Controller, energy management system, and computer program

Abstract

To make it possible to efficiently transmit power by reducing power-transmission loss.SOLUTION: A controller according to the present embodiment is a controller for a power system capable of feeding power to a loading device in a plurality of demand areas based on first to N-th power devices each capable of at least either discharging or charging power, which are provided in first to N-th installation areas, respectively. The controller comprises a control part for determining control parameters regarding inputting / outputting of the power, that are arranged in the first to N-th power devices according to distances between the demand areas and the first to N-th installation areas by detecting the demand areas in which power consumption is varied larger than conventional, based on information about the power consumption in each of the demand areas.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present embodiment relates to a control device, an energy management system, and a computer program. [Background technology]

[0002] Electricity generated at power plants incurs transmission losses while being transmitted to the area where it is actually used. Transmission losses occur when, as current flows through an electric wire, some of the electricity turns into heat and escapes into the air due to the resistance of the wire. Local production and consumption of electricity has attracted attention as a way to reduce power losses due to transmission losses. With local production and consumption, electricity generated locally (in a microgrid) is used on the spot, shortening the transmission distance and making it possible to reduce transmission losses. As a technology related to local production and consumption, a local production and consumption system has also been proposed, which allows electricity generated locally from renewable energy sources to be used efficiently within the region.

[0003] However, although this system can reduce transmission loss through local production and consumption, no consideration is given to ways to further reduce transmission loss within the microgrid.For example, even within a microgrid, if the distance from the power generation source (power supply source) to the supply destination area is long, transmission loss becomes relatively large, but there is no disclosure of how to reduce such transmission loss. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2020-43660 Summary of the Invention [Problem to be solved by the invention]

[0005] The present embodiment provides a control device, an energy management system, and a computer program that enable efficient transmission of electric power by reducing transmission loss. [Means for solving the problem]

[0006] The control device of this embodiment is a control device for an electric power system capable of supplying electric power to load devices in a plurality of demand areas based on first to Nth power devices capable of at least one of discharging or charging electric power installed in first to Nth installation areas, and is equipped with a control unit that detects a demand area in which the power consumption has fluctuated more than normal based on information on the power consumption for each demand area, and determines control parameters related to the input and output of electric power to be set for the first to Nth power devices depending on the distance between the demand area and the first to Nth installation areas. [Brief description of the drawings]

[0007] [Figure 1] 1 is a block diagram showing an example of an overall view of a power system 1 according to a first embodiment. [Diagram 2] FIG. 1 is a block diagram showing an example of an energy management system. [Diagram 3] 10 is a flowchart illustrating an example of processing by a control unit. [Figure 4] FIG. 13 is a diagram showing an example of controlling the inertial force and the adjustment force according to the distance from each power device to the load fluctuation area. [Diagram 5] FIG. 1 is a diagram showing a configuration example in which a power system is a microgrid. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. (First embodiment) 1 is a block diagram showing an example of an overall view of a power system 1 according to a first embodiment. Solid straight lines connecting components of the power system 1 represent power connections, and dashed straight lines represent communication connections.

[0009] The power system 1 is a system for supplying power generated or stored in a power grid 2 (power source side) to load devices 3 (consumers) in a supply area on the demand side. The power system 1 efficiently realizes frequency control to suppress fluctuations in the frequency of the power grid 2 and stabilize the frequency, even when the balance between the generated power and the power consumption of the consumers changes.

[0010] The supply destination area is divided into a plurality of demand areas in the overall map targeted by the energy management system 100, and FIG. 1 exemplarily shows demand area X and demand area Y. One or more load devices 3 that consume power are arranged in each of the demand areas X and Y. Specifically, the load devices 3 are consumers that consume power. The load devices 3 may be home appliances in an office or home, industrial equipment in a factory, devices equipped with rechargeable batteries such as EVs, or other devices. The load devices 3 or consumers are provided with a smart meter that measures power consumption and a GPS (Global Positioning System). The smart meter is an example of a measuring device having a function of measuring power consumption and a communication function. The GPS is an example of a position detection device that detects the position of the load device 3. The load devices 3 in each of the demand areas X and Y are connected to a power transmission and distribution line 4 in the power system 2. A substation or the like may be interposed between the load devices 3 and the power transmission and distribution line 4. When the power supply of the load device 3 in the demand areas X and Y is turned from OFF to ON or vice versa, when a new load device 3 is connected, when the operation of the load device 3 is changed, etc., the power consumption (power demand) in the demand areas X and Y may temporarily fluctuate significantly. In other words, the power consumption in the demand areas may fluctuate more than usual.

[0011] Information communication devices 51X and 51Y are provided in the demand areas X and Y. The information communication devices 51X and 51Y can communicate wirelessly or wired with the smart meters of the load devices 3 in their respective demand areas, and acquire information on the power consumption of the load devices 3 at regular time intervals or at any timing. The information communication devices 51X and 51Y calculate the power consumption in the demand area (power demand in the demand area) by summing up the acquired power consumption between the load devices 3 in the demand area. The information communication devices 51X and 51Y may also acquire location information of the load devices 3 (e.g., location information detected by GPS) along with the power consumption information.

[0012] The information communication devices 51X and 51Y may include a storage unit that stores the power consumption history of each load device 3 and the history of the total power consumption (power consumption in the demand area) of these load devices 3. The power consumption history of each load device 3 may further include location information of each load device 3. Furthermore, the total power consumption history (power consumption in the demand area) may include information on a representative position calculated from the location information of each load device 3. The representative position may be the center of gravity of these pieces of location information, or may be one selected from these pieces of location information. The one selected may be the location information of the load device 3 with the highest power consumption, the location information of the load device 3 with the largest fluctuation in power consumption, or randomly selected location information.

[0013] The information communication devices 51X and 51Y can communicate with the energy management system 100 wirelessly or wired. The information communication devices 51X and 51Y may be provided with a GPS. When the information communication devices 51X and 51Y are in a demand area, the location information of the information communication devices 51X and 51Y may be used as the location information of the demand area. The information communication devices 51X and 51Y may transmit power consumption information and location information (information of representative location) of the demand areas X and Y, respectively, to the energy management system 100 at regular time intervals or at any timing. The transmission may be performed spontaneously or in response to a request from the energy management system 100.

