JP2001183248A - Transmission line load sensor devcie and its installing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly detect the fluctuation of the load of a transmission line by eliminating the harmful effect of the fluctuation of an environmental temperature. SOLUTION: One of connecting parts 4a, 4b is formed as a suspending part for suspending a transmission line, and the other is formed as a fixed part, and a main shaft 3 is expanded and contracted in accompany with the fluctuation of the load of the transmission line. A grating part 5 is fixed to a main shaft 3 for detecting the distortion. A temperature compensation shaft 14 made of a material same as that of the main shaft 3 is mounted on a flange 13 in a configuration of a cantilever beam in adjacent and approximately in parallel to the main shaft 3. A temperature compensation grating part 15 is fixed to the temperature compensation shaft 14. A heat insulating layer 17 and a reflecting layer 18 are formed on a surface of a housing 2 for inhibiting the fluctuation of a temperature inside of the housing 2. The harmful effect of the fluctuation of a center wavelength caused by the fluctuation of the environmental temperature in the reflected returned light of a distortion detecting grating part 5 can be eliminated by utilizing the fluctuation of the center wavelength of the reflected returned light of the temperature compensation grating part 15 caused only by the fluctuation of the environmental temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission line load sensor device for monitoring load fluctuation of a transmission line and a method of installing the same.

[0002]

2. Description of the Related Art As is well known, when snow accumulates on power transmission lines,
Due to the weight of the accumulated snow, a serious situation such as a break of a transmission line may occur. Therefore, a transmission line load monitoring system for monitoring the load of the transmission line to prevent the above-mentioned situation from occurring has been constructed. The present applicant is conducting research and development of a transmission line load sensor device (optical load cell) using an optical fiber for use in the transmission line load monitoring system.

FIG. 4 (a) schematically shows an example of a transmission line load sensor device in a state where a part of the inside of a housing is visible, and FIG. 4 (b) shows an example of installation of the transmission line load sensor device. Is schematically shown. As shown in FIG. 4A, the main shaft 3 is provided inside the housing 2 of the transmission line load sensor device 1.
In addition, connecting portions 4 (4a, 4a) connected to both ends of the main shaft 3 are provided on the surface of the housing 2 respectively.
b) is formed to project.

The main shaft 3 is provided with a strain detecting grating portion 5 composed of an FBG (Fiber Bragg Grating), which is a kind of optical fiber, so that the traveling direction of light and the longitudinal direction of the main shaft 3 substantially coincide with each other. The strain detecting grating portion 5 is mounted so as to expand and contract with the expansion and contraction of the main shaft 3 (that is, the center wavelength of the reflected return light varies with the expansion and contraction of the main shaft 3). Optical fibers 6 for light propagation are respectively coupled to both ends of the strain detecting grating portion 5, and the optical fibers 6 are connected from the inside of the housing 2 to the outside through a connector (not shown) of the housing 2. Have been withdrawn.

[0005] Transmission line load sensor device 1 shown in FIG.
Is constructed as described above, and is mounted between the tower 7 and the transmission line 8 as shown in FIG. That is,
One of the connection portions 4a and 4b of the transmission line load sensor device 1 is fixed to the steel tower 7 via an insulator (not shown),
The other functions as a suspending unit, and the transmission line 8 is suspended.

The optical fiber 6 is routed between the towers 7 as an overhead ground wire (OPGW), and the strain detecting grating portions 5 of the plurality of transmission line load sensor devices 1 attached to the tower 7 are connected in series. As described above, the optical fiber 6 is provided with the strain detecting grating portion 5 of each transmission line load sensor device 1. A light source 10 and a measuring device 1 are connected to one end of the optical fiber 6 via a duplexer (not shown).
1 is connected.

[0007] When light having a broadband wavelength is output from the light source 10, the transmission line load sensor device 1 receives the light.
The grating section 5 for distortion detection reflects the reflected return light toward the measuring instrument 11. As described above, the reflected return lights of the plurality of strain detecting grating units 5 connected in series have different center wavelengths from each other for easy identification.

