JP2005218279A - Mounting object for reducing wind noise of overhead transmission line - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce corona ham noise generated attributable to corona discharge when water is adhered while suppressing wind noise. <P>SOLUTION: Super hydrophilic treatment is applied on the surface of a mounting object 2 for reducing the wind noise of an overhead transmission line 1 which is fitted by spiral winding or the like around the surface of the overhead transmission line 1 to reduce wind noise generated by the overhead transmission line 1, wettability is improved, and a contact angle with water adhered on the surface is changed smaller to reduce the corona ham noise generated when the water is adhered. When super a hydrophilic coating is applied to the surface of the fitting stuff 2 for reducing wind noise, the super hydrophilic coating is preferably formed of a super hydrophilic material containing a titanium oxide. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an attachment for reducing wind noise of an overhead power transmission line. More specifically, the present invention is a technique for reducing corona ham noise generated during rainfall in an overhead power transmission line having a wind noise reduction attachment mounted on its surface, such as by winding a wind noise reduction spiral line. About.

  When wind blows to an overhead transmission line in a power transmission system, particularly a high-voltage power transmission system, an unpleasant wind noise may occur due to eddy current (Karman vortex) generated on the back side of the electric wire. Conventionally, as one of the techniques for reducing such a so-called wind noise, there is a technique of forming a step by winding a spiral wire for wind noise countermeasures on the surface of an electric wire (see Patent Document 1). The overhead power transmission wind noise reduction attachment is a member made of, for example, aluminum and having a length of about several tens of centimeters, and is wound spirally around the surface of the electric wire. Makes it possible to significantly reduce wind noise.

  On the other hand, when water drops adhere to the surface of an overhead power transmission line during rain, corona discharge may occur from the water drop, resulting in corona noise. As described above, spiral lines are wound around the power transmission line surface to form steps. If this is the case, there is a problem that the corona noise characteristic is deteriorated as a result of water droplets being easily collected at the stepped portion. In other words, the spiral wire for the overhead power transmission line exhibits the effect of reducing wind noise, but on the structure that the spiral wire is spirally wound around the surface of the smoothly formed electric wire, There is a problem that the electric field at the end of the protruding portion (spiral line) becomes high and corona discharge is likely to occur. Especially in the case of light rain like drizzle, fine water droplets adhere to this spiral line, and even higher protrusions are formed, and the adhesion time until it falls from the spiral line becomes longer, from which corona discharge occurs and the transmission line It may cause audible corona noise problems and radio / radio disturbances along the line. Such corona noise includes random noise of audible noise from about 500 Hz to about 20 kHz and corona hum sound having a frequency twice the power supply frequency. The latter corona hum sound is 100 Hz and 60 Hz in an area where the power supply frequency is 50 Hz. Although it will be generated as 120Hz sound in the area, this corona hum sound is not so much in nature, so it is easily perceived as noise by humans, and it is an important issue among corona noise in terms of environment. ing.

  Thus, conventionally, in order to effectively reduce the corona hum sound, the number of spiral wires in the overhead power transmission line and how to wind it has been devised, for example, based on the tendency that the corona hum sound decreases as the number of spiral wires increases, Measures such as winding two spiral wires as a set around the transmission line so as to be always diagonal, or winding three spiral wires as a set around the transmission line so as to be equidistant from each other are being considered. ing. Furthermore, measures to change the thickness of the spiral line are also being considered. In addition, a technique has been proposed in which the spiral wire has a non-circular cross-sectional shape or the resin film has a non-circular cross-sectional shape whose height is smaller than the width (see Patent Document 1 above).

JP 2000-278850 A

  However, even when the number of spiral lines is increased in this way, water droplets naturally adhere to the spiral lines, so it is not possible to effectively suppress the corona hum sound. It may be a situation that hinders the reduction of wind noise, which is the purpose of this. In addition, measures other than increasing the spiral line, for example, measures such as changing the cross-sectional shape as described above, have not led to effective reduction of corona hum noise. In addition, if measures are taken to make the cross section of the spiral wire irregular, it is difficult to effectively use a spiral wire that has been used or is expected to be used in the future (generally a circular shape). Become.

  Then, an object of this invention is to provide the attachment for wind noise reduction of an overhead power transmission line which can reduce effectively the corona hum sound which arises when water adheres.

