System and method for creating system switching candidate

Abstract

The present invention provides a system and a method for creating system switching candidates for power systems in which it is possible to improve the efficiency of work accompanied by system switching including a work stop plan. A system for creating a system switching candidate in a power system in which a plurality of pieces of equipment are interconnected via opening / closing devices, said system for creating a system switching candidate being characterized in comprising: data on one or more pieces of work-designated equipment; a storage device for storing system configuration data and information on the opening / closing state of the opening / closing devices; an opening / closing device search function for searching for a normally open opening / closing device in the vicinity within the data on pieces of work-designated equipment; a loop detection function for searching for a closed circuit including a normally open opening / closing device and piece of work-designated equipment on the basis of the searched-for normally open opening / closing device and data on the piece of work-designated equipment; and an opening / closing state combination generating function for generating a combination of the opening / closing device included in the closed circuit and the normally open opening / closing device, the combination of the opening / closing devices being used as a system switching candidate.

Description

System switching candidate creation system and system switching candidate creation method

[0001] The present invention relates to a system for generating a power system switching candidate and a method for generating a power system switching candidate.

[0002] In recent years, the environment surrounding the power grid has been rapidly changing due to the expansion of renewable energy. Furthermore, the need for maintenance and inspection is increasing due to the aging of power grid equipment. When performing maintenance and inspection of power grid equipment, the equipment in question must be shut down. In this case, the shutdown of grid equipment reduces grid reliability, resulting in power outages and reduced power generation. In order to minimize the burden on grid users, grid operators change the transmission route to consumers and implement grid switching to ensure grid reliability.

[0003] In this regard, Patent Document 1 proposes that "an automatic equipment shutdown plan drafting device is disclosed that includes a work schedule generation mechanism that generates work schedules for work that involve the shutdown of power system equipment, and a reliability system planning mechanism that drafts a reliability system for each section of the work schedule generated by the work schedule generation mechanism. In this automatic equipment shutdown plan drafting device, the work schedule generation mechanism efficiently generates combinations of work that are expected to improve the evaluation function based on various conditions, and the reliability system planning mechanism repeatedly drafts a system configuration that ensures system reliability for each section of the generated work schedule."

[0004] JP 2012-10501 A

[0005] Patent Document 1 describes a system that can develop an equipment shutdown plan after evaluating system reliability. It states that system switching can be considered during the process. Although there is no specific description of how system switching is considered, it is thought that the system is considered in advance by a human system or by a thorough search of switching candidates.

[0006] When considering a work outage plan, reliability and system switching are generally considered for a multi-faceted system, so there is an issue that devising system switching candidates manually one by one places a heavy burden on the work planner. On the other hand, generating system switching candidates through exhaustive search requires an enormous amount of calculation time as the range of systems considered in the work outage plan increases.

[0007] One approach to this problem is to store the system configuration after grid switching as data based on the planner's knowledge in advance and call it up as needed, but with the rapid advances in power operation technology and rapid changes in systems these days, the data itself is prone to becoming outdated, which remains an issue.In addition, there are problems with data maintenance and guaranteeing the validity of registered grid switching.

[0008] In view of the above, an object of the present invention is to provide a system and method for creating a system switching candidate for a power system that can improve the efficiency of tasks involving system switching, such as work suspension planning.

[0009] In view of the above, the present invention provides "a system for creating system switching candidates in an electric power system in which a plurality of facilities are interconnected via switchgear, the system comprising: a storage device for storing data on one or more facilities to be worked on, system configuration data, and open / close state information of the switchgear; a switchgear search function for searching for a switchgear in a normally open state that is located near the data on the facility to be worked on; a loop detection function for searching for a closed circuit including a switchgear in a normally open state and the facility to be worked on based on the searched switchgear in the normally open state and the data on the facility to be worked on; and an open / close state combination generation function for generating a combination of a switchgear included in the closed circuit and a switchgear in a normally open state, the system being characterized in that the combination of switchgears is used as a system switching candidate."

