Electronic device and simulation method thereof

Abstract

According to an embodiment disclosed in the present document, an electronic device may comprise: an equivalent circuit model for describing characteristics of an LFP battery including a plurality of battery stacks; and a processor for simulating the equivalent circuit model, wherein the equivalent circuit model includes a plurality of sub-models which correspond one-to-one to the plurality of battery stacks and are connected in parallel, and the processor sets a parameter value of each of the plurality of sub-models, sets a current source connected to the plurality of sub-models, calculates a terminal current and a terminal voltage of each of the plurality of sub-models, and analyzes the characteristics of the battery on the basis of the terminal voltage of each of the plurality of sub-models.

Description

Electronic device and its simulation method

[0001] The embodiments disclosed in this document relate to an electronic device and a method for simulating the same.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 2024-0124008 dated September 11, 2024, and all contents disclosed in the document of said Korean Patent Application are incorporated herein as part of this specification.

[0003] Recently, active research and development on secondary batteries has been underway. Here, secondary batteries refer to rechargeable batteries, encompassing conventional Ni / Cd and Ni / MH batteries as well as the more recent lithium-ion batteries. Among secondary batteries, lithium-ion batteries have the advantage of significantly higher energy density compared to conventional Ni / Cd and Ni / MH batteries. Furthermore, lithium-ion batteries can be manufactured in a compact and lightweight manner, making them suitable for use as power sources for mobile devices. Recently, their scope of application has expanded to include electric vehicles, drawing attention as a next-generation energy storage medium.

[0004] To analyze the behavior and characteristics of such batteries, an equivalent circuit model describing the battery is used. However, since batteries exhibit different behaviors and characteristics depending on their composition and type, it is necessary to utilize an appropriate equivalent circuit model to analyze them according to the specific battery type. In particular, conventional circuit models had a problem in that it was difficult to describe the behavioral characteristics of LFP batteries.

[0005] One objective of the embodiments disclosed in this document is to provide an electronic device and a method for simulating the same, capable of designing an equivalent circuit model to describe the characteristics of an LFP battery and describing and analyzing the characteristics of an LFP battery through the simulation of the equivalent circuit model.

[0006] The technical problems of the embodiments disclosed in this document are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below.

[0007] According to an embodiment disclosed in this document, an electronic device comprises: an equivalent circuit model for describing the characteristics of an LFP battery including a plurality of battery stacks; and a processor for simulating the equivalent circuit model, wherein the equivalent circuit model includes a plurality of sub-models connected in parallel and corresponding one-to-one to the plurality of battery stacks, and the processor can set the values ​​of parameters for each of the plurality of sub-models, set current sources connected to the plurality of sub-models, calculate terminal currents and terminal voltages for each of the plurality of sub-models, and analyze the characteristics of the battery based on the terminal voltages of each of the plurality of sub-models.

[0008] According to an embodiment, each of the plurality of sub-models may include a voltage source; a first resistor connected in series with the voltage source; and at least one RC circuit connected in series with the first resistor.

[0009] According to an embodiment, the parameters of the plurality of sub-models include the capacity of the corresponding battery stack, and the processor can set a deviation of the capacity of the battery stack corresponding to each of the plurality of sub-models.

[0010] According to an embodiment, the processor can analyze the slope of the terminal voltage of each of the plurality of sub-models due to the deviation in capacity of the battery stack.

[0011] According to an embodiment, the processor can calculate a distribution current in which a current provided from the current source is distributed to each of the plurality of sub-models, calculate a relative current in which a first sub-model included in the plurality of sub-models is distributed from the first sub-model to each of the other sub-models, and calculate a terminal current and a terminal voltage for each of the plurality of sub-models based on the distribution current and the relative current calculated for each of the plurality of sub-models.

[0012] According to an embodiment, the processor can set a current pattern of the current source to correspond to the charge / discharge pattern of the battery and analyze the change in terminal voltage of each of the plurality of sub-models according to the current pattern.

[0013] According to an embodiment, the processor sets a plurality of current patterns of the current source to correspond to a plurality of charge / discharge patterns having different C-rates, obtains a plurality of simulation results corresponding to each current pattern, and can analyze the voltage gradient relaxation phenomenon of the battery based on the plurality of simulation results.

[0014] According to an embodiment disclosed in this document, a method for simulating an equivalent circuit model comprising a plurality of sub-models connected in parallel and corresponding one-to-one to a plurality of battery stacks included in an LFP battery may include: a step of setting the value of a parameter for each of the plurality of sub-models; a step of setting a current source connected to the plurality of sub-models; a step of calculating a terminal current and a terminal voltage for each of the plurality of sub-models; and a step of analyzing the characteristics of the battery based on the terminal voltage of each of the plurality of sub-models.

