Battery management device and method, and battery pack including the battery management device

Abstract

A battery management device according to one embodiment of the present invention includes a measurement unit configured to measure the voltages of a plurality of batteries connected in series with each other, and a control unit configured to estimate the SOCs of the plurality of batteries based on the voltages and control the charging and discharging of the plurality of batteries so that the SOCs of the plurality of batteries fall within a plurality of usable SOC intervals preset for the plurality of batteries.

Description

[Technical Field]

[0001] This application claims priority based on Korean Patent Application No. 10-2023-0018298, filed on February 10, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof.

[0002] The present invention relates to a battery management device and method, and a battery pack including the battery management device, and more particularly to a battery management device that controls a battery so as to efficiently use the battery, and a battery pack including the battery management device. [Background technology]

[0003] In recent years, as demand for portable electronic products such as laptops, video cameras, and mobile phones has grown rapidly and the development of electric vehicles, energy storage batteries, robots, and artificial satellites has gained momentum, active research has been conducted into high-performance batteries that can be repeatedly charged and discharged.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among these, lithium batteries are attracting attention due to their advantages of being able to be freely charged and discharged since they have almost no memory effect compared to nickel-based batteries, as well as their extremely low self-discharge rate and high energy density.

[0005] In graphite-based batteries, a staging phenomenon can occur, in which lithium is inserted between the graphite layers. In the staging phenomenon associated with the lithium insertion reaction, a transition from a higher stage to a lower stage is observed as the lithium insertion concentration increases. Meanwhile, the transition occurs in the opposite direction during the lithium desorption reaction (discharge reaction).

[0006] The SOC range where graphite staging occurs is called the staging range. A battery may deteriorate more when it is charged and discharged in the staging range than when it is charged and discharged in a range other than the staging range. That is, a battery that is charged and discharged in the staging range may deteriorate more than a battery that is not charged and discharged in the staging range.

[0007] Therefore, there is a need to develop technology that can extend the expected life of a battery by limiting charging and discharging in areas that may affect battery degradation. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been devised to solve the above problems, and aims to provide a battery management device and method for controlling the charging and discharging of a battery so as to extend the battery's lifespan, and a battery pack including the battery management device.

[0009] Other objects and advantages of the present invention can be understood from the following description and become more apparent from the embodiments of the present invention, and can be realized by the means and combinations thereof as set forth in the claims. [Means for solving the problem]

[0010] A battery management device according to one embodiment of the present invention includes a measurement unit configured to measure the voltages of multiple batteries connected in series with each other, and a control unit configured to estimate the SOCs of the multiple batteries based on the voltages and control the charging and discharging of the multiple batteries so that the SOCs of the multiple batteries fall within multiple usable SOC intervals preset for the multiple batteries.

[0011] The available SOC intervals may be divided based on a preset unused SOC interval and may be set so as not to overlap with each other.

[0012] The control unit may be configured to control charging and discharging of the plurality of batteries by controlling an operating state of a bypass switch located in a bypass path connected in parallel with each of the plurality of batteries.

[0013] The control unit may be configured to select a target battery whose SOC has reached an upper limit value of the corresponding usable SOC range during a charging process of the plurality of batteries, and to control the operation state of a bypass switch connected in parallel with the target battery to a turned-on state.

[0014] The control unit may be configured to select a target battery whose SOC has reached a lower limit value of the corresponding usable SOC range during a discharging process of the plurality of batteries, and control an operating state of a bypass switch connected in parallel with the target battery to a turned-on state.

[0015] The control unit may be configured to, when discharging of the plurality of batteries is requested even though the SOCs of the plurality of batteries have reached lower limits of corresponding usable SOC ranges, set priorities for the plurality of usable SOC ranges in descending order of range values, and discharge the corresponding batteries in descending order of priority.

[0016] The control unit may be configured to discharge the battery corresponding to the next-ranked usable SOC interval when the SOC of the battery to be discharged reaches a lower limit value of the next-ranked usable SOC interval.

[0017] The control unit may be configured to set the sizes of the available SOC intervals to be equal.

[0018] The control unit may be configured to set different numbers of batteries corresponding to each of the plurality of usable SOC ranges.

