profile may be a profile that represents the relationship between the voltage and capacity (or SOC, resistance) obtained during discharge when a reference battery preset to correspond to the battery to be diagnosed is in a BOL state.

[0105] The reference charge profile and reference discharge profile may be recorded in advance in the storage unit (140).

[0106] The method in which the diagnostic unit (120) determines the diagnostic value based on the integrated value of the voltage difference between the reference charge profile and the discharge profile (DP) for the target section (TS) is similar to the method in which the diagnostic unit (120) determines the hysteresis characteristic value based on the integrated value of the voltage difference between the charge profile (CP) and the discharge profile (DP) for the target section (TS), as described above.

[0107] Specifically, the diagnostic unit (120) can calculate the voltage difference between the voltage value of the reference charge profile and the voltage value of the reference discharge profile corresponding to the same capacity within the target section (TS). In addition, the diagnostic unit (120) can determine the value as the integrated value for the voltage difference within the target section (TS).

[0108] The diagnostic unit (120) detects any capacity (Q) within the target section (TS). x ) can calculate the voltage difference between the voltage value of the reference charge profile and the voltage value of the discharge profile (DP). Then, the diagnostic unit (120) can determine the value integrated for the voltage difference in the target section (TS) as the diagnostic value.

[0109] For example, the diagnostic unit (120) can determine a diagnostic value using Equation 2.

[0110] [Formula 2]

[0111]

[0112] Here, D represents the diagnostic value, and V RCP (Q) represents the voltage value of the corresponding reference charge profile when the capacity is Q, and V RDP (Q) represents the voltage value of the corresponding reference discharge profile when the capacity is Q.

[0113]

[0114] The battery management device (100) may further include a control unit (130). The control unit (130) may be configured to set usage conditions for the battery based on the diagnosis results.

[0115] If the battery condition is diagnosed as normal, the control unit (130) may not change the usage conditions for the battery. Conversely, if the battery condition is diagnosed as abnormal, the control unit (130) may change the usage conditions for the battery.

[0116] For example, the control unit (130) may reduce the maximum charge / discharge rate for the battery. As another example, the control unit (130) may reduce the charge cutoff voltage of the battery. The charge cutoff voltage may refer to the maximum voltage allowed when charging the battery. As another example, the control unit (130) may increase the discharge cutoff voltage of the battery. The discharge cutoff voltage may refer to the minimum voltage allowed when discharging the battery.

[0117] The rate of decrease in the maximum charge / discharge rate, the rate of decrease in the end-of-charge voltage, or the rate of increase in the end-of-discharge voltage may be determined to be proportional to the difference or ratio between the hysteresis characteristic value of the battery and the diagnostic value. For example, if the ratio of the hysteresis characteristic value of the battery to the diagnostic value is 1.1, the maximum charge / discharge rate may be set to decrease at a ratio of 1 / 1.1 compared to the previous rate.

[0118] A battery management device (100) according to one embodiment of the present invention can prevent battery deterioration or accelerated deterioration by appropriately setting the usage conditions of the battery based on the status diagnosis results for the battery.

[0119]

[0120] 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 profile acquisition unit (110), the diagnostic unit (120), the control unit (130), and the storage unit (140) of the battery management device (100) can be implemented as components of the BMS.

[0121] Additionally, the battery management device (100) according to the present invention may be provided in a battery pack. That is, the battery pack according to the present invention may include the battery management device (100) described above and one or more batteries. Additionally, the battery pack may further include electrical components (relays, fuses, etc.) and a case.

[0122] FIG. 3 is a drawing showing an exemplary configuration of a battery pack (10) according to another embodiment of the present invention.

[0123] The positive terminal of the battery (11) can be connected to the positive terminal (P+) of the battery pack (10), and the negative terminal of the battery (11) can be connected to the negative terminal (P-) of the battery pack (10).

[0124] 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 a positive terminal of the battery (11) through the first sensing line (SL1), and can be connected to a 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 voltage measured at each of the first sensing line (SL1) and the second sensing line (SL2).

[0125] And, the measuring unit (12) can be connected to the current measuring unit (A) through the third sensing line (SL3). 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 (11). The measuring unit (12) can measure the charging current of the battery (11) through the third sensing line (SL3) to calculate the charging amount. In addition, the measuring unit (12) can measure the discharging current of the battery (11) through the third sensing line (SL3) to calculate the discharging amount.

