Islanding operation planning device, islanding operation planning method and program

Abstract

To provide a stand-alone operation planning device capable of formulating an appropriate stand-alone operation plan.SOLUTION: A stand-alone planning device 1 is provided with: a stand-alone operation planning unit 7 that, in order to independently operate power system zones separated from a power system, plans a stand-alone operation plan proposal DP by setting, among areas sectioned by switches included in the separated power system zones and being adjacent to each other, areas internally having at least distributed power supplies or capable of stationing a power-supply car as stand-alone operation zones; a system analysis unit 10 that performs a system analysis on the basis of the stand-alone operation plan proposal DP and determines whether or not a stand-alone operation is possible; and a constraint addition unit 11 that adds a constraint condition CC used when planning the stand-alone operation plan proposal DP when the system analysis unit 10 determines that the stand-alone operation is impossible and causes the stand-alone operation planning unit 7 to replan the stand-alone operation plan proposal DP.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an isolated operation planning device, an isolated operation planning method, and a program. [Background technology]

[0002] In recent years, the introduction of distributed power sources, such as renewable energy sources, into power grids has been progressing. However, large-scale disasters such as typhoons and floods have been on the rise, resulting in the emergence of cases of large-scale power outages and prolonged recovery times due to faults in the main grid or multiple faults in the distribution grid. Power infrastructure is being called upon to respond to these power supply disruptions. In the future, new power grid operations will be required to maximize the use of distributed power sources connected to the power grid, achieve widespread and rapid power recovery from outages, and subsequently ensure a stable power supply.

[0003] In particular, within the power infrastructure, the introduction of distributed power sources such as solar power generation has progressed significantly in the power distribution system, and islanding operation in times of emergency is being considered. However, in islanding operation, it is expected that issues will arise in the stable supply of power due to the demand within the islanding system, the output of the distributed power source, and transient phenomena during islanding operation. For this reason, there is a need to be able to continue stable islanding operation in the power distribution system in times of emergency, and to maximize the number of consumers who can recover from a power outage.

[0004] Background art in this technical field is described in Patent Document 1. The abstract of this document states, "The power conditioner 100 includes a first isolated operation output terminal 107 and a second isolated operation output terminal 108, an inverter 102, a first current sensor 105 that detects a first current output by the inverter 102, a second current sensor 106 that detects a second current supplied to either the first isolated operation output terminal 107 or the second isolated operation output terminal 108, a control unit 111 that issues a warning or stops operation of the inverter 102 when the first current is equal to or greater than a predetermined first threshold or when the second current is equal to or greater than a predetermined second threshold, and a memory unit 109, and the control unit 111 controls the inverter 102 in accordance with the current flowing through the isolated operation output terminal with a lower priority and the current of a load connected to the isolated operation output terminal with a higher priority." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-48412 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the above-mentioned technology, there is a demand for formulating a more appropriate isolated operation plan. The present invention has been made in view of the above-mentioned circumstances, and has an object to provide an isolated operation planning device, an isolated operation planning method, and a program that are capable of formulating an appropriate isolated operation plan. [Means for solving the problem]

[0007] In order to solve the above problems, the islanding operation planning device of the present invention is characterized by comprising: an islanding operation planning unit that prepares an islanding operation plan for an area that is included in the isolated power system section and is divided by adjacent switches, and that at least has a distributed power source inside or can deploy a power supply vehicle, as the islanding operation section, in order to operate the power system section isolated from the power system; a system analysis unit that performs system analysis based on the islanding operation plan and determines whether islanding operation is possible; and a constraint addition unit that, if the system analysis unit determines that islanding operation is not possible, adds constraint conditions when preparing the islanding operation plan and causes the islanding operation planning unit to re-prepare the islanding operation plan. [Effects of the Invention]

[0008] According to the present invention, an appropriate isolated operation plan can be formulated. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram of an isolated operation planning device according to a first embodiment. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a power distribution system. [Figure 3] FIG. 2 is a diagram illustrating an example of a data configuration of system information. [Figure 4] FIG. 2 is a diagram illustrating an example of a data configuration of facility damage information. [Figure 5] FIG. 2 is a diagram illustrating an example of a data configuration of power outage information. [Figure 6] FIG. 10 is a diagram illustrating an example of a data configuration of important load information. [Figure 7] FIG. 2 is a diagram illustrating an example of a data configuration of map information. [Figure 8] FIG. 2 is a diagram illustrating an example of a data configuration of resource information. [Figure 9] FIG. 2 is a diagram illustrating an example of a data configuration of past demand data. [Figure 10] FIG. 2 is a diagram illustrating an example of a data configuration of past distributed power source output data. [Figure 11] 10 is a flowchart of an isolated operation plan creation routine. [Figure 12] FIG. 10 is a diagram showing an example of an islanding operation data matrix C. [Figure 13] 10 is a flowchart of a system analysis routine. [Figure 14] 10 is a flowchart of a constraint addition routine. [Figure 15] 10 is a flowchart of a display processing routine. [Figure 16] 10 is a diagram showing an example of the configuration of a screen that a screen output unit causes a display device to display; FIG. [Figure 17] FIG. 1 is a block diagram of a computer. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Prerequisites for the embodiment] The applicant has proposed technology related to isolated operation in Patent Application No. 2021-075032. This technology makes it possible to plan the final system configuration for islanded operation so that as much load as possible can be restored as quickly as possible. However, the order in which power is restored to each switch section (area) is not taken into consideration, making it difficult to evaluate system stability up to the final system configuration. This may result in repeated outages during the process of arriving at the final system configuration, and may prevent the load capacity to be restored from outages from being maximized. Therefore, the embodiments described below provide an isolated operation planning device and an isolated operation planning method that plan the system configuration for each time period during isolated operation of a distribution system, and can maximize the load capacity for recovery from a power outage while confirming that power can be supplied without power outages at each time period.

