JP4434529B2 - Switchgear - Google Patents

Description

【０００１】
【発明の属する技術分野】
本発明は、絶縁性能が優れ、環境に調和した開閉装置に関する。
【０００２】
【従来の技術】
従来の開閉装置について、２２／３３ｋＶ、６６／７７ｋＶクラスの特高変電設備を例にとって説明する。このクラスの開閉装置は、建設費、用地の高騰とともに、充電部汚損、安全性、騒音などの問題から開閉装置の小形化や密閉化が要求され、ガス絶縁式開閉装置（ＧＩＳ：Ｇａｓ Ｉｎｓｕｌａｔｅｄ Ｓｗｉｔｃｈｇｅａｒ）やキュービクル形ガス絶縁開閉装置（Ｃ−ＧＩＳ：Ｃｕｂｉｃｌｅ ｔｙｐｅ ＧＩＳ）が開発されてきている。
【０００３】
ＧＩＳは各電気機器をパイプ状の金属容器で覆い、絶縁媒体として高圧のＳＦ₆ガスを封入し小形化、密閉化したものである。
【０００４】
これに対して、Ｃ−ＧＩＳはＧＩＳに対して、より高い信頼性、安全性、保守・点検の簡素化と同時に、狭い用地に短期間で建設でき、かつ周囲との環境に調和させる要請にも対応すべく開発された開閉装置である。これは大気圧近傍の低圧力絶縁ガスを利用したキュービクル形の容器に各電気機器を一括して収納し、内部を構成単位ごとに区分したものであり、他の閉鎖配電盤と同様の外観である。このように最近ではＳＦ₆ガスを絶縁媒体として用いた開閉装置が多数運転されるようになった。
【０００５】
代表的なキュービクル形ガス絶縁開閉装置の一例の構成を図１５に示す。同図において、外周を軟鋼板で気密に囲まれた箱体１の内部は、ＳＦ₆ガス２が密封されており、受電室１ａ、遮断器室１ｂ、及び母線室１ｃにガス区分されている。
【０００６】
受電室１ａには、ガス−気中の区分をしたケーブルヘッド３が箱１の側面に取付けられ、避雷器４および検電がいし５が収納され、それぞれが接続導体７で接続されている。なお、ケーブルヘッド３には、変流器８を貫通した電力用ケーブル９が接続されている。
【０００７】
また、遮断器室１ｂには、受電室１ａとガス区分される下段の絶縁スペーサ１０ａを介して、図示していない真空バルブを収納した遮断器１１が収納され、この遮断器１１は接続導体７を介して母線室１ｃとガス区分される上段の絶縁スペーサ１０ｂに接続されている。遮断器１１は絶縁・消弧媒体として高真空を用いている。また、断路器６は絶縁・消弧媒体としてＳＦ₆ガスを用いている。
【０００８】
【発明が解決しようとする課題】
上述のように、このような構成において断路器６は絶縁・消弧媒体としてＳＦ₆ガスを用いている。このＳＦ₆ガスは空気と比較して約１００倍の消弧性能と約３倍の絶縁性能を持つことが知られている。このＳＦ₆ガスは通常の運転状態では、無色、無臭、無味、不燃性の非常に安定した気体であり、しかも無毒である。
【０００９】
しかしながら、ＳＦ₆ガス中でアーク放電が発生すると、ＳＦ₆ガスはＳＯＦ₂、ＳＯ₂、ＳＯ₂Ｆ₂、ＳＯＦ₄、ＨＦ、ＳｉＦ₄等の分解生成物や分解ガスを発生する。このＳＦ₆ガスの分解生成物や分解ガスは毒性が強いため、分解したガスを回収する場合、特別な処理や管理が必要になる。事故電流などの遮断は遮断器１１で行うため、分解生成物や分解ガスの発生はないが、変電所内の母線切替えや線路切替えを断路器６で行う。従って、断路器６はループ電流の遮断責務を要求される。このループ電流は定格電流に近い電流値となり、その際断路器６で分解生成物や分解ガスを発生する。このような断路器６のガスを回収する場合、吸着材を通して回収するなど取扱いに苦慮している。
【００１０】
また、ＳＦ₆ガスは地球温暖化の原因となる温室効果ガスであり、温室効果係数が二酸化炭素の２４０００倍である。そのため、１９９７年１２月に京都で開催された第３回気候変動に関する国際連合枠組み条約締約国会議（ＣＯＰ３）において、ＳＦ₆も削減対象ガスとして加えられ、排出の抑制と削減についての対応が要求されている。このように環境面からも、断路器の絶縁・消弧媒体としてＳＦ₆ガスを使用しないのが望ましい。
【００１１】
そこで、断路器の絶縁媒体を真空とした真空断路器が考えられるが、無負荷で接点を開閉しただけでも絶縁性能の低下が大きく、かつ絶縁性能のばらつきが大きくなる。
【００１２】
例えば、絶縁性能のばらつきを標準偏差で表すと、ＳＦ₆ガスが６〜７％に対して真空ギャップは通常１０〜１３％程度であるが、開閉条件によっては１８％程度に達することもある。断路器では安全性の観点から絶縁の信頼性が強く要求されているが、このように真空を絶縁媒体として用いた断路器は接点の開閉によって絶縁性能が低下し、絶縁の信頼性に欠けるという欠点がある。このため、真空を断路器の絶縁媒体として用いる場合、何らかの対策が求められている。
【００１３】
このような理由から、ＳＦ₆ガスを使用しない開閉装置の実現が困難になっているのが実状である。
【００１４】
そこで本発明の目的は、ＳＦ₆ガスの使用量を抑制し、構造が簡単で信頼性が高い、真空バルブを使用した開閉装置を提供するにある。
【００１５】
【課題を解決するための手段】
本発明に係る開閉装置は、両端がそれぞれ金属端板で気密に封着された絶縁容器内に、一方の金属端板を貫通する固定通電軸に固着された固定側接点を設け、他方の金属端板を貫通する可動通電軸がベローズを介して固着されると共に、可動通電軸に固着された可動側接点を固定側接点と対向するように配置し、可動通電軸および固定通電軸のそれぞれにより支持され、可動側接点および固定側接点を包囲する金属部材がそれぞれ設けられ、それぞれの金属部材にはその先端が可動側接点または固定側接点よりも突出した凸部と、可動側接点または固定側接点よりもへこんだ凹部とを設け、固定側接点と可動側接点とが接触した位置において、可動側の金属部材および固定側の金属部材の凸部と凹部とが嵌め合うように配置し、金属部材の凹部と対向する接点の端部を通電軸よりもへこませた真空バルブを有することを特徴とする。
【００１６】
このような構成により、無負荷開閉を行っても絶縁性能の優れた真空バルブを有する開閉装置を提供することができる。
【００１７】
【発明の実施の形態】
以下、本発明の実施形態について図面を参照して詳細に説明する。
【００１８】
（第１の実施形態）
図１は、本発明の第１の実施形態として、本発明に係る開閉装置、例えば断路器に使用される真空バルブの構成例を示す縦断面図である。例えば、従来の技術で示した図１５の断路器６用の真空バルブの構成例を示すものである。
【００１９】
図１において、セラミックまたはガラスからなる絶縁容器２１を使って真空容器が形成され、両端開口部が、固定側端板２２および可動側端板２３ａ、２３ｂでそれぞれ密封され、気密な容器を構成する。固定側端板２２には固定側接点２４を接合した固定通電軸２５が支持固定され、この固定側接点２４と対向して可動側接点２６が可動通電軸２７に接合されている。この可動通電軸２７は図示していない操作機構に連結されている。可動通電軸２７と可動側端板２３ｂとの間にはベローズ２０が設けられ、可動側接点２６や可動通電軸２７が直線的に移動できる。絶縁容器２１の中間部にはシールド２８が封着金具２９ａ、２９ｂを介して取付けられている。金属部材３０は固定通電軸２５に支持固定され、固定側接点２４の側面を包囲するように配置されている。金属部材３１は可動通電軸２７に支持固定され、可動側接点２６の側面を包囲するように配置されている。
【００２０】
図２は、本実施形態における可動側接点２６および金属部材３１の構造を示す。金属部材３１は可動側接点２６よりも突き出た凸部（突出部）３１ａとへこんだ凹部３１ｂで構成されている。固定側接点２４および金属部材３０についても、可動側と同様の構成となっていて、金属部材３０は固定側接点２４よりも突き出た凸部（突出部）とへこんだ凹部で構成されている。接点の投入時には可動側の金属部材３１の凸部３１ａと固定側の金属部材３０の凹部が嵌め合うように構成されている。ただし、接点２４、２６が接触した状態で、金属部材３１と金属部材３０とは接触しない。
