Battery management device and method

Abstract

A battery management apparatus according to an embodiment of the present disclosure includes: a measurement unit configured to measure a charge amount and a discharge amount of a battery, and to measure a voltage of the battery; and a control unit configured to determine a charge / discharge state of the battery based on a charge / discharge amount according to the charge amount and the discharge amount, determine a first SOC and a second SOC corresponding to the voltage based on a curve corresponding to the determined charge / discharge state, and estimate the SOC of the battery from the first SOC and the second SOC using a weight corresponding to the charge / discharge amount.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2022-0183777 filed in Korea on December 23, 2022, the disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to a battery management apparatus and method, and more particularly, to a battery management apparatus and method capable of estimating the SOC (State of Charge) of a battery. Background Art

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

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

[0005] In order to operate a battery efficiently and safely, the SOC (state of charge) of the battery must be accurately estimated. Several techniques for estimating the SOC are known. A representative technique is to obtain the SOC corresponding to the OCV of the battery from a predetermined OCV-SOC curve which is a correspondence relationship between the OCV (open circuit voltage) of the battery and the SOC.

[0006] The battery is used by repeatedly undergoing charge and discharge, which causes the battery to hysteresis in opposite directions. The charge curve is an OCV-SOC curve that shows the corresponding relationship between the OCV and SOC of the battery during charge. The discharge curve is an OCV-SOC curve that shows the corresponding relationship between the OCV and SOC of the battery during discharge.

[0007] Figure 1 is a diagram schematically showing a charge curve and a discharge curve of a battery. Specifically, Figure 1 is a diagram schematically showing a charge curve and a discharge curve of an LFP (lithium iron phosphate) battery, which has a characteristic showing good hysteresis.

[0008] exist Figure 1 In the embodiment of , the SOC of the charging curve corresponding to the voltage 3.3 [V] may be 25%, and the SOC of the discharging curve may be 63%. In other words, there is a problem that the SOC at the same voltage differs by about 38% due to hysteresis. Summary of the invention

[0009] Technical issues

[0010] The present disclosure aims to solve the problems of the related art. Therefore, the present disclosure aims to provide a battery management device and a method for estimating a battery SOC taking into account the charge and discharge hysteresis.

[0011] These and other objects and advantages of the present disclosure can be understood from the following detailed description, and will become more fully apparent from the exemplary embodiments of the present disclosure. Moreover, it will be easily understood that the objects and advantages of the present disclosure can be achieved by the means shown in the appended claims and their combinations.

[0012] Technical Solution

[0013] A battery management device according to one aspect of the present disclosure may include: a measuring unit configured to measure a charge and discharge amount of a battery and to measure a voltage of the battery; and a control unit configured to determine a charge and discharge state of the battery based on a charge and discharge amount according to the charge and discharge amounts, determine a first SOC and a second SOC corresponding to the voltage based on a curve corresponding to the determined charge and discharge state, and estimate the SOC of the battery from the first SOC and the second SOC using a weight corresponding to the charge and discharge amount.

[0014] The curve may include: a charging curve corresponding to a first state and preset to represent a corresponding relationship between SOC and voltage; a discharging curve corresponding to a second state and preset to represent a corresponding relationship between SOC and voltage; and an average curve preset to represent an average voltage value of each SOC of the charging curve and the discharging curve.

[0015] The voltage of each SOC of the charging curve may be set to be higher than or equal to the voltage of each SOC of the discharging curve.

[0016] The control unit may be configured to determine a first SOC corresponding to the voltage of the battery using a charging curve or a discharging curve according to a charging and discharging state, and determine a second SOC corresponding to the voltage of the battery using an average curve.

[0017] The control unit may be configured to calculate the first weight and the second weight by calculating a ratio of a preset reference amount to the charge and discharge amount, and estimate the SOC of the battery by adding the first weight and the second weight to the first SOC and the second SOC, respectively.

[0018] When the charge and discharge amount is less than a reference amount, the control unit may be configured to estimate the SOC of the battery using the charge curve and the average curve or using the discharge curve and the average curve according to the charge and discharge state of the battery.

[0019] When the charge and discharge amount is greater than or equal to a reference amount, the control unit may be configured to estimate the SOC of the battery using a charge curve or a discharge curve according to a charge and discharge state of the battery.

