Battery management device and method of operation thereof

Abstract

A battery management device according to one embodiment disclosed in this document includes a voltage measurement unit that measures the voltage of each of a plurality of battery banks, and a controller, wherein the controller selects a first value for each of the plurality of battery banks based on a first value that is the amount of change in voltage of each of the plurality of battery banks during a certain period and a second value that is the standard deviation of the amount of voltage change per unit time of each of the plurality of battery banks, sets a rank for each of the plurality of battery banks based on a first reference value that indicates the ratio of the selected first value for each of the plurality of battery banks to the average value of the selected first values ​​for each of the plurality of battery banks, and diagnoses an abnormality in at least one of the plurality of battery banks based on the rank of each of the plurality of battery banks at a specific point in time.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0172718, filed December 1, 2023, Korean Patent Application No. 10-2023-0047829, filed April 11, 2023, and Korean Patent Application No. 10-2022-0182381, filed December 22, 2022, and all contents disclosed in the documents of these patent applications are incorporated herein by reference.

[0002] SUMMARY OF THE INVENTION The embodiments disclosed herein relate to a battery management device, a method of operation thereof, and a storage device. [Background technology]

[0003] Electric vehicles generate power by charging batteries with an external power supply and then driving a motor with the voltage charged in the battery. Batteries undergo internal deformation and modification due to various charging and discharging processes during production and use, which can cause changes in their physicochemical properties. This can lead to defects in which lithium ions released from the battery's positive electrode are not reduced into the negative electrode and instead precipitate on the surface of the negative electrode.

[0004] If the lithium deposition (dendrite) phenomenon is repeated continuously, an internal short circuit may occur between the negative and positive electrodes of the battery, and the battery with the internal short circuit may experience an undervoltage fault, where the voltage drops below a certain level, or an increased risk of fire. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the embodiments disclosed herein is to provide a battery management device and an operating method thereof that can accurately diagnose an abnormal battery bank using the voltage behavior of the battery bank during rest periods. [Means for solving the problem]

[0006] In some embodiments, the battery management device includes a voltage measurement unit that measures the voltage of each of a plurality of battery banks; and a controller, the controller being capable of communicating with the voltage measurement unit and configured to select a first value for each of the plurality of battery banks based on a first value that is an amount of change in voltage of each of the plurality of battery banks during a certain period and a second value that is a standard deviation of the amount of change in voltage per unit time for each of the plurality of battery banks, set a rank for each of the plurality of battery banks based on a first reference value that indicates a ratio of the selected first value for each of the plurality of battery banks to an average value of the selected first values ​​for each of the plurality of battery banks, and diagnose an abnormality in at least one of the plurality of battery banks based on the rank of each of the plurality of battery banks at a specific time point.

[0007] In some embodiments, when the first value of at least one of the plurality of battery banks is smaller than a value obtained by multiplying the second value of the at least one battery bank by a lower threshold, the controller initializes the first value without using it to diagnose an abnormality in the battery bank.

[0008] In some embodiments, when a first value of at least one of the plurality of battery banks exceeds a value obtained by multiplying a second value of the at least one battery bank by an upper threshold, the controller selects the first value to use for diagnosing an abnormality in the battery bank.

[0009] In some embodiments, the controller accumulates the first values ​​of at least one battery bank among the plurality of battery banks and diagnoses an abnormality in the battery bank when the first value of at least one battery bank is greater than or equal to a value obtained by multiplying the second value of the at least one battery bank by a lower threshold and is less than or equal to a value obtained by multiplying the second value by an upper threshold.

[0010] In some embodiments, the controller calculates the first reference value for each of the plurality of battery banks as a ratio of the selected first value for each of the plurality of battery banks to the maximum value among an average value of the selected first values ​​for each of the plurality of battery banks and a value obtained by multiplying the second value for each of the plurality of battery banks by an upper threshold.

[0011] In some embodiments, the controller ranks the plurality of battery banks according to the order of highest first reference value, and determines the first battery bank as the first ranked battery bank, the second battery bank as the second ranked battery bank, and the third battery bank as the last ranked battery bank among the plurality of battery banks.

[0012] In some embodiments, the controller calculates a first deviation, which is the difference between a first reference value of the first battery bank and a first reference value of the second battery bank, calculates a second deviation, which is the difference between the first reference value of the second battery bank and a first reference value of the third battery bank, and diagnoses whether or not there is an abnormality in the first battery bank at the specific time point based on the second reference value, which is the ratio of the first deviation to the second deviation.

[0013] In some embodiments, the controller diagnoses the first battery bank as an abnormal battery bank if the first reference value of the first battery bank exceeds a first threshold and the second reference value of the first battery bank exceeds a second threshold.

[0014] In some embodiments, a method for operating a battery management device includes the steps of measuring a voltage of each of a plurality of battery banks; calculating a first value that is a change in voltage of each of the plurality of battery banks during a certain period; calculating a second value that is a standard deviation of the change in voltage per unit time of each of the plurality of battery banks; selecting a first value for each of the plurality of battery banks based on the first value and the second value for each of the plurality of battery banks; setting a rank for each of the plurality of battery banks based on a first reference value that is a ratio of the selected first value for each of the plurality of battery banks to an average value of the selected first values ​​for the plurality of battery banks; and diagnosing an abnormality in at least one of the plurality of battery banks based on the rank of each of the plurality of battery banks at the specific time point.

[0015] In some embodiments, the step of comparing the first value and the second value calculated at the predetermined time intervals and selecting a first value for each of the plurality of battery banks includes initializing the first value without using it for diagnosing an abnormality in the battery bank if the first value of at least one of the plurality of battery banks is smaller than a value obtained by multiplying the second value of the at least one battery bank by a lower threshold.

[0016] In some embodiments, the step of selecting the first value for each of the plurality of battery banks based on the first value and the second value for each of the plurality of battery banks includes maintaining the first value for use in diagnosing an abnormality in the battery bank if the first value of at least one of the plurality of battery banks exceeds a value obtained by multiplying the second value of the at least one battery bank by an upper threshold.

[0017] In some embodiments, the step of selecting the first value for each of the plurality of battery banks based on the first value and the second value for each of the plurality of battery banks includes accumulating the first values ​​to diagnose an abnormality in the battery bank if the first value of at least one of the plurality of battery banks is greater than or equal to the second value of the at least one battery bank multiplied by a lower threshold and less than or equal to the second value multiplied by an upper threshold.