【００２１】
このような構成で、図示していない開閉装置の制御回路または手動による断路器の断路指令があった場合、可動側接点２６及び可動通電軸２７が移動し、断路状態となる。断路状態での固定側接点２４と可動側接点２６間の電界強度は、金属部材３０、３１によって電界が緩和され、電界強度が低減される。また、金属部材３０の凸部、金属部材３１の凸部３１ａの電界強度は、それぞれ接点２６、２７よりも突き出ているため接点２６、２７よりも高くなることが考えられる。
【００２２】
図３は、接点の無負荷開閉を行い、接点に機械的衝撃を加えた場合の絶縁破壊確率分布を示す。機械的衝撃が加わると破壊電圧のばらつきが非常に大きくなり、例えば破壊確率（累積破壊破壊確率）が０．１％となる電圧は機械的衝撃を加えることによって３０〜４０％程度低下する。
【００２３】
断路器においては確実な電源の切り離しや安全性の観点から、より高い絶縁の信頼性が要求される。このため、破壊確率で表すと５０％破壊電圧よりも、例えば０．１％などの低破壊確率での絶縁性能が問題となる。
【００２４】
本実施形態の金属部材３０、３１を設けることにより接点２６、２７の電界強度が低減され、破壊電圧が向上する。これに対して、金属部材３０、３１間の絶縁性能は、前述したように電界強度が高くなるが、図３に示すように機械的衝撃が加わらないので、破壊電圧のばらつきが小さくなる。このため、低破壊確率の電圧は向上する。このように、無負荷開閉を行っても絶縁性能の優れた断路器用真空バルブを提供することができる。
【００２５】
（第２の実施形態）
次に本発明の第２の実施形態について説明する。この実施形態は、図１及び図２に示す第１の実施形態の真空バルブにおいて、金属部材３１の凸部３１ａの先端部が可動側接点２６より突出した長さ（可動側接点２６よりも突出した金属部材３１の凸部３１ａの先端部と可動側接点２６との距離）をＨ₁とし、金属部材３１の凹部３１ｂの幅をＷとし、可動側接点２６と固定側接点２４との間のギャップ長をｄとすると、前記Ｈ₁、Ｗ、ｄの関係が、
Ｈ₁＝（０．０８〜０．３）ｄ、Ｗ≦７．０・Ｈ₁
となるような金属部材３１を用いたものである。また、可動側について記述したが、固定側についてもＨ₁、Ｗ、ｄの関係は同様である。
【００２６】
図１及び図２に示す構成において、金属部材３１の凸部３１ａに対向する可動側接点の位置２６ａでは凸部３１ａによって十分に電界強度が低減されるが、金属部材３１の凹部３１ｂに対向する可動側接点２６の位置２６ｂでは十分に電界強度が低減しないことが考えられる。このため、金属部材３１の凸部３１ａの先端部が可動側接点２６より突出した長さ（可動側接点２６よりも突出した金属部材３１の凸部３１ａの先端部と可動側接点２６との距離）をＨ₁とし、金属部材３１の凹部３１ｂの幅をＷとし、可動側接点２６と固定側接点２４との間のギャップ長をｄとした場合のＨ₁、Ｗ、ｄと可動側接点の２６ｂの位置での電界強度の関係を発明者が調査した。
【００２７】
図４は、前述のＨ₁、Ｗ、ｄと可動側接点の２６ｂの位置での電界強度の関係を示す。ここで、Ｅａは金属部材３１が無い場合の電界強度を示す。Ｈ₁／ｄが大きくなるほど、つまり金属部材３１の凸部３１ａの高さが高くなるほど２６ｂの電界強度は低くなり、Ｈ₁／ｄを０．０８以上にすると金属部材３１が無い場合より２６ｂの電界強度が２０％以上低減される。また、金属部材３１の凹部３１ｂの幅Ｗが広くなるほど、電界強度が高くなり、Ｈ₁／ｄが０．０８以上では凹部の幅Ｗを７．０Ｈ₁以下にすると、金属部材３１が無い場合よりも２６ｂの電界強度は２０％以上低減される。
【００２８】
次に、図５は金属部材３１の凸部３１ａの電界強度とＨ₁、ｄの関係を示す。ここで、Ｅｂは無負荷開閉を行わない場合の破壊確率０．１％の電界強度を示す。Ｈ₁／ｄが大きくなるほど、つまり金属部材３１の凸部３１ａの高さが高くなるほど突出部３１ａの電界強度は高くなり、Ｈ₁／ｄが０．３より大きな値になると、Ｅｂよりも高くなる。従って、Ｈ₁／ｄが０．０８〜０．３の範囲で、Ｗを７．０Ｈ₁以下にすると、接点の電界強度も低減され、金属部材からの絶縁破壊の確率が低く、絶縁性能の優れた断路器用真空バルブを提供することができる。
【００２９】
（第３の実施形態）
図６は、本発明の第３の実施形態として、本発明に係る開閉装置、例えば断路器に使用される真空バルブの構成例を示す縦断面図であり、図１と同一部分には同一符号を付してその説明を省略し、異なる部分についてのみ述べる。図６において、金属部材３２は固定通電軸２５に支持固定され、金属部材３３は可動通電軸２７に支持固定されている。
【００３０】
図７は、本実施形態における可動側接点２６および金属部材３３の構造を示す。金属部材３３は可動側接点２７よりも突き出した凸部（突出部）３３ａと可動側接点よりもへこんだ凹部３３ｂで構成されている。金属部材３３の凸部３３ａの半径方向の断面は半円筒状の形状をしている。固定側接点２４および金属部材３２についても、可動側と同様の構成となっている。固定側接点２４と可動側接点２６の投入時には可動側の金属部材３３の凸部３３ａと固定側の金属部材３２の凹部が嵌め合うように構成されている。ただし、接点２４、２６が接触した状態で、金属部材３２と金属部材３３とは接触しない。
【００３１】
このような構成により、断路状態での固定側接点２４と可動側接点２６の電界強度は金属部材３２、３３によって電界緩和され、電界強度が低減される。また、金属部材３２の凸部、金属部材３３の凸部３３ａの電界強度は、接点２４、２６よりも突き出ているため接点２４、２６よりも高くなることが考えられる。しかしながら、金属部材３２の凸部、金属部材３３の凸部３３ａは、接点２４、２６の開閉を行っても接触しないので、図３に示すように破壊電圧の低下やばらつきが大きくなることもない。
【００３２】
従って、第１の実施形態で説明したように固定側接点２４と可動側接点２６の電界強度が低減されるので、無負荷開閉を行っても絶縁性能の優れた断路器用真空バルブを提供することができる。
【００３３】
（第４の実施形態）
この実施形態は、図６及び図７に示す第３の実施形態の真空バルブにおいて、金属部材３３の凸部３３ａの先端部が可動側接点２６より突出した長さ（可動側接点２６よりも突出した金属部材３３の凸部３３ａの先端部と可動側接点２６との距離）をＨ₂、可動側接点２６と固定側接点２４との間のギャップ長をｄとすると、前記Ｈ₂、ｄの関係が
Ｈ₂＝（０．１〜０．３）ｄ
となるような金属部材３３を用いたものである。また、可動側について記述したが、固定側についても、Ｈ₂、ｄの関係は同様である。
【００３４】
図６及び図７に示す構成において、金属部材３３の凸部３３ａに対向する可動側接点の位置２６ａでは凸部３３ａによって十分に電界強度が低減されるが、金属部材３３の凸部３３ａから離れた可動側接点２６の位置２６ｂでは十分に電界強度が低減しないことが考えられる。このため、金属部材３３の凸部３３ａの先端部が可動側接点２６より突出した長さ（可動側接点２６よりも突出した金属部材３３の凸部３３ａの先端部と可動側接点２６との距離）をＨ₂とし、可動側接点２６と固定側接点２４の間のギャップ長をｄとした場合のＨ₂、ｄと可動側接点の２６ｂの位置での電界強度の関係を発明者が調査した。
【００３５】
