Electronic device, recording medium, and method for calculating output reduction rate of battery cell

Abstract

An electronic device disclosed in the present document comprises: an information acquisition interface for acquiring time-series information related to voltage, current, temperature, and state of charge of a plurality of battery cells included in a battery pack; a memory; and a processor, wherein the processor can: calculate a first resistance of a first battery cell on the basis of the current and the voltage of the first battery cell; calculate a second resistance of the first battery cell on the basis of the temperature and the SoC of the first battery cell; calculate an instantaneous resistance increase rate of the first battery cell on the basis of the first resistance and the second resistance; calculate an average resistance increase rate of the first battery cell on the basis of a plurality of instantaneous resistance increase rates of the first battery cell, corresponding to respective time points; and calculate an output decrease rate of the first battery cell on the basis of the average resistance increase rate of the first battery cell.

Description

Method for calculating the output decay rate of electronic devices, recording media, and battery cells

[0001] Embodiments disclosed in this document relate to methods for calculating output reduction rates of electronic devices, recording media, and battery cells.

[0002] Recently, research and development on secondary batteries has been actively conducted. Here, secondary batteries are rechargeable and include both conventional Ni / Cd and Ni / MH batteries, as well as recent lithium-ion batteries. Among secondary batteries, lithium-ion batteries have the advantage of having a much higher energy density than conventional Ni / Cd and Ni / MH batteries. Furthermore, lithium-ion batteries can be manufactured in a compact and lightweight form, making them suitable for use as power sources for mobile devices. Recently, their use has expanded to include power sources for electric vehicles, attracting attention as a next-generation energy storage medium.

[0003] For batteries installed in vehicles, it's crucial to verify and diagnose battery data to ensure quality control. In particular, it's crucial to accurately estimate battery resistance as the vehicle drives to determine the rate of battery output decline.

[0004] According to one embodiment of the present disclosure, a technical problem is to calculate a stable and accurate resistance increase rate by calculating a resistance increase rate (or resistance degradation rate) using the instantaneous resistance and the estimated resistance at the beginning of life (BOL) state without applying a filter to remove noise when measuring (or estimating) the instantaneous resistance of a battery cell.

[0005] According to one embodiment of the present disclosure, a technical solution is to minimize measurement errors due to changes in the state of charge (SoC) or temperature of a battery by applying a filter for noise removal to a resistance increase rate measured for each driving cycle of a vehicle (i.e., a charge / discharge cycle of a battery).

[0006] According to one embodiment of the present disclosure, a technical solution is to calculate an output decrease rate using a resistance increase rate of a battery cell.

[0007] The technical problems of the embodiments disclosed in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the descriptions below.

[0008] An electronic device according to an embodiment of the present disclosure includes an information acquisition interface for acquiring time-series information about voltage, current, temperature, and state of charge (SoC) of a plurality of battery cells included in a battery pack; a memory; and a processor, wherein the processor may be configured to calculate a first resistance of the first battery cell based on the current and voltage of the first battery cell, calculate a second resistance of the first battery cell based on the temperature and SoC of the first battery cell, calculate an instantaneous resistance increase rate of the first battery cell based on the first resistance and the second resistance, calculate an average resistance increase rate of the first battery cell based on a plurality of instantaneous resistance increase rates of the first battery cell corresponding to a plurality of points in time, and calculate an output decrease rate of the first battery cell based on the average resistance increase rate of the first battery cell.

[0009] According to one embodiment, the processor may be configured to determine whether the current has changed by more than a predetermined threshold value during a predetermined period of time, calculate a voltage change amount and a current change amount during the predetermined period of time in response to the current changing by more than the threshold value, and calculate the first resistance based on the voltage change amount and the current change amount.

[0010] In one embodiment, the processor is configured to check a resistance map for the first battery cell in a BOL (beginning of life) state, and calculate the second resistance based on the resistance map, the temperature and SoC of the first battery cell, and the resistance map may be a table indicating the resistance according to the temperature and SoC of the first battery cell in the BOL state.

[0011] In one embodiment, the processor may be configured to determine whether a first measurement condition regarding a temperature range is satisfied based on a temperature of the first battery cell, determine whether a second measurement condition regarding a SoC range is satisfied based on an SoC of the first battery cell, and determine the validity of an instantaneous resistance increase rate of the first battery cell in response to satisfying the first measurement condition and the second measurement condition.

[0012] According to one embodiment, the processor may be configured to determine whether a third measurement condition regarding a temperature deviation is satisfied based on the temperatures of the plurality of battery cells, determine whether a fourth measurement condition regarding a SoC error is satisfied based on the SoCs of the plurality of battery cells, and determine to calculate an instantaneous resistance increase rate of the first battery cell in response to satisfying all of the first measurement condition to the fourth measurement condition.

[0013] According to one embodiment, the processor may be configured to calculate an average resistance increase rate of the first battery cell by applying the plurality of instantaneous resistance increase rates corresponding to the plurality of time points and the effective judgment values ​​of the plurality of instantaneous resistance increase rates to a recursive average filter.

[0014] According to one embodiment, the processor may be configured to determine a maximum average resistance increase rate and a minimum average resistance increase rate based on a plurality of average resistance increase rates calculated at each of the plurality of time points, and to determine whether the average resistance increase rate of the first battery cell has converged based on the maximum average resistance increase rate and the minimum average resistance increase rate.

