Battery management device, battery pack, electric vehicle, and battery management method

Abstract

The invention provides a battery management apparatus, a battery pack, an electric vehicle, and a battery management method. A battery management apparatus according to the present disclosure includes: a state detection unit configured to obtain a plurality of cell state parameters indicating an electrical state of each of a plurality of battery cells; a balancing processing unit configured to perform a balancing process, which is a process of selectively discharging or charging each of the plurality of battery cells, to suppress a deviation between electrical states of the plurality of battery cells; and a control unit configured to control the balancing processing unit to perform a balancing process on at least one battery cell among the plurality of battery cells based on the plurality of cell state parameters.

Description

Technical Field

[0001] The present disclosure relates to a battery management device which differentially applies a balancing process to each of a plurality of battery cells according to an electrical state of each of the plurality of battery cells.

[0002] This application claims priority to Korean Patent Application No. 10-2022-0113716 filed in Korea on September 7, 2022, and Korean Patent Application No. 10-2023-0098407 filed in Korea on July 27, 2023, the disclosures of which are incorporated herein by reference. Background Art

[0003] As the demand for portable electronic products such as laptop computers, cameras and mobile phones that use electricity as a driving source is rapidly increasing, and mobile robots, electric bicycles, electric carts and electric vehicles are becoming widely commercialized, research on high-performance secondary batteries that can be repeatedly charged and discharged is also being actively conducted.

[0004] Currently commercially available rechargeable secondary batteries (hereinafter referred to as "battery cells" or "cells") include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium secondary batteries, and the like. Among these, lithium secondary batteries have the advantage of being freely charged and discharged because the memory effect rarely occurs, and have a very low self-discharge rate compared to other types of secondary batteries. In addition, they have high energy density and high operating voltage, so they have been studied more intensively than other types of secondary batteries and are also more widely used in actual products.

[0005] Recently, battery cells have been widely used not only in small devices such as portable electronic devices but also in medium and large devices such as electric vehicles and energy storage systems (ESS).

[0006] In this case, a battery module in which a plurality of electrically connected battery cells are stored together inside a module housing is mainly applied. In addition, when high power or large capacity is required, a battery pack in which a plurality of battery modules are electrically connected in series and / or in parallel may also be applied.

[0007] Since these battery modules or battery packs (hereinafter collectively referred to as "batteries") are devices that provide power, energy efficiency is an important issue. Therefore, various efforts are being made to increase energy density, such as using multiple unit stacks to implement electrode assemblies, improving the physical properties of battery cells, and increasing electrochemical efficiency.

[0008] In this regard, a balancing process is being applied to optimize battery performance by controlling a plurality of battery cells included in a battery to have uniform (including an appropriate error range) electrical characteristics (voltage, SOC, etc.) by appropriately using a charging or discharging circuit.

[0009] Due to differences in individual dynamic states caused by material properties of internal resistors, human deviations due to usage environments, cooling efficiency and capacity, etc., multiple battery cells may have non-uniform electrical characteristics (such as voltage or SOC, etc.).

[0010] When such deviations in electrical characteristics occur, the actually available resources are not used in an optimized manner, which leads to a problem in which the performance of the battery module is reduced compared to the actually available capacity or available output. Additionally, if at least one battery cell reaches the highest electrical characteristics earlier than the other battery cells, the charging process ends without completing the charging of the other battery cells having sufficient internal capacity, and thus the amount of charge in the entire battery module is greatly limited.

[0011] Although this is an extreme example, if one cell has the lowest voltage (charging voltage) and another cell has the highest voltage, the battery cannot be charged (energy storage) and cannot be discharged (power supply) even if the other cells have appropriate voltages.

[0012] In addition, if battery use continues without the voltage deviation being properly resolved, the voltage deviation becomes more serious, which not only worsens the deterioration of battery performance but may also cause safety problems such as fire due to overcharge.

[0013] The balancing process is the solution to this problem. By continuously controlling multiple battery cells to maintain a uniform electrical state, it can provide benefits such as maintaining stable battery performance, increasing service life, and increasing output efficiency.

[0014] The balancing process is applied by charging a battery cell with relatively lower electrical characteristics through a separate power source, transferring energy from a battery cell with relatively higher electrical characteristics to a battery cell with relatively lower electrical characteristics, etc., and in order to facilitate circuit configuration, stability, prevent malfunctions, clarity of operation, etc., a method of discharging a battery cell with relatively higher electrical characteristics through a resistance circuit (load circuit) etc. is mainly applied.

[0015] However, this balancing is done based only on externally measured or calculated formal values, such as the voltage of the battery cells, without taking into account the actual characteristics of the battery cells.

[0016] For example, in the case of a battery cell with a high degree of degradation due to an increase in internal resistance, the electrical characteristics become relatively lower than those of other battery cells during discharge. Even in this case, a conventional balancing process is performed to discharge normal cells with high electrical characteristics, which may cause problems such as unnecessary consumption of available resources.

[0017] As seen earlier, balancing is performed continuously depending on the battery state at the current point, so this problem recurs as battery use continues. In addition, the degree of degradation has a behavior characteristic that accelerates over time, so the cycle in which the balancing process is performed becomes shorter, further exacerbating unnecessary energy waste and driving performance degradation, and also exerting a serious negative impact on the battery life itself. Summary of the invention

[0018] Technical issues

[0019] The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure aims to provide a battery management device and method, which can further optimize the driving performance of the battery module by selectively or differentially performing a balancing process of at least one battery cell among the multiple battery cells by additionally considering the electrical state of each battery cell included in the multiple battery cells and also considering the behavioral characteristics of each battery cell among the multiple battery cells.

[0020] The technical problems that the present disclosure intends to solve are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

[0021] Technical Solution

[0022] A battery management device according to one aspect of the present disclosure is provided for a battery module including a plurality of battery cells. The battery management device includes: a state detection unit configured to obtain a plurality of cell state parameters indicating an electrical state of each of the plurality of battery cells; a balancing processing unit configured to perform a balancing process to suppress deviations in electrical states between the plurality of battery cells, the balancing process being a process of selectively discharging or charging each of the plurality of battery cells; and a control unit configured to control the balancing processing unit to perform a balancing process on at least one of the plurality of battery cells based on the plurality of cell state parameters.

[0023] The battery management device may further include a cell classification unit configured to classify each of the plurality of battery cells as a degraded cell or a normal cell based on a plurality of cell state parameters. The control unit may be configured to control the balancing processing unit so that the balancing process is differentially performed based on the cell state parameters of the degraded cells and the cell state parameters of the normal cells.

[0024] The control unit may be configured to control the balancing processing unit so that a balancing process is performed on the degraded cell when a cell state parameter of the degraded cell is greater than a cell state parameter of a normal cell. The cell state parameter may represent at least one of a voltage and an SOC (State of Charge).

[0025] The cell classification unit may include: an input unit configured to obtain multiple cell state parameters from a state detection unit; a calculation processing unit configured to calculate multiple battery cell behavior parameters based on the multiple battery cell state parameters, the multiple battery cell behavior parameters representing the behavior characteristics of the electrical state of each of the multiple battery cells; and a selection unit configured to classify each of the multiple battery cells as a degraded cell or a normal cell based on the relative difference between the multiple battery cell behavior parameters.

[0026] The cell behavior parameter may include a change rate of the cell state parameter. The cell classification unit may be configured to classify each battery cell mapped to n (n is a natural number of 1 or more) cell behavior parameters ranked higher in magnitude among the plurality of cell behavior parameters as a deteriorated cell.

[0027] The cell behavior parameter may include a rate of change of the cell state parameter. The cell classification unit is configured to select each battery cell that satisfies the following two conditions as a deteriorated cell: the cell behavior parameter of the battery module during charging is greater than or equal to a first reference value and the cell behavior parameter of the battery module during discharging is greater than or equal to a second reference value.

[0028] The state detection unit may be configured to obtain the SOC of the battery module as a module state parameter representing an electrical state of the battery module.

[0029] The control unit may be configured to control the balancing processing unit so that a balancing process is performed on the degraded cell under a condition that a module state parameter during charging of the battery module is greater than or equal to a reference SOC.

[0030] The battery management device may further include: an SOC information storage unit configured to store first SOC time series data and second SOC time series data; a statistical processing unit configured to calculate an SOC statistical value based on the first SOC time series data and the second SOC time series data; and a reference setting unit configured to set a reference SOC equal to the SOC statistical value.

[0031] The first SOC time series data may include first to (k-1)th starting SOCs, the first to (k-1)th starting SOCs representing the SOC of the battery module at the starting point of each of the first to (k-1)th charging processes performed on the battery module in the past. The second SOC time series data may include first to (k-1)th ending SOCs, the first to (k-1)th ending SOCs representing the SOC of the battery module at the ending point of each of the first to (k-1)th charging processes. k is a natural number of 2 or greater.

[0032] The statistics processing unit may be further configured to calculate the SOC statistics value further based on the SOH of the battery module.

[0033] The statistical processing unit may be configured to determine a reference number based on the SOH of the battery module. The statistical processing unit may be configured to extract the (kj)th to (k-1)th starting SOC from the first SOC time series data. The statistical processing unit may be configured to extract the (kj)th to (k-1)th ending SOC from the second SOC time series data. The statistical processing unit may be configured to calculate the SOC statistical value to be the same as the average value of the (kj)th to (k-1)th starting SOC and the (kj)th to (k-1)th ending SOC. j is a reference number.

