Battery management apparatus and method, and battery pack including the same

Abstract

A battery management device according to one embodiment of the present invention comprises: a measurement unit for measuring voltages of a plurality of batteries connected in series with each other; and a control unit for estimating the SOC of the plurality of batteries based on the voltage, and controlling the charging and discharging of the plurality of batteries such that the SOC of the plurality of batteries is included in a plurality of available SOC sections preset to correspond to the plurality of batteries.

Description

Technical Field

[0001] This application is based on and claims the benefit of priority from Korean Patent Application No. 10-2023-0018298 filed in the Korean Intellectual Property Office on February 10, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates to a battery management device, a battery management method, and a battery pack including the battery management device. Background Art

[0003] In recent years, the demand for portable electronic products including laptop computers, cameras, and mobile phones has increased dramatically, and the development of electric vehicles, energy storage batteries, robots, and satellites has accelerated. Under such circumstances, research on high-performance rechargeable batteries is being actively conducted.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among these batteries, lithium batteries are becoming the most popular batteries because, compared with nickel-based batteries, lithium batteries are not affected by the memory effect and are therefore freely rechargeable, have a low self-discharge rate, and have a high energy density.

[0005] In graphite-based batteries, staging may occur when lithium is intercalated into graphite layers. In the staging phenomenon associated with lithium intercalation reactions, a transition from high to low order is observed as the lithium insertion concentration increases. In contrast, in lithium deintercalation reactions (discharge reactions), the transition occurs in the opposite direction.

[0006] The SOC (state of charge) band in which the graphite stepping phenomenon occurs may be referred to as a step band. The degradation of the battery may be accelerated when charging and discharging in the step band compared to when charging and discharging outside the step band. For example, a battery that has been continuously charged and discharged in the step band may degrade faster than a battery that has not yet been charged and discharged in the step band.

[0007] Therefore, there is a need to develop technology for improving the life expectancy of batteries by limiting charging and discharging in a band that may affect degradation of the batteries. Summary of the invention

[0008] The present disclosure is designed to solve the above-mentioned problems, and provides a battery management device and a battery management method for controlling charging and discharging of a battery to extend the life of the battery, and a battery pack including the battery management device.

[0009] The advantages of the present disclosure can be understood from the following description and can be more clearly appreciated from the embodiments of the present disclosure. In addition, it will be apparent that the objects and advantages of the present disclosure can be achieved by the means defined in the claims and combinations thereof.

[0010] According to one aspect of the present disclosure, a battery management device may include: a measuring unit that measures voltages of a plurality of batteries connected in series with each other; and a control unit that estimates a state of charge (SOC) of the plurality of batteries based on the measured voltages, and controls charging and discharging of the plurality of batteries so that the estimated SOCs of the plurality of batteries fall within a plurality of available SOC bands preset to correspond to the plurality of batteries.

[0011] A plurality of available SOC bands may be divided based on a preset unavailable SOC band and be set not to overlap with each other.

[0012] The control unit may control an operation state of a bypass switch connected in parallel to a bypass path arranged in each of the plurality of batteries to control the charging and discharging of the plurality of batteries.

[0013] During charging of the plurality of batteries, the control unit may select a target battery having an SOC reaching an upper limit value of an available SOC band corresponding to the target battery and control an operation state of a bypass switch connected in parallel to the target battery to an on state.

[0014] During discharge of the plurality of batteries, the control unit may select a target battery having an SOC reaching a lower limit value of an available SOC band corresponding to the target battery and control an operation state of a bypass switch connected in parallel to the target battery to an on state.

[0015] When discharging of the multiple batteries is requested even though the SOCs of the multiple batteries have reached the lower limit values ​​of the available SOC bands corresponding to the multiple batteries, the control unit may set priorities among the multiple available SOC bands in descending order of the band values ​​of the multiple available SOC bands, and discharge the multiple batteries from the battery corresponding to the available SOC band with the highest priority to the battery corresponding to the available SOC band with the lowest priority.

[0016] When the SOC of the further discharged battery reaches a lower limit value of an available SOC band having the next priority, the control unit may further discharge the battery corresponding to the available SOC band having the next priority.

[0017] The control unit may set the intervals of the plurality of available SOC bands to be equal to each other.

[0018] The control unit may set a different number of batteries to correspond to each of the plurality of available SOC bands.

[0019] The control unit may set the number of different batteries so that the larger the band value of the available SOC band is, the larger the number of batteries corresponding to the SOC band is.

[0020] According to another aspect of the present disclosure, a battery pack may include the battery management device.

