Apparatus and method for estimating state of health (SOH)

Abstract

An apparatus for estimating an SOH, according to one embodiment of the present invention, comprises: a profile acquisition unit for acquiring a discharge profile representing a corresponding relationship between a discharge current and a voltage of a battery; and a control unit for determining whether the discharge profile satisfies a preset condition, and, when the discharge profile satisfies the preset condition, estimating an SOH of the battery on the basis of the discharge profile.

Description

SOH Estimation Device and Method

[0001] This application is a priority claim application for Korean Patent Application No. 10-2024-0139417 filed on October 14, 2024, and all contents disclosed in the specification and drawings of said application are incorporated into this application by reference.

[0002] The present invention relates to an apparatus and method for estimating the State of Health (SOH) of a battery based on selected discharge data.

[0003] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has increased rapidly, and the development of electric vehicles, energy storage batteries, robots, and satellites has accelerated, research on high-performance batteries capable of repeated charging and discharging is actively underway.

[0004] Currently commercialized batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium batteries. Among these, lithium batteries are gaining attention for their advantages, such as the ability to freely charge and discharge with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.

[0005] While much research is being conducted on these batteries in terms of increasing capacity and density, improving lifespan and safety is also important. To enhance battery safety, technology capable of accurately diagnosing the battery's current state is required.

[0006] Conventionally, the State of Health (SOH) of a battery was estimated using charging data. However, when a battery is actually operated in a vehicle, the charging frequency is inevitably significantly lower than the discharging frequency. For instance, considering the entire cycle history of a battery in a vehicle, the period during which the battery is discharged (i.e., the period during which the vehicle is driven) is significantly longer than the period during which it is charged. Therefore, a technology is required to estimate the battery's SOH based on data that accounts for a larger proportion, such as discharge data.

[0007] The present invention is devised to solve the above-mentioned problems and aims to provide an SOH estimation apparatus and method for estimating the SOH of a battery using discharge data.

[0008] Other objects and advantages of the present invention may be understood from the following description and will become more clearly apparent from the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0009] A SOH estimation device according to one aspect of the present invention may include: a profile acquisition unit configured to acquire a discharge profile representing a correspondence between a discharge current and a voltage of a battery; and a control unit configured to determine whether the discharge profile satisfies a preset condition, and if the discharge profile satisfies the preset condition, to estimate the SOH of the battery based on the discharge profile.

[0010] The above preset conditions may be set to include at least one of: a first condition corresponding to the discharge termination C-rate of the discharge profile; a second condition corresponding to the stress indicator value of the battery and the termination voltage of the discharge profile; and a third condition corresponding to the average voltage of the discharge profile and the termination voltage.

[0011] The control unit may be configured to compare the discharge termination C-rate with a preset threshold C-rate and determine whether the first condition is satisfied based on the comparison result.

[0012] The control unit may be configured to determine that the discharge profile satisfies the first condition when the discharge termination C-rate is less than or equal to the threshold C-rate.

[0013] The control unit may be configured to determine a reference C-rate from a plurality of reference profiles of a reference battery that is preset to correspond to the battery, calculate the frequency for the determined plurality of reference C-rates, and set a minimum reference C-rate, in which the cumulative frequency is greater than or equal to a preset threshold, as the threshold C-rate.

[0014] The control unit above may be configured to calculate the stress indicator value based on the accumulated current and accumulated power of the battery.

[0015] The control unit may be configured to compare the stress indicator value and the termination voltage, and to determine whether the second condition is satisfied based on the comparison result.

[0016] The control unit may be configured to determine that the discharge profile satisfies the second condition when the stress indicator value is greater than or equal to the termination voltage or exceeds the termination voltage.

[0017] The control unit may be configured to compare the voltage difference between the average voltage and the termination voltage with a preset threshold voltage, and to determine whether the third condition is satisfied based on the comparison result.

[0018] The control unit may be configured to determine that the discharge profile satisfies the third condition when the voltage difference is greater than or equal to the threshold voltage or exceeds the threshold voltage.

[0019] A battery pack according to another aspect of the present invention may include an SOH estimation device according to one aspect of the present invention.

[0020] An automobile according to another aspect of the present invention may include an SOH estimation device according to one aspect of the present invention.

[0021] A server according to another aspect of the present invention may include an SOH estimation device according to one aspect of the present invention.

[0022] A method for estimating SOH according to another aspect of the present invention may include: a profile acquisition step for acquiring a discharge profile representing a correspondence between a discharge current and a voltage of a battery; a condition determination step for determining whether the discharge profile satisfies a preset condition; and a SOH estimation step for estimating the SOH of the battery based on the discharge profile if the discharge profile satisfies the preset condition.

