【０００１】
【発明の属する技術分野】
本発明は電力系統や配電系統等で使用される変圧器、リアクトル等の静止誘導電気機器に関するものである。
【０００２】
【従来の技術】
従来、電力系統や配電系統等で使用される電気機器の中で巻線を有する電気機器として変圧器、リアクトル等の静止誘導電気機器がある。静止誘導電気機器の一例として変圧器を例に説明する。
【０００３】
一般的に、高電圧、大容量の変圧器は鉄心脚の周りに同心状に二次巻線、一次巻線が配置され、巻線間のギャップを絶縁筒で分割し、この変圧器中身を鋼板製のタンク内に収納し、冷却絶縁媒体として絶縁油またはＳＦ６ガスをタンク内に変圧器中身と共に充填している。絶縁油は冷却効率がよく、幅広く使用されているが引火点が低く火災の危険性があり、屋内や人家密集地帯では消火設備や防火設備等の付帯設備が必要となる。これに対してＳＦ６ガスは不燃性であり、冷却、絶縁性は絶縁油に劣るものの屋内や人家密集地帯で用いる場合も安全であり、近年多く採用されている。油絶縁変圧器の場合もガス絶縁変圧器の場合もいずれも変圧器の基本的な構造に大きな違いはない。
【０００４】
図１０はこのような高電圧、大容量内鉄形変圧器の巻線絶縁構造の一部を示す断面図である。図において、鉄心脚１に巻回されるように内側から円筒型の低圧巻線２と高圧巻線３とが同心状に配置されている。低圧巻線２と高圧巻線３との間には第１の絶縁筒４と第２の絶縁筒５がお互いに適宜の間隙（ギャップ）を置いて配設されている。また、高圧巻線３の外側には他相あるいは接地部との絶縁のために絶縁物６が配設されている。それぞれの巻線２、３はヨーク鉄心７などの接地部に対し固体絶縁物からなる締め付けリング８、支持絶縁物９により軸方向に締め付けられ、支持されている。
【０００５】
図１１は高圧巻線３が円板巻線の場合の巻線絶縁構造の一部を示す断面図である。低圧巻線２の外側には第１の絶縁筒４が配設され、高圧巻線３の内側には第２の絶縁筒５が配設されている。それぞれの巻線２、３の間隔を保つために、絶縁物のスペーサ１０が円周方向に沿って等配に設置されている。高圧巻線３側のスペーサ１０は第２の絶縁筒５に取り付けられた絶縁物のレール１１に嵌合され、このレール１１の外側に円板巻線から成る高圧巻線３が巻回されている。低圧巻線２側のスペーサ１０も図では省略してあるが、巻枠となる低圧巻線２の内側の絶縁筒に取り付けられたレールに嵌合させてある。
【０００６】
さらに、前記第１の絶縁筒４と第２の絶縁筒５との間には、両者間の間隙を保ち、高、低圧巻線３、２間の半径方向の力を受けるように間隔片１２が配設されている。
【０００７】
このように構成された鉄心、巻線から成る変圧器中身を図示しないタンク内に収納し、絶縁、冷却媒体である絶縁油やＳＦ６ガスを封入する。従って、前記スペーサ１０やレール１１および間隔片１２等によって生じるギャップ部は絶縁、冷却媒体である絶縁油やＳＦ６ガスの流路と成る。
【０００８】
このような変圧器の巻線導体には、変圧器の運転中に漏れ磁束によって渦電流が誘導され、渦電流損失が発生する。渦電流損失は巻線温度を上昇させ効率を低下させる。この渦電流損を減らす目的と巻線作業を容易にするために、複数本の導体を並列に使用する手段が考えられている。このような並列導体を漏れ磁束と直角方向に重ねて用いる場合には、各導体間の循環電流を防止するために並列導体の相互位置を途中で変えて、全長にわたって漏れ磁束の鎖交量を平均させる転位という巻線手段が行われる。
【０００９】
例えば低圧巻線２が３導体並列のヘリカル巻線や円筒巻線の場合には図１２に示すように巻線工程の途中で転位部１３において内側導体が外側に、外側導体が内側に位置するように転位をする。円板巻線の場合も同様にセクション間の渡り部分で転位を行う。
【００１０】
しかし、高電圧で並列に使用する導体本数が多い場合には各導体の絶縁厚さが厚くなり占積率が悪くなる。そこで図１３に示すように、特殊な撚り線機を用いて、循環電流を防止するためのエナメル皮膜等の薄い絶縁被覆を施した複数本の平角導体１４を一定のピッチで転位し、その後で導体全体を紙巻やフィルム巻きして絶縁した転位撚り線で巻線を構成したりすることも行われている。
【００１１】
【特許文献１】
実開平５−００１１１５号公報（第４−５頁 図１、図２）
【００１２】
【発明が解決しようとする課題】
このような高電圧、大容量の静止誘導電気機器の巻線では、巻線の転位を行おうとすると、巻線中に転位スペースを必要とする。このため巻線寸法が大きくなったり、転位部の絶縁補強が必要になるなど、巻線工程での転位作業は巻線作業を複雑にしている。
【００１３】
また、転位撚り線は構成導体が平角導体であるために設計の自由度が小さく、剛性が大きいために巻線転位作業がしづらい等の問題がある。このような点から巻線作業性がよく、小形化および効率向上が図れる渦電流損失の低減が可能な巻線が要望されていた。
【００１４】
更に、防災面では難燃性であり、地球環境への影響の少ない変圧器が望まれている。絶縁油の場合には優れた冷却、絶縁媒体であるが、火災の危険性が伴うために防災設備が必要になる。またＳＦ６ガスは不活性で優れた絶縁性を有するが、地球環境を破壊するために耐環境面での制約が多いためＳＦ６ガスを使用しない変圧器が要望されている。
本発明は上記課題を解決し、巻線作業が容易に行え、渦電流損失の少ない小型で、耐環境性に優れた静止誘導電気機器を提供することを目的とする。
【００１５】
【課題を解決するための手段】
上記目的を達成するために請求項１に記載の発明は、静止誘導電気機器の巻線において、絶縁皮膜で覆われた複数本の丸導体を、一定のピッチで捻りながら断面形状が平角形状になるように圧縮成形した複導体で巻線を構成し、この巻線の表面に接地層を形成したことを特徴とする。
この発明によれば、複導体を巻線の軸方向、径方向のいずれかに積層して巻回することにより静止誘導電気機器の巻線を構成する。
【００１６】
請求項２に記載の発明は、請求項１に記載の静止誘導電気機器の巻線において、巻線が鉄心に対して同心状に多重に巻線された円筒巻線であることを特徴とする。
この発明によれば、複導体を巻線の軸方向に積層して巻回することにより円筒型の静止誘導電気機器の巻線を構成する。
【００１７】
請求項３に記載の発明は、請求項１に記載の静止誘導電気機器の巻線において、巻線が鉄心に対して円板状に巻回された円板巻線であることを特徴とする。
