Battery management method, battery management device and battery pack for performing the same

Abstract

To ensure rapid state balancing between a replaced battery module and an existing battery module.SOLUTION: A battery management device for a battery pack 10 including a plurality of battery modules includes a detection device for detecting status information of battery cells constituting a plurality of battery modules and a control device that, when at least one battery module is replaced, enters a replacement mode and activates a first protection function that performs balancing for the plurality of battery modules and, while operating in the replacement mode, performs a protective operation due to a state imbalance within each battery module. When the first protection function is activated, the control device detects a cell voltage or SOC imbalance condition for each of the plurality of battery modules on the basis of condition information. When a battery module is detected among the plurality of battery modules whose imbalance state satisfies a preset first condition, the protective operation is performed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a battery management method, a battery management device, and a battery pack that perform the method.

Background Art

[0002] A secondary battery differs from a primary battery that provides only irreversible conversion of chemical substances into electrical energy in that charging and discharging can be repeated. Low-capacity secondary batteries are used as power sources for small electronic devices such as mobile phones, notebook computers, and camcorders, and high-capacity secondary batteries are used as power sources for hybrid vehicles and the like.

[0003] Generally, a secondary battery cell includes an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, a case that houses the electrode assembly, and electrode terminals electrically connected to the electrode assembly. An electrolytic solution is injected into the case to enable charging and discharging of the battery cell through electrochemical reactions of the positive electrode, the negative electrode, and the electrolytic solution. The shape of the case, such as cylindrical or rectangular, varies depending on the use of the battery cell.

[0004] Battery cells can be connected in series and / or in parallel with each other to form a battery module having a high energy density. A battery pack can be configured to include one or more such battery modules according to required specifications.

[0005] Conventionally, even if a failure occurs in any one of the battery cells or battery modules that make up a battery pack, the entire battery pack has to be replaced, resulting in excessive replacement costs. Therefore, recently, attempts have continued to replace only the failed battery cell or battery module.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The problem to be solved through the present disclosure is to enable replacement of only a malfunctioning battery module, and when the battery module is replaced, to provide a battery management method capable of quickly performing state balancing such as voltage or capacity between the replaced battery module and existing battery modules, and a battery management device and a battery pack for performing the same.

Means for Solving the Problems

[0007] A battery management device for a battery pack including a plurality of battery modules according to an embodiment for solving the above problems includes a detection device that detects state information of battery cells constituting the plurality of battery modules, and when at least one battery module among the plurality of battery modules is replaced, enters an exchange mode to perform balancing on the plurality of battery modules, and includes a control device that activates a first protection function for performing a protection operation due to state imbalance within each battery module while operating in the exchange mode. When the first protection function is activated, the control device detects an imbalance state of cell voltage or SOC (state of charge) for each of the plurality of battery modules based on the state information, and when a battery module that satisfies a first condition in which the imbalance state is preset is detected among the plurality of battery modules, the control device can execute the protection operation.

[0008] When the first protection function is activated, the control device obtains a voltage difference between a battery cell with the maximum cell voltage and a battery cell with the minimum cell voltage for each of the plurality of battery modules, and when a battery module having a voltage difference equal to or greater than a critical value is detected among the plurality of battery modules, the control device can execute the protection operation.

[0009] When the first protection function is activated, the control device obtains the SOC difference between the battery cell with the maximum SOC and the battery cell with the minimum SOC for each of the plurality of battery modules, and when a battery module among the plurality of battery modules having an SOC difference equal to or greater than a critical value is detected, the protection operation can be executed.

[0010] Before at least one of the battery modules is replaced or after the balancing of the plurality of battery modules in the replacement mode is completed, the control device operates in the normal mode, and while operating in the normal mode, a second protection function for performing the protection operation due to state imbalance in the battery pack is activated. When the second protection function is activated, the imbalance state of the cell voltage or SOC of the entire plurality of battery modules is detected based on the state information, and when the imbalance state of the cell voltage or SOC of the entire plurality of battery modules satisfies a preset second condition, the protection operation can be executed.

[0011] When the second protection function is activated, the control device obtains the voltage difference between the battery cell with the maximum cell voltage and the battery cell with the minimum cell voltage of the entire plurality of battery modules, and when the voltage difference is equal to or greater than a critical value, the protection operation can be executed.