[0023] A computer-readable recording medium according to another aspect of the present invention may store a computer program for executing a SOH estimation method comprising: a profile acquisition step of acquiring a discharge profile representing a correspondence relationship between a discharge current and a voltage of a battery; a condition determination step of determining whether the discharge profile satisfies a preset condition; and an SOH estimation step of estimating the SOH of the battery based on the discharge profile if the discharge profile satisfies the preset condition.

[0024] According to one aspect of the present invention, the SOH estimation device estimates the SOH of a battery according to a discharge profile selected based on preset conditions, and thus has the advantage of high accuracy and reliability of the estimation result.

[0025] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0026] The following drawings attached to this specification serve to further enhance understanding of the technical concept of the invention in conjunction with the detailed description of the invention set forth below; therefore, the invention should not be interpreted as being limited only to the matters described in such drawings.

[0027] FIG. 1 is a schematic diagram illustrating an SOH estimation device according to one embodiment of the present invention.

[0028] FIG. 2 is a schematic diagram illustrating whether the conditions of a plurality of discharge profiles of a battery according to one embodiment of the present invention are satisfied.

[0029] Figures 3 and 4 are schematic diagrams illustrating comparative examples and embodiments.

[0030] Figure 5 is a diagram schematically illustrating the frequency of multiple reference C-rates.

[0031] FIG. 6 is a schematic diagram illustrating a battery pack according to another embodiment of the present invention.

[0032] FIG. 7 is a schematic drawing illustrating an automobile according to another embodiment of the present invention.

[0033] FIG. 8 is a schematic diagram illustrating a server according to another embodiment of the present invention.

[0034] FIG. 9 is a schematic diagram illustrating a method for estimating SOH according to another embodiment of the present invention.

[0035] Terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0036] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0037] In addition, in describing the present invention, if it is determined that a detailed description of related known components or functions may obscure the essence of the invention, such detailed description is omitted.

[0038] Terms including ordinal numbers, such as first, second, etc., are used for the purpose of distinguishing one of the various components from the rest, and are not used to limit the components by such terms.

[0039] Throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0040] Additionally, throughout the specification, when it is said that a part is "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other components in between.

[0041]

[0042] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0043] FIG. 1 is a schematic diagram illustrating a State of Health (SOH) estimation device according to one embodiment of the present invention.

[0044] Referring to FIG. 1, the SOH estimation device (100) may include a profile acquisition unit (110) and a control unit (120).

[0045] The profile acquisition unit (110) can be configured to acquire a discharge profile that indicates the corresponding relationship between the discharge current and voltage of the battery.

[0046] Here, a battery refers to a single independent cell that is physically separable and equipped with a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium-polymer battery may be considered a battery. Additionally, the type of battery may be cylindrical, prismatic, or pouch type. Furthermore, a battery may refer to a battery bank, battery module, or battery pack in which a plurality of cells are connected in series and / or parallel.

[0047] Specifically, the profile acquisition unit (110) can acquire a discharge profile that indicates the corresponding relationship between the discharge current and the voltage measured during the process of discharging the battery.

[0048] For example, the profile acquisition unit (110) can acquire a discharge profile by receiving a discharge profile from the outside.

[0049] As another example, the profile acquisition unit (110) can receive battery information regarding the discharge current and voltage of the battery from an external source. Then, the profile acquisition unit (110) can generate a discharge profile based on the received battery information. That is, the profile acquisition unit (110) can acquire a discharge profile by directly generating a discharge profile from the received battery information.

[0050] As another example, the profile acquisition unit (110) can directly measure the discharge current and voltage of the battery during the process of the battery being discharged. That is, the profile acquisition unit (110) can acquire a discharge profile by generating a discharge profile based on the measured discharge current and voltage.

[0051] The profile acquisition unit (110) can be connected to communicate with the control unit (120) via wired and / or wireless means. The profile acquisition unit (110) transmits the acquired discharge profile to the control unit (120), and the control unit (120) can estimate the SOH of the battery based on the discharge profile.

[0052] The control unit (120) may be configured to determine whether the discharge profile satisfies preset conditions.

[0053] Here, the preset conditions may include at least one of the first condition, the second condition, and the third condition.

[0054] The first condition is a condition corresponding to the discharge termination C-rate of the discharge profile. Specifically, the first condition is a condition regarding the magnitude of the discharge termination C-rate of the discharge profile. For example, it can be determined whether the discharge profile satisfies the first condition based on the result of comparing the discharge termination C-rate with a preset value.

