Battery SOH estimation device and method

Abstract

A battery SOH estimation device according to one embodiment of the present invention includes a battery information acquisition unit configured to acquire battery information including at least one of voltage, current, temperature, and SOC, and a control unit configured to calculate deterioration information of the battery from the battery information, predetermined reference information, and predetermined acceleration information based on a predetermined deterioration model, and to estimate the SOH of the battery from the deterioration information based on a predetermined nonlinear estimation model.

Description

[Technical Field]

[0001] This application claims priority based on Korean Patent Application No. 10-2022-0157819, filed on November 22, 2022, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof.

[0002] The present invention relates to a battery SOH estimation device and method, and more particularly to a battery SOH estimation device and method that can effectively estimate the SOH (State of health) of a battery. [Background technology]

[0003] In recent years, as demand for portable electronic products such as laptops, video cameras, and mobile phones has grown rapidly and the development of electric vehicles, energy storage batteries, robots, and artificial satellites has gained momentum, active research has been conducted into high-performance batteries that can be repeatedly charged and discharged.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among these, lithium batteries are attracting attention due to their advantages of being able to be freely charged and discharged since they have almost no memory effect compared to nickel-based batteries, as well as their extremely low self-discharge rate and high energy density.

[0005] Various techniques have been used to estimate the degree of battery deterioration. For example, a typical technique is to estimate the degree of battery deterioration by estimating the SOH based on the deterioration of capacity based on the battery's OCV (Open Circuit Voltage). The estimated degree of battery deterioration can be used as a measure of the current lifespan of the battery.

[0006] However, such conventional techniques estimate the degree of battery degradation by comparing the initial capacity of the battery with the current capacity, but are limited in obtaining information about factors that cause battery degradation. For example, because battery degradation can be affected by nonlinear factors such as anode side reactions, cathode side reactions, and dissolution of transition metals, conventional degradation estimation techniques have difficulty identifying the factors that cause such degradation.

[0007] In addition, even if the degradation level of a battery is the same, the residual value of the battery may vary depending on factors that affect the degradation level. In other words, the accuracy of estimating the battery state using conventional technologies is limited. Therefore, there is a need for a technology that can estimate the battery state by taking into account various factors that affect the battery degradation level. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been devised to solve the above problems, and aims to provide a battery SOH estimation device and method that can estimate the state of a battery by taking into account various factors that affect battery degradation.

[0009] Other objects and advantages of the present invention can be understood from the following description and become more apparent from the embodiments of the present invention, and can be realized by the means and combinations thereof set forth in the claims. [Means for solving the problem]

[0010] A battery SOH estimation device according to one aspect of the present invention includes a battery information acquisition unit configured to acquire battery information including at least one of voltage, current, temperature, and SOC (State of charge), and a control unit configured to calculate deterioration information of the battery from the battery information, predetermined reference information, and predetermined acceleration information based on a predetermined deterioration model, and to estimate the SOH of the battery from the deterioration information based on a predetermined nonlinear estimation model.

[0011] The control unit may be configured to calculate first acceleration information from the battery information and the reference information based on the deterioration model, calculate second acceleration information based on the first acceleration information and a predetermined acceleration profile, and set the calculated second acceleration information as the acceleration information.

[0012] The control unit may be configured to determine a reference range from the acceleration profile based on the battery temperature among the battery information, and calculate the second acceleration information according to the result of comparing the determined reference range with the first acceleration information.

[0013] The control unit may be configured to calculate the first acceleration information as the second acceleration information if the first acceleration information falls within the reference range.

[0014] The control unit may be configured to calculate an upper limit value of the reference range as the second acceleration information if the first acceleration information exceeds the reference range.

[0015] The control unit may be configured to, if the first acceleration information is less than the reference range, calculate a lower limit value of the reference range as the second acceleration information.

[0016] The control unit may be configured to estimate a reference SOH from the battery information based on a preset linear estimation model, and set the reference information based on the SOH and the reference SOH.

[0017] The control unit may be configured to calculate a weight based on the SOH and the reference SOH, and set a value obtained by adding the weight to the degradation information as the reference information.

[0018] The nonlinear estimation model may consist of a nonlinear Kalman filter.

[0019] The linear estimation model may consist of a linear Kalman filter.

[0020] The control unit may be configured to calculate a Kalman gain based on the SOH and the reference SOH as the weighted value, and set a value obtained by adding the Kalman gain to the degradation information as the reference information.

[0021] The control unit may be configured to update the reference information based on the degradation information, the SOH, and the reference SOH every time the SOH is estimated.

[0022] When the control unit calculates the deterioration information for the first time, the control unit may be configured to set a predetermined reference value as the reference information so as to correspond to the deterioration information of a battery in a BOL (Beginning of Life) state.

[0023] The control unit may be configured to calculate, as the deterioration information, at least one of an amount of side reaction at the negative electrode, an amount of side reaction at the positive electrode, and an amount of elution of transition metals.

[0024] A battery pack according to another aspect of the present invention includes a battery SOH estimation device according to an aspect of the present invention.

