Device and method for estimating temperature of battery

Abstract

A device and method for estimating the temperature of a battery according to an embodiment and an experimental example of the present invention may: measure a voltage variation according to a current variation for any one target battery among batteries at one or more reference time points during a charging process of a battery assembly; generate a temperature estimation model by reflecting, to an initial temperature estimation model, the voltage variation measured at the reference time point according to the current variation for the target battery; correct the temperature estimation model by reflecting a pre-stored correction ratio to the temperature estimation model; and estimate the temperature of the target battery by using the corrected temperature estimation model.

Description

Battery temperature estimation device and method

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2025-0049836 filed with the Korean Intellectual Property Office on April 17, 2025, and all contents disclosed in the document of said Korean patent application are incorporated into this specification.

[0002] The present invention relates to a battery temperature estimation apparatus and method, and more specifically, to a battery temperature estimation apparatus and method for estimating the temperatures of batteries within a battery assembly using a temperature estimation model.

[0003] As fossil fuels are depleted and concerns about environmental pollution intensify, the importance of eco-friendly alternative energy sources is gradually increasing. Among various alternative energy sources, the demand for rechargeable batteries is rising rapidly.

[0004] Batteries are being applied in various industrial sectors, ranging from mobile devices to automobiles, robots, and energy storage devices, as a response to environmental regulations and high oil prices.

[0005] Most modern batteries are provided as rechargeable lithium batteries. However, since rechargeable lithium batteries pose a risk of ignition or explosion in the event of internal or external defects, it is important to diagnose their condition in real time.

[0006] Meanwhile, since conventional batteries are provided as assembly structures of modules or more containing multiple unit batteries, it is difficult to measure the temperature of each individual unit battery.

[0007] Accordingly, conventionally, voltage intensity and temperature are monitored to diagnose abnormal conditions of unit batteries.

[0008] However, conventional battery condition diagnostic methods have the disadvantage that measured values ​​are prone to fluctuation due to surrounding environmental factors.

[0009] The objective of the present invention to solve the above-mentioned problems is to provide a battery temperature estimation device.

[0010] Another objective of the present invention to solve the above-mentioned problems is to provide a battery temperature estimation method using a battery temperature estimation device.

[0011] A battery temperature estimation device according to an embodiment of the present invention for achieving the above objective is a device for estimating the temperature of a plurality of batteries in a battery assembly, comprising at least one memory and a processor that executes at least one instruction in the at least one memory, wherein the at least one instruction comprises: a instruction to measure a voltage change amount according to a current change amount for any one of the target batteries at one or more reference points during the charging process of the battery assembly; a instruction to generate a temperature estimation model by reflecting the voltage change amount according to the current change amount for the target battery measured at the reference point into an initial temperature estimation model; a instruction to correct the temperature estimation model by reflecting a correction ratio stored in the temperature estimation model; and a instruction to estimate the temperature of the target battery using the corrected temperature estimation model.

[0012] Here, the reference point may include a point in time when the current changes by more than a threshold value within the same State of Charge (SOC) range of the battery assembly.

[0013] In addition, the above reference point may include at least one of the start and end sections of the rapid charging section.

[0014] Meanwhile, the above at least one command may further include a command to linearize the generated temperature estimation model.

[0015] Additionally, the command for correcting the temperature estimation model may include a command for correcting the temperature estimation model of the target battery by reflecting the correction ratio obtained using the temperature value of the reference battery among the batteries into the temperature estimation model.

[0016] Meanwhile, the above at least one command further includes a command for calculating the correction ratio, wherein the command for calculating the correction ratio may include: a command for measuring a voltage change amount according to a current change amount for a reference battery among the batteries at the reference time; a command for generating a first temperature estimation model for the reference battery by reflecting the voltage change amount according to the current change amount for the reference battery measured at the reference time into the temperature estimation initial model; a command for generating a second temperature estimation model for the reference battery by reflecting the voltage change amount according to the current change amount for the reference battery measured at the reference time and the temperature value of the reference battery into the temperature estimation initial model; a command for linearizing the first temperature estimation model and the second temperature estimation model, respectively; and a command for calculating the correction ratio of the second temperature estimation model relative to the first temperature estimation model.

