JP4043670B2

JP4043670B2 - Combined pipe and CV cable dry termination connection

Info

Publication number: JP4043670B2
Application number: JP30494399A
Authority: JP
Inventors: 徳偉米村; 宏明鈴木; 毅志後藤; 芳勝堀
Original assignee: Furukawa Electric Co Ltd; Tokyo Electric Power Co Inc
Current assignee: Furukawa Electric Co Ltd; Tokyo Electric Power Co Holdings Inc
Priority date: 1999-10-27
Filing date: 1999-10-27
Publication date: 2008-02-06
Anticipated expiration: 2019-10-27
Also published as: JP2001126562A

Description

【０００１】
【発明の属する技術分野】
本発明は、電力ケーブルの終端部等に設置される複合碍管と、ＣＶケーブル乾式終端接続部に関するものである。
【０００２】
【従来の技術】
複合碍管は軽くて扱い易いことから、送配電線での利用が増加している。従来の複合碍管は、図１４に示すように、ガラス繊維強化樹脂よりなる中空（又は中実）の芯材１と、この芯材１の上端及び下端に取り付けられた上部金具２及び下部金具３と、前記芯材１の外周面に被覆された高分子材料の絶縁被覆部４とで構成されている。絶縁被覆部４は円筒部４ａの外周に一定間隔で多数の笠部４ｂを形成した形態である。
【０００３】
芯材１を構成するガラス繊維強化樹脂のバインド材としては機械的強度と絶縁性にすぐれたエポキシ系樹脂が主に使用され、絶縁被覆部の高分子材料としては絶縁性と撥水性にすぐれたシリコーンゴムが主に使用されている。
【０００４】
芯材１が中空の場合は、中空部に電力ケーブル端末部を挿入した後、ケーブル端末部と芯材内面の間の空隙に、絶縁性の油又はコンパウンド等を充填して、電気絶縁性を高めている。
複合碍管に電力ケーブル端末部を挿入する場合は、ケーブルの端末部を段剥ぎした状態で挿入するが、そのままではケーブル絶縁層のシース先端部に電界が集中してしまうため、ケーブル端末部にストレスコーンを装着して電界を緩和している。
【０００５】
【発明が解決しようとする課題】
しかしながらストレスコーンを装着したとしても、ストレスコーンの外側に位置する複合碍管の芯材及び絶縁被覆部で電界が集中し、この電界集中部で絶縁破壊または表面閃絡を引き起こすという問題がある。さらに、ケーブル導体と直結している上部金具付近においても、電界の集中に起因する絶縁破壊または表面閃絡を引き起こすという問題がある。
【０００６】
同様な問題は、ＣＶケーブル（架橋ポリエチレン絶縁電力ケーブル）端部のケーブル絶縁体の外周に多段に笠部を有する高分子材料の絶縁被覆部を設け、この絶縁被覆部の基部とケーブル絶縁体との間にストレスコーンを設けてなるＣＶケーブル乾式終端接続部においても生じている。
【０００７】
本発明の目的は、以上のような問題点に鑑み、電界の集中を緩和して耐電圧特性を向上させた複合碍管及びＣＶケーブル乾式終端接続部を提供することにある。
【０００８】
【課題を解決するための手段】
この目的を達成するため本発明は、ガラス繊維強化樹脂よりなる芯材と、この芯材の上端及び下端に取り付けられた金具と、前記芯材の外周に被覆された多段に笠部を有する高分子材料の絶縁被覆部とからなる複合碍管において、前記絶縁被覆部の上端から上端と下端の間までの区間若しくは下端から下端と上端の間までの区間又はその両方の区間の、少なくとも内層部分を、前記絶縁被覆部より誘電率の高い高誘電率絶縁層で構成したことを特徴とするものである。
上記のように高誘電率絶縁層を設けると、電界の集中が緩和され、耐電圧特性が向上する。
【０００９】
高誘電率絶縁層は、電界の集中が最も厳しい、絶縁被覆部の下端からの中間までの区間、好ましくは絶縁被覆部の下端から絶縁被覆部の長さの１／３の区間に設けるとよい。
また高誘電率絶縁層は、電界の集中が厳しい、絶縁被覆部の上端からの中間までの区間、好ましくは絶縁被覆部の上端から絶縁被覆部の長さの２／３の区間に設けるとよい。
【００１０】
また高誘電率絶縁層は、誘電率５〜２０の材料で構成することが好ましい。これは、誘電率が５未満では所望の電界緩和効果をもたらすことができず、また誘電率が２０を越えると高誘電率絶縁層の先端に電界が集中し、そこが新たな電気的弱点となり易いからである。
また高誘電率絶縁層の厚さは、絶縁被覆部の円筒部の厚さの３／４以下であることが好ましい。これは、絶縁被覆部の外面まで高誘電率絶縁層が形成されていると、高誘電率絶縁層の先端部分への電界集中度が高くなり、高誘電率絶縁層を設けた効果が少なくなるからである。
【００１１】
また高誘電率絶縁層は、絶縁被覆部の笠部にも形成されていてもよい。
また本発明の中空の複合碍管を用いて電力ケーブル終端部を構成する場合は、内部に用いるモールド絶縁体、ストレスコーン及びケーブル絶縁体のいずれかの外周部又は全ての外周部に高誘電率絶縁層を設けると、同終端部の耐電圧特性の向上にさらに効果的である。