[0014] The power system 2 is a system that generates electric power (generates electricity) using various power generation devices, stores electric power using various power storage devices, and transmits and distributes electric power using transmission and distribution lines. The power system 2 may be a trunk system that handles a large amount of electric power, or a local system (microgrid) that handles a smaller amount of electric power than the trunk system. In the following, the trunk system is mainly assumed, and the case of a microgrid will be described in the second embodiment.

[0015] A plurality of power supply devices (power devices) 31A, 31B, 31C, 31D, and 31E are installed as distributed power sources on the power transmission and distribution line 4 in the power system 2. When these power devices are not particularly distinguished, they are described as power devices 31. Information communication devices 41A, 41B, 41C, 41D, and 41E are provided between each of the power devices 31A to 31E and the power transmission and distribution line 4. The information communication devices 41A to 41E can communicate with the power devices 31A to 31E by wire or wirelessly, and can also communicate with the energy system 100 by wire or wirelessly. The information communication devices 41A to 41E provide information such as facility information and status of the power devices 31A to 31E to the energy management system 100, and also obtain command information from the energy management system 100 and provide the obtained command information to the power devices 31A to 31E. The command information may include, for example, information on control parameters to be set in the power devices, or information on active power and reactive power to be input / output to / from the power devices. In this example, the information communication devices 41A to 41E are installed between the power transmission / distribution line 4 and the power devices 31A to 31E, but they may be installed at other locations.

[0016] The power devices 31A to 31E are installed in different geographical areas. The installation area of ​​the power device 31A is separated from the installation area of ​​the power device 31B by a distance H1, the installation area of ​​the power device 31B is separated from the installation area of ​​the power device 31C by a distance H2, the installation area of ​​the power device 31C is separated from the installation area of ​​the power device 31D by a distance H3, and the installation area of ​​the power device 31D is separated from the installation area of ​​the power device 31E by a distance H4. The distances H1, H2, H3, and H4 are, for example, 200 km, 100 km, 100 km, and 200 km. The installation areas of the power devices 31A to 31E are described as installation areas A to E, respectively. The distance is basically the distance along the power line of the power system 2, but if the distance along the power line can be approximated to a geographical distance, it is also possible to use the distance between the positions (coordinates) of the installation areas. The position of the installation area may be the position of the power device or the address of the area. In this example, one power device is arranged for each installation area, but multiple power devices may be arranged for each installation area.

[0017] The distance of each demand area to the installation areas A to E is different. For example, the demand area X is closest to the installation area of ​​the power device 31B, followed by the installation area of ​​the power device 31C, and then the installation area of ​​the power device 31D and the installation area of ​​the synchronous generator 31A, which are equally close, and the installation area of ​​the power device 31E is the furthest. Similarly, the demand area Y is different in distance from the installation areas A to E. The farther the installation area is, the longer the power line (transmission and distribution line) is, and the greater the attenuation of the transmitted power is. Also, the magnitude of attenuation is greater the higher the frequency component. The distance between the demand area and the installation area is basically the distance along the power line of the power system 2 (which may include the wiring within the demand area), but if the distance along the power line can be approximated to a geographical distance, it is also possible to use the distance between the position (coordinates) of the demand area and the position (coordinates) of the installation area.

[0018] Hereinafter, a detailed description will be given of the power devices 31A to 31E installed in the installation areas A to E, respectively. The power devices 31A to 31E correspond to first to N-th (N is an integer of 2 or more) power devices that are arranged in a power system and capable of at least one of charging and discharging (inputting and outputting) power.

[0019] The power device 31A is a synchronous power generating device that generates AC power and outputs it to the power transmission and distribution line 4. The power device 31A is also referred to as a synchronous power generating device 31A. Synchronous generators are provided, for example, in electric power companies, and specifically, are thermal power plants, hydroelectric power plants, nuclear power plants, geothermal power plants, and the like. The operation of the power device 31A is controlled by command information (command values) of the energy management system 100.

[0020] The power device 31B includes a voltage control inverter 11B and a power storage device 21B connected to the voltage control inverter 11B. The power storage device 21B is a storage battery that can charge power supplied from the power transmission / distribution line 4 and discharge stored power to the power transmission / distribution line 4. The charging / discharging operation of the power storage device 21B is controlled by the voltage control inverter 11B. The voltage control inverter 11B is controlled by command information of the energy management system 100. The voltage control inverter 11B operates as a voltage source, and in the case of discharging, converts DC power input from the power storage device 21B into AC power and outputs it to the power transmission / distribution line 4 side, and in the case of charging, converts AC power input from the power transmission / distribution line 4 into DC power and outputs it to the power storage device 21B. The voltage control inverter may also be called a power conversion device or a PCS (Power Conditioning System).

[0021] The power device 31C includes a voltage control inverter 11C and a home solar power generation device 21C connected to the voltage control inverter 11C. The home solar power generation device 21C can discharge solar-generated power to the power transmission and distribution line 4. The operation of the home solar power generation device 21C is controlled by the voltage control inverter 11C. The voltage control inverter 11C is controlled by command information from the energy management system 100. The home solar power generation device 21C may include a storage battery that stores solar-generated power. The voltage control inverter 11C operates as a voltage source, converting DC power input from the home solar power generation device 21C into AC power and outputting it to the power transmission and distribution line 4 side.

[0022] The power device 31D includes a voltage control inverter 11D and an electric vehicle 21D connected to the voltage control inverter 11D. The electric vehicle 21D includes a storage battery and can be connected to the power system 2 by inserting a plug or the like, and can be separated from the power system 2 by unplugging the plug or the like. The electric vehicle 21D connected to the power system 2 can charge the internal storage battery with power supplied from the power transmission and distribution line 4 or power supplied from an external storage (not shown), and can discharge the power stored in the storage battery to the power transmission and distribution line 4. The operation of the electric vehicle 21D is controlled by the voltage control inverter 11D. The operation of the voltage control inverter 11D is controlled by command information of the energy management system 100. The voltage control inverter 11D operates like a voltage source, and in the case of discharging, converts DC power input from the storage battery of the electric vehicle 21D into AC power and outputs it to the power transmission and distribution line 4 side, and in the case of charging, converts AC power input from the power transmission and distribution line 4 into DC power and outputs it to the storage battery of the electric vehicle 21D.