[0017] In addition, the above-mentioned initial temperature estimation model may include a model in which the relationship between the change in voltage and the change in current according to temperature is defined.

[0018]

[0019] A battery temperature estimation method according to another embodiment of the present invention for achieving the above objective is a method for estimating the temperature of a plurality of batteries in a battery assembly using a battery temperature estimation device, comprising: a step of measuring a voltage change amount according to a current change amount for one of the target batteries at one or more reference points during the charging process of the battery assembly; a step of generating a temperature estimation model by reflecting the voltage change amount according to the current change amount for the target battery measured at the reference point into an initial temperature estimation model; a step of correcting the temperature estimation model by reflecting a correction ratio stored in the temperature estimation model; and a step of estimating the temperature of the target battery using the corrected temperature estimation model.

[0020] Here, the reference point may include a point in time when the current changes by more than a threshold value within the same State of Charge (SOC) range of the battery assembly.

[0021] In addition, the above reference point may include at least one of the start and end sections of the rapid charging section.

[0022] Meanwhile, the battery temperature estimation method may further include a step of linearizing the generated temperature estimation model.

[0023] Additionally, the step of correcting the temperature estimation model may include the step of correcting the temperature estimation model of the target battery by reflecting the correction ratio obtained using the temperature value of the reference battery among the batteries into the temperature estimation model.

[0024] Meanwhile, the battery temperature estimation method further includes a step of calculating the correction ratio, wherein the step of calculating the correction ratio may include: a step of measuring a voltage change amount according to a current change amount for a reference battery among the batteries at the reference time; a step of generating a first temperature estimation model for the reference battery by reflecting the voltage change amount according to the current change amount for the reference battery measured at the reference time into the initial temperature estimation model; a step of generating a second temperature estimation model for the reference battery by reflecting the voltage change amount according to the current change amount for the reference battery measured at the reference time and the temperature value of the reference battery into the initial temperature estimation model; a step of linearizing the first temperature estimation model and the second temperature estimation model, respectively; and a step of calculating the correction ratio of the second temperature estimation model relative to the first temperature estimation model.

[0025] In addition, the above-mentioned initial temperature estimation model may include a model in which the relationship between the change in voltage and the change in current according to temperature is defined.

[0026] The battery temperature estimation device and method according to an embodiment of the present invention can estimate the temperature of each battery without a separate temperature measuring device for measuring the temperature of the batteries in a battery assembly.

[0027] FIG. 1 is a block diagram of a battery system to which an embodiment of the present invention can be applied.

[0028] FIG. 2 is a block diagram of a battery temperature estimation device according to an embodiment of the present invention.

[0029] FIG. 3 is a flowchart illustrating a battery temperature estimation method according to an embodiment of the present invention.

[0030] FIG. 4 is a flowchart illustrating a method for calculating a correction ratio among the battery temperature estimation methods according to an embodiment of the present invention.

[0031] FIG. 5 is a charging control graph of a battery assembly according to an experimental example of the present invention.

[0032] FIG. 6 is a graph for verifying the temperature estimation models before correction for each of the first to eighth batteries according to the experimental example of the present invention.

[0033] FIG. 7 is a graph illustrating the corrected temperature estimation models for each of the first to eighth batteries according to the experimental example of the present invention.

[0034] FIG. 8 is a graph illustrating the corrected temperature estimation models for each of the first to eighth batteries according to the experimental example of the present invention.

[0035] 100: Battery temperature estimation device

[0036] 110: Memory 120: Processor

[0037] 130: Transmitter / receiver device 140: Input interface device

[0038] 150: Output interface device 160: Storage device

[0039] 170: Bus

[0040] The present invention is susceptible to various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. Similar reference numerals have been used for similar components in the description of each drawing.

[0041] Terms such as first, second, A, B, etc., may be used to describe various components, but said components shall not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" includes a combination of a plurality of related described items or any of a plurality of related described items.

