Battery management device and battery balancing method thereby

Abstract

A battery management device according to an embodiment of the present invention is located in a battery system including a plurality of batteries, and may include: at least one processor; and a memory that stores at least one command executed through the at least one processor. Here, the at least one command may include: a command for collecting state information including charging state values of the batteries; a command for identifying whether the charging state value of at least one of the batteries belongs to a predefined low charging state section or a predefined high charging state section; a command for determining whether a balancing start condition defined to correspond to a current charging state section is satisfied, based on the state information of the batteries; and a command for determining whether to start a balancing mode for balancing the batteries, according to a result of the condition satisfaction determination.

Description

Battery management device and battery balancing method using the same

[0001] This application claims the benefit of Korean Patent Application No. 10-2023-0188254 filed with the Korean Intellectual Property Office on December 21, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] The present invention relates to a battery system and a battery balancing method thereof, and more particularly, to a battery management device and a battery balancing method using the same for balancing a battery having a voltage plateau in a charge characteristic curve.

[0003] Secondary batteries are batteries that can be reused by charging even after discharge, and can be used as an energy source for small devices such as mobile phones, tablet PCs, and vacuum cleaners, and are also used as an energy source for medium and large devices such as automobiles and ESS (Energy Storage Systems) for smart grids.

[0004] Secondary batteries are applied to systems in the form of assemblies, such as battery modules, in which multiple battery cells are connected in series and parallel, or battery packs, in which battery modules are connected in series and parallel, depending on the system requirements. For medium- to large-sized devices such as electric vehicles, high-capacity battery systems, in which multiple battery packs are connected in parallel, can be applied to meet the device's capacity requirements.

[0005] Carbon materials are mainly used as negative active materials for lithium secondary batteries, and lithium-containing cobalt oxide (LiCoO2) is mainly used as positive active materials. In addition, the use of lithium-containing manganese oxide (LiMnO2, LiMn2O4, etc.) and lithium-containing nickel oxide (LiNiO2) is also being considered.

[0006] Recently, lithium iron phosphate (LiFePO4) compounds have been used as cathode active materials in lithium secondary batteries. Lithium iron phosphate (LFP) batteries, which use LiFePO4 as the cathode active material, boast superior thermal stability and cost-effectiveness compared to other batteries. However, LFP batteries exhibit flat characteristics, with a voltage plateau in their charge characteristic curve (the curve relating open circuit voltage to SOC). This plateau makes it difficult to accurately estimate the SOC (State of Charge).

[0007] In order to resolve the imbalance between battery cells during the operation of a battery system, cell balancing control based on the estimated value of SOC is essential. However, in the case of LFP batteries, it is difficult to accurately estimate SOC in flat sections, so cell balancing control is performed only in uneven sections (e.g., sections where SOC is 90% or higher).

[0008] Accordingly, an appropriate control technology is required for balancing batteries having a voltage flat section in the charge characteristic curve, such as LFP batteries.

[0009] An object of the present invention to solve the above problems is to provide a battery management device for balancing a battery having a voltage flat section in a charge characteristic curve.

[0010] Another object of the present invention to solve the above problems is to provide a battery balancing method using such a battery management device.

[0011] Another object of the present invention to solve the above problems is to provide a battery system including such a battery management device.

[0012] According to one embodiment of the present invention for achieving the above purpose, a battery management device is a battery management device located in a battery system including a plurality of batteries, and may include at least one processor; and a memory storing at least one command executed through the at least one processor.

[0013] Here, the at least one command may include: a command for collecting state information including state of charge values ​​of the batteries; a command for determining whether the state of charge values ​​of one or more of the batteries fall within a predefined low state of charge range or high state of charge range; a command for determining whether a balancing initiation condition defined in correspondence with a current state of charge range is satisfied based on the state information of the batteries; and a command for determining whether to initiate a balancing mode for balancing the batteries based on the determination result.

[0014] The above low charge state section may be defined as a section that is lower than or equal to a preset first charge state value, and the above high charge state section may be defined as a section that is higher than or equal to a preset second charge state value.

[0015] The balancing initiation condition in the above low charge state section may include at least one of a first condition in which the difference between the SOH (State of Health) of the batteries is within a preset threshold range, a second condition in which the temperature of the batteries is higher than the preset threshold temperature, and a third condition in which the idle period of the batteries exceeds the preset first period.

[0016] The balancing initiation condition in the high-charge state section may include at least one of a second condition in which the temperature of the batteries is higher than a preset threshold temperature, and a fourth condition in which the idle period of the batteries exceeds the preset second period.

[0017] The at least one command may further include a command for determining a battery to be balanced based on a difference between the state of charge values ​​of the batteries when the balancing mode is initiated; and a command for performing a predefined balancing control on the battery to be balanced.