[0126] 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). Accordingly, 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) may be electrically connected.

[0127] For example, the external device may be a charger or a load such as a motor of an electric vehicle that is powered by a battery (11).

[0128]

[0129] Figure 4 is a schematic drawing of a vehicle (1) according to another embodiment of the present invention.

[0130] Referring to FIG. 4, a battery pack (10) according to an embodiment of the present invention may be included in a vehicle (1), such as an electric vehicle (EV) or a hybrid vehicle (HV). Here, the battery pack (10) described above may be applied. In addition, the battery pack (10) may drive the vehicle (1) by supplying power to a motor through an inverter provided in the vehicle (1). Here, the battery pack (10) may include a battery management device (100) according to an embodiment of the present invention. That is, the vehicle (1) may include the battery management device (100). In this case, the battery management device (100) may be an on-board device included in the vehicle (1).

[0131]

[0132] FIG. 5 is a schematic diagram illustrating a battery management method according to another embodiment of the present invention.

[0133] 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.

[0134] Referring to FIG. 5, in step S510, the profile acquisition unit (110) can acquire a charge profile (CP) and a discharge profile (DP) representing the charge and discharge characteristics of the battery.

[0135] A charge profile can represent the relationship between voltage and capacity (or SOC: State of Charge, resistance) during the battery's charging process. A discharge profile can represent the relationship between voltage and capacity (or SOC, resistance) during the battery's discharging process.

[0136] In step S520, the diagnostic unit (120) can calculate a hysteresis characteristic value based on voltage difference information between the charge profile (CP) and the discharge profile (DP) in the target section (TS).

[0137] For example, the diagnostic unit (120) may be configured to determine the target section (TS) by comparing the capacity range (or SOC range, resistance range) of the charge profile (CP) with the capacity range (or SOC range, resistance range) of the discharge profile (DP).

[0138] As another example, the target interval (TS) may be predetermined.

[0139] The diagnostic unit (120) can be configured to calculate a hysteresis characteristic value based on the integrated value of the voltage difference between the voltage of the charge profile (CP) and the voltage of the discharge profile (DP) with respect to the target section (TS).

[0140] In step S530, the diagnostic unit (120) can diagnose the state of the battery by comparing the hysteresis characteristic value with the diagnostic value.

[0141] In one embodiment, the diagnostic unit (120) can diagnose the condition of the battery based on the difference between the hysteresis characteristic value and the diagnostic value. For example, if the difference between the hysteresis characteristic value and the diagnostic value is less than a preset first threshold value, the diagnostic unit (120) can be configured to diagnose the condition of the battery as normal. In another example, if the difference between the hysteresis characteristic value and the diagnostic value is greater than or equal to the first threshold value, the diagnostic unit (120) can be configured to diagnose the condition of the battery as abnormal.

[0142] In another embodiment, the diagnostic unit (120) may diagnose the condition of the battery based on the ratio between the hysteresis characteristic value and the diagnostic value. For example, if the ratio of the hysteresis characteristic value to the diagnostic value is less than a preset second threshold value, the diagnostic unit (120) may be configured to diagnose the condition of the battery as normal. In another example, if the ratio of the hysteresis characteristic value to the diagnostic value is greater than or equal to the second threshold value, the diagnostic unit (120) may be configured to diagnose the condition of the battery as abnormal.

[0143] FIG. 6 is a schematic diagram illustrating a battery management method according to another embodiment of the present invention.

[0144] Referring to Figure 5, any content that overlaps with the previously described content is omitted or briefly explained.

[0145] Referring to FIG. 6, in step S610, the profile acquisition unit (110) can acquire a charge profile (CP) and a discharge profile (DP) representing the charge and discharge characteristics of the battery.

[0146] In step S620, the diagnostic unit (120) can compare the capacity range of the charge profile (CP) and the capacity range of the discharge profile (DP) to determine the target section (TS).

[0147] For example, the diagnostic unit (120) may be configured to determine a target section (TS) by comparing the capacity range of the charge profile (CP) with the capacity range of the discharge profile (DP). The target section (TS) may be all or part of the capacity section common to the charge profile (CP) and the discharge profile (DP).

[0148] In step S630, the diagnostic unit (120) can calculate a hysteresis characteristic value based on voltage difference information between the charge profile (CP) and the discharge profile (DP) in the target section (TS).

