Power supply management system and power supply control method

Abstract

To provide a power supply management system and a power supply control method that enable efficient operation of system power supply while making best use of output power of dispersion power supply.SOLUTION: A power supply management system 1 comprises an MG (Micro Grid 100) that is a regional independent system capable of being disconnected from a power system 12 and has a dispersion power supply connected to the regional independent system, and a management device (lower server 300) that manages the regional independent system. The management device comprises a prediction unit that predicts an error range of difference between a first prediction value of demand power in the regional independent system and a second prediction value of output power in the dispersion power supply on the basis of the first prediction value and the second prediction value, a generation unit that generates power plan information regarding an operation plan of a system power supply for supplying power to the regional independent system on the basis of a prediction value of the error range of difference between the first prediction value and the second prediction value, and a transmission unit that transmits the power plan information to an upper device that controls the system power supply.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power management system and a power control method. [Background technology]

[0002] In recent years, the use of distributed power sources such as solar cell devices, power storage devices, fuel cell devices, etc., has been attracting attention. For example, a regional independent system (so-called microgrid) connected to a power grid can be considered as a power supply system that uses such distributed power sources.

[0003] In addition to the above-mentioned distributed power sources, internal combustion engines such as diesel generators (hereinafter, referred to as grid power sources) are considered as power sources capable of supplying power to the regional independent grid.

[0004] Under such assumptions, a technology has been proposed that determines whether or not to interconnect a new system power source to the regional independent system based on the difference (surplus power or shortage power) between the predicted value of the output power of a distributed power source such as a solar cell device and the predicted value of the power demand of the regional independent system. Specifically, when the surplus power of the regional independent system can be charged to a power storage device, or when the surplus power of the regional independent system can be discharged from the power storage device, control is executed not to interconnect the new system power source to the regional independent system (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-93050 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, the output power of a power system is variable, but from the viewpoint of power generation efficiency of the power system, an upper limit and a lower limit (output power range) of the output power of the power system is determined.

[0007] Against this background, the inventors have, after careful consideration, found that control that determines whether or not to connect a new system power source to a regional independent system based on the surplus or excess power of the regional independent system may not be able to operate the system power source efficiently, and may not be able to make maximum use of the output power of the distributed power source.

[0008] Therefore, the present invention has been made to solve the above-mentioned problems, and aims to provide a power management system and a power control method that enable efficient operation of a system power supply while making maximum use of the output power of a distributed power supply. [Means for solving the problem]

[0009] One aspect of the disclosure is a power supply management system that includes a distributed power source connected to a regional independent system, and a management device that manages the regional independent system, wherein the management device includes a prediction unit that predicts an error range of a difference between a first predicted value of a demand power of the regional independent system and a second predicted value of an output power of the distributed power source based on the first predicted value and the second predicted value, a generation unit that generates power plan information regarding an operation plan of a system power source that supplies power to the regional independent system based on a predicted value of the error range of the difference between the first predicted value and the second predicted value, and a transmission unit that transmits the power plan information to a higher-level device that controls the system power source.

[0010] One aspect of the disclosure is a power management method used in a power management system including a distributed power source connected to a regional independent system and a management device that manages the regional independent system, the power management method comprising the steps of: the management device predicting an error range of a difference between a first predicted value of power demand of the regional independent system and a second predicted value of an output power of the distributed power source based on the first predicted value and the second predicted value; the management device generating power planning information regarding an operation plan of a system power source that supplies power to the regional independent system based on a predicted value of the error range of the difference between the first predicted value and the second predicted value; and the management device transmitting the power planning information to a higher-level device that controls the system power source. Effect of the Invention

[0011] According to the present invention, it is possible to provide a power management system and a power control method that enable efficient operation of a system power supply while maximizing the use of the output power of a distributed power supply. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a power management system 1 according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing the MG 100 according to the embodiment. [Diagram 3] FIG. 3 is a diagram showing the MG_EMS 150 according to the embodiment. [Figure 4] FIG. 4 is a diagram showing the lower level server 300 according to the embodiment. [Diagram 5] FIG. 5 is a diagram for explaining power plan information according to the embodiment. [Figure 6] FIG. 6 is a diagram for explaining power plan information according to the embodiment. [Figure 7] FIG. 7 is a diagram showing a power supply control method according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the embodiments will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic.

[0014] [Embodiment] (Power Management System) A power supply management system according to an embodiment will be described below. 1, the power supply management system 1 has an MG (Micro Grid) 100. The power supply management system 1 may include a system power supply 10, may include a higher-level server 200, and may include a lower-level server 300. The MG 100 is a section (regional independent system) that can be disconnected from the power system 12 by a sectionalizing switch 191 described later, and is an area downstream of the sectionalizing switch 191. Downstream means a direction away from the system power supply 10.

[0015] The system power source 10 is connected to a power system 12 and supplies power to the MG 100 via the power system 12. The system power source 10 may include an internal combustion engine. The system power source 10 may include a power plant. The system power source 10 may be interpreted as a base load power source.

