Energy management device and energy management method

Abstract

An energy management device according to an embodiment of the present invention interworks with a power system, a power generation device, an energy storage system (ESS), and a bidirectional electric vehicle (EV) charger. The energy management device comprises: at least one processor; and a memory storing at least one command that is executed via the at least one processor. Here, the at least one command may include: a command to collect basic information including information about a power generation state and a power consumption state, and grid power cost information; a command to use the collected basic information to create an ESS operation schedule for controlling a charging / discharging operation of an ESS battery, and an EV operation schedule for controlling a charging / discharging operation of an EV battery; and a command to control so that the ESS battery and the EV battery are charged and discharged according to the ESS operation schedule and the EV operation schedule.

Description

Energy management device and energy management method

[0001] This application claims the benefit of Korean Patent Application No. 10-2023-0101159 filed with the Korean Intellectual Property Office on August 2, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] The present invention relates to an energy management device and an energy management method, and more particularly, to an energy management device and an energy management method using the energy management device, which are interlocked with a power system, a power generation device, an energy storage system, and a bidirectional electric vehicle charger.

[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] Recently, an ESS linked to a photovoltaic (PV) system and an electric vehicle (EV) charging system has been proposed. Here, the upper control unit of the PV and EV-linked ESS is configured to appropriately distribute grid power, power generated by the PV system, and stored power from the ESS to supply loads and EV chargers, and store any remaining power in a battery system.

[0005] PV and EV-linked ESSs operate based on a variety of factors, including the PV system's power generation, the power demand of the load and EV charger, and the battery's state of charge. However, the most important goal for ESS users is minimizing power purchase costs. However, conventional ESSs operate with the goal of maximizing PV generation, maximizing battery performance, or minimizing grid power consumption.

[0006] Accordingly, appropriate energy management technology is needed to enable optimal operation considering PV power generation, load, EV charger power demand, and battery charge status, while simultaneously minimizing power purchase costs.

[0007] The purpose of the present invention to solve the above problems is to provide an energy management device that can minimize the cost of purchasing power from a grid.

[0008] Another object of the present invention to solve the above problems is to provide an energy management method using such an energy management device.

[0009] An energy management device according to one embodiment of the present invention for achieving the above object is an energy management device that is interlocked with a power system, a power generation device, an energy storage system (ESS), and a two-way electric vehicle (EV) charger, and may include at least one processor; and a memory that stores at least one command executed through the at least one processor.

[0010] Here, the at least one command may include: a command for collecting basic information including information on power generation status and power consumption status and system power cost information; a command for establishing an ESS operation schedule for controlling charge and discharge operations of an ESS battery and an EV operation schedule for controlling charge and discharge operations of an EV battery using the collected basic information; and a command for controlling charge and discharge of the ESS battery and the EV battery according to the ESS operation schedule and the EV operation schedule.

[0011] The command for establishing the above operation schedule may include a command for deriving the charge / discharge amount of the ESS battery per time interval and the charge / discharge amount of the EV battery per time interval, which minimizes the purchase cost of system power.

[0012] The command for establishing the above ESS operation schedule and EV operation schedule may include a command for deriving the charge / discharge amount of the ESS battery for each time interval and the charge / discharge amount of the EV battery for each time interval using an objective function defined as the purchase cost of system power.

[0013] The above objective function 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 / 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 power conversion device, and a fifth condition regarding the binarization of the charge / discharge state of the ESS battery. Here, the constraints may further include at least one of 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.

[0014] The command for collecting the above basic information may include a command for collecting basic information including information on a power production status and a power consumption status for a predefined first period. Here, the command for establishing the ESS operation schedule and the EV operation schedule may include a command for generating power production prediction information and power consumption prediction information for a predefined second period after the first period using the collected basic information; and a command for generating an ESS operation schedule and an EV operation schedule for the second period based on the generated prediction information.

[0015] The command for collecting the above basic information may include a command for receiving load schedule information from a user terminal, wherein a time period for operating in an on or off state is set for an on / off controllable load. Here, the command for establishing the ESS operation schedule and EV operation schedule may include a command for generating an ESS operation schedule and an EV operation schedule based on the load schedule information.

[0016] The command for collecting the above basic information may include a command for receiving EV schedule information from a user terminal, wherein the time period during which the EV is connected to a two-way EV charger is set. Here, the command for establishing the ESS operation schedule and the EV operation schedule may include a command for generating the ESS operation schedule and the EV operation schedule based on the EV schedule information.

[0017] The command for controlling the charging and discharging of the ESS battery and the EV battery may include a command for providing the ESS operation schedule to a power conversion device linked to the ESS battery and providing the EV operation schedule to the bidirectional EV charger, so that the ESS battery is charged and discharged according to the ESS operation schedule and the EV battery is charged and discharged according to the EV operation schedule.

