Battery soh estimation device and method

Abstract

A battery SOH estimation device according to a disclosed embodiment includes: an SOH estimation unit configured to estimate a first SOH of a battery based on measured voltage and current of the battery; an SOC change calculation unit configured to calculate an SOC change section and an SOC change amount of the battery based on the measured voltage; a weight calculation unit configured to calculate a weight based on an SOC section factor calculated by comparing the SOC change section with a preset reference SOC section, an SOC change amount factor based on the SOC change amount, and a temperature factor based on a measured temperature of the battery; and an SOH correction unit configured to correct the first SOH according to the calculated weight and a preset second SOH.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2021-0078998, filed in Korea on June 17, 2021, the disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to a battery SOH estimation apparatus and method, and more specifically, to a battery SOH estimation apparatus and method capable of estimating the SOH of a battery more accurately. Background Technology

[0003] Recently, demand for portable electronic products such as laptops, cameras, and mobile phones has increased dramatically, and there is serious development underway for electric vehicles, energy storage batteries, robots, and satellites. Therefore, high-performance batteries that allow for repeated charging and discharging are being actively researched.

[0004] Currently available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among them, lithium batteries have attracted much attention because they have almost no memory effect compared to nickel-based batteries, and also have a very low self-discharge rate and high energy density.

[0005] The capacity of such batteries decreases depending on the usage environment, usage time, and number of charge and discharge cycles. The State of Health (SOH) of a battery is an indicator of how much its capacity has decreased from its initial capacity and is one of the important parameters for evaluating battery life.

[0006] Generally, the ampere counting method can be used to estimate the state of charge (SOH) of a battery. The ampere counting method estimates the SOH by measuring the battery capacity via ampere counting after a full charge and discharge and comparing it to the initial battery capacity. If variations in temperature or discharge rate can be properly compensated for, this method can estimate the SOH very accurately; however, it is inefficient because the battery must be fully charged and then fully discharged. Furthermore, errors accumulate during the ampere counting process due to variations in offset caused by deterioration of the current sensor measuring the battery current, so the estimation results may be inaccurate. Summary of the Invention

[0007] Technical issues

[0008] This disclosure is designed to solve problems in related technologies. Therefore, this disclosure is committed to providing a battery SOH estimation device and method, which can correct the estimated SOH of the battery based on the battery's SOC change, SOC change region and temperature, thereby more accurately estimating the battery's SOH.

[0009] These and other objects and advantages of this disclosure will become apparent from the following detailed description and will become even more apparent from the exemplary embodiments thereof. Furthermore, it will be readily understood that the objects and advantages of this disclosure can be achieved by the means and combinations thereof shown in the appended claims.

[0010] Technical solution

[0011] A battery SOH estimation apparatus according to one aspect of this disclosure may include: an SOH estimation unit configured to estimate a first SOH of the battery based on the measured voltage and current of the battery; a SOC change calculation unit configured to calculate a SOC change region and a SOC change amount of the battery based on the measured voltage; a weight calculation unit configured to calculate weights based on a SOC region factor calculated by comparing the SOC change region with a preset standard SOC region, a SOC change amount factor based on the SOC change amount, and a temperature factor based on the measured temperature of the battery; and an SOH correction unit configured to correct the first SOH according to the calculated weights and a preset second SOH.

[0012] The weight calculation unit can be configured to calculate the SOC region factor based on whether at least a portion of the SOC variation region belongs to the standard SOC region.

[0013] A standard SOC region can include multiple SOC regions.

[0014] The weight calculation unit can be configured to calculate the SOC region factor based on whether at least a portion of the SOC change region belongs to each of the multiple SOC regions.

[0015] The weight calculation unit can be configured to: calculate the number of SOC regions, including at least a portion of the SOC variation region, among multiple SOC regions; and calculate the SOC region factor based on the calculated number.

[0016] The weighting calculation unit can be configured to: calculate the SOC change factor as proportional to the SOC change; and calculate the temperature factor based on the region to which the battery temperature belongs among multiple preset temperature regions.

[0017] The weight calculation unit can be configured to calculate weights by multiplying by the SOC region factor, the SOC change factor, and the temperature factor.

[0018] The SOH correction unit can be configured to correct the first SOH using the following equation.

[0019] [Equation]

[0020] SOH MOD =(SOH1×α)+(SOH2×(1-α))

[0021] Where SOH MOD It is the first SOH that is corrected, SOH1 is the first SOH, SOH2 is the second SOH, and α is a weight above 0 and below 1.