[0019] The control unit may be configured to set a larger number of corresponding batteries as the range values ​​of the plurality of usable SOC ranges become larger.

[0020] A battery pack according to another aspect of the present invention includes a battery management device according to an aspect of the present invention.

[0021] According to yet another aspect of the present invention, a battery management method includes a voltage measurement step of measuring voltages of a plurality of batteries connected in series with each other, an SOC estimation step of estimating SOCs of the plurality of batteries based on the voltages, and a charge / discharge control step of controlling charge / discharge of the plurality of batteries so that the SOCs of the plurality of batteries fall within a plurality of usable SOC intervals preset for the plurality of batteries. [Effects of the Invention]

[0022] A battery management device according to an aspect of the present invention can control charging and discharging of a plurality of batteries so that the SOC of the plurality of batteries does not fall within a non-use SOC interval.

[0023] According to one aspect of the present invention, the expected life span of a plurality of batteries can be increased, and uneven deterioration of the plurality of batteries can be prevented.

[0024] The effects of the present invention are not limited to the effects described above, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0025] The following drawings attached to this specification, together with the detailed description of the invention to be described later, serve to further understand the technical concept of the present invention, and the present invention should not be interpreted as being limited to the matters described in the drawings. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a diagram illustrating a battery management device according to an embodiment of the present invention; [Figure 2] 10 is a diagram schematically illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention. [Figure 3] 1 is a diagram illustrating a first embodiment according to the present invention; [Figure 4] 1 is a diagram illustrating a first embodiment according to the present invention; [Figure 5] 1 is a diagram illustrating a first embodiment according to the present invention; [Figure 6] 1 is a diagram illustrating a first embodiment according to the present invention; [Figure 7] 1 is a diagram illustrating a first embodiment according to the present invention; [Figure 8] FIG. 10 is a diagram illustrating a second embodiment of the present invention. [Figure 9] FIG. 10 is a diagram illustrating a second embodiment of the present invention. [Figure 10] FIG. 10 is a diagram illustrating a second embodiment of the present invention. [Figure 11] FIG. 10 is a diagram illustrating a second embodiment of the present invention. [Figure 12] FIG. 10 is a diagram illustrating a second embodiment of the present invention. [Figure 13] FIG. 10 is a diagram illustrating a battery management method according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] The terms and words used in this specification and claims should not be interpreted as being limited to their ordinary and dictionary meanings, but should be interpreted as having meanings and concepts that correspond to the technical ideas of the present invention, in accordance with the principle that the inventor himself can appropriately define the concepts of terms in order to best explain the invention.

[0028] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0029] Furthermore, in the description of the present invention, if it is determined that a detailed description of related known structures or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0030] Terms including ordinal numbers such as first, second, etc. are used to distinguish one of various components from other components, and do not limit the components.

[0031] Throughout this specification, when a part is said to "comprise" a certain element, this does not mean that it excludes other elements, but that it may further include other elements, unless otherwise specified.

[0032] Furthermore, throughout this specification, when a part is referred to as being "connected" to another part, this includes not only a "direct connection" but also an "indirect connection" via other elements.

[0033] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0034] FIG. 1 is a diagram illustrating a battery management system 100 according to an embodiment of the present invention.

[0035] Referring to FIG. 1, a battery management device 100 includes a measurement unit 110 and a control unit 120.

[0036] The measurement unit 110 may be configured to measure the voltages of a plurality of batteries B connected in series with each other.

[0037] Here, a battery refers to a single independent cell that has a negative terminal and a positive terminal and can be physically separated. For example, a lithium ion battery or a lithium polymer battery may be considered a battery. A battery may also refer to a battery module in which multiple cells are connected in series and / or parallel. Hereinafter, for convenience of explanation, a battery will be described as meaning a single independent cell.

[0038] The measurement unit 110 may be communicatively connected to the control unit 120. The measurement unit 110 may measure the voltage of each of the plurality of batteries B and transmit the measured voltage information to the control unit 120.

[0039] The control unit 120 may be configured to estimate the SOC (State of Charge) of the plurality of batteries B based on the voltages received from the measurement unit 110.

