Battery management device and operating method thereof

Abstract

A battery management apparatus according to an embodiment disclosed herein includes: an information acquisition unit configured to measure a cell current of each of a plurality of battery cells; and a controller, and a controller configured to calculate an available capacity of each of the plurality of battery cells based on the cell current, extract a reference battery cell having a minimum available capacity among the available capacities of the plurality of battery cells and set the minimum available capacity as a reference capacity, set a reference DOD as a DOD value set within a random depth of discharge (DOD) range, and output the reference DOD as a DOD value set within the DOD range. A first reference voltage corresponding to the reference DOD of the reference battery cell is calculated, and equalization is performed on each of the plurality of battery cells based on the first reference voltage.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0102876, filed on August 7, 2023, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. TECHNICAL FIELD

[0003] Embodiments disclosed herein relate to a battery management device and an operating method thereof. BACKGROUND

[0004] When a battery pack is used for a long time, the degree of aging and internal resistance of a plurality of battery cells can be different, and cell deviation can occur between the plurality of battery cells. In this case, the cell deviation can refer to a deviation in available capacity (Ah) and a deviation in cell voltage. As the cell deviation increases, overcharging or overdischarging can occur, such that the overall capacity of the battery pack can decrease and the lifespan of the battery pack can be shortened.

[0005] To solve such a problem, a battery system performs battery cell equalization by reducing the deviation between cells. The battery system calculates a cell equalization current value based on an open circuit voltage (OCV) value, and performs cell equalization for an equalization time calculated based on the equalization current value.

[0006] Meanwhile, when battery cell equalization is performed at a point corresponding to an SOC (State of Charge) of 0% or 100% of a battery cell, the lower limit or the upper limit of the SOC of the battery cell can be repeatedly used, thereby accelerating the degradation of the battery cell. SUMMARY

[0007] TECHNICAL PROBLEM

[0008] Embodiments disclosed herein aim to provide a battery management device and an operating method thereof in which equalization can be performed based on the capacity of each battery cell included in a plurality of battery cells.

[0009] Embodiments disclosed herein aim to provide a battery management device and an operating method thereof in which the frequency of use can be adjusted according to the cell voltage cycle of a battery cell.

[0010] The technical problems of embodiments disclosed herein are not limited to the aforementioned technical problems, and one of ordinary skill in the art can clearly understand other unmentioned technical problems from the following description.

[0011] TECHNICAL SOLUTION

[0012] A battery management apparatus according to embodiments disclosed herein includes an information acquisition unit configured to measure a cell current of each of a plurality of battery cells, and a controller configured to calculate an available capacity of each of the plurality of battery cells based on the cell current, extract a reference battery cell having a minimum available capacity among the available capacities of the plurality of battery cells and set the minimum available capacity as a reference capacity, set a reference DOD as a DOD value set within a random reference DOD range, calculate a first reference voltage corresponding to the reference DOD of the reference battery cell, and perform balancing on each of the plurality of battery cells based on the first reference voltage.

[0013] According to embodiments, the controller can be further configured to adjust a cell voltage of each of the plurality of battery cells such that a comparison voltage corresponding to the reference DOD of each of the plurality of battery cells corresponds to the first reference voltage.

[0014] According to embodiments, the controller can be further configured to set an operating voltage range of each of the plurality of battery cells such that an operating capacity of each of the plurality of battery cells corresponds to the reference capacity.

[0015] According to embodiments, the plurality of battery cells can include a first battery cell and a second battery cell, the available capacity of the second battery cell being different from the available capacity of the first battery cell, and the operating voltage range of the first battery cell being different from the operating voltage range of the second battery cell.

[0016] According to embodiments, the available capacity of the first battery cell can be less than the available capacity of the second battery cell, and the operating voltage range of the first battery cell can include the operating voltage range of the second battery cell.

[0017] According to embodiments, the controller can be further configured to 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.

[0018] According to embodiments, the operating capacities of each of the plurality of battery cells corresponding to the operating voltage can be identical to each other.

[0019] According to embodiments, when a difference between a maximum available capacity and a minimum available capacity of the plurality of battery cells is greater than or equal to a preset value, the controller can be further configured to perform balancing on each of the plurality of battery cells.

[0020] According to embodiments, the reference DOD can be defined as a DOD of 50% or half of the available capacity of the battery cell.

[0021] The battery management method according to the embodiments disclosed herein includes 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 the plurality of battery cells and setting the minimum available capacity as a reference capacity, setting a reference depth of discharge (DOD) as a DOD value set within a random DOD range, calculating a first reference voltage corresponding to the reference DOD of the reference battery cell, and performing balancing on each of the plurality of battery cells based on the first reference voltage.