[0015] According to one embodiment, the processor may be configured to calculate an output decrease rate of the first battery cell based on the average resistance increase rate of the first battery cell when it is determined that the average resistance increase rate of the first battery cell has converged.

[0016] According to one embodiment, the processor may be configured to calculate a plurality of output reduction rates of the first battery cell for each of a plurality of driving cycles of a vehicle including the battery pack.

[0017] According to one embodiment, the processor may be configured to calculate a long-term output reduction rate of the first battery cell based on the plurality of output reduction rates.

[0018] In one embodiment, the processor may be configured to provide a long-term output reduction rate of the first battery cell to the vehicle.

[0019] According to one embodiment, the first resistance may represent an instantaneous measured resistance of the first battery cell.

[0020] According to one embodiment, the second resistance may represent an estimated resistance of the first battery cell in a BOL state.

[0021] A method for calculating an output decrease rate of a battery cell performed by an electronic device according to one embodiment of the present disclosure may include: calculating a first resistance of a first battery cell based on a current and a voltage of the first battery cell; calculating a second resistance of the first battery cell based on a temperature and an SoC of the first battery cell; calculating an instantaneous resistance increase rate of the first battery cell based on the first resistance and the second resistance; calculating an average resistance increase rate of the first battery cell based on a plurality of instantaneous resistance increase rates of the first battery cell corresponding to a plurality of points in time; and calculating an output decrease rate of the first battery cell based on the average resistance increase rate of the first battery cell.

[0022] According to one embodiment of the present disclosure, a computer-readable recording medium storing a program for executing a method for calculating an output decrease rate of a battery cell performed by an electronic device, the method for calculating an output decrease rate of the battery cell may include: calculating a first resistance of the first battery cell based on a current and a voltage of the first battery cell; calculating a second resistance of the first battery cell based on a temperature and an SoC of the first battery cell; calculating an instantaneous resistance increase rate of the first battery cell based on the first resistance and the second resistance; calculating an average resistance increase rate of the first battery cell based on a plurality of instantaneous resistance increase rates of the first battery cell corresponding to a plurality of points in time; and calculating an output decrease rate of the first battery cell based on the average resistance increase rate of the first battery cell.

[0023] According to one embodiment of the present disclosure, a stable and accurate resistance increase rate can be calculated by calculating a resistance increase rate (or resistance degradation rate) using the instantaneous resistance and the estimated resistance at the beginning of life (BOL) state without applying a filter to remove noise when measuring (or estimating) the instantaneous resistance of a battery cell.

[0024] According to one embodiment of the present disclosure, by applying a filter for noise removal to the resistance increase rate measured for each driving cycle of a vehicle (i.e., a charge / discharge cycle of a battery), measurement errors due to changes in the state of charge (SoC) or temperature of the battery can be minimized.

[0025] According to one embodiment of the present disclosure, an output decrease rate can be calculated using a resistance increase rate of a battery cell.

[0026] In addition, various effects may be provided, either directly or indirectly, through this document.

[0027] FIG. 1 is a block diagram of an electronic device according to one embodiment of the present disclosure.

[0028] FIG. 2 is a flowchart illustrating the operation of an electronic device according to one embodiment of the present disclosure.

[0029] FIG. 3 is a flowchart of the operation of an electronic device according to one embodiment of the present disclosure.

[0030] FIG. 4 is a graph illustrating a count of effective instantaneous resistance reduction rates over time according to one embodiment of the present disclosure.

[0031] FIG. 5 is a diagram showing the distribution of instantaneous resistance increase rates according to counts according to one embodiment of the present disclosure.

[0032] FIG. 6 is a graph showing the variation in the average resistance increase rate according to the count according to one embodiment of the present disclosure.

[0033] Hereinafter, various embodiments of the present invention will be described with reference to the attached drawings. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that the present invention encompasses various modifications, equivalents, and / or alternatives of the embodiments.

[0034] In this document, the singular form of a noun corresponding to an item may include one or more of said items, unless the context clearly indicates otherwise. In this document, phrases such as "A or B," "at least one of A and B," "at least one of A or B," "A, B, or C," "at least one of A, B, and C," and "at least one of A, B, or C" may each include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as "first," "second," or "first" or "second" may be used merely to distinguish the corresponding element from other corresponding elements, and do not limit the corresponding elements in any other respect (e.g., importance or order). When a component (e.g., a first component) is referred to as being "coupled" or "connected" to another component (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0035] Each component (e.g., a module or a program) described in this document may include one or more entities. According to various embodiments, one or more components or operations of the components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to integration. According to various embodiments, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0036] The term "module" or "part" used in this document may include a unit implemented in hardware, software, or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit. A module may be an integral component, or a minimum unit or part of such a component that performs one or more functions. For example, according to one embodiment, a module may be implemented in the form of an application-specific integrated circuit (ASIC).

[0037] Various embodiments of the present document may be implemented as software (e.g., a program or an application) including one or more instructions stored in a machine-readable storage medium (e.g., memory). For example, a processor of the device may call at least one instruction among the one or more instructions stored from the storage medium and execute it. This enables the device to operate to perform at least one function according to the at least one instruction called. The one or more instructions may include code generated by a compiler or code executable by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Here, "non-transitory" only means that the storage medium is a tangible device and does not contain a signal (e.g., electromagnetic waves), and this term does not distinguish between cases where data is stored semi-permanently and cases where it is stored temporarily in the storage medium.