[0025] A server according to yet another aspect of the present invention includes a battery SOH estimation device according to an aspect of the present invention.

[0026] According to yet another aspect of the present invention, a battery SOH estimation method includes a battery information acquisition step of acquiring battery information including at least one of voltage, current, temperature, and SOC; a deterioration information calculation step of calculating deterioration information of the battery from the battery information and predetermined reference information based on a predetermined deterioration model; and a SOH estimation step of estimating the SOH of the battery from the deterioration information based on a predetermined nonlinear estimation model.

[0027] The battery SOH estimation method may further include, after the SOH estimation step, a reference SOH estimation step of estimating a reference SOH from the battery information based on a predetermined linear estimation model, and a reference information setting step of setting the reference information based on the SOH and the reference SOH.

[0028] The battery SOH estimation method may further include, after the SOH estimation step, an acceleration information setting step of calculating first acceleration information from the battery information and the reference information based on the deterioration model, calculating second acceleration information based on the first acceleration information and a predetermined acceleration profile, and setting the calculated second acceleration information as the acceleration information. [Effects of the Invention]

[0029] According to one aspect of the present invention, the SOH of a battery can be estimated based on various factors that affect battery degradation, particularly based on nonlinear information about the battery.

[0030] The effects of the present invention are not limited to the effects described above, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0031] The following drawings attached to this specification, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention, and the present invention should not be interpreted as being limited to the matters described in the drawings. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a diagram illustrating a battery SOH estimation device according to an embodiment of the present invention;

[0033] [Figure 2] 1 is a diagram illustrating an operation configuration of a battery SOH estimation device according to an embodiment of the present invention for estimating the SOH of a battery.

[0034] [Figure 3] FIG. 2 is a diagram illustrating a schematic of an acceleration profile according to an embodiment of the present invention.

[0035] [Figure 4] 10A and 10B are diagrams illustrating results of SOH estimation according to an embodiment of the present invention, together with comparative examples.

[0036] [Figure 5] FIG. 10 is a schematic diagram of a battery pack according to another embodiment of the present invention.

[0037] [Figure 6] FIG. 10 is a diagram schematically illustrating a battery system according to yet another embodiment of the present invention.

[0038] [Figure 7] 10 is a diagram illustrating a battery SOH estimation method according to another embodiment of the present invention.

[0039] [Figure 8] 10 is a diagram illustrating a battery SOH estimation method according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0040] The terms and words used in this specification and claims should not be interpreted as being limited to their ordinary and dictionary meanings, but should be interpreted as having meanings and concepts that correspond to the technical ideas of the present invention, in accordance with the principle that the inventor himself can appropriately define the concepts of terms in order to best explain the invention.

[0041] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0042] Furthermore, in the description of the present invention, if it is determined that a detailed description of related known structures or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0043] Terms including ordinal numbers such as first, second, etc. are used to distinguish one of various components from other components, and do not limit the components.

[0044] Throughout this specification, when a part is said to "comprise" a certain element, this does not mean that it excludes other elements, but that it may further include other elements, unless otherwise specified.

[0045] Furthermore, throughout this specification, when a part is referred to as being "connected" to another part, this includes not only a "direct connection" but also an "indirect connection" via other elements.

[0046] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0047] FIG. 1 is a diagram illustrating a battery SOH estimation device 100 according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating an operational configuration of the battery SOH estimation device 100 according to an embodiment of the present invention for estimating the SOH of a battery.

[0048] Here, a battery refers to a single independent cell that has a negative terminal and a positive terminal and can be physically separated. For example, a lithium ion battery or a lithium polymer battery may be considered a battery. A battery may also refer to a battery module or a battery pack in which multiple cells are connected in series and / or parallel. Hereinafter, for convenience of explanation, a battery will be described as meaning a single independent cell.

[0049] Referring to FIG. 1, a battery SOH estimation device 100 includes a battery information acquisition unit 110 and a control unit 120.

[0050] The battery information acquisition unit 110 may be configured to acquire battery information including at least one of voltage, current, temperature, and SOC.

[0051] Specifically, the voltage, current, and temperature are information measured from the battery, and the SOC may be information estimated based on the measured information.

[0052] For example, the battery information acquisition unit 110 may periodically or aperiodically receive and acquire battery information. As another example, the battery information acquisition unit 110 may periodically or aperiodically directly measure the voltage, current, and temperature of the battery and estimate the SOC based on the measured information.

[0053] The control unit 120 may be configured to calculate battery deterioration information from the battery information, the preset reference information, and the preset acceleration information based on a preset deterioration model.

[0054] Specifically, the degradation information may include information that can be calculated based on at least one of battery information, preset reference information, and preset acceleration information, and that indicates a state of the battery that has electrochemically changed as the battery deteriorates. For example, the degradation information may include information that quantitatively indicates a state change between the battery in a BOL state and the current battery.

[0055] As a specific example, the control unit 120 may be configured to calculate at least one of the amount of side reaction at the negative electrode, the amount of side reaction at the positive electrode, and the amount of elution of transition metals as the deterioration information. For example, the deterioration model may include a first model for calculating the amount of side reaction at the negative electrode, a second model for calculating the amount of side reaction at the positive electrode, and a third model for calculating the amount of elution of transition metals.