[0022] According to an embodiment, the battery management method can further include, before performing the balancing, determining whether a difference between a maximum available capacity and a minimum available capacity among the plurality of battery cells is greater than or equal to a preset value.

[0023] According to an embodiment, performing the balancing can include adjusting a cell voltage of each of the plurality of battery cells so that a comparison voltage corresponding to the reference DOD of each of the plurality of battery cells corresponds to the first reference voltage.

[0024] According to an embodiment, performing the balancing can include setting an operating voltage range of each of the plurality of battery cells so that an operating capacity of each of the plurality of battery cells corresponds to the reference capacity.

[0025] According to an embodiment, performing the balancing can include setting 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.

[0026] According to an embodiment, the plurality of battery cells can include a first battery cell and a second battery cell, the available capacity of the second battery cell being different from the available capacity of the first battery cell, and the operating voltage range of the first battery cell being different from the operating voltage range of the second battery cell.

[0027] According to an embodiment, the available capacity of the first battery cell can be less than the available capacity of the second battery cell, and the operating voltage range of the first battery cell can include the operating voltage range of the second battery cell.

[0028] According to an embodiment, the operating capacity of each of the plurality of battery cells corresponding to the operating voltage can be the same as each other.

[0029] According to an embodiment, the reference DOD can be defined as a DOD of 50% or half of the available capacity of the battery cell.

[0030] Specific details of other embodiments include those described in the detailed description and drawings.

[0031] Advantages

[0032] The battery management apparatus according to embodiments disclosed herein and the operating method thereof can adjust an operating voltage range of a battery cell to manage available capacity of each of a plurality of battery cells.

[0033] The battery management apparatus according to embodiments disclosed herein and the operating method thereof can adjust an operating voltage range of a battery cell to prevent overcharging and overdischarging of the battery cell and improve a lifespan of the battery cell.

[0034] The battery management apparatus according to embodiments disclosed herein and the operating method thereof can improve a lifespan of a battery by reducing a frequency of passive balancing.

[0035] Technical effects of the battery inspection apparatus according to embodiments disclosed in the present document and the operating method thereof are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those of ordinary skill in the art in light of the disclosure of the present document. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a block diagram of a battery system according to embodiments disclosed herein.

[0037] Figure 2 is a graph illustrating that a battery management apparatus according to embodiments disclosed herein performs balancing on a plurality of battery cells.

[0038] Figure 3 is a flowchart illustrating a cell balancing method according to embodiments disclosed herein.

[0039] Figure 4 is a flowchart illustrating an operation of performing balancing on each of a plurality of battery cells based on a first reference voltage in Figure 3

[0040] Figure 5 is a block diagram of a computing system performing a cell balancing method according to embodiments disclosed herein.

[0041] With regard to the description of the drawings, like reference numerals can be used to refer to like or associated elements. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, this description is not intended to limit the present disclosure to specific embodiments, which should be interpreted to include various modifications, equivalents and / or alternatives according to embodiments of the present disclosure.

[0043] ​It should be understood that the embodiments of the present document and the terms used therein are not intended to limit the technical features set forth herein to particular embodiments, but include various changes, equivalents or replacements of the corresponding embodiments according to the technical features set forth herein. In the description of the drawings, similar reference numerals can be used to refer to similar or related elements. It should be understood that a singular form of a noun corresponding to an object includes one or more of the objects, unless the relevant context clearly dictates otherwise. As used herein, each of such phrases as "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 include any one of the items enumerated alone or in combination. Unless otherwise noted, such terms as "first," "second," "first," "second," "A," "B," "(a)" or "(b)" used herein can be used to simply distinguish one element from another element, and do not limit the elements or the order thereof in other respects.

[0044] As used herein, each of such phrases as "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 include any one of the items enumerated alone or in combination. Unless otherwise noted, such terms as "first," "second," "first," "second," "A," "B," "(a)" or "(b)" used herein can be used to simply distinguish one element from another element, and do not limit the elements or the order thereof in other respects.

[0045] Herein, it should be understood that when an element (for example, a first element) is referred to as being "connected," "coupled," or "linked" to another element (for example, a second element), or as being "coupled to" or "connected to" another element (for example, a second element), it means that the element can be directly connected to the other element (for example, wiredly or wirelessly) or indirectly connected to the other element (for example, via a third element).

