Operation support apparatus and method for energy storage system

Abstract

An operation support apparatus, according to an embodiment of the present invention, is an operation support apparatus for an energy storage system and may comprise at least one processor, and a memory storing at least one instruction that is executed by the at least one processor. The at least one instruction may include the instructions of: collecting information about batteries that can be applied to the energy storage system; deriving, on the basis of the structure of the energy storage system, a plurality of combinations, each including one or more batteries that can be applied to the energy storage system; calculating an operating cost of the energy storage system for each of the combinations; and generating recommended combination information including information about a combination that, among the combinations, represents the minimum operating cost.

Description

Device and method for supporting operation of energy storage system

[0001] This application claims the benefit of Korean Patent Application No. 10-2024-0046636 filed with the Korean Intellectual Property Office on April 5, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to an operation support device and method for an energy storage system, and more particularly, to an operation support device and method for an energy storage system that helps minimize the operation cost of an energy storage system.

[0003] Energy Storage Systems (ESS) utilize batteries that store energy and operate in conjunction with renewable energy sources and the power grid. With the recent expansion of smart grids and renewable energy sources, coupled with an emphasis on power grid efficiency and stability, demand for energy storage systems is steadily increasing to regulate power supply and demand and improve power quality. Depending on the intended use, energy storage systems can vary in output and capacity. Multiple battery systems can be interconnected to form large-capacity energy storage systems.

[0004] Among ESS, ESS linked to PV (Photovoltaic; solar power generation) systems is becoming increasingly widespread. PV-linked ESS is configured to appropriately distribute power supplied from the power grid and power generated by PV systems to supply loads, storing any remaining power in a battery system.

[0005] The most important goal for ESS users is minimizing their operating costs. These costs, which arise during ESS operation, consist of the purchase cost of grid power, which must be paid periodically, and the battery replacement cost, which occurs at each battery replacement cycle. Typically, ESS is controlled by considering various factors, such as the PV system's power generation, the load's power demand, and the battery's state of charge. However, conventional technologies focus on ESS control methods to improve power efficiency or battery performance, limiting their ability to minimize user costs from a long-term perspective.

[0006] Accordingly, there is a need for appropriate energy storage system operation support technology that can help minimize long-term operating costs of energy storage systems.

[0007] As a related prior literature, there is KR 10-1380530.

[0008] The purpose of the present invention to solve the above problems is to provide an operation support device for an energy storage system that helps minimize the operating cost of the energy storage system.

[0009] Another object of the present invention to solve the above problems is to provide an operation support method using such an operation support device.

[0010] An operation support device according to one embodiment of the present invention for achieving the above purpose may include an operation support device of an energy storage system, which may include at least one processor and a memory that stores at least one command executed through the at least one processor.

[0011] The at least one command may include: a command for collecting information about batteries applicable to the energy storage system; a command for deriving a plurality of combinations, each of which comprises one or more batteries applicable to the energy storage system, based on a structure of the energy storage system; a command for calculating an operating cost of the energy storage system for each of the combinations; and a command for generating recommended combination information including information about a combination exhibiting the lowest operating cost among the combinations.

[0012] The command for collecting information about the batteries may include a command for collecting, for each of the one or more batteries, one or more of a model name, a capacity, a critical SOC range, and a purchase cost.

[0013] The command for deriving the plurality of combinations may include a command for deriving the plurality of combinations applicable to the energy storage system based on the capacity of each battery and the design structure of the battery system.

[0014] The command for calculating the operating cost of the energy storage system may include a command for calculating a grid power purchase cost and a battery purchase cost for each of the combinations; and a command for calculating the operating cost based on the grid power purchase cost and the battery purchase cost.

[0015] The command for calculating the operating cost of the energy storage system may include a command for calculating a system power purchase cost for a preset period for each of the combinations based on past history information for at least one of the energy storage system, a load linked to the energy storage system, and a power generation device linked to the energy storage system, and charge / discharge schedule information of a two-way electric vehicle (EV) charger linked to the energy storage system.

[0016] The command for calculating the above system power purchase cost may include a command for deriving an operation schedule including a time interval charge / discharge amount that minimizes the system power purchase cost by using an objective function defined as the system power purchase cost; and a command for calculating the system power purchase cost for a preset period for each of the combinations by applying the operation schedule and system power cost information to an energy storage system according to each of the above combinations.

[0017] The above objective function may be defined as a constraint including at least one of a first condition regarding the balance of power supply and power consumption, a second condition regarding the state of charge (SOC) according to the charge / discharge efficiency of the ESS battery, a third condition regarding the limit charge amount of the ESS battery, a fourth condition regarding the limit output of the inverter, a fifth condition regarding the binarization of the charge / discharge state of the ESS battery, a sixth condition regarding the state of charge (SOC) according to the charge / discharge efficiency of the EV battery, a seventh condition regarding the limit charge amount of the EV battery, an eighth condition regarding the limit output of a bidirectional EV charger, and a ninth condition regarding the binarization of the charge / discharge state of the bidirectional EV charger.

[0018] The at least one command may further include a command for providing the generated recommended combination information to a user terminal linked to the energy storage system.

[0019] The above recommended combination information may include at least one of the model name, capacity, number, and connection structure of the batteries applied to the energy storage system.