[0034] A battery pack according to another aspect of the present invention includes the battery management device.

[0035] An electric vehicle according to still another aspect of the present invention includes the battery pack.

[0036] A battery management method according to another aspect of the present invention may be performed by a battery management device. The battery management method includes: obtaining a plurality of cell state parameters indicating the electrical state of each of a plurality of battery cells by a state detection unit; and controlling a balancing processing unit to perform a balancing process on at least one of the plurality of battery cells based on the plurality of cell state parameters by a control unit to suppress deviations in the electrical states between the plurality of battery cells.

[0037] The step of controlling the balancing processing unit may include: classifying each of the plurality of battery cells as a degraded cell or a normal cell based on a plurality of cell state parameters; and controlling the balancing processing unit so that a balancing process is differentially performed based on the cell state parameters of the degraded cells and the cell state parameters of the normal cells.

[0038] The step of controlling the balancing processing unit may include: obtaining the SOC of the battery module as a module state parameter representing the electrical state of the battery module; and controlling the balancing processing unit so that a balancing process is performed on the degraded cells under the condition that the module state parameter is greater than or equal to a reference SOC during charging of the battery module.

[0039] Beneficial Effects

[0040] According to at least one embodiment of the present disclosure, time series changes in the electrical state and / or behavioral characteristics of each battery cell among a plurality of battery cells can be used to identify operating conditions that do not result in a reduction in the driving performance of the battery module, and a balancing process of at least one battery cell among the plurality of battery cells can be selectively performed when the identified operating conditions are met.

[0041] In addition, according to at least one embodiment of the present disclosure, each of a plurality of battery cells in a battery module can be accurately classified as a normal cell or a degraded cell, and the classification result can be organically incorporated into the control operation for the balancing process, thereby improving the performance of the battery module.

[0042] In addition, according to at least one embodiment of the present disclosure, taking into account the difference in behavioral characteristics between normal cells and degraded cells, a balancing process of at least one battery cell can be selectively implemented, thereby effectively solving the problem that the available capacity or output of normal cells is unnecessarily limited and the performance degradation becomes permanent or the life is shortened.

[0043] In addition, according to at least one embodiment of the present disclosure, the efficiency of the balancing process can be improved by calculating a statistical value of the SOC (state of charge) swing range, which is the main usage range of the battery module, based on the charging history and / or discharging history that the battery module has experienced, and using the statistical value as a criterion for differentiating the balancing process.

[0044] In addition, according to at least one embodiment of the present disclosure, the balancing process can be performed only on battery cells classified as either a degraded cell or a normal cell. If the balancing process is performed only on degraded cells instead of normal cells, there is an advantage of quickly resolving the state deviation between normal cells and degraded cells. When the balancing process is performed only on normal cells instead of degraded cells, the charging and discharging of the degraded cells by the balancing process is reduced to a degree that helps to equalize the life deviation between normal cells and degraded cells.

[0045] In addition, the present disclosure may have various other effects, and these effects will be explained in each embodiment, or the explanation will be omitted for effects that can be easily inferred by those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are used to provide a further understanding of the technical features of the present disclosure, and therefore, the present disclosure should not be construed as being limited to the accompanying drawings.

[0047] Figure 1 is a block diagram schematically showing a configuration of a battery pack according to an embodiment of the present disclosure.

[0048] Figure 2 It is schematically shown Figure 1 Figure 2 shows the configuration of the monomeric taxa shown in Figure 2 .

[0049] Figure 3 is a block diagram schematically showing a configuration of a battery pack according to another embodiment of the present disclosure.

[0050] Figure 4 It is schematically shown Figure 3 A block diagram of the configuration of the reference processing unit shown in FIG.

[0051] Figure 5 The explanation can be Figure 1 Flowchart of an example of a battery management method executed by a battery management device shown in FIG.

[0052] Figure 6 The explanation can be Figure 1 A flowchart of another example of a battery management method executed by a battery management device shown in FIG.

[0053] Figure 7 The explanation can be Figure 1 Flow chart of another example of a battery management method executed by a battery management device shown in .

[0054] Figure 8 is a flowchart explaining a process of classifying each of a plurality of battery cells as a normal cell or a deteriorated cell.

[0055] Fig. 9 The explanation can be Figure 3 Flow chart of the process performed by the battery management device shown in .

[0056] Fig.10 is a flowchart referred to to explain a process of determining a reference SOC.

[0057] Fig.11 is a graph referred to to illustratively explain the change in SOC of a battery cell over time.

[0058] Fig.12 are graphs referred to to explain the behavior characteristics of a normal cell and a deteriorated cell, respectively.

[0059] Fig.13 yes Fig.12 Magnified view of the dashed area shown in .

[0060] Fig.14is a graph referred to to explain that a balancing process is differentially performed on a degraded cell and a normal cell according to a reference SOC.

[0061] Fig.15 is a graph referred to in order to explain a differential balancing process achieved when the reference SOC is 80%.

[0062] Fig.16 is referred to schematically to explain Figure 1 and Figure 3 An example of a balanced processing unit is shown in FIG.

[0063] Fig.17 is referred to schematically to explain Figure 1 and Figure 3 FIG. 4 is a diagram of another example of a balancing processing unit shown in FIG. DETAILED DESCRIPTION

[0064] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in this specification and the appended claims should not be understood as being limited to the general and dictionary meanings, but should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure on the principle of allowing the inventor to appropriately define the terms for the best interpretation.

[0065] Therefore, the descriptions presented herein are merely preferred examples for illustrative purposes only, and are not intended to limit the scope of the present disclosure, and it should be appreciated that other equivalents and modifications may be made thereto without departing from the scope of the present disclosure.

[0066] Terms including ordinal numbers such as “first” and “second” may be used to distinguish one element from another element among various elements, but are not intended to limit the elements by the terms.

[0067] Throughout the specification, when a part is referred to as "including" or "comprising" any element, it means that the part may also include other elements without excluding other elements unless otherwise specifically stated. Additionally, terms such as "unit" described in the specification refer to a unit that processes at least one function or operation, and may be implemented as hardware, software, or a combination of hardware and software.

[0068] In addition, throughout the specification, when a part is referred to as being “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.

[0069] Figure 1 is a block diagram schematically showing a configuration of a battery pack according to an embodiment of the present disclosure, and Figure 5 The explanation can be Figure 1 Flowchart of an example of a battery management method executed by a battery management device shown in FIG.

[0070] like Figure 1 As shown in , the battery pack 10 includes a battery module 50 and a battery management device 100 .

[0071] The battery module 50 includes a plurality of battery cells #1 to #N. N is a natural number of 2 or more and may represent the total number of battery cells included in the battery module 50. The plurality of battery cells #1 to #N may be electrically connected in series with each other. In the common explanation of the plurality of battery cells #1 to #N, reference numeral 51 may be used to refer to the battery cell. Although the battery cell 51 is Figure 1 5 is shown as a single object, but this is only an example, and depending on the embodiment, the battery cell 51 may be a cell assembly in which a plurality of cell units connected in parallel are grouped.

[0072] The battery management device 100 may monitor an electrical state of each of the plurality of battery cells # 1 to #N and an electrical state of the battery module 50 .

[0073] As will be described later, the battery management device 100 performs and controls a balancing process of a plurality of battery cells #1 to #N.

[0074] In order to stably maintain and manage charging and discharging efficiency and electrical characteristics, it may be desirable to configure the plurality of battery cells #1 to #N to have the same level of performance or specifications.

[0075] The battery management device 100 may include a measuring unit 110 , a state detecting unit 120 , a balancing processing unit 130 , a control unit 140 , a cell classification unit 150 , and an interface unit 160 .

[0076] Obviously, the battery management device 100 can be implemented by various combinations of electronic devices and components such as storage devices, processing devices, and input / output devices. It should be understood that Figure 1 Each component of the battery management device 100 shown in FIG. 1 may be physically separated, or alternatively, may be functionally or logically separated.

[0077] In other words, each component corresponds to a logical component for realizing the technical idea of ​​the present disclosure, so even if each component is integrated or separated, if the function performed by the logical component of the present disclosure can be realized, it should be interpreted as being within the scope of the present disclosure, and if the component performs the same or similar function, it should be interpreted as being within the scope of the present disclosure, regardless of whether the name is consistent or whether the component is divided or integrated. Figures 2 to 4 The structure of the present disclosure shown in is also similar to this.

[0078] The state detection unit 120 calculates a plurality of cell state parameters indicating the electrical state of each of the plurality of battery cells #1 to #N and / or a module state parameter indicating the electrical state of the battery module 50 (S520, see Figure 5 ). The module state parameter is based on the electrical characteristics of the entire battery module 50 and may depend on a plurality of cell state parameters. The module state parameter may be a value representing a plurality of cell state parameters. For example, based on the plurality of cell state parameters, the SOC of the battery module 50 as the module state parameter may be determined to be the same as the average SOC of the plurality of battery cells #1 to #N.

