Battery management device and battery pack comprising the same

Abstract

A battery management device according to one embodiment of the present application includes a measurement unit for measuring a voltage of each of a plurality of battery cells, a converter connected to a corresponding battery cell among the plurality of battery cells and forming a charging or discharging path between the connected battery cells according to an operation state of a switch provided therein, and a control unit for receiving a voltage value of each of the plurality of battery cells from the measurement unit, controlling the operation state of the switch provided in the converter, calculating a voltage change rate of a cell charged by the converter according to the control of the operation state of the switch, and determining whether the charged cell is deteriorated based on the calculated voltage change rate.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a battery management device, and more particularly, to a battery management device for determining whether each of a plurality of battery cells is deteriorated and a battery pack including the same. BACKGROUND

[0002] Recently, the demand for portable electronic products such as notebook computers, camcorders, and portable phones has sharply increased, and electric vehicles, energy storage batteries, robots, satellites, etc. have been developed vigorously. Accordingly, high-performance batteries that allow repeated charging and discharging are being actively researched.

[0003] Currently commercially available batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, lithium batteries, etc. Among these batteries, lithium batteries are of great interest because they have almost no memory effect compared to nickel-based batteries and also have very low self-discharge rates and high energy densities.

[0004] Meanwhile, a battery can be deteriorated due to various factors. One of the indicators that measures the degree of deterioration of a battery is the internal resistance of the battery. Conventionally, various methods for estimating the aging of a battery using the internal resistance of the battery have been proposed.

[0005] As an example, Patent Document 1 discloses a battery aging diagnosis method and system. Here, an equivalent circuit model including a voltage source, an internal resistance, and a Warburg impedance is modeled as a battery, and the aging of the battery is diagnosed according to the internal resistance of the modeled battery.

[0006] However, in Patent Document 1, since the method of diagnosing the aging of the battery is configured differently depending on the presence or absence of an external resistance, there is a problem in that a separate process is required to determine the presence or absence of an external resistance before diagnosing the aging / deterioration of the battery. In addition, in Patent Document 1, since the aging of the battery is diagnosed based on the internal resistance of the modeled battery using a recursive least squares method or the like, there is a problem in that a large amount of time and system resources are required for diagnosis of the aging.

[0007] (Patent Document 1) KR 10-2019-0035441A SUMMARY

[0008] TECHNICAL PROBLEM

[0009] The disclosure aims to solve the problems of the related art, and thus an object of the disclosure is to provide a battery management device that can detect whether each battery cell is deteriorated due to internal resistance while a plurality of battery packs are being charged and discharged.

[0010] These and other objects and advantages of the present disclosure can be understood from the following detailed description, and will become more apparent from the exemplary embodiments of the present disclosure. Also, it will be easily understood that the objects and advantages of the present disclosure can be realized by the means shown in the claims and combinations thereof.

[0011] Technical Solution

[0012] In one aspect of the present disclosure, a battery management device is provided, including: a measurement unit configured to measure a voltage of each of a plurality of battery cells; a converter connected to a corresponding battery cell among the plurality of battery cells and configured to form a charge-discharge path between the connected battery cells according to an operating state of a switch included therein; and a control unit configured to receive a voltage value of each of the plurality of battery cells from the measurement unit, control the operating state of the switch included in the converter, calculate a voltage change rate of a charging cell charged by the converter according to the control of the operating state of the switch, and determine whether the charging cell is deteriorated based on the calculated voltage change rate.

[0013] The control unit can be configured to obtain an initial voltage value of the charging cell from the measurement unit, calculate a voltage change rate of the charging cell during a predetermined time based on the initial voltage value, and determine whether the charging cell is deteriorated according to a comparison result between the calculated voltage change rate and a reference rate.

[0014] The converter can be provided in plurality to be connected to a corresponding battery cell among the plurality of battery cells.

[0015] The control unit can be configured to control the operating state of the switch included in each of the plurality of converters and determine whether each charging cell charged by the plurality of converters is deteriorated.

[0016] The control unit can be configured to determine whether each of the plurality of battery cells is deteriorated by sequentially controlling the operating state of the switch included in the plurality of converters to an on state.

[0017] The control unit can be configured to select one target converter from among the plurality of converters every predetermined time interval and control the operating state of the switch included in the selected target converter to an on state.

[0018] The converter can include a first circuit in which the switch, a discharge cell corresponding to the charging cell, and a first inductor are connected in series, and a second circuit in which the charging cell and a second inductor corresponding to the first inductor are connected in series.

[0019] When the operation state of the switch is controlled to the on state, the second circuit can be configured to charge the charging unit using an induced electromotive force of the second inductor induced by the first inductor.

[0020] The second circuit can further include a third inductor connected in series between the second inductor and the charging unit, and when the operation state of the switch is changed from the on state to the off state, the second circuit can be configured to charge the charging unit using an induced electromotive force of the third inductor induced by a change in the induced electromotive force of the second inductor.

[0021] The measurement unit can be configured to measure a charging current of the charging unit.

[0022] The control unit can be configured to control the operation state of the switch such that a magnitude of the charging current measured by the measurement unit is included in a predetermined current range.

[0023] In another aspect of the disclosure, the battery management device can further include a cell selector connected between the plurality of battery units and the converter and configured to receive a cell selection command from the control unit and connect some of the plurality of battery units to the converter based on the received cell selection command.

[0024] A battery pack according to still another aspect of the disclosure can include a battery management device according to the disclosure.

[0025] Technical Effects

[0026] According to one aspect of the disclosure, since not only whether each of the plurality of battery units is deteriorated but also an internal resistance is estimated, accuracy and reliability of deterioration determination can be improved.

[0027] Further, according to one aspect of the disclosure, since the charging current is prevented from rapidly changing using the plurality of inductors, there is an advantage that deterioration of the battery unit caused by rapid change of the charging current can be prevented in advance.

[0028] Effects of the disclosure are not limited to the above, and those skilled in the art will clearly understand other effects not mentioned herein from the appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings illustrate preferred embodiments of the disclosure and, together with the foregoing disclosure, provide further understanding of the technical features of the disclosure, and therefore the disclosure is not construed as being limited to the accompanying drawings.

[0030] Figure 1 is a block diagram schematically illustrating a battery pack including a battery management device according to an embodiment of the disclosure.

[0031] Figure 2FIG. 1 is a diagram schematically showing a configuration of a battery pack including a battery management device according to an embodiment of the present disclosure.

[0032] Figure 3 FIG. 2 is a diagram schematically showing a battery pack including a battery management device according to an embodiment of the present disclosure.

[0033] Figure 4 FIG. 3 is a diagram showing a connection configuration between a converter and a battery cell of a battery management device according to an embodiment of the present disclosure.

[0034] Figure 5 FIG. 4 is a diagram showing a connection configuration of Figure 4 FIG. 5 is a diagram showing a current flow when an operation state of a switch provided in a first circuit is an on state in the connection configuration of

[0035] Figure 6 FIG. 6 is a diagram showing a current flow when an operation state of a switch provided in a first circuit is changed from an on state to an off state in the connection configuration of Figure 4

[0036] Figure 7 FIG. 7 is a diagram showing a current flow in the connection configuration of Figure 5 and Figure 6 FIG. 8 is a diagram showing a change in current with time in the current flow shown in

[0037] Figure 8 FIG. 9 is a diagram schematically showing a configuration of a battery pack including a battery management device according to another embodiment of the present disclosure.

