Wind condition information providing system and wind condition information providing method

Abstract

The objective of the present invention is to provide stable and meaningful wind condition information using Distributed Acoustic Sensing (DAS). A wind condition information providing system is configured to include a light analysis unit and an information processing device, and acquires wind condition information, which is information indicating the current wind condition in the span between power transmission lines, on the basis of the vibration intensity of an optical fiber acquired by DAS with respect to measurement points set along the optical fiber installed along the power transmission lines, and detects the presence or absence of a saturated state, which is a state where a period during which the magnitude of the vibration intensity is equal to or greater than a predetermined threshold range continues for a predetermined threshold time or longer. The wind condition information providing system acquires the wind condition information on the basis of a wind condition estimation component, which is a component of the vibration intensity in a predetermined frequency band, and detects the presence or absence of the saturation state on the basis of a saturation determination component, which is a component of the vibration intensity in a higher frequency band than the abovementioned frequency band.

Description

Wind condition information providing system and wind condition information providing method

[0001] The present invention relates to a wind condition information providing system and a wind condition information providing method.

[0002] Patent Document 1 describes detecting the speed and direction of wind blowing against a power transmission line using a technology (distributed multipoint vibration measurement method, hereinafter referred to as "DAS" (Distributed Acoustic Sensing)) that calculates vibrations caused by the expansion and contraction of an optical fiber based on the time from when pulsed light is incident on the optical fiber of an OPGW (optical fiber composite overhead ground wire) until the backward Rayleigh scattered light returns, and the phase difference and intensity of the backward Rayleigh scattered light.

[0003] Japanese Patent Application Laid-Open No. 2023-50245

[0004] "Study on the vibration characteristics of power lines during strong winds", Urban Disaster Management, Ken Inayoshi, Kyushu University, [online], Internet <URL: https: / / www.hues.kyushu-u.ac.jp / wp-content / uploads / 2022 / 10 / 2HE02019E.pdf>, retrieved September 8, 2023. "On the influence of wind due to terrain and obstacles", Omuro Kogen, [online], Internet <URL: http: / / www.chl-izu.jp / weather / expfiles / expwind.htm>, retrieved September 8, 2023.

[0005] In the above-mentioned Patent Document 1, information on wind conditions at a site where a power transmission line is present (hereinafter referred to as "wind condition information") is obtained remotely using a DAS.

[0006] However, this technology has the problem that during strong winds, the vibration intensity remains constant and barely changes (hereinafter, this state will be referred to as "saturation state"), making it impossible to obtain meaningful wind information.

[0007] Therefore, in order to obtain stable and meaningful wind information using this technology, a mechanism is needed to detect when the optical fiber is saturated and a mechanism to supplement wind information during periods when the optical fiber is saturated.

[0008] The present invention has been made in consideration of the above background, and aims to provide a wind condition information providing system and a wind condition information providing method that can stably provide meaningful wind condition information using a DAS.

[0009] One means for solving the above problem is a wind condition information providing system that includes an optical analysis unit and an information processing device, and acquires wind condition information that indicates the current wind conditions in the span of the power line based on the vibration intensity of the optical fiber acquired by DAS (Distributed Acoustic Sensing) at measurement points set along the optical fiber installed along the power line, and detects whether or not a saturation state exists, which is a state in which the magnitude of the vibration intensity remains above a predetermined threshold range for a period of time that continues for more than a predetermined threshold time.

[0010] In addition, the wind condition information providing system acquires the wind condition information based on a wind condition estimation component, which is a component of the vibration intensity in a specified frequency band, and detects whether or not the saturation state is present based on a saturation determination component, which is a component of the vibration intensity in a frequency band higher than the specified frequency band.

[0011] Furthermore, when the wind condition information providing system detects the saturation state, it acquires the actual values ​​of the change in wind speed over time at other observation points that are not in the saturated state during the saturation period in which the saturation state occurs, estimates the wind speed during the saturation period of the span based on the correlation between the actual measured value of the change in wind speed over time at the span and the actual value of the change in wind speed over time at the observation points, and complements the wind condition information during the saturation period of the span with the estimated wind speed.

[0012] Other problems and solutions disclosed in the present application will be made clear in the detailed description and drawings.