[0018] The command for determining the above-mentioned balancing target battery may include a command for determining, as the balancing target battery, a battery having a state of charge value whose difference from the minimum state of charge value is equal to or greater than a preset first threshold value when the balancing mode is initiated in the low state of charge section; and a command for determining, as the balancing target battery, a battery having a state of charge value whose difference from the minimum state of charge value is equal to or greater than a preset second threshold value when the balancing mode is initiated in the high state of charge section.

[0019] Here, the first threshold value may be set to a value greater than the second threshold value.

[0020] The command for performing the above balancing control may include a command for calculating a balancing period based on the capacity of the balancing target battery; and a command for performing the balancing control during the balancing period.

[0021] The command for performing the above balancing control may include a command for monitoring whether, during the process of performing the above balancing control, the charge state value of one or more of the batteries enters the high charge state section.

[0022] The command for performing the above balancing control may include a command for re-determining the balancing target battery when the state of charge value of one or more of the batteries enters the high state of charge section and satisfies a balancing initiation condition in the high state of charge section.

[0023] The command for performing the above balancing control may include a command for monitoring whether, during the process of performing the balancing control, the state of charge value of one or more of the batteries decreases below a predefined third state of charge value; and a command for stopping the balancing control if the state of charge value decreases below the third state of charge value.

[0024]

[0025] According to an embodiment of the present invention for achieving the above-described other object, a battery balancing method is provided, which is a battery balancing method by a battery management device that manages a plurality of batteries, comprising: a step of collecting state information including state of charge values ​​of the batteries; a step of confirming whether the state of charge values ​​of at least one of the batteries fall into a predefined low state of charge section or high state of charge section; a step of determining whether a balancing initiation condition defined in correspondence with a current state of charge section is satisfied based on the state information of the batteries; and a step of determining whether to initiate a balancing mode for balancing the batteries based on the determination result.

[0026] The above low charge state section may be defined as a section that is lower than or equal to a preset first charge state value, and the above high charge state section may be defined as a section that is higher than or equal to a preset second charge state value.

[0027] The balancing initiation condition in the above low charge state section may include at least one of a first condition in which the difference between the SOH (State of Health) of the batteries is within a preset threshold range, a second condition in which the temperature of the batteries is higher than the preset threshold temperature, and a third condition in which the idle period of the batteries exceeds the preset first period.

[0028] The balancing initiation condition in the high-charge state section may include at least one of a second condition in which the temperature of the batteries is higher than a preset threshold temperature, and a fourth condition in which the idle period of the batteries exceeds the preset second period.

[0029] The above battery balancing method may further include, when the balancing mode is initiated, a step of determining a battery to be balanced based on a difference between the state of charge values ​​of the batteries; and a step of performing a predefined balancing control on the battery to be balanced.

[0030] The step of determining the battery to be balanced may include the step of determining, as the battery to be balanced, a battery having a state of charge value whose difference from the minimum state of charge value is equal to or greater than a preset first threshold value when the balancing mode is initiated in the low state of charge section; and the step of determining, as the battery to be balanced, a battery having a state of charge value whose difference from the minimum state of charge value is equal to or greater than a preset second threshold value when the balancing mode is initiated in the high state of charge section.

[0031] Here, the first threshold value may be set to a value greater than the second threshold value.

[0032] The step of performing the above balancing control may include a step of calculating a balancing period based on the capacity of the battery to be balanced; and a step of performing the balancing control during the balancing period.

[0033] The step of performing the above balancing control may include a step of monitoring whether, during the process of performing the balancing control, the state of charge value of one or more of the batteries enters the high state of charge section.

[0034] The step of performing the above balancing control may include a step of re-determining the battery to be balanced when the state of charge value of one or more of the batteries enters the high state of charge section and satisfies a balancing initiation condition in the high state of charge section.

[0035] The step of performing the above balancing control may include a step of monitoring whether, during the process of performing the balancing control, the state of charge value of one or more of the batteries decreases below a predetermined third state of charge value; and a step of stopping the balancing control if the state of charge value decreases below the third state of charge value.

[0036]

[0037] A battery system according to one embodiment of the present invention for achieving the above-described further object may include a plurality of batteries; and a battery management device that collects status information of the batteries and manages and controls the batteries based on the collected status information.

[0038] Here, the battery management device can determine whether a charge state value of one or more of the batteries falls within a predefined low charge state section or high charge state section, determine whether a balancing initiation condition defined in correspondence with a current charge state section is satisfied based on the state information of the batteries, and determine whether to initiate a balancing mode for balancing the batteries based on the determination result.

[0039] According to the above-described embodiment of the present invention, for batteries having flat characteristics, more balancing control is performed so that the state of charge of the batteries can be maintained more uniformly, and the capacity of the battery system can be utilized to the maximum.

[0040] Figure 1 shows the charging characteristic curve of an LFP battery.