[0038] Figure 9 FIG. 10 is a diagram showing an example of a current flow in the battery pack shown in Figure 8

[0039] (Explanation of Reference Signs)

[0040] 1: Battery pack

[0041] 10: Battery module

[0042] 100: Battery management device

[0043] 110: Measurement unit

[0044] 120: Converter

[0045] 120a: First converter

[0046] 120b: Second converter

[0047] 120c: Third converter

[0048] 120d: Fourth converter

[0049] ​​130: control unit

[0050] 140: cell selector

[0051] B1: first battery cell

[0052] B2: second battery cell

[0053] B3: third battery cell DETAILED DESCRIPTION

[0054] It should be understood that the terms used in the specification and the appended claims are not to be interpreted as limiting the general and dictionary meanings, but are to be interpreted in conjunction with the meaning and concepts of the technique corresponding to the technical aspects of the present disclosure based on the principle that the inventor is given the appropriate definitions to define the terms to obtain the best explanation of the present disclosure.

[0055] Accordingly, the description set forth herein is by way of example only and is not intended to limit the scope of the present disclosure, as it is appreciated that other equivalents and modifications of the disclosure will be apparent to those skilled in the art in view of the description set forth herein, and that the scope of the disclosure should be limited only by the claims and their equivalents.

[0056] Also, in describing the present disclosure, when it is considered that a detailed description of related known elements or functions makes the key subject of the present disclosure unclear, a detailed description is omitted herein.

[0057] The terms including ordinal numbers such as "first," "second," or the like can be used to distinguish one element from another element among various elements, but are not intended to limit the elements by the terms.

[0058] Throughout the specification, when a part is referred to as "including" or "comprising" any element, unless otherwise specifically stated, it means that the part can further include other elements, not excluding the other elements. Also, the term "control unit" described in the specification means a unit processing at least one function or operation, and can be implemented by hardware, software, or a combination of hardware and software.

[0059] Also, throughout the specification, when a part is referred to as "connected" to another part, it is not limited to the case where they are "directly connected", but also includes the case where they are "indirectly connected" with another element interposed therebetween.

[0060] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0061] Figure 1 is a block diagram schematically showing a battery pack 1 including a battery management device 100 according to an embodiment of the present disclosure. Figure 2 is a diagram schematically showing a configuration of a battery pack 1 including a battery management device 100 according to an embodiment of the present disclosure. Figure 3FIG. 1 is a diagram schematically illustrating a battery pack 1 including a battery management device 100 according to an embodiment of the disclosure.

[0062] Referring to Figure 1 and Figure 2 , the battery pack 1 can include a battery module 10 and the battery management device 100.

[0063] The battery module 10 can be a battery assembly including at least one battery cell. Here, the battery cell refers to one independent unit having a negative terminal and a positive terminal and being physically separable. For example, one pouch-type lithium polymer cell can be considered as a battery cell.

[0064] If a plurality of battery cells, such as 3 battery cells B1 to B3, are included in the battery module 10, the plurality of battery cells B1 to B3 can be connected in series and / or in parallel. For example, referring to Figure 1 , the battery module 10 can include a first battery cell B1, a second battery cell B2, and a third battery cell B3. The number of battery cells that can be included in the battery module 10 is not limited, but for convenience of description, it will be described that the first battery cell B1, the second battery cell B2, and the third battery cell B3 are included in the battery module 10.

[0065] In addition, referring to Figure 2 , the positive terminal of the battery module 10 can be connected to the positive terminal (P+) of the battery pack 1. The negative terminal of the battery module 10 can be connected to the negative terminal (P-) of the battery pack 1.

[0066] Referring to Figure 1 , the battery management device 100 can include a measurement unit 110, a converter 120, and a control unit 130.

[0067] The measurement unit 110 can be configured to measure a voltage of each of the plurality of battery cells B1 to B3.

[0068] Specifically, the measurement unit 110 can measure the voltage of each of the plurality of battery cells B1 to B3 by measuring potentials at both ends of the plurality of battery cells B1 to B3 and calculating a difference between the potentials measured at both ends.

[0069] For example, in an embodiment of Figure 3 , the measurement unit 110 can be connected to each of the plurality of battery cells B1 to B3 through a plurality of connected sensing lines. Specifically, the measurement unit 110 can be connected to the first battery cell B1 through a first sensing line SL1 and a second sensing line SL2 and to the second battery cell B2 through the second sensing line SL2 and a third sensing line SL3. In addition, the measurement unit 110 can be connected to the third battery cell B3 through the third sensing line SL3 and a fourth sensing line SL4.

[0070] In addition, the measurement unit 110 can measure the positive electrode potential of the first battery cell B1 through the first sensing line SL1 and measure the negative electrode potential of the first battery cell B1 through the second sensing line SL2. Furthermore, the measurement unit 110 can measure the voltage of the first battery cell B1 by calculating the difference between the measured positive electrode potential and the measured negative electrode potential of the first battery cell B1. In this way, the measurement unit 110 can measure the voltage of the second battery cell B2 and the voltage of the third battery cell B3.

[0071] The converter 120 can be configured to be connected to a corresponding battery cell among the plurality of battery cells B1 to B3. Here, the converter 120 can be a DC-DC converter that receives and converts a DC current and outputs the converted DC current. That is, the converter 120 can be connected to a battery cell that receives a DC current and a battery cell to which the converted DC current is applied.

[0072] For example, the converter 120 can be connected to the first battery cell B1 and the second battery cell B2 among the plurality of battery cells B1 to B3 as illustrated. Figure 1 In this case, the converter 120 can receive a DC current from the first battery cell B1, convert the received DC current, and output the converted DC current to the second battery cell B2.

[0073] In addition, the converter 120 can be configured to form a charge / discharge path between the connected battery cells according to the operation state of the switch included therein.

[0074] The converter 120 can include a switch therein to turn on / off the operation state of the converter 120.

[0075] For example, as in the previous embodiment, it is assumed that the converter 120 is connected to the first battery cell B1 and the second battery cell B2. The converter 120 can receive a DC current from the first battery cell B1 only when the operation state of the switch included therein is an on state. Thereafter, the converter 120 can convert the DC current input from the first battery cell B1. In addition, the converter 120 can output the converted DC current to the second battery cell B2. In this process, the first battery cell B1 can be discharged and the second battery cell B2 can be charged.

[0076] The control unit 130 can be configured to receive the voltage value of each of the plurality of battery cells B1 to B3 from the measurement unit 110.

[0077] Specifically, the control unit 130 can be electrically connected to the measurement unit 110. That is, the control unit 130 can be connected to the measurement unit 110 by wire and / or wirelessly, and can be configured to communicate with the measurement unit 110. Accordingly, the control unit 130 can receive a measured value measured by the measurement unit 110 from the measurement unit 110.

[0078] For example, with reference to an embodiment of Figure 3 the measurement unit 110 and the control unit 130 can be connected by a wired line. The measurement unit 110 can measure the voltage of each of the plurality of battery cells B1 to B3 through a plurality of sensing lines, and transmit the voltage value of the measured voltage to the control unit 130 in the form of a digital signal. The control unit 130 can receive the digital signal from the measurement unit 110 and interpret the digital signal to obtain the voltage value of each of the plurality of battery cells B1 to B3 measured by the measurement unit 110.