[0022] The SOH estimation unit can be configured to estimate the first SOH in the current cycle based on the battery voltage and current measured in the current cycle.

[0023] The SOH correction unit can be configured to correct the first SOH based on a second SOH and a weight preset before this cycle.

[0024] The second SOH can be the first SOH corrected in the previous cycle of this cycle.

[0025] According to another aspect of this disclosure, a battery pack may include a battery SOH estimation device according to one aspect of this disclosure.

[0026] A battery SOH estimation method according to another aspect of this disclosure may include: an SOH estimation step of estimating a first SOH of the battery based on the measured voltage and current of the battery; a SOC change calculation step of calculating the SOC change region and the amount of SOC change of the battery based on the measured voltage; a weight calculation step of calculating weights based on a SOC region factor calculated by comparing the SOC change region with a preset standard SOC region, a SOC change factor based on the amount of SOC change, and a temperature factor based on the measured temperature of the battery; and an SOH correction step of correcting the first SOH according to the calculated weights and a preset second SOH.

[0027] Beneficial effects

[0028] According to one aspect of this disclosure, since not only the battery's voltage, current, and SOC changes are considered, but also the results of comparing the battery's SOC change region with a standard SOC region, the battery's SOH can be estimated more accurately.

[0029] The effects of this disclosure are not limited to those described above, and those skilled in the art will clearly understand, based on the appended claims, other effects not mentioned herein. Attached Figure Description

[0030] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are intended to provide a further understanding of the technical features of the present disclosure. Therefore, the present disclosure is not to be construed as limited to the drawings.

[0031] Figure 1This is a schematic diagram illustrating a battery SOH estimation apparatus according to an embodiment of the present disclosure.

[0032] Figure 2 This is a diagram schematically illustrating the SOH estimation process performed by a battery SOH estimation device according to an embodiment of the present disclosure.

[0033] Figure 3 It is a schematic diagram showing the differential curve of the negative electrode of the battery.

[0034] Figure 4 It is a schematic diagram showing the differential curve of the positive electrode of the battery.

[0035] Figure 5 This is a diagram schematically illustrating an example of a SOC region factor table set in a battery SOH estimation apparatus according to an embodiment of the present disclosure.

[0036] Figure 6 This is a diagram schematically illustrating an example of a SOC change factor table set in a battery SOH estimation apparatus according to an embodiment of the present disclosure.

[0037] Figure 7 This is a diagram schematically illustrating an example of a temperature factor table set in a battery SOH estimation device according to an embodiment of the present disclosure.

[0038] Figure 8 This is a diagram schematically illustrating an exemplary configuration of a battery pack according to another embodiment of the present disclosure.

[0039] Figure 9 This is a diagram schematically illustrating a battery SOH estimation method according to another embodiment of the present disclosure. Detailed Implementation

[0040] It should be understood that the terminology used in this specification and the appended claims should not be construed as limited to its general and dictionary meaning, but rather interpreted based on the meaning and concept corresponding to the technical aspects of this disclosure, on the basis of allowing the inventors to appropriately define the terminology for best description.

[0041] Therefore, the description presented herein is merely a preferred example for illustrative purposes only and is not intended to limit the scope of this disclosure. It should be understood that other equivalents and modifications may be made thereto without departing from the scope of this disclosure.

[0042] Additionally, in describing this disclosure, detailed descriptions are omitted herein when it is considered that such detailed descriptions of relevant known elements or functions would obscure the key subject matter of this disclosure.

[0043] Ordinal terms such as “first” and “second” can be used to distinguish one element from another among various elements, rather than to limit the elements by the terminology.

[0044] Throughout this specification, when a section is referred to as “comprising” or “including” any element, it means that the section may further include other elements without excluding them, unless otherwise specifically stated.

[0045] Furthermore, throughout the specification, when one part is referred to as "connected" to another part, this is not limited to the case where they are "directly connected," but also includes the case where they are "indirectly connected" using another element inserted between them.

[0046] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0047] Figure 1 This is a schematic diagram illustrating a battery SOH estimation device 100 according to an embodiment of the present disclosure.

[0048] refer to Figure 1 The battery SOH estimation device 100 may include an SOH estimation unit 110, an SOC change calculation unit 120, a weight calculation unit 130, and an SOH correction unit 140.

