Estimation program, estimation method, information processing device, and estimation system

Abstract

To accurately estimate sag of a power transmission line.SOLUTION: An information processing device according to one embodiment comprises a control unit which estimates sag of a power transmission line in a section between supports which support the power transmission line at an object point on the basis of wind velocity at the object point to be estimated on the basis of vibration of an optical fiber at the object point detected on the basis of light passing through the optical fiber disposed along the power transmission line, temperature at the object point, and calorific power by current flowing in the power transmission line at the object point.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to an estimation program, an estimation method, an information processing device, and an estimation system. [Background technology]

[0002] When current flows through a power line, the temperature rises and the line becomes more sagging. If there is an obstacle such as a forest under a sagging power line, contact between the power line and the obstacle can lead to a serious accident such as a fire. For this reason, a large safety margin is estimated, and the allowable current is calculated so that the temperature rating of the power line used in harsh natural conditions is not exceeded.

[0003] In this regard, a technique related to the temperature of a power transmission line is known (for example, Patent Document 1). Also, for example, a technique related to the temperature and sag of an overhead ground wire is known (for example, Patent Document 2 and Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-013038 A [Patent Document 2] Japanese Patent Application Publication No. 03-257381 [Patent Document 3] JP 2016-201267 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the proportion of renewable energy in Japan is increasing year by year. The existing power grid is designed to connect planned power plants with demand areas, and is not designed to transmit the electricity generated by decentralized renewable energy. Therefore, there are concerns about a shortage of transmission capacity due to the expansion of renewable energy. If the sag of transmission lines relative to the amount of electricity transmitted could be estimated with high accuracy, the safety margin of the amount of electricity transmitted could be reduced, making it possible to increase the amount of electricity transmitted. Therefore, there is a demand for technology that can estimate the sag of transmission lines with high accuracy.

[0006] In one aspect, the present invention aims to estimate the sag of a power transmission line with high accuracy. [Means for solving the problem]

[0007] An information processing device of one embodiment of the present invention includes a control unit that estimates the sag of a power line in a section between supports supporting the power line at a target point based on the wind speed at a target point estimated based on vibrations of an optical fiber at the target point detected based on light passing through an optical fiber deployed along the power line, the temperature at the target point, and the amount of heat generated by the current flowing through the power line at the target point. Effect of the Invention

[0008] The sag of the power line can be estimated with high accuracy. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 illustrates an estimation system according to an embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a block configuration of a server according to the embodiment. [Diagram 3] FIG. 13 is a diagram illustrating a graph showing a relationship between vibration and wind speed. [Figure 4] FIG. 11 is a diagram illustrating coefficient information according to the embodiment. [Diagram 5] FIG. 13 is a diagram illustrating a graph showing the relationship between heat transfer coefficient and wind speed. [Figure 6] FIG. 4 is a diagram illustrating power transmission line information according to the embodiment. [Figure 7] FIG. 13 is a diagram illustrating an example of the relationship between the distance between supports, the length of a power line, and the sag. [Figure 8] 11 is a diagram illustrating allowable slackness information according to an embodiment; [Figure 9] FIG. 13 is a diagram showing an exemplary determination result. [Figure 10] FIG. 11 is a diagram illustrating an example of an operational flow of a slackness estimation process according to the embodiment. [Figure 11] FIG. 2 is a diagram illustrating an example of a hardware configuration of a computer for implementing a server according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, several embodiments of the present invention will be described in detail with reference to the drawings. Note that the same reference numerals are used to designate corresponding elements in the various drawings.

[0011] As mentioned above, the allowable current is calculated with a large safety margin so as not to exceed the temperature rating of the wire used even under harsh natural conditions. However, in recent years, the proportion of renewable energy has increased, and there are concerns about a shortage of transmission capacity.

[0012] If it were possible to estimate the sag of a power transmission line with high accuracy, it would be possible to reduce the safety margin for the amount of power transmission and increase the amount of power transmission. Therefore, there is a need for a technology that can estimate the sag of a power transmission line with high accuracy.

[0013] In order to estimate the allowable current of a power transmission line more accurately, for example, it is possible to install sensors such as temperature sensors at each point of the power transmission line and measure the temperature of the power transmission line with the sensors. However, in order to comprehensively grasp the temperature of the power transmission lines in a wide area where the power transmission lines are installed, a very large number of sensors would be installed. In addition, since power transmission lines are installed in mountainous areas that are outside the service area of ​​the public line network, the sensors are required to have a wireless relay function in order to collect temperature information.