[0018]

[0019] According to another embodiment of the present invention for achieving the above-described further object, an energy management method is provided, which is an energy management method by an energy management device that is interlocked with a power system, a power generation device, an energy storage system (ESS), and a bidirectional electric vehicle (EV) charger, the method comprising: a step of collecting basic information including information on a power generation status and a power consumption status, and system power cost information; a step of establishing an ESS operation schedule for controlling a charge / discharge operation of an ESS battery and an EV operation schedule for controlling a charge / discharge operation of an EV battery using the collected basic information; and a step of controlling the ESS battery and the EV battery to be charged / discharged according to the ESS operation schedule and the EV operation schedule.

[0020] The step of establishing the above operation schedule may include a step of deriving the charge / discharge amount of the ESS battery per time interval and the charge / discharge amount of the EV battery per time interval, which minimizes the purchase cost of system power.

[0021] The step of establishing the above ESS operation schedule and EV operation schedule may include a step of deriving the charge / discharge amount of the ESS battery for each time interval and the charge / discharge amount of the EV battery for each time interval using an objective function defined as the purchase cost of system power.

[0022] The above objective function 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 / 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 power conversion device, and a fifth condition regarding the binarization of the charge / discharge state of the ESS battery. Here, the constraints may further include at least one of 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.

[0023] The step of collecting the above basic information may include a step of collecting basic information including information on a power production status and a power consumption status for a predefined first period. Here, the step of establishing the ESS operation schedule and the EV operation schedule may include a step of generating power production prediction information and power consumption prediction information for a second period, which is a predefined period after the first period, using the collected basic information; and a step of generating an ESS operation schedule and an EV operation schedule for the second period based on the generated prediction information.

[0024] The step of collecting the above basic information may include a step of receiving load schedule information from a user terminal, wherein a time period for operating in an on or off state is set for a load that can be controlled on or off. Here, the step of establishing the ESS operation schedule and EV operation schedule may include a step of generating an ESS operation schedule and an EV operation schedule based on the load schedule information.

[0025] The step of collecting the above basic information may include a step of receiving EV schedule information from a user terminal, wherein the EV schedule information includes a time period during which the EV is connected to a two-way EV charger. Here, the step of establishing the ESS operation schedule and the EV operation schedule may include a step of generating the ESS operation schedule and the EV operation schedule based on the EV schedule information.

[0026] The step of controlling the ESS battery and the EV battery to be charged and discharged may include a step of providing the ESS operation schedule to a power conversion device linked to the ESS battery and providing the EV operation schedule to the bidirectional EV charger, so that the ESS battery is charged and discharged according to the ESS operation schedule and the EV battery is charged and discharged according to the EV operation schedule.

[0027] According to the above-described embodiment of the present invention, an operating schedule of an ESS and an EV charger that can minimize the cost of purchasing grid power is derived, and by controlling the ESS and EV charger according to the derived operating schedule, the operating cost of a PV and EV-linked ESS can be minimized.

[0028] Figure 1 is a block diagram of an energy storage system to which the present invention can be applied.

[0029] Figure 2 shows an implementation example of an energy storage system to which the present invention can be applied.

[0030] Figure 3 is a flowchart of an energy management method according to an embodiment of the present invention.

[0031] Figure 4 is a flowchart of a method for establishing an operation schedule according to an embodiment of the present invention.

[0032] FIG. 5 is an example screen of a user terminal for explaining EV schedule information according to an embodiment of the present invention.

[0033] Figure 6 is an example of a screen of a user terminal for explaining load schedule information according to an embodiment of the present invention.

[0034] Figure 7 is a block diagram of an energy management device according to an embodiment of the present invention.

[0035] 100: Grid

[0036] 200: Subordinate

[0037] 300: Power generation device

[0038] 400: EV charger

[0039] 500: Energy storage system

[0040] 600: Energy management device

[0041] 700: User terminal

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047]

[0048] Some terms used in this specification are defined as follows:

[0049] 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 [%].

[0050] 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.

[0051]

[0052] Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

[0053]

[0054] Figure 1 is a block diagram of an energy storage system to which the present invention can be applied.

[0055] The energy management device (600) can be connected to a grid (100), a load (200), a power generation device (300), an electric vehicle (EV) charger (400), and an energy storage system (500).

[0056] The energy storage system (500) is electrically connected to the grid (100) and the power generation device (300), and can receive power from the grid (100) and the power generation device (300) and store it internally.