[0055] The second condition is a condition corresponding to the stress indicator value of the battery and the termination voltage of the discharge profile. Specifically, it can be determined whether the discharge profile satisfies the second condition based on the result of comparing the stress indicator value and the termination voltage of the discharge profile.

[0056] The stress index value is a metric that evaluates how harsh an environment a battery has been used in by considering various conditions that affect its performance and lifespan. A higher stress index value indicates that the battery was used in relatively light environments and conditions, while a lower value indicates that it was used in more difficult environments and conditions. In other words, a lower stress index value indicates that the battery has been exposed to harsher environments, which poses a greater risk of performance degradation.

[0057] For example, the stress index value can be calculated based on at least one of the battery temperature, charge C-rate, discharge C-rate, usage cycles, range of change in State of Charge (SOC), accumulated power, and accumulated current. Here, accumulated power represents the total amount of power supplied by the battery over a certain period. A higher accumulated power indicates that the battery supplied a larger amount of power over a certain period. Similarly, accumulated current represents the total amount of current that flowed through the battery over a certain period.

[0058] The third condition is a condition corresponding to the average voltage and termination voltage of the discharge profile. Specifically, it can be determined whether the discharge profile satisfies the third condition based on the result of comparing the voltage difference between the average voltage and the termination voltage with a preset value.

[0059] For example, the control unit (120) may determine that the discharge profile satisfies a preset condition if the discharge profile satisfies at least one of the first to third conditions. However, to estimate a more accurate SOH, the control unit (120) may determine that the discharge profile satisfies a preset condition if the discharge profile satisfies all of the first to third conditions.

[0060] The control unit (120) can be configured to estimate the SOH of the battery based on the discharge profile when the discharge profile satisfies preset conditions.

[0061] Specifically, the control unit (120) can determine a first SOC, a second SOC, and an accumulated current amount from a discharge profile that satisfies preset conditions. Here, the first SOC is the discharge start SOC of the battery, and the second SOC is the discharge end SOC of the battery. The control unit (120) can estimate the SOH of the battery based on the first SOC, the second SOC, the capacity, and the BOL (Beginning of Life) capacity. Here, the BOL capacity is a preset reference capacity for the battery, which represents the maximum energy amount when the battery in a fully charged BOL state is fully discharged.

[0062] For example, the control unit (120) can estimate the SOH of the battery using the following formula 1.

[0063] [Formula 1]

[0064]

[0065] Here, i represents the time of diagnosis. That is, SOH i is the SOH at the time of the i-th diagnosis, and SOC1 i is the discharge start SOC at the i-th diagnosis point, and SOC2 i is the discharge end SOC at the i-th diagnosis point, and Q i is the accumulated current amount at the i-th diagnosis point, and Q BOL is the BOL capacity.

[0066] FIG. 2 is a schematic diagram illustrating whether the conditions of a plurality of discharge profiles of a battery according to an embodiment of the present invention are satisfied. The embodiment of FIG. 2 is a diagram showing whether the conditions of discharge profiles (D1 to D10) obtained at a first time point (t1) to a tenth time point (t10) are satisfied.

[0067] For example, the first discharge profile (D1) satisfies the second and third conditions but not the first condition. The second discharge profile (D2) satisfies the first and second conditions but not the third condition. The third to fifth discharge profiles (D3, D4, and D5) satisfy all of the first to third conditions. The sixth discharge profile (D6) satisfies the first and third conditions but not the second condition. The seventh and eighth discharge profiles (D7 and D8) satisfy all of the first to third conditions. The ninth discharge profile (D9) does not satisfy all of the first to third conditions. The tenth discharge profile (D10) satisfies all of the first to third conditions.

[0068] When the control unit (120) estimates the SOH of the battery based on a discharge profile satisfying the first to third conditions, the SOH of the battery can be estimated only at the third time point (t3), the fourth time point (t4), the fifth time point (t5), the seventh time point (t7), the eighth time point (t8), and the tenth time point (t10) in the embodiment of FIG. 2. That is, the discharge profiles (D1, D2, D6, and D9) obtained at the first time point (t1), the second time point (t2), the sixth time point (t6), and the ninth time point (t9) are discharge profiles that do not satisfy the preset conditions, so the SOH estimated according to these discharge profiles (D1, D2, D6, and D9) may not be accurate. Therefore, the control unit (120) can improve the accuracy and reliability of the estimated SOH by estimating the battery SOH by considering only the discharge profiles that satisfy the conditions.

[0069] The SOH estimation device (100) according to one embodiment of the present invention has the advantage of high accuracy and reliability of the estimation result because it estimates the SOH of a battery according to a discharge profile selected based on preset conditions.