[0023] The power device 31E includes a voltage control inverter 11E and a large-scale photovoltaic power generation device 21E connected to the voltage control inverter 11E. The large-scale photovoltaic power generation device 21E is a photovoltaic power generation device with a power generation capacity (output power) larger than that of the home photovoltaic power generation device 21B. The large-scale photovoltaic power generation device 21E can discharge solar-generated power to the power transmission and distribution line 4. The operation of the large-scale photovoltaic power generation device 21E is controlled by the voltage control inverter 11E. The voltage control inverter 11E is controlled by a command value of the energy management system 100. The large-scale photovoltaic power generation device 21E may include a storage battery that accumulates solar-generated power. The voltage control inverter 11E operates as a voltage source, converting DC power input from the large-scale photovoltaic power generation device 21E into AC power and outputting it to the power transmission and distribution line 4 side.

[0024] It is also possible to provide a type of power device other than the power devices 31A to 31E. For example, a power device including a wind power generating device may be provided.

[0025] The synchronous generator (power device) 31A and the power devices 31B to 31E (more specifically, the voltage control inverters 11B to 11E) have a frequency control function or a capability for stabilizing the frequency when the frequency of the power system 2 fluctuates. Hereinafter, this frequency control function will be described.

[0026] The synchronous generator 31A is equipped with inertia, droop control (governor free), LFC (Load Frequency Control), and ELD (Economic Load Dispatching). Droop control (governor free) corresponds to the primary regulation capability, LFC corresponds to the secondary regulation capability, and ELD corresponds to the tertiary regulation capability. LFC and ELD are performed by generating and outputting power (active power and reactive power) according to command information from the energy management system 100.

[0027] Inertia is the inertial force of the rotating body of the power generation device (such as a turbine or motor), and is the force that absorbs the difference between the total generated power and the total consumed power by accelerating or decelerating the rotating body (by increasing or decreasing the amount of power generated). This action due to inertia is also called inertial response. For periodic fluctuations of less than a few seconds, frequency control is performed by inertia.

[0028] For frequency fluctuations with periods of a few seconds to a few minutes, frequency control is performed by droop control (governor free) corresponding to the primary control capability. Droop control is performed by a governor of the synchronous generator 31A. When the size of the load connected to the power system 2 fluctuates, the rotational speed of the rotor changes and the generator frequency varies from the reference frequency, but droop control controls the rotation to suppress this frequency change and increases or decreases the power generation output. Droop control can respond to load fluctuations and supply-demand mismatches that cannot be followed by LFC and ELD.

[0029] Frequency fluctuations with periods of several minutes to several tens of minutes are controlled by LFC (load frequency control) corresponding to secondary control capability. To keep the system frequency constant (reference frequency), the energy management system 100 calculates the power generation output that eliminates the deviation from the frequency deviation of the power system 2, and controls by issuing an output command of the calculated power to the synchronous generator 31A.

[0030] For frequency fluctuations with a period exceeding several tens of minutes, frequency control is performed by ELD (economic load dispatch) corresponding to tertiary control capability. In order to handle relatively long-term load fluctuations (periods of about 10 minutes to several hours), the energy management system 100 calculates the power generation output in advance in accordance with the demand forecast, and controls the synchronous generator 31A by issuing an output command of the calculated power.

[0031] The voltage control inverters 11B to 11E are equipped with simulated inertia, droop control (governor free), LFC (load frequency control), and ELD (economic load dispatch). Droop control (governor free) corresponds to the primary regulation capability, LFC corresponds to the secondary regulation capability, and ELD corresponds to the tertiary regulation capability. LFC and ELD are performed by generating and outputting power (active power and reactive power) according to commands from the energy management system 100.

[0032] Pseudo-inertia is a control method that uses intelligent control to make a power generation device and a power storage device that do not provide inertia operate in a manner similar to the inertia of a synchronous power generation device. Pseudo-inertia is realized by using a known mechanism. Droop control of the voltage control inverters 11B to 11E is realized by simulating an operation similar to the droop control of a synchronous power generation device using intelligent control. The LFC and ELD are the same as those of the synchronous power generation device 31A.

[0033] The magnitude or extent of the inertial response of the synchronous generator 31A can be adjusted by an inertial force constant, which is a control parameter. As the inertial constant increases, the change in the power output due to the inertial response also increases. The magnitude or extent of the inertial response (simulated inertial response) of the voltage control inverters 11B to 11E having pseudo inertia can also be adjusted by the value of a constant, which is a control parameter. This constant in the case of simulated inertia is also called the inertial constant.

[0034] The magnitude or degree of the droop control of the synchronous generator 31A, that is, the first regulating force, can be adjusted by the value of a speed regulating rate (droop rate) which is a control parameter. The speed regulating rate is the ratio of the "change in rotation speed" to the "change in output" when the output of a power generating device operating at a certain output is changed, and may be called the first regulating force constant. The larger the droop rate, the larger the output power (output active power) to the power system 2. The droop characteristics of the voltage controlled inverters 11B to 11E which simulate the droop characteristics of the synchronous generator also use a parameter equivalent to the speed regulating rate (droop rate), and the magnitude or degree of the droop control can be adjusted by this parameter. This parameter is also called the speed regulating rate (droop rate).

[0035] The control parameters are not limited to the above-mentioned inertia constant and droop rate, and may be other types of parameters as long as they are parameters related to the input and output of power from the power device to the power system 2.

[0036] The magnitude of the secondary control capability (LFC) or the magnitude of the tertiary control capability (ELD) is adjusted by the energy management system 100 controlling the magnitude of the active power and reactive power to be commanded to the power devices 31A to 31E based on the frequency deviation of the grid or a demand forecast, etc. That is, the secondary control capability and the tertiary control capability are performed by general control of active power and reactive power.

[0037] The energy management system 100 acquires information on each demand area X, Y (e.g., information on the total power consumption and representative location of the demand area) from the information communication devices 51X, 51Y, and also acquires information on the power devices 31A to 31E from the information communication devices 51A to 51E, and performs frequency control to stabilize the frequency in the power system 2 based on the acquired information.