[0079] Depending on the embodiment, the state detection unit 120 may be linked to the measurement unit 110, which may be implemented using various voltage sensors, current sensors, temperature sensors, measurement devices, etc. known at the time of submission. When the measurement unit 110 measures the electrical characteristics (voltage, current, and / or temperature) of a plurality of battery cells #1 to #N or a battery module 50 (S510), the state detection unit 120 may collect (obtain) a fixed sampling rate or a variable sampling rate of the measured values ​​of the electrical characteristics of the battery cell 51. At this time, the measured values ​​of the electrical characteristics of the battery cell 51 themselves may be the cell state parameters. Alternatively, the state detection unit 120 may be configured to determine the cell state parameters of the battery cell 51 and the module state parameters (e.g., SOC, SOH, etc.) of the battery module 50 by applying a function calculation process to the measured values ​​of the electrical characteristics of the battery cell 51.

[0080] The cell state parameter indicates the electrical state of the battery cell 51 and may include at least one of voltage, current, temperature, SOC (State of Charge) and SOH (State of Health). Of course, the cell state parameter may be periodically generated per unit time, which may be variably set according to the design of hardware or software.

[0081] Depending on the embodiment, as the discharge or charge rate increases, the period for obtaining the cell state parameter may be set shorter, and as the discharge or charge rate decreases, the period for obtaining the cell state parameter may be set longer. The correspondence between the discharge or charge rate and the period for obtaining the cell state parameter may be pre-recorded as a lookup table.

[0082] According to this embodiment, since power usage occurs rapidly, more accurate information can be provided to users etc., and the efficiency of data processing can be increased by reducing the calculation processing speed and calculation amount in a section where the demand for providing accurate information is relatively low.

[0083] The cell state parameters and / or module state parameters are desirably configured to be generated in each of a charging process and a discharging process so that the electrical state or behavioral characteristics of the battery cell 51 can be more accurately identified. During the charging process, power is supplied (stored) to the battery module 50 from an external power supply device, and during the discharging process, power is supplied to a load such as a motor.

[0084] The balancing processing unit 130 is a component that performs a balancing process on a plurality of battery cells #1 to #N constituting the battery module 50, and as is well known, it may include hardware components such as relays (switches), load resistors, and timers. Of course, the balancing processing unit 130 may be electrically connected to the battery cells 51, and may be configured to perform functions such as discharging and / or charging the corresponding battery cells 51 according to control signals. This will be referred to later. Fig.16 and Fig.17 The hardware implementation of the balancing processing unit 130 is described separately.

[0085] When the module state parameter of the battery module 50 is generated, the control unit 140 performs a process (S530) of determining whether the module state parameter satisfies a predetermined specific condition that triggers the execution of a balancing process. As an example, the specific condition may be a combination of (i) the module state parameter is greater than or equal to the reference SOC and (ii) the voltage of the degraded cell is higher than the voltage of the normal cell. As another example, the specific condition may be a combination of (i) the module state parameter is less than or equal to the reference SOC and (ii) the voltage of the normal cell is higher than the voltage of the degraded cell. If the value of step S530 is "yes", the control unit 140 controls the balancing processing unit 130 to perform a balancing process on at least one battery cell among the multiple battery cells #1 to #N (S540).

[0086] Of course, if there is no event such as power off, firmware replacement, or meeting a preset end condition, the above-mentioned process of the present disclosure can be designed to be applied cyclically so that continuous battery management can be maintained. Figure 5 In the method, the step of checking whether the termination condition is satisfied (S550) may be omitted. The termination condition may be, for example, that the voltage deviation (eg, the difference between the maximum voltage and the minimum voltage) of the plurality of battery cells #1 to #N is within a certain allowable range.

[0087] When a balancing necessary event occurs in which the voltage deviation of any battery cell (e.g., #1) among multiple battery cells #1 to #N is greater than or equal to a reference deviation, the battery management device 100 can actively determine a negative situation in which performance degradation of the battery module 50 or deterioration of the battery cell (e.g., #1) may occur due to the balancing process, rather than immediately performing a balancing process on the battery cell (e.g., #1).

[0088] The battery management device 100 is configured to perform a balancing process on a battery cell (e.g., #1) only when it is determined that performing a balancing process on the battery cell (e.g., #1) will not cause negative consequences. Here, the voltage deviation of a certain battery cell (e.g., #1) may mean a difference between an average voltage value of a plurality of battery cells #1 to #N and the voltage value of the battery cell (e.g., #1).

[0089] Figure 6 The explanation can be Figure 1 A flowchart of another example of a battery management method executed by a battery management device shown in FIG.

[0090] refer to Figure 6 , the state detection unit 120 obtains a plurality of cell state parameters indicating the electrical state of each of the plurality of battery cells #1 to #N (S610). By cooperating with the measurement unit 110, the state detection unit 120 may generate and store the cell state parameters of each of the plurality of battery cells #1 to #N.

[0091] Depending on the embodiment, the state detection unit 120 can utilize the monomer state parameters measured by the measuring unit 110 intactly, but if the signal output from the measuring unit 110 includes noise components such as pulses or fluctuating waves due to signal interference, distortion, disturbance, etc., a hardware configuration for appropriately adjusting or filtering it can be included in the state detection unit 120, or an algorithm for processing this in software can be installed in the state detection unit 120.

[0092] The battery management device 100 corresponds to the following embodiment, in which by comparing the electrical states and / or behavioral characteristics of multiple battery cells #1 to #N, battery cells corresponding to the normal category (hereinafter referred to as 'normal cells') and battery cells with relatively degraded behavioral characteristics (hereinafter referred to as 'degraded cells') are classified in time series according to the passage of time, and the balancing process is differentially performed on the multiple battery cells #1 to #N using the results.

[0093] The voltage value has the advantages of being able to be measured or generated using a relatively simple circuit configuration (such as a configuration for measuring the voltage difference between the two ends of the battery cell 51), and the characteristic of clearly representing the inherent characteristics of the battery cell 51 from the outside, so when this is used as raw data, it is possible to clearly estimate and select whether the battery cell is a degraded cell.

[0094] In this regard, the cell state parameter is not particularly limited as long as it can represent the electrical state of the battery cell 51 as described above, and generally includes a voltage value of the battery cell 51 .

[0095] When the cell state parameter (e.g., voltage value) of each of the plurality of battery cells #1 to #N is obtained by the state detection unit 120 (S610), the cell classification unit 150 may classify the plurality of battery cells #1 to #N of the battery module 50 as degraded cells or normal cells using the voltage value of each of the plurality of battery cells #1 to #N (S620). Details of the present disclosure of classifying normal cells and degraded cells will be described later.

[0096] In this case, the control unit 140 controls the balancing processing unit 130 so that the balancing process is differentially performed according to the cell state parameters of the degraded cells and the normal cells (S640).

[0097] Specifically, in step S630, the control unit 140 may determine whether the module state parameter satisfies a predetermined specific condition for triggering the execution of the balancing process. Step S630 may be performed under the condition that the module state parameter is greater than or equal to the reference SOC or the module state parameter is less than or equal to the reference SOC.

[0098] Fig.14 is a graph referred to to explain that a balancing process is differentially performed on a degraded cell and a normal cell according to a reference SOC.

[0099] The control unit 140 may control the balancing process to be performed on the degraded cell (S640). For example, when the module state parameter is greater than or equal to the reference SOC, the control unit 140 may control the balancing processing unit (130, see Fig.16 ) During the time period when the voltage of the deteriorated cell is higher than the voltage of the normal cell (see Fig.14 As another example, when the module state parameter is less than or equal to the reference SOC, the control unit 140 may control the balancing processing unit (130, see Fig.17 ) During the time period when the voltage of a normal cell is higher than the voltage of a deteriorated cell (see Fig.14 A balancing process is performed on the degraded cells (reference symbol 'DI' in FIG. 1 ).

[0100] Here, the balancing process of the degraded cell may refer to a balancing process of each battery cell classified as a degraded cell among the plurality of battery cells #1 to #N.

[0101] On the other hand, if the value of step S630 is "No", the balancing processing unit 130 may be controlled so that the balancing process of both the degraded cell and the normal cell is deactivated. Of course, the above process may also be configured to be recursively applied depending on whether the end condition is satisfied, as explained above. Depending on the embodiment, the step of checking whether the end condition is satisfied (S650) may be omitted.

[0102] In the following, reference Figure 2 , Figure 7 and Figure 8 , a specific embodiment of the present disclosure of classifying each of a plurality of battery cells #1 to #N as a degraded cell or a normal cell will be described in detail.

[0103] like Figure 2 As shown in , the monomer classification unit 150 may include an input unit 151, a calculation processing unit 153 and a selection unit 155.

[0104] refer to Fig.11 and Fig.12 etc., the behavior characteristics of the battery cells 51 will be described, and a specific function of the selection unit 155 for selecting degraded cells and normal cells by organically reflecting these behavior characteristics will be described in detail later.

[0105] Fig.11 is a graph referred to to illustratively explain a change in the SOC of the battery cell 51 over time. The SOC of the battery cell 51 may be included as a cell state parameter of the battery cell 51 .

[0106] refer to Fig.11 , the battery cell 51 has a behavior characteristic that the voltage value increases during the charging period (t0-t1). Therefore, the SOC estimated by applying the function operation to the voltage value of the battery cell 51 also exhibits an increasing behavior characteristic.

[0107] After charging is completed (for example, the fully charged state reaches SOC 100%), if other external factors such as standby current consumption are not taken into consideration, the SOC of the battery cell 51 is maintained constant during a rest period (t1 to t2) in which both charging and discharging are stopped. Subsequently, during a discharge period (t2 to t3) for driving a load device (motor, etc.), the voltage value and SOC of the battery cell 51 have a decreasing (reducing) behavior.