[0013] According to the present invention, meaningful wind condition information can be stably provided using a DAS.

[0014] 1 is a diagram illustrating a schematic configuration of a wind condition information providing system; FIG. 2 is a diagram illustrating a mechanism for measuring vibration states using a DAS; FIG. 3 is an example of a measured wind speed (in a direction parallel to the extension direction of the optical fiber); FIG. 4 is an example of a measured wind speed (in a direction perpendicular to the extension direction of the optical fiber); FIG. 5 is an example of a time change in vibration intensity; FIG. 6 is an example of a time change in vibration intensity for each frequency; FIG. 7 is an example of a time change in vibration intensity when there is no saturation period; FIG. 8 is an example of a time change in wind speed when there is no saturation period; FIG. 9 is an example of a time change in vibration intensity when there is a saturation period; FIG. 10 is an example of a time change in wind speed when there is a saturation period;

[0015] 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" before a reference numeral denotes a processing step.

[0016] 1 shows a schematic configuration of a wind condition information providing system (hereinafter referred to as "wind condition information providing system 1") described as one embodiment of the present invention. As shown in the figure, wind condition information providing system 1 includes a wind condition information providing device 100 installed in a substation 6 or the like, and a wind condition information utilization device 300 that is communicatively connected to wind condition information providing device 100. Both wind condition information providing device 100 and wind condition information utilization device 300 are configured using information processing devices (computers).

[0017] The wind condition information providing device 100 uses an optical fiber 4 a of an OPGW 4 (optical fiber composite overhead ground wire) installed on a power transmission line 3 as a vibration detection sensor, and measures the vibration state (vibration intensity, vibration frequency) due to the expansion and contraction of the optical fiber 4 a at each of a plurality of measurement positions (hereinafter, each point will be referred to as a "measurement point") set along the optical fiber 4 a using a technology (distributed multipoint vibration measurement method (hereinafter, referred to as "DAS" (Distributed Acoustic Sensing)) to acquire (estimate) the wind conditions (wind direction, wind speed) at each measurement point based on the vibration state at each measurement point. With DAS, the vibration state at each measurement point is acquired, for example, using the principle of a C-OTDR (Coherent Detection Optical Time Domain Reflectometer).

[0018] FIG. 2 illustrates how the wind condition information device 100 measures the vibration state at each measurement point using a DAS. As shown in the figure, the wind condition information device 100 emits a light pulse (laser pulse, hereinafter also referred to as "incident light") from the end face of the optical fiber 4a and measures the rate of change (≒ expansion / contraction 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 wind condition information 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 wind condition information 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 wind condition information device 100 also determines the position (distance from the end face) of each measurement point based on the elapsed time from when the incident light is incident on the end face to 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 wind condition information providing device 100 acquires the vibration state for each span (between adjacent transmission towers 2) of the power transmission line 3 based on the vibration state at each measurement point. As described in Non-Patent Document 1 ("Study on Vibration Characteristics of Power Lines During Strong Winds," Urban Disaster Management, Ken Inayoshi, Kyushu University, [online], Internet <URL: https: / / www.hues.kyushu-u.ac.jp / wp-content / uploads / 2022 / 10 / 2HE02019E.pdf>), the vibration state of the optical fiber 4a in a span has a certain correlation with the wind conditions in the span. Therefore, a model (statistical model, machine learning model, etc.) representing this correlation is generated in advance, and the vibration states acquired at the measurement points in the span can be input into the model to acquire the wind conditions in the span.

[0021] Note that, since the vibration mode (natural vibration mode) of the vibration state of the optical fiber 4a differs depending on the wind speed (the vibration state is nonlinear with respect to changes in wind speed), the above model is generated for each range of wind speed (for example, a model is generated for when the wind speed is less than 3 (m / s) and a model is generated for when the wind speed is 3 (m / s) or more). In addition, since the characteristics of the vibration state of the optical fiber 4a differ for each span due to differences in the span length and the installation state of the OPGW 4, the above model is generated for each span.

[0022] Furthermore, if the predetermined interval d (m) is shorter than the span of the transmission tower 2, multiple measurement points will be included in one span, but in that case, the method for acquiring the wind conditions for that span based on the vibration state at each measurement point is not necessarily limited. For example, the wind conditions for the span may be the wind conditions at the measurement point with the highest wind speed among the multiple measurement points or the average value of the wind conditions at each measurement point.

