Battery management device and method for operating same

Abstract

A battery management device according to an embodiment disclosed herein comprises an information acquisition unit for measuring a cell current of each of multiple battery cells, and a controller for: calculating an available capacity of each of the multiple battery cells on the basis of the cell current; extracting a reference battery cell having the minimum available capacity among the available capacities of the respective multiple battery cells; configuring the minimum available capacity as a reference capacity; configuring a reference depth of discharge (DOD), which is a DOD value configured within a predetermined DOD range; calculating a first reference voltage corresponding to the reference DOD of the reference battery cell; and performing balancing of each of the multiple battery cells on the basis of the first reference voltage.

Description

Battery management device and method of operation thereof

[0001] Cross-citation with related applications

[0002] This invention claims the benefit of priority from Korean Patent Application No. 10-2023-0102876, filed on August 7, 2023, and all contents of the document in that Korean Patent Application are incorporated herein by reference.

[0003] Technology field

[0004] Embodiments disclosed in this document relate to a battery management device and an operating method thereof.

[0005] Over time, battery packs can experience variations in the aging and internal resistance of individual battery cells, leading to cell-to-cell variations. Cell variations can refer to variations in available capacity (Ah) and cell voltage. As cell variations increase, overcharging or overdischarging can occur, reducing the overall capacity of the battery pack and shortening its lifespan.

[0006] To address these issues, battery systems perform cell balancing to reduce cell-to-cell variation. The battery system calculates a cell balancing current based on the open circuit voltage (OCV) value and performs cell balancing for a balancing time calculated based on the balancing current value.

[0007] Meanwhile, when performing cell balancing based on the point where the SOC of the battery cell is 0% or the point where the SOC is 100%, there was a problem of promoting the deterioration of the battery cell by repeatedly using the lower or upper end of the SOC of the battery cell.

[0008] One purpose of the embodiments disclosed in this document is to provide a battery management device and an operating method thereof capable of performing balancing by considering the capacity of each battery cell included in a plurality of battery cells.

[0009] One purpose of the embodiments disclosed in this document is to provide a battery management device and an operating method thereof capable of controlling a usage frequency according to a cell voltage range of a battery cell.

[0010] The technical problems of the embodiments described in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0011] A battery management device according to an embodiment disclosed in the present document includes an information acquisition unit that measures cell current of each of a plurality of battery cells, and a controller that calculates an available capacity of each of the plurality of battery cells based on the cell current, extracts a reference battery cell having a minimum available capacity among the available capacities of each of the plurality of battery cells, sets the minimum available capacity as a reference capacity, sets a reference DOD (Depth of Discharge) that is a DOD value set within an arbitrary DOD range, calculates a first reference voltage corresponding to the reference DOD of the reference battery cell, and performs balancing of each of the plurality of battery cells based on the first reference voltage.

[0012] According to one embodiment, the controller can adjust the cell voltage of each of the plurality of battery cells so that a comparison voltage corresponding to a reference DOD of each of the plurality of battery cells corresponds to the first reference voltage.

[0013] According to one embodiment, the controller can set an operating voltage range of each of the plurality of battery cells so that the operating capacity of each of the plurality of battery cells corresponds to the reference capacity.

[0014] According to one embodiment, the plurality of battery cells include a first battery cell and a second battery cell having a different available capacity than the first battery cell, and an operating voltage range of the first battery cell may be different from an operating voltage range of the second battery cell.

[0015] According to one embodiment, the available capacity of the first battery cell may be less than the available capacity of the second battery cell, and the operating voltage range of the first battery cell may include the operating voltage range of the second battery cell.

[0016] According to one embodiment, the controller can set a modified State of Charge (SOC) of each of the plurality of battery cells based on the operating voltage range of each of the plurality of battery cells.

[0017] According to one embodiment, the operating capacity corresponding to the operating voltage of each of the plurality of battery cells may be the same.

[0018] According to one embodiment, the controller may perform balancing of each of the plurality of battery cells when a difference between the maximum available capacity and the minimum available capacity of the plurality of battery cells is greater than or equal to a preset value.

[0019] In one embodiment, the reference DOD may be defined as a DOD of 50% or half of the available capacity of the battery cell.

[0020] A battery management method according to an embodiment disclosed in the present document includes the steps of calculating an available capacity of each of a plurality of battery cells, extracting a reference battery cell having a minimum available capacity among the available capacities of each of the plurality of battery cells, setting the minimum available capacity as a reference capacity, setting a reference DOD (Depth of Discharge) which is a DOD value set within an arbitrary DOD range, calculating a first reference voltage corresponding to the reference DOD of the reference battery cell, and performing balancing of each of the plurality of battery cells based on the first reference voltage.

[0021] According to one embodiment, the step of performing the balancing may further include a step of determining whether a difference between the maximum available capacity and the minimum available capacity of the plurality of battery cells is greater than or equal to a preset value.

[0022] According to one embodiment, the step of performing the balancing may include the step of adjusting the cell voltage of each of the plurality of battery cells so that a comparison voltage corresponding to a reference DOD of each of the plurality of battery cells corresponds to the first reference voltage.