[0016] The MG 100 is connected to the power grid 12. The MG 100 can be electrically connected to the power grid 10 or the power grid 12 by an area switch 13, and can be electrically disconnected from the power grid 10 or the power grid 12 by the area switch 13. The MG 100 may be referred to as a regional independent system. The MG 100 may be a unit (e.g., a village or a town) that utilizes a distributed power source in the region. The MG 100 may be a complex facility including two or more facilities.

[0017] In Fig. 1, MG100A to MG100C are illustrated as examples of MG100. MG100A is connected to the power system 12 between the area switch 13A and the area switch 13B. MG100B is connected to the power system 12 between the area switch 13B and the area switch 13C. MG100C is connected to the power system 12 downstream of the area switch 13C. Note that downstream may be considered as a term indicating a side away from the system power source 10. Details of MG100 will be described later (see Fig. 2).

[0018] The upper server 200 manages the system power supply 10. The upper server 200 may be considered to be a server managed by a business operator. The business operator may be a general electricity transmission and distribution business operator or a general electric utility company that manages the power system 12.

[0019] The lower server 300 manages the MG 100. The lower server 300 may be considered to be a server managed by a business operator. The business operator may be a retail electricity supplier that sells electricity to the facilities included in the MG 100. The lower server 300 may be capable of communicating with a device (e.g., the MG_EMS 150 described later) installed in the MG 100. Details of the lower server 300 will be described later (see FIG. 4).

[0020] In the embodiment, the lower server 300 is an example of a management device that manages the regional independent system (MG100).

[0021] (Regional independent system) The following describes a regional grid (MG) according to an embodiment. As shown in Fig. 2, the MG 100 includes a distributed power source 110, a switch 121, a load 130, a switch 131, an MG_EMS (Energy Management System) 150, a section switch 191, and a transfer trip function (hereinafter, TTS) 192.

[0022] The distributed power source 110 is connected to a power line 14 in the MG 100. The power line 14 may be referred to as an area independent system. The distributed power source 110 has a power source 111 and a PCS (Power Conditioning System) 112. The power source 111 may be a solar cell device, a power storage device, or a fuel cell device. The PCS 112 converts the output voltage of the power source 111. If the power source 111 is a power storage device, the PCS 112 converts the input voltage of the power storage device.

[0023] In FIG. 2, the distributed power source 110 is exemplified by a distributed power source 110A having a power source 111A and a PCS 112A, and a distributed power source 110B having a power source 111B and a PCS 112B.

[0024] The switch 121 is disposed between the distributed power source 110 and the power line 14. The switch 121 connects the distributed power source 110 to the power line 14 or disconnects the distributed power source 110 from the power line 14.

[0025] In FIG. 2, the switch 121 is exemplified by a switch 121A that connects / disconnects the distributed power source 110A and a switch 121B that connects / disconnects the distributed power source 110B.

[0026] In the embodiment, when a power outage is detected in MG100, the distributed power source 110 may transition from an operation in a state where it is connected to MG100 (power line 14) (independent operation of MG100 described below) to an independent operation in a state where it is disconnected from MG100 (power line 14). In other words, when a power outage is detected in MG100, the switch 121 may disconnect the distributed power source 110 from the power line 14. The disconnection of the distributed power source 110 may be executed autonomously by the switch 121 or may be executed by MG_EMS 150.

[0027] The load 130 is a device that consumes power. For example, the load 130 may include an air conditioner, a heat pump water heater, a lighting device, and the like.

[0028] MG_EMS 150 is connected to the distributed power sources 110 and the switches 121, and controls the distributed power sources 110 and the switches 121. MG_EMS 150 is connected to the loads 130 and the switches 131, and controls the loads 130 and the switches 131. Details of MG_EMS 150 will be described later (see FIG. 3).

[0029] The MG_EMS150 may have an interface with a cloud system or the like that controls the output of the distributed power sources in real time, and may have a function for exchanging information between the systems. The MG_EMS150 may have a function for predicting weather, etc., and may formulate a plan (operation plan) for the output power of the distributed power sources based on information predicted by the prediction function, and may execute output or planned value commands to the distributed power sources while coordinating with other power sources such as internal combustion engines that are connected to the same system (MG100) as the distributed power sources.

[0030] The section switch 191 is disposed between the power system 12 and the MG 100 (the power line 14). The section switch 191 connects the MG 100 to the power system 12 or disconnects the MG 100 from the power system 12.

[0031] The TTS 192 receives a disconnection signal from the MG_EMS 150 to disconnect the MG 100 from the power grid 12. The TTS 192 controls the sectional switch 191 in response to the disconnection signal to disconnect the MG 100 from the power grid 12. The TTS 192 may receive a grid connection signal from the MG_EMS 150 to connect the MG 100 to the power grid 12. The TTS 192 may control the sectional switch 191 in response to the grid connection signal to connect the MG 100 to the power grid 12.

[0032] In the embodiment, the operating states of the distributed power source 110 may include the operating states shown below. Specifically, the operating state of the distributed power source 110 may include a grid-connected operation in which the distributed power source 110 is connected to the power line 14. The operating state of the distributed power source 110 may include an independent operation in which the distributed power source 110 is disconnected from the power line 14. The operating state of the distributed power source 110 may include a stopped state in which the distributed power source 110 is stopped.