  In order to achieve such an object, the present inventor has conducted various studies and tests, and has come to know a technique for reducing corona hum noise while suppressing wind noise. The present invention is based on such knowledge, and the invention according to claim 1 is an overhead transmission line that is mounted on the surface of the overhead transmission line by being spirally wound or the like and reduces wind noise generated in the overhead transmission line. In the wind noise reduction attachment, the surface is subjected to super hydrophilic treatment. Here, “superhydrophilic treatment is applied” refers to all treatments for imparting some superhydrophilicity to the surface of the wind noise reduction attachment. In addition, the “wind noise reduction attachment” in this specification includes not only a spiral wire that is generally used, but also a wire that runs along a thin wire parallel to the power transmission wire, or parallel to the spiral wire. This includes everything that is attached to the surface to reduce wind noise in overhead power transmission lines, such as those combined with wires.

  According to a second aspect of the present invention, in the attachment for reducing wind noise of an overhead power transmission line according to the first aspect, a super hydrophilic coating is formed by applying a super hydrophilic coating.

  The hydrophilic paint in this case is preferably made of a superhydrophilic material containing titanium oxide as described in claim 3. The term super-hydrophilicity expresses a state where the property as hydrophilicity is more exerted, and it is an expression that is commonly used as can be seen from the fact that paint is used on, for example, mirror surfaces and building exterior walls. Further explanation will be given here, which means that when water adheres to the surface, the water does not form water droplets and spreads uniformly over the surface or is completely adapted to the surface. To further explain, the contact angle with water on the surface of a substance called hydrophilic (the angle formed between the tangent of the droplet and the solid surface) is usually about 20 to 30 degrees (see FIG. 5). In the case of super hydrophilicity, the value is greatly below this value, and in some cases it is 10 degrees or less, and generally 0 degrees. In other words, in the case of super-hydrophilicity, the wettability of the attached water is remarkably improved as a result of sufficient compatibility with water, the fluidity becomes extremely high, and a uniform thin water film is formed without water droplets. become. In addition, titanium oxide contained in superhydrophilic materials is a functional material that is used for photocatalysts, and when used as superhydrophilic materials for attachments to reduce wind noise in overhead power transmission lines. In addition, the wettability in the wind noise reduction attachment is greatly improved to increase the water fluidity.

  When the super-hydrophilic treatment is performed as in the invention of claim 1, the affinity between the wind noise reduction attachment and water becomes stronger, and the wettability on the surface of the wind noise reduction attachment becomes better. Even if rainwater adheres to the surface of the wind noise reduction fitting, the rainwater moves to the lowest point without slipping or forming almost no water droplets. Then slide down from there (see FIGS. 1 and 2). In this case, the time required for the water to adhere to the surface of the wind noise reduction attachment, that is, the time required for running out of water is shorter than before, and large water droplets are formed on the wind noise reduction attachment. Therefore, the corona hum sound is surely reduced as compared with the case where such super hydrophilic treatment is not performed. In other words, if there is a protrusion on the surface of the transmission line, a discharge that induces a corona hum sound (this corona discharge may be expressed as “corona ham discharge” in particular in this specification) is likely to occur. Both the wind noise and the corona ham noise can be simultaneously reduced by hydrophilizing the surface while maintaining the existing state of the object. Moreover, since it is not necessary to make the cross-section of the wind noise reduction attachment unusual, it is possible to effectively use the wind noise reduction attachment of a general shape that has been used or is expected to be used in the future, It is also advantageous in terms of cost.

  According to the second aspect of the present invention, the superhydrophilic paint applied to the surface of the wind noise reduction attachment exhibits superhydrophilicity, and immediately reduces the water adhering to the wind noise reduction while forming almost no water droplets. Corona ham noise that may be generated from the wind noise reduction attachment is reduced by acting to slide off the attachment. In addition, according to the present invention, super hydrophilicity can be imparted by a coating operation, so that there is an advantage that the operation is often relatively simple.

  According to the invention of claim 3, since the titanium oxide or the superhydrophilic material containing this titanium oxide is applied to the surface of the wind noise reduction attachment, the surface of the wind noise reduction attachment and water As a result, the water does not become water droplets on the surface, but a film is always stretched and water droplets are hardly formed. Accordingly, the wettability of the attached water is remarkably improved, the fluidity is extremely high, water droplets or the like are hardly formed, and the corona hum generated due to the corona discharge is further reduced.

  Hereinafter, the configuration of the present invention will be described in detail based on embodiments shown in the drawings.

  1 to 2 show an embodiment of the present invention. The wind noise reduction attachment 2 for the overhead power transmission line 1 according to the present invention is mounted by being spirally wound around the overhead power transmission line 1 to reduce wind noise generated in the overhead power transmission line 1. In the form, the surface is a super-hydrophilic surface. For example, in the case of this embodiment, the surface of the attachment 2 for reducing wind noise is subjected to super hydrophilic treatment so that a uniform film of water is stretched. In other words, if there are any protrusions on the surface of the overhead power transmission line 1, corona ham discharge is likely to occur from the water droplets collected there, but this protrusion (that is, the wind noise reduction attachment 2) remains on the surface as it is. By performing the superhydrophilic treatment, it is possible to suppress an increase in the electric field at the end of the protrusion, and to simultaneously and effectively reduce both corona ham discharge and wind noise.