[0057] The energy storage system (500) is electrically connected to a load (200) and an EV charger (400), and can supply power stored in a battery (hereinafter, ESS battery) included in the energy storage system to the load (200) and the EV charger (400). Meanwhile, the load (200) is electrically connected to a grid (100) and a power generation device (300), and can receive power from the grid (100) and the power generation device (300).

[0058] The power generation device (300) 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 (300) is not an essential component of the present invention, the scope of the present invention is not limited to these entities.

[0059] The EV charger (400) is electrically connected to the grid (100), the power generation device (300), and the energy storage system (500), and can receive power from the grid (100), the power generation device (300), and the energy storage system (500).

[0060] In an embodiment, the EV charger (400) may correspond to a bidirectional EV charger. In this case, the EV charger (400) 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 (400), the bidirectional EV charger and EV battery may function in the same manner as the energy storage system (500) according to the present invention.

[0061] When the EV charger (400) is configured as a bidirectional charger, the EV charger (400) can supply power stored therein to the load (200) and the energy storage system (500).

[0062] The energy management device (600) may be configured to be connected to one or more of a load (200), a power generation device (300), an EV charger (400), and an energy storage system (500) through a network to transmit and receive data with each other.

[0063] The energy management device (600) may be configured to be included within the energy storage system (500), or may be separately provided outside the energy storage system (500). For example, the energy management device (600) may be implemented to be included within the HEMS (Home Energy Management System), which is the top-level control system of a residential ESS, or may be implemented to be included within the server of an ESS management company and connected to the HEMS via a network.

[0064] The energy management device (600) can collect one or more of the operating status of the energy storage system (500), the power generation status of the power generation device (300), and the power consumption status of the load (200), and can establish an operation schedule for optimal operation of the energy storage system (500) and the EV charger (400) using the collected information. Here, the energy management device (600) can establish an ESS operation schedule for controlling the energy storage system (500) and an EV operation schedule for controlling the EV charger (400) using a predefined operation schedule generation algorithm.

[0065] The operating schedule may include the charge / discharge amount (or reference power amount) for each time period. Specifically, the ESS operating schedule may include the charge / discharge amount of the ESS battery for each time period, and the EV operating schedule may include the charge / discharge amount of the EV battery for each time period.

[0066] The energy management device (600) can control the charging and discharging of the ESS battery according to the ESS operating schedule by transmitting the established ESS operating schedule to the battery charging and discharging control device of the energy storage system (500).

[0067] In addition, the energy management device (600) can control charging and discharging of the EV battery according to the EV operation schedule by transmitting the established EV operation schedule to the EV charger (400).

[0068]

[0069] Figure 2 shows an implementation example of an energy storage system to which the present invention can be applied.

[0070] Referring to FIG. 2, an energy storage system (500) may be configured to include an ESS battery (510) that stores power, and an inverter (520) that controls the charging and discharging operation of the ESS battery (510).

[0071] The ESS battery (510) 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.

[0072] Each 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.

[0073] The inverter (520), also referred to as a power conditioning system (PCS) or a power conversion system (PCS), can control power supplied to the battery from the outside and power supplied from the battery to the outside.

[0074] The inverter (520) may include a power management system (PMS), and the energy management device (600) may be configured to be linked with the power management system of the inverter (520) to mutually transmit and receive data.

[0075] The load (200) may be configured to include a plurality of loads (200-1 to 200-N). Here, at least some of the loads (200-1 to 200-N) may be first loads that cannot be turned on and off, and the remaining some may be configured as second loads that can be turned on and off.

[0076] 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 energy management device. 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 energy management device. Here, the second load may be defined based on a selection signal input by a user.

[0077] The PV system may be configured to include a PV module (310) (e.g., a solar panel) and a PV inverter (320) which is an AC / DC inverter, and the AC terminal of the PV inverter (320) and the AC terminal of the inverter (520) of the energy storage system may be configured to be connected to an AC link.

[0078] The EV charger may correspond to a bidirectional EV charger (420). Here, the bidirectional EV charger (420) is configured to include an AC / DC inverter, and an AC terminal may be connected to an AC link.

[0079] A two-way EV charger (420) can control the charging and discharging operation of an EV battery included in an EV (410).

[0080] The energy management device (600) is an upper control device of a grid, a plurality of loads, a PV system, a bidirectional EV charger, and an energy storage system, and can be configured to collect status information of each component and control operations of one or more of the loads, the PV system, the bidirectional EV charger, and the energy storage system based on the collected status information.

[0081] The energy management device (600) can establish an operation schedule capable of minimizing the cost of purchasing power from the grid based on one or more of the charge / discharge amount of the ESS battery, the charge / discharge amount of the EV battery, the power generation amount of the PV, and the power consumption amount of the loads. Here, the energy management device (600) can establish an ESS operation schedule for controlling the energy storage system (500) and an EV operation schedule for controlling the EV charger (400) using a predefined objective function and constraints.