[0040] For example, the control unit 120 may estimate the SOC from the voltage of each of the plurality of batteries B using a table showing the correspondence between voltage and SOC. The table may be initially set based on a battery in a BOL (Beginning of Life) state. The table may then be updated to correspond to the degradation state of the plurality of batteries B. That is, the updated table may show the correspondence between voltage and SOC for a degraded battery.

[0041] The control unit 120 may be configured to control the charging and discharging of the plurality of batteries B so that the SOC of the plurality of batteries B falls within a plurality of usable SOC intervals preset for the plurality of batteries B.

[0042] Here, the usable SOC range may be divided based on a preset unused SOC range. The usable SOC ranges may be set so as not to overlap with each other. For example, the unused SOC range may be a preset SOC range that is set to be excluded from use due to the risk of accelerating battery degradation during charging and discharging. Specific examples of the unused SOC range include an SOC range including an SOC range of 90% to 100% where the battery is fully charged, an SOC range of 0% to 10% where the battery is fully discharged, and an SOC range known as a graphite staging range. Note that these are merely examples, and the unused SOC range may be further set experimentally depending on whether or not battery degradation is accelerated.

[0043] The control unit 120 may set a plurality of usable SOC intervals based on a preset unused SOC interval. The control unit 120 may then set a usable SOC interval corresponding to each of the plurality of batteries B.

[0044] For example, assume that four batteries are provided and a first usable SOC interval U1 and a second usable SOC interval U2 are set. The controller 120 may set the first battery B1 and the second battery B2 to correspond to the first usable SOC interval U1. The controller 120 may set the third battery B3 and the fourth battery B4 to correspond to the second usable SOC interval U2. That is, the controller 120 may arbitrarily set the corresponding usable SOC intervals without being based on the current SOC or voltage of the plurality of batteries B.

[0045] 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 the corresponding usable SOC intervals.

[0046] 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 the corresponding usable SOC interval.

[0047] For example, if the SOC of one battery reaches the lower limit of the corresponding usable SOC range, the control unit 120 may terminate discharging of the battery. Conversely, if the SOC of another battery reaches the upper limit of the corresponding usable SOC range, the control unit 120 may terminate charging of the battery.

[0048] That is, the battery management unit 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 within the unused SOC range. Therefore, according to one embodiment of the present invention, the expected life of the plurality of batteries B can be increased.

[0049] Meanwhile, the control unit 120 included in the battery management device 100 may selectively include a processor, an ASIC (Application-Specific Integrated Circuit), other chipsets, logic circuits, registers, a communication modem, a data processing device, etc., known in the art, to execute various control logics performed in the present invention. Furthermore, when the control logic is embodied as software, the control unit 120 may be embodied as a collection of program modules. In this case, the program modules may be recorded in memory and executed by the control unit 120. The memory may be provided inside or outside the control unit 120 and may be connected to the control unit 120 by various known means.

[0050] The battery management system 100 may further include a recording unit 130. The recording unit 130 may store data and programs necessary for each component of the battery management system 100 to operate and function, or data generated during the operation and function. The recording unit 130 may be any known information recording means capable of recording, erasing, updating, and reading data. For example, the information recording means may include RAM, flash memory, ROM, EEPROM, registers, etc. The recording unit 130 may also store program code defining processes executable by the control unit 120.

[0051] For example, the recording unit 130 may store information on unused SOC intervals, information on available SOC intervals, and information on the correspondence between a plurality of available SOC intervals and a plurality of batteries.

[0052] The control unit 120 may be configured to control the charging and discharging of the plurality of batteries B by controlling the operating state of the bypass switch S located in the bypass path connected in parallel with each of the plurality of batteries B.

[0053] Specifically, the plurality of batteries B may be connected in series to one another. Therefore, a bypass switch S may be connected in parallel to each of the plurality of batteries B for charge / discharge control by the control unit 120. The control unit 120 may control charge / discharge of the plurality of batteries B by controlling the operation state of the bypass switch S to a turn-on state or a turn-off state.

[0054] FIG. 2 is a diagram schematically illustrating an exemplary configuration of a battery pack 1 according to another embodiment of the present invention.