In the above transmission line load sensor device 1, the main shaft 3 is connected via the connecting portion 4 which functions as a hanging portion.
When the load of the power transmission line 8 is applied to the main shaft 3, a tension corresponding to the load of the power transmission line 8 is applied to the main shaft 3 to expand and deform. The amount of elongation deformation of the main shaft 3 fluctuates according to the load of the transmission line 8. That is, when the load of the transmission line 8 changes, the main shaft 3 expands and contracts with the change. Since the strain detecting grating portion 5 also expands and contracts with the expansion and contraction of the main shaft 3, the center wavelength of the reflected return light of the strain detecting grating portion 5 also changes with the load change of the transmission line 8. Since the relationship between the load variation of the transmission line 8 and the center wavelength variation of the reflected return light of the strain detecting grating unit 5 is previously determined, the reflection return of the strain detecting grating unit 5 detected by the measuring instrument 11 is obtained. Based on the center wavelength variation of light, the transmission line 8
Can be detected.

[0009]

However, since the main shaft 3 changes in expansion and contraction not only due to a change in the load of the transmission line 8 but also to a change in the surrounding environmental temperature,
The center wavelength of the reflected return light of the strain detecting grating unit 5 will fluctuate due not only to the load fluctuation of the transmission line 8 but also to the environmental temperature fluctuation.

Since the transmission line load sensor device 1 is installed outdoors and is exposed to direct sunlight, the environmental temperature of the main shaft 3 inside the housing 2 fluctuates greatly, and the environmental temperature fluctuation due to the reflected return light of the strain detecting grating unit 5. Therefore, there is a serious problem that the fluctuation of the load on the transmission line 8 cannot be accurately detected due to the fluctuation of the environmental temperature.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a transmission system capable of accurately detecting a load variation of a transmission line without being adversely affected by an environmental temperature variation. An object of the present invention is to provide an electric wire load sensor device and an installation method thereof.

[0012]

Means for Solving the Problems In order to achieve the above object, the present invention has the following structure to solve the above problems. That is, in the transmission line load sensor device according to the first aspect of the present invention, a suspending portion for suspending the transmission line is provided on a surface portion of the housing, and a change in the load of the transmission line suspended by the hanging portion is provided inside the housing. A main shaft that expands and contracts in accordance with the above, and a strain detecting grating portion of an optical fiber that is attached to the main shaft and that changes the center wavelength of the reflected return light with the expansion and contraction of the main shaft. A transmission line load sensor device for detecting a change in a load from a transmission line by using a change in a center wavelength of reflected return light of a grating portion, wherein the housing has a structure in accordance with an environmental temperature change around the main shaft. A temperature compensating shaft that expands and contracts is provided in a form in which a load from the transmission line is not applied, and the temperature compensating shaft is provided with a temperature compensating grating portion of an optical fiber. The center wavelength of the reflected return light is mounted so as to fluctuate in accordance with the expansion and contraction of the temperature compensation shaft. The above-mentioned problem is solved by a configuration for removing the adverse effect of the center wavelength fluctuation caused by the environmental temperature fluctuation in the reflected return light.

According to a second aspect of the present invention, there is provided a transmission line load sensor device having the configuration of the first aspect, wherein the temperature compensating shaft is formed of the same material as the main shaft, and the temperature compensating shaft is formed of the main shaft. , And are provided in the form of a cantilever.

According to a third aspect of the present invention, there is provided a transmission line load sensor device having the configuration of the first or second aspect, wherein the strain detecting grating section and the temperature compensating grating section are connected in series, and the strain detecting grating section is provided. And the reflected return light of the temperature compensating grating section propagates in the same optical fiber, and the center wavelength of the reflected return light of the temperature compensating grating section is the same as that of the strain detecting grating section. This is characterized in that it is different from the center wavelength of the reflected return light.

According to a fourth aspect of the present invention, there is provided a transmission line load sensor device having the configuration of the first, second, or third aspect, wherein a heat insulating layer and a reflective layer are laminated on the surface of the housing. It is configured as a feature.