この発明によれば、複導体を巻線の径方向に積層して巻回することにより円板型の静止誘導電気機器の巻線を構成する。
【００１８】
請求項４に記載の発明は、請求項１乃至３のいずれかに記載の静止誘導電気機器の巻線において、巻線を樹脂で注型して一体に固めて、固体絶縁物で覆ったことを特徴とする。
この発明によれば、巻線に樹脂が含浸または注型し、導体の剛性を高め、巻線の熱伝導率を大きくし、絶縁耐力を高める。
【００１９】
請求項５に記載の発明は、請求項２に記載の静止誘導電気機器の巻線において、巻線と巻線の間にヒートパイプを配設したことを特徴とする。
この発明によれば、隣接巻線で発生する損失熱がヒートパイプに伝達されて冷却され、また、ヒートパイプ内の熱移送により巻線の軸方向の温度分布を均一化する。
【００２０】
請求項６に記載の発明は、請求項４に記載の静止誘導電気機器の巻線において、樹脂層の外側に接地層が設けられていることを特徴とする。
この発明によれば、巻線と接地層の間で電気的ストレスを分担し、絶縁耐力を高める。
【００２１】
請求項７に記載の発明は、請求項６に記載の静止誘導電気機器の巻線において、接地層がネット状導電材であることを特徴とする。
この発明によれば、樹脂がネットの間に入り込み、接地層と樹脂層が一体化される。
【００２２】
請求項８に記載の発明は、請求項３に記載の静止誘導電気機器の巻線において、円板巻線の周囲にネット状シールドを設けたことを特徴とする。
この発明によれば、円板状巻線間の電位をネット状のシールド層と巻線間で負担し、巻線間の絶縁は樹脂の固体絶縁に持たせる。
【００２３】
請求項９に記載の発明は、請求項１に記載の静止誘導電気機器の巻線において、丸導体の絶縁被覆に無機充填材の微粒子を混入させた絶縁ワニスを焼き付けたことを特徴とする。
この発明によれば、無機充填材により、絶縁被覆の線膨張率を下げ、絶縁被覆と導体、絶縁被覆と外部の注型樹脂との線膨張率差によって発生する界面の応力を低減する。
【００２４】
請求項１０に記載の発明は、請求項１に記載の静止誘導電気機器の巻線において、個々の丸導体の絶縁被覆上に熱融着性の塗膜を施したことを特徴とする。
この発明によれば、巻線を巻回後に加熱することによって巻線上の熱融着性の絶縁被覆層が軟化し、隣接導体間を固着する。
【００２５】
請求項１１に記載の発明は、請求項１に記載の静止誘導電気機器の巻線において、絶縁被覆した丸導体の細線を捻り合わせた複導体の集合体をさらに複数個圧縮成形しながら捻り合わせて平角形状にした細線の複導体で巻線を構成したことを特徴とする。
この発明によれば、巻線導体がより細分化され、渦電流損失をより低減し、巻線の占積率を向上させる。
【００２６】
【発明の実施の形態】
以下、本発明の静止誘導電気機器の実施の形態を図面を参照して説明する。
図１は本発明の第１の実施の形態を示す図で、高電圧内鉄形変圧器の巻線絶縁構造の一部を示す断面図である。鉄心脚１に巻回された円筒巻線２１を注型樹脂２２で注型して注型巻線を形成し、その外周部に接地層２３を形成した低圧巻線２４と、その外側に同じく円筒巻線２５を注型樹脂２２で注型して注型巻線を形成し、その外側に接地層２３を形成した高圧巻線２６とを同心状に配置している。それぞれの低圧巻線２４、および高圧巻線２６はヨーク鉄心７などに対して固体絶縁物からなる締め付けリング２７、支持絶縁物２８により軸方向に締め付けられ、支持されている。低圧巻線２４および高圧巻線２６を構成する円筒巻線２１、２５は、図２に示すようにホルマール、ポリエステル、ポリイミド等の絶縁被覆を施して束ねられた複数本の丸導体２９を一定ピッチで捻りながら断面形状が平角形状に圧縮成形した複導体３０を用いて構成されている。
【００２７】
低圧巻線２４および高圧巻線２６を鉄心脚１の周囲に同心状に配置する場合、注型樹脂２２と同一の注型樹脂で製作した図示しないスペーサを介在させながら金型もしくは巻枠に同心状に多層に巻回して構成する。変圧器の容量によっては図３に示すように低圧巻線２４と高圧巻線２６とをスペーサで適切な間隔を保持して両巻線間にヒートパイプ３１を同時に巻回する。その後、金型にセットして注型樹脂２２で低圧巻線２４、高圧巻線２６およびヒートパイプ３１を一体的に注型して樹脂層で囲まれた低圧巻線２４や高圧巻線２６を得るようにしてもよい。一体にした注型巻線は樹脂層表面をサンドブラスト等で荒らした後、導電塗料を塗布して接地層２３を形成する。
【００２８】
本実施の形態では、低圧巻線２４および高圧巻線２６がホルマール、ポリエステル、ポリイミド等の絶縁被覆を施して束ねられた複数本の丸導体２９をあらかじめ一定ピッチで捻りながら平角形状に圧縮成形した複導体３０で構成されているために巻線工程では１本の巻線導体と同じ方法で巻線の軸方向、径方向のいずれの方向にも積層して巻回することができ、巻線作業が容易におこなえる。また、転位等の複雑な巻線工程も必要なく巻線作業が簡単に行える。しかも、導体２９の丸導体の絶縁皮膜は循環電流を防止するに足りる薄い絶縁皮膜でよく、捻りながら成形することにより各丸導体の巻回長は同じになるために丸導体間に巻線全体としての循環電流を殆ど無くすことができる。渦電流損失は磁束に対して直角方向の寸法が大きくなるほど多くなるため、丸導体のサイズを従来の平角線より小さくすることで低減が可能となる。
【００２９】
また、多重巻線構成の巻線と巻線の間にヒートパイプを配設することによって、隣接巻線で発生する損失熱がヒートパイプに伝達され、巻線の冷却効率が向上する。また、ヒートパイプを用いることにより、ヒートパイプ内で熱移送が行われるため巻線の軸方向の温度分布を均一化することができる。このために巻線の冷却効率が向上するために電流密度を上げることができ、巻線を小さくすることができる。
【００３０】
更に、低圧巻線２４および高圧巻線２６の複導体３０のサイズは異なるが、複導体３０を構成する丸導体２９を同一サイズにすることもできる。この場合、丸導体２９の製作が１種類になるために製作工程が標準化され、製造コストを低く抑えることができる。
【００３１】