[0070]

[0071] Figures 3 and 4 are schematic diagrams illustrating comparative examples and embodiments.

[0072] Specifically, FIG. 3 is a comparative example showing the SOH estimated based on all discharge profiles, and FIG. 4 is an example showing the SOH estimated based on a discharge profile selected by the SOH estimation device (100). Specifically, FIG. 3 and FIG. 4 show the SOH of a battery included in a vehicle, and represent the correspondence relationship between the SOH of the battery and the driving distance of the vehicle.

[0073] Referring to the comparative example in Fig. 3, it can be seen that the frequency of SOH estimated from all discharge profiles has a very large deviation. On the other hand, referring to the comparative example in Fig. 4, it can be seen that the frequency of SOH estimated from discharge profiles satisfying preset conditions has a constant shape. That is, since the SOH estimation device (100) treats discharge profiles that do not satisfy preset conditions as noise, it has the advantage of being able to more accurately estimate the SOH of the battery using only selected discharge profiles.

[0074] In addition, since the SOH estimated by the SOH estimation device (100) is a highly reliable value, it can also be used to determine the SOH trend of the battery or to track and diagnose the condition of the battery.

[0075]

[0076] Meanwhile, the profile acquisition unit (110) and / or control unit (120) provided in the SOH estimation device (100) may optionally include a processor, an ASIC (application-specific integrated circuit), another chipset, a logic circuit, a register, a communication modem, a data processing device, etc., known in the art, to execute various control logics performed in the present invention. Additionally, when the control logic is implemented in software, the profile acquisition unit (110) and / or control unit (120) may be implemented as a set of program modules. In this case, the program modules may be stored in memory and executed by the profile acquisition unit (110) and / or control unit (120). The memory may be located inside or outside the profile acquisition unit (110) and / or control unit (120) and may be connected to the profile acquisition unit (110) and / or control unit (120) by various well-known means.

[0077] Additionally, the SOH estimation device (100) may further include a storage unit (130). The storage unit (130) may store data or programs necessary for each component of the SOH estimation device (100) to perform operations and functions, or data generated during the process of performing operations and functions. The storage unit (130) is not subject to any special restrictions on its type as long as it is a known information storage means capable of recording, erasing, updating, and reading data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, etc. Additionally, the storage unit (130) may store program codes that define processes executable by each component of the SOH estimation device (100).

[0078]

[0079] Below, an embodiment in which the control unit (120) determines whether the first condition of the discharge profile is satisfied is described in detail.

[0080] The control unit (120) may be configured to compare the discharge end C-rate with a preset threshold C-rate.

[0081] Specifically, the control unit (120) can calculate the discharge C-rate at the time when the discharge ends from the discharge profile. And, the control unit (120) can compare the magnitude between the calculated discharge end C-rate and the threshold C-rate.

[0082] Here, the threshold C-rate is a value set to detect a discharge profile in which the discharge has ended abnormally. For example, in the case where the discharge has ended normally, the discharge end C-rate may be less than or equal to the threshold C-rate. Accordingly, the control unit (120) can determine whether the first condition of the discharge profile is satisfied by comparing the discharge end C-rate with the threshold C-rate.

[0083] Additionally, the control unit (120) may be configured to determine whether the first condition is satisfied based on the comparison result. For example, the control unit (120) may be configured to determine that the discharge profile satisfies the first condition when the discharge end C-rate is below the threshold C-rate.

[0084]

[0085] In one embodiment, the control unit (120) can set a threshold C-rate based on a plurality of reference profiles of a reference battery that are preset to correspond to the battery.

[0086] First, the control unit (120) may be configured to determine a reference C-rate from a plurality of reference profiles of a reference battery that are preset to correspond to the battery.

[0087] Here, the reference battery is a battery that is pre-set to correspond to the battery, and is an experimentally or theoretically set battery. The control unit (120) can calculate the discharge end C-rate for each of the plurality of reference profiles for the reference battery and set the calculated discharge end C-rate as the reference C-rate.

[0088] Additionally, the control unit (120) may be configured to calculate the frequency for a plurality of determined reference C-rates. Specifically, the control unit (120) may calculate the frequency for each of the plurality of reference C-rates. That is, the control unit (120) may calculate how many times each of the plurality of reference C-rates was calculated in the plurality of reference profiles.

[0089] FIG. 5 is a diagram schematically illustrating the frequency of a plurality of reference C-rates. For example, in the embodiment of FIG. 5, the frequency of a plurality of reference C-rates can be represented as an XY graph in which the X-axis is set as the reference C-rate and the Y-axis is set as the frequency.