[0108] After the rest time (t3 to t4) after the discharge period (t2 to t3), the charge period (t4 to t5) may be performed again by an external power supply device or the like, and the voltage value and SOC of the battery cell 51 increase again during the charge period (t4 to t5). These behavior characteristics of the battery cell 51 are repeated in a time series during charge, rest and / or discharge.

[0109] Fig.11It is a diagram illustrated based on an embodiment in which full charge (SOC 100%) and full discharge (SOC 0%) are performed. The behavior characteristics in which the SOC of the battery cell 51 increases during charge (oblique line S1) and the SOC of the battery cell 51 decreases during discharge (oblique line S2) correspond to the basic characteristics of the battery cell 51.

[0110] For reference, in Fig.11 In the figures, for the sake of convenience, the behavior characteristics of the battery cell 51 are shown to change linearly over time. Of course, the actual behavior characteristics of the battery cell 51 may be a mixture of linear and nonlinear. Of course, when the measurement and generation of electrical characteristics are intermittently performed at a specific time period, if post-processing such as interpolation is not considered, it may be done discontinuously unlike the attached figure.

[0111] Fig.12 are diagrams referred to to explain the behavior characteristics of a normal cell N-Cell and a degraded cell D-Cell, respectively, and Fig.13 yes Fig.12 An enlarged view of the dashed area B shown in FIG.

[0112] As previously referenced Fig.11 It can be seen that the voltage values ​​of both the normal cell N-Cell and the degraded cell D-Cell increase during charging and decrease during discharging.

[0113] If performance deterioration occurs in the battery cell 51 due to aging depending on the usage period, as well as material characteristics, artificial usage environment, etc., the cause or factor causing such performance deterioration is mainly represented by an inherent resistance component, so the internal resistance of the cell where performance degradation or deterioration occurs and the corresponding resistance component (collectively referred to as 'internal resistance') increase.

[0114] According to the general law of correlation between voltage and current (Ohm's law), in a battery cell 51 having a relatively increased internal resistance, even when the same amount of current is introduced, a relatively higher voltage rise occurs due to the increased internal resistance compared to other battery cells 51. In other words, even if a relatively small current is introduced, the voltage rises to the same level as other battery cells 51.

[0115] As explained above, the SOC can be calculated as a function based on the voltage of the battery cell 51 , and thus the SOC also has a characteristic change corresponding to the change in voltage.

[0116] From the perspective of discharge, discharge is performed when the amount of charge (charge, current component) stored in the battery cell 51 is released to the outside, so when the same amount of current is released to the outside, the voltage drop is relatively larger than other battery cells 51 due to the deviation of the internal resistance.

[0117] refer to Fig.12 , in the same charging period (t0 to t1), the voltage of the degraded cell D-Cell increases greatly from Va2 to Va1, while the voltage of the normal cell N-Cell increases slightly from Vb2 to Vb1. In other words, in the case of the degraded cell D-Cell, the voltage change in the same charging period is relatively greater than that of the normal cell N-Cell.

[0118] In the same discharge period (t2 to t3), the voltage of the degraded cell D-Cell decreases from Va1 to Va2, while the voltage of the normal cell N-Cell decreases from Vb1 to Vb2, so during the discharge period (t2 to t3), the voltage change rate of the degraded cell D-Cell is greater than the voltage change rate of the normal cell N-Cell. In other words, in both the charging and discharging processes, the degraded cell D-Cell has a relatively large change rate of electrical characteristics (voltage, etc.) compared to the normal cell N-Cell.

[0119] In the accompanying drawings, the behavioral characteristics of the charging and discharging processes are shown to correspond to each other (symmetrically), however, due to the influence of external factors such as the power characteristics and specifications of the external power supply device, the load device (motor, etc.), and the inherent electrochemical properties in charging and discharging, the behavioral characteristics of the charging and discharging processes may not correspond (symmetrically).

[0120] Based on these behavioral characteristics, such as Fig.13 As shown in , the monomer behavior parameters of the normal monomer N-Cell and the degraded monomer D-Cell are expressed by the following equations respectively.

[0121] [Equation]

[0122]

[0123] In the above equation, It is a predetermined minute time. SD is the rate of change of the voltage value as the cell characteristic parameter of the degraded cell D-Cell. SN is the rate of change of the voltage value as the cell characteristic parameter of the normal cell N-Cell. Therefore, during charging, SD has a larger value than SN, and during discharging, SD has a larger value than SN (based on absolute value).

[0124] In this way, the level of performance degradation of the battery cell 51 can be effectively identified based on the voltage value of the battery cell 51 at a specific timing and / or the trend of change in the voltage value over time (cell behavior parameter).

[0125] Furthermore, by relatively comparing the magnitude (absolute value magnitude) of the hourly rate of change of each state parameter of each battery cell among the plurality of battery cells #1 to #N, the degree or magnitude of degradation of each battery cell among the plurality of battery cells #1 to #N can be mathematically quantified. That is, the plurality of battery cells #1 to #N can be ranked in descending or ascending order based on each cell behavior parameter (corresponding to the degree of degradation).

[0126] The cell classification unit 150 is configured to classify each of the plurality of battery cells #1 to #N as a degraded cell D-Cell or a normal cell N-Cell based on a plurality of cell behavior parameters representing behavior characteristics of an electrical state of each of the plurality of battery cells #1 to #N.

[0127] Figure 7 The explanation can be Figure 1 Flow chart of another example of a battery management method executed by a battery management device shown in .

[0128] refer to Figure 7 When the input unit 151 receives the cell state parameters (eg, voltage, SOC, etc.) of the battery cell 51 from the state detection unit 120 in time series ( S710 ), the calculation processing unit 153 calculates the cell behavior parameters representing the behavior characteristics of the cell state parameters of the battery cell 51 ( S720 ).

[0129] As seen above, the cell behavior parameter of any battery cell 51 may include the hourly change rate of the cell state parameter of the corresponding battery cell 51. Depending on the embodiment, the hourly change rate of SOC or the magnitude difference of SOC generated by functional processing of the difference of electrical characteristics, voltage values, etc. at each of multiple points or multiple time sections may be used as the behavior characteristic.

[0130] When the cell behavior parameters of the battery cells 51 are calculated, the selection unit 155 classifies each of the plurality of battery cells #1 to #N as a degraded cell D-Cell or a normal cell N-Cell based on the relative difference between the plurality of cell behavior parameters corresponding one-to-one to the plurality of battery cells #1 to #N.

[0131] If the number of target cells identified in step S730 is less than or equal to the set number (n, which is a natural number greater than or equal to 1 and less than N), all identified target cells may be classified as degraded cells. If the number of target cells identified in step S730 exceeds the set number (n), step S740 may be performed.

[0132] In step S740, the selection unit 155 may sort the plurality of cell behavior parameters mapped one-to-one to the plurality of target cells identified in step S730 in order of magnitude, and select each of the battery cells mapped to the set number (n) of cell behavior parameters corresponding to the higher ranking as a degraded cell D-Cell (S740). Each of the remaining battery cells that are not selected as the degraded cell D-Cell in step S740 is classified as a normal cell.

[0133] The setting number (n) may be a predetermined constant. Alternatively, the selection unit 155 may determine the setting number (n) based on environmental information such as battery efficiency, current output characteristics, specifications of a load device (motor, etc.), battery cell durability, battery cell usage period, charge / discharge cycle, SOH, etc. Of course, the above process may also be configured to be recursively applied depending on whether the end condition is met, as described above. Depending on the embodiment, the step of checking whether the end condition is met (S750) may be omitted.

[0134] In addition, the selection unit 155 may be configured to determine whether there are battery cells (hereinafter referred to as 'target cells') of the battery cells 51 whose cell behavior parameters (hourly change rate of the cell state parameter or its absolute value, etc.) are greater than or equal to the reference value (S730), and then select at least one of the target cells as a degraded cell D-Cell (S740).

[0135] In this way, according to an embodiment in which the target cell is predetermined before selecting the degraded cell D-Cell, errors due to noise signals, etc., the instantaneous nature of deviations, voltage deviations that do not adversely affect the normal operation of the battery, etc. can be filtered more accurately, thereby allowing the efficiency of differentiated applications of the balancing process to be further optimized.

[0136] The reference value (which may also be referred to as a 'reference change rate') may be set to a calculated average value, a weighted average value, a change rate with a standard deviation range, an average value excluding a maximum value and a minimum value, etc. of the cell behavior parameters of all battery cells #1 to #N constituting the battery module 50. The reference value may be separately predetermined for charging and discharging, respectively.

[0137] Additionally, based on the number of selected cells, the reference value may also be set to a value that allows the number of normal cells N-Cell to be greater than the number of degraded cells D-Cell. For example, if the total number N of battery cells #1 to #N included in the battery module 50 is 30, a value that allows the number of battery cells 51 classified as normal cells N-Cell to be at least 16 may be set as the reference change rate.

[0138] According to this embodiment configuration, the time period in which the balancing process is disabled can be optimized, and the energy consumption of the degraded single cell D-Cell can be appropriately limited through the balancing process, so that the output performance of the entire battery module 50 can be maintained without significantly deviating from the normal range.

