Battery SOH estimation device and method

Abstract

A battery SOH estimation device according to one embodiment of the present invention comprises: a battery information acquisition unit for acquiring battery information including at least one of a voltage, a current, a temperature, and an SOC; and a control unit for calculating degradation information on the battery from the battery information and the preset reference information based on a preset degradation model, and estimating the SOH of the battery from the degradation information based on a preset nonlinear estimation model.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2022-0142745 filed in Korea on October 31, 2022, the disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to a battery SOH estimation apparatus and method, and more particularly, to a battery SOH estimation apparatus and method capable of effectively estimating the SOH of a battery. Background Art

[0003] Recently, the demand for portable electronic products such as notebook computers, video cameras, and portable phones has increased dramatically, and electric vehicles, energy storage batteries, robots, satellites, etc. have been vigorously developed. Therefore, high-performance batteries that allow repeated charging and discharging are being actively studied.

[0004] Currently available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among these batteries, lithium batteries have attracted much attention because compared with nickel-based batteries, lithium batteries have almost no memory effect, extremely low self-discharge rate and high energy density.

[0005] Conventionally, various techniques have been applied to estimate the degree of degradation of a battery. For example, a representative technique is to estimate the degree of degradation of a battery by estimating the SOH (state of health) based on capacity degradation based on the OCV (open circuit voltage) of the battery. The degree of degradation of a battery estimated in this way can be a measure of the current life of the battery.

[0006] However, this conventional technology estimates the degree of degradation of the battery by comparing the initial capacity of the battery with the current capacity, but has limitations in obtaining information about what factors cause the battery degradation. For example, since battery degradation may be affected by nonlinear factors such as negative electrode side reactions, positive electrode side reactions, and transition metal dissolution, it is difficult to identify the degradation factors using conventional techniques for estimating the degree of degradation.

[0007] In addition, even if the degree of degradation estimated according to conventional technology is applied to the same battery, the residual value of the battery may vary depending on the factors affecting the degree of degradation. In other words, there are limitations in accurately estimating the state of the battery using only conventional technology. Therefore, it is necessary to develop a technology that can estimate the state of the battery by considering various factors affecting the degree of degradation of the battery. Summary of the invention

[0008] Technical issues

[0009] The present disclosure is intended to solve the problems of the related art, and thus the present disclosure is directed to providing a battery SOH estimation apparatus and method, which can estimate the state of a battery by considering various factors that affect battery degradation.

[0010] These and other purposes and advantages of the present disclosure can be understood from the following detailed description and will become more apparent from the exemplary embodiments of the present disclosure. In addition, it will be easily understood that the purposes and advantages of the present disclosure can be achieved by the means shown in the appended claims and their combinations.

[0011] Technical Solution

[0012] A battery SOH estimation device according to one aspect of the present disclosure may include: a battery information acquisition unit, which is configured to acquire battery information including at least one of voltage, current, temperature and SOC; and a control unit, which is configured to calculate the degradation information of the battery based on the battery information and preset reference information based on a preset degradation model, and estimate the SOH of the battery based on the degradation information based on a preset nonlinear estimation model.

[0013] 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.

[0014] 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.

[0015] The nonlinear estimation model may be configured using a nonlinear Kalman filter.

[0016] The linear estimation model may be configured using a linear Kalman filter.

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

[0018] The control unit 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.

[0019] When calculating the degradation information for the first time, the control unit may be configured to set a preset standard value as the degradation information corresponding to the battery in the BOL state as the reference information.

[0020] The control unit may be configured to calculate at least one of a negative electrode side reaction amount, a positive electrode side reaction amount, and a transition metal dissolution amount as the degradation information.

[0021] A battery pack according to another aspect of the present disclosure may include the battery SOH estimating device according to one aspect of the present disclosure.

[0022] A server according to still another aspect of the present disclosure may include the battery SOH estimating device according to one aspect of the present disclosure.

[0023] According to another aspect of the present disclosure, a battery SOH estimation method may include the following steps: a battery information acquisition step, wherein the battery information acquisition step acquires battery information including at least one of voltage, current, temperature and SOC; a degradation information calculation step, wherein the degradation information calculation step calculates the degradation information of the battery based on a preset degradation model according to the battery information and preset reference information; and an SOH estimation step, wherein the SOH estimation step estimates the SOH of the battery according to the degradation information based on a preset nonlinear estimation model.