[0033] Here, the interconnected operation of the distributed power source 110 may include an interconnected operation in a state where the MG 100 is interconnected to the power system 12B by the sectional switch 191 and the distributed power source 110 is interconnected to the power line 14. The interconnected operation of the distributed power source 110 may also include an interconnected operation in a state where the MG 100 is disconnected from the power system 12B by the sectional switch 191 and the distributed power source 110 is interconnected to the power line 14.

[0034] Furthermore, in a state where MG100 is disconnected from power system 12A by area switch 13, the state where dispersed power source 110 operates in the interconnected operation may be referred to as isolated operation of MG100. That is, the isolated operation of MG100 may include a first isolated operation in which MG100 is connected to power system 12B by section switch 191, and a second isolated operation in which MG100 is disconnected from power system 12B by section switch 191.

[0035] The independent operation of the distributed power source 110 may include an operation in a state where the MG 100 is connected to the power system 12B by the sectional switch 191, and the distributed power source 110 is disconnected from the power line 14. The independent operation of the distributed power source 110 may include an operation in a state where the MG 100 is disconnected from the power system 12B by the sectional switch 191, and the distributed power source 110 is disconnected from the power line 14.

[0036] (MG_EMS) The MG_EMS according to the embodiment will be described below. As shown in FIG.

[0037] The communication unit 151 is configured by a communication module. The communication module may be a wireless communication module conforming to a standard such as IEEE802.11a / b / g / n / ac / ax, ZigBee, Wi-SUN, LTE, 5G, or 6G, or may be a wired communication module conforming to a standard such as IEEE802.3.

[0038] For example, the communication unit 151 communicates with the lower server 300. The communication unit 151 may also communicate with the distributed power source 110. The communication unit 151 may transmit the following information to the lower server 300.

[0039] The communication unit 151 may transmit a predicted value of the power demand of MG100 (hereinafter, a first predicted value) to the lower server 300. The power demand of MG100 may be considered to be the power consumption of the load 130. The communication unit 151 may transmit an actual value of the power demand of MG100 to the lower server 300.

[0040] The communication unit 151 may transmit a predicted value of the output power of the distributed power source 110 (hereinafter, referred to as a second predicted value) to the lower server 300. The output power of the distributed power source 110 may be interpreted as the output power of the PCS 112. For example, in a case where the power source 111 is a solar cell device and a power storage device, and the solar cell device and the power storage device are connected to the PCS 112 by DC, the output power of the distributed power source 110 may be considered to be AC ​​power output from the PCS 112. The communication unit 151 may transmit an actual value of the output power of the distributed power source 110 to the lower server 300.

[0041] For example, the communication unit 151 communicates with the distributed power source 110. The communication unit 151 transmits a control command for controlling the distributed power source 110 to the distributed power source 110.

[0042] The management unit 152 is configured with a storage medium such as a hard disk drive (HDD), a solid state drive (SSD), or a non-volatile memory.

[0043] For example, the management unit 152 may manage the specifications of the distributed power sources 110 installed in the MG 100. The specifications may include the rated power generation of the solar cell device, the rated charging power of the power storage device, the rated discharging power of the power storage device, and the rated output power of the fuel cell device. The specifications may also include the rated capacity and maximum charging / discharging power of the power storage device.

[0044] The control unit 153 may include at least one processor. The at least one processor may be configured by a single integrated circuit (IC), or may be configured by a plurality of circuits (such as integrated circuits and / or discrete circuits) communicatively connected to each other.

[0045] For example, the control unit 153 may specify a first predicted value of the power demand of the MG 100. The control unit 153 may specify the predicted value of the power demand based on past actual values ​​of the power demand. The control unit 153 may specify the predicted value of the power demand by machine learning of the correlation between the power demand and an attribute. Although not particularly limited, the attribute may be a parameter that affects the power demand (for example, a time period, a day of the week, a season, weather, temperature, humidity, etc.).

[0046] For example, the control unit 153 may specify a second predicted value of the output power of the distributed power source 110. The control unit 153 may specify the predicted value of the output power based on past actual values ​​of the output power. The control unit 153 may specify the predicted value of the output power by machine learning of the correlation between the output power and the attribute. Although not particularly limited, the attribute may be a parameter that affects the output power (for example, a time period, a day of the week, a season, weather, temperature, humidity, etc.).

[0047] For example, the control unit 153 may execute peak cut control to suppress the procurement power of MG100 to a threshold value or less. The procurement power of MG100 is power that MG100 procures from the power grid 12. The procurement power of MG100 may be considered to be power obtained by subtracting the output power of the distributed power source 110 from the demand power of MG100. The peak cut control may be executed by increasing the discharge power of the distributed power source 110 (power storage device). In such a case, the output power of the distributed power source 110 may be considered to be power that reflects the peak cut control.

[0048] For example, the control unit 153 may execute cost suppression control to suppress the price of power procured by MG 100. The cost suppression control may be control to charge the distributed power source 110 (power storage device) in a time period when the price of power procured by MG 100 is equal to or lower than a first threshold, and to discharge the distributed power source 110 (power storage device) in a time period when the price of power procured by MG 100 is equal to or higher than a second threshold. The first threshold and the second threshold may have hysteresis.