[0020] The reference amount may be preset as an SOC included in an SOC section, wherein a lower limit value is an SOC where a change rate of a voltage of an SOC of a charging curve is less than a preset threshold, and an upper limit value is an SOC where a change rate of a discharge curve is less than the threshold.

[0021] The control unit may be configured to estimate the SOC of the battery by summing a value obtained by adding the first weight to the first SOC and a value obtained by adding the second weight to the second SOC.

[0022] The control unit may be configured to calculate a ratio of the charge and discharge amount to a reference amount as the first weight, and calculate a 1's complement of the first weight as the second weight.

[0023] The control unit may be configured to calculate the charge and discharge amount by calculating a difference between the charge and discharge amounts, and determine the charge and discharge state of the battery to be the first state or the second state based on the calculated charge and discharge amount.

[0024] A battery pack according to another aspect of the present disclosure may include the battery management device according to an aspect of the present disclosure.

[0025] An energy storage system according to still another aspect of the present disclosure may include the battery management device according to an aspect of the present disclosure.

[0026] According to another aspect of the present disclosure, a battery management method may include: a current measurement step, which measures the charge and discharge amounts of the battery; a voltage measurement step, which measures the voltage of the battery; a charge and discharge state determination step, which determines the charge and discharge state of the battery based on the charge and discharge amounts according to the charge and discharge amounts; an SOC determination step, which determines a first SOC and a second SOC corresponding to the voltage based on a curve corresponding to the determined charge and discharge state; and an SOC estimation step, which estimates the SOC of the battery from the first SOC and the second SOC using weights corresponding to the charge and discharge amounts.

[0027] Beneficial Effects

[0028] According to one aspect of the present disclosure, a battery management device has an advantage of being able to more accurately estimate the SOC of a battery by considering the charge and discharge state of the battery and the hysteresis of the battery.

[0029] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0031] Figure 1 is a diagram schematically showing a charge curve and a discharge curve of a battery.

[0032] Figure 2 is a diagram schematically illustrating a battery management device according to an embodiment of the present disclosure.

[0033] Figure 3 is a diagram schematically showing a curve according to an embodiment of the present disclosure.

[0034] Figure 4 is a diagram showing a preset SOC section in a curve according to an embodiment of the present disclosure.

[0035] Figure 5 is a diagram schematically showing an exemplary configuration of a battery pack according to another embodiment of the present disclosure.

[0036] Figure 6 is a diagram schematically showing a vehicle according to still another embodiment of the present disclosure.

[0037] Figure 7 is a diagram schematically showing an energy storage system according to yet another embodiment of the present disclosure.

[0038] Figure 8 is a diagram schematically illustrating a battery management method according to yet another embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] It should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to general and dictionary meanings, but should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure based on the principle allowing the inventor to appropriately define the terms for the best interpretation.

[0040] Therefore, the descriptions presented herein are merely preferred examples for illustrative purposes, and are not intended to limit the scope of the present disclosure, and it should be appreciated that other equivalent substitutions and modifications may be made thereto without departing from the scope of the present disclosure.

[0041] Furthermore, in describing the present disclosure, when it is considered that the detailed description of related known elements or functions makes the key subject matter of the present disclosure unclear, the detailed description is omitted herein.

[0042] Terms including ordinal numbers such as “first,” “second,” etc. may be used to distinguish one element from another of various elements, but are not intended to limit the elements by the terms.

[0043] Throughout the specification, when a part is referred to as “including” or “comprising” any elements, it means that the part may further include other elements, without excluding other elements, unless explicitly stated otherwise.

[0044] Furthermore, throughout the specification, when a part is referred to as being “connected” to another part, it is not limited to the case where they are “directly connected” but also includes the case where they are “indirectly connected” with another element interposed therebetween.

[0045] The preferred embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0046] Figure 2 is a diagram schematically showing a battery management device 100 according to an embodiment of the present disclosure.

[0047] Reference Figure 2 The battery management device 100 may be configured to include a measuring unit 110 and a control unit 120 .

[0048] Here, a battery refers to a physically separable independent battery cell including a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer battery can be regarded as a battery. In the following, for the sake of convenience, a battery is interpreted as meaning an independent battery cell.

[0049] The measuring unit 110 may be configured to measure a charge amount and a discharge amount of a battery.