[0011] More specifically, in the embodiment described later, an islanding operation planning device for restoring a power system section isolated due to a power system accident is defined as "a switch section (area) divided by adjacent switches for the isolated power system section." Also, in the embodiment described later, an islanding operation planning unit is provided that defines at least an area that has a distributed power source therein or that has a power supply vehicle deployed as an islanding operation section and formulates an islanding operation plan taking into account the time of power supply to each area. Furthermore, in the embodiment described later, a system analysis unit is provided that evaluates system stability at each time section for the selected islanding operation plan, and a constraint addition unit is provided that estimates a stable plan based on the system analysis results and adds plan selection constraints to the islanding operation planning unit.

[0012] As a result, according to the embodiment described below, an appropriate isolated operation plan can be formulated that includes the timing of power restoration in each area in order to restore power to the power outage area as quickly and widely as possible while avoiding further power outages in the process leading up to the final system configuration in isolated operation of the power system.

[0013] [First embodiment] <Configuration of the first embodiment> FIG. 1 is a block diagram of an isolated operation planning device 1 (computer) according to the first embodiment. The isolated operation planning device 1 includes an isolated operation planning unit 7 (islanding operation planning means), a system analysis unit 10 (system analysis means), a constraint adding unit 11 (constraint adding means), a screen output unit 12 (screen output process), a display device 13, and a database unit DB. Note that the display device 13 is preferably a display including, for example, a liquid crystal panel or an organic EL (Electro Luminescence) panel.

[0014] The isolated operation planning unit 7 outputs a proposed isolated operation plan DP (details will be described later). The system analysis unit 10 determines whether the proposed isolated operation plan DP is adoptable. If it is adoptable, it outputs that fact to the display device 13 via the screen output unit 12. On the other hand, if the proposed isolated operation plan DP is not adoptable, it outputs unadoptable information DN indicating that fact to the constraint adding unit 11. In accordance with the unadoptable information DN, the constraint adding unit 11 outputs constraint conditions CC, which serve as constraints when creating the proposed isolated operation plan DP, to the isolated operation planning unit 7. Details of the isolated operation planning unit 7, system analysis unit 10, and constraint adding unit 11 will be described later.

[0015] The database unit DB stores system information D1, equipment damage information D2, power outage information D3, important load information D4, map information D5, resource information D6, past demand data D8, and past distributed power source output data D9.

[0016] Fig. 17 is a block diagram of the computer 980. The isolated operation planning device 1 shown in Fig. 1 includes one or more computers 980 shown in Fig. 17. That is, the isolated operation planning device 1 may be configured with one computer 980, or may be configured by interconnecting multiple computers 980. 17, a computer 980 includes a CPU 981, a storage unit 982, a communication I / F (interface) 983, an input / output I / F 984, and a media I / F 985.

[0017] Here, the storage unit 982 includes a RAM 982a, a ROM 982b, and an HDD 982c. The communication I / F 983 is connected to a communication circuit 986. The input / output I / F 984 is connected to an input / output device 987. The media I / F 985 reads and writes data from a recording medium 988. The ROM 982b stores control programs executed by the CPU, various data, etc. The CPU 981 realizes various functions by executing application programs read into the RAM 982a. The interior of the isolated operation planning device 1 shown in FIG. 1 above is a block diagram showing functions realized by application programs, etc.

[0018] FIG. 2 is a diagram showing an example of the configuration of a power distribution system L (power system section) applicable to this embodiment. The power distribution system L includes a plurality of consumers LD1 to LD14, a plurality of distributed power sources G1 to G3, and a plurality of switches SW1 to SW4. Here, the term "switch" is a concept that also includes circuit breakers and the like. The power distribution system L is part of the power system GL, and is connected to other parts of the power system GL via switch SW3. In the power system GL, an external power source GX is provided outside the power distribution system L.

[0019] In the illustrated example, two damaged locations AC1 and AC2 have occurred in the power distribution system L. Here, a "damaged location" refers to a location where power distribution is disrupted due to an accident, a malfunction, or the like. As described above, the sections separated by switches SW1 to SW4 are called "areas." In the illustrated example, the power distribution system L includes four areas L1 to L4.

[0020] When there is no damage to the affected areas AC1 and AC2 and normal operation is being performed, for example, the switches SW1 to SW4 are closed. This allows each of the consumers LD1 to LD14 to receive power from the external power source GX and the distributed power sources G1 to G3. However, if an accident occurs at the damaged areas AC1 and AC2, the switches SW1 to SW4 are opened, and the power distribution system L is disconnected from the external power source GX. Then, after the accident is resolved, the switches SW1 to SW4 are closed again, allowing the power distribution system L to be restored.

[0021] The islanding operation planning device 1 (see FIG. 1) of this embodiment plans how to operate the grid during the recovery waiting period after an accident occurs. For example, when a large-scale power outage occurs due to an earthquake or the like, the recovery period is gradually extended, but it is expected that the period until recovery may take from several days to 10 days. Therefore, this embodiment is particularly useful when a long-term power outage occurs.

[0022] In this type of recovery wait state, initially, switches SW1 to SW4 are all open. However, a section that includes one or more areas in the power distribution system L and that includes consumers and distributed power sources may be able to form an islanding operation section. For example, in Figure 2, area L2, which is divided by switches SW1 and SW3, includes consumers LD1 to LD3 and distributed power source G3, and therefore may be able to form an islanding operation section.

[0023] Similarly, area L1, which is divided by switches SW1, SW2, and SW4, includes consumers LD4 to LD7 and a distributed power source G1, and therefore has the potential to form an islanding operation section. Similarly, area L4, which is divided by switch SW2, includes consumers LD9 to LD14 and a distributed power source G2, and therefore has the potential to form an islanding operation section. However, area L3, which is divided by switch SW4, includes consumer LD8 but does not include a distributed power source. Therefore, area L3 cannot form an islanding operation section when switch SW4 is opened.