[0012] When the second protection function is activated, the control device obtains the SOC difference between the battery cell with the maximum SOC (state of charge) and the battery cell with the minimum SOC of the entire plurality of battery modules, and when the SOC difference is equal to or greater than a critical value, the protection operation can be executed.

[0013] While operating in the replacement mode, the control device can deactivate the second protection function.

[0014] While operating in the exchange mode, the control device can deactivate the second protection function by not executing the function for performing the second protection function.

[0015] While operating in the exchange mode, the control device can also deactivate the second protection function by adjusting the threshold value constituting the second condition upward so that the protection operation is not executed.

[0016] While operating in the normal mode, the control device can deactivate the first protection function.

[0017] The control device can detect the replacement of the battery module based on the replacement information received from at least one of an input device, an external terminal, or a host controller.

[0018] The control device can also detect the replacement of the battery module by comparing the identification information received from the plurality of battery modules with the previously stored identification information.

[0019] While operating in the exchange mode, the control device can allow only one of charging and discharging for the plurality of battery modules.

[0020] A battery pack according to an embodiment can include a plurality of battery modules connected in series with each other and a battery management device including at least one of the above-described features.

[0021] According to one embodiment, a battery management method for a battery pack including a plurality of battery modules includes the steps of switching to an exchange mode when an exchange of a battery module is detected, balancing the plurality of battery modules in a state where only one of charging and discharging is allowed while operating in the exchange mode, and performing a first protection function that causes a protection operation to be executed due to state imbalance within each battery module while operating in the exchange mode. The step of performing the first protection function includes obtaining a first imbalance state of cell voltage or SOC for each of the plurality of battery modules, and when a battery module that satisfies a first condition in which the first imbalance state is preset is detected among the plurality of battery modules, causing the protection operation to be executed.

[0022] The step of obtaining the first imbalance state may include obtaining a voltage difference between a battery cell with the maximum cell voltage and a battery cell with the minimum cell voltage for each of the plurality of battery modules, or obtaining an SOC difference between a battery cell with the maximum SOC and a battery cell with the minimum SOC for each of the plurality of battery modules. The step of causing the protection operation to be executed may include causing the protection operation to be executed when a battery module among the plurality of battery modules having a voltage difference equal to or greater than a critical value is detected, or causing the protection operation to be executed when a battery module among the plurality of battery modules having an SOC difference equal to or greater than a critical value is detected.

[0023] The battery management method may further include a stage of operating in a normal mode if the replacement of the battery module is not detected, a stage of controlling the charging and discharging of the plurality of battery modules according to the states of the plurality of battery modules during the operation in the normal mode, and a stage of performing a second protection function of executing the protection operation due to state imbalance in the entire plurality of battery modules during the operation in the normal mode. The stage of performing the second protection function may include a stage of obtaining a second imbalance state of cell voltage or SOC for the entire plurality of battery modules, and a stage of executing the protection operation when the second imbalance state satisfies a preset second condition.

[0024] The stage of obtaining the second imbalance state may include a stage of obtaining a voltage difference between the battery cell with the maximum cell voltage and the battery cell with the minimum cell voltage for the entire plurality of battery modules, or a stage of obtaining an SOC difference between the battery cell with the maximum SOC and the battery cell with the minimum SOC for the entire plurality of battery modules. The stage of executing the protection operation may include a stage of executing the protection operation when the voltage difference is equal to or greater than a critical value, or a stage of executing the protection operation when the SOC difference is equal to or greater than a critical value.

[0025] The battery management method may further include a stage of deactivating the second protection function during the operation in the replacement mode.

[0026] The stage of deactivating may include a stage of deactivating the second protection function by not executing a function for performing the second protection function, or a stage of deactivating the second protection function by upwardly adjusting a critical value constituting the second condition so that the protection operation is not executed.

[0027] The battery management method may further include a stage of detecting the replacement of the battery module based on replacement information received from at least one of an input device, an external terminal, or a host controller.

[0028] The battery management method may further include a step of detecting replacement of a battery module by comparing the identification information received from the plurality of battery modules with the previously stored identification information.

Advantages of the Invention

[0029] According to the present disclosure, it is possible to replace only the battery module in which a failure has occurred, and when the battery module is replaced, balancing between the replaced battery module and the existing battery modules can be quickly performed.