[0041] Figure 2 is a block diagram illustrating a battery system according to the present invention.

[0042] Figure 3 is an operation flowchart of a battery balancing method according to an embodiment of the present invention.

[0043] Figure 4 is a flowchart illustrating an operation of a battery balancing method after initiation of a balancing mode according to an embodiment of the present invention.

[0044] Figures 5 and 6 are flowcharts of operations of a battery balancing method according to another embodiment of the present invention.

[0045] Figure 7 is a block diagram of a battery management device according to an embodiment of the present invention.

[0046] 10: Battery

[0047] 100: Battery assembly

[0048] 200, 700: Battery management device

[0049] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. Throughout the description of each drawing, similar reference numerals have been used to designate similar components.

[0050] Terms such as "first," "second," "A," and "B" may be used to describe various components, but these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, the first component could be referred to as the "second component," and similarly, the second component could also be referred to as the "first component." The term "and / or" includes any combination of multiple related items listed or any one of multiple related items listed.

[0051] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0052] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0053] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0054]

[0055] Some terms used in this specification are defined as follows:

[0056] A battery cell is the smallest unit that stores electricity, and a battery module is a collection of multiple battery cells that are electrically connected.

[0057] A battery rack is a single-structure system that connects module units specified by the battery manufacturer in series or parallel, enabling monitoring and control via a BMS (Battery Management System). It can be configured to include multiple battery modules and a single BPU (Battery Protection Unit) or protection device. Depending on the device or system in which the battery is used, the battery module may also be referred to as a battery pack.

[0058] A battery bank can refer to a large-scale battery rack system comprised of multiple battery racks connected in parallel. A battery bank-level BMS can monitor and control the rack BMS (RBMS) at the battery rack level.

[0059] A battery assembly is a collection of multiple electrically connected battery cells that function as a power source when applied to a specific system or device. Here, the battery assembly may refer to a battery module, battery pack, battery rack, or battery bank, but the scope of the present invention is not limited to these entities.

[0060] SOC (State of Charge) is the current charged state of the battery expressed as a percentage [%], and SOH (State of Health) is the current remaining state of the battery expressed as a percentage [%].

[0061] Nominal Capacity (Nominal Capa.) may refer to the set capacity [Ah] of the battery set by the battery manufacturer during development.

[0062]

[0063] Figure 1 shows the charging characteristic curve of an LFP battery.

[0064] More specifically, Fig. 1 shows the charge characteristic curve of a lithium iron phosphate (LFP) battery using lithium iron phosphate as a positive electrode active material. The charge characteristic curve shows the relationship between the open circuit voltage (OCV) measured during the battery charging process and the SOC.

[0065] To address imbalances between battery cells during battery system operation, the battery management system compares the State-of-Cells (SOC) of battery cells to determine imbalances. If the imbalance exceeds a predefined threshold, balancing control can be implemented. To determine imbalances between battery cells, a commonly used method is to measure the battery's open-circuit voltage (OCV) and estimate the battery's SOC based on the measured open-circuit voltage.

[0066] Referring to Figure 1, the charge characteristic curve of an LFP battery has a voltage plateau in the SOC range of about 10% to about 90%. For an LFP battery with such a plateau characteristic, it is difficult to accurately estimate the SOC in the plateau range, and therefore balancing control needs to be performed in the uneven range.

[0067] When balancing an LFP battery in a low SOC range (e.g., a range where the SOC is 10% or less), it is difficult to accurately select an unbalanced battery (a battery to be balanced), and the voltage of the battery may decrease rapidly due to balancing control, which may cause over-discharge.

[0068] Accordingly, in battery systems using LFP, balancing control is typically performed in high SOC ranges (e.g., SOCs above 90%). However, in battery systems linked to PV (Photovoltaic; solar power generation systems), the full charge state (high SOC range) is often not reached due to weather conditions, resulting in low frequency of balancing control, which can lead to uneven battery life and potential state deviations.

[0069] The present invention has been devised to solve these problems, and a preferred embodiment of the present invention will be described in detail below with reference to the attached drawings.

[0070]

[0071] Figure 2 is a block diagram illustrating a battery system according to the present invention.

[0072] Referring to FIG. 2, the battery system may include a battery assembly (100) including a plurality of batteries (10) and a battery management device (200).

[0073] A plurality of batteries (10) can be electrically connected to each other and configured in a battery assembly.

[0074] Battery (10) may mean a battery cell, a battery module, or a battery rack.

[0075] The battery (10) may correspond to an LFP battery cell, or may correspond to a battery module or battery rack including a plurality of LFP batteries. However, the scope of the present invention is not limited to these entities. That is, the battery according to the present invention may correspond to a battery having at least a portion of a voltage flat section in its charge characteristic curve, or may correspond to a battery module or battery rack including the same.