[0015] According to an embodiment, the step of calculating the terminal current and terminal voltage of each of the plurality of sub-models may include: a step of calculating a distribution current in which the current provided from the current source is distributed to each of the plurality of sub-models; a step of calculating a relative current in which the first sub-model is distributed to each of the other sub-models for a first sub-model included in the plurality of sub-models; and a step of calculating the terminal current and terminal voltage of each of the plurality of sub-models based on the distribution current and the relative current calculated for each of the plurality of sub-models.

[0016] The electronic device and the simulation method according to the embodiments disclosed in this document can improve the description of the characteristics of an LFP battery.

[0017] In addition, various effects that can be identified directly or indirectly through this document may be provided.

[0018] FIG. 1 is a block diagram showing the configuration of an electronic device according to one embodiment disclosed in this document.

[0019] FIG. 2 is a drawing showing an example of an equivalent circuit model according to one embodiment disclosed in this document.

[0020] FIGS. 3 to 5 are drawings showing the interpretation of an equivalent circuit model according to one embodiment disclosed in this document.

[0021] FIGS. 6a and 6b are drawings showing examples of the characteristics of an LFP battery according to one embodiment disclosed in this document.

[0022] FIGS. 7a to 7c are drawings showing examples of simulation results according to one embodiment disclosed in this document.

[0023] FIG. 8 is a diagram showing an example of analyzing the voltage slope relaxation phenomenon resulting from the simulation of an equivalent circuit model according to one embodiment disclosed in this document.

[0024] FIG. 9 is a flowchart illustrating a simulation method according to one embodiment disclosed in this document.

[0025] Hereinafter, various embodiments of the present invention are described with reference to the accompanying drawings. However, this is not intended to limit the present invention to specific embodiments and should be understood to include various modifications, equivalents, and / or alternatives of the embodiments of the present invention.

[0026] In this document, the singular form of a noun corresponding to an item may include one or more of said items unless the relevant context clearly indicates otherwise. In this document, each of the 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 include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. Terms such as “first,” “second,” or “first” or “second” may be used simply to distinguish a component from another corresponding component and do not limit the components in any other aspect (e.g., importance or order). Where any (e.g., 1st) component is referred to as “coupled” or “connected” to another (e.g., 2nd) component, with or without the terms “functionally” or “communicationly,” it means that said any component may be connected to said other component directly (e.g., via a wire), wirelessly, or through a third component.

[0027] Each component (e.g., module or program) of the components described in this document may include a singular or multiple entities. According to various embodiments, one or more of the components or operations may be omitted, or one or more other components or operations may be added. Generally or additionally, multiple components (e.g., module or 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 multiple components in the same or similar manner as they were performed by the corresponding component among the multiple components prior to the integration. According to various embodiments, 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.

[0028] As used in this document, the terms "module" or "...part" 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, for example. A module may be a component formed integrally, or a minimum unit of said component or a part thereof 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).

[0029] 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 code or program instructions for executing a plurality of steps. In one embodiment, the recording medium may be implemented as a device such as, for example, a server, a hard disk drive (HDD), a solid state drive (SSD), read-only memory (ROM), random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, or an optical data storage device. In one embodiment, if a camera of a machine such as a computer identifies a QR code or a document, the QR code or the document may also be considered a recording medium, and there is no limitation on the type of recording medium 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 it may be distributed and stored on multiple recording media within a networked computer system to execute parts of the program in a distributed manner.

[0030] In one embodiment, a computer-readable recording medium may be provided in the form of a non-transitory recording medium. Here, the term "non-transitory" means that the recording medium is a tangible device and is not a transient signal (e.g., electromagnetic waves), and is not intended to distinguish between cases where data stored on the recording medium is stored semi-permanently and cases where it is stored temporarily. Meanwhile, this is merely one embodiment, and the recording medium may be modified to be transitory.

[0031] The method according to one embodiment may be provided by being included in a computer program product. The computer program product may be distributed in the form of a computer-readable medium (e.g., CD-ROM), distributed online through an application store (e.g., upload, download), or distributed directly between two or more terminal devices. The method according to one embodiment may be implemented as the computer program itself.

[0032]

[0033] FIG. 1 is a block diagram showing the configuration of an electronic device (10) according to one embodiment disclosed in this document.

[0034] Referring to FIG. 1, the electronic device (10) may include an equivalent circuit model (100) and a processor (200). The electronic device (10) can simulate the equivalent circuit model (100) to represent and analyze the behavior and characteristics of the battery. For example, the behavior of the battery may include voltage behavior and SOC behavior, and the characteristics of the battery may include the flattening or relaxation characteristics of the voltage slope. As an example, the electronic device (10) can simulate the equivalent circuit model (100) to describe the voltage behavior of the battery and analyze the voltage behavior to analyze the relaxation characteristics of the voltage slope of the battery.

