【発明の詳細な説明】[Detailed description of the invention]
本発明は、アルミニウム撚線導体から成る超高
圧送電線のコロナ放電を防止する目的でその表面
を処理する方法に関するものである。
超高圧送電線のコロナ放電による可聴音は主に
降雨後電線に残留する雨滴によつて発生する。特
にこの可聴音は500kV以上の送電線で著しい。こ
のコロナ放電現象は布設後長時間経過した電線よ
りも新しい電線で顕著に発生することが経験上知
られている。その理由は撚線機を通つて出てきた
撚線（電線）は表面に油が付着しているのでこの
油によつて電線表面に雨の水滴が第２図Ｃのよう
に付着してコロナ放電を起すが、電線が古くなつ
てくると、電線の表面が汚れて雨が降つても水滴
は第２図Ａに示すようになつてコロナ放電の発生
が少なくなることにある。このような経験に基づ
いてコロナ放電を防止する方法が提案されてい
る。その１つは電線の素線表面に水酸基を有する
化合物を形成する方法（特公昭36―14076号）で
あり、他は電線の素線表面にサンドブラストによ
り粗面を形成する方法（特公昭36―14185号）で
ある。しかし、これらの方法はいずれも素線に表
面処理を施すのでその後これらの素線を撚る際に
相互の摩擦が大きくなつて撚ることが難しく機械
的損失が大きく、また素線間の摩擦によつて処理
された表面が破壊される欠点があつた。
本発明の目的は、撚線を困難にすることなく、
また超高圧下でもコロナ放電を発生することがな
いようにすることができるアルミニウム撚線導体
の表面処理方法を提供することにある。
本発明の実施例を図面を参照して詳細にのべる
と、第１図は本発明の方法を概略的に示す。アル
ミニウム撚線導体１０は図示しない撚線機によつ
て撚られた後粉末付着装置１２を通つて亜鉛、ア
ルミニウム、マグネシウムのいずれかの粉末又は
これらの２種以上の混合物の如き金属粉１４を付
着する。この金属粉の付着は撚線の表面に付着さ
れてコロナ放電の原因となつている油によつて行
なわれるので特別の付着手段を必要としない。次
いでこの金属粉１４が付着されたアルミニウム撚
線導体１０は加熱炉１６を通つて加熱されて油は
金属粉と共に焼付けられる。この加熱炉での加熱
温度は300℃以下とする。加熱時間は300℃以下の
範囲内で温度が高くなるにつれて短かくなる。加
熱温度が300℃以上であるとアルミニウム素線が
軟化し劣化するので好ましくない。
次に本発明の方法とそれ以外の方法とを施した
横断面積が240mm2の鋼心アルミニウム撚線につい
て実験の結果を下記の表に示す。この実験では処
理後の撚線にシヤワーで注水し、１時間経過後注
水を止め、その直後に撚線表面の水滴の付着状態
を観察し、更にこの水滴が消滅するまでの時間を
測定した。尚、表中において水滴の付着状態の
Ａ，Ｂ，Ｃはそれぞれ第２図のＡ，Ｂ，Ｃを示
し、Ａは親水性が最もよくコロナ放電の発生が少
なく、Ｂ，Ｃと親水性が悪くコロナ放電が大きく
なる。
The present invention relates to a method for treating the surface of an ultra-high voltage power transmission line made of stranded aluminum conductors in order to prevent corona discharge. Audible sounds caused by corona discharge on ultra-high voltage power transmission lines are mainly caused by raindrops remaining on the power lines after rainfall. This audible sound is especially noticeable on power transmission lines of 500kV or higher. It is known from experience that this corona discharge phenomenon occurs more noticeably in new electric wires than in electric wires that have been installed for a long time. The reason for this is that the stranded wire (electric wire) that comes out of the stranding machine has oil attached to its surface, and this oil causes rain droplets to adhere to the surface of the wire as shown in Figure 2 C, creating a corona. However, as the wire gets older, the surface of the wire becomes dirty and even when it rains, water droplets form as shown in Figure 2A, which reduces the occurrence of corona discharge. Based on such experience, methods for preventing corona discharge have been proposed. One of them is a method of forming a compound having a hydroxyl group on the surface of an electric wire (Japanese Patent Publication No. 14076, 1976), and the other is a method of forming a rough surface by sandblasting on the surface of an electric wire (Japanese Patent Publication No. 14076, 1983). No. 14185). However, in both of these methods, surface treatment is applied to the strands, so when these strands are twisted afterwards, mutual friction increases, making it difficult to twist, resulting in large mechanical losses, and the friction between the strands increases. The disadvantage was that the treated surface was destroyed. The purpose of the present invention is to avoid making twisting difficult;
Another object of the present invention is to provide a surface treatment method for aluminum stranded wire conductors that can prevent corona discharge from occurring even under ultra-high pressure. Embodiments of the invention will now be described in detail with reference to the drawings, in which FIG. 1 schematically shows the method of the invention. After the aluminum stranded wire conductor 10 is twisted by a twisting machine (not shown), it passes through a powder coating device 12 and is coated with metal powder 14 such as zinc, aluminum, or magnesium powder