[0076] A battery management device (200) can collect status information on a plurality of batteries (10) and perform a predefined control operation based on the collected status information to manage and control a battery assembly (100). Here, the battery management device (200) can control charging and discharging of batteries, diagnose whether the batteries are faulty, and determine the imbalance of the batteries to perform balancing control.

[0077] The battery management device (200) may correspond to a BMS located inside the battery system, or may be implemented as included in the BMS.

[0078] The battery system according to an embodiment of the present invention may be implemented as part of an energy storage system (ESS), but the scope of the present invention is not limited to these entities. That is, the battery system according to the present invention may be applied to various devices, such as electric vehicles.

[0079]

[0080] Figure 3 is an operation flowchart of a battery balancing method according to an embodiment of the present invention.

[0081] A battery balancing method according to an embodiment of the present invention can be performed by a battery management device located within a battery system.

[0082] The battery management device can collect status information of batteries (S310). Here, the status information may include one or more of a state of charge value, temperature, and SOH for each battery.

[0083] In the present invention, the state of charge value means a value indicating the state of charge of the battery, and may include one or more of the SOC value, the voltage value, and the open circuit voltage value (OCV) of the battery.

[0084] The battery management device can determine whether the battery system falls within a predefined state of charge interval based on the state of charge values ​​of the batteries (S320). Here, the battery management device can determine whether the state of charge values ​​of one or more batteries fall within a predefined low state of charge interval or high state of charge interval.

[0085] A low state of charge interval may be defined as an interval that is lower than or equal to a preset first state of charge value, and a high state of charge interval may be defined as an interval that is higher than or equal to a preset second state of charge value. For example, a low state of charge interval may be defined as an interval where the SOC is lower than or equal to 35%, and a high state of charge interval may be defined as an interval where the SOC is higher than or equal to 95%.

[0086] In an embodiment, the battery management device may determine that the battery system is in a low charge state interval if the number of batteries having a state of charge value lower than or equal to a first state of charge value is a preset number N or more. For example, if the state of charge values ​​of all batteries are determined to be 35% or lower, the battery management device may determine that the battery system is in a low charge state interval.

[0087] In an embodiment, the battery management device may determine that the battery system is in a high-charge state range if the number of batteries having a state of charge value greater than or equal to a second state of charge value is a preset number M or more. For example, if it is determined that there is one or more batteries having a state of charge value greater than or equal to 95%, the battery management device may determine that the battery system is in a high-charge state range.

[0088] When the battery system is in a low charge state or high charge state (Y in S320), the battery management device can determine whether predefined balancing initiation conditions are satisfied (S330). Here, the battery management device can determine whether the balancing initiation conditions defined in correspondence with the current charge state period are satisfied based on the status information of the batteries.

[0089] The balancing initiation condition in the low charge state section may include at least one of a first condition in which the difference between the SOHs of the batteries is within a preset threshold range, a second condition in which the temperature of the batteries is higher than the preset threshold temperature, and a third condition in which the idle period of the batteries exceeds the preset first period.

[0090] For example, the balancing initiation conditions in the low charge state section may include a first condition in which the difference between the SOHs of the batteries is within 3%, a second condition in which the temperature of all batteries is 0 degrees Celsius or higher, and a third condition in which the idle period of the batteries exceeds 60 minutes. Here, if the current charge state section confirmed in S320 is the low charge state section, the battery management device may determine whether the first condition, the second condition, and the third condition are satisfied based on the status information of the batteries.

[0091] The balancing initiation conditions in the high-charge state section may include at least one of a second condition in which the temperature of the batteries is above a preset threshold temperature, and a fourth condition in which the idle period of the batteries exceeds a preset second period. Here, the second period may be defined as a period shorter than the first period.

[0092] For example, the balancing initiation conditions in the high-charge state section may include a second condition in which the temperature of all batteries is 0 degrees Celsius or higher, and a fourth condition in which the idle period of the batteries exceeds 10 minutes. Here, if the current charge state section confirmed in S320 is the high-charge state section, the battery management device may determine whether the second and fourth conditions are satisfied based on the status information of the batteries.

[0093] Meanwhile, the balancing initiation condition in the low state of charge section, unlike the high state of charge section, may further include a condition (first condition) regarding the balance of SOH. Accordingly, when there is no or very little difference in SOH between batteries, balancing control can be performed in both the low state of charge and the high state of charge. On the other hand, when the difference in SOH between batteries is large (for example, when a specific battery is replaced), balancing control may not be performed in the low state of charge, but only in the high state of charge. When the difference in SOH between LFP batteries is large, it is difficult to accurately determine the SOH values ​​of the batteries in the low state of charge section. According to the above embodiment, when the difference in SOH between batteries is large, balancing control is performed only in the high state of charge section, thereby resolving the problem of reduced accuracy of balancing control.