[0056] The amount of side reactions at the anode may be the amount of side reactions occurring during reduction of the anode. For example, a side reaction occurring during reduction of the anode may be decomposition of the electrolyte in the graphite-based metal. The control unit 120 may be configured to calculate the amount of side reactions at the anode of the battery from at least one of the battery information, the reference information, and the acceleration information using the first model. For example, the control unit may calculate the amount of decomposition of the electrolyte in the graphite-based metal (i.e., the amount of side reactions at the anode) using the battery information, the reference information, and the acceleration information.

[0057] The amount of side reactions at the positive electrode may be the amount of side reactions occurring during oxidation of the positive electrode. For example, a side reaction occurring during reduction of the positive electrode may be decomposition of the electrolyte in the NCM (Ni, Co, Mn) material. The control unit 120 may be configured to calculate the amount of side reactions at the positive electrode of the battery from at least one of the battery information, the reference information, and the acceleration information using the second model. For example, the control unit may calculate the amount of decomposition of the electrolyte in the NCM material (i.e., the amount of side reactions at the positive electrode) using the battery information, the reference information, and the acceleration information.

[0058] The amount of eluted transition metal may be the amount of eluted transition metal. For example, the amount of eluted transition metal may refer to the amount of precipitation of lithium metal. The control unit 120 may be configured to calculate the amount of eluted transition metal of the battery from at least one of the battery information, the reference information, and the acceleration information using the third model. For example, the control unit may calculate the amount of eluted lithium metal (i.e., the amount of eluted transition metal) using the battery information, the reference information, and the acceleration information.

[0059] The reference information may be information corresponding to the degradation information. For example, the reference information may be a preset reference value or a correction value of the degradation information previously calculated. The reference information will be described in detail later.

[0060] The acceleration information may also be information indicating the degree of battery deterioration. For example, the acceleration information may be an index indicating the rate of battery deterioration. That is, the acceleration information may be a deterioration index that numerically represents how quickly the battery is deteriorating. Specifically, the control unit may calculate the acceleration information from the battery information and the reference information based on a deterioration model. The acceleration information will be described in detail below.

[0061] In the embodiment of FIG. 2, n means a time point and is assumed to have a value equal to or greater than 1. The control unit 120 receives battery information (U n ), Reference Information (R n ) and Acceleration Information (A n ) can be input to the degradation model. The degradation model uses the input battery information (U n ), Reference Information (R n ) and Acceleration Information (A n ) into the relation (X n =f1(R n ,U n ,A n )) to obtain the degradation information (X n The control unit 120 may be configured in advance to output battery information (U n ), Reference Information (R n ) and Acceleration Information (A n ) to the deterioration information (Xn ) can be calculated.

[0062] For example, when a plurality of pieces of degradation information are output through the degradation model, a number of pieces of reference information corresponding to the degradation information may be input to the degradation model. That is, the reference information may be preset to correspond to the degradation information output from the degradation model. As a specific example, when the degradation information output through the degradation model includes the amount of a side reaction at the anode, the amount of a side reaction at the cathode, and the amount of elution of transition metals, reference information corresponding to the amount of side reaction at the anode, the amount of side reaction at the cathode, and the amount of elution of transition metals may be input to the degradation model, respectively.

[0063] The control unit 120 may be configured to estimate the SOH of the battery from the deterioration information based on a preset nonlinear estimation model.

[0064] Here, the nonlinear estimation model may be a nonlinear Kalman filter, such as an extended Kalman filter (EKF) or a sigma point Kalman filter (SPKF).

[0065] Specifically, the control unit 120 can estimate the SOH of the battery by inputting the deterioration information calculated using the deterioration model into a nonlinear estimation model. That is, the control unit 120 can estimate the SOH of the battery by taking into account the nonlinearity of the deterioration information.

[0066] In the embodiment of FIG. 2, the control unit 120 receives the degradation information (X n ) can be input to the nonlinear estimation model. The nonlinear estimation model calculates the degradation information (X n ) into the equation (SOH=g(X n )) to get SOH(SOH n ) can be preset to output the degradation information (X n) to the battery SOH (SOH n ) can be estimated.

[0067] Generally, batteries can deteriorate due to various factors, and the main deterioration mode may vary from battery to battery. For example, a first battery may have a side reaction at the negative electrode as the main deterioration mode, while a second battery may have a side reaction at the positive electrode as the main deterioration mode. Furthermore, battery deterioration information may be nonlinear.

[0068] Therefore, battery SOH estimation device 100 has an advantage in that it can calculate deterioration information closely related to the degree of battery deterioration from battery information, reference information, and acceleration information, and estimate the SOH of the battery taking into account the nonlinearity of the calculated deterioration information. In other words, the SOH estimated by battery SOH estimating device 100 is estimated based on nonlinear deterioration information, and therefore can better represent the current state of the battery than an SOH estimated directly from battery information.