[0046] The method according to various embodiments disclosed herein can be included and provided in a computer program product. The computer program product can be traded as a product between a seller and a buyer. The computer program product can be distributed in the form of a machine-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or be distributed online via an application store (e.g., Google Play Store™, Apple App Store™, or Microsoft Store). In the case of online distribution, at least a portion of the computer program product can be temporarily stored in a storage medium such as a memory of a manufacturer's server, an application store's server, or a relay server.

[0047] According to the embodiments disclosed herein, each of the above-described components (e.g., a module or a program) can include a single entity or a plurality of entities, some of which can be separately set on other components. According to the embodiments disclosed herein, one or more of the above-described components or operations can be omitted, or one or more other components or operations can be added. Alternatively or additionally, a plurality of components (e.g., modules or programs) can be integrated into a single component. In this case, the integrated component can perform one or more functions of each of the plurality of components before the integration in a similar or identical manner as each component before the integration. According to the embodiments disclosed herein, operations performed by the module, the program, or another component can be executed sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations can be executed in a different order or omitted, or one or more other operations can be added.

[0048] Figure 1 is a block diagram of a battery system according to the embodiments disclosed herein.

[0049] Referring to Figure 1 , the battery system 1 can include a battery pack 10 and an upper controller 20.

[0050] The battery pack 10 can 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 can be a group of battery cells including at least two battery cells. Each of the battery cells included in the plurality of battery cells 100 can be connected in series to each other or connected in parallel to each other.

[0051] The plurality of battery cells 100 can include two or more battery cells. According to an embodiment, the plurality of battery cells 100 can include a first battery cell 110 and a second battery cell 120. Here, the first battery cell 110 and the second battery cell 120 can be different battery cells.

[0052] Available capacities of the battery cells included in the plurality of battery cells 100 can be different from each other. Here, the available capacity can mean an amount of electrons that can be stored in a battery cell. According to an embodiment, due to factors such as a production deviation, a temperature, a voltage, etc., deterioration speeds of the battery cells included in the plurality of battery cells 100 can be different from each other. According to an embodiment, due to the difference in the deterioration speeds of each of the battery cells included in the plurality of battery cells 100, the available capacities of the battery cells included in the plurality of battery cells 100 can be different from each other.

[0053] 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 can be different from each other. Here, the available capacity of the first battery cell 110 can be defined as a [Ah]. The available capacity of the second battery cell 120 can be defined as b [Ah]. a and b can be different from each other.

[0054] According to an embodiment, the available capacity of the first battery cell 110 can 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 can be less than the available capacity b [Ah] of the second battery cell 120.

[0055] 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 of the plurality of battery cells 100. According to an embodiment, the battery management device 200 can monitor the voltage, the current, the temperature, etc. of the battery pack 10 to prevent overcharging and overdischarging, etc. 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 control the ON / OFF of the switching unit 400, and the battery management device can be connected to the plurality of battery cells 100 to monitor the state of each of the plurality of battery cells 100.

[0056] The battery management device 200 can include an information acquisition unit 210 and a controller 220. Here, the information acquisition unit 210 can acquire the current of each of the plurality of battery cells 100. Accordingly, the information acquisition unit 210 can acquire the current information of the first battery cell 110 and the current information of the second battery cell 120. According to an embodiment, the information acquisition unit 210 can be directly connected to the first battery cell 110 and the second battery cell 120 to acquire the current of the first battery cell 110 and the second battery cell 120, or the information acquisition unit 210 can receive the current information acquired by the sensor 300 from the sensor 300. The information acquisition unit 210 can transmit the current information of the plurality of battery cells 100 to the controller 220.

[0057] 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 cells 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 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 and the available capacity of the second battery cell 120 calculated by the controller 220 can be a [Ah] and b [Ah], respectively.

[0058] The controller 220 can perform balancing on the plurality of battery cells 100. That is, the controller 220 can perform balancing on the first battery cell 110 and the second battery cell 120. The balancing operation of the controller 220 will be described in detail with reference to Figure 2

[0059] 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. 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.

[0060] 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 the preset value, the controller 220 can perform cell balancing. When the difference between the maximum available capacity and the minimum available capacity is less than the preset value, the controller 220 can not perform cell balancing.

[0061] According to an embodiment, the controller 220 can provide the balancing result to the user. When balancing is performed on the plurality of battery cells 100, the controller 220 can provide information related to the balancing to the user. For example, the controller 220 can provide information related to the balancing to the user terminal through the communication unit (not shown), or can provide information about the balancing through the display provided in the vehicle, the charger, etc.