[0038] FIG. 1 is a block diagram of an electronic device (100) according to one embodiment of the present disclosure. Referring to FIG. 1, the electronic device (100) may include a processor (110), a memory (120), and an information acquisition interface (130). At least one of the components included in the electronic device (100) may be omitted, or another component may be added to the electronic device (100). Additionally or alternatively, some of the components may be implemented in an integrated manner, or may be implemented as a single or multiple entities. At least some of the components within the electronic device (100) may be implemented in an integrated manner, or may be implemented as a single or multiple entities.

[0039] An electronic device (100) can diagnose the status of multiple battery cells included in a battery pack. The battery pack may include multiple battery cells arranged in series and / or parallel. The battery pack may also be configured as a battery module (or battery bank), which is a collection of battery cells. The battery pack may be mounted in various devices, for example, in an electric vehicle.

[0040] The electronic device (100) can obtain voltage information and / or current information of a plurality of battery cells. The electronic device (100) can diagnose the status of each of the plurality of battery cells by calculating voltage relationship information according to the state of charge of each of the plurality of battery cells (e.g., OCV-SOC profile) or voltage relationship according to capacity (e.g., capacity-voltage profile). The electronic device (100) can diagnose the status of the battery cells using field data of the battery.

[0041] The electronic device (100) may be a battery management device (or battery management system, BMS) included in a battery pack, an on-board diagnostics (OBD) device included in an electric vehicle, a server or cloud device, or a charger and discharger.

[0042] According to one embodiment, the processor (110) of the electronic device (100) is a configuration capable of performing calculations or data processing related to control and / or communication of each component of the electronic device (100), and may be operatively connected to the components of the electronic device (100). The processor (110) may load commands or data received from other components of the electronic device (100) into the memory (120), process the commands or data stored in the memory (120), and store result data. Unless there are special circumstances, the processor (110) in the present disclosure may mean a set of one or more processors (110).

[0043] The memory (120) of the electronic device (100) according to one embodiment may store various data used by at least one component (e.g., the processor (110)). The memory (120) may store instructions for the operation of the processor (110) described above. The program may be stored as software in the memory (120) and may include, for example, an operating system, middleware, or an application. Unless otherwise specified, the memory (120) in the present disclosure may mean a set of one or more memories (120).

[0044] An information acquisition interface (130) according to one embodiment can acquire voltage information and / or current information of a plurality of battery cells included in a battery pack. The information acquisition interface (130) can acquire time-series information regarding the voltage and current of a plurality of battery cells.

[0045] The information acquisition interface (130) may be a component, for example, a sensor, that directly measures the state of the battery pack when the electronic device (100) is a battery management system (BMS) of the battery pack. In addition, the information acquisition interface (130) may be a communication interface that receives measured information from a component (for example, a battery management system of the battery pack) that measures the state of the battery pack when the electronic device (100) is an OBD device, a server, a cloud, or a charger / discharger.

[0046] The information acquisition interface (130) can acquire voltage information or current information of a plurality of battery cells included in a battery pack. The voltage information of the plurality of battery cells may refer to the operating voltage or open circuit voltage (OCV) of each battery cell. For example, the information acquisition interface (130) can acquire the operating voltage of the battery cell when the battery pack is in operation, and can acquire the open circuit voltage of the battery cell when the battery pack is in an idle state. In addition, the current information of the battery cells may include the current of each battery cell and the current of the battery pack. The current of the battery pack and the current of each battery cell may be the same. The information acquisition interface (130) can continuously acquire the voltage and current information of the battery pack over time. For example, the information acquisition interface (130) can periodically acquire the voltage and current information of the battery pack. According to one embodiment, the information acquisition interface (130) can acquire the voltage information and current information of the plurality of battery cells in an OTA (over the air) manner. For example, the information acquisition interface (130) can acquire voltage information and current information of the battery cell from the battery management device of the battery pack in an OTA manner.

[0047] The information acquisition interface (130) can acquire information about the temperature and state-of-charge (SoC) of a plurality of battery cells included in a battery pack. The information acquisition interface (130) can acquire time-series information about the temperature and SoC of a plurality of battery cells. The processor can also determine (or estimate) information about the SoC based on information about the voltage and / or current of the battery cells. Using an SoC estimation algorithm, the processor can calculate the SoC using the voltage and / or current information of the battery cells.

[0048] According to one embodiment, the processor (110) may calculate the instantaneous resistance of the battery cell based on the current and voltage of the battery cell. The instantaneous resistance may refer to the measured resistance of the battery cell corresponding to the time at which the current and voltage are measured (i.e., the present time). The processor (110) may calculate the estimated resistance of the battery cell in the BOL state based on the temperature and SoC of the battery cell. The estimated resistance may be an estimated resistance calculated using a resistance map for the first battery cell in the BOL state and the current and voltage measured at the present time. The BOL state is information related to the lifespan of the battery cell and may refer to the state at the time the battery cell is produced and shipped.