[0035] Batteries can exhibit different behaviors and characteristics depending on their composition and type. Accordingly, the electronic device (10) can design a suitable equivalent circuit model (100) to describe the characteristics of the battery according to the type of battery.

[0036] According to one embodiment, the battery may be an LFP battery, and the equivalent circuit model (100) may be designed as a model to more appropriately describe the characteristics of the LFP battery. For example, the LFP battery may have SOC-OCV curve characteristics different from other types of batteries, such as MCN batteries, and these characteristics of the LFP battery may be difficult to describe with conventional circuit models. Accordingly, the electronic device (10) may design and simulate the equivalent circuit model (100) according to the embodiment disclosed in this document to describe the characteristics of the LFP battery.

[0037] The equivalent circuit model (100) may refer to a circuit model for describing the characteristics of an LFP battery including multiple battery stacks. An LFP battery may be configured by connecting multiple battery stacks in parallel, and the equivalent circuit model (100) may be a model for describing the characteristics of an LFP battery including multiple battery stacks.

[0038] According to one embodiment, the equivalent circuit model (100) may include a plurality of sub-models that correspond one-to-one with a plurality of battery stacks and are connected in parallel. Each of the plurality of sub-models may correspond one-to-one with a battery stack and may be connected in parallel with one another.

[0039] The equivalent circuit model (100) can individually describe each battery stack by including a plurality of sub-models that correspond one-to-one to the battery stack. For example, each of the plurality of sub-models can describe the voltage behavior and current behavior of the corresponding battery stack.

[0040] In addition, the equivalent circuit model (100) includes multiple sub-models, thereby enabling the description of LFP battery characteristics through the interaction between the multiple sub-models. For example, existing models for describing batteries could not account for deviations between battery stacks, and consequently, there were limitations in describing the characteristics of LFP batteries. However, since the equivalent circuit model (100) comprises multiple sub-models and can account for the interaction between the multiple sub-models, it can account for deviations between battery stacks and describe and analyze the behavior and characteristics of LFP batteries accordingly.

[0041] For example, the equivalent circuit model (100) can describe the voltage and current behavior of an LFP battery with capacity variation of the battery stack taken into account. In this way, the equivalent circuit model (100) can describe the characteristics of an LFP battery by including a plurality of sub-models corresponding to each battery stack, taking into account the interaction of the battery stacks.

[0042] According to one embodiment, each of the plurality of sub-models may include a voltage source, a first resistor connected in series with the voltage source, and at least one RC circuit connected to the first resistor. Each sub-model may be connected to a terminal. The terminal to which each sub-model is connected may include, for example, a positive terminal and a negative terminal, and at least one RC circuit of each sub-model may be connected to the positive terminal, and the negative terminal of the voltage source may be connected to the negative terminal.

[0043] For example, referring to FIG. 2, the equivalent circuit model (100) may include a plurality of sub-models (110, 120, 130), and each sub-model (110, 120, 130) may be connected to a positive terminal (+) and a negative terminal (-).

[0044] Additionally, each sub-model may include a voltage source, a first resistor, and at least one RC circuit. For example, a first sub-model (110) may include a voltage source (111), a first resistor (113), and an RC circuit (115, 117). Likewise, a second sub-model (120) may include a voltage source (121), a first resistor (123), and an RC circuit (125, 127), and a third sub-model (130) may include a voltage source (131), a first resistor (133), and an RC circuit (135, 137).

[0045] Figure 2 illustrates an example in which three sub-models are connected in parallel, but the number of sub-models is not limited thereto and can be designed to correspond to the number of battery stacks. Additionally, in Figure 2, the RC circuit of each sub-model is illustrated as a first-order RC circuit, but this is merely an example, and the structure may include an n-order RC circuit (where n is a natural number greater than or equal to 2) in which multiple RC circuits are connected in series.

[0046] The processor (200) can simulate the equivalent circuit model (100). For example, the processor (200) can simulate the equivalent circuit model (100) to calculate the current and voltage components of each sub-model in the equivalent circuit model (100). Through the simulation of the equivalent circuit model (100), the processor (200) can verify whether the equivalent circuit model (100) describes the behavior and characteristics of the battery. Additionally, the processor (200) can analyze the characteristics of the battery by analyzing the simulation results of the equivalent circuit model (100).

[0047] According to one embodiment, the processor (200) can set the values ​​of the parameters of the equivalent circuit model (100). The processor (200) can set the parameter values ​​of each of the plurality of sub-models of the equivalent circuit model (100) for the simulation of the equivalent circuit model (100).