[0010] Furthermore, the present invention provides a "system switching candidate creation method in an electric power system in which a plurality of facilities are interconnected via switchgear, the method comprising: a computer having a storage device, a calculation unit, and an output unit; the storage device storing data on one or more facilities to be worked on, system configuration data, and open / close state information of the switchgear; the calculation unit searching for a switchgear in a normally open state near the facility data to be worked on; searching for a closed circuit including the switchgear in the normally open state and the facility to be worked on based on the searched switchgear in the normally open state and the facility data to be worked on; generating a combination of the switchgear included in the closed circuit and the switchgear in the normally open state; and the output unit outputting the combination of the switchgear as a system switching candidate."

[0011] According to the present invention, it is possible to output system switching candidates in real time based on information on switches and system configuration, which are suited to specific purposes, thereby improving the efficiency of tasks involving system switching, such as work stoppage planning.

[0012] FIG. 1 is a diagram showing a hardware configuration and an auxiliary storage unit configuration of a system for creating a system switching candidate for an electric power system according to a first embodiment of the present invention. FIG. 2 is a diagram showing an example of system configuration data D1. FIG. 3 is a diagram showing an example of switching device information data D2. FIG. 4 is a flowchart showing a system switching candidate creation procedure according to a first embodiment of the present invention. FIG. 5 is a diagram showing an image of the process of creating a system switching candidate. FIG. 6 is a diagram showing an example of output from the system switching candidate creation system. FIG. 7 is a flowchart showing a system switching candidate creation procedure according to a second embodiment of the present invention. FIG. 8 is a diagram showing original system power generation constraint amount data in the second embodiment. FIG. 9 is a flowchart showing a system switching candidate creation procedure according to a third embodiment of the present invention.

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] In Example 1, details of an operation mode for generating system switching candidates when a certain facility that is the target of work suspension is given will be described. In Example 2, details of an operation for satisfying system reliability and minimizing power generation constraints will be described as an example of an operation for narrowing down the obtained system switching candidates for some purpose. In Example 3, details of an operation for extracting facilities that are available for work at a predetermined date and time, taking system switching into consideration, using the system configuration determination method described in Example 2 will be described.

[0015] 1 shows an example of the hardware configuration of a power system switching candidate creation system according to a first embodiment of the present invention. The power system switching candidate creation system 1 is generally configured with a computer device, and therefore includes a central processing unit 10 configured with a computer or computer server (CPU: Central Processing Unit), a main memory unit 11 configured with a storage device such as an HDD, an auxiliary memory unit 12 configured with an HDD, memory, etc., a communication unit 13, an input unit 14, and an output unit 15.

[0016] Of these, the central processing unit 10 may be configured as one or more semiconductor chips, or may be configured as a computer device such as a calculation server.

[0017] The communication unit 13 includes a circuit and a communication protocol for connecting to a communication network.

[0018] The input unit 14 can be configured to include at least one of a keyboard switch, a pointing device such as a mouse, a touch panel, a voice instruction device, and the like.

[0019] The output unit 15 is configured as, for example, a display device, but may be configured to use a printer device, an audio output device, etc. instead of or in addition to the display device. The output unit 15 outputs data processed by the central processing unit 10 or data recorded in the main memory unit 11 and the auxiliary memory unit 12 in a form suitable for the device. Examples of output will be described later.

[0020] The external system 20 is a system that cooperates with the power system switching candidate creation system 1. There may be no or multiple systems that cooperate with the external system 20.

[0021] In FIG. 1, the auxiliary storage unit 12 stores system configuration data D1, switching device information data D2, a switching device search program Pr1, a loop detection program Pr2, and a switching state combination generation program Pr3.

[0022] An example of the configuration of the system configuration data D1 is shown in Figure 2. In the system configuration data D1, multiple sets of system configurations of the power system are prepared, and for each system configuration, the equipment belonging to the corresponding system configuration and its parameters are stored in each layer. For convenience, each of the multiple system configuration data in Figure 2 will be referred to as a sheet. Furthermore, each sheet is prepared for a different operating time and operating conditions of the power system.

[0023] 2, one of a plurality of different system configurations is shown at the front of the illustration. According to the configuration example of each sheet, the system configuration data D1 includes system configuration definition information D11, upper layer information D12, and lower layer information D13. Note that the system configuration data D1 may be stored in any format, but here, an example in which an upper-lower layer structure is adopted will be described from the viewpoint of ease of handling.