[0062] ​The sensor 300 may acquire information about the plurality of battery cells 100. The sensor 300 may be connected to the plurality of battery cells 100 to acquire information about the plurality of battery cells 100. The sensor 300 may transmit the information acquired from the plurality of battery cells 100 to the battery management device 200. According to an embodiment, the sensor 300 may be the same component as the information acquisition unit 210 included in the battery management device 200. According to an embodiment, the sensor 300 may be a component that acquires information different from the information acquired by the information acquisition unit 210.

[0063] The switching unit 400 may control the flow of current through the plurality of battery cells 100. That is, the switching unit 400 may be connected to the plurality of battery cells 100 by being connected in series to the first terminal side and / or the second terminal side of the plurality of battery cells 100 to control the flow of charge and discharge current through the battery cells 100. Depending on the embodiment, the switching unit 400 may include an electromagnetic contactor, at least one relay, or the like, based on the specifications of the battery pack 10.

[0064] The upper controller 20 may transmit a control signal regarding the battery cells 110 to the battery management device 200. Therefore, the operation of the battery management device 200 may be controlled based on the control signal applied from the upper controller 20.

[0065] Figure 2 FIG. 1 is a diagram illustrating a battery management apparatus according to an embodiment disclosed herein performing balancing on a plurality of battery cells.

[0066] Reference Figure 2 , the controller 220 may perform balancing on the plurality of battery cells 100. That is, the controller 220 may perform balancing on the first battery cell 110 and the second battery cell 120. Although Figure 2 Cell balancing with respect to two battery cells (ie, the first battery cell 110 and the second battery cell 120 ) is illustrated, but the following description may be substantially identically applied to cell balancing with respect to two or more battery cells.

[0067] The controller 220 may extract a reference battery cell having the smallest available capacity. That is, the controller 220 may compare the available capacity of each of the plurality of battery cells 100 to extract a reference battery cell having the smallest available capacity. For example, the reference battery cell having the smallest available capacity may be the first battery cell 110.

[0068] The controller 220 may define the available capacity of the reference battery cell as the reference capacity. Therefore, 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].

[0069] The controller 220 can also set other battery cells among the plurality of battery cells 100 except for the reference battery cell as target battery cells. For example, the target battery cells can include the second battery cell 120.

[0070] Hereinafter, for convenience of description, it can be assumed that the reference battery cell is the first battery cell 110. It can be assumed that the target battery cell is the second battery cell 120.

[0071] The controller 220 can set a reference depth of discharge (DOD) of the first battery cell 110. Here, the reference DOD can refer to a DOD value set within a random DOD range of the battery cell, and can include, for example, a DOD value randomly set by a user between 30% and 70%.

[0072] According to an embodiment, the reference DOD can be set to a middle value of the available capacity. Here, the middle value of the available capacity can be defined as half of the available capacity of the battery cell. In this case, the reference DOD of the first battery cell 110 can be a / 2 [Ah], that is, half of the available capacity of the first battery cell 110.

[0073] The controller 220 can acquire a first reference voltage corresponding to the reference DOD of the first battery cell 110. The controller 220 can also acquire a second reference voltage corresponding to the reference DOD of the second battery cell 120.

[0074] The controller 220 can perform balancing for each of the plurality of battery cells 100 based on the first reference voltage. The controller 220 can perform balancing for 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 for the second battery cell 120 by sequentially adjusting the cell voltage of the second battery cell 120.

[0075] The controller 220 can initially 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 initially adjust the operating voltage range of the second battery cell 120 (target battery cell) while maintaining the operating voltage range of the first battery cell 110 (reference battery cell). According to an embodiment, the operating voltage range can refer to a range from a voltage of a fully discharged state of a battery cell to a voltage of a fully charged state of the battery cell. The operating voltage range of the first battery cell 110 can be defined as a first operating voltage range V1. The operating voltage range of the second battery cell 120 before the initial voltage adjustment can be defined as a second operating voltage range V2. The operating voltage range of the second battery cell 120 after the initial voltage adjustment can be defined as a third operating voltage range V3.

[0076] Here, the initial voltage adjustment can be an adjustment for changing the start point and the end point of the operating voltage range while maintaining the size of the operating voltage range. That is, the size of the second operating voltage range V2 and the size of the third operating voltage range V3 are the same as each other, the start point of the third operating voltage range V3 is lower than the start point of the second operating voltage range V2, and the end point of the third operating voltage range V3 can be lower than the end point of the second operating voltage range V2.