[0069] Meanwhile, the control unit 120 included in the battery SOH estimation apparatus 100 may selectively include a processor, an ASIC (Application-Specific Integrated Circuit), other chipsets, logic circuits, registers, a communication modem, a data processing device, etc., known in the art, to execute various control logics performed in the present invention. Furthermore, when the control logic is embodied as software, the control unit 120 may be embodied as a collection of program modules. In this case, the program modules may be recorded in memory and executed by the control unit 120. The memory may be provided inside or outside the control unit 120 and may be connected to the control unit 120 by various known means.

[0070] The battery SOH estimation apparatus 100 may further include a recording unit 130. The recording unit 130 may store data and programs necessary for each component of the battery SOH estimation apparatus 100 to operate and function, or data generated during the operation and function. The recording unit 130 may be any known information recording means capable of recording, erasing, updating, and reading data. For example, the information recording means may include RAM, flash memory, ROM, EEPROM, registers, etc. The recording unit 130 may also store program code defining processes executable by the control unit 120.

[0071] For example, the recording unit 130 may store the battery information acquired by the battery information acquisition unit 110. The recording unit 130 may also store the deterioration information, reference information, SOH, and reference SOH calculated by the control unit 120.

[0072] An embodiment in which the control unit 120 sets the acceleration information will be specifically described below.

[0073] The control unit 120 may be configured to calculate the first acceleration information from the battery information and the reference information based on the deterioration model.

[0074] Specifically, the control unit 120 may input the battery information, the reference information, and the acceleration information into the deterioration model to calculate the deterioration information and the acceleration information.

[0075] The control unit 120 receives battery information (U n ), Reference Information (R n ) and Acceleration Information (A n ) can be input to the degradation model. The degradation model uses the input battery information (U n ), Reference Information (R n ) and Acceleration Information (A n ) into the relation (X n =f1(R n ,U n ,A n )) to obtain the degradation information (X n) can be preset to output the degradation model. n ) and reference information (R n ) into the relation (A n+1 =f2(R n ,U n )) to obtain the acceleration information (A n+1 ) can be preset to output the battery information (U n ), Reference Information (R n ) and Acceleration Information (A n ) to the deterioration information at the nth point (X n ) and acceleration information at time n+1 (A n+1 ) can be calculated.

[0076] The control unit 120 may be configured to calculate second acceleration information based on the first acceleration information and a preset acceleration profile, and to set the calculated second acceleration information as the acceleration information.

[0077] Specifically, the control unit 120 can be configured to determine the reference range from the acceleration profile based on the battery temperature among the battery information.

[0078] Here, the acceleration profile may be a profile in which a correspondence relationship between the battery temperature and the acceleration information is preset. Specifically, the acceleration profile may be a profile in which an upper limit value and a lower limit value of the acceleration information are preset according to the battery temperature. Therefore, the control unit 120 may determine a reference range (a range from a lower limit value to an upper limit value) corresponding to the battery temperature based on the acceleration profile.

[0079] FIG. 3 is a schematic diagram of an acceleration profile P according to an embodiment of the present invention.

[0080] Referring to FIG. 3, the acceleration profile P is the upper limit value of the acceleration information according to the temperature (P U ) and lower limit (P L) can be a profile that is preset. For example, if the temperature is 25°C, the upper limit of the reference range (P U ) is 1.2, and the lower limit (P L ) can be 0.9. As another example, if the temperature is below 10°C, the upper limit of the reference range (P U ) is 3, and the lower limit (P L ) can be 1.

[0081] The control unit 120 may be configured to calculate second acceleration information according to a result of comparing the determined reference range with the first acceleration information.

[0082] Specifically, the control unit 120 may calculate the second acceleration information depending on whether the first acceleration information falls within a reference range. That is, the control unit 120 may compare the first acceleration information with the reference range and calculate the first acceleration information, the upper limit of the reference range, or the lower limit of the reference range as the second acceleration information based on the comparison result.

[0083] For example, if there are no upper and lower limits on the acceleration information calculated by the degradation model, acceleration information having a value that is too large or too small may be applied to calculate the degradation information depending on the embodiment. n+1 ) and reference information (R n+1 ) is recursively input to the degradation model, so the degradation model may generate incorrect acceleration information (A n+1 ) is calculated, the estimated SOH (SOH n ) may accumulate errors. Therefore, the control unit 120 may compare the first acceleration information calculated based on the deterioration model with a reference range according to a preset acceleration profile, and set the second acceleration information calculated based on the comparison result as the acceleration information.

[0084] For example, if the first acceleration information falls within the reference range, the control unit 120 may calculate the first acceleration information as the second acceleration information. That is, if the first acceleration information falls within the determined reference range, the control unit 120 may set the first acceleration information as the second acceleration information. For example, in the embodiment of FIG. 2, the first acceleration information (A n+1 ) can be set as the second acceleration information as it is. That is, in the embodiment of FIG. n+1 =A n+1 may apply.

[0085] As another example, if the first acceleration information exceeds the reference range, the control unit 120 may calculate the upper limit of the reference range as the second acceleration information. That is, if the first acceleration information exceeds the upper limit of the reference range, the control unit 120 may set the upper limit of the reference range as the second acceleration information. For example, in the embodiment of FIG. 2, the first acceleration information (A n+1 ) exceeds the reference range, the upper limit of the reference range (A t ) can be set as the second acceleration information. That is, in the embodiment of FIG. n+1 =A t may apply.

