JP4315438B2 - Trolley wire wear judgment method and trolley wire wear judgment system - Google Patents

Description

  The present invention relates to a trolley wire wear determination method and a trolley wire wear determination system that easily measure wear of a trolley wire without going directly to the site.

The following are known as conventional techniques related to wear determination of an aerial trolley wire (hereinafter simply referred to as a trolley wire) for power supply in an electric railway. (For example, refer to Patent Document 1.)
JP 09-159414 A (FIG. 1, FIG. 4, paragraphs (0002) to (0000))

The following description is made in the above publication.
FIG. 7 shows an outline of an erection structure of an aerial trolley wire (hereinafter simply referred to as a trolley wire) for feeding in an electric railway.
A suspension wire 3 is continuously laid between the supporting power poles 2 planted in an appropriate span, and the trolley wire 1 is suspended from the suspension wire 3 by a hanger 4 and extended horizontally.
As shown in the enlarged view, the hanger 4 includes a wire 41 having an upper end coupled to the suspension wire 3 and an ear 42 connected to the lower end thereof.
The ear 42 has two fixing tools 421a and 421b. The lower ends of the ears 42 are fitted into the grooves m on both sides of the trolley wire 1 at the lower ends, and fastened with bolts 43 to fix the trolley wire 1.

The bottom surface S (referred to as a sliding surface) of the trolley wire 1 gradually wears due to sliding contact with the pantograph of the traveling train, and when this reaches the limit, there is a risk of cutting, so measure this amount of wear. However, it is essential for maintenance management of the trolley wire 1.
There is a manual measurement method using a micrometer as a method of measuring the amount of wear, but since this is a contact type, it is inefficient to work in high places and is dangerous due to high voltage when the trolley wire 1 is live. In addition, since it is point measurement, there are many disadvantages such as details of wear are difficult to understand.

In contrast, at present, the amount of wear is continuously measured in a non-contact manner using an optical measuring device.
FIG. 8 is a block diagram of a conventional wear measuring apparatus 8 as an example.
In FIG. 8, the wear measuring device 8 includes an imaging unit 81, a pan head 82, a tripod 83, a data processing unit 84, and a battery 85.
In the imaging unit 81, a video camera 813 having a zoom lens 811 with an autofocus function and a liquid crystal monitor 812, and a projector 814 are fixed to a fixed plate 815, and the fixed plate 815 is attached to a tripod 83 via a pan head 82. It is done.
The battery 85 supplies power to the projector 814 and the data processing unit 84. The video camera 813 is a battery built-in type.
For the video camera 813, tripod 83, and pan head 82, commercially available appropriate ones are used, and other components are made as small and light as possible.
In the wear measurement, the video camera 813 is placed together with the tripod 83 directly below the measurement location of the trolley wire 1 and the spot light SP is projected from the projector.

When the pan head 82 is operated so that the image of the trolley line 1 appears on the liquid crystal monitor 812 and the autofocus function is operated, the video camera is focused, and the liquid crystal monitor 812 has both sides of the trolley line 1 Images of the edge lines E1, E2 and the sliding surface S are obtained, and the video camera 813 outputs this image signal.
In the above, when the length of the measurement location is several times the field of view of the video camera 813, the pan head 82
In the case of the connecting part 5 of the trolley wire 1, the field of view is moved sequentially to the two trolley wires 1 (A) and 1 (B) and measurement is performed in the same manner as above. Do.
However, when the measurement location is very long, the video camera 813 is moved together with the tripod 83.

  However, the conventional trolley wire wear detection device has a problem that the measurement device is complicated as shown in FIG. 8 and the measurement device needs to be carried to the trolley wire construction site for measurement.

An object (object) of the present invention is to use a Brillouin scattered light in an optical fiber to easily measure trolley wire wear from a remote location without going directly to the site, and to determine trolley wire wear. To provide a system.
In addition, when measuring trolley wire wear, the optical fiber distortion due to temperature change and the optical fiber strain due to actual trolley wire wear are combined to produce temperature-corrected light. It is an object of the present invention to provide a temperature correction method for separating fiber strain.