According to a fifth aspect of the present invention, there is provided a transmission line load sensor device having the configuration of any one of the first to fourth aspects of the invention.
The transmission line load sensor device is characterized in that a mark indicating an installation direction of the device is formed on an outer surface of the transmission line load sensor device.

According to a sixth aspect of the present invention, there is provided a transmission line load sensor device having the configuration of the fifth aspect, wherein the main shaft and the temperature compensating shaft in the housing are provided so as to be biased at a position closer to the north side in the mounting direction of the device. It is characterized by having.

According to a seventh aspect of the present invention, there is provided the transmission line load sensor device according to the fifth aspect of the present invention, wherein the main shaft and the temperature compensating shaft are marked so that the main shaft and the temperature compensation shaft are unevenly distributed toward the north side in the shaded housing. The transmission line load sensor device is installed by determining the installation direction of the sensor device.

In the invention having the above structure, the center wavelength variation of the reflected return light of the strain detecting grating portion is affected not only by the load variation of the transmission line but also by the environmental temperature variation.
By using the central wavelength variation of the reflected return light of the temperature compensation grating unit, that is, the central wavelength variation according to only the environmental temperature variation, the environmental temperature variation can be calculated from the central wavelength variation of the reflected return light of the strain detection grating unit. It is possible to remove the center wavelength fluctuation component caused by the above, and to obtain the center wavelength fluctuation component corresponding only to the load fluctuation of the transmission line. Thereby, it becomes possible to accurately detect the load fluctuation of the transmission line.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same reference numerals are given to the same components as those in the configuration shown in FIG. 4, and the description will be omitted or simplified.

FIG. 1 is a sectional view showing an embodiment of a transmission line load sensor device according to the present invention. What is characteristic in this embodiment is that a unique means is provided for temperature-compensating the central wavelength variation of the reflected return light of the grating 5 for strain detection.

That is, in FIG.
A connecting portion 4a is formed at a central portion of the bottom wall 2a so as to protrude toward the outside along the central axis of the housing 2. A through hole 2c is formed at the center of the top wall 2b of the housing 2, and a connection portion 4b is inserted into the through hole 2c from the inside of the housing 2 to the outside. A flange 13 is formed so as to protrude from a portion located inside the housing 2.

A main shaft 3 is disposed inside the housing 2 along the central axis of the housing 2, and one end of the main shaft 3 is connected to a bottom wall 2 a of the housing 2, The side is connected to the flange 13 of the connection portion 4b. At the center of the main shaft 3, a strain detecting grating portion 5 is attached so that the center wavelength of the reflected return light fluctuates as the main shaft 3 expands and contracts as in the conventional case.

A temperature-compensating shaft 14 characteristic of this embodiment is attached to the flange 13 in the form of a cantilever. This shaft for temperature compensation 14
Are made of the same material as the main shaft 3 and are disposed substantially parallel to and adjacent to the main shaft 3. In other words, the temperature compensating shaft 14 is placed under substantially the same temperature environment as the main shaft 3, and when the main shaft 3 expands and contracts due to a change in the environmental temperature, the amount of expansion and contraction of the main shaft 3 is substantially the same. It expands and contracts by the same amount of expansion and contraction fluctuation.

The temperature compensating shaft 14 is provided with a temperature compensating grating section 15 of an optical fiber so that the center wavelength of the reflected return light varies with expansion and contraction of the temperature compensating shaft 14 and the strain detecting grating. It is fixed so as to be adjacent to the part 5.

In this embodiment, the strain detecting grating section 5 and the temperature compensating grating section 15 are connected in series by an optical fiber 6, as shown in FIGS. Each reflected return light of the section 5 and the temperature compensation grating section 15 is configured to be propagated to the measuring instrument 11 via the same optical fiber 6.