[0020]

[0021] According to an embodiment of the present invention for achieving the above another object, an operation support method may include a step of collecting information on a battery applicable to the energy storage system; a step of deriving a plurality of combinations composed of one or more batteries applicable to the energy storage system based on a structure of the energy storage system; a step of calculating an operation cost of the energy storage system for each of the combinations; and a step of generating recommended combination information including information on a combination exhibiting the minimum operation cost among the combinations.

[0022] The step of collecting information about the batteries may include collecting, for each of the one or more batteries, one or more of a model name, a capacity, a critical SOC range, and a purchase cost.

[0023] The step of deriving the plurality of combinations may include a step of deriving the plurality of combinations applicable to the energy storage system based on the capacity of each battery and the design structure of the battery system.

[0024] The step of calculating the operating cost of the energy storage system may include the step of calculating the system power purchase cost and the battery purchase cost for each of the combinations; and the step of calculating the operating cost based on the system power purchase cost and the battery purchase cost.

[0025] The step of calculating the operating cost of the energy storage system may include a step of calculating a system power purchase cost for a preset period for each of the combinations based on past history information for at least one of the energy storage system, a load linked to the energy storage system, and a power generation device linked to the energy storage system, and charge / discharge schedule information of a two-way electric vehicle (EV) charger linked to the energy storage system.

[0026] The step of calculating the system power purchase cost may include a step of deriving an operation schedule including a time interval charge / discharge amount that minimizes the system power purchase cost by using an objective function defined as the system power purchase cost; and a step of calculating the system power purchase cost for a preset period for each of the combinations by applying the operation schedule and system power cost information to an energy storage system according to each of the combinations.

[0027] The above objective function may be defined as a constraint including at least one of a first condition regarding the balance of power supply and power consumption, a second condition regarding the state of charge (SOC) according to the charge / discharge efficiency of the ESS battery, a third condition regarding the limit charge amount of the ESS battery, a fourth condition regarding the limit output of the inverter, a fifth condition regarding the binarization of the charge / discharge state of the ESS battery, a sixth condition regarding the state of charge (SOC) according to the charge / discharge efficiency of the EV battery, a seventh condition regarding the limit charge amount of the EV battery, an eighth condition regarding the limit output of a bidirectional EV charger, and a ninth condition regarding the binarization of the charge / discharge state of the bidirectional EV charger.

[0028] The above operation support method may further include a step of providing the generated recommended combination information to a user terminal linked with the energy storage system.

[0029] The above recommended combination information may include at least one of the model name, capacity, number, and connection structure of the batteries applied to the energy storage system.

[0030] According to the above-described embodiment of the present invention, it is possible to minimize user costs incurred during long-term operation of an energy storage system.

[0031] Figure 1 is a block diagram of an energy storage system to which the present invention can be applied.

[0032] Figure 2 shows an implementation example of an energy storage system to which the present invention can be applied.

[0033] Figure 3 is a flowchart of a method for supporting operation of an energy storage system according to an embodiment of the present invention.

[0034] Figure 4 is a reference table for explaining battery information according to an embodiment of the present invention.

[0035] FIG. 5 is a reference table for explaining a method for deriving battery combinations according to an embodiment of the present invention.

[0036] Figure 6 is a reference table for explaining a method for deriving an optimal combination according to an embodiment of the present invention.

[0037] Figure 6 is a reference table for explaining a method for deriving an optimal combination according to an embodiment of the present invention.

[0038] FIG. 7 is an example screen of a user terminal for explaining charge / discharge schedule information of an EV charger according to an embodiment of the present invention.

[0039] Figure 8 is a block diagram of an operation support device of an energy storage system according to an embodiment of the present invention.

[0040] 100: Energy storage system

[0041] 200: Subordinate

[0042] 300: EV charger

[0043] 400: Power generation device

[0044] 500: Operational Support Device

[0045] 600: User terminal

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051]

[0052] Some terms used in this specification are defined as follows:

[0053] SOC (State of Charge) is the current charged state of the battery expressed as a percentage [%], and SOH (State of Health) is the current deterioration state of the battery expressed as a percentage [%].

[0054] Power Limit (PL) refers to the output power limit, which is preset by the battery manufacturer based on battery condition or set based on the SOC. Power limits can be categorized into charge power limits and discharge power limits, depending on whether the battery is being charged or discharged.

[0055]

[0056] Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

[0057]

[0058] Figure 1 is a block diagram of an energy storage system to which the present invention can be applied.

[0059] The energy storage system (100) is electrically connected to a load (200), an EV (Electric Vehicle) charger (300), a power generation device (400), and a power system, and can receive power from the power system and the power generation device (400) and store it internally.

[0060] The energy storage system (100) is electrically connected to a load (200) and can supply power stored therein to the load (200). Meanwhile, the load (200) is electrically connected to a bidirectional EV charger (300), a power generation device (400), and a power system, and can receive power from the bidirectional EV charger (300), the power generation device (400), and the power system.

[0061] The EV charger (300) is electrically connected to a power system, a power generation device (400), and an energy storage system (100), and can receive power from the power system, the power generation device (400), and the energy storage system (100).