[0018] In some embodiments, the step of setting the ranking of each of the plurality of battery banks based on a first reference value that is a ratio of the selected first value of each of the plurality of battery banks to an average value of the selected (corrected) first values ​​of each of the plurality of battery banks calculates, as the first reference value for each of the plurality of battery banks, a ratio of the selected first value of each of the plurality of battery banks to the maximum value among the average value of the selected first values ​​of each of the plurality of battery banks and values ​​obtained by multiplying the second value of each of the plurality of battery banks by an upper threshold.

[0019] In some embodiments, the step of ranking each of the plurality of battery banks based on a first reference value, which is the ratio of the selected (corrected) first value of each of the plurality of battery banks to the average value of the selected (corrected) first values ​​of the plurality of battery banks, ranks the plurality of battery banks in descending order of first reference value, and determines the first battery bank as the first ranked, the second battery bank as the second ranked, and the third battery bank as the last ranked among the plurality of battery banks.

[0020] In some embodiments, the step of diagnosing whether or not there is an abnormality in at least one of the plurality of battery banks based on the rankings of the plurality of battery banks at the specific time point includes calculating a first deviation that is the difference between a first reference value of the first battery bank and the first reference value of the second battery bank, calculating a second deviation that is the difference between the first reference value of the second battery bank and the first reference value of the third battery bank, and diagnosing whether or not there is an abnormality in the first battery bank at the specific time point based on the second reference value that is the ratio of the first deviation to the second deviation.

[0021] In some embodiments, the step of diagnosing at least one battery bank among the plurality of battery banks based on the rankings of the plurality of battery banks at the specific time point diagnoses the first battery bank as an abnormal battery bank if the first reference value of the first battery bank exceeds a first threshold and the second reference value of the first battery bank exceeds a second threshold.

[0022] In some embodiments, the controller includes a memory and a processing unit coupled to the memory and configured to perform a method of operating the battery management unit.

[0023] In some embodiments, a non-transitory computer-readable storage medium stores a program for performing the steps of measuring a voltage of each of a plurality of battery banks; calculating a first value that is a change in voltage of each of the plurality of battery banks during a certain period; calculating a second value that is a standard deviation of a change in voltage per unit time of each of the plurality of battery banks; selecting a first value for each of the plurality of battery banks based on the first value and the second value for each of the plurality of battery banks; setting a rank for each of the plurality of battery banks based on a first reference value that is a ratio of the selected first value for each of the plurality of battery banks to an average value of the selected first values ​​for the plurality of battery banks; and diagnosing an abnormality in at least one of the plurality of battery banks based on the rank of each of the plurality of battery banks at the specific time point.

[0024] In some embodiments, the step of diagnosing whether or not there is an abnormality in at least one of the plurality of battery banks based on the rankings of the plurality of battery banks at the specific time point includes calculating a first deviation that is the difference between a first reference value of the first battery bank and the first reference value of the second battery bank, calculating a second deviation that is the difference between the first reference value of the second battery bank and the first reference value of the third battery bank, and diagnosing whether or not there is an abnormality in the first battery bank at the specific time point based on the second reference value that is the ratio of the first deviation to the second deviation.

[0025] In some embodiments, if the first reference value of the first battery bank exceeds a first threshold and the second reference value of the first battery bank exceeds a second threshold, the first battery bank is diagnosed as an abnormal battery bank. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 illustrates a battery pack according to one embodiment disclosed herein. [Figure 2] 1 is a block diagram showing the configuration of a battery management device according to an embodiment disclosed in this document. [Figure 3] 1 is a flowchart illustrating a method of operating a battery management device according to one embodiment disclosed herein. [Figure 4] 10 is a flowchart illustrating a method of operating a battery management device according to another embodiment disclosed herein. [Figure 5] 1 is a graph illustrating voltage changes over time intervals during a rest period for a battery bank according to an embodiment disclosed herein; [Figure 6] 1 is a graph illustrating the change in a first value over a period of time for a battery bank according to an embodiment disclosed herein. [Figure 7] 10 is a graph illustrating the change in the second value over a period of time for a battery bank according to an embodiment disclosed herein. [Figure 8] 1 is a graph illustrating the change in a first reference value over a period of time for a battery bank according to an embodiment disclosed herein. [Figure 9] FIG. 1 is a block diagram showing the hardware configuration of a computing system that implements an operation method of a battery management device according to an embodiment disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0027] Some embodiments disclosed herein will be described in detail below with reference to exemplary drawings. When assigning reference numerals to components in each drawing, it should be noted that the same reference numerals are assigned to the same components as long as possible when they appear in other drawings. Furthermore, when describing the embodiments disclosed herein, if a detailed description of related known structures or functions is deemed to hinder understanding of the embodiments disclosed herein, such detailed description will be omitted.

[0028] In describing components of the embodiments disclosed herein, terms such as first, second, A, B, (a), (b), etc. may be used. Such terms are merely used to distinguish the component from other components and do not limit the nature, order, or sequence of the components. Furthermore, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments disclosed herein pertain. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the context of the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0029] 1 is a diagram illustrating a battery pack according to one embodiment disclosed herein. The battery pack 1000 may include a battery module 100, a battery management unit 200, and a relay 300. According to various embodiments, the battery module 100 may be a battery cell. In this case, the battery pack 1000 may have a cell-to-pack structure in which the modules are directly assembled into a pack, omitting the modules, unlike conventional batteries in which multiple cells form modules and the modules form a package.

[0030] Although only one battery module 100 is shown in FIG. 1, the battery pack 1000 may have a stacked structure of multiple battery modules. The battery module 100 may include multiple battery banks 110, 120, 130, 140, 150, 160, and 170. Although FIG. 1 shows seven battery banks, the number is not limited thereto, and the battery module 100 may include n battery banks (n is a natural number equal to or greater than 1).

[0031] The battery module 100 can supply power to a target device (not shown). To this end, the battery module 100 can be electrically connected to the target device. Here, the target device can include an electrical, electronic, or mechanical device that operates by receiving power from a battery pack 1000 including the battery module 100. For example, the target device can be, but is not limited to, an electric vehicle (EV) or an energy storage system (ESS).