[0038] Each of the power devices 31A-31E performs an operation based on the inertia and droop control described above individually (autonomously), and the energy management system 100 performs secondary regulation capability control and tertiary regulation capability control for each of the power devices 31A-31E, thereby performing frequency control to stabilize the frequency in the power system 2 even when the balance between the generated power and the power consumption (demanded power) of the consumer changes. At this time, one of the features of the energy management system 100 is that it adjusts the inertia constant and the speed arbitration rate of each power device according to the distance between each demand area X, Y and the installation area of ​​each power device, and controls the secondary regulation capability and the tertiary regulation capability. This makes it possible to control the frequency stabilization while suppressing the transmission loss low even when the supply and demand balance in the power system 2 changes suddenly.

[0039] 2 is a block diagram showing an example of an energy management system 100. The energy management system 100 includes a communication unit 101, a facility information acquisition unit 102, a position information acquisition unit 103, a situation information acquisition unit 104, a database 105, a control unit 106, and a control command unit 107. The control unit 106 has a main function corresponding to the control device according to this embodiment. The control device according to this embodiment may further include at least one or all of the functions of the functional units 101 to 105 and 107 in addition to the control unit 106. The facility information acquisition unit 102, the position information acquisition unit 103, and the situation information acquisition unit 104 are examples of an acquisition unit that acquires information.

[0040] The communication unit 101 communicates wirelessly or wired with the information communication devices 51X and 51Y corresponding to the demand areas X and Y. The communication unit 101 also communicates wirelessly or wired with the information communication devices 41A to 41E corresponding to the power devices 31A to 31E. The communication may be performed by connecting a communication path (link) at all times, or a communication path may be established each time communication is performed and the communication path may be disconnected after the communication is completed. The communication method may be a dedicated protocol or a general-purpose protocol.

[0041] The database 105 internally stores the information acquired by the communication unit 101. The storage location is determined in advance according to the type of information acquired.

[0042] The information acquired from the information communication devices 41A to 41E on the side of the power devices 31A to 31E includes facility information and status information of the power devices 31A to 31E, and information on the installation areas A to E in which the power devices 31A to 31E are installed.

[0043] An example of the facility information of the power devices 31A to 31E is the specification information of the power devices 31A to 31E. When the power device includes a power generation device, the facility information may include output power (power generation capacity) (kW). When the power device includes a power storage device (including the case of an EV), the facility information may include at least one of SOC (State Of Charge) and output power (kW). Here, SOC indicates the ratio of the remaining power amount of the power storage device. When the power device includes a power storage device, the facility information may include inertial energy information. Inertial energy is a value obtained by multiplying the inertial constant of the power device in operation by the output power (kW) of the power storage device, and is information held by the power device. The frequency of acquiring information from the information communication devices 41A to 41E may be at regular intervals or at any timing. Examples of any timing include a timing instructed by the control unit 106 or a timing at a specified time. The frequency of acquiring information may differ depending on the type of information.

[0044] Examples of the status information of the power devices 31A to 31E include, for example, the control parameters (inertia constant, primary adjustment force constant (droop rate)) of the power devices 31A to 31E. There is also information on the current output power of the power devices 31A to 31E. There is also information on control commands (higher order control commands) that the power devices 31A to 31E have received from the energy management system 100 and are executing. The information may be a control command that is currently being executed, or information on a control command that has been executed or received within a certain period of time. Note that the history of control commands issued by the energy management system 100 to the power devices 31A to 31E may be managed by the system itself.

[0045] An example of the information on the installation areas A to E is the position information of the installation areas A to E. This position information may be the position information of the power devices 31A to 31E. If the power devices 31A to 31E are provided with a GPS, it may be the position information detected by the GPS. The position information may be a representative position of the installation areas A to E. The position information may be coordinates represented by longitude, latitude, altitude, etc., or may be an address or an area name. In the case of an area name, the energy management system 100 (the position information acquisition unit 103 or the control unit 106) may specify the position of the installation area from the name using map data. The information on the installation area may also include information indicating the distance from other installation areas. Information on the distance from the installation areas of other power devices may be stored in each power device. The energy management system 100 (the position information acquisition unit 103 or the control unit 106) may calculate the distance between the installation areas from the position information of each installation area.

[0046] The information acquired from the information communication devices 51X and 51Y on the demand areas X and Y side includes the position information and power consumption information of the demand areas X and Y, respectively.

[0047] The location information of the demand area may be a representative location of the demand area or the demand area name. In the case of the name of the demand area, the energy management system 100 (the location information acquisition unit 103 or the control unit 106) may specify the location information of the demand area from the name using map data. The location information of the demand area may also include information indicating the distance between the demand area and each installation area of ​​the power devices 31A to 31E. The energy management system 100 (the location information acquisition unit 103 or the control unit 106) may calculate the distance between the demand area and each installation area from the position of the demand area and the position of each installation area. Instead of acquiring the power consumption information of the demand area, information on the power consumption of each load device in the demand area may be acquired, and the energy management system 100 may calculate the power consumption information of the demand area by adding up these power consumptions.

[0048] The facility information acquisition unit 102 acquires facility information of the power devices 31A to 31E from the database 105 and sends it to the control unit.

[0049] The location information acquisition unit 103 acquires installation area information of the power devices 31A to 31E and location information of the demand areas X and Y from the database 105, and sends them to the control unit 106. At this time, distance information indicating the distance between the demand areas X and Y and the installation areas A to E may also be sent.

[0050] The status acquisition unit 104 acquires status information of the power devices 31A to 31E from the database 105, and sends it to the control unit .

[0051] The control unit 106 may transmit requests for information from the facility information acquisition unit 102, the position information acquisition unit 103, and the situation information acquisition unit 104 at regular time intervals, and acquire the information.

[0052] The control unit 106 controls the operations of the power devices 31A to 35E based on the information acquired from the facility information acquisition unit 102, the position information acquisition unit 103, and the situation information acquisition unit 104. Specifically, the control unit 106 controls the inertia force (control of the inertia constant), the primary adjustment capability (control of the primary adjustment constant or the droop rate), the secondary adjustment capability (control of the active and reactive power), and the tertiary adjustment capability (control of the active and reactive power) in the power devices 31A to 35E. The control command unit 107 transmits a control command according to the content determined by the control unit 106 to the power devices 31A to 35E. The power devices 31A to 35E perform charge and discharge control according to the control command.