[0086] As yet another example, if the first acceleration information is less than the reference range, the control unit 120 may calculate the lower limit of the reference range as the second acceleration information. That is, if the first acceleration information is less than the lower limit of the reference range, the control unit 120 may set the lower limit of the reference range as the second acceleration information. For example, in the embodiment of FIG. 2, the first acceleration information (A n+1 If the reference range is less than the lower limit of the reference range (A t ) can be set as the second acceleration information. That is, in the embodiment of FIG. n+1 =A t may apply.

[0087] Meanwhile, when the deterioration information is calculated for the first time, the control unit 120 may input BOL acceleration information, which is preset to correspond to a battery in a BOL state, into the deterioration model.

[0088] 2, A1 may be preset BOL acceleration information corresponding to a battery in a BOL state. When the controller 120 calculates the deterioration information (X1), there is no previously calculated deterioration information (X0), so the preset BOL acceleration information (A1) may be input to the deterioration model as acceleration information.

[0089] The battery SOH estimation device according to an embodiment of the present invention estimates the SOH by further considering acceleration information indicating the deterioration rate of the battery, thereby enabling more accurate estimation of the current state of the battery.

[0090] An embodiment in which the control unit 120 sets the reference information will be specifically described below.

[0091] The control unit 120 may be configured to estimate the reference SOH from the battery information based on a preset linear estimation model.

[0092] Here, the linear estimation model may be configured as a linear Kalman filter, for example, a Kalman filter (KF).

[0093] In the embodiment of FIG. 2, the control unit 120 receives battery information (U n ) can be input to the linear estimation model. The linear estimation model uses the input battery information (U n ) into the relation (rSOH=h(U n )) to obtain the reference SOH (rSOH n The control unit 120 may be configured in advance to output battery information (U n ) to the battery reference SOH (rSOH n ) can be estimated.

[0094] Reference SOH (rSOH n ) is calculated using a linear estimation model to estimate the battery information (U n) and SOH(SOH n ) is calculated by using a nonlinear estimation model to estimate the deterioration information (X n ) is the value calculated from the reference SOH (rSOH n ) and SOH(SOH n ) differ in the factors they consider (battery information and degradation information), the nature of the factors they consider (linearity and nonlinearity), and the type of estimation model they use depending on the factors they consider (linear estimation model and nonlinear estimation model).

[0095] The control unit 120 may then be configured to set the reference information based on the SOH and the reference SOH.

[0096] Specifically, the reference information may be a preset reference value or a correction value of previously calculated degradation information. In the embodiment of FIG. 2, the reference information is R1 or R n+1 It could be.

[0097] When the deterioration information is calculated for the first time, the control unit 120 may be configured to set a predetermined reference value corresponding to the deterioration information of the battery in the BOL state as reference information.

[0098] 2, R1 may be a preset reference value corresponding to the deterioration information of the battery in the BOL state. When the deterioration information (X1) is calculated by the control unit 120, since there is no previously calculated deterioration information (X0), the preset reference value (R1) may be input to the deterioration model as reference information.

[0099] If the calculation of the degradation information is not the first time (if previously calculated degradation information exists), the control unit 120 may be configured to update the reference information based on the degradation information, the SOH, and the reference SOH each time the SOH is estimated.

[0100] In the embodiment of FIG. 2, the control unit 120 receives the degradation information (X n ) and weighted value (K n ) into the relation (R n+1 =X n +Kn ) and enter the reference information (R n+1 ) can be calculated, where the reference information (R n+1 ) is the degradation model (X n+1 =f1(R n+1 ,U n+1 , An+1)). Reference information calculated at a previous point in time can be used to calculate degradation information at a next point in time. That is, the reference information can be used to calculate degradation information at a next point in time through a recursive structure.

[0101] Specifically, the control unit 120 may be configured to calculate a weight value based on the SOH and the reference SOH, and may be configured to set a value obtained by adding the weight value to the degradation information as reference information.

[0102] Referring to the above-described embodiment, it is assumed that the nonlinear estimation model is a nonlinear Kalman filter and the linear estimation model is a linear Kalman filter. In this case, the control unit 120 may be configured to calculate a Kalman gain based on the SOH and the reference SOH as weights. The control unit 120 may also be configured to set a value obtained by adding the Kalman gain to the degradation information as reference information.

[0103] Specifically, the Kalman gain may be calculated based on the SOH calculated by the nonlinear Kalman filter and the reference SOH calculated by the linear Kalman filter. That is, the Kalman gain may be calculated based on the SOH and the reference SOH obtained from different estimation models. The Kalman gain calculated in this way may be added to the degradation information, thereby updating the reference information.