[0024] In the above description, the area divided by adjacent switches is defined as the islanding operation section, but multiple adjacent areas among areas L1 to L4 may also be defined as the islanding operation section. Furthermore, the distributed power sources G1 to G3 may be renewable energy sources such as solar power generation and wind power generation, or may be cogeneration equipment, power storage facilities, mobile power supply vehicles, electric vehicles, etc. As described above, areas L1, L2, and L4 have the potential to form islanding operation sections, but other conditions must be checked to determine whether or not an islanding operation section can actually be formed. Details of these other conditions for forming an islanding operation section will be provided later.

[0025] Next, various types of data contained in the database unit DB (see FIG. 1) will be described in detail. FIG. 3 is a diagram showing an example of the data configuration of the system information D1. In Figure 3, system information D1 includes records (rows) for each area, and each record includes a switch number D11, an adjacent switch number D12, a load capacity D13, a customer number D14, a distributed power source number D15, a distributed power source capacity D16, and voltage source presence / absence information D17.

[0026] The system information D1 shown in Fig. 3 is linked to the distribution system L (see Fig. 2) managed by the isolated operation planning device 1. The switch number D11 indicates one switch that divides the area related to the record. The adjacent switch number D12 indicates another switch that divides the area. The load capacity D13 indicates the total load capacity of the consumers included in the area.

[0027] The consumer number D14 indicates the identification number of the consumer included in the area. The distributed power source number D15 indicates the identification number of the distributed power source included in the area. The distributed power source capacity D16 indicates the total power source capacity of the distributed power sources included in the area. The voltage source presence / absence information D17 indicates whether or not a voltage source with the capacity required to operate the area as an isolated operation section exists.

[0028] FIG. 4 is a diagram showing an example of the data configuration of the facility damage information D2. 4, the equipment damage information D2 includes a record (row) for each damaged location (AC1, AC2 in the example of FIG. 2), and each record includes an equipment damage number D21, a switch number D22, and an equipment damage type D23. The equipment damage number D21 stores information on a serial number that identifies an accident or equipment damage within the power distribution system L. In the illustrated example, information that identifies the damaged locations AC1 and AC2 (see FIG. 2) is stored.

[0029] Here, the damaged location corresponding to the equipment damage number D21 is generally sandwiched between a pair of switches. The section sandwiched between these pair of switches is called a switch section. The switch number D22 stores the switch numbers that sandwich the switch section. For example, for the damaged location AC1, the switch numbers of switches SW1 and SW2 are stored. Also, for the damaged location AC2, the switch numbers of switches SW2 and SW4 are stored.

[0030] The equipment damage type D23 stores information indicating the accident or equipment damage corresponding to the equipment damage number D21, such as "electric pole breakage" or "high-voltage line damage." In the illustrated example, it can be seen that "electric pole breakage" occurred at damaged location AC1 and "high-voltage line damage" occurred at damaged location AC2. The equipment damage information D2 may further include information indicating the detailed location of the damaged location, such as coordinate information linked to the power distribution system L.

[0031] FIG. 5 is a diagram showing an example of the data configuration of the power outage information D3. 5, the power outage information D3 includes a record (row) for each switch section, and each record includes a switch number D31 and a power outage flag D32. The switch number D31 stores the switch numbers that sandwich the switch section in the record. The power outage flag D32 stores a power outage flag that is set to "1" (power outage state) or "0" (power on state) for the switch section.

[0032] FIG. 6 is a diagram showing an example of the data configuration of the important load information D4. 6, the important load information D4 includes a record (row) for each important load (important consumer), which is a part of the multiple consumers LD1 to LD14 (see FIG. 2). Here, "important consumers" are, for example, hospitals and evacuation shelters, but the scope can be arbitrarily determined. The important load information D4 includes, for each record, a customer number D41, a load capacity D42, and an importance level D43.

[0033] The consumer number D41 is a unique identification number that identifies the consumer related to the record, and corresponds to the consumer number D14 in the system information D1 (see FIG. 3). The load capacity D42 is the load capacity of the consumer. The importance D43 indicates the importance of the consumer. The importance D43 is, for example, a number from "1" to "5," with a higher number indicating a higher importance. The importance D43 is not limited to this as long as it can be handled in processing by the islanding operation planning unit 7 and the restoration work planning unit 9, which will be described later. Note that, although details will be described later, the islanding operation planning unit 7 does not necessarily have to use the importance D43.

[0034] FIG. 7 is a diagram showing an example of the data configuration of the map information D5. 7, map information D5 includes road information D51 and impassable area information D52. The road information D51 is information indicating roads in an area that includes the power distribution system L (see FIG. 2). The impassable area information D52 is information indicating parts of these roads that are impassable. The map information D5 also includes information indicating buildings and the like that belong to the power distribution system L.

[0035] FIG. 8 is a diagram showing an example of the data configuration of the resource information D6. 8, the resource information D6 includes a record (row) for each resource such as a maintenance vehicle that can be used in the power distribution system L. The resource information D6 includes a resource type D61 and a resource count D62 for each record.

[0036] The resource type D61 is information indicating the type of vehicle resource. A vehicle is, for example, a high-voltage generator vehicle (hereinafter referred to as a power supply vehicle), and capacity information such as "power supply vehicle (1200 kVA)" and "power supply vehicle (1500 kVA)" is stored, and power supply vehicles with different capacities can be stored as different resource types.

[0037] FIG. 9 is a diagram showing an example of the data configuration of the past demand data D8. In FIG. 9, the past demand data D8 includes records (rows) for each of the consumers LD1 to LD14. The past demand data D8 includes, for each record, a customer number D81 and actual power consumption amount D82.

[0038] The consumer number D81 is a unique identification number that identifies the consumer related to the record, and corresponds to the consumer number D14 in the grid information D1 (see FIG. 3). The actual power consumption D82 is past time-series data on the power used by the consumer. For example, the actual power consumption D82 may be a measurement result obtained by a smart meter owned by a power company. The actual power consumption D82 may also include the output of various distributed power sources, such as low-voltage solar power generation.