[0055] 2, 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 with the first battery B1, and the second bypass switch S2 may be connected in parallel with the second battery B2. The third bypass switch S3 may be connected in parallel with the third battery B3, and the fourth bypass switch S4 may be connected in parallel with the fourth battery B4.

[0056] The control unit 120 may be configured to select a target battery whose SOC has reached an upper limit of a corresponding usable SOC interval during the charging process 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 with the target battery to a turned-on state.

[0057] For example, in the embodiment of FIG. 2, assume that the SOC of the first battery B1 has reached the upper limit of the corresponding usable SOC range, and the SOCs of the second battery B2, the third battery B3, and the fourth battery B4 have not yet reached the upper limit of the corresponding usable SOC range. The controller 120 may select the first battery B1 as the target battery. The controller 120 may then control the operation state of the first bypass switch S1 to a turned-on state and the operation states of the second bypass switch S2, the third bypass switch S3, and the fourth bypass switch S4 to a turned-off state. In this case, charging of the first battery B1 may be terminated, and charging of the second battery B2, the third battery B3, and the fourth battery B4 may continue.

[0058] Conversely, the control unit 120 may be configured to select a target battery whose SOC has reached the lower limit of the corresponding usable SOC interval during the discharging process 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 with the target battery to a turned-on state.

[0059] For example, in the embodiment of FIG. 2, assume that the SOCs of the second battery B2 and the fourth battery B4 have reached the lower limits of their corresponding usable SOC ranges, and the SOCs of the first battery B1 and the third battery B3 have not yet reached the lower limits of their corresponding usable SOC ranges. The controller 120 may select the second battery B2 and the fourth battery B4 as the target batteries. The controller 120 may then control the operating states of the second bypass switch S2 and the fourth bypass switch S4 to a turned-on state and the operating states of the first bypass switch S1 and the third bypass switch S3 to a turned-off state. In this case, the discharge of the second battery B2 and the fourth battery B4 may be terminated, and the discharge of the first battery B1 and the third battery B3 may continue.

[0060] 3 to 7 are diagrams illustrating a first embodiment of the present invention.

[0061] In the following, in the first embodiment, it is assumed that a first unused SOC zone N1 is set to an SOC of more than 90% and less than 100%, a first usable SOC zone U1 is set to an SOC of 60% to 90%, a second unused SOC zone N2 is set to an SOC of more than 40% and less than 60%, a second usable SOC zone U2 is set to an SOC of 10% to 40% and a third unused SOC zone N3 is set to an SOC of 0% to less than 10%. It is also assumed that the first battery B1 and the second battery B2 are set to correspond to the first usable SOC zone U1, and the third battery B3 and the fourth battery B4 are set to correspond to the second usable SOC zone U2.

[0062] 3, the first battery B1, the second battery B2, the third battery B3, and the fourth battery B4 may initially be fully charged, i.e., the SOC of the first battery B1, the second battery B2, the third battery B3, and the fourth battery B4 may be 100%.

[0063] 4, the first battery B1, the second battery B2, the third battery B3, and the fourth battery B4 may be discharged, and the SOC of the first battery B1, the second battery B2, the third battery B3, and the fourth battery B4 may reach 60%, which is the lower limit of the first usable SOC interval U1.

[0064] The control unit 120 may set the first battery B1 and the second battery B2 as the target battery because the SOCs of the first battery B1 and the second battery B2 have reached the lower limit of the corresponding first usable SOC range U1. 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.

[0065] 5, the third battery B3 and the fourth battery B4 may continue to discharge, and the SOC of the third battery B3 and the fourth battery B4 may reach 10%, which is the lower limit of the second usable SOC interval U2.

[0066] Thereafter, the control unit 120 may control the charging and discharging of the first battery B1 and the second battery B2 within the first usable SOC range U1, and may control the charging and discharging of the third battery B3 and the fourth battery B4 within the second usable SOC range U2.

[0067] When discharge of the plurality of batteries B is requested even though the SOC of the plurality of batteries B has reached the lower limit value of the corresponding usable SOC range, the control unit 120 may set priorities among the plurality of usable SOC ranges in descending order of range value, and may be configured to discharge the corresponding batteries in descending order of priority.