[0030] In addition, it is possible to prevent unnecessary protection operations from being performed by restricting the protection operation in pack units while balancing is being performed by replacing the battery module.

Brief Description of the Drawings

[0031]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. Hereinafter, the effects, features, and implementation methods of the embodiments will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals indicate the same components, and redundant descriptions thereof will be omitted. However, the present invention can be embodied in various forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided as examples so that this disclosure can be thorough and complete, and can fully convey the aspects and features of the present invention to those of ordinary skill in the art.

[0033] Therefore, for a complete understanding of the aspects and features of the present invention, processes, elements, and techniques that are considered not necessary for those of ordinary skill in the art may not be described. In the drawings, the relative sizes of elements, layers, and regions may be exaggerated for clarity.

[0034] In this document, the term "and / or" includes all combinations or any combination of a plurality of related listed items. When describing embodiments of the present invention, the use of "can be" means "one or more embodiments of the present invention". In the following description of embodiments of the present invention, terms in the singular form can include the plural form unless explicitly stated otherwise in the context.

[0035] The terms "first" and "second" are used to describe various components, but these components are not limited by these terms. This term is only used for the purpose of distinguishing one component from another. For example, without departing from the scope of the rights of the present invention, the second component may be named the first component, and similarly, the first component may also be named the second component.

[0036] In this document, when one component or layer is described as being "on", "connected to", or "coupled to" another component or layer, the terms "on", "connected to", and "coupled to" all include being formed directly or via one or more other components or layers. Also, when one component or layer is described as being "between" two components or layers, it should be understood that it can be the only component or layer between the two components or layers, or there can be one or more intervening other elements or layers.

[0037] In this document, the phrase "electrically connect" two components can include not only the case where the two components are directly connected, but also the case where they are connected via other components between the two components. The other components can include switches, resistors, capacitors, etc. When describing embodiments, the expression "connect" means electrically connect if there is no expression of direct connection.

[0038] Hereinafter, a battery management method according to an embodiment, and a battery management device and a battery pack for performing the same will be described in detail with reference to the necessary drawings.

[0039] FIG. 1 schematically shows a battery pack according to an embodiment.

[0040] Referring to FIG. 1, a battery pack 10 according to an embodiment can include a battery 11 and a battery management device for managing the balancing of the battery 11. Also, the battery management device can include a detection device 12, a balancing device 13, and a control device 14.

[0041] The battery 11 can include a plurality of battery modules 111 connected in series with each other. The plurality of battery modules 111 can be connected in series or in parallel with each other. Each battery module 111 can include a plurality of cells (not shown) connected in series or in parallel with each other.

[0042] The detection device 12 can sense the state (such as voltage, current, temperature, etc.) of the battery 11 and detect state information indicating the state of the battery 11. The detection device 12 can detect the voltage of each cell or each battery module 111 that makes up the battery 11. The detection device 12 can also detect the current flowing through the battery module 111 or each battery module 111 that makes up the battery 11. The detection device 12 can also detect the temperature at at least one point of the battery 11.

[0043] The balancing device 13 can perform a balancing operation on the battery cells that make up the battery 11.

[0044] The control device 14 can receive state information (voltage, current, temperature) of the battery module 111 from the detection device 12. The control device 14 can monitor the state (voltage, current, temperature, state of charge (SOC), state of health (SOH), etc.) of the battery module 111 based on the state information received from the detection device 12. Further, the control device 14 can also perform control functions (such as temperature control, balancing control, charge and discharge control, etc.) and protection functions (such as over-discharge prevention, over-charge prevention, over-current prevention, etc.) based on the state monitoring results. Also, the control device 14 can perform a communication function with an external device (such as an upper controller, etc.) of the battery pack 10.

[0045] The control device 14 can detect the presence or absence of replacement of the battery module 111 that makes up the battery 11, and when the replacement of the battery module 111 is detected, it can control the charge and discharge operation and the protection operation of the battery 11 so that the voltage imbalance between the replaced battery module 111 and the existing battery module 111 can be quickly eliminated. For this purpose, the control device 14 can include an exchange detection unit 141, a charge and discharge control unit 142, a balancing control unit 143, and a protection unit 144.

[0046] The replacement detection unit 141 can detect the replacement of the battery module 111 that constitutes the battery 11. The replacement detection operation of the battery module 111 can be performed by various methods.