  In order to solve the above-mentioned problem, a step of entering a light pulse from one measurement end with respect to an optical fiber fixed integrally with a trolley wire; Detecting a corresponding Brillouin scattered light, and measuring a strain distribution in the length direction of the optical fiber based on a Brillouin frequency shift amount of the Brillouin scattered light, and a trolley corresponding to the strain distribution in the longitudinal direction of the optical fiber. The wear of the trolley wire is determined by the step of calculating the wear amount in the longitudinal direction of the wire. (Claim 1)

Further, the calculation includes a temperature correction step for performing correction according to the outside air temperature where the trolley wire is installed. (Claim 2)
The temperature correction step is executed based on the measurement result of the distortion amount in the temperature correction reference section set in the trolley line portion where the panda graph does not contact. (Claim 3)
Further, the temperature correction step is executed based on a measurement result of a strain distribution of the temperature correction optical fiber that is parallel to the optical fiber and is freely disposed on the trolley wire. (Claim 4)
Further, a measurement result accumulating unit is provided, and wear is determined by comparison with past measurement results. (Claim 5)
In addition, the wear measurement of the trolley wire due to the incidence of the light pulse is executed every predetermined period, and an alarm is issued when the wear of the trolley wire reaches a specified value. (Claim 6)

An optical fiber fixed integrally with the trolley wire; and an optical fiber analyzer that receives a light pulse from one measurement end of the optical fiber and detects Brillouin scattered light corresponding to the incident light pulse; The strain distribution in the length direction of the optical fiber is measured based on the Brillouin frequency shift amount of the Brillouin scattered light measured by the optical fiber analyzer , and the wear of the trolley wire corresponding to the strain distribution in the longitudinal direction of the optical fiber is measured. A trolley wire wear determination system is constituted by the calculation means for calculating the quantity. (Claim 7)
Further, a temperature detecting means for measuring the temperature at which the trolley wire is installed is provided, and correction according to the measured temperature is performed. (Claim 8)
Further, the temperature correction means is executed based on the measurement result of the distortion amount in the temperature correction reference section set in the trolley line portion where the panda graph does not contact. (Claim 9)
Further, the temperature correction means is executed based on a measurement result of a strain distribution of the temperature correction optical fiber that is parallel to the optical fiber and is freely disposed on the trolley wire. (Claim 10)

According to the first aspect of the present invention, a step of entering a light pulse from one measurement end with respect to an optical fiber fixed integrally with a trolley wire, and the light pulse incident on the one measurement end. Detecting a Brillouin scattered light corresponding to the Brillouin scattered light, and measuring a strain distribution in the length direction of the optical fiber based on a Brillouin frequency shift amount of the Brillouin scattered light, and corresponding to the strain distribution in the longitudinal direction of the optical fiber. The wear of the trolley wire is determined by the step of calculating the wear amount in the longitudinal direction of the trolley wire, so that the wear of the trolley wire does not go directly to the site,
It can be easily measured from a remote location.
In addition, this measurement method can be performed even while the train is running.

In the invention according to claim 2, since the calculation is corrected in accordance with the outside air temperature on which the trolley wire is installed, it can be applied even when the outside air temperature changes greatly in winter and summer.
Further, in the invention according to claim 3, since it is executed based on the measurement result of the strain amount in the temperature correction reference section set in the trolley line portion where the panda graph does not contact, the temperature can be obtained without providing a special configuration. Correction can be realized.
According to a fourth aspect of the present invention, the temperature correction is performed based on a measurement result of a strain distribution of a temperature correction optical fiber that is parallel to the optical fiber and disposed freely on a trolley wire. Therefore, reliable temperature correction can be performed.
Further, in the invention according to claim 5, since the measurement result accumulating means is provided and the wear is judged by comparison with the past measurement result, it is possible to always compare with the strain amount at the initial stage of the installation of the trolley wire. The amount of wear when worn out can be determined.
Further, in the invention described in claim 6, the wear measurement of the trolley wire by the incidence of the light pulse is executed every predetermined period, and an alarm is issued when the wear of the trolley wire reaches a specified value. Thus, automatic measurement without human intervention becomes possible.