[0082] The energy management device (600) can be configured to be connected to a user terminal (700) through a network and to mutually transmit and receive data.

[0083] A user terminal (700) may refer to a computing device used by an owner or manager of an energy storage system, and may correspond to, for example, a personal computer (PC), a mobile phone, or a tablet PC.

[0084] The energy management device (600) can receive load schedule information for the second load from the user terminal (700). Here, the load schedule information can include information regarding a time period set by the user for each of the second loads to operate in an on or off state.

[0085] The energy management device (600) can control the on / off of the second load based on load schedule information received from the user terminal (700). For example, if load schedule information including [load 4, off at 14:00, on at 16:00] is received, the energy management device (600) can turn off the power of load 4 at 14:00 or cut off the power supply to load 4. Thereafter, the energy management device (600) can turn on the power of load 4 at 16:00 or release the power supply cutoff to load 4.

[0086] The energy management device (600) can receive EV schedule information for the EV (410) from the user terminal (700). Here, the EV schedule information can include information regarding the time period set by the user during which the EV is connected to the bidirectional EV charger. For example, the energy management device (600) can receive EV schedule information including [EV connection time, 17:00 ~ 19:00, 21:00 ~ 24:00] from the user terminal (700).

[0087] The load schedule information and EV schedule information received from the user terminal (700) can be used as basic information in the process of establishing the ESS operation schedule and EV operation schedule.

[0088] The energy management device (600) transmits the established ESS operation schedule to the inverter (520) of the energy storage system (500), and the inverter (520) can control the charging and discharging operation of the ESS battery (510) according to the ESS operation schedule. For example, the inverter (520) can receive the ESS operation schedule for a specific day from the energy management device (600), and control the charging and discharging operation of the ESS battery (510) according to the reference power for each time section included in the ESS operation schedule.

[0089] The energy management device (600) transmits the established EV operation schedule to the bidirectional EV charger (420), and the bidirectional EV charger (420) can control the charging and discharging operation of the EV battery according to the EV operation schedule. For example, the bidirectional EV charger (420) can receive the EV operation schedule for a specific day from the energy management device (600), and control the charging and discharging operation of the EV battery according to the reference power for each time section included in the EV operation schedule.

[0090] The energy storage system illustrated in Fig. 2 is an AC coupled ESS in which a PV system, a bidirectional EV charger, a load, and an energy storage system are connected over an AC link. Meanwhile, the present invention can also be applied to a DC coupled ESS in which the output terminal of the PV system, the input terminal of the EV charger, and the output terminal of the energy storage system are connected over a DC link, and the DC link is connected to one terminal of an AC / DC inverter.

[0091]

[0092] Figure 3 is a flowchart of an energy management method according to an embodiment of the present invention.

[0093] An energy management method according to an embodiment of the present invention can be performed by an energy management device that is interlocked with a power system, a power generation device, an energy storage system, and a bidirectional EV charger.

[0094] The energy management device can collect basic information for establishing an operating schedule (S310). Here, the basic information may include information on power production status, power consumption status, and system power cost information.

[0095] The energy management device can establish an ESS operation schedule for controlling the charging and discharging operations of the ESS battery and an EV operation schedule for controlling the charging and discharging operations of the EV battery using the collected basic information (S320). Here, the ESS operation schedule may include the charging and discharging amounts (or reference power amounts) of the ESS battery for each time period, and the EV operation schedule may include the charging and discharging amounts (or reference power amounts) of the EV battery for each time period.

[0096] In an operating schedule, time intervals can be defined in various ways, such as 30-minute, 15-minute, or 1-minute increments. The operating schedule may include information about the operating period. For example, the start time of an operation may be defined as 00:00 on a specific day, and the end time may be defined as 24:00 on that day. The energy management device can derive an ESS operating schedule and an EV operating schedule that minimize the cost of purchasing grid power by utilizing an optimization technique utilizing an objective function.

[0097] The energy management device can control the ESS battery and EV battery to be charged and discharged according to the operation schedule established in S320 (S330).

[0098] Specifically, the energy management device transmits the ESS operation schedule to the inverter of the energy storage system, and the inverter can control the charging and discharging operation of the ESS battery according to the charging and discharging amount for each time interval included in the ESS operation schedule. In addition, the energy management device transmits the EV operation schedule to the bidirectional EV charger, and the bidirectional EV charger can control the charging and discharging operation of the EV battery according to the charging and discharging amount for each time interval included in the EV operation schedule.