As described above, in this embodiment, since the reflected return lights of the strain detecting grating section 5 and the temperature compensating grating section 15 propagate through the same optical fiber 6, the strain detecting grating in the measuring instrument 11 is used. In order to obtain the reflected return light of the temperature compensation grating unit 15 and the reflection return light of the temperature compensation grating unit 15 separately, the center wavelength of the reflection return light of the temperature compensation grating unit 15 is the reflection return light of the strain detection grating unit 5. Is different from the center wavelength of the light.

Transmission line load sensor device 1 of this embodiment
Is configured as described above, and one of the connecting portions 4a and 4b is fixed to the steel tower 7, and the other side functions as a suspending portion, and the transmission line 8 is suspended, as in the conventional example. Thus, the transmission line load sensor device 1 is installed using the connection portion 4. In the installed state, as described above, the main shaft 3 expands and contracts in accordance with the load fluctuation of the transmission line 8, whereby the central wavelength of the reflected return light of the strain detecting grating unit 5 is reduced. 8 changes according to the load change.

Also in this embodiment, as in the above-mentioned conventional example, the main shaft 3 expands and contracts due to not only the load fluctuation of the transmission line 8 but also the environmental temperature fluctuation. The center wavelength of the reflected return light of the grating unit 5 fluctuates due to load fluctuation of the transmission line 8 and environmental temperature fluctuation. However, in this embodiment, since the temperature compensation shaft 14 and the temperature compensation grating section 15 described above are provided, it is possible to perform temperature compensation for the center wavelength fluctuation of the reflected return light of the strain detection grating section 5. it can.

That is, since the temperature compensating shaft 14 is provided in such a form that the load of the transmission line 8 is not applied, the temperature compensating shaft 14 does not expand and contract due to the fluctuation of the load of the transmission line 8, but only the environmental temperature fluctuation. It expands and contracts according to. Further, since the temperature compensating shaft 14 is placed under substantially the same temperature environment as the main shaft 3, the amount of expansion and contraction fluctuation of the temperature compensating shaft 14 depends on the expansion and contraction fluctuation of the main shaft 3 due to the environmental temperature fluctuation. Same as quantity.

From this, the temperature compensation shaft 1
The fluctuation amount of the center wavelength of the reflected return light from the temperature compensation grating unit 15 fixed to 4 is the fluctuation amount of the center wavelength fluctuation amount of the reflected return light of the strain detection grating unit 5 due to the environmental temperature fluctuation. It is almost equal to the minute. Thus, the temperature compensating grating unit 1 can be determined based on the center wavelength fluctuation amount of the reflected return light of the distortion detecting grating unit 5.
By subtracting the amount of change in the center wavelength of the reflected return light 5, it is possible to remove the adverse effect of the change in the center wavelength due to the environmental temperature change in the reflected return light of the strain detection grating 5. Temperature compensation of the center wavelength fluctuation of the reflected return light is performed.

As described above, the temperature compensation is performed, so that the load fluctuation of the transmission line 8 can be accurately detected without being affected by the environmental temperature fluctuation.

In this embodiment, in order to detect the load fluctuation of the transmission line 8 with higher accuracy, means for suppressing the temperature fluctuation inside the housing 2 is provided. That is, as shown in FIG. 1, a heat insulating layer 17 and a reflective layer 18 are sequentially laminated on the surface of the housing 2. Reflective layer 18
Is a material that easily reflects sunlight, for example, a metal plate member such as aluminum or stainless steel, a metal plate plated on the outer surface of a plastic plate, or a metal tape attached to the outer surface of a plastic plate as well. It is composed of a material or a material coated with a paint containing metal powder. The heat insulation layer 1
Reference numeral 7 denotes a member that insulates the inside and the outside of the housing 2 from each other. For example, the housing 7 is formed by filling a heat insulating material such as glass fiber or foamed resin between the housing 2 and a metal plate member that is the reflective layer 18. I have.