[0050] Specifically, the measuring unit 110 can measure the charging current and the discharging current of the battery. In addition, the measuring unit 110 can measure the charging capacity of the battery based on the charging current amount during the charging process. Similarly, the measuring unit 110 can measure the discharging capacity of the battery based on the discharging current amount during the discharging process.

[0051] The measuring unit 110 may be configured to measure a voltage of a battery.

[0052] Specifically, the measuring unit 110 may measure the voltage across the battery. For example, the measuring unit 110 may measure the battery voltage by measuring the positive electrode voltage and the negative electrode voltage of the battery and calculating the difference between the positive electrode voltage and the negative electrode voltage.

[0053] Preferably, the measuring unit 110 can measure the OCV of the battery. Here, OCV refers to the voltage of the battery when the battery remains in a no-load state for a predetermined period of time. For example, when both charging and discharging of the battery are completed and the battery remains in a no-load state for a predetermined period of time, the measuring unit 110 can measure the OCV.

[0054] The control unit 120 may be configured to determine a charge and discharge state of the battery based on a charge and discharge amount according to a charge amount and a discharge amount.

[0055] Specifically, the control unit 120 may be configured to calculate the charge and discharge amount by calculating the difference between the charge and discharge amounts. In addition, the control unit 120 may be configured to determine whether the charge and discharge state of the battery is the first state or the second state based on the calculated charge and discharge amount.

[0056] Here, the first state indicates a state in which the battery is charged, and the second state indicates a state in which the battery is discharged.

[0057] For example, when the charge amount exceeds the discharge amount, the control unit 120 may determine the charge and discharge state of the battery as the first state. Conversely, if the charge amount is less than the discharge amount, the control unit 120 may determine the charge and discharge state of the battery as the second state. That is, even if the charge and discharge of the battery are repeated, the control unit 120 may determine the charge and discharge state of the battery as the first state or the second state based on the difference between the total charge amount and the total discharge amount.

[0058] The control unit 120 may be configured to determine the first SOC and the second SOC corresponding to the voltage based on a curve corresponding to the determined charge and discharge state.

[0059] The curve may be preset to include a charging curve and a discharging curve. Here, the curve may be set in advance to represent the corresponding relationship between SOC and voltage. For example, if the X axis is set to SOC and the Y axis is set to voltage, the curve may be represented as an XY graph.

[0060] Specifically, the charging curve is a curve corresponding to the first state of the battery, and can be preset to represent the corresponding relationship between SOC and voltage. That is, the charging curve can be a curve corresponding to a charging battery.

[0061] In addition, the discharge curve is a curve corresponding to the second state of the battery, and may be preset to represent the corresponding relationship between the SOC and the voltage. In other words, the discharge curve may be a curve corresponding to a discharged battery.

[0062] Figure 3 is a diagram schematically showing a curve according to an embodiment of the present disclosure. Specifically, Figure 3 An embodiment of FIG. 1 is a graph showing a charge curve Pc corresponding to a first state and a discharge curve Pd corresponding to a second state.

[0063] Preferably, the charging curve may be set so that the voltage of each SOC is higher than or equal to the voltage of each SOC of the discharging curve. Figure 3The voltage of SOC 25% in the embodiment is 3.3 [V] according to the charge curve Pc, and 3.262 [V] according to the discharge curve Pd. The difference in voltage at each SOC between the charge curve Pc and the discharge curve Pd is due to the hysteresis of the battery.

[0064] The control unit 120 may select a charging curve or a discharging curve according to the charging and discharging state of the battery. For example, if the control unit 120 determines that the charging and discharging state of the battery is the first state, the control unit 120 may select a charging curve. On the contrary, if the control unit 120 determines that the charging and discharging state of the battery is the second state, the control unit 120 may select a discharging curve.

[0065] The control unit 120 may estimate the first SOC corresponding to the voltage based on the selected curve. For example, when the charging curve is selected, the control unit 120 may estimate the first SOC by substituting the measured voltage into the charging curve.

[0066] In addition, the control unit 120 may estimate the second SOC corresponding to the voltage based on the charging curve and the discharging curve. In other words, the second SOC may be estimated not only based on the charging curve or the discharging curve, but may be estimated by considering both the charging curve and the discharging curve.