[0021] According to another aspect of the present disclosure, a battery management method may include: measuring the voltage of multiple batteries connected in series with each other; estimating the SOC of the multiple batteries based on the voltage; and controlling the charging and discharging of the multiple batteries so that the SOC of the multiple batteries falls within a plurality of available SOC bands preset to correspond to the multiple batteries.

[0022] According to one aspect of the present disclosure, a battery management device may control charging and discharging of a plurality of batteries so that an SOC (State of Charge) of each of the plurality of batteries does not fall within an unusable SOC band.

[0023] According to one aspect of the present disclosure, there is an advantage in extending the life expectancy of a plurality of batteries and preventing imbalance of degradation of the plurality of batteries.

[0024] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood from the claims by those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Since the drawings attached hereto are used to facilitate understanding of the technical idea of ​​the present disclosure in conjunction with the following detailed description of the present invention, the present disclosure should not be interpreted as being limited to the contents illustrated in the drawings.

[0026] Figure 1 is a view schematically illustrating a battery management device according to an embodiment of the present disclosure.

[0027] Figure 2 is a view schematically illustrating an example of a configuration of a battery pack according to another embodiment of the present disclosure.

[0028] Figures 3 to 7 is a diagram illustrating Example 1 according to the present disclosure.

[0029] Figures 8 to 12 is a diagram illustrating Example 2 according to the present disclosure.

[0030] Fig.13 is a flow chart schematically illustrating a battery management method according to yet another embodiment of the present disclosure. DETAILED DESCRIPTION

[0031] The words and terms used in the detailed description and claims of this document should not be construed as limited to their ordinary or dictionary meanings, but should be construed as having meanings and concepts corresponding to the technical ideas of the present disclosure, consistent with the principle that the inventor can appropriately define the terms and concepts for the purpose of best describing the present disclosure.

[0032] Therefore, it can be appreciated that the embodiments described herein and the configurations illustrated in the drawings are merely example embodiments of the present disclosure, which do not exhaustively represent the technical ideas of the present disclosure, and various equivalents and modifications may be made to replace the present disclosure when the present disclosure is filed.

[0033] Furthermore, when describing the present disclosure, if it is determined to make the gist of the present disclosure unclear, a detailed description of related well-known configurations or functions may be omitted.

[0034] Terms having ordinal numbers such as first, second, etc. may be used to distinguish various components from one another and should not be construed as limiting the components.

[0035] Throughout the description herein, when a certain portion “includes” a specific component, the description does not indicate that the certain portion excludes other components but indicates that the portion may further include other components unless otherwise defined.

[0036] Furthermore, throughout the description herein, when two components are “connected” to each other, the description not only indicates that the two components are “directly connected” to each other but also indicates that the two components are “indirectly connected” to each other via another component.

[0037] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0038] Figure 1 is a view schematically illustrating a battery management device 100 according to an embodiment of the present disclosure.

[0039] refer to Figure 1 The battery management device 100 may include a measuring unit 110 and a control unit 120 .

[0040] The measuring unit 110 may be configured to measure, for example, voltages of a plurality of batteries B connected in series to each other.

[0041] Here, each battery refers to a physically separable single independent cell including an anode terminal and a cathode terminal. For example, the battery may be a lithium ion battery or a lithium polymer battery. In addition, the battery may refer to a battery module including a plurality of cells connected in series and / or in parallel to each other. Hereinafter, for ease of description, it is assumed that the battery refers to a single independent cell.

[0042] The measuring unit 110 may be connected to the control unit 120 for communication with the control unit 120. The measuring unit 110 may measure a voltage of each of the plurality of batteries B and transmit information of the measured voltage to the control unit 120.

[0043] The control unit 120 may be configured to estimate the SOC (State of Charge) of each of the plurality of batteries B based on the voltage received from the measurement unit 110 .

[0044] For example, the control unit 120 may estimate the SOC according to the voltage of each of the plurality of batteries B by using a table (e.g., a lookup table (LUT)) indicating an association relationship between the voltage and the SOC. The table may be initially set based on a battery in a BOL (beginning of life) state. The table may be updated to correspond to the degradation state of the plurality of batteries B. For example, the updated table may indicate an association relationship between the voltage and the SOC of a degraded battery.

[0045] The control unit 120 may be configured to control charging and discharging of the plurality of batteries B so that the SOCs of the plurality of batteries B fall within a plurality of available SOC bands that are set in advance to correspond to the plurality of batteries B.

