JP2004335390A

JP2004335390A - Cone type insulation spacer

Info

Publication number: JP2004335390A
Application number: JP2003132795A
Authority: JP
Inventors: Toshiaki Rokunohe; 敏昭六戸; Fumimasa Endo; 奎将遠藤; Yoshitoyo Yagihashi; 義豊八木橋
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2003-05-12
Filing date: 2003-05-12
Publication date: 2004-11-25

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cone type insulation spacer improving insulation performance to a conductive foreign material when mixed. <P>SOLUTION: The cone type insulation spacer 3 supporting a high voltage conductor 1 comprises a projection part side 3a made of an alumina filling epoxy resin using alumina as a filler, a middle part 3b made of a mixture filling epoxy resin using a mixture of alumina and silica as the filler, and a recess surface side 3c made of a silica filling epoxy resin using silica as the filler, which are arranged along the axial direction of the high voltage conductor 1, so that plurality of materials having different dielectric constants are arranged in the axial direction of the high voltage conductor 1, and its recess surface is made of a material other than a material with the highest dielectric constant. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、接地金属容器内に高電圧導体を絶縁支持するコーン形絶縁スペーサに関する。
【０００２】
【従来の技術】
一般に、絶縁媒体を封入した接地金属容器内に高電圧導体を絶縁支持して構成したガス絶縁電気機器は、絶縁信頼性や小型化の点で優れているため変電所や開閉所等で広く用いられている。最近では、より高い信頼性と経済性が要求される中でのコンパクト化が強く望まれているが、このコンパクト化における一つの課題として接地金属容器内への導電性異物等の混入がある。接地金属容器内に導電性異物等が混入した場合、その形状や材質等によって導電性異物等が電荷を帯び、接地金属容器内で跳ねたり、高電圧導体と接地金属容器との間を往復したりする。ところで、ガス絶縁電気機器においては、接地金属容器から電気的に絶縁した状態で高電圧導体を支持するために絶縁スペーサが用いられており、この導電性異物等が絶縁スペーサの沿面に付着した状態で雷インパルスや断路器サージ等の過電圧が高電圧導体に加わると、絶縁スペーサの沿面に沿って地絡する可能性が非常に高くなる。
【０００３】
ガス絶縁電気機器における地絡事故の主な原因は、上述のような導電性異物による絶縁スペーサの沿面絶縁破壊であり、導電性異物等の管理は重要な課題であるが、装置製造時における導電性異物等の混入をなくすことは非常に難しく、導電性異物等の混入を考慮した絶縁設計が必要となる。そこで、コンパクト化をはかりながら沿面絶縁破壊を防止するため、コーン形絶縁スペーサの誘電率を径方向に変化させてその表面の沿面方向成分の電界を低減する検討がなされている（例えば、非特許文献１参照）。
【０００４】
【非特許文献１】
電気学会電力・エネルギー部門大会「傾斜誘電率材料を用いたＧＩＳスペーサの絶縁性能向上効果の検討」、Ｖｏｌ．Ｂ，Ｎｏ．４０５，ｐｐ１７８−１７９，２０００
【０００５】
【発明が解決しようとする課題】