[0067] The control unit 120 may be configured to estimate the SOC of the battery from the first SOC and the second SOC using a weight corresponding to the charge and discharge amount.

[0068] Specifically, the control unit 120 may add a weight to each of the first SOC and the second SOC. In addition, the control unit 120 may estimate the final SOC of the battery by summing the first SOC to which the weight is added and the second SOC to which the weight is added.

[0069] For example, the first SOC is an SOC generated by a charging curve or a discharging curve selected according to the charging and discharging state of the battery. In addition, the second SOC is independent of the charging and discharging state of the battery and is an SOC caused by the charging curve and the discharging curve. That is, the control unit 120 can estimate the first SOC by considering the charging and discharging state of the battery, and estimate the second SOC by considering the hysteresis of the battery. The final SOC of the battery can be estimated based on the first SOC and the second SOC estimated in this way.

[0070] Therefore, the battery management device 100 has an advantage of being able to estimate the SOC of the battery more accurately by taking into account the charge and discharge state of the battery and the hysteresis of the battery.

[0071] Meanwhile, the control unit 120 provided in the battery management device 100 may selectively include a processor, an application specific integrated circuit (ASIC), other chipsets, logic circuits, registers, communication modems, data processing devices, etc. known in the art to execute various control logics executed in the present disclosure. In addition, when the control logic is implemented in software, the control unit 120 may be implemented as a set of program modules. At this time, the program modules may be stored in a memory and executed by the control unit 120. The memory may be located inside or outside the control unit 120 and may be connected to the control unit 120 in various well-known ways.

[0072] In addition, the battery management device 100 may further include a storage unit 130. The storage unit 130 may store data required for the operation and function of each component of the battery management device 100, data generated in the process of performing an operation or function, and the like. The type of the storage unit 130 is not particularly limited as long as it is a known information storage device capable of recording, erasing, updating, and reading data. As an example, the information storage device may include a RAM, a flash memory, a ROM, an EEPROM, a register, and the like. In addition, the storage unit 130 may store a program code in which a process executable by the control unit 120 is defined.

[0073] For example, the curve of the battery may be previously stored in the storage unit 130. The control unit 120 may access the storage unit 130 to obtain the curve of the battery.

[0074] The curve may be preset to further include an average curve. That is, the curve may include a charging curve, a discharging curve, and an average curve.

[0075] The average curve may be preset to represent an average voltage value for each SOC of the charging curve and the discharging curve.

[0076] For example, in Figure 3 In the embodiment of the present invention, the average curve Pavg may be set to represent the average voltage value of the voltage of each SOC of the charging curve Pc and the voltage of each SOC of the discharging curve Pd. Figure 3 In the embodiment of the present invention, the voltage of SOC 25% is 3.3 [V] according to the charging curve Pc, 3.262 [V] according to the discharging curve Pd, and 3.281 [V] according to the average curve Pavg. In other words, the voltage 3.281 [V] according to the average curve Pavg may be an average value of the voltage 3.3 [V] according to the charging curve Pc and the voltage 3.262 [V] according to the discharging curve Pd.

[0077] The control unit 120 may be configured to determine a first SOC corresponding to the voltage of the battery using a charging curve or a discharging curve according to a charging and discharging state.

[0078] For example, if the control unit 120 determines the charge and discharge state of the battery as the first state, the control unit 120 can estimate the first SOC by substituting the measured voltage into the charge curve. Conversely, if the control unit 120 determines the charge and discharge state of the battery as the second state, the control unit 120 can estimate the first SOC by substituting the measured voltage into the discharge curve.

[0079] The control unit 120 may be configured to determine a second SOC corresponding to the voltage of the battery using the average curve.

[0080] For example, the control unit 120 can estimate the second SOC by substituting the measured voltage into the average curve. That is, the control unit 120 can estimate the second SOC based on the average curve regardless of the charge and discharge state of the battery. In other words, the control unit 120 can estimate the second SOC corresponding to the voltage using the average curve set based on the charging curve and the discharging curve.

[0081] In addition, the control unit 120 can estimate the SOC of the battery using the first SOC estimated based on the charging curve or the discharging curve and the second SOC estimated based on the average curve. Thus, the battery management device 100 has an advantage of being able to more accurately estimate the SOC of the battery by considering the hysteresis of the battery.