[0046] The available SOC band may be set based on a preset unavailable SOC band. In addition, the available SOC bands may be set so as not to overlap with each other. For example, the unavailable SOC band may be a SOC band that is preset to be unavailable because the degradation of the battery may be accelerated during charging and discharging in the unavailable SOC band. As an example, the unavailable SOC band may include an SOC band including 90% to 100% SOC in which the battery is fully charged, an SOC band including 0% to 10% SOC in which the battery is fully discharged, and an SOC band known as a graphite graded band. These are merely examples, and the unavailable SOC band may be further set by experiments on whether the battery degradation is accelerated.

[0047] The control unit 120 may set a plurality of available SOC bands based on the preset unavailable SOC bands. Then, the control unit 120 may set an available SOC band corresponding to each of the plurality of batteries B.

[0048] For example, it is assumed that four batteries B1 to B4 are provided, and a first available SOC band U1 and a second available SOC band U2 are set. The control unit 120 may set the first battery B1 and the second battery B2 to correspond to the first available SOC band U1. The control unit 120 may set the third battery B3 and the fourth battery B4 to correspond to the second available SOC band U2. For example, the control unit 120 may set any available SOC band corresponding to the plurality of batteries B, regardless of the current SOC or voltage of the plurality of batteries B.

[0049] The control unit 120 may be configured to control the charging and discharging of the plurality of batteries B so that the SOCs of the plurality of batteries B fall within their corresponding available SOC bands.

[0050] Specifically, the control unit 120 may control the charging and discharging of each of the plurality of batteries B so that the SOC of each of the plurality of batteries B falls within its corresponding available SOC band.

[0051] For example, when the SOC of a battery reaches the lower limit of the available SOC band corresponding to the battery, the control unit 120 can terminate the discharge of the battery. At the same time, when the SOC of another battery reaches the upper limit of the available SOC band corresponding to the battery, the control unit 120 can terminate the charging of the battery.

[0052] That is, the battery management device 100 can control the charging and discharging of the plurality of batteries B so that the SOC of the plurality of batteries B does not fall into the unusable SOC band. According to the present disclosure, the life expectancy of the plurality of batteries B is extended.

[0053] Meanwhile, the control unit 120 of the battery management device 100 may selectively include, for example, a processor, an application specific integrated circuit (ASIC), other chipsets, logic circuits, registers, communication modems, and data processors well known in the art to perform various control logics according to the present disclosure. When the control logic is implemented by software, the control unit 120 may be implemented as a collection of program modules. At this time, the program modules may be stored in a memory and executed by the control unit 120. The memory may be provided inside or outside the control unit 120 and connected to the control unit 120 as a well-known device.

[0054] The battery management device 100 may further include a storage unit 130. The storage unit 130 may store, for example, data or programs necessary when each component of the battery management device 100 performs its operation and function, data generated during the execution of the operation and function, etc. The type of the storage unit 130 is not particularly limited as long as the storage unit 130 is a known information storage device in which recording, erasing, updating, and reading of data can be performed. Examples of information storage devices may include RAM, flash memory, ROM, EEPROM, and registers. In addition, the storage unit 130 may store program codes that define processes that can be executed by the control unit 120.

[0055] For example, the storage unit 130 may store information of unavailable SOC bands, information of available SOC bands, and information of association relationships between a plurality of available SOC bands and a plurality of batteries.

[0056] The control unit 120 may be configured to control an operation state of a bypass switch S disposed in a bypass path connected in parallel to each of the plurality of batteries B, thereby controlling charging and discharging of the plurality of batteries B.

[0057] Specifically, the plurality of batteries B may be connected in series with each other. Therefore, the bypass switch S may be connected in parallel to each of the plurality of batteries B for charge and discharge control by the control unit 120. The control unit 120 may control the charge and discharge of the plurality of batteries B by controlling the operation state of the bypass switch S to an on or off state.

[0058] Figure 2 is a view schematically illustrating an example of a configuration of a battery pack 1 according to another embodiment of the present disclosure.

[0059] exist Figure 2 In an embodiment of the present invention, the plurality of batteries B may include a first battery B1, a second battery B2, a third battery B3, and a fourth battery B4. The plurality of bypass switches S may include a first bypass switch S1, a second bypass switch S2, a third bypass switch S3, and a fourth bypass switch S4. The first bypass switch S1 may be connected in parallel to the first battery B1, and the second bypass switch S2 may be connected in parallel to the second battery B2. The third bypass switch S3 may be connected in parallel to the third battery B3, and the fourth bypass switch S4 may be connected in parallel to the fourth battery B4.