[0099] In an embodiment, the energy management device may adjust the operating schedule while the ESS battery and EV battery are operating according to the operating schedule. Here, the energy management device may adjust the operating schedule based on the difference between the predicted value utilized in the process of establishing the operating schedule and the actual measured value collected during the operation according to the operating schedule.

[0100]

[0101] FIG. 4 is a flowchart of a method for establishing an operating schedule according to an embodiment of the present invention. Below, specific embodiments of steps S310 to S320 of FIG. 3 will be described in detail with reference to FIG. 4.

[0102] The energy management device collects basic information (S410).

[0103] The basic information may include ESS battery-related parameters, EV battery-related parameters, grid power cost information, and information regarding power production and power consumption status for a predefined first period. Here, the basic information may further include load schedule information and EV schedule information.

[0104] ESS battery related parameters may include one or more of capacity, SOC upper limit, SOC lower limit, charge / discharge efficiency of the power conversion device, and output limit of the power conversion device for the ESS battery.

[0105] The EV battery-related parameters may include one or more of the following: capacity, charge / discharge efficiency, SOC upper limit, SOC lower limit, charge / discharge efficiency of a bidirectional EV charger, and output limit of a bidirectional EV charger for the EV battery. Here, the energy management device may receive information on one or more of the SOC upper limit and SOC lower limit from the user terminal. For example, the user terminal may receive a minimum guaranteed SOC of the EV battery from the user and transmit the received minimum guaranteed SOC to the energy management device. In this case, the energy management device may define the minimum guaranteed SOC received from the user terminal as the SOC lower limit of the EV battery.

[0106] The grid power cost information may include grid power costs by time interval.

[0107] Information about the power generation status and power consumption status may include the power generation amount of the power generation device for each time period and the power consumption amount of each load for each time period.

[0108] The first period can be defined in various ranges considering the prediction accuracy of the prediction information, and can be defined, for example, from one year prior to a specific day (day n) to one day prior to that day (day n-1).

[0109] The energy management device can generate prediction information for a second period, which is predefined as a period after the first period, using the collected basic information (S420).

[0110] The prediction information may include power generation prediction information and power consumption prediction information. Here, the power generation prediction information may include a predicted power generation amount of a power generation device for each time period, and the power consumption prediction information may include a predicted consumption amount of a load for each time period.

[0111] The second period may be defined as the operating period of the operating schedule, for example, from 0:00 to 24:00 on a specific day (n days).

[0112] In an embodiment, the energy management device may derive pattern information, including a power production pattern and a power consumption pattern, based on information regarding power production status and power consumption status included in the basic information, and may generate power production prediction information and power consumption prediction information using the derived pattern information. For example, the energy management device may derive predicted power generation and power consumption for a specific day by calculating an average value for power generation and power consumption by time interval over a one-year period.

[0113] In another embodiment, the energy management device may generate power production prediction information and power consumption prediction information using an artificial function-based predictive model. For example, the predictive model may be configured to pre-learn learning data regarding power production and power consumption status, and, when basic information is input as input data, output power production prediction information and power consumption prediction information (predicted power generation and consumption by time interval for a specific day) as output data.

[0114] The energy management device can generate an ESS operation schedule and an EV operation schedule for a second period based on the generated prediction information (S430). Here, the energy management device can derive the ESS operation schedule and the EV 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.

[0115] The energy management device can derive an ESS operation schedule including the charge / discharge amounts of the ESS battery for each time interval and an EV operation schedule including the charge / discharge amounts of the EV battery for each time interval using an objective function defined by the purchase cost of grid power. Here, the objective function can be defined as in Mathematical Expression 1 below.

[0116]

[0117] (Here, Pgrid(t) is the grid power schedule and λgrid(t) is the grid power cost.)

[0118]

[0119] Mathematical expression 1 is an objective function for deriving the charge / discharge amount of the ESS battery and the charge / discharge amount of the EV battery by time interval that can minimize the cost of purchasing grid power.

[0120] Here, the objective function according to mathematical expression 1 may have one or more constraints defined.

[0121] The constraints may include 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 power conversion device, and a fifth condition regarding the binarization of the charge and discharge state of the ESS battery. Here, the constraints may further include at least one of 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 the 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, 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, Ppvp(t) is the predicted power generation, and Ploadp(t) is the predicted 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 power conversion device, ηdch is the discharging efficiency of the power conversion device, 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 power conversion device.)

[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] The first condition can be implemented by mathematical expression 2, and the decision variables Pgrid(t), PBatch(t), PBatdch(t), PEVch(t), and PEVdch(t) function to determine the balance between the supply and demand of electricity.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] The eighth and ninth conditions can be implemented by mathematical expressions 10 to 12, and function to prevent the decision variables PEVch(t) and PEVdch(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.