さらに、碍管の上端に位置する上部金具に、シールドリングを形成すると、碍管上端部における電界の緩和に、より効果的である。
【００１２】
また本発明は、ＣＶケーブル端部のケーブル絶縁体の外周に、多段に笠部を有する高分子材料の絶縁被覆部を設け、この絶縁被覆部の基部とケーブル絶縁体との間にストレスコーンを設けてなるＣＶケーブル乾式終端接続部にも適用でき、その場合は、前記絶縁被覆部の内層部分に、前記ストレスコーンの内部から外部にかけて高誘電率絶縁層を設けたことを特徴とするものである。
【００１３】
【発明の実施の形態】
以下、本発明の実施形態を図面を参照して詳細に説明する。図１〜図６はそれぞれ本発明に係る複合碍管の実施形態を示す。図において、１はガラス繊維強化樹脂よりなる中空の芯材、２は芯材１の上端に取り付けられた上部金具、３は芯材１の下端に取り付けられた下部金具、４は芯材１の外周に被覆されたシリコーンゴムよりなる絶縁被覆部、５は絶縁被覆部４の上端又は下端から中間（上端と下端の間）までの区間に設けられた高誘電率絶縁層である。絶縁被覆部４は従来同様、円筒部４ａと笠部４ｂから構成されている。
【００１４】
図１の複合碍管は、絶縁被覆部４の下端から絶縁被覆部の長さの１／３までの区間の、絶縁被覆部４の内層部分を高誘電率絶縁層５で構成したものである。
図２の複合碍管は、絶縁被覆部４の上端から絶縁被覆部の長さの２／３までの区間の、絶縁被覆部４の内層部分を高誘電率絶縁層５で構成したものである。
図３の複合碍管は、絶縁被覆部４の下端から絶縁被覆部の長さの１／５までの区間の、絶縁被覆部４の内層部分を高誘電率絶縁層５で構成したものである。
図４の複合碍管は、絶縁被覆部４の下端から絶縁被覆部の長さの１／３までの区間の、絶縁被覆部４の全層を高誘電率絶縁層５で構成したものである。
図５の複合碍管は、絶縁被覆部４の上端から絶縁被覆部の長さの２／３までの区間の、絶縁被覆部４の全層を高誘電率絶縁層５で構成したものである。
図６の複合碍管は、絶縁被覆部４の下端から絶縁被覆部の長さの１／３までの区間の、絶縁被覆部４の内層部分を笠部４ｂの内部も含めて高誘電率絶縁層５で構成したものである。
【００１５】
高誘電率絶縁層５は、エラストマー又はシリコーンゴムに、充填材としてカーボンブラック又は炭化珪素、酸化チタン若しくはチタン酸バリウム等の高誘電率粒子を配合したものである。ベースゴムにシリコーンゴムを使用すると、絶縁被覆部４との接着性がよくなるため界面特性が向上するという利点がある。また高誘電率絶縁層５は絶縁被覆部４と一体で架橋することが好ましい。両者を一体で架橋すると、両者間の接着性がさらによくなり、複合碍管の絶縁破壊特性をさらに向上させることができる。
また、高誘電率絶縁層及び／又は絶縁被覆部を構成するゴム組成物のベース材料として、接着性を有するものを使用すると、その界面あるいはゴム層とＦＲＰ層の界面の接着性が向上し、碍管全体の特性向上に効果的である。
【００１６】
充填材としてカーボンブラックを用いる場合、その添加量はベース樹脂１００重量部に対して１０〜１００重量部とすることが好ましい。また充填材として高誘電率粒子を用いる場合、その添加量はベース樹脂１００重量部に対して５０〜５００重量部とすることが好ましい。これは、ベース樹脂１００重量部に対し、カーボンブラックを１００重量部を越えて又は高誘電率粒子を５００重量部を越えて配合すると、得られるコンパウンドの可撓性が著しく低下するからである。
【００１７】
次に本発明の複合碍管の製造方法の一例を説明する。まずガラス繊維強化樹脂で中空円筒状の芯材１を製作し、その両端に金具２、３を圧着により取り付ける。次に芯材１の表面に高誘電率絶縁層５を設ける。高誘電率絶縁層５は芯材１上に金型成形するか、予めチューブ状に成形したものをゴム弾性力で芯材１上に被せることにより設けられる。
【００１８】
高誘電率絶縁層５を架橋する条件は使用する架橋剤によって異なる。架橋剤として過酸化物を使用する場合は、１５０℃から１８０℃で５分から３０分程度加熱する必要がある。また架橋剤として白金化合物を使用する場合は、７０℃から１８０℃で１分から６０分程度の加熱が必要となる。後者は比較的低温で架橋反応が進むのが特徴であり、架橋剤として白金化合物を使用することは、高誘電率絶縁層を架橋する際の熱履歴で芯材１の強度を低下させないという利点がある。また、高誘電率絶縁層５を芯材１上で架橋する際に、芯材表面にプライマー層を形成することにより芯材１と高誘電率絶縁層５の接着性を向上させることができる。
【００１９】
高誘電率絶縁層５を芯材１上に形成したのち、絶縁被覆部４を形成する。絶縁被覆部を形成する場合は、ベースゴムとしてシリコーンゴムを使用し、架橋剤として過酸化物又は白金化合物を使用する。シリコーンゴムは液状のものを使用すると笠部の成形性がよい。また高誘電率絶縁層の表面にプライマリー層を形成しておくと、高誘電率絶縁層と絶縁被覆部との接着性を高めることができる。
【００２０】
次に本発明の複合碍管を使用したケーブル終端接続部についての試験結果を、従来の複合碍管を使用したケーブル終端接続部と比較して表１に示す。交流破壊電圧は、初期課電電圧／時間が２００ｋＶ／３０分、ステップ課電電圧／時間が２０ｋＶ／３０分の条件で測定した。
【００２１】
【表１】

