Battery control device for handling communication abnormality and energy storage system including the same

Abstract

An energy storage system according to one embodiment of the present invention may include a plurality of BMSs each corresponding to a plurality of batteries, and an upper control device that collects status information regarding the plurality of batteries from the plurality of BMSs and monitors or controls the plurality of batteries based on the collected status information. Here, when the upper control device does not receive status information of the first battery from the first BMS due to a communication abnormality, it can select one or more second batteries from the batteries connected in parallel with the first battery based on pre-recorded battery history information, and estimate status information of the first battery based on the status information of the one or more second batteries.

Description

[Technical Field]

[0001] This application claims the benefit of the filing dates of Korean Patent Application No. 10-2022-0122240 filed with the Korean Intellectual Property Office on September 27, 2022, and Korean Patent Application No. 10-2023-0018665 filed with the Korean Intellectual Property Office on February 13, 2023, and all of the contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery control device and an energy storage system including the same, and more particularly to a battery control device and an energy storage system including the same that can stably operate the energy storage system even when a loss of communication (LOC) state occurs. [Background technology]

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

[0004] Secondary batteries are used in systems in the form of assemblies such as battery modules in which a number of battery cells are connected in series or parallel, or battery packs in which battery modules are connected in series or parallel, depending on the requirements of the system.

[0005] The integrated control device (or upper control device) of an energy storage system monitors and controls battery assemblies based on battery status information, such as State of Charge (SOC), collected from the battery assemblies. If a communication error (LOC) occurs in a specific battery assembly, the integrated control device is unable to receive battery status information from the battery assembly, making it impossible to control the energy storage system. In this case, the operation of the energy storage system must be stopped for maintenance work on the communication error module. Meanwhile, in an energy storage system using LFP (lithium iron phosphate) batteries, the battery assemblies must be fully charged or fully discharged so that they can be connected in parallel when all battery assemblies have the same SOC.

[0006] To solve these problems of the conventional technology, an appropriate control technique is needed that can stably operate the energy storage system without shutting down when a communication abnormality occurs in a specific battery assembly. Summary of the Invention [Problem to be solved by the invention]

[0007] In order to solve the above problems, an object of the present invention is to provide a battery control device that can stably operate an energy storage system without stopping it when a communication abnormality occurs in a specific battery assembly.

[0008] Another object of the present invention to solve the above problems is to provide a battery control method using such a battery control device.

[0009] Another object of the present invention to solve the above problems is to provide an energy storage system including such a battery control device. [Means for solving the problem]

[0010] To achieve the above object, an energy storage system according to one embodiment of the present invention may include a plurality of BMSs provided corresponding to a plurality of batteries, respectively, and a host control device that collects status information on the plurality of batteries from the plurality of BMSs and monitors or controls the plurality of batteries based on the collected status information.

[0011] Here, when the upper control device does not receive status information of the first battery from the first BMS due to a communication abnormality, it can select one or more second batteries from among the batteries connected in parallel with the first battery based on pre-recorded battery history information, and estimate status information of the first battery based on the status information of the one or more second batteries.

[0012] The upper control device can monitor or control the plurality of batteries using the estimated status information as status information of the first battery without stopping operation of the energy storage system even if status information of the first battery is not received from the first BMS.

[0013] The upper control device may record the estimated state information as state information of the first battery during a period in which state information of the first battery is not received.

[0014] When the SOC (State of Charge) of the first battery is not received from the first BMS, the upper control device can select multiple second batteries, calculate the average or median SOC value for the selected second batteries, and estimate the calculated value as the SOC of the first battery.

[0015] The upper control device can select the second battery using the adjacent distance from the first battery and history information regarding one or more of the battery's SOC, temperature value, and cumulative charge / discharge amount.

[0016] The upper control device can compare the history information of the first battery with the history information of the top N batteries (N is a predetermined natural number greater than or equal to 2) that are closest to the first battery, calculate the similarity with the first battery, and determine the top M batteries (M is a predetermined natural number greater than or equal to 2) that have the highest similarity as the second battery.

[0017] The upper control device can exclude from the comparison any battery among the N batteries that has a failure history recorded within a predetermined period.

[0018] The upper control device is After the M second batteries are selected, if a failure occurs in a specific battery among the second batteries, the failed battery can be replaced with a battery having a lower similarity, and the second batteries can be updated.

[0019] If the SOC of the first battery is not received, the upper control device may check the latest SOC of the first battery or one or more of the N batteries and check whether the checked latest SOC is within a threshold SOC range predefined as an SOC estimation impossible interval. Here, if the checked latest SOC is outside the threshold SOC range, the upper control device may determine the top M batteries among the N batteries that have a high similarity to history information regarding the SOC of the first battery as the second battery.

[0020] If there are more than M upper batteries having a high similarity to the historical information regarding the SOC of the first battery, the upper control device can determine M second batteries based on the similarity between the historical information regarding one or more of temperature values ​​and cumulative charge / discharge amounts.

[0021] If the confirmed latest SOC is within the threshold SOC range, the upper control device can determine the top M batteries that have a high similarity to historical information regarding one or more of the temperature value and cumulative charge / discharge amount of the first battery as the second battery.

[0022] The upper control device may determine the top M batteries having a high similarity to the history information on the temperature value of the first battery as the second battery. In this case, if the number of top batteries having a high similarity exceeds M, the upper control device may determine the M second batteries based on the similarity between the history information on the accumulated charge / discharge amounts.

[0023] In order to achieve the above-mentioned other object, a battery control device according to one embodiment of the present invention is a battery control device that works in conjunction with a plurality of BMSs that are respectively provided corresponding to a plurality of batteries, and can include at least one processor and a memory that stores at least one instruction that is executed through the at least one processor.

[0024] Here, the at least one instruction may include an instruction to collect status information on the plurality of batteries from the plurality of BMSs and monitor or control the plurality of batteries based on the collected status information, an instruction to select one or more second batteries from among the batteries connected in parallel with the first battery based on pre-recorded battery history information when status information of the first battery is not received from the first BMS due to a communication abnormality, and an instruction to estimate status information of the first battery based on status information of the one or more second batteries.