[0068] Specifically, the control unit 120 may terminate the discharge of a target battery whose SOC reaches the lower limit of the corresponding usable SOC interval, while discharging the plurality of batteries B. However, even after the discharge of all of the plurality of batteries B has been terminated, a discharge request may still be received. In this case, the control unit 120 may prioritize the usable SOC intervals based on the interval values ​​of the plurality of usable SOC intervals.

[0069] Here, the interval value is a value included in the available SOC interval, and may be, for example, the upper limit, lower limit, average, or median value of the available SOC interval. Since multiple available SOC intervals do not overlap, the interval values ​​of multiple available SOC intervals cannot overlap either.

[0070] For example, in the example of Figure 5, the SOCs of the first battery B1, the second battery B2, the third battery B3, and the fourth battery B4 have all reached the lower limit of their corresponding usable SOC ranges. Therefore, under normal circumstances, the discharge of the first battery B1, the second battery B2, the third battery B3, and the fourth battery B4 should be terminated. However, because the first battery B1 and the second battery B2 can still be discharged, a discharge request continues.

[0071] The controller 120 may assign a higher priority to the first usable SOC interval U1 than to the second usable SOC interval U2 because the interval value of the first usable SOC interval U1 is greater than the interval value of the second usable SOC interval U2. The controller 120 may then additionally discharge the first battery B1 and the second battery B2 corresponding to the first usable SOC interval U1.

[0072] 6, the SOCs of the first battery B1 and the second battery B2 may reach the lower limit of the second usable SOC interval U2, and 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.

[0073] 7, the first battery B1 and the second battery B2 may be charged until the SOC reaches the upper limit of a first usable SOC interval U1, and the third battery B3 and the fourth battery B4 may be charged until the SOC reaches the upper limit of a second usable SOC interval U2. The controller 120 may control the charging and discharging of the first battery B1 and the second battery B2 within the first usable SOC interval U1, and the charging and discharging of the third battery B3 and the fourth battery B4 within the second usable SOC interval U2.

[0074] The battery management system 100 according to an embodiment of the present invention can increase the expected life of the battery by controlling the charging and discharging of the battery in a corresponding usable SOC range. However, if further discharging is required, the battery management system 100 may additionally discharge the battery.

[0075] 8 to 12 are diagrams illustrating a second embodiment of the present invention.

[0076] In the second embodiment, it is assumed that the following SOC zones are set: a first unused SOC zone N1 of over 90% and under 100% SOC, a first usable SOC zone U1 of between 70% and 90% SOC, a second unused SOC zone N2 of over 60% and under 70% SOC, a second usable SOC zone U2 of between 40% and 60% SOC, a third unused SOC zone N3 of over 30% and under 40% SOC, a third usable SOC zone U3 of between 10% and 30% SOC, and a fourth unused SOC zone N4 of between 0% and under 10% SOC. It is also assumed that the fifth battery B5 and the sixth battery B6 are set to correspond to the first usable SOC zone U1, the seventh battery B7 and the eighth battery B8 are set to correspond to the second usable SOC zone U2, and the ninth battery B9 and the tenth battery B10 are set to correspond to the third usable SOC zone U3.

[0077] Meanwhile, the usable SOC interval and unused SOC interval shown in Figures 7 and 8 are arbitrarily selected intervals for convenience of explanation. Therefore, a buffer interval (an SOC interval for preventing full charge and full discharge) and a graphite staging interval that are appropriately set through experiments may be set as the unused SOC interval. The usable SOC interval may then be set according to the set unused SOC interval. In other words, it should be noted that the usable SOC interval and unused SOC interval are not limited by the embodiments shown in Figures 7 and 8.

[0078] In the example of Figure 8, the SOC of the fifth battery B5 and the sixth battery B6 is 90%, which is equal to the upper limit of the first usable SOC interval U1. The SOC of the seventh battery B7 and the eighth battery B8 is 60%, which is equal to the upper limit of the second usable SOC interval U2. The SOC of the ninth battery B9 and the tenth battery B10 is 30%, which is equal to the upper limit of the third usable SOC interval U3.