また、巻線全体を樹脂で注型して一体化するために複導体の隙間に樹脂が入り込み複導体の剛性を高め、内部の空隙が樹脂に置換されるために巻線の熱伝導率を大きくできる。また、巻線周囲も樹脂で固められるので複導体の外周部にできている楔上の空隙部が絶縁耐力の高い樹脂で埋まるために導体外周部の電位傾度を上げることができる。このために、電磁力に対して強く、冷却効率の良い巻線を構成することができ、巻線間および巻線外周の絶縁寸法を小さくできる。しかも巻線内の隙間は注型樹脂で充填されているためにＳＦ６ガスや空気に比べて一様な熱伝導になり、巻線表面が放熱面として活用できる。この場合、より熱伝導性のよい注型樹脂２２を使用すれば更に熱放散がよくなるのはいうまでもないことである。
【００３２】
一方、巻線の外層には接地層２３が形成されているために巻線と接地層の間で電気的ストレスを分担することになる。これにより樹脂層の絶縁耐力は大きく取れるため、絶縁上の樹脂層厚さを小さくできる。また、樹脂層の外側が接地層となるために汚損されても樹脂層の電気的ストレスは変わらないために、汚損されても洗浄等が不要でメンテナンスが容易になり、絶縁強度が増大し、絶縁距離を小さくできる。
【００３３】
また、支持絶縁物２８に熱伝導性のよい材料を使用し、締め付けリング２７に外部冷却装置を接続すれば、冷却効率は向上し、コンパクトな変圧器を提供できる。
【００３４】
支持絶縁物２８や締め付けリング２７は注型巻線の外周に接地層２３が設けられているため絶縁面を考慮する必要がなく、磁気回路的な配慮をすればステンレス等の金属材料でもよい。
【００３５】
更に、締め付けリング２７をヒートパイプ構造にして冷却効率を向上させることもできる。一方、容量の大きい巻線では中間の巻線間にヒートパイプを埋め込むために温度分布が均一化でき電流密度を上げることができる。ヒートパイプの両側は樹脂で覆われているために絶縁厚さを厚くすることなく埋め込むことができる。このように従来の絶縁ガスや絶縁油を使用することなく、耐環境性に優れたコンパクトな巻線を得ることができる。
【００３６】
なお、これまでの実施の形態の説明では平角形状に圧縮成形した複導体を一般的に用いられているフラットワイズ方向に巻回した例で説明したが、図４に示すように、巻線軸方向Ａより巻線径方向Ｂの方の寸法が大きくなるように複導体３０をエッジワイズ方向に巻回して多重巻線を構成することもできる。複導体３０は断面形状が角形に圧縮成形した複数本の丸導体で巻線導体が構成されているために、個々の断面積の大きい平角線の複導体（転位線）より剛性が小さいのでエッジワイズ巻も可能で、１層当たりの巻回数の多い多重円筒巻線を構成することもでき、最適設計に対する自由度が大きくなる。このため、エッジワイズに巻回できることにより１層あたりの巻回数を多くすることができるので全体の層数を減らすことが可能となり、設計の自由度が大きくなる。また、層数を減らすことにより層間の電圧分担が高くなるが、樹脂の絶縁耐力が高いので絶縁寸法を大きくする必要がなく、全体としてコンパクトな巻線を形成できる。
【００３７】
図５は本発明の第２の実施の形態を示す図で、静止誘導電気機器の巻線として円板巻線を採用した場合の要部断面図である。図５において、図２に示すような複導体３０を巻線径方向Ｂに巻回し、積層した円板巻線３２を注型樹脂２２で固めて一体の注型巻線にしたものである。円板巻線３２は１枚ずつ巻回して、図示していないスペーサを介して内型に組み立てて、その後電気的に接続して１つの巻線を形成した後、上型、下型および外型を配置して、注型して一体の注型巻線とする場合と、巻枠を兼ねた内型に連続して円板巻線３２を順次巻回、形成したのちに上型、下型および外型を配置して、注型して一体の注型巻線とする場合がある。一体に注型した注型巻線は樹脂層表面をサンドブラスト等で荒らした後、導電塗料を塗布して接地層２３を形成する。
【００３８】
本実施の形態では本発明を円板巻線に実施した場合で、第１の実施の形態における作用効果に加えて、巻線全体の電圧は円板巻線数で分担することになるので、円板巻線３２間の分担電圧を低くすることが容易で、高電圧の巻線に適する。
【００３９】
また、全体の電圧が高く、個々の円板巻線３２間の電圧が高い場合には図６に示すように、複導体３０にさらに絶縁テープ３３を巻回した複導体３４を用いて形成したり、円板巻線３２にネット状シールド材３５を巻回して巻線を構成することもできる。この場合、複導体３０上に巻回する絶縁テープ３３は絶縁方式により変わるが、紙、合成紙（例えばアラミッド紙）、フィルム、不織布、ガラステープ等がある。円板巻線３２で構成された巻線では円板巻線３２間の電圧が高くなると隣接する複導体３０間の楔部分に空隙等が残る場合があり、その部分で部分放電が発生する恐れがある。また、複導体を構成する導体自身の曲率によっても異なるが、電位傾度が厳しくなる部分も出てくる。円板巻線３２上にネット状シールド材３５を巻回することにより、巻線表面の電位が均一に成り、このネット状シールド材３５と導体間の電位を下げることができ、楔部分にボイド等が存在しても部分放電の発生を防ぐことができる。
【００４０】
また、部分的にはこの円板巻線３２間は電位が上がるが、この円板巻線３２間は注型樹脂等の絶縁媒体で満たされるため、絶縁信頼度の高い絶縁構成が得られる。
【００４１】
図７は本発明の第３の実施の形態を示す図で、巻線を注型した後の注型巻線の要部断面図である。図７において、第１、第２の実施の形態のような巻線３６を形成し、巻線３６から所要絶縁距離を離してネット状導電材３７が配設され、この巻線３６とネット状導電材３７とを注型樹脂２２で一体に固めてある。ネット状導電材３７としてカーボン繊維、ガラス繊維や有機ポリマー繊維に導電材を塗布したもの、あるいは金属繊維等でネット状に織ったものが考えられる。
【００４２】
本実施の形態では、ネット状の導電性織物にエポキシ樹脂を含浸、塗布してＢステージのプリプレグにし、金型に組み込む前に成形して金型内に配設する。巻線３６を内型に直接巻回する場合には、金型上に前期ネット状導電材３７を配置し、スペーサ等を介して巻線３６を形成する。巻線３６形成後、巻線３６上にスペーサを配置して成形したネット状導電材３７を配置して外型を組み立て、注型する。
【００４３】
本実施の形態では、ネット状導電材３７が接地層となるので接地層の形成が注型時に同時にできるので、巻線工程が簡単になる。また、樹脂がネットの間に入り込むため接地層と樹脂層が一体化されネット状導電材３７になっているために繊維の周囲が樹脂で覆われるために表面の樹脂層は機械的に強度が強くなり、耐クラック性が向上するほか巻線内部の短絡による樹脂の飛散防止や異物等が当たったときの保護層にもなる。さらに、カーボン繊維の本数を変えたり、抵抗率等の異なる導電繊維を選択できるので適正な渦電流損失に合った抵抗値に容易に調整することができる。特に、カーボン繊維の場合にはカーボン繊維の本数により抵抗調節が容易にできる。