[0062] In an embodiment, the EV charger (300) may correspond to a bidirectional EV charger. In this case, the EV charger (300) may charge a battery (hereinafter, "EV battery") included in the EV using externally supplied power, and discharge power stored in the EV battery to the outside. In other words, when the EV is connected to the EV charger (300), the bidirectional EV charger and EV battery may function in the same manner as the energy storage system (100) according to the present invention.

[0063] When the EV charger (300) is configured as a bidirectional charger, the EV charger (300) can supply power stored therein to the load (200) and the energy storage system (100).

[0064] The power generation device (400) is a device that generates power using a power generation device, and may be configured to include at least one of a solar power generation device, a solar thermal power generation device, a wind power generation device, and a geothermal power generation device. Meanwhile, since the type of the power generation device (400) is not an essential component of the present invention, the scope of the present invention is not limited to these entities.

[0065] The energy storage system (100) may be configured to be connected to a user terminal (600) via a network and to mutually transmit and receive data. For example, if the energy storage system (100) is a residential ESS, the user terminal (600) may be configured to be connected to a HEMS (Home Energy Management System), which is the top-level control system of the residential ESS, via a network and to mutually transmit and receive data.

[0066] The user terminal (600) is a computing device used by the owner or manager of the energy storage system (100), and may correspond to, for example, a personal computer (PC), a mobile phone, or a tablet PC.

[0067] The energy storage system (100) can transmit information about one or more of the operating status of the energy storage system (100), the power generation status of the power generation device (400), the operating status of the EV charger (300), and the power consumption status of the load (200) to the user terminal (600). Here, the user terminal (600) can output the received information through a predefined GUI (Graphical User Interface).

[0068] The user terminal (600) transmits a selection signal input by the user to the energy storage system (100), and the energy storage system (100) can perform a control operation corresponding to the selection signal. For example, when an off request signal for a specific load is received through the user terminal (600), the EMS of the energy storage system (100) can block the electrical path for the load, thereby cutting off the power supply to the load.

[0069] The operation support device (500) may be configured to be connected to the energy storage system (100) via a network and to mutually transmit and receive data. In addition, the operation support device (500) may be configured to be connected to one or more of the power generation device (400) and the user terminal (600) via a network and to mutually transmit and receive data.

[0070] The operation support device (500) may be configured and included within the energy storage system (100), or may be separately provided outside the energy storage system (100). For example, the operation support device (500) may be implemented and included in the HEMS of a residential ESS, or may be implemented and included in the server of an ESS management company.

[0071] The operation support device (500) can collect information about batteries applicable to the energy storage system (100) and generate recommendation information on battery combinations that can minimize the operating costs of the energy storage system. Here, the operation support device (500) can provide the generated recommendation information to one or more of the energy storage system (100) and the user terminal (600). Meanwhile, details regarding the method for generating the recommended combination information will be described later.

[0072] The operation support device (500) can establish an operation schedule capable of minimizing the power purchase cost of the energy storage system (100) based on past history information for at least one of the energy storage system (100), the load (200), and the power generation device (400) and the charge / discharge schedule of the EV charger (300). Here, the operation schedule can include the charge / discharge amount of the battery for each time period. The operation support device (500) can transmit the established operation schedule to the battery charge / discharge control device of the energy storage system (100), thereby allowing the battery of the energy storage system (100) to be charged / discharged according to the operation schedule.

[0073]

[0074] Figure 2 shows an implementation example of an energy storage system to which the present invention can be applied.

[0075] Referring to FIG. 2, the energy storage system (100) may be configured to include an ESS battery (110) that stores power, an inverter (120) that controls the charging and discharging operation of the ESS battery (110), and an EMS (130) that integrates and manages the configurations of the energy storage system and power devices linked to the energy storage system.

[0076] An ESS battery (110) that performs the role of storing power can be typically implemented in a form where multiple battery packs form a battery rack, and multiple battery racks form a battery bank. Here, depending on the device or system in which the battery is used, the battery pack may also be referred to as a battery module.

[0077] Each ESS battery can be equipped with a Battery Management System (BMS). The BMS monitors the current, voltage, and temperature of each battery rack (or pack) it manages, calculates the State of Charge (SOC) based on the monitoring results, and controls charging and discharging.

[0078] The inverter (120) is also referred to as a power conditioning system (PCS) or a power conversion system (PCS), and can control power supplied to the battery from the outside and power supplied from the battery to the outside.

[0079] The inverter (120) may include a power management system (PMS), and the operation support device (500) may be configured to be linked with the power management system of the inverter (120) to mutually transmit and receive data.

[0080] The inverter (120) can control the charging and discharging operation of the ESS battery (110) according to an operating schedule by the operating support device (500). For example, the inverter (120) can receive an operating schedule for a specific day from the operating support device (500) and control the charging and discharging operation of the ESS battery (110) according to the reference power for each time period included in the operating schedule.

[0081] EMS (130) can be linked with loads, power generation devices, and inverters, and monitor and control the linked components.

[0082] The load (200) may be configured to include a plurality of loads. Here, at least some of the loads may be first loads that cannot be turned on and off, and the remaining some may be second loads that can be turned on and off.

[0083] A first load may refer to a load that cannot be turned off or whose power supply cannot be interrupted under the control of an EMS. Furthermore, a second load may refer to a load that can be turned off or whose power supply can be interrupted under the control of an EMS. Here, the second load may be defined based on a selection signal input by a user.

