Power outage risk evaluation system and power outage risk evaluation method

Abstract

To contribute to the discussion of a rational measure for reducing the risk of power outage.SOLUTION: A power outage risk evaluation system 1 comprises: a system configuration database 7 which stores information indicative of a power system configuration or a connection status; a disaster hazard database 9 which stores information on natural disaster hazards and information on a yearly excess frequency; an event tree creation unit 15 which creates an event tree used to evaluate the power outage provability of the power system for a hazard to be evaluated from the information stored in the system configuration database 7; a fault tree creation unit 16 which creates a fault tree used to calculate the branch probability of the event tree using the disaster hazard database 9; a power outage provability evaluation unit 12 which analyzes the power system by the event tree and evaluates the power outage provability of the power system; and a power outage risk evaluation unit 14 which evaluates the power outage risk of the power system on the basis of the power outage provability.SELECTED DRAWING: Figure 17

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present invention relates to power outage risk assessment techniques. [Background technology]

[0002] Generally, power system analysis is performed to analyze a series of power systems from upstream to downstream, from power plants where electricity is generated, through the transmission system and distribution network, to consumers. This involves modeling power equipment in a simulator, and using the analysis results in facility planning or to investigate the causes of abnormal events. This power system analysis has traditionally been used with the aim of providing a stable supply of high-quality electricity. Here, as a result of an abnormal event in the power system, power transmission or distribution becomes impossible, resulting in a power outage. There are multiple factors that cause power outages, but the impact of natural disasters has been widely studied as it is related to the prediction of power outages and the recovery from power outages.

[0003] For example, a technique is known for predicting typhoon damage based on typhoon forecasts and past damage information. A technique is also known for predicting the number of households that will experience power outages based on equipment resistance and weather forecast data. A technique is also known for calculating the average power outage duration for consumers, the amount of power outage damage, and the cost-effectiveness of countermeasures based on data on past natural disasters and the number of power outages. A technique is also known for modeling a target power distribution network, calculating the power distribution route and damage probability, calculating the expected value of the demand or power supply of consumers using an event tree, and calculating the change in the power supply rate over time. These techniques basically evaluate the impact of power outages on the presence or absence of a power distribution route based on the physical damage probability of each component of the power distribution network. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5044243 [Patent Document 2] Patent No. 5931830 [Patent Document 3] Patent No. 5088628 [Non-patent literature]

[0005] [Non-Patent Document 1] Study on earthquake resilience evaluation method for power distribution grids with distributed power sources Journal of the Japan Association for Earthquake Engineering Vol. 19, No. 7, 2019 Summary of the Invention [Problem to be solved by the invention]

[0006] Power outages are caused by natural disasters such as earthquakes, typhoons, lightning strikes, and floods, or by other factors. If the risk of power outages due to various disasters can be quantitatively understood in advance, power consumers can take reasonable and effective measures based on that information. For example, as a measure to reduce the risk of power outages, power outages can be avoided by installing storage batteries, fuel cells, private power generation equipment, etc., and supplying power from these equipment when power supply from the power distribution network is stopped. In addition, there is a power distribution automation system that monitors the power distribution network or controls system switching, etc., using each device via a communication network, with the aim of maintaining and improving the power quality or supply reliability of the power distribution network.

[0007] FIG. 21 shows a schematic diagram of a conventional power distribution automation system. This schematic diagram shows the flow of restoration by the power distribution automation system when an accident occurs in a power distribution network. For example, a power distribution line extending from a substation is divided into multiple sections (1) to (6) by automatic switches. Under normal circumstances, power is transmitted through this power distribution line. Now, assume that an accident that affects the power distribution line occurs in a specified section (3). When the accident occurs, the relay of the automatic switch is operated and the automatic switch is opened. Furthermore, the substation stops transmitting power. When the circuit is reclosed, power transmission from the substation is resumed, and each automatic switch is closed in sequence, and power is transmitted to the accident point. At this time, the specified section (3) is identified as the accident section. The automatic switch on the power supply side of this accident section (3) is locked. Power is transmitted to sections (1) to (2) on the power supply side of the accident section (3). However, power is not transmitted to the accident section (3) because the automatic switch is locked. In this case, sections (4) to (6) on the load side of the fault section (3) will experience a power outage, even though no fault has occurred. These sections (4) to (6) are called healthy power outage sections. When a power outage occurs, the distribution automation system aims to minimize the scale of the outage by detecting the accident, identifying the fault section, and performing reverse transmission. Here, reverse transmission means supplying power from a different route to healthy power outage sections (4) to (6) on the load side of the fault section (3). This reverse transmission can reduce the number of power outages.

[0008] In this way, when damage or failure occurs at a specific point in the power distribution network and the power supply route is cut off, the point of the accident is identified, power is transmitted from an alternative route, and measures are taken to minimize the blackout section. In order to take measures against blackouts in advance, it is necessary to evaluate the return on investment of the measures, such as whether the measures are effective for the investment. Since there are various disasters that cause blackouts and the scale and form of blackouts, it is necessary to consider the components of the power system and their respective relationships and roles, quantitatively evaluate the blackout risk, and then evaluate the risk reduction of the measures to be introduced.

[0009] In the power distribution automation system, when damage occurs in a specific section of the power distribution network, the section is identified and operations are performed to transmit power from a detour route. However, even if a route for transmitting power is secured, the functions of the equipment necessary for this series of operations may be lost due to a disaster. In the conventional technology, the impact of power outage damage according to the role of each device in the power distribution network in the system is not taken into consideration. In addition, it is difficult to grasp what functions of the power distribution network should be strengthened to efficiently reduce the risk of power outage. Furthermore, the reduction of power outage damage due to equipment installed by consumers is not taken into consideration, or even if it is taken into consideration, it is evaluated based on the simple assumption that it will function without exception in the event of a disaster, and the risk of loss of function of the power outage countermeasures themselves is not taken into consideration. Therefore, it cannot contribute to the consideration of rational measures to reduce the risk of power outage.