[0023] According to one embodiment, the step of performing the balancing may include the step of setting an operating voltage range of each of the plurality of battery cells so that the operating capacity of each of the plurality of battery cells corresponds to the reference capacity.

[0024] According to one embodiment, the step of performing the balancing may include the step of setting a corrected State of Charge (SOC) of each of the plurality of battery cells based on the operating voltage range of each of the plurality of battery cells.

[0025] According to one embodiment, the plurality of battery cells include a first battery cell and a second battery cell having a different available capacity than the first battery cell, and an operating voltage range of the first battery cell may be different from an operating voltage range of the second battery cell.

[0026] According to one embodiment, the available capacity of the first battery cell may be less than the available capacity of the second battery cell, and the operating voltage range of the first battery cell may include the operating voltage range of the second battery cell.

[0027] According to one embodiment, the operating capacity corresponding to the operating voltage of each of the plurality of battery cells may be the same.

[0028] In one embodiment, the reference DOD may be defined as a DOD of 50% or half of the available capacity of the battery cell.

[0029] Specific details of other embodiments are included in the detailed description and drawings.

[0030] The battery management device and its operating method according to the embodiments disclosed in this document can manage the available capacity of each of a plurality of battery cells by adjusting the operating voltage range of the battery cells.

[0031] The battery management device and its operating method according to the embodiments disclosed in this document can prevent overcharge and overdischarge problems of the battery cell and improve the lifespan of the battery cell by adjusting the operating voltage range of the battery cell.

[0032] The battery management device and its operating method according to the embodiments disclosed in this document can improve battery life by reducing the frequency of manual balancing.

[0033] The effects of the battery inspection device and the operating method thereof according to the disclosure of this document are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art according to the disclosure of this document.

[0034] FIG. 1 is a block diagram showing a battery system according to one embodiment disclosed in this document.

[0035] FIG. 2 is a diagram showing a method by which a battery management device according to one embodiment disclosed in this document performs balancing of a plurality of battery cells.

[0036] FIG. 3 is a flowchart showing a cell balancing method according to one embodiment disclosed in this document.

[0037] FIG. 4 is a flowchart specifically showing an operation of performing balancing of each of a plurality of battery cells based on the first reference voltage of FIG. 3.

[0038] FIG. 5 is a block diagram showing a computing system executing a cell balancing method according to one embodiment disclosed in this document.

[0039] In connection with the description of the drawings, the same or similar reference numerals may be used for identical or similar components.

[0040] Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that the present invention encompasses various modifications, equivalents, and / or alternatives of the embodiments.

[0041] The embodiments and terminology used in this document are not intended to limit the technical features described in this document to a specific embodiment, but should be understood to encompass various modifications, equivalents, or alternatives of the embodiment. In connection with the description of the drawings, similar reference numerals may be used to refer to similar or related components. The singular form of a noun corresponding to an item may include one or more of the item, unless the relevant context clearly indicates otherwise.

[0042] In this document, the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" can each include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as "first", "second", "first", "second", "A", "B", "(a)", or "(b)" may be used merely to distinguish the corresponding component from other corresponding components, and do not limit the corresponding components in any other respect (e.g., importance or order) unless specifically stated otherwise.

[0043] In this document, when a component (e.g., a first component) is referred to as being “connected,” “coupled,” or “connected,” with or without the terms “functionally” or “communicatively,” or “coupled” or “connected,” it means that the component can be connected to the other component directly (e.g., wired or wirelessly), or indirectly (e.g., via a third component).

[0044] The methods according to various embodiments disclosed in this document may be provided as included in a computer program product. The computer program product may be traded as a commodity between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory, CD-ROM), or may be distributed online (e.g., downloaded or uploaded) through an application store or directly between two user devices. In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0045] According to the embodiments disclosed in this document, each component (e.g., a module or a program) of the above-described components may include one or more entities, and some of the entities may be separated and placed in other components. According to the embodiments disclosed in this document, one or more components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. According to the embodiments disclosed in this document, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0046] FIG. 1 is a block diagram showing a battery system according to one embodiment disclosed in this document.

[0047] Referring to FIG. 1, the battery system (1) may include a battery pack (10) and an upper controller (20).

[0048] A battery pack (10) may include a plurality of battery cells (100), a battery management device (200), a sensor (300), and a switching unit (400). The plurality of battery cells (100) may be a set of battery cells including at least two battery cells. Each of the battery cells included in the plurality of battery cells (100) may be connected in series or in parallel with each other.

[0049] The plurality of battery cells (100) may include two or more battery cells. According to an embodiment, the plurality of battery cells (100) may include a first battery cell (110) and a second battery cell (120). Here, the first battery cell (110) and the second battery cell (120) may be different battery cells.

[0050] The available capacities of the battery cells included in the plurality of battery cells (100) may differ from each other. Here, the available capacity may refer to the amount of electrons that the battery cell can store. According to an embodiment, the degradation rates of each battery cell included in the plurality of battery cells (100) may differ from each other due to production deviations, temperature, voltage, etc. According to an embodiment, the available capacities of each battery cell included in the plurality of battery cells (100) may differ from each other due to differences in the degradation rates of each battery cell included in the plurality of battery cells (100).