[0094] The battery management device can determine whether to initiate a balancing mode for balancing the batteries based on the judgment result of S330.

[0095] If it is determined that the balancing initiation condition corresponding to the current charging state section is satisfied (Y of S330), the battery management device can initiate balancing mode (S340).

[0096] If it is determined that the balancing initiation condition is not satisfied (N of S330), the battery management device may return to S310 without initiating the balancing mode.

[0097]

[0098] Figure 4 is a flowchart illustrating an operation of a battery balancing method after initiation of a balancing mode according to an embodiment of the present invention.

[0099] When the balancing mode is initiated (S410), the battery management device can determine one or more balancing target batteries based on the difference between the charge state values ​​of the batteries (S420).

[0100] Specifically, the battery management device can select batteries that satisfy predefined conditions based on the difference between the state of charge values ​​of the batteries and determine the selected batteries as batteries to be balanced. Here, the battery management device can determine a battery whose state of charge value differs from the minimum state of charge value by a predefined threshold value or more as the battery to be balanced.

[0101] Conditions for selecting a battery to be balanced can be defined in response to the current state of charge section.

[0102] When the balancing mode is initiated in the low state of charge section, the battery management device may determine a battery having a state of charge value whose difference from the minimum state of charge value is greater than or equal to a preset first threshold value as the target battery for balancing. For example, the battery management device may determine a battery having a state of charge value whose difference from the minimum state of charge value among the batteries is greater than or equal to 5% as the target battery for balancing.

[0103] When the balancing mode is initiated in the high state of charge section, the battery management device may determine a battery having a state of charge value whose difference from the minimum state of charge value is greater than or equal to a preset second threshold value as the target battery for balancing. Here, the first threshold value may be set to a value greater than the second threshold value. For example, the battery management device may determine a battery having an SOC value whose difference from the minimum value among the SOC values ​​of the batteries is greater than or equal to 2% as the target battery for balancing.

[0104] As the second threshold value is set to a value smaller than the first threshold value, the frequency of performing balancing control in the high-charge state section can be increased, and the missetting of the balancing target battery in the low-charge state can be minimized.

[0105] Once the target battery for balancing is determined, the battery management device can calculate the balancing period (S430).

[0106] A battery management device can calculate a balancing period based on the capacity of the battery to be balanced. Here, the battery management device can set a preset ratio of the capacity of the battery to be balanced as a balancing limit, and calculate the balancing period based on the balancing limit and the balancing speed. For example, the battery management device can set the balancing limit to 0.1% of the lowest capacity among the capacities of each of the batteries to be balanced, and calculate the balancing period based on the set balancing limit and the discharge rate (discharge amount per unit time) by the balancing circuit.

[0107] The battery management device can perform predefined balancing control on the battery to be balanced (S440).

[0108] A battery management device can perform balancing control by controlling a balancing circuit included in a battery system to reduce imbalances between battery cells. For example, the battery management device can control a manual balancing circuit included in the battery system to forcefully discharge a battery being balanced, thereby reducing differences in the state of charge between the batteries.

[0109] The battery management device can perform balancing control during the balancing period calculated in S430. Specifically, after the balancing control is initiated, the battery management device can monitor whether the balancing period is completed (S450), and if the balancing period is completed (Y in S450), can terminate the balancing control (end the balancing mode) (S460).

[0110] The battery management device can check whether the balancing initiation condition in the high-charge state section is satisfied based on the status information of the batteries during the process of performing balancing control (N of S450) (S470).

[0111] Specifically, the battery management device may monitor whether the state of charge value of one or more batteries enters a high-charge state range during the balancing control process. If the state of charge value of one or more batteries enters a high-charge state range and satisfies the balancing initiation condition in the high-charge state range, the battery management device may return to step S420 and re-determine the target battery for balancing.

[0112] After the balancing mode is initiated in a low-charge state, the battery system can be switched to a high-charge state by charging. Accordingly, the battery management device, during the balancing control process, can check whether the system has entered a high-charge state section and whether the balancing initiation conditions (e.g., the second condition and the fourth condition) in the high-charge state section are satisfied, and if the conditions are satisfied, can update the balancing target battery and then perform balancing control.

[0113] The battery management device may monitor whether the state of charge value of one or more batteries decreases below a predetermined third state of charge value during the balancing control process. If the state of charge value decreases below the third state of charge value, the battery management device may stop the balancing control. For example, the battery management device may monitor the voltage values ​​of the batteries during the balancing control process, and stop the balancing control if it is determined that the minimum value among the voltage values ​​decreases below 2.7 V.

[0114] After the balancing control is interrupted, the battery management device can monitor whether the state of charge value of one or more of the batteries increases above a predefined fourth state of charge value. If the state of charge value increases above the fourth state of charge value, the battery management device can release the suspension of the balancing control and resume the balancing control. For example, if it is determined that the minimum value among the voltage values ​​increases above 3.22 V after the balancing control is interrupted, the battery management device can release the suspension of the balancing control and resume the balancing control.