[0049] (Sub-server) The lower server according to the embodiment will be described below. As shown in FIG.

[0050] The communication unit 310 is configured by a communication module. The communication module may be a wireless communication module conforming to standards such as IEEE802.11a / b / g / n / ac / ax, ZigBee, Wi-SUN, LTE, 5G, and 6G, or may be a wired communication module conforming to standards such as IEEE802.3.

[0051] For example, the communication unit 310 may communicate with the host server 200. The communication unit 310 may receive the following information from the host server 200.

[0052] The communication unit 310 may receive information indicating an output power range defined by an upper limit and a lower limit of the output power of the grid power source 10 from the upper server 200. The output power range may be defined by the type of the grid power source 10, the number of the grid power sources 10, the maximum output power of the grid power source 10, the minimum output power of the grid power source 10, the tracking performance of the output power of the grid power source 10, etc. The tracking performance may include the increase rate of the output power of the grid power source 10 and may include the decrease rate of the output power of the grid power source 10. The increase rate of the output power of the grid power source 10 may be interpreted as the power of the grid power source 10 that can be increased per unit time. The decrease rate of the output power of the grid power source 10 may be interpreted as the power of the grid power source 10 that can be decreased per unit time.

[0053] The communication unit 310 may receive maintenance information of the power system 10 from the upper server 200. The maintenance information may be interpreted as operation information. The maintenance information may include a time period during which maintenance of the power system 10 is performed.

[0054] The communication unit 310 may receive construction information of the power system 12 from the upper server 200. The construction information may include a time period during which the power system 12 to which the MG 100 is connected will be disconnected.

[0055] For example, the communication unit 310 may communicate with MG_EMS 150. The communication unit 310 may receive a first predicted value of the power demand of MG 100 from MG_EMS 150. The communication unit 310 may receive a second predicted value of the output power of the distributed power source 110 from MG_EMS 150. The communication unit 310 may receive an actual value of the power demand of MG 100 from MG_EMS 150. The communication unit 310 may receive an actual value of the output power of the distributed power source 110 from MG_EMS 150.

[0056] The management unit 320 is configured with a storage medium such as a hard disk drive (HDD), a solid state drive (SSD), or a non-volatile memory.

[0057] For example, the management unit 320 may manage information received from the upper server 200. The management unit 320 may manage information indicating an output power range of the grid power source 10. The management unit 320 may manage maintenance information of the grid power source 10. The management unit 320 may manage construction information of the power grid 12.

[0058] For example, the management unit 320 may manage information received from the MG_EMS 150. The management unit 320 may manage a first predicted value of the power demand of the MG 100. The management unit 320 may manage a second predicted value of the output power of the distributed power source 110. The management unit 320 may manage an actual value of the power demand of the MG 100. The management unit 320 may manage an actual value of the output power of the distributed power source 110.

[0059] The control unit 330 may include at least one processor. The at least one processor may be configured by a single integrated circuit (IC), or may be configured by a plurality of circuits (such as integrated circuits and / or discrete circuits) communicatively connected to each other.

[0060] In the embodiment, the control unit 330 may be configured as a prediction unit that predicts an error range of a difference between a first predicted value and a second predicted value based on a first predicted value of the power demand of MG100 and a second predicted value of the output power of the distributed power source 110. The difference between the first predicted value and the second predicted value may be interpreted as a predicted value of the power procurement of MG100.

[0061] In the embodiment, the control unit 330 may be configured as a generation unit that generates power plan information related to the operation plan of the grid power source 10 based on the error range of the difference between the first predicted value and the second predicted value.

[0062] The power plan information may include the operation plan itself of the grid power source 10. Note that since the operation plan of the grid power source 10 is ultimately formulated by the upper server 200, the operation plan of the grid power source 10 included in the power plan information may be considered as a plan of output power desired as the output power of the grid power source 10. The power plan information may include a range of output power desired as the output power of the grid power source 10.

[0063] The power plan information may include an error range between the first predicted value and the second predicted value. The power plan information may be a plan for power procurement of MG 100. The plan for power procurement of MG 100 may be considered to be an error range between the first predicted value and the second predicted value.

[0064] The control unit 330 may generate the power planning information according to the following options.

[0065] In option 1, the control unit 330 may generate the power plan information based on an output power range defined by an upper limit and a lower limit of the output power of the grid power source 10. Specifically, the control unit 330 may generate the power plan information such that the error range of the difference between the first predicted value and the second predicted value falls within the output power range.

[0066] In option 2, the control unit 330 may generate the power plan information based on at least one of an increase rate and a decrease rate of the output power of the grid power source 10. Specifically, the control unit 330 may generate the power plan information based on an increase rate of the output power of the grid power source 10 so that the increase in the output power of the grid power source 10 can follow an increase in the difference between the first predicted value and the second predicted value. The control unit 330 may generate the power plan information based on a decrease rate of the output power of the grid power source 10 so that the decrease in the output power of the grid power source 10 can follow a decrease in the difference between the first predicted value and the second predicted value.