しかしながら、上述した従来のコーン形絶縁スペーサは、その沿面絶縁破壊を防止する上で有益であるが、導電性異物等による絶縁破壊はリーダチャンネルに供給される注入エネルギーと合わせて考える必要があり、このリーダチャンネルは導電性異物等と過電圧により電界集中が起こるために形成される。リーダチャンネルの導電率は非常に高く、長さ方向の電位傾度は０．１〜０．２（ｋＶ／ｍｍ）に過ぎず、ガス圧［ｂａｒ］をＰとするときストリーマコロナの電位傾度３〜４×Ｐ（ｋＶ／ｍｍ）に比べて桁違いに小さい。リーダチャネル先端の電界がＥｃｒ（コロナ開始電界）以上になると放電を開始し、強く発光を伴うストリーマコロナになる。そして、ストリーマコロナの作る空間電荷により電界が緩和されて放電が停止し、発生した電子は分子と衝突してリーダチャネルを加熱する。リーダチャネル形成のためは約２０００Ｋの加熱が必要であり、通常１０７Ｊ／ｋｇの注入エネルギーΔｈが必要である。この注入エネルギーを供給するために必要な電圧Ｖｃｒはエネルギーの釣り合いの条件により、数１で与えられる。
【数１】

ここで、Ａはスケーリング係数、Ｐはガス圧、Ｃはリーダチャネルと対向電極間の静電容量、Ｌはリーダチャネル長である。
【０００６】
注入エネルギーは、リーダチャネルと対向電極間の静電容量を介して供給され、放電が進展するため、リーダチャネルと対向電極間にある絶縁スペーサの比誘電率が大きくなると、静電容量Ｃが大きくなりＶｃｒが小さくなるため沿面破壊電圧が低くなる。従って、従来のコーン形絶縁スペーサ表面における沿面方向成分の電界とリーダチャネル進展に必要な注入エネルギーの両方を考慮することが必要となる。例えば、従来のようにコーン形絶縁スペーサにおける径方向に誘電率を変化させた場合、コーンス形絶縁ペーサ形状で最も導電性異物等に対して弱い凹面側の沿面方向成分を低減するために高電圧導体側の誘電率を高くし接地金属容器側の誘電率を低くするため、沿面方向成分の電界を低下させることができるが、高電圧導体と導電性異物間の静電容量Ｃが大きくなり、必ずしもコーン形絶縁スペーサの絶縁耐力向上には結びつかない。
【０００７】
本発明の目的は、混入した導電性異物等に対する絶縁性能を向上したコーン形絶縁スペーサを提供することにある。
【０００８】
【課題を解決するための手段】
本発明は上記目的を達成するために、接地金属容器内に収納されて、高電圧導体を支持すると共に上記高電圧導体の軸方向の一方の面を凸面とし他方を凹面としたコーン形絶縁スペーサにおいて、上記高電圧導体の軸方向における誘電率を変え、かつ上記高電圧導体の近傍に位置する上記凹面側の誘電率を最も大きな誘電率の部分より小さな誘電率としたことを特徴とする。
【０００９】
本発明によるコーン形絶縁スペーサは、高電圧導体の軸方向における誘電率を変え、かつ高電圧導体の近傍に位置する凹面側の誘電率を最も大きな誘電率の部分より小さな誘電率としたため、凹面における表面沿面方向成分の電界の最大値を低減し、従来の径方向に誘電率を変えたコーン形絶縁スペーサに比べて高電圧導体と導電性異物間の静電容量を小さくして、混入した導電性異物等の対する絶縁耐力を向上させることができる。
【００１０】
また請求項２に記載の本発明は上記目的を達成するために、請求項１記載のものにおいて、上記高電圧導体の長手方向における充填剤の混合割合および充填剤の種類の少なくともいずれか一方を変えたことを特徴とする。このようなコーン形絶縁スペーサによれば、高電圧導体の軸方向における誘電率を容易に変えて製作することができる。
【００１１】
また請求項３に記載の本発明は、請求項１記載のものにおいて、上記高電圧導体の近傍に位置する上記凸面側の誘電率より、上記高電圧導体の近傍に位置する上記凹面側の誘電率を小さくしたことを特徴とする。このようなコーン形絶縁スペーサによれば、凹面側の誘電率を高めることなく、混入した導電性異物などによって凹面における表面沿面方向成分の電界の最大値を低減することができ、従来の径方向に誘電率を変えたコーン形絶縁スペーサに比べて高電圧導体と導電性異物間の静電容量を小さくして、混入した導電性異物等に対する絶縁耐力を向上させることができる。
【００１２】
また請求項４に記載の本発明は、請求項１記載のものにおいて、上記高電圧導体の軸方向における誘電率を連続的に変化したことを特徴とする。このようなコーン形絶縁スペーサによれば、誘電率の変化部における境界面を明確に形成しないため、この境界部における絶縁特性をより安定させて信頼性を高めることができる。
【００１３】
さらに請求項６に記載の本発明は、接地金属容器内に遮断部を収納し、この遮断部に電気的に接続した高電圧導体を支持すると共に上記高電圧導体の軸方向の一方の面を凸面とし他方を凹面としたコーン形絶縁スペーサを有する遮断器において、上記コーン形絶縁スペーサは、上記高電圧導体の軸方向における誘電率を変え、かつ上記高電圧導体の近傍に位置する凸面側よりも上記高電圧導体の近傍に位置する凹面側の誘電率を小さくし、上記コーン形絶縁スペーサの凸面側を遮断部側に向けて配置したことを特徴とする。このような遮断器によれば、凸面側に充填剤としてフッ酸に強いアルミナを用いたアルミナ充填エポキシ樹脂を使用することができ、コーン形絶縁スペーサの腐食の面では有利になり、長期間にわたって絶縁信頼性を確保することができるようになる。