[0160] 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-connected status. Here, the EV connection status value can be defined based on EV schedule information received from the user terminal.

[0161]

[0162] Meanwhile, when one or more second loads (loads capable of on / off control) are included among the plurality of loads, mathematical expression 2 can be modified as in mathematical expressions 13 and 14 below.

[0163]

[0164] (Here, Pload_cp(t) is the predicted power consumption of the first load, and Pload_np(t) is the predicted power consumption of the second load.)

[0165]

[0166]

[0167] (Here, βload_n is the on / off state value of the load with a value of 0 or 1)

[0168]

[0169] When the loads are configured to include a first load and a second load, in S420, the energy management device can generate a predicted power consumption for the first load and a predicted power consumption for the second load. Here, the first condition regarding the balance of power supply and power consumption can be reflected in the on / off schedule of the second load, as in mathematical expression 13.

[0170] The on / off state value βload_n of the load reflected in mathematical expression 14 can be defined as [1] when the state is on and [0] when the state is off. Here, the on / off state value of the load can be defined based on the load schedule information received from the user terminal.

[0171] The energy management device can derive Pgrid(t), PBatch(t), PBatdch(t), PEVch(t), and PEVdch(t) that satisfy the objective function and constraints (the first to ninth conditions), and generate an ESS operation schedule including PBatch(t) and PBatdch(t), and an EV operation schedule including PEVch(t) and PEVdch(t). Meanwhile, the objective function and constraints for establishing the operation schedule may have various modified examples, and the rights of the present invention are not limited to the mathematical formulas described above.

[0172]

[0173] FIG. 5 is an example screen of a user terminal for explaining EV schedule information according to an embodiment of the present invention.

[0174] The energy management 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 schedule information.

[0175] 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).

[0176] For example, as illustrated in FIG. 5, the user terminal may receive a specific SOC value (75%) as a minimum guaranteed SOC from the user, and may receive EV schedule information for time periods (Time 1: 00:00 to 07:00, Time 2: 17:00 to 19:00, Time 3: 21:00 to 24:00) during which the EV is connected to a two-way EV charger. Thereafter, the user terminal may transmit the minimum guaranteed SOC and EV schedule information input by the user to the energy management device.

[0177] The energy management 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 operating schedule. In addition, the energy management 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 operating schedule.

[0178] The energy management device derives Pgrid(t), PBatch(t), PBatdch(t), PEVch(t), and PEVdch(t) that satisfy the objective function according to mathematical expression 1 and constraints (first to ninth conditions) in which information received from a user terminal is reflected, and can generate an ESS operation schedule including PBatch(t) and PBatdch(t), and an EV operation schedule including PEVch(t) and PEVdch(t).

[0179]

[0180] Figure 6 is an example of a screen of a user terminal for explaining load schedule information according to an embodiment of the present invention.

[0181] An energy management device can receive load schedule information, in which a time period for operating in an on or off state is set for an on / off controllable load, from a user terminal, and generate an operation schedule based on the received load schedule information.

[0182] More specifically, the user terminal can input load schedule information for the second load through a predefined GUI.

[0183] For example, as illustrated in FIG. 6, the user terminal can output a list of second loads (Load 4, 5, 6, 7) that can be turned on and off among a plurality of loads (Load 1 to Load N). Thereafter, the user terminal can receive information from the user about a time period during which each of the second loads operates in an on or off state ([Load 4, 14:00 ~ 16:00, on], [Load 5, 15:00 ~ 18:00, on], [Load 6, 12:00 ~ 13:00, on], [Load 7, 14:00 ~ 18:00, off]).

[0184] Thereafter, the user terminal can transmit the load schedule information entered by the user to the energy management device.

[0185] The energy management device can control the on / off state of the second load based on load schedule information received from the user terminal. For example, the energy management device can switch load 4 from an off state to an on state at 2:00 PM, and from an on state to an off state at 4:00 PM. Additionally, the energy management device can switch load 7 from an on state to an off state at 2:00 PM, and from an off state to an on state at 6:00 PM.

[0186] The energy management device can reflect load schedule information received from a user terminal in the first condition (Mathematical Formulas 13 and 14) among the constraints for deriving an operation schedule.

[0187] The energy management device derives Pgrid(t), PBatch(t), PBatdch(t), PEVch(t), and PEVdch(t) that satisfy the objective function according to mathematical expression 1 and constraints (first to ninth conditions) in which information received from a user terminal is reflected, and can generate an ESS operation schedule including PBatch(t) and PBatdch(t), and an EV operation schedule including PEVch(t) and PEVdch(t).

[0188]

[0189] Figure 7 is a block diagram of an energy management device according to an embodiment of the present invention.