[0053] 4 is a flowchart of an example of the process of the control unit 106. The control unit 106 performs this process, for example, at regular intervals.

[0054] It is determined whether the power consumption in each demand area (demand areas X, Y) has fluctuated more than usual (S110). Here, it is determined whether it has fluctuated (increased or decreased) by a certain amount or more per unit time (S110). If it has fluctuated by a certain amount or more, the distance between the demand area where the fluctuation occurred (called a load fluctuation area) and the installation areas A to E in which the power devices 31A to 31E are installed is identified. The distance may be calculated from the position information of the load fluctuation area and the position information of each installation area, or the information on the distance may be stored in advance in the database 105 of the energy management system 100. Here, it is assumed that the consumer area X is a load fluctuation area.

[0055] The inertia force (including pseudo inertia force) of the power devices 31A to 31E is adjusted so that the closer the installation area of ​​the power device is to the load variation area, the larger the inertia force (including pseudo inertia force) (S120). That is, the inertia constant is controlled to be larger. When the load variation area is the demand area X, the distance from the demand area X is closer in the order of the installation area B, the installation area C, the installation areas A and D, and the installation area E. In this case, when the inertia constants of the power devices 31A to 31E are VA to VE, VB is the largest, followed by VC, VA and VD are next largest, and VE is the smallest. As a specific method of determining each value, correspondence information (table or function) that associates the amount of fluctuation in power consumption of the demand area, the distance between the load variation area and the installation area, and the value of the inertia constant may be stored in the database 105 or another storage unit, and the values ​​of the inertia constant may be determined based on this correspondence information. The correspondence information may be in any form such as a table or a function.

[0056] Here, the inertia constant is determined based only on the distance, but the inertia constant may be determined by further considering the state of each power device as a condition.

[0057] For example, when the power device includes a power generation device (power devices 31A, 31C, and 31E in FIG. 1), the inertia constant may be increased as the power generation capacity increases. This reduces power loss in power transmission and distribution, and also improves the safety of the power generation device. The power generation capacity is a value (kW) that indicates how much power the power generation device can generate, and is also called output capacity. The larger the power generation capacity of the power generation device, the more leeway or ability the power generation device has to deal with fluctuations in inertia force even when power consumption rises sharply. Specifically, as a method of reflecting the power generation capacity in the amount of fluctuation in the inertia constant, the power generation capacity may be added to the above-mentioned correspondence information. In this case, the amount of fluctuation in the inertia constant corresponding to the distance from the installation area of ​​the power generation device and the power generation capacity of the power generation device may be obtained from the above-mentioned correspondence information.

[0058] Furthermore, if the power device includes a power storage device, the inertia constant may be increased according to the SOC (State Of Charge) of the power storage device. For example, when power consumption in a demand area increases suddenly, the higher the SOC, the greater the margin or ability to respond to fluctuations in inertial force. Therefore, the higher the SOC, the greater the inertia constant may be. The power storage device may be combined with a home photovoltaic power generation device or a large-scale photovoltaic power generation device to store the power generated by the photovoltaic power generation device (hereinafter the same).

[0059] Furthermore, when the power device includes a power storage device, the inertia constant may be increased according to the inertia energy held by the power device. For example, when power consumption in a demand area increases suddenly, the larger the inertia energy, the greater the margin or ability to respond to fluctuations in inertial force, so the larger the inertia energy, the larger the inertia constant may be.

[0060] The control command unit 107 transmits to each of the power devices 31A-31E command information of the inertia constant determined for the power devices 31A-31E by the control unit 106. The command information may be the value of the inertia constant after the change, or may be the amount of variation from the current value of the inertia constant in each power device.

[0061] 4 shows an example in which the inertial force is adjusted according to the distance from each of the power devices 31A to 31E to a load fluctuation area (demand area X in this example). The magnitude of the inertial constant is shown diagrammatically by the thickness of the arrow. Here, it is assumed that the inertial constant is increased by an amount corresponding to the thickness of the arrow.

[0062] Changing the inertial force is effective for adjustment within a few seconds after the occurrence of a demand fluctuation (power consumption in a demand area). For frequency fluctuations with a period of a few seconds to a few minutes, frequency control is performed by adjusting the primary control capability. Therefore, after performing control to adjust the inertial forces of the power devices 31A to 31E, the control unit 106 next performs control to adjust the primary control capability (S130). Adjusting the primary control capability means adjusting the droop rate (primary control capability constant). As with adjusting the inertial force, the adjustment of the primary control capability may be performed according to the distance between the load fluctuation area and each installation area.

[0063] That is, for the power devices 31A to 31E, the closer the installation area of ​​each power device is to the load fluctuation area, the larger the primary control capability is, that is, the larger the droop rate (primary control capability constant) is controlled. When the load fluctuation area is the demand area X, the above-mentioned installation area B, installation area C, installation area A·D, and installation area E are closer in distance to the demand area X in this order. In this case, if the primary control capability constants of each power device 31A to 31E are WA to WE, WB is the largest, followed by WC, then WA and WD, and WE is the smallest. As a specific method for determining the amount of variation, correspondence information that associates the amount of variation in total power consumption, the distance between the load fluctuation area and the installation area, and the primary control capability constant is stored in the database 105 or another storage unit, and the amount of variation may be determined based on this correspondence information. The correspondence information may be a table or a function. The control command unit 107 transmits command information of the primary control capability constant determined for the power devices 31 to 31E by the control unit 106 to each power device 31A to 31E. The command information may be the value of the primary adjustment power constant after the change, or may be the amount of deviation from the current value of the primary adjustment power constant in each power device.

[0064] Here, the primary adjustment force constant is determined based only on the distance. However, similar to the case of the adjustment of the inertial force, the primary adjustment force constant may be determined by further including the status of each power device as a condition.