[0032] Each of the battery banks 110 to 170 included in the battery module 100 may be composed of a single cell or a plurality of battery cells arranged in series or parallel. For example, each battery bank may have the same number of cells connected in series or parallel.

[0033] According to the embodiment, the plurality of battery banks 110 to 170 may be electrically connected in series or parallel to each other within the battery module 100 to form a cell module assembly (CMA).

[0034] Each of the multiple battery cells included in each of the multiple battery banks 110 to 170 is a basic unit of a battery that can be used by charging and discharging electrical energy, and may be, but is not limited to, a lithium-ion (Li-ion) battery, a lithium-ion polymer (Li-ion polymer) battery, a nickel-cadmium (Ni-Cd) battery, a nickel-metal hydride (Ni-MH) battery, etc.

[0035] The battery management system (BMS) 200 can manage and / or control the state and / or operation of the battery module 100. For example, the battery management system 200 can manage the charging and / or discharging of the plurality of battery banks 110 to 170 included in the battery module 100, and can manage and / or control the state and / or operation of the battery module 100.

[0036] In addition, the battery management unit 200 can control the operation of the relay 300. For example, the battery management unit 200 can short-circuit the relay 300 to supply power to a target device, and can short-circuit the relay 300 when a charging device is connected to the battery pack 1000.

[0037] The battery management unit 200 can also monitor the voltage, current, temperature, etc. of the battery module 100 and / or each of the plurality of battery banks 110-170 included in the battery module 100. For monitoring via the battery management unit 200, sensors and various measurement modules (not shown) can be further provided at any position in the battery module 100 or in the charge / discharge path. The battery management unit 200 can calculate parameters indicating the state of the battery module 100, such as SOC (State of Charge) or SOH (State of Health), based on the measured values ​​of the monitored voltage, current, temperature, etc.

[0038] As the duration or number of uses of the battery banks 110-170 increases, various factors within the battery banks may change, such as a decrease in capacity and an increase in internal resistance, etc. The battery management unit 200 can diagnose abnormal phenomena within the battery banks 110-170 based on data on these various factors that change as the battery banks deteriorate.

[0039] Specifically, the battery management device 200 can diagnose as abnormal a battery bank among the battery banks 110-170, using voltage data for each of the battery banks 110-17. The battery bank includes a battery cell with an open electrode tab or a battery cell with both an open electrode tab and lithium deposition (dendrite). Lithium deposition is a phenomenon in which lithium ions released from the positive electrode of a battery cell during charging fail to chemically bond with the negative electrode, resulting in the lithium ions remaining in metallic form on the surface of the negative electrode. In a normal battery cell, lithium ions released from the positive electrode of the battery cell are reduced into the negative electrode during charging. However, in a defective battery cell, some lithium ions may deposit in the form of metallic lithium on the surface of the negative electrode. Repeated lithium deposition and the growth of lithium by-products can cause contact with the positive electrode or positive electrode current collector, resulting in an internal short between the negative and positive electrodes of the battery cell. In a battery bank including a battery cell with an internal short, self-discharge over time can cause voltage deviations from a normal battery bank.

[0040] In addition, battery cells can experience breaks in their positive or negative electrode tabs due to various reasons, such as defects during production, internal deformation and denaturation due to repeated charge / discharge cycles, or external impact. If both lithium deposition and electrode tab breakage occur in a battery cell, the electrodes of the broken battery cell and those of a healthy battery cell may be connected to each other through lithium deposits. If the negative electrode of the broken battery cell has a higher state of charge (SOC) than the negative electrode of the healthy battery, the negative electrodes of the two battery cells may come into contact through lithium deposits, causing charging from the negative electrode of the broken battery cell to the negative electrode of the healthy battery. Therefore, a battery cell experiencing both lithium deposition and electrode tab breakage may experience faster and larger voltage changes than a healthy battery cell.

[0041] Therefore, the battery management device 200 can diagnose a battery bank including a battery cell in which an electrode tab breakage and lithium deposition simultaneously occur as a problematic bank by comparing voltage data during the resting period of a battery bank in which an electrode tab breakage and lithium deposition simultaneously occur with statistically normal voltage data during the resting period of a normal battery bank, based on the phenomenon that a battery cell in which an electrode tab breakage and lithium deposition simultaneously occur experiences a faster and larger voltage change during the resting period than a normal battery cell. The resting period of a battery cell or module refers to a state in which the battery cell or module is not charging or discharging, or is not electrically connected to a load. For example, the battery management device 200 can detect whether a battery module or cell is in a resting state by monitoring the cell voltage value or the charge / discharge current value of a battery module.

[0042] In addition, the following operation of the battery management device 200 may be performed by wired or wireless signals in various devices such as a server, cloud, charger, or charger / discharger connected to the battery management device 200 or a vehicle in which the battery management device 200 is installed.

[0043] FIG. 2 is a block diagram showing the configuration of a battery management device 200 according to an embodiment disclosed in this document. The configuration of the battery management device 200 may vary depending on the usage environment and purpose of the battery pack 1000 including the battery module 100, and may include various different operating components.

[0044] 2, the battery management device 200 may include a voltage measurement unit 210 and a controller 220. In one embodiment, the controller 220 may include a calculation unit 230, a diagnosis unit 240, and a control unit 250. In another embodiment, the battery management device 200 may further include a current measurement unit and / or a temperature measurement unit in addition to the voltage measurement unit 210.

[0045] The voltage measurement unit 210 is configured with a measuring device, such as a voltmeter, capable of measuring the voltage of the battery bank and / or cells, and measures the voltage of each of the plurality of battery banks 110 to 170 at regular time intervals to calculate time-series voltage data for each of the plurality of battery banks 110 to 170. Specifically, the voltage measurement unit 210 can calculate the rise and fall of the voltage during charging, discharging, and resting periods, as well as long-term relaxation data.

[0046] The calculation unit 230 uses the voltage data measured by the voltage measurement unit 210 to perform various calculations for diagnosing an abnormal battery bank, which will be described later. The diagnosis unit 240 uses the calculation results to check the conditions, etc., which will be described later, to diagnose whether or not there is an abnormality in the battery bank. The control unit 250 uses the diagnosis results to take appropriate measures for the battery bank, such as monitoring the abnormal battery bank or notifying the user of the presence or absence of an abnormality.