[0047] For example, the replacement information of the battery module 111 can be input to the replacement detection unit 141 of the control device 14 by the operator who performed the replacement work of the battery pack 10. The operator inputs the identification information, position information, etc. of the replaced battery module 111 through an input device (not shown), and the input information can be transmitted from the input device to the replacement detection unit 141 of the control device 14. The operator inputs the identification information, position information, etc. of the replaced battery module 111 to the operator terminal (not shown) or the upper controller of the battery pack 10, and the input information can also be transmitted from the operator terminal or the upper controller to the replacement detection unit 141 of the control device 14 through wired or wireless communication.

[0048] Also, for example, the replacement detection unit 141 can receive unique identification information (such as a serial number, etc.) for identifying each battery module 111 from the battery module 111 that constitutes the battery 11, and detect the replacement of the battery module 111 based on this. The replacement detection unit 141 compares the identification information of the battery module 111 previously stored in the internal memory (not shown) of the battery pack 10 with the identification information newly received from the battery module 111. When identification information different from the identification information stored in the memory is received from at least one battery module 111, it can be determined that the corresponding battery module 111 has been replaced.

[0049] When the replacement detection unit 141 detects the replacement of at least one battery module 111, the control device 14 can be switched from the normal mode to the retrofit mode. The normal mode is the operation mode of the control device 14 when no replacement of the battery module 111 has occurred, and the retrofit mode indicates the operation mode of the control device 14 when at least one battery module 111 has been replaced.

[0050] The charge / discharge control unit 142 can control the charge and discharge of the battery 11. In the normal mode, all charging and discharging of the battery 11 may be permitted. In the normal mode, the charge / discharge control unit 142 can control the battery 11 to be charged or discharged according to the state of the battery 11 and the like. In the retrofit mode, only one of the charging and discharging operations of the battery module 111 may be permitted. For example, if the control device 14 operates in the retrofit mode, the charge / discharge control unit 142 can permit only the charging of the battery 11 and limit the discharging of the battery 11. Also, for example, if the control device 14 operates in the retrofit mode, the charge / discharge control unit 142 can permit only the discharging of the battery 11 and limit the charging of the battery 11. Thus, when only one of charging and discharging is permitted in the retrofit mode, the voltage imbalance caused by the replacement of the battery module 111 can be quickly eliminated. Which of the charging and discharging operations is to be performed in the retrofit mode can be preset by the user, and the charge / discharge control unit 142 can permit only one of the charging and discharging operations according to the preset setting information.

[0051] The balancing control unit 143 can control the balancing operation of the balancing device 13 based on the state information of the battery 11 received through the detection device 12. The balancing control unit 143 can control the balancing device 13 so that the balancing of battery cells is performed in at least one of the top balancing and bottom balancing methods according to the preset setting information. Top balancing is a balancing method that equalizes in a region where the cell voltage of the battery cell is high, and bottom balancing is a balancing method that equalizes in a region where the cell voltage of the battery cell is low. In the case of top balancing, the balancing control unit 143 can control the balancing device 13 so that balancing is performed while the battery 11 is being charged or while the battery 11 has reached a fully charged state and is waiting. In the case of bottom balancing, the balancing control unit 143 can control the balancing device 13 so that balancing is performed while the battery 11 is being discharged or while the battery 11 has reached a fully discharged state and is waiting.

[0052] When only charging of the battery 11 is permitted in the replacement mode, the balancing control unit 143 can control the balancing device 13 to perform balancing of battery cells in the top balancing method. When only discharging of the battery 11 is permitted in the replacement mode, the balancing control unit 143 can control the balancing device 13 to perform balancing of battery cells in the bottom balancing method.

[0053] When the balancing of battery cells is completed in the replacement mode, the control device 14 can cancel the replacement mode and return to the normal mode.

[0054] The protection unit 144 can detect the imbalance state of the battery cells constituting the battery 11 and perform a protection operation accordingly. The protection unit 144 can perform a module imbalance protection function and a pack imbalance protection function.