[0190] The energy management device (600) according to an embodiment of the present invention may be configured to be included within an energy storage system, or may be separately provided outside the energy storage system. For example, the energy management device (600) may be implemented by being included within a HEMS, which is the top-level control system of a residential ESS, or may be implemented by being included within a server of an ESS management company and connected to the HEMS via a network.

[0191] An energy management device (600) may include at least one processor (610), a memory (620) that stores at least one command executed through the processor, and a transmission / reception device (630) that is connected to a network and performs communication.

[0192] The at least one command may include: a command for collecting basic information including information on power generation status and power consumption status and system power cost information; a command for establishing an ESS operation schedule for controlling charge and discharge operations of an ESS battery and an EV operation schedule for controlling charge and discharge operations of an EV battery using the collected basic information; and a command for controlling charge and discharge of the ESS battery and the EV battery according to the ESS operation schedule and the EV operation schedule.

[0193] The command for establishing the above operation schedule may include a command for deriving the charge / discharge amount of the ESS battery per time interval and the charge / discharge amount of the EV battery per time interval, which minimizes the purchase cost of system power.

[0194] The command for establishing the above ESS operation schedule and EV operation schedule may include a command for deriving the charge / discharge amount of the ESS battery for each time interval and the charge / discharge amount of the EV battery for each time interval using an objective function defined as the purchase cost of system power.

[0195] The above objective function 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 / 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 power conversion device, and a fifth condition regarding the binarization of the charge / discharge state of the ESS battery. Here, the constraints may further include at least one of 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.

[0196] The command for collecting the above basic information may include a command for collecting basic information including information on a power production status and a power consumption status for a predefined first period. Here, the command for establishing the ESS operation schedule and the EV operation schedule may include a command for generating power production prediction information and power consumption prediction information for a predefined second period after the first period using the collected basic information; and a command for generating an ESS operation schedule and an EV operation schedule for the second period based on the generated prediction information.

[0197] The command for collecting the above basic information may include a command for receiving load schedule information from a user terminal, wherein a time period for operating in an on or off state is set for an on / off controllable load. Here, the command for establishing the ESS operation schedule and EV operation schedule may include a command for generating an ESS operation schedule and an EV operation schedule based on the load schedule information.

[0198] The command for collecting the above basic information may include a command for receiving EV schedule information from a user terminal, wherein the time period during which the EV is connected to a two-way EV charger is set. Here, the command for establishing the ESS operation schedule and the EV operation schedule may include a command for generating the ESS operation schedule and the EV operation schedule based on the EV schedule information.

[0199] The command for controlling the charging and discharging of the ESS battery and the EV battery may include a command for providing the ESS operation schedule to a power conversion device linked to the ESS battery and providing the EV operation schedule to the bidirectional EV charger, so that the ESS battery is charged and discharged according to the ESS operation schedule and the EV battery is charged and discharged according to the EV operation schedule.

[0200] The energy management device (600) may also include an input interface device (640), an output interface device (650), a storage device (660), etc. Each component included in the energy management device (600) may be connected by a bus (670) to communicate with each other.

[0201] Here, the processor (610) 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).

[0202] 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.

[0203] 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.

[0204] 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. An energy management device that is linked to a power system, a power generation device, an energy storage system (ESS), and a two-way electric vehicle (EV) charger. 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 basic information including information on power generation status and power consumption status, and information on grid power cost; A command to establish an ESS operation schedule for controlling the charging and discharging operation of an ESS battery and an EV operation schedule for controlling the charging and discharging operation of an EV battery using the collected basic information; and An energy management device including a command for controlling charging and discharging of the ESS battery and the EV battery according to the ESS operation schedule and the EV operation schedule.

2. In claim 1, The order establishing the above operating schedule is: An energy management device including a command for deriving a charge / discharge amount of an ESS battery per time interval and a charge / discharge amount of an EV battery per time interval, which minimizes the purchase cost of grid power.

3. In claim 1, The command to establish the above ESS operation schedule and EV operation schedule is: An energy management device including a command for deriving a charge / discharge amount of an ESS battery per time interval and a charge / discharge amount of an EV battery per time interval using an objective function defined as a purchase cost of system power.

4. In claim 3, The above objective function is, An energy management device, 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 a power conversion device, and a fifth condition regarding the binarization of the charge / discharge state of an ESS battery.

5. In claim 4, The above constraints are, An energy management device further comprising at least one of a sixth condition regarding a state of charge (SOC) according to a charge / discharge efficiency of an EV battery, a seventh condition regarding a limit charge amount of an EV battery, an eighth condition regarding a limit output of a bidirectional EV charger, and a ninth condition regarding binarization of a charge / discharge state of a bidirectional EV charger.