[0104] In the embodiment of FIG. 2, the control unit 120 calculates the reference SOH (rSOH n ) and SOH(SOH n ) into the relation (K n =k(SOH n ,rSOH n )) and enter the weights (K n) can be calculated. Here, the relation (K n =k(SOH n ,rSOH n )) is the reference SOH (rSOH n ) and SOH(SOH n ) and the Kalman gain (K n ) can be set in advance. Then, the control unit 120 calculates the relational expression (R n+1 =X n +K n ) to obtain the degradation information (X n ) to the Kalman gain (K n ) at the time point n+1, the degradation model (X n+1 =f1(R n+1 ,U n+1 ,An+1)) n+1 ) can be calculated.

[0105] Battery SOH estimation device 100 may update the reference information for calculating degradation information every time the SOH of the battery is estimated. That is, battery SOH estimation device 100 not only updates the reference information to correspond to the current state of the battery, but also estimates the SOH of the battery using the updated reference information, thereby enabling highly accurate estimation of the SOH of the battery.

[0106] FIG. 4 is a diagram showing the results of SOH estimation according to one embodiment of the present invention together with a comparative example.

[0107] Specifically, FIG. 4 shows various SOH profiles of a battery over T cycles.

[0108] P0 is a comparative example, and is an SOH profile showing the actual SOH of the battery.

[0109] P1 is a comparative example, which is an SOH profile obtained using a conventional SOH estimation method. For example, in the embodiment of FIG. 2, the SOH profile of the reference SOH obtained using a linear estimation model is P1. That is, P1 is the result of estimating the SOH of a battery without considering nonlinear factors such as anode side reactions, cathode side reactions, and transition metal elution.

[0110] P2 is a comparative example, which is a SOH profile when the acceleration information is not taken into account in the degradation model. For example, in the embodiment of FIG. 2, the degradation model is expressed by the relationship (X n =f1(R n ,U n )) based on the deterioration information (X n ) can be calculated. That is, P2 is the result of estimating the SOH of the battery without considering the acceleration information for the battery.

[0111] P3 is an embodiment of the present invention, which is a SOH profile when all of the battery information, reference information, and acceleration information are taken into consideration. For example, in the embodiment of FIG. 2, the deterioration model is expressed by the relationship (X n =f1(R n ,U n ,A n )) based on the deterioration information (X n ) is calculated, and the nonlinear estimation model is based on the relation (SOH=g(X n )) based on SOH(SOH n ) can be calculated. That is, P3 is the result of estimating the SOH of the battery according to the embodiment of FIG.

[0112] P4 is a profile of acceleration information used in the process of estimating the SOH of a battery by the battery SOH estimation device 100 according to an embodiment of the present invention. For example, in the embodiment of Fig. 4, the battery SOH estimation device 100 uses the acceleration information according to P4 when estimating the SOH of a battery according to P3. In other words, the acceleration information according to P4 is calculated in the process of estimating the SOH of a battery according to P3.

[0113] The battery SOH estimation device 100 according to the present invention may be applied to a battery management system (BMS). That is, the BMS according to the present invention may include the battery SOH estimation device 100 described above. In this configuration, at least some of the components of the battery SOH estimation device 100 may be implemented by complementing or adding functions of components included in a conventional BMS. For example, the battery information acquisition unit 110, the control unit 120, and the recording unit 130 of the battery SOH estimation device 100 may be implemented as components of the BMS.

[0114] The battery SOH estimation device 100 according to the present invention may be provided in a battery pack. That is, the battery pack according to the present invention may include the above-described battery SOH estimation device 100 and one or more battery cells. The battery pack may further include electrical components (relays, fuses, etc.), a case, etc.

[0115] FIG. 5 is a diagram schematically illustrating a battery pack according to another embodiment of the present invention.

[0116] The positive terminal of the battery 51 may be connected to the positive terminal P+ of the battery pack 5 , and the negative terminal of the battery 51 may be connected to the negative terminal P− of the battery pack 5 .

[0117] The measuring unit 52 may be connected to a first sensing line SL1, a second sensing line SL2, a third sensing line SL3, and a fourth sensing line SL4.

[0118] Specifically, the measurement unit 52 may be connected to the positive terminal of the battery 51 through a first sensing line SL1 and to the negative terminal of the battery 51 through a second sensing line SL2. The measurement unit 52 may measure the voltage of the battery 51 based on the voltages measured on the first sensing line SL1 and the second sensing line SL2.

[0119] The measuring unit 52 may also be connected to a current measuring unit A through a third sensing line SL3. For example, the current measuring unit A may be an ammeter or a shunt resistor capable of measuring the charging current and discharging current of the battery 51. The measuring unit 52 may measure the charging current of the battery 51 through the third sensing line SL3 to calculate the charged amount. The measuring unit 52 may also measure the discharging current of the battery 51 through the third sensing line SL3 to calculate the discharged amount.

[0120] Furthermore, the measuring unit 52 can measure the temperature of the battery 51 through the fourth sensing line SL4.

[0121] An external device (not shown) can be connected to the positive terminal P+ and the negative terminal P- of the battery pack 5. For example, the external device may be a charging device or a load that receives power from the battery 51.