[0082] The control unit 120 may be configured to calculate the first weight and the second weight by calculating a ratio of a preset reference amount to the charge and discharge amount.

[0083] Here, the ratio of the reference amount to the charge and discharge amount may be calculated according to the formula “charge and discharge amount÷reference amount”.

[0084] Specifically, the control unit 120 may be configured to calculate a ratio of the charge and discharge amount to the reference amount as the first weight. In addition, the control unit 120 may be configured to calculate the complement of 1 of the first weight as the second weight.

[0085] Here, the 1's complement of the first weight may be calculated as the difference between 1 and the first weight. In other words, the 1's complement of the first weight may be calculated according to the formula "1-first weight". That is, the sum of the first weight and the second weight may be 1.

[0086] The control unit 120 may be configured to estimate the SOC of the battery by adding a first weight and a second weight to the first SOC and the second SOC, respectively.

[0087] Specifically, the control unit 120 may be configured to estimate the SOC of the battery by summing a value obtained by adding the first weight to the first SOC and a value obtained by adding the second weight to the second SOC.

[0088] For example, the control unit 120 may estimate the SOC of the battery by calculating the formula “(first SOC×first weight)+(second SOC×second weight)”.

[0089] The battery management device 100 can estimate the SOC of the battery using a first SOC estimated due to the charge and discharge state of the battery and a second SOC estimated due to the hysteresis of the battery (estimated by the average curve). That is, since the battery management device 100 estimates the SOC of the battery by considering the charge and discharge state of the battery and the hysteresis, it has the advantage of being able to more accurately estimate the SOC of the battery in which hysteresis occurs. As the hysteresis increases, the SOC estimated by the battery management device 100 can be significantly more accurate than the SOC estimated using only the charge curve or the discharge curve.

[0090] In one embodiment, the reference amount may be a value set by experiment. For example, the charge amount of the experimental battery may be increased and a charge threshold SOC may be selected in which the voltage of each SOC of the experimental battery and the voltage of each SOC of the charge curve are the same. In addition, the discharge amount of the experimental battery may be increased and a discharge threshold SOC may be selected in which the voltage of each SOC of the experimental battery and the voltage of each SOC of the discharge curve are the same. In addition, the larger value of the charge threshold SOC and the discharge threshold SOC may be set as the reference amount.

[0091] In another embodiment, the reference amount may be preset as an SOC included in an SOC section in which a lower limit value is an SOC in which a change rate of a voltage of an SOC of a charging curve is less than a preset threshold, and an upper limit value is an SOC in which a change rate of a discharge curve is less than a threshold.

[0092] Figure 4 is a diagram showing a preset SOC section in a curve according to an embodiment of the present disclosure.

[0093] refer to Figure 4 , the rate of change of the voltage of the SOC can indicate the slope of the curve. In other words, a section where the rate of change of the voltage relative to the SOC is less than the threshold means a section where the voltage change according to the change of the SOC is not significant. For example, this section is called a platform section or a flat section, and has characteristics often seen in batteries with an olivine structure. For example, a platform section may often appear in the charge and discharge curve of an LFP battery.

[0094] exist Figure 4In the embodiment of the present invention, the platform section of the charging curve Pc may have an SOC of 25% to 60% and 65% to 98%. In addition, the platform section of the discharge curve Pd may have an SOC of 35% to 63% and 67% to 98%. Here, the lower limit value of the SOC section R may correspond to a SOC 25% where the rate of change of the voltage of the SOC of the charging curve Pc is less than a threshold value, and the upper limit value of the SOC section R may correspond to a SOC 35% where the rate of change of the voltage of the SOC of the discharge curve Pd is less than a threshold value. Therefore, the SOC section R may be set to a section of SOC 25% to 35%.

[0095] In addition, the reference amount can be set in advance to any SOC belonging to the SOC section. That is, the reference amount can be selected between the starting SOC of the plateau section of the charging curve and the starting SOC of the plateau section of the discharging curve. Figure 4 In the embodiment of FIG. 1 , the reference amount may be set to SOC 30% included in the SOC section R of SOC 25% or more and SOC 35% or less.

[0096] The control unit 120 may be configured to compare the charge and discharge amount with a reference amount and estimate the SOC of the battery based on the comparison result.