[0060] In the process of charging the plurality of batteries B, the control unit 120 may be configured to select a target battery whose SOC reaches an upper limit value of an available SOC band corresponding to the target battery during the charging of the plurality of batteries B. The control unit 120 may be configured to control the operation state of the bypass switch S connected in parallel to the target battery to be in an on state.

[0061] For example, in Figure 2 In the embodiment of , it can be assumed that the SOC of the first battery B1 reaches the upper limit value of the corresponding available SOC band, and the SOC of the second battery B2, the third battery B3 and the fourth battery B4 do not reach the upper limit value of the corresponding available SOC band. The control unit 120 can select the first battery B1 as the target battery. Then, the control unit 120 can control the operating state of the first bypass switch S1 to the on state, and control the operating state of the second bypass switch S2, the third bypass switch S3 and the fourth bypass switch S4 to the off state. In this case, the charging of the first battery B1 is terminated, while the charging of the second battery B2, the third battery B3 and the fourth battery B4 can continue.

[0062] Meanwhile, in the process of discharging the plurality of batteries B, the control unit 120 may be configured to select a target battery whose SOC reaches a lower limit value of an available SOC band corresponding to the target battery during the discharging of the plurality of batteries B. The control unit 120 may be configured to control the operation state of the bypass switch S connected in parallel to the target battery to be an on state.

[0063] For example, in Figure 2 In the embodiment of , it can be assumed that the SOC of the second battery B2 and the fourth battery B4 reaches the lower limit value of the corresponding available SOC band, while the SOC of the first battery B1 and the third battery B3 does not reach the lower limit value of the corresponding available SOC band. The control unit 120 can select the second battery B2 and the fourth battery B4 as the target battery. Then, the control unit 120 can control the operating state of the second bypass switch S2 and the fourth bypass switch S4 to the on state, and control the operating state of the first bypass switch S1 and the third bypass switch S3 to the off state. In this case, the discharge of the second battery B2 and the fourth battery B4 can be terminated, and the discharge of the first battery B1 and the third battery B3 can continue.

[0064] Figures 3 to 7 is a diagram illustrating Example 1 according to the present disclosure.

[0065] Hereinafter, Example 1 will be described, assuming that an SOC range of 90% or more and 100% or less is set as a first unavailable SOC band N1, an SOC range of 60% to 90% is set as a first available SOC band U1, an SOC range of 40% or more and 60% or less is set as a second unavailable SOC band N2, an SOC range of 10% to 40% is set as a second available SOC band U2, and an SOC range of 0% or more and 10% or less is set as a third unavailable SOC band N3. In addition, it is assumed that the first battery B1 and the second battery B2 are set to correspond to the first available SOC band U1, and the third battery B3 and the fourth battery B4 are set to correspond to the second available SOC band U2.

[0066] exist Figure 3 In the example of FIG. 1 , the first battery B1 , the second battery B2 , the third battery B3 , and the fourth battery B4 may be initially in a fully charged state. For example, the SOC of the first battery B1 , the second battery B2 , the third battery B3 , and the fourth battery B4 may be 100%.

[0067] exist Figure 4 In the example of , the first battery B1, the second battery B2, the third battery B3 and the fourth battery B4 can be discharged. The SOC of the first battery B1, the second battery B2, the third battery B3 and the fourth battery B4 can reach 60%, which is the lower limit value of the first available SOC band U1.

[0068] Since the SOCs of the first battery B1 and the second battery B2 reach the lower limit value of the first available SOC band U1, the control unit 120 may set the first battery B1 and the second battery B2 as target batteries. Then, the control unit 120 may terminate the discharge of the first battery B1 and the second battery B2, and continue the discharge of the third battery B3 and the fourth battery B4.

[0069] exist Figure 5 In the example of , the third battery B3 and the fourth battery B4 can continue to be discharged. The SOC of the third battery B3 and the fourth battery B4 can reach 10%, which is the lower limit value of the second available SOC band U2.

[0070] Then, the control unit 120 may control the charging and discharging of the first battery B1 and the second battery B2 within the first available SOC band U1 , and control the charging and discharging of the third battery B3 and the fourth battery B4 within the second available SOC band U2 .

[0071] When multiple batteries B are requested to be discharged even though their SOCs have reached the lower limit values ​​of their corresponding available SOC bands, the control unit 120 may sort the priorities among the multiple available SOC bands in descending order of band value. Then, the control unit 120 may discharge the batteries in descending order of priority.

[0072] Specifically, the control unit 120 may discharge the plurality of batteries B while terminating the discharge of the target battery, and the SOC of the target battery reaches the lower limit value of the available SOC band corresponding to the target battery. Even when the discharge of all of the plurality of batteries B is terminated, the discharge request may continue. In this case, the control unit 120 may set the priority among the available SOC bands based on the band values ​​of the plurality of available SOC bands.

