KR0173100B1 - Sensor for detecting wire corrosion - Google Patents

Abstract

The present invention relates to a detection sensor of a corrosion detecting apparatus used to measure an internal corrosion degree of a transmission line by an eddy current flaw detection method, so that the transmission line can be easily inserted into the detection sensor in the same direction in an adjacent conductor. An upper semi-cylindrical coil portion wound to flow a current through the wire, and a lower semi-cylindrical coil portion wound to flow current in the same direction in an adjacent conductive line, and the upper semi-cylindrical coil portion and the lower semi-cylindrical coil portion are disposed correspondingly. It consists of a measuring instrument for measuring the change of electrical characteristics at both terminals of the coil part.

Description

Wire Corrosion Detection Sensor

1A and 1B show the shape and cross section of a general transmission line, respectively.

2 shows a conventional detection sensor consisting of a measuring device for measuring a change in solenoid and electrical properties to measure the degree of internal corrosion of a transmission line.

3 is a view showing a semi-cylindrical coil provided in the detection sensor of the present invention.

4 is a block diagram showing a schematic configuration of a detection sensor according to the present invention.

Figure 5 is a schematic perspective view showing the mutual coupling of the semi-cylindrical panel provided with the coil portion of the detection sensor according to the present invention.

FIG. 6 is a perspective view showing a shape in which the first coil shown in FIG. 5 is wound on a semi-cylindrical panel. FIG.

* Explanation of symbols for main parts of the drawings

1: core wire 2: aluminum wire

3: zinc film 10: transmission line

12: AC power supply 14, 25: detection sensor

21, 22: semi-cylindrical panel 31, 32, 33, 34: coil

26: hinge 23: protrusion member

41, 42: semi-cylindrical coil

The present invention relates to a sensor that can detect the corrosion of the wire, and more particularly, to a detection sensor for measuring the degree of internal corrosion of the wire used to transmit power generated in the power plant to the substation and the general household and consumers.

In general, transmission lines that transmit electric power generated from power plants to substations and homes and consumers can be roughly divided into power lines dedicated to the transportation of power and overhead lines of the transmission tower. The power line should have electrical properties with good conductivity and mechanical properties capable of maintaining its inherent shape against external forces so as to stably supply power. The role of the processing ground line is also responsible for protecting the power line from the dead and important functions used as a return environment of the fault current.

Most of the current transmission lines are made of ACSR (Aluminum Conductors Steel Reinforced) wires, which are called galvanized steel core strands. The ACSR wire is provided with a plurality of aluminum wires having excellent electric mobility on the surface, and a plurality of steel core wires made of steel (Fe) having excellent tensile strength are provided inside these aluminum wires. The zinc core is plated on the surface of the steel core, because the steel core uses a material having an affinity with aluminum to prevent corrosion caused by rust in combination with atmospheric air, especially oxygen. The zinc film has a plating thickness of about 0.4 (mm) and is formed through the manufacturing process of impregnation.

On the other hand, when the ACSR line is installed as a power transmission line, if the rain falls while the pollutants such as salt or sulfurous acid gas contained in the air are accumulated on the wire, water penetrates into the wire and the electrolyte is in contact with three metals. It causes the same action as the local battery is formed between the dissimilar metals. As a result, aluminum, zinc and iron are corroded in order, and further, electrolytic corrosion occurs due to ionization, and thus, the aluminum wire has a weakened function as a conductor, and the steel core wire has a weak mechanical strength, which may lead to disconnection. This condition occurs inside the wire while the outside is dry, so it is hardly distinguished by the naked eye. This phenomenon is particularly acute when the ACSR wire is used in coastline or industrial area.

When such a phenomenon occurs, an obviously disadvantageous situation may be caused, such as a stable power supply being hindered, so that it is necessary to detect this in advance and take precautionary measures.

In order to inspect the degree of corrosion in the interior of the transmission line as described above, it was necessary to cut the transmission line in the past and examine the inside thereof.

However, this method requires a lot of manpower and time since the sample is taken from the transmission line and the wire is dismantled to investigate the corrosion condition. Has a problem.