According to the seventh aspect of the present invention, an optical fiber fixed integrally with the trolley wire and a light pulse incident from one measurement end of the optical fiber, and a Brillouin scattering corresponding to the incident light pulse. A strain distribution in the length direction of the optical fiber is measured by an optical fiber analyzer for detecting light, and a Brillouin frequency shift amount of the Brillouin scattered light measured by the optical fiber analyzer . The trolley wire wear judgment system is configured by the calculation means that calculates the wear amount of the trolley wire corresponding to the strain distribution, so the trolley wire can be easily measured from a remote location without going directly to the site. A wear determination system can be configured.
Further, in the invention described in claim 8, there is provided a system that can be adapted even when the temperature of the outside air changes greatly in winter and summer by providing an outside temperature detecting means for measuring the outside temperature on which the trolley wire is installed. realizable.
In the invention according to claim 9, since it is executed based on the measurement result of the distortion amount in the temperature correction reference section set in the trolley line portion where the panda graph does not contact, temperature correction is realized with a simple configuration. it can.
According to a tenth aspect of the present invention, the temperature correction means is executed based on a measurement result of a strain distribution of a temperature correction optical fiber that is parallel to the optical fiber and that is disposed freely on a trolley wire. Therefore , reliable temperature correction can be performed.

First, the measurement principle of the optical fiber strain analyzer (BOTDR method) used in the trolley wire wear determination method and trolley wire wear determination system of the present invention will be described with reference to FIG.
The BOTDR method is a system that measures strain distribution by detecting Brillouin scattered light.
Brillouin scattered light is a phenomenon in which incident light having high monochromaticity (coherency) interacts with sound waves generated in a medium and is scattered with a frequency that is unique to the medium.
This frequency is called Brillouin frequency shift νB and is given by the following equation.
νB = 2nVA / λn: refractive index VA of optical fiber: speed of sound λ: wavelength of incident light

As shown in FIG. 3, the change in Brillouin frequency shift is proportional to the change in strain in the longitudinal direction of the optical fiber, and the changes are 581 MHz /% and 493 MHz /% in the 1.3 μm band and 1.5 μm band, respectively. become.
Therefore, the strain applied to the optical fiber can be measured by obtaining the Brillouin frequency shift amount.

FIG. 1 is a conceptual diagram for explaining measurement by an optical fiber strain analyzer (BOTDR).
In FIG. 1, reference numeral 31 denotes an optical fiber to be measured (an optical fiber for a strain sensor). Pulse light (monochromatic light having high coherency) is incident from an optical fiber strain analyzer (BOTDR) 32, and Brillouin scattered light is measured. .
That is, when pulsed light enters from one end of the optical fiber 31, scattered light is generated in the optical fiber, and a part of the light returns to the incident end as backscattered light.
Of the backscattered light, Brillouin scattered light is detected by the optical fiber strain analyzer 21.
Since the Brillouin frequency shift shifts in proportion to the amount of distortion generated in the optical fiber, the amount of distortion generated in the optical fiber can be known by measuring the frequency shift amount.

In the three-dimensional graph in FIG. 1, the lower right axis indicates the distance from the input end along the optical fiber, the upper right axis indicates the rear Brillouin scattered light frequency, and the vertical axis indicates the measured power of the Brillouin scattered light. Yes.
The power of the Brillouin scattered light was obtained as continuous data in the distance direction by changing the time from the incident of the light pulse to receiving the scattered light and the speed of light in the optical fiber into the distance, and changed. You can know the location.

Here, the relationship between the Brillouin frequency shift and the elongation strain applied to the optical fiber can be expressed by the following equation.
Thereby, the Brillouin scattering frequency shift νB (ε) in the length direction of the optical fiber can be obtained.
νB (ε) = νB (0) (1 + Cε)
ν B (ε): Brillouin frequency shift when there is distortion ν B (0): Brillouin frequency shift when there is no strain C: proportional coefficient ε: strain amount

This relationship is shown in FIG.
In FIG. 2, the horizontal axis represents the Brillouin frequency shift and the vertical axis represents the Brillouin scattering power, and the relationship between the Brillouin frequency shift proportional to the amount of distortion is shown depending on whether the optical fiber is distorted or not. ing.

Next, the principle of measuring the wear amount of the trolley wire according to the present invention will be described with reference to FIG.
FIG. 4 is a diagram showing an outline of a trolley wire wear determination system.
In FIG. 4, 1 is a trolley line, which is the same as the trolley line in FIG.
Reference numeral 31 denotes an optical fiber for strain detection, which is integrally fixed to the trolley wire 1 by a clip 35 every predetermined length.
In FIG. 4, the optical fiber is not fixed directly to the trolley wire 1, but the copper tube is fixed to the trolley wire using an optical fiber containing a copper tube, but the optical fiber is not connected to the copper tube. It may be fixed directly to the trolley wire.
Further, although the clip 35 is used as the fixing means, it goes without saying that other fixing means may be used as long as the trolley wire and the optical fiber can be fixed integrally.
In FIG. 4, the optical fiber is fixed to the trolley wire at the top of the trolley wire (on the opposite side of the sliding surface). However, the extension of the trolley wire can be detected. Any part can be selected if it is not received.