[0090] The control unit (120) may be configured to set a minimum reference C-rate, where the cumulative frequency is greater than or equal to a preset threshold, as the threshold C-rate.

[0091] Specifically, the control unit (120) can compare the frequency of the lowest reference C-rate with a preset threshold. If the frequency of the lowest reference C-rate is less than the threshold, the control unit (120) can calculate the cumulative frequency of the lowest reference C-rate and the second lowest reference C-rate. Then, the control unit (120) can compare the calculated cumulative frequency with the threshold again. If the calculated cumulative frequency is greater than or equal to the threshold, the minimum reference C-rate for which the cumulative frequency is greater than or equal to the preset threshold is the second lowest reference C-rate. Therefore, the control unit (120) can set the second lowest reference C-rate as the threshold C-rate.

[0092] For example, the threshold value can be pre-set to half of the total frequency. That is, the control unit (120) can set the minimum reference C-rate, among a plurality of reference C-rates, as the threshold C-rate, where the cumulative frequency accounts for more than half of the total frequency.

[0093] In the embodiment of FIG. 5, the reference C-rate is from 0.01 to 0.08, the total frequency is about 4,000,000, and the preset threshold is half of the total frequency (about 2,000,000). Since the cumulative frequency when the reference C-rate is 0.01 is about 2,500,000, the control unit (120) can set the threshold C-rate to 0.01.

[0094]

[0095] Below, an embodiment in which the control unit (120) determines whether the second condition of the discharge profile is satisfied is described in detail.

[0096] The control unit (120) may be configured to calculate a stress indicator value based on the accumulated current and accumulated power of the battery.

[0097] Specifically, the control unit (120) can calculate a stress index value by calculating the ratio of the accumulated power amount to the accumulated current amount. For example, the control unit (120) can calculate the stress index value using the following Equation 2.

[0098] [Equation 2]

[0099]

[0100] Here, S i is the stress index value at the time of the i-th diagnosis, and W i is the accumulated power at the time of the i-th diagnosis, and Q i is the accumulated current amount at the i-th diagnosis point.

[0101] The control unit (120) can be configured to compare the stress indicator value and the termination voltage.

[0102] Specifically, the control unit (120) can compare the stress indicator value and the termination voltage. That is, the control unit (120) can determine whether the discharge profile satisfies the second condition by directly comparing the stress indicator value and the termination voltage.

[0103] The control unit (120) may be configured to determine whether the second condition is satisfied based on the comparison result.

[0104] Specifically, the control unit (120) may be configured to determine that the discharge profile satisfies the second condition when the stress indicator value is above or above the termination voltage or exceeds the termination voltage. For example, the control unit (120) may determine that the discharge profile satisfies the second condition when the stress indicator value is above the termination voltage. As another example, if the determination of whether the second condition is satisfied must be strict, the control unit (120) may determine that the discharge profile satisfies the second condition only when the stress indicator value exceeds the termination voltage. Preferably, since accurately estimating the SOH is very important for diagnosing the condition of the battery, the control unit (120) may determine that the discharge profile satisfies the second condition only when the stress indicator value exceeds the termination voltage.

[0105]

[0106] Below, an embodiment in which the control unit (120) determines whether the third condition of the discharge profile is satisfied is described in detail.

[0107] The control unit (120) may be configured to compare the voltage difference between the average voltage and the termination voltage with a preset threshold voltage. Here, the average voltage is the average voltage of the discharge profile.

[0108] Specifically, the control unit (120) can calculate the voltage difference between the average voltage and the end voltage. For example, the control unit (120) can calculate the voltage difference using the following Equation 3.

[0109] [Equation 3]

[0110]

[0111] Here, i represents the time of diagnosis. △V i is the voltage difference at the i-th diagnosis point, and V avg_i is the average voltage at the i-th diagnosis time, and V end_i is the termination voltage at the i-th diagnosis point.

[0112] In addition, the control unit (120) can compare the magnitude between the calculated voltage difference and the preset threshold voltage. That is, the control unit (120) can determine whether the discharge profile satisfies the third condition by directly comparing the magnitude between the voltage difference between the average voltage and the termination voltage of the discharge profile and the preset threshold voltage.

[0113] The control unit (120) may be configured to determine whether the third condition is satisfied based on the comparison result.