[0010] The embodiment of the present invention has been made in consideration of these circumstances, and aims to provide a power outage risk assessment technology that can contribute to the consideration of rational measures for reducing the risk of power outages. [Means for solving the problem]

[0011] A power outage risk assessment system according to an embodiment of the present invention includes a system configuration database that stores information indicating the configuration or connection status of a power system, a disaster hazard database that stores information on natural disaster hazards and information on annual exceedance frequencies, an event tree creation unit that creates an event tree used to evaluate the power outage probability of the power system for the hazard to be evaluated from the information stored in the system configuration database, a fault tree creation unit that uses the disaster hazard database to create a fault tree used to calculate the branching probability of the event tree, a power outage probability evaluation unit that analyzes the power system using the event tree and evaluates the power outage probability of the power system, and a power outage risk evaluation unit that evaluates the power outage risk of the power system based on the power outage probability. Effect of the Invention

[0012] According to an embodiment of the present invention, a power outage risk assessment technique is provided that can contribute to the consideration of rational measures for reducing the risk of power outages. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a block diagram showing a power outage risk assessment system. [Diagram 2] FIG. 2 is a block diagram showing a main control unit. [Diagram 3] FIG. 2 is an image diagram showing a configuration of a power system stored in a power system configuration database. [Figure 4] FIG. 4 is an explanatory diagram showing a system configuration management table. [Diagram 5] FIG. 4 is an explanatory diagram showing a consumer configuration management table. [Figure 6] FIG. 4 is an explanatory diagram showing a first device management table. [Figure 7] FIG. 11 is an explanatory diagram showing a second device management table. [Figure 8] A graph showing the relationship between the severity of a disaster and the probability of equipment damage (equipment strength), in the case where the disaster is an earthquake. [Figure 9] FIG. 4 is an explanatory diagram showing a hazard management table. [Figure 10] A graph showing the relationship between disaster intensity and annual exceedance frequency (disaster hazard) for the case of an earthquake. [Figure 11] FIG. 1 is an image showing a hazard map stored in a disaster hazard database. [Figure 12] FIG. 13 is an explanatory diagram showing an accident response and maintenance performance record table. [Figure 13] FIG. 4 is an explanatory diagram showing a material management table. [Figure 14] FIG. 4 is an explanatory diagram illustrating a resource management table. [Figure 15] FIG. 13 is an explanatory diagram illustrating an example of an event tree. [Figure 16] FIG. 1 is an explanatory diagram showing an example of a fault tree. [Figure 17] FIG. 13 is an explanatory diagram showing an example of a power outage risk curve. [Figure 18] FIG. 13 is an explanatory diagram showing an example of a presented menu of measures for consumers. [Figure 19] A graph showing the relationship between time and electricity demand (trends in electricity demand). [Figure 20] 1 is a flow chart showing a power outage risk assessment method. [Figure 21] FIG. 1 is an explanatory diagram showing a flow of restoration in a conventional power distribution automation system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of a power outage risk assessment system and a power outage risk assessment method will be described in detail with reference to the drawings.

[0015] Reference numeral 1 in Fig. 1 denotes a power outage risk assessment system of this embodiment. This power outage risk assessment system 1 is for assessing the power outage risk of a power system. In this embodiment, an example of a mode used for calculating the power outage risk of a power system is illustrated.

[0016] An electric power system is a system that includes the generation of electricity (generation), the transportation of electricity (transmission and transformation), the supply of electricity (distribution), and the demand for electricity (consumption). This electric power system is a very large-scale system that includes everything from generation to consumption, and is highly controlled so that the voltage and frequency of the entire system remain within a certain range. The equipment that makes up this electric power system includes equipment installed by electric power companies and equipment installed by consumers.

[0017] In a power system, electricity generated at power plants is supplied to consumers (homes, factories, businesses, etc.) via a power transmission network and a power distribution network. This series of supply routes, from upstream to downstream, differs depending on the region. Power Outage Risk Assessment System 1 quantifies the power outage risk in the region to accurately grasp the risk. It then implements more effective and necessary capital investments. Power Outage Risk Assessment System 1 uses an event tree (Figure 15) and a fault tree (Figure 16) to assess the risk of power outages.

[0018] Here, an event tree (Fig. 15) is a tree diagram that generally shows how an abnormal event that occurs in a plant or the like may spread depending on the system configuration and other conditions at the time. It is usually a logical diagram that branches sequentially depending on the success (branching upwards in Fig. 15) or failure (branching downwards in Fig. 15) of the operation of the components. If the branching probability of this event tree can be quantified, it is possible to estimate the probability of various outcomes brought about by an abnormal event.

[0019] A fault tree (Fig. 16) is a tree-like analysis method that places an undesirable event such as a loss of functionality or failure to accomplish a mission of an engineered system at the top, logically expands the factors that cause it, and traces it back to the root cause. It is then used to calculate the probability of occurrence of the top event by giving the probability of occurrence of each root cause. In this embodiment, the branching probability of the event tree is calculated using a fault tree to estimate the probability of various outcomes caused by an abnormal event.

[0020] Next, the system configuration of the power failure risk assessment system 1 will be described with reference to the block diagrams shown in FIG. 1 and FIG.

[0021] As shown in FIG. 1, the power failure risk assessment system 1 includes a main control unit 2, an input unit 3, an output unit 4, a storage unit 5, and a communication unit 6.

[0022] Furthermore, the power outage risk assessment system 1 includes a system configuration database 7, an equipment database 8, a disaster hazard database 9, an accident response and maintenance performance database 10, and a materials and resource database 11. These are collections of information stored in memory, HDD, or cloud storage capacity and organized so that they can be searched or accumulated.

[0023] The power outage risk assessment system 1 of this embodiment is configured as a computer having hardware resources such as a CPU, a ROM, a RAM, and a HDD, and the CPU executes various programs to realize information processing by software using the hardware resources. Furthermore, the power outage risk assessment method of this embodiment is realized by having the computer execute various programs.

[0024] Each component of the power outage risk assessment system 1 does not necessarily have to be provided on one computer. For example, one power outage risk assessment system 1 may be realized using multiple computers connected to each other via a network. For example, the various databases 7 to 11 may each be installed on an individual computer.

