Facility monitoring system and facility monitoring method

Abstract

The present invention achieves a system for monitoring a facility using infrasound efficiently at low cost. This facility monitoring system comprises an optical analysis unit and an information processing device. The facility monitoring system: acquires, using distributed acoustic sensing (DAS), temporal variations in vibration intensity for each frequency of an optical fiber installed along a power transmission line at each of a plurality of measurement points set along the optical fiber; monitors whether or not a pattern attributed to infrasound is present in the temporal variations in the vibration intensity for each frequency at each measurement point; acquires disaster information from another communicatively connected device if the pattern is detected, the disaster information being information related to a disaster that occurred in an area in which a span section of the power transmission line having the measurement point at which the pattern was detected in a predetermined period before and after the date and time of the detection of the pattern; and outputs facility influence information generated by associating infrasound detection information and the disaster information with each other, the infrasound detection information being information based on the detected pattern.

Description

Facility monitoring system and facility monitoring method

[0001] The present invention relates to a facility monitoring system and a facility monitoring method.

[0002] Patent Document 1 describes an abnormality detection device that acquires backward Rayleigh scattered light from an OPGW (optical fiber composite overhead ground wire), generates vibration information for a frequency range including the natural frequency of the optical fiber composite overhead ground wire based on the acquired backward Rayleigh scattered light, and detects abnormalities in power transmission equipment based on the generated vibration information.

[0003] Patent Document 2 describes a tsunami detection device that acquires information about tsunamis using infrasound (infrasound, micro-pressure waves). The tsunami detection device determines whether an earthquake detected by an earthquake detection unit is of a predetermined magnitude or greater, measures infrasound, and, if an earthquake of a predetermined magnitude or greater is detected, determines whether a tsunami has occurred based on the magnitude of the change in sound pressure of the measured infrasound.

[0004] Non-Patent Document 1 describes micro-pressure oscillation data that is being experimentally observed in a study titled "Research on early detection of tsunamis using observation results of micro-pressure oscillations."

[0005] JP 2023-50257 A JP 2016-8865 A

[0006] "Infrasound Monitoring Network", Japan Weather Association, [online], Internet <URL: https: / / micos-sc.jwa.or.jp / infrasound-net / observed / >, retrieved November 1, 2023

[0007] Infrasound is generated by large-scale physical phenomena that cause disasters, such as earthquakes, tsunamis, typhoons, volcanic eruptions, and meteorite falls, and has the property of propagating long distances through the atmosphere. Therefore, it is expected to be used as a remote sensing tool to obtain disaster prevention information from remote locations. Furthermore, as described in Patent Document 2 and Non-Patent Document 1, research and development are underway on disaster prevention systems that utilize infrasound.

[0008] Incidentally, when a large-scale physical phenomenon that generates infrasound occurs, it is not rare that some kind of impact occurs on power transmission and transformation facilities (power transmission lines, power transmission towers, substation facilities, etc.). Here, for example, if it is attempted to accurately identify the power transmission and transformation facilities that are affected by the disaster using infrasound information acquired by the mechanisms described in Patent Document 2 and Non-Patent Document 1, it would be necessary to place a large number of sensors at key points along the power transmission lines, for example, which would require a great deal of effort and cost to secure installation locations and maintain and manage the facilities.

[0009] The present invention has been made in view of the above background, and aims to provide an equipment monitoring system and an equipment monitoring method that can efficiently and low-costly implement an equipment monitoring mechanism using infrasound.

[0010] One means for solving the above problem is an equipment monitoring system that includes an optical analysis unit and an information processing device, and acquires, using DAS (Distributed Acoustic Sensing), the change over time in vibration intensity for each frequency of the optical fiber at each of a plurality of measurement points set along the optical fiber installed along the power transmission line, and monitors whether there is an infrasound-related feature in the change over time in vibration intensity for each frequency at the measurement points.If the system detects the feature, it acquires disaster information, which is information about a disaster that occurred in an area where a span of the power transmission line is located that has the measurement point where the feature was detected within a predetermined period before and after the date and time when the feature was detected, from another device that is communicatively connected, and outputs equipment impact information, which is information that associates infrasound detection information, which is information based on the detected feature, with the disaster information.

[0011] Other problems and solutions disclosed in the present application will be made clear in the detailed description and drawings.

[0012] According to the present invention, a facility monitoring system using infrasound can be realized efficiently and at low cost.