[0114] Specifically, the control unit (120) may be configured to determine that the discharge profile satisfies the third condition when the voltage difference is greater than or equal to the threshold voltage or exceeds the threshold voltage. For example, the control unit (120) may determine that the discharge profile satisfies the third condition when the voltage difference is greater than or equal to the threshold voltage. As another example, if the determination of whether the third condition is satisfied must be strict, the control unit (120) may determine that the discharge profile satisfies the third condition only when the voltage difference exceeds the threshold voltage. Preferably, since accurately estimating the SOH is very important for diagnosing the condition of the battery, the control unit (120) may determine that the discharge profile satisfies the third condition only when the calculated voltage difference exceeds a preset threshold voltage.

[0115] Here, the threshold voltage can be set experimentally and / or theoretically. If the threshold voltage is set too high, the number of discharge profiles satisfying the third condition may decrease. In this case, since the battery's SOH is estimated to be low, problems may arise in diagnosing the battery's condition or tracking changes in the battery's condition. Conversely, if the threshold voltage is set too low, the number of discharge profiles satisfying the third condition may increase. For example, if the SOH is estimated for each discharge profile as in the embodiment of FIG. 3, problems may arise in diagnosing the battery's condition. Therefore, it is important that the threshold voltage is set appropriately, taking into account the accuracy of SOH estimation.

[0116] For example, the threshold voltage can be set to 0.05[V]. In this case, the control unit (120) can determine that the discharge profile satisfies the third condition if the difference between the average voltage of the discharge profile and the end voltage exceeds 0.05[V].

[0117]

[0118] The SOH estimation device (100) according to the present invention can be applied to a Battery Management System (BMS). That is, the BMS according to the present invention may include the SOH estimation device (100) described above. In this configuration, at least some of the components of the SOH estimation device (100) may be implemented by supplementing or adding the functions of the components included in a conventional BMS. For example, the profile acquisition unit (110), control unit (120), and storage unit (130) of the SOH estimation device (100) may be implemented as components of the BMS.

[0119] For example, the control unit (120) can control at least one of charging and discharging the battery based on the estimated SOH of the battery. As another example, the control unit (120) can set at least one of the upper charging voltage and upper discharging voltage of the battery based on the estimated SOH of the battery.

[0120]

[0121] In addition, the 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 SOH estimation device (100) described above and one or more battery cells. In addition, the battery pack may further include electrical components (relays, fuses, etc.) and a case, etc.

[0122] FIG. 6 is a schematic diagram illustrating a battery pack (10) according to another embodiment of the present invention.

[0123] A battery set (11) may include one or more battery cells. If a battery set (11) includes multiple battery cells, the multiple battery cells may be electrically connected in series and / or parallel.

[0124] The positive terminal of the battery assembly (11) can be connected to the positive terminal (P+) of the battery pack (10), and the negative terminal of the battery assembly (11) can be connected to the negative terminal (P-) of the battery pack (10).

[0125] The measuring unit (12) is electrically connected to the battery set (11) and can measure the voltage of the battery set (11).

[0126] Additionally, the measuring unit (12) may be electrically connected to a current measuring unit (A). 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 assembly (11). The measuring unit (12) can calculate the charging amount by measuring the charging current of the battery assembly (11) through the current measuring unit (A). Furthermore, the measuring unit (12) can calculate the discharging amount by measuring the discharging current of the battery assembly (11) through the current measuring unit (A).

[0127] An external device may be connected to the positive terminal (P+) and the negative terminal (P-) of the battery pack (10). For example, the external device may be a charging device or a load. Also, the positive terminal of the battery assembly (11), the positive terminal (P+) of the battery pack (10), the external device, the negative terminal (P-) of the battery pack (10), and the negative terminal of the battery assembly (11) may be electrically connected.

[0128] In the embodiment of FIG. 6, the profile acquisition unit (110) can receive a discharge profile of the battery set (11) from the measurement unit (12). As another example, the profile acquisition unit (110) can receive battery information from the measurement unit (12) and generate a discharge profile of the battery set (11) based on the received battery information.

[0129]

[0130] FIG. 7 is a schematic drawing illustrating a vehicle (700) according to another embodiment of the present invention.

[0131] Referring to FIG. 7, a battery pack (710) according to an embodiment of the present invention may be included in a vehicle (700), such as an electric vehicle (EV) or a hybrid vehicle (HV). The battery pack (710) can drive the vehicle (700) by supplying power to a motor through an inverter provided in the vehicle (700). Here, the battery pack (710) may include a SOH estimation device (100). That is, the vehicle (700) may include a SOH estimation device (100). In this case, the SOH estimation device (100) may be an on-board device included in the vehicle (700).

[0132]

[0133] FIG. 8 is a schematic diagram illustrating a server (800) according to another embodiment of the present invention.

[0134] A server (800) according to another embodiment of the present invention may include an SOH estimation device (100) according to one embodiment of the present invention.