[0048] According to one embodiment, parameters of a plurality of sub-models may include the capacity of the corresponding battery stack. Even if a plurality of battery stacks included in a battery are set to the same specifications, variations in capacity may occur depending on manufacturing and use. When variations in the capacity of the battery stacks occur, the behavior of the battery stacks may differ, such as changes in SOC due to the variation in capacity of each battery stack, even under the same usage conditions of the battery (e.g., same charging conditions). Accordingly, the processor (200) can simulate an equivalent circuit model (100) by setting the variation in capacity of the battery stacks corresponding to each of the plurality of sub-models.

[0049] Additionally, the value of each parameter of the sub-model may include the voltage value of the voltage source, the resistance value of the first resistor, and the values ​​of the resistor and capacitor constituting the RC circuit. For example, the specifications of the battery stack may all be set to be the same, and the processor (200) may set the resistance value of the first resistor of each of the plurality of sub-models, and the values ​​of the resistor and capacitor constituting the RC circuit to be the same.

[0050] However, the state of the battery stack may vary depending on the use of the battery, and accordingly, it may be possible to set the values ​​of the parameters of each sub-model differently. For example, the internal resistance of a specific battery stack may change depending on use, and when performing a simulation for such a case, the processor (200) may set at least some of the resistance values ​​of the first resistor of some sub-models, the resistors constituting the RC circuit, and the capacitor values ​​differently from other sub-models. Additionally, the processor (200) may set the values ​​of the parameters according to the purpose of the simulation of the equivalent circuit model (100).

[0051] According to one embodiment, the processor (200) may set a current source connected to a plurality of sub-models. The current source may be provided between terminals connected to each of the plurality of sub-models. For example, the current source may be provided between the positive terminal and the negative terminal of the equivalent circuit model (100).

[0052] As described above, the battery stack may have a capacity variation, and if there is a capacity variation of the battery stack, the behavior of the battery may differ even under the same usage conditions. Accordingly, the processor (200) may set a current source to analyze the behavior of the battery stack and apply current to the equivalent circuit model (100). For example, the processor (200) may set a current pattern and set a current value provided by the current source according to the current pattern.

[0053] For example, the current supplied by the current source may result in variations in current distribution due to capacity deviations in each battery stack, and voltage deviations may occur in each sub-model. In this case, interactions between battery stacks may occur depending on the current and voltage deviations of the battery stacks. For instance, current redistribution between battery stacks may take place.

[0054] According to one embodiment, the processor (200) can calculate the terminal current and terminal voltage of each of a plurality of sub-models. The processor (200) can calculate the terminal current and terminal voltage of each of a plurality of sub-models to simulate an equivalent circuit model (100) and analyze the simulation results.

[0055] According to one embodiment, the processor (200) can calculate a distribution current in which a current provided from a current source is distributed to each of the plurality of sub-models, and for a first sub-model included in the plurality of sub-models, calculate a relative current in which a first sub-model is distributed to each of the other sub-models.

[0056] According to one embodiment, the processor (200) can calculate the distributed current and relative current of each of a plurality of sub-models based on the principle of superposition. The superposition theorem may refer to a method of superimposing the responses to power sources (voltage sources and current sources) in a linear circuit by calculating each of them. In applying the principle of superposition, the processor (200) can superimpose the circuit by selecting one independent power source among the plurality of power sources, short-circuiting the other voltage sources, and opening the current sources. For example, the processor (200) can construct a circuit in which one of the voltage sources of each of the plurality of sub-models is selected and the other voltage sources are short-circuited, and calculate the relative current distributed from the sub-model containing the selected voltage source to another sub-model.

[0057] According to one embodiment, the processor (200) can calculate the terminal current and terminal voltage of each of the plurality of sub-models based on the distributed current and the relative current calculated for each of the plurality of sub-models.

[0058] For example, the processor (200) can calculate the terminal current and terminal voltage of each of the multiple sub-models by solving multiple relational equations obtained in the process of calculating the distribution current and relative current of each of the multiple sub-models.

[0059] Additionally, the processor (200) can calculate the terminal voltage of the LFP battery. For example, the processor (200) can calculate the average of the terminal voltages of each of the multiple sub-models as the terminal voltage of the LFP battery.

[0060] The process of the processor (200) calculating the distributed current and relative current and the process of calculating the terminal current and terminal voltage of each of the plurality of sub-models will be described later with reference to FIGS. 3 to 5.

[0061] According to one embodiment, the processor (200) can analyze the characteristics of the battery based on the terminal voltage of each of the plurality of sub-models. For example, the processor (200) can analyze the change in the terminal voltage of each of the plurality of sub-models and analyze the voltage behavior characteristics of the battery.