[0073] Here, the band value refers to a value included in the corresponding available SOC band, and may be, for example, an upper limit value, a lower limit value, a mean value, or a median value of the corresponding available SOC band. Since the multiple available SOC bands do not overlap with each other, the band values ​​of the multiple available SOC bands may also not overlap with each other.

[0074] For example, in Figure 5 In the example of FIG. 1 , the SOC of all of the first battery B1, the second battery B2, the third battery B3, and the fourth battery B4 reaches the lower limit value of the corresponding available SOC band. Under normal circumstances, the discharge of all of the first battery B1, the second battery B2, the third battery B3, and the fourth battery B4 needs to be terminated. However, since the first battery B1 and the second battery B2 may be further discharged, the discharge request may continue.

[0075] Since the band value of the first available SOC band U1 is greater than the band value of the second available SOC band U2, the control unit 120 may set the priority of the first available SOC band U1 higher than the priority of the second available SOC band U2. Then, the control unit 120 may further discharge the first battery B1 and the second battery B2 corresponding to the first available SOC band U1.

[0076] For example, in Figure 6 In the example of , the SOC of the first battery B1 and the second battery B2 may reach the lower limit value of the second available SOC band U2. Then, the control unit 120 may terminate the discharge of the first battery B1, the second battery B2, the third battery B3, and the fourth battery B4.

[0077] Afterwards, in Figure 7 During the charging process in the example of , the first battery B1 and the second battery B2 may be charged until their SOCs reach the upper limit value of the first available SOC band U1, and the third battery B3 and the fourth battery B4 may be charged until their SOCs reach the upper limit value of the second available SOC band U2. Then, the control unit 120 may control the charging and discharging of the first battery B1 and the second battery B2 within the first available SOC band U1, and control the charging and discharging of the third battery B3 and the fourth battery B4 within the second available SOC band U2.

[0078] The battery management device 100 according to one embodiment of the present disclosure can extend the expected life of the battery by controlling the charging and discharging of the battery within its corresponding available SOC band. When additional discharge of the battery is necessary, the battery management device 100 can further discharge the battery.

[0079] Figures 8 to 12 is a diagram illustrating Example 2 according to the present disclosure.

[0080] Hereinafter, Example 2 will be described, assuming that an SOC range of 90% or more and 100% or less is set as a first unavailable SOC range N1, an SOC range of 70% to 90% is set as a first available SOC range U1, an SOC range of 60% or more and 70% or less is set as a second unavailable SOC range N2, an SOC range of 40% to 60% is set as a second available SOC range U2, an SOC range of 30% or more and 40% or less is set as a third unavailable SOC range N3, an SOC range of 10% to 30% is set as a third available SOC range U3, and an SOC range of 0% or more and 10% or less is set as a fourth unavailable SOC range N4. In addition, it is assumed that the fifth battery B5 and the sixth battery B6 are set to correspond to the first available SOC band U1, the seventh battery B7 and the eighth battery B8 are set to correspond to the second available SOC band U2, and the ninth battery B9 and the tenth battery B10 are set to correspond to the third available SOC band U3.

[0081] Figure 7 and Figure 8 The available SOC band and the unavailable SOC band illustrated in the figure are bands arbitrarily selected for the convenience of description. Therefore, the buffer band (SOC band for preventing full charge and full discharge) and the graphite step band appropriately set by experiment can be set as the unavailable SOC band. Then, the available SOC band can be set according to the set unavailable SOC band. For example, the available SOC band and the unavailable SOC band are not limited to Figure 7 and Figure 8 Those in the example.

[0082] exist Figure 8 In the example of , the SOC of the fifth battery B5 and the sixth battery B6 is 90%, which may be the same as the upper limit value of the first available SOC band U1. The SOC of the seventh battery B7 and the eighth battery B8 is 60%, which may be the same as the upper limit value of the second available SOC band U2. The SOC of the ninth battery B9 and the tenth battery B10 is 30%, which may be the same as the upper limit value of the third available SOC band U3.

[0083] exist Fig. 9 In the example of , the fifth battery B5, the sixth battery B6, the seventh battery B7, the eighth battery B8, the ninth battery B9 and the tenth battery B10 can be discharged. The SOC of the fifth battery B5 and the sixth battery B6 is 70%, which can be the same as the lower limit value of the first available SOC band U1. The SOC of the seventh battery B7 and the eighth battery B8 is 40%, which can be the same as the lower limit value of the second available SOC band U2. The SOC of the ninth battery B9 and the tenth battery B10 is 10%, which can be the same as the lower limit value of the third available SOC band U3.