[0149] In step S640, the diagnostic unit (120) can calculate a diagnostic value in the target section (TS).

[0150] In one embodiment, the diagnostic unit (120) may determine a reference value mapped to one of the reference capacity intervals corresponding to the target interval (TS) among a plurality of reference capacity intervals as a diagnostic value.

[0151] In another embodiment, the diagnostic unit (120) can calculate diagnostic values ​​based on preset reference charge profiles and reference discharge profiles.

[0152] For example, the diagnostic unit (120) may be configured to determine a diagnostic value based on the integrated value of the voltage difference between the voltage of the reference charge profile and the voltage of the discharge profile (DP) with respect to the target section (TS).

[0153] For example, the diagnostic unit (120) can calculate the voltage difference between the voltage value of the reference charge profile and the voltage value of the reference discharge profile corresponding to the same capacity within the target section (TS). Then, the diagnostic unit (120) can determine the value as the integrated value for the voltage difference within the target section (TS).

[0154] In step S650, the diagnostic unit (120) can diagnose the state of the battery by comparing the hysteresis characteristic value with the diagnostic value.

[0155]

[0156] 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.

[0157] 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.

[0158] 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.

[0159]

[0160] [Explanation of symbols]

[0161] 1: Electric vehicles

[0162] 10: Battery pack

[0163] 100: Diagnostic Device

[0164] 110: Profile acquisition section

[0165] 120: Diagnostic Department

[0166] 130: Control unit

[0167] 140: Storage

Claims

1. A profile acquisition unit configured to acquire a charge profile and a discharge profile representing the charge and discharge characteristics of a battery; and A battery management device including a diagnostic unit configured to calculate a hysteresis characteristic value based on voltage difference information between the charge profile and the discharge profile in the target section and to diagnose the state of the battery by comparing the hysteresis characteristic value with a diagnostic value.

2. In paragraph 1, The above diagnostic section, A battery management device configured to determine the target section by comparing the capacity range of the charge profile with the capacity range of the discharge profile.

3. In paragraph 2, The above diagnostic section, A battery management device configured to determine all or part of a capacity section common to the above charge profile and the above discharge profile as the target section.

4. In paragraph 1, A battery management device wherein the above target range is predetermined.

5. In paragraph 1, The above diagnostic section, A battery management device configured to calculate the hysteresis characteristic value based on the integrated value of the voltage difference between the voltage of the charge profile and the voltage of the discharge profile for the target section.

6. In paragraph 1, Including more storage, The above storage unit stores a lookup table in which multiple reference capacity sections and multiple diagnostic values are mapped one-to-one. The above diagnostic section, A battery management device characterized in that a reference value mapped to one of the plurality of reference capacity sections corresponding to the target section is determined as the diagnostic value.

7. In paragraph 1, The above diagnostic section, A battery management device configured to produce the above diagnostic values based on preset reference charge profiles and reference discharge profiles.

8. In paragraph 7, The above diagnostic section, A battery management device configured to determine the diagnostic value based on an integrated value of the voltage difference between the voltage of the reference charge profile and the voltage of the discharge profile for the target section.

9. In paragraph 1, The above diagnostic section, If the difference between the hysteresis characteristic value and the diagnostic value is less than a preset first threshold value, the state of the battery is diagnosed as normal, A battery management device that diagnoses the state of the battery as abnormal when the difference between the hysteresis characteristic value and the diagnostic value is greater than or equal to the first threshold value.

10. In paragraph 1, The above diagnostic section, A battery management device that diagnoses the state of the battery as normal when the ratio of the hysteresis characteristic value to the diagnostic value is less than a preset second threshold value, and diagnoses the state of the battery as abnormal when the ratio of the hysteresis characteristic value to the diagnostic value is greater than or equal to a preset second threshold value.

11. In paragraph 1, Including more control units, The above control unit, A battery management device configured to set usage conditions for the battery based on the diagnostic results.

12. A battery pack comprising a battery management device according to any one of claims 1 to 11.

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

14. A step of obtaining a charge profile and a discharge profile representing the charge and discharge characteristics of a battery; A step of calculating a hysteresis characteristic value based on voltage difference information between the charge profile and the discharge profile in the target section; and A battery management method comprising a step of diagnosing the state of the battery by comparing the hysteresis characteristic value with a diagnostic value.

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