図８は、前述のＨ₂、ｄと可動側接点の２６ｂの位置での電界強度の関係を示す。ここで、Ｅａは金属部材３３が無い場合の電界強度を示す。Ｈ₂／ｄが大きくなるほど、つまり金属部材３３の凸部３３ａの高さが高くなるほど２６ｂの電界強度は低くなり、Ｈ₂／ｄを０．１以上にすると金属部材３３が無い場合より２６ｂの電界強度が２０％以上低減される。
【００３６】
次に、金属部材３３の凸部３３ａの電界強度とＨ₂、ｄは前述した図５に示すような関係になる。第２の実施形態で説明したように、Ｅｂは無負荷開閉を行わない場合の破壊確率０．１％の電界強度を示す。Ｈ₂／ｄが大きくなるほど、つまり金属部材３３の凸部３３ａの高さが高くなるほど凸部３３ａの電界強度は高くなり、Ｈ₂／ｄが０．３より大きな値になると、Ｅｂよりも高くなる。従って、Ｈ₂／ｄを０．１〜０．３の範囲にすると、接点の電界強度も低減され、金属部材からの絶縁破壊の確率が低く、絶縁性能の優れた断路器用真空バルブを提供することができる。
【００３７】
（第５の実施形態）
図９は、本発明の第５の実施形態として、本発明に係る開閉装置、例えば断路器に使用される真空バルブの構成例を示す縦断面図である。図９に示す断路器用真空バルブにおいて、可動通電軸２７および固定通電軸２５に支持され、可動側接点２６と固定側接点２４を包囲する円筒状の金属部材３５、３４を設け、それぞれの金属部材３５、３４の先端部が前記可動側接点２６と固定側接点２４よりも突出し、可動側の金属部材３５の内径が固定側の金属部材３４の外径よりも大きくなるように構成している。図９においては可動側の金属部材３５の直径が大きくなるように構成されているが、金属部材３４、３５のいずれか一方の内径が他方の外径より大きいことが本実施形態の趣旨である。
【００３８】
図９に示す断路器用真空バルブにおいて、固定側接点２４の電界強度は金属部材３４によって電界緩和され、可動側接点２６の電界強度は金属部材３５によって電界緩和されるので、電界強度が低減される。従って、無負荷開閉などの機械的衝撃が加わる部分の電界強度が低減されるので、第１乃至第４の実施形態で説明したように絶縁性能の優れた断路器用真空バルブを提供することができる。
【００３９】
（第６の実施形態）
この実施形態は、図９に示す第５の実施形態の断路器用真空バルブにおいて、可動側接点２６と固定側接点２４を包囲する円筒状の金属部材３５、３４のうち、一方の直径が大きい方の金属部材の先端部、例えば金属部材３５の先端部３５ａが可動側接点２６より突出した長さ（可動側接点２６よりも突出した金属部材３５の先端部３５ａと可動側接点２６との距離）をＨ₄、もう一方の直径が小さい方の金属部材３４の先端部３４ａが固定側接点２４より突出した長さ（固定側接点２４よりも突出した金属部材３４の先端部３４ａと固定側接点２４との距離）をＨ₃、可動側接点２６と固定側接点２４の間のギャップ長をｄとすると、前記Ｈ₃、Ｈ₄の関係が、
Ｈ₃＝（０．０５〜０．３）ｄ
Ｈ₄＝（０．１〜０．４）ｄ
となるような金属部材３５、３４を用いたものである。また、金属部材３４、３５の内径はいずれかの金属部材の内径が大きく、接点２４、２６が投入された状態では、金属部材３４、３５同士が接触しないように構成されている。
【００４０】
図９に示す構成において、金属部材３４、３５によって固定側接点２４や可動側接点２６の電界強度は低減される。可動側接点２６と固定側接点２４をそれぞれ包囲する円筒状の金属部材３５、３４のうち、一方の直径が小さい方の金属部材の先端部、例えば金属部材３４の先端部３４ａが固定側接点２４より突出した長さ（固定側接点２４よりも突出した金属部材３４の先端部３４ａと固定側接点２４との距離）をＨ₃、もう一方の直径が大きい方の金属部材の先端部、例えば金属部材３５の先端部３５ａが可動側接点２６より突出した長さ（可動側接点２６よりも突出した金属部材３５の先端部３５ａと可動側接点２６との距離）をＨ₄、可動側接点２６と固定側接点２４の間のギャップ長をｄとした場合の固定側接点２４や可動側接点の２６の電界強度について発明者が調査した。
【００４１】
図１０は、前述のＨ₃、Ｈ₄と固定側接点２４や可動側接点２６の電界強度の関係を示す。図中のＨ₃が固定側接点２４、Ｈ₄が可動側接点２６の電界強度を示す。ここで、Ｅａは図４及び図８と同様に、金属部材３４、３５が無い場合の電界強度を示す。Ｈ₃／ｄ、Ｈ₄／ｄが大きくなるほど、つまり金属部材３４、３５の突出部の高さが高くなるほど接点の電界強度は低くなり、金属部材の直径が小さい固定側はＨ₃／ｄを０．０５以上にすると金属部材３４が無い場合より固定側接点２４の電界強度が２０％以上低減される。また、可動側においては、金属部材３５の直径が大きくなるので、金属部材３５が無い場合よりも可動側接点２６の電界強度を２０％低くするためには、Ｈ₄／ｄを０．１以上にしなければならない。
【００４２】
次に、金属部材３４、３５の先端部３４ａ、３５ａの電界強度とＨ₃、Ｈ₄、ｄの関係を図５に示す。ここで、Ｅｂは第２の実施形態で説明したように、無負荷開閉を行わない場合の破壊確率０．１％の電界強度を示す。Ｈ₃／ｄ、Ｈ₄／ｄが大きくなるほど、つまり金属部材３４、３５の先端部３４ａ、３５ａの高さが高くなるほど先端部３４ａ、３５ａの電界強度は高くなり、固定側の金属部材３４の先端部３４ａの電界強度は、Ｈ₃／ｄが０．３より大きな値になると、Ｅｂよりも高くなる。従って、Ｈ₃／ｄが０．０５〜０．３の範囲にすると、接点の電界強度も低減され、さらに金属部材からの絶縁破壊の確率も低くなる。同様に、可動側の金属部材３５の先端部３５ａの電界強度はＨ₄／ｄが０．４より大きな値になると、Ｅｂよりも高くなる。従って、Ｈ₄／ｄが０．１〜０．４の範囲にすると、接点の電界強度も低減され、さらに金属部材からの絶縁破壊の確率も低くなる。このように、最適な金属部材の突出部の高さＨ₃、Ｈ₄にすることにより絶縁性能の優れた断路器用真空バルブを提供することができる。
【００４３】
（第７の実施形態）
図１１は、本発明の第７の実施形態として、本発明に係る開閉装置、例えば断路器に使用される真空バルブの可動側接点４０および金属部材３１の構造を示す。図１１において、金属部材３１の凹部３１ｂと対向する可動側接点４０の端部が可動通電軸２７よりもへこんだ形状をしている。図１１は可動側について示しているが、固定側についても同様に金属部材３０の凹部３０ｂと対向する固定側接点の端部は固定通電軸よりもへこんだ形状をしている。
【００４４】
図１１に示す断路器用真空バルブにおいて、金属部材３１の凹部３１ｂに対向した可動側接点４０の端部４０ａの電界強度が低減され、機械的衝撃が加わる部分の電界強度が低減されるので、種々の開閉を行っても絶縁性能の優れた断路器用真空バルブを提供することができる。
【００４５】
（第８の実施形態）
次に、本発明の第８の実施形態について説明する。本実施形態は、図１、図２、図６、図７、図９、及び図１１に示す断路器用真空バルブにおいて、金属部材３０、３１、３２、３３、３４、３５の材質をステンレス鋼またはタングステンにしたものである。
【００４６】
このように、図１、図２、図６、図７、図９、及び図１１に示す断路器用真空バルブにおいて、金属部材３０、３１、３２、３３、３４、３５の材質をステンレス鋼またはタングステンにすることにより、固定側と可動側の金属部材との間の絶縁性能が向上する。
【００４７】
図１２は本発明者等が行った雷インパルス耐電圧性能と材料との比較を示す。なお、材料は銅（無酸素銅）、ステンレス鋼（ＳＵＳ３０４）、タングステンである。また、試験に用いた電極形状は直径３４ｍｍの平板電極で、ギャップ長は１．５ｍｍである。
【００４８】
図１２において、銅材と比較してステンレス鋼で１．７倍、タングステンで１．９倍である。ただし、銅材の表面に真空蒸着などの手法によりタングステンをコーティングしても同様な効果が得られるので、本実施形態の範囲は金属部材の表面材料をステンレス鋼またはタングステンとする。このように、金属部材の材質をステンレス鋼またはタングステンとすることにより、絶縁性能の優れた断路器用真空バルブを提供することができる。