【００４４】
図８は本発明の第４の実施の形態を示す図で、複導体に用いる絶縁被覆導体の断面図である。銅やアルミの導体３８の上にポリエステル、エステルイミド、アミドイミド等の絶縁ワニスにシリカ等の無機充填材の微粒子を混入させた絶縁ワニスを焼き付けて第１の絶縁皮膜３９を形成し、この上に目的に応じて第２の絶縁皮膜４０を設ける。第２の絶縁皮膜４０は、第１の絶縁皮膜３９に用いた絶縁ワニスに熱伝導率のよい無機充填材の微粒子を混入した絶縁ワニスを焼き付けたり、電界緩和等を考慮するときには導電性微粒子を混入させたり、耐コロナ性の無機充填材を混入させたり目的に応じて変えることができる。また、隣接導体間の固着が必要な場合には、第２の絶縁皮膜４０に熱融着性の塗膜を付けることもできる。このようにすると、巻線を巻回後に加熱することによって巻線上の熱融着性の絶縁被膜層が軟化し隣接導体間を固着させる。このため、巻線構成後、巻枠から巻線を取り外しても巻線形態が崩れることなく、テープ等で巻線を固定する付帯作業を無くすことが可能となる。また、隣接導体間が熱融着性の絶縁層で固着されるので、複導体の剛性を向上させることができ、電磁機械力に対する耐力が向上する。
これらの第２の絶縁皮膜４０はエナメル線製造工程の中では絶縁ワニス層を仕切るのみで製造できる。
【００４５】
本実施の形態によれば、絶縁ワニスに無機充填材を混入させることにより絶縁皮膜の線膨張率を下げることができ、線膨張率の差により絶縁被覆と導体、絶縁被覆と外部の注型樹脂との間に発生する界面応力を低減でき、界面での剥離やクラックを防止できる。
【００４６】
さらに、第１の実施の形態のごとく、一次巻線と二次巻線を有する変圧器の巻線では複導体を構成する導体のサイズを同じにして、複導体の導体本数を変えることにより複導体のサイズを変えるようにすれば、導体の製作は同じで、量が増えるため製造コストを下げることができる。
【００４７】
図９は本発明の第５の実施の形態を示す図で、複導体に用いる導体にエナメル細線４１を用い、このエナメル細線４１で断面が円形形状のリッツ線４２を構成し、このリッツ線４２を用いて変圧器巻線に必要な平角形状の複導体４３を構成するようにしたものである。この複導体４３は使用される絶縁媒体や巻線構造によりフィルム、ガラステープ、不織布、紙等の絶縁被覆４４を複導体製作時に形成する。巻線に発生する渦電流損失は導体が細いほど小さくできるが、捻りながら複導体に成形する場合に多数のエナメル細線をセットせねばならず、撚り線機が大掛かりになり、セッティング作業が複雑になる。本実施例のようにエナメル線で円形のリッツ線を製作し、このリッツ線を組み合わせて捻りながら圧縮成形すれば、装置が大掛かりにならず、また、巻線導体がより細分化されるため、渦電流損失を低減することができる。また、平角形状に成形してあるために多重円筒巻線構成や円板巻線構成が可能で、円形形状のみに捻り合わせた複導体より巻線の占積率を向上させることができる。さらに、絶縁被覆は絶縁形態に応じて複導体製作時に容易に巻回することができ、経済的に製作することができる。
【００４８】
【発明の効果】
以上のごとく本発明によれば、絶縁皮膜で覆われた複数本の丸導体を、一定ピッチで捻りながら断面形状が平角形状になるように圧縮成形した複導体で巻線を構成し、この巻線の表面に接地層を形成するようにしたので、渦電流損失が低減でき、熱効率がよく、絶縁性の優れたコンパクトな巻線を備えた静止誘導電気機器を得ることができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態による変圧器の巻線絶縁構造の一部を示す断面図。
【図２】本発明の実施の形態による複導体を示す斜視図。
【図３】本発明の第１の実施の形態の巻線の変形例を示す断面図。
【図４】本発明の第１の実施の形態の巻線の変形例を示す断面図。
【図５】本発明の第２の実施の形態による変圧器の巻線絶縁構造の一部を示す断面図。
【図６】本発明の第２の実施の形態の巻線の変形例を示す断面図。
【図７】本発明の第３の実施の形態による変圧器の巻線絶縁構造の一部を示す断面図。
【図８】本発明の第４の実施の形態による変圧器の巻線を示す断面図。
【図９】本発明の第５の実施の形態による変圧器の巻線を示す断面図。
【図１０】従来の変圧器の巻線絶縁構造の一部を示す断面図。
【図１１】従来の変圧器の巻線絶縁構造の一部を示す平面図。
【図１２】従来の巻線の転位構造を示す正面図。
【図１３】従来の転位撚り線を示す斜視図。
【符号の説明】
１…鉄心脚、７…ヨーク鉄心、９…支持絶縁物、１０…スペーサ、１１…レール、１２…間隔片、１３…転位部、２１，２５…円筒巻線、２２…注型樹脂、２３…接地層、２４…低圧巻線、２６…高圧巻線、２７…締め付けリング、２８…支持物、２９…丸導体、３０，４３…複導体、３１…ヒートパイプ、３２…円板巻線、３３，４４…絶縁被覆、３４…絶縁被覆導体、３５…ネット状シールド材、３６…巻線、３７…ネット状導電材、３８…導体、３９，４０…絶縁被覆、４１…エナメル細線、４２…リッツ線、[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a stationary induction electric device such as a transformer or a reactor used in an electric power system or a distribution system.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there are stationary induction electric devices such as transformers and reactors as electric devices having windings among electric devices used in power systems and distribution systems. A transformer will be described as an example of stationary induction electric equipment.