[0014] In addition, when measuring the temperature of power lines, the sensor must be directly attached to the high-voltage power line, and must be insulated from the outside. This makes it difficult to supply power from outside, and it is therefore desirable for the sensor to be equipped with a power generation system.

[0015] Furthermore, once the sensors are attached to power lines, they are difficult to remove until the operation of the power line is stopped. And because the sensors are used outdoors, they are required to be highly reliable and maintenance-free, even when exposed to wind and rain.

[0016] Therefore, it is very costly to install sensors at each point of the power transmission line to grasp the temperature of the power transmission line, and therefore it is difficult to collect the temperature of the power transmission line using sensors.

[0017] In the embodiment described below, the temperature of a local power transmission line is estimated from the temperature and vibration measured using an optical fiber such as an OPGW (optical fiber overhead ground wire) installed alongside the power transmission line, and the sag of the power transmission line is estimated based on the temperature. Note that the OPGW is, for example, an overhead ground wire with an optical fiber cable mounted inside. The overhead ground wire is installed, for example, mainly to protect high-voltage power transmission lines from lightning.

[0018] By using optical fiber installed alongside a power transmission line such as OPGW, for example, it becomes possible to monitor the temperature of the power transmission network without installing many sensors, and to estimate the sag of the power transmission line from the temperature. Therefore, the allowable current can be estimated more accurately. Furthermore, it becomes possible to improve the shortage of power transmission capacity. The embodiment will be described in more detail below.

[0019] FIG. 1 is a diagram illustrating an estimation system 100 according to an embodiment. The estimation system 100 includes, for example, a server 101 and a measurement device 102. The server 101 and the measurement device 102 may be connected via a network 105 such as a public line network and the Internet. The server 101 may be an information processing device having a calculation function such as a server computer, a personal computer (PC), or a mobile PC. The measurement device 102 may include a device such as a DTS and a DAS that are installed so as to be connected to an optical fiber passing through an OPGW or the like on a support 110 such as a steel tower supporting a power transmission line. Note that DTS is an abbreviation for Distributed Temperature Sensing system, and is, for example, a device that measures temperature based on light passing through an optical fiber. Also, DAS is an abbreviation for Distributed Acoustic Sensing system, and is, for example, a device that measures vibration based on light passing through an optical fiber.

[0020] The server 101 estimates the temperature of the power line at each point where the power line is installed based on the measurement values ​​collected from the measuring device 102, and estimates the sag of the power line based on the estimated temperature of the power line. In one example, the server 101 may control the amount of power transmitted through the power line based on the estimated sag.

[0021] 2 is a diagram illustrating a block configuration of the server 101 according to the embodiment. The server 101 includes, for example, a control unit 201, a storage unit 202, and a communication unit 203. The control unit 201 may control each unit of the server 101. The storage unit 202 of the server 101 stores information such as coefficient information 400, power transmission line information 600, and allowable sag information 800, which will be described later. The communication unit 203 communicates with the measurement device 102 according to, for example, an instruction from the control unit 201. Details of each of these units and details of the information stored in the storage unit 202 will be described later.

[0022] Hereinafter, estimation of the temperature of the power transmission line based on the measurement value measured by the measuring device 102 will be described.

[0023] The control unit 201 of the server 101 calculates, for example, the amount of heat Q generated by the current flowing through the power line at the target point for estimating the temperature. The amount of heat Q generated by the power line can be calculated, for example, from the current I and the electrical resistance R using the following formula 1. Q=I 2 ×R...Formula 1

[0024] Here, the current I is, for example, a current flowing through the power line and is a known value. The electrical resistance is, for example, a known value that can be estimated from the diameter and length of the power line. Therefore, the control unit 201 can obtain the heat value Q of the power line at the target point.

[0025] Next, the control unit 201 estimates, for example, the wind speed at the target point. The wind speed at the target point can be estimated, for example, from the vibration of an overhead ground wire installed together with the power transmission line. The vibration of the overhead ground wire can be estimated, for example, from the light passing through the optical fiber of the overhead ground wire.

[0026] For example, when a pulse of light is input into an optical fiber, the light propagates while being scattered at each part. There are several types of scattered light. For example, among the scattered light, Rayleigh scattered light depends on the non-uniformity of the optical fiber, and some of it becomes backward Rayleigh scattered light that returns to the input end. For example, by inputting a pulse of light into an optical fiber and calculating the distance from the time it takes for the backward Rayleigh scattered light to return, and also calculating the vibration from the phase, it is possible to calculate the vibration distribution along the optical fiber.