[0079] In the example of Figure 9, 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 may be discharged. The SOC of the fifth battery B5 and the sixth battery B6 is 70%, which is equal to the lower limit of the first usable SOC interval U1. The SOC of the seventh battery B7 and the eighth battery B8 is 40%, which is equal to the lower limit of the second usable SOC interval U2. The SOC of the ninth battery B9 and the tenth battery B10 is 10%, which is equal to the lower limit of the third usable SOC interval U3.

[0080] If the discharge request continues, the control unit 120 may prioritize the first available SOC interval U1, the second available SOC interval U2, and the third available SOC interval U3 in this order according to the magnitude of the interval value.

[0081] 10, the fifth battery B5 and the sixth battery B6 may further discharge, causing the SOCs of the fifth battery B5 and the sixth battery B6 to reach the lower limit of the second usable SOC interval U2. If the fifth battery B5 and the sixth battery B6 further discharge, the fifth battery B5 and the sixth battery B6 may also discharge in the third unused SOC interval N3. In this case, the deterioration of the multiple batteries B may progress unevenly.

[0082] Therefore, in order to achieve balanced deterioration of multiple batteries B, the control unit 120 may be configured to discharge the battery corresponding to the next usable SOC range when the SOC of the battery to be discharged reaches the lower limit of the next usable SOC range.

[0083] 10, the SOCs of the fifth battery B5, the sixth battery B6, the seventh battery B7, and the eighth battery B8 are 40%, which is equal to the lower limit of the second usable SOC interval U2. If discharge requests continue, the control unit 120 may discharge the seventh battery B7 and the eighth battery B8, which correspond to the next usable SOC interval U2.

[0084] 11, the seventh battery B7 and the eighth battery B8 may be discharged. The SOC of the seventh battery B7 and the eighth battery B8 is 10%, which is equal to the lower limit of the third usable SOC interval U3. That is, the SOC of the seventh battery B7, the eighth battery B8, the ninth battery B9, and the tenth battery B10 is equal to the lower limit of the third usable SOC interval U3.

[0085] If the discharge request continues, the ninth battery B9 and the tenth battery B10, which correspond to the next third usable SOC section U3, cannot be discharged any further, and the fifth battery B5 and the sixth battery B6, which correspond to the first usable SOC section U1, may be discharged again.

[0086] 12, the fifth battery B5 and the sixth battery B6 may be discharged. The SOC of the fifth battery B5 and the sixth battery B6 is 10%, which is equal to the lower limit of the third usable SOC interval U3. That is, the SOC 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 are all equal to 10%.

[0087] In the subsequent charging process, the fifth battery B5 and the sixth battery B6 may be charged until their SOCs reach the upper limit of the first usable SOC interval U1, the seventh battery B7 and the eighth battery B8 may be charged until their SOCs reach the upper limit of the second usable SOC interval U2, and the ninth battery B9 and the tenth battery B10 may be charged until their SOCs reach the upper limit of the third usable SOC interval U3. The controller 120 may then control the charging and discharging of the fifth battery B5 and the sixth battery B6 within the first usable SOC interval U1, the seventh battery B7 and the eighth battery B8 within the second usable SOC interval U2, and the ninth battery B9 and the tenth battery B10 within the third usable SOC interval U3.

[0088] The battery management device 100 according to an embodiment of the present invention can control the charging and discharging of the plurality of batteries B so that the deterioration of the plurality of batteries B is balanced even when a discharge request continues.

[0089] The control unit 120 may be configured to set the interval sizes of the multiple available SOC intervals to be equal.

[0090] If the sizes of the available SOC sections are different, there is a risk that the deterioration of the battery will be uneven depending on the corresponding available SOC section.

[0091] For example, assume that the size of the N-1th available SOC interval is 30% and the size of the Nth available SOC interval is 40%. Here, the interval size refers to the range of SOC included in the available SOC interval and can be calculated using the formula "upper limit - lower limit."

[0092] In this case, the battery corresponding to the N-1th usable SOC interval will be charged and discharged within a 30% SOC range, while the battery corresponding to the Nth usable SOC interval will be charged and discharged within a 40% SOC range. Because the charge and discharge SOC intervals of the multiple batteries B are different, the battery corresponding to the Nth usable SOC interval may be more degraded than the battery corresponding to the N-1th usable SOC interval.