[0003]
Generally, a high-voltage, large-capacity transformer has a secondary winding and a primary winding arranged concentrically around an iron core leg, and a gap between the windings is divided by an insulating cylinder, and the contents of the transformer are separated. It is housed in a steel plate tank and filled with insulating oil or SF6 gas as a cooling insulating medium together with the contents of the transformer. Insulating oil has good cooling efficiency and is widely used, but has a low flash point and there is a risk of fire. In indoor or densely populated areas, additional equipment such as fire extinguishing equipment and fire protection equipment is required. On the other hand, SF6 gas is nonflammable, and although its cooling and insulating properties are inferior to insulating oil, it is safe when used indoors or in densely populated areas, and has been widely used in recent years. There is no significant difference in the basic structure of the transformer between the oil-insulated transformer and the gas-insulated transformer.
[0004]
FIG. 10 is a cross-sectional view showing a part of the winding insulation structure of such a high-voltage, large-capacity iron-type transformer. In the figure, cylindrical low-voltage windings 2 and high-voltage windings 3 are arranged concentrically from the inside so as to be wound around an iron core leg 1. A first insulating tube 4 and a second insulating tube 5 are disposed between the low-voltage winding 2 and the high-voltage winding 3 with an appropriate gap therebetween. An insulator 6 is provided outside the high-voltage winding 3 for insulation from another phase or the ground. Each of the windings 2 and 3 is axially fastened and supported by a fastening ring 8 and a supporting insulator 9 made of a solid insulator with respect to a ground portion such as a yoke core 7.
[0005]
FIG. 11 is a sectional view showing a part of the winding insulation structure when the high-voltage winding 3 is a disk winding. A first insulating tube 4 is disposed outside the low-voltage winding 2, and a second insulating tube 5 is disposed inside the high-voltage winding 3. In order to keep the interval between the windings 2 and 3, insulating spacers 10 are installed evenly along the circumferential direction. The spacer 10 on the high-voltage winding 3 side is fitted to an insulating rail 11 attached to the second insulating cylinder 5, and the high-voltage winding 3 made of a disk winding is wound around the rail 11. I have. The spacer 10 on the low-voltage winding 2 side is also omitted in the drawing, but is fitted to a rail attached to an insulating cylinder inside the low-voltage winding 2 serving as a winding frame.
[0006]
Further, a gap is provided between the first insulating cylinder 4 and the second insulating cylinder 5 so that a gap between the first insulating cylinder 4 and the second insulating cylinder 5 is received so as to receive a radial force between the high and low voltage windings 3 and 2. Are arranged.
[0007]
The contents of the transformer composed of the iron core and the winding configured as described above are housed in a tank (not shown), and insulating oil or SF6 gas as an insulating and cooling medium is filled therein. Therefore, the gaps formed by the spacers 10, the rails 11, the spacing pieces 12, and the like serve as flow paths for insulating oil and SF6 gas, which are insulating and cooling media.
[0008]
An eddy current is induced in the winding conductor of such a transformer by leakage magnetic flux during operation of the transformer, and eddy current loss occurs. Eddy current losses increase winding temperature and reduce efficiency. For the purpose of reducing the eddy current loss and facilitating the winding operation, means for using a plurality of conductors in parallel has been considered. When such parallel conductors are used in a direction perpendicular to the leakage magnetic flux, the mutual positions of the parallel conductors are changed halfway to prevent circulating current between the conductors, and the amount of interlinkage of the leakage magnetic flux over the entire length is reduced. Winding means called averaging dislocations is performed.
[0009]
For example, when the low-voltage winding 2 is a three-conductor parallel helical winding or a cylindrical winding, the inner conductor is located outside and the outer conductor is located inside in the dislocation portion 13 during the winding process as shown in FIG. Dislocations. Similarly, in the case of a disk winding, dislocation is performed at a transition portion between sections.
[0010]
However, when the number of conductors used in parallel at a high voltage is large, the insulation thickness of each conductor increases, and the space factor deteriorates. Therefore, as shown in FIG. 13, using a special stranded wire machine, a plurality of rectangular conductors 14 provided with a thin insulating coating such as an enamel coating for preventing circulating current are transposed at a constant pitch, and thereafter, It has also been practiced to form a winding with a displaced stranded wire insulated by winding the entire conductor on paper or film.
[0011]
[Patent Document 1]
Japanese Utility Model Laid-Open No. 5-001115 (FIGS. 1 and 2 on page 4-5)
[0012]
[Problems to be solved by the invention]
In such high-voltage, large-capacity windings of static induction electric equipment, transposition of the windings requires a transposition space in the windings. For this reason, the transposition operation in the winding step complicates the winding operation, for example, the winding size becomes large, and the insulation reinforcement of the dislocation portion becomes necessary.
[0013]
Further, the dislocation stranded wire has a problem that the degree of freedom in design is small because the constituent conductor is a rectangular conductor, and the winding transposition work is difficult because the rigidity is large. In view of the above, there has been a demand for a winding having good winding workability and capable of reducing the eddy current loss, which can reduce the size and improve the efficiency.
[0014]
Further, there is a demand for a transformer which is flame-retardant in terms of disaster prevention and has little effect on the global environment. Insulating oil is an excellent cooling and insulating medium, but requires fire prevention equipment because of the risk of fire. Although SF6 gas is inert and has excellent insulation properties, there are many restrictions on environmental resistance in order to destroy the global environment, and thus there is a demand for a transformer that does not use SF6 gas.
An object of the present invention is to solve the above-mentioned problems, and to provide a stationary induction electric device which can perform winding work easily, has a small eddy current loss, and has excellent environmental resistance.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 provides a winding of a stationary induction electric device, in which a plurality of round conductors covered with an insulating film are twisted at a constant pitch to form a rectangular cross section. A winding is constituted by a double conductor which is compression-molded as described above, and a ground layer is formed on a surface of the winding.
According to the present invention, the winding of the static induction electric device is configured by stacking and winding the multiple conductors in either the axial direction or the radial direction of the winding.
[0016]
According to a second aspect of the present invention, in the winding of the static induction electric device according to the first aspect, the winding is a cylindrical winding which is wound multiple times concentrically with respect to an iron core. .