[0024] Here we will explain the upper and lower layers of equipment included in a system configuration. Equipment belonging to the upper layer includes large-scale facilities such as substations and power plants (sometimes collectively referred to as electric power stations). These large-scale facilities are made up of multiple smaller power facilities. Taking a substation as an example, it is generally made up of power facilities (multiple smaller power facilities) such as transformers, transmission lines, and buses. A lower layer represents a more detailed group of equipment belonging to such upper layer facilities. In other words, upper layer equipment included in a certain system configuration has a system configuration inside it that is made up of equipment belonging to the lower layer.

[0025] Returning to FIG. 2, the system configuration definition information D11 includes a system configuration ID (A in the illustrated example) for identifying the system configuration, and a master ID indicating the main component facilities that make up this power system (for example, electric power stations such as power plants and substations that belong to the upper layer).

[0026] The upper layer information D12 is composed of a space-time ID that defines the space-time, a space ID that defines the space, the name of the upper layer equipment (a substation in the above example), parameters, and lower-level equipment belonging to the substation (for example, power system components such as busbars, circuit breakers, switches, and transmission lines).

[0027] The lower layer information D13 includes a space-time ID that defines the space-time, a space ID that defines the space, the name of the lower layer equipment (in the above example, power system components such as busbars, circuit breakers, switches, and transmission lines that make up a substation), and parameters.

[0028] In Figure 2, the parameters of the upper layer are determined from the equipment group in the lower layer. Since a relational database is assumed, the parameters required for the upper layer must be determined in advance and the database must be constructed. In this case, the parameters of the upper and lower layers do not need to match. Therefore, a flexible structure can be adopted, in which geographical location information is input for facilities, but this information can be simplified as it is not important for equipment. For convenience, the terms upper and lower are used, but it is also possible to have a similar structure with three or more layers. Also, in this case, only information on the power transmission system is input, but the system configuration on the power distribution system side can also be input.

[0029] As described above, the system configuration definition information D11 stores the ID of each system configuration and the master ID of the equipment included in that configuration. The upper layer information D12 represents the equipment in the upper layer, and stores the master ID and equipment ID of that equipment, various specified parameters, and the master ID of the lower layer equipment. The lower layer information D13 represents the equipment in the lower layer, and, like the upper layer, stores the master ID, equipment ID, and specified parameters. Here, the master ID is an ID uniquely assigned across all time and equipment, and the equipment ID is an ID uniquely assigned to each piece of equipment within each system configuration.

[0030] Next, the switching device information data D2 stored in the auxiliary storage unit 12 of FIG. 1 will be described. An example of the configuration of the switching device information data D2 is shown in FIG. 3. The switching device information data D2 records the normal open / close state of each switching device. A switching device is a device that can change the connection relationship of the power system, and is typified by a switch switch (LS) and a circuit breaker (CB). The normal open / close state here indicates whether each switching device is in the open state or the closed state in a normal state when the power system is operating normally. Although the switching device information data D2 of FIG. 2 shows the minimum amount of data, other data linked to the switching device ID may also be included.

[0031] The system configuration data D1 and the switching device information data D2 stored in the auxiliary storage unit 12 in Fig. 1 may be data created in another system, or the database itself may exist in another system. The switching device search program Pr1, the loop detection program Pr2, and the switching state combination generation program Pr3 will be described later.

[0032] 4 is a flowchart showing the processing of the system switching candidate creation system according to the first embodiment of the present invention. In this processing, in addition to the system configuration data D1 and the switching device information data D2 shown in FIG. 1, work target facility data D3 (not shown in FIG. 1) is used.

[0033] In the first processing step S1 in Fig. 4, processing corresponding to the switchgear search program Pr1 is executed. In processing step S1, system configuration data D1, switchgear information data D2, and work target facility data D3 are read. The work target facility data D3 is data for which a single facility ID is specified and is set by another system or a user. In the following explanation, it is assumed that the user has specified substation SS1, which is one of the substations positioned in the upper layer, as the work target facility.