[0097] For example, if the charge and discharge amount is less than a reference amount, the control unit 120 may be configured to estimate the SOC of the battery using a charge curve and an average curve or using a discharge curve and an average curve according to the charge and discharge state of the battery.

[0098] Here, if the charge and discharge amount is less than the reference amount, it means that the voltage of each SOC of the battery has not yet converged to the state of the charge curve or the discharge curve. That is, if the charge and discharge amount is less than the reference amount, the voltage of each SOC of the battery may be between the charge curve and the average curve or between the discharge curve and the average curve. Therefore, the control unit 120 can estimate the SOC of the battery based on the first SOC and the second SOC.

[0099] As another example, the control unit 120 may be configured to estimate the SOC of the battery using a charging curve or a discharging curve according to the charging and discharging state of the battery if the charging and discharging amount is greater than or equal to a reference amount.

[0100] If the charge and discharge amount is greater than or equal to the reference amount, it means that the voltage of each SOC of the battery has converged to the charge curve or the discharge curve. That is, if the charge and discharge amount is greater than or equal to the reference amount, the voltage of each SOC of the battery can follow the charge curve or the discharge curve. Therefore, the control unit 120 can estimate the SOC of the battery based on the charge curve or the discharge curve by considering the charge and discharge state of the battery. For example, the control unit 120 can determine the first SOC as the SOC of the battery.

[0101] According to the previous embodiment, the ratio of the reference amount to the charge and discharge amount can be calculated according to the formula "charge and discharge amount ÷ reference amount". For example, if the charge and discharge amount is greater than or equal to the reference amount, the ratio of the reference amount to the charge and discharge amount can be greater than or equal to 1. In this case, since the second weight is the complement of 1 of the first weight, the second weight can be not calculated. Therefore, if the charge and discharge amount is greater than or equal to the reference amount, the control unit 120 can estimate the first SOC as the SOC of the battery. Here, it should be noted that the first weight is not attached to the first SOC, and the first SOC is directly estimated as the SOC of the battery.

[0102] The battery management device 100 can change the battery SOC estimation method by comparing the charge and discharge amount with the reference amount. That is, since the battery management device 100 estimates the battery SOC using an appropriate method according to the current charge and discharge state of the battery, the accuracy and reliability of the estimated SOC can be improved.

[0103] The battery management device 100 according to the present disclosure may be applied to a BMS (battery management system). That is, the BMS according to the present disclosure may include the above-mentioned battery management device 100. In this configuration, at least some components of the battery management device 100 may be implemented by supplementing or adding functions of a configuration included in a conventional BMS. For example, the control unit 120 and the storage unit 130 may be implemented as components of the BMS.

[0104] The battery management device 100 according to the present disclosure may be provided in a battery pack. That is, the battery pack according to the present disclosure may include the above-mentioned battery management device 100 and one or more battery cells. In addition, the battery pack may further include electrical devices (relays, fuses, etc.) and a housing.

[0105] Figure 5 is a diagram schematically showing an exemplary configuration of a battery pack 1 according to another embodiment of the present disclosure.

[0106] The positive terminal of the battery B may be connected to the positive terminal P+ of the battery pack 10 , and the negative terminal of the battery B may be connected to the negative terminal P− of the battery pack 10 .

[0107] The measuring unit 110 may be connected to the first sensing line SL1, the second sensing line SL2, and the third sensing line SL3. Specifically, the measuring unit 110 may be connected to the positive terminal of the battery B through the first sensing line SL1, and may be connected to the negative terminal of the battery B through the second sensing line SL2. The measuring unit 110 may measure the voltage of the battery B based on the voltage measured at each of the first sensing line SL1 and the second sensing line SL2.

[0108] In addition, the measuring unit 110 may be connected to an ammeter A through a third sensing line SL3. For example, the ammeter A may be an ammeter or a shunt resistor capable of measuring a charging current and a discharging current of the battery B. The measuring unit 110 may calculate a charging amount by measuring a charging current of the battery B through the third sensing line SL3. In addition, the measuring unit 110 may calculate a discharging amount by measuring a discharging current of the battery B through the third sensing line SL3.

[0109] The external device may be connected to the positive terminal P+ and the negative terminal P- of the battery pack 10. The external device may be a charge and discharge device capable of charging the battery B. As another example, the external device may be a load that receives power from the battery B.