According to the present invention, the winding of the cylindrical stationary induction electric device is formed by stacking and winding the multiple conductors in the axial direction of the winding.
[0017]
According to a third aspect of the present invention, in the winding of the stationary induction electric device according to the first aspect, the winding is a disk winding wound in a disk shape around an iron core. .
According to the present invention, a winding of a disk-shaped stationary induction electric device is formed by stacking and winding multiple conductors in the radial direction of the winding.
[0018]
According to a fourth aspect of the present invention, in the winding of the stationary induction electric device according to any one of the first to third aspects, the winding is cast with a resin, solidified integrally, and covered with a solid insulator. It is characterized by.
According to the present invention, the winding is impregnated or cast with resin, the rigidity of the conductor is increased, the thermal conductivity of the winding is increased, and the dielectric strength is increased.
[0019]
According to a fifth aspect of the present invention, in the winding of the static induction electric device according to the second aspect, a heat pipe is provided between the windings.
According to the present invention, the heat loss generated in the adjacent winding is transmitted to the heat pipe to be cooled, and the temperature distribution in the axial direction of the winding is made uniform by the heat transfer in the heat pipe.
[0020]
According to a sixth aspect of the present invention, in the winding of the static induction electric device according to the fourth aspect, a ground layer is provided outside the resin layer.
According to the present invention, electric stress is shared between the winding and the ground layer, and the dielectric strength is increased.
[0021]
According to a seventh aspect of the present invention, in the winding of the stationary induction electric device according to the sixth aspect, the ground layer is a net-shaped conductive material.
According to the present invention, the resin enters between the nets, and the ground layer and the resin layer are integrated.
[0022]
According to an eighth aspect of the present invention, in the winding of the static induction electric device according to the third aspect, a net-shaped shield is provided around the disk winding.
According to the present invention, the electric potential between the disk-shaped windings is shared between the net-shaped shield layer and the windings, and the insulation between the windings is provided by solid insulation of resin.
[0023]
According to a ninth aspect of the present invention, in the winding of the static induction electric device according to the first aspect, an insulating varnish in which fine particles of an inorganic filler are mixed in the insulating coating of the round conductor is baked.
According to the present invention, the inorganic filler reduces the coefficient of linear expansion of the insulating coating, and reduces the stress at the interface caused by the difference in the coefficient of linear expansion between the insulating coating and the conductor, and between the insulating coating and the external casting resin.
[0024]
According to a tenth aspect of the present invention, in the winding of the static induction electric device according to the first aspect, a heat-fusible coating film is applied on the insulating coating of each round conductor.
According to the present invention, by heating the winding after winding, the heat-fusible insulating coating layer on the winding is softened, and the adjacent conductors are fixed.
[0025]
According to an eleventh aspect of the present invention, in the winding of the static induction electric device according to the first aspect, a plurality of aggregates of multiple conductors obtained by twisting the thin wires of the insulated coated round conductors are further twisted while compression-molding a plurality of them. The winding is made up of a thin wire double conductor made flat.
According to the present invention, the winding conductor is further divided, the eddy current loss is further reduced, and the space factor of the winding is improved.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a stationary induction electric device according to the present invention will be described with reference to the drawings.
FIG. 1 is a view showing a first embodiment of the present invention, and is a cross-sectional view showing a part of a winding insulation structure of a high-voltage iron-type transformer. A low-voltage winding 24 in which a cylindrical winding 21 wound around the iron core leg 1 is cast with a casting resin 22 to form a casting winding, and a ground layer 23 is formed on the outer periphery thereof, A cylindrical winding 25 is cast with a casting resin 22 to form a casting winding, and a high-voltage winding 26 having a ground layer 23 formed outside thereof is arranged concentrically. Each of the low-voltage winding 24 and the high-voltage winding 26 is axially fastened to the yoke core 7 and the like by a fastening ring 27 and a supporting insulator 28 made of a solid insulator. As shown in FIG. 2, the cylindrical windings 21 and 25 constituting the low-voltage winding 24 and the high-voltage winding 26 are formed of a plurality of round conductors 29 bundled by applying an insulating coating such as formal, polyester, or polyimide at a constant pitch. The cross-sectional shape is formed by using a multiple conductor 30 which is compression-molded into a rectangular shape while being twisted.
[0027]
When the low-voltage winding 24 and the high-voltage winding 26 are arranged concentrically around the iron core leg 1, the low-voltage winding 24 and the high-voltage winding 26 are concentric with a mold or a bobbin while interposing a spacer (not shown) made of the same casting resin as the casting resin 22. It is configured to be wound in multiple layers. Depending on the capacity of the transformer, as shown in FIG. 3, the heat pipe 31 is simultaneously wound between the low-voltage winding 24 and the high-voltage winding 26 while maintaining an appropriate distance between the two windings with a spacer. Then, the low-voltage winding 24, the high-voltage winding 26, and the heat pipe 31 are integrally cast with the casting resin 22 using the casting resin 22 to form the low-voltage winding 24 and the high-voltage winding 26 surrounded by the resin layer. It may be obtained. After the surface of the resin layer is roughened by sand blasting or the like, the integrated casting winding is coated with a conductive paint to form the ground layer 23.
[0028]
In the present embodiment, the low-voltage winding 24 and the high-voltage winding 26 are compression-molded into a rectangular shape while twisting at predetermined pitches a plurality of round conductors 29 bundled by applying an insulating coating such as formal, polyester, or polyimide. Since it is composed of the multiple conductors 30, in the winding step, it can be laminated and wound in either the axial direction or the radial direction of the winding in the same manner as a single winding conductor. Work can be done easily. Further, the winding operation can be easily performed without requiring a complicated winding step such as dislocation. In addition, the insulating film of the round conductor of the conductor 29 may be a thin insulating film sufficient to prevent a circulating current. Since the winding length of each round conductor becomes the same by forming while twisting, the entire winding between the round conductors is formed. Circulating current can be almost eliminated. Since the eddy current loss increases as the dimension in the direction perpendicular to the magnetic flux increases, it can be reduced by making the size of the round conductor smaller than that of the conventional rectangular wire.
[0029]
Further, by disposing the heat pipe between the windings having the multiple winding configuration, the heat loss generated in the adjacent winding is transmitted to the heat pipe, and the cooling efficiency of the winding is improved. Further, by using the heat pipe, heat transfer is performed in the heat pipe, so that the temperature distribution in the axial direction of the winding can be made uniform. Therefore, the current density can be increased to improve the cooling efficiency of the winding, and the winding can be reduced in size.