[0049] According to one embodiment, the processor (110) can calculate an instantaneous resistance increase rate of the battery cell using the instantaneous resistance and the estimated resistance of the battery cell. The processor (110) can calculate a plurality of instantaneous resistance increase rates during a plurality of charge / discharge cycles, and can calculate an average resistance increase rate of the battery cell based on the plurality of instantaneous resistance increase rates. The processor (110) can calculate an output decrease rate of the battery cell based on the average resistance increase rate of the battery cell. The processor (110) can diagnose whether the battery cell is abnormal based on the output decrease rate of the battery cell.

[0050] FIG. 2 is a flowchart illustrating the operation of an electronic device (100) according to one embodiment of the present disclosure.

[0051] Referring to the flowchart 200, the processor (110) of the electronic device (100) according to one embodiment may calculate a first resistance of a first battery cell in step 210. The processor (110) may calculate the first resistance of the first battery cell based on the current and voltage of the first battery cell. The first resistance of the first battery cell may refer to an instantaneous resistance corresponding to a point in time at which the current and voltage of the first battery cell are measured. The first resistance may be an ohmic resistance. The processor (110) may determine the first resistance of the first battery cell by calculating a slope (dV / dI) of a voltage graph according to current for the first battery cell.

[0052] The processor (110) can determine the first resistance of the first battery cell using a tuning factor. The processor (110) can check whether the current of the first battery cell changes by more than a predetermined threshold value during a predetermined period of time. For example, the processor (110) can check whether the current of the first battery cell changes by more than 5 A during 0.1 seconds. The predetermined period of time (e.g., 0.1 seconds) can be set to a sufficiently short time to measure the instantaneous resistance. The predetermined threshold value for the current (e.g., 5 A) can be variously set as the tuning factor. If the current changes by more than the threshold value, the processor (110) can calculate the first resistance using the following mathematical expression 1. In response to the current changing by more than the threshold value, the processor (110) can calculate the amount of voltage change and the amount of current change during the predetermined period of time. The processor (110) can calculate the first resistance based on the amount of voltage change and the amount of current change.

[0053]

[0054] R1 is the first resistor, is the voltage change, is the change in current. Vpresent and I present are the voltage and current at the current point in time, and V presious and I previous can be the voltage and current at the previous point in time. The unit of the first resistance can be Ω.

[0055] The previous point in time and the current point in time may differ by a predetermined time (e.g., 0.1 s). The current point in time may be a time after the current changes beyond a threshold value for a predetermined time, and the previous point in time may be a time before the current changes beyond the threshold value. Through the above-described method, the processor (110) can calculate the first resistance, which is the instantaneous resistance of the first battery cell. That is, the calculated first resistance is not a value to which a filter (e.g., a recursive least squares (RLS) algorithm) for removing noise is applied. That is, since the first resistance is a value to which the instantaneous resistance is not excessively and stably tuned by applying a filter, it is possible to track the change in the instantaneous resistance due to a change in temperature or SoC of the first battery cell.

[0056] According to one embodiment, the processor (110) may calculate the second resistance of the first battery cell in step 220. The second resistance may represent an estimated resistance of the first battery cell in the BOL state. That is, the second resistance may be a resistance confirmed by applying the SoC and temperature measured at the current point in time to a resistance map for the first battery cell in the BOL state. The unit of the second resistance may be Ω. The processor (110) may confirm the resistance map for the first battery cell in the BOL state. The resistance map may be stored in the memory (120) of the electronic device (100) or may be obtained from an external device (e.g., a server) through the information acquisition interface (130). The resistance map may be a table defined in advance for the first battery cell in the BOL state, and may be information as in the table below, for example. The table below is an exemplary table, and the resistance values ​​included in the table may change depending on the type of battery cell. The processor (110) can use the resistance map to check the resistance value corresponding to the temperature and SoC of the first battery cell, and determine the checked resistance value as the second resistance of the first battery. For example, when the temperature of the first battery cell is 25°C and the SoC is 50%, the processor (110) can determine the second resistance of the first battery cell as 1.000Ω.

[0057] SoC temperature0℃10℃25℃40℃60℃100%1.261Ω1.067Ω0.970Ω0.922Ω0.902Ω75%1.274Ω1.078Ω0.980Ω0.931Ω0.911Ω50%1.3 00Ω1.100Ω1.000Ω0.950Ω0.930Ω25%1.339Ω1.133Ω1.030Ω0.979Ω0.958Ω0%1.430Ω1.210Ω1.100Ω1.045Ω1.023Ω

[0058]

[0059] According to one embodiment, the processor (110) may calculate an instantaneous resistance increase rate of the first battery cell at step 230. The processor (110) may calculate the instantaneous resistance increase rate of the first battery cell based on the first resistance and the second resistance. The processor (110) may calculate the instantaneous resistance increase rate using the following mathematical expression 2.

[0060]

[0061] SOHR instant is the instantaneous resistance increase rate and the unit can be %. R1 can be the first resistor and R2 can be the second resistor.