[0065] For example, when the power device includes a power generation device (power devices 31A, 31C, and 31E in FIG. 1), the primary control power constant may be increased as the power generation capacity increases. The larger the power generation capacity of the power generation device, the more margin or capability the power generation device has to respond to fluctuations in the primary control power even when power consumption rises sharply. Specifically, as a method of reflecting the power generation capacity in the value of the primary control power constant, the power generation capacity may be added to the above correspondence information. In this case, the value of the primary control power constant corresponding to the distance from the installation area of ​​the power generation device and the power generation capacity of the power generation device may be obtained from the above correspondence information.

[0066] Furthermore, if the power device includes a power storage device, the primary control capability constant may be increased according to the SOC (State Of Charge) of the power storage device. For example, when the total power consumption increases suddenly, the higher the SOC, the greater the margin or ability to respond to fluctuations in primary control capability. Therefore, the primary control capability constant may be increased as the SOC increases.

[0067] Furthermore, when the power device includes a power storage device, the primary adjustment capability constant may be increased according to the inertial energy held by the power device. For example, when the total power consumption increases suddenly, the larger the inertial energy, the more room or capacity there is to cope with this. Therefore, the primary adjustment capability constant may be increased as the inertial energy increases.

[0068] The control command unit 107 transmits command information of the primary adjustment capacity constant determined for the power devices 31-31E by the control unit 106 to each of the power devices 31A-31E. The command information may be the value of the primary adjustment capacity constant after the change, or may be the amount of variation from the current value of the primary adjustment capacity constant in each power device.

[0069] 4 above shows an example in which the primary control capability of the power devices 31A to 31E is adjusted according to the distance from the power devices 31A to 31E to the load fluctuation area (demand area X in this example). The magnitude of the primary control capability of the power devices 31A to 31E is shown typically by the thickness of the arrow. Here, it is assumed that the primary adjustment constant is increased by an amount corresponding to the thickness of the arrow.

[0070] After performing control to adjust the primary control capability of the power devices 31A to 31E, the control unit 106 then performs control to adjust the secondary control capability (S140). For frequency fluctuations with a period of several minutes to several tens of minutes, frequency control is performed by adjusting the secondary control capability (LFC: load frequency control). The secondary control capability is adjusted by general control of active power and reactive power. As with the adjustment of the inertial force and the adjustment of the primary control capability, the secondary control capability may also be adjusted according to the distance between the load fluctuation area and each installation area. The secondary control capability may be adjusted by utilizing the history of previous upper command values ​​(command values ​​of active power and reactive power to be output) for the power devices 31A to 31E.

[0071] For example, if the power consumption in the demand area increases significantly, the active power of the power devices 31A-31E is changed more significantly as the installation area of ​​the power device is closer to the load fluctuation area. As in the case of adjusting the inertial force and the primary control capability, the secondary control capability may be adjusted by further including the conditions of the individual power devices (power generation capacity, SOC, inertial energy, etc.) as conditions other than distance. The method of adjustment may be the same as in the case of adjusting the inertial force and the primary control capability.

[0072] The control command unit 107 transmits command information of the secondary control capability (designation of active power and reactive power to be output) determined for the power devices 31A to 31E by the control unit 106 to each of the power devices 31A to 31E.

[0073] 4 above shows an example in which the secondary control capability of the power devices 31A to 31E is adjusted according to the distance from the power devices 31A to 31E to the load fluctuation area (demand area X in this example). The magnitude of the secondary control capability of the power devices 31A to 31E is shown typically by the thickness of the arrow. Here, it is assumed that the active power is increased by an amount corresponding to the thickness of the arrow.

[0074] After performing control to adjust the secondary control capability of the power devices 31A to 31E, the control unit 106 then performs control to adjust the tertiary control capability (S150). For frequency fluctuations with a period exceeding several tens of minutes, frequency control is performed by adjusting the tertiary control capability (ELD: economic load dispatch). The adjustment of the tertiary control capability is performed by general control of active power and reactive power. The adjustment of the tertiary control capability may be performed according to the distance between the load fluctuation area and each installation area, similar to the adjustment of the inertial force and the adjustment of the primary control capability. The adjustment of the tertiary control capability may be performed by utilizing the history of previous upper command values ​​(command values ​​of the active power and reactive power to be output) for the power devices 31A to 31E.

[0075] For example, if the power consumption in the demand area increases significantly, the active power of the power devices 31A-31E is changed more significantly as the installation area of ​​the power device is closer to the load fluctuation area. As in the case of adjusting the inertial force and the primary control capability, the secondary control capability may be adjusted by further including the conditions of the individual power devices (power generation capacity, SOC, inertial energy, etc.) as conditions other than distance. The method of adjustment may be the same as in the case of adjusting the inertial force and the primary control capability.

[0076] The control command unit 107 transmits command information of the tertiary control capability (designation of active power and reactive power to be output) determined for the power devices 31A to 31E by the control unit 106 to each of the power devices 31A to 31E.

[0077] 4 above shows an example in which the tertiary adjustment capability of the power devices 31A to 31E is adjusted according to the distance from the power devices 31A to 31E to the load fluctuation area (demand area X in this example). The magnitude of the tertiary adjustment capability of the power devices 31A to 31E is shown typically by the thickness of the arrow. Here, it is assumed that the active power is increased by an amount corresponding to the thickness of the arrow.

[0078] The process of this flowchart may be repeated at regular intervals. When the fluctuation in power consumption in the load fluctuation area has settled down in step S110 (for example, if the fluctuation in power consumption is below a threshold for a predetermined time), the control unit 106 may perform control to return the inertial force and the adjustment force (primary, secondary, tertiary) to the original state. The order of return may be determined in advance.

[0079] The processing of this flowchart can also be realized by a computer program. In this case, the computer program is stored in a storage medium such as a memory, and the computer reads the computer program from the storage medium and executes it. The computer may be a general arithmetic device equipped with a CPU, memory, and input / output circuits.

[0080] As described above, according to this embodiment, by controlling the inertia force and regulating force of the power device to be larger as the distance between the load fluctuation area and the installation area of ​​each power device is closer, it becomes possible to control the frequency of the power system while reducing the overall transmission loss, compared to increasing the inertia force and regulating force of the power device in a distant installation area.