【００１４】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づいて説明する。
図１は、本発明の一実施の形態によるコーン形絶縁スペーサを示す断面図である。
絶縁媒体が封入された接地金属容器２内には、高電圧導体１がコーン形絶縁スペーサ３によって接地金属容器２から電気的に絶縁した状態で支持されている。このコーン形絶縁スペーサ３は、高電圧導体１の軸方向に沿った両側に凸面と凹面を有するコーン形状に成されており、ここでは高電圧導体１の軸方向に凸部側３ａと、中間部３ｂと、凹面側３ｃとを有し、各部間にカップリング剤を用いて界面を緊密に接着して一体的に形成している。これら凸部側３ａ、中間部３ｂおよび凹面側３ｃの誘電率をそれぞれε３ａ、ε３ｂ、ε３ｃとするとき、ε３ｂ＞ε３ａ＝ε３ｃとなるように各部の充填剤を選定している。つまり、コーン形絶縁スペーサ３は高電圧導体１の軸方向に誘電率の異なる複数の材料で構成されると共に、その凹面は最も高い誘電率を持つ材料よりも誘電率の小さい材料で形成している。例えば、凸部側３ａは充填剤としてシリカを用いたシリカ充填エポキシ樹脂（ε３ａ＝４．０）で、中間部３ｂは充填剤としてアルミナを用いたアルミナ充填エポキシ樹脂（ε３ｂ＝６．０）で、また凹面側３ｃは最も誘電率の高いアルミナ充填エポキシ樹脂よりも低誘電率のシリカ充填エポキシ樹脂（ε３ｃ＝４．０）で構成している。
【００１５】
図２は、電界分布特性図を示している。
電界分布曲線７は、図１に示したコーン形絶縁スペーサにおける表面沿面方向成分の電界分布を示しており、電界分布曲線８は、充填剤として単一のアルミナを用いたアルミナ充填エポキシ樹脂のみで形成したコーン形絶縁スペーサの表面沿面方向成分の電界分布を示している。両者の比較から分かるように、高電圧導体１の軸方向に誘電率の異なる複数の材料で構成したコーン形絶縁スペーサ３は、従来のコーン形絶縁スペーサと比べて凹面および凸面における表面沿面方向成分の電界値の最大が若干低くなっている。
【００１６】
また、コーン形絶縁スペーサ３の凹面側３ｃに導電性異物等が付着した場合、この凹面側３ｃは低誘電率のシリカ充填エポキシ樹脂で構成しているため、リーダチャネルに注入されるエネルギーに関係する電極間の静電容量は、従来のシリカ充填エポキシ樹脂のみの場合とほぼ同じであるから、導電性異物に対する絶縁耐力はシリカ充填エポキシ樹脂のみの場合よりも向上することになる。これは、従来の径方向に誘電率を変えたコーン形絶縁スペーサに比べて、凸面側３ａおよび凹面側３ｃにおける高電圧導体１の近傍の誘電率を高めないので、高電圧導体と導電性異物間の静電容量が小さく、混入した導電性異物等に対する絶縁耐力を一層向上させることができる。
【００１７】
図３は、本発明の一実施の形態によるコーン形絶縁スペーサを示す断面図である。
接地金属容器２内の高電圧導体１を支持したコーン形絶縁スペーサ３は、高電圧導体１の軸方向に沿った両側に凸面と凹面を有するコーン形状に成形されており、ここでは高電圧導体１の軸方向にそれぞれ誘電率が異なる凸部側３ａと、中間部３ｂと、凹面側３ｃとを有している。これら凸部側３ａ、中間部３ｂおよび凹面側３ｃの誘電率をそれぞれε３ａ、ε３ｂ、ε３ｃとするとき、ε３ａ＞ε３ｂ＞ε３ｃとなるように各部の充填剤を選定している。つまり、コーン形絶縁スペーサ３は高電圧導体１の軸方向に誘電率の異なる複数の材料で構成されると共に、その凹面は最も高い誘電率を持つ材料以外の他の材料で形成している。例えば、凸部側３ａは充填剤としてアルミナを用いたアルミナ充填エポキシ樹脂（ε３ａ＝６．０）で、中間部３ｂは充填剤としてアルミナとシリカの混合を用いた混合充填エポキシ樹脂（ε３ｂ＝５．０）で、さらに凹面側３ｃは充填剤としてシリカを用いたシリカ充填エポキシ樹脂（ε３ｃ＝４．０）で構成している。
【００１８】
図４は、電界分布特性図を示している。
電界分布曲線９は、図３に示したコーン形絶縁スペーサにおける表面沿面方向成分の電界分布を示しており、電界分布曲線８は、充填剤として単一のアルミナを用いたアルミナ充填エポキシ樹脂のみで形成したコーン形絶縁スペーサの表面沿面方向成分の電界分布を示している。両者の比較から分かるように、高電圧導体１の軸方向に誘電率の異なる複数の材料で構成し、かつ、凹面側３ｃを他の部分の誘電率よりも小さくしたコーン形絶縁スペーサ３は、従来のコーン形絶縁スペーサと比べて凹面および凸面における表面沿面方向成分の電界の最大値を小さくすることができ、しかも、凹面側３ｃを構成する絶縁物の比誘電率を小さく保つことができるため、混入した導電性異物等に対する絶縁性能を向上させることができる。
【００１９】
図５は、上述したコーン形絶縁スペーサの製造方法を示す製作途中状態の断面図である。