[0051] The available capacity of the first battery cell (110) and the available capacity of the second battery cell (120) included in the plurality of battery cells (100) may be different from each other. Here, the available capacity of the first battery cell (110) may be defined as a [Ah]. In addition, the available capacity of the second battery cell (120) may be defined as b [Ah]. In addition, a and b may be different from each other.

[0052] According to an embodiment, the available capacity of the first battery cell (110) may be less than the available capacity of the second battery cell (120). That is, the available capacity a [Ah] of the first battery cell (110) may be less than the available capacity b [Ah] of the second battery cell (120).

[0053] The battery management device (200) can manage the battery pack (10). The battery management device (200) can manage each of the plurality of battery cells (100) based on information about the plurality of battery cells (100). According to an embodiment, the battery management device (200) can prevent overcharging and overdischarging by monitoring voltage, current, temperature, etc. of the battery pack (10). In addition, the battery management device (200) can include a plurality of terminals for receiving information as an interface for receiving information about the plurality of battery cells (100). Meanwhile, the battery management device (200) can also control the ON / OFF of the switching unit (400), and can be connected to the plurality of battery cells (100) to monitor the status of each of the plurality of battery cells (100).

[0054] The battery management device (200) may include an information acquisition unit (210) and a controller (220). Here, the information acquisition unit (210) may acquire current of each of the plurality of battery cells (100). Accordingly, the information acquisition unit (210) may acquire current information of the first battery cell (110) and current information of the second battery cell (120). According to an embodiment, the information acquisition unit (210) may be directly connected to the first battery cell (110) and the second battery cell (120) to acquire current of the first battery cell (110) and the second battery cell (120), or may receive current information acquired by the sensor (300) from the sensor (300). In addition, the information acquisition unit (210) may transmit current information of the plurality of battery cells (100) to the controller (220).

[0055] The controller (220) can calculate the available capacity of each of the plurality of battery cells (100). According to an embodiment, the controller (220) can calculate the available capacity of the battery cell based on the current information. That is, the controller (220) can calculate the available capacity of the first battery cell (110) based on the current information of the first battery cell (110) received from the information acquisition unit (210), and can calculate the available capacity of the second battery cell (120) based on the current information of the second battery cell (120). According to an embodiment, the available capacity of the first battery cell (110) calculated by the controller (220) can be a [Ah], and the available capacity of the second battery cell (120) can be b [Ah].

[0056] The controller (220) can perform balancing of a plurality of battery cells (100). That is, the controller (220) can perform balancing of the first battery cell (110) and the second battery cell (120). The balancing operation of the controller (220) is described in detail in FIG. 2.

[0057] The controller (220) can compare the difference between the maximum available capacity and the minimum available capacity of the plurality of battery cells (100) with a preset value. That is, the controller (220) can compare the available capacity of each of the plurality of battery cells (100) to select the maximum available capacity and the minimum available capacity. In addition, the controller (220) can calculate the maximum available capacity and the minimum available capacity. In addition, the controller (220) can compare the difference between the maximum available capacity and the minimum available capacity with a preset value. Here, the preset value can be set based on the specifications of the battery cells included in the plurality of battery cells (100).

[0058] The controller (220) may perform cell balancing when the difference between the maximum available capacity and the minimum available capacity of the plurality of battery cells (100) is greater than or equal to a preset value. The controller (220) may not perform cell balancing when the difference between the maximum available capacity and the minimum available capacity is less than the preset value.

[0059] According to an embodiment, the controller (220) may provide the balancing result to the user. When balancing a plurality of battery cells (100), the controller (220) may provide the user with information related to the balancing. For example, the controller (220) may provide balancing-related information to a user terminal via a communication unit (not shown), and may also provide balancing-related information via a display provided in a vehicle or charger.

[0060] The sensor (300) can obtain information on a plurality of battery cells (100). The sensor (300) is connected to a plurality of battery cells (100) and can obtain information on the plurality of battery cells (100). In addition, the sensor (300) can transmit information obtained from the plurality of battery cells (100) to the battery management device (200). According to an embodiment, the sensor (300) may have the same configuration as the information acquisition unit (210) included in the battery management device (200). According to an embodiment, the sensor (300) may have a configuration that obtains different information from the information acquisition unit (210).

[0061] The switching unit (400) can control the current flow of the plurality of battery cells (100). That is, the switching unit (400) is connected in series to the plurality of battery cells (100) and the first terminal side and / or the second terminal side of the plurality of battery cells (100) to control the charge and discharge current flow of the battery cells (110). According to an embodiment, the switching unit (400) can include at least one relay, magnetic contactor, etc. based on the specifications of the battery pack (10).

[0062] The upper controller (20) can transmit a control signal for the battery cell (110) to the battery management device (200). Accordingly, the operation of the battery management device (200) can be controlled based on the signal received from the upper controller (20).

[0063] FIG. 2 is a diagram showing a method by which a battery management device according to one embodiment disclosed in this document performs balancing of a plurality of battery cells.