[0139] In this way, if each of the plurality of battery cells #1 to #N is classified as a normal cell N-Cell or a degraded cell D-Cell, the control unit 140 may control the balancing process of the degraded cell D-Cell to be performed at least in the time section DA, such as Fig.12 The time section DA may belong to the charging period of the battery module 50 , and in the time section DA, the voltage value of the degraded cell D-Cell is greater than or equal to the voltage value of the normal cell N-Cell.

[0140] In the section (DI) in which the voltage value of the degraded cell D-Cell is lower than the voltage value of the normal cell N-Cell, that is, when the voltage value of the normal cell N-Cell is higher than the voltage value of the degraded cell D-Cell, even if a voltage deviation occurs, the control unit 140 controls the balancing process not to be performed. This time section (DI) may belong to the discharge period of the battery module 50.

[0141] Meanwhile, if the voltage deviations of all the battery cells among the plurality of battery cells #1 to #N are less than the reference deviation, the balancing process is naturally not performed on any one of the plurality of battery cells #1 to #N.

[0142] The battery management device 100 can perform the balancing process differentially by selecting normal cells N-Cell and degraded cells D-Cell and using the behavior characteristics of their electrical characteristics (voltage values, etc.). The following Table 1 is an example of operating conditions referred to in performing the balancing process.

[0143]

[0144] Figure 8 is a flowchart explaining a process of classifying each of a plurality of battery cells #1 to #N as a normal cell N-Cell or a degraded cell D-Cell.

[0145] refer to Figure 8 When the cell state parameters (e.g., voltage, etc.) of the battery cell 51 are input from the state detection unit 120 to the input unit 151 (S810), the calculation processing unit 153 calculates the cell behavior parameters according to the cell state parameters of the battery cell 51 (S820). Since the calculation contents of the cell behavior parameters, etc. are similar to those previously described with reference to Figure 7 The contents described correspond, so their detailed description will be omitted.

[0146] Subsequently, the selection unit 155 may be configured to select a degraded cell D-Cell or the like based on the charging process and the discharging process, respectively.

[0147] Specifically, in at least one of the discharging process and the charging process, the selection unit 155 may rank the plurality of battery cells #1 to #N by sorting the plurality of cell behavior parameters mapped one-to-one to the plurality of battery cells #1 to #N in order of size.

[0148] The selection unit 155 may be configured to perform a process of identifying whether there is a first target cell, which is a cell whose cell behavior parameter obtained during charging is greater than or equal to a first reference value (S830), and a process of identifying whether there is a second target cell, which is a cell whose cell behavior parameter (absolute value) obtained during discharging is greater than or equal to a second reference value (S840), based on a plurality of cell behavior parameters representing the behavior characteristics of each of the plurality of cell #1 to #N input in a time series from the calculation processing unit 153. The cell behavior parameter obtained during the charging process may be referred to as a first cell behavior parameter, and the cell behavior parameter obtained during the discharging process may be referred to as a second cell behavior parameter. The first reference value may be an average value of the first cell behavior parameters of the plurality of cell #1 to #N. The second reference value may be an average value of the second cell behavior parameters of the plurality of cell #1 to #N.

[0149] In order to optimize each reference value, the time length of the charging process for determining the first cell behavior parameter and the time length of the discharging process for determining the second cell behavior parameter may be respectively set to a predetermined reference time or longer.

[0150] In this way, a process of checking whether a cell behavior parameter of each of a plurality of battery cells #1 to #N is greater than or equal to a first reference value based on the charging time and a process of checking whether a cell behavior parameter of each of a plurality of battery cells #1 to #N is greater than or equal to a second reference value based on the discharging time can be performed in advance.

[0151] The selection unit 155 may be configured to select the battery cell 51 identified as having a cell behavior parameter greater than or equal to a reference value in both the charging process and the discharging process among the plurality of battery cells #1 to #N as a degraded cell D-Cell (S850).

[0152] In step S850, when the number of battery cells corresponding to both the first target cell and the second target cell among the plurality of battery cells #1 to #N is less than or equal to a threshold number (m, where m is a natural number greater than or equal to 1 and less than N), each battery cell corresponding to both the first target cell and the second target cell can be selected as a degraded cell D-Cell.

[0153] On the other hand, if the number of battery cells corresponding to both the first target cell and the second target cell among the plurality of battery cells #1 to #N exceeds the threshold number (m), the selection unit 155 may select only the threshold number (m) of battery cells among the battery cells corresponding to both the first target cell and the second target cell as degraded cells D-Cell (S850). In this case, each of the threshold number (m) of battery cells may be selected as a degraded cell D-Cell in descending order of the average value of the cell behavior parameter associated with the charging process and the cell behavior parameter associated with the discharging process.

[0154] According to this embodiment configuration, as described above, errors due to noise signals and the like, as well as time deviations and the like can be eliminated in advance, thereby improving the overall efficiency and accuracy of the balancing process.

[0155] The threshold number (m) may be a predetermined constant. Alternatively, the threshold number (m) is desirably configured to be variably set based on environmental information such as battery efficiency, current output characteristics, specifications of a load device (motor, etc.), battery cell durability, battery cell usage period, charge / discharge cycle, SOH, etc.

[0156] Although the figures do not separately show the input / output or measured data or information, calculated data or information, etc., it goes without saying that they can be stored, updated, read, and utilized in the hardware device that implements the corresponding functions. Figure 8 The process shown in can also be designed to be applied cyclically. Depending on the embodiment, the step of checking whether the end condition is satisfied (S860) may be omitted.

[0157] The control unit 140 may intentionally not perform the balancing process on the normal cell N-Cell in the time segment in which the voltage of the normal cell N-Cell is maintained higher than the voltage of the degraded cell D-Cell. On the other hand, the balancing process may be controlled to be performed on the degraded cell D-Cell only in the time segment in which the voltage of the degraded cell D-Cell is maintained higher than the voltage of the normal cell N-Cell.

[0158] Therefore, it is possible to prevent the energy charged in a normal single cell N-Cell having sufficient available capacity and excellent behavioral characteristics from being unnecessarily consumed by the balancing process, and it is possible to effectively solve the problem of the available capacity of the battery module 50 not being fully utilized due to the SOC of the battery module 50 being limited prematurely due to the behavioral characteristics of the degraded single cell D-Cell.

[0159] The control unit 140 may be configured to transmit various information and data generated by the above-described processes to an external control device 200 installed in an electric vehicle or the like through the interface unit 160. The control unit 140 may be configured to perform various processes according to the present disclosure based on a control signal or a setting value received from the external control device 200 through the interface unit 160.

[0160] In addition, when it is confirmed that a battery cell (e.g., #1) is selected as a degraded cell D-Cell continuously within a certain period of time or repeatedly within a certain number of times, the cell classification unit 150 or the control unit 140 can be configured to send an alarm message about the need to replace the battery cell (e.g., #1) to the external control device 200 through the interface unit 160.

[0161] In this regard, when identification information of the battery cells 51 constituting the battery module 50 is previously stored in a database, information physically identifying the battery cells 51 classified as degraded cells D-Cell may also be transmitted to the external control device 200 together with the alarm information.

[0162] Figure 3 is a block diagram schematically showing a configuration of a battery pack according to another embodiment of the present disclosure, and Fig. 9 The explanation can be Figure 3 Flow chart of the process performed by the battery management device shown in .

[0163] Figure 3 The battery pack 10 shown in FIG. 1 includes a battery module 50 and a battery management device 100 .

[0164] The battery management apparatus 100 is provided to control by reflecting a reference SOC or a statistical value calculated by a user's charging and discharging pattern, etc., so that a balancing process of each of the plurality of battery cells #1 to #N is differentially performed.

[0165] Relative to Figure 1 The detailed configuration shown in Figure 3 It is shown that the reference processing unit 170 is replaced by the cell classification unit 150. However, this is merely one embodiment, and the battery management device 100 may also be implemented as an embodiment including both the reference processing unit 170 and the cell classification unit 150.

[0166] The reference processing unit 170 stores a reference SOC used for differential control of the balancing process performed by the balancing processing unit 130 .

[0167] In step S910 , the state detection unit 120 obtains a plurality of cell state parameters (eg, voltage values, etc.) mapped one-to-one to the plurality of battery cells # 1 to #N from the measurement unit 110 .

[0168] In step S920, the state detection unit 120 calculates a module state parameter indicating an electrical state of the battery module 50 based on the plurality of cell state parameters. The module state parameter includes the SOC of the battery module 50. The SOC of the battery module 50 may be an average value, a minimum value, or a maximum value of the SOCs of the plurality of battery cells #1 to #N based on the plurality of cell state parameters.

[0169] In step S930, the control unit 140 may determine whether the module state parameter (e.g., SOC, etc.) at the current point is greater than or equal to the reference SOC stored in the reference processing unit 170. If the value of step S930 is "yes", the process may proceed to step S932. The value of step S930 is "no" which means that the module state parameter is less than the reference SOC. If the value of step S930 is "no", the process may proceed to step S934.

[0170] In step S932, the control unit 140 may determine whether the voltage of the degraded cell is higher than the voltage of the normal cell. If the value of step S932 is "yes", the process may proceed to step S940.

[0171] In step S934, the control unit 140 may determine whether the voltage of the normal cell is higher than the voltage of the degraded cell. If the value of step S934 is "yes", the process may proceed to step S940.