[0062] According to one embodiment, the processor (110) may calculate an instantaneous resistance increase rate when the first battery cell satisfies at least one measurement condition. The at least one measurement condition may include a first measurement condition regarding a temperature range, a second measurement condition regarding an SoC range, a third measurement condition regarding a temperature deviation, or a fourth measurement condition regarding an SoC error. For example, the processor (110) may determine to calculate an instantaneous resistance increase rate when the first battery cell satisfies all of the first to fourth measurement conditions. For example, the processor (110) may determine not to calculate an instantaneous resistance increase rate when the first battery cell does not satisfy any one of the first to fourth measurement conditions. The first to fourth measurement conditions may be conditions regarding whether the first resistance measured for the first battery cell is reliable. FIG. 3 is an operational flowchart of an electronic device (100) according to one embodiment of the present disclosure. Specifically, FIG. 3 is an operational flowchart for determining whether to calculate an instantaneous resistance increase rate.

[0063] Referring to the flowchart 300, the processor (110) of the electronic device (100) according to one embodiment may determine, in step 310, whether a first measurement condition regarding a temperature range is satisfied. The first measurement condition may be a condition regarding whether the temperature of the first battery cell is within a predetermined temperature range. For example, the first measurement condition may be a condition regarding whether the temperature of the first battery cell is greater than 10°C and less than 50°C. The processor (110) may determine that the first measurement condition is satisfied when the temperature of the first battery cell is within the temperature range. The above-described temperature range values ​​are exemplary and may, of course, be changed by a tuning factor.

[0064] In one embodiment, the processor (110) may determine, at step 320, whether a second measurement condition regarding the SoC range is satisfied. The second measurement condition may be a condition regarding whether the SoC of the second battery cell is within a predetermined SoC range. For example, the second measurement condition may be a condition regarding whether the SoC of the first battery cell is greater than 30% and less than 90%. The processor (110) may determine that the second measurement condition is satisfied when the SoC of the first battery cell is within the SoC range. The above-described SoC range value is exemplary and may be changed by a tuning factor.

[0065] In one embodiment, the processor (110) may determine, at step 330, whether a third measurement condition regarding a temperature deviation is satisfied. The third measurement condition may be a condition regarding whether a temperature deviation determined based on the temperatures of a plurality of battery cells included in a battery pack is less than a predetermined threshold deviation. Here, the battery pack may refer to a battery pack including a first battery cell. For example, the third measurement condition may be a condition regarding whether the determined temperature deviation is less than 3°C. The processor (110) may check a maximum temperature and a minimum temperature among the temperatures of the plurality of battery cells, and determine the difference between the maximum temperature and the minimum temperature as the temperature deviation. The processor (110) may determine whether the determined temperature deviation is less than the threshold deviation. If the temperature deviation is less than the threshold deviation, the processor (110) may determine that the third measurement condition is satisfied. The above-described temperature deviation value is exemplary and may be changed by a tuning factor.

[0066] In one embodiment, the processor (110) may determine, at step 340, whether a fourth measurement condition regarding SoC error is satisfied. The fourth measurement condition may be a condition regarding whether an SoC error range determined based on the SoC of a plurality of battery cells included in a battery pack is less than a predetermined threshold error value. Here, the battery pack may refer to a battery pack including a first battery cell. For example, the fourth measurement condition may be a condition regarding whether the determined SoC error range is less than 3%. The processor (110) may calculate an error range based on the SoC of the plurality of battery cells and determine whether the calculated error range is less than the predetermined threshold error. If the error range is less than the threshold error, the processor (110) may determine that the fourth measurement condition is satisfied. The above-described SoC error range value is exemplary and may be changed by a tuning factor.

[0067] The processor (110) according to one embodiment may determine whether to calculate the instantaneous resistance increase rate of the first battery cell based on whether the first measurement condition to the fourth measurement condition is satisfied. If the first battery cell satisfies all of the first measurement condition to the fourth measurement condition described above, the processor (110) may determine a valid determination value (Valid instant ) can be determined as T (true). If the valid judgment value is determined as T, the processor (110) can determine that the first resistor is reliable and determine to calculate the instantaneous resistance increase rate. The processor (110) can calculate the instantaneous resistance increase rate using the first resistor and the second resistor.

[0068] According to one embodiment, the processor (110) may determine a valid judgment value as F (false) if the first battery cell does not satisfy at least one of the first to fourth measurement conditions described above. If the valid judgment value is determined to be F, the processor (110) may determine that the first resistance is unreliable and may determine not to calculate an instantaneous resistance increase rate.

[0069] Returning to FIG. 2 again, the processor (110) according to one embodiment may, at step 240, calculate an average resistance increase rate of the first battery cell. The processor (110) may calculate the average resistance increase rate of the first battery cell based on a plurality of instantaneous resistance increase rates of the first battery cell corresponding to a plurality of points in time.

[0070] The processor (110) can calculate the average resistance increase rate of the first battery cell by applying a plurality of instantaneous resistance increase rates corresponding to a plurality of points in time and a valid judgment value of the plurality of instantaneous resistance increase rates to a recursive average filter. The processor (110) can increase the count by +1 each time a valid instantaneous resistance increase rate is calculated. For example, when the valid judgment value is T, the processor (110) can increase the count by +1, and when the valid judgment value is F, the processor (110) can not change the count. The processor (110) can calculate the average resistance increase rate of the first battery cell by using a recursive average filter as in Mathematical Expression 3 below.