[0039] FIG. 10 is a diagram showing an example of the data configuration of the past distributed power supply output data D9. In FIG. 10, the past distributed power source output data D9 includes a record (row) for each of the dispersed power sources G1 to G3. The past distributed power source output data D9 includes a distributed power source number D91 and a distributed power source output record D92 for each record.

[0040] The distributed power source number D91 is a unique identification number that identifies the distributed power source related to the record, and corresponds to the distributed power source number D15 in the system information D1 (see FIG. 3). The distributed power source output record D92 is past time-series data related to the power consumption of the distributed power source. For example, past time-series data related to the output of a distributed power source owned by a power company can be applied as the distributed power source output record D92.

[0041] <Operation of the First Embodiment> Next, the operation of the first embodiment will be described. First, FIG. 11 is a flowchart of the isolated operation plan creation routine. This routine is executed by the isolated operation planning unit 7 (see FIG. 1). When the processing proceeds to step S71 (islanding operation planning process) in FIG.

[0042] FIG. 12 is a diagram showing an example of the islanding operation data matrix C. As shown in FIG. Each row of the islanding operation data matrix C corresponds to an area (for example, L1 to L4 shown in Figure 2) that can become an islanding operation section. An "area that can become an islanding operation section" is an area that has dispersed power sources G1 to G3 inside, or an area where a power supply vehicle can be placed.

[0043] In the above-mentioned step S71, the islanding operation planning unit 7 extracts all switch numbers D11 belonging to the distribution system L managed by the islanding operation planning device 1 from the system information D1 (see FIG. 3), and includes these as switch numbers C1 in the islanding operation data matrix C. Furthermore, the islanding operation planning unit 7 reads all adjacent switch numbers D12 adjacent to the above-mentioned switch number D11 from the system information D1, and includes these as adjacent switch numbers C2 in the islanding operation data matrix C.

[0044] Furthermore, the isolated operation planning unit 7 assigns an area number such as "L1," "L2," etc. (see FIG. 2) to each row of the isolated operation data matrix C, and includes this as area number C3 in the isolated operation data matrix C. Through these processes, the switch numbers of the switches required to identify each area and adjacent areas, i.e., areas separated by the same switch, can be identified in a unified manner by the area number.

[0045] Furthermore, the islanding operation planning unit 7 reads out the load capacity D13, distributed power generation capacity D16 and voltage source presence / absence information D17 (see Figure 3) of each area, reads these out from the system information D1 as load capacity C4, distributed power generation capacity C5 and voltage source presence / absence information C6, respectively, and includes these in the islanding operation data matrix C as load capacity C4.

[0046] Furthermore, the isolated operation planning unit 7 identifies the area to which each damaged location belongs based on the switch number D22 in the equipment damage information D2 (see FIG. 4). In the example shown in FIG. 4, it is determined that both damaged locations AC1 and AC2 belong to area L1 (see FIG. 2). Then, the isolated operation planning unit 7 includes equipment damage presence / absence information C7, which is binary information that is "1" if a damaged location exists and "0" if no damaged location exists, in the islanding operation data matrix C. However, the equipment damage presence / absence information C7 is not limited to binary information and may include detailed information on the damaged location. For example, it may include the content of the equipment damage type D23 (see FIG. 4) in the equipment damage information D2, or may include coordinate information of the damaged location, etc.

[0047] Furthermore, the islanding operation planning unit 7 reads out the power outage flag D32 of each switch section from the power outage information D3 (see FIG. 5). If the power outage flag D32 of any switch section belonging to a certain area is "1" (power outage state), the area is in a "power outage" state. Also, if the power outage flag D32 of all switch sections belonging to an area is "0" (power on state), the area is in a "power on" state. The islanding operation planning unit 7 includes this "power outage" or "power on" state in the islanding operation data matrix C as state data C8.

[0048] Furthermore, the islanding operation planning unit 7 reads out the load capacity D42 and importance D43 for each important load from the important load information D4 (see FIG. 6) and calculates the product of the two (D42 × D43). Then, the islanding operation planning unit 7 calculates the sum of the products (D42 × D43) for each area related to the important loads belonging to that area, and includes the calculated sum as the weighted capacity C9 of the important load in the islanding operation data matrix C. Here, the weighted capacity C9 of the important load is not necessarily required, and the user can arbitrarily decide in advance whether or not to use the weighted capacity C9 of the important load. If the weighted capacity C9 of the important load is not required, it is recommended that all of the weighted capacities C9 of the important loads in the islanding operation data matrix C be set to "0".

[0049] Furthermore, the isolated operation planning unit 7 calculates the required travel time C10 based on the road information D51 and impassable road information D52 in the map information D5, and includes the calculated required travel time C10 in the isolated operation data matrix C. Here, a method for calculating the required travel time C10 will be explained. First, the power supply vehicle, workers, etc. are staying at a known initial location, such as a sales office. The location of the restoration switch that restores power to the area in a power outage is also known. The isolated operation planning unit 7 calculates the shortest time required for the power supply vehicle, workers, etc. to travel from the initial location to the restoration switch. This calculated shortest time is the required travel time C10.

[0050] The required travel time C10 can be calculated by dividing the length of the shortest route from the initial position to the return switch by an average travel speed, such as 30 km / h. If the shortest route from the initial position to the return switch includes an impassable road section, a route that bypasses that section may be used instead of the shortest route. However, the average travel speed while traveling through the impassable road section may be reduced to, for example, 15 km / h, to estimate the required travel time for the detour, and the estimated required travel time may be used as the required travel time C10. The above-mentioned average travel speeds, such as 30 km / h and 15 km / h, may be set in advance, and are not limited to these speeds.