[0079] In addition, the control unit 130 can be configured to control the operation state of the switch included in the converter 120.

[0080] Specifically, the control unit 130 can be electrically connected to the converter 120 as well as the measurement unit 110. The converter 120 does not require a separate operation power source, and can be turned on / off according to the operation state of the switch included therein. Accordingly, the control unit 130 can be electrically connected to the switch included in the converter 120. That is, the control unit 130 can control the operation state of the switch to be in an on or off state by transmitting a signal to the switch included in the converter 120.

[0081] In addition, the control unit 130 can be configured to calculate the voltage change rate of the charging cell charged by the converter 120 according to the control of the operation state of the switch.

[0082] Here, the charging cell can be a battery cell to which a DC current output from the converter 120 is applied. That is, in the foregoing embodiment, the second battery cell B2 can correspond to the charging cell.

[0083] Specifically, the measurement unit 110 can continuously measure the voltage of the charging cell while the charging cell is being charged. In addition, the control unit 130 can receive the voltage value of the charging cell measured by the measurement unit 110 and calculate the voltage change rate while the charging cell is being charged.

[0084] Here, the voltage change rate can be the rate at which the voltage of the charging cell changes during the charging time. For example, based on the voltage value of the charging cell measured by the measurement unit 110, the control unit 130 can calculate the voltage change rate in which the voltage of the charging cell increases by how much compared to the initial charging stage.

[0085] Finally, the control unit 130 can be configured to determine whether the charging unit is deteriorated based on the calculated voltage change rate.

[0086] Preferably, the control unit 130 can determine whether the charging unit is deteriorated based on an absolute value of the calculated voltage change rate.

[0087] Considering Ohm's law, when the amount of current applied to the battery increases during the charging process and / or the internal resistance of the battery unit itself increases, the absolute value of the voltage change rate of the battery unit can increase while the battery unit is being charged. Accordingly, by determining whether the charging unit is deteriorated based on the calculated voltage change rate, the control unit 130 can determine whether the internal resistance of the charging unit increases and estimate the internal resistance value of the charging unit.

[0088] The battery management apparatus 100 has an advantage of determining whether the battery unit is deteriorated and estimating the internal resistance value of the battery unit with a simple circuit configuration of charging and discharging the battery unit by the converter 120.

[0089] Accordingly, even if a separate measuring device for measuring the internal resistance of the battery unit is not provided, the battery management apparatus 100 has an advantage of easily estimating the internal resistance of the battery unit.

[0090] Meanwhile, the control unit 130 provided to the battery management apparatus 100 can optionally include a processor, an application specific integrated circuit (ASIC), another chip set, a logic circuit, a register, a communication modem, a data processing device, etc. known in the art to perform various control logics performed in the present disclosure. In addition, when the control logic is implemented in software, the control unit 130 can be implemented as a set of program modules. In this case, the program modules can be stored in a memory and executed by the control unit 130.

[0091] That is, the memory can store data or programs required for the control unit 130 to determine whether the battery unit is deteriorated. That is, the memory can store data required for the operation and functions of each component of the battery management apparatus 100, data generated in the process of performing the operation or function, etc. The memory is not particularly limited in its kind as long as it is a known information storage device that can record, erase, update, and read data. As an example, the information storage device can include a RAM, a flash memory, a ROM, an EEPROM, a register, etc. In addition, the memory can store program codes in which processes executable by the control unit 130 are defined. The memory can be disposed inside or outside the control unit, or can be connected to the control unit 130 using a well-known means.

[0092] The control unit 130 can be configured to obtain an initial voltage value of the charging unit from the measuring unit 110.

[0093] The control unit 130 can obtain an initial voltage value of the charging unit to calculate a voltage change rate of the charging unit while the charging unit is being charged. Preferably, the control unit 130 can transmit an on command to the switch included in the converter 120 and then obtain the initial voltage value of the charging unit from the measurement unit 110. More preferably, the control unit 130 can transmit an on command to the switch and immediately acquire the initial voltage value of the charging unit from the measurement unit 110 after the lapse of a time until the on command reaches the switch.

[0094] The control unit 130 can be configured to calculate a voltage change rate of the charging unit for a predetermined time based on the initial voltage value.

[0095] That is, the control unit 130 can calculate a voltage change rate of the charging unit for a predetermined time based on the obtained initial voltage value. For example, if the initial voltage value of the charging unit obtained by the control unit 130 is 3.0 V and the voltage of the charging unit after the lapse of a predetermined time is 3.3 V, the control unit 130 can calculate the voltage change rate to be 10%.

[0096] In addition, the control unit 130 can be configured to determine whether the charging unit is deteriorated according to a comparison result of the calculated voltage change rate with a reference rate.

[0097] Here, the reference rate is a value stored in the control unit 130 or a separate storage unit, and can be a preset rate as a voltage change rate when a battery unit in a BOL (beginning of life) state and thus not deteriorated is charged for a predetermined time. Accordingly, the control unit 130 can determine whether the battery unit is deteriorated by comparing the reference rate with the voltage change rate.

[0098] In addition, the control unit 130 can estimate an internal resistance increase rate of the charging unit with respect to an internal resistance of a BOL battery unit by comparing the reference rate with the measured voltage change rate and comparing a current change amount at the time when the reference rate is set with a current change rate at the time when the charging unit is charged.

[0099] For example, assume that the preset reference rate is 8% and the voltage variation rate of the charging cell as calculated by the control unit 130 in the previous embodiment is 10%. Also, assume that the current variation amount during the predetermined time when the reference rate is set is the same as the current variation amount during the predetermined time when the charging cell is being charged. In this case, the control unit 130 can estimate that the internal resistance of the charging cell has increased by 2% compared to the internal resistance of the BOL battery cell. Thus, if the internal resistance of the BOL battery cell is known, the control unit 130 can estimate the internal resistance of the charging cell at the present time based on the voltage variation rate while the charging cell is being charged.

[0100] That is, since the battery management device 100 determines whether the charging cell is deteriorated by comparing the reference rate and the calculated voltage variation rate, it is possible to quickly determine whether the charging cell is deteriorated even if the charging cell is not fully charged but is charged only for a predetermined time. Also, the battery management device 100 is advantageous in that it is convenient to estimate the internal resistance value and whether the battery cell charged by the converter 120 is deteriorated.

[0101] The converter 120 can be provided in plural to be connected to a corresponding battery cell among the plurality of battery cells B1 to B3.

[0102] Each of the plurality of converters (e.g., 120a to 120c) can be connected to a corresponding battery cell among the plurality of battery cells (e.g., B1 to B3). Preferably, each of the plurality of converters 120a to 120c can be connected to a battery cell for introducing a DC current and a battery cell for outputting a converted DC current. That is, among the plurality of battery cells B1 to B3, two battery cells can form a pair and be connected to any one of the plurality of converters 120a to 120c.

[0103] For example, referring to Figure 3 Corresponding to the number of the plurality of battery cells B1 to B3 included in the battery module 10, the battery management device 100 can include a first converter 120a, a second converter 120b, and a third converter 120c.