[0030]
Further, although the sizes of the multiple conductors 30 of the low-voltage winding 24 and the high-voltage winding 26 are different, the round conductors 29 constituting the multiple conductor 30 may have the same size. In this case, since one type of the round conductor 29 is manufactured, the manufacturing process is standardized, and the manufacturing cost can be reduced.
[0031]
In addition, the resin enters the gap between the multiple conductors to cast and integrate the entire winding with resin, increasing the rigidity of the double conductor, and replacing the internal voids with resin to reduce the thermal conductivity of the winding. Can be larger. Further, since the periphery of the winding is also solidified with resin, the gap on the wedge formed on the outer periphery of the multiple conductor is filled with resin having high dielectric strength, so that the potential gradient of the outer periphery of the conductor can be increased. For this reason, it is possible to configure windings that are strong against electromagnetic force and have high cooling efficiency, and it is possible to reduce insulation dimensions between the windings and the outer circumference of the windings. Moreover, since the gap in the winding is filled with the casting resin, the heat conduction becomes more uniform than that of SF6 gas or air, and the winding surface can be used as a heat radiation surface. In this case, it goes without saying that the heat dissipation is further improved by using the casting resin 22 having better heat conductivity.
[0032]
On the other hand, since the ground layer 23 is formed on the outer layer of the winding, electric stress is shared between the winding and the ground layer. Thereby, the dielectric strength of the resin layer can be increased, so that the thickness of the resin layer on the insulation can be reduced. In addition, even if the outside of the resin layer becomes a ground layer and becomes soiled, the electrical stress of the resin layer does not change. The insulation distance can be reduced.
[0033]
If a material having good heat conductivity is used for the supporting insulator 28 and an external cooling device is connected to the fastening ring 27, the cooling efficiency is improved and a compact transformer can be provided.
[0034]
Since the support insulator 28 and the fastening ring 27 are provided with the ground layer 23 on the outer periphery of the casting winding, there is no need to consider the insulating surface, and a metal material such as stainless steel may be used if magnetic circuits are taken into consideration.
[0035]
Further, the fastening ring 27 can be formed into a heat pipe structure to improve cooling efficiency. On the other hand, in a winding having a large capacity, a heat pipe is embedded between the intermediate windings, so that the temperature distribution can be made uniform and the current density can be increased. Since both sides of the heat pipe are covered with resin, they can be embedded without increasing the insulation thickness. Thus, a compact winding having excellent environmental resistance can be obtained without using a conventional insulating gas or insulating oil.
[0036]
In the above description of the embodiment, a description has been given of an example in which a double conductor compression-molded into a rectangular shape is wound in a generally used flatwise direction, but as shown in FIG. The multiple conductor 30 may be wound in the edgewise direction so that the dimension in the winding radial direction B is larger than that in A to form a multiple winding. Since the winding conductor is composed of a plurality of round conductors having a cross-sectional shape of a rectangular shape, the rigidity of each of the multiple conductors 30 is smaller than that of a rectangular multiple conductor (dislocation line) having a large cross-sectional area. Wise winding is also possible, and a multi-cylinder winding having a large number of windings per layer can be formed, thereby increasing the degree of freedom for an optimum design. For this reason, since the winding can be performed edgewise, the number of windings per layer can be increased, so that the total number of layers can be reduced, and the degree of freedom in design increases. Further, although the voltage sharing between the layers is increased by reducing the number of layers, the insulation strength of the resin is high, so that it is not necessary to increase the insulation size, and a compact winding as a whole can be formed.
[0037]
FIG. 5 is a view showing a second embodiment of the present invention, and is a cross-sectional view of a main part when a disk winding is adopted as a winding of a stationary induction electric device. In FIG. 5, a multiple conductor 30 as shown in FIG. 2 is wound in the winding radial direction B, and a laminated disk winding 32 is solidified with a casting resin 22 to form an integral casting winding. The disc windings 32 are wound one by one, assembled into an inner mold via a spacer (not shown), and then electrically connected to form one winding. The mold is arranged and cast to form an integral cast winding, and the disc winding 32 is sequentially wound and formed successively on the inner mold also serving as a winding frame, and then the upper mold and the lower mold are formed. In some cases, a mold and an outer mold are arranged and cast to form an integral cast winding. The casting layer integrally cast is formed by roughening the surface of the resin layer by sandblasting or the like, and then applying a conductive paint to form the ground layer 23.
[0038]
In the present embodiment, the present invention is applied to a disk winding, and in addition to the functions and effects of the first embodiment, the voltage of the entire winding is shared by the number of disk windings. It is easy to lower the shared voltage between the disk windings 32 and is suitable for high-voltage windings.
[0039]
When the overall voltage is high and the voltage between the individual disk windings 32 is high, as shown in FIG. 6, the multi-conductor 30 is formed using a multi-conductor 34 in which an insulating tape 33 is further wound. Alternatively, a net-shaped shield material 35 may be wound around the disk winding 32 to form a winding. In this case, the insulating tape 33 wound on the multiple conductor 30 varies depending on the insulating method, but includes paper, synthetic paper (for example, aramid paper), film, nonwoven fabric, glass tape, and the like. In the winding composed of the disk windings 32, when the voltage between the disk windings 32 increases, a gap or the like may remain in a wedge portion between the adjacent multiple conductors 30, and a partial discharge may occur in that portion. There is. Further, depending on the curvature of the conductor itself constituting the multiple conductor, there are some portions where the potential gradient becomes severe. By winding the net-shaped shield material 35 on the disk winding 32, the electric potential on the surface of the winding becomes uniform, and the electric potential between the net-shaped shield material 35 and the conductor can be reduced. Etc., the occurrence of partial discharge can be prevented.
[0040]
Although the potential between the disk windings 32 partially increases, the space between the disk windings 32 is filled with an insulating medium such as a casting resin, so that an insulating configuration with high insulation reliability can be obtained.
[0041]
FIG. 7 is a view showing a third embodiment of the present invention, and is a cross-sectional view of a main part of a casting winding after casting a winding. In FIG. 7, a winding 36 as in the first and second embodiments is formed, and a net-shaped conductive material 37 is disposed at a required insulating distance from the winding 36, and the winding 36 and the net-shaped conductive material 37 are arranged. The conductive material 37 is integrally fixed with the casting resin 22. As the net-shaped conductive material 37, a material obtained by applying a conductive material to carbon fiber, glass fiber, or organic polymer fiber, or a material woven in a net shape with metal fiber or the like can be considered.