[0013] It is a diagram showing a schematic configuration of an equipment monitoring system. It is a diagram explaining a mechanism for measuring vibration states by DAS. It is a graph showing time changes for each frequency of the vibration state at each measurement point. It is a diagram showing the main configuration of an equipment monitoring device. It is a diagram showing the main functions of an equipment monitoring device. It is a flowchart explaining equipment impact information provision processing. It is an example of an equipment impact information output screen. It is an example of an equipment impact information search screen.

[0014] The present invention will be described below in accordance with one embodiment with reference to the accompanying drawings. At least the following matters will become clear from the description of this specification and the accompanying drawings. In the following description, the letter "S" added before a reference numeral means a processing step.

[0015] 1 shows a schematic configuration of an equipment monitoring system 1 according to an embodiment of the present invention. The equipment monitoring system 1 includes an equipment monitoring device 100 provided in a substation 6 or the like, and a disaster monitoring system 300.

[0016] The facility monitoring device 100 is configured using an information processing device (computer). The facility monitoring device 100 is communicably connected to a disaster monitoring system 300 via a communication network 5. The communication network may be, for example, a local area network (LAN), a wide area network (WAN), the internet, a power line communication (PLC), a public communication network, a dedicated line, or the like.

[0017] The equipment monitoring device 100 uses an optical fiber 4a of an optical fiber composite overhead ground wire (OPGW4) installed on the power transmission line 3 as a vibration detection sensor, and acquires the vibration state at each of a plurality of measurement positions (hereinafter referred to as "measurement points") set along the optical fiber 4a by a technique (distributed acoustic sensing (DAS)) that measures the vibration state (vibration intensity, vibration frequency) based on the expansion and contraction of the optical fiber 4a at each of the measurement points. The DAS acquires the vibration state at each measurement point by, for example, the principle of a coherent detection optical time domain reflectometer (C-OTDR).

[0018] FIG. 2 illustrates how the equipment monitoring device 100 measures the vibration state at each measurement point using a DAS. As shown in the figure, the equipment monitoring device 100 emits a light pulse (laser pulse, hereinafter also referred to as "incident light") through the end face of the optical fiber 4a and measures the rate of change (≈stretching frequency) of the phase difference of the backscattered light of the light pulse at each measurement point. The phase difference is estimated from the intensity change due to interference between the backscattered lights. Based on the measured rate of change, the equipment monitoring device 100 then determines the vibration frequencies (e.g., vibration frequencies in the range of up to 10 kHz) of the longitudinal and transverse waves of the optical fiber 4a at each measurement point. The equipment monitoring device 100 also determines the vibration intensity (spectral intensity, vibration amplitude) at each measurement point based on the phase difference for each vibration frequency. The equipment monitoring device 100 also determines the position (distance from the end face) of each measurement point based on the elapsed time between when the incident light is incident on the end face and when the returned light is received.

[0019] The measurement points are set, for example, along the optical fiber at predetermined intervals d (m) that are shorter than the span of the transmission tower 2 (0 (m), d (m), ..., N (m), N + d (m), N + 2 d (m)). For example, as shown in Figure 1, if the predetermined interval d is 5 (m) and measurement points are set over a maximum range of 70 (km) of the transmission line 3, approximately 14,000 measurement points will be set along the optical fiber.

[0020] The vibration state of the optical fiber 4a at each measurement point is affected by the sound (sound pressure) received by the optical fiber 4a from outside. That is, the optical fiber 4a between adjacent transmission towers 2 (span) is a string with the transmission towers 2 at both ends as fixed ends, and resonates with the sound of a specific frequency received from outside, generating natural vibrations.

[0021] The facility monitoring device 100 acquires information about infrasound (infrasound, micro-pressure waves) based on the time change in the vibration state at each measurement point (time change in vibration intensity for each frequency). For example, if the speed of sound is 340 (m / s), and the frequency of infrasound is 1 Hz, in order to observe infrasound (20 Hz or less), the length of the power transmission line 3 needs to be at least 1 / 2 (= 170 m) of the wavelength (= 340 (m / s) / 1 (Hz)). Most existing power transmission lines 3 meet this condition.