[0051] As described above, according to the example of the isolated operation data matrix C shown in Figure 12, for each area that may become an isolated operation section, various conditions in that area and problems during recovery are comprehensively organized and summarized.

[0052] Returning to FIG. 11, when the processing next proceeds to step S72 (islanding operation planning process), the islanding operation planning unit 7 prepares an islanding operation plan DP based on the islanding operation data matrix C. That is, the islanding operation planning unit 7 performs optimization calculations having the objective function and constraint conditions described below to prepare the islanding operation plan DP. This makes it possible to maximize the load capacity that can be restored from power outages when islanding operation is possible, i.e., to identify areas where power outage damage can be minimized. It is also possible to prepare an islanding operation plan DP that includes the timing of power restoration for each area in the process up to the final system configuration for islanding operation.

[0053] (Objective function) First, a binary variable BV (not shown) is assumed for each area, which is "0" if the hypothetical state for each area is a power outage and "1" if the hypothetical state is an islanding operation. Also, for each area, a virtual load capacity LC (not shown) is assumed, which is the sum of the load capacity C4 and the weighted capacity C9 of the important load shown in FIG. 12. The sum of the virtual load capacities LC in all areas is defined as a total virtual load capacity LCA (not shown).

[0054] The objective function for the optimization calculation is the total virtual load capacity LCA for each time step. In other words, the objective of this embodiment is to maximize the total virtual load capacity LCA for each time step. Here, the time step can be set arbitrarily by the user, for example, to 5 minutes. This makes it possible to create an islanding operation plan DP that includes the power restoration timing for each switch section so that as many loads as possible are restored from the power outage as quickly as possible. This makes it possible to create an islanding operation plan that prioritizes power restoration according to the importance of important loads when considering them.

[0055] (constraint conditions) The constraints for performing optimization calculations are mainly the following constraints CA, CB, and CC. Constraint condition CA is that "equipment damage information C7 (see Figure 12) must be "0", that is, "there must be no accidents or equipment failures in the area." This is because if islanding is performed in the area despite the existence of an accident or equipment failure, there is a possibility that power outages will occur again or that damage from electric shock will occur.

[0056] Constraint condition CB is that "areas where voltage source presence information C6 (see Figure 12) is "0" (no voltage source) shall not operate in an isolated mode unless connected to another area." Here, when adjacent areas operate in an isolated mode, they shall always operate in an interconnected mode. Adjacent areas should be identified based on the adjacent switch number C2 (see Figure 12). This makes it possible to operate in an isolated mode by connecting to another area if there is no voltage source in the area where isolated operation is planned. The constraint conditions CC are conditions added by the constraint adding unit 11 (see FIG. 1). Details of the constraint conditions CC will be described later, but at the stage when the system analysis routine (FIG. 13) described later is first executed, the constraint conditions CC are not particularly set.

[0057] FIG. 13 is a flowchart of a system analysis routine executed by the system analysis unit 10, and this routine performs system analysis through steps SS102 to S112 (system analysis process). When the process proceeds to step S102 in Fig. 13, the system analysis unit 10 creates a demand forecast E1 and a distributed power source output forecast E2 for the proposed islanding operation plan DP previously created by the islanding operation planning unit 7. Here, the demand forecast E1 is a forecast of power demand after the start of power supply in each area where islanding operation will be performed. Also, the distributed power source output forecast E2 is a forecast of the output of the distributed power source after the start of power supply in each area where islanding operation will be performed. The system analysis unit 10 creates the demand forecast E1 and the distributed power source output forecast E2 by, for example, regression analysis based on past demand data D8 (see Fig. 9), past distributed power source output data D9 (see Fig. 10), etc.

[0058] Next, when the process proceeds to step S104, the system analysis unit 10 simulates the current and the like in the power distribution system L. To this end, the system analysis unit 10 creates a power distribution system model LM (not shown) that simulates the power distribution system L (see FIG. 2). This power distribution system model LM includes a voltage source model, a load model, a transformer model, a contracted load model, and the like that simulate voltage sources, loads, transformers, and the like. The system analysis unit 10 sets time-series parameters of these various models at current analysis time intervals (e.g., 1 millisecond) that are arbitrarily set in advance by the user, and simulates the behavior, particularly the current, and the like, within the power distribution system model LM. As a result, the system analysis unit 10 calculates the inrush current at each time.

[0059] The user arbitrarily determines in advance trip criteria for simulating tripping each distributed power source. These criteria include a current value trip criteria related to the current value and a frequency trip criteria related to the frequency. The current value trip criteria is, for example, a criterion such as "simulating tripping a distributed power source when a current exceeding the rated output of the distributed power source occurs for one second or more." In this case, in the distribution system model LM, the distributed power source is simulated to trip when the current value trip criteria is satisfied. Note that the transformers and loads in the distribution system L may be modeled, for example, using their respective equivalent circuits.

[0060] Next, when the process proceeds to step S106, the system analysis unit 10 simulates the frequency stability and the like in the power distribution system L. That is, based on the demand forecast E1, the distributed power output forecast E2, and the simulation results of step S104, the system analyzer 10 simulates the supply and demand frequency stability and the like at a frequency analysis time interval (e.g., 1 second) preset by the user. As described above, the tripping criteria that the user can arbitrarily determine also include a frequency tripping criteria. This frequency tripping criteria is, for example, a criterion such as "an event has occurred in which the frequency falls below the reference frequency by 2.5 Hz or more." Therefore, in the power distribution system model LM, the distributed power source is tripped at the time when this criterion is met. This makes it possible to simulate the change over time in frequency deviation and the tripping of the distributed power source due to frequency deviation.

[0061] In the above-described steps S104 and S106, simulations were performed to analyze the inrush current, frequency, etc., but the physical quantities analyzed here are not limited to these. For example, voltage analysis using power flow calculations, simulation of remaining energy in energy storage equipment, etc., may be added to steps S104 and S106.