[0042] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0043] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0044] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0045]

[0046] FIG. 1 is a block diagram of a battery system to which an embodiment of the present invention can be applied.

[0047] Referring to FIG. 1, a battery pack or battery module may be configured to include a plurality of battery cells connected in series. The battery cells or module may be connected to a load through positive and negative terminals to perform charging and discharging operations. The most commonly used battery cells are lithium-ion (Li-Ion) battery cells.

[0048] These battery cells or battery modules can be linked with a Battery Management System (BMS).

[0049] A Battery Management System (BMS) monitors the current, voltage, and temperature of each battery cell or module under its control, calculates the Status of Charge (SOC) based on the monitoring results, and controls charging and discharging. Here, State of Charge (SOC) is the battery's currently charged state expressed as a percentage, and State of Health (SOH) is the battery's current degradation state expressed as a percentage.

[0050] As such, the Battery Management System (BMS) can monitor battery cells, read cell voltages, and transmit them to other systems connected to the battery.

[0051] In addition, the battery management device (BMS) can transmit status data of at least one electrical component constituting the battery system to another device by monitoring it. To this end, the battery management device (BMS) may include a communication module for communicating with another device within the device included in the battery system.

[0052] A battery management system (BMS) can communicate with other systems within the device using a Controller Area Network (CAN). In this case, electronic components, modules, or systems within the battery management system (BMS) are connected to each other via a CAN bus. Accordingly, the battery management system (BMS) can remotely transmit status data obtained through monitoring of a battery pack or module and at least one electronic component constituting the battery management system (BMS) to another system using CAN communication.

[0053] Meanwhile, the battery management system (BMS) balances the charge of the battery cells evenly to extend the lifespan of the battery system.

[0054] To perform such operations, a battery management device (BMS) may include various components such as fuses, current sensing elements, thermistors, switches, and balancers, and in most cases, it additionally includes a Micro Controller Unit (MCU) or a Battery Monitoring Integrated Chip (BMIC) to interact with and control these components. Here, the BMIC may be an IC-type component located inside the battery management device (BMS) that measures information such as voltage, temperature, and current of a battery cell or battery module. According to an embodiment, the battery management device (BMS) may be applied to an automobile.

[0055] Meanwhile, generally, a Battery Management System (BMS) is linked with a battery protection device, which cuts off the charge / discharge circuit in the event of a battery malfunction. In other words, the battery protection circuit typically restricts battery usage by cutting off the charge / discharge circuit if a malfunction occurs in any single battery cell or battery module.

[0056] Here, the battery temperature estimation device according to an embodiment of the present invention may be implemented by being included in the configuration of a battery management device (BMS).

[0057] Hereinafter, preferred embodiments according to the present invention will be described in more detail with reference to the attached drawings.

[0058]

[0059] FIG. 2 is a block diagram of a battery temperature estimation device according to an embodiment of the present invention.

[0060] Referring to FIG. 2, the battery temperature estimation device (100) can individually estimate the temperature of a plurality of batteries in a battery assembly being charged without a temperature measuring device.

[0061] To explain in more detail by configuration, the battery temperature estimation device (100) may include a memory (110), a processor (120), a transceiver (130), an input interface device (140), an output interface device (150), and a storage device (160).

[0062] According to an embodiment, each component (110, 120, 130, 140, 150, 160) included in the battery temperature estimation device (100) can communicate with each other by being connected by a bus (170).

[0063] Among the above configurations (110, 120, 130, 140, 150, 160), the memory (110) and the storage device (160) may be configured as at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (110) and the storage device (160) may be configured as at least one of a read-only memory (ROM) and a random access memory (RAM).

[0064] Among these, the memory (110) may include at least one instruction executed by the processor (120). According to an embodiment, the at least one instruction includes: a instruction to measure a voltage change amount according to a current change amount for any one of the target batteries at one or more reference points during the charging process of the battery assembly; a instruction to generate a temperature estimation model by reflecting the voltage change amount according to the current change amount for the target battery measured at the reference point into an initial temperature estimation model; a instruction to correct the temperature estimation model by reflecting a correction ratio stored in the temperature estimation model; and a instruction to estimate the temperature of the target battery using the corrected temperature estimation model.