[0034] For example, Figure 5 is a diagram showing an example of a power system configuration that illustrates the process of creating a system switching candidate. The left side of Figure 5 shows an example of a configuration during normal operation in which power is supplied clockwise from the upstream substation SS1 to substations SS2-SS3 and counterclockwise to substations SS4-SS5-SS6. However, as shown in the example of the switchgear information data D2 in Figure 3, substations SS3 and SS6 are not connected by the normally open switchgear CBB, and the power system does not form a closed loop. In processing step S1, it is assumed that the upstream substation SS1 is specified as the work target facility by the work target facility data D3.

[0035] Next, in processing step S1, the above data is used to search for switchgears whose normally open state is located near substation SS1, the equipment to be worked on. The nearby switchgears are determined by the number of pieces of equipment and the physical distance from substation SS1, the equipment to be worked on, to the relevant switchgears. A possible search method is a breadth-first search method, which searches by tracing the relevant equipment and its node edge to a normally open switchgear. This process allows the search for the switchgear that is closest to substation SS1, the equipment to be worked on, and serves as the starting point for a grid switching candidate. In the example of Figure 5, a normally open switchgear CBB between substations SS3 and SS6 is detected. The data for the discovered normally open switchgear CBB is passed on to processing step S2.

[0036] In processing step S2, processing corresponding to the loop detection program Pr2 is executed. In processing step S2, the normally open switchgear CBB found in processing step S1, the system configuration data D1, and the work target equipment data D3 are read. In processing step S2, a search is made for the minimum loop including the normally open switchgear CBB found in processing step S1 and the equipment specified in the work target equipment data D3. Various methods can be considered for searching for loops, such as the breadth-first search used in processing step S1 or a depth-first search based on existing graph theory. If a loop is not detected, empty data is passed on to processing step S3. If a loop is detected, all of the switchgears belonging to that loop are passed on to processing step S3. This processing makes it possible to find the minimum closed circuit including the switchgear that is the starting point of system switching and the work target equipment. In the example of FIG. 5, it is assumed that it has been found that a minimum loop (SS1-SS2-SS3-SS6-SS5-SS4-SS1) can be formed by using a normally open switchgear CBB between substations SS3 and SS6.

[0037] In processing step S3, processing corresponding to the switching state combination generation program Pr3 is executed. In processing step S3, the switching device group searched for in processing step S2 and the normally open switching device data searched for in processing step S1 are read. In processing step S3, a combination is generated between a switching device in the normally open state and one or one segment of the switching device group included in the searched loop. In this case, one segment refers to a group of all switching devices when switching devices such as switch-breaker-switch are connected to each other. This processing generates pairs of switching devices in the normally open state and individual switching devices present in other loops. System switching can be achieved by switching the switching state of the switching device pairs generated here.

[0038] In the example of Figure 5, system switching can be achieved by swapping the open / closed states of the switchgear pair consisting of normally closed switchgear CBA and normally open switchgear CBB between substations SS1 and SS4. The system configuration after system switching will be as shown on the right side of Figure 5, supplying power clockwise from the upper substation SS1 to substations SS2-SS3-SS6-SS5-SS4. The system configuration generated by this combination of open devices is handed over to processing step S4 as a system switching candidate.

[0039] FIG. 5 , which shows an overview of the process implemented by the above processing steps S1 to S3, explains the background to the above processing. In the system under normal operation shown on the left side of FIG. 5 , the normally open switchgear CBB is generally kept open to prevent any system reliability violations (such as short-circuit capacity constraints) that would occur if a loop were created in that area. However, in the event of a work stoppage at substation SS1, for example, a deterioration in system reliability or a power outage may occur. In this case, the normally open switchgear CBB may be closed as a detour, and the other normally closed switchgear CBA may be opened to change the transmission path and ensure system reliability. The above processing steps S1 to S3 achieve this. The right side of the figure shows an example of switching the open / close state of one of the combinations. As shown in the figure, a new transmission path is constructed and the system is switched. While the figure shows one combination, candidates for opening all transmission lines within the loop are generated.

[0040] In processing step S4, the data generated in processing step S3 is registered in a database or output. An example of the output is shown in FIG. 6. In FIG. 6, the normal system is drawn on the left side of one screen, and system switching candidates are drawn on the right side. In addition, by selecting a system switching ID, a system diagram of the selected system switching candidate can be drawn on the right side. The system configuration diagram may be drawn not only as a schematic configuration diagram shown in the figure, but also as a single-line diagram or on a map linked to the physical reality.