[0071]

[0072] SOHR mean is the average resistance increase rate at the current point in time, count is the count, and SOHR mean,prev is the average resistance increase rate of the previous point, and SOHR instant is the instantaneous resistance increase rate at the current point in time. That is, the processor (110) can calculate the average resistance increase rate by gradually accumulating the valid instantaneous resistance increase rate using a recursive average filter. The recursive average is a technique that adds one more data while using the definition of the average, and is a different technique from the batch method that collects all data and calculates the average at once.

[0073] According to one embodiment, the processor (110) can determine whether the average resistance increase rate has converged. The processor (110) can determine the maximum average resistance increase rate and the minimum average resistance increase rate based on a plurality of average resistance increase rates calculated at each of a plurality of points in time. The processor (110) can determine whether the average resistance increase rate of the first battery cell has converged based on the maximum average resistance increase rate and the minimum average resistance increase rate.

[0074] When calculating the average resistance increase rate using a recursive average filter, the processor (110) can know multiple average resistance increase rates for each of multiple points in time because the effective average resistance increase rate at each point in time is accumulated to calculate the average resistance increase rate. The processor (110) can determine the maximum average resistance increase rate (SOHR) among the multiple average resistance increase rates. mean,max ) and minimum average resistance increase rate (SOHR mean,min ) and calculate the difference between the maximum average resistance increase rate and the minimum average increase rate. The processor (110) can check whether the difference between the maximum average resistance increase rate and the minimum average increase rate is less than a predetermined convergence judgment criterion value (e.g., 2.5). If the difference between the maximum average resistance increase rate and the minimum average increase rate is less than the convergence judgment criterion value, the processor (110) can determine that the average resistance increase rate has converged and determine the convergence flag value as T (true). If the difference between the maximum average resistance increase rate and the minimum average increase rate is equal to or greater than the convergence judgment criterion value, the processor (110) can determine that the average resistance increase rate has not converged and determine the convergence flag value as F (false).

[0075] According to one embodiment, the processor (110) may calculate an output decrease rate of the first battery cell in step 250. If the processor (110) determines that the average resistance increase rate of the first battery cell has converged, the processor (110) may calculate the output decrease rate of the first battery cell based on the average resistance increase rate of the first battery cell. If the convergence flag value is F, the processor (110) may determine that the average resistance increase rate of the first battery cell has not yet converged, and may decide not to calculate the output decrease rate of the first battery cell. If the convergence flag value is T, the processor (110) may determine that the average resistance increase rate of the first battery cell has converged, and may calculate the output decrease rate of the first battery cell. The processor (110) may calculate the output decrease rate of the first battery cell using the following mathematical expression 4.

[0076]

[0077] SOHP st is the output reduction rate, and the unit can be %, and SOHR mean is the average resistance increase rate and the unit can be %.

[0078] According to one embodiment, a processor (110) may calculate a plurality of output reduction rates of a first battery cell for a plurality of driving cycles of a vehicle including the battery pack. The processor (110) may calculate a plurality of output reduction rates for each of a plurality of driving cycles and accumulate the output reduction rates to calculate a long-term output reduction rate. For example, the processor (110) may calculate 20 output reduction rates for the most recent 20 driving cycles and accumulate the 20 output reduction rates to calculate a long-term output reduction rate. The long-term output reduction rate may be an average value of the plurality of output reduction rates. The long-term output reduction rate may be an average value of the remaining output reduction rates excluding the maximum output reduction rate and the minimum output reduction rate among the plurality of output reduction rates.

[0079] A processor (110) according to one embodiment can provide a long-term power reduction rate to a vehicle. The processor (110) can transmit the long-term power reduction rate to a control unit (ECU, electronic control unit) of the vehicle via a communication interface (e.g., a CAN communication module, a LIN communication module).

[0080] FIG. 4 is a graph (400) illustrating a count of valid instantaneous resistance reduction rates over time according to one embodiment of the present disclosure.

[0081] Referring to FIG. 4, the processor (110) can calculate multiple instantaneous resistance reduction rates during one driving cycle. As described above, if at least one measurement condition is satisfied at a specific measurement point in time, the processor (110) can determine that the first resistance calculated at the specific measurement point in time is valid (i.e., determine the valid determination value as T) and calculate the instantaneous resistance reduction rate. The count can be the number of times the valid determination value is determined as T. In other words, the count can mean the number of times the instantaneous resistance reduction rate is calculated.

[0082] FIG. 5 is a drawing (500) showing the distribution of SOHR according to counts according to one embodiment of the present disclosure.

[0083] Referring to Fig. 5, the SOHR value corresponding to each count is marked with a point (501), so that the distribution of SOHR according to the count can be confirmed. The graph (503) indicated by the solid line is a graph showing a plurality of instantaneous resistance increase rates calculated using a plurality of first resistors to which a filter (e.g., RLS filter, moving average filter) for removing noise is applied to a plurality of first resistors calculated at a plurality of points in time. When a noise removal filter is applied to the first resistor, it can be confirmed that the trend of the graph (503) is unstable due to changes in resistance characteristics according to changes in SoC and temperature of the battery cell.