[0084] Then, when a discharge request is continued, the control unit 120 may set priorities of available SOC bands in the order of the first available SOC band U1 , the second available SOC band U2 , and the third available SOC band U3 , which are sorted in order from the highest band value to the lowest band value.

[0085] For example, in Fig.10 In the example of , the fifth battery B5 and the sixth battery B6 are further discharged, and the SOC of the fifth battery B5 and the sixth battery B6 may reach the lower limit value of the second available SOC band U2. Here, when the fifth battery B5 and the sixth battery B6 are further discharged, the fifth battery B5 and the sixth battery B6 may be discharged even in the third unavailable SOC band N3. In this case, the plurality of batteries B may be degraded unevenly.

[0086] To help the multiple batteries B degrade evenly, the control unit 120 may be configured to discharge the battery corresponding to the available SOC band with the next priority when the SOC of the battery being discharged reaches the lower limit value of the available SOC band with the next priority.

[0087] For example, in Fig.10 In the example of FIG. 1 , the SOCs of the fifth battery B5, the sixth battery B6, the seventh battery B7, and the eighth battery B8 are all 40%, which may be the same as the lower limit value of the second available SOC band U2. When the discharge request continues, the control unit 120 may discharge the seventh battery B7 and the eighth battery B8 corresponding to the second available SOC band U2 having the next priority.

[0088] For example, in Fig.11 In the example of , the seventh battery B7 and the eighth battery B8 can be discharged. For example, the seventh battery B7 and the eighth battery B8 can be 10% SOC, which can be the same as the lower limit value of the third available SOC band U3. Therefore, the SOCs of the seventh battery B7, the eighth battery B8, the ninth battery B9, and the tenth battery B10 can be the same as the lower limit value of the third available SOC band U3.

[0089] Assume that the discharge request continues thereafter. In this case, since the ninth battery B9 and the tenth battery B10 corresponding to the third available SOC band U3 having the last priority may no longer be discharged, the fifth battery B5 and the sixth battery B6 corresponding to the first available SOC band U1 may be further discharged again.

[0090] For example, in Fig.12In the example of , the fifth battery B5 and the sixth battery B6 can be discharged. The fifth battery B5 and the sixth battery B6 can be 10% SOC, which can be the same as the lower limit value of the third available SOC band U3. That is, the SOC of all of the fifth battery B5, the sixth battery B6, the seventh battery B7, the eighth battery B8, the ninth battery B9, and the tenth battery B10 can be the same at 10% SOC.

[0091] During the subsequent charging process, the fifth battery B5 and the sixth battery B6 may be charged until their SOCs reach the upper limit value of the first available SOC band U1, the seventh battery B7 and the eighth battery B8 may be charged until their SOCs reach the upper limit value of the second available SOC band U2, and the ninth battery B9 and the tenth battery B10 may be charged until their SOCs reach the upper limit value of the third available SOC band U3. Then, the control unit 120 may control the charging and discharging of the fifth battery B5 and the sixth battery B6 within the first available SOC band U1. The control unit 120 may control the charging and discharging of the seventh battery B7 and the eighth battery B8 within the second available SOC band U2. The control unit 120 may control the charging and discharging of the ninth battery B9 and the tenth battery B10 within the third available SOC band U3.

[0092] The battery management device 100 according to one embodiment of the present disclosure may control charging and discharging of the plurality of batteries B so that the plurality of batteries B are evenly degraded even when discharge requests are continuously made.

[0093] The control unit 120 may set equal intervals for a plurality of available SOC bands.

[0094] If the intervals of the available SOC bands are different from each other, degradation of the battery may become unbalanced according to the corresponding available SOC bands.

[0095] For example, it can be assumed that the interval of the N-1th available SOC band is 30% SOC and the interval of the Nth available SOC band is 40% SOC. Here, the interval of the SOC band refers to the SOC range included in the available SOC band and can be calculated by the formula of "lower limit value-upper limit value".

[0096] In this case, the battery corresponding to the N-1th available SOC band may be charged and discharged at an interval of 30% SOC, while the battery corresponding to the Nth available SOC band may be charged and discharged at an interval of 40% SOC. Since the intervals of the charge and discharge SOC bands among the plurality of batteries B are different, the battery corresponding to the Nth available SOC band may degrade faster than the battery corresponding to the N-1th available SOC band.