[0042]
In the present embodiment, a net-shaped conductive fabric is impregnated with an epoxy resin and applied to form a B-stage prepreg, which is molded and disposed in a mold before being incorporated into the mold. When the winding 36 is directly wound around the inner mold, the net-shaped conductive material 37 is arranged on a mold, and the winding 36 is formed via a spacer or the like. After the formation of the windings 36, a net-shaped conductive material 37 formed by arranging spacers on the windings 36 is arranged to assemble an outer mold and casting.
[0043]
In the present embodiment, since the net-like conductive material 37 serves as a ground layer, the ground layer can be formed at the same time as the casting, so that the winding process is simplified. In addition, since the resin enters between the nets, the ground layer and the resin layer are integrated to form the net-shaped conductive material 37, so that the periphery of the fiber is covered with the resin. It becomes stronger, improves crack resistance, prevents resin scattering due to a short circuit inside the winding, and serves as a protective layer in the event of foreign matter or the like. Furthermore, since the number of carbon fibers can be changed, or a conductive fiber having a different resistivity or the like can be selected, the resistance value can be easily adjusted to an appropriate eddy current loss. In particular, in the case of carbon fibers, the resistance can be easily adjusted by the number of carbon fibers.
[0044]
FIG. 8 is a view showing a fourth embodiment of the present invention, and is a cross-sectional view of an insulated conductor used for a multiple conductor. A first insulating film 39 is formed by baking an insulating varnish obtained by mixing fine particles of an inorganic filler such as silica with an insulating varnish such as polyester, ester imide, or amide imide on a copper or aluminum conductor 38. A second insulating film 40 is provided according to the purpose. The second insulating film 40 is formed by baking an insulating varnish obtained by mixing fine particles of an inorganic filler having good thermal conductivity into the insulating varnish used for the first insulating film 39, or by using conductive fine particles when considering electric field relaxation or the like. It can be mixed or a corona-resistant inorganic filler can be mixed or can be changed according to the purpose. Further, when it is necessary to fix the adjacent conductors, a heat-fusible coating film can be applied to the second insulating film 40. In this case, by heating the winding after winding, the heat-fusible insulating coating layer on the winding is softened, and the adjacent conductors are fixed. Therefore, even after the winding is formed, even if the winding is removed from the winding frame, it is possible to eliminate the incidental work of fixing the winding with a tape or the like without breaking the winding form. Further, since the adjacent conductors are fixed by the heat-fusible insulating layer, the rigidity of the multiple conductors can be improved, and the proof strength against the electromagnetic mechanical force is improved.
These second insulating films 40 can be manufactured only by partitioning the insulating varnish layer in the enamel wire manufacturing process.
[0045]
According to the present embodiment, the linear expansion coefficient of the insulating film can be reduced by mixing the inorganic filler into the insulating varnish, and the difference between the linear expansion coefficients can cause the insulating coating and the conductor, the insulating coating and the external casting resin to be different. Can be reduced, and peeling and cracking at the interface can be prevented.
[0046]
Further, as in the first embodiment, in the winding of the transformer having the primary winding and the secondary winding, the size of the conductors constituting the multiple conductors is set to be the same, and the number of the multiple conductors is changed. If the size of the conductor is changed, the production of the conductor is the same, and the production cost can be reduced because the amount is increased.
[0047]
FIG. 9 is a view showing a fifth embodiment of the present invention, in which an enameled thin wire 41 is used as a conductor used for a multiple conductor, and the enameled thin wire 41 forms a litz wire 42 having a circular cross section. Is used to form a rectangular conductor 43 required for the transformer winding. The multiple conductor 43 is formed by forming an insulating coating 44 such as a film, a glass tape, a nonwoven fabric, or paper at the time of manufacturing the multiple conductor, depending on an insulating medium and a winding structure used. The eddy current loss generated in the winding can be reduced as the conductor becomes thinner.However, when forming into multiple conductors while twisting, it is necessary to set a large number of enameled wires, and the stranding machine becomes large-scale, and the setting work becomes complicated. Become. If a circular litz wire is manufactured from an enameled wire as in the present embodiment, and the litz wire is compression-molded while being twisted in combination, the device does not become large-scale, and the winding conductor is further subdivided. Eddy current loss can be reduced. In addition, since it is formed in a rectangular shape, a multiple cylindrical winding configuration or a disk winding configuration is possible, and the space factor of the winding can be improved compared to a double conductor twisted only in a circular shape. Further, the insulating coating can be easily wound at the time of manufacturing the multiple conductor according to the insulating form, and can be manufactured economically.
[0048]
【The invention's effect】
As described above, according to the present invention, a plurality of round conductors covered with an insulating film are formed by winding a plurality of round conductors, which are compression-molded so that the cross-sectional shape becomes a rectangular shape while being twisted at a constant pitch. Since the ground layer is formed on the surface of the wire, the eddy current loss can be reduced, the thermal efficiency is good, and a static induction electric device having a compact winding with excellent insulation can be obtained.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a part of a winding insulation structure of a transformer according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing a multiple conductor according to the embodiment of the present invention.
FIG. 3 is a sectional view showing a modified example of the winding according to the first embodiment of the present invention.
FIG. 4 is a sectional view showing a modified example of the winding according to the first embodiment of the present invention.
FIG. 5 is a sectional view showing a part of a winding insulation structure of a transformer according to a second embodiment of the present invention.
FIG. 6 is a sectional view showing a modified example of the winding according to the second embodiment of the present invention.
FIG. 7 is a sectional view showing a part of a winding insulation structure of a transformer according to a third embodiment of the present invention.
FIG. 8 is a sectional view showing a winding of a transformer according to a fourth embodiment of the present invention.
FIG. 9 is a sectional view showing a winding of a transformer according to a fifth embodiment of the present invention.
FIG. 10 is a cross-sectional view showing a part of a winding insulation structure of a conventional transformer.
FIG. 11 is a plan view showing a part of a winding insulation structure of a conventional transformer.
FIG. 12 is a front view showing a conventional winding dislocation structure.
FIG. 13 is a perspective view showing a conventional dislocation stranded wire.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Iron leg, 7 ... Yoke iron core, 9 ... Support insulator, 10 ... Spacer, 11 ... Rail, 12 ... Spacing piece, 13 ... Dislocation part, 21, 25 ... Cylindrical winding, 22 ... Casting resin, 23 ... Ground layer, 24: low-voltage winding, 26: high-voltage winding, 27: fastening ring, 28: support, 29: round conductor, 30, 43: double conductor, 31: heat pipe, 32: disk winding, 33 , 44: insulating coating, 34: insulating coating conductor, 35: net-shaped shield material, 36: winding, 37: net-shaped conductive material, 38: conductor, 39, 40: insulating coating, 41: enamel fine wire, 42: litz line,