Among the conventional nondestructive methods for solving this problem, a method known to be feasible and reliable is to use eddy currents.

The eddy current means a circular current induced in an electric conductor adjacent to the coil by a magnetic field generated by the coil. When an alternating current is applied to the coil, a magnetic field is formed, and the eddy current is generated in the electric conductor plate by the magnetic field. The generated eddy currents form a new magnetic field in the opposite direction to the magnetic field generated by the test coil, and the two kinds of magnetic fields interact to cause a change in the impedance of the test coil.

In addition, when a test body such as a transmission line is inserted into the solenoid and an alternating current is applied to the coil, a main magnetic field is generated, and an eddy current is generated inside the test body by the main magnetic field. The generated eddy current generates an eddy current magnetic field toward the solenoid, thereby canceling the main magnetic field generated in the coil.

This results in a change in magnitude and phase of the current i (t) flowing in the coil. The change in magnitude and phase of this current eventually changes the impedance of the coil. Therefore, the magnitude and phase of the impedance can be calculated from the applied voltage υ (t) and the measured current. As a result, the size and shape of the defect contained in the test body such as the transmission line can be estimated from the information on the magnitude and phase of the calculated impedance. Such nondestructive inspection is called eddy current inspection.

As a detection sensor used when inspecting a sample of a transmission line by a conventional vortex flaw detection method, a method of inserting a test body such as a transmission line into a detection sensor made of a solenoid and applying AC power to the coil is used.

As described above, when AC power is applied to a detection sensor made of a solenoid, a magnetic field is formed in the coil, and an eddy current is generated in the transmission line by the magnetic field. The eddy currents thus generated form a new magnetic field in the opposite direction to the human magnetic field, and these two types of magnetic fields result in a change in the impedance of the solenoid, thereby measuring the change in electrical characteristics connected in parallel to the solenoid. Detect changes In addition, the degree of corrosion of the transmission line is detected by comparing the change in electrical characteristics measured by the method described above with the standard data on the change in electrical characteristics of the transmission line in which normal transmission lines and various internal corrosion occurrences are confirmed.

However, in the case of the detection sensor provided with the solenoid wound long as described above, there are many difficulties in inspecting the transmission line or the elongated transmission line actually installed in the pole. In other words, the work required to dismantle the transmission line installed in the electric pole to insert the transmission line into the solenoid. As a result, it is not only time-consuming to inspect the degree of internal corrosion of the already installed transmission line, but also has a problem in that work is not easy and a lot of manpower and expense are required.

Therefore, in order to solve the problem of the wire corrosion detection sensor made of the above-mentioned cylindrical solenoid, the coil is made of a semi-cylindrical coil and the semi-cylindrical coil can be combined with a cylindrical coil to have the same effect as the solenoid. It is an object of the present invention to provide a wire corrosion detection sensor that can be easily inserted and removed from the inside of the detection sensor.

In the present invention for achieving the above object, the upper semi-cylindrical coil portion wound with the conductive wire so that the circular current flows in the same direction in the adjacent conductive wires,

Symmetrical with the upper semi-cylindrical coil part to form a cylinder when mutually coupled, and in the mutually adjacent conductors the current flow direction is the same, and the current in the same direction on the same cylinder and the circular current flowing through the upper semi-cylindrical coil A lower semi-cylindrical coil part in which a conductive wire is wound so that

It is connected to both terminals of the upper semi-cylindrical coil portion and the lower semi-cylindrical coil portion to provide a detection sensor of the corrosion detection device used to measure the inner precision of the wire consisting of a measuring device for measuring a change in electrical characteristics.

According to the present invention described above, since the upper semi-cylindrical coil part and the lower semi-cylindrical coil part can be easily inserted into and removed from the detection sensor, the degree of corrosion of the transmission line can be easily detected without cutting the transmission line even where the transmission line is installed. I can do it.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1A shows an ACSR wire in a general transmission line, and shows that a plurality of aluminum wires 2 are provided in a multi-layer structure on an outer surface thereof, and a strong core wire 1 is provided therein.