[0081] (Modification) In the above-described embodiment, the inertia force and adjustment force of each power device are adjusted to be larger as the distance between the load fluctuation area and the installation area of ​​each power device is closer, but the inertia force and adjustment force of each power device may be adjusted so that the adjustment amount from the current value is larger as the distance is closer. For example, the adjustment amount of the inertia constant may be larger as the distance is closer. This makes it possible to control the frequency of the power system while reducing the overall power transmission loss, compared to increasing the adjustment amount of the inertia constant of a distant power device.

[0082] Second embodiment In the configuration of FIG. 1, it is assumed that the power system 2 is a backbone system, but in the second embodiment, the power system 2 is a microgrid.

[0083] FIG. 4 shows a configuration example in which the power system 2 is a microgrid. The microgrid is connected to the backbone system 200 via a switch 250. The microgrid is a part of the power system 2, and is a small-scale power system installed within a region. The communication unit 101 of the energy management system 100 communicates with the switch 250 and can acquire information indicating the open / closed state of the switch 250. For example, the open / close information may be acquired at regular time intervals, or when the switch is switched from open to closed or closed to open. Alternatively, the open / close information may be acquired from another device such as the information communication devices 51X, 51Y, and 41A to 41E.

[0084] Under normal circumstances, the switch 250 is closed (the switch 250 is on), and power is also supplied from the utility grid 200 to the microgrid. When an abnormality such as a blackout or disaster occurs in the utility grid 200, the switch 250 opens (the switch 250 is off), and the microgrid is separated from the utility grid 200 and operates independently. In other words, the microgrid alone covers the power within the area. A microgrid separated from the utility grid 200 is called an off-grid, and a microgrid connected to the utility grid 200 is called an on-grid. Even in the off-grid case, the energy management system 100 controls the inertia force and adjustment force (primary, secondary, tertiary) of each power device in response to the occurrence of a load fluctuation area in the demand area by the same operation as in the configuration of FIG. 1.

[0085] Here, the method by which the energy management system 100 controls the inertia force and regulation force of each power device may be changed depending on whether it is off-grid or on-grid. In the on-grid case, the operation of the above-described embodiment is performed, and in the off-grid case, since the total power capacity is smaller than that on-grid because no power is supplied from the utility grid 200, the values ​​or change range of the inertia force and regulation force (primary, secondary, tertiary) may be reduced. For this reason, the above-mentioned correspondence information may be prepared separately for off-grid and on-grid, and switched depending on whether it is off-grid or on-grid.

[0086] By determining whether it is off-grid or on-grid, it is possible to set the optimal inertia constant and adjustment capacity for on-grid and off-grid, respectively. In other words, when it is separated from the main grid during a power outage or disaster, it is possible to determine the appropriate inertia constant or adjustment capacity depending on the actual environment of the microgrid, and it is possible to reduce power losses in transmission and distribution even when so-called local production and consumption is performed.

[0087] The present invention is not limited to the above-described embodiment, and the components can be modified and embodied in the implementation stage without departing from the gist of the invention. In addition, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, components from different embodiments may be appropriately combined.

[0088] This embodiment can also be configured as follows. [Item 1] A control device for an electric power system capable of supplying electric power to load devices in a plurality of demand areas based on first to Nth electric power devices each capable of at least one of discharging and charging electric power and installed in first to Nth installation areas, a control unit that detects a demand area in which the power consumption has fluctuated significantly more than normal based on information on the power consumption for each demand area, and determines control parameters related to input and output of power to be set in the first to Nth power devices in accordance with a distance between the demand area and the first to Nth installation areas. A control device comprising: [Item 2] The first to Nth power devices have an inertial force with respect to the power system, The control parameter is the inertia constant Item 1. The control device according to item 1. [Item 3] The control unit increases the inertia constant of the power device in the installation area that is closer to the power device. Item 2. The control device according to item 2. [Item 4] The first to Nth power devices are capable of droop control for the power grid, The control parameter is the droop rate. 3. The control device according to item 1 or 2. [Item 5] The control unit increases the droop rate of the power device in the installation area that is closer to the power device. Item 4. The control device according to item 4. [Item 6] The control unit performs control to adjust the secondary control capabilities of the first to Nth power devices in accordance with the distances between the demand area and the first to Nth installation areas. The control device according to any one of items 1 to 5. [Item 7] The control unit performs control to adjust the tertiary adjustment capabilities of the first to Nth power devices in accordance with the distances between the demand area and the first to Nth installation areas. The control device according to any one of items 1 to 6. [Item 8] At least one of the first to Nth power devices has a power generation device, The control unit changes a control parameter of the power device having the power generation device further based on a power generation capacity of the power generation device. The control device according to any one of items 1 to 7. [Item 9] At least one of the first to Nth power devices has a power storage device, The control unit changes a control parameter of the power device having the power storage device further based on a charging state of the power storage device. The control device according to any one of items 1 to 8. [Item 10] At least one of the power devices further includes a power generation device, and the power storage device stores the power generated by the power generation device. Item 10. The control device according to item 9. [Item 11] The power system is connected to a main power system via a switch, The control unit changes the control parameters further based on switching state information indicating whether the switch is open or closed. The control device according to any one of items 1 to 10. [Item 12] The first to Nth power devices each include a synchronous generator or a constant voltage inverter, and the synchronous generator or the constant voltage inverter has an inertial force with respect to the power system. The control device according to any one of items 1 to 11. [Item 13] The first to Nth power devices each include a synchronous generator or a constant voltage inverter, and the synchronous generator or the constant voltage inverter has a function of performing the droop control. The control device according to any one of items 1 to 11. [Item 14] The distance between the demand area and the first to Nth installation areas is the distance along the power line in the power system. The control device according to any one of items 1 to 13. [Item 15] The distance between the demand area and the first to Nth installation areas is a geographical distance. The control device according to any one of items 1 to 14. [Item 16] The power consumption of the demand area is the sum of the power consumption of the load devices in the demand area. The control device according to any one of items 1 to 15. [Item 17] An energy management system for an electric power system capable of supplying electric power to load devices in a plurality of demand areas based on first to Nth power devices provided in first to Nth installation areas and capable of at least one of discharging and charging electric power, a communication unit that communicates with a plurality of information communication devices corresponding to the plurality of demand areas; an acquisition unit that acquires information on power consumption for each of the demand areas from the plurality of information communication devices; a control unit that detects a demand area in which the power consumption has fluctuated significantly more than usual based on the acquired information, and determines control parameters related to input and output of power of the first to Nth power devices according to a distance between the demand area and the first to Nth installation areas; a control command unit that transmits command information to the first to Nth power devices to command the first to Nth power devices to input / output the power based on the control parameters; An energy management system equipped with [Item 18] A computer program for causing a computer to execute a power system capable of supplying power to load devices in a plurality of demand areas based on first to Nth power devices provided in first to Nth installation areas and capable of at least one of discharging and charging power, acquiring information on power consumption for each of the demand areas; detecting a demand area in which the power consumption has fluctuated significantly more than usual based on the acquired information; changing a control parameter related to input / output of power of the first to Nth power devices according to a distance between the demand area and the first to Nth installation areas; transmitting command information to the first to Nth power devices to instruct them to input / output the power based on the control parameters; A computer program comprising: [Explanation of symbols]