  The overhead power transmission line 1 in the present embodiment is not particularly novel, and includes all of the electric wires that may cause wind noise and corona discharge as they are or in which a protrusion such as a spiral is formed on the surface thereof. . Therefore, not only wires that are actually installed and used at present, but also new wires that appear in the future due to improvements in materials and structures may cause wind noise and corona discharge, and some measures are required. Anything can be applied to the wind noise reduction fitting 2 for the overhead power transmission line 1 according to the present invention.

  In addition, the wind noise reduction attachment 2 according to the present invention includes, as described above, an overhead power transmission line 1 such as a structure in which a thin line is parallel to the overhead power transmission line 1 or a combination of a spiral line and a parallel line. In the following, a spiral line generally used as a “wind noise reduction attachment” (hereinafter referred to as “spiral line 2”) is used. The embodiment to which the present invention is applied will be described.

  The spiral line 2 in the present embodiment serves to reduce wind noise by partially preventing the generation of eddy currents on the back side of the overhead power transmission line 1. The structure does not need to be changed from the existing one. For example, the spiral wire 2 may have a convex shape formed on the surface thereof at the same time as the overhead power transmission line 1 is manufactured, or a member such as a spiral rod may be retrofitted to the surface after the overhead power transmission wire 1 is manufactured. In short, it is sufficient if it can function in an actually installed state in order to reduce wind noise in the transmission line. In addition, when retrofitting the spiral wire 2, the work of sequentially winding a single member wire around the entire overhead power transmission line 1 extending to several tens or hundreds of meters is complicated, but the length of the wire is, for example, about 2 m. If the spiral rods are formed by dividing them into pieces, and these are sequentially connected and wound around the surface of the overhead power transmission line 1, the work becomes easier. As the material of the spiral wire 2, for example, a hard material mainly made of aluminum is generally used, but other than this, for example, it can be made of rubber having low conductivity.

  In the present embodiment, the spiral wire 2 as described above exhibits super hydrophilicity on the surface thereof, and does not retain water adhering to the surface of the spiral wire 2 due to rainfall, so that the lowermost portion of the spiral wire 2 is retained. The surface is subjected to super-hydrophilic treatment so as to exhibit the property of being immediately moved to and sliding down (see FIGS. 1 and 2). The super-hydrophilic treatment means a general treatment for imparting some super-hydrophilicity to the surface of the spiral wire 2 as described above. For example, in this embodiment, the surface of the spiral wire 2 is applied. However, the content of the hydrophilic treatment in this application is not particularly limited to such a coating, and at least the wettability of the surface of the spiral wire 2 is improved. Thus, it is sufficient if it exhibits super hydrophilicity. For example, if the surface of the spiral wire 2 is subjected to a blasting process such as sand blasting, it is equivalent to or less than the coating of a superhydrophilic paint so that it exhibits superhydrophilicity. This may correspond to the super-hydrophilic treatment referred to in the specification.

  In this way, when the surface of the spiral wire 2 is subjected to super hydrophilic treatment, it is possible to reduce water droplets as much as possible by utilizing the surface tension. That is, as a result of the action of surface tension, when the water droplets stick together, the surface area as a whole is reduced. As a result, the water droplets on the spiral line 2 are reduced and a thin film of water is formed on the surface. . In this case, the water newly adhering to the spiral wire 2 is integrated so as to be dissolved in the thin film, and is guided to the lowermost part to be drained. If it is done, it will only be of a size that does not cause a problem. Therefore, it is possible to further reduce the corona hum sound generated on the surface of the spiral wire 2 due to the corona ham discharge.

  In view of the above, it is preferable that the water thin film formed on the surface of the spiral wire 2 is as uniform as possible. For that purpose, it is preferable that the wettability on the surface of the spiral wire 2 is improved. From this viewpoint, it is preferable that the superhydrophilic treatment as described above is performed using a superhydrophilic material capable of exhibiting better wettability. In such a case, the surface of the spiral wire 2 and the water become more familiar with each other, the wettability of the attached water becomes much better, and the fluidity becomes extremely high. The contact angle of water on the surface of the superhydrophilic surface is extremely small in many cases such as almost 0 degrees, and a uniform thin water film is formed on the surface of the spiral line 2 without forming water droplets. (See FIGS. 1 and 2). According to this, it is possible to further reduce the corona hum generated due to the corona discharge on the surface of the spiral wire 2.