[0084] The two-way EV station (320) can control the charging and discharging operation of the EV battery included in the EV (310).

[0085] The PV system may be configured to include a PV module (410) (e.g., a solar panel) and a PV inverter (420) which is an AC / DC inverter, and the AC terminal of the PV inverter (420) and the AC terminal of the inverter (120) of the energy storage system may be connected to an AC link.

[0086] The energy storage system illustrated in Fig. 2 is an AC coupled ESS in which a PV system, a load, and an energy storage system are connected on an AC link.

[0087] When the energy storage system has an AC coupled structure, the operation support device (500) can collect basic information for generating recommended combination information by linking with one or more of the inverter (120), PV inverter (420), EMS (130), and user terminal (600).

[0088] Meanwhile, the present invention is also applicable to a DC coupled ESS in which the output terminal of a PV system and the output terminal of a battery are connected via a DC link, and the DC link is connected to one terminal of an inverter. In the case where the energy storage system has a DC coupled structure, since the PV inverter (420) is omitted, the operation support device (500) can collect basic information for generating recommended combination information by interworking with one or more of the inverter (120), EMS (130), and user terminal (600).

[0089]

[0090] Figure 3 is a flowchart of a method for supporting operation of an energy storage system according to an embodiment of the present invention.

[0091] The operation support method of an energy storage system according to an embodiment of the present invention can be performed by an operation support device linked to the energy storage system.

[0092] The operation support device can collect information about batteries applicable to the energy storage system (S310). Here, the operation support device can receive battery information from one or more of a storage device, an external storage device connected by an administrator, or a user terminal.

[0093] The battery information may include, for each of one or more batteries, one or more of the following: model name, capacity, critical SOC range, and purchase cost.

[0094] Figure 4 is a reference table for explaining battery information according to an embodiment of the present invention.

[0095] Referring to FIG. 4, the operation support device can collect a battery list including a model name (or identifier), capacity, SOC lower limit, SOC upper limit, and purchase cost for each of a plurality of batteries that can be applied to the energy storage system.

[0096] The operation support device can receive model information of an ESS battery from an energy storage system or a user terminal, and determine a battery applicable to the energy storage system based on the received model information.

[0097] Referring again to FIG. 3, the operation support device can derive multiple battery combinations applicable to the energy storage system based on the structure of the energy storage system (S320). Here, each battery combination may include one or more batteries applicable to the energy storage system.

[0098] FIG. 5 is a reference table for explaining a method for deriving battery combinations according to an embodiment of the present invention.

[0099] For example, in the design structure of an energy storage system, if 3 to 5 series-connected batteries can be connected to an inverter, and 4 battery models (Bat#1 to #4) applicable to the energy storage system are identified, the operation support device can derive a total of 12 battery combinations (C #1 to #12), as shown in Fig. 5(A). The 15 combinations derived from the above example are [Bat#1, serial connection, 3], [Bat#2, serial connection, 3], [Bat#3, serial connection, 3], [Bat#4, serial connection, 3], [Bat#1, serial connection, 4], [Bat#2, serial connection, 4], [Bat#3, serial connection, 4], [Bat#4, serial connection, 4], [Bat#1, serial connection, 5], [Bat#2, serial connection, 5], [Bat#3, serial connection, 5], [Bat#4, serial connection, 5], as shown in Fig. 5(A).

[0100] In an embodiment, the operation support device may derive multiple battery combinations applicable to the energy storage system based on the battery capacity and the inverter's limit capacity. For example, the operation support device may derive multiple battery combinations such that the total capacity of the battery combination exceeds the minimum guaranteed capacity of the energy storage system and falls below the limit capacity based on the inverter's output limit.

[0101] For example, in the design structure of the energy storage system, if 3 to 5 series-connected batteries can be connected to the inverter, and the capacities of the battery models (Bat#1 to #4) applicable to the energy storage system are confirmed to be 3 kWh, 3.5 kWh, 4 kWh, and 4.5 kWh, and the minimum guaranteed capacity of the energy storage system is 10 kWh and the limit capacity of the inverter is 18 kWh, the operation support device can derive a total of 9 (C #1 to #9) battery combinations, as shown in Fig. 5(B). The nine combinations derived from the above example are [Bat#2, serial connection, 3], [Bat#3, serial connection, 3], [Bat#4, serial connection, 3], [Bat#1, serial connection, 4], [Bat#2, serial connection, 4], [Bat#3, serial connection, 4], [Bat#4, serial connection, 4], [Bat#1, serial connection, 5], [Bat#2, serial connection, 5], as shown in Fig. 5(B).

[0102] Referring again to FIG. 3, the operating support device can calculate the operating cost of the energy storage system for each of the battery combinations derived in S320 (S330). Here, the operating cost of the energy storage system can be calculated based on the grid power purchase cost and the battery purchase cost.

[0103] Thereafter, the operation support device can derive a battery combination that exhibits the minimum operating cost among battery combinations (S340) and determine the combination as the optimal battery combination.

[0104] Figure 6 is a reference table for explaining a method for deriving an optimal combination according to an embodiment of the present invention.