In FIG. 4, reference numeral 32 denotes an optical fiber strain measuring device (means) for measuring the strain distribution in the longitudinal direction of the optical fiber. For example, the optical fiber strain analyzer (BOTDR) shown in FIG. it can.
34 is a wear judging personal computer for judging the wear of the trolley wire fixed to the optical fiber based on the longitudinal strain distribution which is the measurement result of the optical fiber strain measuring instrument. is there.
Also, 33 is a temperature measuring device for removing the influence of the temperature change because the length of the trolley wire changes according to the temperature change when the temperature of the construction site of the trolley wire changes greatly. In some cases, it can be removed.

Next, the reason why the wear of the trolley wire can be judged by measuring the strain distribution in the longitudinal direction of the optical fiber fixed integrally with the trolley wire (the principle of the wear judgment system) will be described with reference to FIG. To do.
FIG. 5A shows a state where the optical fiber is fixed integrally to a new trolley wire.
Since the optical fiber fixed integrally with the trolley wire is pulled by a certain tension, there is no wear when the trolley wire is new. It becomes a certain distortion according to the cross-sectional area.

  However, when the trolley wire shown in FIG. 5 (b) is worn (in this case, the wear is concentrated only in a predetermined section), the cross-sectional area of the trolley wire in the worn portion is shown. Is smaller than other parts, so the trolley wire is pulled with a constant tension, so the elongation (distortion) of the trolley wire in the wear part is larger than the other parts, so it is integrated with the trolley wire. The strain of the optical fiber that is fixed is larger than that of other portions.

FIG. 5 (b) shows the case where the wear is concentrated only in a predetermined section. However, when the trolley wire is worn out as a whole when the trolley wire is used for a long time, The cross-sectional area becomes small due to wear over the entire trolley wire.
Therefore, if the tension for pulling the trolley wire is constant, the strain of the optical fiber increases as a whole, so that it can be determined that it is totally worn by comparing with the strain amount in the initial strain distribution.

Next, FIG. 6 shows an example of strain distribution in the longitudinal direction of the optical fiber in trolley wire wear determination in the present invention.
In FIG. 6, from this measurement result, the measured strain amount is 6-7 m and the 12-14 m portion, the strain amount is larger than the other portions, especially the 12-14 m portion is a problem. It can be judged that there is.

A temperature correction technique in measuring the strain of an optical fiber, which is a further object of the present invention, will be described.
FIG. 9 is a conceptual diagram for explaining a first temperature correction technique in the measurement of strain of an optical fiber.
The configuration of FIG. 9 is obtained by adding temperature correction means to the diagram showing the outline of the trolley wire wear determination system of FIG.
In FIG. 9, reference numeral 31 denotes an optical fiber (optical fiber strain sensor) for detecting wear (strain) fixed in the longitudinal direction of the trolley wire, and is connected to an optical fiber strain analyzer (BOTDR).
A section where the panda graph does not contact a predetermined portion of the optical fiber (wear does not occur because the panda graph does not contact) is set, and this section is set as a temperature correction aiming section.

Next, temperature correction in the measurement of strain of the optical fiber in FIG. 9 will be described with reference to FIGS.
FIG. 10 is a graph showing the result of measuring the strain distribution of the optical fiber in each wear state of the trolley wire, where the horizontal axis indicates the distance (m) and the vertical axis indicates the relative strain amount (%).
When the measurement temperature environment changes, thermal expansion of the trolley wire occurs, and even if the trolley wire is not worn, the amount of distortion corresponding to the temperature change is detected. In actual measurement, distortion of the optical fiber due to temperature change and the actual trolley wire It appears in combination with the distortion of the optical fiber due to wear.