[0122] The battery information acquisition unit 110 may acquire battery information regarding the voltage, current, and temperature of the battery 51 from the measurement unit 52. The measurement unit 52 may then estimate the SOC of the battery 51 based on the measured information and transmit the estimated SOC to the battery information acquisition unit 110.

[0123] Meanwhile, in another embodiment of the present invention, the battery information acquiring unit 110 may be directly connected to the first sensing line SL1, the second sensing line SL2, the third sensing line SL3, and the fourth sensing line SL4 to directly measure the voltage, current, and temperature of the battery 51. Furthermore, the battery information acquiring unit 110 may directly estimate the SOC of the battery 51 based on the measured information.

[0124] FIG. 6 is a schematic diagram of a battery system 6 according to yet another embodiment of the present invention.

[0125] 6, the battery system may include one or more BMSs 62 and a server 61. The server 61 may include the battery SOH estimation device 100. For example, the server 61 may be a cloud server.

[0126] The server 61 may be communicatively connected to one or more BMSs 62. Preferably, the server 61 may be communicatively connected to the BMSs 62 via wired and / or wireless communication.

[0127] Each BMS 62 may collect battery information of the connected batteries and send the collected battery information to the server 61. The server 61 may then estimate the SOH of the batteries connected to each BMS 62 based on the received battery information.

[0128] For example, assume that each BMS 62 is installed in a separate vehicle. The first BMS (62_1), the second BMS (62_2), and the nth BMS (62_n) may collect battery information about their corresponding batteries and transmit the collected battery information to the server 61 via wireless communication. The server 61 may estimate the SOH of a first battery included in the first vehicle corresponding to the first BMS (62_1) based on the battery information received from the first BMS (62_1). The server 61 may estimate the SOH of a second battery included in the second vehicle corresponding to the second BMS (62_2) based on the battery information received from the second BMS (62_2). The server 61 may also estimate the SOH of an nth battery included in the nth vehicle corresponding to the nth BMS (62_n) based on the battery information received from the nth BMS (62_n).

[0129] 7 and 8 are diagrams illustrating a battery SOH estimation method according to still another embodiment of the present invention.

[0130] Preferably, each step of the battery SOH estimation method may be performed by the battery SOH estimation device 100. Hereinafter, for convenience of explanation, content that overlaps with the above explanation will be omitted or briefly explained.

[0131] Referring to FIG. 7, the battery SOH estimation method includes a battery information acquisition step S100, a deterioration information calculation step S200, and a SOH estimation step S300.

[0132] The battery information acquiring step S100 is a step of acquiring battery information including at least one of voltage, current, temperature, and SOC, and may be performed by the battery information acquiring unit 110.

[0133] For example, the battery information acquiring unit 110 may receive and acquire the battery information through a communication network. As another example, the battery information acquiring unit 110 may directly measure and estimate the battery information.

[0134] The deterioration information calculation step S200 is a step of calculating deterioration information of the battery from battery information and preset reference information based on a preset deterioration model, and may be performed by the control unit 120.

[0135] For example, the control unit 120 can calculate the deterioration information of the battery by inputting the battery information and the reference information into a preset deterioration model.

[0136] Here, the deterioration information may include information that allows quantitative comparison and determination of the degree of deterioration of the battery, such as the amount of side reactions at the negative electrode, the amount of side reactions at the positive electrode, and the amount of eluted transition metals.

[0137] The SOH estimation step S300 is a step of estimating the SOH of the battery from the deterioration information based on a preset nonlinear estimation model, and can be performed by the control unit 120.

[0138] For example, the control unit 120 can estimate the SOH of the battery by inputting the deterioration information into a preset nonlinear estimation model.

[0139] Here, the nonlinear estimation model may be a model preset to estimate the SOH of the battery from the degradation information having nonlinearity, for example, a nonlinear Kalman filter such as an EKF or an SPKF.

[0140] Referring to FIG. 8, the battery SOH estimation method may further include a reference SOH estimation step S400, a reference information setting step S500, and an acceleration information setting step S600.

[0141] The reference SOH estimation step S400 is a step of estimating a reference SOH from battery information based on a preset linear estimation model after the SOH estimation step S300, and may be performed by the control unit 120.

[0142] For example, the control unit 120 may estimate a reference SOH for the battery by inputting battery information into a linear estimation model.

[0143] Here, the linear estimation model may be a model preset to estimate the reference SOH of the battery from linear battery information, for example, a linear Kalman filter such as a KF.

[0144] The reference information setting step S500 is a step of setting reference information based on the SOH and the reference SOH, and can be performed by the control unit 120.

[0145] For example, the control unit 120 may calculate a Kalman gain between the estimated SOH and an estimated reference SOH. Then, the control unit 120 may set reference information by adding the Kalman gain to the degradation information. The reference information set in this manner may be used to calculate battery degradation information at the next time point. That is, the reference information set at the current time point may be input to the degradation model at the next time point.

[0146] The acceleration information setting step S600 is a step that can be executed by a control unit after the SOH estimation step S300, in which first acceleration information is calculated from battery information and reference information based on a deterioration model, second acceleration information is calculated based on the first acceleration information and a predetermined acceleration profile, and the calculated second acceleration information is set as acceleration information.