[0084] Accordingly, according to various embodiments of the present disclosure, instead of applying a noise removal filter to the first resistor, an instantaneous resistance increase rate is calculated using a first resistor to which a noise removal filter is not applied, and a recursive average filter is applied to multiple instantaneous resistance increase rates calculated at multiple points in time to calculate an average resistance increase rate, thereby obtaining a graph (505) indicated by a dashed-dotted line representing an average resistance increase rate according to a count with a stable trend. For example, the instantaneous resistance increase rate can be measured and accumulated for 1000 driving cycles, and the average resistance increase rate can be calculated using this. Since the graph (505) indicated by the dashed-dotted line applies a recursive average filter, it can converge as the counts accumulate, thereby stabilizing the trend. Referring to FIG. 5, it can be confirmed that the average resistance increase rate in the graph (505) converges to a convergence value (510). The convergence value can be, for example, 109%.

[0085] FIG. 6 is a drawing (600) showing a graph showing the variation in the average resistance increase rate according to the count according to one embodiment of the present disclosure.

[0086] Referring to FIG. 6, the graph (601) is a graph showing the fluctuation range of the average resistance increase rate over a recent set period (e.g., the recent 300 counts). The convergence judgment criterion value (610) indicated by the dotted line may be, for example, 2.5%. Since the average resistance increase rate is calculated using a recursive average filter, it can be confirmed through the graph (505) of FIG. 5 that the average resistance increase rate converges as the counts accumulate. Accordingly, it can be confirmed through the graph (601) that the fluctuation range of the average resistance increase rate decreases.

[0087] Through the above-described process, the instantaneous resistance value, which varies depending on the temperature and SoC of the battery cell, can be calculated, and the instantaneous resistance increase rate can be calculated using this. By calculating the average resistance increase rate and output decrease rate based on the instantaneous resistance increase rate, the dependence on the temperature and SoC of the battery cell can be eliminated, and the accuracy of the result value can be increased. Since opportunities to measure the first resistance, which is the instantaneous resistance, occur frequently during the vehicle's driving cycle, a large amount of resistance data can be accumulated in a short period of time, allowing the resistance increase rate and output decrease rate to converge to an estimated value in a short period of time.

[0088] Meanwhile, the present specification and drawings disclose preferred embodiments of the present disclosure, and although specific terms are used, they are used in a general sense only to easily explain the technical contents of the present disclosure and to help understand the embodiments, and are not intended to limit the scope of the present disclosure. It will be apparent to those skilled in the art to which the embodiments of the present disclosure pertain that other modified examples based on the technical idea of ​​the present disclosure are possible in addition to the embodiments disclosed herein.

[0089] The device or terminal according to the above-described embodiments may include a processor, a memory for storing and executing program data, a permanent storage such as a disk drive, a communication port for communicating with an external device, a user object device such as a touch panel, a key, a button, etc. The methods implemented as software modules or algorithms may be stored on a computer-readable recording medium as computer-readable codes or program commands that can be executed on the processor. Here, the computer-readable recording medium includes a magnetic storage medium (e.g., a read-only memory (ROM), a random-access memory (RAM), a floppy disk, a hard disk, etc.) and an optical reading medium (e.g., a CD-ROM, a Digital Versatile Disc (DVD)). The computer-readable recording medium may be distributed to computer systems connected through a network, so that the computer-readable code can be stored and executed in a distributed manner. The medium is readable by a computer, stored in a memory, and executed by a processor.

[0090] The methods implemented by the software or algorithms disclosed in this document may be implemented as a program and stored on a computer-readable recording medium (or storage medium). The program may include computer-readable codes or program instructions for executing a plurality of steps. In one embodiment, the recording medium may be implemented as a device such as a server, a hard disk drive (HDD), a solid state drive (SSD), a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, or an optical data storage device. In one embodiment, when a camera of a machine such as a computer identifies a QR code or a document, the QR code or the document may also correspond to the recording medium, and the recording medium is not limited in type as long as it can be read and executed by a computer. In one embodiment, the program may be stored on a single recording medium, or may be distributed and stored on multiple recording media within a network-connected computer system so that portions of the program may be executed in a distributed manner.

[0091] In one embodiment, the computer-readable recording medium may be provided in the form of a non-transitory recording medium. The term "non-transitory" here means that the recording medium is a tangible device and not a transitory signal (e.g., electromagnetic waves). It does not distinguish between cases where data stored on the recording medium is stored semi-permanently and cases where data is stored temporarily. Furthermore, this is merely an example, and the recording medium may be modified to be a non-transitory recording medium.

[0092] The method according to one embodiment may be provided as a computer program product. The computer program product may be distributed in the form of a computer-readable medium (e.g., a CD-ROM), distributed online (e.g., uploaded or downloaded) through an application store, or distributed directly between two or more terminal devices. The method according to one embodiment may also be implemented as a computer program itself.

[0093] The present embodiment may be represented by functional block configurations and various processing steps. These functional blocks may be implemented by various hardware and / or software configurations that perform specific functions. For example, the embodiment may employ integrated circuit configurations such as memory, processing, logic, look-up tables, etc., which may perform various functions under the control of one or more microprocessors or other control devices. Similarly, the present embodiment may be implemented in a programming or scripting language such as C, C++, Java, assembler, Python, etc., including various algorithms implemented as a combination of data structures, processes, routines, or other programming configurations. Functional aspects may be implemented as algorithms that execute on one or more processors. Furthermore, the present embodiment may employ conventional techniques for electronic configuration, signal processing, and / or data processing. Terms such as "mechanism," "element," "means," and "composition" can be used broadly and are not limited to mechanical or physical structures. These terms can also encompass a series of software routines, such as those associated with a processor.