[0025] The at least one instruction may further include an instruction to monitor or control the plurality of batteries using the estimated status information as status information of the first battery without ceasing operation of the energy storage system even if status information of the first battery is not received from the first BMS.

[0026] The instruction to estimate the state information of the first battery may further include an instruction to record the estimated state information as state information of the first battery during a period when state information of the first battery is not received.

[0027] The instruction to estimate the state information of the first battery may include an instruction to calculate an average or median value of the SOC for multiple second batteries, and an instruction to estimate the calculated value as the SOC of the first battery.

[0028] The instruction to select the one or more second batteries may include an instruction to select the second battery using the proximity distance to the first battery and historical information regarding one or more of the battery's SOC, temperature value, and cumulative charge / discharge amount.

[0029] The instruction to select one or more second batteries may include an instruction to compare history information of the first battery with history information of the top N batteries (N is a predetermined natural number of 2 or more) that are closest to the first battery, and calculate the similarity with the first battery, and an instruction to determine the top M batteries (M is a predetermined natural number of 2 or more) that have the highest similarity as the second battery.

[0030] The instruction to select one or more second batteries may include an instruction to exclude from the comparison any battery among the N batteries that has a history of failure recorded within a predetermined period of time.

[0031] The at least one instruction may further include an instruction to, if a failure occurs in a specific battery among the second batteries after the M second batteries are selected, replace the failed battery with a battery having a lower similarity and update the second battery.

[0032] The instruction to select the one or more second batteries may include an instruction to confirm the latest SOC of the first battery or one or more of the N batteries if the SOC of the first battery is not received, an instruction to confirm whether the confirmed latest SOC is within a threshold SOC range predefined as an SOC estimation impossible interval, and an instruction to determine, if the confirmed latest SOC is outside the threshold SOC range, the top M batteries among the N batteries that have a high similarity to historical information regarding the SOC of the first battery as the second batteries.

[0033] The instruction to select one or more second batteries may further include an instruction to determine M second batteries based on the similarity between history information regarding one or more of a temperature value and a cumulative charge / discharge amount when there are more than M top batteries having a high similarity to history information regarding the SOC of the first battery.

[0034] The instruction to select the one or more second batteries may include an instruction to determine, if the confirmed latest SOC is within the threshold SOC range, the top M batteries having a high similarity to history information regarding one or more of the temperature value and cumulative charge / discharge amount of the first battery as the second batteries.

[0035] The instruction to select one or more second batteries may include an instruction to determine the top M batteries having a high similarity with historical information regarding the temperature value of the first battery as the second batteries, and if the number of top batteries having a high similarity exceeds M, an instruction to determine the M second batteries based on the similarity between historical information regarding cumulative charging and discharging amounts.

[0036] To achieve yet another object of the present invention, a battery control method according to one embodiment of the present invention is a battery control method using a battery control device that works in conjunction with a plurality of BMSs that correspond to a plurality of batteries, and includes the steps of collecting status information about the plurality of batteries from the plurality of BMSs and monitoring or controlling the plurality of batteries based on the collected status information, selecting one or more second batteries from among the batteries connected in parallel with the first battery based on pre-recorded battery history information when status information about a first battery is not received from a first BMS due to a communication abnormality, and estimating status information about the first battery based on the status information of the one or more second batteries.

[0037] The battery control method may further include a step of monitoring or controlling the plurality of batteries using the estimated status information as status information of the first battery without ceasing operation of the energy storage system even if status information of the first battery is not received from the first BMS.

[0038] The step of estimating the state information of the first battery may further include a step of recording the estimated state information as state information of the first battery during a period in which state information of the first battery is not received.

[0039] The step of estimating the state information of the first battery may include a step of calculating an average or median value of the SOC for a plurality of second batteries, and a step of estimating the calculated value as the SOC of the first battery.

[0040] The step of selecting the one or more second batteries may include selecting the second batteries using the proximity distance to the first battery and historical information regarding one or more of the battery's SOC, temperature value, and cumulative charge / discharge amount.

[0041] The step of selecting one or more second batteries may include a step of comparing history information of the first battery with history information of the top N batteries (N is a predetermined natural number of 2 or more) that are closest to the first battery to calculate the similarity with the first battery, and a step of determining the top M batteries (M is a predetermined natural number of 2 or more) that have the highest similarity as the second batteries.

[0042] The step of selecting one or more second batteries may include the step of excluding from the comparison any battery among the N batteries that has a history of failure recorded within a predetermined period of time.

[0043] The battery control method may further include a step of, after the M second batteries are selected, if a failure occurs in a specific battery among the second batteries, replacing the failed battery with a battery having a lower similarity and updating the second batteries.

[0044] The step of selecting the one or more second batteries may include the steps of: if the SOC of the first battery is not received, checking the latest SOC of the first battery or one or more of the N batteries; checking whether the checked latest SOC is within a threshold SOC range predefined as an SOC estimation impossible interval; and if the checked latest SOC is outside the threshold SOC range, determining the top M batteries of the N batteries that have a high similarity to historical information regarding the SOC of the first battery as the second batteries.

[0045] The step of selecting one or more second batteries may further include a step of determining M second batteries based on the similarity between the history information regarding one or more of a temperature value and a cumulative charge / discharge amount when the number of top batteries having a high similarity to the history information regarding the SOC of the first battery exceeds M.

[0046] The step of selecting the one or more second batteries may include a step of determining, when the confirmed latest SOC is within the threshold SOC range, the top M batteries having a high similarity to historical information regarding one or more of the temperature value and cumulative charge / discharge amount of the first battery as the second batteries.