[0047] FIG. 3 is a flow chart illustrating a method of operation of a battery management device according to one embodiment disclosed herein. 3, the operating method of the battery management device may include steps S11 to S16. According to an embodiment, the operating method of the battery management device may be performed by the battery management device 200.

[0048] In step (S11), the battery management unit 200 can measure the voltage of each of the plurality of battery banks. In step (S12), the battery management unit 200 can calculate a first value that is the amount of change in voltage of each of the plurality of battery banks during a certain period. In step (S13), the battery management unit 200 can calculate a second value that is the standard deviation of the amount of change in voltage per unit time of each of the plurality of battery banks.

[0049] In step (S14), the battery management unit 200 can select a first value for each of the plurality of battery banks based on the first value and the second value for each of the plurality of battery banks. In step (S15), the battery management unit 200 can set a ranking for each of the plurality of battery banks based on a first reference value that is a ratio of the selected first value for each of the plurality of battery banks to an average value of the selected first values ​​for the plurality of battery banks. In step (S16), the battery management unit 200 can diagnose at least one of the plurality of battery banks based on the ranking of each of the plurality of battery banks at a specific time point.

[0050] FIG. 4 is a flow chart illustrating a method of operation of the battery management unit 200 according to one embodiment disclosed herein. Referring to FIG. 4, the operating method of the battery management device includes the steps of: measuring a first voltage of each of a plurality of battery banks at a regular time interval (S110); calculating a first value, which is a voltage change amount of each of the first voltages of each of the plurality of battery banks measured at the regular time intervals, using the first voltages at the regular time intervals (S120); measuring a second voltage per unit time during the regular time intervals of each of the plurality of battery banks and calculating a second value, which is a standard deviation of the voltage change amount of the second voltage measured per unit time at the regular time intervals, for each of the plurality of battery banks at the regular time intervals, using the second voltages (S130); selecting a first value for each of the plurality of battery banks based on a result of comparing the first value and the second value calculated at the regular time intervals (S140); and comparing the first voltages of each of the plurality of battery banks with an average value of the selected first voltages of each of the plurality of battery banks at the regular time intervals. the first reference value (R1) using an equation indicating a ratio of the selected first values ​​to the first battery bank (S150); setting the battery bank rankings at a specific time point to the first battery bank, the second battery bank, and the third battery bank based on the calculated first reference value (R1) (S160); calculating a second reference value (R2) using the calculated first reference value (R1) and the ranking data (S170); checking whether the first battery bank determined in S160 has the largest value in the battery module 100 at the specific time point (S180); determining whether the first reference value (R1) of the first battery bank is equal to or greater than a first threshold value at the specific time point (S190); determining whether the second reference value (R2) is equal to or greater than a second threshold value at the specific time point (S200); and determining the first battery bank as an abnormal battery bank (S210).

[0051] The operation of the device at each of these steps and how to diagnose an abnormal battery bank will be described in more detail below with reference to FIG. In step S110, the voltage measurement unit 210 measures the voltage of each of the battery banks 110-170 at regular time intervals during the rest period, and the controller 220 can generate a graph showing the voltage change of each of the battery banks 110-170.

[0052] FIG. 5 is a graph showing the voltages of each of the battery banks 110-170 according to an embodiment of the present disclosure, measured and recorded at time points t1-t12, which are set at 600-second intervals from time point t0 when the rest period begins. In the example of FIG. 5, t0 on the horizontal axis indicates the time when the rest period begins, and t12 indicates the time when 7,200 seconds have elapsed since the start of the rest period. Generally, a battery bank or cell exhibits a relatively rapid voltage decrease within a relatively short period of time (e.g., about 600 seconds) after the start of the rest period, followed by a gradual decrease. In the example of FIG. 5, the voltage of each battery bank exhibits a value of approximately 3.98 Volts at time point t0 when the rest period begins, and then rapidly decreases to approximately 3.92 Volts at time point t1, 600 seconds after time point t0. 5, the voltage measurement unit 210 may measure the voltage of each of the battery banks 110-170 at time t1, which is 600 seconds after time t0, when the resting period begins. Next, assuming that the fixed time interval is 600 seconds, the voltage measurement unit 210 measures the voltage of each of the battery banks 110-170 at time t2, which is 600 seconds after time t1. Thereafter, the voltage measurement unit 210 measures the voltage of each of the battery banks 110-170 at time t3, which is 600 seconds after time t2 (i.e., 1,200 seconds after time t1). Next, the voltage measurement unit 210 repeatedly measures the voltage of each of the battery banks 110-170 at times t4-t12, respectively, to generate a graph such as that shown in FIG. 5.

[0053] In step S120, the calculation unit 230 can use the voltage data measured in step S110 to calculate a first value (ΔV) that is the amount of change in voltage over a certain time interval (e.g., 600 seconds) for each of the battery banks 110 to 170. For example, referring to FIG. 6, which is a graph showing the first value (ΔV) of each battery bank according to an embodiment disclosed herein, the calculation unit 230 can calculate the first reference value (ΔV) from time t1 to time t2, for example, by subtracting the voltage value at time t2 from the voltage value at time t1. That is, in one embodiment, the calculation unit 230 compares the voltage measured at time t1, 600 seconds after the start of the rest period, with the voltage measured at time t2, 1,200 seconds after the start of the rest period, to calculate a first value (ΔV) representing the change in voltage of each of the battery banks 110-170 over 600 seconds. The calculation unit 230 may then display the first value (ΔV) calculated at time t2. The calculation unit 230 repeats this process to calculate and display the first value (ΔV) of each of the battery banks 110-170 at each of the remaining times t3-t12. In the graph of FIG. 6, the first value (ΔV) of the battery bank 170 is higher than the other battery banks between time t11 and time t12, indicating that the battery bank 170 may be an abnormal battery bank. In another embodiment, the voltage change may be calculated using a fixed time interval of 200 seconds instead of 600 seconds.