[0172] In step S940 , the control unit 140 may control the balancing processing unit 130 to perform a balancing process on at least one battery cell classified as a degraded cell D-Cell among the plurality of battery cells # 1 to #N.

[0173] When the process proceeds from step S932 to step S940, the control unit 140 may control Fig.16 The balancing processing unit 130 shown in FIG. performs a balancing process on the degraded cell D-Cell. On the other hand, when the process proceeds from step S934 to step S940, the control unit 140 may control Fig.17 The balancing processing unit 130 shown in FIG. 1 performs a balancing process on the degraded cell D-Cell.

[0174] Of course, the above process may also be configured to be applied recursively depending on whether the end condition is met, as described above. Depending on the embodiment, the step of checking whether the end condition is met (S950) may be omitted.

[0175] In this regard, in order to classify each of the plurality of battery cells #1 to #N as a degraded cell D-Cell or a normal cell N-Cell, at least one of a charging process and a discharging process may need to be performed before this. Therefore, the charging process and the discharging process performed before the cell classification process may be referred to as a preliminary charging process and a preliminary discharging process, respectively.

[0176] For example, Figure 5 Step S510, Figure 6 Step S610, Figure 7 Step S710, Figure 8 Step S810 and Fig. 9 The steps S910 may each be performed while at least one of the preliminary charging process and the preliminary discharging process is being performed.

[0177] in addition, Figure 5 Step S540, Figure 6 Step S640 and Fig. 9 The step S940 may be performed in the charging process and / or the discharging process after the preliminary charging process and / or the preliminary discharging process, respectively.

[0178] As mentioned above Fig.11 As described in , the monomer behavior parameters of the degraded monomer D-Cell may be relatively greater than the monomer behavior parameters of the normal monomer N-Cell. In other words, when the same current flows, the degraded monomer D-Cell has a higher behavior characteristic of charge and discharge rate than the normal monomer N-Cell.

[0179] The SOC of the battery module 50 may be determined according to the battery cell 51 having a relatively higher voltage among the plurality of battery cells # 1 to #N.

[0180] Assuming that the SOC of the battery module 50 is higher than an appropriate level, it can be said that among the plurality of battery cells #1 to #N, a battery cell having a higher voltage has a higher probability of being determined as a deteriorated cell D-Cell than other battery cells.

[0181] From a corresponding perspective, if the SOC of the battery module 50 is lower than an appropriate level, the battery cell 51 having a relatively high voltage is more likely to be determined as a normal cell N-Cell than other battery cells.

[0182] Taking these points into consideration, the reference processing unit 170 may set the reference SOC to a value matching the overall behavior characteristics of the battery module 50 .

[0183] When the current SOC of the battery module 50 is higher than the reference SOC, the control unit 140 may control the balancing process to be performed on the degraded cell D-Cell.

[0184] On the other hand, when the current SOC of the battery module 50 is less than the reference SOC, the control unit 140 may deactivate the balancing process for both the degraded cell D-Cell and the normal cell N-Cell.

[0185] If the balancing process is controlled to be performed differentially in this way, it is possible to solve not only the problem that the energy stored in the normal single cell N-Cell is repeatedly and unnecessarily consumed so that the available capacity of the battery module 50 cannot be fully used as a driving source, but also various problems derived therefrom, such as performance degradation, shortened life, overcharging, etc.

[0186] refer to Fig.14 , the first SOC section (Section 1) corresponds to the SOC of the battery module 50 being greater than or equal to the reference SOC (Z R ), and the second SOC section (Section 2) corresponds to the SOC of the battery module 50 being less than the reference SOC (Z R ) area.

[0187] The first SOC section (Section 1) can be estimated as a region where the influence of the degraded cell D-Cell is relatively large. Therefore, the control unit 140 can control the balancing processing unit 130 to activate the balancing process of the degraded cell D-Cell in the time section DA from Ta to Tb corresponding to the first SOC section (Section 1).

[0188] The second SOC section (Section 2) may correspond to a region where the influence of the normal cell N-Cell is relatively large. Therefore, the control unit 140 may control the balancing processing unit 130 so that the balancing process of all the battery cells #1 to #N among the plurality of battery cells is not performed in the time section (DI) from Tb to Tc corresponding to the second SOC section (Section 2).

[0189] Figure 4 It is schematically shown Figure 3 , and Fig.10 is a flowchart referred to to explain a process of determining a reference SOC.

[0190] refer to Figure 4, the reference processing unit 170 may include an SOC information storage unit 171 , a statistical processing unit 173 , a reference setting unit 175 , and an SOH calculation unit 177 .

[0191] Each time the charging process of the battery module 50 is performed, the SOC information storage unit 171 may store the first SOC and the second SOC in conjunction with the state detection unit 120 by mapping the first SOC, which is the SOC of the battery module 50 at the starting point of the charging process, and the second SOC, which is the SOC of the battery module 50 at the ending point, to the turn number of the charging process. Therefore, the first SOC time series data and the second SOC time series data may be stored in the SOC information storage unit 171.

[0192] The first SOC time series data includes first to (k-1)th starting SOCs, which represent the SOC of the battery module 50 at each starting point of the first to (k-1)th charging processes performed on the battery module 50 in the past. k is an index indicating a turn of the most recent charging process, and is a natural number of 2 or more. That is, k increases by 1 each time the previous charging process of the battery module 50 is completed and a new charging process is performed.

[0193] The second SOC time series data includes first to (k-1)th ending SOCs, which represent the SOC of the battery module 50 at each ending point of the first to (k-1)th charging processes.

[0194] In step S1010 , the statistical processing unit 173 obtains the first SOC time series data and the second SOC time series data from the SOC information storage unit 171 .

[0195] In step S1020, the statistical processing unit 173 may extract the (kj)th to (k-1)th starting SOCs from the first SOC time series data. Additionally, the statistical processing unit 173 may extract the (kj)th to (k-1)th ending SOCs from the second SOC time series data. Wherein, j is a reference number.

[0196] The reference number (j) may be a predetermined natural number greater than or equal to 1. Alternatively, the statistical processing unit 173 may determine the reference number (j) based on the SOH of the battery module.

[0197] In step S1030, the statistics processing unit 173 may calculate the SOC statistics as an average value of the (kj)th to (k-1)th starting SOCs and the (kj)th to (k-1)th ending SOCs. The SOC statistics may be used to calculate a reference SOC to be applied in a period from the end of the (k-1)th charging process to the start of the (k+1)th charging process.

[0198] In step S1040 , the reference setting unit 175 determines a reference SOC based on the SOC statistical value calculated by the statistical processing unit 173 .

[0199] according to Fig.10 The method may be configured to be recursively applied depending on whether an end condition is satisfied. Depending on the embodiment, the step of checking whether the end condition is satisfied (S1060) may be omitted.

[0200] The statistics processing unit 173 may update the first SOC time series data, the second SOC time series data, and the SOC statistics used in the previous round of the charging process each time a new round of the charging process is completed.

[0201] For example, if the current charging process is the 31st charging process (i.e., k=31), 30 first SOCs and 30 second SOCs may have been stored in the SOC information storage unit 171 through the first to 30th charging processes. The statistics processing unit 173 may calculate the SOC statistics of the current charging process based on at least one of the 30 first SOCs and at least one of the 30 second SOCs.

[0202] Depending on the embodiment, the statistics processing unit 173 may calculate the SOC statistics by selectively using only S (greater than or equal to 1 and less than k) first SOCs and second SOCs in reverse order based on the current order. For example, when k=31 and S=5, the SOC statistics of the current charging process may be calculated based on the 5 first SOCs and 5 second SOCs obtained in the 26th to 30th charging processes.

[0203] According to this embodiment configuration, the SOC statistical value is calculated using the latest result, so the past charging and discharging pattern of the battery module 50 can be more efficiently reflected in the differentiated execution of the balancing process.

[0204] As an example, the SOC statistic may be an average of S first SOCs and S second SOCs. The reference setting unit 175 may determine the reference SOC to be the same as the SOC statistic or the same as a value obtained by multiplying the SOC statistic by a correction coefficient. The correction coefficient may be a predetermined constant or an adjustable value based on the SOH of the battery module 50.

[0205] Fig.15 is a diagram referred to to explain the differential balancing process achieved when the reference SOC is 80%. Fig.15 , the SOC swing range is illustrated as 60% to 100%, and the reference SOC is 80%, which is the exact center of the SOC swing range.

[0206] Fig.15 The embodiment shown in may not be completely the same as the above-mentioned embodiment in which the balancing process is differentially performed by calculating and comparing the voltage values ​​(electrical characteristics) of the degraded cells D-Cell and the normal cells N-Cell. However, as described above, the method using the SOC value of the battery module 50 inherently reflects the behavioral characteristics of the degraded cells D-Cell and the normal cells N-Cell, so both can provide corresponding results.

[0207] At the same time, the SOH calculation unit 177 can be configured to calculate the SOH of the battery cell 51 and / or the battery module 50 using information about the electrical characteristics of the battery cell 51 or the battery module 50 input from the status detection unit 120, previously stored information such as the durability or life of the battery cell 51, etc.

[0208] SOH is information indicating a degree of degradation, and as the degree of degradation increases, the rate of change of electrical characteristics accelerates due to an increase in internal resistance.