[0064] Referring to FIG. 2, the controller (220) can perform balancing of a plurality of battery cells (100). That is, the controller (220) can perform balancing of a first battery cell (110) and a second battery cell (120). Although FIG. 2 illustrates cell balancing of two battery cells (i.e., the first battery cell (110) and the second battery cell (120)), the contents described below can be substantially equally applied to cell balancing of two or more battery cells.

[0065] The controller (220) can extract a reference battery cell having a minimum available capacity. That is, the controller (220) can compare the available capacities of each of the plurality of battery cells (100) and extract a reference battery cell having a minimum available capacity. For example, the reference battery cell having a minimum available capacity may be the first battery cell (110).

[0066] The controller (220) may define the available capacity of the reference battery cell as the reference capacity. Accordingly, the reference capacity may be defined as the available capacity of the first battery cell (110). For example, the reference capacity may be defined as a [Ah].

[0067] Additionally, the controller (220) can set the remaining battery cells, excluding the reference battery cell, among the plurality of battery cells (100), as target battery cells. For example, the target battery cell may be the second battery cell (120).

[0068] For convenience of explanation, below, it is assumed that the reference battery cell is the first battery cell (110). In addition, it is assumed that the target battery cell is the second battery cell (120).

[0069] The controller (220) can set a reference DOD (Depth of Discharge) of the first battery cell (110). Here, the reference DOD may mean a DOD value set within an arbitrary DOD range of the battery cell, and may include, for example, a DOD value arbitrarily set by a user between 30% and 70%.

[0070] According to an embodiment, the reference DOD may be set to the center value of the available capacity. Here, the center of the available capacity may be defined as half of the available capacity of the battery cell. In this case, the reference DOD of the first battery cell (110) may be a / 2 [Ah], which is half of the available capacity of the first battery cell (110).

[0071] The controller (220) can obtain a first reference voltage corresponding to the reference DOD of the first battery cell (110). In addition, the controller (220) can obtain a second reference voltage corresponding to the reference DOD of the second battery cell (120).

[0072] The controller (220) can perform balancing of each of the plurality of battery cells (100) based on a first reference voltage. The controller (220) can perform balancing of the second battery cell (120) by adjusting the cell voltage of the second battery cell (120) based on the first reference voltage of the first battery cell (110). Specifically, the controller (220) can perform balancing of the second battery cell (120) by sequentially adjusting the cell voltage of the second battery cell (120).

[0073] First, the controller (220) can primarily adjust the cell voltage of the second battery cell (120). The controller (220) can adjust the cell voltage of the second battery cell (120) so that the second reference voltage of the second battery cell (120) corresponds to the first reference voltage. That is, the controller (220) can maintain the operating voltage range of the first battery cell (110), which is a reference battery cell, and primarily adjust the operating voltage range of the second battery cell (120), which is a target battery cell. According to an embodiment, the operating voltage range may mean from the voltage at a maximum discharged state of the battery cell to the voltage at a maximum charged state. In addition, the operating voltage range of the first battery cell (110) may be defined as a first operating voltage range (V1). The operating voltage range of the second battery cell (120) before the primary voltage adjustment may be defined as a second operating voltage range (V2). After the first voltage adjustment, the operating voltage range of the second battery cell (120) can be defined as the third operating voltage range (V3).

[0074] Here, the primary voltage adjustment may be an adjustment that maintains the size of the operating voltage range the same, but changes the start and end points of the operating voltage range. That is, the sizes of the second operating voltage range (V2) and the third operating voltage range (V3) may be the same, the start point of the third operating voltage range (V3) may be smaller than the start point of the second operating voltage range (V2), and the end point of the third operating voltage range (V3) may be smaller than the end point of the second operating voltage range (V2).

[0075] The controller (220) can maintain the first operating voltage range (V1) and adjust the second operating voltage range (V2) to the third operating voltage range (V3) so that the second reference voltage of the second battery cell (120) corresponds to the first reference voltage. Accordingly, the reference DOD of the first battery cell (110) and the reference DOD of the second battery cell (120) can correspond.

[0076] The controller (220) can secondarily adjust the operating voltage range of the second battery cell (120). The controller (220) can adjust the operating voltage range of the second battery cell (120) so that the available capacity of the second battery cell (120) corresponds to the available capacity of the first battery cell (110).

[0077] Since the cell voltage and capacity of the battery cell correspond to each other, the operating voltage range of the battery cell can correspond to the available capacity of the battery cell. Accordingly, the controller (220) can adjust the available capacity of the second battery cell (120) by adjusting the operating voltage range of the second battery cell (120). That is, the controller (220) can reduce the available capacity of the second battery cell (120) by reducing the operating voltage range of the second battery cell (120).

[0078] The controller (220) can adjust the third operating voltage range (V3) of the second battery cell (120) so that the available capacity of the second battery cell (120) corresponds to the available capacity of the first battery cell (110). That is, the controller (220) can reduce the third operating voltage range (V3) of the second battery cell (120) so that the available capacity corresponding to the operating voltage range of the second battery cell (120) corresponds to the available capacity of the first battery cell (110).