[0065] Here, the reference point may include a point in time when the current changes by more than a threshold value within the same State of Charge (SOC) range of the battery assembly.

[0066] In addition, the above reference point may include at least one of the start and end sections of the rapid charging section.

[0067] Meanwhile, the above at least one command may further include a command to linearize the generated temperature estimation model.

[0068] Additionally, the command for correcting the temperature estimation model may include a command for correcting the temperature estimation model of the target battery by reflecting the correction ratio obtained using the temperature value of the reference battery among the batteries into the temperature estimation model.

[0069] Meanwhile, the above at least one command further includes a command for calculating the correction ratio, wherein the command for calculating the correction ratio may include: a command for measuring a voltage change amount according to a current change amount for a reference battery among the batteries at the reference time; a command for generating a first temperature estimation model for the reference battery by reflecting the voltage change amount according to the current change amount for the reference battery measured at the reference time into the temperature estimation initial model; a command for generating a second temperature estimation model for the reference battery by reflecting the voltage change amount according to the current change amount for the reference battery measured at the reference time and the temperature value of the reference battery into the temperature estimation initial model; a command for linearizing the first temperature estimation model and the second temperature estimation model, respectively; and a command for calculating the correction ratio of the second temperature estimation model relative to the first temperature estimation model.

[0070] In addition, the above-mentioned initial temperature estimation model may include a model in which the relationship between the change in voltage and the change in current according to temperature is defined.

[0071] Meanwhile, the processor (120) may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed.

[0072] As previously described, the processor (120) can execute at least one program command stored in memory (110).

[0073] The battery temperature estimation device according to an embodiment of the present invention has been described above. Below, a battery temperature estimation method performed by a process operation within the battery temperature estimation device will be described.

[0074]

[0075] FIG. 3 is a flowchart illustrating a battery temperature estimation method according to an embodiment of the present invention.

[0076] Referring to FIG. 3, the processor (120) of the battery temperature estimation device (100) can charge a battery assembly comprising a plurality of batteries (S310). Here, the battery assembly may be configured such that a plurality of batteries are connected in series or in parallel. For example, the battery assembly may be a battery module, and the plurality of batteries may be provided as battery cells. However, not limited to what is disclosed, depending on the system to which the battery assembly is applied, the battery assembly may also be provided as a battery pack or a battery rack.

[0077] Subsequently, when the charging process of the battery assembly enters the Quick Charge section, the processor (120) can calculate the voltage change amount based on the current change amount at one or more reference points within the Quick Charge section for any one of the target batteries (S320).

[0078] According to one embodiment, the processor (120) can calculate a voltage change amount based on a current change amount in either a section where rapid charging starts or a section where rapid charging ends for the target battery.

[0079] Here, the section where rapid charging begins and ends may be a section where the magnitude of the current changes rapidly above a threshold value while the State of Charge (hereinafter SOC) of the battery assembly remains constant. In other words, the processor (120) can calculate the voltage change amount according to the current change amount of the target battery at any reference point where the SOC of the battery assembly being charged remains constant and the magnitude of the current changes rapidly above a threshold value.

[0080] According to another embodiment, the processor (120) can calculate a first change amount, which is a voltage change amount according to the current change amount in the section where rapid charging begins, for the target battery. Additionally, the processor (120) can calculate a second change amount, which is a voltage change amount according to the current change amount in the section where rapid charging ends, for the target battery. In other words, the processor (120) can calculate the first change amount and the second change amount of the target battery, respectively, at two or more reference points where the SOC of the battery assembly being charged is maintained constant and the magnitude of the current changes rapidly above a threshold value.

[0081] Subsequently, the processor (120) can generate a temperature estimation model of the target battery (S330). According to an embodiment, the processor (120) can generate a temperature estimation model of the target battery using an initial temperature estimation model. Here, the initial temperature estimation model may be a model in which the relationship between the change in voltage and the change in current according to temperature is defined. For example, the initial temperature estimation model may be formulated as shown in [Equation 1] below.