[0022] The equipment monitoring device 100 generates information about infrasound observed by the DAS (hereinafter referred to as "infrasound detection information"). The infrasound detection information includes information such as the date and time when infrasound was detected, the identifier of the span including the measurement point where infrasound was detected (hereinafter referred to as "span ID"), and information used as the basis for determining that infrasound was detected (for example, information obtained from the graph shown in FIG. 3).

[0023] In addition, the facility monitoring device 100 acquires information relating to disasters (earthquakes, tsunamis, typhoons, volcanic eruptions, meteorite falls, etc.) from the disaster monitoring system 300 (including information indicating the date and time when the disaster occurred, the area where the disaster occurred (the area affected by the disaster), the type of disaster that occurred, the scale of the disaster that occurred, etc.; hereinafter referred to as "disaster information").

[0024] In addition, the equipment monitoring device 100 generates information that associates infrasound detection information with disaster information (hereinafter referred to as "equipment impact information"), and provides information based on the generated equipment impact information to managers and maintainers of the power transmission equipment via a user interface.

[0025] 1 , the disaster monitoring system 300 is an information processing system configured using information processing devices (computers) that can communicate with the facility monitoring device 100 via the communication network 5, and provides real-time disaster information to the facility monitoring device 100. The disaster monitoring system 300 is operated, for example, by an organization that performs disaster monitoring (such as a public institution or a corporate research institute).

[0026] Next, the relationship between infrasound and the time change (time change of vibration intensity for each frequency) of the vibration state (vibration intensity, vibration frequency) of each measurement point acquired by the equipment monitoring device 100 using DAS will be described.

[0027] FIG. 3 is a graph showing the time variation of vibration intensity for each frequency at each measurement point on a power transmission line 3 stretching from Hiroshima Prefecture to Shimane Prefecture, acquired by the equipment monitoring device 100 using the DAS when an earthquake (seismic intensity "4") occurred in the Hyuga-nada Sea at approximately 9:14 PM on July 22, 2023. Each of the three graphs shows the time variation of vibration intensity for each frequency of the optical fiber 4a, measured at measurement points on three adjacent spans (spans with identifiers (hereinafter referred to as "span IDs"): "K1," "K2," and "K3") of the power transmission line 3 near Hatsukaichi City, Hiroshima Prefecture. In each graph, time flows from top to bottom on the page. The shade of color in the figure represents the vibration intensity (arbitrary unit) for each frequency (the lighter the color, the greater the vibration intensity).

[0028] As shown in the figure, vibrations with a frequency of 3 to 4 Hz caused by infrasound were observed at all measurement points around 21:15:30. Also, during the same time period, vibrations caused by infrasound were observed across a wide frequency band at measurement points on each span due to the shaking of the earthquake. When the observation results shown in the figure were compared with micro-pressure vibration observation data for the same time period from an observation point in the "Infrasound Monitoring Network" described in Non-Patent Document 1 (an observation point installed at the Aki City Fire and Disaster Prevention Center (Aki City, Kochi Prefecture). Hatsukaichi City, Hiroshima Prefecture, and Aki City, Kochi Prefecture, are located approximately equidistant from the Hyuga-Nada Sea), it was confirmed that the standard deviation of atmospheric pressure fluctuations increased for approximately 10 seconds during the same time period, and that the standard deviation of atmospheric pressure fluctuations peaked at 21:15:33.

[0029] In this way, infrasound can be detected by monitoring whether or not there is a pattern attributable to infrasound in the temporal change in vibration intensity for each frequency at each measurement point.

[0030] 4A is a diagram showing the main configuration of the equipment monitoring device 100. As shown in the figure, the equipment monitoring device 100 includes a processor 101, a main storage device 102 (memory), an auxiliary storage device 103 (external storage device), an input device 104, an output device 105, a communication device 106, and an optical analysis unit 107. These are communicatively connected via a bus, a communication cable, or the like. Note that all or part of the equipment monitoring device 100 may be realized using virtual information processing resources, such as a virtual server provided by a cloud system, for example.

[0031] The processor 101 is configured using, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a GPU (Graphics Processing Unit), an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), an AI (Artificial Intelligence) chip, etc.

[0032] The main memory device 102 is a memory device used when the processor 101 executes a program, and is, for example, a read-only memory (ROM), a random access memory (RAM), or a non-volatile memory (NVRAM).