[0110] Figure 6 is a diagram schematically showing a vehicle 600 according to yet another embodiment of the present disclosure.

[0111] refer to Figure 6 The battery pack 610 according to an embodiment of the present disclosure may be included in a vehicle 600 such as an electric vehicle (EV) or a hybrid vehicle (HV). In addition, the battery pack 610 may supply power to a motor through an inverter provided in the vehicle 600 to drive the vehicle 600. In addition, the battery pack 610 may include the battery management device 100.

[0112] Figure 7 is a diagram schematically illustrating an energy storage system (ESS) according to yet another embodiment of the present disclosure.

[0113] refer to Figure 7 , the energy storage system 700 includes a plurality of battery modules 720 and a rack case 710. The plurality of battery modules 720 may be configured to be accommodated in the rack case 710 in a vertical arrangement. In addition, each battery module 720 may include a battery management device 100.

[0114] Figure 8 FIG. 4 is a schematic diagram of a battery management method according to another embodiment of the present disclosure.

[0115] Preferably, each step of the battery management method may be performed by the battery management device 100. Hereinafter, for the convenience of explanation, contents overlapping with the previously described contents will be omitted or briefly described.

[0116] refer to Figure 8 , the battery management method may include a current measuring step ( S100 ), a voltage measuring step ( S200 ), a charge and discharge state determining step ( S300 ), an SOC determining step ( S400 ), and an SOC estimating step ( S500 ).

[0117] The current measuring step ( S100 ) is a step of measuring the charge and discharge amount of the battery, and may be performed by the measuring unit 110 .

[0118] For example, the measuring unit 110 can measure the charging current and the discharging current of the battery. In addition, the measuring unit 110 can measure the charging capacity of the battery based on the charging current amount during the charging process. Similarly, the measuring unit 110 can measure the discharging capacity of the battery based on the discharging current amount during the discharging process.

[0119] The voltage measuring step ( S200 ) is a step of measuring the voltage of the battery and may be performed by the measuring unit 110 .

[0120] For example, the measuring unit 110 may measure the voltage of the battery by calculating the difference between the positive electrode voltage and the negative electrode voltage. Preferably, the measuring unit 110 may measure the OCV of the battery.

[0121] The charge and discharge state determination step ( S300 ) is a step of determining the charge and discharge state of the battery based on the charge and discharge amount according to the charge amount and the discharge amount, and may be performed by the control unit 120 .

[0122] For example, the control unit 120 may be configured to calculate the charge and discharge amount by calculating the difference between the charge amount and the discharge amount. In addition, the control unit 120 may be configured to determine the charge and discharge state of the battery as a first state or a second state based on the calculated charge and discharge amount. Here, the first state indicates a state in which the battery is charged, and the second state indicates a state in which the battery is discharged.

[0123] The SOC determination step ( S400 ) is a step of determining the first SOC and the second SOC corresponding to the voltage based on a curve corresponding to the determined charge and discharge state, and may be performed by the control unit 120 .

[0124] For example, if the control unit 120 determines the charge and discharge state of the battery as the first state, the control unit 120 can estimate the first SOC by substituting the measured voltage into the charge curve. Conversely, if the control unit 120 determines the charge and discharge state of the battery as the second state, the control unit 120 can estimate the first SOC by substituting the measured voltage into the discharge curve. Furthermore, the control unit 120 can estimate the second SOC by substituting the measured voltage into the average curve.

[0125] The SOC estimating step ( S500 ) is a step of estimating the SOC of the battery from the first SOC and the second SOC using a weight corresponding to the charge and discharge amount, and may be performed by the control unit 120 .

[0126] For example, the control unit 120 may calculate the first weight and the second weight by calculating the ratio of the preset reference amount to the charge and discharge amount. The control unit 120 may add a weight to each of the first SOC and the second SOC. In addition, the control unit 120 may estimate the final SOC of the battery by summing the first SOC to which the weight is added and the second SOC to which the weight is added.

[0127] The above-mentioned embodiments of the present disclosure can be implemented not only by devices and methods, but also by programs that implement functions corresponding to the configurations of the embodiments of the present disclosure or recording media that record the programs. Those skilled in the art can easily implement the programs or recording media from the description of the above embodiments.

[0128] The present disclosure has been described in detail. However, the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by way of illustration only, since various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from this detailed description.