[0062] According to one embodiment, the processor (200) can analyze the slope of the terminal voltage of each of the plurality of sub-models due to the deviation in the capacity of the battery stack. That is, due to the deviation in the capacity of the battery stack, the sensitivity to changes in the SOC of the battery stack may differ even under the same operating conditions, and accordingly, a deviation in the current distribution of the sub-models may occur, and in the process, the voltage slope may change. Accordingly, the processor (200) can analyze the slope of the terminal voltage of each sub-model. In addition, the processor (200) can analyze the slope of the terminal voltage of the LFP battery.

[0063] According to one embodiment, the processor (200) can set the current pattern of the current source to correspond to the charge / discharge pattern of the battery. For example, the processor (200) can set the current pattern provided from the current source to the battery as the C-rate pattern during charge / discharge. The C-rate pattern may refer to a pattern of the amount of charge provided to the battery. For example, the processor (200) can set the charge / discharge C-rate pattern corresponding to a pattern of repeatedly charging and discharging the SOC of the battery stack between 90% and 10% as the current pattern of the current source.

[0064] Additionally, the processor (200) can analyze the change in terminal voltage of each of the plurality of sub-models according to the current pattern of the current source. For example, the processor (200) can analyze the change in terminal voltage over time and / or the change in terminal voltage according to SOC for each of the plurality of sub-models.

[0065] Additionally, at each point in time, the terminal voltage of the LFP battery can be calculated as the average of the terminal voltages of each of the multiple sub-models, and the processor (200) can analyze the change in the terminal voltage of the LFP battery. Likewise, the processor (200) can analyze the change in the terminal voltage of the LFP battery over time and / or the change in the terminal voltage according to the SOC.

[0066] According to one embodiment, the processor (200) can set a plurality of current patterns of a current source to correspond to a plurality of charge / discharge patterns having different C-rates, and obtain a plurality of simulation results corresponding to each current pattern. For example, the processor (200) can perform a plurality of simulations by setting a plurality of current patterns to correspond to a plurality of charge / discharge patterns having different C-rates in order to analyze the characteristics of an LFP battery in which the voltage slope is mitigated in a specific SOC range as the C-rate changes.

[0067] The processor (200) can analyze the voltage slope mitigation phenomenon of the battery based on multiple simulation results. For example, the processor (200) can analyze the voltage slope mitigation phenomenon of the LFP battery by comparing the change in the slope of the terminal voltage of the LFP battery in a specific SOC range in multiple simulation results.

[0068] FIGS. 3 to 5 are drawings showing the interpretation of an equivalent circuit model (100) according to one embodiment disclosed in this document.

[0069] First, referring to FIG. 3, the processor (200) can set a deviation in the capacity of a battery stack corresponding to each of a plurality of sub-models. For example, as shown in FIG. 3, the processor (200) can set the capacity of the first sub-model (310) to 80% of the reference capacity, the capacity of the second sub-model (320) to 90% of the reference capacity, and the capacity of the fifth sub-model (350) to 120% of the reference capacity. Here, the reference capacity may refer to the standard capacity of the battery stack. The above-described capacity deviation is merely an example, and the numerical values ​​may be set differently.

[0070] Additionally, the processor (200) can set a current source (360) provided between the two ends of the equivalent circuit model (100) for simulating the equivalent circuit model (100).

[0071] The processor (200) can calculate the terminal current and terminal voltage of each sub-model by simulating the equivalent circuit model (100). For example, the processor (200) can calculate the relative current and divided current of each sub-model by applying the principle of superposition to the equivalent circuit model (100).

[0072] For example, the processor (200) can construct a circuit model in which only a voltage source for one sub-model exists and analyze the current distribution by the selected voltage source to calculate the relative current distributed from the selected sub-model to other sub-models. As illustrated in FIG. 4, the processor (200) can calculate the relative current distributed from the first sub-model to other sub-models in a superposition circuit in which only the voltage source of the first sub-model is selected.

[0073] For example, the processor (200) can derive a relationship for each relative current (i12, i13, i14, i15) distributed to other sub-models (420 to 450) based on the voltage source of the first sub-model (410) in the superposition circuit of FIG. 4. The processor (200) can derive relationships such as [Equation 1] below in the superposition circuit for the first sub-model (410) by Kirchhoff's law.

[0074] [Mathematical Formula 1]

[0075]

[0076] Here, is the value of the voltage source of the first sub-model (410), The resistance value of the first resistor of the j-th sub-model, The relative current distributed from the first sub-model (410) to the j-th sub-model, This can refer to the voltage across the RC circuit of the j sub-model.