[0104] The first converter 120a can be connected to the first battery cell B1 and the second battery cell B2. Specifically, the first converter 120a can be connected to the first battery cell B1 through the first line CL1 and the second line CL2 and to the second battery cell B2 through the third line CL3 and the fourth line CL4. Here, the first converter 120a can be configured to receive a DC current from the first battery cell B1 through the first line CL1 and the second line CL2 and output a converted DC current to the second battery cell B2 through the third line CL3 and the fourth line CL4.

[0105] Similarly, the second converter 120b can be connected to the second battery cell B2 via the fifth line CL5 and the sixth line CL6, and to the third battery cell B3 via the seventh line CL7 and the eighth line CL8.

[0106] Additionally, the third converter 120c can be connected to the third battery cell B3 via the ninth line CL9 and the tenth line CL10, and to the first battery cell B1 via the eleventh line CL11 and the twelfth line CL12.

[0107] The control unit 130 can be configured to control the operating state of the switches included in each of the plurality of converters 120a to 120c.

[0108] Specifically, a switch capable of turning the operating state of converter 120 on / off can be provided in each of the plurality of converters 120a to 120c. Control unit 130 can be electrically connected to the switch included in each of the plurality of converters 120a to 120c to send an on command or an off command.

[0109] For example, in Figure 3 In this embodiment, the control unit 130 can send a signal to the switch included in the first converter 120a via the first command line C1. Additionally, the control unit 130 can send a signal to the switch included in the second converter 120b via the second command line C2. Furthermore, the control unit 130 can send a signal to the switch included in the third converter 120c via the third command line C3.

[0110] Here, it is assumed that the control unit 130 outputs a shutdown signal via the first command line C1 and the third command line C3, and an activation signal via the second command line C2. Only the operation of the second converter 120b can be activated, and the current from the second battery cell B2 can flow into the second converter 120b via the fifth line CL5 and the sixth line CL6. Furthermore, the second converter 120b can output the converted current to the third battery cell B3 via the seventh line CL7 and the eighth line CL8. In this case, the second battery cell B2 can be discharged, and the third battery cell B3 can be charged. That is, the second battery cell B2 can be a discharging unit, and the third battery cell B3 can be a charging unit.

[0111] The control unit 130 can be configured to determine whether each charging unit charged by the plurality of converters 120a to 120c is degraded.

[0112] For example, in Figure 3In an embodiment of the battery management apparatus 100, the control unit 130 can discharge and charge all of the battery cells included in the battery module 10 according to a line in which a turn-on command is received among the first command line C1, the second command line C2, and the third command line C3. In this case, the control unit 130 can determine whether each of the plurality of battery cells B1 to B3 is deteriorated while each of the plurality of battery cells B1 to B3 is being charged.

[0113] Specifically, for example, in Figure 3 In an embodiment of the battery management apparatus 100, the control unit 130 can transmit a turn-on command through the first command line C1. Also, the control unit 130 can determine whether the second battery cell B2 serving as a charging cell is deteriorated. Thereafter, the control unit 130 can transmit a turn-on command through the third command line C3. Also, the control unit 130 can determine whether the first battery cell B1 serving as a charging cell is deteriorated.

[0114] That is, the battery management apparatus 100 is advantageous in that whether each of the plurality of battery cells B1 to B3 is deteriorated is determined without a complex circuit configuration by controlling the operation state of the switch included in each of the plurality of converters 120a to 120c.

[0115] Also, since the battery management apparatus 100 can independently control the switches included in the plurality of converters 120a to 120c, it is advantageous in that whether the plurality of battery cells B1 to B3 is deteriorated is selectively and independently determined.

[0116] The control unit 130 can be configured to sequentially control the operation state of the switches included in the plurality of converters 120a to 120c to the turn-on state.

[0117] The control unit 130 can control the operation state of the switches included in the plurality of converters 120a to 120c according to the identification numbers of the plurality of converters 120a to 120c. For example, the control unit 130 can sequentially control the operation state of the switches included in the first converter 120a, the second converter 120b, and the third converter 120c through the first command line C1, the second command line C2, and the third command line C3.

[0118] Also, the control unit 130 can sequentially control the plurality of converters 120a to 120c so that they are not repeatedly controlled. That is, the sequential control in this case can mean that the switches included in the plurality of converters 120a to 120c, respectively, are controlled only once without being repeatedly controlled. For example, in Figure 3In an embodiment of the present application, if it is assumed that the control unit 130 transmits the turn-on command through the first command line C1 multiple times, and transmits the turn-on command through the second command line C2 and the third command line C3 only once, the capacity and the degree of deterioration between the first battery unit B1, the second battery unit B2, and the third battery unit B3 can be different. Accordingly, the control unit 130 can be configured to transmit the turn-on command to the switch included in each of the plurality of converters 120a to 120c only once without repetition.

[0119] Preferably, in Figure 3 In an embodiment of the present application, the control unit 130 can output a turn-on signal through the first command line C1 to control the operation state of the switch included in the first converter 120a to the turn-on state. In addition, after a predetermined time elapses, the control unit 130 can output an off signal through the first command line C1 to control the operation state of the switch included in the first converter 120a to the off state.

[0120] Thereafter, the control unit 130 can output a turn-on signal through the second command line C2 to control the operation state of the switch included in the second converter 120b to the turn-on state. In addition, after a predetermined time elapses, the control unit 130 can output an off signal through the second command line C2 to control the operation state of the switch included in the second converter 120b to the off state.

[0121] Finally, the control unit 130 can output a turn-on signal through the third command line C3 to control the operation state of the switch included in the third converter 120c to the turn-on state. In addition, after a predetermined time elapses, the control unit 130 can output an off signal through the third command line C3 to control the operation state of the switch included in the third converter 120c to the off state.

[0122] That is, the control unit 130 can output a turn-on signal through different command lines at predetermined time intervals to sequentially control the operation state of the switch included in the plurality of converters 120a to 120c to the turn-on state or the off state.

[0123] As described above, if the control unit 130 sequentially controls the operation state of the switch included in the plurality of converters 120a to 120c, each of the plurality of battery units B1 to B3 can be charged and discharged at least once. That is, since the number of times of charge and discharge of the plurality of battery units B1 to B3 is maintained to be the same through the sequential control of the control unit 130, the performance deviation of the plurality of battery units B1 to B3 can be minimized.

[0124] In addition, the control unit 130 can be configured to determine whether each of the plurality of battery units B1 to B3 is deteriorated.

[0125] Specifically, the control unit 130 can sequentially control the operation state of the switches included in the plurality of converters 120a to 120c to determine whether the corresponding charging unit is deteriorated.

[0126] For example, as in the previous embodiment, if the control unit 130 outputs the turn-on signal through the first command line C1, since the second battery unit B2 is charged by the first converter 120a, the control unit 130 can determine whether the second battery unit B2 is deteriorated. Also, the control unit 130 can output the turn-off signal through the first command line C1.

[0127] Thereafter, if the control unit 130 outputs the turn-on signal through the second command line C2 at a predetermined time interval, since the third battery unit B3 is charged by the second converter 120b, the control unit 130 can determine whether the third battery unit B3 is deteriorated. Also, the control unit 130 can output the turn-off signal through the second command line C2.

[0128] Finally, if the control unit 130 outputs the turn-on signal through the third command line C3 at a predetermined time interval, since the first battery unit B1 is charged by the third converter 120c, the control unit 130 can determine whether the first battery unit B1 is deteriorated. Also, the control unit 130 can output the turn-off signal through the third command line C3.