[0147] Preferably, the acceleration information setting step S600 can be performed in parallel with the reference SOH estimation step S400 and the reference information setting step S500.

[0148] For example, the control unit 120 may calculate first acceleration information from the battery information and the reference information using a deterioration model. Then, the control unit 120 may determine a reference range corresponding to the battery temperature based on a preset acceleration profile. The control unit 120 may compare the first acceleration information with the reference range and calculate the first acceleration information, the upper limit value of the reference range, or the lower limit value of the reference range as second acceleration information based on the comparison result. Finally, the control unit 120 may set the calculated second acceleration information as acceleration information to be input to the deterioration model at the next time point.

[0149] The above-described embodiments of the present invention may be realized not only by an apparatus and a method, but also by a program that realizes functions corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such realization can be easily realized by a person skilled in the art from the description of the above-described embodiments.

[0150] As described above, the present invention has been described using limited embodiments and drawings, but the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the equivalent scope of the claims.

[0151] Furthermore, the present invention described above can be variously replaced, modified, and changed by a person having ordinary knowledge in the technical field to which the present invention belongs, within the scope that does not deviate from the technical concept of the present invention, and is not limited to the above-described embodiments and the accompanying drawings, but can be configured by selectively combining all or part of each embodiment for various modifications. [Explanation of symbols]

[0152] 5: Battery pack 51: Battery 52: Measuring part 6: Battery system 61: Server 62:BMS 100: Battery SOH estimation device 110: Battery information acquisition unit 120: Control unit 130: Recording section

Claims

1. a battery information acquisition unit configured to acquire battery information including at least one of a voltage, a current, a temperature, and an SOC for the battery; a control unit configured to calculate deterioration information of the battery from the battery information, predetermined reference information, and predetermined acceleration information based on a predetermined deterioration model, and to estimate the SOH of the battery from the deterioration information based on a predetermined nonlinear estimation model.

2. The control unit The battery SOH estimation device of claim 1, configured to calculate first acceleration information from the battery information and the reference information based on the deterioration model, calculate second acceleration information based on the first acceleration information and a predetermined acceleration profile, and set the calculated second acceleration information as the acceleration information.

3. The control unit The battery SOH estimation device of claim 2, configured to determine a reference range from the acceleration profile based on the temperature of the battery among the battery information, and calculate the second acceleration information based on the result of comparing the determined reference range with the first acceleration information.

4. The control unit If the first acceleration information falls within the reference range, the first acceleration information is calculated as the second acceleration information; If the first acceleration information exceeds the reference range, an upper limit value of the reference range is calculated as the second acceleration information; The battery SOH estimation device according to claim 3 , wherein if the first acceleration information is less than the reference range, a lower limit value of the reference range is calculated as the second acceleration information.

5. The control unit The battery SOH estimation device according to claim 1 , configured to estimate a reference SOH from the battery information based on a predetermined linear estimation model, and to set the reference information based on the SOH and the reference SOH.

6. The control unit The battery SOH estimation device according to claim 5 , configured to calculate a weighted value based on the SOH and the reference SOH, and set a value obtained by adding the weighted value to the deterioration information as the reference information.

7. the nonlinear estimation model is composed of a nonlinear Kalman filter; the linear estimation model comprises a linear Kalman filter; The control unit 7. The battery SOH estimation device according to claim 6, wherein the battery SOH estimation device is configured to calculate a Kalman gain based on the SOH and the reference SOH as the weighted value, and set a value obtained by adding the Kalman gain to the deterioration information as the reference information.

8. The control unit The battery SOH estimation device according to claim 5 , configured to update the reference information based on the deterioration information, the SOH, and the reference SOH every time the SOH is estimated.

9. The control unit The battery SOH estimation device of claim 1, wherein when the deterioration information is calculated for the first time, a predetermined reference value corresponding to the deterioration information of a battery in a BOL state is set as the reference information.

10. The control unit 2. The battery SOH estimation device according to claim 1, configured to calculate at least one of an amount of side reaction at the negative electrode, an amount of side reaction at the positive electrode, and an amount of elution of transition metals as the deterioration information.

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

12. A server comprising the battery SOH estimation device according to any one of claims 1 to 10.

13. acquiring battery information about the battery, the battery information including at least one of a voltage, a current, a temperature, and an SOC; a deterioration information calculation step of calculating deterioration information of the battery from the battery information, predetermined reference information, and predetermined acceleration information based on a predetermined deterioration model; and an SOH estimation step of estimating the SOH of the battery from the deterioration information based on a preset nonlinear estimation model.

14. a reference SOH estimation step of estimating a reference SOH from the battery information based on a predetermined linear estimation model after the SOH estimation step; The battery SOH estimation method of claim 13 , further comprising: setting the reference information based on the SOH and the reference SOH.

15. 14. The battery SOH estimation method of claim 13, further comprising, after the SOH estimation step, an acceleration information setting step of calculating first acceleration information from the battery information and the reference information based on the deterioration model, calculating second acceleration information based on the first acceleration information and a predetermined acceleration profile, and setting the calculated second acceleration information as the acceleration information.

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