[0082]

[0083]

[0084] Here, T is temperature, μ is the change in voltage, I is the change in current, and a and b can be constants.

[0085] To explain more specifically according to one embodiment, the processor (120) can generate a temperature estimation model by reflecting the voltage change amount according to the current change amount of the target battery measured at any reference point in the initial temperature estimation model according to [Equation 1]. Here, the initial temperature estimation model can be represented as a function graph passing through the origin. In other words, the processor (120) can generate a temperature estimation model of the target battery by reflecting the voltage change amount according to the current change amount of the target battery in the initial temperature estimation model according to [Equation 1].

[0086] To explain more specifically according to another embodiment, the processor (120) can generate a temperature estimation model by reflecting the first change amount and the second change amount of the target battery in the initial temperature estimation model according to [Equation 1]. In other words, the processor (120) can generate a temperature estimation model of the target battery by fitting the first change amount and the second change amount of the target battery to the initial temperature estimation model.

[0087] Afterward, the processor (120) can linearize the generated temperature estimation model (S340). However, not limited to what is disclosed, the processor (120) may not perform step S340 and may linearize the temperature estimation model by applying a linear fitting function when correcting the temperature estimation model in the subsequent step S350.

[0088] Meanwhile, the processor (120) can correct the temperature estimation model by reflecting the correction ratio stored in the linearized temperature estimation model at step S340 (S350).

[0089] Here, the pre-stored correction ratio is a ratio calculated by comparing the first temperature estimation model and the second temperature estimation model of the reference battery, and can be pre-calculated during the initial execution of the processor (120) and stored in memory (110) or storage space (160).

[0090] Subsequently, the processor (120) can output the temperature of the target battery by inputting a voltage change amount according to the current change amount of the target battery into the corrected temperature estimation model (S360). In other words, the processor (120) can output the temperature of the target battery by inputting at least one value among the first change amount and the second change amount of the target battery into the corrected temperature estimation model.

[0091]

[0092] FIG. 4 is a flowchart illustrating a method for calculating a correction ratio among the battery temperature estimation methods according to an embodiment of the present invention.

[0093] Referring to FIG. 4, the processor (120) can measure a voltage change amount according to a current change amount for the reference battery at one or more reference points (S410). According to an embodiment, the processor (120) can measure at least one of a first change amount and a second change amount of the reference battery at the reference point. Here, the reference battery may be a battery among the batteries in the battery assembly whose temperature can be measured by a temperature measuring device.

[0094] Subsequently, the processor (120) can generate a first temperature estimation model by reflecting at least one of the first change amount and the second change amount for the reference battery in the initial temperature estimation model according to [Equation 1] (S420). In other words, the processor (120) can generate a first temperature estimation model of the reference battery by fitting at least one of the first change amount and the second change amount of the reference battery based on the initial temperature estimation model passing through the origin.

[0095] Subsequently, the processor (120) can receive a temperature value of the reference battery from a temperature measuring device (S430). According to the embodiment, the temperature of the reference battery can be measured in real time by the temperature measuring device. Accordingly, the processor (120) can receive a temperature value from the temperature measuring device at the time when the voltage change amount corresponding to the current change amount of the reference battery is measured. However, not limited to what is disclosed, the processor (120) can receive a first temperature value and a second temperature value measured at two or more reference times by the temperature measuring device, calculate a representative value thereof, and set it as the temperature value of the reference battery. Here, the first temperature value may be the temperature at the reference time when the first change amount of the reference battery is measured, and the second temperature value may be the temperature at the reference time when the second change amount of the reference battery is measured. In addition, the representative value may be one of the average value, maximum value, and minimum value of the first temperature value and the second temperature value.

[0096] Subsequently, the processor (120) may incorporate at least one of the first change amount and the second change amount of the reference battery measured in step S410 and the temperature value of the reference battery measured in step S430 into an initial temperature estimation model according to [Equation 1]. Accordingly, the processor (120) may generate a second temperature estimation model for the reference battery (S440).