【００４９】
（第９の実施形態）
次に、本発明の第９の実施形態について説明する。本実施形態は図１、図２、図６、図７、図９、及び図１１に示す断路器用真空バルブにおいて、金属部材３０、３１、３２、３３、３４、３５の表面に複合電解研磨処理または電子ビーム処理（電子ビームによる改質層を設ける処理）を施したものである。
【００５０】
このように、図１、図２、図６、図７、図９、及び図１１に示す断路器用真空バルブの金属部材３０、３１、３２、３３、３４、３５の表面に複合電解研磨処理または電子ビーム処理を施し、表面を平滑化することにより、固定側と可動側の金属部材との間の絶縁性能を向上させることができる。
【００５１】
図１３は、金属部材の表面状態の違いと雷インパルス破壊電圧の比較を示す。発明者らは表面粗さ約１μｍ程度に仕上げた電極とその電極を複合電解研磨処理した電極の雷インパルス耐電圧特性を比較した。電解液は、りん酸と硫酸の混合液である。一般に真空中の絶縁破壊は、図１３からもわかるように絶縁破壊を繰り返すたびに破壊電圧が高くなる。これをコンディショニング効果と呼び、これを利用したコンディショニング処理を真空バルブの製造の最終工程で行っている。
【００５２】
図１３から明らかなように、複合電解研磨処理を行うことにより、少ない破壊回数で高い絶縁性能を示し、かつ最終の破壊電圧も約２０ｋＶ高い。
【００５３】
このように、複合電解研磨処理を行うことにより、コンディショニング処理に要する時間を短縮することができるという利点がある。
【００５４】
図１４は、金属部材に電子ビーム処理を行った場合の耐電圧特性の比較を示す。
【００５５】
図１４から明らかなように電子ビーム処理を行うことにより、少ない破壊回数で高い絶縁性能を示し、かつ最終の破壊電圧も約２０ｋＶ高い。
【００５６】
このように、電子ビーム処理（電子ビームによる改質層を設ける処理）を行うことにより、コンディショニング処理に要する時間を短縮することができるという利点がある。
【００５７】
【発明の効果】
以上説明したように、本発明によれば、構造が簡単で、絶縁信頼性の高い真空バルブを有する開閉装置を提供することができ、ＳＦ₆ガスの使用量を抑制し、環境に調和した開閉装置を提供することができる。
【図面の簡単な説明】
【図１】 本発明の第１及び第２の実施形態に係る断路器用真空バルブの構成を示す縦断面図。
【図２】 本発明の第１及び第２の実施形態における主要部の構成を示す斜視図。
【図３】 本発明の第１及び第２の実施形態の作用を示すグラフ。
【図４】 本発明の第２の実施形態の作用を示すグラフ。
【図５】 本発明の第２、第４、及び第６の実施形態の作用を示すグラフ。
【図６】 本発明の第３及び第４の実施形態に係る断路器用真空バルブの構成を示す縦断面図。
【図７】 本発明の第３及び第４の実施形態における主要部の構成を示す斜視図。
【図８】 本発明の第４の実施形態の作用を示すグラフ。
【図９】 本発明の第５及び第６の実施形態に係る断路器用真空バルブの構成を示す縦断面図。
【図１０】本発明の第６の実施形態の作用を示すグラフ。
【図１１】本発明の第７の実施形態における主要部の構成を示す斜視図。
【図１２】本発明の第８の実施形態の作用を示すグラフ。
【図１３】本発明の第９の実施形態の作用（複合電解研磨処理の場合）を示すグラフ。
【図１４】本発明の第９の実施形態の作用（電子ビーム処理の場合）を示すグラフ。
【図１５】従来の開閉装置の構成を示す縦断面図。
【符号の説明】
１…開閉装置の箱体
１ａ…受電室
１ｂ…遮断器室
１ｃ…母線室
２…ＳＦ₆ガス
３…ケーブルヘッド
４…避雷器
５…検電がいし
６…断路器
７…接続導体
８…変流器
９…ケーブル
１０ａ、１０ｂ…スペーサ
１１…遮断器
１２…接続母線
１３…操作機構
１４…制御箱
２０…ベローズ
２１、３３…絶縁容器
２２…固定側端板
２３（２３ａ、２３ｂ）…可動側端板
２４…固定側接点
２５…固定通電軸
２６、４０…可動側接点
２７…可動通電軸
２８…シールド
２９ａ、２９ｂ…封着金具
３０、３１、３２、３３、３４、３５…金属部材
３１ａ、３３ａ…凸部（突出部）
３４ａ、３５ａ…先端部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a switchgear having excellent insulation performance and harmonizing with the environment.
[0002]
[Prior art]
A conventional switchgear will be described by taking a 22/33 kV, 66/77 kV class extra high-voltage transformer facility as an example. This class of switchgear is required to reduce the size and seal of the switchgear due to problems such as contamination of the charging section, safety, noise, etc., along with soaring construction costs, land, and gas insulated switchgear (GIS: Gas Insulated Switchgear). ) And cubicle type gas insulated switchgear (C-GIS).
[0003]
GIS covers each electrical device with a pipe-shaped metal container and uses high-pressure SF as an insulating medium.₆The gas is sealed and miniaturized and sealed.
[0004]
On the other hand, C-GIS requests GIS to have higher reliability, safety, simplification of maintenance and inspection, and at the same time, it can be built on a small site in a short period of time and harmonizes with the surrounding environment. Is a switchgear that was developed to cope with this. This is a cubicle-type container that uses a low-pressure insulating gas near atmospheric pressure, and each electrical device is stored in one unit, and the interior is divided into structural units, and has the same appearance as other closed switchboards. . In this way, recently, SF₆Many switchgears using gas as an insulating medium have been operated.