[0129] That is, by sequentially outputting the turn-on signal through the plurality of command lines, the control unit 130 can sequentially determine whether each of the plurality of battery units B1 to B3 included in the battery module 10 is deteriorated.

[0130] The battery management device 100 can independently determine whether each of the plurality of battery units B1 to B3 included in the battery module 10 is deteriorated while minimizing the performance deviation of the plurality of battery units B1 to B3 by sequentially outputting signals for controlling the switches included in the plurality of converters 120a to 120c, respectively.

[0131] The control unit 130 can be configured to select one target converter at a predetermined time interval among the plurality of converters.

[0132] That is, the control unit 130 can select the target converter so that some of the battery units are not repeatedly determined to be deteriorated before completely determining whether the plurality of battery units B1 to B3 are deteriorated.

[0133] For example, control unit 130 can be configured to set individual flags to check which converters among the plurality of converters 120a to 120c are identified as degraded, and to select a target converter from among the converters not identified as degraded. Specifically, control unit 130 can set the flag for converters not identified as degraded to 0 and the flag for converters identified as degraded to 1. Additionally, control unit 130 can select a target converter from among the converters whose flags are set to 0.

[0134] Additionally, the control unit 130 can be configured to control the operating state of the switches included in the selected target converter to the ON state.

[0135] For example, in Figure 3 In this implementation, it is assumed that the first converter 120a, the second converter 120b, and the third converter 120c were not previously selected. The control unit 130 can select the first converter 120a as the target converter from among the first converter 120a, the second converter 120b, and the third converter 120c according to the converter identification number. In addition, the control unit 130 can control the operation state of the switches included in the first converter 120a to the on state by sending an on signal via the first command line C1 corresponding to the first converter 120a as the target converter.

[0136] When it is determined whether multiple battery cells B1 to B3 have deteriorated, the battery management device 100 can control multiple converters 120a to 120c the same number of times to maintain the same number of charge and discharge cycles for each battery cell. Therefore, by reducing the performance deviation among the multiple battery cells B1 to B3, the efficiency of the battery module 10 can ultimately be maximized.

[0137] In the following text, reference will be made to Figure 4 Describe the converter's internal configuration in detail.

[0138] Figure 4 This is a diagram showing the connection configuration between the converter 120 and the battery cell of a battery management device 100 according to an embodiment of the present disclosure.

[0139] Specifically, Figure 4 This diagram illustrates the connection configuration of the first battery unit B1, the second battery unit B2, and the first converter 120a.

[0140] More specifically, refer to Figure 4The first converter 120a can be connected to the positive terminal of the first battery cell B1 through a first line CL1, and the first converter 120a can be connected to the negative terminal of the first battery cell B1 through a second line CL2. Also, the first converter 120a can be connected to the positive terminal of the second battery cell B2 through a third line CL3, and the first converter 120a can be connected to the negative terminal of the second battery cell B2 through a fourth line CL4.

[0141] The converter 120 can be configured to include a first circuit in which the switch SW, the discharge cell corresponding to the charging cell, and the first inductor L1 are connected in series.

[0142] For example, in an embodiment of the disclosure, Figure 4 the closed circuit in which the first battery cell B1, the switch SW, and the first inductor L1 are connected in series can be the first circuit. That is, the first battery cell B1 connected to the first circuit can be regarded as a discharge cell that outputs a DC current to the first converter 120a.

[0143] Referring to an embodiment of the disclosure, Figure 4 one end of the switch SW can be directly connected to the positive terminal of the first battery cell B1, and the other end can be directly connected to one end of the first inductor L1. Also, the other end of the first inductor L1 can be directly connected to the negative terminal of the first battery cell B1, such that the first circuit forms a closed circuit. However, since Figure 4 the embodiment of the disclosure is an embodiment of the first circuit, the switch SW can also be provided between the first inductor L1 and the negative terminal of the first battery cell B1.

[0144] Also, the converter 120 can be configured to include a second circuit in which the charging cell and the second inductor L2 corresponding to the first inductor L1 are connected in series.

[0145] That is, in an embodiment of the disclosure, Figure 4 the circuit connecting the second battery cell B2 and the second inductor L2 can be the second circuit.

[0146] Specifically, the second circuit can include a first diode D1 for controlling the flow of a current caused by a second induced electromotive force generated at the second inductor L2. Here, the first diode D1 can be provided on the second circuit between the second inductor L2 and the positive terminal of the second battery cell B2, such that a direction toward the positive terminal of the second battery cell B2 is a forward direction.

[0147] The second circuit can be configured to charge the charging cell with an induced electromotive force of the second inductor L2 induced by the first inductor L1 when the operation state of the switch SW is controlled to be an on state.

[0148] For example, the first inductor L1 can be a primary coil, and the second inductor L2 can be a secondary coil. Accordingly, according to a change in current flowing through the first inductor L1 as a primary coil, an induced electromotive force can be induced at the second inductor L2 as a secondary coil. The second circuit can charge the charging unit with current generated by the induced electromotive force of the second inductor L2.

[0149] Specifically, if the operation state of the switch SW of the first circuit is controlled to be an on state, the battery unit provided in the first circuit can be discharged. In this case, current output from the battery unit can flow through the first inductor L1, and a magnetic field can be formed around the first inductor L1. The first inductor L1 and the second inductor L2 can be provided at a distance from each other that can be affected by the magnetic field formed around them.

[0150] Accordingly, since the magnetic field formed around the first inductor L1 affects the second inductor L2, an induced electromotive force can be induced at the second inductor L2. In addition, current can flow through the second circuit due to the induced electromotive force of the second inductor L2. In this case, the direction of the current flowing through the second circuit can be the forward direction of the first diode D1. Accordingly, the current generated by the induced electromotive force of the second inductor L2 can be applied to the positive terminal of the second battery unit B2, so that the second battery unit B2 can be charged.

[0151] Reference will be made to Figure 5 The direction of current flowing through the first circuit and the second circuit according to the operation state of the switch SW provided in the first circuit will be described in more detail.

[0152] Figure 5 is a diagram illustrating the flow of current when the operation state of the switch SW provided in the first circuit is an on state.

[0153] Reference will be made to Figure 5 If the operation state of the switch SW of the first circuit is controlled to be an on state, the first battery unit B1 provided in the first circuit can be discharged. In this case, current output from the battery unit can flow through the first inductor L1, and a magnetic field can be formed around the first inductor L1.

[0154] Referring to the direction of current of the first circuit, the direction of the magnetic field formed around the first inductor L1 can be the direction in which current flows through the first circuit. That is, the magnetism of the other end of the first inductor L1 connected to the negative terminal of the first battery unit B1 can be N, and the magnetism of one end of the first inductor L1 connected to the other end of the switch SW can be S.

[0155] A magnetic field can also be formed around the second inductor L2 due to the magnetic field formed around the first inductor L1.

[0156] In addition, the second inductor L2 can be affected by the magnetic field formed around the first inductor L1, such that an induced electromotive force is induced.

[0157] That is, referring to FIG. 1, Figure 5 The discharge current output from the first battery cell B1 can flow through the first circuit. In addition, a charging current that charges the second battery cell B2 based on the induced electromotive force generated at the second inductor L2 can flow in the second circuit. In this case, the charging current can flow to the positive terminal of the second battery cell B2.