[0049] SOH estimation unit 110 can be configured to estimate the first SOH of the battery based on the measured voltage and current of the battery.

[0050] Here, a battery refers to a physically separable, independent single unit having a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer cell can be considered a battery. Alternatively, a battery can refer to a battery module in which multiple cells are connected in series and / or parallel. In the following text, for the sake of convenience, a battery will be described as referring to an independent single unit.

[0051] The SOH estimation unit 110 can receive battery information about the battery's voltage, current, and temperature from an external source or can pre-store this battery information. Alternatively, the SOH estimation unit 110 can be configured to directly measure the battery's voltage, current, and temperature.

[0052] In addition, the SOH estimation unit 110 can estimate the first SOH of the battery based on the battery's voltage and current.

[0053] For example, the SOH estimation unit 110 can estimate the first SOH of the battery based on the battery capacity change. The SOH estimation unit 110 can estimate the corresponding state of charge (SOC) based on the battery voltage.

[0054] Here, a SOC curve representing the relationship between battery voltage and SOC can be preset, and the SOH estimation unit 110 can estimate the corresponding SOC from the battery voltage based on the SOC curve. Alternatively, a SOC curve can be preset to represent the relationship between battery voltage, temperature, and SOC. In this case, the SOH estimation unit 110 can estimate the SOC corresponding to the battery voltage and temperature based on the SOC curve.

[0055] Furthermore, the SOH estimation unit 110 can calculate the battery capacity Q based on the estimated SOC and battery current. Subsequently, the SOH estimation unit 110 can estimate the battery's first SOH by calculating the ratio between a preset standard capacity Qref and the calculated battery capacity Q. Here, the standard capacity Qref is a preset value of the battery's capacity in the BOL (Start of Life) state, and can be a capacity value corresponding to the battery's OCV calculated by the SOH estimation unit 110.

[0056] As another example, the SOH estimation unit 110 can estimate the first SOH of the battery based on the change in the battery's internal resistance. The SOH estimation unit 110 can estimate the battery's internal resistance R based on Ohm's law and the battery's voltage and current. Alternatively, the SOH estimation unit 110 can estimate the first SOH of the battery by calculating the ratio between a preset standard resistance Rref and the battery's calculated internal resistance R. Here, the standard resistance Rref can be a preset value of the battery's internal resistance in the BOL state.

[0057] The first SOH of the battery estimated by the SOH estimation unit 110 can be based on the SOH values ​​of the battery voltage and current measured in this cycle.

[0058] The SOC change calculation unit 120 can be configured to calculate the SOC change region and the amount of SOC change of the battery based on the measured voltage.

[0059] Specifically, the measured battery voltage can be a complex number. Preferably, the battery voltage can be measured during charging and / or discharging, and can include a start voltage and a finish voltage. Additionally, the SOC change calculation unit 120 can estimate the SOC for the measured voltages (start voltage and finish voltage) by referring to an SOC curve. The SOC change calculation unit 120 can calculate the SOC change region including the estimated SOC. Furthermore, the SOC change calculation unit 120 can calculate the amount of SOC change by calculating the difference between the estimated SOCs.

[0060] For example, assuming the measured battery voltages are V1 and V2, and the battery is charged from voltage V1 to voltage V2, the SOC change calculation unit 120 can estimate SOC1 corresponding to voltage V1 and SOC2 corresponding to voltage V2, respectively. The SOC change calculation unit 120 can calculate the SOC change region including SOC1 and SOC2 by setting the starting SOC of the SOC change region to SOC1 and the ending SOC of the SOC change region to SOC2. Furthermore, the SOC change calculation unit 120 can calculate the SOC change amount using the formula "|SOC2-SOC1|". Here, the SOC change amount can be expressed as ΔSOC and can be calculated as values ​​above 0% and below 100%.

[0061] The weight calculation unit 130 can be configured to calculate weights based on a SOC region factor calculated by comparing the SOC change region with a preset standard SOC region, a SOC change factor based on the amount of SOC change, and a temperature factor based on the measured temperature of the battery.

[0062] Specifically, the weight calculation unit 130 can receive the battery temperature from an external source or pre-store the battery temperature. Alternatively, the weight calculation unit 130 can be configured to directly measure the battery temperature.

[0063] In addition, the weight calculation unit 130 can be configured to calculate the SOC region factor, the SOC change factor, and the temperature factor, respectively.