[0079] That is, the controller (220) can reduce the operating voltage range of the second battery cell (120) so that the available capacity b [Ah] of the second battery cell (120) corresponds to the available capacity a [Ah] of the first battery cell (110).

[0080] Specifically, the controller (220) can reduce the third operating voltage range (V3) of the second battery cell (120) by limiting the upper adjustment range (V6) and the lower adjustment range (V5) of the third operating voltage range (V3) of the second battery cell (120). For example, the controller (220) can increase the starting point of the third operating voltage range (V3) by the lower adjustment range (V5) and decrease the end point of the third operating voltage range (V3) by the upper adjustment range (V6). In an embodiment, the size of the upper adjustment range (V6) and the size of the lower adjustment range (V5) may be the same, but is not limited thereto. In an embodiment, the sum of the fourth operating voltage range (V4), the lower adjustment range (V5), and the upper adjustment range (V6) may be the same as the third operating voltage range (V3).

[0081] After the second adjustment, the operating voltage range of the second battery cell (120) can be changed to the fourth operating voltage range (V4). That is, the operating voltage range of the second battery cell (120) can be adjusted from the third operating voltage range (V3) to the fourth operating voltage range (V4) through the second adjustment.

[0082] According to an embodiment, the fourth operating voltage range (V4) may be different from the first operating voltage range (V1). That is, the fourth operating voltage range (V4), which is the operating voltage range after the second adjustment of the second battery cell (120), may be different from the first operating voltage range (V1), which is the operating voltage range of the first battery cell (110). In other words, the available capacity of the second battery cell (120) after the second adjustment of the second battery cell (120) is the same as the available capacity of the first battery cell (110), but the fourth operating voltage range (V4) may be different from the first operating voltage range (V1). According to an embodiment, since the available capacities of the first battery cell (110) and the second battery cell (120) are different before voltage adjustment due to differences in degradation rates, etc., even if the available capacities are matched by the secondary adjustment of the second battery cell (120), the operating voltage range may not be matched.

[0083] According to an embodiment, the first operating voltage range (V1) may include a fourth operating voltage range (V4). That is, the starting point of the first operating voltage range (V1) may be smaller than the starting point of the fourth operating voltage range (V4), and the end point of the first operating voltage range (V1) may be larger than the end point of the fourth operating voltage range (V4).

[0084] The controller (220) can control the operation of the second battery cell (120) so that the second battery cell (120) does not use a capacity corresponding to the lower adjustment range (V5) and the upper adjustment range (V6) of the second battery cell (120) through secondary voltage regulation. According to an embodiment, the controller (220) can control the second battery cell (120) so that the cell voltage of the second battery cell (120) does not go beyond the starting point of the fourth operating voltage range (V4) even when the cell voltage of the second battery cell (120) is fully discharged. In addition, the controller (220) can regulate the second battery cell (120) so that the cell voltage of the second battery cell (120) does not go beyond the end point of the fourth operating voltage range (V4) even when the cell voltage of the second battery cell (120) is fully charged. Accordingly, the usage frequencies of the fourth operating voltage range (V4), the lower adjustment range (V5), and the upper adjustment range (V6) corresponding to the third operating voltage range (V3) of the second battery cell (120) may be different.

[0085] Through this, the battery system (1) can reduce the frequency of use in the upper or lower portions of the operating voltage range of the battery cells and improve the frequency of use in the voltage range corresponding to the middle portion. Accordingly, problems such as reduced battery cell life and overcharge / overdischarge due to frequent use of the upper and lower portions of the battery cells can be alleviated. In other words, the battery system (1) can improve the life of the battery cells by adjusting the frequency of use according to the battery operating voltage.

[0086] According to an embodiment, the controller (220) can set a modified SOC (State of Charge). The controller (220) can set a modified SOC (State of Charge) for each of the plurality of battery cells (100) based on the operating voltage range after balancing. The controller (220) can set a modified SOC by modifying the SOC based on the operating voltage changed through the primary cell voltage adjustment and the secondary cell voltage adjustment.

[0087] For example, before balancing the second battery cell (120), the SOC corresponding to the cell voltage of the second battery cell (120) at the start point of the second operating voltage range (V2) may be 0%, and the SOC corresponding to the end point of the second operating voltage range (V2) may be 100%.

[0088] After balancing the second battery cell (120), the controller (220) can set the corrected SOC of the second battery cell (120). The controller (220) can set the corrected SOC based on the operating voltage range after balancing the second battery cell (120). That is, the controller (220) can set the corrected SOC to 0% when the cell voltage of the second battery cell (120) corresponds to the starting point of the fourth operating voltage range (V4). In addition, the controller (220) can set the corrected SOC to 100% when the cell voltage of the second battery cell (120) corresponds to the end point of the fourth operating voltage range (V4). That is, the controller (220) can set the corrected SOC by correcting the SOC based on the fourth operating voltage range (V4). According to an embodiment, the controller (220) can also set the corrected DOD in the same manner as the setting of the corrected SOC.