[0027] In one example, vibrations at a point of interest on an optical fiber passing through an overhead ground wire may be obtained using a measurement device 102 such as a DAS.

[0028] Next, the control unit 201 estimates the wind speed at the target point from the vibration of the optical fiber passing through the overhead ground wire at the target point.

[0029] For example, by measuring the vibration intensity using a DAS from an optical fiber passing through an installed overhead ground wire at a number of different wind speeds and plotting the relationship between the vibration intensity and the wind speed, a graph 300 showing the relationship between the vibration intensity and the wind speed can be obtained.

[0030] Fig. 3 is a diagram illustrating a graph 300 showing the relationship between vibration and wind speed. Fig. 3 shows data points indicating wind speeds at four points and the vibration strength of the overhead ground wire at those wind speeds. For example, a function 301 showing the relationship between vibration strength and wind speed can be obtained by fitting the data points with a function such as a straight line.

[0031] Then, the control unit 201 can obtain the wind speed at a target point by using a function 301 from vibrations at the target point of an optical fiber passing through an overhead ground wire obtained using a measuring device 102 such as a DAS.

[0032] Next, the control unit 201 obtains the heat transfer coefficient of the power line to the air corresponding to the wind speed from the obtained wind speed and design parameters such as the shape of the power line.

[0033] For example, the heat transfer coefficient h between a power line and the air can be expressed by the following Equation 2: h = Nu λ / d Equation 2

[0034] where Nu is the Nusselt number, λ is the thermal conductivity of the transmission line, and d is the diameter of the transmission line. The thermal conductivity of the transmission line, λ, and the diameter of the transmission line, d, are design parameters of the transmission line and are known values.

[0035] Moreover, the Nusselt number Nu is, for example, a value expressed by the following formula 3. Nu=C·Re m ·Pr 1 / 3 ...Formula 3

[0036] Here, Re is the Reynolds number, Pr is the Prandtl number, and C and m are coefficients. Note that the coefficients C and m may be values ​​determined according to the Reynolds number Re, for example, and may have the relationship shown in FIG. 4, for example.

[0037] Fig. 4 is a diagram illustrating coefficient information 400 showing the relationship between the Reynolds number Re and the coefficients C and m according to the embodiment. In the coefficient information 400 in Fig. 4, records are registered in which the range of the Reynolds number Re is associated with the values ​​of the coefficients C and m in that range. Therefore, the control unit 201 can determine the coefficients C and m from the Reynolds number Re by referring to the coefficient information 400.

[0038] Moreover, the Reynolds number may be expressed, for example, by the following Equation 4. Re = ρ v d / μ Equation 4

[0039] where ρ is the density of the fluid, v is the flow velocity of the fluid, and μ is the viscosity of the fluid.

[0040] Moreover, the Prandtl number may be expressed, for example, by the following Equation 5. Pr = μ Cp / λ Equation 5

[0041] Here, Cp is, for example, the specific heat of the fluid.

[0042] In the above, the fluid may be, for example, air, and the flow velocity v of the fluid may be the wind speed estimated from the vibration. The density ρ, viscosity μ, and specific heat Cp of the air are known values. Therefore, for example, the above formula can be used to obtain a relational expression that relates the heat transfer coefficient h between the power transmission line and the air to the wind speed.

[0043] 5 is a diagram illustrating a graph 500 showing the relationship between the heat transfer coefficient h and the wind speed. For example, as shown in FIG 5, the heat transfer coefficient h between the power transmission line and the air can be calculated from the wind speed according to the above formula.

[0044] Moreover, the temperature difference ΔT between the environmental temperature Ta and the temperature Tw of the power transmission line can be expressed, for example, by the following Equation 6. ΔT = Tw - Ta = Q / (h × A) Equation 6

[0045] By modifying equation 6, we can obtain equation 7, which calculates the transmission line temperature Tw. Tw = Q / (h × A) + Ta Equation 7

[0046] Here, Ta is the ambient temperature (K), Q is the amount of heat generated (W), and h is the heat transfer coefficient (W / m 2 K), the acquisition of which is described above. A is the heat dissipation area of ​​the transmission line (m 2 ) and is a known value that can be estimated from the shape of the installed transmission line, such as its diameter and length.

[0047] Next, the control unit 201 estimates, for example, the temperature at the target point. The temperature at the target point can be estimated, for example, from light of an optical fiber passing through an overhead ground wire or the like installed together with the power transmission line.