高電圧導体１の軸方向に二分割した金型４ａ，４ｂを用い、その対向部にコーン形絶縁スペーサ３の形状に対応する充填部１０ａ，１０ｂを形成している。高電圧導体１あるいは高電圧導体１を取り付ける埋め込み導体を図示のように金型４ａ，４ｂの中心部に保持し、注入口５から、先ず、凸面側３ａとなる充填剤としてアルミナを用いたアルミナ充填エポキシ樹脂を流し込み、このアルミナ充填エポキシ樹脂がゲル状になった状態のとき、注入口５から中間部３ｂとなる充填剤としてアルミナとシリカの混合を用いた混合充填エポキシ樹脂を流し込み、この混合充填エポキシ樹脂がゲル状になった状態のとき、さらに注入口５から凹面側３ｃとなる充填剤としてシリカを用いたシリカ充填エポキシ樹脂を流し込み、硬化させる。
【００２０】
このような製造方法によれば、高電圧導体１の軸方向に誘電率の異なる複数の材料で構成したコーン形絶縁スペーサ３を容易に製作することができ、しかも、凹面側３ｃを他の部分の誘電率よりも小さくしたり、最も高い誘電率の部分よりも低い誘電率とするのが容易である。また、高電圧導体１などを垂直に配置して作業することができるので、高電圧導体１の軸方向に誘電率の異なる複数の材料を用いても各材料の境界面は水平となり、安定した特性を持つコーン形絶縁スペーサ３を得ることができる。
【００２１】
図６は、上述したコーン形絶縁スペーサの他の製造方法を示す製作途中状態の断面図である。
高電圧導体１の軸方向に二分割した金型４ａ，４ｂを用い、その対向部にコーン形絶縁スペーサ３の形状に対応する充填部１０ａ，１０ｂを形成している。高電圧導体１あるいは高電圧導体１を取り付ける埋め込み導体を図示のように金型４ａ，４ｂの中心部に保持し、注入口５から、所定の充填剤を混入したエポキシ樹脂などの絶縁材料を注入する。その後、金型４ａ，４ｂを矢印で示す上下方向に振動もしくは遠心分離させると、エポキシ樹脂よりも充填剤の比重が小さい場合には、金型４ａ，４ｂの上部における充填剤の密度が大きくなり、しかも充填剤の密度が連続的に変化する。一方、エポキシ樹脂よりも充填剤の比重が大きい場合には、金型４ａ，４ｂの下部における充填剤の密度が大きくなり、しかも、充填剤の密度が連続的に変わる。このため、コーン形絶縁スペーサ３の比誘電率を接地金属容器２および高電圧導体１の軸方向に連続的に変化させることができる。
【００２２】
このように高電圧導体１の軸方向に比誘電率が連続的に変化した場合、先の製造方法に比べて凸部側３ａと、中間部３ｂと、凹面側３ｃとの界面が存在しないため、導電性異物に対する絶縁性能を向上しながら、機械的信頼性を高めたコーン形絶縁スペーサ３を得ることができる。
【００２３】
図７は、上述したコーン形絶縁スペーサ３を用いて構成したガス遮断器の要部断面図である。
上述したコーン形絶縁スペーサ３は、高電圧導体１の軸方向に誘電率の異なる複数の材料を用い、しかも、最も誘電率の高い部分よりも低い誘電率の材料で凹面側３ｃを構成したため、必然的に凸面側３ａは比誘電率の大きい材料を使用することになる。接地金属容器２内に封入した絶縁媒体、例えばＳＦ６ガスあるいは混合ガスを用いたガス遮断器６では、他のガス絶縁電気機器、例えば、断路器や接続用母線における接地金属容器２との連結部にガス区画の機能を有するコーン形絶縁スペーサ３を用いる。このとき、図示のようにガス遮断器６の遮断部側に凸面側３ａが位置するようにコーン形絶縁スペーサ３を取り付けている。
【００２４】
高電圧導体１の軸方向における誘電率の関係の条件を満たすために、凹面側３ｃに充填剤としてシリカを用いたシリカ充填エポキシ樹脂を使用し、凸面側３ａに充填剤としてアルミナを用いたアルミナ充填エポキシ樹脂を使用すると、凸面側３ａは、フッ酸につよいアルミナ充填エポキシ樹脂が高電界側の遮断部側に配置されることになるため、コーン形絶縁スペーサ３の腐食の面では有利になり、長期間にわたって絶縁信頼性を確保することができる。
【００２５】
【発明の効果】
以上説明したように本発明のコーン形絶縁スペーサによれば、従来の径方向に誘電率を変えた場合のように凹面側の誘電率が最大とはならないため、導電性異物等に対する絶縁性能を向上させることができ、絶縁信頼性とコンパクト化を両立したガス絶縁電気機器を提供することができる。
【図面の簡単な説明】
【図１】本発明の一実施の形態によるコーン形絶縁スペーサを示す断面図である。
【図２】図１に示したコーン形絶縁スペーサの電界分布特性図である。
【図３】本発明の他の実施の形態によるコーン形絶縁スペーサを示す断面図である。
【図４】図３に示したコーン形絶縁スペーサの電界分布特性図である。
【図５】図３に示したコーン形絶縁スペーサの製造方法を示す製作途中状態を示す断面図である。
【図６】図３に示したコーン形絶縁スペーサの他の製造方法を示す製作途中状態を示す断面図である。
【図７】本発明の一実施の形態によるガス遮断器を示す要部断面図である。
【符号の説明】
１高電圧導体
２接地金属容器
３コーン形絶縁スペーサ
３ａ凸面側
３ｂ中間部
３ｃ凹面側
４ａ，４ｂ金型
５注入口
６ガス遮断器
１０ａ、１０ｂ充填部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cone-shaped insulating spacer for insulatingly supporting a high-voltage conductor in a grounded metal container.