[0047] The step of selecting one or more second batteries may include a step of determining the top M batteries having a high similarity with historical information regarding the temperature value of the first battery as the second batteries, and if the number of top batteries having a high similarity exceeds M, a step of determining the M second batteries based on the similarity between the historical information regarding the accumulated charge / discharge amounts. [Effects of the Invention]

[0048] According to the above-described embodiment of the present invention, even if a communication abnormality occurs in a specific battery assembly, the energy storage system can continue to operate stably without being stopped. [Brief explanation of the drawings]

[0049] [Figure 1] FIG. 1 is a block diagram of a typical energy storage system. [Figure 2] The charging characteristic curve of an LFP battery is shown. [Figure 3] FIG. 1 is a flow diagram of a general method of operating an energy storage system when a communication anomaly occurs. [Figure 4] FIG. 1 is a block diagram of an energy storage system according to an embodiment of the present invention. [Figure 5] FIG. 2 is a flowchart of a battery control method for the battery control device according to the embodiment of the present invention. [Figure 6] FIG. 2 is a flow diagram of a reference battery selection method according to an embodiment of the present invention. [Figure 7] 3 is a look-up table for explaining a reference battery selection method according to an embodiment of the present invention. [Figure 8] 1 is a block diagram of a battery control device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0050] Although the present invention can be modified in various ways and can have various embodiments, specific embodiments are illustrated in the drawings and will be described in detail below. It is not intended to limit the present invention to the specific embodiments, but it should be understood that the present invention includes all modifications, equivalents, and alternatives that fall within the spirit and technical scope of the present invention. Similar reference numerals are used to refer to similar components throughout the description of the drawings.

[0051] Terms such as "first," "second," "A," and "B" may be used to describe various components, but the components should not be limited by these terms. These terms are used only to distinguish one component from another. For example, a first component can be designated as a second component, and similarly, a second component can be designated as a first component, without departing from the scope of the present invention. The term "and / or" includes a combination of multiple associated listed items or any one of multiple associated listed items.

[0052] When a component is referred to as being "coupled" or "connected" to another component, it is understood that the component may be directly coupled or connected to the other component, but that there may be other components in between. Conversely, when a component is referred to as being "directly coupled" or "directly connected" to another component, it is understood that there are no other components in between.

[0053] The terms used in this specification are merely used to describe particular embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly indicates otherwise. It should be understood that the terms "comprise" or "have" and the like are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and do not preclude the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0054] Unless otherwise specified, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this invention belongs. Terms as defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted as idealized or overly formal unless expressly defined herein.

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

[0056] A battery cell is the smallest unit that serves to store power, and a battery module refers to an assembly of multiple battery cells that are electrically connected together.

[0057] A battery rack refers to a system with the smallest single structure that can be monitored and controlled through a BMS (Battery Management System) by connecting modules set by a battery manufacturer in series / parallel, and may be composed of multiple battery modules and one BPU or protection device.

[0058] A battery bank can refer to a large-scale collection of battery rack systems consisting of multiple racks connected in parallel. The battery bank BMS can monitor and control the rack BMS (RBMS) for each battery rack.

[0059] A battery assembly refers to an assembly including a plurality of electrically connected battery cells that is employed in a specific system or device and functions as a power supply source. Here, the battery assembly may refer to a battery module, a battery pack, a battery rack, a battery bank, or the like, but the scope of the present invention is not limited to these.

[0060] A BSC (Battery System Controller) is a device that performs top-level control for a battery system including a battery system in units of a battery bank, and may also be used as a control device in a battery system with a multi-bank level structure.

[0061] 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 [%].

[0062] FIG. 1 is a block diagram of a typical energy storage system.

[0063] The smallest unit of a battery that stores power in an energy storage system (ESS) is typically a battery cell. A series / parallel combination of battery cells constitutes a battery module, and a number of battery packs can constitute a battery rack. That is, a battery rack is a series / parallel combination of battery packs and can be the smallest unit of a battery system. Here, a battery pack can also be called a battery module depending on the device or system in which the battery is used.

[0064] 1, one battery rack 10 can include multiple battery modules and one BPU or protection device. The battery rack can be monitored and controlled through a Rack BMS (RBMS). The RBMS monitors the current, voltage, and temperature of each battery rack it manages, calculates the SOC of the battery based on the monitoring results, and controls charging and discharging.

[0065] Meanwhile, a Battery Protection Unit (BPU) is a device for protecting batteries from abnormal current and fault current in each battery rack. The BPU can include a main contactor (MC), fuse, circuit breaker (CB), or disconnect switch (DS). The BPU can control the battery system in each rack by controlling the on / off of the main contactor through the control of the RBMS. The BPU can also protect the battery from short-circuit current using a fuse when a short circuit occurs. As such, conventional battery systems may be controlled through protection devices such as a BPU and switchgear.

[0066] Meanwhile, a BSC 20 is provided in each battery section, which includes a number of batteries and peripheral circuits and devices, and can monitor and control control targets such as voltage, current, temperature, and circuit breakers. The BSC is the highest-level control device in a battery system, including a bank-based battery system including multiple battery racks, and can also be used as a control device in a battery system with a multiple-bank structure.

[0067] In addition, a power conversion system (PCS) 40 provided for each battery section is a device that actually charges and discharges based on a charge / discharge command from the EMS 30, and can be configured to include a power conversion unit (DC / AC inverter) and a controller. Meanwhile, the output of each BPU may be connected to a power generation device (e.g., a solar power generation device) and the PCS 40 via a DC bus, and the PCS 40 may be connected to the grid. In addition, the EMS (Energy Management System) 30 or PMS (Power Management System) manages the ESS system as a whole.

[0068] Figure 2 shows the charging characteristic curve of an LFP battery.

[0069] Carbon materials are primarily used as the negative electrode active material for lithium secondary batteries, and lithium-containing cobalt oxide (LiCoO2) is primarily used as the positive electrode active material, although lithium-containing manganese oxide (LiMnO2, LiMn2O4, etc.) and lithium-containing nickel oxide (LiNiO2) are also being considered for use.

[0070] In recent years, lithium iron phosphate (LiFePO4)-based compounds have been used as the positive electrode active material in lithium secondary batteries. LFP (Lithium Iron Phosphate) batteries, which use lithium iron phosphate as the positive electrode active material, are superior to other batteries in terms of thermal stability and cost efficiency.

[0071] During the operation of an energy storage system, balancing control or charge / discharge control may be performed based on the SOC of the battery. To calculate the SOC of the battery, a commonly used method is to measure the open-circuit voltage of the battery and estimate the SOC of the battery based on the measured open-circuit voltage.

[0072] FIG. 2 is a charging characteristic curve of an LFP battery, showing the relationship between the open circuit voltage (OCV) measured during the charging process of the LFP battery and the SOC.