[0025] Predetermined information is input to the input unit 3 in response to operations by a user who uses the power outage risk assessment system 1. For example, various information such as the system configuration of the region or area where the power outage risk assessment is to be performed, equipment fragility information, disaster hazard information, past accident response or maintenance information, and material or resource information is input to the input unit 3.

[0026] The input unit 3 includes input devices such as a mouse and a keyboard. That is, predetermined information is input to the input unit 3 in response to the operation of these input devices. When inputting information, the user assigns a unique ID to each piece of information such as the system configuration and the equipment. An ID is identification information required to individually identify the corresponding information, and a unique ID is assigned in association with each piece of information.

[0027] The components (devices) of this embodiment include substations, distribution lines (transmission lines), distribution poles, and pole-mounted devices such as switches. They also include power receiving devices of consumers who use the power system, or devices that may be introduced as a countermeasure against power outages. Specific examples include storage batteries, solar power generation systems, fuel cells, emergency diesel generators, and gas engines.

[0028] The output unit 4 outputs predetermined information. For example, the output unit 4 outputs the evaluation results of the main control unit 2 and information stored in the databases 7 to 11. The power outage risk assessment system 1 of this embodiment includes a device for displaying images, such as a display that outputs the analysis results. In other words, the output unit 4 controls the images displayed on the display. The display may be separate from the computer main body, or may be integrated with it.

[0029] The power outage risk assessment system 1 of this embodiment may control images displayed on a display of another computer connected via a network. In that case, the output unit 4 of the other computer may control the output of the assessment results derived by the main control unit 2.

[0030] In this embodiment, a display is exemplified as a device that displays an image, but other modes may be used. For example, a projector may be used to display information. Furthermore, a printer that prints information on a paper medium may be used instead of a display. In other words, the objects controlled by the output unit 4 may include a projector or a printer.

[0031] The storage unit 5 stores various pieces of information required for evaluating the risk of a power outage based on the information stored in each of the databases 7-11.

[0032] The communication unit 6 communicates with other computers via a communication line such as the Internet. In this embodiment, the power outage risk assessment system 1 and the other computers are connected to each other via the Internet, but other configurations are also possible. For example, they may be connected to each other via a LAN (Local Area Network), a WAN (Wide Area Network), or a mobile communication network.

[0033] The system configuration database 7 stores information indicating the configuration or connection status of the power system. This information includes geographical information on the power system, the relative positions of various pieces of equipment, and the distances between the various pieces of equipment. For example, the system configuration database 7 stores information indicating the configuration of the power system (FIG. 3), a system configuration management table (FIG. 4), and a consumer configuration management table (FIG. 5).

[0034] Figure 3 is an example of an image showing the configuration of a power system. Information showing the configuration of a power system can be displayed in two dimensions on a display or the like. This allows the user to understand the positional relationship or configuration of various facilities in the power system.

[0035] In addition, the power outage risk assessment system 1 has a function of showing the system configuration and displaying it by overlaying it on an actual map. Each system configuration is managed by a unique system configuration ID.

[0036] FIG. 4 is an example of a system configuration management table. In this system configuration management table, information on devices related to each system configuration is registered. In this system configuration management table, various information is registered using a system configuration ID as a primary key. For example, a device ID, a device detail ID, a device name, and coordinates / altitude are registered in association with the system configuration ID.

[0037] Here, the system configuration ID is identification information capable of individually identifying each system configuration. The equipment ID is identification information capable of individually identifying each equipment. The equipment detail ID is identification information capable of individually identifying each data recording detailed information of the equipment. Based on this equipment detail ID, detailed data of the equipment stored in other areas of the system configuration database 7 can be read out. The equipment name is a name indicating the type of equipment. The coordinates and altitude are the coordinates and altitude of the location where the equipment is installed. These coordinates and altitude are specific information capable of identifying whether or not the equipment will lose its function due to a disaster.

[0038] FIG. 5 is an example of a consumer configuration management table. In this consumer configuration management table, information on consumers who receive power from each system is registered. In this consumer configuration management table, various information is registered using a system configuration ID as a primary key. For example, a consumer ID, coordinates, altitude, business type, consumer name, contracted power capacity, normal power usage, emergency power demand, countermeasure equipment, and countermeasure equipment capacity are registered in association with the system configuration ID.

[0039] Here, the customer ID is identification information that can individually identify each customer. The coordinates and altitude are the coordinates and altitude of the customer's location. These coordinates and altitude are specific information that can identify whether equipment will lose function due to a disaster. The industry is the industry of the customer. For example, this is the type of customer, such as a home, a medical institution, an office building, or a government office. The customer name is a name that can identify the customer. The contracted power capacity is the power capacity that the power company has contracted with the customer.

[0040] The normal power usage is the power that the consumer uses in normal times. The emergency power demand is the power that the consumer needs in the event of a power outage. Note that multiple patterns may be registered in the items of the normal power usage and the emergency power demand. The multiple patterns include, for example, summer and winter patterns, and day and night patterns.

[0041] The countermeasure equipment is equipment for continuing the supply of power during a power outage. For example, it is an emergency diesel generator. This countermeasure equipment includes equipment that supplies power not only during emergencies but also during normal times. Note that information indicating the presence or absence of countermeasure equipment may be registered in the countermeasure equipment item. The countermeasure equipment capacity is the power capacity that can be supplied from the countermeasure equipment to consumers.

[0042] The equipment database 8 stores information indicating the strength information (fragility) or failure probability of equipment that is a component of the power system. For example, the equipment database 8 stores a first equipment management table (FIG. 6), a second equipment management table (FIG. 7), and information indicating the relationship between earthquake acceleration as an example of disaster intensity and equipment damage probability (FIG. 8).

[0043] 6 is an example of a first equipment management table. In this first equipment management table, information related to equipment required for supplying power from a power plant is registered. In this first equipment management table, various information is registered using an equipment ID as a primary key. For example, equipment use, equipment name, equipment strength, and design criteria are registered in association with the equipment ID.