[0067] In option 3, the control unit 330 may generate power plan information based on maintenance information of the grid power source 10. Specifically, the control unit 330 may generate power plan information on the assumption that the output power of the grid power source 10 on which maintenance is performed is zero during the time period in which maintenance is performed on the grid power source 10. It should be noted that when the output power of the grid power source 10 on which maintenance is performed is zero, the output power range defined by the upper and lower limits of the output power of the grid power source 10 changes.

[0068] In option 4, the control unit 330 may generate the power plan information based on construction information of the power grid 12. Specifically, the control unit 330 may identify the distributed power source 110 to be disconnected from the power grid 12 based on the construction information, and generate the power plan information by assuming that the output power of the identified distributed power source 110 is zero. It should be noted that when the output power of the distributed power source 110 to be disconnected from the power grid 12 is zero, the second predicted value of the output power of the distributed power source 110 changes.

[0069] In an embodiment, two or more options selected from Option 1 to Option 4 may be combined.

[0070] The control unit 330 instructs the communication unit 310 to transmit the power plan information. In the embodiment, the communication unit 310 constitutes a transmission unit that transmits the power plan information to the upper server 200.

[0071] Here, the upper server 200 refers to the power plan information to formulate an operation plan for the grid power supply 10. When the power plan information is the operation plan itself of the grid power supply 10, the upper server 200 may adopt the operation plan of the grid power supply 10 received from the lower server 300, or may not adopt the operation plan of the grid power supply 10 received from the lower server 300. When the power plan information is a plan for power procurement of the MG100, the upper server 200 may formulate an operation plan for the grid power supply 10 in accordance with the plan for power procurement of the MG100 so as to ensure the power procurement of the MG100.

[0072] (System power supply operation plan) The operation plan of the system power supply 10 will be described below.

[0073] The period for which an operation plan for the grid power source 10 is formulated may be defined as a target period (e.g., one day). The operation plan for the grid power source 10 may be formulated for each unit period (e.g., 30-minute units) included in the target period. In such a case, the operation plan for the grid power source 10 may be formulated at a timing prior to the target period (e.g., 12:00 on the day before the target period). The operation plan for the grid power source 10 may be revised to a timing prior to the unit period included in the target period (e.g., one hour before the unit period).

[0074] First, a case where a solar cell device (PV) is installed will be described with reference to Fig. 5. The solar cell device may be a solar cell device to which the Feed-in Tariff (FIT) system is applied.

[0075] In FIG. 5, the first predicted value of the power demand of MG 100 is represented by "predicted value of power demand (Demand)". The second predicted value of the output power of the distributed power source 110 is represented by "predicted value of PV power generation (FIT)". The minimum value of the difference between the first predicted value and the second predicted value is represented by "minimum predicted value of procurement plan (Gmin)". The maximum value of the difference between the first predicted value and the second predicted value is represented by "maximum predicted value of procurement plan (Gmax)". In other words, the error range of the difference between the first predicted value and the second predicted value is defined by the minimum predicted value of procurement plan (Gmin) and the maximum predicted value of procurement plan (Gmax).

[0076] Here, the minimum forecast value (Gmin) of the procurement plan may be expressed as Gmin = (Demand - FIT) x 100%. The maximum forecast value (Gmax) of the procurement plan may be expressed as Gmax = (Demand - FIT x 10%) x α, where α is the reserve rate of power supplied from the system power source 10 to the MG 100 (hereinafter, the supply reserve rate).

[0077] In such a case, it is preferable to formulate an operation plan for the system power source 10 so that the error range of the difference between the first predicted value and the second predicted value falls within the output power range of the system power source 10. The output power range is defined by an upper limit of the output power of the system power source 10 (simply an upper limit in FIG. 5) and a lower limit of the output power of the system power source 10 (simply a lower limit in FIG. 5).

[0078] In the embodiment, the lower server 300 generates power plan information based on the error range of the difference between the first predicted value and the second predicted value, and transmits the generated power plan information to the upper server 200. The power plan information may include the operation plan of the system power source 10 itself, or may include the error range between the first predicted value and the second predicted value (i.e., the plan for power procurement of the MG 100).

[0079] According to this configuration, the upper server 200 can appropriately formulate an operation plan for the system power supply 10 so that the error range of the difference between the first predicted value and the second predicted value falls within the output power range of the system power supply 10.

[0080] Secondly, a case where a distributed power source 110 (DER; Distributed Energy Resources) in which a solar cell device (PV) and a power storage device are connected via DC is installed will be described with reference to Fig. 6. The solar cell device (PV) may be a solar cell device to which the Feed-in Tariff (FIT) system is applied.

[0081] In addition, one or more distributed power sources 110 (DER) in which a solar cell device (PV) and a power storage device are connected via DC may be connected to another power source (GFM (Grid Forming) power source) that can form the voltage or frequency of the MG 100.

[0082] In FIG. 6, the first predicted value of the power demand of MG 100 is represented by "predicted value of power demand (Demand)." The second predicted value of the output power of the distributed power source 110 is represented by "predicted value of output power (DER)." The minimum value of the difference between the first predicted value and the second predicted value is represented by "minimum predicted value of procurement plan (Gmin')." The maximum value of the difference between the first predicted value and the second predicted value is represented by "maximum predicted value of procurement plan (Gmax')." In other words, the error range of the difference between the first predicted value and the second predicted value is defined by the minimum predicted value of the procurement plan (Gmin') and the maximum predicted value of the procurement plan (Gmax').