【００２２】
実施例１〜１０と従来例１の比較によれば、絶縁被覆部の上端から中間まで又は下端から中間までの少なくとも内層部分を高誘電率絶縁層で置換した複合碍管は、従来の複合碍管に比較して交流破壊電圧が向上していることがわかる。また実施例１と８、６と９の比較によれば、交流破壊電圧を向上させる効果は、高誘電率絶縁層の厚さが、シリコーンゴム層の厚さ４ｍｍに対して２〜３ｍｍである場合に最も大きいことがわかる。また実施例１と７の比較によれば、交流破壊電圧を向上させる効果は、高誘電率絶縁層の長さが長いほど大きいことがわかる。さらに実施例１〜４と従来例１の比較によれば、交流破壊電圧を向上させる効果は、高誘電率絶縁層の誘電率が５〜２０のときに大きいことがわかる。
【００２３】
図７は本発明の他の実施形態を示す。この複合碍管は、シリコーンゴムよりなる絶縁被覆部４の両端から笠２枚目までの区間（碍管表面の電界集中部）の、絶縁被覆部４の全層を高誘電率絶縁層５で構成したものである。それ以外の構成は図１〜図６に示した実施形態と同様であるので、同一部分には同一符号を付してある。図７のような構成にすると、絶縁被覆部４の両端部表面の電界集中が緩和され、碍管表面の漏れ電流を抑制することができ、耐電圧の高い複合碍管を得ることができる。
【００２４】
因みに、図８は図７の複合碍管の電界の解析結果を、図９は同じサイズの従来の複合碍管の電界の解析結果を示したものである。図８の方が絶縁被覆部の両端部で絶縁被覆部表面の電界が緩和されていることが分かる。図７の複合碍管の高誘電率絶縁層５はシリコーンゴムにカーボンブラックを混入して誘電率ε＝１０としたものである。カーボンブラックを混入しないシリコーンゴムは誘電率ε＝３〜４である。
【００２５】
次に図１０（ａ）は本発明に係るＣＶケーブル乾式終端接続部の一実施形態を示し、同図（ｂ）はそれに対応する従来のＣＶケーブル乾式終端接続部を示す。図において、１１はＣＶケーブル、１２はケーブル絶縁体、１３はケーブル導体、１４は導体引出棒、１５は上部金具、１６は下部金具、１７は多段に笠部を有するシリコーンゴム製の絶縁被覆部、１８はストレスコーンである。（ａ）の本発明の終端接続部が（ｂ）の従来の終端接続部と異なる点は、ストレスコーン１８近傍の絶縁被覆部１７内に２層に高誘電率絶縁層５ａ、５ｂを設けたことである。内層側の高誘電率絶縁層５ａはストレスコーン１８の内部から外部にかけて設けられ、外層側の高誘電率絶縁層５ｂはストレスコーン１８の外部に内層側の高誘電率絶縁層５ａと一部ラップするように設けられている。高誘電率絶縁層５ａ、５ｂとしては誘電率ε＝１０〜２０のものが用いられる。
【００２６】
図１１は図１０（ａ）の乾式終端接続部のストレスコーン付近の電界の解析結果を示す。これに対し高誘電率絶縁層が内層のみの場合の電界の解析結果は図１２のとおりであり、高誘電率絶縁層のない従来の乾式終端接続部の電界の解析結果は図１３のとおりであった。いずれも１５４ｋＶ乾式終端接続部で、高誘電率絶縁層５ａ、５ｂの誘電率ε＝１５、絶縁被覆部１７の胴部の最大径１７０mm、笠部の最大径２９０mm、基準電圧は９３ｋＶ（＝154 ×√3 ×1.15/1.1）である。図１２のものは図１３のものより絶縁被覆部表面の電界が緩和され、図１１のものは図１２、図１３のものより絶縁被覆部表面の電界が大幅に緩和されることが分かる。絶縁被覆部１７の表面の最大電界は、図１３のもので1.08ｋＶ／mm、図１２のもので1.04ｋＶ／mm（従来より３％低減）、図１１のもので0.98ｋＶ／mm（同10％低減）であった。
【００２７】
【発明の効果】
以上説明したように本発明によれば、ガラス繊維強化樹脂よりなる芯材の外周に高分子材料の絶縁被覆部を設けた複合碍管及び高分子材料の絶縁被覆部を有するＣＶケーブル乾式終端接続部の耐電圧特性を向上させることができる。
【図面の簡単な説明】
【図１】本発明に係る複合碍管の一実施形態を示す半截正面図。
【図２】本発明に係る複合碍管の他の実施形態を示す半截正面図。
【図３】本発明に係る複合碍管のさらに他の実施形態を示す半截正面図。
【図４】本発明に係る複合碍管のさらに他の実施形態を示す半截正面図。
【図５】本発明に係る複合碍管のさらに他の実施形態を示す半截正面図。
【図６】本発明に係る複合碍管のさらに他の実施形態を示す半截正面図。
【図７】本発明に係る複合碍管のさらに他の実施形態を示す断面図。
【図８】図７の複合碍管の電界の解析結果を示すグラフ。
【図９】図７の複合碍管に対応する従来の複合碍管の電界の解析結果を示すグラフ。
【図１０】（ａ）は本発明に係るＣＶケーブル乾式終端接続部の一実施形態を示す半截正面図、（ｂ）は（ａ）の終端接続部に対応する従来のＣＶケーブル乾式終端接続部を示す半截正面図。
【図１１】図１１（ａ）の終端接続部の電界の解析結果を示すグラフ。
【図１２】図１１（ａ）と同様な終端接続部で、高誘電率絶縁層が１層の場合の解析結果を示すグラフ。
【図１３】図１１（ａ）の終端接続部に対応する従来のＣＶケーブル乾式終端接続部の電界の解析結果を示すグラフ。
【図１４】従来の複合碍管の一例を示す半截正面図。
【符号の説明】
１：芯材
２：上部金具
３：下部金具
４：絶縁被覆部
４ａ：円筒部
４ｂ：笠部
５：高誘電率絶縁層
１１：ＣＶケーブル
１２：ケーブル絶縁体
１３：ケーブル導体
１７：絶縁被覆部
１８：ストレスコーン
５ａ、５ｂ：高誘電率絶縁層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a composite steel pipe installed at a terminal end portion of a power cable and a CV cable dry terminal connecting portion.
[0002]
[Prior art]
Since composite steel pipes are light and easy to handle, their use in transmission and distribution lines is increasing. As shown in FIG. 14, the conventional composite steel pipe includes a hollow (or solid) core material 1 made of glass fiber reinforced resin, and an upper metal fitting 2 and a lower metal fitting 3 attached to the upper and lower ends of the core material 1. And an insulating coating portion 4 made of a polymer material coated on the outer peripheral surface of the core material 1. The insulation coating portion 4 has a form in which a large number of shade portions 4b are formed at regular intervals on the outer periphery of the cylindrical portion 4a.