[0023] For example, by inputting the vibration state of the measurement points along the span into the above model, the wind condition information providing device 100 determines the wind speed components (referred to as the "parallel direction component" and the "orthogonal direction component") in the direction along the optical fiber 4a (the direction of longitudinal waves; the extension direction of the optical fiber 4a; hereinafter referred to as the "parallel direction") and in the direction perpendicular to the extension direction of the optical fiber 4a (the direction of transverse waves; hereinafter referred to as the "orthogonal direction"), and determines the wind conditions (wind direction and wind speed) along the span based on the determined parallel direction component and orthogonal direction component.

[0024] FIG. 3A shows an example of the time variation (time series data) of the parallel component of wind speed (hereinafter referred to as "measured value (parallel direction)") in a certain span, calculated using the above-described method. FIG. 3B shows an example of the time variation of the perpendicular component of wind speed (hereinafter referred to as "measured value (perpendicular direction)") in the above span, calculated by the wind condition information providing device 100. The horizontal axis of the graphs shown in each figure is time, and the vertical axis is wind speed (m / s). In the following description, "wind speed" refers to at least either the parallel component of wind speed or the perpendicular component of wind speed.

[0025] The wind condition information providing device 100 provides (transmits) information indicating the current wind conditions (hereinafter referred to as "wind condition information") for each span (hereinafter referred to as "site") of the power transmission line 3, which is obtained by the above mechanism, to the wind condition information utilization device 300.

[0026] Returning to FIG. 1 , the wind condition information utilization device 300 performs or supports tasks or work using wind condition information provided by the wind condition information providing device 100. For example, the wind condition information utilization device 300 provides wind condition information to an operator of an unmanned aerial vehicle (drone) that flies along a power transmission line 3 to patrol and inspect power facilities (such as a transmission tower 2, a power transmission line 3, and a substation 4), to determine whether or not the drone should fly. Furthermore, for example, the wind condition information utilization device 300 wirelessly communicates with the unmanned aerial vehicle and functions as an element of a flight control system that monitors the unmanned aerial vehicle, provides various information, and controls its flight. Furthermore, for example, the wind condition information utilization device 300 functions as an element of an information processing system that uses wind condition information to perform dynamic rating (a technology for operating power transmission and substation facilities by constantly monitoring the condition of the facilities and adjusting the current capacity according to local conditions).

[0027] However, there are the following issues when obtaining wind information using the above system.

[0028] 4A shows the change over time in vibration intensity of the optical fiber 4a measured for a certain span of the power transmission line 3. The horizontal axis of the graph in the figure represents time (h), and the vertical axis represents vibration intensity (arbitrary units). In the figure, the solid line represents the average value of vibration intensity in a frequency band (e.g., 0 to 25 Hz) used to estimate wind conditions among the frequency components of vibration intensity (hereinafter referred to as the "wind condition estimation component"). On the other hand, the dotted line represents the average value of vibration intensity in a frequency band (e.g., 450 to 475 Hz) higher than the wind condition estimation component among the frequency components of vibration intensity (hereinafter referred to as the "saturation determination component").

[0029] On the other hand, Figure 4B shows the time-series data of the vibration intensity for each frequency in a specified frequency range (0 to 500 Hz) measured for the above span. In this figure, the horizontal axis is frequency (Hz) and the vertical axis is time (h). In this figure, time flows from top to bottom on the page. Also, in this figure, the shade of color represents the vibration intensity (the lighter the color, the greater the vibration intensity).

[0030] 4A and 4B, the vibration intensity of both the wind condition estimation component and the saturation determination component remains constant and barely changes during the period from 26 to 36 hours. In particular, the vibration intensity of the saturation determination component remains almost constant throughout the period (hereinafter, this state will be referred to as the "saturation state").