[0041] In short, the configuration of Example 1 is as follows: "A system switching candidate creation system 1 in an electric power system in which a plurality of facilities are interconnected via switchgears, comprising: an auxiliary storage unit 12 that stores one or more pieces of work target facility data D3, system configuration data D1, and switchgear information data D2 that is open / closed state data of the switchgears; a switchgear search function (processing step S1) that searches for a switchgear in a normally open state that is located near the work target facility data D3; a loop detection (loop system search) function (processing step S2) that searches for a closed circuit including a switchgear in a normally open state and the work target facility based on the searched switchgear in the normally open state and the work target facility data D3; and an open / closed state combination creation function (processing step S3) that creates a combination of a switchgear included in the closed circuit and a switchgear in a normally open state, and the system switching candidate creation system is characterized in that the combination of the switchgears is used as a system switching candidate."

[0042] According to the first embodiment, a candidate for system switching can be obtained as a system configuration created as a result of a combination of circuit breaker opening and closing. In addition, the candidate system configuration is guaranteed to have no nodes that will be disconnected due to the system switching, i.e., no substations or loads that will be affected by power outages. This function can be used to support the creation of plans that require system switching, such as work stoppage plans.

[0043] In the second embodiment, a case will be described in which the system switching candidate generation system shown in the first embodiment presents switching candidates that have high system reliability and can minimize a certain objective function. This time, the operation in the case of minimizing the power generation constraint amount will be described in detail as an example of the objective function. Note that the description of the same components and operations as those in the first embodiment will be omitted.

[0044] A flowchart of the processing in Example 2 is shown in Figure 7. The processing steps S1-S4, system configuration data D1, switching device information data D2, and work target facility data D3 in the figure are the same as those in Example 1, so a description of these parts will be omitted.

[0045] In processing step S5, a predetermined system reliability analysis is performed as the next step for each of the system switching candidates generated by the switching state combinations obtained in processing step S3 of Fig. 1. The system reliability analyzed here may include, for example, determining the overload of a transmission line using a general power flow calculation, or determining N-1 reliability, which determines whether a power outage will occur in the system in the event of a fault. The analysis results are passed on to processing step S6. This processing makes it possible to quantitatively obtain the system reliability for each system configuration of the system switching candidate group.

[0046] In processing step S6, a determination is made as to whether there are any further violations of the analysis results obtained in processing step S5. Taking the transmission line overload determination and N-1 reliability determination described in processing step S5 as an example, if an overload occurs on the transmission line, that is, if the ratio of the power flow to the operational capacity of the transmission line exceeds 100% or if a power outage occurs in the N-1 system (system during an accident), a reliability violation is determined to have occurred, and the process moves to the right side of processing step S6 in Figure 7, where the corresponding system switching candidate is discarded, and the subsequent processing is terminated, or the process moves to determining whether the next system switching candidate has a system reliability violation. If there is no reliability violation, the system switching candidate is passed on to processing step S7.

[0047] In step S7, the amount of power generation constraint is calculated for each of the group of grid switching candidates that have no reliability violations and that have been passed on from step S6. The power generation constraint here refers to having power generation companies reduce the output of generators when transmission line overload is expected.

[0048] There is some debate about how to calculate the power generation constraint amount, but one possible example is to follow the calculation method described in the Work Outage Planning Manual of the Organization for Cross-regional Coordination of Transmission Operators in Japan. This makes it possible to obtain the power generation constraint amount for the entire system configuration and the power generation constraint amount for each generator, which are then passed on to processing step S8. This process makes it possible to calculate the power generation constraint amount for each system configuration in the system switching candidate group.

[0049] In processing step S8, the power generation constraint amount for each system configuration of the system switching candidate group inherited from processing step S7 is compared with the power generation constraint amount for the original system configuration stored in the original system power generation constraint amount data D4. If the comparison shows that the power generation constraint amount is complied with, the process proceeds to processing step S4, where data registration and output processing are performed, and if the power generation constraint is violated, the process proceeds to the right side of processing step S8 in Fig. 7, where the corresponding system switching candidate is discarded, and the subsequent processing is terminated, or the process proceeds to determining whether the next system switching candidate violates the power generation constraint.