FIG. 10 shows measurement results before temperature correction, where the wear level is 2 mm, the wear level is 3 mm, the wear level is 3 and the wear level is 5 mm.
In FIG. 10 , the horizontal axis indicates the distance (m), the vertical axis indicates the relative strain amount (%), and the portion near 124 m in the measurement range of 122 m to 132 m as the distance is the temperature correction reference section.
In FIG. 10, it can be understood that there is a part where the wear level of 3 mm at the part where the panda graph contacts is larger than the value of the wear level of 5 mm, which is unnatural.

In the present invention, correction is performed so that the strain amount in the temperature correction reference section becomes zero.
FIG. 11 shows a graph in which the strain distribution of the optical fiber in each worn state of the corrected trolley wire is temperature corrected.
Also in FIG. 11, the horizontal axis indicates the distance (m), and the vertical axis indicates the relative strain amount (%).
In the graph of the temperature-corrected measurement result in FIG. 11, the portion where the wear level of 3 mm at the portion where the panda graph contacts is larger than the one of the wear level of 5 mm is eliminated.

The second temperature correction technique in the measurement of strain of the optical fiber of the present invention will be described.
FIG. 12 is a conceptual diagram for explaining a temperature correction technique in measurement of distortion of an optical fiber.
The configuration of FIG. 12 is obtained by adding temperature correction means to the diagram showing the outline of the trolley wire wear determination system of FIG.
In FIG. 12, 31-a is an optical fiber (optical fiber strain sensor) for detecting wear (strain) fixed in the longitudinal direction of the trolley wire, and 31-b is an optical fiber for temperature correction, which is a metal tube. An optical fiber is inserted into the optical fiber 31-a in a free state so as not to follow the elongation of the trolley wire.
The strain measuring optical fiber 31-a and the temperature correcting optical fiber 31-b are connected to an optical fiber strain analyzer (BOTDR) via an optical channel selector 31-c.

Next, temperature correction in the measurement of distortion of the optical fiber in FIG. 12 will be described with reference to FIGS.
FIG. 13 is a graph showing the result of measuring the strain distribution of the optical fiber in each wear state of the trolley wire, where the horizontal axis indicates the distance (m) and the vertical axis indicates the relative strain amount (%).
When the measurement temperature environment changes, thermal expansion of the trolley wire occurs, and even if the trolley wire is not worn, the amount of distortion corresponding to the temperature change is detected. In actual measurement, distortion of the optical fiber due to temperature change and the actual trolley wire It appears in combination with the distortion of the optical fiber due to wear.

FIG. 13 shows measurement results before temperature correction, where the wear level is 2 mm, the wear level is 4 mm, the wear level is 5 mm, and the wear level is 5 mm.
Also in FIG. 13, it can be understood that the wear level of 4 mm is unnatural because the measured strain amount is larger than that of the wear level of 5 mm.

FIG. 14 is a graph showing the result of measuring the strain distribution of the temperature-correcting optical fiber at each wear level of the trolley wire.
Also in FIG. 14, the horizontal axis indicates the distance (m) and the vertical axis indicates the relative strain amount (%).
Since it is known that the strain amount change with respect to the temperature change of the temperature correcting optical fiber is 0.002% per 1 ° C., the strain amount change in FIG. 14 can be converted into a temperature change.
For example, when the amount of strain changes by 0.01%, the temperature of the trolley wire changes by about 5 ° C.

FIG. 15 is a graph in which the strain distribution of the optical fiber in each wear state of the trolley wire in FIG. 13 is temperature-corrected based on the result of measuring the strain distribution of the temperature correction optical fiber in each wear level of the trolley wire in FIG. It is.
Also in FIG. 15, the horizontal axis indicates the distance (m), and the vertical axis indicates the relative strain amount (%).
In the graph of the measurement result corrected for temperature in FIG. 15, the portion where the amount of strain measured when the wear level is 4 mm is larger than that when the wear level is 5 mm is eliminated.

  In invention of Claims 1-10, the trolley wire wear determination method and trolley wire which measure easily the wear of a trolley wire from a remote place, without going to the site directly using the Brillouin scattered light in an optical fiber In addition to providing a wear determination system, when measuring the wear of a trolley wire, temperature correction is performed so that the distortion of the optical fiber due to temperature change and the distortion of the optical fiber due to the actual wear of the trolley wire are combined. Thus, the temperature correction for separating the distortion of the optical fiber due to the temperature change can be performed, so that the industrial applicability is extremely large.