[0033] The auxiliary storage device 103 is a device that stores programs and data, and can be configured, for example, with an SSD (Solid State Drive), a hard disk drive, or an optical storage device (CD (Compact Disc), DVD (Digital Versatile Disc), etc.). Programs and data can be read into the auxiliary storage device 103 from other information processing devices equipped with non-transitory recording media or non-transitory storage devices via a recording medium reading device or a communication device 106. The programs and data stored in the auxiliary storage device 103 are read into the main storage device 102 as needed.

[0034] The input device 104 is an interface that accepts input of information from the outside, and is, for example, a keyboard, a mouse, a touch panel, a voice input device, or the like.

[0035] The output device 105 is an interface that outputs various information such as processing progress and processing results to the outside. The output device 105 is, for example, a display device (liquid crystal monitor, LCD (Liquid Crystal Display) or the like) that visualizes the various information, a device that converts the various information into audio (audio output device (speaker or the like)), or a device that converts the various information into text (printer or the like). Note that, for example, the information processing device 10 may be configured to input and output information to and from other devices via the communication device 106.

[0036] The input device 104 and the output device 105 constitute a user interface that realizes interactive processing with the user (receiving information, providing information, etc.).

[0037] The communication device 106 is a device that realizes communication with other devices via a communication network 5 (such as a local area network (LAN), a wide area network (WAN), the Internet, a public communication network, or a dedicated line). The communication device 106 is a wired or wireless communication interface that realizes communication with other devices via a communication medium, and is, for example, a network interface card (NIC), a wireless communication module, or a universal serial bus (USB) module.

[0038] The optical analyzing unit 107 is a device that measures the vibration state of a measurement point using a DAS and includes a vibration measuring device using a C-OTDR and a signal processing circuit. The optical analyzing unit 107 includes a CW (continuous wave) laser light source that generates an optical pulse (laser light) to be input to the end face of the optical fiber 4a, an optical pulse generator, an optical amplifier, optical devices (photodetector, optical interferometer), a signal processing circuit (phase calculation circuit, etc.), etc. The optical analyzing unit 107 and the optical fiber 4a are connected, for example, by optically connecting the output of the laser light source of the optical analyzing unit 107 to a connection port (socket) of the core wire of an OPGW installed in a substation. Therefore, the connection does not cause any impact on the power system, such as a power outage.

[0039] The equipment monitoring device 100 may be equipped with, for example, an operating system, a file system, a DBMS (DataBase Management System) (relational database, NoSQL, etc.), a KVS (Key-Value Store), etc.

[0040] The various functions of the equipment monitoring device 100 are realized by the processor 101 reading and executing programs stored in the main memory device 102, or by the hardware (FPGA, ASIC, AI chip, etc.) that constitutes the equipment monitoring device 100. The equipment monitoring device 100 stores various types of information (data), for example, as tables in a database or files managed by a file system.

[0041] 4B is a block diagram illustrating the main functions of the facility monitoring device 100. As shown in the figure, the facility monitoring device 100 includes the following functions: a memory unit 110, a vibration state measurement unit 120, an infrasound detection unit 125, a disaster information acquisition unit 130, a facility impact information generation unit 132, and a facility impact information provision unit 135.

[0042] Of the above functions, the storage unit 110 stores vibration status at each measurement point 111, infrasound detection information 112, disaster information 113, and facility impact information 114.

[0043] The vibration state measurement unit 120 uses the DAS to measure the change over time in the vibration state (vibration intensity, vibration frequency) at each measurement point on each span (change over time in vibration intensity for each frequency), and manages the measurement results as the vibration state for each measurement point 111. The vibration state for each measurement point 111 includes, for example, information on the graph shown in FIG.

[0044] The infrasound detection unit 125 detects infrasound based on the change over time in the vibration intensity for each frequency at each measurement point included in the vibration state for each measurement point 111 during the above-mentioned period. The infrasound detection unit 125 detects infrasound by monitoring whether or not there is a feature attributable to infrasound in the change over time in the vibration intensity for each frequency at each measurement point. The infrasound detection unit 125 detects infrasound by, for example, performing data analysis (background noise removal, signal identification, etc.) on the graph shown in FIG. 3 .

[0045] When the infrasound detection unit 125 detects infrasound, it manages information indicating that infrasound has been detected and information based on aspects of the change over time in the vibration intensity for each frequency at the measurement point that are attributable to infrasound, as infrasound detection information 112. For example, the infrasound detection unit 125 manages, as infrasound detection information 112, information indicating the date and time when infrasound was detected and information used as the basis for determining that infrasound has been detected (for example, information acquired from the graph shown in FIG. 3 ).