[0115]

[0116] Figures 5 and 6 are flowcharts illustrating the operation of a battery balancing method according to another embodiment of the present invention. Specifically, Figures 5 and 6 are implementation examples of the battery balancing method illustrated in Figures 3 and 4.

[0117] First, referring to FIG. 5, the battery management device can collect status information of batteries. Here, the status information can include a state of charge value, temperature, and SOH for each battery.

[0118] The battery management device can check whether the temperature of the batteries is higher than a preset threshold temperature (Td) (whether the second condition is satisfied) (S510).

[0119] When the temperature of all batteries is higher than the critical temperature (Td) (Y of S510), the battery management device can check whether the difference between the SOHs of the batteries is within a preset critical range (SOHd) ​​(whether the first condition is satisfied) (S520).

[0120] If the difference between the SOHs of the batteries is within a preset threshold range (SOHd) ​​(Y in S520), the battery management device can check whether the battery system is currently in a low charge state section and whether the idle period of the batteries exceeds a preset first period (t1) (whether the third condition is satisfied) (S531). Here, if the battery system is in a low charge state section and the idle period exceeds the first period (Y in S531), the battery management device can determine a battery to be balanced (S541). Specifically, the battery management device can determine a battery having a charge state value whose difference from the minimum charge state value is equal to or greater than a preset first threshold value as the battery to be balanced.

[0121] If the battery system does not belong to the low state of charge section or the idle period is less than or equal to the first period (N of S531), the battery management device can check whether the battery system currently belongs to the high state of charge section and whether the idle period of the batteries exceeds the preset second period (t2) (whether the fourth condition is satisfied) (S532). Meanwhile, if the difference between the SOHs of the batteries is outside the preset threshold range (SOHd) ​​(N of S520), the battery management device can perform S532. Here, if the battery belongs to the high state of charge section and the idle period exceeds the second period (Y of S532), the battery management device can determine the battery to be balanced (S542). Specifically, the battery management device can determine the battery having the state of charge value whose difference from the minimum state of charge value is greater than or equal to the preset second threshold value as the battery to be balanced. Here, the first threshold value can be set to a value greater than the second threshold value.

[0122] If there is one or more batteries to be balanced (Y of S541, Y of S542), the battery management device can set a balancing period (S550). Here, the battery management device can set a preset ratio of the capacity of the batteries to be balanced as a balancing limit, and calculate the balancing period based on the balancing limit and the balancing speed.

[0123] The battery management device can initiate balancing control for the target batteries (S560). For example, the battery management device can control a manual balancing circuit included in the battery system to forcefully discharge the target batteries, thereby reducing the difference in state of charge between the batteries.

[0124] Next, referring to FIG. 6, when balancing control is initiated, the battery management device can monitor whether the balancing period is completed (S610).

[0125] When the balancing period is completed (Y of S610), the battery management device can terminate balancing control (end balancing mode) (S620) and initialize parameters related to balancing control (S630).

[0126] The battery management device can check whether the balancing initiation condition in the high-charge state section is satisfied based on the status information of the batteries during the process of performing balancing control (N of S610) (S640).

[0127] If the battery system enters a high-charge state section and the balancing initiation condition in the high-charge state section is satisfied (Y of S640), the battery management device can re-determine the battery to be balanced (S650).

[0128] If there is one or more batteries to be balanced (Y of S650), the battery management device can initiate balancing control (S560) after setting a balancing period for the re-determined balancing target batteries (S550).

[0129] If the balancing initiation condition in the high charge state section is not satisfied (N of S640), the battery management device can check whether the minimum value among the voltage values ​​of the batteries decreases below a set value (V1; third charge state value) (S660). Here, if it decreases below the set value (Y of S660), the battery management device can stop balancing control (S670).

[0130] If it does not decrease below the third state of charge value (N of S660), the battery management device can check whether the minimum value among the voltage values ​​of the batteries increases above the set value (V2; fourth state of charge value) (S680). Here, if it increases above the set value, the battery management device can release the suspension of balancing control and resume balancing control (S690).

[0131]

[0132] Figure 7 is a block diagram of a battery management device according to an embodiment of the present invention.

[0133] A battery management device (700) according to an embodiment of the present invention is located within a battery system including a plurality of batteries and can manage and control the batteries.

[0134] The battery management device (700) may correspond to a BMS located inside the battery system, or may be implemented as included in the BMS.

[0135] A battery management device (700) may include at least one processor (710), a memory (720) that stores at least one command executed through the processor, and a transmission / reception device (730) that is connected to a network and performs communication.