[0089] The controller (220) can transmit a corrected SOC to the user. According to an embodiment, the controller (220) can transmit a corrected SOC to the user for each battery cell included in the plurality of battery cells (100), or can calculate an average of the corrected SOCs of each of the plurality of battery cells (100) and transmit the average of the corrected SOCs to the user.

[0090] The battery system (1) can reduce the frequency of manual balancing. The battery system (1) can reduce the frequency of manual balancing by performing cell balancing based on the reference DOD of the battery cell having the minimum available capacity. That is, the battery system (1) can reduce the frequency of manual balancing by using manual balancing only in the primary voltage adjustment stage of each of the plurality of battery cells (100). Accordingly, the battery system (1) can improve power efficiency by preventing power consumption due to manual balancing. In addition, the battery system (1) can mitigate the risk of heat generation and fire in the battery cells through this.

[0091] FIG. 3 is a flowchart showing a battery management method according to an embodiment disclosed in this document.

[0092] The embodiment illustrated in FIG. 3 is only one embodiment, and the order of operations according to various embodiments of the present invention may be different from that illustrated in FIG. 3, and some of the steps illustrated in FIG. 3 may be omitted, the order between the steps may be changed, or the steps may be merged.

[0093] Referring to FIG. 3, the battery management method may include an operation (S100) of calculating the available capacity of each of a plurality of battery cells (100), an operation (S200) of determining whether a difference between a maximum available capacity and a minimum available capacity of the plurality of battery cells (100) is equal to or greater than a preset value, an operation (S300) of extracting a reference battery cell having a minimum available capacity among the available capacities of each of the plurality of battery cells (100), setting the minimum available capacity as a reference capacity, setting a reference DOD (Depth of Discharge), and calculating a first reference voltage corresponding to the reference DOD of the reference battery cell, and an operation (S400) of performing balancing of each of the plurality of battery cells (100) based on the first reference voltage.

[0094] Below, the above operations S100 to S40 are specifically described with reference to FIGS. 1 to 3.

[0095] In operation S100, the battery management device (200) can calculate the available capacity of each of the plurality of battery cells (100). According to an embodiment, the battery management device (200) can calculate the available capacity of each of the plurality of battery cells (100) based on current information of each of the plurality of battery cells (100).

[0096] In operation S200, the battery management device (200) can determine whether the difference between the maximum available capacity and the minimum available capacity of the plurality of battery cells (100) is greater than or equal to a preset value.

[0097] The battery management device (200) can compare the difference between the maximum available capacity and the minimum available capacity of the plurality of battery cells (100) with a preset value. That is, the battery management device (200) can compare the capacities of each of the plurality of battery cells (100) to select the maximum available capacity and the minimum available capacity. In addition, the battery management device (200) can calculate the maximum available capacity and the minimum available capacity. In addition, the battery management device (200) can compare the difference between the maximum available capacity and the minimum available capacity with a preset value. Here, the preset value can be set based on the specifications of the battery cells included in the plurality of battery cells (100).

[0098] The battery management device (200) may perform operation S300 if the difference between the maximum available capacity and the minimum available capacity is greater than or equal to a preset value. The battery management device (200) may terminate the battery management method if the difference between the maximum available capacity and the minimum available capacity is less than the preset value.

[0099] In operation S300, the battery management device (200) can extract a reference battery cell having the minimum available capacity among the available capacities of each of the plurality of battery cells (100), set the minimum available capacity as the reference capacity, set a reference DOD (Depth of Discharge), and calculate a first reference voltage corresponding to the reference DOD of the reference battery cell.

[0100] The battery management device (200) can extract a battery cell having a minimum available capacity. That is, the battery management device (200) can compare the available capacities of each of a plurality of battery cells (100) and extract a battery cell having a minimum available capacity. Here, the battery cell having a minimum available capacity can be defined as a reference battery cell.

[0101] The battery management device (200) can set a reference capacity. According to an embodiment, the battery management device (200) can define the capacity of a reference battery cell as the reference capacity. That is, the available capacity of a battery cell with the minimum available capacity can be defined as the reference capacity.

[0102] The battery management device (200) can set a reference DOD (Depth of Discharge) of a reference battery cell. Here, the reference DOD may be a DOD point arbitrarily set by the user between a point where the DOD is 30% and a point where the DOD is 70%.

[0103] In an embodiment, the user may set the center of available capacity as the reference DOD. Here, the center of available capacity may be defined as the point where the DOD of a battery cell is 50% or half of the available capacity of the battery cell.

[0104] The battery management device (200) can calculate a voltage corresponding to the reference DOD of the reference battery cell. Here, the voltage corresponding to the reference DOD of the reference battery cell can be defined as a first reference voltage.

[0105] In operation S400, the battery management device (200) can perform balancing of each of the plurality of battery cells (100) based on the first reference voltage. This is described in detail in FIG. 4.

[0106] FIG. 4 is a flowchart specifically showing an operation of performing balancing of each of a plurality of battery cells (100) based on the first reference voltage of FIG. 3.