[0003]
Epoxy resin with excellent mechanical strength and insulation is mainly used as the binding material of the glass fiber reinforced resin constituting the core material 1, and the insulation and water repellency are excellent as the polymer material of the insulation coating portion. Silicone rubber is mainly used.
[0004]
When the core material 1 is hollow, after inserting the power cable end portion into the hollow portion, the gap between the cable end portion and the inner surface of the core material is filled with insulating oil or compound, etc. It is increasing.
When inserting a power cable end into a composite steel pipe, the cable end is inserted in a stripped state, but if it is left as it is, the electric field concentrates on the sheath tip of the cable insulation layer, so stress is applied to the cable end. A cone is attached to ease the electric field.
[0005]
[Problems to be solved by the invention]
However, even if the stress cone is mounted, there is a problem that the electric field concentrates on the core material and the insulating coating portion of the composite soot tube located outside the stress cone, and this electric field concentration portion causes dielectric breakdown or surface flashing. In addition, there is a problem that dielectric breakdown or surface flashing is caused near the upper metal fitting directly connected to the cable conductor due to concentration of the electric field.
[0006]
A similar problem is that an insulating coating portion made of a polymer material having multiple shades is provided on the outer periphery of the cable insulator at the end of the CV cable (cross-linked polyethylene insulated power cable). This also occurs in the CV cable dry-type terminal connection portion in which a stress cone is provided therebetween.
[0007]
In view of the above-described problems, an object of the present invention is to provide a composite soot tube and a CV cable dry termination connection portion in which the electric field concentration is reduced and the withstand voltage characteristics are improved.
[0008]
[Means for Solving the Problems]
In order to achieve this object, the present invention provides a core material made of glass fiber reinforced resin, metal fittings attached to the upper end and the lower end of the core material, and a multi-stage covering portion coated on the outer periphery of the core material. in the composite ceramic tube made of an insulating covering part of the molecular material, the insulating coating part from the upper end of the section, or both from the section or the lower end up between the upper and lower ends to between the lower end and the upper end section of at least an inner layer portion , And a high dielectric constant insulating layer having a dielectric constant higher than that of the insulating coating portion.
When the high dielectric constant insulating layer is provided as described above, the concentration of the electric field is alleviated and the withstand voltage characteristics are improved.
[0009]