[0002]
[Prior art]
In general, gas-insulated electrical equipment, which is constructed by insulating and supporting a high-voltage conductor in a grounded metal container enclosing an insulating medium, is widely used in substations and switchyards because of its excellent insulation reliability and miniaturization. Have been. Recently, there is a strong demand for compactness in a situation where higher reliability and economy are required, but one problem in this compactness is the incorporation of conductive foreign substances and the like into the grounded metal container. When a conductive foreign matter enters the grounded metal container, the conductive foreign matter, etc., is charged by its shape and material, etc., and jumps in the grounded metal container or reciprocates between the high-voltage conductor and the grounded metal container. Or By the way, in a gas-insulated electric device, an insulating spacer is used to support a high-voltage conductor in a state in which it is electrically insulated from a grounded metal container. When an overvoltage such as a lightning impulse or a disconnector surge is applied to the high-voltage conductor, the possibility of ground fault along the surface of the insulating spacer is greatly increased.
[0003]
The main cause of ground faults in gas insulated electrical equipment is the surface insulation breakdown of insulating spacers due to conductive foreign substances as described above, and management of conductive foreign substances is an important issue. It is very difficult to eliminate the inclusion of conductive foreign matter and the like, and an insulation design that takes into account the inclusion of conductive foreign matter and the like is required. Therefore, in order to prevent creeping insulation breakdown while reducing the size, studies have been made to reduce the electric field of the creeping direction component of the surface by changing the dielectric constant of the cone-shaped insulating spacer in the radial direction (for example, non-patented). Reference 1).
[0004]
[Non-patent document 1]
The Institute of Electrical Engineers of Japan, Power and Energy Division Conference, "Study on the Insulation Performance Improvement Effect of GIS Spacer Using Gradient Dielectric Material", Vol. B, No. 405, pp 178-179, 2000
[0005]
[Problems to be solved by the invention]
However, the above-mentioned conventional cone-shaped insulating spacer is useful in preventing the creepage dielectric breakdown thereof, but it is necessary to consider the dielectric breakdown due to conductive foreign substances and the like in conjunction with the injected energy supplied to the reader channel, The leader channel is formed because electric field concentration occurs due to conductive foreign substances and overvoltage. The conductivity of the leader channel is very high, the potential gradient in the length direction is only 0.1 to 0.2 (kV / mm), and when the gas pressure [bar] is P, the potential gradient of the streamer corona is 3 to It is orders of magnitude smaller than 4 × P (kV / mm). When the electric field at the tip of the leader channel becomes equal to or higher than Ecr (corona start electric field), discharge starts and a streamer corona with strong light emission is obtained. Then, the electric field is relaxed by the space charge generated by the streamer corona to stop the discharge, and the generated electrons collide with the molecules and heat the leader channel. Approximately 2000K of heating is required to form the leader channel, and usually an injection energy Δh of 107 J / kg is required. The voltage Vcr necessary to supply this implantation energy is given by Equation 1 according to the condition of energy balance.
(Equation 1)

Here, A is a scaling coefficient, P is a gas pressure, C is a capacitance between a leader channel and a counter electrode, and L is a leader channel length.
[0006]
The injected energy is supplied through the capacitance between the leader channel and the counter electrode, and the discharge progresses. Therefore, when the relative dielectric constant of the insulating spacer between the leader channel and the counter electrode increases, the capacitance C increases. Vcr becomes smaller, so that the creeping breakdown voltage becomes lower. Therefore, it is necessary to consider both the electric field of the surface direction component on the surface of the conventional cone-shaped insulating spacer and the implantation energy required for the extension of the leader channel. For example, when the dielectric constant of the cone-shaped insulating spacer is changed in the radial direction as in the conventional case, a high voltage is applied in order to reduce the concave surface side component on the concave side which is weakest against conductive foreign substances in the cone-shaped insulating spacer shape. Since the dielectric constant on the conductor side is increased and the dielectric constant on the grounded metal container side is decreased, the electric field of the surface direction component can be reduced, but the capacitance C between the high-voltage conductor and the conductive foreign matter increases, This does not necessarily lead to an improvement in the dielectric strength of the cone-shaped insulating spacer.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide a cone-shaped insulating spacer having improved insulating performance against mixed conductive foreign substances and the like.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a cone-shaped insulating spacer which is housed in a grounded metal container, supports a high-voltage conductor, and has a convex surface on one surface in the axial direction of the high-voltage conductor and a concave surface on the other. Wherein the permittivity in the axial direction of the high-voltage conductor is changed, and the permittivity on the concave side located near the high-voltage conductor is set to a smaller permittivity than a portion having the largest permittivity.