6. In claim 1, The command to collect the above basic information is: Includes a command to collect basic information including information on power production status and power consumption status for a predefined first period, The command to establish the above ESS operation schedule and EV operation schedule is: A command for generating power production forecast information and power consumption forecast information for a second period predefined as a period after the first period using the collected basic information; and An energy management device comprising a command for generating an ESS operation schedule and an EV operation schedule for the second period based on the generated prediction information.

7. In claim 1, The command to collect the above basic information is: For an on-off controllable load, a command is included for receiving load schedule information from a user terminal, wherein a time period for operating in an on or off state is set, The command to establish the above ESS operation schedule and EV operation schedule is: An energy management device including a command for generating an ESS operation schedule and an EV operation schedule based on the above load schedule information.

8. In claim 1, The command to collect the above basic information is: Includes a command for receiving EV schedule information from a user terminal, wherein a time period during which the EV is connected to a bidirectional EV charger is set; The command to establish the above ESS operation schedule and EV operation schedule is: An energy management device including a command for generating an ESS operation schedule and an EV operation schedule based on the above EV schedule information.

9. In claim 1, The command for controlling the charging and discharging of the above ESS battery and the above EV battery is: An energy management device comprising a command for providing the ESS operation schedule to a power conversion device linked to the ESS battery and providing the EV operation schedule to the bidirectional EV charger, so that the ESS battery is charged and discharged according to the ESS operation schedule and the EV battery is charged and discharged according to the EV operation schedule.

10. An energy management method using an energy management device that is linked to a power system, a power generation device, an energy storage system (ESS), and a two-way electric vehicle (EV) charger. A step of collecting basic information including information on power production status and power consumption status and information on system power cost; A step of establishing an ESS operation schedule for controlling the charging and discharging operation of an ESS battery and an EV operation schedule for controlling the charging and discharging operation of an EV battery using the collected basic information; and An energy management method comprising a step of controlling charging and discharging of the ESS battery and the EV battery according to the ESS operation schedule and the EV operation schedule.

11. In claim 10, The steps for establishing the above operating schedule are: An energy management method, comprising a step of deriving a charge / discharge amount of an ESS battery per time interval and a charge / discharge amount of an EV battery per time interval, which minimizes the purchase cost of grid power.

12. In claim 10, The steps for establishing the above ESS operation schedule and EV operation schedule are: An energy management method comprising a step of deriving the charge / discharge amount of an ESS battery for each time interval and the charge / discharge amount of an EV battery for each time interval using an objective function defined as the purchase cost of system power.

13. In claim 12, The above objective function is, An energy management method, wherein constraints are 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 a power conversion device, and a fifth condition regarding the binarization of the charge / discharge state of an ESS battery.

14. In claim 13, The above constraints are, An energy management method further comprising at least one of a sixth condition regarding a state of charge (SOC) according to a charge / discharge efficiency of an EV battery, a seventh condition regarding a limit charge amount of an EV battery, an eighth condition regarding a limit output of a bidirectional EV charger, and a ninth condition regarding binarization of a charge / discharge state of a bidirectional EV charger.

15. In claim 10, The steps of collecting the above basic information are: Comprising a step of collecting basic information including information on power production status and power consumption status for a predefined first period, The steps for establishing the above ESS operation schedule and EV operation schedule are: A step of generating power production forecast information and power consumption forecast information for a second period predefined as a period after the first period using the collected basic information; and An energy management method comprising a step of generating an ESS operation schedule and an EV operation schedule for the second period based on the generated prediction information.

16. In claim 10, The steps of collecting the above basic information are: For an on-off controllable load, a step of receiving load schedule information from a user terminal, wherein a time period for operating in an on or off state is set, The steps for establishing the above ESS operation schedule and EV operation schedule are: An energy management method comprising a step of generating an ESS operation schedule and an EV operation schedule based on the above load schedule information.

17. In claim 10, The steps of collecting the above basic information are: A step of receiving EV schedule information from a user terminal, wherein a time period during which the EV is connected to a bidirectional EV charger is set, The steps for establishing the above ESS operation schedule and EV operation schedule are: An energy management method comprising a step of generating an ESS operation schedule and an EV operation schedule based on the above EV schedule information.

18. In claim 10, The step of controlling the charging and discharging of the above ESS battery and the above EV battery is as follows: An energy management method comprising the step of providing the ESS operation schedule to a power conversion device linked to the ESS battery and providing the EV operation schedule to the bidirectional EV charger, so that the ESS battery is charged and discharged according to the ESS operation schedule and the EV battery is charged and discharged according to the EV operation schedule.

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