[0055] The module imbalance protection function is a function that detects the imbalance state of the battery cells for each battery module 111 and performs a protection operation (for example, charging and discharging interruption of the battery 11) when the imbalance state of the battery cells satisfies a predetermined condition in at least one battery module 111. That is, the module imbalance protection function is a function for detecting the imbalance state of the battery cells in units of battery modules and performing a protection operation accordingly. For example, when the module imbalance protection function is activated, the protection unit 144 detects the battery cell with the maximum cell voltage and the battery cell with the minimum cell voltage for each battery module 111 constituting the battery 11, and if there is a battery module 111 in which the voltage difference (ΔV) between the maximum cell voltage and the minimum cell voltage thus detected is equal to or greater than a critical value, a protection operation can be performed. Also, for example, when the module imbalance protection function is activated, the protection unit 144 detects the battery cell with the maximum SOC and the battery cell with the minimum SOC for each battery module 111 constituting the battery 11, and if there is a battery module 111 in which the SOC difference (ΔSOC) between the maximum SOC and the minimum SOC thus detected is equal to or greater than a critical value, a protection operation can also be performed.

[0056] The pack imbalance protection function is a function that detects the imbalance state of all the battery cells constituting the battery 11 and performs a protection operation (for example, cut-off of charge and discharge of the battery 11) when the imbalance state detected in all the battery cells satisfies a predetermined condition. That is, the pack imbalance protection function is a function for detecting the imbalance state of battery cells in units of battery packs and performing a protection operation thereby. For example, when the pack imbalance protection function is activated, the protection unit 144 detects the battery cell with the maximum cell voltage and the battery cell with the minimum cell voltage among all the battery cells constituting the battery 11, and when the voltage difference (ΔV) between the maximum cell voltage and the minimum cell voltage thus detected is equal to or greater than the critical value, the protection operation can be performed. Also, for example, when the pack imbalance protection function is activated, the protection unit 144 detects the battery cell with the maximum SOC and the battery cell with the minimum SOC among all the battery cells constituting the battery 11, and when the SOC difference (ΔSOC) between the maximum SOC and the minimum SOC thus detected is equal to or greater than the critical value, the protection operation can also be performed.

[0057] When replacing some of the battery modules 111 that make up the battery 11, if the pack imbalance protection function is activated, the protection operation may be necessarily performed due to the state imbalance between the battery cells of the replaced battery module 111 and the battery cells of the existing battery module 111. Such a protection operation may also affect the execution of the cell balancing operation. Therefore, the protection unit 144 can control the activation of the pack imbalance protection function and the module imbalance protection function according to the operation mode of the control device 14. For example, if the control device 14 operates in the normal mode, the protection unit 144 can activate only the pack imbalance protection function or activate both the pack imbalance protection function and the module imbalance protection function. Also, for example, if the control device 14 operates in the replacement mode, the protection unit 144 can deactivate the pack imbalance protection function and activate only the module imbalance protection function. In this way, the protection unit 144 can prevent the execution of unnecessary protection operations by deactivating the pack imbalance protection function in the replacement mode and improve the balancing speed. On the contrary, the protection unit 144 can ensure safety by activating the module imbalance protection function in the replacement mode.

[0058] The protection unit 144 can deactivate each protection function by upwardly adjusting the threshold value compared with the voltage difference (ΔV) / SOC difference (ΔSOC) in each protection function (pack imbalance protection function, module imbalance protection function) to a very high value. The protection unit 144 can also deactivate each protection function by not calling the function that performs each protection function (pack imbalance protection function, module imbalance protection function).

[0059] The control device 14 having the above-described configuration may be implemented by a battery management system (BMS) of the battery pack 10.

[0060] Hereinafter, a battery management method according to an embodiment will be described in detail with reference to FIGS. 2 to 4. The method shown in FIGS. 2 to 4 may be performed by the control device 14 described with reference to FIG. 1.

[0061] FIG. 2 schematically shows a battery management method for the battery pack 10 according to an embodiment.

[0062] Referring to FIG. 2, while operating in the normal mode (S11), when the replacement of at least one battery module 111 constituting the battery 11 is detected (S12), the control device 14 can switch to the replacement mode (S13).

[0063] In step S12, the control device 14 can detect the replacement of the battery module 111 in various ways. For example, the control device 14 can receive the input of the replacement information of the battery module 111 from an operator through an input device (not shown), or receive the replacement information of the battery module 111 from an external terminal or a host controller through wired or wireless communication. Also, for example, the control device 14 can receive unique identification information (such as a serial number, etc.) for identifying each battery module 111 from the battery modules 111 constituting the battery 11, and detect the replacement of the battery module 111 based on this.