  Here, as the paint in the case of applying a superhydrophilic paint to the spiral wire 2, a paint containing titanium oxide which is the most specific and practical material showing superhydrophilicity at present is preferable. An example of a suitable superhydrophilic material is a coating agent in which titanium oxide is combined with silicone resin. This is based on the technology that forms a super-hydrophilic state in which water is familiar to the surface of the substance among the technologies including organic matter decomposition technology, etc., and the hydrophilic property is exhibited more strongly than the normal hydrophilic state. In order to achieve super hydrophilicity, titanium oxide is used which is considered to be the most concrete and effective at present. Titanium oxide is widely used as a photocatalytic material, and a thin film combining this titanium oxide with an appropriate composition initially has a contact angle with water of several tens of degrees. It decreases and finally becomes 0 degree, and exhibits a phenomenon that it does not play water at all (superhydrophilic). One reason for explaining why this phenomenon occurs is that a very small amount of hydrophobic molecules originally adsorbed on the surface of the material is decomposed by photocatalysis, resulting in a very thin physical adsorption water layer. There is an idea that it is for. In addition, although the titanium oxide considered to be the most suitable in the present situation was illustrated and explained here, the super hydrophilic material referred to in the present application is not limited to this titanium oxide.

  In addition, when the surface of the spiral wire 2 for the overhead power transmission line 1 is subjected to superhydrophilic treatment, a technique called “nanohydrophilicity” can be used. This nano-hydrophilic technology is a technology that forms a nano-sized water film by arranging a large number of silanol groups (Si-OH) on the surface of the material in the manufacturing process or after-treatment. Can be achieved. In general, there is data that water molecules in the atmosphere are continuously adsorbed on the surface of the outer wall material using nano-hydrophilicity and a thin water film is always formed. In view of the fact that it is not affected by daytime and nighttime, seasonal differences, etc., it is suitable for use in the spiral line 2 for the overhead power transmission line 1. In the case of utilizing such nano-hydrophilic technology, for example, a nanometer-size ultrafine silica solution is uniformly applied onto the coating film, and the membrane is formed by the water retention action of ultrafine silica that exhibits superhydrophilicity The technology of forming can also be used.

  According to the spiral wire 2 for the overhead power transmission line 1 of the present embodiment described so far, depending on the material of the super hydrophilic paint or the content of the super hydrophilic treatment, the spiral wire not subjected to the super hydrophilic treatment. The wettability on the surface is improved at least as compared to 2, and when water adheres to the surface, the property that the water and the surface of the spiral wire 2 attract each other, that is, the affinity becomes stronger. The surface of the wire 2 spreads in the form of a film while flowing toward the lowest position of the spiral wire 2, and slides down from the spiral wire 2 at the lowest position (FIG. 1, (See FIG. 2). In this case, specific numerical values such as the speed at which water flows on the surface of the coating, the time from when the water adheres to sliding down are the factors such as the material of the superhydrophilic paint or the content of the superhydrophilic treatment described above, and aging In addition, although it depends on natural factors such as the installation environment, weather, and timing of the overhead power transmission line 1, in any case, the water adhering to the surface of the spiral line 2 has a short time as described above. Soon, it will come off from this spiral wire 2, and the time which has stayed on the surface of the spiral wire 2 will be shortened reliably. Further, since the wettability is improved as described above by performing the super-hydrophilic treatment, the contact angle of water on the spiral wire 2 is about 4 degrees or less, generally 0 degrees, which can be said to be a general hydrophilic state. Thus, no protruding water droplets are formed on the spiral line 2, or even if formed, they are extremely small and gentle (see FIGS. 1 and 2). In addition, since a spiral path that allows easy flow of water is formed on the surface of the overhead power transmission line 1, drainage along this path is facilitated even when water adheres to the overhead power transmission line 1. Excellent. As a result, even if water adheres to the surface of the spiral wire 2 due to rain, the generation of corona ham discharge on the spiral wire 2 can be suppressed and the corona hum sound can be reduced. Needless to say, the spiral wire 2 for the overhead power transmission line 1 according to the present invention can also achieve the original purpose, that is, the purpose of reducing the so-called wind noise generated in the overhead power transmission line 1. It is possible to simultaneously solve the two problems of wind noise and corona hum noise.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, the spiral wire 2 targeted in the present embodiment is wound around the overhead power transmission line 1 in a spiral manner. However, when the spiral wire 2 is wound here, the spiral power wire 1 is predetermined as the spiral power wire 1. The case where it is in the state equivalent to being wound on the surface of the overhead power transmission line 1 is not limited to the case where it is attached to the place afterwards. That is, there is no point in that the spiral protrusion integrally formed on the surface of the overhead power transmission line 1 and the spiral wire 2 attached later as in the present embodiment are also formed to reduce wind noise. Accordingly, the technique according to the present invention is not changed, so that the same effects as those of the present embodiment can be obtained even when applied to the spiral protrusion formed integrally.