[0005]
FIG. 15 shows a configuration of an example of a typical cubicle type gas insulated switchgear. In the figure, the inside of the box 1 whose outer periphery is hermetically surrounded by mild steel plate is SF₆The gas 2 is sealed and is divided into a power receiving chamber 1a, a circuit breaker chamber 1b, and a busbar chamber 1c.
[0006]
In the power receiving chamber 1 a, a cable head 3 divided into gas and air is attached to the side surface of the box 1, and a lightning arrester 4 and a voltage detection insulator 5 are accommodated, and each is connected by a connection conductor 7. The cable head 3 is connected to a power cable 9 penetrating the current transformer 8.
[0007]
The circuit breaker chamber 1b accommodates a circuit breaker 11 containing a vacuum valve (not shown) through a lower insulating spacer 10a that is gas-separated from the power receiving chamber 1a. The circuit breaker 11 is connected to the connection conductor 7a. Is connected to an upper insulating spacer 10b which is separated from the bus bar chamber 1c by gas. The circuit breaker 11 uses high vacuum as an insulating / arcing medium. Moreover, the disconnector 6 is SF as an insulating / arcing medium.₆Gas is used.
[0008]
[Problems to be solved by the invention]
As described above, in such a configuration, the disconnector 6 is SF as an insulating / arcing medium.₆Gas is used. This SF₆It is known that gas has about 100 times arc extinguishing performance and about 3 times insulation performance compared to air. This SF₆Under normal operating conditions, gas is a very stable gas that is colorless, odorless, tasteless, non-flammable and non-toxic.
[0009]
However, SF₆When arc discharge occurs in gas, SF₆Gas is SOF₂, SO₂, SO₂F₂, SOF_Four, HF, SiF_FourIt generates decomposition products and decomposition gas. This SF₆Since the decomposition products and decomposition gas of gas are highly toxic, special treatment and management are required when recovering the decomposed gas. Since the circuit breaker 11 cuts off the accident current and the like, no decomposition products or cracked gas is generated, but the busbar switching and line switching in the substation are performed by the disconnector 6. Therefore, the disconnector 6 is required to take responsibility for breaking the loop current. This loop current has a current value close to the rated current, and at that time, the disconnecting device 6 generates decomposition products and decomposition gas. When recovering such gas from the disconnector 6, it is difficult to handle such as recovering through the adsorbent.
[0010]
SF₆Gas is a greenhouse gas that causes global warming, and its greenhouse effect coefficient is 24,000 times that of carbon dioxide. Therefore, at the 3rd Conference of the Parties to the United Nations Framework Convention on Climate Change (COP3) held in Kyoto in December 1997, SF₆Is also added as a reduction target gas, and measures to control and reduce emissions are required. In this way, SF is also used as an insulation / extinguishing medium for disconnectors from the environmental aspect.₆It is desirable not to use gas.
[0011]
Thus, a vacuum disconnector in which the insulating medium of the disconnector is vacuum can be considered. However, even if the contact is opened and closed with no load, the deterioration of the insulation performance is large, and the variation in the insulation performance becomes large.
[0012]
For example, if the variation in insulation performance is expressed by standard deviation, SF₆The vacuum gap is usually about 10 to 13% with respect to 6 to 7% of the gas, but it may reach about 18% depending on the open / close conditions. In the disconnector, the reliability of insulation is strongly required from the viewpoint of safety. However, the disconnector using vacuum as an insulating medium in this way deteriorates the insulation performance by opening and closing the contact, and lacks the reliability of insulation. There are drawbacks. For this reason, when using a vacuum as an insulating medium of a disconnector, some countermeasure is required.
[0013]
For this reason, SF₆In reality, it is difficult to realize a switchgear that does not use gas.
[0014]
Therefore, the object of the present invention is to₆An object of the present invention is to provide a switchgear using a vacuum valve, which suppresses the amount of gas used, has a simple structure and is highly reliable.
[0015]
[Means for Solving the Problems]
  The switchgear according to the present invention is provided with a fixed-side contact fixed to a fixed energizing shaft that penetrates one metal end plate in an insulating container hermetically sealed with metal end plates at both ends, and the other metal The movable energizing shaft that penetrates the end plate is fixed via the bellows, and the movable contact fixed to the movable energizing shaft is arranged to face the fixed contact, and each of the movable energizing shaft and the fixed energizing shaft Metal members that are supported and surround the movable side contact and the fixed side contact are provided, and each metal member has a convex portion whose tip protrudes from the movable side contact or the fixed side contact, and the movable side contact or the fixed side. A recessed part that is recessed from the contact point is provided, and at the position where the fixed contact point and the movable contact point are in contact with each other, the metal part on the movable side and the convex part and the recessed part of the metal member on the fixed side are arranged to fit with each other.The end of the contact point facing the concave part of the metal member was recessed from the current-carrying shaftIt has a vacuum valve.
[0016]
With such a configuration, it is possible to provide an opening / closing device having a vacuum valve with excellent insulation performance even when performing no-load opening / closing.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
(First embodiment)
FIG. 1 is a longitudinal sectional view showing a configuration example of a vacuum valve used in a switchgear according to the present invention, for example, a disconnector, as a first embodiment of the present invention. For example, a configuration example of a vacuum valve for the disconnector 6 of FIG. 15 shown in the prior art is shown.
[0019]
In FIG. 1, a vacuum container is formed using an insulating container 21 made of ceramic or glass, and both end openings are sealed by a fixed side end plate 22 and movable side end plates 23a and 23b, respectively, to form an airtight container. . A fixed energizing shaft 25 joined with a fixed contact 24 is supported and fixed to the fixed end plate 22, and a movable contact 26 is joined to a movable energizing shaft 27 so as to face the fixed contact 24. The movable energizing shaft 27 is connected to an operation mechanism (not shown). A bellows 20 is provided between the movable energizing shaft 27 and the movable end plate 23b, and the movable contact 26 and the movable energizing shaft 27 can move linearly. A shield 28 is attached to an intermediate portion of the insulating container 21 via sealing fittings 29a and 29b. The metal member 30 is supported and fixed to the fixed energizing shaft 25 and is disposed so as to surround the side surface of the fixed contact 24. The metal member 31 is supported and fixed to the movable energizing shaft 27 and is disposed so as to surround the side surface of the movable contact 26.
[0020]
FIG. 2 shows the structure of the movable contact 26 and the metal member 31 in the present embodiment. The metal member 31 includes a convex portion (protruding portion) 31 a protruding from the movable contact 26 and a concave portion 31 b that is recessed. The fixed side contact 24 and the metal member 30 have the same configuration as that on the movable side, and the metal member 30 is configured by a protruding portion (projecting portion) protruding from the fixed side contact 24 and a recessed portion recessed. When the contact is inserted, the convex portion 31a of the movable metal member 31 and the concave portion of the fixed metal member 30 are fitted together. However, the metal member 31 and the metal member 30 are not in contact with the contacts 24 and 26 in contact.
[0021]
With such a configuration, when there is a disconnection command for a switch circuit (not shown) or a manual disconnector, the movable contact 26 and the movable energizing shaft 27 are moved to be disconnected. The electric field strength between the fixed contact 24 and the movable contact 26 in the disconnected state is relaxed by the metal members 30 and 31, and the electric field strength is reduced. Moreover, since the electric field strength of the convex part of the metal member 30 and the convex part 31a of the metal member 31 protrudes from the contacts 26 and 27, respectively, it is considered that the electric field strength is higher than the contacts 26 and 27.