[0073] Referring to Figure 2, the charging characteristic curve of an LFP battery has a voltage plateau in the SOC range of approximately 10% to approximately 90%. For an LFP battery with such a plateau characteristic, it is difficult to accurately estimate the SOC in the plateau range, and accurate estimation is possible only in the non-plateau range (e.g., the range where the SOC is 90% or more or the range where the SOC is 10% or less). In other words, a battery system using an LFP battery can accurately estimate the SOC only in a very limited SOC range.

[0074] FIG. 3 is a flow diagram of a general method of operating an energy storage system when a communication anomaly occurs.

[0075] A host controller (e.g., BSC or EMS) of the energy storage system can monitor and control the battery racks based on the SOC collected from the RBMS. If a loss of communication (LOC) occurs in a specific battery rack (S310), the host controller will no longer be able to receive the SOC from the RBMS of the corresponding battery rack (the rack where the LOC occurred).

[0076] If the SOC of the battery rack where the communication abnormality occurred is leaked, the operation of the energy storage system becomes impossible, and the operation of the energy storage system is stopped (S320). In order to resolve the communication abnormality, the battery rack is opened and inspection and repair work is carried out (S330).

[0077] When the communication abnormality of the corresponding battery rack is resolved, the corresponding battery rack may be reconnected to the energy storage system. Here, for stable operation of the energy storage system, the corresponding battery rack needs to be reconnected to the energy storage system when the SOC between the corresponding battery rack and other battery racks is very similar.

[0078] In the case of a battery rack using LFP batteries, accurate SOC estimation is possible only in uneven sections (e.g., sections where the SOC is 90% or more or 10% or less), so the battery rack must be fully charged or fully discharged (S340). After that, once the battery rack is electrically connected, the energy storage system can be restarted (S350).

[0079] That is, if a communication abnormality occurs in a specific battery rack during the operation of the energy storage system, the entire system is shut down and a full charge or full discharge process must be performed, which takes a considerable amount of time before the system can be restarted.

[0080] The present invention has been devised to solve these problems, and relates to a battery control device and an energy storage system including the same, which can operate stably without stopping the energy storage system even if a communication abnormality occurs in a specific battery assembly.

[0081] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0082] FIG. 4 is a block diagram of an energy storage system according to an embodiment of the present invention.

[0083] Referring to FIG. 4, an energy storage system according to an embodiment of the present invention may include a plurality of batteries 100 and a plurality of BMSs (Battery Management Systems) 200 provided in correspondence with each of the plurality of batteries to manage and control the corresponding batteries.

[0084] The plurality of batteries 100 may be electrically connected in parallel with one another.

[0085] In the present invention, the battery 100 may refer to a battery assembly, that is, the battery 100 according to the present invention may correspond to a battery module, a battery pack, a battery rack, or a battery bank.

[0086] In an embodiment, the battery 100 may correspond to a battery assembly including one or more battery cells (e.g., LFP battery cells) having at least a partial voltage plateau in a charging characteristic curve.

[0087] The BMS 200 can collect status information about the corresponding battery 100 and perform predetermined control operations based on the collected status information to manage and control the corresponding battery 100. Here, the BMS 200 can control the charging and discharging of the battery and diagnose whether or not there is a failure in the battery cell based on the battery status information.

[0088] Each of the multiple BMSs 200 may be connected to the upper control device 300 via a network, configured to transmit battery status information such as the battery's SOC to the upper control device 300, and receive control commands from the upper control device 300 to operate.

[0089] The upper control device 300 can collect status information on the plurality of batteries from the plurality of BMSs 200 and monitor or control the plurality of batteries based on the collected status information. Here, the upper control device 300 can correspond to a BSC (Battery System Controller), an EMS (Energy Management System), or a PMS (Power Management System).

[0090] When a communication abnormality occurs in a specific battery (first battery) and the upper control device 300 is unable to receive status information from the BMS (first BMS) corresponding to the battery, the upper control device 300 may be configured to select one or more reference batteries (second batteries) that are estimated to have a similar status to the battery (first battery), estimate status information of the battery with the communication abnormality (first battery) based on the status information of the selected one or more reference batteries (second batteries), and operate the energy system.

[0091] That is, even if status information is not received from a specific BMS (first BMS), the upper control device 300 may be configured to estimate status information of the battery with communication abnormality (first battery) based on status information of one or more selected reference batteries (second batteries) without ceasing operation of the energy storage system, and to monitor or control multiple batteries by using the estimated status information as status information of the first battery.

[0092] In an embodiment, the upper control device 300 can select multiple second batteries from among the batteries connected in parallel with the first battery, based on battery history information stored in the memory device 310. For example, the upper control device 300 can select multiple batteries having an operating pattern similar to that of the first battery, using history information stored in the memory device 310 regarding one or more of the SOC, cumulative charge / discharge amount, and temperature value for the multiple batteries connected in parallel with the first battery, and determine the selected multiple batteries as the second batteries.

[0093] FIG. 5 is a flowchart of a battery control method of the battery control device according to the embodiment of the present invention.

[0094] The control method shown in Fig. 5 can be performed by a battery control device that operates in conjunction with a plurality of BMSs that are provided corresponding to a plurality of batteries. Here, the battery control device is a higher-level control device for the plurality of BMSs, and can correspond to, for example, a BSC, an EMS, or a PMS.

[0095] The battery control device collects status information about the batteries from the BMSs (S510), where the status information may include one or more of the battery's SOC, voltage, current, charge / discharge amount, and temperature.

[0096] The battery control device can monitor or control the plurality of batteries based on the collected status information (S520). For example, the battery control device can control charging and discharging of each of the batteries based on the collected status information.

[0097] The battery control device can detect whether a communication abnormality has occurred in a specific battery among the plurality of batteries (S530). Here, if the battery control device does not receive status information from a specific battery, it can determine that a communication abnormality has occurred in the corresponding battery.

[0098] If a communication abnormality occurs in a specific battery (first battery) and status information is not received from the BMS (first BMS) that manages the battery (Y in S530), the battery control device can determine one or more reference batteries (second batteries) for the battery (first battery) with the communication abnormality (S540). In an embodiment, multiple reference batteries (second batteries) may be determined.