[0062] Next, when the process proceeds to step S108, the system analysis unit 10 determines whether or not the proposed isolated operation plan DP previously prepared by the isolated operation planning unit 7 can be adopted, based on the simulation results of steps S104, S106, etc. The user can arbitrarily set the criteria for determining whether or not a plan is adoptable. For example, if a distributed power source trips even once in the simulation of steps S104, S106, etc., it may be determined that the plan is "not adoptable." In this way, it is advisable to determine whether or not to adopt the proposed islanding operation plan DP prepared by the islanding operation planning unit 7 depending on factors such as whether or not there is a possibility of causing a recurrence of power outages if the plan is executed.

[0063] If the determination in step S108 is "Yes" (adoptable), the process proceeds to step S110. Here, the system analysis unit 10 outputs the proposed isolated operation plan DP via the screen output unit 12, the display device 13, etc. (see FIG. 1). On the other hand, if the determination in step S108 is "No" (not adoptable), the process proceeds to step S112. Here, the system analysis unit 10 outputs non-adoptable information DN to the constraint adding unit 11 (see FIG. 1). This non-adoptable information DN should include the event that caused the determination that isolated operation was not possible and the time in the simulation when that event occurred.

[0064] FIG. 14 is a flowchart of a constraint adding routine executed by the constraint adding unit 11. This routine adds the above-mentioned constraint condition CC to the isolated operation planning unit 7 through steps S120 to S126 (constraint adding process). 14, when the process proceeds to step S120, the constraint adding unit 11 calculates the real-time time step at which an event that makes islanding impossible occurs for the distribution system model LM that has been determined to be "islanding impossible." That is, the simulation time at which the event that makes islanding impossible occurs is converted into a time step. This makes it possible to determine at which time step an event that may cause a recurrence of a power outage may occur in the proposed islanding operation plan.

[0065] Next, when the process proceeds to step S122, a constraint equation is generated for a time step in which an event that will cause a recurrence of power outage may occur, to be input to the isolated operation planning unit 7. This constraint equation is preferably related to a physical quantity that is correlated with the event that will cause a recurrence of power outage, among the input information or variables handled by the isolated operation planning unit 7 described above.

[0066] As an example, consider the case where the event that causes a recurrence of a power outage is the tripping of a distributed power source due to frequency deviation. In this case, it is possible to constrain the load capacity of a certain consumer in an area correlated with the frequency to be less than a predetermined value in that time step. In this case, there are various possible methods for constraining the load capacity, and the method for constraining the load capacity is not limited. Furthermore, a physical quantity other than the load capacity in the area may be selected as a physical quantity correlated with frequency deviation or other phenomena, and can be set arbitrarily by the user in advance.

[0067] Next, when the processing proceeds to step S124 in Fig. 14, the constraint adding unit 11 outputs the constraint equation generated in the above-mentioned step S122 to the isolated operation planning unit 7 as constraint conditions CC. As a result, the isolated operation planning unit 7 sets the constraint conditions CC for the isolated operation planning unit 7. Next, when the processing proceeds to step S126, the constraint adding unit 11 instructs the isolated operation planning unit 7 to re-execute the isolated operation plan creation routine (Fig. 11) taking into account the constraint conditions CC. This ends the processing of this routine.

[0068] As a result, the isolated operation planning unit 7 re-executes the isolated operation plan creation routine (FIG. 11) based on the newly added constraint condition CC to recreate the isolated operation plan. Then, the system analysis unit 10 re-executes the system analysis routine (FIG. 13) to re-determine whether or not the new isolated operation plan can be adopted. As described above, since the new isolated operation plan was created after adding the above-mentioned constraint condition CC, there is a high possibility that it will be determined as "Yes" (adoptable) in step S108 of FIG. 13.

[0069] However, there are also cases where the new proposed isolated operation plan may be determined as "No" (unadoptable) in step S108. In this case, the constraint adding routine (FIG. 14) is executed again, and the constraint adding unit 11 updates the contents of the constraint conditions CC. As described above, the execution of the proposed isolated operation plan creation routine (FIG. 11) by the isolated operation planning unit 7, the execution of the system analysis routine (FIG. 13) by the system analysis unit 10, and the execution of the constraint adding routine (FIG. 14) by the constraint adding unit 11 are cyclically repeated until the created proposed isolated operation plan is determined to be "adoptable."

[0070] This makes it possible to formulate an islanding operation plan that can restore as many loads as possible as quickly as possible while avoiding recurrence of power outages at each time step in the process of actually configuring an islanding system in each area. Here, the above-mentioned islanding operation plan includes a combination of multiple areas and power restoration timing information. Furthermore, the power restoration timing information includes either the power restoration time (power restoration timing) or the power restoration order for each area.

[0071] Furthermore, in the series of processes, the isolated operation planning unit 7 may be able to select a solution of "not executing isolated operation in any area" to prevent the process from never ending. For example, if the isolated operation planning unit 7 creates an isolated operation plan a predetermined number of times but does not determine that it is "adoptable," it may be possible to prevent isolated operation from being executed in any area.

[0072] FIG. 15 is a flowchart of a display processing routine executed in the screen output unit 12. 15, when the process proceeds to step S20, the screen output unit 12 receives, from the user, a selection input of an item to be displayed on the display device 13. Next, when the process proceeds to step S21, the screen output unit 12 causes the display device 13 to display the content related to the selected item. In this way, the screen output unit 12 has a function of selecting and displaying the content to be displayed on the display device 13.

[0073] FIG. 16 is a diagram showing an example of the configuration of a screen 131 that the screen output unit 12 causes the display device 13 to display. In FIG. 16, a screen 131 includes panes 132, 133, and 134 that are connected in sequence in the horizontal direction. As described above, the screen output unit 12 displays the content selected by the user on the display device 13 as the screen 131. The display content selection pane 132 is provided so that the operator can operate and select the display content to be selected and processed by the screen output unit 12. As a result, the display content selected in the display content selection pane 132 is displayed in the other panes.