[0077] Additionally, the processor (200) can construct a superposition circuit for the voltage sources of all sub-models, apply Kirchhoff's laws, and derive relational equations such as [Equation 1]. When five sub-models are provided, the processor (200) can derive relational equations for the voltage sources of each sub-model to obtain a total of 20 relational equations.

[0078] Additionally, the processor (200) can also construct a superposition circuit for a current source. For example, in the superposition circuit for a current source shown in FIG. 5, the processor (200) can apply the current division rule. For example, in FIG. 5, the current provided from the current source (560) may be equal to the sum of the currents distributed to each of the sub-models (510, 520, 530, 540, 550).

[0079] That is, the relationship of the current distributed to each sub-model from the current source (560) can be expressed as [Equation 2] below.

[0080] [Mathematical Formula 2]

[0081]

[0082] Here, is the current value of the current source, can mean the current value distributed to each sub-model.

[0083] The processor (200) can calculate the distribution current and relative current of each sub-model by solving the relationship equations calculated as [Equation 1] and [Equation 2]. And, the processor (200) can calculate the terminal current and terminal voltage of each of the multiple sub-models based on the distribution current and relative current of each sub-model.

[0084] For example, the processor (200) can express the terminal current of the first sub-model (310) as shown in [Equation 3] below.

[0085] [Mathematical Formula 3]

[0086]

[0087] In this way, the processor (200) can calculate the terminal current of each of the multiple sub-models by interpreting the relational equations calculated as [Equation 1] and [Equation 2] described above. Additionally, the processor (200) can express the voltage across the RC circuit of the first sub-model (310) as shown in [Equation 4] below.

[0088] [Mathematical Formula 4]

[0089]

[0090] In conclusion, the processor (200) can express the terminal voltage of the first sub-model (310) as shown in [Equation 5] below.

[0091] [Mathematical Formula 5]

[0092]

[0093] It can be calculated as follows. In this case, since multiple sub-models are connected in parallel, the terminal voltage of each sub-model can be the same.

[0094] FIGS. 6a and 6b are drawings showing examples of the characteristics of an LFP battery according to one embodiment disclosed in this document.

[0095] First, referring to Fig. 6a, the characteristics of the SOC-voltage curve according to the C-rate during the charging and discharging process of an LFP battery are illustrated. Referring to Fig. 6a, it can be seen that as the C-rate increases during the charging and discharging of the LFP battery, the slope of the voltage in the SOC-voltage curve becomes gentler in a specific SOC range.

[0096] More specifically, if we examine region A of Fig. 6a, we can see that the voltage slope becomes gentler as the C-rate increases during charging and discharging in the range of 60% to 67% SOC of the LFP battery. That is, in the LFP battery, when the C-rate during charging and discharging is 0.05C, the voltage slope changes abruptly in the range of approximately 65% ​​SOC, whereas when the C-rate during charging and discharging is 0.5C, there is almost no change in the voltage slope.

[0097] FIG. 6b illustrates the SOC-OCV curve characteristics of an LFP battery according to the C-rate. In FIG. 6b, graph (620) represents the OCV during the charging idle period, and graph (630) represents the OCV during the discharging idle period. In FIG. 6b, it can be seen that there is almost no change in the OCV value of the LFP battery even though the C-rate changes.

[0098] Therefore, the phenomenon in which the voltage slope of an LFP battery decreases according to the C-rate during charging and discharging can be interpreted as being due to deviations between battery stacks during the charging and discharging process, rather than due to OCV.

[0099] The characteristics of such a battery were difficult to describe in existing equivalent circuit models, and the electronic device (10) can design and simulate an equivalent circuit model (100) to describe and analyze the characteristics of such an LFP battery.

[0100] FIGS. 7a to 7c are drawings showing examples of simulation results according to one embodiment disclosed in this document.

[0101] FIG. 7a illustrates examples of a graph (710) showing the change in SOC over time of an equivalent circuit model (100) when the C-rate is a current pattern of 0.05C, and a graph (720) showing the change in SOC over time of an equivalent circuit model (100) when the C-rate is a current pattern of 0.5C. In graphs (710) and (720), the change in SOC over time of each of the five sub-models is shown.

[0102] Regions B1 and B2 in Fig. 7a represent the SOC range of approximately 60% to 65%. Referring to regions B1 and B2, it can be observed that the SOC deviation between sub-models decreases in the SOC range of 60% to 65%. Here, deviation may refer to the difference in SOC between the sub-model of the model with the largest SOC and the sub-model with the smallest SOC. For example, in region B1, it can be observed that the SOC deviation between sub-models decreased to 3.5% in the SOC range of 60% to 65% compared to the range where the SOC was less than 60%.