[0089] 1. Power System 2 Power system 200 Core System 3 Load device 4 Transmission and distribution lines 11B Voltage Control Inverter 11C Voltage Control Inverter 11D Voltage Control Inverter 11E Voltage Control Inverter 21B Energy storage device 21B Home solar power generation equipment 21C Home solar power generation equipment 21D Electric Vehicle 21E Large-scale solar power generation equipment 31 Power equipment 31A power supply device (power device) 31A power equipment 31A Installation Area 31A synchronous generator 31A synchronous generator (power device) 31A synchronous generator 31B Power equipment 31B Installation area 31C power equipment 31C Installation area 31D Power Equipment 31D Installation area 31E Power equipment 31E Installation area 35E Power Equipment 41A~41E Information and communication devices 51A~51E Information communication equipment 51X Information and communication devices 100 Energy Management Systems 100 Energy Management System 100 Energy Systems 101 Communications Department 102 Equipment information acquisition department 103 Location information acquisition unit 104 Status Information Acquisition Unit 104 Status Acquisition Unit 105 Database 106 Control section 107 Control Command Department 200 Core System 250 Switchgear H1~H4 Distance X Demand Area Y Demand Area

Claims

1. A control device for an electric power system capable of supplying electric power to load devices in a plurality of demand areas based on first to Nth electric power devices each capable of at least one of discharging and charging electric power and each installed in first to Nth installation areas, a control unit that detects a demand area in which the power consumption has fluctuated significantly more than normal based on information on the power consumption for each demand area, and determines control parameters related to the input and output of power to be set in the first to Nth power devices in accordance with the distance between the demand area and the first to Nth installation areas. A control device comprising:

2. the first to Nth power devices have an inertial force with respect to the power system; The control parameter is the inertia constant The control device according to claim 1 .

3. The control unit increases the inertia constant of the power device in the installation area that is closer to the power device. The control device according to claim 2.

4. The first to Nth power devices are capable of droop control for the power grid; The control parameter is the droop rate. The control device according to claim 1 .

5. The control unit increases the droop rate of the power device in the installation area that is closer to the power device. The control device according to claim 4.

6. The control unit performs control to adjust secondary control capabilities of the first to Nth power devices in accordance with the distances between the demand area and the first to Nth installation areas. The control device according to claim 1 .

7. The control unit performs control to adjust the tertiary adjustment capabilities of the first to Nth power devices in accordance with the distances between the demand area and the first to Nth installation areas. The control device according to claim 1 .

8. At least one of the first to Nth power devices has a power generation device; The control unit changes a control parameter of the power device having the power generation device further based on a power generation capacity of the power generation device. The control device according to claim 1 .

9. At least one of the first to Nth power devices has a power storage device; The control unit changes a control parameter of the power device having the power storage device further based on a charging state of the power storage device. The control device according to claim 1 .

10. At least one of the power devices further includes a power generation device, and the power storage device stores the power generated by the power generation device. The control device according to claim 9.

11. The power system is connected to a main power system via a switch, The control unit changes the control parameters further based on switching state information indicating whether the switch is open or closed. The control device according to claim 1 .

12. The first to Nth power devices include a synchronous generator or a constant voltage inverter, and the synchronous generator or the constant voltage inverter has an inertial force with respect to the power system. The control device according to claim 2 or 3.

13. The first to Nth power devices include a synchronous generator or a constant voltage inverter, and the synchronous generator or the constant voltage inverter has a function of performing the droop control. The control device according to claim 4 or 5.

14. The distance between the demand area and the first to Nth installation areas is the distance along the power line in the power system. The control device according to claim 1 .

15. The distance between the demand area and the first to Nth installation areas is a geographical distance. The control device according to claim 1 .

16. The power consumption of the demand area is the sum of the power consumption of the load devices in the demand area. The control device according to claim 1 .

17. An energy management system for an electric power system capable of supplying electric power to load devices in a plurality of demand areas based on first to Nth electric power devices provided in first to Nth installation areas and capable of at least one of discharging and charging electric power, comprising: a communication unit that communicates with a plurality of information communication devices corresponding to the plurality of demand areas; an acquisition unit that acquires information on power consumption for each of the demand areas from the plurality of information communication devices; a control unit that detects a demand area in which the power consumption has fluctuated significantly more than usual based on the acquired information, and determines control parameters related to input and output of power of the first to Nth power devices in accordance with a distance between the demand area and the first to Nth installation areas; a control command unit that transmits command information to the first to Nth power devices to instruct the first to Nth power devices to input / output the electric power based on the control parameters; An energy management system equipped with

18. A computer program executed by a computer for a power system capable of supplying power to load devices in a plurality of demand areas based on first to Nth power devices provided in first to Nth installation areas and capable of at least one of discharging and charging power, acquiring information on power consumption for each of the demand areas; detecting a demand area in which the power consumption has fluctuated significantly more than usual based on the acquired information; changing a control parameter related to input / output of power of the first to Nth power devices according to a distance between the demand area and the first to Nth installation areas; transmitting command information to the first to Nth power devices to instruct them to input / output the electric power based on the control parameters; A computer program comprising:

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