[0099] The battery control device can select one or more second batteries based on battery history information stored in the storage device.

[0100] The battery control device can determine a second battery from among the plurality of batteries using history information for a predetermined period. Here, the history information can include history data related to one or more of SOC, temperature, and cumulative charge / discharge amount. For example, the battery control device can select a second battery from among the plurality of batteries having an operating pattern similar to that of the first battery using history data related to SOC, temperature, or cumulative charge / discharge amount from the time of the communication abnormality up to three days prior.

[0101] The battery control device can compare history information of a first battery with history information of a battery connected in parallel with the first battery to calculate a similarity to the first battery and determine multiple second batteries based on the calculated similarity. For example, the battery control device can calculate a difference between state values ​​(e.g., SOC, temperature value, or accumulated charge / discharge amount) for each point in time included in the history data, accumulate the calculated difference values, and calculate a similarity based on the accumulated difference values. Here, the lower the accumulated difference value, the higher the calculated similarity.

[0102] In an embodiment, the battery control device compares history information of a first battery with history information of the top N batteries (N is a predetermined natural number equal to or greater than 2) that are closest to the first battery, calculates the similarity to the first battery, and determines a second battery based on the calculated similarity. Here, the battery control device can determine the top M batteries (M is a predetermined natural number equal to or greater than 2) that are most similar to the first battery as the second battery. For example, the battery control device can calculate the similarity for the top six batteries that are closest to the first battery, and select the top three batteries with the highest similarity as the second battery.

[0103] In an embodiment, the battery control device may exclude from comparison any battery connected in parallel with the first battery that has a history of failures recorded within a predetermined period. For example, any battery that has a history of voltage abnormalities or the detection of a fire event recorded within the period from the time of the communication abnormality occurring up to three days prior may be excluded from candidates for the second battery.

[0104] The battery control device can estimate the state information of the first battery based on the state information of the selected second battery (S550).

[0105] When there is one second battery, the battery control device can estimate the state information of the second battery as the state information of the first battery.

[0106] If there are multiple second batteries, the battery control device can calculate an average or median value of the status information for the selected second batteries and estimate the calculated value as the status information for the first battery. For example, the battery control device can estimate an average or median value of the SOC for each of the selected second batteries as the SOC of the first battery.

[0107] The battery control device can monitor or control the plurality of batteries using the state information estimated based on the state information of the first battery as state information of the first battery without stopping operation of the energy storage system (S560). For example, the battery control device can operate the energy storage system using the SOC of the second battery as the SOC of the first battery.

[0108] The battery control device can record, in the storage device, the state information estimated based on the state information of the second battery as the state information of the first battery during a period in which the state information of the first battery is not received.

[0109] In an embodiment, after a plurality of second batteries are selected, if a failure occurs in a specific battery among the second batteries, the battery control device can replace the failed battery with a battery having a lower similarity and update the second battery. For example, if a communication abnormality occurs in Rack #1, the top three racks (Racks #2 to #4) with the highest similarity among the top six racks (Racks #2 to #7) adjacent to Rack #1 are selected as reference racks, and the average SOC of Racks #2 to #4 is used as the SOC of Rack #1 to operate the energy storage system. If a failure occurs in Rack #2 during the operation of the energy storage system, Rack #5, which has the next highest similarity after Racks #2 to #4, may be substituted as the reference battery.

[0110] The battery control device can check whether the communication abnormality state related to the first battery has been resolved. Here, if the battery control device receives status information from the first BMS, it can determine that the communication abnormality state related to the first battery has been resolved.

[0111] When the communication abnormality state regarding the first battery is cleared, the battery control device does not use the estimated status information as status information for the first battery, but can monitor and control the batteries using the status information for each of the batteries.

[0112] FIG. 6 is a flow diagram of a reference battery selection method according to an embodiment of the present invention.

[0113] The battery control device can determine a plurality of second batteries among the plurality of batteries connected in parallel with the first battery using history information for a predetermined period of time, where the history information may include history data on one or more of SOC, temperature value, and cumulative charge / discharge amount.

[0114] In an embodiment, the battery control device can determine the second battery based on a predefined priority for each of the adjacent distance from the first battery, the SOC immediately before the communication abnormality occurred, and the history data items, where the priority may be predefined in the order of SOC, temperature, and cumulative charge / discharge amount.

[0115] Referring to Figure 6, if a communication abnormality occurs in a specific battery (first battery) and status information is not received from the BMS (first BMS) that manages the battery, the battery control device can determine that a communication abnormality has occurred in the first battery.

[0116] The battery control device can select the top N batteries (N is a predetermined natural number equal to or greater than 2) that are closest to the first battery from among the batteries connected in parallel with the first battery (S610). Here, the battery control device can calculate the distance to the first battery based on the identifiers of each battery and the arrangement information between the batteries stored in the storage device, and select the top N batteries that are closest in distance.

[0117] The battery control device can check the latest SOC of the first battery or the selected N batteries (S620). For example, if a communication abnormality occurs, the battery control device can check the SOC of each battery that was last recorded in the storage device.

[0118] The battery control device may check whether the latest confirmed SOC is within a threshold SOC range, which is predefined as a range where SOC estimation is not possible (S630). Here, the threshold SOC range may be predefined as a SOC range where the amount of change in voltage relative to the amount of change in SOC is equal to or less than a predetermined threshold in a curve corresponding to the SOC and voltage of the battery, and may be defined as, for example, more than 10 and less than 90.

[0119] If the confirmed latest SOC is outside the threshold SOC range (N in S630), the battery control device can compare historical information regarding the SOC between the first battery and the selected N batteries (S640) to determine the top M batteries with high similarity. For example, if the latest SOC of the first battery is outside the threshold SOC range (i.e., if a communication abnormality occurs in the first battery when the SOC of the first battery is in a state where it is possible to estimate the SOC), the battery control device can compare historical information of the SOC predefined as the first comparison item to determine multiple second batteries.

[0120] Here, if there are M batteries that have a high degree of similarity with the history information regarding the SOC of the first battery (N in S650), the M batteries may be determined to be the second battery (S660).