[0064] By operating in the replacement mode, the control device 14 can deactivate the pack imbalance protection function and activate the module imbalance protection function (S14). The module imbalance protection function is a function that performs a protection operation due to the imbalance state of battery cells in units of battery modules 111, and the pack imbalance protection function is a function that performs a protection operation due to the imbalance state of all the battery cells constituting the battery pack 10. The method of performing the module imbalance protection function and the method of performing the pack imbalance protection function will be described in detail below with reference to FIGS. 3 and 4.

[0065] By operating in the exchange mode, the control device 14 can allow only one of the charging and discharging operations (S15). For example, the control device 14 can allow only the charging of the battery 11 and cut off the discharging of the battery 11. Also, for example, the control device 14 can allow only the discharging of the battery 11 and cut off the charging of the battery 11.

[0066] The control device 14 can control the balancing device 13 to perform cell balancing of the battery 11 in a state where only one of the charging and discharging operations is allowed (S16). For example, when only the charging of the battery 11 is allowed in the exchange mode, the control device 14 can control the balancing device 13 to perform balancing of the battery cells in the top balancing method during the charging of the battery 11 or during the standby time after full charge. Also, for example, when only the discharging of the battery 11 is allowed in the exchange mode, the control device 14 can control the balancing device 13 to perform balancing of the battery cells in the bottom balancing method during the discharging of the battery 11 or during the standby time after full discharge.

[0067] When the balancing of the battery cells is completed in the exchange mode (S17), the control device 14 can release the exchange mode and operate in the normal mode again.

[0068] FIG. 3 schematically shows a method for performing the module imbalance protection function of the battery pack 10 according to an embodiment.

[0069] Referring to FIG. 3, the control device 14 can acquire the maximum cell voltage and the minimum cell voltage, or the maximum SOC and the minimum SOC for each battery module 111, respectively (S21).

[0070] In step S21, the control device 14 can detect the cell voltages of the battery cells constituting each battery module 111 through the detection device 12, and select the maximum cell voltage and the minimum cell voltage among the cell voltages detected for each battery module 111. Further, the control device 14 can detect the SOC of the battery cells constituting each battery module 111 based on the state information detected through the detection device 12, and also select the maximum SOC and the minimum SOC among the SOCs detected for each battery module 111.

[0071] Thereafter, the control device 14 can calculate the voltage difference (ΔV) between the maximum cell voltage and the minimum cell voltage, or the SOC difference (ΔSOC) between the maximum SOC and the minimum SOC for each battery module 111 (S22). When the voltage difference (ΔV) or the SOC difference (ΔSOC) calculated through step S22 in at least one battery module 111 is equal to or greater than the threshold value (S23), the control device 14 can determine that a protection operation is necessary and perform the protection operation (S24). For example, the control device 14 can cut off the charging and discharging of the battery 11.

[0072] FIG. 4 schematically shows a method for performing the pack imbalance protection function of the battery pack 10 according to an embodiment.

[0073] Referring to FIG. 4, the control device 14 can obtain the maximum cell voltage and the minimum cell voltage, or the maximum SOC and the minimum SOC, respectively, for the entire battery modules 111 constituting the battery pack 10 (S31).

[0074] In step S31, the control device 14 can detect the cell voltages of the battery cells constituting the battery module 111 through the detection device 12, and select the maximum cell voltage and the minimum cell voltage among the detected cell voltages. Also, the control device 14 can detect the SOC of the battery cells constituting the entire battery module 111 based on the state information detected through the detection device 12, and select the maximum SOC and the minimum SOC among the detected SOCs.

[0075] Thereafter, the control device 14 can calculate the voltage difference (ΔV) between the maximum cell voltage and the minimum cell voltage, or the SOC difference (ΔSOC) between the maximum SOC and the minimum SOC, for the entire battery module 111 (S32). When the voltage difference (ΔV) or the SOC difference (ΔSOC) calculated in step S32 is equal to or greater than the threshold value (S33), the control device 14 can determine that a protection operation is necessary and perform the protection operation (S34). For example, the control device 14 can cut off the charging and discharging of the battery 11.