FIG. 1B is a cross-sectional view of the ACSR wire shown in FIG. 1A. For example, a zinc film 3 is plated on the surface of the steel core element 1 shown in FIG. It is shown to be configured to prevent corrosion in combination.

2 shows a detection sensor 14 for detecting internal corrosion of a transmission line manufactured according to the prior art. The detection sensor 14 includes a measuring device 13 for measuring a change in electrical characteristics at both terminals of the solenoid 11. Is connected.

On the other hand, in order to detect the degree of corrosion of the transmission line 10 as described above when inserting the transmission line 10 inside the detection sensor 14 and applying the AC power supply 12 to both terminals of the solenoid 11 According to whether the transmission line 10 is corroded or not, the electrical characteristic change, for example, the impedance is changed, which is measured by the measuring device 13.

The problem and operating principle of the detection sensor 14 made of the solenoid described above have been mentioned in the above prior art, and thus description thereof will be omitted.

3 is a view showing the upper semi-cylindrical coil 41 and the lower semi-cylindrical coil 42 of the detection sensor manufactured by the present invention, wherein the upper semi-cylindrical coil 41 is formed of the first and second coils 31. 32, the lower semi-cylindrical coil 42 is provided with third and fourth coils 33 and 34, and both terminals of the first to fourth coils 31, 32, 33 and 34 are ai, ao, bi, bo, ci, co, di, do, respectively, and one side of the terminal, for example, the ai, bi, ci, di of the first to fourth coils (31, 32, 33, 34) When the current flows in, the direction of the current becomes like an arrow. As will be described later, in the case of the first to second coils, the direction of current flow between adjacent conductors is the same, which is the same in the third and fourth coils.

In the figure, coils wound at the center portion have a circular current in a counterclockwise direction, whereas coils wound at both ends have a circular current in a clockwise direction.

When the upper semi-cylindrical coil 41 and the lower semi-cylindrical coil 42 are combined in a cylindrical shape, they act as if a circular current flows like a conventional solenoid. At this time, when the upper semi-cylindrical coil 41 and the lower semi-cylindrical coil 42 correspond to each other when coupled in a cylindrical shape, current flowing in the closest portion is different from the upper semi-cylindrical coil 41 and the lower semi-cylindrical coil 42. The magnetic fields generated in this part cancel each other out in opposite directions.

FIG. 4 shows one terminal (ai, bi, ci, di) of the first to fourth coils 31, 32, 33 and 34 provided in the upper and lower semi-cylindrical coils 41 and 42 shown in FIG. ) And an AC power source 44 connected to the measuring device 45 for measuring a change in electrical characteristics to the other terminals ao, bo, co, and do of the first to fourth coils 31, 32, 33, and 34. Shows that.

For reference, when the AC power supply 44 constantly applies voltage or current, the impedance generated in the coil varies according to the degree of corrosion of the transmission line inserted into the detection sensor. I can measure it.

FIG. 5 is a perspective view showing the coil portion of the detection sensor 25 manufactured according to the present invention, wherein the first and second coils are formed on the surface of the upper semi-cylindrical panel 22 and the surface of the lower semi-cylindrical panel 21. 31 and 32 and the third and fourth coils 33 and 34 are wound a plurality of times, respectively, and the coils are adjacent to the first and second coils 31 and 32 and the third and fourth coils 33 and 34. In the central portion is wound so that the circular current flows in the same direction.

The direction of the circular current flowing in the coils located at the center and left and right ends of the detection sensor 25 is reversed, and the part in which the coils are densely wound in the detection sensor 25 is divided into three areas. The spaces are spaced apart at regular intervals, of which the area used as the sensing part is the center part and the length is L, and other areas except the center part of the detection sensor 25 are used as the non-sensing part.

For reference, in order to facilitate opening and closing of the upper semi-cylindrical panel 22 and the lower semi-cylindrical panel 21, for example, the hinge 26 on one side of the upper semi-cylindrical panel 22 and the lower semi-cylindrical panel 21. It may be provided with a fixing means (not shown) on the opposite side. In addition, while the upper semi-cylindrical panel 22 and the lower semi-cylindrical panel 21 are inserted, a separate auxiliary means capable of opening and closing the plate cylindrical panel can be used.