[0054] In step S130, the voltage measurement unit 210 and the calculation unit 230 measure the voltage change amount per unit time (for example, 1 second) at regular time intervals for each of the plurality of battery banks 110 to 170, and calculate a second value (σ dvFor example, apart from step S110 described above, the voltage measurement unit 210 measures the voltage of each of the plurality of battery banks 110 to 170 at one-second intervals within each fixed time interval (e.g., starting from each of time points t2 to t12 to the next time point), that is, 600 seconds, and based on the voltage values ​​measured per unit time, the calculation unit 230 calculates a second value (σ dv ) can be calculated.

[0055] FIG. 7 shows the second values ​​(σ dv ) is a graph showing changes in the voltage. For example, the calculation unit 230 measures the voltage every second for 600 seconds starting from time t1 (e.g., 600 seconds after the resting period) to time t2 (e.g., 1,200 seconds after the resting period), calculates the amount of voltage change per unit time and the standard deviation (σ) between time t1 and time t2, and records these at time t2. Next, the calculation unit 230 measures the voltage every second for 600 seconds starting from time t2 to time t3 (e.g., 1,800 seconds after the resting period), calculates the amount of voltage change per unit time and the standard deviation (σ) between time t2 and time t3, and records these at time t3. The calculation unit 230 then measures the voltage every second for 600 seconds starting from time t3 to time t4 (e.g., 2,400 seconds after the resting period), calculates the voltage change per unit time and the standard deviation (σ) between time t3 and time t4, and records these values ​​at time t4. This measurement, calculation, and recording process is repeated until time t12 (e.g., 7,200 seconds after the resting period), thereby generating a graph such as that shown in FIG. 7. In another embodiment, the voltage per hour may be measured at 200-second intervals rather than at 600-second intervals, and the second value may be calculated.

[0056] On the other hand, the second value (σ dvSince the step of calculating (ΔV) can be performed in a separate process from the step of calculating the first value (ΔV), the order may also be changed, for example, so that the step of calculating (ΔV) can be performed before the step of calculating the first value (ΔV).

[0057] In step S140, the calculation unit 230 calculates the first value (ΔV) and the second value (σ dv ) and select the first value (ΔV). Here, selecting the first value (ΔV) means that the calculated first value (ΔV) is equal to or greater than the second value (σ dv ) is a valid value that can be used to diagnose an abnormal battery bank. dv ) is a value related to a noise level that can determine whether the first value (ΔV) of each of the plurality of battery banks 110 to 170 is a valid value or noise data. For example, the calculation unit 230 calculates the first value (ΔV) of each of the plurality of battery banks 110 to 170 at each of the times t2 to t12 by dividing the first value (ΔV) by the second value (σ dv ), and if it is determined that each first value (ΔV) is equal to or less than the value calculated using the second value, it can be determined that the data is noise data that cannot be used to diagnose the battery bank. In this case, the calculation unit 230 can initialize the first value (ΔV).

[0058] For example, the first value (ΔV) at a particular time (e.g., t3) of a particular battery bank 110 is 0.2 mV, and the second value (σ dv ) is 0.3 mV, and the lower threshold (LT) is 1, the first value (ΔV) of 0.2 mV at a particular time is dv ) 0.3 mV multiplied by the lower threshold (LT) 1. Therefore, the first value (ΔV) of 0.2 mV at this point is determined to be noise data and is initialized without being used in diagnosing the battery bank.

[0059] On the other hand, the calculation unit 230 calculates whether the first value (ΔV) of at least one of the battery banks 110 to 170 is equal to or greater than the second value (σ dv If the first value (ΔV) exceeds a value obtained by multiplying the first value (ΔV) by an upper threshold (UT), the first value (ΔV) can be determined as a value that can be used to diagnose the battery bank, and the first value (ΔV) can be maintained as valid data for the diagnosis. For example, if the first value (ΔV) of the battery bank 110 at a specific time point (e.g., t3) is 0.7 mV and the second value (σ dv ) is 0.3 mV, and the upper threshold (UT) is 2, the first value (ΔV) of 0.7 mV at a particular time is dv ) 0.3 mV by the upper threshold (UT) 2, which is 0.6 mV. Therefore, the first value (ΔV) of 0.7 mV at this time point is determined to be valid data and will be used for diagnosing an abnormality in the battery bank. That is, for example, the calculation unit 230 calculates the first value (ΔV) of 0.7 mV at this time point (e.g., t3) for the battery bank (e.g., 110) as the second value (σ dv ) can be determined as the selected first value (ΔV). According to one embodiment, the selected first value (ΔV) can be distinguished from the first value (ΔV) before selection and can be represented by, for example, dV.

[0060] The calculation unit 230 also calculates whether the first value (ΔV) of at least one of the battery banks 110 to 170 is equal to or greater than the second value (σ dv ) multiplied by the lower threshold (LT), and the second value (σ dv ) is equal to or less than the upper threshold (UT), the first value (ΔV) of the battery bank is accumulated and can be used for subsequent diagnosis of the battery bank. That is, for example, the calculation unit 230 calculates whether the first value (ΔV) of the battery bank is equal to or less than the second value (σ dv) multiplied by a lower threshold (LT) (e.g., 0.3 mV) and is equal to or greater than a value obtained by multiplying the second value by an upper threshold (UT) (e.g., 0.6 mV), the first value (ΔV) of the battery bank is not determined to be noise data, but the magnitude of the first value (ΔV) is determined to be insufficient to diagnose the battery bank. The first values ​​(ΔV) of the battery bank are accumulated, and the battery bank can be subsequently diagnosed based on the accumulated amount of the first values ​​(ΔV) over multiple periods. Therefore, the calculation unit 230 recalculates the voltage of each of the multiple battery banks 110 to 170, adds the newly calculated first value (ΔV) to the already stored first value (ΔV), and converts the accumulated first value (ΔV) into the second value (σ dv ) can be compared again.

[0061] Through this process, the calculation unit 230 converts the first value (ΔV) of each of the plurality of battery banks 110 to 170 into the second value (σ dv ), and the first value (ΔV) determined to be noise data can be initialized, or the first value (ΔV) over multiple periods can be accumulated. Therefore, unnecessary diagnosis due to the reflection of noise data can be avoided, thereby preventing overdetection of the battery bank. Although not shown, as an example, the first value (ΔV) selected by comparing the first value (ΔV) with the second value can be represented by a graph similar to that of FIG. 6.