[0097] Subsequently, the processor (120) may linearize the first temperature estimation model and the second temperature estimation model, respectively (S450). However, not limited to what is disclosed, the processor (120) may perform linearization individually in subsequent steps after the first temperature estimation model and the second temperature estimation model are generated in steps S420 and S440. Additionally, not limited to what is disclosed, the processor (120) may obtain the linearized second temperature estimation model by applying a linear fitting function during the correction of the first temperature estimation model in the subsequent step S460, without performing step S450.

[0098] Meanwhile, the processor (120) can calculate a correction ratio by comparing the first temperature estimation model and the second temperature estimation model that have been linearized in step S450 (S460).

[0099] To explain more specifically according to the embodiment, the processor (120) can graph the first temperature estimation model to generate a reference graph for the voltage change amount according to the current change amount of the reference battery. Subsequently, the processor (120) can calculate the slope of the reference graph.

[0100] Additionally, the processor (120) can graph the second temperature estimation model to generate a comparison graph of the voltage change amount according to the current change amount, which reflects the temperature value of the reference battery. Afterward, the processor (120) can calculate the slope of the comparison graph.

[0101] Subsequently, the processor (120) can calculate a correction ratio by comparing the slope of the reference graph with the slope of the comparison graph. According to an embodiment, the processor (120) can calculate a correction ratio based on the slope of the comparison graph relative to the slope of the reference graph. In other words, the processor (120) can calculate a correction ratio of the second temperature estimation model relative to the first temperature estimation model.

[0102] Subsequently, the processor (120) may store the calculated correction ratio in memory (110) or storage device (160). Accordingly, when the processor (120) corrects the temperature estimation model of any one battery (target battery) among a plurality of batteries in a battery assembly, excluding the existing battery, as in step S350, the processor (120) may correct the temperature estimation model of the target battery using the correction ratio stored in memory (110) or storage device (160).

[0103]

[0104] Correction experiment of temperature estimation models according to the experimental example of the present invention

[0105] A battery assembly including the first to eighth batteries was charged.

[0106] Subsequently, during the charging of the battery assembly, at the point when the rapid charging section begins, the voltage change amount (first change amount) according to the current change amount of the first to eighth batteries was calculated.

[0107] In addition, at the point where the rapid charging section ends, the voltage change amount (second change amount) according to the current change amount of the 1st to 8th batteries was calculated.

[0108] Subsequently, temperature estimation models for each of the 1st to 8th batteries were calculated.

[0109] Subsequently, the temperature estimation models of each of the first to eighth batteries were corrected using the correction ratio.

[0110]

[0111] FIG. 5 is a charging control graph of a battery assembly according to an experimental example of the present invention.

[0112] Referring to FIG. 5, according to an experimental example of the present invention, during the charging process of a battery assembly, a first CC (Constant Current) charge, a quick charge, a second CC (Constant Current) charge, and a CV (Constant Voltage) charge were sequentially performed.

[0113] At this time, at 0.23h, when the first CC charge ends and the Quick Charge begins, it can be seen that the magnitude of the current changed rapidly from 80A to 460A and the magnitude of the voltage changed from 28.6V to 30V. Additionally, at 0.75h, when the Quick Charge ends and the second CC charge begins, it can be seen that the magnitude of the current changed rapidly from 160A to 80A and the magnitude of the voltage changed from 33.6V to 33.1V.

[0114] In other words, at the first time point (P1) of 0.23h, when the state of charge (SOC) of the battery assembly remains the same, it can be seen that the change in current increased by 380A and the change in voltage decreased by 1.4V. Additionally, at the second time point (P2) of 0.75h, when the state of charge (SOC) of the battery assembly remains the same, it can be seen that the change in current decreased by 80A and the change in voltage decreased by 0.5V.

[0115] As explained earlier, at the first time point (P1, 0.23h) and the second time point (P2, 0.75h), the SOC remains the same. In other words, since the resistance value remains fixed without change at the first time point (P1, 0.23h) and the second time point (P2, 0.75h), the change in voltage can be viewed as overpotential.