[0121] On the other hand, if there are more than M higher-ranking batteries having a high similarity to the history information regarding the SOC of the first battery (Y in S650), the battery control device may determine M batteries among the corresponding batteries that have a high similarity to the history information regarding one or more of the temperature value and the accumulated charge / discharge amount of the first battery as the second battery (S670-690). That is, if the M reference batteries are not determined based on the same similarity as a result of comparing the first comparison item with the predefined SOC history, the battery control device may determine M reference batteries by sequentially comparing subsequent history items.

[0122] For example, if there are more than M batteries having the highest similarity to the history information regarding the SOC of the first battery, the battery control device may compare history information regarding temperature values ​​between the first battery and other batteries (second order) (S670) to determine M batteries having the highest similarity. If there are more than M batteries having the highest similarity to the history information regarding the temperature values ​​of the first battery (Y in S680), the battery control device may compare history information regarding accumulated charge / discharge amounts between the first battery and other batteries (third order) (S690) to determine M batteries having the highest similarity. If M batteries are selected, the reference battery selection process may be completed (S660). On the other hand, if M batteries cannot be selected even after comparing the accumulated charge / discharge amounts, the top M batteries having the same similarity and closest to the first battery may be finally selected as the second battery.

[0123] If the confirmed latest SOC is within the threshold SOC range in S630 (Y in S630), the battery control device can determine the top M batteries that have a high similarity to the history information regarding one or more of the temperature value and cumulative charge / discharge amount of the first battery as the second battery (S670-690). For example, if the latest SOC of the first battery is within the threshold SOC range (i.e., if a communication abnormality occurs in the first battery in a state where SOC estimation is not possible), the battery control device can determine the reference battery by sequentially comparing history items of subsequent orders without comparing the first-ranked battery with the predefined SOC history information.

[0124] FIG. 7 is a look-up table for explaining a reference battery selection method according to an embodiment of the present invention.

[0125] In an embodiment, a comparison priority for each of the SOC estimation impossible section and the history items for selecting a reference battery may be predefined. Here, the battery control device can select a reference battery for a battery with communication abnormality based on the SOC estimation impossible section and the comparison priority stored in the storage device.

[0126] For example, referring to FIG. 7, the SOC estimation impossible interval (threshold SOC range) may be defined as more than 10 and less than 90.

[0127] The history items to be compared may include SOC, average temperature, maximum temperature, minimum temperature, cumulative charge / discharge current (Ah), and cumulative charge / discharge energy (Wh). Here, the comparison priority of the history items may be defined in the order of SOC, average temperature, maximum temperature, minimum temperature, cumulative charge / discharge current (Ah), and cumulative charge / discharge energy (Wh).

[0128] When the battery voltages are predefined as in the table of FIG. 7, the battery control device can determine the reference battery (second battery) as follows:

[0129] If the latest SOC of the first battery is outside the threshold SOC range, the battery control device can sequentially compare historical information regarding the SOC, average temperature, maximum temperature, minimum temperature, cumulative charge / discharge current (Ah), and cumulative charge / discharge energy (Wh) until a single reference battery is derived.

[0130] If the latest SOC of the first battery is within the threshold SOC range, the battery control device can sequentially compare historical information regarding the average temperature, maximum temperature, minimum temperature, cumulative charge / discharge current (Ah), and cumulative charge / discharge energy (Wh) until a single reference battery is derived.

[0131] On the other hand, if a single battery is not selected as a result of the comparison of the history items, the battery that is closest to the first battery among the batteries having the same similarity may be finally selected as the second battery.

[0132] FIG. 8 is a block diagram of a battery control device according to an embodiment of the present invention.

[0133] The battery control device 800 according to an embodiment of the present invention may correspond to a host control device located in an energy storage system and linked to a plurality of BMSs provided corresponding to a plurality of batteries, respectively. For example, the battery control device 800 may correspond to a BSC, an EMS, or a PMS, or may be embodied as being included in any one of them.

[0134] The battery control device 800 may include at least one processor 810, a memory 820 that stores at least one instruction executed by the processor, and a transceiver 830 that is connected to a network for communication.

[0135] The at least one instruction may include an instruction to collect status information on the plurality of batteries from the plurality of BMSs and monitor or control the plurality of batteries based on the collected status information, an instruction to select one or more second batteries from among the batteries connected in parallel with the first battery based on pre-recorded battery history information when status information of the first battery is not received from the first BMS due to a communication abnormality, and an instruction to estimate status information of the first battery based on status information of the one or more second batteries.

[0136] The at least one instruction may further include an instruction to monitor or control the plurality of batteries using the estimated status information as status information of the first battery without ceasing operation of the energy storage system even if status information of the first battery is not received from the first BMS.

[0137] The instruction to estimate the state information of the first battery may further include an instruction to record the estimated state information as state information of the first battery during a period when state information of the first battery is not received.

[0138] The instruction to estimate the state information of the first battery may include an instruction to calculate an average or median value of the SOC for multiple second batteries, and an instruction to estimate the calculated value as the SOC of the first battery.

[0139] The instruction to select the one or more second batteries may include an instruction to select the second battery using the proximity distance to the first battery and historical information regarding one or more of the battery's SOC, temperature value, and cumulative charge / discharge amount.

[0140] The instruction to select one or more second batteries may include an instruction to compare history information of the first battery with history information of the top N batteries (N is a predetermined natural number of 2 or more) that are closest to the first battery, and calculate the similarity with the first battery, and an instruction to determine the top M batteries (M is a predetermined natural number of 2 or more) that have the highest similarity as the second battery.

[0141] The instruction to select one or more second batteries may include an instruction to exclude from the comparison any battery among the N batteries that has a history of failure recorded within a predetermined period of time.

[0142] The at least one instruction may further include an instruction to, if a failure occurs in a specific battery among the second batteries after the M second batteries are selected, replace the failed battery with a battery having a lower similarity and update the second battery.

[0143] The instruction to select the one or more second batteries may include an instruction to confirm the latest SOC of the first battery or one or more of the N batteries if the SOC of the first battery is not received, an instruction to confirm whether the confirmed latest SOC is within a threshold SOC range predefined as an SOC estimation impossible interval, and an instruction to determine, if the confirmed latest SOC is outside the threshold SOC range, the top M batteries among the N batteries that have a high similarity to historical information regarding the SOC of the first battery as the second batteries.