[0062] In step S150, the calculation unit 230 can calculate the average value (AVG_ΔV) of the selected first values ​​(ΔV) of each of the battery banks 110 to 170. The calculation unit 230 also calculates the average value (AVG_ΔV) of the selected first values ​​(ΔV) of each of the battery banks 110 to 170 and the second values ​​(σ dv ) by an upper threshold (UT) (for example, 2), the maximum value (Max) can be calculated.

[0063] The calculation unit 230 calculates the average value (AVG_ΔV) of the selected first values ​​of the plurality of battery banks 110 to 170 and the second values ​​(σ dvThe ratio (Ratio) of the selected first value (ΔV) of each of the plurality of battery banks to the maximum value among the values ​​obtained by multiplying the upper limit threshold (UT) by the upper limit threshold (UT) can be calculated as the first reference value (R1) for each of the plurality of battery banks 110 to 170 at a fixed time interval.

[0064] In one embodiment, the calculation unit 230 can calculate the first reference value (R1) for each of the plurality of battery banks 110 to 170 based on the following [Equation 1].

[0065] [Formula 1]

number

[0066] As described above, the calculation unit 230 can use the Max function in the denominator of [Equation 1] for calculating the first reference value (R1). Specifically, the calculation unit 230 uses the Max function to calculate the average value (AVG_ΔV) of the selected first values ​​of the plurality of battery banks 110 to 170 and the second values ​​(σ dv The calculation unit 230 uses the Max function in the denominator of [Equation 1] to calculate the second value (σ dv The battery bank can be diagnosed using the first reference value (R1) only when the first reference value (R2) is equal to or greater than a certain level compared to the value obtained by multiplying the first reference value (R1) by the upper threshold (UT), thereby reducing unnecessary diagnoses.

[0067] FIG. 8 is a graph illustrating the change in the first reference value of a battery bank according to an embodiment disclosed herein. 8 shows the first reference value (R1) of each of the battery banks 110-170 calculated by the calculation unit 230 over time periods from t2 to t12 (for example, 600 seconds). Each of these first reference values ​​(R1) is calculated, for example, by the calculation unit 230 at intervals of 600 seconds (or 200 seconds) based on the selected first value (ΔV) and second value (σ dv ) into Equation 1. Other aspects of FIG. 8, including the calculation of the second reference value (R2), will be described later.

[0068] In S160, the calculation unit 230 can set the rank of each of the battery banks 110-170 at time intervals t2-t12 or at specific points in time based on the calculated first reference value (R1) of each of the battery banks 110-170. In the example of Fig. 8, the calculation unit 230 sets time t12 as the diagnosis time, recognizes the battery bank 170 with the largest first reference value (R1) at the specific time t12 as the battery bank ranked first and designates it as the first battery bank B1, recognizes the battery bank 160 with the next largest first reference value (R1) at the specific time t12 as the battery bank ranked second and designates it as the second battery bank B2, and recognizes the battery bank 110 with the smallest first reference value (R1) at the specific time t12 as the battery bank ranked last and designates it as the third battery bank B3.

[0069] In step S170, the calculation unit 230 calculates the second reference value (R2) using the first reference value (R1) shown in FIG. 8 and the following formula 2.

[0070] [Formula 2]

number

[0071] That is, according to one embodiment, as shown in FIG. 8, the calculation unit 230 calculates the first reference value (R1) of the first battery bank B1, which is the battery bank to be diagnosed as having the largest voltage change amount based on the first reference value (R1) at time t12, which is the time of diagnosis.B1 ) and the first reference value (R1 B2 ) and the first reference value (R1) of the second battery bank B2, which has the second largest voltage change amount based on the first reference value (R1). B2 ) and the first reference value (R1 B3 ) can be calculated as the second reference value (R2).

[0072] Once the first reference value (R1) and the second reference value (R2) are calculated in this manner, the diagnosis unit 240 further checks the conditions described below and makes a final determination as to whether the first battery bank B1 (e.g., battery bank 170) that shows the largest value based on the first reference value (R1) is an abnormal battery bank.

[0073] In step S180, the diagnosis unit 240 checks whether the first battery bank (e.g., battery bank 170) determined in S160 at a specific time point (e.g., t12) exhibits the largest first reference value (R1) in the battery module 100 (first condition). In the example of Fig. 8, the battery bank 170 determined to be the first battery bank B1 is determined to exhibit the largest first reference value (R1) in the battery module 100.

[0074] In step S190, the diagnosis unit 240 checks whether the first reference value (R1) of the first battery bank (e.g., battery bank 170) is equal to or greater than a predetermined first threshold (R1_threshold) at a specific time point t12. In the example of Fig. 8, it is determined that the first reference value of the battery bank 170 is greater than the predetermined first threshold of 1.5 (second condition).

[0075] In step S200, the diagnosis unit 240 checks whether the calculated second reference value (R2) is greater than a predetermined second threshold (R2_threshold) at a specific time point t12 (third condition). In the example of Fig. 8, at the specific diagnosis time point t12, the first reference value (R1) of the battery bank 170 is 1.75, the first reference value (R1) of the battery bank 160 is 1.05, and the first reference value (R1) of the battery bank 110 is 0.7. Therefore, the second reference value is 2 (0.7 / 0.35), which is greater than the predetermined second threshold (R2_threshold) of 1.

[0076] In step S210, the diagnosis unit 240 checks all three of the above conditions and diagnoses the battery bank 170 determined to be the first battery bank B1 as a problematic battery bank because the battery bank 170 satisfies all three of the conditions at time t12, which is the diagnosis time. That is, in one embodiment, the diagnosis unit 240 can diagnose the battery bank 170 as a battery bank including a battery cell in which an electrode tab has been broken, or a battery cell in which an electrode tab has been broken and lithium deposition has occurred.

[0077] Thereafter, the control unit 250 may track and monitor whether an internal short circuit has occurred in the battery bank 170 diagnosed as an abnormal battery bank, and may also provide a user with information about the battery bank 170. For example, the control unit 250 may provide information about the battery bank 170 in which a break in an electrode tab or a break in an electrode tab and lithium deposition has occurred to a user terminal via a communication unit (not shown), and may also provide information about the battery bank 170 via a display provided in the vehicle or a charger.

[0078] If at a particular time t12 any one of the conditions of steps S180, S190, or S200 is not met, the process returns to step S110 to continue measurements and calculations. In other embodiments, the process does not return to step S110, but returns to one of the previous steps to continue diagnosis.