[0105] Referring to FIG. 6, the operation support device can calculate the power system purchase cost and the battery and inverter purchase cost for each of the nine battery combinations (C #1 to #9) derived from FIG. 5(B). Thereafter, the operation support device can calculate the total operating cost for each battery combination by adding the power system purchase cost and the battery purchase cost. Here, the operation support device can determine [Bat#4, series connection, 3] (C #3) as the optimal battery combination, which has the lowest total operating cost among the nine combinations.

[0106] In an embodiment, the operating cost of the energy storage system can be calculated as the sum of the grid power purchase cost (C_p) and the battery inverter purchase cost (C_b) (C_t = C_p + C_b), as illustrated in FIG. 6.

[0107] In another embodiment, the operating cost of the energy storage system can be calculated as the sum of a value reflecting a predefined weighting factor (a) for the grid power purchase cost (C_p) and a value reflecting a predefined weighting factor (b) for the battery purchase cost (C_b) (C_t = a*C_p + b*C_b).

[0108] In another embodiment, the operating cost of the energy storage system can be calculated as a value (C_t = a*C_p * b*C_b) that is the product of a value that reflects a predefined weighting factor (a) for the grid power purchase cost (C_p) and a value that reflects a predefined weighting factor (b) for the battery purchase cost (C_b).

[0109] That is, the operating cost of an energy storage system can be calculated in various ways depending on the needs.

[0110] Referring again to FIG. 3, at S330, the operation support device can calculate a grid power purchase cost for a preset period for each of the battery combinations derived at S320 based on past history information for one or more of the energy storage system, the load, and the power generation device, and the charge / discharge schedule information of the bidirectional EV charger.

[0111] The operation support device can receive past history information for a certain period of time from one or more of a user terminal, an EMS, an inverter of an ESS, and a PV inverter. Here, the past history information can include one or more of power consumption status information of a load (e.g., power consumption per hour), power production status information of a power generation device (e.g., power production per hour), and charge / discharge schedule information of an ESS battery (e.g., charge / discharge per hour).

[0112] In addition, the operation support device can receive charge / discharge schedule information (or charge / discharge plan information) of a bidirectional EV charger from a user terminal. Here, the charge / discharge schedule information of the EV charger can include information regarding the time intervals during which the EV is connected to the EV charger and the charge / discharge plan for each time interval, set by the user. For example, the operation support device can receive EV charge / discharge schedule information including [discharging from 17:00 to 19:00, charging from 21:00 to 24:00] from the user terminal.

[0113] The operation support device can conduct simulations using historical information and EV charging / discharging schedules for energy storage systems equipped with batteries according to each combination (C #1 to #9). Then, based on the hourly grid power usage and hourly grid power cost information derived from the simulation results, the operation support device can calculate the grid power purchase cost for each combination over a preset period (e.g., one month).

[0114] In an embodiment, the operation support device can derive an operation schedule (charge / discharge amount per unit time) of a battery that minimizes the purchase cost of grid power based on past history information about loads and power generation devices and EV charge / discharge schedule information, and calculate the cost of grid power purchase using the derived operation schedule.

[0115] Specifically, the operation support device can collect information on power generation status and power consumption status over a certain period of time (e.g., over the past year), and receive EV charging / discharging schedule information from the user terminal. Thereafter, the operation support device can derive an operation schedule for a certain period of time (e.g., one day) that minimizes the purchase cost of system power, using an objective function defined as the purchase cost of system power.

[0116] The operation control unit can derive an operation schedule using an objective function defined based on Mixed-integer Linear Programming (MILP). Below, a specific implementation example of this operation schedule generation method is described in detail.

[0117] The operation control device can derive an operation schedule including the battery charge / discharge amount for each time interval using an objective function defined by the purchase cost of system power. Here, the objective function can be defined as in Mathematical Expression 1 below.

[0118]

[0119] (Here, Pgrid(t) is the grid power schedule and λgrit(t) is the grid power cost.)

[0120]

[0121] Mathematical expression 1 is an objective function for deriving the amount of charge or discharge of a battery for each time interval that can minimize the cost of purchasing power from the system. Here, the objective function according to Mathematical expression 1 may define constraints including at least one of a first condition regarding the balance of power supply and power consumption, a second condition regarding the state of charge (SOC) according to the charge and discharge efficiency of the ESS battery, a third condition regarding the limit charge amount of the ESS battery, a fourth condition regarding the limit output of the inverter, a fifth condition regarding the binarization of the charge and discharge state of the ESS battery, a sixth condition regarding the state of charge (SOC) according to the charge and discharge efficiency of the EV battery, a seventh condition regarding the limit charge amount of the EV battery, an eighth condition regarding the limit output of a bidirectional EV charger, and a ninth condition regarding the binarization of the charge and discharge state of the bidirectional EV charger.

[0122]

[0123]

[0124] (Here, Ppv(t) is the power generation of PV, Pbatch(t) is the charging power of the ESS battery, Pbatdch(t) is the discharging power of the ESS battery, PEVch(t) is the charging power of the EV battery, PEVdch(t) is the discharging power of the EV battery, and Pload(t) is the power consumption.)