FIG. 3 shows experimental results of the effect of suppressing temperature fluctuation in the housing 2 when the heat insulating layer 17 and the reflective layer 18 are provided. That is, the chain line A shown in FIG.
When the heat insulation layer 17 and the reflection layer 18 are provided, how the temperature inside the housing 2 changes with respect to a predetermined reference temperature is shown. A solid line B indicates the heat insulation layer 17 and the reflection layer 18. When not provided, it shows how the temperature inside the housing 2 changes with respect to a predetermined reference temperature. As shown by the solid line B, when the heat insulating layer 17 and the reflecting layer 18 are not provided, the temperature difference with respect to the predetermined reference temperature is larger than 1 ° C. As shown in A, when the heat insulating layer 17 and the reflective layer 18 are provided, the temperature difference with respect to the predetermined reference temperature does not exceed 1 ° C. and is suppressed to less than 1 ° C. It is within the range of the error.

As described above, by providing the heat insulating layer 17 and the reflective layer 18, the temperature fluctuation in the housing 2 can be largely suppressed. Thereby, it is possible to reduce the adverse effect of the environmental temperature fluctuation on the center wavelength fluctuation of the reflected return light of the distortion detecting grating unit 5. in addition,
As described above, since the temperature compensation of the center wavelength fluctuation of the reflected return light of the strain detecting grating unit 5 can be performed, the load fluctuation of the transmission line 8 can be more accurately detected more reliably.

Further, in this embodiment, means is provided for suppressing environmental temperature fluctuation around the main shaft 3 and the temperature compensating shaft 14. That is, in this embodiment, although not shown, a mark indicating the mounting direction of the transmission line load sensor device 1 is provided on the outer surface of the transmission line load sensor device 1, that is, on the reflection layer 18. This mark is a mark drawn on the surface of the reflective layer 18,
An appropriate form, such as a surface having irregularities on the surface of the reflective layer 18, can be adopted. Thus, in this embodiment, when installing the transmission line load sensor device 1 with the mark, the main shaft 3 and the temperature compensation shaft 14 are shaded by using the mark. The installation direction is determined so as to be closer to the north side inside the housing 2 and the transmission line load sensor device 1 is attached.

By attaching the transmission line load sensor device 1 in this manner, the main shaft 3 and the temperature compensating shaft 14 are unevenly distributed toward the north side in the shaded housing 2 and closer to the south side in the housing 2. As compared with the above, the environmental temperature fluctuation around the main shaft 3 and the temperature compensating shaft 14 is remarkably small. As a result, the adverse effect of the environmental temperature fluctuation on the center wavelength fluctuation of the reflected return light of the strain detecting grating unit 5 can be further reduced,
The detection accuracy of the load fluctuation of the transmission line 8 can be further improved.

According to this embodiment, as described above,
A temperature-compensating shaft 14 that expands and contracts only due to environmental temperature fluctuations is provided. A temperature-compensating grating section 15 is provided on the temperature-compensating shaft 14 so that the center wavelength of the reflected return light varies with the expansion and contraction of the temperature-compensating shaft 14. Therefore, the center wavelength of the reflected return light of the temperature compensating grating section 15 does not change even if the load of the transmission line 8 changes, but changes only in accordance with the environmental temperature change. As a result, the center wavelength fluctuation amount of the reflected return light of the temperature compensation grating unit 15 is subtracted from the fluctuation amount of the center wavelength of the reflected return light of the distortion detection grating unit 5, whereby the distortion detection grating unit 5 is obtained.
The amount of change in the center wavelength of the reflected return light caused by the environmental temperature change can be removed, and the amount of change in the center wavelength of the reflected return light corresponding only to the load change of the transmission line 8 can be obtained. This can avoid the conventional problem, that is, the problem that the load fluctuation of the transmission line 8 cannot be accurately detected due to the environmental temperature fluctuation.

In this embodiment, since the heat insulating layer 17 and the reflective layer 18 are sequentially formed on the surface of the housing 2, the temperature fluctuation inside the housing 2 can be suppressed. From this, it is possible to reduce the adverse effect of the temperature fluctuation on the center wavelength fluctuation of the reflected return light of the strain detecting grating unit 5. In addition, as described above, since the temperature compensation of the center wavelength fluctuation of the reflected return light of the strain detecting grating unit 5 is performed, the detection accuracy of the load fluctuation of the transmission line 8 can be further improved.