[0077] 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 to each other.

[0078] 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.

[0079] The voltage and the capacity of the battery cell correspond to each other, and thus 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 narrowing the operating voltage range of the second battery cell 120.

[0080] 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 narrow 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.

[0081] That is, the controller 220 can narrow 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.

[0082] Specifically, the controller 220 can limit the up-adjustment range V6 and the down-adjustment range V5 of the third operating voltage range V3 of the second battery cell 120 to narrow the third operating voltage range V3 of the second battery cell 120. For example, the controller 220 can increase the start point of the third operating voltage range V3 by the down-adjustment range V5 and decrease the end point of the third operating voltage range V3 by the up-adjustment range V6. According to an embodiment, the size of the up-adjustment range V6 and the size of the down-adjustment range V5 can be the same as each other, but the present disclosure is not limited thereto. According to an embodiment, the sum of the fourth operating voltage range V4, the down-adjustment range V5, and the up-adjustment range V6 can be equal to the third operating voltage range V3.

[0083] After the secondary 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 by the secondary adjustment.

[0084] According to an embodiment, the fourth operating voltage range V4 can be different from the first operating voltage range V1. That is, the fourth operating voltage range V4 (i.e., the operating voltage range of the second battery cell 120 after the secondary adjustment) can be different from the first operating voltage range V1 (i.e., the operating voltage range of the first battery cell 110). In other words, after the secondary adjustment of the second battery cell 120, the available capacity of the second battery cell 120 can be equal to the available capacity of the first battery cell 110, but the fourth operating voltage range V4 can be different from the first operating voltage range V1. According to an embodiment, due to a difference in a deterioration rate or the like, the first battery cell 110 and the second battery cell 120 can have different available capacities before the voltage adjustment, so that even when the available capacities correspond to each other by the secondary adjustment of the second battery cell 120, the operating voltage ranges can not correspond to each other.

[0085] According to an embodiment, the first operation voltage range V1 can include the fourth operation voltage range V4. That is, a start point of the first operation voltage range V1 can be less than a start point of the fourth operation voltage range V4, and an end point of the first operation voltage range V1 can be greater than an end point of the fourth operation voltage range V4.

[0086] The controller 220 can control the operation of the second battery cell 120 so that the second battery cell 120 does not use the capacity corresponding to the lower adjustment range V5 of the second battery cell 120 and the capacity corresponding to the upper adjustment range V6 of the second battery cell 120 through the secondary voltage adjustment. 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 exceed the start point of the fourth operation voltage range V4 even in the case of full discharge. The controller 220 can adjust the second battery cell 120 so that the cell voltage of the second battery cell 120 does not exceed the end point of the fourth operation voltage range V4 even in the case of full charge. Accordingly, the use frequency of the fourth operation voltage range V4, the lower adjustment range V5, and the upper adjustment range V6 corresponding to the third operation voltage range V3 of the second battery cell 120 can be different.

[0087] In this way, the battery system 1 can reduce the use frequency of the upper or lower part of the operation voltage range of the battery cell and increase the use frequency of the voltage range corresponding to the middle part. Accordingly, it is possible to alleviate problems such as shortening of the life of the battery cell, overcharging / overdischarging, etc. due to frequent use of the upper and lower parts of the battery cell. That is, the battery system 1 can improve the life of the battery cell by adjusting the use frequency of each operation voltage of the battery.

[0088] According to an embodiment, the controller 220 can set a modified SOC. The controller 220 can set the modified SOC of each of the plurality of battery cells 100 based on the operation voltage range after the balancing. The controller 220 can modify the SOC based on the operation voltage changed by the primary cell voltage adjustment and the secondary cell voltage adjustment, thereby setting the modified SOC.

[0089] For example, before the second battery cell 120 is balanced, the SOC in which the cell voltage of the second battery cell 120 corresponds to the start point of the second operation voltage range V2 is 0%, and the SOC in which the cell voltage corresponds to the end point of the second operation voltage range V2 is 100%.

[0090] The controller 220 can set a modified SOC of the second battery cell 120 after performing the balancing on the second battery cell 120. The controller 220 can set the modified SOC based on the operating voltage range after the balancing on the second battery cell 120. That is, when the cell voltage of the second battery cell 120 corresponds to the start point of the fourth operating voltage range V4, the controller 220 can set the modified SOC to 0%. When the cell voltage of the second battery cell 120 corresponds to the end point of the fourth operating voltage range V4, the controller 220 can set the modified SOC to 100%. That is, the controller 220 can modify the SOC based on the fourth operating voltage range V4 and set the modified SOC. According to an embodiment, the controller 220 can set the modified DOD in the same method as setting the modified SOC.