A coil is wound around the surface of the semi-cylindrical panel in turn, and thus a method of winding the coil in such a manner that the current flowing in the adjacent conductor is the same will be described in more detail with reference to FIG. 6.

6 illustrates a method of winding a coil on the semi-cylindrical panel. For example, when the first coil 31 is wound on the upper semi-cylinder panel 22, the upper and lower sides of the upper semi-cylindrical panel 22 are wound. For example, C1..C10 and K1..K10 protruding members 23 are provided at an end spaced apart from each other by a predetermined interval, and one terminal terminal ai of the first coil 31 is disposed in the same current direction in adjacent conductors. It is drawn out from the outermost projection member, and the other terminal ao of the first coil 31 is drawn out to the inner projection member. That is, the winding direction of the coil continues in the order of the outermost protrusion member C1 to K1, K10, C10, C2, K2, K9, and C9 and is drawn out to the outside through the innermost protrusion members K6 and C6. The coil wound on the protruding members in the clockwise direction, and the coil wound on the protruding members on the right side is wound so as to proceed in the counterclockwise direction.

For reference, the spacing between C5, K5 and C6, K6 of the protruding member should be larger than the spacing between the other protruding members so as not to affect the sensing region by the coil wound in the non-sensing region.

The coil is wound around the second coil 32 and the first coil 31 has a symmetrical structure with respect to the center portion, and the third and fourth coils 33 and 34 are the first and second coils. The coil is wound in a vertical symmetrical structure with the coils 31 and 32.

Another embodiment of the present invention is similar to the above embodiment, but the first coil 31 and the third coil 33 on the upper semi-cylindrical coil 41 and the lower lower semi-cylindrical coil 42 of the detection sensor 25. Only to be provided, and to increase the number of turns. In this case, if only one side of the left and right sides is used as the sensing area, the same effects as in the above-described embodiment can be obtained.

On the other hand, the following factors affect the eddy current inspection method applied to the above-described sensor.

First, the applied AC frequency; If the AC frequency is large, the eddy current will be large, but the skin effect only affects the surface, so these two effects should be selected properly.

Second, the conductivity of the test object: The greater the conductivity, the greater the magnitude of the eddy current. However, the conductivity is inherent in the test subject and thus is not an externally controllable factor.

Third, the permeability of the test subject: The greater the permeability, the more eddy currents are generated.

Fourth, the shape and dimensions of the test coil and the relative position of the test coil and the test object.

The present invention described above is made of the upper semi-cylindrical coil and the lower semi-cylindrical coil to easily insert the transmission line into the detection sensor for detecting the corrosion degree of the transmission line, even without the transmission line is installed even when the transmission line is installed The degree of corrosion can be easily detected. As a result, the time used to detect the degree of corrosion of the transmission line can be saved, and the cost can be reduced by minimizing the required manpower.

Claims (17)