Further, in this embodiment, a mark indicating the mounting direction is provided on the outer surface of the transmission line load sensor device 1, and when the transmission line load sensor device 1 is mounted on the steel tower 7, the mark is used. The installation direction of the transmission line load sensor device 1 can be determined and mounted so that the main shaft 3 and the temperature compensation shaft 14 are unevenly distributed to the north side in the shaded housing 2. Thus, by attaching the transmission line load sensor device 1 so that the main shaft 3 and the temperature compensating shaft 14 are unevenly distributed toward the north side in the shaded housing 2, the main shaft 3 and the temperature compensating shaft 14 are Ambient temperature fluctuation can be further suppressed, and as described above, the detection accuracy of the load fluctuation of the transmission line 8 can be further improved.

As described above, in this embodiment, the effect of providing the temperature compensating shaft 14 and the temperature compensating grating portion 15, the effect of providing the heat insulating layer 17 and the reflecting layer 18, The transmission line 8 in the transmission line load sensor device 1 is combined with the effect of providing a mark indicating the direction and distributing the main shaft 3 and the connection portion 4 toward the north side in the shaded housing 2.
An excellent effect that the detection accuracy of the load fluctuation can be dramatically improved.

Further, in this embodiment, the strain detecting grating 5 and the temperature compensating grating 15 are used.
Are connected in series, and each of the reflected return lights of the strain detecting grating unit 5 and the temperature compensating grating unit 15 propagates through the same optical fiber 6, so that only one optical fiber 6 needs to be routed. Since the center wavelengths of the reflected return lights of the strain detecting grating unit 5 and the temperature compensating grating unit 15 are set to different wavelengths, as described above, the strain detecting grating unit 5 and the temperature compensating grating unit 15 are used. Can be obtained in a state where the center wavelengths of the respective reflected return lights of the strain detecting grating unit 5 and the temperature compensation grating unit 15 are separated from each other. 11 facilitates the optical signal processing.

It should be noted that the present invention is not limited to the above-described embodiment, but can adopt various embodiments. For example, in the above embodiment, the temperature compensating shaft 14 is provided on the flange 13. However, for example, the temperature compensating shaft 14 is placed in a temperature environment similar to that of the main shaft 3 and the load of the transmission line 8 is changed. The temperature compensation shaft 14 may be provided in the form of a cantilever on the bottom wall surface 2a of the housing 2, for example.

Further, in the above embodiment, the strain detecting grating section 5 and the temperature compensating grating section 15 are connected in series, and the reflected return lights of the strain detecting grating section 5 and the temperature compensating grating section 15 are the same. The reflected return light of the strain detecting grating unit 5 and the temperature compensating grating unit 15 is transmitted to the measuring device 11 through the
May be used for propagation.

Further, in the above-described embodiment, the mark indicating the mounting direction of the transmission line load sensor device 1 is formed. However, for example, when a shade or the like that shades the entire transmission line load sensor device 1 is provided. The main shaft 3 and the temperature compensation shaft 1 are shaded by the shade effect of the shade.
Since the environmental temperature fluctuation around 4 is suppressed, it is not necessary to worry about the mounting direction of the transmission line load sensor device 1. In such a case, it is not necessary to provide a mark indicating the mounting direction.

Further, in the above embodiment, the temperature compensating shaft 14 is made of the same material as the main shaft 3, but the temperature compensating shaft 14 may be made of a material different from that of the main shaft 3. However, in this case, it is necessary to perform the optical signal processing of the reflected return light of the temperature compensation grating unit 15 in consideration of the difference in the thermal expansion coefficient of the temperature compensation shaft 14 with respect to the thermal expansion coefficient of the main shaft 3.

Further, in the above-described embodiment, the casing 2 is cylindrical, but the shape of the casing 2 is not limited to a cylindrical shape, and can take various appropriate shapes.