[0074] The screen output unit 12 preferably displays, for example, buttons, pull-down menus, etc. in the display content selection pane 132. When the operator presses or selects one or more buttons, pull-down menus, etc. displayed on the display device 13, the screen output unit 12 outputs the display content selected by the operator to another pane displayed on the display device 13. In the example of FIG. 16 , selectable items in the display content selection pane 132 include, for example, the power supply area, switch status, fault point information, maps of roads and houses, etc., according to the proposed islanding operation plan formulated by the islanding operation planning unit 7, and the islanding operation sequence. When the user selects one of these items, the screen output unit 12 accepts the selection input of the item to be displayed on the screen in step S21 of the display processing routine ( FIG. 15 ). Thereafter, in step S22 of the same routine, the screen output unit 12 displays a display screen according to the selection in the map pane 133 and the plan information pane 134.

[0075] The map pane 133 displays the islanding operation plan and a map of roads, houses, etc., whose locational relationships correspond to the plan, superimposed on it. The islanding operation plan is a system diagram colored so that each system can be identified, and on the system diagram, for example, open and closed switch states in the system are displayed in different colors to indicate the switch state, and the location of an accident point is displayed with a symbol such as a cross. On the map, for example, areas that can supply power through islanding operation are displayed in color.

[0076] The plan information pane 134 displays specific details of the item selected in the display content selection pane 132. The example in Fig. 16 shows an example in which detailed information is displayed when the islanding operation sequence is selected. The islanding operation sequence is a screen that shows whether each area is in an islanding state, a powered state, or a power outage state at each time.

[0077] The islanding operation planning device 1 of this embodiment can also be used for purposes other than islanding operation planning. For example, this embodiment can be used during normal times when no disaster has occurred, and candidate locations for installing distributed power sources such as storage batteries and solar power generation facilities can be input. By simulating the area where power will be restored, it is possible to confirm the effect of installing distributed power sources in the candidate locations in reducing power outage damage, contributing to decision-making regarding the installation of distributed power sources. For example, when attempting to identify faulted sections using a timed sequential transmission method with distributed power sources as power sources, this embodiment can also be used to plan the time, timing, and sequence of power restoration. In these applications, even when the demand-side situation changes due to power consumption control by smart meters or demand response, the change in information can be reflected in the input data, allowing for the creation of plans.

[0078] When developing a business using this embodiment, several examples are conceivable. For example, an entity other than a power distribution operator may own the islanding operation planning device 1 according to this embodiment, and when a power distribution company requires a service according to this embodiment, the entity may provide the required input information to the entity, and the entity may provide a plan proposal as a service. In addition, for example, in order for the power distribution operator to own the islanding operation planning device 1, the entity may trade the service of formulating an islanding operation plan. In addition, for example, the islanding operation planning device 1 according to this embodiment may be installed as a function in an existing device or system owned by the power distribution operator, and the entity may trade the service of formulating an islanding operation plan.

[0079] [Effects of the embodiment] According to the above-described embodiment, the islanding operation planning device 1 is equipped with an islanding operation planning unit 7 that prepares a proposed islanding operation plan DP for islanding operation of a power system section (L) that has been separated from the power system GL, by setting as the islanding operation section at least the areas L1 to L4 that have distributed power sources G1 to G3 therein or in which a power supply vehicle can be deployed, out of the areas L1 to L4 that are included in the separated power system section (L) and are divided by adjacent switches SW1 to SW4; a system analysis unit 10 that performs system analysis based on the proposed islanding operation plan DP and determines whether islanding is possible; and a constraint addition unit 11 that, when the system analysis unit 10 determines that islanding is not possible, adds a constraint condition CC when preparing the proposed islanding operation plan DP and causes the islanding operation planning unit 7 to re-prepare the proposed islanding operation plan DP.

[0080] As a result, the system analysis unit 10 performs system analysis based on the proposed isolated operation plan DP, and the constraint addition unit 11 can add constraint conditions CC based on the system analysis results, thereby making it possible to formulate an appropriate isolated operation plan that has a high probability of realizing isolated operation.

[0081] Furthermore, if it is determined that islanding operation is not possible, the system analysis unit 10 outputs unadaptable information DN including the timing of the event that made islanding operation impossible, and it is more preferable that the islanding operation planning unit 7 includes in the proposed islanding operation plan DP the final open / close states of the switches SW1 to SW4 and either time-series information for changing the open / close states of the switches SW1 to SW4 or the order in which the open / close states of the switches SW1 to SW4 are changed. This makes it possible to specify the open / close states of the switches SW1 to SW4 according to the timing of the event that made islanding operation impossible, and to formulate a more appropriate proposed islanding operation plan DP.

[0082] Furthermore, it is more preferable that the proposed islanding operation plan DP plans the configuration of the islanding system for each of a plurality of time steps, thereby enabling the formulation of a more appropriate proposed islanding operation plan DP corresponding to each time step.

[0083] Furthermore, it is more preferable that the constraint adding unit 11 outputs a constraint condition CC that resolves an event that makes islanding operation impossible at the timing when the event occurs, to the isolated operation planning unit 7. This further increases the possibility that the isolated operation planning unit 7 can output a proposed isolated operation plan DP that makes islanding operation possible.

[0084] Furthermore, it is more preferable that the isolated operation planning device 1 further includes a screen output unit 12 that displays on the display device 13 any of the timing when an event that makes islanding impossible occurs, the final open / close states of the switches SW1 to SW4, time-series information on changing the open / close states of the switches SW1 to SW4, or the order in which the open / close states of the switches SW1 to SW4 are changed. This allows the user to visually grasp the contents of the proposed islanding operation plan DP.

[0085] It is more preferable that the isolated operation planning unit 7 be able to create an isolated operation plan DP that does not island all of the areas L1 to L4, thereby allowing the user to recognize when islanding is difficult.