[0031] Here, the vibration intensity is expressed as the time series difference (-π to +π) (hereinafter referred to as the "phase difference") of the phase shift of the vibration caused by the expansion and contraction of the optical fiber 4a. For example, if the vibration is small and the phase difference is 2π or less, the vibration intensity can be observed as a continuous change. However, if the phase difference exceeds 2π due to the influence of a strong wind, the change in the vibration intensity becomes extremely small as in the above period, and the optical fiber 4a reaches a saturated state. Note that the level of wind required to saturate the optical fiber 4a depends on the type of optical fiber 4a, etc. For example, a small-diameter optical fiber 4a is lighter, so it reaches a saturated state at a lower wind speed than a large-diameter optical fiber 4a.

[0032] 4A, when the optical fiber 4a is saturated, the vibration intensity of the saturation determination component remains constant and hardly changes, which is a noticeable phenomenon. Therefore, by monitoring the vibration intensity of the saturation determination component, it is possible to accurately determine whether the optical fiber 4a is saturated.

[0033] Fig. 5A shows an example of the time variation of the vibration intensity of the wind condition estimation component and the saturation determination component (time variation of vibration intensity obtained by DAS) when there is no period in which the optical fiber 4a is saturated (hereinafter referred to as the "saturation period"). Fig. 5B also shows an example of an estimated value of the time variation of wind speed obtained based on the wind condition estimation component of Fig. 5A. Fig. 5B also shows the time variation of wind speed observed by a reference anemometer (Doppler LIDAR). As shown in the figure, the estimated value of the time variation of wind speed based on the wind condition estimation component and the observed value of the reference anemometer are in good agreement throughout the entire period shown in the figure.

[0034] On the other hand, Fig. 6A shows an example of the time variation of the vibration intensity of the wind condition estimation component and the saturation determination component (time variation of vibration intensity calculated by DAS) when a saturation period is present. Fig. 6B shows an example of an estimated value of the time variation of wind speed calculated based on the wind condition estimation component of Fig. 6A. Fig. 6B also shows the time variation of wind speed observed by a reference anemometer (Doppler LIDAR). As shown in the figure, the estimated value of the time variation of wind speed based on the wind condition estimation component and the observed value of the reference anemometer match during periods other than the saturation period, but the two differ significantly during the saturation period.

[0035] In this way, when estimating wind conditions based on the time variation of vibration intensity obtained by DAS, it becomes impossible to obtain accurate wind conditions when the optical fiber 4a becomes saturated. Therefore, the wind condition information providing device 100 monitors in real time whether the optical fiber 4a is saturated, and when it detects that the optical fiber 4a is saturated, it complements the wind conditions (wind condition information) during the saturated period using the following method.

[0036] For example, the wind condition information providing device 100 determines the change in wind speed over time during the saturation period of a span in which a saturation state exists (hereinafter referred to as the "first span") based on the correlation between the actual value of the change in wind speed over time of the first span and the actual value of the change in wind speed over time of another span in the vicinity of the first span that is not in a saturated state during the saturation period of the first span (hereinafter referred to as the "second span") (hereinafter this method will be referred to as the "first complementation method").

[0037] Due to differences in topography and other factors, even if the first span is saturated, the second span may not be saturated (see, for example, Non-Patent Document 2 ("On the Influence of Topography and Obstacles on Wind," Omuro Kogen, [searched September 8, 2023], [online], Internet <URL: http: / / www.chl-izu.jp / weather / expfiles / expwind.htm>)). In such cases, the second span can correctly obtain the time change in wind speed during the saturation period of the first span. Therefore, the first interpolation method uses the time change in wind speed in the second span to estimate the wind speed during the saturation period of the first span.

[0038] 7A and 7B are schematic diagrams illustrating a first interpolation method. As shown in FIG. 7A, the wind condition information providing device 100 calculates the correlation between the actual value of the time change in wind speed in the first span and the actual value of the time change in wind speed in the second span (here, the correlation is the average value of the ratio between the two). Then, as shown in FIG. 7B, the wind condition information providing device 100 calculates the wind speed during the saturation period of the first span by multiplying the wind speed during the saturation period of the second span by the average value of the ratio. Note that the method for obtaining the correlation is not necessarily limited, and the correlation may be obtained using other methods such as statistical techniques or machine learning.

[0039] Furthermore, for example, the wind condition information providing device 100 determines the time change in wind speed during the saturation period of a span that is in a saturated state based on the correlation between the actual value of the time change in wind speed in that span and the observed value of the time change in wind speed at a specified observation point for wind conditions located near that span (hereinafter, this method will be referred to as the "second complementation method").