The high-dielectric-constant insulating layer is provided in a section from the lower end of the insulating coating portion to the middle where the electric field concentration is most severe, preferably in a section of 1/3 of the length of the insulating coating portion from the lower end of the insulating coating portion. .
The high dielectric constant insulating layer may be provided in a section where the concentration of the electric field is severe and from the upper end of the insulating coating part to the middle, preferably in a section of 2/3 of the length of the insulating coating part from the upper end of the insulating coating part. .
[0010]
The high dielectric constant insulating layer is preferably composed of a material having a dielectric constant of 5 to 20. This is because if the dielectric constant is less than 5, the desired electric field relaxation effect cannot be achieved, and if the dielectric constant exceeds 20, the electric field concentrates on the tip of the high dielectric constant insulating layer, which becomes a new electrical weak point. It is easy.
Further, the thickness of the high dielectric constant insulating layer is preferably 3/4 or less of the thickness of the cylindrical portion of the insulating coating portion. This is because when the high dielectric constant insulating layer is formed up to the outer surface of the insulating coating portion, the electric field concentration at the tip portion of the high dielectric constant insulating layer increases, and the effect of providing the high dielectric constant insulating layer is reduced. Because.
[0011]
The high dielectric constant insulating layer may also be formed on the shade portion of the insulating coating portion.
Further, when the power cable termination is configured by using the hollow composite steel pipe of the present invention, high dielectric constant insulation is provided at any or all of the outer periphery of the mold insulator, stress cone and cable insulator used inside. Providing a layer is more effective in improving the withstand voltage characteristics of the terminal portion.
Furthermore, if a shield ring is formed on the upper metal fitting located at the upper end of the soot tube, it is more effective in reducing the electric field at the top end of the soot tube.
[0012]
In the present invention, a polymer material insulation coating portion having a plurality of shade portions is provided on the outer periphery of the cable insulation at the end of the CV cable, and a stress cone is provided between the base portion of the insulation coating portion and the cable insulation. The present invention can also be applied to a CV cable dry termination connecting portion provided, and in that case, a high dielectric constant insulating layer is provided on the inner layer portion of the insulating coating portion from the inside of the stress cone to the outside. is there.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 to 6 each show an embodiment of a composite soot tube according to the present invention. In the figure, 1 is a hollow core made of glass fiber reinforced resin, 2 is an upper metal fitting attached to the upper end of the