[0024] The battery SOH estimation method according to another aspect of the present disclosure may further include the following steps: a reference SOH estimation step, which estimates the reference SOH according to the battery information based on a preset linear estimation model after the SOH estimation step; and a reference information setting step, which sets the reference information based on the SOH and the reference SOH.

[0025] Beneficial Effects

[0026] According to one aspect of the present disclosure, advantageously, the SOH of a battery can be estimated based on various factors that affect battery degradation. Specifically, the SOH of a battery can be estimated based on nonlinear information about the battery.

[0027] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned herein will be clearly understood by those skilled in the art from the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings illustrate preferred embodiments of the present disclosure and together with the foregoing disclosure are used to provide a further understanding of the technical features of the present disclosure, and therefore, the present disclosure is not interpreted as being limited to the accompanying drawings.

[0029] Figure 1 is a diagram schematically showing a battery SOH estimation device according to one embodiment of the present disclosure.

[0030] Figure 2is a diagram schematically showing an operation configuration of a battery SOH estimation apparatus for estimating SOH of a battery according to one embodiment of the present disclosure.

[0031] Figure 3 is a diagram schematically showing a battery pack according to still another embodiment of the present disclosure.

[0032] Figure 4 is a diagram schematically showing a battery system according to still another embodiment of the present disclosure.

[0033] Figure 5 and Figure 6 is a diagram schematically illustrating a battery SOH estimation method according to still another embodiment of the present disclosure. DETAILED DESCRIPTION

[0034] It should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general and dictionary meanings, but should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure on the basis of the principle allowing the inventor to appropriately define the terms for the best interpretation.

[0035] Therefore, the descriptions presented herein are merely preferred examples for illustrative purposes only, and are not intended to limit the scope of the present disclosure, and it should be appreciated that other equivalents and modifications may be made thereto without departing from the scope of the present disclosure.

[0036] Furthermore, in describing the present disclosure, when it is deemed that a detailed description of related known elements or functions makes the key subject matter of the present disclosure obscure, the detailed description is omitted herein.

[0037] Terms including ordinal numbers such as “first,” “second,” etc. may be used to distinguish one element from other elements among various elements, but are not intended to limit the elements by the terms.

[0038] Throughout the specification, when a part is referred to as “including” or “comprising” any element, it means that the part may further include other elements, without excluding other elements, unless specifically stated otherwise.

[0039] In addition, throughout the specification, when a part is referred to as being “connected” to another part, it is not limited to the case where they are “directly connected” but also includes the case where they are “indirectly connected” with another element interposed therebetween.

[0040] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0041] Figure 1 is a diagram schematically showing a battery SOH estimation apparatus 100 according to one embodiment of the present disclosure. Figure 2 is a diagram schematically showing an operation configuration of a battery SOH estimation apparatus 100 for estimating SOH of a battery according to one embodiment of the present disclosure.

[0042] Here, a battery refers to a physically separable independent battery cell having a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer battery may be regarded as a battery. In addition, a battery may refer to a battery module or a battery pack in which a plurality of battery cells are connected in series and / or in parallel. Hereinafter, for ease of description, a battery will be described as meaning an independent battery cell.

[0043] Reference Figure 1 The battery SOH estimation device 100 may include a battery information acquisition unit 110 and a control unit 120 .

[0044] The battery information acquisition unit 110 may be configured to acquire battery information including at least one of voltage, current, temperature, and SOC (State of Charge).

[0045] Specifically, voltage, current, and temperature may be information measured from the battery, and SOC may be information estimated based on the measured information.

[0046] For example, the battery information acquisition unit 110 may periodically or aperiodically receive and acquire the 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.

[0047] The control unit 120 may be configured to calculate degradation information about the battery from the battery information and preset reference information based on a preset degradation model.

[0048] Specifically, the degradation information is information that can be calculated based on the battery information and preset reference information, and can include information that can indicate the state of the battery that changes electrochemically as the battery degrades. For example, the degradation information can include information that can quantitatively indicate the state change between a battery in a BOL (beginning of life) state and the current battery.