[0044] 7 is an example of the second equipment management table. In this second equipment management table, information related to countermeasure facilities is mainly registered. In this second equipment management table, various information is registered using an equipment ID as a primary key. For example, an equipment name, an equipment capacity, an equipment strength, and a design standard are registered in association with the equipment ID.

[0045] Here, equipment use is information indicating the use of the equipment. Equipment resistance is information indicating the durability of equipment against the intensity of a disaster. When the disaster is an earthquake, the intensity of the disaster is the seismic acceleration, and the equipment resistance is information indicating the durability of equipment against the seismic acceleration. When the disaster is a typhoon, the intensity of the disaster is the wind speed, and the equipment resistance is information indicating the durability of equipment against the wind speed. When the disaster is a lightning strike, the intensity of the disaster is the lightning current value, and the equipment resistance is information indicating the durability of equipment against the lightning current value. When the disaster is a flood, the intensity of the disaster is the flood depth, and the equipment resistance is information indicating the durability of equipment against the flood depth.

[0046] The design criteria is information indicating the design standard value that equipment can withstand against the intensity of the disaster. When the disaster is an earthquake, the intensity of the disaster is the seismic acceleration, and the design criteria is information indicating the design standard value that equipment can withstand against the seismic acceleration. When the disaster is a typhoon, the intensity of the disaster is the wind speed, and the design criteria is information indicating the design standard value that equipment can withstand against the wind speed. When the disaster is a lightning strike, the intensity of the disaster is the lightning current value, and the design criteria is information indicating the design standard value that equipment can withstand against the lightning current value. When the disaster is a flood, the intensity of the disaster is the flood depth, and the design criteria is information indicating the design standard value that equipment can withstand against the flood depth. These equipment strength and design criteria are specific information that can identify whether or not the equipment will lose its function due to a disaster. The installed capacity is the power capacity that can be supplied from the equipment to consumers.

[0047] The equipment resistance is information that indicates the relationship between the intensity of a disaster and the probability of equipment damage. For example, the equipment resistance may be shown as in the graph in Figure 8. As shown in this graph, when there are three types of equipment, even if the design standards for each are the same, the equipment resistance will be different for each piece of equipment.

[0048] The graph in Figure 8 shows the relationship between the severity of a disaster and the probability of equipment damage, taking the case where the disaster is an earthquake as an example, with the severity of the disaster on the horizontal axis being earthquake acceleration. For example, the severity of the disaster on the horizontal axis of the graph in Figure 8 would be wind speed if the disaster was a typhoon, lightning current value if the disaster was a lightning strike, and flood depth if the disaster was a flood. For other disasters, the horizontal axis can also be the severity of the disaster and the vertical axis can be the probability of equipment damage.

[0049] Information on the hazards of various natural disasters and information on the annual exceedance frequency are stored in the disaster hazard database 9. This information includes hazard maps published by the national government, local governments, and other organizations.

[0050] Furthermore, the power outage risk assessment system 1 can extract necessary points from the hazard map stored in the disaster hazard database 9. For example, the disaster hazard database 9 stores a hazard management table (FIG. 9), information showing the relationship between earthquake acceleration and annual exceedance frequency (disaster hazard) as an example of disaster intensity (FIG. 10), and information showing the hazard map stored in the disaster hazard database 9 (FIG. 11).

[0051] The graph in Figure 10 shows the relationship between disaster intensity and annual exceedance frequency (disaster hazard) by illustrating the case where the disaster is an earthquake, with the horizontal axis representing the intensity of the disaster being earthquake acceleration. For example, the horizontal axis of the graph in Figure 10 represents the intensity of the disaster if the disaster is a typhoon, the lightning current value if the disaster is a lightning strike, and the flood depth if the disaster is a flood. For other disasters, the horizontal axis can also represent the intensity of the disaster, and the vertical axis can represent the annual exceedance frequency.

[0052] 9 is an example of a hazard management table. In this hazard management table, information on various hazards is registered using a hazard ID as a primary key. For example, a hazard type, a disaster hazard, and a reference source are registered in association with a hazard ID.

[0053] Here, the hazard ID is identification information that can individually identify each type of hazard. The hazard type is information that indicates the type of hazard. The hazard details are detailed information about each type of hazard. The reference source is information that indicates the reference source from which the information about the hazard was obtained.

[0054] The hazard details are information that indicates the relationship between the intensity of a disaster and the annual exceedance frequency. For example, the hazard details may be shown as in the graph in Figure 10. As shown in this graph, if there are three locations, the annual exceedance frequency of each location will be different.

[0055] The graph in Figure 10 shows the relationship between disaster intensity and annual exceedance frequency (disaster hazard) by illustrating the case where the disaster is an earthquake, with the horizontal axis representing the intensity of the disaster being earthquake acceleration. For example, the horizontal axis of the graph in Figure 10 represents the intensity of the disaster if the disaster is a typhoon, the lightning current value if the disaster is a lightning strike, and the flood depth if the disaster is a flood. For other disasters as well, the horizontal axis should represent the intensity of the disaster, and the vertical axis should represent the annual exceedance frequency.

[0056] The hazard details may also include a hazard details ID, which is identification information that can individually identify each data that records information related to the hazard details. Based on this hazard details ID, detailed hazard data stored in other areas of the disaster hazard database 9 can be read out. For example, the hazard map in FIG. 11 may be linked to the hazard management table.

[0057] The accident response and maintenance record database 10 stores information on past power system accidents and the recovery time required to respond to the accidents, etc. For example, the accident response and maintenance record database 10 stores an accident response and maintenance record record table (FIG. 12).

[0058] FIG. 12 is an example of an accident response and maintenance record table. In this accident response and maintenance record table, various information is registered using the equipment ID as the primary key. For example, in association with the equipment ID, the equipment detail ID, equipment use, equipment name, accident details, maintenance date and time, required time, required personnel, equipment used, and base distance are registered. Note that in the accident response and maintenance record table, the same equipment can be managed collectively using the equipment ID.

[0059] Here, the accident details are the type of accident. The maintenance date and time are the date and time when the maintenance was performed. The required time is the time required for accident response or maintenance. The required personnel are the number of personnel required for accident response or maintenance. The equipment used is the equipment required for accident response or maintenance. The base distance is the distance from the office that serves as the base for accident response or maintenance to the work site.