[0209] Therefore, the reference setting unit 175 may further determine the reference SOC based on the SOH of the battery module 50. As an example, the reference setting unit 175 may determine the correction coefficient corresponding to the current SOH of the battery module 50 based on a predetermined negative correspondence between the SOH and the correction coefficient, and then determine the reference SOC by multiplying the determined correction coefficient by the SOC statistical value. According to this, as the SOH of the battery module 50 decreases, the correction coefficient increases. Therefore, even if the SOC statistical value is the same, as the SOH of the battery module 50 decreases, the reference SOC increases.

[0210] As mentioned above, if the reference SOC is determined by reflecting the SOH of the battery module 50, the section in which the cell state parameter of the degraded cell D-Cell is higher than the cell state parameter of the normal cell N-Cell can be more accurately distinguished, thereby also increasing the efficiency of the differentiated balancing process.

[0211] The battery pack 10 may include various other components in addition to the battery module 50 and the battery management device 100 , for example, components of a battery pack known at the time of filing of the present disclosure, such as a BMS, a bus bar, a pack case, a relay, a current sensor, etc.

[0212] The battery management device 100 may be included in an electric vehicle. That is, the electric vehicle according to the present disclosure may include the aforementioned battery management device 100 or a battery pack including the battery management device 100. In addition, the electric vehicle according to the present disclosure may include various other components such as a vehicle body, a motor, and an ECU (electronic control unit) in addition to the battery management device 100 or the battery pack.

[0213] Fig.16 is referred to schematically to explain Figure 1 and Figure 3 An example of a balanced processing unit is shown in FIG. To aid understanding, Fig.16 The configuration of the balancing processing unit 130 and the coupling relationship between the battery module 50 and the balancing processing unit 130 are shown.

[0214] refer to Fig.16 , the balancing processing unit 130 may include a plurality of step-down balancing circuits D#1 to D#N.

[0215] The control unit 140 is operably coupled to the plurality of buck balancing circuits D#1 to D#N to output a control signal to each of the plurality of buck balancing circuits D#1 to D#N.

[0216] The control signal output from the control unit 140 to each of the plurality of buck balancing circuits D# 1 to D#N may be a PWM (Pulse Width Modulation) signal in which a high level voltage and a low level voltage are alternately repeated.

[0217] The plurality of buck balancing circuits D#1 to D#N are provided one-to-one with the plurality of battery cells #1 to #N. In other words, when i is a natural number N or less, the buck balancing circuit D#i is provided to selectively implement the balancing process of the battery cell #i.

[0218] The buck balancing circuit D#i may include a balancing switch SW and a resistor R. In other words, the buck balancing circuit D#i includes a series circuit of the balancing switch SW and the resistor R. The buck balancing circuit D#i is connected in parallel to the battery cell #i.

[0219] The balancing switch SW may be turned on in response to a control signal from the control unit 140 being a high level voltage. The balancing switch SW may be turned off in response to a control signal from the control unit 140 being a low level voltage.

[0220] When the balancing switch SW is turned on, a closed circuit including the step-down balancing circuit D#i and the battery cell #i is formed, and current flows through the closed circuit.

[0221] During a rest period (eg, Fig.14 When the balancing switch SW of the step-down balancing circuit D#i is turned on during the period from time t1 to t2 in FIG. 5 , the energy stored in the battery cell #i is consumed by the step-down balancing circuit D#i, and the cell state parameter of the battery cell #i gradually deteriorates.

[0222] When the battery module 50 is in a charging period (eg, Fig.14When the balancing switch SW of the step-down balancing circuit D#i is turned on during the period from time Ta to t1, the charging current of the battery module 50 is distributed to the battery cell #i and the step-down balancing circuit D#i. Therefore, the charging speed of the battery cell #i is slowed down.

[0223] When in the discharge period of the battery module 50 (for example, Fig.14 When the balancing switch SW of the step-down balancing circuit D#i is turned on during the time from t2 to Tb), the battery cell #i can be additionally discharged not only by the discharge current of the battery module 50 but also by the step-down balancing circuit D#i. Therefore, the discharge speed of the battery cell #i becomes faster.

[0224] <Balance process of only degraded monomers among normal monomers and degraded monomers>

[0225] Assume that battery cell #1 is a degraded cell D-Cell and battery cell #2 is a normal cell N-Cell. Then, in the range corresponding to the SOC being greater than or equal to the reference SOC (Z R ) period (for example, Fig.14 During the period from time Ta to time Tb in FIG. 1 , the balancing switch SW of the buck balancing circuit D#1 provided to the battery cell #1 will remain turned on, while the balancing switch SW of the buck balancing circuit D#2 provided to the battery cell #2 will remain turned off. In other words, the balancing process of the battery cell #1 and the battery cell #2 is performed differentially.

[0226] During the charging period (e.g. Fig.14 In the period from time Ta to t1, the charging speed of only the battery cell #1 is reduced among the battery cell #1 and the battery cell #2.

[0227] During rest periods (e.g. Fig.14 In the period from time t1 to time t2, only battery cell #1 is discharged among battery cell #1 and battery cell #2.

[0228] During the discharge period (e.g. Fig.14 In the period from time t2 to Tb), the discharge rate of battery cell #1 is faster than the discharge rate of battery cell #2.

[0229] As a result, a differentiated balancing process is implemented during the period from time Ta to time Tb, so that the cell state parameters of battery cell #1 as a degraded cell D-Cell and the cell state parameters of battery cell #2 as a normal cell N-Cell can be efficiently balanced.

[0230] <Balance process of normal monomers only among normal monomers and degraded monomers>

[0231] Assume that battery cell #1 is a degraded cell D-Cell and battery cell #2 is a normal cell N-Cell. Then, in the range corresponding to the SOC being less than or equal to the reference SOC (Z R ) period (for example, Fig.14 During the period from time Tb to time Tc in FIG. 1 , the balancing switch SW of the buck balancing circuit D#1 provided to the battery cell #1 will remain turned off, while the balancing switch SW of the buck balancing circuit D#2 provided to the battery cell #2 will remain turned on. In other words, the balancing process of the battery cell #1 and the battery cell #2 is performed differentially.

[0232] During the discharge period (e.g. Fig.14 During the period from time Tb to time t3), the discharge rate of battery cell #2 is accelerated by the step-down balancing circuit D#2.

[0233] During rest periods (e.g. Fig.14 In the period from time t3 to time t4 ), only the battery cell #2 is discharged among the battery cell #1 and the battery cell #2.

[0234] During the charging period (e.g. Fig.14 In the period from time t4 to Tc), of the battery cell #1 and the battery cell #2, only the charging speed of the battery cell #2 is reduced by the step-down balancing circuit D#2.

[0235] As a result, a differentiated balancing process is implemented during the period from time Tb to time Tc, so the cell state parameters of battery cell #1 as a degraded cell D-Cell and the cell state parameters of battery cell #2 as a normal cell N-Cell can be efficiently balanced.

[0236] Fig.17 is referred to schematically to explain Figure 1 and Figure 3 To help understand, Fig.17 The configuration of the balancing processing unit 130 and the coupling relationship between the battery module 50 and the balancing processing unit 130 are shown.

[0237] and Fig.16 Compared with the balancing processing unit 130 shown in FIG. Fig.17 The balancing processing unit 130 shown in FIG. 1 may include a plurality of boosting balancing circuits U# 1 to U#N.

[0238] The control unit 140 is operably coupled to the plurality of boost balancing circuits U#1 to U#N to output a control signal to each of the plurality of boost balancing circuits U#1 to U#N.

[0239] The plurality of boost balancing circuits U#1 to U#N are provided one-to-one with the plurality of battery cells #1 to #N. In other words, when i is a natural number less than or equal to N, the boost balancing circuit U#i is provided to selectively implement the balancing process of the battery cell #i.

[0240] The boost balancing circuit U#i may be a DC voltage source, such as a DC-DC converter.

[0241] The boost balancing circuit U#i supplies charging power to the battery cell #i during operation in response to a control signal from the control unit 140 .

[0242] When the boost balancing circuit U#i is in the discharge period of the battery module 50 (for example, Fig.14 When operating during the period from time Tb to t3 in FIG. 1 , the discharge power of the battery cell #i is compensated by the charge power supplied from the step-up balancing circuit U#i. As a result, the discharge speed of the battery cell #i is slowed down.

[0243] When the boost balancing circuit U#i is in the rest period of the battery module 50 (for example, Fig.14 When operating during the period from time t3 to t4 in FIG. 1 , the cell state parameter of battery cell #i gradually increases.

[0244] When the boost balancing circuit U#i is in the charging period of the battery module 50 (for example, Fig.14 When operating during the period from time t4 to Tc in FIG. 1 , the battery cell #i can be charged not only by the charging current of the battery module 50 but also by the boost balancing circuit U#i. Therefore, the charging speed of the battery cell #i becomes faster.

[0245] <Balance process of only degraded monomers among normal monomers and degraded monomers>

[0246] Assume that battery cell #1 is a degraded cell D-Cell and battery cell #2 is a normal cell N-Cell. Then, in the range corresponding to the SOC being less than or equal to the reference SOC (Z R ) time period (e.g. Fig.14 During the period from time Tb to time Tc in FIG. 1 , the boost balancing circuit U#1 provided in the battery cell #1 will operate, while the boost balancing circuit U#2 provided to the battery cell #2 will stop operating.