[0083] The "minimum predicted value of the procurement plan (Gmin)" is the minimum difference between the predicted value of the output power of the solar cell device (PV) and the predicted value of the power demand of MG100, assuming that there is no charging or discharging of the power storage device (similar to FIG. 5). The "maximum predicted value of the procurement plan (Gmax)" is the maximum difference between the predicted value of the output power of the solar cell device (PV) and the predicted value of the power demand of MG100, assuming that there is no charging or discharging of the power storage device (similar to FIG. 5).

[0084] Here, the minimum forecast value (Gmin') of the procurement plan may be expressed as Gmin' = (Demand - DER) x 100%. The maximum forecast value (Gmax') of the procurement plan may be expressed as Gmax = (Demand - DER x 10%). As will be described later, in the case shown in FIG. 6, the supply reserve rate (α) does not need to be assumed.

[0085] In such a case, it is preferable to formulate an operation plan for the system power source 10 so that the error range of the difference between the first predicted value and the second predicted value falls within the output power range of the system power source 10. The output power range is defined by an upper limit of the output power of the system power source 10 (simply an upper limit in FIG. 6 ) and a lower limit of the output power of the system power source 10 (simply a lower limit in FIG. 6 ).

[0086] In the embodiment, the lower server 300 generates power plan information based on the error range of the difference between the first predicted value and the second predicted value, and transmits the generated power plan information to the upper server 200. The power plan information may include the operation plan of the system power source 10 itself, or may include the error range between the first predicted value and the second predicted value (i.e., the plan for power procurement of the MG 100).

[0087] According to this configuration, the upper server 200 can appropriately formulate an operation plan for the system power supply 10 so that the error range of the difference between the first predicted value and the second predicted value falls within the output power range of the system power supply 10.

[0088] Furthermore, in the case shown in FIG. 6, the lower level server 300 may execute the following operations.

[0089] The subordinate server 300 identifies a predicted value of power demand (Demand) and a solar cell device (PV). The subordinate server 300 formulates (assumes) an operation plan for the power system 10 based on the predicted value of power demand (Demand) and the solar cell device (PV).

[0090] The lower server 300 formulates a plan for the output power of the distributed power source 110 (DER) in which a photovoltaic device (PV) and a power storage device are connected via DC, based on the operation plan of the system power source 10. Specifically, the lower server 300 formulates a plan for the output power of the distributed power source 110 (DER) in the following procedure.

[0091] In step 1, the lower server 300 predicts the power generation of the solar cell device that constitutes the distributed power source 110 (DER) based on the actual values ​​of the past power generation of the solar cell device that constitutes the distributed power source 110 (DER) and the weather forecast for the target period, etc.

[0092] In step 2, the lower server 300 formulates a plan for the output power of the distributed power sources 110 (DER) so that the predicted value of the output power (DER) does not exceed the difference between the minimum predicted value (Gmin) of the procurement plan and the lower limit.

[0093] In step 3, the lower server 300 formulates a plan for the output power of the distributed power source 110 (DER) so that the minimum predicted value (Gmin) of the procurement plan does not fall below the lower limit. For example, the lower server 300 executes discharge of the power storage device during a time period when the minimum predicted value (Gmin) of the procurement plan falls below the lower limit. Such discharge may be considered as an example of peak cut control.

[0094] 6, the lower server 300 formulates (assumes) an operation plan for the grid power source 10 based on the predicted value of power demand (Demand) and the solar cell device (PV), and then creates an operation plan for the distributed power source 110 (DER) (i.e., a plan for charging and discharging the power storage device). Therefore, even if the above-mentioned supply reserve rate (α) is not assumed, the error range of the difference between the first predicted value and the second predicted value can be kept within the output power range of the grid power source 10.

[0095] That is, the lower server 300 may formulate (estimate) an operation plan for the grid power source 10, formulate a plan for the output power of the distributed power source 110, and specify the second predicted value of the output power of the distributed power source 110 based on the formulated plan. With such a configuration, the accuracy of the power plan information that the upper server 200 refers to when formulating the operation plan for the grid power source 10 is improved.

[0096] (Power management method) A power management method according to an embodiment will be described below.

[0097] 7, in step S10, MG_EMS 150 specifies a first predicted value of the power demand of MG 100. MG_EMS 150 may specify the first predicted value for each unit period (for example, each 30-minute frame) included in the target period.

[0098] In step S12, MG_EMS 150 specifies a second predicted value of the output power of the distributed power source 110. MG_EMS 150 may specify the second predicted value for each unit period (for example, each 30-minute frame) included in the target period.

[0099] In step S14, the MG_EMS 150 transmits the first predicted value and the second predicted value to the lower-level server 300.

[0100] In step S16, the downstream server 300 predicts an error range of the difference between the first predicted value and the second predicted value, based on the first predicted value of the power demand of the MG 100 and the second predicted value of the output power of the distributed power source 110. The downstream server 300 generates power plan information related to an operation plan of the grid power source 10, based on the error range of the difference between the first predicted value and the second predicted value.