[0046] For example, the infrasound detection unit 125 determines that infrasound has been detected when vibration intensity equal to or greater than a predetermined magnitude is observed in the infrasound frequency band (20 Hz or less) at each measurement point on a predetermined number or more adjacent spans. Furthermore, for example, the infrasound detection unit 125 determines that infrasound has been detected when vibration equal to or greater than a predetermined magnitude is observed across a wide frequency band at each measurement point on a predetermined number or more adjacent spans. Note that the infrasound detection unit 125 may detect infrasound by applying methods or criteria other than those described above to the temporal change in vibration intensity for each frequency at each measurement point. Furthermore, multiple methods and criteria may be combined to improve detection accuracy.

[0047] When the infrasound detection unit 125 detects infrasound, the disaster information acquisition unit 130 acquires disaster information for a predetermined period before and after the date and time when infrasound is detected from the disaster monitoring system 300 via the communication network 5. Note that the predetermined period is set, for example, based on the time difference between the date and time when a disaster occurred in the past and the date and time when infrasound caused by the disaster was detected. Furthermore, the predetermined period may be set (adjusted) by the user via a user interface.

[0048] The facility impact information generation unit 132 generates facility impact information based on the infrasound detection information 112 and the disaster information 113, and manages the generated facility impact information as facility impact information 114. For example, the facility impact information generation unit 132 generates facility impact information by combining the content of the infrasound detection information 112 with the content of the disaster information 113. Note that the facility impact information generation unit 132 may provide a user interface for setting how the content of the infrasound detection information 112 and the content of the disaster information 113 are to be combined.

[0049] The facility impact information generator 132 also determines whether an abnormality (e.g., a broken wire or partial deformation) has occurred in the power transmission and substation equipment, and manages the result (the possibility of an abnormality in the power transmission and substation equipment) in the facility impact information 114. The facility impact information generator 132 determines whether an abnormality has occurred in the power transmission and substation equipment on the span or in the vicinity of the span by, for example, comparing the natural frequency of the optical fiber 4a determined from the vibration intensity for each frequency after the detection time of infrasound at the measurement point on the span with the natural frequency of the optical fiber 4a determined from the vibration intensity for each frequency at the measurement point on the span during normal times (before the detection time of infrasound) that has been stored in advance. For example, the facility impact information generator 132 determines that an abnormality has occurred in the power transmission and substation equipment on the span or in the vicinity of the span when a predetermined number or more natural frequencies different from the natural frequency during normal times are observed.

[0050] The facility impact information providing unit 135 provides information based on the facility impact information 114 to a user by outputting the information to an output device (a display device, an audio output device (speaker), etc.). The facility impact information providing unit 135 may also provide information based on the facility impact information 114 to another information processing device that is communicably connected.

[0051] 5 is a flowchart explaining the processing performed by the equipment monitoring device 100 (hereinafter referred to as "equipment impact information provision processing S500"). The equipment impact information provision processing S500 will be explained below with reference to this figure. Note that the following explanation is premised on the assumption that the vibration state measurement unit 120 of the equipment monitoring device 100 measures the time change (time change of vibration strength for each frequency) of the vibration state (vibration intensity, vibration frequency) at each measurement point on each span in real time using DAS, and manages the latest vibration state of each measurement point as the measurement point vibration state 111.

[0052] As shown in the figure, the infrasound detection unit 125 monitors in real time the change over time in the vibration intensity for each frequency at each measurement point based on the vibration state for each measurement point 111 (S511 to S512: No). When the infrasound detection unit 125 detects an aspect attributable to infrasound in the change over time in the vibration intensity for each frequency at each measurement point acquired from the vibration state for each measurement point 111 (S512: Yes), it generates and manages infrasound detection information 112 for the detected infrasound (S513).

[0053] Next, the disaster information acquisition unit 130 acquires disaster information for a predetermined period before and after the date and time when infrasound was detected from the disaster monitoring system 300 via the communication network 5, and manages the acquired disaster information as disaster information 113 (S514).

[0054] Next, the facility impact information generation unit 132 generates facility impact information based on the infrasound detection information 112 and the disaster information 113, and manages the generated facility impact information as facility impact information 114 (S515).