[0048]

According to the present invention, the temperature compensating shaft which expands and contracts in accordance with the environmental temperature fluctuation around the main shaft is provided in such a form that no load is applied from the power transmission line. The temperature compensating grating portion of the optical fiber is mounted such that the center wavelength of the reflected return light varies with the expansion and contraction of the temperature compensating shaft. The center wavelength of the reflected return light of the temperature compensation grating section is not affected by the load fluctuation of the transmission line,
Since it fluctuates only in accordance with the environmental temperature fluctuation around the main shaft, the fluctuation of the center wavelength of the reflected return light of the temperature compensating grating is used to make the distortion detecting grating mounted on the main shaft. It is possible to remove the adverse effect of the center wavelength fluctuation caused by the environmental temperature fluctuation in the reflected return light. This makes it possible to obtain the amount of change in the center wavelength of the reflected return light in accordance with only the change in the load on the transmission line, and to accurately detect the change in load on the transmission line.

The temperature compensating shaft is formed of the same material as the main shaft, and the temperature compensating shaft is disposed substantially parallel to and adjacent to the main shaft and is provided in the form of a cantilever to provide a temperature compensating shaft. The fluctuation amount of the expansion and contraction of the shaft is the same as the fluctuation amount of the expansion and contraction of the main shaft caused by the environmental temperature fluctuation. For this reason, the center wavelength fluctuation amount of the reflected return light of the temperature compensation grating unit becomes substantially equal to the fluctuation amount of the center wavelength fluctuation amount of the reflected return light of the distortion detection grating unit due to the environmental temperature fluctuation,
By utilizing the change in the center wavelength of the reflected light returned from the grating for temperature compensation, the adverse effect of the change in the center wavelength caused by the environmental temperature change in the reflected light returned from the grating for distortion detection can be more accurately removed. This allows
It becomes possible to more accurately detect the load fluctuation of the transmission line.

The strain detecting grating section and the temperature compensating grating section are connected in series, and each reflected return light of the strain detecting grating section and the temperature compensating grating section propagates in the same optical fiber. Therefore, there is no need to separately provide an optical fiber for transmitting the reflected return light of the strain detecting grating unit and an optical fiber for transmitting the reflected return light of the temperature compensation grating unit, and It is possible to eliminate the trouble of the work of laying the optical fiber, in which each of the separate optical fibers is routed. In addition, since the reflected return lights of the strain detecting grating section and the temperature compensation grating section have different center wavelengths from each other, even if the respective reflected return lights propagate through the same optical fiber as described above, Each reflected return light can be obtained in a separated state.

In the case where the heat insulation layer and the reflection layer are laminated on the surface of the housing, the heat insulation layer and the reflection layer allow the external environmental temperature around the power transmission line load sensor device to vary greatly. In addition, the temperature fluctuation in the housing can be suppressed small. For this reason, the expansion and contraction of the main shaft caused by the environmental temperature fluctuation can be suppressed to a small extent, whereby the center wavelength fluctuation caused by the environmental temperature fluctuation in the reflected return light of the strain detecting grating can be reduced. In addition, as described above, the temperature compensation of the center wavelength fluctuation of the reflected return light of the strain detecting grating portion is performed, so that the load fluctuation of the transmission line can be detected more accurately, and the transmission line load sensor device Detection accuracy can be improved.

In the case where a mark indicating the mounting direction of the device is formed on the outer surface of the power transmission line load sensor device, it is easy to install the power transmission line load sensor device in a predetermined direction using the mark. Becomes Thus, the power transmission line load sensor device can be mounted using the mark in a state where the main shaft and the temperature compensating shaft are biased toward the north side in the shaded housing. so,
By installing the transmission line load sensor device so that the main shaft and the temperature compensation shaft are unevenly distributed to the north side in the shaded housing, it is possible to suppress the environmental temperature fluctuation around the main shaft and the temperature compensation shaft. it can.