[0049] As a specific example, the control unit 120 may be configured to calculate at least one of the negative electrode side reaction amount, the positive electrode side reaction amount, and the transition metal dissolution amount as degradation information. For example, the degradation model may include a first model for calculating the negative electrode side reaction amount, a second model for calculating the positive electrode side reaction amount, and a third model for calculating the transition metal dissolution amount.

[0050] The negative electrode side reaction amount may be the amount of side reactions generated when the negative electrode is reduced. For example, side reactions that may occur due to the reduction of the negative electrode include electrolyte decomposition in graphite-based metals, etc. For example, the control unit 120 may be configured to calculate the negative electrode side reaction amount of the battery based on the battery information and reference information using the first model. That is, the control unit may use the battery information and the reference information to calculate the amount of electrolyte decomposition in the graphite material metal (i.e., the negative electrode side reaction amount).

[0051] The positive electrode side reaction amount may be the side reaction amount generated when the positive electrode is oxidized. For example, side reactions that may occur due to the reduction of the positive electrode include electrolyte decomposition in NCM (Ni, Co, Mn) materials, etc. For example, the control unit 120 may be configured to calculate the positive electrode side reaction amount of the battery based on the battery information and reference information using a second model. That is, the control unit can use the battery information and reference information to calculate the electrolyte decomposition amount (i.e., positive electrode side reaction amount) in the NCM material.

[0052] The amount of transition metal dissolved may be the amount of dissolved transition metal. For example, the amount of transition metal dissolved may represent the amount of lithium metal precipitated. For example, the control unit 120 may be configured to calculate the amount of transition metal dissolved in the battery based on the battery information and the reference information using a third model. That is, the control unit may calculate the amount of lithium metal precipitated (i.e., the amount of transition metal dissolved) using the battery information and the reference information.

[0053] In addition, the reference information may be information corresponding to the degradation information. For example, the reference information may be a preset standard value or a correction value of the degradation information calculated previously. A detailed description of the reference information will be described later.

[0054] exist Figure 2 In the embodiment of , n represents a time point and is assumed to have a value of 1 or greater. The control unit 120 may transfer the battery information (U n ) and reference information (R n ) is input into the degradation model. The received battery information (U n ) and reference information (R n ) into the relation (X n =f(R n , U n )), pre-set the degradation model to output degradation information (X n The control unit 120 may use the degradation model according to the battery information (U n ) and reference information (R n ) to calculate the degradation information (X n ).

[0055] For example, when a plurality of degradation information is outputted by the degradation model, the number of reference information corresponding to the number of degradation information may be inputted into the degradation model. That is, the reference information may be pre-set to correspond to the degradation information to be outputted from the degradation model. As a specific example, when the degradation information outputted by the degradation model includes the amount of negative electrode side reaction, the amount of positive electrode side reaction, and the amount of transition metal dissolution, each reference information corresponding to the amount of negative electrode side reaction, the amount of positive electrode side reaction, and the amount of transition metal dissolution may be inputted into the degradation model.

[0056] The control unit 120 may be configured to estimate the SOH of the battery according to the degradation information based on a preset nonlinear estimation model.

[0057] Here, the nonlinear estimation model may be configured using a nonlinear Kalman filter. For example, the nonlinear estimation model may be a nonlinear Kalman filter such as an extended Kalman filter (EKF) or a sigma point Kalman filter (SPKF).

[0058] Specifically, the control unit 120 may estimate the battery SOH by inputting the degradation information calculated using the degradation model into the nonlinear estimation model. That is, the control unit 120 may estimate the battery SOH using the nonlinear estimation model to estimate the battery SOH by considering the nonlinearity of the degradation information.

[0059] exist Figure 2 In the implementation manner, the control unit 120 may n ) is input into the nonlinear estimation model. The nonlinear estimation model can be preset to be a nonlinear estimation model by inputting the degradation information (X n ) into the relationship (SOH = g (X n )) to output SOH(SOH n The control unit 120 may use a nonlinear estimation model according to the degradation information (X n ) to estimate the battery SOH (SOH n ).