[0116] Accordingly, the first to eighth temperature estimation models for each of the first to eighth batteries were individually obtained by reflecting the first change amount and the second change amount of each of the first to eighth batteries, measured at the first time point (P1, 0.23h) and the second time point (P2, 0.75h), into the initial temperature estimation model ([Equation 1]) derived using Ohm's law and the Arrhenius equation.

[0117]

[0118] FIG. 6 is a graph for verifying the temperature estimation models before correction for each of the first to eighth batteries according to an experimental example of the present invention, and FIG. 7 and FIG. 8 are graphs for explaining the corrected temperature estimation models for each of the first to eighth batteries according to an experimental example of the present invention.

[0119] Referring to FIG. 6, the graph shows the patterns of the temperature estimation models at 20°C, 25°C, 35°C, 45°C, 55°C, and 65°C before correction for each of the first to eighth batteries, as well as the voltage change amounts (B1_1 to B8_1) corresponding to the current change amount measured at the first point (P1) of each of the first to eighth batteries and the voltage change amounts (B1_2 to B8_2) corresponding to the current change amount measured at the second point (P2).

[0120] Referring to FIG. 6, it was confirmed that the reliability of the model is not high because the voltage change amounts (B1_1 to B8_1, and B1_2 to B8_2) corresponding to the current change amounts of each of the first to eighth batteries measured at the first point (P1) and the second point (P2) are not located on the patterns of the temperature estimation model before correction.

[0121] Meanwhile, FIG. 7 shows patterns of the corrected temperature estimation model for each of the first to eighth batteries (linear graph patterns at 20°C, 25°C, 35°C, 45°C, 55°C, and 65°C), voltage change amounts (M1_1 to M8_1) according to the current change amount measured at the first point (P1) for each of the first to eighth batteries, and voltage change amounts (M1_2 to M8_2) according to the current change amount measured at the second point (P2).

[0122] Referring to FIG. 7, it was confirmed that the voltage change amounts (M1_1 to M8_1, and M1_2 to M8_2) corresponding to the current change amounts of each of the first to eighth batteries measured at the first point (P1) and the second point (P2) are located on the patterns of the corrected temperature estimation model, thereby confirming that the reliability of the corrected temperature estimation model is high.

[0123] In addition, referring to FIG. 8, the patterns of the corrected temperature estimation models of each of the first to eighth batteries (linear graph patterns at 20°C, 25°C, 35°C, 45°C, 55°C, and 65°C) and the temperature values ​​(absolute temperature, K) measured from the reference battery were displayed on the graph and compared.

[0124] As a result of the comparison, it was confirmed that the patterns of the corrected temperature estimation model and the temperature values ​​are located in close proximity, thus confirming the reliability of the corrected temperature estimation model according to the embodiment of the present invention.

[0125]

[0126] The battery temperature estimation apparatus and method according to the embodiments and experimental examples of the present invention have been described above.

[0127] The battery temperature estimation apparatus and method according to the embodiments and experimental examples of the present invention provide a temperature estimation model corrected based on the voltage change amount according to the temperature-dependent current change amount of a reference battery among a plurality of batteries in a battery assembly that is capable of temperature measurement, thereby enabling the estimation of the temperature of each of the other batteries in the battery assembly without a separate temperature measuring device.

[0128]

[0129] The operation of the method according to the embodiments and experimental examples of the present invention can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes all types of recording devices in which data that can be read by a computer system is stored. Additionally, the computer-readable recording medium may be distributed across networked computer systems, allowing computer-readable programs or code to be stored and executed in a distributed manner.

[0130] In addition, computer-readable recording media may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Program instructions may include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.

[0131] Some aspects of the invention have been described in the context of a device, but may also be described according to a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described according to a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most important method steps may be performed by such a device.

[0132] Although the present invention has been described with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims.

Claims

1. A device for estimating the temperature of multiple batteries within a battery assembly, At least one memory; It includes a processor that executes at least one instruction within at least one memory, and The above at least one command is, A command to measure a voltage change amount according to a current change amount for any one of the target batteries at one or more reference points during the charging process of the battery assembly above, A command to generate a temperature estimation model by reflecting the voltage change amount according to the current change amount for the target battery measured at the reference point in the initial temperature estimation model. A command to correct the temperature estimation model by reflecting a correction ratio stored in the temperature estimation model, and A battery temperature estimation device comprising a command to estimate the temperature of the target battery using the corrected temperature estimation model.