[0009]
The cone-shaped insulating spacer according to the present invention changes the dielectric constant in the axial direction of the high-voltage conductor, and sets the dielectric constant on the concave side located near the high-voltage conductor to a dielectric constant smaller than that of the largest dielectric constant. Reduced the maximum value of the electric field of the surface creepage direction component and reduced the capacitance between the high-voltage conductor and the conductive foreign matter compared to the conventional cone-shaped insulating spacer whose dielectric constant was changed in the radial direction. The dielectric strength against conductive foreign matter and the like can be improved.
[0010]
According to a second aspect of the present invention, in order to achieve the above object, in the first aspect, at least one of the mixing ratio of the filler and the type of the filler in the longitudinal direction of the high-voltage conductor is adjusted. It is characterized by having changed. According to such a cone-shaped insulating spacer, the high-voltage conductor can be manufactured by easily changing the dielectric constant in the axial direction.
[0011]
According to a third aspect of the present invention, in the first aspect, the dielectric constant on the concave side near the high-voltage conductor is higher than the dielectric constant on the convex side near the high-voltage conductor. It is characterized in that the rate is reduced. According to such a cone-shaped insulating spacer, it is possible to reduce the maximum value of the electric field of the surface creeping direction component on the concave surface due to mixed conductive foreign substances without increasing the dielectric constant on the concave surface side. The capacitance between the high-voltage conductor and the conductive foreign matter can be made smaller than that of a cone-shaped insulating spacer having a different dielectric constant, and the dielectric strength against mixed conductive foreign matter can be improved.
[0012]
According to a fourth aspect of the present invention, in the first aspect, the dielectric constant in the axial direction of the high-voltage conductor is continuously changed. According to such a cone-shaped insulating spacer, since a boundary surface at a portion where the dielectric constant changes is not clearly formed, insulation characteristics at this boundary portion can be further stabilized and reliability can be improved.
[0013]
Further, according to the present invention as set forth in claim 6, the interrupting portion is housed in a grounded metal container, the high-voltage conductor electrically connected to the interrupting portion is supported, and one surface of the high-voltage conductor in the axial direction is supported. In a circuit breaker having a cone-shaped insulating spacer having a convex surface and the other having a concave surface, the cone-shaped insulating spacer changes the dielectric constant in the axial direction of the high-voltage conductor, and is closer to the convex surface than the high-voltage conductor. Also, the dielectric constant on the concave side located near the high-voltage conductor is reduced, and the convex side of the cone-shaped insulating spacer is arranged so as to face the blocking section. According to such a circuit breaker, it is possible to use an alumina-filled epoxy resin using alumina resistant to hydrofluoric acid as a filler on the convex side, which is advantageous in terms of corrosion of the cone-shaped insulating spacer, and for a long time. Insulation reliability can be ensured.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing a cone-shaped insulating spacer according to one embodiment of the present invention.
A high-voltage conductor 1 is supported in a grounded metal container 2 in which an insulating medium is sealed, while being electrically insulated from the grounded metal container 2 by a cone-shaped insulating spacer 3. The cone-shaped insulating spacer 3 is formed in a cone shape having a convex surface and a concave surface on both sides along the axial direction of the high-voltage conductor 1. It has a portion 3b and a concave side 3c, and the interface is tightly adhered to each other using a coupling agent between the portions to be integrally formed. When the dielectric constants of the convex side 3a, the intermediate part 3b and the concave side 3c are ε3a, ε3b and ε3c, respectively, the filler of each part is selected so that ε3b> ε3a = ε3c. That is, the cone-shaped insulating spacer 3 is formed of a plurality of materials having different dielectric constants in the axial direction of the high-voltage conductor 1, and its concave surface is formed of a material having a smaller dielectric constant than the material having the highest dielectric constant. I have. For example, the convex side 3a is a silica-filled epoxy resin using silica as a filler (ε3a = 4.0), and the intermediate portion 3b is an alumina-filled epoxy resin using alumina as a filler (ε3b = 6.0). The concave side 3c is made of a silica-filled epoxy resin (ε3c = 4.0) having a lower dielectric constant than the alumina-filled epoxy resin having the highest dielectric constant.
[0015]
FIG. 2 shows an electric field distribution characteristic diagram.
The electric field distribution curve 7 shows the electric field distribution of the surface creeping direction component in the cone-shaped insulating spacer shown in FIG. 1, and the electric field distribution curve 8 shows that only the alumina-filled epoxy resin using a single alumina as the filler is used. 5 shows an electric field distribution of a component along a surface along a surface of a formed cone-shaped insulating spacer. As can be seen from the comparison between the two, the cone-shaped insulating spacer 3 made of a plurality of materials having different dielectric constants in the axial direction of the high-voltage conductor 1 has a surface creepage component on the concave surface and the convex surface which is smaller than that of the conventional cone-shaped insulating spacer. The maximum of the electric field value is slightly lower.