[0060] Generally, a battery may deteriorate due to various factors, and a main degradation mode may also appear differently for each battery. For example, a first battery may have a negative electrode side reaction as a main degradation mode, and a second battery may have a positive electrode side reaction as a main degradation mode. In addition, the degradation information of the battery may be nonlinear information.

[0061] Therefore, the battery SOH estimation device 100 has the following advantages: the degradation information closely related to the degradation degree of the battery is calculated based on the battery information and the SOH of the battery is estimated considering the nonlinearity of the calculated degradation information. That is, because the SOH estimated by the battery SOH estimation device 100 is estimated based on the nonlinear degradation information, it can better represent the current state of the battery than the SOH estimated directly based on the battery information.

[0062] In addition, the control unit 120 included in the battery SOH estimation device may optionally include a processor, an application-specific integrated circuit (ASIC), other chipsets, logic circuits, registers, communication modems, data processing devices, etc. known in the art for executing various control logics executed in the present disclosure. In addition, when the control logic is implemented as software, the control unit 120 can be implemented as a set of program modules. At this time, the program module can be stored in the memory and executed by the control unit 120. The memory can be inside or outside the control unit 120 and can be connected to the control unit 120 by various well-known means.

[0063] In addition, the battery SOH estimation device 100 may further include a storage unit 130. The storage unit 130 may store data required for the operation and function of each component of the battery SOH estimation device 100, data generated in the process of performing an operation or function, and the like. The type of the storage unit 130 is not particularly limited as long as it is a known information storage device capable of recording, erasing, updating, and reading data. As an example, the information storage device may include RAM, flash memory, ROM, EEPROM, registers, and the like. In addition, the storage unit 130 may store program codes that define processes executable by the control unit 120.

[0064] For example, the storage unit 130 may store the battery information acquired by the battery information acquisition unit 110. In addition, the storage unit 130 may store the degradation information, the reference information, the SOH, and the reference SOH calculated by the control unit 120.

[0065] Hereinafter, an embodiment in which the control unit 120 sets the reference information will be described in detail.

[0066] The control unit 120 may be configured to estimate the reference SOH from the battery information based on a preset linear estimation model.

[0067] Here, the linear estimation model may be configured using a linear Kalman filter. For example, the linear estimation model may be a linear Kalman filter such as a Kalman filter (KF).

[0068] exist Figure 2 In the implementation manner, the control unit 120 can store the battery information (U n) is input into the linear estimation model. The linear estimation model can be preset to be input by n ) into the relationship (rSOH = h(U n )) to output the reference SOH (rSOH n The control unit 120 can use a linear estimation model to estimate the battery information (U n ) to estimate the reference SOH (rSOH) of the battery n ).

[0069] Reference SOH (rSOH n ) is a linear estimation model based on battery information (U n ) and SOH(SOH n ) is a nonlinear estimation model based on the degradation information (X n ) calculated. In other words, the reference SOH (rSOH n ) and SOH(SOH n ) differ in the factors to be considered (battery information and degradation information), the nature of the factors to be considered (linear and nonlinear), and the type of estimation model (linear estimation model and nonlinear estimation model).

[0070] In addition, the control unit 120 may be configured to set reference information based on the SOH and the reference SOH.

[0071] Specifically, the reference information may be a preset standard value or a correction value of previously calculated degradation information. Figure 2 In the implementation manner, the reference information may be R1 or R n+1 .

[0072] When calculating the degradation information for the first time, the control unit 120 may be configured to set a preset standard value as degradation information corresponding to the battery in the BOL state as reference information.

[0073] exist Figure 2 In the embodiment of , R1 may represent a preset standard value to correspond to the degradation information of the battery in the BOL state. When the degradation information (X1) is calculated by the control unit 120, since the previously calculated degradation information (X0) does not exist, the preset standard value (R1) may be input to the degradation model as reference information.

[0074] If the degradation information is not calculated for the first time (if the degradation information was previously calculated), 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.