or a mixture of two or more of these. do. The attachment of the metal powder is carried out by the oil that is attached to the surface of the stranded wire and causes corona discharge, so no special attachment means is required. Next, the aluminum stranded wire conductor 10 to which the metal powder 14 is attached is heated through a heating furnace 16 so that the oil is baked together with the metal powder. The heating temperature in this heating furnace is 300°C or less. The heating time becomes shorter as the temperature increases within a range of 300°C or less. If the heating temperature is 300° C. or higher, the aluminum wire will soften and deteriorate, which is not preferable. Next, the results of experiments on steel-core aluminum stranded wires having a cross-sectional area of 240 mm 2 which were subjected to the method of the present invention and other methods are shown in the table below. In this experiment, water was poured into the stranded wire after treatment using a shower, water injection was stopped after one hour, and immediately after that, the adhesion state of water droplets on the surface of the stranded wire was observed, and the time until the water droplets disappeared was measured. In addition, in the table, A, B, and C in the state of water droplet adhesion indicate A, B, and C in Figure 2, respectively, and A has the best hydrophilicity and less occurrence of corona discharge, and B and C have the highest hydrophilicity. Worse, corona discharge becomes larger.
【表】
上記の表から明らかなように本発明の例の１〜
７では比較例12と同様に親水性を有し水滴の発生
が少なく消滅も短時間でコロナ放電が少ないこと
が判る。比較例10では親水性がよいが、300℃の
加熱であるため素線が軟化し、また鋼心の亜鉛メ
ツキ層が部分的に剥れるため好ましくない。尚、
親水性を付与する面からは亜鉛、アルミニウム、
マグネシウム以外の金属粉も考えられるが、他の
金属粉では処理後大気中で腐蝕を起すので上記の
３つのいずれかがよい。
本発明によれば、上記のように、撚線後に表面
処理するので撚線作業は抵抗なく容易に行うこと
ができ、また表面処理によつて親水性が向上し水
滴の発生が少なくその消滅が短時間であるのでコ
ロナ放電が少なくて済み、騒音の発生、電気的損
失を防止することができる。更に金属粉を付着し
て加熱するので加熱時間が少なくて済む上に特別
の付着手段を必要としないため作業性がよく、且
つ金属粉は耐蝕性のよいものを用いるので品質を
低下することはない。[Table] As is clear from the above table, Examples 1 to 1 of the present invention
It can be seen that Sample No. 7 has hydrophilic properties similar to Comparative Example 12, generates few water droplets, disappears in a short time, and has little corona discharge. Comparative Example 10 has good hydrophilicity, but heating at 300°C softens the strands and partially peels off the galvanized layer of the steel core, which is not preferable. still,
Zinc, aluminum,
Metal powders other than magnesium may also be considered, but since other metal powders will corrode in the atmosphere after treatment, any of the three mentioned above is preferable. According to the present invention, as described above, since the wire is surface-treated after the wire is twisted, the wire-twisting work can be easily performed without resistance, and the surface treatment improves hydrophilicity, which reduces the generation of water droplets and prevents their disappearance. Since the time is short, there is less corona discharge, and noise generation and electrical loss can be prevented. Furthermore, since the metal powder is attached and heated, the heating time is short and no special attachment means are required, making it easy to work with.Also, since the metal powder used has good corrosion resistance, there is no deterioration in quality. do not have.
【図面の簡単な説明】[Brief explanation of the drawing]
第１図は本発明の方法を実施する装置の概略系
統図、第２図は撚線に付着すする水滴の状態を示
す概略断面図である。
１０……アルミニウム撚線導体、１４……金属
粉、１６……加熱炉。
FIG. 1 is a schematic system diagram of an apparatus for carrying out the method of the present invention, and FIG. 2 is a schematic sectional view showing the state of water droplets adhering to twisted wires. 10...Aluminum stranded wire conductor, 14...Metal powder, 16...Heating furnace.