[0079] As described above, the battery management device 200 according to one embodiment disclosed in this document can diagnose a battery bank including a battery cell in which an electrode tab has been broken, or a battery bank including a battery cell in which an electrode tab has been broken and lithium deposition has occurred, using the voltage behavior of the battery bank during the rest period.

[0080] Conventional methods for diagnosing the lithium deposition phenomenon use voltage data from a rest period after charging a battery in which a large amount of lithium deposition has occurred. However, this method has the problem that it is difficult to determine whether or not an abnormal voltage exists because the effect of lithium deposition on the measured voltage of the battery is minimal.

[0081] In contrast, the battery management device 200 of the present invention can accurately diagnose abnormal battery banks based on the voltage change amounts of multiple battery banks during their rest periods, for example, by comparing the voltage change amounts of each of the multiple battery banks and ranking each battery bank according to the voltage change amounts, and can analyze all the characteristics (features) of the short-term voltage behavior and long-term voltage behavior of the battery banks.

[0082] Furthermore, the battery management unit 200 of the present invention can diagnose a battery bank in which electrode tab disconnection or lithium deposition has occurred early using the amount of voltage change in the battery bank, thereby ensuring the safety and reliability of battery energy. Furthermore, the battery management unit 200 diagnoses a battery bank in which electrode tab disconnection or lithium deposition has occurred while the battery is installed in a vehicle, which has the advantage of eliminating the need to separately separate the battery and allowing for quick and easy battery bank diagnosis.

[0083] FIG. 9 is a block diagram showing the hardware configuration of a computing system that implements the method of operating a battery management device according to an embodiment disclosed herein.

[0084] Referring to FIG. 9, a computing system 2000 according to one embodiment disclosed herein may include an MCU 2100, a memory 2200, an input / output I / F 2300, and a communication I / F 2400.

[0085] The MCU 2100 may be a processor that executes various programs stored in the memory 2200, processes various data used in such programs, and performs the functions of the battery management device 200 shown in Figure 1 described above.

[0086] The memory 2200 can store various programs related to the operation of the battery management unit 200 and operation data of the battery management unit 200 for diagnosing the battery bank. A plurality of such memories 2200 may be provided as needed. The memory 2200 may be a volatile memory or a non-volatile memory. The memory 2200 as a volatile memory may be a RAM, a DRAM, an SRAM, etc. The memory 2200 as a non-volatile memory may be a ROM, a PROM, an EAROM, an EPROM, an EEPROM, a flash memory, etc. The examples of the memory 2200 listed above are merely illustrative and are not limited to these examples.

[0087] The input / output I / F 2300 can provide an interface that connects input devices (not shown) such as a keyboard, mouse, or touch panel, and output devices such as a display (not shown), to the MCU 2100, enabling data to be sent and received.

[0088] The communication I / F 2400 is configured to be able to send and receive various data to and from a server, and may be any device that supports wired or wireless communication. For example, programs for voltage measurement and abnormality diagnosis, various data, and the like can be sent and received via wired or wireless communication from a separately provided external server via the communication I / F 2400.

[0089] The above description merely exemplifies the technical ideas of the present disclosure, and various modifications and variations are possible by a person having ordinary knowledge in the technical field to which the present disclosure pertains, without departing from the essential characteristics of the present disclosure.

[0090] Therefore, the embodiments disclosed in this disclosure are intended to illustrate, not limit, the technical idea of ​​the disclosure, and the scope of the technical idea of ​​the disclosure is not limited by such embodiments. The scope of protection of the disclosure should be interpreted by the claims below, and all technical ideas within the equivalent range should be interpreted as being included in the scope of rights of the disclosure. [Explanation of symbols]

[0091] 1000: Battery pack 100: Battery module 110: Battery bank 120: Battery bank 130: Battery bank 140: Battery bank 150: Battery bank 160: Battery bank 170: Battery bank 200:Battery management device 210: Voltage measurement unit 220: Controller 300: Relay 2000: Computing Systems 2100:MCU 2200:Memory 2300: Input / output interface 2400:Communication I / F R1: First value R2: Second value D1: First deviation

Claims

1. a voltage measurement unit for measuring the voltage of each of the plurality of battery banks; A controller; Including, the controller is capable of communicating with the voltage measurement unit; selecting a first value for each of the plurality of battery banks based on a first value representing a voltage change amount during a fixed period for each of the plurality of battery banks and a second value representing a standard deviation of a voltage change amount per unit time for each of the plurality of battery banks; setting a ranking of each of the plurality of battery banks based on a first reference value indicating a ratio of the selected first value of each of the plurality of battery banks to an average value of the selected first value of each of the plurality of battery banks; A battery management device configured to diagnose an abnormality in at least one battery bank among the plurality of battery banks based on a ranking of each of the plurality of battery banks at a specific time point.

2. 2. The battery management device according to claim 1, wherein, when the first value of at least one of the plurality of battery banks is smaller than a value obtained by multiplying the second value of the at least one battery bank by a lower threshold, the controller initializes the first value without using the first value in diagnosing an abnormality in the battery bank.

3. 3. The battery management device according to claim 2, wherein, when a first value of at least one battery bank among the plurality of battery banks exceeds a value obtained by multiplying a second value of the at least one battery bank by an upper threshold, the controller selects the first value and uses the first value to diagnose an abnormality in the battery bank.

4. 4. The battery management device according to claim 3, wherein when the first value of at least one battery bank among the plurality of battery banks is equal to or greater than a value obtained by multiplying the second value of the at least one battery bank by a lower threshold and is equal to or less than a value obtained by multiplying the second value by an upper threshold, the controller accumulates the first values ​​of the at least one battery bank to diagnose an abnormality in the battery bank.

5. 5. The battery management device according to claim 4, wherein the controller calculates, as the first reference value for each of the plurality of battery banks, a ratio of the selected first value for each of the plurality of battery banks to a maximum value among an average value of the selected first values ​​for each of the plurality of battery banks and values ​​obtained by multiplying the second values ​​for each of the plurality of battery banks by an upper threshold.