[0125]

[0126]

[0127] (Here, SOC(t) is the SOC of the ESS battery, Ecap is the capacity of the ESS battery, ηch is the charging efficiency of the inverter, ηdch is the discharging efficiency of the inverter, and tstep is the time interval)

[0128]

[0129]

[0130] (Here, SOCmin is the lower limit of the SOC of the ESS battery, and SOCmax is the upper limit of the SOC of the ESS battery)

[0131]

[0132]

[0133] (Here, μch is the battery state for charging with a value of 0 or 1, and Pinv_max is the maximum output of the inverter)

[0134]

[0135]

[0136] (Here, μdch is the battery state for discharging, which has a value of 0 or 1)

[0137]

[0138]

[0139]

[0140]

[0141] (Here, SOCEV(t) is the SOC of the EV battery, Ecap_EV is the capacity of the EV battery, ηch_EV is the charging efficiency of the bidirectional EV charger, ηdch_EV is the discharging efficiency of the bidirectional EV charger, and tstep is the time interval.)

[0142]

[0143]

[0144] (Here, SOCEVmin is the lower limit of the SOC of the EV battery, and SOCEVmax is the upper limit of the SOC of the EV battery)

[0145]

[0146]

[0147] (Here, βEV is the EV connection status value with a value of 0 or 1, μEVch is the charge status value with a value of 0 or 1, and PEV_max is the maximum output of the bidirectional EV charger.)

[0148]

[0149]

[0150] (Here, μEVdch is a discharge state value with a value of 0 or 1)

[0151]

[0152]

[0153]

[0154] The first condition can be implemented using Equation 2, and the decision variables Pgrid(t), Pbatch(t), and Pbatdch(t) function to determine the balance between power supply and demand. Meanwhile, in Equation 2, Ppv(t) and Pload(t) can be applied to the power production and power consumption per unit of time based on past history information.

[0155] The second condition can be implemented by mathematical expression 3, and functions such that the SOC of the ESS battery in the next time interval is determined based on the capacity of the ESS battery and the charge / discharge efficiency of the power conversion device.

[0156] The third condition can be implemented by mathematical expression 4, and functions to determine the SOC of the ESS battery within a set critical range.

[0157] The fourth and fifth conditions can be implemented by mathematical expressions 5 to 7, and function to prevent the decision variables Pbatch(t) and Pbatdch(t) from exceeding the output limit of the power conversion device (e.g., inverter), and to prevent the charging power amount and the discharging power amount from being determined simultaneously.

[0158] The sixth condition can be implemented by mathematical expression 8, and functions such that the SOC of the EV battery in the next time interval is determined based on the capacity of the EV battery and the charge / discharge efficiency of the two-way EV charger.

[0159] The seventh condition can be implemented using mathematical expression 9 and functions to determine the SOC of an EV battery within a set threshold range. Here, at least one of the lower and upper SOC limits of the EV battery can be set by the user. For example, the lower SOC limit of the EV battery can be defined as the minimum guaranteed SOC of the EV battery received from the user terminal. According to the operation schedule derived through the objective function reflecting the seventh condition, the EV battery can perform charge and discharge operations at a state above the minimum guaranteed SOC.

[0160] The eighth and ninth conditions can be implemented by mathematical expressions 10 to 12, and function to prevent Pbatch(t) and Pbatdch(t) from exceeding the output limit of the bidirectional EV charger, and to prevent the charging power amount and the discharging power amount from being determined simultaneously.

[0161] The EV connection status value βEV reflected in mathematical expressions 10 and 11 can be defined as [1] in the case of a connection status and [0] in the case of a non-connection status. Here, the EV connection status value can be defined based on EV charging / discharging schedule information received from the user terminal.

[0162] The operation control device can derive Pbatch(t) and Pbatdch(t) that satisfy the above objective function and constraints and generate an operation schedule including the same.

[0163] The operation support device can conduct simulations using historical power consumption and power production information and generated operation schedules for energy storage systems equipped with batteries according to each combination (C #1 to #9). Thereafter, based on the hourly system power usage and hourly system power cost information derived from the simulation results, the operation support device can calculate the system power purchase cost for each combination for a preset period (e.g., one month).

[0164] Once the optimal battery combination representing the minimum operating cost is determined in S340, the operation support device can generate recommended combination information including information on the optimal combination (S350). Here, the recommended combination information may include at least one of the following: the model name, capacity, number, and connection structure of the batteries applied to the energy storage system. For example, the recommended combination information may be implemented as [Bat 9158, 4kWh, 3, serial connection].

[0165] The operation support device can provide the recommended combination information generated in S350 to the user terminal (S360). Here, the user terminal can output the received recommended combination information through a predefined GUI.

[0166] In an embodiment, the operation support device may provide an optimal operation schedule corresponding to an optimal combination to a user terminal, an EMS, or an inverter. Here, the optimal operation schedule may correspond to an operation schedule derived according to an objective function and constraints when calculating the system power purchase cost for the optimal combination. In other words, the operation support device may provide the optimal operation schedule corresponding to the recommended combination to the user terminal as a reference operation schedule so that, when the energy storage system is operated with the optimal battery combination in the future, the system power purchase cost is minimized.

[0167]

[0168] FIG. 7 is an example screen of a user terminal for explaining charge / discharge schedule information of an EV charger according to an embodiment of the present invention.

[0169] The operation support device can receive minimum guaranteed SOC and EV schedule information from a user terminal and generate an operation schedule based on the received minimum guaranteed SOC and EV charge / discharge schedule information.