In the detection sensor for measuring the internal corrosion of the electric wire by the full flow flaw detection method, the upper semi-cylindrical coil portion wound so that the circular current flows in the same direction in the mutually adjacent conductors, and the upper semi-cylindrical coil portion is symmetrical with each other. The lower semi-cylindrical coil part is wound to form a cylinder when mutually coupled, and the current flowing in adjacent conductors is in the same direction, and the current flows in the same direction on the same circumference as the circular current flowing in the upper semi-cylindrical coil. And a wire corrosion detection sensor configured to be connected to both terminals of the upper semi-cylindrical coil part and the lower semi-cylindrical coil part to measure a change in electrical characteristics. The wire corrosion detection sensor of claim 1, further comprising a semi-cylindrical panel provided to support a coil inside the upper and lower semi-cylindrical coils. The wire corrosion detection sensor of claim 2, wherein the semi-circular ends of the semi-cylindrical panel include a plurality of protrusion members provided to engage when the coil is wound. The coil wound around the upper and lower semi-cylindrical coil parts is gradually inward from the outermost protrusion member among the plurality of protrusion members provided in the semi-cylindrical panel. Wire corrosion detection sensor, characterized in that the direction of the circular current is wound in the coil wound on the left and right side of the semi-cylindrical panel is reversed with each other. According to claim 1 or claim 2, wherein the upper semi-cylindrical coil portion of the first and second coils are wound independently of the left and right sides of the semi-cylindrical panel, and the lower semi-cylindrical coil portion of the semi-cylindrical panel Wire winding detection sensor, characterized in that consisting of a third coil and a fourth coil wound independently to have a symmetrical structure with the first coil and the second coil. 6. The method of claim 5, wherein the first coil is wound from the outermost projection member in the projection member provided in the left direction at the center of the semi-cylindrical panel is gradually wound to the inner projection member, the second coil is Wire corrosion detection sensor, characterized in that the winding from the outermost projection member of the projection member provided in the right direction in the center portion of the semi-cylindrical panel gradually to the inner projection member. The method of claim 6, wherein the first coil is wound from the upper side to the lower side of the left outermost of the semi-cylindrical panel, from the left to the right of the lower side, from the right to the upper side of the lower side, from the upper side to the upper side of the right side. Wire corrosion detection sensor. The method of claim 6, wherein the second coil is wound from the upper side to the lower side, the lower right side to the left side, the lower side to the upper side of the left side, and the upper left side to the right side of the semi-cylindrical panel. Wire corrosion detection sensor. According to claim 1, wherein the upper semi-cylindrical coil portion and the lower semi-cylindrical coil portion corresponding to the same circumference, while the same circular current flows while the upper semi-cylindrical coil portion and the lower semi-cylindrical coil portion both ends of the coil Wire corrosion detection sensor, characterized in that connected to the AC power in parallel with each other. The conductive wires of claim 5, wherein the conductive wires of the upper semi-cylindrical coil portion and the lower semi-cylindrical coil portion corresponding to the same circumference of the adjacent conductive wires have the same direction of the circular current while both ends of the first to fourth coils flow. Wire corrosion detection sensor, characterized in that connected to the AC power in parallel. The wire corrosion detection sensor according to claim 2, wherein a coil region of any one of coils wound on left and right sides of the semi-cylindrical panel is used as a sensing region. 6. The electric wire according to claim 5, wherein a wound area of the center of the upper and lower semi-cylindrical panels is used as a sensing area of the sensor among the first to fourth coils wound on the center of the upper and lower semi-cylindrical panels. Corrosion detection sensor. 3. The wire corrosion detection sensor according to claim 2, wherein an opening and closing means is provided on the surface of the semi-cylindrical panel or the outside of the semi-cylindrical panel so as to easily insert the electric wire into the upper and lower semi-cylindrical panels. In the detection sensor of the corrosion detection device used to measure the internal corrosion of the electric wire by the eddy current flaw detection method, the upper semi-cylindrical type in which the coil is wound on the surface of the semi-cylindrical panel so that the circular current flows in the same direction in adjacent conductors. The coil part and the upper semi-cylindrical coil part are symmetrical to form a cylinder when they are coupled to each other. In the adjacent wires, the currents flow in the same direction, and the same circular current flows in the upper semi-cylindrical coil. It is a measuring device that is connected to both terminals of the lower semi-cylindrical coil part, the coil of which is wound on the surface of the semi-cylindrical panel so that current flows in the direction, and the change of electrical characteristics. Wire corrosion detection sensor composed. The wire corrosion detection sensor according to claim 13, wherein the semi-circular ends of the semi-cylindrical panel include a plurality of protrusion members provided to engage when the coil is wound. The coil wound around the upper and lower semi-cylindrical coil portions is wound from the outermost projection member of the plurality of projection members provided on the semi-cylindrical panel to the inner projection member gradually. Wire corrosion detection sensor, characterized in that the direction of the circular current flowing through the coil wound on the left, right side of the semi-cylindrical panel opposite each other. 15. The coil of claim 14, wherein the upper semi-cylindrical coil part is wound on the left and right sides of the semi-cylindrical panel independently from the first coil and the second coil, and the lower semi-cylindrical coil part is independently on the left and right sides of the semi-cylindrical panel. Wire corrosion detection sensor consisting of a third coil and a fourth coil to be symmetrical structure with the first coil and the second coil.