[0075] exist Figure 2In the embodiment of the present invention, the control unit 120 can n ) and weights (K n ) Input relation (R n+1 =X n +K n ) to calculate the reference information (R n+1 ). Here, the reference information (R n+1 ) can be input into the degradation model (X n+1 =f(R n+1 , U n+1 )). The reference information calculated at the previous time point can be used to calculate the degradation information at the next time point. In other words, the reference information can be used to calculate the degradation information at the next time point through a recursive structure.

[0076] Specifically, the control unit 120 may be configured to calculate a weight based on the SOH and the reference SOH. The control unit 120 may be configured to set a value obtained by adding the weight to the degradation information as reference information.

[0077] With reference to the foregoing 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 the Kalman gain as a weight based on the SOH and the reference SOH. In addition, the control unit 120 may be configured to set the value obtained by adding the Kalman gain to the degradation information as the reference information.

[0078] Specifically, the Kalman gain can be calculated based on the SOH calculated from the nonlinear Kalman filter and the reference SOH calculated from the linear Kalman filter. That is, the Kalman gain can be calculated based on the SOH and the reference SOH obtained from different estimation models. In addition, the reference information can be updated by adding the Kalman gain calculated in this way to the degradation information.

[0079] exist Figure 2 In the embodiment of the present invention, the control unit 120 can obtain the reference SOH (rSOH n ) and SOH(SOH n ) is input into the relation (K n = k(SOH n , rSOH n )) to calculate the weight (K n Here, the relationship (K n = k(SOH n , rSOH n )) to calculate the reference SOH (rSOH n ) and SOH(SOHn ) between the Kalman gain (X n In addition, the control unit 120 can use the relationship (R n+1 =X n +K n ) The Kalman gain (K n ) and degradation information (X n ) are added to calculate the reference information (R n+1 ), the reference information (R n+1 ) can be input into the degradation model (X n+1 =f(R n+1 , U n+1 ))middle.

[0080] The battery SOH estimation device 100 can update the reference information used to calculate the degradation information each time the battery SOH is estimated. That is, since the battery SOH estimation device 100 not only updates the reference information to correspond to the current state of the battery, but also uses the updated reference information to estimate the battery SOH, the battery SOH can be estimated with high accuracy.

[0081] The battery SOH estimation device 100 according to the present disclosure may be applied to a battery management system (BMS). That is, the BMS according to the present disclosure may include the above-mentioned battery SOH estimation device 100. In this configuration, at least some of the components of the battery SOH estimation device 100 may be implemented by supplementing or adding the functions of the components included in the conventional BMS. For example, the battery information acquisition unit 110, the control unit 120, and the storage unit 130 of the battery SOH estimation device 100 may be implemented as components of the BMS.

[0082] In addition, the battery SOH estimation device 100 according to the present disclosure may be provided to a battery pack. That is, the battery pack according to the present disclosure may include the above-mentioned battery SOH estimation device 100 and one or more battery cells. In addition, the battery pack may also include electrical components (relays, fuses, etc.) and a housing.

[0083] Figure 3 is a diagram schematically showing a battery pack according to still another embodiment of the present disclosure.

[0084] The positive terminal of the battery 31 may be connected to the positive terminal P+ of the battery pack 3 , and the negative terminal of the battery 31 may be connected to the negative terminal P− of the battery pack 3 .

[0085] The measuring unit 32 may be connected to the first, second, third, and fourth sensing lines SL1, SL2, SL3, and SL4.

[0086] Specifically, the measuring unit 32 may be connected to the positive terminal of the battery 31 through the first sensing line SL1, and may be connected to the negative terminal of the battery 31 through the second sensing line SL2. The measuring unit 32 may measure the voltage of the battery 31 based on the voltage measured at each of the first sensing line SL1 and the second sensing line SL2.

[0087] In addition, the measuring unit 32 may be connected to the current measuring unit A through the 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 the discharging current of the battery 31. The measuring unit 32 may calculate the charging amount by measuring the charging current of the battery 31 through the third sensing line SL3. In addition, the measuring unit 32 may calculate the discharging amount by measuring the discharging current of the battery 31 through the third sensing line SL3.

[0088] In addition, the measuring unit 32 may measure the temperature of the battery 31 through the fourth sensing line SL4 .

[0089] An external device (not shown) may be connected to the positive terminal P+ and the negative terminal P- of the battery pack 3. For example, the external device may be a charging device or a load that receives power from the battery 31.