[0060] The material and resource database 11 stores information such as spare part inventory status and resource information on maintenance and restoration personnel. For example, the material and resource database 11 stores a material management table (FIG. 13) and a resource management table (FIG. 14).

[0061] 13 is an example of a materials management table. In this materials management table, information on various materials is registered with the equipment ID of the equipment that is the material as a primary key. For example, the equipment use, equipment name, storage quantity, storage location, base ID, and supplier are registered in association with the equipment ID.

[0062] 14 is an example of a resource management table. In this resource management table, information on the resources of maintenance and restoration personnel is registered with a base ID as a primary key. For example, a personnel ID, a responsible job, and a responsible device are registered in association with the base ID.

[0063] Here, the storage quantity is the number of materials stored. The storage location is the storage location of the materials. The base ID is identification information that can individually identify an accident response or maintenance base. The supplier is the supplier of the materials. The personnel ID is identification information that can individually identify each personnel. The work assigned is the type of work that the personnel can handle. The assigned equipment is the equipment that the personnel can handle. In this assigned equipment item, for example, an equipment ID is registered.

[0064] As shown in Fig. 2, the main control unit 2 comprehensively controls the power outage risk assessment system 1. This main control unit 2 includes a power outage probability assessment unit 12, a recovery time assessment unit 13, and a power outage risk assessment unit 14. These are realized by the CPU executing programs stored in the memory or HDD.

[0065] The power outage probability assessment unit 12 includes an event tree creation unit 15 and a fault tree creation unit 16. The power outage probability assessment unit 12 analyzes the power system using an event tree, and assesses the power outage probability of the power system.

[0066] The power outage probability evaluation unit 12 calculates the branching probability of the event tree based on at least a fault tree related to the equipment required for the supply of power. In this way, the branching probability of the event tree can be quantitatively calculated using the fault tree.

[0067] The devices in this embodiment include those installed by consumers who receive power supply. The power outage probability evaluation unit 12 calculates the branching probability of the event tree based on the function loss probability of the devices installed by the consumers. In this way, the power outage probability can be calculated from the function loss probability of the devices installed by the consumers, and the expected damage can be evaluated based on this.

[0068] The event tree creation unit 15 creates an event tree (FIG. 15) used to evaluate the probability of power outage in the power system. The fault tree creation unit 16 creates a fault tree (FIG. 16) used to calculate the branching probability of the event tree.

[0069] 15 is an example of an event tree created by the event tree creation unit 15. First, attention is paid to the headings (events that set branches) at the top of the event tree. For example, 13 headings are set from event A to event M. Note that an item indicating the occurrence of a disaster is set as the root event at the left end of the event tree.

[0070] An item for a distribution substation is set for event A. An item for nearby power transmission equipment is set for event B. The branching from event A to event B is set in order to evaluate whether or not power will be supplied from the distribution substation to the area being evaluated due to a failure of the distribution substation or an inability to transmit power to the distribution substation.

[0071] For event C, the items of core system, fault clearance, and relay operation are set. For event D, the items of core system, fault spread prevention, and relay operation are set. For event E, the items of core system, backup protection, and relay operation are set. For event F, the items of core system and reclosing are set. These branches from event C to event F are set in order to evaluate whether or not it is possible to prevent the spread of an accident that occurs in the core system.

[0072] For event G, the item for FCB tripping is set. For event H, the items for reclosing and time-limited forwarding are set. For event I, the item for determining the fault section is set. For event J, the item for creating a reverse transfer procedure is set. For event K, the item for automatic execution of the reverse transfer procedure is set. For event L, the item for automatic switch and on / off operation is set. These branches from event G to event L are set in order to evaluate whether or not the distribution automation system can determine the fault section and minimize the blackout section by reverse transfer.

[0073] A countermeasure equipment item is set for event M. This branch for event M is set to evaluate whether or not the supply of power can be continued by using some kind of power generation equipment or power storage system in an emergency when commercial power from the power company cannot be received.

[0074] In this way, the branches of the event tree in this embodiment are composed of four elements: distribution substation, main grid, distribution automation system, and countermeasure equipment. Note that the branches of the event tree may be set based on other elements. Also, only events related to a part of the four elements of the countermeasure equipment exemplified here (for example, only the distribution automation system) may be extracted, and the probability of function loss of the relevant component may be evaluated.

[0075] In this embodiment, the configurations of the distribution substation, the main grid, the distribution automation system, and the countermeasure equipment are set in this order in the branches from the root side at the left end of the event tree to the consequence side at the right end. In this way, by setting the configuration of the countermeasure equipment that has a large impact on consumers on the consequence side in the branches of the event tree, it is possible to contribute to a more detailed consideration of the installation of the countermeasure equipment.

[0076] By setting the branches of the event tree based on the configuration of countermeasure equipment for continuing the supply of power during a power outage, the risk of power outage can be evaluated taking into account the countermeasure equipment installed by consumers.

[0077] By setting the branches of the event tree based on the configuration of a distribution automation system that monitors the power distribution network of the power system or controls system switching, it is possible to evaluate the risk of power outages taking into account the distribution automation system.

[0078] The branches of the event tree are set based on the configuration of the distribution substations of the power system, so that the risk of a power outage can be evaluated taking into account the distribution substations.

[0079] By setting the branches of the event tree based on the configuration of the backbone system of the power distribution network of the power system, it is possible to evaluate the risk of power outage taking into account the backbone system.

[0080] Next, we focus on the result state at the right end of the event tree. In this embodiment, 27 patterns of power outage modes from P1 to P27 are set as the result states of the event tree. These power outage modes indicate the state of the power system that occurs during a power outage. Note that the power outage modes include not only the state during a power outage, but also the state after recovery from a power outage.

[0081] Pattern P1 is a power outage mode in which there is no long-term power outage. This pattern P1 indicates that the distribution automation system has succeeded in reclosing and time-limited sequential transmission, and power transmission has resumed.