[0158] In addition, the second circuit can include a capacitor C and a plurality of resistors R1, R2, Rout for smoothing the current formed by the induced electromotive force generated at the second inductor L2. Here, the capacitor C can be connected in parallel to the second battery cell B2 or the second inductor L2. In addition, among the plurality of resistors, the resistors R1, R2 can be connected in parallel to the second battery cell B2 or the second inductor L2. In addition, the resistor Rout can be connected in series to the second battery cell B2.

[0159] According to this configuration of the present disclosure, since the current flowing through the second circuit is smoothed by the capacitor C and the plurality of resistors R1, R2, Rout provided in the second circuit, noise included in the current flowing through the second circuit can be removed.

[0160] As a result, the second circuit can charge the second battery cell B2 with the current generated by the induced electromotive force of the second inductor L2 through the first diode D1.

[0161] The second circuit can be configured to further include a third inductor L3 connected in series between the second inductor L2 and the charging unit.

[0162] In the embodiment of FIG. 1, Figure 4 In the embodiment of FIG. 1, one end of the third inductor L3 can be connected to the other end of the first diode D1, and the other end of the third inductor L3 can be connected to the positive terminal of the second battery cell B2.

[0163] Therefore, referring to FIG. 1, Figure 5 If the switch SW provided in the first circuit is controlled to be in an on state, the current can flow from one end of the third inductor L3 to the other end of the third inductor L3. Preferably, the inductance of the second inductor L2 can be greater than or equal to the inductance of the third inductor L3. More preferably, the inductance of the second inductor L2 can be greater than the inductance of the third inductor L3.

[0164] Further, if the operation state of the switch SW changes from the on state to the off state, the second circuit can be configured to charge the charging unit using an induced electromotive force of the third inductor L3 induced by a change in the induced electromotive force of the second inductor L2.

[0165] In detail, if the operation state of the switch SW provided in the first circuit changes from the on state to the off state, since no current flows in the first circuit, a magnetic field formed around the first inductor L1 can disappear. In this case, the induced electromotive force of the second inductor L2 changes due to electromagnetic inertia, and a current generated by the induced electromotive force of the second inductor L2 can not flow through the second circuit due to the first diode D1.

[0166] In addition, an induced electromotive force of the third inductor L3 can be induced by electromagnetic inertia. The second circuit can charge the charging unit by applying a current generated by the induced electromotive force of the third inductor L3 to the positive terminal of the charging unit. That is, if the operation state of the switch SW changes from the on state to the off state, the third inductor L3 can output stored power to the charging unit. Therefore, the second circuit can charge the charging unit using the induced electromotive force of the third inductor L3.

[0167] Referring to Figure 6 The configuration in which a current flows through the first circuit and the second circuit according to the operation state of the switch SW provided in the first circuit will be described in more detail.

[0168] Figure 6 is a view illustrating a current flow when the operation state of the switch SW provided in the first circuit changes from the on state to the off state in the connection configuration of Figure 4

[0169] Referring to Figure 6 The second circuit can further include a second diode D2. One end of the second diode D2 can be connected between the other end of the first diode D1 and one end of the third inductor L3, and the other end of the second diode D2 can be connected between the other end of the second inductor L2 and the negative terminal of the second battery unit B2. That is, the second diode D2 can be connected in parallel to the second inductor L2 and the second battery unit B2, and a forward direction of the second diode D2 can be a direction toward the third inductor L3 and the positive terminal of the second battery unit B2.

[0170] ​If the switch SW provided in the first circuit changes to the off state, no current can flow in the first circuit. Also, due to electromagnetic inertia, the high potential and the low potential of the induced electromotive force of the second inductor L2 can change from each other. That is, one end of the second inductor L2 connected to one end of the first diode D1 can change to the low potential, and the other end of the second inductor L2 can change to the high potential. In this case, the current generated by the induced electromotive force of the second inductor L2 can not flow in the second circuit due to the first diode D1.

[0171] Meanwhile, when the operation state of the switch SW is the on state, the current can flow from one end of the third inductor L3 to the other end of the third inductor L3. Thereafter, if the operation state of the switch SW changes to the off state so that the current generated by the induced electromotive force of the second inductor L2 cannot flow in the second circuit, the induced electromotive force of the third inductor L3 can be due to electromagnetic inertia. In this case, one end of the third inductor L3 connected to the other end of the first diode D1 can be the low potential, and the other end side of the third inductor L3 can be the high potential. Accordingly, the third inductor L3 can output the stored power to the second battery cell B2, and at this time, the flow direction of the current can be the same as the forward direction of the second diode D2, as Figure 6 indicated.

[0172] In this way, even if the switch SW of the first circuit is controlled to the off state, the current can be supplied to the charging unit by the third inductor L3. That is, in the embodiment of Figure 6 , the current generated by the induced electromotive force of the third inductor L3 can be applied to the positive terminal of the second battery cell B2 so that the second battery cell B2 is charged. However, if the operation state of the switch SW changes from the on state to the off state, the size of the charging current applied to the second battery cell B2 can gradually decrease compared to when the operation state of the switch SW is the on state.

[0173] If the battery management apparatus 100 according to the embodiment of the disclosure is used, since the charging unit is charged using a plurality of inductors L1 to L3 and the induced electromotive force, it is possible to prevent the charging current from suddenly changing. Accordingly, it is possible to prevent the charging unit from deteriorating as the rapidly changing charging current is applied thereto.

[0174] In addition, the battery management apparatus 100 according to the embodiment of the disclosure can improve the accuracy and reliability of determining whether the charging unit is deteriorated by preventing the rapid change of the charging current.

[0175] The measuring unit 110 can be configured to measure the charging current of the charging unit.

[0176] For example, in the embodiment of the disclosure, the measuring unit 110 can measure the charging current of the charging unit by measuring the current flowing in the second circuit.Figure 4 In an embodiment of the present application, the measurement unit 110 can measure the voltage at both ends of the resistor Rout provided in the second circuit. In addition, the measurement unit 110 can calculate the charging current applied to the second battery unit B2 based on the difference between the resistance of the resistor Rout and the voltage at both ends of the resistor Rout.

[0177] As another example, in an embodiment of the present application, the measurement unit 110 can measure the voltage at both ends of the second resistor R2 provided in the second circuit. In addition, the measurement unit 110 can calculate the charging current applied to the second battery unit B2 based on the difference between the resistance of the second resistor R2 and the voltage at both ends of the second resistor R2. Figure 4

[0178] As another example, in an embodiment of the present application, the measurement unit 110 can measure the voltage at both ends of the second resistor R2 provided in the second circuit. In addition, the measurement unit 110 can calculate the charging current applied to the second battery unit B2 based on the difference between the resistance of the second resistor R2 and the voltage at both ends of the second resistor R2. Figure 4

[0179] The control unit 130 can be configured to control the operation state of the switch SW such that the magnitude of the charging current measured by the measurement unit 110 is included in a predetermined current range.

[0180] Hitherto, the flow of the charging current applied to the charging unit according to the operation state of the switch SW has been described with reference to Figure 5 and Figure 6 .

[0181] Hereinafter, the variation amount of the charging current according to the operation state of the switch SW will be described with reference to Figure 7 .

[0182] Figure 7 are graphs showing the variation of the current with time in the currents shown in Figure 5 and Figure 6 .

[0183] With reference to Figure 7 , 0(s) corresponds to the time at which the control unit 130 transmits an on command to the switch SW through the command line.