[0136] The at least one command may include: a command for collecting status information including state of charge values ​​of the batteries; a command for determining whether the state of charge values ​​of one or more of the batteries fall within a predefined low state of charge range or high state of charge range; a command for determining whether a balancing initiation condition defined in correspondence with a current state of charge range is satisfied based on the state information of the batteries; and a command for determining whether to initiate a balancing mode for balancing the batteries based on the determination result.

[0137] The above low charge state section may be defined as a section that is lower than or equal to a preset first charge state value, and the above high charge state section may be defined as a section that is higher than or equal to a preset second charge state value.

[0138] The balancing initiation condition in the above low charge state section may include at least one of a first condition in which the difference between the SOH (State of Health) of the batteries is within a preset threshold range, a second condition in which the temperature of the batteries is higher than the preset threshold temperature, and a third condition in which the idle period of the batteries exceeds the preset first period.

[0139] The balancing initiation condition in the high-charge state section may include at least one of a second condition in which the temperature of the batteries is higher than a preset threshold temperature, and a fourth condition in which the idle period of the batteries exceeds the preset second period.

[0140] The at least one command may further include a command for determining a battery to be balanced based on a difference between the state of charge values ​​of the batteries when the balancing mode is initiated; and a command for performing a predefined balancing control on the battery to be balanced.

[0141] The command for determining the above-mentioned balancing target battery may include a command for determining, as the balancing target battery, a battery having a state of charge value whose difference from the minimum state of charge value is equal to or greater than a preset first threshold value when the balancing mode is initiated in the low state of charge section; and a command for determining, as the balancing target battery, a battery having a state of charge value whose difference from the minimum state of charge value is equal to or greater than a preset second threshold value when the balancing mode is initiated in the high state of charge section.

[0142] Here, the first threshold value may be set to a value greater than the second threshold value.

[0143] The command for performing the above balancing control may include a command for calculating a balancing period based on the capacity of the balancing target battery; and a command for performing the balancing control during the balancing period.

[0144] The command for performing the above balancing control may include a command for monitoring whether, during the process of performing the above balancing control, the charge state value of one or more of the batteries enters the high charge state section.

[0145] The command for performing the above balancing control may include a command for re-determining the balancing target battery when the state of charge value of one or more of the batteries enters the high state of charge section and satisfies a balancing initiation condition in the high state of charge section.

[0146] The command for performing the above balancing control may include a command for monitoring whether, during the process of performing the balancing control, the state of charge value of one or more of the batteries decreases below a predefined third state of charge value; and a command for stopping the balancing control if the state of charge value decreases below the third state of charge value.

[0147] The battery management device (700) may also include an input interface device (740), an output interface device (750), a storage device (760), etc. Each component included in the battery management device (700) may be connected by a bus (770) and communicate with each other.

[0148] Here, the processor (710) may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. The memory (or storage device) may be comprised of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory may be comprised of at least one of a read-only memory (ROM) and a random access memory (RAM).

[0149]

[0150] The operations of the method according to an embodiment of the present invention can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes any type of recording device that stores data readable by a computer system. Furthermore, a computer-readable recording medium can be distributed across network-connected computer systems, allowing the computer-readable program or code to be stored and executed in a distributed manner.

[0151]

[0152] While some aspects of the present invention have been described in the context of a device, they may also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described as a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most significant method steps may be performed by such a device.

[0153] Although the present invention has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. A battery management device located within a battery system including a plurality of batteries, at least one processor; and A memory comprising at least one instruction to be executed via at least one processor, At least one of the above commands, A command to collect status information including the charge status values ​​of the above batteries; A command to determine whether the state of charge value of one or more of the above batteries falls within a predefined low state of charge interval or high state of charge interval; A command for determining whether the balancing initiation condition defined in correspondence with the current charging state section is satisfied based on the status information of the above batteries; and A battery management device, comprising a command for determining whether to initiate a balancing mode for balancing the batteries based on the judgment result.

2. In claim 1, The above low charge state interval is defined as an interval lower than or equal to a preset first charge state value, A battery management device, wherein the above high charge state section is defined as a section equal to or greater than a preset second charge state value.

3. In claim 1, The balancing initiation condition in the above low-charge state section is: A battery management device comprising at least one of a first condition in which a difference between the SOH (State of Health) of the batteries is within a preset threshold range, a second condition in which a temperature of the batteries is higher than or equal to a preset threshold temperature, and a third condition in which a rest period of the batteries exceeds the preset first period.

4. In claim 1, The balancing initiation condition in the above high-charge state section is: A battery management device comprising at least one of a second condition in which the temperature of the batteries is higher than a preset threshold temperature, and a fourth condition in which a rest period of the batteries exceeds the preset second period.

5. In claim 1, At least one of the above commands, When the above balancing mode is initiated, a command for determining a battery to be balanced based on the difference between the charge state values ​​of the batteries; and A battery management device further comprising a command for performing a predefined balancing control on the above balancing target battery.