2. In Claim 1, The above reference point is, A battery temperature estimation device including a point in time when the current changes by more than a threshold value within the same State of Charge (SOC) range of the battery assembly.

3. In Claim 1, The above reference point is, A battery temperature estimation device comprising at least one of a start section and an end section of a rapid charging section.

4. In Claim 1, The above at least one command is, A battery temperature estimation device further comprising a command to straighten the generated temperature estimation model.

5. In Claim 1, The command to correct the above temperature estimation model is, A battery temperature estimation device comprising a command to correct the temperature estimation model of the target battery by reflecting the correction ratio obtained using the temperature value of a reference battery among the batteries in the temperature estimation model.

6. In Claim 1, The above at least one command is, Further including a command to calculate the above correction ratio, The command for calculating the above correction ratio is, A command to measure the voltage change amount according to the current change amount of the reference battery among the batteries at the above reference point, A command to generate a first temperature estimation model for the reference battery by reflecting the voltage change amount according to the current change amount for the reference battery, measured at the reference point, into the initial temperature estimation model above. A command to generate a second temperature estimation model for the reference battery by reflecting in the above initial temperature estimation model, the voltage change amount according to the current change amount for the reference battery measured at the above reference point, and the temperature value of the above reference battery. A command to linearize the first temperature estimation model and the second temperature estimation model, respectively, and A battery temperature estimation device comprising a command to calculate the correction ratio of the second temperature estimation model relative to the first temperature estimation model.

7. In Claim 1, The above initial temperature estimation model is, A battery temperature estimation device comprising a model in which the relationship between the change in voltage and the change in current according to temperature is defined.

8. A method for estimating the temperatures of multiple batteries within a battery assembly using a battery temperature estimation device, wherein A step of measuring a voltage change amount according to a current change amount for any one of the target batteries at one or more reference points during the charging process of the battery assembly; A step of generating a temperature estimation model by reflecting the voltage change amount according to the current change amount for the target battery measured at the reference point in the initial temperature estimation model; A step of correcting the temperature estimation model by reflecting a correction ratio previously stored in the temperature estimation model; and A battery temperature estimation method comprising the step of estimating the temperature of the target battery using the corrected temperature estimation model.

9. In Claim 8, The above reference point is, A battery temperature estimation method including a point in time when the current changes by more than a threshold value during the same State of Charge (SOC) interval of the battery assembly.

10. In Claim 8, The above reference point is, A battery temperature estimation method comprising at least one of a start section and an end section of a rapid charging section.

11. In Claim 8, A battery temperature estimation method comprising a step of further linearizing the generated temperature estimation model.

12. In claim 8, The step of correcting the above temperature estimation model is, A battery temperature estimation method comprising the step of correcting the temperature estimation model of the target battery by reflecting the correction ratio obtained using the temperature value of a reference battery among the batteries in the temperature estimation model.

13. In Claim 8, The above correction ratio further includes a step of calculating the above correction ratio, The step of calculating the above correction ratio is, A step of measuring the voltage change amount according to the current change amount of the reference battery among the batteries at the above reference point; A step of generating a first temperature estimation model for the reference battery by reflecting the voltage change amount according to the current change amount for the reference battery, measured at the reference point, in the initial temperature estimation model above; A step of generating a second temperature estimation model for the reference battery by reflecting in the initial temperature estimation model the voltage change amount according to the current change amount for the reference battery measured at the reference point and the temperature value of the reference battery; A step of linearizing the first temperature estimation model and the second temperature estimation model, respectively; and A battery temperature estimation method comprising the step of calculating the correction ratio of the second temperature estimation model relative to the first temperature estimation model.

14. In Claim 8, The above initial temperature estimation model is, A battery temperature estimation method including a model in which the relationship between the change in voltage and the change in current according to temperature is defined.

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