[0040] The observed values ​​of the time change in wind speed at the above observation points are provided to the wind condition information providing device 100 via a communication network from, for example, other wind condition observation systems (systems that collect information about each observation point from wind condition acquisition equipment such as anemometers installed at observation points in various locations) operated by organizations (public institutions, private organizations, etc.) that provide meteorological information in various locations.

[0041] 8A and 8B are schematic diagrams illustrating a second interpolation method. As shown in FIG. 8A , for example, the wind condition information providing device 100 calculates the correlation (here, the average value of the ratio between the actual value of the time change in wind speed in a given span and the observed value of the time change in wind speed at an observation point located near the given span) between the actual value of the time change in wind speed in a given span and the observed value of the time change in wind speed at an observation point located near the given span. Then, as shown in FIG. 8B , the wind condition information providing device 100 calculates the wind speed in the saturation period of the given span by multiplying the observed value in the saturation period at the observation point by the average value of the ratio. Note that the method for obtaining the correlation is not necessarily limited, and the correlation may be obtained using other methods such as statistical techniques or machine learning.

[0042] =Details of the wind condition information providing device= Fig. 9A is a diagram showing the main configuration of the wind condition information providing device 100. As shown in the figure, the wind condition information providing 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 wind condition information providing device 100 may be realized using virtual information processing resources, such as a virtual server provided by a cloud system, for example.

[0043] 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.

[0044] 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).

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.).

[0049] The communication device 106 is a device that realizes communication with other devices via a communication network (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, such as a network interface card (NIC), a wireless communication module, or a universal serial bus (USB) module.

[0050] 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 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, for example. Therefore, the connection does not cause any impact on the power system, such as a power outage.

[0051] The wind condition information providing 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.

[0052] The various functions of the wind condition information providing 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 wind condition information providing device 100. The wind condition information providing device 100 stores various types of information (data), for example, as database tables or files managed by a file system.

[0053] 9B is a block diagram showing the main functions of the wind condition information providing device 100. As shown in the figure, the wind condition information providing device 100 has the functions of a memory unit 110, a vibration state measurement unit 120, a span-by-span wind condition information generation unit 130, a saturation state determination unit 135, a complementary use information acquisition unit 140, a complementary processing unit 145, and a wind condition information providing unit 150.

[0054] Of the above functions, the storage unit 110 stores a vibration state for each measurement point 111, a model 112, complementary use information 113, and wind condition information for each span 114.

[0055] The vibration state measurement unit 120 measures the time change (time series data) of the vibration state at each measurement point using DAS, and manages the time change of the vibration state (vibration intensity, vibration frequency) measured for each measurement point as the vibration state for each measurement point 111 by corresponding it to the identifier of each measurement point.

[0056] The span-by-span wind condition information generator 130 acquires the vibration state of each span of the power transmission line 3 (the vibration state of each measurement point of each span) based on the vibration state of each measurement point in the measurement point vibration state 111, and inputs the acquired vibration state into the model 112 (the above-mentioned model generated for each wind speed range and each span) to acquire the time variation of the wind speed in each span (time-series data). The span-by-span wind condition information generator 130 manages the acquired time variation of the wind speed as span-by-span wind condition information 114, for example, by associating it with the identifier of each span or the identifier of each measurement point.

[0057] The saturation state presence / absence determining unit 135 monitors the vibration state for each measurement point 111 in real time and determines whether or not the above-mentioned saturation period exists. Specifically, when a period in which the magnitude of the vibration intensity is equal to or greater than a predetermined threshold range continues for a predetermined threshold time or longer in the time change of the saturation determination component acquired from the vibration state for each measurement point 111, the saturation state presence / absence determining unit 135 determines that the period is a saturation period.

[0058] The complementary use information acquisition unit 140 acquires information used to complement the wind speed during the saturation period and manages the acquired information as complementary use information 113. For example, when the first complementation method described above is adopted, the complementary use information acquisition unit 140 acquires actual values ​​of the time change in wind speed for each of the first span and the second span described above. Furthermore, when the second complementation method described above is adopted, the complementary use information acquisition unit 140 acquires actual measured values ​​of the time change in wind speed for the span and observed values ​​of the time change in wind speed at observation points located near the span.