[0064] Here, the SOC region factor can be calculated based on whether the preset standard SOC region and the SOC change region calculated by the SOC change calculation unit 120 overlap. For example, the weight calculation unit can calculate the SOC region factor based on whether at least a portion of the SOC change region belongs to the standard SOC region. (See later...) Figures 3 to 5 A specific implementation of calculating the SOC region factor is described in detail.

[0065] The SOC change factor is a factor calculated based on the SOC change calculated by the SOC change calculation unit 120. For example, the weight calculation unit 130 can calculate the SOC change factor as proportional to the SOC change. (See later...) Figure 6 A specific implementation method for calculating the SOC change factor is described in detail.

[0066] The temperature factor is a factor calculated based on the battery temperature. For example, the weighting calculation unit 130 can calculate the temperature factor as proportional to the battery temperature. (See later...) Figure 7 A specific implementation of the calculation of the temperature factor is described in detail.

[0067] Furthermore, the weight calculation unit 130 can be configured to calculate weights based on the calculated SOC region factor, the calculated SOC change factor, and the calculated temperature factor. For example, the weight calculation unit 130 can calculate weights by multiplying by the SOC region factor, the SOC change factor, and the temperature factor. Here, the weights calculated by the weight calculation unit 130 can be set to values ​​greater than 0 and less than 1.

[0068] SOH correction unit 140 can be configured to correct the first SOH based on the calculated weight and a preset second SOH.

[0069] Specifically, the first SOH estimated by the SOH estimation unit 110 based on voltage and current can be corrected by the SOH correction unit 140 based on weights and the second SOH.

[0070] Figure 2 This is a diagram schematically illustrating the SOH estimation process of a battery SOH estimation device 100 according to an embodiment of the present disclosure.

[0071] refer to Figure 2 The first SOH (SOH1) can be estimated based on the battery's voltage and current. Furthermore, the first SOH (SOH1) can be corrected based on the second SOH (SOH2) and a weight (α), and the corrected first SOH (SOH1) can be calculated. MOD ).

[0072] For example, the SOH correction unit 140 can be configured to correct the first SOH using the following equation.

[0073] [Equation]

[0074] SOH MOD =(SOH1×α)+(SOH2×(1-α))

[0075] Here, SOH MOD It is the first SOH that is corrected, SOH1 is the first SOH, SOH2 is the second SOH, and α is a weight that can be greater than 0 and less than 1.

[0076] In the embodiment according to the above equation, the SOH correction unit 140 can multiply the first SOH (SOH1) by the weight (α) and multiply the second SOH (SOH2) by the complement (1-α) of the weight (α). Additionally, the SOH correction unit 140 can multiply the first SOH (SOH1) by the weight (α) by the weight (α). MOD The corrected first SOH(SOH) is calculated by adding the first SOH(SOH) multiplied by its complement (1-α) and the second SOH(SOH2). MOD ).

[0077] Further reference Figure 2 The SOH estimation unit 110 can be configured to estimate the first SOH (SOH1) in the current cycle based on the voltage and current of the battery measured in the current cycle.

[0078] Specifically, the SOH estimation unit 110 can estimate the first SOH (SOH1) of the battery in the current cycle based on the battery voltage and current measured in each charge and discharge cycle of the battery. In addition, the SOH correction unit 140 can be configured to correct the first SOH (SOH1) according to a weight (α) and a second SOH (SOH2) preset before the current cycle.

[0079] Additionally, refer to Figure 2 The second SOH (SOH2) can be the first SOH (SOH) corrected in the previous cycle of this cycle. MOD In other words, the corrected SOH (SOH) calculated in this cycle can be used to... MOD It is used as the second SOH (SOH2) in the next cycle.

[0080] The battery SOH estimation device 100 according to an embodiment of the present disclosure has the advantage of estimating the battery SOH more accurately by taking into account not only the battery voltage, current and SOC change, but also the result of comparing the battery's SOC change region with a standard SOC region.

[0081] Furthermore, as the battery charging and discharging cycles continue, the battery SOH estimation device 100 can recursively estimate the battery's SOH in the current cycle by considering the battery's SOH estimated in the previous cycle (second SOH) and the weights calculated in the current cycle, thus having the advantage of improving the accuracy of battery SOH estimation.