[0093] Therefore, the battery management unit 100 can prevent imbalance in deterioration of the plurality of batteries B by setting the sizes of the plurality of usable SOC intervals to be equal.

[0094] The control unit 120 may be configured to set different numbers of batteries corresponding to each of a plurality of usable SOC ranges.

[0095] Preferably, the control unit 120 may be configured to set a larger number of batteries as the range values ​​of the plurality of usable SOC ranges increase.

[0096] 8, if the number of batteries B is increased, the number of batteries corresponding to the first usable SOC interval U1 may be greater than the number of batteries corresponding to the second usable SOC interval U2, and then to the third usable SOC interval U3. That is, the number of batteries corresponding to the first usable SOC interval U1 may be the greatest, and the number of batteries corresponding to the third usable SOC interval U3 may be the least.

[0097] Batteries B may be initially fully charged (SOC 100%) and then discharged according to their corresponding usable SOC intervals. During this discharge process, batteries corresponding to lower usable SOC intervals must pass through more unused SOC intervals than batteries corresponding to higher usable SOC intervals. For example, in the example of FIG. 8, the fifth battery B5 and the sixth battery B6 discharge only through the first unused SOC interval N1, while the seventh battery B7 and the eighth battery B8 discharge through the first unused SOC interval N1 and the second unused SOC interval N2. Furthermore, the ninth battery B9 and the tenth battery B10 discharge through the first unused SOC interval N1, the second unused SOC interval N2, and the third unused SOC interval N3. That is, during this discharge process, the ninth battery B9 and the tenth battery B10, which correspond to the third usable SOC interval U3 with a lower interval value, may deteriorate more than the other batteries. Therefore, by setting the number of batteries corresponding to the usable SOC interval with a high interval value to be greater than the number of batteries corresponding to the usable SOC interval with a low interval value, the overall deterioration level of the multiple batteries can be reduced.

[0098] In view of this, the battery management unit 100 can increase the expected life of the plurality of batteries B by setting different numbers of corresponding batteries according to the range values ​​of the usable SOC ranges.

[0099] A battery management system 100 according to an embodiment of the present invention may be applied to a battery management system (BMS). That is, a BMS according to the present invention may include the above-described battery management system 100. In this configuration, at least some of the components of the battery management system 100 may be implemented by complementing or adding functions of components included in a conventional BMS. For example, the measurement unit 110, the control unit 120, and the recording unit 130 of the battery management system 100 may be implemented as components of a BMS.

[0100] The battery management system 100 according to an embodiment of the present invention may be included in a battery pack 1. That is, the battery pack 1 according to the present invention may include the above-described battery management system 100 and one or more battery cells. The battery pack 1 may further include electrical components (relays, fuses, etc.), a case, etc.

[0101] In the embodiment of FIG. 2, the positive terminal of battery B may be connected to the positive terminal P+ of battery pack 1, and the negative terminal of battery B may be connected to the negative terminal P− of battery pack 1.

[0102] An external device can 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 can be electrically connected.

[0103] For example, the external device may be a charge / discharge device, or may be a load such as a motor of an electric vehicle that receives power from a plurality of batteries B.

[0104] FIG. 13 is a diagram illustrating a battery management method according to yet another embodiment of the present invention.

[0105] Preferably, each step of the battery management method may be performed by the battery management device 100. Hereinafter, for convenience of explanation, the contents overlapping with the above explanation will be omitted or briefly explained.

[0106] Referring to FIG. 13, the battery management method includes a voltage measurement step S100, an SOC estimation step S200, and a charge / discharge control step S300.

[0107] The voltage measuring step S100 is a step of measuring the voltages of a plurality of batteries B connected in series with each other, and may be performed by the measuring unit 110.

[0108] Specifically, the measurement unit 110 can measure the voltage of each of the plurality of batteries B. Then, the measurement unit 110 can transmit the measured voltage information to the control unit 120.

[0109] The SOC estimation step S200 is a step of estimating the SOC of the plurality of batteries B based on the voltage, and may be performed by the control unit 120.

[0110] Specifically, the control unit 120 can estimate the SOC of each of the plurality of batteries B using a table that indicates the correspondence between voltage and SOC.