[0091] The controller 220 can transmit the modified SOC to the user. According to an embodiment, the controller 220 can transmit the modified SOC to the user with respect to each battery cell included in the plurality of battery cells 100, or calculate an average value of the modified SOC of each of the plurality of battery cells 100 and transmit the average value of the modified SOC to the user.

[0092] The battery system 1 can reduce the frequency of passive balancing. The battery system 1 can perform cell balancing with respect to the reference DOD of the battery cell having the smallest available capacity, thereby reducing the frequency of passive balancing. That is, the battery system 1 can use passive balancing only at the time of the initial voltage adjustment of each of the plurality of battery cells 100, thereby reducing the frequency of passive balancing. Accordingly, the battery system 1 can improve power efficiency by preventing power consumption caused by passive balancing. In addition, the battery system 1 can reduce the risk of heat generation and fire of the battery cell.

[0093] Figure 3 FIG. 1 is a flowchart illustrating a battery management method according to an embodiment disclosed herein.

[0094] Figure 3 The illustrated embodiment is only one embodiment, and the order of operations of various embodiments according to the disclosure can be different from Figure 3 that illustrated in FIG. 1, some operations illustrated in Figure 3 may be omitted, or the order of operations or operations can be changed.

[0095] Reference will now be made to Figure 3The battery management method can include: operation S100, calculating available capacities of each of the plurality of battery cells 100; operation S200, determining whether a difference between a maximum available capacity and a minimum available capacity of the plurality of battery cells 100 is greater than or equal to a preset value; operation S300, extracting a reference battery cell having the minimum available capacity among the available capacities of the plurality of battery cells 100, setting the minimum available capacity as a reference capacity, setting a reference DOD, and calculating a first reference voltage corresponding to the reference DOD of the reference battery cell; and operation S400, performing balancing on each of the plurality of battery cells 100 based on the first reference voltage.

[0096] Hereinafter, a description will be given with reference to Figures 1 to 3 Operations S100 to S40 will be specifically described.

[0097] In operation S100, the battery management device 200 can calculate available capacities of each of the plurality of battery cells 100. According to an embodiment, the battery management device 200 can calculate the available capacities of each of the plurality of battery cells 100 based on current information of each of the plurality of battery cells 100.

[0098] In operation S200, the battery management device 200 can determine whether a difference between a maximum available capacity and a minimum available capacity of the plurality of battery cells 100 is greater than or equal to a preset value.

[0099] 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 the preset value. That is, the battery management device 200 can compare the available 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. The battery management device 200 can compare the difference between the maximum available capacity and the minimum available capacity with the 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.

[0100] When the difference between the maximum available capacity and the minimum available capacity is greater than or equal to the preset value, the battery management device 200 can perform operation S300. When the difference between the maximum available capacity and the minimum available capacity is less than the preset value, the battery management device 200 stops the battery management method.

[0101] In operation S300, the battery management device 200 can extract a reference battery cell having the minimum available capacity among the available capacities of the plurality of battery cells 100, set the minimum available capacity as a reference capacity, set a reference DOD, and calculate a first reference voltage corresponding to the reference DOD of the reference battery cell.

[0102] The battery management device 200 can extract the battery cell having the minimum available capacity. That is, the battery management device 200 can compare the available capacity of each of the plurality of battery cells 100 to extract the battery cell having the minimum available capacity. Here, the battery cell having the minimum available capacity can be defined as a reference battery cell.

[0103] The battery management device 200 can set a reference capacity. According to an embodiment, the battery management device 200 can define the capacity of the reference battery cell as the reference capacity, that is, the available capacity of the battery cell having the minimum available capacity can be defined as the reference capacity.

[0104] The battery management device 200 can set a reference depth of discharge (DOD) of the reference battery cell. Here, the reference DOD can be a DOD randomly set by a user between 30% of the DOD and 70% of the DOD.

[0105] According to an embodiment, the user can set a middle value of the available capacity as the reference DOD. Here, the middle value of the available capacity can be defined as a point at which the DOD of the battery cell is 50% or half of the available capacity of the battery cell.

[0106] 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.

[0107] In operation S400, the battery management device 200 can perform balancing for each of the plurality of battery cells 100 based on the first reference voltage. Here, a detailed description thereof will be made with reference to Figure 4 A detailed description thereof will be made.