[0022]
FIG. 3 shows a breakdown probability distribution when the contact is opened and closed without load and a mechanical shock is applied to the contact. When a mechanical shock is applied, the variation of the breakdown voltage becomes very large. For example, the voltage at which the breakdown probability (cumulative breakdown failure probability) is 0.1% is reduced by about 30 to 40% by applying the mechanical shock.
[0023]
In the disconnector, higher insulation reliability is required from the viewpoint of reliable power supply disconnection and safety. For this reason, in terms of the breakdown probability, the insulation performance with a low breakdown probability such as 0.1% becomes a problem rather than the 50% breakdown voltage.
[0024]
By providing the metal members 30 and 31 of this embodiment, the electric field strength of the contacts 26 and 27 is reduced, and the breakdown voltage is improved. On the other hand, in the insulation performance between the metal members 30 and 31, the electric field strength is increased as described above, but since the mechanical shock is not applied as shown in FIG. 3, the variation in the breakdown voltage is reduced. For this reason, the voltage with a low breakdown probability is improved. Thus, a vacuum valve for a disconnector having excellent insulation performance can be provided even when no-load switching is performed.
[0025]
(Second Embodiment)
Next, a second embodiment of the present invention will be described. In this embodiment, in the vacuum valve of the first embodiment shown in FIGS. 1 and 2, the length of the tip of the convex portion 31 a of the metal member 31 protruding from the movable contact 26 (projecting from the movable contact 26). The distance between the tip of the convex part 31a of the metal member 31 and the movable contact 26) is H₁Where the width of the recess 31b of the metal member 31 is W, and the gap length between the movable contact 26 and the fixed contact 24 is d, the H₁, W, d
H₁= (0.08-0.3) d, W ≦ 7.0 · H₁
The metal member 31 is used. Although the movable side is described, the fixed side is also H.₁, W, d are the same.
[0026]
In the configuration shown in FIGS. 1 and 2, the electric field strength is sufficiently reduced by the convex portion 31 a at the position 26 a of the movable contact point facing the convex portion 31 a of the metal member 31, but it opposes the concave portion 31 b of the metal member 31. It is conceivable that the electric field strength is not sufficiently reduced at the position 26 b of the movable contact 26. For this reason, the length of the tip of the convex portion 31a of the metal member 31 protruding from the movable contact 26 (the distance between the tip of the convex portion 31a of the metal member 31 protruding from the movable contact 26 and the movable contact 26). ) H₁H when the width of the recess 31b of the metal member 31 is W and the gap length between the movable contact 26 and the fixed contact 24 is d.₁The inventors investigated the relationship between the electric field intensity at the position of the movable contact 26b, W, d.
[0027]
FIG. 4 shows the aforementioned H₁, W, d and the electric field strength at the position 26b of the movable side contact. Here, Ea indicates the electric field strength when there is no metal member 31. H₁The greater the / d, that is, the higher the height of the convex portion 31a of the metal member 31, the lower the electric field strength of 26b.₁When / d is 0.08 or more, the electric field strength of 26b is reduced by 20% or more compared to the case where the metal member 31 is not provided. In addition, as the width W of the recess 31b of the metal member 31 increases, the electric field strength increases, and H₁When / d is 0.08 or more, the width W of the recess is 7.0H.₁In the following, the electric field strength of 26b is reduced by 20% or more compared to the case where there is no metal member 31.
[0028]
Next, FIG. 5 shows the electric field strength and H of the convex portion 31a of the metal member 31.₁, D is shown. Here, Eb indicates the electric field strength with a breakdown probability of 0.1% when no load switching is performed. H₁The greater the / d, that is, the higher the height of the protrusion 31a of the metal member 31, the higher the electric field strength of the protrusion 31a.₁When / d becomes a value larger than 0.3, it becomes higher than Eb. Therefore, H₁/ D is in the range of 0.08 to 0.3 and W is 7.0H.₁If it makes below, the electric field strength of a contact is also reduced, the probability of the dielectric breakdown from a metal member is low, and the vacuum valve for disconnectors excellent in insulation performance can be provided.
[0029]
(Third embodiment)
FIG. 6 is a longitudinal sectional view showing a configuration example of a vacuum valve used in a switchgear according to the present invention, for example, a disconnector, as a third embodiment of the present invention. The description is omitted and only different parts are described. In FIG. 6, the metal member 32 is supported and fixed to the fixed energizing shaft 25, and the metal member 33 is supported and fixed to the movable energizing shaft 27.
[0030]
FIG. 7 shows the structure of the movable contact 26 and the metal member 33 in this embodiment. The metal member 33 includes a convex portion (projecting portion) 33a protruding from the movable contact 27 and a concave portion 33b recessed from the movable contact. The cross section in the radial direction of the convex portion 33a of the metal member 33 has a semi-cylindrical shape. The fixed side contact 24 and the metal member 32 have the same configuration as that on the movable side. When the stationary contact 24 and the movable contact 26 are turned on, the convex portion 33a of the movable metal member 33 and the concave portion of the stationary metal member 32 are fitted together. However, the metal member 32 and the metal member 33 are not in contact with the contacts 24 and 26 in contact.
[0031]
With such a configuration, the electric field strength of the stationary contact 24 and the movable contact 26 in the disconnected state is relaxed by the metal members 32 and 33, and the electric field strength is reduced. Moreover, since the electric field strength of the convex part of the metal member 32 and the convex part 33a of the metal member 33 protrudes from the contact points 24 and 26, it can be considered to be higher than the contact points 24 and 26. However, since the convex portion of the metal member 32 and the convex portion 33a of the metal member 33 do not come into contact with each other even when the contacts 24 and 26 are opened and closed, the breakdown voltage does not decrease or vary greatly as shown in FIG. .
[0032]
Accordingly, as described in the first embodiment, since the electric field strength of the fixed contact 24 and the movable contact 26 is reduced, a vacuum valve for a disconnector having excellent insulation performance even when no-load switching is performed is provided. Can do.
[0033]
(Fourth embodiment)
In this embodiment, in the vacuum valve of the third embodiment shown in FIGS. 6 and 7, the length of the protruding portion 33 a of the metal member 33 protruding from the movable contact 26 (projecting from the movable contact 26). The distance between the tip of the convex portion 33a of the metal member 33 and the movable contact 26) is H₂When the gap length between the movable contact 26 and the fixed contact 24 is d, the H₂, D relationship
H₂= (0.1-0.3) d
The metal member 33 is used. Although the movable side is described, the fixed side is also H₂, D are the same.
[0034]
6 and 7, the electric field strength is sufficiently reduced by the convex portion 33 a at the position 26 a of the movable contact point facing the convex portion 33 a of the metal member 33, but it is separated from the convex portion 33 a of the metal member 33. It is conceivable that the electric field strength is not sufficiently reduced at the position 26b of the movable contact 26. Therefore, the length of the tip of the convex portion 33a of the metal member 33 protruding from the movable contact 26 (the distance between the tip of the convex portion 33a of the metal member 33 protruding from the movable contact 26 and the movable contact 26). ) H₂And H when the gap length between the movable contact 26 and the fixed contact 24 is d.₂The inventors investigated the relationship between the electric field strength at the position 26b of the movable contact 26 and d.
[0035]
FIG. 8 shows the above-mentioned H₂, D and the electric field strength at the position 26b of the movable contact. Here, Ea indicates the electric field strength when the metal member 33 is not provided. H₂The greater the / d, that is, the higher the height of the convex portion 33a of the metal member 33, the lower the electric field strength of 26b.₂When / d is 0.1 or more, the electric field strength of 26b is reduced by 20% or more than when there is no metal member 33.