[0111] The charge / discharge control step S300 is a step of controlling the charge / discharge of the plurality of batteries B so that the SOC of the plurality of batteries B falls within a plurality of usable SOC intervals preset for the plurality of batteries B, and can be performed by the control unit 120.

[0112] Specifically, each of the plurality of batteries B may be preset to correspond to one of the plurality of usable SOC intervals, and the control unit 120 may control the charging and discharging of the plurality of batteries B so that the SOC of each of the plurality of batteries B falls within the corresponding usable SOC interval.

[0113] 2, the control unit 120 may set a target battery whose SOC has reached the lower limit of the corresponding usable SOC range and control the bypass switch S connected in parallel with the target battery to be turned on. In this case, the target battery is excluded from the charge / discharge process, and the charge / discharge of the target battery is interrupted.

[0114] The above-described embodiments of the present invention may be realized not only by an apparatus and a method, but also by a program that realizes functions corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such realization can be easily realized by a person skilled in the art from the description of the above-described embodiments.

[0115] As described above, the present invention has been described using limited embodiments and drawings, but the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the equivalent scope of the claims.

[0116] Furthermore, the present invention described above can be variously replaced, modified, and changed by a person having ordinary knowledge in the technical field to which the present invention belongs within the scope that does not deviate from the technical concept of the present invention, and is not limited to the above-described embodiments and the accompanying drawings, but can be configured by selectively combining all or part of each embodiment for various modifications. [Explanation of symbols]

[0117] 1: Battery pack 100: Battery management device 110: Measuring part 120: Control unit 130: Recording section

Claims

1. a measuring unit configured to measure the voltages of a plurality of batteries connected in series with one another; a control unit configured to estimate the SOC of the plurality of batteries based on the voltage, and to control charging and discharging of the plurality of batteries so that the SOC of the plurality of batteries falls within a plurality of usable SOC intervals preset for the plurality of batteries.

2. The plurality of usable SOC zones include: The battery management device according to claim 1 , wherein the battery management devices are divided based on preset unused SOC ranges and are set so as not to overlap each other.

3. The control unit 2. The battery management device according to claim 1, configured to control charging and discharging of the plurality of batteries by controlling the operating state of a bypass switch located in a bypass path connected in parallel with each of the plurality of batteries.

4. The control unit 4. The battery management device according to claim 3, wherein, in a charging process of the plurality of batteries, a target battery whose SOC has reached an upper limit value of the corresponding usable SOC section is selected, and an operating state of a bypass switch connected in parallel with the target battery is controlled to a turned-on state.

5. The control unit 4. The battery management device according to claim 3, wherein, during a discharge process of the plurality of batteries, a target battery whose SOC has reached a lower limit value of the corresponding usable SOC section is selected, and an operation state of a bypass switch connected in parallel with the target battery is controlled to a turned-on state.

6. The control unit 6. The battery management device according to claim 1, wherein, when discharge of a plurality of the batteries is requested even though the SOCs of the plurality of the batteries have reached the lower limit values ​​of the corresponding usable SOC ranges, the device is configured to set priorities for the plurality of usable SOC ranges in descending order of range values, and to discharge the corresponding batteries in descending order of priority.

7. The control unit 7. The battery management device according to claim 6, configured to discharge the battery corresponding to the next-order usable SOC section when the SOC of the battery to be discharged reaches a lower limit value of the next-order usable SOC section.

8. The control unit The battery management device according to claim 1 , wherein the battery management device is configured to set the sizes of the plurality of usable SOC intervals to be equal.

9. The control unit The battery management device according to claim 1 , wherein the number of batteries corresponding to each of the plurality of usable SOC sections is set to be different.

10. The control unit The battery management device according to claim 9 , configured to set a larger number of corresponding batteries as the range values ​​of the plurality of usable SOC ranges become larger.

11. A battery pack comprising the battery management device of claim 1.

12. a voltage measurement stage for measuring the voltages of a plurality of batteries connected in series with each other; an SOC estimation step of estimating an SOC of the plurality of batteries based on the voltages; a charge / discharge control step of controlling charge / discharge of the plurality of batteries so that the SOCs of the plurality of batteries are included within a plurality of usable SOC intervals preset for the plurality of batteries.

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