[0170]

[0171] More specifically, the user terminal can receive minimum guaranteed SOC and EV schedule information for the EV battery from the user through a predefined GUI (Graphical User Interface).

[0172] For example, as illustrated in FIG. 7, the user terminal may receive a specific SOC value (75%) as a minimum guaranteed SOC from the user, and information about time periods during which the EV is connected to a two-way EV charger, and a charge / discharge schedule for each time period (Time 1; charge; 00:00 ~ 07:00, Time 2; discharge; 17:00 ~ 19:00, Time 3; charge; 21:00 ~ 24:00). Thereafter, the user terminal may transmit the minimum guaranteed SOC and EV charge / discharge schedule information input by the user to the operation support device.

[0173] The operation support device can reflect the minimum guaranteed SOC received from the user terminal in the seventh condition (Mathematical Formula 9) among the constraints for deriving the operation schedule. In addition, the operation support device can reflect the EV schedule information received from the user terminal in the eighth and ninth conditions (Mathematical Formulas 10 and 11) among the constraints for deriving the operation schedule.

[0174] The operation support device can derive Pgrid(t), Pbatch(t) and Pbatdch(t) that satisfy the objective function according to mathematical expression 1 and constraints (first to ninth conditions) reflecting information received from a user terminal, and can generate an ESS operation schedule including Pbatch(t) and Pbatdch(t).

[0175]

[0176] Figure 8 is a block diagram of an operation support device of an energy storage system according to an embodiment of the present invention.

[0177] The operation support device (500) according to an embodiment of the present invention may be incorporated into an energy storage system or provided separately outside the energy storage system. For example, the operation support device (500) may be implemented by being incorporated into a Home Energy Management System (HEMS), which is the top-level control system of a residential ESS, or may be implemented by being incorporated into a server of an ESS management company.

[0178] The operation support device (500) may include at least one processor (510), a memory (520) that stores at least one command executed through the processor, and a transmission / reception device (530) that is connected to a network and performs communication.

[0179] The at least one command may include: a command for collecting information about batteries applicable to the energy storage system; a command for deriving a plurality of combinations, each of which comprises one or more batteries applicable to the energy storage system, based on a structure of the energy storage system; a command for calculating an operating cost of the energy storage system for each of the combinations; and a command for generating recommended combination information including information about a combination exhibiting the lowest operating cost among the combinations.

[0180] The command for collecting information about the batteries may include a command for collecting, for each of the one or more batteries, one or more of a model name, a capacity, a critical SOC range, and a purchase cost.

[0181] The command for deriving the plurality of combinations may include a command for deriving the plurality of combinations applicable to the energy storage system based on the capacity of each battery and the design structure of the battery system.

[0182] The command for calculating the operating cost of the energy storage system may include a command for calculating a grid power purchase cost and a battery purchase cost for each of the combinations; and a command for calculating the operating cost based on the grid power purchase cost and the battery purchase cost.

[0183] The command for calculating the operating cost of the energy storage system may include a command for calculating a system power purchase cost for a preset period for each of the combinations based on past history information for at least one of the energy storage system, a load linked to the energy storage system, and a power generation device linked to the energy storage system, and charge / discharge schedule information of a two-way electric vehicle (EV) charger linked to the energy storage system.

[0184] The command for calculating the above system power purchase cost may include a command for deriving an operation schedule including a time interval charge / discharge amount that minimizes the system power purchase cost by using an objective function defined as the system power purchase cost; and a command for calculating the system power purchase cost for a preset period for each of the combinations by applying the operation schedule and system power cost information to an energy storage system according to each of the above combinations.

[0185] The above objective function may be defined as a constraint including at least one of a first condition regarding the balance of power supply and power consumption, a second condition regarding the state of charge (SOC) according to the charge / discharge efficiency of the ESS battery, a third condition regarding the limit charge amount of the ESS battery, a fourth condition regarding the limit output of the inverter, a fifth condition regarding the binarization of the charge / discharge state of the ESS battery, a sixth condition regarding the state of charge (SOC) according to the charge / discharge efficiency of the EV battery, a seventh condition regarding the limit charge amount of the EV battery, an eighth condition regarding the limit output of a bidirectional EV charger, and a ninth condition regarding the binarization of the charge / discharge state of the bidirectional EV charger.

[0186] The at least one command may further include a command for providing the generated recommended combination information to a user terminal linked to the energy storage system.

[0187] The above recommended combination information may include at least one of the model name, capacity, number, and connection structure of the batteries applied to the energy storage system.

[0188] The operation support device (500) may also include an input interface device (540), an output interface device (550), a storage device (560), etc. Each component included in the operation support device (500) may be connected by a bus (570) and communicate with each other.

[0189] Here, the processor (510) 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).

[0190] 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.

[0191] 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.

[0192] 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. As an operation support device for an energy storage system (ESS), at least one processor; and A memory that stores at least one instruction to be executed through at least one processor, At least one of the above commands, A command to collect information about a battery applicable to the above energy storage system; A command for deriving a plurality of combinations, each of which comprises one or more batteries applicable to the energy storage system, based on the structure of the energy storage system; A command for calculating the operating cost of the energy storage system for each of the above combinations; and An operation support device comprising a command to generate recommended combination information including information about a combination representing the minimum operating cost among the above combinations.