[0135] Specifically, the server (800) may be connected to communicate with a plurality of BMSs (810) via wired and / or wireless means. Here, the BMS may be installed in a vehicle, an Energy Storage System (ESS), or a diagnostic device, etc. In a preferred embodiment, the BMS may be installed in a vehicle. However, the BMS may be applied without limitation as long as it can measure and diagnose the state of an electrically connected battery.

[0136] Additionally, the server (800) can store discharge profiles received from multiple BMSs (810). Preferably, the server (800) can store the discharge profiles of each of the multiple BMSs (810) separately.

[0137] For example, the discharge profile received from the first BMS and the discharge profile received from the second BMS can be stored separately. And, if the discharge profile received from the first BMS satisfies a preset condition, the server (800) can estimate the SOH of the battery corresponding to the first BMS and transmit the estimated SOH to the first BMS. Additionally, if the discharge profile received from the second BMS satisfies a preset condition, the server (800) can estimate the SOH of the battery corresponding to the second BMS and transmit the estimated SOH to the second BMS.

[0138]

[0139] FIG. 9 is a schematic diagram illustrating a method for estimating SOH according to another embodiment of the present invention.

[0140] Referring to FIG. 9, the SOH estimation method may include a profile acquisition step (S100), a condition determination step (S200), and an SOH estimation step (S300).

[0141] Preferably, each step of the SOH estimation method can be performed by the SOH estimation device (100). For convenience of explanation, details that overlap with previously described content will be omitted or briefly explained below.

[0142] The profile acquisition step (S100) is a step of acquiring a discharge profile that represents the corresponding relationship between the discharge current and voltage of the battery, and can be performed by the profile acquisition unit (110).

[0143] For example, the profile acquisition unit (110) can acquire a discharge profile by receiving a discharge profile from the outside.

[0144] As another example, the profile acquisition unit (110) can receive battery information regarding the discharge current and voltage of the battery from an external source. Then, the profile acquisition unit (110) can generate a discharge profile based on the received battery information. That is, the profile acquisition unit (110) can acquire a discharge profile by directly generating a discharge profile from the received battery information.

[0145] As another example, the profile acquisition unit (110) can directly measure the discharge current and voltage of the battery during the process of the battery being discharged. That is, the profile acquisition unit (110) can acquire a discharge profile by generating a discharge profile based on the measured discharge current and voltage.

[0146] The condition determination step (S200) is a step for determining whether the discharge profile satisfies a preset condition, and can be performed by the control unit (120).

[0147] Here, the preset conditions may include at least one of the first condition, the second condition, and the third condition. For example, the control unit (120) may determine that the discharge profile satisfies the preset conditions if the discharge profile satisfies all of the first to third conditions.

[0148] The SOH estimation step (S300) is a step of estimating the SOH of a battery based on a discharge profile when the discharge profile satisfies a preset condition, and can be performed by the control unit (120).

[0149] For example, the control unit (120) can determine the first SOC, the second SOC, and the accumulated current amount from a discharge profile that satisfies preset conditions. Also, the control unit (120) can estimate the SOH of the battery using Equation 1.

[0150]

[0151] The embodiments of the present invention described above are not limited to implementation through devices and methods, but may also be implemented through a program that realizes a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which such a program is recorded. Such implementation can be easily achieved by a person skilled in the art to which the present invention pertains, based on the description of the embodiments described above.

[0152] Another embodiment of the present invention may provide a computer-readable recording medium having a program recorded thereon for executing the various embodiments described above on a computer.

[0153] A program may be implemented as hardware components, software components, and / or a combination of hardware and software components. A program may be executed by any system capable of executing computer-readable instructions.

[0154] Software may include computer programs, code, instructions, or a combination thereof, and may configure a processing unit to operate as desired or command the processing unit independently or collectively.

[0155] Software can be implemented as a computer program containing instructions stored on a computer-readable storage media. Examples of computer-readable storage media include magnetic storage media (e.g., ROM (read-only memory), RAM (random-access memory), floppy disks, hard disks, etc.) and optical reading media (e.g., CD-ROMs, DVDs (Digital Versatile Discs)). Computer-readable storage media can be distributed across networked computer systems, allowing computer-readable code to be stored and executed in a distributed manner. The storage media can be read by a computer, stored in memory, and executed by a processor.

[0156] Computer-readable recording media may be provided in the form of non-transitory recording media. Here, 'non-transitory storage media' simply means that it is a tangible device and does not contain a signal (e.g., electromagnetic waves), and the term does not distinguish between cases where data is stored semi-permanently and cases where it is stored temporarily. For example, 'non-transitory storage media' may include a buffer in which data is stored temporarily.