[0184] The variation of the current magnitude during the time between 0(s) and t1(s) corresponds to the variation of the charging current magnitude after the operation state of the switch SW is controlled from the off state to the on state. That is, if the control unit 130 transmits an on command to the switch SW through the command line at the time point 0(s), the magnitude of the charging current applied to the charging unit can gradually increase from 0 [A] to Imax [A]. ​​

[0185] That is, the change in the current size during the time between 0 (s) and t1 (s) can correspond to Figure 5 the change in the charging current size in the embodiment shown.

[0186] t1 (s) corresponds to the time when the control unit 130 sends an off command to the switch SW through the command line.

[0187] The change in the current size during the time between t1 (s) and t2 (s) corresponds to the change in the charging current size when the operating state of the switch SW is controlled from the on state to the off state. That is, if the control unit 130 sends an off command to the switch SW through the command line at the time point t1 (s), the size of the charging current applied to the charging unit can gradually decrease from Imax [A] to Imin [A].

[0188] That is, the change in the current size during the time between t1 (s) and t2 (s) can correspond to Figure 6 the change in the charging current size in the embodiment shown.

[0189] t2 (s) corresponds to the time when the control unit 130 sends an on command to the switch SW through the command line.

[0190] The change in the current size during the time between t2 (s) and t3 (s) corresponds to the change in the charging current size when the operating state of the switch SW is controlled from the off state to the on state. That is, if the control unit 130 sends an on command to the switch SW through the command line, the size of the charging current applied to the charging unit can gradually increase from Imin [A] to Imax [A].

[0191] Referring to the embodiment of Figure 7 , the control unit 130 can control the operating state of the switch SW provided in the converter 120 so that the size of the charging current applied to the charging unit is included in a predetermined current range (for example, in the range of Imin [A] to Imax [A]).

[0192] Preferably, if the magnitude of the charging current reaches the upper limit (Imax) of the predetermined current range, the control unit 130 can transmit an off command to the switch SW through the command line so that the magnitude of the charging current is contained within the predetermined current range and remains constant. In addition, if the magnitude of the charging current reaches the lower limit (Imin) of the predetermined current range, the control unit 130 can transmit an on command to the switch SW through the command line. That is, even if the state of the switch SW is controlled to the on state or the off state by the plurality of inductors L1 to L3, the magnitude of the charging current is gently increased or decreased, and thus the magnitude of the charging current can be contained within the predetermined current range.

[0193] In this way, the control unit 130 can constantly maintain the magnitude of the charging current within a certain range by controlling the operation state of the switch SW provided in the converter 120. In addition, since the charging current is prevented from changing too much and is maintained within a certain range, the control unit can easily identify the internal resistance value of the charging unit (i.e., its deterioration rate) by calculating the voltage variation rate of the charging unit within a predetermined time without considering the current variation rate.

[0194] Considering Ohm's law, in the case where the magnitude of the charging current is maintained constant, the voltage can be proportional to the resistance. Thus, if the internal resistance value of the charging unit increases, it can be determined that the voltage variation rate of the charging unit also increases more than the reference rate.

[0195] Thus, the control unit 130 can compare the voltage variation rate of the measured charging unit with the reference rate by maintaining the magnitude of the charging current relatively constant, and estimate the internal resistance value of the charging unit based on the result. For example, assuming that the magnitude of the charging current is maintained constant and the reference rate is 8%. If the voltage variation rate of the charging unit measured during a predetermined time is 10%, the control unit 130 can estimate that the charging unit is deteriorated and the internal resistance value of the charging unit is increased by about 2% compared to the BOL battery unit.

[0196] Thus, the battery management device 100 can prevent the charging current from rapidly changing by means of the plurality of inductors L1 to L3 included therein.

[0197] In addition, the battery management device 100 can estimate the internal resistance value of the battery unit through the amount of voltage variation of the battery unit without a separate device by controlling the switch SW to maintain the magnitude of the charging current constant. Thus, since the internal resistance value of the battery unit is estimated together, it is not only possible to determine whether the battery unit is deteriorated, but also to improve the accuracy and reliability of determining whether the battery unit is deteriorated.

[0198] Figure 8 FIG. 1 is a diagram schematically illustrating a configuration of a battery pack 1 including a battery management device 100 according to an embodiment of the disclosure.

[0199] In the following text, features that differ from those of the battery management device 100 described above will be described, and features that are the same as those of the device will not be described.

[0200] at the same time, Figure 8 The fourth converter 120d shown is intended to refer to a converter different from the first converter 120a, second converter 120b, and third converter 120c in the preceding figures. Therefore, according to... Figure 8 The battery management device 100 of the embodiment may not include the first converter 120a, the second converter 120b, and the third converter 120c. Similarly, the thirteenth line CL13, the fourteenth line CL14, the fifteenth line CL15, and the sixteenth line CL16 are also intended to refer to lines different from the first lines CL1 to twelfth lines CL12 in the previous figures. Similarly, the fourth command line C4 is also intended to refer to a line different from the first command lines C1 to third command lines C3 in the previous figures.

[0201] Reference Figure 1 and Figure 8 The battery management device 100 may also include a cell selection unit 140.

[0202] The cell selector 140 can be configured to connect between multiple battery cells B1 to B3 and the converter 120.

[0203] One side of the cell selector 140 can be connected to each of the plurality of battery cells B1 to B3 included in the battery module 10, and the other side of the cell selector 140 can be connected to the converter 120. In this case, the battery management device 100 may include a converter 120.

[0204] Preferably, the cell selector 140 can be connected to each of the plurality of battery cells B1 to B3 via at least two wires. That is, the cell selector 140 can be connected to both the positive and negative terminals of each of the plurality of battery cells B1 to B3.

[0205] For example, in Figure 8 In this embodiment, the unit selector 140 can be connected to the positive and negative terminals of the first battery unit B1 via the first unit selection line CS1 and the second unit selection line CS2. Additionally, the unit selector 140 can be connected to the positive and negative terminals of the second battery unit B2 via the third unit selection line CS3 and the fourth unit selection line CS4. Furthermore, the unit selector 140 can be connected to the positive and negative terminals of the third battery unit B3 via the fifth unit selection line CS5 and the sixth unit selection line CS6.

[0206] Additionally, refer toFigure 8 The cell selector 140 can be connected to the fourth converter 120d through a total of four lines. Here, two lines can be connected to the first circuit of the fourth converter 120d, and the other two lines can be connected to the second circuit thereof. Specifically, the cell selector 140 can be connected to the first circuit of the converter 120 through the thirteenth line CL13 and the fourteenth line CL14 and to the second circuit of the fourth converter 120d through the fifteenth line CL15 and the sixteenth line CL16.

[0207] The cell selector 140 can be configured to receive a cell selection command from the control unit 130.

[0208] Referring to Figure 8 The control unit 130 can transmit a cell selection command to the cell selector 140 through a cell selection command line S.

[0209] For example, the control unit 130 can transmit a command to connect the first battery cell B1 to the discharging unit and the second battery cell B2 to the charging unit to the cell selector 140 through the cell selection command line S.

[0210] The cell selector 140 can be configured to connect some of the plurality of battery cells B1 to B3 to the converter 120 based on the received cell selection command.