[0108] Figure 4 is a flowchart illustrating an operation of performing balancing for each of the plurality of battery cells 100 based on the first reference voltage in Figure 3

[0109] With reference to Figure 4 , the operation of performing balancing for each of the plurality of battery cells 100 based on the first reference voltage can include: operation S410, adjusting a cell voltage of each of the plurality of battery cells 100 so that a second reference voltage corresponding to the reference DOD of each of the plurality of battery cells 100 corresponds to the first reference voltage; operation S420, 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 the reference capacity; and operation S430, setting a modified SOC of each of the plurality of battery cells 100 based on the operating voltage range of each of the plurality of battery cells 100.

[0110] ​In operation S410 , the battery management device 200 may adjust 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.

[0111] The battery management device 200 may initially adjust the cell voltage of each of the plurality of battery cells 100. That is, the battery management device 200 may 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 may perform passive balancing on each of the plurality of battery cells 100 other than the reference battery cell to 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. Here, the voltage corresponding to the reference DOD of each of the plurality of battery cells 100 may be defined as a second reference voltage. In other words, the battery management device 200 may adjust the cell voltage so that the second reference voltage of the plurality of battery cells 110 corresponds to the first reference voltage by using passive balancing.

[0112] In operation S420 , the battery management device 200 may set 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.

[0113] The battery management device 200 can secondary adjust the cell voltages 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 corresponding to each of the plurality of battery cells 100 corresponds to the available capacity of a reference battery cell. The reference battery cell may be the cell with the smallest available capacity among the plurality of battery cells 100, and thus the battery management device 200 can adjust the available capacity by narrowing 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 by narrowing the operating voltage range so that the available capacity of each of the plurality of battery cells 100 corresponds to the smallest available capacity.

[0114] Specifically, the battery management device 200 can narrow the operating voltage range of a 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 can be the same. Therefore, the operating capacities of the battery cells included in the plurality of battery cells 100 can correspond to each other.

[0115] In operation S430, the battery management device 200 can set the modified SOC of each of the plurality of battery cells 100 based on the operating voltage range of each of the plurality of battery cells 100.

[0116] The battery management device 200 can set the modified SOC. The battery management device 200 can set the modified SOC of each of the plurality of battery cells 100 based on the operating voltage range after the balancing. The battery management device 200 can modify the SOC based on the operating voltage changed by the primary cell voltage adjustment and the secondary cell voltage adjustment, thereby setting the modified SOC.

[0117] Figure 5 is a block diagram illustrating a computing system that performs a battery management method according to an embodiment disclosed herein.

[0118] Referring to Figure 5 , the computing system 500 according to the embodiment disclosed herein can include an MCU (Microcontroller Unit) 510, a memory 520, an input / output I / F 530, and a communication I / F 540.

[0119] The MCU 510 can be a processor that executes various programs (e.g., an SOH calculation program, a cell balancing target determination program, etc.) stored in the memory 520, processes various data including the SOCs of the plurality of battery cells, the SOH, etc. through the programs, and performs the above-described functions of the battery management device 200 described with reference to Figures 1 to 3 .

[0120] The memory 520 can store various programs regarding SOH calculation of the battery cells, cell balancing target determination, etc. In addition, the memory 520 can store various data such as the SOC data, the SOH data, etc. of each battery cell.

[0121] The memory 520 can be provided with a plurality of memories according to necessity. The memory 520 can be a volatile memory or a non-volatile memory. For the memory 520 as a volatile memory, a random access memory (RAM), a dynamic random access memory (DRAM), a static random access memory (SRAM), or the like can be used. For the memory 520 as a non-volatile memory, a read-only memory (ROM), a programmable read-only memory (PROM), an electrically alterable read-only memory (EAROM), an erasable and programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, or the like can be used. The above-listed examples of the memory 520 are merely examples, and are not limited thereto.

[0122] The input / output I / F 530 can provide an interface for transmitting and receiving data by connecting an input device (not shown) such as a keyboard, a mouse, a touch panel, or the like and an output device such as a display (not shown) or the like to the MCU 510.

[0123] The communication I / F 540, which is a component capable of transmitting and receiving various data to and from a server, can be various devices capable of supporting wired or wireless communication. For example, a program or various data for SOH calculation or equalization target determination of a battery cell, or the like can be transmitted to and received from an externally provided server through the communication I / F 540.

[0124] As such, the battery management method according to the embodiments disclosed herein can be recorded in the memory 520 and executed by the MCU 510.