[0086] [Variations] The present invention is not limited to the above-described embodiments and various modifications are possible. The above-described embodiments are provided as examples to facilitate understanding of the present invention and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to delete part of the configuration of each embodiment, or to add or replace other configurations. Furthermore, the control lines and information lines shown in the figures are those considered necessary for explanation, and do not necessarily represent all control lines and information lines necessary for the product. In reality, it is acceptable to consider that almost all components are interconnected. Possible modifications of the above-described embodiments include, for example, the following:

[0087] (1) Since the hardware of the isolated operation planning device 1 in the above embodiment can be realized by a general computer, the flowcharts shown in Figures 11 and 13 to 15 and other programs for executing the various processes described above may be stored in a storage medium (a computer-readable storage medium on which a program is recorded) or distributed via a transmission path.

[0088] (2) In the above embodiments, the processes shown in Figures 11, 13 to 15, and the other processes described above are described as software processes using programs, but some or all of them may be replaced with hardware processes using ASICs (Application Specific Integrated Circuits) or FPGAs (Field Programmable Gate Arrays), etc.

[0089] (3) The various processes executed in the above embodiment may be executed by a server computer via a network (not shown), and the various data stored in the above embodiment may also be stored in the server computer. [Explanation of symbols]

[0090] 1. Isolated operation planning device (computer) 7. Isolated operation planning unit (isolated operation planning means) 10 System analysis section (system analysis means) 11 Constraint addition section (constraint addition means) 12 Screen output section (screen output process) 13 Display device L Distribution system (power system section) CC constraints DN Not applicable information DP independent operation plan GL power system G1~G3 Distributed power supply L1~L4 area Steps S71 and S72 (islanding operation planning process) SW1~SW4 switches S102~S112 (System analysis process) S120~S126 (Constraint addition process)

Claims

1. an islanding operation planning unit that formulates an islanding operation plan for an electric power system section that has been isolated from the electric power system, by defining as an islanding operation section at least an area that has a distributed power source therein or that can be equipped with a power supply vehicle, among areas that are included in the isolated electric power system section and are divided by adjacent switches; a system analysis unit that performs a system analysis based on the proposed isolated operation plan and determines whether or not isolated operation is possible; a constraint adding unit that, when the system analysis unit determines that islanding is not possible, adds a constraint condition for formulating the islanding operation plan and causes the islanding operation planning unit to re-formulate the islanding operation plan. An isolated operation planning device characterized by:

2. When it is determined that the isolated operation is not possible, the system analysis unit outputs unadaptable information including the timing of the occurrence of the event that makes the isolated operation not possible, The isolated operation planning unit includes in the proposed isolated operation plan the final open / closed state of the switch, time-series information for changing the open / closed state of the switch, or an order for changing the open / closed state of the switch. The isolated operation planning device according to claim 1 .

3. The proposed isolated operation plan plans the configuration of the isolated operation system at each of a plurality of time steps. The isolated operation planning device according to claim 2 .

4. The constraint adding unit outputs, to the isolated operation planning unit, the constraint condition that resolves the event at the timing when the event that makes the isolated operation impossible occurs. The isolated operation planning device according to claim 2 .

5. The system further includes a screen output unit that displays on a display device any of the timing at which the event that makes the isolated operation impossible occurs, the final open / close state of the switch, time-series information for changing the open / close state of the switch, or the order in which the open / close state of the switch is changed. The isolated operation planning device according to claim 2 .

6. The isolated operation planning unit is capable of formulating the isolated operation plan in which all of the areas are not operated in an isolated manner. The isolated operation planning device according to claim 1 .

7. an islanding operation planning process for preparing an islanding operation plan for an isolated operation section of a power system that has been isolated from the power grid, the area being included in the isolated power system section and divided by adjacent switches, and that at least has a distributed power source therein or can deploy a power supply vehicle; a system analysis process of performing a system analysis based on the proposed isolated operation plan and determining whether or not isolated operation is possible; and a constraint addition step of adding a constraint condition when formulating the isolated operation plan and re-executing the isolated operation planning step if it is determined that the isolated operation is not possible in the system analysis step. The isolated operation planning method according to the present invention.

8. the system analysis step is a step of outputting unadaptable information including a timing of an event that makes the islanding operation impossible when it is determined that the islanding operation is impossible, The islanding operation planning process is a process of including in the islanding operation plan the final switching state of the switch, time-series information for changing the switching state of the switch, or the order in which the switching state of the switch is changed. The method for planning an isolated operation according to claim 7 .

9. The proposed isolated operation plan plans the configuration of the isolated operation system at each of a plurality of time steps. The method for planning an isolated operation according to claim 8 .

10. The constraint addition process outputs the constraint condition that resolves the event that makes the isolated operation impossible at the timing when the event occurs to the isolated operation planning process. The method for planning an isolated operation according to claim 8 .

11. The computer is further caused to execute a screen output process of displaying on a display device any of the timing at which the event that makes the isolated operation impossible occurs, the final open / close state of the switch, time-series information for changing the open / close state of the switch, or the sequence for changing the open / close state of the switch. The method for planning an isolated operation according to claim 8 .

12. The isolated operation planning process can formulate the isolated operation plan in which all of the areas are not operated in an isolated manner. The method for planning an isolated operation according to claim 7 .

13. Computer, an islanding operation planning means for preparing an islanding operation plan for an electric power system section isolated from the electric power system, the islanding operation plan being an area that is included in the isolated electric power system section and is divided by adjacent switches, and that has at least a distributed power source therein or that can be equipped with a power supply vehicle; a system analysis means for performing a system analysis based on the proposed isolated operation plan and determining whether or not isolated operation is possible; a constraint adding means for adding a constraint condition when formulating the isolated operation plan and causing the isolated operation planning means to re-formulate the isolated operation plan when the system analysis means determines that the isolated operation is not possible; A program to function as a

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