[0129] In addition, without departing from the technical aspects of the present disclosure, those skilled in the art may make many substitutions, modifications and changes to the present disclosure, and the present disclosure is not limited to the above-mentioned embodiments and drawings, and each embodiment may be selectively combined in part or in whole to allow various modifications.

[0130] (Explanation of reference symbols)

[0131] 10: Battery Pack

[0132] 11: Battery

[0133] 100: Battery management device

[0134] 110: Measurement unit

[0135] 120: Control unit

[0136] 130: Storage unit

[0137] 600: Vehicles

[0138] 610: Battery Pack

[0139] 700: Energy Storage Systems

[0140] 710: Frame housing

[0141] 720: Battery module

Claims

1. A battery management device, comprising: a measuring unit configured to measure a charge amount and a discharge amount of a battery and to measure a voltage of the battery; as well as A control unit configured to determine a charge and discharge state of the battery based on a charge and discharge amount according to the charge amount and the discharge amount, determine a first SOC and a second SOC corresponding to the voltage based on a curve corresponding to the determined charge and discharge state, and estimate the SOC of the battery from the first SOC and the second SOC using a weight corresponding to the charge and discharge amount.

2. The battery management device according to claim 1, in, The curves include: a charging curve corresponding to the first state and preset to represent a corresponding relationship between the SOC and the voltage; a discharge curve corresponding to the second state and preset to represent a corresponding relationship between the SOC and the voltage; and An average curve is preset to represent an average voltage value for each SOC of the charging curve and the discharging curve.

3. The battery management device according to claim 2, in, The voltage of each SOC of the charging curve is set to be higher than or equal to the voltage of each SOC of the discharging curve.

4. The battery management device according to claim 2, in, The control unit is configured to determine a first SOC corresponding to the voltage of the battery using the charging curve or the discharging curve according to the charging and discharging state, and determine a second SOC corresponding to the voltage of the battery using the average curve.

5. The battery management device according to claim 2, in, The control unit is configured to calculate a first weight and a second weight by calculating a ratio of a preset reference amount to the charge and discharge amount, and estimate the SOC of the battery by adding the first weight and the second weight to the first SOC and the second SOC, respectively.

6. The battery management device according to claim 5, in, When the charge and discharge amount is less than the reference amount, the control unit is configured to estimate the SOC of the battery using the charge curve and the average curve or using the discharge curve and the average curve according to the charge and discharge state of the battery.

7. The battery management device according to claim 6, in, When the charge and discharge amount is greater than or equal to the reference amount, the control unit is configured to estimate the SOC of the battery using the charge curve or the discharge curve according to the charge and discharge state of the battery.

8. The battery management device according to claim 5, in, The reference amount is preset as an SOC included in an SOC section in which a lower limit value is an SOC in which a change rate of a voltage of the SOC of the charging curve is less than a preset threshold value, and an upper limit value is an SOC in which a change rate of a discharge curve is less than the threshold value.

9. The battery management device according to claim 5, in, The control unit is configured to estimate the SOC of the battery by summing a value obtained by adding the first weight to the first SOC and a value obtained by adding the second weight to the second SOC.

10. The battery management device according to claim 5, in, The control unit is configured to calculate a ratio of the charge and discharge amount to the reference amount as the first weight, and calculate a 1's complement of the first weight as the second weight.

11. The battery management device according to claim 1, in, The control unit is configured to calculate the charge and discharge amount by calculating a difference between the charge amount and the discharge amount, and determine whether the charge and discharge state of the battery is the first state or the second state based on the calculated charge and discharge amount.

12. A battery pack comprising the battery management device according to any one of claims 1-11.

13. An energy storage system comprising the battery management device according to any one of claims 1-11.

14. A battery management method, comprising: a current measuring step, wherein the current measuring step measures the charge and discharge amounts of the battery; a voltage measuring step, wherein the voltage measuring step measures the voltage of the battery; a charge and discharge state determining step of determining the charge and discharge state of the battery based on the charge and discharge amounts according to the charge amount and the discharge amount; an SOC determining step of determining a first SOC and a second SOC corresponding to the voltage based on a curve corresponding to the determined charge and discharge state; as well as An SOC estimating step estimates an SOC of the battery from the first SOC and the second SOC using a weight corresponding to the charge and discharge amount.

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