[0048] For example, among the scattered light, Raman scattered light depends on the temperature of the optical fiber, and a part of it becomes backward Raman scattered light that returns to the input end. Therefore, for example, by inputting pulsed light into the optical fiber and calculating the distance from the time it takes for the backward Raman scattered light to return, and also calculating the temperature from the intensity, it is possible to calculate the temperature distribution along the optical fiber.

[0049] In one example, the temperature at the target point may be obtained from light passing through the optical fiber of the overhead ground wire using a measurement device 102 such as a DTS. Since the overhead ground wire is installed along the power transmission line, the temperature at the target point estimated from the optical fiber of the overhead ground wire can be used as the environmental temperature Ta (K) for the power transmission line at the target point.

[0050] Then, the control unit 201 can calculate the temperature Tw of the power transmission line by substituting the temperature at the target point obtained above as the environmental temperature Ta in Equation 7.

[0051] In addition, the length l of the transmission line, which changes depending on the temperature of the transmission line, can be calculated using the following equation 8. l=l0{1+α(T-T0)}...Equation 8

[0052] Here, l is the length of the transmission line after the temperature change (m). l0 is the reference length of the transmission line before the temperature change (m). T is the temperature after the temperature change of the transmission line corresponding to the length of l (K). T0 is the reference temperature before the temperature change of the transmission line corresponding to the length of l0 (K). α is the linear expansion coefficient of the transmission line, a known value determined according to the material of the transmission line, etc.

[0053] For example, the section of the power transmission line for which the lengths of l and l0 are to be specified can be set to any length. For example, it is assumed that the supports 110 are installed at intervals of 200 m. Then, for example, it is assumed that the installation interval of 200 m is divided into 20, and the length of the power transmission line is estimated at intervals of 10 m. In this case, the section of the power transmission line between two supports 110 is divided into 20, and the length of l0 and the temperature T0 at that time in each divided section are obtained in advance by measurement or the like and stored in the storage unit 202. For example, the length of l0 and the temperature T0 at that time may be obtained when the power transmission line is installed.

[0054] FIG. 6 is a diagram illustrating the power line information 600 according to the embodiment. In the power line information 600, for example, a record that associates a section, a length of l0, and a temperature of T0 is registered. The section of the power line information 600 is, for example, information indicating a section of the power line. For example, as described above, when dividing the section of the power line between two supports 110 into 20 and acquiring the length of l0 in the divided section, identification information such as a point number that identifies the points at both ends of the divided section may be registered in the section of the power line information 600. In addition, the length of l0 in the power line information 600 is the length of the power line in the section of the record. The temperature of T0 in the power line information 600 is the temperature of the power line when the length l0 of the power line in the section of the record is acquired.

[0055] The control unit 201 can obtain the changed temperature T of the power line and the length l of the power line in the corresponding divided section, for example, by using the above-mentioned formula 8 based on the information of the power line information 600.

[0056] Next, the control unit 201 obtains, for example, the length L of the power transmission line between the two supports 110 for which sag is desired, by adding up the lengths l of the divided sections included between the two supports 110. Note that by obtaining the length L of the power transmission line in the target section for which sag is desired in this manner by adding up the lengths of the power transmission line in the multiple divided sections, the length of the power transmission line that changes depending on the temperature can be more accurately estimated.

[0057] The relationship between the length L of the transmission line in the section between the two supports 110 that support the transmission line and the sag D can be expressed by, for example, the following Equation 9. L=S+8D 2 / 3S...Formula 9

[0058] Equation 10 can be obtained by converting the left side of equation 9 into slack D.

number

[0059] where L is the length of the transmission line (m), S is the distance between supports 110 (m), and D is the sag (m).

[0060] 7 is a diagram illustrating an example of the relationship between the distance S between the supports 110 supporting the power line of which sag is to be estimated, the length L of the power line, and the sag D. The control unit 201 can estimate the sag D of the power line supported by the two supports 110 at a changed temperature (e.g., the current temperature) using, for example, Equation 10.

[0061] For example, by acquiring information on the height of the supports 110 and the height of obstacles such as forests growing between the supports 110 in advance and storing it in the memory unit 202, it becomes possible to determine whether the power line will come into contact with an obstacle such as a forest based on the estimated sag D of the power line.