Claims

1. In electronic devices, An information acquisition interface for acquiring time series information on voltage, current, temperature, and state of charge (SoC) of multiple battery cells included in a battery pack; memory; and Contains a processor, The above processor, Based on the current and voltage of the first battery cell, the first resistance of the first battery cell is calculated, Based on the temperature and SoC of the first battery cell, the second resistance of the first battery cell is calculated, Based on the first resistance and the second resistance, the instantaneous resistance increase rate of the first battery cell is calculated, Based on a plurality of instantaneous resistance increase rates of the first battery cell corresponding to a plurality of points in time, an average resistance increase rate of the first battery cell is calculated, An electronic device configured to calculate an output decrease rate of the first battery cell based on an average resistance increase rate of the first battery cell.

2. In paragraph 1, The above processor, Check whether the current has changed by more than a predetermined threshold value during a predetermined period of time, In response to the above current changing by more than the above threshold value, the voltage change amount and the current change amount for the predetermined time are calculated, An electronic device configured to calculate the first resistance based on the voltage change amount and the current change amount.

3. In paragraph 1, The above processor Check the resistance map for the first battery cell in the BOL (beginning of life) state, configured to calculate the second resistance based on the resistance map, the temperature and SoC of the first battery cell, An electronic device wherein the resistance map is a table representing the resistance according to the temperature and SoC of the first battery cell in the BOL state.

4. In paragraph 1, The above processor, Based on the temperature of the first battery cell, it is determined whether the first measurement condition regarding the temperature range is satisfied, Based on the SoC of the first battery cell, it is determined whether the second measurement condition regarding the SoC range is satisfied, An electronic device configured to determine the validity of an instantaneous resistance increase rate of the first battery cell in response to satisfying the first measurement condition and the second measurement condition.

5. In paragraph 4, The above processor, Based on the temperatures of the plurality of battery cells, it is determined whether the third measurement condition regarding temperature deviation is satisfied, Based on the SoC of the plurality of battery cells, it is determined whether the fourth measurement condition regarding SoC error is satisfied, An electronic device configured to determine, in response to satisfying all of the first measurement condition to the fourth measurement condition, the calculation of the instantaneous resistance increase rate of the first battery cell.

6. In paragraph 5, The above processor, An electronic device configured to calculate an average resistance increase rate of the first battery cell by applying the plurality of instantaneous resistance increase rates corresponding to the plurality of points in time and the effective judgment values ​​of the plurality of instantaneous resistance increase rates to a recursive average filter.

7. In paragraph 6, The above processor, Based on the multiple average resistance increase rates calculated at each of the multiple points in time, the maximum average resistance increase rate and the minimum average resistance increase rate are confirmed, An electronic device configured to determine whether the average resistance increase rate of the first battery cell has converged based on the maximum average resistance increase rate and the minimum average resistance increase rate.

8. In paragraph 7, The above processor, An electronic device configured to calculate an output decrease rate of the first battery cell based on the average resistance increase rate of the first battery cell when it is determined that the average resistance increase rate of the first battery cell has converged.

9. In paragraph 1, The above processor, An electronic device configured to calculate a plurality of output reduction rates of the first battery cell for each of a plurality of driving cycles of a vehicle including the battery pack.

10. In paragraph 9, The above processor, An electronic device configured to calculate a long-term output reduction rate of the first battery cell based on the plurality of output reduction rates.

11. In paragraph 1, The above processor, An electronic device configured to provide a long-term output reduction rate of the first battery cell to a vehicle.

12. In paragraph 1, An electronic device wherein the first resistance represents an instantaneous measured resistance of the first battery cell.

13. In paragraph 1, An electronic device wherein the second resistance represents an estimated resistance of the first battery cell in a BOL state.

14. A method for calculating the output reduction rate of a battery cell performed by an electronic device, A step of calculating a first resistance of a first battery cell based on the current and voltage of the first battery cell; A step of calculating a second resistance of the first battery cell based on the temperature and SoC of the first battery cell; A step of calculating an instantaneous resistance increase rate of the first battery cell based on the first resistance and the second resistance; A step of calculating an average resistance increase rate of the first battery cell based on a plurality of instantaneous resistance increase rates of the first battery cell corresponding to a plurality of points in time; and A method for calculating an output decrease rate of a battery cell, comprising the step of calculating an output decrease rate of the first battery cell based on an average resistance increase rate of the first battery cell.

15. A computer-readable recording medium having recorded thereon a program for executing a method for calculating a rate of output reduction of a battery cell performed by an electronic device, A method for calculating the output reduction rate of the above battery cell is as follows: A step of calculating a first resistance of a first battery cell based on the current and voltage of the first battery cell; A step of calculating a second resistance of the first battery cell based on the temperature and SoC of the first battery cell; A step of calculating an instantaneous resistance increase rate of the first battery cell based on the first resistance and the second resistance; A step of calculating an average resistance increase rate of the first battery cell based on a plurality of instantaneous resistance increase rates of the first battery cell corresponding to a plurality of points in time; and A recording medium comprising a step of calculating an output decrease rate of the first battery cell based on an average resistance increase rate of the first battery cell.

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