[0082] Meanwhile, the SOH estimation unit 110, SOC change calculation unit 120, weight calculation unit 130 and SOH correction unit 140 included in the battery SOH estimation device 100 may optionally include application-specific integrated circuits (ASICs), another chipset, logic circuits, registers, communication modems and data processing devices, etc., known in the art to perform various control logics disclosed below.

[0083] Additionally, the battery SOH estimation device 100 may further include a storage unit 150. The storage unit 150 may store data necessary for the operation and function of each component of the battery SOH estimation device 100, data generated during the execution of operations or functions, etc. The storage unit 150 is not particularly limited in its type, as long as it is a known information storage device capable of recording, erasing, updating, and retrieving data. As examples, the information storage device may include RAM, flash memory, ROM, EEPROM, registers, etc. Furthermore, the storage unit 150 may store program code that defines the processes that can be executed by the SOH estimation unit 110, the SOC change calculation unit 120, the weight calculation unit 130, and the SOH correction unit 140.

[0084] The following describes an example of calculating the SOC region factor based on the SOC change region.

[0085] The weight calculation unit 130 can be configured to calculate the SOC region factor based on whether at least a portion of the SOC variation region belongs to the standard SOC region.

[0086] Preferably, the standard SOC region can be configured to include multiple SOC regions. Therefore, the weight calculation unit 130 can be configured to calculate the SOC region factor based on whether at least a portion of the SOC variation region belongs to each of the multiple SOC regions.

[0087] Figure 3 It is a schematic diagram showing the differential curve of the negative electrode of the battery. Figure 4 It is a schematic diagram showing the differential curve of the positive electrode of the battery.

[0088] Figure 3 and Figure 4 The differential curve is preset for a battery in the BOL state and can be a differential curve representing the relationship between the differential voltage (dV / dSOC) and the SOC. Specifically, the differential voltage can be the instantaneous rate of change of voltage (V) relative to SOC. Furthermore, when X is SOC and Y is the differential voltage (dV / dSOC), the differential curve can be expressed as an XY graph.

[0089] exist Figure 3 In the negative electrode differential curve of the embodiment, the intrinsic stress region of the negative electrode active material may appear in the SOC 0% to 40% region and the SOC 70% to 100% region. Additionally, in Figure 4 In the positive electrode differential curve of the embodiment, the intrinsic stress region of the positive electrode active material may appear in the SOC 60% to 100% region.

[0090] Therefore, multiple standard SOC regions can be pre-defined for each of the intrinsic stress regions of the positive electrode active material and the negative electrode active material. For example, refer to Figure 3 and Figure 4 The first standard SOC region A can be set to the SOC 0% to 40% region, the second standard SOC region B can be set to the SOC 70% to 100% region, and the third standard SOC region C can be set to the SOC 60% to 100% region.

[0091] However, in Figure 3 and Figure 4 In the embodiments described, a total of three standard SOC regions are set for the battery. However, it should be noted that the number and size of the standard SOC regions can be changed according to the composition of the battery's active materials.

[0092] In addition, the weight calculation unit 130 can be configured to calculate the number of SOC regions, including at least a portion of the SOC change region, among a plurality of SOC regions, and calculate the SOC region factor based on the calculated number.

[0093] Figure 5 This is a diagram schematically illustrating an example of a SOC region factor table set in a battery SOH estimation apparatus 100 according to an embodiment of the present disclosure.

[0094] Specifically, Figure 5 The SOC region factor table can be a lookup table, where the SOC region factor is preset based on the number of SOC regions to which at least a portion of the battery's SOC variation region belongs.

[0095] exist Figure 5 In the embodiments described, when at least a portion of the battery's SOC variation region belongs to all the first to third standard SOC regions (A, B, C), the SOC region factor can be 1. For example, when the battery's SOC variation region is the SOC 30% to 80% region, the battery's SOC region factor can be set to 1.

[0096] However, due to Figure 5 The embodiment described is one with three preset standard SOC regions. Therefore, it should be noted that if the number of preset standard SOC regions changes, the SOC region factor can also change accordingly. For example, with... Figure 5The implementation method differs, assuming five standard SOC regions are set. In this case, at least a portion of the SOC variation region belongs to a number of SOC regions that can be 5, 4, 3, 2, or 1. The SOC region factor can be set to 1 (belonging to 5 SOC regions), 0.8 (belonging to 4 SOC regions), 0.6 (belonging to 3 SOC regions), 0.4 (belonging to 2 SOC regions), and 0.2 (belonging to 1 SOC region).