[0062] FIG. 8 is a diagram illustrating the allowable sag information 800 according to the embodiment. In the example of FIG. 8, the allowable sag information 800 has, for example, the height (m) of the support 110, the height (m) of the obstacle, and the allowable value (m) of the sag registered for each section. For example, identification information for identifying a section of the power line supported by two supports 110 is registered in the section. In the example of FIG. 8, a point number indicating the installation point of the two supports 110 is registered. In addition, for example, information indicating the height of the support 110 in the allowable sag information 800 may be registered that indicates the height of the two supports 110 that support the power line in the section of the record. For example, information indicating the height of an obstacle such as a forest growing in the section of the record may be registered in the allowable sag information 800, and in one example, the maximum height of the forest growing in the section may be registered. For example, a sag tolerance estimated from the height of the support 110 of the record and the height of an obstacle such as a forest may be registered as the sag tolerance of the allowable sag information 800. In one example, a length obtained by subtracting a predetermined value (for example, 3 m to 10 m, such as 5 m in one example) as a margin from the difference between the height of the support 110 of the record and the height of the obstacle may be registered as the sag tolerance of the allowable sag information 800.

[0063] Then, the control unit 201 may determine whether the sag of the power transmission line is dangerous or not, for example, depending on whether the sag estimated for the section exceeds the allowable sag value of the allowable sag information 800.

[0064] FIG. 9 is a diagram showing an exemplary determination result 900. The determination result 900 shows a determination result for a section of the allowable sag information 800. In the example of FIG. 9, in the section: 0021-0040, the estimated sag D is 23 m, which is shorter than the allowable sag value of 25 m, so the sag is within the allowable range. In this case, the control unit 201 may determine that there is no risk. In this case, the control unit 201 may not execute control such as reducing the current flowing through the power transmission line. In one example, the control unit 201 may execute control of the amount of power transmission such as increasing the current flowing through the power transmission line. On the other hand, in the section: 0041-0060, the estimated sag is 28 m, which exceeds the allowable sag value of 25 m. In this case, the control unit 201 may determine that the risk is an alert. In this case, the control unit 201 may control the amount of power transmission, for example, by reducing the current flowing through the power transmission line in the target section: 0021-0040.

[0065] Thereby, the control unit 201 can determine with high accuracy whether the amount of power transmission of the power transmission line is within the allowable range. Even if the safety margin of the amount of power transmission is small, the sag can be estimated with high accuracy, so that power can be transmitted safely. Furthermore, for example, the control unit 201 may execute control such as increasing the amount of power transmission when there is a margin of sag. Therefore, according to the embodiment, it is possible to improve the shortage of power transmission capacity. On the other hand, when the sag of the power transmission line exceeds the allowable sag and there is an increased risk of contacting an obstacle such as a forest, the control unit 201 can notify that the sag has become dangerously long by notifying a warning (alert) to a terminal of the manager of the power transmission line. Furthermore, in one example, when the sag of the power transmission line exceeds the allowable sag, the control unit 201 may control the amount of power transmission to be reduced by reducing the current, for example. This can suppress the occurrence of accidents such as forest fires.

[0066] Next, an operation flow of the slackness estimation process according to the embodiment will be described. Fig. 10 is a diagram illustrating an example of an operation flow of the slackness estimation process according to the embodiment. The control unit 201 of the server 101 may start the operation flow of Fig. 10 when an instruction to execute the slackness estimation process is input, for example.

[0067] In S1001, the control unit 201 of the server 101 acquires information on vibration in a target section for sag estimation. For example, the control unit 201 may instruct the measuring device 102 installed at a position where the vibration in the target section can be measured, and collect vibration information from the measuring device 102. In one example, the measuring device 102 may include a DAS, and upon receiving an instruction from the server 101, calculates a distance from backward Rayleigh scattering light of light passing through an optical fiber included in an overhead ground wire, and calculates vibration from the phase to calculate a vibration distribution along the optical fiber. Then, the measuring device 102 may transmit the obtained vibration distribution to the server 101. The control unit 201 of the server 101 may acquire information on the vibration of the optical fiber in the target section from the vibration distribution received from the measuring device 102.

[0068] In S1002, the control unit 201 estimates the wind speed at a target point of the wind speed estimation from information on the vibration of the optical fiber in the target section. In one example, the control unit 201 may obtain the wind speed corresponding to the vibration at the target point based on the function 301 showing the relationship between the vibration and the wind speed in FIG.

[0069] In S1003, the control unit 201 estimates the heat transfer coefficient of the target point from the wind speed at the target point. For example, the control unit 201 may obtain the heat transfer coefficient of the target point based on the above-mentioned formula 2.