[0016]
Also, if conductive foreign matter or the like adheres to the concave side 3c of the cone-shaped insulating spacer 3, since the concave side 3c is made of a low dielectric constant silica-filled epoxy resin, the concave side 3c is not affected by the energy injected into the reader channel. Since the capacitance between the electrodes is almost the same as that of the conventional case using only the silica-filled epoxy resin, the dielectric strength against the conductive foreign matter is improved as compared with the case using only the silica-filled epoxy resin. This is because the dielectric constant in the vicinity of the high-voltage conductor 1 on the convex side 3a and the concave side 3c is not increased as compared with the conventional cone-shaped insulating spacer in which the dielectric constant is changed in the radial direction. The capacitance between them is small, and the dielectric strength against mixed conductive foreign substances and the like can be further improved.
[0017]
FIG. 3 is a sectional view showing a cone-shaped insulating spacer according to one embodiment of the present invention.
The cone-shaped insulating spacer 3 supporting the high-voltage conductor 1 in the grounded metal container 2 is formed in a cone shape having a convex surface and a concave surface on both sides along the axial direction of the high-voltage conductor 1. 1 has a convex side 3a, an intermediate part 3b, and a concave side 3c having different dielectric constants in the axial direction. When the dielectric constants of the convex side 3a, the intermediate part 3b and the concave side 3c are ε3a, ε3b and ε3c, respectively, the filler of each part is selected so that ε3a>ε3b> ε3c. That is, the cone-shaped insulating spacer 3 is made of a plurality of materials having different dielectric constants in the axial direction of the high-voltage conductor 1, and the concave surface is formed of a material other than the material having the highest dielectric constant. For example, the convex portion side 3a is an alumina-filled epoxy resin (ε3a = 6.0) using alumina as a filler, and the intermediate portion 3b is a mixed-filled epoxy resin (ε3b = 5) using a mixture of alumina and silica as a filler. .0), and the concave side 3c is made of a silica-filled epoxy resin using silica as a filler (ε3c = 4.0).
[0018]
FIG. 4 shows an electric field distribution characteristic diagram.
An electric field distribution curve 9 shows an electric field distribution of a surface creeping direction component in the cone-shaped insulating spacer shown in FIG. 3, and an electric field distribution curve 8 is obtained only with an alumina-filled epoxy resin using a single alumina as a filler. 5 shows an electric field distribution of a component along a surface along a surface of a formed cone-shaped insulating spacer. As can be seen from the comparison between the two, the cone-shaped insulating spacer 3 made of a plurality of materials having different dielectric constants in the axial direction of the high-voltage conductor 1 and having the concave side 3c smaller than the dielectric constants of the other parts, As compared with the conventional cone-shaped insulating spacer, the maximum value of the electric field of the surface creeping direction component on the concave surface and the convex surface can be reduced, and the relative permittivity of the insulator constituting the concave side 3c can be kept small. In addition, it is possible to improve the insulation performance against mixed conductive foreign substances and the like.
[0019]
FIG. 5 is a cross-sectional view of a state in the course of manufacturing, showing a method of manufacturing the above-described cone-shaped insulating spacer.
Filling portions 10a and 10b corresponding to the shape of the cone-shaped insulating spacer 3 are formed at the opposing portions using dies 4a and 4b divided into two in the axial direction of the high-voltage conductor 1. The high-voltage conductor 1 or the embedded conductor to which the high-voltage conductor 1 is attached is held at the center of the molds 4a and 4b as shown in the figure, and from the injection port 5, first, alumina using alumina as a filler to be the convex side 3a is used. The filled epoxy resin is poured, and when the alumina-filled epoxy resin is in a gel state, a mixed filled epoxy resin using a mixture of alumina and silica as a filler to be the intermediate portion 3b is poured from the injection port 5, and When the filled epoxy resin is in a gel state, a silica-filled epoxy resin using silica as a filler to be the concave side 3c is further poured from the injection port 5 and cured.
[0020]
According to such a manufacturing method, the cone-shaped insulating spacer 3 made of a plurality of materials having different dielectric constants in the axial direction of the high-voltage conductor 1 can be easily manufactured, and the concave side 3c is connected to another part. It is easy to make the permittivity smaller than the permittivity or lower than the portion having the highest permittivity. In addition, since the high voltage conductor 1 and the like can be arranged vertically and work can be performed, even if a plurality of materials having different dielectric constants are used in the axial direction of the high voltage conductor 1, the boundary surface of each material is horizontal and stable. A cone-shaped insulating spacer 3 having characteristics can be obtained.
[0021]
FIG. 6 is a cross-sectional view showing another method of manufacturing the above-described cone-shaped insulating spacer in the middle of manufacturing.
Filling portions 10a and 10b corresponding to the shape of the cone-shaped insulating spacer 3 are formed at the opposing portions using dies 4a and 4b divided into two in the axial direction of the high-voltage conductor 1. The high-voltage conductor 1 or a buried conductor for mounting the high-voltage conductor 1 is held at the center of the molds 4a and 4b as shown in the figure, and an insulating material such as an epoxy resin mixed with a predetermined filler is injected from the injection port 5. I do. Thereafter, when the dies 4a and 4b are vibrated or centrifuged in the vertical direction indicated by arrows, when the specific gravity of the filler is smaller than that of the epoxy resin, the density of the filler in the upper portions of the dies 4a and 4b increases. In addition, the density of the filler changes continuously. On the other hand, when the specific gravity of the filler is larger than that of the epoxy resin, the density of the filler in the lower part of the molds 4a and 4b increases, and the density of the filler changes continuously. Therefore, the dielectric constant of the cone-shaped insulating spacer 3 can be continuously changed in the axial direction of the grounded metal container 2 and the high-voltage conductor 1.