core

1, 3 is a lower metal fitting attached to the lower end of the

core

1, and 4 is the core 1. An insulating coating portion 5 made of silicone rubber coated on the outer periphery is a high dielectric constant insulating layer provided in a section from the upper end or lower end of the insulating coating portion 4 to the middle (between the upper end and the lower end) . The insulation coating part 4 is comprised from the cylindrical part 4a and the cap part 4b like the past.
[0014]
In the composite soot tube of FIG. 1, the inner layer portion of the insulating coating portion 4 in the section from the lower end of the insulating coating portion 4 to ３ of the length of the insulating coating portion is configured by the high dielectric constant insulating layer 5.
The composite pipe shown in FIG. 2 is configured such that the inner layer portion of the insulating coating portion 4 in the section from the upper end of the insulating coating portion 4 to 2/3 of the length of the insulating coating portion is composed of the high dielectric constant insulating layer 5.
In the composite soot tube of FIG. 3, the inner layer portion of the insulating coating portion 4 in the section from the lower end of the insulating coating portion 4 to 1/5 of the length of the insulating coating portion is configured by the high dielectric constant insulating layer 5.
The composite steel pipe shown in FIG. 4 is configured such that the entire layer of the insulating coating portion 4 in the section from the lower end of the insulating coating portion 4 to 1/3 of the length of the insulating coating portion is composed of the high dielectric constant insulating layer 5.
The composite soot tube of FIG. 5 is configured such that the entire layer of the insulating coating portion 4 in the section from the upper end of the insulating coating portion 4 to 2/3 of the length of the insulating coating portion is composed of the high dielectric constant insulating layer 5.
6 includes a high dielectric constant insulating layer including the inner layer portion of the insulating coating portion 4 including the inside of the shade portion 4b in the section from the lower end of the insulating coating portion 4 to 1/3 of the length of the insulating coating portion. 5.
[0015]
The high dielectric constant insulating layer 5 is a mixture of elastomer or silicone rubber with high dielectric constant particles such as carbon black or silicon carbide, titanium oxide, or barium titanate as a filler. When silicone rubber is used for the base rubber, there is an advantage that the adhesiveness with the insulating coating portion 4 is improved and the interface characteristics are improved. The high dielectric constant insulating layer 5 is preferably crosslinked integrally with the insulating coating 4. When both are integrally cross-linked, the adhesion between the two is further improved, and the dielectric breakdown characteristics of the composite soot tube can be further improved.
Further, when a material having adhesiveness is used as the base material of the rubber composition constituting the high dielectric constant insulating layer and / or the insulating coating portion, the adhesiveness at the interface or between the rubber layer and the FRP layer is improved, It is effective for improving the characteristics of the entire tub tube.
[0016]
When carbon black is used as the filler, the amount added is preferably 10 to 100 parts by weight with respect to 100 parts by weight of the base resin. Moreover, when using a high dielectric constant particle as a filler, it is preferable that the addition amount shall be 50-500 weight part with respect to 100 weight part of base resins. This is because if the amount of carbon black exceeds 100 parts by weight or the amount of high dielectric constant particles exceeds 500 parts by weight with respect to 100 parts by weight of the base resin, the flexibility of the resulting compound is significantly reduced.
[0017]
Next, an example of the manufacturing method of the composite soot pipe of this invention is demonstrated. First, a hollow cylindrical core material 1 is made of glass fiber reinforced resin, and

metal fittings

2 and 3 are attached to both ends thereof by pressure bonding. Next, a high dielectric constant insulating layer 5 is provided on the surface of the core material 1. The high dielectric constant insulating layer 5 is provided by molding on the core material 1 or covering the core material 1 with a rubber elastic force that has been previously molded into a tube shape.
[0018]
The conditions for crosslinking the high dielectric constant insulating layer 5 vary depending on the crosslinking agent used. When using a peroxide as a crosslinking agent, it is necessary to heat at 150 to 180 ° C. for about 5 to 30 minutes. Moreover, when using a platinum compound as a crosslinking agent, the heating for about 1 minute to 60 minutes is needed at 70 to 180 degreeC. The latter is characterized in that the crosslinking reaction proceeds at a relatively low temperature, and the use of a platinum compound as a crosslinking agent is advantageous in that the strength of the core material 1 is not reduced by the thermal history when the high dielectric constant insulating layer is crosslinked. There is. Further, when the high dielectric constant insulating layer 5 is crosslinked on the core material 1, the adhesion between the core material 1 and the high dielectric constant insulating layer 5 can be improved by forming a primer layer on the surface of the core material.
[0019]
After the high dielectric constant insulating layer 5 is formed on the core material 1, the insulating coating portion 4 is formed. When forming the insulating coating portion, silicone rubber is used as the base rubber, and a peroxide or a platinum compound is used as the cross-linking agent. If the silicone rubber is liquid, the moldability of the shade is good. Further, if a primary layer is formed on the surface of the high dielectric constant insulating layer, the adhesion between the high dielectric constant insulating layer and the insulating coating portion can be improved.
[0020]
Next, Table 1 shows the test results of the cable termination connection portion using the composite soot tube of the present invention in comparison with the cable termination connection portion using the conventional composite soot tube. The AC breakdown voltage was measured under conditions of an initial applied voltage / time of 200 kV / 30 minutes and a step applied voltage / time of 20 kV / 30 minutes.
[0021]
[Table 1]