[0125] The above description is merely an illustration of the technical idea of the present disclosure, and various modifications and changes will be possible for those of ordinary skill in the art to which the embodiments disclosed herein belong, without departing from the essential characteristics of the embodiments of the present disclosure.

[0126] Accordingly, the embodiments disclosed herein are intended to be illustrative only and not limiting of the scope of the inventive spirit of the embodiments disclosed herein, and the scope of the inventive spirit of the present disclosure is not limited by these embodiments disclosed herein. The scope of protection of the inventive spirit disclosed herein should be interpreted by the appended claims, and all technical spirits within the same scope should be understood to be included within the scope of the present document.

[0127] BRIEF DESCRIPTION OF DRAWINGS

[0128] 1 battery system

[0129] 10 battery pack

[0130] 100 plurality of battery cells

[0131] 110 first battery cell

[0132] 120 second battery cell

[0133] 210 information acquisition unit

[0134] 220 controller

Claims

1. A battery management device, comprising: an information acquisition unit configured to measure a cell current of each of the plurality of battery cells; and A controller, wherein the controller is configured as: calculating an available capacity of each of the plurality of battery cells based on the cell current; extracting a reference battery cell having a minimum available capacity among available capacities of the plurality of battery cells, and setting the minimum available capacity as a reference capacity; Setting a reference depth of discharge (DOD), wherein the reference DOD is a DOD value set within a random DOD range; calculating a first reference voltage corresponding to the reference DOD of the reference battery cell; as well as Balancing is performed on each of the plurality of battery cells based on the first reference voltage.

2. The battery management device according to claim 1, wherein: The controller is further configured to adjust a cell voltage of each of the plurality of battery cells so that a comparison voltage corresponding to the reference DOD of each of the plurality of battery cells corresponds to the first reference voltage.

3. The battery management device according to claim 1, wherein: The controller is further configured to set an operating voltage range of each of the plurality of battery cells such that an operating capacity of each of the plurality of battery cells corresponds to the reference capacity.

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

5. The battery management device according to claim 4, wherein: The available capacity of the first battery cell is smaller than the available capacity of the second battery cell, and The operating voltage range of the first battery cell includes the operating voltage range of the second battery cell. The battery management device according to claim 3 , wherein: The controller is further configured to set a modified state of charge (SOC) for each of the plurality of battery cells based on the operating voltage range of each of the plurality of battery cells.

7. The battery management device according to claim 3, wherein: The operating capacity of each of the plurality of battery cells corresponding to the operating voltage is identical to one another.

8. The battery management device according to claim 1, wherein: When a difference between a maximum available capacity and a minimum available capacity of the plurality of battery cells is greater than or equal to a preset value, the controller is further configured to perform balancing on each of the plurality of battery cells.

9. The battery management device according to claim 1, wherein: The reference DOD is defined as 50% DOD or half of the available capacity of the battery cell.

10. A battery management method, comprising: calculating an available capacity of each of the plurality of battery cells; extracting a reference battery cell having a minimum available capacity among available capacities of the plurality of battery cells, and setting the minimum available capacity as a reference capacity; Setting a reference depth of discharge (DOD), wherein the DOD is a DOD value set within a random DOD range; calculating a first reference voltage corresponding to the reference DOD of the reference battery cell; as well as Balancing is performed on each of the plurality of battery cells based on the first reference voltage.

11. The battery management method according to claim 10, further comprising: Before performing the balancing, it is determined whether a difference between a maximum available capacity and a minimum available capacity of the plurality of battery cells is greater than or equal to a preset value.

12. The battery management method according to claim 10, wherein: The performing balancing includes adjusting a cell voltage of each of the plurality of battery cells so that a comparison voltage corresponding to the reference DOD of each of the plurality of battery cells corresponds to the first reference voltage.

13. The battery management method according to claim 12, wherein: The performing balancing includes setting an operating voltage range of each of the plurality of battery cells so that an operating capacity of each of the plurality of battery cells corresponds to the reference capacity.

14. The battery management method according to claim 13, wherein: The performing balancing includes setting 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.

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

16. The battery management method according to claim 15, wherein: The available capacity of the first battery cell is smaller than the available capacity of the second battery cell, and The operating voltage range of the first battery cell includes the operating voltage range of the second battery cell.

17. The battery management method according to claim 15, wherein: The operating capacity of each of the plurality of battery cells corresponding to the operating voltage is identical to one another.

18. The battery management method according to claim 10, wherein: The reference DOD is defined as 50% DOD or half of the available capacity of the battery cell.

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