[0050] An example of the configuration of the original system power generation constraint data D4 is shown in Figure 8. The original system power generation constraint data D4 records power generation constraint data for each generator in the system state before system switching. In the example of Figure 8, in addition to the power generation constraint data for each generator A, B, and C, the total value (SUM) of the power generation constraint data for the entire system is stored. This data may be provided externally or may be generated within the system using the power generation constraint calculation function in processing step S7.

[0051] The power generation constraint amounts to be compared may be those of the entire system configuration, or those of the generators involved in the work stoppage specified in the work target facility data D3. In either case, if the power generation constraint amount has been reduced by the system switching, it is determined that the power generation constraint amount has been improved by the system switching, and the system switching candidate is passed on to processing step S4. If the constraint amount has not been improved, the system switching candidate is discarded.

[0052] The configuration of the second embodiment is the same as that of the first embodiment, but further includes "a system switching candidate generation system characterized by including a system reliability analysis function (processing step S5) that performs a system reliability analysis on a system configuration created from the generated combination of switching devices, and a system reliability violation determination function (processing step S6) that determines a violation of the system reliability by comparing the obtained system reliability analysis result with a predetermined threshold value."

[0053] According to the second embodiment, it is possible to extract, from among the grid switching candidates, a switching candidate that can improve the power generation constraint amount while satisfying grid reliability. Although the second embodiment gives an example of the objective of improving the power generation constraint amount, it is also possible to extract a grid switching candidate that minimizes / maximizes the objective function calculated by the same flow for other objectives.

[0054] In the third embodiment, a case will be described in which the system switching candidate generation system shown in the first and second embodiments is used to present whether a group of work applications input in a system cross section at a certain date and time can be stopped, and if so, which system configuration can most fully achieve the power generation constraint amount. Note that explanations of the same configuration parts and operations as those in the first and second embodiments will be omitted.

[0055] A flowchart of the processing in the third embodiment is shown in Fig. 9. The processing steps S1 to S7, the system configuration data D1, and the switching device information data D2 in the figure are the same as those in the first and second embodiments, so a description of these parts will be omitted.

[0056] In the case of Example 3, the work application data is a data set in which multiple pieces of work target equipment data D3 are registered, and multiple equipment IDs that may be stopped at a single cross section on the relevant date and time are specified, and is data set by another system or a user.

[0057] In processing step S9, all combinations are generated from the multiple equipment IDs registered in the work application data (multiple pieces of work target equipment data D3). That is, if the IDs of equipment A, equipment B, and equipment C are registered, the generated combinations will be seven: (equipment A), (equipment B), (equipment C), (equipment A, equipment B), (equipment B, equipment C), (equipment A, equipment C), and (equipment A, equipment B, equipment C). The obtained combinations are passed on to processing step S10. This processing makes it possible to generate equipment combinations for determining which combination of shutdown requests is ultimately capable of being shut down at the relevant date and time.

[0058] In processing step S10, for each of the equipment combinations for which shutdown requests have been made in processing step S9, a system cross section is created in which the designated set of equipment is stopped. One possible method for creating this cross section is to open the circuit breakers at both ends of the equipment designated in the equipment combination for which shutdown requests have been made. This process creates a system cross section that reflects the equipment shutdowns, and prepares for subsequent analysis processing.

[0059] In processing step S11, a determination is made based on the system reliability analysis result and the power generation constraint calculation result obtained in processing steps S5 and S7. Specifically, the same determination as in processing steps S6 and S8 in Fig. 7 is used, and if there is a reliability violation in the system reliability analysis result or the power generation constraint amount is not 0, processing is handed over to processing step S1. If there is no reliability violation in the system reliability analysis result and the power generation constraint amount is 0, data is handed over to processing step S12.

[0060] In process step S12, it is determined whether all of the combinations of stopped equipment generated in process step S9 have been analyzed. If there are combinations that have not yet been analyzed, the process returns to process step S10, where a new combination of stopped equipment is analyzed. If all of the combinations of stopped equipment have been analyzed, the process returns to process step S4.