[0157] In addition, the program may be provided by being included in a computer program product. A computer program product may be traded between a seller and a buyer as a product.

[0158] A computer program product may include a software program or a computer-readable recording medium on which the software program is stored. For example, a computer program product may include a product in the form of a software program that is distributed electronically through a manufacturer of an electronic device or an electronic market (e.g., a downloadable application). For electronic distribution, at least a portion of the software program may be stored on a recording medium or temporarily created. In this case, the recording medium may be a server of the manufacturer of the electronic device, a server of the electronic market, or a recording medium of a relay server that temporarily stores the software program.

[0159] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0160] Furthermore, since the present invention described above allows for various substitutions, modifications, and changes within the scope of the technical concept of the present invention to those skilled in the art without departing from the technical spirit of the present invention, it is not limited by the aforementioned embodiments and attached drawings, but rather all or part of each embodiment may be selectively combined to allow for various modifications.

[0161] (Explanation of symbols)

[0162] 10: Battery pack

[0163] 11: Battery assembly

[0164] 12: Measurement section

[0165] 100: SOH Estimation Device

[0166] 110: Profile Acquisition Section

[0167] 120: Control unit

[0168] 130: Storage section

[0169] 700: Car

[0170] 710: Battery pack

[0171] 800: Server

[0172] 810: Multiple BMS

Claims

1. A profile acquisition unit configured to acquire a discharge profile representing the corresponding relationship between the discharge current and voltage of a battery; and An SOH estimation device comprising a control unit configured to determine whether the above discharge profile satisfies a preset condition, and if the above discharge profile satisfies the preset condition, to estimate the SOH of the battery based on the discharge profile.

2. In Paragraph 1, The above preset conditions are, A SOH estimation device configured to include at least one of: a first condition corresponding to the discharge termination C-rate of the discharge profile; a second condition corresponding to the stress indicator value of the battery and the termination voltage of the discharge profile; and a third condition corresponding to the average voltage of the discharge profile and the termination voltage.

3. In Paragraph 2, The above control unit is, An SOH estimation device configured to compare the above discharge termination C-rate with a preset threshold C-rate and determine whether the above first condition is satisfied based on the comparison result.

4. In Paragraph 3, The above control unit is, An SOH estimation device configured to determine that the discharge profile satisfies the first condition when the discharge termination C-rate is less than or equal to the threshold C-rate.

5. In Paragraph 3, The above control unit is, A reference C-rate is determined from a plurality of reference profiles of a reference battery that is preset to correspond to the above battery, and Calculates the frequency for multiple determined reference C-rates, SOH estimation device configured to set a minimum reference C-rate, where the cumulative frequency is greater than or equal to a preset threshold, as the threshold C-rate.

6. In Paragraph 2, The above control unit is, SOH estimation device configured to calculate the stress indicator value based on the accumulated current and accumulated power of the battery.

7. In Paragraph 2, The above control unit is, An SOH estimation device configured to compare the above stress indicator value with the above termination voltage and determine whether the above second condition is satisfied based on the comparison result.

8. In Paragraph 7, The above control unit is, An SOH estimation device configured to determine that the discharge profile satisfies the second condition when the stress indicator value is greater than or equal to the termination voltage or exceeds the termination voltage.

9. In Paragraph 2, The above control unit is, An SOH estimation device configured to compare the voltage difference between the above average voltage and the above termination voltage with a preset threshold voltage, and to determine whether the above third condition is satisfied based on the comparison result.

10. In Paragraph 9, The above control unit is, An SOH estimation device configured to determine that the discharge profile satisfies the third condition when the above voltage difference is greater than or equal to the above threshold voltage or exceeds the above threshold voltage.

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

12. An automobile comprising an SOH estimation device according to any one of claims 1 to 10.

13. A server comprising an SOH estimation device according to any one of claims 1 to 10.

14. A profile acquisition step for acquiring a discharge profile that indicates the correspondence between the discharge current and voltage of a battery; A condition determination step for determining whether the above discharge profile satisfies preset conditions; and A method for estimating SOH that includes a step of estimating the SOH of the battery based on the discharge profile when the discharge profile satisfies the preset conditions.

15. A profile acquisition step for acquiring a discharge profile that indicates the correspondence between the discharge current and voltage of a battery; A condition determination step for determining whether the above discharge profile satisfies preset conditions; and A computer-readable recording medium storing a computer program for executing a SOH estimation method comprising a SOH estimation step of estimating the SOH of the battery based on the discharge profile when the discharge profile satisfies the preset conditions.

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