[0144] The instruction to select one or more second batteries may further include an instruction to determine M second batteries based on the similarity between history information regarding one or more of a temperature value and a cumulative charge / discharge amount when there are more than M top batteries having a high similarity to history information regarding the SOC of the first battery.

[0145] The instruction to select the one or more second batteries may include an instruction to determine, if the confirmed latest SOC is within the threshold SOC range, the top M batteries having a high similarity to history information regarding one or more of the temperature value and cumulative charge / discharge amount of the first battery as the second batteries.

[0146] The instruction to select one or more second batteries may include an instruction to determine the top M batteries having a high similarity with historical information regarding the temperature value of the first battery as the second batteries, and if the number of top batteries having a high similarity exceeds M, an instruction to determine the M second batteries based on the similarity between historical information regarding cumulative charging and discharging amounts.

[0147] The battery control device 800 may further include an input interface device 840, an output interface device 850, a memory device 860, etc. The components included in the battery control device 800 are connected by a bus 870 to communicate with each other.

[0148] Here, the processor 810 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the method according to the embodiment of the present invention is performed. The memory (or storage device) may be composed of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory may be composed of at least one of a read-only memory (ROM) and a random access memory (RAM).

[0149] The operations of the method according to the embodiment of the present invention may be embodied as a computer-readable program or code on a computer-readable recording medium. The computer-readable recording medium may include any type of storage device in which data that can be read by a computer system is stored. The computer-readable recording medium may also be distributed among computer systems connected via a network, so that the computer-readable program or code may be stored and executed in a distributed manner.

[0150] Some aspects of the invention have been described in the context of an apparatus, but they may also be described in terms of a corresponding method, where a block or apparatus corresponds to a method step or feature of a method step. Similarly, aspects described in the context of a method may be described in terms of a corresponding block or item or feature of a corresponding apparatus. Some or all of the method steps may be performed by (or using) a hardware apparatus, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most important method steps may be performed by such an apparatus.

[0151] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that various modifications and variations can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. [Explanation of symbols]

[0152] 100:Battery 200:BMS 300: Upper control device 310: Storage device 800: Battery control device

Claims

1. A plurality of BMSs provided corresponding to the plurality of batteries, respectively; a host control device that collects status information on the plurality of batteries from the plurality of BMSs and monitors or controls the plurality of batteries based on the collected status information; The upper control device When the state information of the first battery is not received from the first BMS due to a communication abnormality, select one or more second batteries from among the batteries connected in parallel with the first battery based on pre-recorded battery history information, and estimate state information of the first battery based on state information of the one or more second batteries; The upper control device comparing history information of the first battery with history information of the top N batteries that are closest to the first battery to calculate a similarity to the first battery, and determining the top M batteries with the highest similarity as second batteries; N is a predetermined natural number of 2 or more, and M is a predetermined natural number of 2 or more. Energy storage systems.

2. The upper control device monitoring or controlling the plurality of batteries using the estimated status information as status information of the first battery without stopping operation of the energy storage system even if status information of the first battery is not received from the first BMS; The energy storage system of claim 1 .

3. The upper control device recording the estimated state information as state information of the first battery during a period when state information of the first battery is not received; The energy storage system of claim 1 .

4. The upper control device If the SOC of the first battery is not received from the first BMS, selecting a plurality of second batteries, calculating an average or median value of the SOCs of the selected second batteries, and estimating the calculated value as the SOC of the first battery. The energy storage system of claim 1 .

5. The upper control device selecting the second battery using the proximity distance to the first battery and history information related to one or more of the battery's SOC, temperature value, and accumulated charge / discharge amount; 5. The energy storage system of claim 4.

6. The upper control device Among the N batteries, batteries that have a recorded failure history within a predetermined period are excluded from the comparison. The energy storage system of claim 1 .

7. The upper control device After the M second batteries are selected, if a failure occurs in a specific battery among the second batteries, the battery in which the failure occurs is replaced with a battery having a lower similarity, and the second batteries are updated. The energy storage system of claim 1 .

8. The upper control device If the SOC of the first battery is not received, checking the latest SOC of the first battery or one or more of the N batteries; Check whether the confirmed latest SOC is within a threshold SOC range predefined as an SOC estimation impossible section; If the confirmed latest SOC is outside the range of the threshold SOC, determine the top M batteries among the N batteries that have a high similarity to the history information regarding the SOC of the first battery as the second battery. The energy storage system of claim 1 .

9. The upper control device If the number of top batteries having a high similarity to the history information regarding the SOC of the first battery exceeds M, determining M second batteries based on the similarity between history information relating to one or more of the temperature value and the accumulated charge / discharge amount; 9. The energy storage system of claim 8.

10. The upper control device If the confirmed latest SOC is within the threshold SOC range, the top M batteries having a high similarity to history information regarding one or more of the temperature value and the accumulated charge / discharge amount of the first battery are determined as second batteries.

9. The energy storage system of claim 8.

11. The upper control device The top M batteries having a high similarity to the history information relating to the temperature value of the first battery are determined as the second battery. If there are more than M top batteries with high similarity, determining M second batteries based on the similarity between the history information regarding the cumulative charge / discharge amounts; 11. The energy storage system of claim 10.

12. A battery control device that operates in conjunction with a plurality of BMSs that are provided corresponding to a plurality of batteries, at least one processor; and a memory for storing at least one instruction to be executed by said at least one processor; The at least one instruction: instructions for collecting status information regarding the plurality of batteries from the plurality of BMSs and monitoring or controlling the plurality of batteries based on the collected status information; a command to select one or more second batteries from among the batteries connected in parallel with the first battery based on pre-recorded battery history information when status information of the first battery is not received from the first BMS due to a communication abnormality; and instructions for estimating state information of the first battery based on state information of the one or more second batteries; The instructions to select the one or more second batteries include: an instruction to compare history information of the first battery with history information of the top N batteries that are closest to the first battery, and calculate a similarity between the first battery and the first battery; and The method includes an instruction to determine the top M batteries having the highest similarity as the second battery, N is a predetermined natural number of 2 or more, and M is a predetermined natural number of 2 or more. Battery control device.