[0082] Pattern P2 is set to a power outage mode in which the accident section loses power. Note that this power outage area does not include areas where independent operation is possible, where the system can operate independently without receiving power from the power grid. This pattern P2 shows that the countermeasure equipment was successful in supplying power in event M.

[0083] A power outage mode in which only the fault section is powered down is set in pattern P3. This pattern P3 indicates that the fault section is identified by the power distribution automation system, reverse transmission is successful, and only the fault section is powered down.

[0084] Patterns P4, P6, and P8 are set to power outage modes in which the load side of the fault point is powered down. Note that these power outage areas do not include areas where independent operation is possible. These patterns P4, P6, and P8 indicate that the countermeasure equipment was successful in supplying power in event M.

[0085] Patterns P5, P7, and P9 are set to a power outage mode in which the load side of the fault point is blacked out. These patterns P5, P7, and P9 indicate that the fault section was identified by the power distribution automation system, but the reverse transmission failed, resulting in a power outage on the load side of the fault point.

[0086] For patterns P10, P12, P14, P16, P18, P20, P22, P24, and P26, a power outage mode is set in which only areas where autonomous operation is possible avoid power outages. These patterns P10, P12, P14, P16, P18, P20, P22, P24, and P26 indicate that the countermeasure equipment successfully supplied power during event M.

[0087] Patterns P11 and P13 are set to a power outage mode in which the entire feeder is powered down. These patterns P11 and P13 indicate that the entire target feeder is powered down due to failure in FCB tripping or failure in fault section determination.

[0088] A power outage mode in which a wide area is blacked out is set for patterns P15, P19, P23, P25, and P27. These patterns P15, P19, P23, P25, and P27 indicate that a wide area connected to the main grid is blacked out due to a failure of the main grid.

[0089] Patterns P17 and P21 are set as power outage modes in which a wide area below the distribution substation is blacked out. These patterns P17 and P21 indicate that the effects of an accident in the trunk system spread to the distribution substation and below, causing a blackout in a wide area below the distribution substation.

[0090] In addition, the power outage modes of patterns P2, P4, P6, P8, P10, P12, P14, P16, P18, P20, P22, P24, and P26 are the power outage modes when the power supply by the countermeasure equipment fails due to event M, minus the amount of power supplied by the countermeasure equipment.

[0091] In the event tree of this embodiment, the order of branches may be changed, and branches may be added or deleted, as necessary.

[0092] The event tree creation unit 15 creates an event tree for the hazard to be evaluated from the system configuration to be evaluated stored in the system configuration database 7. Then, the power outage risk assessment unit 14 quantitatively evaluates the impact on the power system when the target hazard occurs at an occurrence frequency (annual exceedance frequency).

[0093] The branching probability of the event tree can be the fault tree generated by the fault tree creation unit 16 or the one stored in advance in the equipment database 8. As a result of analyzing this event tree, the probability of power outage for each power outage mode caused by differences in the progression of events in the event tree can be obtained.

[0094] 16 is an example of a fault tree created by the fault tree creation unit 16. Events that occur in equipment (substations, power transmission lines) are registered as lower-level items in the fault tree of this embodiment. Events include, for example, equipment failures (trouble), equipment shutdowns, and equipment inspections. These lower-level items are associated with each other by logic gates (AND gates, OR gates) to construct a fault tree.

[0095] In addition, events that occur in association with the occurrence of an event in a lower-level item are registered in a middle-level item in the fault tree, and events that occur in association with the occurrence of an event in a middle-level item are registered in a higher-level item in the fault tree.

[0096] The fault tree is used to determine whether the occurrence of an event of a lower item causes an event (fault mode) of a higher item. Alternatively, the fault tree is used to calculate the occurrence probability of an event of a higher item. In this embodiment, the determination result of the fault tree includes the function loss probability of the equipment. In this way, it is possible to perform a power outage risk evaluation including the function loss probability.

[0097] As shown in Fig. 2, the fault tree creation unit 16 creates a fault tree that takes into consideration the system configuration, the system equipment configuration, and the connection status, which are the targets of the power outage risk evaluation, using the system configuration database 7, the equipment database 8, and the disaster hazard database 9. The equipment resistance and disaster hazard can be input into this fault tree to calculate the equipment failure probability.

[0098] In this embodiment, a power outage mode corresponding to the state of the power system that occurs during a power outage is set as a result state of the event tree. The power outage probability evaluation unit 12 can evaluate the power outage risk corresponding to various patterns of power outages by calculating the power outage probability of each power outage mode.

[0099] The restoration time evaluation unit 13 includes a target task identification unit 17 and a restoration time calculation unit 18. The restoration time evaluation unit 13 evaluates the restoration time from a power outage of the power system. In this way, it is possible to evaluate restoration times corresponding to various patterns of power outages.

[0100] The target work specification unit 17 specifies the target work required for recovery from the power outage corresponding to the power outage mode. The work required for recovery differs depending on the power outage mode. Therefore, the power outage mode is obtained using the event tree created by the event tree creation unit 15. Then, the target work corresponding to the power outage mode is specified by referring to past cases in the accident response and maintenance performance database 10.

[0101] The restoration time calculation unit 18 calculates the time required for restoration based on the work identified by the target work identification unit 17. For example, it refers to the geographical distance of the system stored in the system configuration database 7. It refers to past accident response or maintenance performance values ​​stored in the accident response and maintenance performance database 10. It refers to the inventory status of spare parts or resource information on maintenance and restoration personnel stored in the material and resource database 11. It calculates the time required for restoration by referring to this information.

[0102] The power outage risk assessment unit 14 includes a power outage risk curve creation unit 19 and a damage calculation unit 20. The power outage risk assessment unit 14 assesses the power outage risk of the power system based on the power outage probability obtained by analysis using an event tree. In this way, it is possible to contribute to the consideration of rational measures for reducing the power outage risk.