6. In claim 5, The command to determine the above balancing target battery is: When the balancing mode is initiated in the above low charge state section, a command for determining a battery having a charge state value whose difference from the minimum charge state value is equal to or greater than a preset first threshold value as the balancing target battery; and, When the balancing mode is initiated in the above high-charge state section, a command is included for determining a battery having a charge state value whose difference from the minimum charge state value is equal to or greater than a preset second threshold value as the balancing target battery. A battery management device, wherein the first threshold value is set to a value greater than the second threshold value.

7. In claim 5, The command to perform the above balancing control is: A command for calculating a balancing period based on the capacity of the above balancing target battery; and A battery management device comprising a command for performing the balancing control during the balancing period.

8. In claim 5, The command to perform the above balancing control is: A battery management device, comprising a command for monitoring whether a charge state value of one or more of the batteries enters the high charge state section during the process of performing the above balancing control.

9. In claim 8, The command to perform the above balancing control is: A battery management device, comprising a command to re-determine the battery to be balanced when the state of charge value of one or more of the batteries enters the high state of charge section and satisfies a balancing initiation condition in the high state of charge section.

10. In claim 5, The command to perform the above balancing control is: A command for monitoring whether, during the process of performing the above balancing control, the charge state value of one or more of the batteries decreases below a predefined third charge state value; and A battery management device comprising a command to stop said balancing control when the state of charge decreases below a third state of charge value.

11. A battery balancing method using a battery management device that manages multiple batteries, A step of collecting status information including charge status values ​​of the above batteries; A step of determining whether the state of charge value of one or more of the above batteries falls within a predefined low state of charge range or high state of charge range; A step of determining whether the balancing initiation condition defined in correspondence with the current charging state section is satisfied based on the status information of the above batteries; and A battery balancing method, comprising a step of determining whether to initiate a balancing mode for balancing the batteries based on the judgment result.

12. In claim 11, The above low charge state interval is defined as an interval lower than or equal to a preset first charge state value, A battery balancing method, wherein the above high charge state section is defined as a section equal to or greater than a preset second charge state value.

13. In claim 11, The balancing initiation condition in the above low-charge state section is: A battery balancing method comprising at least one of a first condition in which a difference between the SOH (State of Health) of the batteries is within a preset threshold range, a second condition in which a temperature of the batteries is higher than or equal to a preset threshold temperature, and a third condition in which a rest period of the batteries exceeds the preset first period.

14. In claim 11, The balancing initiation condition in the above high-charge state section is: A battery balancing method comprising at least one of a second condition in which the temperature of the batteries is higher than a preset threshold temperature, and a fourth condition in which the idle period of the batteries exceeds the preset second period.

15. In claim 11, When the above balancing mode is initiated, a step of determining a battery to be balanced based on the difference between the charge state values ​​of the batteries; and A battery balancing method further comprising a step of performing a predefined balancing control on the above balancing target battery.

16. In claim 15, The step of determining the battery to be balanced is as follows: When the balancing mode is initiated in the above low charge state section, a step of determining a battery having a charge state value whose difference from the minimum charge state value is equal to or greater than a preset first threshold value as the balancing target battery; and, When the balancing mode is initiated in the above high-charge state section, a step is included for determining a battery having a charge state value whose difference from the minimum charge state value is equal to or greater than a preset second threshold value as the balancing target battery. A battery balancing method, wherein the first threshold value is set to a value greater than the second threshold value.

17. In claim 15, The steps for performing the above balancing control are: A step of calculating a balancing period based on the capacity of the above balancing target battery; and A battery balancing method, comprising the step of performing the balancing control during the balancing period.

18. In claim 15, The steps for performing the above balancing control are: A battery balancing method, comprising a step of monitoring whether a charge state value of one or more of the batteries enters the high charge state section during the process of performing the above balancing control.

19. In claim 18, The steps for performing the above balancing control are: A battery balancing method, comprising the step of re-determining the battery to be balanced when the state of charge value of one or more of the batteries enters the high state of charge section and satisfies a balancing initiation condition in the high state of charge section.

20. In claim 15, The steps for performing the above balancing control are: In the process of performing the above balancing control, a step of monitoring whether the charge state value of one or more of the batteries decreases below a predetermined third charge state value; and A battery balancing method, comprising the step of stopping the balancing control when the state of charge decreases below a third state of charge value.

21. Multiple batteries; and A battery management device is included that collects status information of the batteries and manages and controls the batteries based on the collected status information. The above battery management device, A battery system which determines whether the state of charge value of one or more of the batteries falls within a predefined low state of charge range or high state of charge range, determines whether a balancing initiation condition defined in correspondence with a current state of charge range is satisfied based on state information of the batteries, and determines whether to initiate a balancing mode for balancing the batteries based on the determination result.

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