[0103] FIG. 7b shows a graph (730) representing the change in OCV over time of an equivalent circuit model (100) when the C-rate is a current pattern of 0.05C, and a graph (740) representing the change in OCV over time of an equivalent circuit model (100) when the C-rate is a current pattern of 0.05C. By comparing the C regions of the graph (730) and the graph (740), it can be seen that the slope of the voltage when the C-rate is 0.5C shows less change compared to the slope of the voltage when the C-rate is 0.05C.

[0104] Additionally, FIG. 7c illustrates an example of an SOC-OCV graph for each of the multiple sub-models and an SOC-OCV graph for the equivalent circuit model (100). For example, the characteristics of the equivalent circuit model (100) can be calculated by averaging the characteristics of each of the multiple sub-models. For example, the OCV of the equivalent circuit model (100) may be the average of the OCVs of each sub-model.

[0105] Referring to FIG. 7c, as a result of applying a capacity deviation to each sub-model, deviations may occur in the SOC-OCV graph of each sub-model, but it can be seen that the SOC-OCV graph of the equivalent circuit model (100) averaged thereon depicts a characteristic in which the change in slope becomes gentle.

[0106] That is, with reference to FIGS. 7a to 7c, the processor (200) introduces a capacity deviation between sub-models during the simulation process of the equivalent circuit model (100), and due to the capacity deviation between sub-models, a SOC deviation between sub-models may occur in an environment where the same current source is provided, and a phenomenon in which the voltage (OCV) slope of the equivalent circuit model (100) becomes gentle due to the SOC deviation may be depicted.

[0107] FIG. 8 is a diagram showing an example of analyzing the voltage slope relaxation phenomenon resulting from the simulation of an equivalent circuit model according to one embodiment disclosed in this document.

[0108] FIG. 8 illustrates the results of simulating an equivalent circuit model (100) to correspond to charge / discharge patterns having different C-rates. Referring to FIG. 8, it can be seen that, similar to FIG. 7a to FIG. 7c, the simulation results of the equivalent circuit model (100) depict a phenomenon in which the voltage slope of the LFP battery becomes gentle during charging and discharging.

[0109] That is, referring to the table in Figure 8, it can be seen that as the C-rate of the current pattern increases during simulation, the SOC deviation of each sub-model increases in a specific SOC range (60% to 65% range), and as a result, the change in voltage slope in that specific SOC range is mitigated.

[0110] For example, if you look at region D of FIG. 8, you can see that the simulation result of the equivalent circuit model (100) according to the embodiment disclosed in this document has a shape similar to the actual measurement result of the LFP battery compared to the simulation result of the conventional model, and you can see that the change in voltage slope is mitigated as the C-rate increases.

[0111] In this way, the description of the voltage slope relaxation characteristics of an LFP battery can be realized through the simulation of the equivalent circuit model (100) according to the embodiment disclosed in this document.

[0112] FIG. 9 is a flowchart illustrating a simulation method according to one embodiment disclosed in this document.

[0113] Referring to FIG. 9, in step S910, the processor (200) can set the values ​​of the parameters of each of the plurality of sub-models. The processor (200) can simulate the equivalent circuit model (100) by setting the values ​​of the parameters of each of the plurality of sub-models included in the equivalent circuit model (100).

[0114] In step S920, the processor (200) can set a current source connected to a plurality of sub-models. The processor (200) can simulate the equivalent circuit model (100) by setting the current source and setting the current applied to the equivalent circuit model (100).

[0115] In step S930, the processor (200) can calculate the terminal current and terminal voltage of each of the plurality of sub-models. For example, the processor (200) can use superposition theory to calculate the relative current distributed from each of the plurality of sub-models and the distributed current distributed to each of the plurality of sub-models, and calculate the terminal current and terminal voltage of each of the plurality of sub-models from the relative current and the distributed current.

[0116] In step S940, the processor (200) can analyze the characteristics of the battery. For example, the processor (200) can analyze the characteristics of the battery from the terminal voltage of the equivalent circuit model (100) obtained from the simulation result of the equivalent circuit model (100).

[0117]

[0118] Meanwhile, the present specification and drawings disclose preferred embodiments of the present disclosure. Although specific terms have been used, they are used merely in a general sense to facilitate the explanation of the technical content of the present disclosure and to aid in understanding the embodiments, and are not intended to limit the scope of the present disclosure. It is obvious to those skilled in the art that, in addition to the embodiments disclosed herein, other variations based on the technical concept of the present disclosure are possible.