[0059] The complementing processor 145 generates information for complementing the wind speed during the saturation period (an estimated value of the wind speed during the saturation period) using the complementary use information 113 acquired by the complementary use information acquiring unit 140. For example, when the first complementing method described above is adopted, the complementing processor 145 calculates the average ratio of the time change in wind speed for the span (the first span described above) based on the actual value of the time change in wind speed for the span in question and the actual value of the time change in wind speed for the second span described above, and calculates the wind speed for the first span during the saturation period by multiplying the average ratio by the wind speed for the second span during the saturation period. Furthermore, when the second complementing method described above is adopted, the complementing processor 145 calculates the average ratio of the time change in wind speed for the span in question based on the actual value of the time change in wind speed for the span in question and the observed value of the time change in wind speed at an observation point near the span in question, and calculates the wind speed for the saturation period for the span in question by multiplying the observed value at the observation point by the average ratio.

[0060] The interpolation processing unit 145 reflects the wind speed during the saturation period calculated as described above in the per-span wind condition information 114 (replaces the wind speed during the saturation period in the per-span wind condition information 114 with the wind speed during the saturation period calculated as described above).

[0061] The wind condition information providing unit 150 provides the generated span-by-span wind condition information 114 to the wind condition information utilization device 300 (for example, by transmitting it via a communication network).

[0062] Fig. 10A is a schematic diagram illustrating the process performed by the wind condition information providing device 100 (hereinafter referred to as "wind condition information providing process S1000"), and Fig. 10B is a flowchart illustrating the wind condition information providing process S1000. The wind condition information providing process S1000 will be described below with reference to these figures.

[0063] First, the vibration state measurement unit 120 selects one span (S1011).

[0064] Next, the vibration state measurement unit 120 acquires the vibration state (vibration intensity, vibration frequency) of each measurement point on the selected span using the DAS, performs a fast Fourier transform (FFT) on the acquired vibration state of each measurement point, determines the time change in the average vibration intensity for each frequency at each measurement point, and manages the result as the vibration state for each measurement point 111 (S1012 to S1013).

[0065] Next, the span-by-span wind condition information generating unit 130 calculates the time change in wind speed based on the time change in the wind condition estimation component of the span being selected in the measurement point vibration state 111, and manages it as span-by-span wind condition information 114 (S1014).

[0066] Next, the saturation state determination unit 135 determines whether a saturation period is included in the time change of the saturation determination component of the selected span in the measurement point vibration state 111 (S1015). If a saturation period is included (S1015: Yes), the process proceeds to S1016. On the other hand, if a saturation period is not included (S1015: No), the process proceeds to S1017.

[0067] In S1016, the complementary use information acquisition unit 140 acquires the complementary use information 113. Furthermore, the complementary processing unit 145 uses the complementary use information 113 to estimate the wind speed during the saturation period, for example, by the above-described method (first complementary method, second complementary method), and complements the wind speed during the saturation period of the span-by-span wind condition information 114.

[0068] In S1017, the wind condition information providing device 100 determines whether or not there is a span that has not been selected in S1011. If there is an unselected span (S1017: Yes), the process returns to S1011. If there is no unselected span (S1017: No), the process proceeds to S1018.

[0069] In S1018, the wind condition information providing unit 150 transmits information based on the span-by-span wind condition information 114 to the wind condition information utilization device 300. This completes the wind condition information providing process S1000.

[0070] =Effects, etc.= As described above, according to the wind condition information providing system 1 of this embodiment, it is possible to detect the presence of a saturation state in which the accuracy of estimating wind conditions based on vibration intensity decreases from the time change of vibration intensity acquired by the DAS.

[0071] In addition, the wind condition information providing system 1 detects the saturated state using a saturation judgment component in a frequency band higher than the frequency band of the wind condition estimation component, which is the vibration intensity acquired by the DAS and in which the characteristics of the saturated state are more likely to appear, so that the saturated state can be detected with high accuracy.

[0072] Furthermore, the wind condition information providing system 1 complements the wind conditions during the saturation period using the first complement method and the second complement method, and therefore can provide the wind condition information utilization device 300 with stable and meaningful wind condition information.