[0103] The power outage risk curve creation unit 19 creates a power outage risk curve. For example, the number of consumers (consumer ID), contracted power capacity, normal power usage, and emergency power demand stored in the system configuration database 7 are referenced. The power outage probability for each power outage mode calculated by the power outage probability evaluation unit 12 is referenced. In addition, a predetermined total power outage scale is calculated by the sum of values ​​obtained by multiplying the power outage probability by the restoration time calculated by the restoration time evaluation unit 13 and the number of consumers. Then, the annual exceedance frequency of the predetermined total power outage scale is obtained from the occurrence frequency (annual exceedance frequency) of the assumed hazard. A comprehensive power outage risk curve is created by referring to this information. In addition to hazards with multiple annual exceedance frequencies, a comprehensive power outage risk curve may be created by assuming other types of natural disasters. In addition, the number of consumers may be replaced with the contracted power capacity or normal power usage to calculate the total power outage scale.

[0104] The damage calculation unit 20 calculates the amount of damage by multiplying the total power outage scale of the power outage risk curve created by the power outage risk curve creation unit 19 by the damage to be evaluated.

[0105] For example, when assessing damage to consumers, the amount of damage to consumers caused by a power outage can be obtained by multiplying the total scale of the power outage by the amount of direct or indirect damage per kWh calculated from external data such as statistical data or willingness to pay based on the consumer's industry or business model.

[0106] In addition, when assessing damages suffered by businesses, the amount of loss in electricity revenues of power companies due to outages and the annual frequency of such losses can be obtained by multiplying the total scale of outages by the average electricity price per kWh in the area being assessed.

[0107] In addition, by multiplying the hourly cost of the business loss suffered by customers due to a power outage by the expected hourly cost, it is possible to obtain the customer's loss due to a power outage and its annual frequency of exceedance.

[0108] FIG. 17 is an example of a power outage risk curve. As shown in this power outage risk curve, the curve in the case where the customer does not have countermeasure equipment is depicted higher than the curve in the case where the customer has countermeasure equipment. For example, when comparing the two at the point where the annual exceedance frequency is 0.01, when the customer does not have countermeasure equipment, the total power outage scale is about 3000. In contrast, when the customer has countermeasure equipment, it remains at about 2000. In other words, it was evaluated that the countermeasure equipment can reduce the scale of the power outage. The damage calculation unit 20 can convert the total power outage scale into a monetary value and compare the estimated damage amount before and after the installation of the countermeasure equipment.

[0109] In addition, before calculating the estimated damage amount before and after the installation of countermeasure equipment, various information must be collected and analyzed, and the probability of a power outage must be calculated. However, it is also possible to start the evaluation from the time a power outage occurs and confirm the estimated damage amount and the return on investment of countermeasure equipment.

[0110] For example, the power outage duration can be assumed to be one hour, five hours, 24 hours, etc. In this case, the total power outage scale and estimated damage amount can be calculated as the minimum necessary evaluation of the failure probability of the countermeasure equipment. In addition, by presenting a menu of additional countermeasures to the consumer and having them select from it, it can be added to the existing evaluation process and the total power outage scale can be calculated.

[0111] It is necessary to create two types of event trees, one for when the consumer has no countermeasure equipment and one for when it does. Here, some of the multiple branching probabilities set in the event tree can be set to 1 by accepting an input operation from the user. For example, if there is no countermeasure equipment to continue the power supply during a power outage, the corresponding branching probability is set to 1, meaning that the equipment will definitely break down. On the other hand, if there is countermeasure equipment, the corresponding branching probability is set to an appropriate value. In this way, one event tree can be used by switching between when there is no countermeasure equipment and when there is.

[0112] FIG. 18 is an example of an additional countermeasure menu presentation. A consumer ID, countermeasure equipment, countermeasure equipment capacity, additional countermeasure menu, etc. are presented. Here, the additional countermeasure menu shows emergency diesel generators, hydrogen power generation, solar power generation, and storage batteries. This additional countermeasure menu automatically extracts equipment that will be countermeasure equipment from the information on the equipment stored in the equipment database 8. An event tree and a fault tree are created based on the equipment strength information linked to the equipment ID, and finally a power outage risk curve is created.

[0113] In addition, when considering an actual disaster, it is possible that the demand for electricity will differ from normal demand. For example, when a factory is affected by a disaster, operations will be halted. As a result, the factory's demand for electricity will drop significantly. An evaluation based on such changes in demand for electricity during a disaster is also required.

[0114] Figure 19 shows an example of the recovery of power demand during a disaster. The solid line indicates a sudden drop in power demand and its recovery over time. By changing the power demand value using the emergency power demand value stored in the system configuration database 7 or an arbitrary disaster impact, the effectiveness of countermeasure equipment at a specified time can also be evaluated.

[0115] Next, the power outage risk assessment method of this embodiment will be described using the flowchart of Figure 20. The above-mentioned drawings will be referred to as appropriate. The following steps are at least some of the steps included in the power outage risk assessment method, and other steps may be included in the power outage risk assessment method.

[0116] First, in step S1, the power outage probability evaluation unit 12 determines the evaluation range of the power outage risk evaluation. The user specifies the evaluation range by inputting. Based on this specification, the power outage probability evaluation unit 12 determines the evaluation range.

[0117] In the next step S2, the event tree creation unit 15 and the fault tree creation unit 16 of the power outage probability evaluation unit 12 create an event tree and a fault tree based on the system configuration of the evaluation target stored in the system configuration database 7. For example, for equipment failures, a fault tree is created as necessary from the equipment data stored in the equipment database 8, and the failure probability is calculated. Note that the failure probability of some equipment may be determined by user input operations without using a fault tree.

[0118] In the next step S3, the power outage probability evaluation unit 12 inputs the failure probability calculated in the fault tree of the fault tree creation unit 16 into the event tree created by the event tree creation unit 15.

[0119] In the next step S4, the power outage probability assessment unit 12 acquires the probability of a power outage mode as a result state of the event tree by analyzing the event tree. That is, the power outage probability assessment unit 12 analyzes the power system by the event tree and evaluates the power outage probability of the power system.

[0120] In the next step S5, the target task identifying unit 17 of the recovery time evaluation unit 13 identifies a target task required for recovery from the power outage in accordance with the power outage mode.

[0121] In the next step S6, the recovery time calculation unit 18 of the recovery time evaluation unit 13 calculates the time required for recovery based on the task identified by the target task identification unit 17.