[0107] Referring to FIG. 4, an operation of performing balancing of each of the plurality of battery cells (100) based on a first reference voltage may include an operation of adjusting the cell voltage of each of the plurality of battery cells (100) so that a second reference voltage corresponding to a reference DOD of each of the plurality of battery cells (100) corresponds to the first reference voltage (S410), an operation of setting an operating voltage range of each of the plurality of battery cells (100) so that an operating capacity of each of the plurality of battery cells (100) corresponds to a reference capacity (S420), and an operation of setting a corrected SOC (State of Charge) of each of the plurality of battery cells (100) based on the operating voltage range of each of the plurality of battery cells (100) (S430).

[0108] In operation S410, the battery management device (200) can adjust the cell voltage of each of the plurality of battery cells (100) so that the second reference voltage corresponding to the reference DOD of each of the plurality of battery cells (100) corresponds to the first reference voltage.

[0109] The battery management device (200) can primarily adjust the cell voltage of each of the plurality of battery cells (100). That is, the battery management device (200) can adjust the cell voltage of each of the plurality of battery cells (100) so that the voltage corresponding to the reference DOD of each of the plurality of battery cells (100) corresponds to the first reference voltage. Specifically, the battery management device (200) can perform passive balancing on each of the battery cells excluding the reference battery cell among the plurality of battery cells (100) so that the voltage corresponding to the reference DOD of each of the plurality of battery cells (100) corresponds to the first reference voltage, thereby adjusting the cell voltage of each of the plurality of battery cells (100). Here, the voltage corresponding to the reference DOD of each of the plurality of battery cells (100) can be defined as the second reference voltage. In other words, the battery management device (200) can adjust the second reference voltage of the plurality of battery cells (100) to correspond to the first reference voltage using manual balancing.

[0110] In operation S420, the battery management device (200) can set the operating voltage range of each of the plurality of battery cells (100) so that the operating capacity of each of the plurality of battery cells (100) corresponds to the reference capacity.

[0111] The battery management device (200) can secondarily adjust the cell voltage of the plurality of battery cells (100). The battery management device (200) can adjust the voltage of each of the plurality of battery cells (100) so that the available capacity of each of the plurality of battery cells (100) corresponds to the available capacity of a reference battery cell. Since the reference battery cell is a cell having the minimum available capacity among the plurality of battery cells (100), the battery management device (200) can adjust the available capacity by reducing the operating voltage range of the plurality of battery cells (100). That is, the battery management device (200) can reduce the available capacity of each of the plurality of battery cells (100) so that the available capacity of each of the plurality of battery cells (100) corresponds to the minimum available capacity by reducing the operating voltage range.

[0112] Specifically, the battery management device (200) can reduce the operating voltage range of the battery cell by limiting the upper adjustment range (V6) and the lower adjustment range (V5) of the operating voltage range of the battery cell. According to an embodiment, the size of the upper adjustment range (V6) and the size of the lower adjustment range (V5) may be the same. Accordingly, the operating capacities of each of the battery cells included in the plurality of battery cells (100) may correspond to each other.

[0113] In operation S430, the battery management device (200) can set a modified SOC (State of Charge) of each of the plurality of battery cells (100) based on the operating voltage range of each of the plurality of battery cells (100).

[0114] The battery management device (200) can set a modified SOC (State of Charge). The battery management device (200) can set a modified SOC (State of Charge) for each of the plurality of battery cells (100) based on the operating voltage range after balancing. The battery management device (200) can set a modified SOC by modifying the SOC based on the operating voltage changed through the primary cell voltage adjustment and the secondary cell voltage adjustment.

[0115] FIG. 5 is a block diagram showing a computing system executing a battery management method according to an embodiment disclosed in this document.

[0116] Referring to FIG. 5, a computing system (500) according to an embodiment disclosed in the present document may include an MCU (510), a memory (520), an input / output I / F (530), and a communication I / F (540).

[0117] The MCU (510) may be a processor that executes various programs stored in the memory (520) (e.g., an SOH calculation program, a cell balancing target determination program, etc.), processes various data including SOC, SOH, etc. of multiple battery cells through these programs, and performs the functions of the battery management device (200) described with reference to FIGS. 1 to 3 described above.

[0118] The memory (520) can store various programs related to calculating the SOH of a battery cell and determining whether to perform cell balancing. In addition, the memory (520) can store various data, such as SOC and SOH data for each battery cell.

[0119] Such memories (520) may be provided in multiples as needed. The memories (520) may be volatile memories or non-volatile memories. As volatile memories (520), RAM, DRAM, SRAM, etc. may be used. As non-volatile memories (520), ROM, PROM, EAROM, EPROM, EEPROM, flash memories, etc. may be used. The examples of the memories (520) listed above are merely examples and are not limited to these examples.

[0120] The input / output I / F (530) can provide an interface that enables data transmission and reception between an input device (not shown) such as a keyboard, mouse, or touch panel, and an output device (not shown) such as a display and the MCU (510).

[0121] The communication I / F (540) is a component capable of transmitting and receiving various data with a server, and may be any device capable of supporting wired or wireless communication. For example, programs for calculating the SOH of battery cells or determining balancing targets, as well as various data, can be transmitted and received from a separately provided external server via the communication I / F (540).