[0022]
When the relative permittivity continuously changes in the axial direction of the high-voltage conductor 1 as described above, there is no interface between the convex side 3a, the intermediate part 3b, and the concave side 3c as compared with the previous manufacturing method. In addition, the cone-shaped insulating spacer 3 having improved mechanical reliability while improving insulation performance against conductive foreign substances can be obtained.
[0023]
FIG. 7 is a sectional view of a main part of a gas circuit breaker constituted by using the above-mentioned cone-shaped insulating spacer 3.
Since the above-mentioned cone-shaped insulating spacer 3 uses a plurality of materials having different dielectric constants in the axial direction of the high-voltage conductor 1, and furthermore, the concave side 3c is made of a material having a lower dielectric constant than a portion having the highest dielectric constant. Inevitably, a material having a large relative dielectric constant is used for the convex side 3a. In the gas circuit breaker 6 using an insulating medium, for example, SF6 gas or a mixed gas, sealed in the grounded metal container 2, a connection portion between the grounded metal container 2 and another gas-insulated electric device, for example, a disconnector or a connection bus. A cone-shaped insulating spacer 3 having the function of a gas compartment is used. At this time, the cone-shaped insulating spacer 3 is attached so that the convex side 3a is located on the blocking portion side of the gas circuit breaker 6 as shown.
[0024]
In order to satisfy the condition of the relationship of the dielectric constant in the axial direction of the high-voltage conductor 1, a silica-filled epoxy resin using silica as a filler is used on the concave side 3c, and an alumina using alumina as a filler is used on the convex side 3a. When the filled epoxy resin is used, the convex side 3a is advantageous in terms of corrosion of the cone-shaped insulating spacer 3 because the alumina-filled epoxy resin, which is suitable for hydrofluoric acid, is disposed on the side of the blocking portion on the high electric field side. Thus, insulation reliability can be ensured for a long period of time.
[0025]
【The invention's effect】
As described above, according to the cone-shaped insulating spacer of the present invention, since the dielectric constant on the concave side does not become the maximum unlike the conventional case where the dielectric constant is changed in the radial direction, the insulating performance against conductive foreign substances and the like is improved. It is possible to provide a gas-insulated electrical device that can improve insulation reliability and achieve compactness.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a cone-shaped insulating spacer according to an embodiment of the present invention.
2 is an electric field distribution characteristic diagram of the cone-shaped insulating spacer shown in FIG.
FIG. 3 is a sectional view showing a cone-shaped insulating spacer according to another embodiment of the present invention.
4 is an electric field distribution characteristic diagram of the cone-shaped insulating spacer shown in FIG.
FIG. 5 is a cross-sectional view showing a method of manufacturing the cone-shaped insulating spacer shown in FIG.
FIG. 6 is a cross-sectional view showing another manufacturing method of the cone-shaped insulating spacer shown in FIG.
FIG. 7 is a sectional view of a main part showing a gas circuit breaker according to one embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 High voltage conductor 2 Grounding metal container 3 Cone-shaped insulating spacer 3a Convex side 3b Intermediate part 3c Concave side 4a, 4b Mold 5 Inlet 6 Gas circuit breaker 10a, 10b Filling part

Claims

A cone-shaped insulating spacer that is housed in a grounded metal container, supports the high-voltage conductor, and has a convex surface on one side in the axial direction of the high-voltage conductor and a concave surface on the other side. A cone-shaped insulating spacer, wherein the dielectric constant is changed, and the dielectric constant of the concave surface located near the high-voltage conductor is made smaller than that of the largest dielectric constant.

2. The cone-shaped insulating spacer according to claim 1, wherein at least one of a mixing ratio of the filler and a type of the filler in the longitudinal direction of the high-voltage conductor is changed.

2. The cone-shape according to claim 1, wherein the dielectric constant of the concave surface located near the high-voltage conductor is smaller than the dielectric constant of the convex surface located near the high-voltage conductor. Insulating spacer.

2. The cone-shaped insulating spacer according to claim 1, wherein the dielectric constant of the high-voltage conductor in the axial direction is continuously changed.

A cone-shaped insulating spacer which accommodates a cut-off portion in a grounded metal container, supports a high-voltage conductor electrically connected to the cut-off portion, and has a convex surface on one surface in the axial direction of the high-voltage conductor and a concave surface on the other. Wherein the cone-shaped insulating spacer changes the dielectric constant in the axial direction of the high-voltage conductor, and has a concave surface located closer to the high-voltage conductor than a convex surface located near the high-voltage conductor. A circuit breaker characterized by having a low dielectric constant on a side thereof and a convex surface side of the cone-shaped insulating spacer facing an interrupting portion side.