[0090] The battery information acquisition unit 110 may acquire battery information about the voltage, current, and temperature of the battery 31 from the measurement unit 32. In addition, the measurement unit 32 may estimate the SOC of the battery 31 based on the measured information and transmit the estimated SOC to the battery information acquisition unit 110.

[0091] Furthermore, in another embodiment of the present disclosure, the battery information acquisition unit 110 may be directly connected to the first to fourth sensing lines SL1, SL2, SL3, SL4 to directly measure the voltage, current, and temperature of the battery 31. Furthermore, the battery information acquisition unit 110 may directly estimate the SOC of the battery 31 based on the measured information.

[0092] Figure 4 is a diagram schematically showing a battery system according to still another embodiment of the present disclosure.

[0093] Reference Figure 4 , the battery system may include at least one BMS 42 and a server 41. In addition, the server 41 may include the battery SOH estimating device 100. For example, the server 41 may be a cloud server.

[0094] The server 41 may be connected to communicate with at least one BMS 42. Preferably, the server 41 may be connected to the BMS 42 to implement wired and / or wireless communication.

[0095] Each BMS 42 may collect battery information of the connected battery and transmit the collected battery information to the server 41. Then, the server 41 may estimate the SOH of the battery connected to each BMS 42 based on the received battery information.

[0096] For example, it is assumed that each BMS 42 is a BMS provided in a different vehicle. The first BMS 42_1, the second BMS 42_2, and the nth BMS (42_n) may each collect battery information about the corresponding battery, and transmit the collected battery information to the server 41 through wireless communication. The server 41 may estimate the SOH of the first battery included in the first vehicle corresponding to the first BMS 42_1 based on the battery information received from the first BMS 42_1. In addition, the server 41 may estimate the SOH of the second battery included in the second vehicle corresponding to the second BMS 42_2 based on the battery information received from the second BMS 42_2. In addition, the server 41 may estimate the SOH of the nth battery included in the nth vehicle corresponding to the nth BMS 42_n based on the battery information received from the nth BMS 42_n.

[0097] Figure 5 and Figure 6 is a diagram schematically illustrating a battery SOH estimation method according to still another embodiment of the present disclosure.

[0098] Preferably, each step of the battery SOH estimation method may be performed by the battery SOH estimation device 100. Hereinafter, for the convenience of explanation, contents overlapping with the previously described contents will be omitted or briefly described.

[0099] Reference Figure 5 The battery SOH estimation method may include a battery information acquisition step (S100), a degradation information calculation step (S200), and a SOH estimation step (S300).

[0100] The battery information acquisition 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 acquisition unit 110 .

[0101] For example, the battery information acquisition unit 110 may receive the battery information through a communication network to acquire the battery information. As another example, the battery information acquisition unit 110 may directly measure and estimate the battery information.

[0102] The degradation information calculation step ( S200 ) is a step of calculating degradation information of a battery from battery information and preset reference information based on a preset degradation model, and may be performed by the control unit 120 .

[0103] For example, the control unit 120 may calculate degradation information about the battery by inputting the battery information and reference information into a preset degradation model.

[0104] Here, the degradation information may include information that can quantitatively compare and determine the degradation degree of the battery, such as a negative electrode side reaction amount, a positive electrode side reaction amount, and a transition metal dissolution amount.

[0105] The SOH estimation step ( S300 ) is a step of estimating the SOH of the battery according to the degradation information based on a preset nonlinear estimation model, and may be performed by the control unit 120 .

[0106] For example, the control unit 120 may estimate the SOH of the battery by inputting the degradation information into a preset nonlinear estimation model.

[0107] Here, the nonlinear estimation model may be a model that is pre-set to estimate the SOH of the battery based on degradation information having nonlinearity. For example, the nonlinear estimation model may be a nonlinear Kalman filter such as EKF or SPKF.

[0108] Reference Figure 6 , the battery SOH estimating method may further include a reference SOH estimating step (S400) and a reference information setting step (S500).

[0109] The reference SOH estimating step ( S400 ) is a step of estimating a reference SOH from battery information based on a preset linear estimation model after the SOH estimating step ( S300 ), and may be performed by the control unit 120 .