[0061] In processing step S13, the system configuration with the most improved power generation constraint is extracted from among the system switching candidates analyzed in processing step S7, and processing is passed on to processing step S12. If the power generation constraint of the system configuration before the system switching is the smallest, the configuration before the switching is selected. If all system configurations have been discarded in the previous processing step S6, empty data is passed on to processing step S12.

[0062] The configuration of the third embodiment is the same as that of the first embodiment, but further includes "an objective function calculation (power generation constraint calculation) function (processing step S7) that calculates a predetermined objective function for a system configuration created from the generated combination of switching devices, and a system configuration determination function (processing steps S11, S12, and S13) that determines the system configuration with the most improved objective function from the obtained calculation result of the objective function."

[0063] According to the third embodiment, it is possible to make a shutdown decision that takes into account whether each task can be performed while taking into account grid switching, and if so, which grid configuration is optimal. Although a single date and time has been described in this embodiment, by performing the processing shown in the third embodiment for multiple time periods, it is possible to extract candidate work shutdown dates and create a work shutdown plan schedule that takes grid switching into account. In this example, improvement of power generation constraints has been given as an example of an objective, but for other objectives as well, it is possible to extract grid switching candidates that minimize / maximize the objective function found using the same flow.

[0064] 10: Central processing unit 11: Main memory unit 12: Auxiliary memory unit 13: Communication unit 14: Input unit 15: Output unit

Claims

1. A system for creating system switching candidates in an electric power system in which multiple facilities are interconnected via switchgear, comprising: a storage device that stores data on one or more facilities to be worked on, system configuration data, and switchgear open / close state information; a switchgear search function that searches for switchgears in a normally open state that are located near the facility data to be worked on; a loop detection function that searches for closed circuits that include switchgears in a normally open state and the facility to be worked on based on the searched switchgears in a normally open state and the facility data to be worked on; and an open / close state combination generation function that generates combinations of switchgears included in the closed circuits and the switchgears in the normally open state, and the system switching candidate creation system is characterized in that the combinations of switchgears are used as system switching candidates.

2. A system for creating system switching candidates according to claim 1, characterized in that it comprises a system reliability analysis function for performing system reliability analysis on a system configuration created from the generated combination of switching devices, and a system reliability violation judgment function for judging a violation of system reliability by comparing the obtained system reliability analysis result with a predetermined threshold value.

3. A system for creating system switching candidates according to claim 1 or claim 2, characterized in that it has a function for calculating a predetermined objective function for a system configuration created from the generated combination of switching devices, and a function for determining the system configuration with the most improved objective function from the calculation results of the obtained objective function.

4. A system switching candidate creation system as described in claim 1, comprising: a combination generation function that generates combinations of stopped equipment at a specified date and time based on work application data; a system cross section creation function that stops equipment in the system configuration according to the generated combination of stopped equipment and creates an analyzable system cross section; a system switching candidate extraction function that extracts, from the generated system cross section, a system switching candidate that satisfies system reliability and has the most improved objective function; and a stoppage feasibility determination function that determines whether each combination of stopped equipment at a specified date and time can be stopped.

5. A system for generating system switching candidates according to claim 4, characterized in that it has a function for determining a system switching candidate that most improves a predetermined objective function among equipment that can be stopped for a predetermined period of time and system configurations that can be stopped.

6. A system for creating a system switching candidate according to claim 1, characterized in that the system configuration data is stored in the storage device as a multi-layer structure consisting of an upper layer including large-scale facilities of the power system and their parameters, and a lower layer including facilities within the large-scale facilities and their parameters.

7. A system switching candidate creation method for an electric power system in which a plurality of facilities are interconnected via switchgear, comprising: a computer having a storage device, a calculation unit, and an output unit; the storage device stores data on one or more facilities to be worked on, system configuration data, and switchgear open / close state information; the calculation unit searches for a normally open switchgear in the vicinity of the facility to be worked on data, and searches for a closed circuit including the normally open switchgear and the facility to be worked on based on the normally open switchgear found and the facility to be worked on data, and generates a combination of the switchgear included in the closed circuit and the normally open switchgear; and the output unit outputs the combination of switchgears as a system switching candidate.

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