[0122] In this way, the battery management method according to one embodiment disclosed in this document can be recorded in the memory (520) and executed by the MCU (510).

[0123] The above description is merely an example of the technical idea disclosed in this document, and those skilled in the art to which the embodiments disclosed in this document pertain may make various modifications and variations without departing from the essential characteristics of the embodiments disclosed in this document.

[0124] Accordingly, the embodiments disclosed in this document are intended to illustrate, rather than limit, the technical concepts disclosed in this document, and the scope of the technical concepts disclosed in this document is not limited by these embodiments. The scope of protection of the technical concepts disclosed in this document should be interpreted by the claims below, and all technical concepts within the equivalent scope should be interpreted as being included within the scope of the rights of this document.

[0125] [Explanation of symbols]

[0126] 1: Battery system

[0127] 10: Battery pack

[0128] 100: Multiple battery cells

[0129] 110: 1st battery cell

[0130] 120: Second battery cell

[0131] 210: Information Acquisition Department

[0132] 220: Controller

Claims

1. An information acquisition unit that measures the cell current of each of multiple battery cells; and Calculate the available capacity of each of the plurality of battery cells based on the cell current, Extract a reference battery cell having the minimum available capacity among the available capacities of each of the plurality of battery cells, and set the minimum available capacity as the reference capacity. Set the reference DOD, which is a DOD value set within an arbitrary DOD (Depth of Discharge) range, Calculate a first reference voltage corresponding to the reference DOD of the above reference battery cell, A battery management device including a controller that performs balancing of each of the plurality of battery cells based on the first reference voltage.

2. In claim 1, A battery management device in which the controller adjusts the cell voltage of each of the plurality of battery cells so that the comparison voltage corresponding to the reference DOD of each of the plurality of battery cells corresponds to the first reference voltage.

3. In claim 1, A battery management device in which the controller sets the operating voltage range of each of the plurality of battery cells so that the operating capacity of each of the plurality of battery cells corresponds to the reference capacity.

4. In claim 3, The plurality of battery cells include a first battery cell and a second battery cell having a different available capacity from the first battery cell, A battery management device wherein the operating voltage range of the first battery cell is different from the operating voltage range of the second battery cell.

5. In claim 4, The available capacity of the first battery cell is less than the available capacity of the second battery cell, A battery management device wherein the operating voltage range of the first battery cell includes the operating voltage range of the second battery cell.

6. In claim 3, A battery management device in which the controller sets a corrected SOC (State of Charge) of each of the plurality of battery cells based on the operating voltage range of each of the plurality of battery cells.

7. In claim 3, A battery management device in which the operating capacities corresponding to the operating voltages of each of the plurality of battery cells are the same.

8. In claim 1, A battery management device in which the controller performs balancing of each of the plurality of battery cells when the difference between the maximum available capacity and the minimum available capacity of the plurality of battery cells is greater than or equal to a preset value.

9. In claim 1, The above reference DOD is a battery management device where the DOD is defined as 50% or half of the available capacity of the battery cell.

10. A step of calculating the available capacity of each of a plurality of battery cells; Extract a reference battery cell having the minimum available capacity among the available capacities of each of the plurality of battery cells, and set the minimum available capacity as the reference capacity. Set the reference DOD, which is a DOD value set within an arbitrary DOD (Depth of Discharge) range, A step of calculating a first reference voltage corresponding to the reference DOD of the above reference battery cell; and A battery management method comprising a step of performing balancing of each of the plurality of battery cells based on the first reference voltage.

11. In claim 10, Before performing the above balancing step A battery management method further comprising a step of determining whether the difference between the maximum available capacity and the minimum available capacity of the plurality of battery cells is greater than or equal to a preset value.

12. In claim 10, The steps to perform the above balancing are A battery management method comprising a step of adjusting the cell voltage of each of the plurality of battery cells so that the comparison voltage corresponding to the reference DOD of each of the plurality of battery cells corresponds to the first reference voltage.

13. In claim 12, The steps to perform the above balancing are A battery management method comprising a step of setting an operating voltage range of each of the plurality of battery cells so that the operating capacity of each of the plurality of battery cells corresponds to the reference capacity.

14. In claim 13, The steps to perform the above balancing are A battery management method comprising a step of setting a corrected SOC (State of Charge) of each of the plurality of battery cells based on the operating voltage range of each of the plurality of battery cells.

15. In claim 12, The plurality of battery cells include a first battery cell and a second battery cell having a different available capacity from the first battery cell, A battery management method wherein the operating voltage range of the first battery cell is different from the operating voltage range of the second battery cell.

16. In claim 15, The available capacity of the first battery cell is less than the available capacity of the second battery cell, A battery management method wherein the operating voltage range of the first battery cell includes the operating voltage range of the second battery cell.

17. In claim 15, A battery management method in which the operating capacities corresponding to the operating voltages of each of the plurality of battery cells are the same.

18. In claim 10, The above reference DOD is a battery management method defined as a state where the DOD is 50% or half of the available capacity of the battery cell.

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