[0036]
Next, the electric field strength of the convex portion 33a of the metal member 33 and H₂, D have the relationship shown in FIG. As described in the second embodiment, Eb indicates the electric field strength with a breakdown probability of 0.1% when no load switching is performed. H₂The higher the / d, that is, the higher the height of the convex portion 33a of the metal member 33, the higher the electric field strength of the convex portion 33a.₂When / d becomes a value larger than 0.3, it becomes higher than Eb. Therefore, H₂When / d is in the range of 0.1 to 0.3, the electric field strength of the contact is also reduced, the probability of dielectric breakdown from the metal member is low, and a vacuum valve for a disconnector with excellent insulation performance can be provided.
[0037]
(Fifth embodiment)
FIG. 9 is a longitudinal sectional view showing a configuration example of a vacuum valve used in a switchgear according to the present invention, for example, a disconnector, as a fifth embodiment of the present invention. In the vacuum valve for disconnector shown in FIG. 9, cylindrical metal members 35 and 34 supported by the movable energizing shaft 27 and the fixed energizing shaft 25 and surrounding the movable side contact 26 and the fixed side contact 24 are provided. The distal end portions of 35 and 34 protrude from the movable contact 26 and the fixed contact 24 so that the inner diameter of the movable metal member 35 is larger than the outer diameter of the fixed metal member 34. In FIG. 9, the diameter of the movable metal member 35 is configured to be large, but the gist of the present embodiment is that the inner diameter of one of the metal members 34 and 35 is larger than the outer diameter of the other. .
[0038]
In the vacuum valve for disconnector shown in FIG. 9, the electric field strength of the stationary contact 24 is relaxed by the metal member 34, and the electric field strength of the movable contact 26 is relaxed by the metal member 35, so that the electric field strength is reduced. . Accordingly, the electric field strength at the portion where mechanical shock such as no-load opening / closing is applied is reduced, so that it is possible to provide a vacuum valve for a disconnector having excellent insulation performance as described in the first to fourth embodiments. .
[0039]
(Sixth embodiment)
This embodiment is the disconnector vacuum valve of the fifth embodiment shown in FIG. 9, and one of the cylindrical metal members 35 and 34 surrounding the movable contact 26 and the fixed contact 24 is larger in diameter. The length of the tip of the metal member, for example, the length of the tip 35a of the metal member 35 protruding from the movable contact 26 (the distance between the tip 35a of the metal member 35 protruding from the movable contact 26 and the movable contact 26). H_FourThe length of the tip 34a of the metal member 34 with the smaller diameter projecting from the fixed contact 24 (the distance between the tip 34a of the metal member 34 projecting from the fixed contact 24 and the fixed contact 24). ) H_ThreeWhen the gap length between the movable contact 26 and the fixed contact 24 is d, the H_Three, H_FourRelationship
H_Three= (0.05-0.3) d
H_Four= (0.1-0.4) d
The metal members 35 and 34 are used. Further, the inner diameter of any of the metal members 34 and 35 is large, and the metal members 34 and 35 are not in contact with each other when the contacts 24 and 26 are inserted.
[0040]
In the configuration shown in FIG. 9, the electric field strength of the stationary contact 24 and the movable contact 26 is reduced by the metal members 34 and 35. Of the cylindrical metal members 35, 34 surrounding the movable contact 26 and the fixed contact 24, the tip of the metal member having the smaller diameter, for example, the tip 34 a of the metal member 34 is the fixed contact 24. The length of the protrusion (the distance between the tip 34a of the metal member 34 protruding from the fixed contact 24 and the fixed contact 24) is H._ThreeThe other end of the metal member having a larger diameter, for example, the length of the tip 35a of the metal member 35 protruding from the movable contact 26 (the tip 35a of the metal member 35 protruding from the movable contact 26) Distance from the movable contact 26) to H_FourThe inventors investigated the electric field strength of the fixed side contact 24 and the movable side contact 26 when the gap length between the movable side contact 26 and the fixed side contact 24 is d.
[0041]
FIG. 10 shows the above-mentioned H_Three, H_FourAnd the relationship of the electric field strength of the stationary contact 24 and the movable contact 26 is shown. H in the figure_ThreeIs fixed side contact 24, H_FourIndicates the electric field strength of the movable contact 26. Here, Ea indicates the electric field strength when the metal members 34 and 35 are not provided, as in FIGS. H_Three/ D, H_FourThe larger the / d, that is, the higher the height of the protrusions of the metal members 34 and 35, the lower the electric field strength of the contact._ThreeWhen / d is 0.05 or more, the electric field strength of the stationary contact 24 is reduced by 20% or more compared to the case where the metal member 34 is not provided. On the movable side, since the diameter of the metal member 35 is increased, in order to reduce the electric field strength of the movable side contact 26 by 20% compared to the case without the metal member 35, H_Four/ D must be 0.1 or more.
[0042]
Next, the electric field strength and H of the tips 34a and 35a of the metal members 34 and 35_Three, H_Four, D is shown in FIG. Here, as described in the second embodiment, Eb indicates the electric field strength with a breakdown probability of 0.1% when no load switching is performed. H_Three/ D, H_FourThe higher the / d, that is, the higher the height of the tip portions 34a and 35a of the metal members 34 and 35, the higher the electric field strength of the tip portions 34a and 35a, and the electric field strength of the tip portion 34a of the metal member 34 on the fixed side is , H_ThreeWhen / d becomes a value larger than 0.3, it becomes higher than Eb. Therefore, H_ThreeWhen / d is in the range of 0.05 to 0.3, the electric field strength of the contact is also reduced, and the probability of dielectric breakdown from the metal member is reduced. Similarly, the electric field strength at the tip 35a of the movable metal member 35 is H._FourWhen / d becomes a value larger than 0.4, it becomes higher than Eb. Therefore, H_FourWhen / d is in the range of 0.1 to 0.4, the electric field strength of the contact is also reduced, and the probability of dielectric breakdown from the metal member is also lowered. Thus, the optimal height H of the protrusion of the metal member_Three, H_FourTherefore, it is possible to provide a vacuum valve for a disconnector having excellent insulation performance.
[0043]
(Seventh embodiment)
FIG. 11 shows the structure of a movable contact 40 and a metal member 31 of a vacuum valve used in a switchgear according to the present invention, for example, a disconnector, as a seventh embodiment of the present invention. In FIG. 11, the end of the movable contact 40 facing the recess 31 b of the metal member 31 has a shape that is recessed from the movable energizing shaft 27. Although FIG. 11 shows the movable side, the end of the fixed side contact facing the concave portion 30b of the metal member 30 is also recessed from the fixed energizing shaft on the fixed side.
[0044]
In the vacuum valve for disconnector shown in FIG. 11, the electric field strength at the end 40a of the movable contact 40 facing the concave portion 31b of the metal member 31 is reduced, and the electric field strength at the portion where mechanical shock is applied is reduced. Therefore, it is possible to provide a vacuum valve for a disconnector that is excellent in insulation performance even when the opening and closing is performed.
[0045]
(Eighth embodiment)
Next, an eighth embodiment of the present invention will be described. In this embodiment, in the vacuum valve for disconnector shown in FIGS. 1, 2, 6, 7, 9, and 11, the metal members 30, 31, 32, 33, 34, and 35 are made of stainless steel or It is made of tungsten.
[0046]
Thus, in the vacuum valve for disconnector shown in FIGS. 1, 2, 6, 7, 9, and 11, the metal members 30, 31, 32, 33, 34, and 35 are made of stainless steel or tungsten. As a result, the insulation performance between the fixed side and movable side metal members is improved.
[0047]
FIG. 12 shows a comparison between lightning impulse withstand voltage performance and materials performed by the present inventors. The materials are copper (oxygen-free copper), stainless steel (SUS304), and tungsten. Moreover, the electrode shape used for the test is a plate electrode having a diameter of 34 mm, and the gap length is 1.5 mm.