[0097] Therefore, the battery management device 100 sets equal intervals for the plurality of available SOC bands to prevent imbalance in degradation of the plurality of batteries B.

[0098] The control unit 120 may set the number of different batteries to correspond to each of the plurality of available SOC bands.

[0099] Preferably, the control unit 120 may be configured to set the number of batteries such that the larger the band value of the available SOC band, the larger the number of batteries corresponding to the available SOC band.

[0100] For example, in Figure 8 In the embodiment of the present invention, when the number of the plurality of batteries B is increased, the number of batteries corresponding to each available SOC band may be reduced in the order of the first available SOC band U1, the second available SOC band U2, and the third available SOC band U3. For example, the number of batteries corresponding to the first available SOC band U1 may be the largest, and the number of batteries corresponding to the third available SOC band U3 may be the smallest.

[0101] The plurality of batteries B may be fully charged (100% SOC) at the initial time and discharged according to their corresponding available SOC bands. In this case, the batteries corresponding to the available SOC bands with low band values ​​pass through more unavailable SOC bands than the batteries corresponding to the available SOC bands with high band values. For example, Figure 8 In the embodiment of the present invention, the fifth battery B5 and the sixth battery B6 are discharged only through the first unavailable SOC band N1, while the seventh battery B7 and the eighth battery B8 are discharged through the first unavailable SOC band N1 and the second unavailable SOC band N2. In addition, the ninth battery B9 and the tenth battery B10 are discharged through all of the first unavailable SOC band N1, the second unavailable SOC band N2, and the third unavailable SOC band N3. In this discharge stage, the ninth battery B9 and the tenth battery B10 corresponding to the third available SOC band U3 with a low band value may degrade faster than other batteries. Therefore, when more batteries than batteries corresponding to the available SOC band with a low band value are set to correspond to the available SOC band with a high band value, the overall degradation degree of multiple batteries can be reduced.

[0102] In consideration of this, the battery management apparatus 100 may set the number of batteries corresponding to the available SOC band to be different according to the band value of the available SOC band.

[0103] The battery management device 100 according to the present disclosure may be applied to a battery management system (BMS). For example, the BMS according to the present disclosure may include the above-mentioned battery management device 100. In this configuration, at least a portion of the components of the battery management device 100 may be implemented by enhancing or adding functions of components of a well-known BMS. For example, the measurement unit 110, the control unit 120, and the storage unit 130 of the battery management device 100 may be implemented as components of the BMS.

[0104] In addition, the battery management device 100 according to the present disclosure may be provided in the battery pack 1. For example, the battery pack 1 according to the present disclosure may include the above-mentioned battery management device 100 and one or more battery cells. The battery pack 1 may further include electrical components (eg, relays, fuses), a housing, etc.

[0105] exist Figure 2 In the embodiment of FIG. 1 , the positive terminal of each battery B may be connected to the positive terminal P+ of the battery pack 1 , and the negative terminal of the battery B may be connected to the negative terminal P− of the battery pack 1 .

[0106] An external device may be connected to the positive terminal P+ and the negative terminal P- of the battery pack 1. Therefore, the positive terminal of the battery B, the positive terminal P+ of the battery pack 1, the external device, the negative terminal P- of the battery pack 1, and the negative terminal of the battery B may be electrically connected to each other.

[0107] For example, the external device may be a charging or discharging device, or a load such as a motor of an electric vehicle powered from a plurality of batteries B.

[0108] Fig.13 is a flow chart schematically illustrating a battery management method according to another embodiment of the present disclosure.

[0109] Each step of the battery management method may be performed by the battery management apparatus 100. Hereinafter, for the convenience of description, descriptions overlapping with the above descriptions will be omitted or briefly summarized.

[0110] refer to Fig.13 , the battery management method may include a voltage measuring step ( S100 ), an SOC estimating step ( S200 ), and a charging / discharging controlling step ( S300 ).

[0111] The voltage measuring step S100 is a step of measuring the voltages of the plurality of batteries B connected in series to each other, and may be performed by the measuring unit 110 .

[0112] Specifically, the measuring unit 110 may measure the voltage of each of the plurality of batteries B. Then, the measuring unit 110 may transmit information of the measured voltage to the control unit 120 .

[0113] The SOC estimating step S200 is a step of estimating the SOCs of the plurality of batteries B based on the voltages, and may be performed by the control unit 120 .

[0114] Specifically, the control unit 120 may estimate the SOC of each of the plurality of batteries B by using a table indicating an association relationship between voltage and SOC.