6. 6. The battery management device according to claim 5, wherein the controller sets the order of the plurality of battery banks in descending order of the first reference value, and determines the first battery bank with the first order, the second battery bank with the second order, and the third battery bank with the last order among the plurality of battery banks.

7. the controller calculates a first deviation that is a difference between a first reference value of the first battery bank and a first reference value of the second battery bank; calculating a second deviation that is a difference between a first reference value of the second battery bank and a first reference value of the third battery bank; The battery management device according to claim 6 , wherein the presence or absence of an abnormality in the first battery bank at the specific time point is diagnosed based on a second reference value that is a ratio of the first deviation to the second deviation.

8. 8. The battery management device of claim 7, wherein the controller diagnoses the first battery bank as an abnormal battery bank when the first reference value of the first battery bank exceeds a first threshold and the second reference value of the first battery bank exceeds a second threshold.

9. measuring the voltage of each of the plurality of battery banks; calculating a first value that is a change in voltage of each of the plurality of battery banks during a fixed period; calculating a second value that is a standard deviation of the voltage change amount per unit time for each of the plurality of battery banks; selecting a first value for each of the plurality of battery banks based on a first value and a second value for each of the plurality of battery banks; setting a ranking of each of the plurality of battery banks based on a first reference value that is a ratio of the selected first value of each of the plurality of battery banks to an average value of the selected first values ​​of the plurality of battery banks; diagnosing an abnormality in at least one of the plurality of battery banks based on the ranking of each of the plurality of battery banks at a specific time point; A method of operating a battery management device, comprising:

10. selecting a first value for each of the plurality of battery banks based on a first value and a second value for each of the plurality of battery banks, 10. The method for operating a battery management device according to claim 9, wherein, when the first value of at least one battery bank among the plurality of battery banks is smaller than a value obtained by multiplying the second value of the at least one battery bank by a lower threshold, the first value is initialized without being used for diagnosing an abnormality in the battery bank.

11. selecting a first value for each of the plurality of battery banks based on a first value and a second value for each of the plurality of battery banks, 11. The method of claim 10, wherein when the first value of at least one of the plurality of battery banks exceeds a value obtained by multiplying the second value of the at least one battery bank by an upper threshold, the first value is maintained and used to diagnose an abnormality in the battery bank.

12. selecting a first value for each of the plurality of battery banks based on a first value and a second value for each of the plurality of battery banks, 12. The method of claim 11, further comprising: accumulating the first values ​​to diagnose an abnormality in the battery bank when the first value of at least one of the plurality of battery banks is equal to or greater than a value obtained by multiplying the second value of the at least one battery bank by a lower threshold and is equal to or less than a value obtained by multiplying the second value by an upper threshold.

13. the step of ranking each of the plurality of battery banks based on a first reference value that is a ratio of the selected first value of each of the plurality of battery banks to an average value of the selected first value of each of the plurality of battery banks, 13. The method for operating a battery management device according to claim 12, wherein the first reference value for each of the plurality of battery banks is calculated as a ratio of the selected first value for each of the plurality of battery banks to a maximum value among an average value of the selected first values ​​for each of the plurality of battery banks and values ​​obtained by multiplying the second value for each of the plurality of battery banks by an upper threshold.

14. the step of ranking each of the plurality of battery banks based on a first reference value that is a ratio of the selected first value of each of the plurality of battery banks to an average value of the selected first values ​​of the plurality of battery banks, 14. The method for operating a battery management device according to claim 13, further comprising: setting an order of the plurality of battery banks in descending order of the first reference value; and determining a first battery bank having the first order, a second battery bank having the second order, and a third battery bank having the last order among the plurality of battery banks.

15. the step of diagnosing whether or not there is an abnormality in at least one battery bank among the plurality of battery banks based on the ranking of each of the plurality of battery banks at the specific time point, calculating a first deviation that is a difference between a first reference value of the first battery bank and a first reference value of the second battery bank; calculating a second deviation that is a difference between a first reference value of the second battery bank and a first reference value of the third battery bank; The method of claim 14 , further comprising diagnosing whether or not there is an abnormality in the first battery bank at the specific time point based on a second reference value that is a ratio of the first deviation to the second deviation.

16. The step of diagnosing at least one battery bank among the plurality of battery banks based on the ranking of each of the plurality of battery banks at the specific time point includes:

16. The method of claim 15, further comprising diagnosing the first battery bank as an abnormal battery bank when the first reference value of the first battery bank exceeds a first threshold and the second reference value of the first battery bank exceeds a second threshold.

17. Memory and A processor coupled to the memory and configured to perform the method of operating a battery management device according to any one of claims 9 to 16.

18. measuring the voltage of each of the plurality of battery banks; calculating a first value that is a change in voltage of each of the plurality of battery banks during a fixed period; calculating a second value that is a standard deviation of the voltage change amount per unit time for each of the plurality of battery banks; selecting a first value for each of the plurality of battery banks based on a first value and a second value for each of the plurality of battery banks; setting a ranking of each of the plurality of battery banks based on a first reference value that is a ratio of the selected first value of each of the plurality of battery banks to an average value of the selected first values ​​of the plurality of battery banks; and diagnosing an abnormality in at least one of the plurality of battery banks based on the ranking of each of the plurality of battery banks at a specific point in time.

19. the step of diagnosing whether or not there is an abnormality in at least one battery bank among the plurality of battery banks based on the ranking of each of the plurality of battery banks at the specific time point, ranking the plurality of battery banks in descending order of first reference value, and determining a first battery bank as the first ranked battery bank, a second battery bank as the second ranked battery bank, and a third battery bank as the last ranked battery bank among the plurality of battery banks; calculating a first deviation that is a difference between a first reference value of the first battery bank and a first reference value of the second battery bank; calculating a second deviation that is a difference between a first reference value of the second battery bank and a first reference value of the third battery bank; The program according to claim 18 , further comprising diagnosing whether or not there is an abnormality in the first battery bank at the specific time point based on a second reference value that is a ratio of the first deviation to the second deviation.

20. the step of diagnosing whether or not there is an abnormality in at least one battery bank among the plurality of battery banks based on the ranking of each of the plurality of battery banks at the specific time point, 20. The program of claim 19, wherein the first battery bank is diagnosed as an abnormal battery bank when the first reference value of the first battery bank exceeds a first threshold and the second reference value of the first battery bank exceeds a second threshold.

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