[0101] The power plan information may include the operation plan of the system power source 10 itself, or may include an error range between the first predicted value and the second predicted value (that is, a plan for power procurement by the MG 100).

[0102] In step S18, the lower server 300 transmits the power plan information to the upper server 200.

[0103] In step S20, the upper level server 200 formulates an operation plan for the system power supply 10 based on the power plan information.

[0104] In step S22, the upper server 200 transmits the operation plan of the system power supply 10 to the lower server 300.

[0105] In step S24, the lower server 300 transmits the operation plan of the system power supply 10 to the MG_EMS150.

[0106] In step S26, the MG_EMS 150 controls the distributed power sources 110. The MG_EMS 150 may execute peak cutting control or may execute cost suppression control.

[0107] Here, when an operation plan for the distributed power source 110 is formulated in generating the power plan information, the MG_EMS 150 may control the distributed power source 110 in accordance with the operation plan for the distributed power source 110. When a measured value of the output power of the distributed power source 110 deviates from a predicted value of the output power of the distributed power source 110, the MG_EMS 150 may control charging or discharging of a power storage device constituting the distributed power source 110 so as to bring the measured value closer to the predicted value.

[0108] (Action and Effects) In the embodiment, the lower server 300 generates power plan information regarding an operation plan of the grid power source 10 based on the error range of the difference between the first predicted value of the power demand of the MG 100 and the second predicted value of the output power of the distributed power source 110, and transmits the generated power plan information to the upper server 200. According to such a configuration, the upper server 200 can appropriately formulate an operation plan for the grid power source 10 so that the error range of the difference between the first predicted value and the second predicted value falls within the output power range of the grid power source 10.

[0109] In the embodiment, the lower server 300 may formulate (estimate) an operation plan for the grid power source 10, formulate a plan for the output power of the distributed power source 110, and specify a second predicted value for the output power of the distributed power source 110 based on the formulated plan. This configuration improves the accuracy of the power plan information that the upper server 200 refers to when formulating the operation plan for the grid power source 10.

[0110] [Other embodiments] Although the present invention has been described by the above-mentioned embodiment, the description and drawings forming a part of this disclosure should not be understood as limiting the present invention. From this disclosure, various alternative embodiments, examples and operating techniques will become apparent to those skilled in the art.

[0111] In the above disclosure, the management device that manages MG 100 is the lower server 300. However, the above disclosure is not limited to this. The management device may be MG_EMS 150. The management device may be MG_EMS 150 and the lower server 300.

[0112] In the above disclosure, a case has been exemplified in which the predicted value of the power demand of the MG 100 is determined by the MG_EMS 150. However, the above disclosure is not limited to this. The predicted value of the power demand of the MG 100 may be determined by the lower server 300.

[0113] In the above disclosure, a case has been exemplified in which the predicted value of the output power of the distributed power source 110 is determined by the MG_EMS 150. However, the above disclosure is not limited to this. The predicted value of the output power of the distributed power source 110 may be determined by the lower server 300.

[0114] In the above disclosure, the case where the power management system 1 includes the MGs 100A to MG100C has been exemplified. However, the above disclosure is not limited to this. The power management system 1 only needs to include at least one MG 100.

[0115] In the above disclosure, the distributed power sources 110 may include power sources to which a feed-in tariff is applied. The distributed power sources 110 may also include power sources to which a feed-in tariff is not applied.

[0116] In the above disclosure, the distributed power source 110 may include a distributed power source including a solar cell device and a power control device (PCS 112) to which the solar cell device is connected. The distributed power source 110 may include a distributed power source including a solar cell device, a power storage device, and a power control device (PCS 112) to which the solar cell device and the power storage device are connected.

[0117] In the above disclosure, the distributed power source 110 may include a power source that outputs power from renewable energy. The power source that outputs power from renewable energy may be a solar cell device, a wind power generation device, or a geothermal power generation device.

[0118] In the above disclosure, the distributed power source 110 for which an operation plan is formulated by the subordinate server 300 may include a power storage device, a fuel cell device, or a diesel generator.

[0119] Although not specifically mentioned in the above disclosure, a program may be provided that causes a computer to execute each process performed by MG_EMS 150 or lower-level server 300. The program may also be recorded in a computer-readable medium. Using the computer-readable medium, it is possible to install the program in a computer. Here, the computer-readable medium on which the program is recorded may be a non-transient recording medium. The non-transient recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM.

[0120] Alternatively, a chip may be provided that is configured by a memory that stores a program for executing each process performed by the MG_EMS 150 or the lower level server 300 and a processor that executes the program stored in the memory.

[0121] [Note] The above disclosure may be expressed as follows:

[0122] A first feature is a power supply management system comprising: a distributed power source connected to a regional independent system; and a management device that manages the regional independent system, wherein the management device comprises: a prediction unit that predicts an error range of a difference between a first predicted value of power demand of the regional independent system and a second predicted value of an output power of the distributed power source based on the first predicted value and the second predicted value; a generation unit that generates power plan information regarding an operation plan of a system power source that supplies power to the regional independent system based on a predicted value of the error range of the difference between the first predicted value and the second predicted value; and a transmission unit that transmits the power plan information to a higher-level device that controls the system power source.