It is a conceptual diagram for demonstrating the measurement of an optical fiber distortion analyzer (BOTDR). FIG. 4 is a diagram showing a relationship between Brillouin frequency shift and Brillouin scattering power on the vertical axis. It is a figure explaining the measurement principle of an optical fiber distortion analyzer (BOTDR). It is a figure which shows the outline | summary of the trolley wire wear determination system. It is a figure for demonstrating the principle of the abrasion determination system of a trolley wire. It is a figure which shows the example of the distortion distribution in the longitudinal direction of an optical fiber. It is a figure which shows the construction structure of the overhead trolley line for electric power feeding in an electric railway. It is a figure which shows the structure of the conventional abrasion measuring apparatus. It is a conceptual diagram for explaining a temperature correction technique in the measurement of strain of an optical fiber. 6 is a graph showing the result of measuring the strain distribution of an optical fiber in each wear state of a trolley wire. 11 is a graph obtained by correcting the strain distribution of the optical fiber in each wear state of the trolley wire in FIG. 10. It is a conceptual diagram for demonstrating the temperature correction technique in the measurement of distortion of an optical fiber. 6 is a graph showing the result of measuring the strain distribution of an optical fiber in each wear state of a trolley wire. 6 is a graph showing the results of measuring the strain distribution of the temperature-correcting optical fiber at each wear level of the trolley wire. 15 is a graph in which the strain distribution of the optical fiber in each wear state of the trolley wire in FIG. 13 is corrected based on the measurement result of the strain distribution of the temperature correcting optical fiber in each wear level of the trolley wire in FIG.

DESCRIPTION OF SYMBOLS 1 Trolley wire 31 Optical fiber 31-a Copper pipe optical fiber 32 Fiber strain measuring device 33 Temperature detector 34 Wear judgment personal computer 35 Clip (fixing means)

Claims (10)

Injecting a light pulse from one measurement end to an optical fiber fixed integrally with a trolley wire;
Detecting Brillouin scattered light corresponding to the incident light pulse at the one measurement end; and
A step of measuring a strain distribution in the length direction of the optical fiber based on a Brillouin frequency shift amount of the Brillouin scattered light and calculating a wear amount in the longitudinal direction of the trolley wire corresponding to the strain distribution in the longitudinal direction of the optical fiber. When,
A method for determining wear of a trolley wire, comprising:   The trolley wire wear determination method according to claim 1, wherein the calculation includes a temperature correction step for performing correction according to an outside air temperature where the trolley wire is installed.   3. The trolley wire wear according to claim 2, wherein the temperature correction step is executed based on a measurement result of a strain amount in a temperature correction reference section set in a trolley line portion that is not in contact with the panda graph. Judgment method. 3. The temperature correction step is executed based on a measurement result of a strain distribution of a temperature correction optical fiber that is parallel to the optical fiber and is disposed freely on a trolley wire. The method for determining wear of the described trolley wire.   The trolley wire wear determination method according to any one of claims 1 to 4, further comprising a measurement result accumulating unit, wherein wear is determined by comparison with past measurement results. The trolley wire wear measurement by the incidence of the light pulse is executed at predetermined intervals, and an alarm is issued when the trolley wire wear reaches a specified value. 2. A method for determining wear of a trolley wire according to item 1. An optical fiber fixed integrally with the trolley wire;
An optical fiber analyzer that receives a light pulse from one measurement end of the optical fiber and detects Brillouin scattered light corresponding to the incident light pulse;
The strain distribution in the length direction of the optical fiber is measured based on the Brillouin frequency shift amount of the Brillouin scattered light measured by the optical fiber analyzer , and the wear of the trolley wire corresponding to the strain distribution in the longitudinal direction of the optical fiber is measured. Computing means for computing the quantity;
A trolley wire wear determination system comprising: The trolley wire wear determination system according to claim 7 , further comprising temperature detection means for measuring a temperature at which the trolley wire is installed, and temperature correction means for performing correction according to the measured temperature. . 9. The trolley wire wear according to claim 8 , wherein the temperature correction unit is executed based on a measurement result of a strain amount in a temperature correction reference section set in a trolley line portion that is not in contact with the panda graph. Judgment system. It said temperature correction means to claim 8, which is parallel to the optical fiber, and characterized in that it is performed based on the measurement results of the strain distribution of the contact wire to be disposed in the free temperature correction optical fiber Described trolley wire wear determination system.