[0070] In S1004, the control unit 201 acquires information on the temperature at the target point. For example, the control unit 201 may instruct the measuring device 102 installed at a position where the temperature at the target point can be measured, and collect temperature information from the measuring device 102. In one example, the measuring device 102 may include a DTS, and upon receiving an instruction from the server 101, calculates a distance from backward Raman scattered light of light passing through an optical fiber included in an overhead ground wire, and calculates a temperature distribution along the optical fiber by calculating a temperature from the intensity. Then, the measuring device 102 may transmit the obtained temperature distribution to the server 101. The control unit 201 of the server 101 may acquire information on the temperature of the optical fiber at the target point from the temperature distribution received from the measuring device 102. Note that, in another embodiment, the control unit 201 may collect temperature information from the measuring device 102 together with vibration information in the process of S1001.

[0071] In S1005, the control unit 201 acquires the heat generation amount of the power line at the target point. For example, the control unit 201 may calculate the heat generation amount Q from the current flowing through the power line at the target point and the resistance of the power line by the following formula 1. Q=I 2 ×R...Formula 1

[0072] In S1006, the control unit 201 acquires the temperature of the power transmission line based on the heat transfer coefficient obtained in S1003, the temperature obtained in S1004, and the heat generation amount of the power transmission line obtained in S1005. For example, the control unit 201 may obtain the temperature Tw of the power transmission line at the target point by the above-mentioned Equation 7. Tw = Q / (h × A) + Ta Equation 7

[0073] In S1007, the control unit 201 estimates the length of the power line between the two supports 110 for which sag is to be estimated. For example, the control unit 201 may obtain the length l of the power line of the divided section by the above formula 8 based on the temperature Tw of the power line. Then, the control unit 201 may estimate the length L of the power line supported by the supports 110 by adding up the lengths l of the power line of the divided section between the two supports 110 for which sag is to be estimated. Note that the two supports may be, for example, two supports in front and behind the power line that is installed so as to sandwich the power line for which sag is to be estimated. The two supports 110 may be, for example, adjacent supports 110 among a plurality of supports installed consecutively along the power line.

[0074] In S1008, the control unit 201 acquires the sag of the power line between the two supports 110 of which the sag is to be estimated. For example, the control unit 201 may estimate the sag D from the length L of the power line between the two supports 110 by using Equation 10.

[0075] In S1009, the control unit 201 determines whether the sag is dangerous. For example, the control unit 201 may obtain an allowable value of sag corresponding to the section of the power line in which the sag is estimated from the allowable sag information 800, and determine whether the sag is within the allowable value. If the sag is within the allowable value, the control unit 201 may determine that the sag is not dangerous (NO in S1009), and this operation flow ends. On the other hand, if the sag exceeds the allowable value, the control unit 201 may determine that the sag is dangerous (YES in S1009), and the flow proceeds to S1010.

[0076] In S1010, the control unit 201 executes control for the estimated sag section between the two supports 110 determined to be dangerous, and this operation flow ends. In one example, the control unit 201 may notify a terminal used by a power line manager or the like of information such as a warning (alert) indicating that the sag in the estimated sag section is a dangerous length. In another example, the control unit 201 may notify a terminal managing the power line in the target section of an instruction to perform control to reduce the amount of power transmission by, for example, reducing the current flowing through the power line in the target section. In this case, the terminal managing the power line in the target section may execute control to reduce the current flowing through the power line in the target section.

[0077] In the operation flow of FIG. 10, an example is described in which the operation flow ends when it is determined that the sag is not dangerous (S1009 is NO), but the embodiment is not limited to this. For example, in another embodiment, the control unit 201 may notify the terminal managing the transmission line of the target section of an instruction to control the transmission line of the target section to increase the amount of power transmission by increasing the current flowing through the transmission line of the target section, etc., when it is determined that the sag is not dangerous (S1009 is NO). In this case, the terminal managing the transmission line of the target section may execute control to increase the amount of power transmission through the transmission line of the target section. Furthermore, in yet another embodiment, the control unit 201 may notify the terminal managing the transmission line of the target section of information indicating the current sag margin with respect to the allowable value of sag, when it is determined that the sag is not dangerous (S1009 is NO). This makes it possible, for example, for a user of the terminal managing the transmission line to estimate how much margin there is in the transmission capacity of the transmission line.