[0076] According to the above-described embodiment, it is possible to replace the battery module 111 without performing a pre-balancing operation for eliminating the state imbalance between the new battery module and the existing battery module before replacing the battery module 111. Also, when the battery module is replaced, the imbalance state of the battery module can be quickly eliminated.

[0077] The electronic or electrical devices and / or any other related devices or components according to the embodiments of the present invention described herein may be implemented using any suitable hardware, firmware (e.g., application-specific integrated circuit), software, or a combination of software, firmware, and hardware. For example, the various components of these devices may be formed on one integrated circuit (IC) chip or on individual IC chips. Also, the various components of these devices may be implemented on a flexible printed circuit film, a tape carrier package (TCP), a printed circuit board (PCB), or on one substrate. The electrical connections or interconnections described herein may be implemented, for example, by wiring or conductive elements on a PCB or other types of circuit carriers. The conductive elements may include, for example, metallizations such as surface metallizations, and / or pins, and may include conductive polymers or ceramics.

[0078] Also, the various components of these devices may be executed on one or more processors to perform the various functions described herein, may be executed within one or more computing devices, may execute computer program instructions, and may be a process or thread that interacts with other system components. The computer program instructions may be stored in a memory that may be implemented in a computing device using a standard memory device such as, for example, random access memory (RAM). The computer program instructions may also be stored on other non-transitory computer-readable media such as, for example, a CD-ROM, a flash drive, etc.

[0079] Moreover, those skilled in the art should recognize that the functions of various computing devices can be combined or integrated into a single computing device, or that the functions of a particular computing device can be distributed across one or more other computing devices without departing from the scope of the exemplary embodiments of the present invention.

Explanation of Reference Numerals

[0080] 10: Battery pack 11: Battery 111: Battery module 12: Detection device 13: Balancing device 14: Control device 141: Replacement detection unit 142: Charge / discharge control unit 143: Balancing control unit 144: Protection unit

Claims

1. A battery management device for a battery pack including a plurality of battery modules, comprising: a detection device for detecting state information of battery cells constituting the plurality of battery modules; and a control device that enters an exchange mode to perform balancing on the plurality of battery modules when at least one of the plurality of battery modules is exchanged, and activates a first protection function to perform a protection operation due to state imbalance within each battery module while operating in the exchange mode, wherein when the first protection function is activated, the control device detects an imbalance state of cell voltage or SOC (state of charge) for each of the plurality of battery modules based on the state information, and when a battery module that satisfies a preset first condition for the imbalance state is detected among the plurality of battery modules, causes the protection operation to be executed; the battery management device, wherein when no exchange of a battery module is detected, the control device causes the protection operation to be executed due to a state imbalance of cell voltage or SOC in the entire plurality of battery modules.

2. The battery management device according to claim 1, wherein when the first protection function is activated, the control device obtains a voltage difference between a battery cell with the maximum cell voltage and a battery cell with the minimum cell voltage for each of the plurality of battery modules, and when a battery module having the voltage difference equal to or greater than a critical value is detected among the plurality of battery modules, causes the protection operation to be executed.

3. The battery management device according to claim 1, wherein when the first protection function is activated, the control device obtains an SOC difference between a battery cell with the maximum SOC and a battery cell with the minimum SOC for each of the plurality of battery modules, and when a battery module having the SOC difference equal to or greater than a critical value is detected among the plurality of battery modules, causes the protection operation to be executed.

4. The control device operates in a normal mode before the at least one battery module is exchanged or after the balancing of the plurality of battery modules in the exchange mode is completed. While operating in the normal mode, activate a second protection function that performs the protection operation due to state imbalance within the battery pack. When the second protection function is activated, detect an imbalance state of cell voltages or SOCs across the plurality of battery modules based on the state information, and execute the protection operation when the imbalance state of cell voltages or SOCs across the plurality of battery modules satisfies a preset second condition. The battery management device according to claim 1. **Claim 5** When the second protection function is activated, the control device obtains a voltage difference between the battery cell with the maximum cell voltage and the battery cell with the minimum cell voltage across the plurality of battery modules, and when the voltage difference is equal to or greater than a critical value, executes the protection operation. The battery management device according to claim 4. **Claim 6** When the second protection function is activated, the control device obtains an SOC difference between the battery cell with the maximum SOC and the battery cell with the minimum SOC across the plurality of battery modules, and when the SOC difference is equal to or greater than a critical value, executes the protection operation. The battery management device according to claim 4. **Claim 7** While operating in the replacement mode, the control device deactivates the second protection function. The battery management device according to claim 4. **Claim 8** While operating in the replacement mode, the control device deactivates the second protection function by not executing the function for performing the second protection function. The battery management device according to claim 7. **Claim 9** While operating in the replacement mode, the control device deactivates the second protection function by upwardly adjusting the critical value constituting the second condition so that the protection operation is not executed. The battery management device according to claim 7. **Claim 10** While operating in the normal mode, the control device deactivates the first protection function. The battery management device according to claim 4. **Claim 11** The control device detects replacement of a battery module based on replacement information received from at least one of an input device, an external terminal, or a host controller. The battery management device according to claim 1. **Claim 12** The battery management device according to claim 1, wherein the control device compares identification information received from the plurality of battery modules with pre-stored identification information to detect replacement of the battery modules.