As a result, the expansion and contraction of the main shaft caused by the environmental temperature fluctuation becomes very small, and the center wavelength fluctuation caused by the environmental temperature fluctuation in the reflected return light of the strain detecting grating can be suppressed.
In addition, the temperature compensation of the center wavelength variation of the reflected return light of the strain detecting grating portion is performed, so that the load variation of the transmission line can be detected more accurately, and the detection accuracy of the transmission line load sensor device is improved. Can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a transmission line load sensor device according to the present invention.

FIG. 2 is an explanatory diagram showing a connection example of a strain detecting grating section and a temperature compensation grating section in the embodiment.

FIG. 3 is a graph of an experimental result showing the effect of suppressing temperature fluctuation in the case when a heat insulating layer and a reflective layer are provided on the surface of the case in comparison with a case where there is no heat insulating layer and a reflective layer.

FIG. 4 is an explanatory view showing a conventional structure example of a transmission line load sensor device and an installation example of the transmission line load sensor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power transmission line load sensor apparatus 2 Housing 3 Main shaft 4 Connection part 5 Strain detection grating part 6 Optical fiber 8 Transmission line 14 Temperature compensation shaft 15 Temperature compensation grating part 17 Heat insulation layer 18 Reflection layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) H02G 1/02 323 H02G 1/02 323B (72) Inventor Junichi Iwasaki 1-chome Odori Higashi, Chuo-ku, Sapporo, Hokkaido No. 2 Hokkaido Electric Power Company F-term (reference) 2F051 AA21 AB03 AC04 CA00 2H038 AA05 CA65 2H050 AC84 AD06

Claims (7)

[Claims] 1. A suspending portion for suspending a transmission line is provided on a surface portion of a housing, and a main shaft which expands and contracts according to a change in load of the transmission line suspended on the suspending portion inside the housing. An optical fiber strain detecting grating attached to the main shaft for changing the center wavelength of the reflected return light with expansion and contraction of the main shaft; and the center wavelength of the reflected return light of the strain detecting grating. A transmission line load sensor device that detects a change in load from a transmission line using the fluctuation of the temperature, wherein a temperature compensating shaft that expands and contracts in accordance with environmental temperature fluctuation around the main shaft is provided in the housing. The temperature compensating shaft is provided with a form in which a load from a transmission line is not applied, and the temperature compensating grating of the optical fiber is deflected by the expansion and contraction of the temperature compensating shaft. Attached so that the center wavelength of the reflected light fluctuates, and utilizing the center wavelength fluctuation of the reflected return light of the temperature compensation grating section, to compensate for the environmental temperature fluctuation in the reflected return light of the strain detection grating section. A transmission line load sensor device, which eliminates the adverse effect of the center wavelength fluctuation caused. 2. The temperature compensating shaft is formed of the same material as the main shaft, and the temperature compensating shaft is disposed substantially parallel to and adjacent to the main shaft, and
The transmission line load sensor device according to claim 1, wherein the transmission line load sensor device is provided in the form of a cantilever. 3. The strain detecting grating section and the temperature compensating grating section are connected in series, and the reflected return light of the strain detecting grating section and the reflected return light of the temperature compensating grating section pass through the same optical fiber. 3. The structure according to claim 1, wherein a center wavelength of the reflected return light of the grating for temperature compensation is different from a center wavelength of the reflected return light of the grating for distortion detection. Transmission line load sensor device. 4. The transmission line load sensor device according to claim 1, wherein a heat insulation layer and a reflection layer are laminated on a surface of the housing. 5. The transmission line load according to claim 1, wherein a mark indicating an installation direction of the transmission line load sensor device is formed on an outer surface of the transmission line load sensor device. Sensor device. 6. The transmission line load sensor device according to claim 5, wherein the main shaft and the temperature compensating shaft in the housing are provided so as to be biased at a position closer to the north side in the mounting direction of the device. 7. The installation of the transmission line load sensor device according to claim 5, wherein the main shaft and the temperature compensating shaft are positioned so as to be offset toward the north side in the shaded housing. A method for installing a transmission line load sensor device, comprising installing a sensor device.