[0022]
According to the comparison between Examples 1 to 10 and Conventional Example 1, the composite steel pipe in which at least the inner layer portion from the upper end to the middle or from the lower end to the middle of the insulating coating portion is replaced with a high dielectric constant insulating layer is a conventional composite steel pipe. It can be seen that the AC breakdown voltage is improved in comparison. Further, according to the comparison between Examples 1 and 8 and 6 and 9, the effect of improving the AC breakdown voltage is that the thickness of the high dielectric constant insulating layer is 2 to 3 mm with respect to the thickness of the silicone rubber layer 4 mm. You can see that it is the largest in the case Further, according to a comparison between Examples 1 and 7, it can be seen that the effect of improving the AC breakdown voltage is greater as the length of the high dielectric constant insulating layer is longer. Further, according to the comparison between Examples 1 to 4 and Conventional Example 1, it can be seen that the effect of improving the AC breakdown voltage is large when the dielectric constant of the high dielectric constant insulating layer is 5 to 20.
[0023]
FIG. 7 shows another embodiment of the present invention. In this composite soot tube, the entire layer of the insulating coating part 4 in the section from the both ends of the insulating coating part 4 made of silicone rubber to the second shade (the electric field concentration part on the soot pipe surface) is composed of the high dielectric constant insulating layer 5. Is. Since the other configuration is the same as that of the embodiment shown in FIGS. 1 to 6, the same parts are denoted by the same reference numerals. With the configuration as shown in FIG. 7, the electric field concentration on the surfaces of both ends of the insulating coating portion 4 is alleviated, the leakage current on the surface of the soot tube can be suppressed, and a composite soot tube having a high withstand voltage can be obtained.
[0024]
8 shows the analysis result of the electric field of the composite soot tube of FIG. 7, and FIG. 9 shows the analysis result of the electric field of the conventional composite soot tube of the same size. FIG. 8 shows that the electric field on the surface of the insulating coating is relaxed at both ends of the insulating coating. The high dielectric constant insulating layer 5 of the composite rod shown in FIG. 7 is obtained by mixing carbon black into silicone rubber so that the dielectric constant ε = 10. Silicone rubber not mixed with carbon black has a dielectric constant ε = 3-4.
[0025]
Next, FIG. 10 (a) shows an embodiment of a CV cable dry termination connection according to the present invention, and FIG. 10 (b) shows a conventional CV cable dry termination connection corresponding thereto. In the figure, 11 is a CV cable, 12 is a cable insulator, 13 is a cable conductor, 14 is a conductor lead bar, 15 is an upper metal fitting, 16 is a lower metal fitting, and 17 is an insulating coating made of silicone rubber having multiple shades. , 18 is a stress cone. The terminal connection part of the present invention of (a) is different from the conventional terminal connection part of (b) in that high dielectric constant insulating layers 5 a and 5 b are provided in two layers in the insulating coating part 17 in the vicinity of the stress cone 18. That is. The high dielectric constant insulating layer 5a on the inner layer side is provided from the inside of the stress cone 18 to the outside, and the high dielectric constant insulating layer 5b on the outer layer side is partially wrapped with the high dielectric constant insulating layer 5a on the inner layer side outside the stress cone 18. It is provided to do. High dielectric constant insulating layers 5a and 5b having a dielectric constant of ε = 10 to 20 are used.
[0026]
FIG. 11 shows the analysis result of the electric field in the vicinity of the stress cone of the dry termination connection portion in FIG. On the other hand, the electric field analysis result when the high dielectric constant insulating layer is only the inner layer is as shown in FIG. 12, and the electric field analysis result of the conventional dry termination connection portion without the high dielectric constant insulating layer is as shown in FIG. there were. Both are 154 kV dry termination connections, the dielectric constant ε = 15 of the high dielectric constant insulating layers 5a and 5b, the maximum diameter of the body portion of the insulating coating portion 17 is 170 mm, the maximum diameter of the cap portion is 290 mm, and the reference voltage is 93 kV (= 154). × √3 × 1.15 / 1.1). 12 shows that the electric field on the surface of the insulating coating portion is more relaxed than that of FIG. 13, and that in FIG. 11 significantly reduces the electric field on the surface of the insulating coating portion than those shown in FIGS. 12 and 13. The maximum electric field on the surface of the insulating coating 17 is 1.08 kV / mm in FIG. 13, 1.04 kV / mm in FIG. 12 (down 3% from the prior art), and 0.98 kV / mm in FIG. % Reduction).
[0027]
【The invention's effect】
As described above, according to the present invention, a CV cable dry-type terminal connecting portion having a composite steel pipe provided with an insulating coating portion made of a polymer material on the outer periphery of a core made of glass fiber reinforced resin and an insulating coating portion made of a polymer material Withstand voltage characteristics can be improved.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a front view of a semi-reed showing an embodiment of a composite reed tube according to the present invention.
FIG. 2 is a front view of a semi-reed showing another embodiment of the composite reed tube according to the present invention.
FIG. 3 is a front view of a semi-coil showing still another embodiment of the composite coffin pipe according to the present invention.
FIG. 4 is a front view of a semi-coil showing still another embodiment of the composite coffin pipe according to the present invention.
FIG. 5 is a front view of a semi-coil showing still another embodiment of the composite coffin pipe according to the present invention.
FIG. 6 is a front view of a semi-coil showing still another embodiment of the composite coffin pipe according to the present invention.
FIG. 7 is a sectional view showing still another embodiment of the composite soot tube according to the present invention.
8 is a graph showing the analysis result of the electric field of the composite soot tube of FIG.
9 is a graph showing an analysis result of an electric field of a conventional composite soot tube corresponding to the composite soot tube of FIG.
FIG. 10A is a front view of a half-cage showing an embodiment of a CV cable dry termination connection according to the present invention, and FIG. 10B is a conventional CV cable dry termination connection corresponding to the termination connection of FIG. FIG.
11 is a graph showing the analysis result of the electric field at the terminal connection portion in FIG.
FIG. 12 is a graph showing an analysis result when the high-dielectric-constant insulating layer is one layer in the same termination connection portion as FIG.
13 is a graph showing an analysis result of an electric field of a conventional CV cable dry termination connection portion corresponding to the termination connection portion of FIG.
FIG. 14 is a front view of a half bowl showing an example of a conventional composite soot tube.
[Explanation of symbols]
1: Core material 2: Upper metal fitting 3: Lower metal fitting 4: Insulating coating portion 4a: Cylindrical portion 4b: Cap portion 5: High dielectric constant insulating layer 11: CV cable 12: Cable insulator 13: Cable conductor 17: Insulating coating portion 18: Stress cone 5a, 5b: High dielectric constant insulating layer