[0119] A device or terminal according to the embodiments described above may include a processor, memory for storing and executing program data, permanent storage such as a disk drive, a communication port for communicating with an external device, and user object devices such as a touch panel, a key, a button, etc. Methods implemented as software modules or algorithms may be stored on a computer-readable recording medium as computer-readable code or program instructions executable on the processor. Here, computer-readable recording media include magnetic storage media (e.g., ROM (read-only memory), RAM (random-access memory), floppy disks, hard disks, etc.) and optical reading media (e.g., CD-ROM, DVD (Digital Versatile Disc)). Computer-readable recording media may be distributed across networked computer systems, allowing computer-readable code to be stored and executed in a distributed manner. The medium may be readable by a computer, stored in memory, and executed by a processor.

[0120] The present embodiment may be represented by functional block configurations and various processing steps. These functional blocks may be implemented by various numbers of hardware and / or software configurations that execute specific functions. For example, the embodiment may employ integrated circuit configurations such as memory, processing, logic, look-up tables, etc., capable of executing various functions by the control of one or more microprocessors or other control devices. Similar to how components may be implemented as software programming or software elements, the present embodiment may be implemented in programming or scripting languages ​​such as C, C++, Java, assembler, Python, etc., including various algorithms implemented as combinations of data structures, processes, routines, or other programming configurations. Functional aspects may be implemented as algorithms executed on one or more processors. Additionally, the present embodiment may employ prior art for electronic configuration, signal processing, and / or data processing. Terms such as "mechanism," "element," "means," and "configuration" may be used broadly and are not limited to mechanical and physical configurations. The above terms may include the meaning of a series of software processes (routines) in conjunction with processors, etc.

Claims

1. An equivalent circuit model for describing the characteristics of an LFP battery including multiple battery stacks; and It includes a processor that simulates the above equivalent circuit model, and The above equivalent circuit model is, It includes a plurality of sub-models that correspond one-to-one to the plurality of battery stacks and are connected in parallel, and The above processor is, Set the parameter values ​​for each of the above plurality of sub-models, and A current source connected to the above plurality of sub-models is set, and Calculate the terminal current and terminal voltage of each of the above plurality of sub-models, and Analyzing the characteristics of the battery based on the terminal voltage of each of the plurality of sub-models, Electronic device.

2. In Paragraph 1, Each of the above plurality of sub-models is, Voltage source; A first resistor connected in series with the above voltage source; and A circuit comprising at least one RC circuit connected in series with the first resistor, Electronic device.

3. In Paragraph 1, The parameters of the above plurality of sub-models include the capacity of the corresponding battery stack, and The above processor is, Setting the deviation in capacity of the battery stack corresponding to each of the above plurality of sub-models, Electronic device.

4. In Paragraph 3, The above processor is, Analyzing the slope of the terminal voltage of each of the plurality of sub-models due to the deviation in capacity of the battery stack, Electronic device.

5. In Paragraph 1, The above processor is, Calculate the distribution current in which the current provided from the above current source is distributed to each of the plurality of sub-models, and For a first sub-model included in the plurality of sub-models above, the relative current distributed from the first sub-model to each of the other sub-models is calculated, and Calculating the terminal current and terminal voltage of each of the plurality of sub-models based on the distribution current and the relative current calculated for each of the plurality of sub-models, Electronic device.

6. In Paragraph 1, The above processor is, A current pattern of the current source is set to correspond to the charge / discharge pattern of the battery, and Analyzing the change in terminal voltage of each of the plurality of sub-models according to the above current pattern, Electronic device.

7. In Paragraph 6, The above processor is, A plurality of current patterns of the current source are set to correspond to a plurality of charge / discharge patterns having different C-rates, and a plurality of simulation results corresponding to each current pattern are obtained. Based on the above multiple simulation results, analyzing the voltage gradient relaxation phenomenon of the battery, Electronic device.

8. A method for simulating an equivalent circuit model comprising a plurality of sub-models connected in parallel that correspond one-to-one to a plurality of battery stacks included in an LFP battery, A step of setting the value of each parameter of the plurality of sub-models above; A step of setting a current source connected to the above plurality of sub-models; A step of calculating the terminal current and terminal voltage of each of the plurality of sub-models; and A step comprising analyzing the characteristics of the battery based on the terminal voltage of each of the plurality of sub-models, Simulation method.

9. In Paragraph 8, The step of calculating the terminal current and terminal voltage of each of the plurality of sub-models above is, A step of calculating a distribution current in which the current provided from the current source is distributed to each of the plurality of sub-models; For a first sub-model included in the plurality of sub-models, a step of calculating a relative current distributed from the first sub-model to each of the other sub-models; and The method includes the step of calculating the terminal current and terminal voltage of each of the plurality of sub-models based on the distribution current and the relative current calculated for each of the plurality of sub-models. Simulation method.

10. A computer-readable recording medium having a program for executing the method of paragraph 8 on a computer.

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