[0247] During the discharge period (e.g. Fig.14 During the period from time Tb to t3 in FIG. 1 , the discharge rate of only the battery cell #1 among the battery cell #1 and the battery cell #2 decreases.

[0248] During rest periods (e.g. Fig.14During the period from time t3 to time t4 in FIG. 1 , only battery cell #1 is independently charged among battery cell #1 and battery cell #2.

[0249] During the charging period (e.g. Fig.14 During the period from time t4 to Tc), the charging speed of battery cell #1 is faster than the charging speed of battery cell #2.

[0250] As a result, a differentiated balancing process is implemented during the period from time Tb to time Tc, so the cell state parameters of battery cell #1 as a degraded cell D-Cell and the cell state parameters of battery cell #2 as a normal cell N-Cell can be efficiently balanced.

[0251] <Balance process of normal monomers only among normal monomers and degraded monomers>

[0252] Assume that battery cell #1 is a degraded cell D-Cell and battery cell #2 is a normal cell N-Cell. Then, in the range corresponding to the SOC being greater than or equal to the reference SOC (Z R ) time period (e.g. Fig.14 During the period from time Ta to time Tb in FIG. 1 , the boost balancing circuit U#1 provided to the battery cell #1 will not operate, while the boost balancing circuit U#2 provided in the battery cell #2 will operate.

[0253] During the charging period (e.g. Fig.14 During the period from time Ta to t1), the charging speed of battery cell #2 can be accelerated by the boost balancing circuit U#2.

[0254] During rest periods (e.g. Fig.14 In the period from time t1 to time t2), only battery cell #2 is independently charged among battery cell #1 and battery cell #2.

[0255] During the discharge period (e.g. Fig.14 In the period from time t2 to Tb), the discharge rate of only the battery cell #2 among the battery cell #1 and the battery cell #2 is reduced by the boost balancing circuit U#2.

[0256] As a result, a differentiated balancing process is implemented during the period from time Ta to time Tb, so the cell state parameters of battery cell #1 as a degraded cell D-Cell and the cell state parameters of battery cell #2 as a normal cell N-Cell can be efficiently balanced.

[0257] Meanwhile, the balancing processing unit 130 may include Fig.16 The step-down balancing circuit D#1 to D#N and the Fig.17 Both the boost balancing circuits U#1 to U#N.

[0258] Assume that the battery cell #1 is a degraded cell D-Cell, and the battery cell #2 is a normal cell N-Cell.

[0259] Then, at least temporarily, in a range corresponding to an SOC greater than or equal to the reference SOC (Z R ), during the period from time Ta to time Tb, the balancing switch SW of the step-down balancing circuit D#1 provided to the battery cell #1 may be controlled to be turned on, and the step-up balancing circuit U#2 provided to the battery cell #2 may be controlled to be in an operating state.

[0260] At least temporarily in a range corresponding to an SOC less than or equal to a reference SOC (Z R ), during the period from time Tb to time Tc of the battery cell #1, the boost balancing circuit U#2 provided to the battery cell #1 may be controlled to be in an operating state, and the boost balancing switch SW provided to the battery cell #2 may be controlled to be turned on.

[0261] The balancing process using the step-down balancing circuits D#1 to D#N may be referred to as a step-down balancing process, a passive balancing process, or a first balancing process.

[0262] The balancing process using the boosting balancing circuits U# 1 to U#N may be referred to as a boosting balancing process, an active balancing process, or a second balancing process.

[0263] The embodiments of the present disclosure described above can be implemented not only by means of devices and methods, but also by a program that implements functions corresponding to the configuration of the embodiments of the present disclosure or a recording medium on which the program is recorded. Those skilled in the art can easily implement the program or recording medium from the above description of the embodiments.

[0264] The present disclosure has been described in detail. However, it should be understood that although the detailed description and specific examples indicate preferred embodiments of the present disclosure, these detailed descriptions and specific examples are given by way of illustration only, because various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art based on these detailed descriptions.

[0265] Additionally, those skilled in the art may make many substitutions, modifications and changes to the disclosure described above without departing from the technical aspects of the disclosure, and the disclosure is not limited to the above-described embodiments and drawings, and each embodiment may be selectively combined in part or in whole to allow various modifications.

Claims

1. A battery management device for a battery module including a plurality of battery cells, comprising: a state detection unit configured to obtain a plurality of cell state parameters indicating an electrical state of each of the plurality of battery cells; a balancing processing unit configured to perform a balancing process to suppress the deviation of the electrical state between the plurality of battery cells, the balancing process being a process of selectively discharging or charging each of the plurality of battery cells; as well as A control unit is configured to control the balancing processing unit to perform the balancing process on at least one battery cell among the plurality of battery cells based on the plurality of cell state parameters.

2. The battery management device according to claim 1, further comprising a cell classification unit configured to classify each of the plurality of battery cells as a deteriorated cell or a normal cell based on the plurality of cell state parameters, in, The control unit is configured to control the balancing processing unit so that the balancing process is differentially performed based on the cell state parameters of the degraded cells and the cell state parameters of the normal cells.

3. The battery management device according to claim 2, wherein: The control unit is configured to control the balancing processing unit so that the balancing process is performed on the degraded cell when the cell state parameter of the degraded cell is greater than the cell state parameter of the normal cell, and The cell state parameter indicates at least one of voltage and SOC (state of charge).

4. The battery management device according to claim 2, wherein: The monomeric taxonomic units include: an input unit, the input unit being configured to obtain the plurality of monomer state parameters from the state detection unit; a calculation processing unit configured to calculate a plurality of battery cell behavior parameters based on the plurality of battery cell state parameters, the plurality of battery cell behavior parameters representing behavior characteristics of an electrical state of each of the plurality of battery cells; and A selection unit is configured to classify each of the plurality of battery cells as the degraded cell or the normal cell based on a relative difference between the plurality of battery cell behavior parameters.

5. The battery management device according to claim 4, wherein: The monomer behavior parameter includes the rate of change of the monomer state parameter, and The cell classification unit is configured to classify each battery cell mapped to n cell behavior parameters ranked higher in size among the plurality of cell behavior parameters as the degraded cell, wherein n is a natural number of 1 or greater.

6. The battery management device according to claim 4, wherein: The monomer behavior parameter includes the rate of change of the monomer state parameter, and Among them, the cell classification unit is configured to select each battery cell that meets the following two conditions as the degraded cell: the cell behavior parameter of the battery module during charging is greater than or equal to a first reference value and the cell behavior parameter of the battery module during discharging is greater than or equal to a second reference value.

7. The battery management device according to claim 2, wherein: The state detection unit is configured to obtain the SOC of the battery module as a module state parameter representing the electrical state of the battery module, and The control unit is configured to control the balancing processing unit so that the balancing process is performed on the degraded cell under the condition that the module state parameter is greater than or equal to a reference SOC during charging of the battery module.

8. The battery management device according to claim 7, further comprising: An SOC information storage unit configured to store first SOC time series data and second SOC time series data; a statistical processing unit configured to calculate an SOC statistical value based on the first SOC time series data and the second SOC time series data; as well as a reference setting unit configured to set the reference SOC to be equal to the SOC statistical value, The first SOC time series data includes first to k-1th starting SOCs, wherein the first to k-1th starting SOCs represent the SOCs of the battery module at the starting point of each of the first to k-1th charging processes performed on the battery module in the past, wherein the second SOC time series data includes first to k-1th ending SOCs, the first to k-1th ending SOCs representing the SOCs of the battery module at the end point of each of the first to k-1th charging processes, and Here, k is a natural number of 2 or greater.

9. The battery management device according to claim 8, wherein: The statistical processing unit is configured to calculate the SOC statistical value further based on the SOH of the battery module.

10. The battery management device according to claim 9, wherein: The statistical processing unit is configured to: determining a reference number based on the SOH of the battery module, Extract the kjth to k-1th starting SOC from the first SOC time series data, Extracting kj-th to k-1-th ending SOC from the second SOC time series data, and The SOC statistical value is calculated to be the same as the average value of the kj-th to k-1-th starting SOC and the kj-th to k-1-th ending SOC, Wherein, j is the reference number.

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

12. An electric vehicle comprising the battery pack according to claim 11.

13. A battery control method capable of being executed by the battery management device according to any one of claims 1 to 10, comprising: obtaining, by a state detection unit, a plurality of cell state parameters indicating an electrical state of each of the plurality of battery cells; as well as The control unit controls the balancing processing unit to perform a balancing process on at least one battery cell among the plurality of battery cells based on the plurality of cell state parameters to suppress deviations in electrical states among the plurality of battery cells.

14. The battery control method according to claim 13, wherein: The step of controlling the balancing processing unit comprises: classifying each of the plurality of battery cells as a degraded cell or a normal cell based on the plurality of cell state parameters; and The balancing processing unit is controlled so that the balancing process is differentially performed based on the cell state parameters of the degraded cells and the cell state parameters of the normal cells.

15. The battery control method according to claim 14, wherein: The step of controlling the balancing processing unit comprises: obtaining the SOC of the battery module as a module state parameter representing the electrical state of the battery module; and The balancing processing unit is controlled so that the balancing process is performed on the degraded cell under the condition that the module state parameter is greater than or equal to a reference SOC during charging of the battery module.

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