[0073] 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.

[0074] For example, the determination of whether or not a saturation state is present by the saturation state presence / absence determination unit 135 may be performed using a machine learning model that has been trained to output information indicating whether or not a saturation state is present as a target variable when, for example, feature quantities extracted by performing image recognition processing on the graphs (images) shown in Figures 6A and 6B are input as explanatory variables.

[0075] REFERENCE SIGNS LIST 1 Wind condition information providing system 2 Transmission tower 3 Power transmission line 4 OPGW 4a Optical fiber 6 Substation 100 Wind condition information providing device 107 Optical analysis unit 110 Storage unit 111 Vibration state at each measurement point 112 Model 113 Complementary use information 114 Wind condition information per span 120 Vibration condition measurement unit 130 Wind condition information per span generation unit 135 Saturation state presence / absence determination unit 140 Complementary use information acquisition unit 145 Complementary processing unit 150 Wind condition information providing unit S1000 Wind condition information provision processing

Claims

1. A wind condition information providing system comprising an optical analysis unit and an information processing device, which obtains wind condition information indicating the current wind conditions in the span of a power line based on the vibration intensity of the optical fiber obtained by Distributed Acoustic Sensing (DAS) at measurement points set along the optical fiber installed along the power line, and detects the presence or absence of a saturation state, which is a state in which the magnitude of the vibration intensity is above a predetermined threshold range for a period of time that continues for more than a predetermined threshold time.

2. A wind condition information providing system as described in claim 1, which acquires the wind condition information based on a wind condition estimation component, which is a component in a specified frequency band among the vibration intensity, and detects the presence or absence of the saturation state based on a saturation determination component, which is a component in a frequency band higher than the specified frequency band among the vibration intensity.

3. A wind condition information system as described in claim 1, which, when it detects a saturated state, obtains actual values ​​of the change in wind speed over time at other observation points that are not in the saturated state during the saturation period in which the saturated state occurs, estimates the wind speed during the saturation period of the span based on the correlation between the actual measured values ​​of the change in wind speed over time in the span and the actual values ​​of the change in wind speed over time at the observation points, and complements the wind condition information during the saturation period of the span with the estimated wind speed.

4. A wind condition information system as described in claim 3, wherein the other observation point is a span in the vicinity of the span in which the saturation state has not been detected during the saturation period.

5. A wind condition information providing system as described in claim 3, wherein the other observation point is an observation point of another wind condition observation system that is communicatively connected, and the wind conditions at the observation point are obtained from the other wind condition observation system.

6. A wind condition information system as claimed in claim 1, which stores a model expressing the correlation between the vibration strength of the optical fiber in the span and the wind conditions, and obtains the wind conditions in the span by inputting the vibration strength obtained for the span into the model.

7. A wind condition information providing system comprising an optical analysis unit and an information processing device, which obtains wind condition information indicating the current wind conditions in the span of a power transmission line based on the vibration intensity of the optical fiber obtained by Distributed Acoustic Sensing (DAS) at measurement points set along the optical fiber installed along the power transmission line, and which executes a step of detecting the presence or absence of a saturation state, which is a state in which the magnitude of the vibration intensity is equal to or greater than a predetermined threshold range and continues for a period of time equal to or greater than a predetermined threshold time.

8. A method for providing wind condition information as described in claim 7, wherein the wind condition information providing system further executes the steps of: acquiring the wind condition information based on a wind condition estimation component, which is a component in a predetermined frequency band among the vibration intensity; and detecting the presence or absence of the saturation state based on a saturation determination component, which is a component in a frequency band higher than the frequency band among the vibration intensity.

9. A method for providing wind condition information as described in claim 7, wherein the wind condition information providing system further executes the steps of: when it detects the saturated state, acquiring actual values ​​of the change in wind speed over time at other observation points that are not in the saturated state during the saturation period in which the saturated state occurs; estimating the wind speed during the saturation period of the span based on the correlation between the actual measured values ​​of the change in wind speed over time in the span and the actual values ​​of the change in wind speed over time at the observation points; and complementing the wind condition information during the saturation period of the span with the estimated wind speed.

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