[0122] In the next step S7, the power outage risk curve creation unit 19 of the power outage risk assessment unit 14 creates a power outage risk curve and calculates a predetermined total power outage scale.

[0123] In the next step S8, the damage calculation unit 20 of the power outage risk assessment unit 14 calculates the amount of damage by multiplying the damage to be assessed by the total power outage scale of the power outage risk curve created by the power outage risk curve creation unit 19. In other words, the power outage risk assessment unit 14 evaluates the power outage risk of the power system based on the power outage probability calculated by the event tree.

[0124] In the next step S9, the output unit 4 outputs the evaluation result, and the power outage risk evaluation method is then terminated.

[0125] In the flowcharts of the above-described embodiment, the steps are executed in series, but the order of the steps is not necessarily fixed, and some steps may be executed in reverse. Also, some steps may be executed in parallel with other steps.

[0126] The system of the above embodiment includes a control device with a highly integrated processor such as a dedicated chip, a Field Programmable Gate Array (FPGA), a Graphics Processing Unit (GPU), or a Central Processing Unit (CPU), a storage device such as a Read Only Memory (ROM) or a Random Access Memory (RAM), an external storage device such as a Hard Disk Drive (HDD) or a Solid State Drive (SSD), a display device such as a display, an input device such as a mouse or a keyboard, and a communication interface. This system can be realized with a hardware configuration using a normal computer.

[0127] The programs executed by the systems of the above-described embodiments are provided in advance in a ROM, etc. Alternatively, the programs may be provided in the form of installable or executable files stored in a non-transitory computer-readable storage medium such as a CD-ROM, CD-R, memory card, DVD, or flexible disk (FD).

[0128] The programs executed by this system may be stored on a computer connected to a network such as the Internet and provided by downloading them via the network. This system may also be configured by combining separate modules that independently perform the functions of the components and connect them to each other via a network or dedicated lines.

[0129] In the above embodiment, a power outage occurs due to an accident in a power distribution system of a power system, but other aspects may be used. For example, a risk of a power outage caused by an accident in a higher-level system of the power system may be evaluated.

[0130] According to the embodiment described above, the power outage probability evaluation unit 12 that analyzes the power system using an event tree and evaluates the power outage probability of the power system is provided, which contributes to the consideration of rational measures to reduce the power outage risk. Furthermore, not only the failure probability of the components of the power system but also the function loss probability can be quantitatively calculated to evaluate the power outage risk. In addition, the return on investment or validity of countermeasure equipment that consumers introduce to avoid damage caused by their own power outages can be evaluated.

[0131] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments or modifications thereof are within the scope of the invention and its equivalents as described in the claims, as well as within the scope and spirit of the invention. [Explanation of symbols]

[0132] 1...power outage risk assessment system, 2...main control unit, 3...input unit, 4...output unit, 5...memory unit, 6...communication unit, 7...system configuration database, 8...equipment database, 9...disaster hazard database, 10...accident response and maintenance record database, 11...materials and resource database, 12...power outage probability assessment unit, 13...restoration time assessment unit, 14...power outage risk assessment unit, 15...event tree creation unit, 16...fault tree creation unit, 17...target work identification unit, 18...restoration time calculation unit, 19...power outage risk curve creation unit, 20...damage calculation unit.

Claims

1. A system configuration database that stores information indicating a configuration or connection status of a power system; a disaster hazard database storing information on natural disaster hazards and information on annual exceedance frequencies; An event tree creation unit that creates an event tree used to evaluate a power outage probability of the power system for a hazard to be evaluated from information stored in the system configuration database; a fault tree creation unit that uses the disaster hazard database to create a fault tree used to calculate the branching probability of the event tree; a power outage probability evaluation unit that analyzes the power system using the event tree and evaluates the power outage probability of the power system; A power outage risk assessment unit that assesses a power outage risk of the power system based on the power outage probability; Equipped with Power outage risk assessment system.

2. The branching of the event tree is set based on the configuration of countermeasure facilities for continuing the supply of power during a power outage. The power outage risk assessment system according to claim 1 .

3. The branching of the event tree is set based on a configuration of a power distribution automation system that monitors the power system or controls system switching. The power outage risk assessment system according to claim 1 or 2.

4. the event tree branches are set based on a configuration of distribution substations of the power system; The power outage risk assessment system according to any one of claims 1 to 3.

5. The branching of the event tree is set based on a configuration of a backbone grid of the power system. The power outage risk assessment system according to any one of claims 1 to 4.

6. A power outage mode corresponding to a state of the power system that occurs during a power outage is set as a result state of the event tree; The power outage probability evaluation unit calculates the power outage probability of each of the power outage modes. The power outage risk assessment system according to any one of claims 1 to 5.

7. A recovery time evaluation unit that identifies a target task required for recovery from the power outage in accordance with the power outage mode and evaluates a recovery time from the power outage of the power system. The power outage risk assessment system according to claim 6.

8. The power outage probability evaluation unit calculates the branching probability of the event tree based on the fault tree related to at least equipment required for power supply, The power outage risk assessment system according to any one of claims 1 to 7.

9. The equipment includes equipment installed by a consumer who receives electricity, The power outage probability evaluation unit calculates the branch probability of the event tree based on a function loss probability of the equipment installed by the consumer. The power outage risk assessment system according to claim 8.

10. a database in which specific information is stored that can specify whether or not the device will lose its function due to a disaster by associating the device with an individually identifiable device ID; The power outage risk assessment system according to claim 8 or 9.

11. A step in which a power system configuration database stores information indicating a configuration or connection status of a power system; a disaster hazard database storing information on natural disaster hazards and information on annual exceedance frequencies; An event tree creation unit creates an event tree used to evaluate a power outage probability of the power system for a hazard to be evaluated from information stored in the system configuration database; a fault tree creation unit creating a fault tree used for calculating a branching probability of the event tree by using the disaster hazard database; A power outage probability evaluation unit analyzes the power system using the event tree and evaluates the power outage probability of the power system; A step of a power outage risk assessment unit assessing a power outage risk of the power system based on the power outage probability; Including, Power outage risk assessment methodology.

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