Claims

A composite composed of a core material made of glass fiber reinforced resin, metal fittings attached to the upper and lower ends of the core material, and an insulating coating portion of a polymer material having multi-stage shade portions coated on the outer periphery of the core material in the porcelain bushing, the insulating coating part from the upper end of the section, or both from the section or the lower end up between the upper and lower ends to between the lower end and the upper end section of at least an inner layer portion, higher dielectric constant than the insulation covering portion A composite steel pipe characterized by comprising a high dielectric constant insulating layer.

2. The composite soot tube according to claim 1, wherein the high dielectric constant insulating layer is provided in a section of 1/3 of the length of the insulating coating portion from the lower end of the insulating coating portion.

2. The composite soot tube according to claim 1, wherein the high dielectric constant insulating layer is provided in a section of 2/3 of the length of the insulating coating portion from the upper end of the insulating coating portion.

4. The composite soot tube according to any one of claims 1 to 3, wherein the high dielectric constant insulating layer is made of a material having a dielectric constant of 5 to 20.

The composite dielectric pipe according to any one of claims 1 to 4, wherein the thickness of the high dielectric constant insulating layer is 3/4 or less of the thickness of the cylindrical portion of the insulating coating portion.

6. The composite steel pipe according to claim 1, wherein the cap portion of the insulating coating portion is formed of a high dielectric constant insulating layer.

A CV cable in which an insulation coating portion of a polymer material having a plurality of shade portions is provided on the outer periphery of the cable insulation at the end of the CV cable, and a stress cone is provided between the base of the insulation coating portion and the cable insulation In the dry termination connection portion, a CV cable dry termination connection portion , wherein a high dielectric constant insulating layer is provided on the inner layer portion of the insulating coating portion from the inside to the outside of the stress cone .