13. The battery management device according to claim 1, wherein the control device allows only one of charging and discharging for the plurality of battery modules while operating in the replacement mode.

14. A plurality of battery modules connected in series with each other, and A battery pack including the battery management device according to any one of claims 1 to 13.

15. A battery management method for a battery pack including a plurality of battery modules, comprising: Converting to a replacement mode when replacement of a battery module is detected; Balancing the plurality of battery modules while allowing only one of charging and discharging during operation in the replacement mode; and Performing a first protection function of executing a protection operation due to state imbalance within each battery module while operating in the replacement mode, The step of performing the first protection function includes: Obtaining a first imbalance state of cell voltage or SOC for each of the plurality of battery modules; and When a battery module that satisfies a first condition in which the first imbalance state is preset is detected among the plurality of battery modules, executing the protection operation. The battery management method further includes, when replacement of a battery module is not detected, executing the protection operation due to state imbalance of cell voltage or SOC in the entire plurality of battery modules.

16. The step of obtaining the first imbalance state includes: For each of the plurality of battery modules, obtaining a voltage difference between a battery cell with the maximum cell voltage and a battery cell with the minimum cell voltage; or For each of the plurality of battery modules, obtaining an SOC difference between a battery cell with the maximum SOC and a battery cell with the minimum SOC. The step of executing the protection operation includes: When a battery module having a voltage difference equal to or greater than a critical value is detected among the plurality of battery modules, executing the protection operation; or The battery management method according to claim 15, further comprising: when a battery module having an SOC difference greater than or equal to a critical value among the plurality of battery modules is detected, executing the protection operation.

17. When replacement of a battery module is not detected, the step of executing the protection operation due to state imbalance of cell voltage or SOC across the plurality of battery modules includes: When replacement of a battery module is not detected, operating in a normal mode; During operation in the normal mode, controlling charging and discharging of the plurality of battery modules according to the states of the plurality of battery modules; and During operation in the normal mode, performing a second protection function of executing the protection operation due to state imbalance across the plurality of battery modules, The step of performing the second protection function includes: Obtaining a second imbalance state of cell voltage or SOC for the entire plurality of battery modules; and When the second imbalance state satisfies a preset second condition, executing the protection operation. The battery management method according to claim 15.

18. The step of obtaining the second imbalance state includes: Obtaining a voltage difference between a battery cell with the maximum cell voltage and a battery cell with the minimum cell voltage across the entire plurality of battery modules; or Obtaining an SOC difference between a battery cell with the maximum SOC and a battery cell with the minimum SOC across the entire plurality of battery modules. The step of executing the protection operation includes: When the voltage difference is greater than or equal to a critical value, executing the protection operation; or When the SOC difference is greater than or equal to a critical value, executing the protection operation. The battery management method according to claim 17.

19. The battery management method according to claim 17, further comprising: during operation in the replacement mode, deactivating the second protection function.

20. The step of deactivating includes: Deactivating the second protection function by not executing a function for performing the second protection function; or Deactivating the second protection function by upwardly adjusting a critical value constituting the second condition so that the protection operation is not executed. The battery management method according to claim 19.

21. The battery management method according to claim 15, further comprising the step of detecting replacement of the battery module based on exchange information received from at least one of an input device, an external terminal, or a host controller.

22. The battery management method according to claim 15, further comprising the step of detecting replacement of the battery module by comparing the identification information received from the plurality of battery modules with the previously stored identification information.

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