[0211] Specifically, a plurality of connection switches can be included in the cell selector 140. The cell selector 140 can connect some of the battery cells corresponding to the cell selection command to the converter 120 by controlling the operation state of each of the plurality of connection switches corresponding to the received cell selection command.

[0212] For example, as in the previous embodiment, it is assumed that the control unit 130 transmits a cell selection command to the cell selector 140 to connect the first battery cell B1 to the discharging unit and the second battery cell B2 to the charging unit. In this case, the cell selector 140 can internally connect the thirteenth line CL13 and the first cell selection line CS1 and the fourteenth line CL14 and the second cell selection line CS2 to connect the first battery cell B1 to the first circuit of the fourth converter 120d. In addition, the cell selector 140 can internally connect the fifteenth line CL15 and the third cell selection line CS3 and the sixteenth line CL16 and the fourth cell selection line CS4 to connect the second battery cell B2 to the second circuit of the fourth converter 120d.

[0213] The current flow when the first battery cell B1 and the second battery cell B2 are connected to the converter 120 through the cell selector 140 will be described with reference to Figure 9 ​

[0214] Figure 9 is shown in FIG. 1. Figure 8 is a diagram showing an example of current flow in the battery pack 1 shown in FIG. 1.

[0215] Referring to Figure 9 , the first battery cell B1 connected to the first circuit of the fourth converter 120d can be discharged, and the second battery cell B2 connected to the second circuit of the fourth converter 120d can be charged by the electromotive force induced by the discharge of the first battery cell B1.

[0216] Thereafter, the control unit 130 can determine whether the second battery cell B2 serving as a charging cell is deteriorated by controlling the operation state of the switch SW provided in the fourth converter 120d to the on state or the off state through the fourth command line C4. In addition, the control unit 130 can also estimate the internal resistance value of the second battery cell B2 by maintaining the magnitude of the charging current within the predetermined current range.

[0217] That is, the battery management device 100 can further include the cell selector 140 to connect the battery cell selected by the control unit 130 among the plurality of battery cells B1 to B3 to the converter 120. That is, the battery management device 100 can select various combinations of the discharging cell and the charging cell and connect the corresponding battery cells to the converter 120, rather than sequentially connecting each of the plurality of battery cells B1 to B3 to the converter 120 according to the predetermined arrangement of the battery cells.

[0218] Therefore, since the battery management device 100 can selectively determine whether some of the plurality of battery cells B1 to B3 are deteriorated, determination of whether the battery cells are deteriorated can be flexibly performed.

[0219] The battery management device 100 according to the present disclosure can be applied to a battery management system (BMS). That is, the BMS according to the present disclosure can include the above-described battery management device 100. In this configuration, at least some components of the battery management device 100 can be implemented by supplementing or adding the functions of the components included in a conventional BMS. For example, the measurement unit 110, the converter 120, the control unit 130, and the cell selector 140 can be implemented as components of the BMS. Furthermore, the BMS can utilize at least one of the components of the battery management device 100 to balance the plurality of battery cells B1 to B3 or diagnose the insulation resistors of each of the plurality of battery cells B1 to B3.

[0220] In addition, the battery management device 100 according to the present disclosure can be provided in the battery pack 1. That is, the battery pack 1 according to the present disclosure can include the above-described battery management device 1. Here, the battery pack 1 can include a battery module 10 having at least one battery cell, the battery management device 100, an electrical device (a relay, a fuse, etc.), and a case.

[0221] The above-described embodiments of the present disclosure can be implemented not only by a device and a method but also by a program for implementing functions corresponding to the configuration of the embodiments of the present disclosure or a recording medium on which the program is recorded. From the above description of the embodiments, a person skilled in the art can easily implement the program or the recording medium.

[0222] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by way of illustration only, since various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from this detailed description.

[0223] In addition, since a person skilled in the art can replace, modify, and change the above-described present disclosure in various ways without departing from the technical idea of the present disclosure, the present disclosure is not limited to the above-described embodiments and drawings, and all or some of the embodiments can be selectively combined together to implement various modifications.

[0224] This application claims priority to Korean Patent Application No. 10-2019-0119917, filed on September 27, 2019, in the Republic of Korea, the disclosure of which is incorporated herein by reference.

Claims

1. A battery management device, comprising: a measurement unit configured to measure a voltage of each of a plurality of battery cells; a converter connected to a corresponding battery cell among the plurality of battery cells and configured to form a charge-discharge path between the connected battery cells according to an operation state of a switch included in the converter; and a control unit configured to receive a voltage value of each of the plurality of battery cells from the measurement unit, control the operation state of the switch included in the converter, calculate a voltage change rate of a charge cell charged by the converter according to the control of the operation state of the switch, and determine whether the charge cell is deteriorated based on the calculated voltage change rate, wherein the converter includes: a first circuit in which the switch, a discharge cell corresponding to the charge cell, and a first inductor are connected in series; and a second circuit in which the charge cell, a first diode, and a second inductor corresponding to the first inductor are connected in series, wherein, when the operation state of the switch is controlled to an on state, the second circuit is configured to charge the charge cell with an induced electromotive force of the second inductor induced by the first inductor, wherein the second circuit further includes a third inductor connected in series between the second inductor and the charge cell, a second diode connected in parallel with the second inductor and the charge cell, a capacitor connected in parallel with the charge cell, a plurality of resistors, and a resistor connected in series with the charge cell, and wherein, when the operation state of the switch is changed from the on state to an off state, the second circuit is configured to charge the charge cell with an induced electromotive force of the third inductor induced by a change in the induced electromotive force of the second inductor. 2.The battery management device according to claim 1, wherein the control unit is configured to obtain an initial voltage value of the charge cell from the measurement unit, calculate a voltage change rate of the charge cell during a predetermined time based on the initial voltage value, and determine whether the charge cell is deteriorated according to a comparison result between the calculated voltage change rate and a reference rate. 3.The battery management device according to claim 1, wherein the converter is provided as a plurality of converters to be connected to corresponding battery cells among the plurality of battery cells, and wherein the control unit is configured to control the operation state of the switch included in each of the plurality of converters and determine whether each charge cell charged by the plurality of converters is deteriorated. 4.The battery management device according to claim 3, wherein the control unit is configured to determine whether each of the plurality of battery cells is deteriorated by sequentially controlling the operation state of the switch included in the plurality of converters to the on state. 5.The battery management device according to claim 4, wherein The control unit is configured to select a target converter from among the plurality of converters every predetermined time interval, and control the operation state of a switch included in the selected target converter to an on state.

6. The battery management device of claim 1, wherein, The first diode is used to control the flow of current caused by a second induced electromotive force generated at the second inductor.

7. The battery management device according to claim 1, wherein, The measurement unit is configured to measure a charging current of the charging unit, and The control unit is configured to control the operation state of the switch such that the magnitude of the charging current measured by the measurement unit is contained within a predetermined current range.

8. The battery management device according to claim 1, further comprising: a cell selector connected between the plurality of battery cells and the converter, and configured to receive a cell selection command from the control unit and connect some of the plurality of battery cells to the converter based on the received cell selection command.

9. The battery management device of claim 8, wherein, The cell selector includes a plurality of connection switches, and the cell selector connects some of the battery cells corresponding to the cell selection command to the converter by controlling the operation state of each of the plurality of connection switches corresponding to the received cell selection command.

10. A battery pack including the battery management device according to any one of claims 1 to 9.

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