13. The at least one instruction: and further comprising instructions for monitoring or controlling the plurality of batteries using the estimated status information as status information of the first battery without stopping operation of the energy storage system even if status information of the first battery is not received from the first BMS. The battery control device according to claim 12.

14. The instructions to estimate state information of the first battery include: and further comprising an instruction to record the estimated state information as state information of the first battery during a period in which state information of the first battery is not received. The battery control device according to claim 12.

15. The instructions to estimate state information of the first battery include: instructions for calculating an average or median SOC for the plurality of second batteries; and and an instruction to estimate the calculated value as an SOC of the first battery. The battery control device according to claim 12.

16. The instructions to select the one or more second batteries include: and an instruction to select the second battery using an adjacent distance to the first battery and history information regarding one or more of an SOC, a temperature value, and an accumulated charge / discharge amount of the battery. The battery control device according to claim 15.

17. The instructions to select the one or more second batteries include: a command to exclude from comparison any battery that has a failure history recorded within a predetermined period of time among the N batteries; The battery control device according to claim 12.

18. The at least one instruction: and further comprising an instruction to, if a failure occurs in a specific battery among the second batteries after the M number of second batteries are selected, replace the failed battery with a battery having a lower similarity and update the second batteries. The battery control device according to claim 12.

19. The instructions to select the one or more second batteries include: if the SOC of the first battery is not received, instructions to ascertain the most recent SOC of the first battery or one or more of the N batteries; An instruction to confirm whether the confirmed latest SOC is within a threshold SOC range predefined as an SOC estimation impossible interval; and and if the confirmed latest SOC is outside the range of the threshold SOC, determining, as a second battery, top M batteries among the N batteries that have a high similarity to history information regarding the SOC of the first battery. The battery control device according to claim 12.

20. The instructions to select the one or more second batteries include: If the number of top batteries having a high similarity to the history information regarding the SOC of the first battery exceeds M, and further comprising instructions for determining the M second batteries based on a similarity between history information relating to one or more of a temperature value and an accumulated charge / discharge amount. The battery control device according to claim 19.

21. The instructions to select the one or more second batteries include: and if the confirmed latest SOC is within the threshold SOC range, determining, as a second battery, top M batteries having a high similarity to history information regarding one or more of a temperature value and an accumulated charge / discharge amount of the first battery. The battery control device according to claim 19.

22. The instructions to select the one or more second batteries include: an instruction to determine, as a second battery, the top M batteries having a high similarity to history information regarding the temperature value of the first battery; and and if the number of top batteries having high similarity exceeds M, instructions are included for determining M second batteries based on similarity between history information regarding cumulative charge / discharge amounts. The battery control device according to claim 21.

23. A battery control method using a battery control device that is linked to a plurality of BMSs provided corresponding to a plurality of batteries, collecting status information about the plurality of batteries from the plurality of BMSs, and monitoring or controlling the plurality of batteries based on the collected status information; When the state information of the first battery is not received from the first BMS due to a communication abnormality, selecting one or more second batteries from among the batteries connected in parallel with the first battery based on pre-recorded battery history information; and estimating state information of the first battery based on state information of the one or more second batteries; The step of selecting one or more second batteries comprises: A step of comparing history information of the first battery with history information of top N batteries that are closest to the first battery, and calculating a similarity between the first battery and the first battery; and determining the top M batteries with the highest similarity as second batteries; N is a predetermined natural number of 2 or more, and M is a predetermined natural number of 2 or more. Battery control method.

24. and further comprising: monitoring or controlling the plurality of batteries using the estimated state information as state information of the first battery without stopping operation of the energy storage system even if state information of the first battery is not received from the first BMS.

24. The battery control method of claim 23.

25. The step of estimating state information of the first battery includes: and further comprising recording the estimated state information as state information of the first battery during a period in which state information of the first battery is not received.

24. The battery control method of claim 23.

26. The step of estimating state information of the first battery includes: calculating an average or median SOC for the plurality of second batteries; and estimating the calculated value as an SOC of the first battery; 24. The battery control method of claim 23.

27. The step of selecting one or more second batteries comprises: selecting the second battery using an adjacent distance to the first battery and history information regarding one or more of an SOC, a temperature value, and an accumulated charge / discharge amount of the battery; 27. The battery control method of claim 26.

28. The step of selecting one or more second batteries comprises: a step of excluding from the comparison any battery that has a failure history recorded within a predetermined period of time from among the N batteries; 24. The battery control method of claim 23.

29. and if a failure occurs in a specific battery among the second batteries after the M number of second batteries are selected, the method further includes replacing the failed battery with a battery having a lower similarity, and updating the second batteries.

24. The battery control method of claim 23.

30. The step of selecting one or more second batteries comprises: if the SOC of the first battery is not received, checking the latest SOC of the first battery or one or more of the N batteries; A step of confirming whether the confirmed latest SOC is within a threshold SOC range predefined as an SOC estimation impossible interval; and If the confirmed latest SOC is outside the range of the threshold SOC, determining, as a second battery, the top M batteries among the N batteries that have a high similarity to history information regarding the SOC of the first battery; 24. The battery control method of claim 23.

31. The step of selecting one or more second batteries comprises: If the number of top batteries having a high similarity to the history information regarding the SOC of the first battery exceeds M, determining the M second batteries based on a similarity between history information relating to one or more of a temperature value and an accumulated charge / discharge amount; 31. The battery control method of claim 30.

32. The step of selecting one or more second batteries comprises: and when the confirmed latest SOC is within the threshold SOC range, determining top M batteries having a high similarity to history information regarding one or more of a temperature value and an accumulated charge / discharge amount of the first battery as second batteries.

31. The battery control method of claim 30.

33. The step of selecting one or more second batteries comprises: determining the top M batteries having high similarity to the history information on the temperature value of the first battery as the second battery; and When the number of top batteries having high similarity exceeds M, determining M second batteries based on similarity between history information regarding cumulative charge / discharge amounts; 33. The battery control method of claim 32.

34. A computer program for causing the battery control device to execute the battery control method described in any one of claims 23 to 33.

Images