[0097] Generally, during battery charging and discharging, battery degradation can be accelerated because the battery's SOC is contained within the intrinsic stress regions of the positive electrode active material and / or the negative electrode active material. Therefore, the battery SOH estimation device 100 according to embodiments of this disclosure has the advantage of calculating a SOC region factor based on the intrinsic stress regions of the active materials, taking into account whether battery degradation is accelerated, in order to more accurately estimate the battery SOH.

[0098] The following describes an example of calculating the SOC change factor based on the SOC change.

[0099] The weight calculation unit 130 can be configured to calculate the SOC change factor as proportional to the SOC change.

[0100] Here, the change in SOC is the difference between the initial SOC and the final SOC of the battery in one cycle, and is calculated as "|final SOC - initial SOC|", and can be expressed as ΔSOC.

[0101] Figure 6 This is a diagram schematically illustrating an example of a SOC change factor table set in a battery SOH estimation device 100 according to an embodiment of the present disclosure.

[0102] Specifically, Figure 6 The SOC change factor table can be a lookup table, where the SOC change factor is preset based on the SOC change of the battery.

[0103] exist Figure 6 In one embodiment, the SOC change factor can be preset to be proportional to the SOC change (ΔSOC) of the battery. For example, the SOC change factor can be a value obtained by converting the SOC change (ΔSOC) into a value with a range of 0 to 1.

[0104] For example, as in the previous embodiment, it is assumed that the SOC variation region of the battery is the SOC 30% to 80% region. In this case, the SOC variation (ΔSOC) could be 50%. Therefore, according to Figure 6The SOC change factor table allows you to set the battery's SOC change factor to 0.5.

[0105] In the following text, an embodiment of calculating the temperature factor based on the battery temperature will be described.

[0106] The weighting calculation unit 130 can be configured to calculate the temperature factor based on the region to which the temperature of the battery belongs among multiple preset temperature regions.

[0107] Here, battery temperature can be the average temperature or the highest temperature of the battery during one cycle.

[0108] Figure 7 This is a diagram schematically illustrating an example of a temperature factor table set in a battery SOH estimation device 100 according to an embodiment of the present disclosure.

[0109] Specifically, Figure 7 The temperature factor table can be a lookup table, where the temperature factor is preset based on the battery temperature. Alternatively, the temperature factor can be preset to be proportional to the battery temperature. For example, the temperature factor could be a value obtained by converting the battery temperature into a value with a range of 0 to 1.

[0110] exist Figure 7 In this embodiment, when the battery temperature is above 25°C, the temperature factor can be set to 1. When the battery temperature is 15°C, the temperature factor can be set to 0.5. When the battery temperature is below 0°C, the temperature factor can be set to 0. Additionally, it should be noted that the temperature factor can be calculated by interpolating between 0°C, 15°C, and 25°C. Figure 7 Temperature factors for battery temperature not recorded in the temperature factor table.

[0111] For example, in each case where the battery temperature is 3°C, 6°C, 9°C, 12°C, 18°C, 21°C, or 24°C, the temperature factor can be 0.1, 0.2, 0.3, 0.4, 0.8, or 0.95, respectively.

[0112] The battery SOH estimation device 100 according to embodiments of this disclosure can calculate weights based on the battery's temperature, SOC change amount, and SOC change region. In other words, the battery SOH estimation device 100 has the advantage of more accurately estimating the battery's SOH by considering various factors affecting battery degradation (temperature, SOC change amount, and SOC change region). In particular, since the battery SOH estimation device 100 considers the SOC change region factor caused by the intrinsic stress region of the active material, it has the advantage of reflecting the battery's degradation acceleration factor when estimating the battery's SOH.

[0113] The battery SOH estimation device 100 according to this disclosure can be applied to a battery management system (BMS). That is, the BMS according to this disclosure may include the aforementioned battery SOH estimation device 100. In this configuration, at least some components of the battery SOH estimation device 100 can be implemented by supplementing or adding the functions of components included in a conventional BMS. For example, the SOH estimation unit 110, SOC change calculation unit 120, weight calculation unit 130, SOH correction unit 140, and storage unit 150 of the battery SOH estimation device 100 can be implemented as components of a BMS.

[0114] Furthermore, the battery SOH estimation device 100 according to this disclosure can be installed in a battery pack. That is, a battery pack according to this disclosure may include the aforementioned battery SOH estimation device 100 and one or more individual battery cells. Additionally, the battery pack may further include electrical components (relays, fuses, etc.) and a housing.