[0048]
In FIG. 12, it is 1.7 times for stainless steel and 1.9 times for tungsten compared to copper. However, even if tungsten is coated on the surface of the copper material by a technique such as vacuum deposition, the same effect can be obtained. Therefore, in the present embodiment, the surface material of the metal member is stainless steel or tungsten. Thus, the vacuum valve for disconnectors excellent in insulation performance can be provided by using stainless steel or tungsten as the material of the metal member.
[0049]
(Ninth embodiment)
Next, a ninth embodiment of the present invention will be described. In this embodiment, in the vacuum valve for disconnector shown in FIGS. 1, 2, 6, 7, 9, and 11, the surface of the metal members 30, 31, 32, 33, 34, and 35 is subjected to composite electrolytic polishing treatment. Alternatively, an electron beam treatment (a treatment for providing a modified layer by an electron beam) is performed.
[0050]
Thus, the surface of the metal member 30, 31, 32, 33, 34, 35 of the vacuum valve for disconnector shown in FIGS. 1, 2, 6, 7, 9, and 11 is subjected to the composite electropolishing treatment or By performing electron beam treatment and smoothing the surface, the insulation performance between the fixed-side and movable-side metal members can be improved.
[0051]
FIG. 13 shows a comparison between the surface state difference of the metal member and the lightning impulse breakdown voltage. The inventors compared the lightning impulse withstand voltage characteristics of an electrode finished with a surface roughness of about 1 μm and an electrode obtained by subjecting the electrode to composite electrolytic polishing. The electrolytic solution is a mixed solution of phosphoric acid and sulfuric acid. In general, the breakdown voltage in vacuum increases as the breakdown is repeated, as can be seen from FIG. This is called a conditioning effect, and a conditioning process using this effect is performed in the final process of manufacturing the vacuum valve.
[0052]
As is apparent from FIG. 13, by performing the composite electrolytic polishing treatment, high insulation performance is exhibited with a small number of breakdowns, and the final breakdown voltage is also about 20 kV higher.
[0053]
Thus, there is an advantage that the time required for the conditioning process can be shortened by performing the composite electropolishing process.
[0054]
FIG. 14 shows a comparison of withstand voltage characteristics when an electron beam treatment is performed on a metal member.
[0055]
As is clear from FIG. 14, by performing electron beam processing, high insulation performance is exhibited with a small number of breakdowns, and the final breakdown voltage is also about 20 kV higher.
[0056]
Thus, by performing the electron beam processing (processing for providing a modified layer by an electron beam), there is an advantage that the time required for the conditioning processing can be shortened.
[0057]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a switchgear having a vacuum valve with a simple structure and high insulation reliability.₆It is possible to provide a switchgear that suppresses the amount of gas used and is in harmony with the environment.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing the configuration of a vacuum valve for a disconnector according to first and second embodiments of the present invention.
FIG. 2 is a perspective view showing a configuration of a main part in the first and second embodiments of the present invention.
FIG. 3 is a graph showing the operation of the first and second embodiments of the present invention.
FIG. 4 is a graph showing the operation of the second embodiment of the present invention.
FIG. 5 is a graph showing the operation of the second, fourth, and sixth embodiments of the present invention.
FIG. 6 is a longitudinal sectional view showing a configuration of a disconnector vacuum valve according to third and fourth embodiments of the present invention.
FIG. 7 is a perspective view showing a configuration of a main part in third and fourth embodiments of the present invention.
FIG. 8 is a graph showing the operation of the fourth embodiment of the present invention.
FIG. 9 is a longitudinal sectional view showing a configuration of a disconnector vacuum valve according to fifth and sixth embodiments of the present invention.
FIG. 10 is a graph showing the operation of the sixth embodiment of the present invention.
FIG. 11 is a perspective view showing a configuration of a main part in a seventh embodiment of the present invention.
FIG. 12 is a graph showing the operation of the eighth embodiment of the present invention.
FIG. 13 is a graph showing the action (in the case of composite electrolytic polishing treatment) of the ninth embodiment of the present invention.
FIG. 14 is a graph showing the operation (in the case of electron beam processing) of the ninth embodiment of the present invention.
FIG. 15 is a longitudinal sectional view showing a configuration of a conventional switchgear.
[Explanation of symbols]
1 ... Box body of switchgear
1a ... Power receiving room
1b ... Breaker room
1c: Bus room
2 ... SF₆gas
3 ... Cable head
4. Lightning arrester
5 ... Electricity detection
6 ... Disconnector
7 ... Connection conductor
8 ... Current transformer
9 ... Cable
10a, 10b ... spacer
11 ... circuit breaker
12 ... Connection bus
13 ... Operating mechanism
14 ... Control box
20 ... Bellows
21, 33 ... Insulating container
22 ... Fixed side end plate
23 (23a, 23b) ... movable side end plate
24. Fixed contact
25. Fixed energizing shaft
26, 40 ... movable side contacts
27 ... Movable conducting shaft
28 ... Shield
29a, 29b ... sealing metal fittings
30, 31, 32, 33, 34, 35 ... metal member
31a, 33a ... convex portion (protruding portion)
34a, 35a ... tip

Claims (2)

両端がそれぞれ金属端板で気密に封着された絶縁容器内に、一方の前記金属端板を貫通する固定通電軸に固着された固定側接点を設け、他方の前記金属端板を貫通する可動通電軸がベローズを介して固着されると共に、前記可動通電軸に固着された可動側接点を前記固定側接点と対向するように配置し、前記可動通電軸および前記固定通電軸のそれぞれにより支持され、前記可動側接点および前記固定側接点の側面を包囲する金属部材がそれぞれ設けられ、それぞれの前記金属部材にはその先端が前記可動側接点または前記固定側接点よりも突出した凸部と、前記可動側接点または前記固定側接点よりもへこんだ凹部とを設け、前記固定側接点と前記可動側接点とが接触した位置において、可動側の前記金属部材および固定側の前記金属部材の凸部と凹部とが嵌め合うように配置し、前記金属部材の凹部と対向する接点の端部を通電軸よりもへこませた真空バルブを有することを特徴とする開閉装置。A fixed-side contact fixed to a fixed energizing shaft that penetrates one of the metal end plates is provided in an insulating container hermetically sealed at both ends with metal end plates, and the movable end penetrates the other metal end plate. An energizing shaft is fixed via a bellows, and a movable contact fixed to the movable energizing shaft is arranged to face the fixed contact, and is supported by each of the movable energizing shaft and the fixed energizing shaft. A metal member that surrounds the side surfaces of the movable side contact and the fixed side contact, and each metal member has a protrusion protruding from the movable side contact or the fixed side contact. A movable side contact or a recessed part recessed from the fixed side contact is provided, and at the position where the fixed side contact and the movable side contact are in contact, the movable side metal member and the fixed side metal member It arranged such projections and recesses mate, switchgear, characterized in that it comprises a vacuum valve recessed than current-carrying rod end of the recess facing the contacts of the metal member. 請求項１に記載の開閉装置において、前記金属部材の凸部の先端部が前記可動側接点または前記固定側接点より突出した長さをＨ_１、前記金属部材の凹部の幅をＷ、前記可動側接点と前記固定側接点との間のギャップ長をｄとすると、前記Ｈ_１、Ｗ、ｄの関係が、
Ｈ_１＝（０．０８〜０．３）ｄ、Ｗ≦７．０・Ｈ_１
となるようにしたことを特徴とする開閉装置。2. The switchgear according to claim 1, wherein a length at which a tip of the convex portion of the metal member protrudes from the movable contact or the fixed contact is H ₁ , a width of the concave portion of the metal member is W, and the movable When the gap length between the side contact and the fixed contact is d, the relationship of H ₁ , W, d is
H ₁ = (0.08 to 0.3) d, W ≦ 7.0 · H ₁
An opening and closing device characterized by that.

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