[0078] According to the above operation flow of FIG. 10, the sag of the power transmission line can be estimated with high accuracy. As a result, for example, it can be determined with high accuracy whether the amount of power transmission of the power transmission line is within an allowable range. Furthermore, for example, when there is a margin in the sag, the control unit 201 can also notify information indicating the degree of margin in the sag or execute control such as increasing the amount of power transmission. Therefore, it is possible to improve the shortage of power transmission capacity. On the other hand, for example, when the sag of the power transmission line exceeds the allowable sag and there is an increased risk of contacting an obstacle such as a forest, information such as a warning (alert) is notified to the terminal of the manager of the power transmission line. Furthermore, in one example, when the sag of the power transmission line exceeds the allowable sag, the control unit 201 may control the amount of power transmission to be reduced. This can suppress the occurrence of accidents such as forest fires.

[0079] In the above-described embodiment, the temperature and wind speed information is acquired using an optical fiber passing through an overhead ground wire. Therefore, for example, temperature and wind speed information along a wide range of power lines, from several meters to several kilometers, can be acquired with high accuracy using a measuring device 102 such as a DAS and a DTS. This eliminates the need to install sensors such as a temperature sensor and a wind speed sensor at each point where the temperature and wind speed are to be acquired, thereby reducing costs and improving the accuracy of estimating the sag.

[0080] In the above embodiment, the temperature and wind speed information of the target location is obtained using optical fibers, but the embodiment is not limited thereto. For example, in another embodiment, at least one of the temperature and wind speed of the target location may be obtained from other data such as a weather forecast.

[0081] In addition, in the above-mentioned embodiment, some mathematical expressions are exemplified, but the embodiment is not limited thereto. For example, the above-mentioned Equation 7 for estimating the temperature of the power transmission line and Equation 8 for estimating the sag may further include other parameters such as the material of the power transmission line and further parameters such as meteorological data to improve accuracy.

[0082] Although the embodiment has been exemplified above, the embodiment is not limited thereto. For example, the above-mentioned operation flow is an example, and the embodiment is not limited thereto. If possible, the operation flow may be executed by changing the order of the processes, may include additional processes, or may omit some processes. For example, when the embodiment is used to estimate slackness, the processes of S1009 and S1010 in FIG. 10 may not be executed.

[0083] Fig. 11 is a diagram illustrating a hardware configuration of a computer 1100 for realizing a server 101 according to an embodiment. The hardware configuration for realizing the server 101 in Fig. 11 includes, for example, a processor 1101, a memory 1102, a storage device 1103, a reader 1104, a communication interface 1106, and an input / output interface 1107. The processor 1101, the memory 1102, the storage device 1103, the reader 1104, the communication interface 1106, and the input / output interface 1107 are connected to each other via, for example, a bus 1108.

[0084] The processor 1101 may be, for example, a single processor, a multi-processor, or a multi-core processor. The processor 1101 provides some or all of the functions of the control unit 201 described above by using the memory 1102 to execute a program in which the procedures of the above-mentioned operation flow are described.

[0085] The memory 1102 is, for example, a semiconductor memory, and may include a RAM area and a ROM area. The storage device 1103 is, for example, a semiconductor memory such as a hard disk or a flash memory, or an external storage device. Note that RAM is an abbreviation for Random Access Memory. Also, ROM is an abbreviation for Read Only Memory.

[0086] The reader 1104 accesses the removable storage medium 1105 according to an instruction from the processor 1101. The removable storage medium 1105 is realized by, for example, a semiconductor device, a medium in which information is input and output by magnetic action, or a medium in which information is input and output by optical action. The semiconductor device is, for example, a Universal Serial Bus (USB) memory. The medium in which information is input and output by magnetic action is, for example, a magnetic disk. The medium in which information is input and output by optical action is, for example, a CD-ROM, DVD, Blu-ray Disc, etc. (Blu-ray is a registered trademark). CD is an abbreviation for Compact Disc. DVD is an abbreviation for Digital Versatile Disk.

[0087] The storage unit 202 includes, for example, a memory 1102, a storage device 1103, and a removable storage medium 1105. For example, the storage device 1103 of the server 101 stores information such as the coefficient information 400, the power transmission line information 600, and the allowable sag information 800.

[0088] The communication interface 1106 communicates with other devices according to instructions from the processor 1101. For example, the server 101 may communicate with the measuring device 102 via the communication interface 1106. The communication interface 1106 is an example of the communication unit 203 described above.

[0089] The input / output interface 1107 may be, for example, an interface between an input device and an output device. The input device is, for example, a device such as a keyboard, a mouse, or a touch panel that receives instructions from a user. The output device is, for example, a display device such as a display, and an audio device such as a speaker.

[0090] Each program according to the embodiment is provided to the server 101 in the following form, for example. (1) It is pre-installed in the storage device 1103. (2) Provided by a removable storage medium 1105. (3) Provided from a server such as a program server.