  Further, in the present embodiment, the case where the present invention is applied to the spiral wire 2 that is generally used as a “wind noise reduction attachment” has been described. However, as described above, “wind noise reduction” in this specification is described. All the items that are installed to reduce wind noise in the overhead power transmission line 1, such as those that are parallel to the overhead power transmission line 1 or a combination of spiral and parallel lines. Needless to say, the scope of application is not limited to the spiral line as described above.

Titanium oxide is sprayed onto the surface of spiral wire 2 to form a superhydrophilic film, and two spiral wires 2 having superhydrophilic surface characteristics are attached to the surface of bare aluminum electric wire ACSR810 mm ^{2 in} a close contact state. Electric wires were produced (see FIGS. 1 and 2). And it was confirmed how much difference was found in the state of water sliding down with the same type of electric wire (see FIGS. 3 and 4) in which no surface treatment was applied to the spiral wire 2. As a result, in the electric wire (FIGS. 1 and 2) in which the surface of the spiral wire 2 is super hydrophilic, the adhering water spreads in the form of a film on the surface of the spiral wire 2 and becomes the lowest part of the spiral wire 2. It was confirmed that it flowed to the position and slid down from the spiral line 2 at the lowest position. That is, it has been found that the water adhering to the surface of the spiral line 2 and the surface of the power transmission line does not stay on the surface for a long time and slides down in a short time, so that large water droplets are not formed on the surface of the spiral line 2.

  Then, it was tested to what extent the corona hum generated due to corona discharge was reduced (see FIG. 6). The horizontal axis in FIG. 6 uses the electric field level on the surface of the electric wire used in the actual overhead power transmission line 1 as a parameter, and the vertical axis shows the corona hum sound level. Moreover, the numerical values 14, 15, and 16 in the figure indicate the electric field level [kV / cm]. As a result of this test, it was confirmed that the corona hum sound generated from the spiral wire 2 was reduced as compared with the case of the normal spiral wire not subjected to the super hydrophilic treatment.

  Furthermore, a test was conducted to clarify the relationship between the elapsed time after water injection to the transmission line was stopped and the corona ham sound level (see FIG. 7). As described above, water was injected into the spiral wire (see FIGS. 1 and 2) subjected to the superhydrophilic treatment by spraying titanium oxide and the spiral wire not subjected to any surface treatment (see FIGS. 3 and 4). The corona ham sound level under an electric field level of 16 kV / cm after stopping water injection was measured. As a result, it was confirmed that the spiral wire subjected to the super hydrophilic treatment had better water drainage and the corona hum sound level was reduced earlier than the normal spiral wire not subjected to the surface treatment.

It is the image which closely imaged the state after pouring water on the overhead power transmission line and the spiral line to which the super hydrophilic treatment was performed. It is the image which image | photographed the mode after pouring water into an overhead power transmission line and the spiral wire to which the super hydrophilic treatment was performed. It is the image which imaged the state after pouring water on an overhead power transmission line and a normal spiral line. It is the image which image | photographed the mode after pouring water into an overhead power transmission line and a normal spiral line. It is the schematic which shows the contact angle between the water droplet adhering to the surface of a spiral line, and this spiral line surface. It is a graph which shows the result of having tested how much the corona hum sound in the spiral line in which the super-hydrophilic process was performed reduces compared with a normal spiral line. It is a numerical value and graph of the corona ham sound level at the time of a fixed time passage after water injection, showing the result of testing how much the corona ham sound in the spiral line subjected to super hydrophilic treatment is reduced as compared with a normal spiral line.

Explanation of symbols

1 Overhead power transmission line 2 Spiral line (wind noise reduction equipment)

Claims (3)

  A super-hydrophilic treatment is applied to the surface of an attachment for reducing wind noise generated in the overhead power transmission line that is mounted on the surface of the overhead power transmission line in a spiral manner, etc. An installation for reducing wind noise on overhead power transmission lines.   The attachment for reducing wind noise of an overhead power transmission line according to claim 1, wherein a super hydrophilic coating is formed by applying a super hydrophilic coating.   The attachment for wind noise reduction of an overhead power transmission line according to claim 2, wherein the super hydrophilic paint is made of a super hydrophilic material containing titanium oxide.