[0115] Figure 8 This is a diagram schematically illustrating an exemplary configuration of a battery pack according to another embodiment of the present disclosure.

[0116] The positive terminal of battery 11 can be connected to the positive terminal P+ of battery pack 10, and the negative terminal of battery 11 can be connected to the negative terminal P- of battery pack 10.

[0117] The measurement unit 12 can be connected to the first sensing line SL1, the second sensing line SL2, the third sensing line SL3 and the fourth sensing line SL4.

[0118] Specifically, the measuring unit 12 can be connected to the positive terminal of the battery 11 via the first sensing line SL1, and can be connected to the negative terminal of the battery 11 via the second sensing line SL2. The measuring unit 12 can measure the voltage of the battery 11 based on the voltage measured at each of the first sensing line SL1 and the second sensing line SL2.

[0119] Additionally, the measurement unit 12 can be connected to the current measurement unit 13 via the third sensing line SL3. For example, the current measurement unit 13 can be an ammeter or a shunt resistor capable of measuring the charging and discharging currents of the battery 11. The measurement unit 12 can calculate the charge amount by measuring the charging current of the battery 11 via the third sensing line SL3. Furthermore, the measurement unit 12 can calculate the discharge amount by measuring the discharging current of the battery 11 via the third sensing line SL3.

[0120] In addition, the measurement unit 12 can measure the temperature of the battery 11 through the fourth sensing line SL4.

[0121] The voltage, current, and temperature of the battery 11 measured by the measuring unit 12 can be sent to the battery SOH estimation device 100. The battery SOH estimation device 100 can estimate the SOH of the battery 11 based on the voltage, current, and temperature of the battery 11 received from the measuring unit 12.

[0122] Figure 9 This is a diagram schematically illustrating a battery SOH estimation method according to another embodiment of the present disclosure.

[0123] Preferably, each step of the battery SOH estimation method can be performed by the battery SOH estimation device 100. In the following, content overlapping with the previously described content will be omitted or briefly described.

[0124] refer to Figure 9 The battery SOH estimation method may include an SOH estimation step (S100), a SOC change calculation step (S200), a weight calculation step (S300), and an SOH correction step (S400).

[0125] The SOH estimation step (S100) is a step of estimating the first SOH of the battery based on the measured voltage and current of the battery, and can be executed by the SOH estimation unit 110.

[0126] SOC change calculation step S200 is a step of calculating the SOC change region and SOC change amount of the battery based on the measured voltage, and can be executed by SOC change calculation unit 120.

[0127] The SOC change calculation unit 120 can calculate the SOC change region and the amount of SOC change between the initial SOC and the final SOC of the battery in one cycle.

[0128] For example, when the battery is charged from 30% SOC to 80% SOC, the SOC change calculation unit 120 can calculate the SOC change as 50% and the SOC change region as the SOC 30% to 80% region.

[0129] For ease of explanation, in Figure 9 In the embodiments shown, the SOC change calculation step (S200) is performed after the SOH estimation step (S100). However, it should be noted that the order in which the SOH estimation step (S100) and the SOC change calculation step (S200) are performed is not limited to this. Figure 9 Examples include: For instance, after first performing the SOC change calculation step (S200), the SOH estimation step (S100) can be performed, or the SOH estimation step (S100) and the SOC change calculation step (S200) can be performed in parallel.

[0130] The weight calculation step (S300) is a step of calculating weights based on the SOC region factor calculated by comparing the SOC change region with the preset standard SOC region, the SOC change factor based on the SOC change amount, and the temperature factor based on the measured battery temperature, and can be executed by the weight calculation unit 130.

[0131] For example, the weight calculation unit 130 can calculate the SOC region factor for the SOC change region based on the SOC region factor table. Additionally, the weight calculation unit 130 can calculate the SOC change factor for the SOC change amount based on the SOC change amount factor table. Furthermore, the weight calculation unit 130 can calculate the temperature factor for the battery temperature based on the temperature factor table. Additionally, the weight calculation unit 130 can calculate the weight by multiplying the calculated SOC region factor, the calculated SOC change amount factor, and the calculated temperature factor.

[0132] The SOH correction step (S400) is a step of correcting the first SOH based on the calculated weight and the preset second SOH, and can be executed by the SOH correction unit 140.