[0115] The charging and discharging control step S300 is a step of controlling charging and discharging of the plurality of batteries B so that the SOCs of the plurality of batteries B fall within a plurality of available SOC bands preset to correspond to the plurality of batteries B, and may be performed by the control unit 120 .

[0116] Specifically, each of the plurality of batteries B may be preset to correspond to one of the plurality of available SOC bands. Then, the control unit 120 may control the charging and discharging of the plurality of batteries B so that the SOC of the plurality of batteries B falls within the corresponding available SOC band.

[0117] exist Figure 2 In the embodiment of the present invention, the control unit 120 may set a target battery whose SOC reaches the lower limit value of the corresponding available SOC band, and control the operation state of the bypass switch S connected in parallel to the target battery to be turned on. In this case, the target battery may be excluded from the batteries subjected to charging and discharging, so that the charging and discharging of the target battery may be stopped.

[0118] The embodiments of the present disclosure described above may not be limited to devices and methods, but may also be implemented by a program that implements functions corresponding to the components of the embodiments of the present disclosure or a recording medium storing the program. Those skilled in the art of the present disclosure may easily implement the program or recording medium based on the description of the above embodiments.

[0119] Although the present disclosure has been described using the embodiments and drawings, the present disclosure is not limited thereto. A person skilled in the art to which the present disclosure belongs may make various modifications and changes within the scope equivalent to the technical idea of ​​the present disclosure and the claims set forth below.

[0120] In addition, since ordinary technicians in the field can make various substitutions, modifications and changes to the present disclosure without departing from the technical ideas of the present disclosure, the present disclosure is not limited to the aforementioned embodiments and the drawings attached hereto, but can selectively combine all or some of the embodiments to achieve various modifications.

[0121] Reference numerals list

[0122] 1: Battery Pack

[0123] 100: Battery management device

[0124] 110: Measurement unit

[0125] 120: Control unit

[0126] 130: Storage unit

Claims

1. A battery management device, comprising: a measuring unit configured to measure voltages of a plurality of batteries connected in series to each other; as well as A control unit configured to estimate a state of charge (SOC) of the plurality of batteries based on the voltages, and control charging and discharging of the plurality of batteries so that the SOC of the plurality of batteries falls within a plurality of available SOC bands preset corresponding to the plurality of batteries.

2. The battery management device according to claim 1, wherein: The plurality of available SOC bands are divided based on a preset unavailable SOC band, and are set not to overlap with each other.

3. The battery management device according to claim 1, wherein: The control unit controls an operation state of a bypass switch connected in parallel to a bypass path arranged in each of the plurality of batteries to control the charging and discharging of the plurality of batteries.

4. The battery management device according to claim 3, wherein: During the charging of the plurality of batteries, the control unit selects a target battery having an SOC reaching an upper limit value of an available SOC band corresponding to the target battery, and controls the operation state of the bypass switch connected in parallel to the target battery to an on state.

5. The battery management device according to claim 3, wherein: During the discharging of the plurality of batteries, the control unit selects a target battery having an SOC reaching a lower limit value of an available SOC band corresponding to the target battery, and controls the operation state of the bypass switch connected in parallel to the target battery to an on state.

6. The battery management device according to claim 1, wherein: When discharging of the multiple batteries is requested even though the SOC of the multiple batteries has reached the lower limit value of the available SOC bands corresponding to the multiple batteries, the control unit sets the priorities among the multiple available SOC bands in descending order of the band values ​​of the multiple available SOC bands, and discharges the multiple batteries from the battery corresponding to the available SOC band with the highest priority to the battery corresponding to the available SOC band with the lowest priority.

7. The battery management device according to claim 6, wherein: When the SOC of the discharged battery reaches a lower limit value of an available SOC band having a next priority, the control unit discharges the battery corresponding to the available SOC band having the next priority.

8. The battery management device according to claim 1, wherein: The control unit sets intervals of the plurality of available SOC bands to be equal to each other.

9. The battery management device according to claim 1, wherein: The control unit sets the number of different batteries to correspond to each of the plurality of available SOC bands.

10. The battery management device according to claim 9, wherein: The control unit sets the number of the different batteries so that the larger the band value of an available SOC band is, the larger the number of the batteries corresponding to the SOC band is.

11. A battery pack comprising the battery management device according to any one of claims 1 to 10.

12. A battery management method, comprising: measuring the voltage of a plurality of batteries connected in series with each other; estimating a state of charge (SOC) of the plurality of batteries based on the voltages; as well as Charging and discharging of the plurality of batteries are controlled so that the SOCs of the plurality of batteries fall within a plurality of available SOC bands preset to correspond to the plurality of batteries.

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