[0055] Next, the facility impact information providing unit 135 provides information based on the facility impact information 114 to the user by outputting it to an output device (such as a display device or an audio output device (speaker)) (S516). Then, the process returns to S511.

[0056] FIG. 6 shows an example of a screen (hereinafter referred to as a "facility impact information output screen 600") that is displayed when the facility impact information providing unit 135 outputs the above information.

[0057] As shown in the figure, the illustrated equipment impact information output screen 600 has a display field 611 for the infrasound detection date and time, a display field 612 for the infrasound detection distance, a display field 613 for the disaster occurrence date and time, a display field 614 for the disaster occurrence area, a display field 615 for the type of disaster, a display field 616 for the scale of the disaster, and a display field 617 for the possibility of an abnormality in the transmission and transformation equipment.

[0058] Among these, the infrasound detection date and time display field 611 displays the date and time when the infrasound detection unit 125 detected infrasound.

[0059] Furthermore, the infrasound detection span display field 612 displays the span ID of the span having the measurement point where infrasound was detected.

[0060] In addition, the disaster occurrence date and time display field 613 displays the date and time when the disaster occurred.

[0061] Further, the disaster area display field 614 displays information indicating the area where the disaster occurred.

[0062] In addition, the disaster type display field 615 displays information indicating the type of disaster.

[0063] Furthermore, the disaster scale display field 616 displays information indicating the scale of the disaster.

[0064] Further, a display field 617 for the possibility of an abnormality in the power transmission and transformation equipment displays information indicating the possibility of an abnormality in the power transmission and transformation equipment in the above span or in the vicinity of the above span (abnormality present / abnormality not present).

[0065] As described above, the equipment monitoring system 1 of this embodiment monitors whether or not there is a phenomenon attributable to infrasound in the time change in vibration intensity for each frequency at each measurement point acquired by the DAS, and if such a phenomenon is detected, acquires disaster information, which is information about a disaster that occurred in an area where a power transmission line span having a measurement point where the phenomenon was detected, from another device connected via communication, and generates and outputs equipment impact information, which is information that associates the infrasound detection information, which is information based on the detected phenomenon, with the disaster information, so that the user can easily identify the power transmission and substation equipment affected by the disaster. In this way, the equipment monitoring system 1 of this embodiment can efficiently and low-costly realize an equipment monitoring system that uses infrasound using an existing environment (an environment in which the vibration state of measurement points can be remotely acquired by the DAS).

[0066] The above-described embodiments are provided to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and equivalents thereof are also included in the present invention.

[0067] For example, when the infrasound detection unit 125 inputs the feature quantities extracted by performing image recognition processing on the graph (image) shown in Figure 3 as explanatory variables, it may use a machine learning model that has been trained to output whether or not infrasound has been detected as a target variable.

[0068] For example, the equipment monitoring device 100 may store and manage the equipment impact information 114 in a database for each infrasound detected by the infrasound detection unit 125, and when the user specifies a span via the user interface, the equipment impact information associated with the specified span may be output (presented to the user).

[0069] FIG. 7 shows an example of a screen (hereinafter referred to as a "facility impact information search screen 700") that the facility monitoring device 100 outputs to the display device in this case.

[0070] As shown in the figure, the illustrated facility impact information search screen 700 has a span ID specification field 701, a search button 702, a display field 711 for the infrasound detection date and time, a display field 712 for the disaster occurrence date and time, a display field 713 for the disaster occurrence area, a display field 714 for the type of disaster, a display field 715 for the scale of the disaster, and a display field 716 for the possibility of an abnormality in the transmission and transformation facility.

[0071] When the user inputs a span ID in the span ID specification field 701 and operates the search button 702, the equipment monitoring device 100 searches the database and displays the contents of each of the following fields: infrasound detection date and time display field 711, disaster occurrence date and time display field 712, disaster occurrence area display field 713, disaster type display field 714, disaster scale display field 715, and power transmission / substation equipment abnormality possibility display field 716. The contents of each field are the same as those in FIG. 6.

[0072] When multiple pieces of equipment impact information are found for a span ID specified by the user, the equipment monitoring device 100 may display all of the found equipment impact information. Also, the equipment monitoring device 100 may display a predetermined number of pieces of equipment impact information sorted in descending order of the date and time of the disaster occurrence.

[0073] By using this function, users can easily check what kind of impact the disaster had on a specified span. For example, they can estimate the impact of the disaster on transmission and substation equipment located near the specified span and use this information as reference when determining the need for maintenance, etc.