[0133] For example, the SOH correction unit 140 can correct the first SOH by adding the following values: the value obtained by multiplying the first SOH by the weight (α) and the value obtained by multiplying the second SOH by the complement of the weight (1-α).

[0134] The embodiments of this disclosure described above can be implemented not only by apparatus and methods, but also by a program that implements functions corresponding to the configuration of the embodiments of this disclosure, or a recording medium on which the program is recorded. The program or recording medium can be readily implemented by those skilled in the art based on the above description of the embodiments.

[0135] This disclosure has been described in detail. However, it should be understood that while the detailed description and specific embodiments indicate preferred embodiments of this disclosure, they are given by way of illustration only, as various variations and modifications within the scope of this disclosure will become apparent to those skilled in the art based on this detailed description.

[0136] Furthermore, since the above disclosure can be replaced, modified, and varied 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 embodiments and drawings, and all or some embodiments can be selectively combined to enable various modifications.

[0137] (Explanation of reference numerals in the attached diagram)

[0138] 10: Battery Pack

[0139] 11: Battery

[0140] 12: Measurement Unit

[0141] 13: Current Measurement Unit

[0142] 100: Battery SOH Estimation Device

[0143] 110: SOH Estimation Unit

[0144] 120: SOC Change Calculation Unit

[0145] 130: Weight Calculation Unit

[0146] 140: SOH Correction Unit

[0147] 150: Storage unit

Claims

1. A battery SOH estimation device, comprising: SOH estimation unit, the SOH estimation unit is configured to estimate the first SOH of the battery based on the measured voltage and current of the battery; SOC change calculation unit, the SOC change calculation unit is configured to calculate the SOC change region and SOC change amount of the battery based on the measured voltage; The weight calculation unit is configured to calculate weights based on a SOC region factor calculated by comparing the SOC change region with a preset standard SOC region, a SOC change factor based on the amount of SOC change, and a temperature factor based on the measured temperature of the battery. as well as A SOH correction unit is configured to correct the first SOH by performing a weighted sum of the first SOH and a preset second SOH using the weights. The standard SOC region includes multiple SOC regions, and The weight calculation unit is configured to: calculate the number of SOC regions that include at least a portion of the SOC change region among the plurality of SOC regions; and calculate the SOC region factor based on the calculated number.

2. The battery SOH estimation device according to claim 1, in, The weight calculation unit is configured to: calculate the SOC change factor as proportional to the SOC change; and calculate the temperature factor based on the region to which the battery temperature belongs among multiple preset temperature regions.

3. The battery SOH estimation device according to claim 1, in, The weight calculation unit is configured to calculate the weight by multiplying the SOC region factor, the SOC change factor, and the temperature factor.

4. The battery SOH estimation device according to claim 1, in, The SOH correction unit is configured to correct the first SOH using the following equation. SOH MOD = (SOH1×α) + (SOH2×(1-α)) Where SOH MOD It is the first SOH that is corrected, SOH1 is the first SOH, SOH2 is the second SOH, and α is a weight above 0 and below 1.

5. The battery SOH estimation device according to claim 1, in, The SOH estimation unit is configured to estimate the first SOH in the current cycle based on the voltage and current of the battery measured in the current cycle, and The SOH correction unit is configured to correct the first SOH based on a second SOH preset before the current cycle and the weight.

6. The battery SOH estimation device according to claim 5, in, The second SOH is the first SOH corrected in the previous cycle of this cycle.

7. A battery pack comprising a battery SOH estimation device according to any one of claims 1 to 6.

8. A method for estimating the state of harm (SOH) of a battery, comprising: The SOH estimation step is to estimate the first SOH of the battery based on the measured voltage and current of the battery. The SOC change calculation steps are used to calculate the SOC change range and the amount of SOC change of the battery based on the measured voltage. The weighting calculation steps are based on the SOC region factor calculated by comparing the SOC change region with the preset standard SOC region, the SOC change factor based on the amount of SOC change, and the temperature factor based on the measured temperature of the battery. as well as The SOH correction step for the first SOH is performed by using the weights to perform a weighted sum of the first SOH and a preset second SOH. The standard SOC region includes multiple SOC regions, and The weight calculation unit is configured to: calculate the number of SOC regions that include at least a portion of the SOC change region among the plurality of SOC regions; and calculate the SOC region factor based on the calculated number.

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