[0123] A second feature is a power supply management system in accordance with the first feature, wherein the generation unit generates the power planning information based on an output power range defined by upper and lower limits of output power of a system power supply connected to the regional independent system.

[0124] A third feature is a power supply management system according to the first or second feature, wherein the generation unit generates the power plan information based on at least one of an increase rate and a decrease rate of the output power of the system power supply.

[0125] A fourth feature is the power supply management system in at least one of the first to third features, wherein the generation unit generates the power plan information based on maintenance information of the system power supply.

[0126] A fifth feature is a power supply management system in at least one of the first to fourth features, wherein the power plan information includes a predicted value within an error range of a difference between the first predicted value and the second predicted value.

[0127] A sixth feature is the power supply management system according to at least one of the first to fifth features, wherein the power plan information includes a range of output power desired as the output power of the system power supply.

[0128] A seventh feature is a power supply management system according to at least one of the first to sixth features, wherein the distributed power supply includes a power supply to which a feed-in tariff is applied.

[0129] An eighth feature is a power supply management system according to at least one of the first to seventh features, wherein the distributed power supplies include power supplies to which a feed-in tariff is not applied.

[0130] A ninth feature is a power supply management system in at least one of the first to eighth features, wherein the distributed power supply includes a solar power generation device and a power control device to which the solar power generation device is connected.

[0131] A tenth feature is a power supply management system in at least one of the first to ninth features, wherein the distributed power supply includes a solar power generation device, a power storage device, and a power control device to which the solar power generation device and the power storage device are connected.

[0132] An eleventh feature is a power supply management system in at least one of the first to tenth features, wherein the distributed power supply includes a power supply that outputs power using renewable energy.

[0133] A twelfth feature is a power management method used in a power management system including a distributed power source connected to a regional independent system and a management device that manages the regional independent system, the power management method comprising: a step in which the management device predicts an error range of a difference between a first predicted value and a second predicted value of an output power of the distributed power source based on a first predicted value of a power demand of the regional independent system and a second predicted value of the output power of the distributed power source; a step in which the management device generates power plan information regarding an operation plan of a system power source that supplies power to the regional independent system based on a predicted value of the error range of the difference between the first predicted value and the second predicted value; and a step in which the management device transmits the power plan information to a higher-level device that controls the system power source. [Explanation of symbols]

[0134] 1...power supply management system, 10...system power supply, 12...power system, 13...area switch, 100...MG, 110...distributed power supply, 111...power supply, 112...PCS, 121...switch, 130...load, 131...switch, 150...MG_EMS, 151...communication unit, 152...management unit, 153...control unit, 191...section switch, 192...TTS, 300...subordinate server, 310...communication unit, 320...management unit, 330...control unit

Claims

1. A distributed power source connected to a regional independent grid; A management device for managing the regional independent system, The management device includes: a prediction unit that predicts an error range of a difference between a first predicted value of a power demand of the regional independent grid and a second predicted value of an output power of the distributed power source, based on the first predicted value and the second predicted value; A generation unit that generates power plan information related to an operation plan of a system power source that supplies power to the regional independent system based on a predicted value of an error range of a difference between the first predicted value and the second predicted value; a transmission unit that transmits the power plan information to a higher-level device that controls the system power supply.

2. The power supply management system according to claim 1 , wherein the generation unit generates the power plan information based on an output power range defined by an upper limit and a lower limit of an output power of the power supply system.

3. The power supply management system according to claim 1 , wherein the generation unit generates the power plan information based on at least one of an increase rate and a decrease rate of the output power of the power grid.

4. The power supply management system according to claim 1 , wherein the generation unit generates the power plan information based on maintenance information of the power system.

5. The power management system according to claim 1 , wherein the power planning information includes a predicted value within an error range of a difference between the first predicted value and the second predicted value.

6. The power management system according to claim 1 , wherein the power plan information includes a range of output power desired as the output power of the system power supply.

7. The power management system according to claim 1 , wherein the distributed power sources include power sources to which a feed-in tariff is applied.

8. The power management system according to claim 1 , wherein the distributed power sources include power sources to which a feed-in tariff is not applied.

9. The power management system according to claim 1 , wherein the distributed power source includes a solar power generation device and a power control device to which the solar power generation device is connected.

10. The power supply management system according to claim 1 , wherein the distributed power source includes a solar power generation device, a power storage device, and a power control device to which the solar power generation device and the power storage device are connected.

11. The power management system according to claim 1 , wherein the distributed power sources include power sources that output power from renewable energy.

12. A power management method for use in a power management system including a distributed power source connected to a regional independent system and a management device that manages the regional independent system, comprising: The management device predicts an error range of a difference between a first predicted value and a second predicted value of an output power of the distributed power source based on the first predicted value of a demand power of the regional independent grid and a second predicted value of the output power of the distributed power source; The management device generates power plan information related to an operation plan of a system power source that supplies power to the regional independent system based on a predicted value of an error range of a difference between the first predicted value and the second predicted value; The power supply management method includes a step of transmitting the power plan information by the management device to a higher-level device that controls the system power supply.

Images