2. In claim 1, The command to collect information about the above battery is: An operational support device comprising a command to collect, for each of one or more batteries, one or more of the following: model name, capacity, critical SOC range, and purchase cost.

3. In claim 1, The command to derive the above multiple combinations is: An operation support device comprising a command for deriving a plurality of combinations applicable to the energy storage system based on the capacity of each battery and the design structure of the battery system.

4. In claim 1, A command for calculating the operating cost of the above energy storage system is: A command for calculating the system power purchase cost and battery purchase cost for each of the above combinations; and An operation support device including a command for calculating the operating cost based on the system power purchase cost and battery purchase cost.

5. In claim 4, A command for calculating the operating cost of the above energy storage system is: An operation support device including a command for calculating a system power purchase cost for a preset period for each of the combinations based on past history information for at least one of the energy storage system, a load linked to the energy storage system, and a power generation device linked to the energy storage system, and charge / discharge schedule information of a two-way electric vehicle (EV) charger linked to the energy storage system.

6. In claim 5, The command to calculate the above system power purchase cost is: A command for deriving an operation schedule including the amount of charge and discharge per time interval that minimizes the purchase cost of system power by using an objective function defined as the purchase cost of system power; and An operation support device including a command for calculating a system power purchase cost for a preset period for each of the combinations by applying the operation schedule and system power cost information to the energy storage system according to each of the combinations.

7. In claim 6, The above objective function is, An operation support device in which a constraint condition is defined, including at least one of a first condition regarding the balance of power supply and power consumption, a second condition regarding the state of charge (SOC) according to the charge / discharge efficiency of an ESS battery, a third condition regarding the limit charge amount of an ESS battery, a fourth condition regarding the limit output of an inverter, a fifth condition regarding binarization of the charge / discharge state of an ESS battery, a sixth condition regarding the state of charge (SOC) according to the charge / discharge efficiency of an EV battery, a seventh condition regarding the limit charge amount of an EV battery, an eighth condition regarding the limit output of a bidirectional EV charger, and a ninth condition regarding binarization of the charge / discharge state of a bidirectional EV charger.

8. In claim 1, At least one of the above commands, An operation support device further comprising a command for providing the generated recommended combination information to a user terminal linked to the energy storage system.

9. In claim 8, The above recommended combination information is: An operation support device including at least one of the model name, capacity, number, and connection structure of batteries applied to the energy storage system.

10. As a method for supporting the operation of an energy storage system, A step of collecting information on a battery that can be applied to the above energy storage system; A step of deriving a plurality of combinations, each of which comprises one or more batteries applicable to the energy storage system, based on the structure of the energy storage system; A step of calculating the operating cost of the energy storage system for each of the above combinations; and An operation support method comprising a step of generating recommended combination information including information about a combination representing the minimum operating cost among the above combinations.

11. In claim 10, The steps of collecting information about the above batteries are: An operational support method comprising the step of collecting, for each of one or more batteries, at least one of a model name, a capacity, a critical SOC range, and a purchase cost.

12. In claim 10, The step of deriving the above multiple combinations is: An operation support method comprising a step of deriving a plurality of combinations applicable to the energy storage system based on the capacity of each battery and the design structure of the battery system.

13. In claim 10, The step of calculating the operating cost of the above energy storage system is: A step of calculating the system power purchase cost and battery purchase cost for each of the above combinations; and An operation support method comprising a step of calculating the operating cost based on the system power purchase cost and the battery purchase cost.

14. In claim 13, The step of calculating the operating cost of the above energy storage system is: An operation support method comprising a step of calculating a system power purchase cost for a preset period for each of the combinations based on past history information for at least one of the energy storage system, a load linked to the energy storage system, and a power generation device linked to the energy storage system, and charge / discharge schedule information of a two-way electric vehicle (EV) charger linked to the energy storage system.

15. In claim 14, The step of calculating the above system power purchase cost is: A step of deriving an operation schedule including the charging and discharging amount by time interval that minimizes the purchase cost of system power by using an objective function defined as the purchase cost of system power; and An operation support method comprising a step of calculating a system power purchase cost for a preset period for each of the combinations by applying the operation schedule and system power cost information to the energy storage system according to each of the combinations.

16. In claim 15, The above objective function is, An operation support method, wherein a constraint condition is defined, including at least one of a first condition regarding the balance of power supply and power consumption, a second condition regarding the state of charge (SOC) according to the charge / discharge efficiency of an ESS battery, a third condition regarding the limit charge amount of an ESS battery, a fourth condition regarding the limit output of an inverter, a fifth condition regarding binarization of the charge / discharge state of an ESS battery, a sixth condition regarding the state of charge (SOC) according to the charge / discharge efficiency of an EV battery, a seventh condition regarding the limit charge amount of an EV battery, an eighth condition regarding the limit output of a bidirectional EV charger, and a ninth condition regarding binarization of the charge / discharge state of a bidirectional EV charger.

17. In claim 10, An operation support method further comprising a step of providing the generated recommended combination information to a user terminal linked to the energy storage system.

18. In claim 17, The above recommended combination information is: An operation support method comprising at least one of the model name, capacity, number, and connection structure of batteries applied to the energy storage system.

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