[0110] For example, the control unit 120 may estimate the reference SOH of the battery by inputting the battery information into a linear estimation model.

[0111] Here, the linear estimation model may be a model that is pre-set to estimate the reference SOH of the battery based on battery information having linearity. For example, the linear estimation model may be a linear Kalman filter such as KF.

[0112] The reference information setting step ( S500 ) is a step of setting reference information based on the SOH and the reference SOH, and may be performed by the control unit 120 .

[0113] For example, the control unit 120 may calculate the Kalman gain between the estimated SOH and the estimated reference SOH. In addition, the control unit 120 may set the reference information by adding the Kalman gain to the degradation information. The reference information set in this manner may be used to calculate the degradation information of the battery at the next time point. In other words, the reference information set at the current time point may be input into the degradation model at the next time point.

[0114] The embodiments of the present disclosure described above can be implemented not only by devices and methods, but also by programs that implement functions corresponding to the configurations of the embodiments of the present disclosure or recording media on which the programs are recorded. Those skilled in the art can easily implement the programs or recording media from the descriptions of the embodiments described above.

[0115] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by way of illustration only, as various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from the detailed description.

[0116] In addition, since the above-mentioned disclosure can be replaced, modified and changed in various ways by those skilled in the art without departing from the technical concept of the disclosure, the disclosure is not limited to the above-mentioned embodiments and drawings, and all or some of the embodiments can be selectively combined to achieve various modifications.

[0117] (Explanation of Reference Numerals)

[0118] 3: Battery Pack

[0119] 31: Battery

[0120] 32: Measurement unit

[0121] 4: Battery system

[0122] 41: Server

[0123] 42: BMS

[0124] 100: Battery SOH estimation device

[0125] 110: Battery information acquisition unit

[0126] 120: Control unit

[0127] 130: Storage unit

Claims

1. A battery SOH estimation device, the battery SOH estimation device comprising: a battery information acquisition unit configured to acquire battery information including at least one of voltage, current, temperature, and SOC; as well as A control unit is configured to calculate degradation information of the battery from the battery information and preset reference information based on a preset degradation model, and estimate SOH of the battery from the degradation information based on a preset nonlinear estimation model.

2. The battery SOH estimation device according to claim 1, in, The control unit is 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.

3. The battery SOH estimation device according to claim 2, in, The control unit is 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.

4. The battery SOH estimation device according to claim 3, in, The nonlinear estimation model is configured using a nonlinear Kalman filter, wherein the linear estimation model is configured using a linear Kalman filter, and The control unit is configured to calculate a Kalman gain as the weight based on the SOH and the reference SOH, and set a value obtained by adding the Kalman gain to the degradation information as the reference information.

5. The battery SOH estimation device according to claim 2, in, The control unit is configured to update the reference information based on the degradation information, the SOH, and the reference SOH every time the SOH is estimated.

6. The battery SOH estimation device according to claim 1, in, When calculating the degradation information for the first time, the control unit is configured to set a preset standard value as the degradation information corresponding to the battery in the BOL state as the reference information.

7. The battery SOH estimation device according to claim 1, in, The control unit is configured to calculate at least one of a negative electrode side reaction amount, a positive electrode side reaction amount, and a transition metal dissolution amount as the degradation information. 8 . A battery pack comprising the battery SOH estimation device according to claim 1 . 9 . A server comprising the battery SOH estimation device according to claim 1 .

10. A battery SOH estimation method, the method comprising the following steps: A battery information acquisition step, wherein the battery information acquisition step acquires battery information including at least one of voltage, current, temperature and SOC; a degradation information calculation step, wherein the degradation information calculation step calculates the degradation information of the battery according to the battery information and preset reference information based on a preset degradation model; as well as The SOH estimating step estimates the SOH of the battery according to the degradation information based on a preset nonlinear estimation model.

11. The battery SOH estimation method according to claim 10, further comprising the following steps: a reference SOH estimating step, the reference SOH estimating step estimating a reference SOH according to the battery information based on a preset linear estimation model after the SOH estimating step; as well as A reference information setting step of setting the reference information based on the SOH and the reference SOH.

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