[0074] REFERENCE SIGNS LIST 1 Facility monitoring system 2 Transmission tower 3 Power transmission line 4 OPGW 4a Optical fiber 100 Facility monitoring device 107 Optical analysis unit 110 Storage unit 111 Vibration state at each measurement point 112 Infrasound detection information 113 Disaster information 114 Facility impact information 120 Vibration state measurement unit 125 Infrasound detection unit 130 Disaster information acquisition unit 132 Facility impact information generation unit 135 Facility impact information provision unit 300 Disaster monitoring system S500 Facility impact information provision processing 600 Facility impact information output screen 700 Facility impact information search screen

Claims

1. A facility monitoring system comprising an optical analysis unit and an information processing device, which acquires, by DAS (Distributed Acoustic Sensing), the time change of the vibration intensity for each frequency of the optical fiber at each of a plurality of measurement points set along an optical fiber attached along a power transmission line, monitors whether there is a mode caused by infrasound in the time change of the vibration intensity for each frequency of the measurement points, and when the mode is detected, acquires disaster information, which is information regarding a disaster that occurred in an area where there is a span of the power transmission line having the measurement points where the mode was detected, within a predetermined period before and after the date and time when the mode was detected, from another device communicably connected, and outputs facility impact information, which is information associating the infrasound detection information, which is information based on the detected mode, with the disaster information.

2. The facility monitoring system according to claim 1, wherein the infrasound detection information includes the infrasound detection date and time, which is the date and time when the mode was detected, and information indicating the span of the power transmission line having the measurement points where the mode was detected.

3. The facility monitoring system according to claim 1, wherein the disaster information includes the date and time when the disaster occurred, the area where the disaster occurred, information indicating the type of the disaster, and information indicating the scale of the disaster.

4. The facility monitoring system according to claim 1, which stores and manages the facility impact information in a database, receives a designation of the span from a user via a user interface, and searches for and outputs the facility impact information of the designated span from the database.

5. The facility monitoring system according to claim 1, which determines whether there is an abnormality in the power transmission and transformation equipment of the span having the measurement points by comparing the natural vibration frequency of the optical fiber grasped from the vibration intensity for each frequency after the time when the mode was detected at the measurement points with the natural vibration frequency of the optical fiber grasped from the vibration intensity for each frequency in the normal state of the measurement points stored in advance, and generates information indicating the determined result as the facility impact information.

6. In a facility monitoring system configured to include an optical analysis unit and an information processing device, the information processing device includes: a step of acquiring, by DAS (Distributed Acoustic Sensing), a temporal change in vibration intensity for each frequency of the optical fiber at each of a plurality of measurement points set along an optical fiber attached along a transmission line; a step of monitoring whether there is a mode attributable to infrasound in the temporal change in vibration intensity for each frequency of the measurement point; a step of, when the mode is detected, acquiring disaster information, which is information regarding a disaster that occurred in an area where there is a span of the transmission line having the measurement point where the mode was detected, from another device communicably connected, within a predetermined period before and after the date and time when the mode was detected; and a step of outputting facility impact information, which is information associating the infrasound detection information, which is information based on the detected mode, with the disaster information, wherein the facility monitoring method is executed.

7. The facility monitoring method according to claim 6, wherein the infrasound detection information includes the infrasound detection date and time, which is the date and time when the mode was detected, and information indicating a span of the transmission line having the measurement point where the mode was detected.

8. The facility monitoring method according to claim 6, wherein the disaster information includes the date and time when the disaster occurred, the area where the disaster occurred, information indicating the type of the disaster, and information indicating the scale of the disaster.

9. The facility monitoring method according to claim 6, wherein the information processing device further executes: a step of accumulating and managing the facility impact information in a database; a step of receiving a designation of the span from a user via a user interface; and a step of searching for and outputting the facility impact information of the designated span from the database.

10. The facility monitoring method according to claim 6, further comprising the step of: the information processing apparatus compares the natural vibration frequency of the optical fiber grasped from the vibration intensity for each frequency after the time when the mode is detected at the measurement point with the natural vibration frequency of the optical fiber grasped from the vibration intensity for each frequency in the normal state of the measurement point stored in advance, to determine whether or not an abnormality has occurred in the power transmission and transformation facility in the span having the measurement point, and generates information indicating the determination result as the facility impact information.

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