[0091] Note that the hardware configuration of the computer 1100 for realizing the server 101 described with reference to FIG. 11 is an example, and the embodiment is not limited thereto. For example, a part of the above-mentioned configuration may be deleted, or a new configuration may be added. Also, in another embodiment, for example, a part or all of the functions of the above-mentioned control unit 201 may be implemented as hardware using FPGA, SoC, ASIC, PLD, or the like. Note that FPGA is an abbreviation for Field Programmable Gate Array. SoC is an abbreviation for System-on-a-chip. ASIC is an abbreviation for Application Specific Integrated Circuit. PLD is an abbreviation for Programmable Logic Device.

[0092] In the above, several embodiments are described. However, the embodiments are not limited to the above embodiments, and should be understood as including various modified and alternative forms of the above-mentioned embodiments. For example, it will be understood that the various embodiments can be embodied by modifying the components without departing from the spirit and scope of the embodiments. It will also be understood that various embodiments can be implemented by appropriately combining multiple components disclosed in the above-mentioned embodiments. Furthermore, it will be understood by those skilled in the art that various embodiments can be implemented by deleting some components from all the components shown in the embodiments, or by adding some components to the components shown in the embodiments. [Explanation of symbols]

[0093] 100 Systems 101 Server 102 Measuring Equipment 105 Network 110 Supports 201 Control section 202 Storage section 203 Communications Department 1100 Computer 1101 Processor 1102 Memory 1103 Storage device 1104 Reading device 1105 Removable storage media 1106 Communication Interface 1107 Input / Output Interface 1108 Bus

Claims

1. estimating a sag of the power line in a section between supports supporting the power line at the target point based on a wind speed at the target point estimated based on vibrations of an optical fiber at the target point detected based on light passing through an optical fiber installed along the power line, a temperature at the target point, and a heat generation amount due to a current flowing through the power line at the target point; determining whether the sag of the power transmission line is within the allowable value based on a comparison between the sag and an allowable value set based on the height of the support supporting the power transmission line at the target point and the height of an obstacle in the section between the supports; If the determination result indicates that the sag of the power transmission line is within a tolerance, the amount of power transmitted from the power transmission line at the target point is controlled to be larger. An estimation program that causes a computer to execute the processing.

2. The estimation program according to claim 1 , wherein the temperature at the target point is a temperature detected based on light passing through the optical fiber.

3. estimating a sag of the power line in a section between supports supporting the power line at the target point based on a wind speed at the target point estimated based on vibrations of an optical fiber at the target point detected based on light passing through an optical fiber installed along the power line, a temperature at the target point, and a heat generation amount due to a current flowing through the power line at the target point; determining whether the sag of the power transmission line is within the allowable value based on a comparison between the sag and an allowable value set based on the height of the support supporting the power transmission line at the target point and the height of an obstacle in the section between the supports; If the determination result indicates that the sag of the power transmission line is within a tolerance, the amount of power transmitted from the power transmission line at the target point is controlled to be larger.

4. A computer implemented estimation method comprising:

4. a control unit that estimates a sag of the power transmission line in a section between supports supporting the power transmission line at the target point based on a wind speed at the target point estimated based on vibrations of an optical fiber at the target point detected based on light passing through an optical fiber installed along the power transmission line, a temperature at the target point, and a heat generation amount due to a current flowing through the power transmission line at the target point, and determines whether the sag of the power transmission line is within the allowable value based on a comparison between the sag and a tolerance set based on a height of the support supporting the power transmission line at the target point and a height of an obstacle in the section between the supports, and controls the amount of power transmission of the power transmission line at the target point to be larger when the sag of the power transmission line is within the allowable value as a result of the determination; An information processing device comprising:

5. a measuring device that acquires information on vibration of an optical fiber based on light passing through the optical fiber installed along the power transmission line; an information processing device that estimates a sag of the power transmission line in a section between supports supporting the power transmission line at the target point based on a wind speed at the target point estimated based on vibration of the optical fiber at the target point based on information on the vibration, a temperature at the target point, and a heat generation amount due to a current flowing through the power transmission line at the target point, determines whether the sag of the power transmission line is within the allowable value based on a comparison between the sag and an allowable value set based on a height of the support supporting the power transmission line at the target point and a height of an obstacle in the section between the supports, and controls the amount of power transmission of the power transmission line at the target point to be larger when the sag of the power transmission line is within the allowable value as a result of the determination; An estimation system comprising:

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