JP2005032829A

JP2005032829A - High breakdown voltage transformer, and electric conduction coating single molded coil therefor

Info

Publication number: JP2005032829A
Application number: JP2003193763A
Authority: JP
Inventors: Yasuo Matsuzawa; 保夫松澤
Original assignee: IQ FOUR KK
Current assignee: IQ FOUR KK
Priority date: 2003-07-08
Filing date: 2003-07-08
Publication date: 2005-02-03
Anticipated expiration: 2023-07-08
Also published as: JP3969492B2

Abstract

<P>PROBLEM TO BE SOLVED: To realize miniaturization and weight reduction by preventing insulation deterioration or breakdown of the mold, regarding a dry high breakdown voltage transformer and an electric conduction coating single molded coil for a high breakdown voltage transformer. <P>SOLUTION: An inner coil 1 of a small diameter and an outer coil 2 of large diameter are molded into a single respectively by using insulator. In each of the single molds 3, 4, an inner and an outer edges are formed in a shape with circular cross sections, and electric conduction coating 7 and 8 are performed by using a conductive coating material. Both of the conductive coating single molded coils A, B which are formed to float at the potential corresponding to the respective coils are arranged concentrically at the outer side and the inner side. Further, double molding is correctively performed by using the insulator, and overall electric conduction coating 10 is also performed to the double mold 9 by using the conductive coating material. A window hole 11 is opened in a proper place, and lead-out lines 15, 16 of a high voltage side coil are made to penetrate the center part of the window hole 11. A corona ring 17 is attached to a hole edge of the window hole. An overall conduction coating double molded compound unified coil C is formed and attached on a magnetic core 22, and the magnetic core and the overall conduction coating 10 are electrically connected. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、乾式の高耐圧トランスとその高耐圧トランス用の導電コーティングシングルモールドコイルに関するものである。
【０００２】
【従来の技術】
一次コイルと二次コイルとを一つに巻き重ねて共通の鉄心に装着し、一方のコイルを低電圧系路に、他方のコイルを高電圧系路に接続して使用する湿式の高圧トランスは、既に知られている。
【０００３】
この場合、トランス本体が絶縁油を収容した金属ケースに内装されているので、コイル相互間又はコイルと周辺の導体との間に、高い電位差によるコロナが発生したとしても、絶縁油の対流によりその絶縁性が修復されることから、絶縁性能については特に問題にならない。
【０００４】
【特許文献１】
特開２００２−３６７８３４号公報
【特許文献２】
特開２０００−２６０６３４号公報
【特許文献３】
特開２００２−５７０４０号公報
【０００５】
【発明が解決しようとする課題】
しかし、上述のような湿式の高圧トランスでは、かなり大型化、大重量化する。また、現在は、火災防止など安全面への意識の高まりから絶縁油の使用が敬遠され、難燃性絶縁樹脂でモールドする乾式のモールドトランスが主流になりつつあるが（例えば特開２００２−３６７８３４号公報、特開２０００−０６３４号公報）、モールドトランスでは、固体絶縁物を絶縁材料とするため、トランス内部でコロナが発生すると絶縁油のように修復が効かず、時間の経過とともにそのコロナ発生部における絶縁の劣化が進行し、ついには絶縁破壊を起こしてしまう。
【０００６】
更に、高圧モールドトランスでは、各コイルの端部にエッジがあると該部周辺に電荷が集中してコロナが生じ易くなり、また、各コイルは一端から他端へと電位が次第に高く若しくは低くなることによって周面全般が平等電界には形成されないためにコイルの周辺で局所的に電荷が集中してコロナが生じ易くなる。しかも、トランス外周を導電材で被覆してこれを接地するような場合、高圧側のコイルからの引出線をその導電材の被覆に窓孔を開けて挿通させると、その窓孔の縁部にエッジを作ることになるために該部周辺に電荷が集中してコロナが生じ易くなる。したがって、多くのコロナの発生原因を有してモールドの絶縁劣化乃至絶縁破壊を起こす可能性が高く、耐圧性の改善が求められている。
【０００７】
なお、コイルに挿入する断面角形の鉄心の該断面四隅にそれぞれコロナリング（電界緩和部材）を当てて鉄心と平行に（磁束の流れの方向に）一巡させることにより絶縁材の劣化を防止することは一部のトランスで既に提案されているが（特開２００２−５７０４０号公報）、このような手段では上述のような絶縁材の劣化や絶縁破壊は到底解決できない。
【０００８】
そこで、本発明は、モールドトランスを高耐圧に改善してモールドの絶縁劣化乃至絶縁破壊を防止し、併せて、小型化軽量化を図ろうとするものである。
【０００９】
【課題を解決するための手段】
この観点から、本発明の請求項１の高耐圧トランスは、一次、二次いずれか一方の小径の内コイルと他方の大径の外コイルとをそれぞれ全周面にわたり絶縁材でシングルにモールドし、各シングルモールドには両端の内外縁部を断面円弧状に形成させて導電塗料による導電コーティングを施し、かつ、内外各コイルの適所と当該コイルの導電コーティングとを電気的に接続して各導電コーティングを当該コイルに相応する電位にフロートさせるよう構成し、こうしてできた両導電コーティングシングルモールドコイルを所要間隔で内外同心に配して更に絶縁材で一体的にダブルにモールドし、このダブルモールドにも導電塗料による総合導電コーティングを施すとともに該総合導電コーティングの適所に窓孔を開けて内外いずれか一の高圧側コイルの引出線をその窓孔の中央部に挿通させ、また、その窓孔の孔縁にコロナリングを付設して総合導電コーティングダブルモールド複合一体化コイルを設け、この総合導電コーティングダブルモールド複合一体化コイルを鉄心に装着して該鉄心と上記総合導電コーティングとを電気的に接続したことを特徴とするものであり、請求項２の高耐圧トランス用の導電コーティングシングルモールドコイルは、単独のコイルを全周面にわたり絶縁材でシングルモールドし、該シングルモールドには両端の内外縁部を断面円弧状に形成させて導電塗料による導電コーティングを施し、かつ、該導電コーティングを上記コイルと電気的に接続して当該コイルに相応する電位にフロートさせる構造としたことを特徴とするものである。
【００１０】
【発明の実施の形態】
以下、本発明を図示の実施の形態に基づいて詳細に説明する。
【００１１】
図１乃至図５において、１は一次（低圧側）の小径円筒状の内コイル、２は二次（高圧側）の大径円筒状の外コイルであり、両コイルは、図２乃至図４に示すように、それぞれ全周面にわたり難燃性樹脂の絶縁材でシングルにモールドし、各シングルモールド３，４には両端の内外縁部５，６を断面円弧状に形成させて適宜塗料にアルミニウム等の導電材の粉末を混入した導電塗料による導電コーティング７，８を施し、内外各コイル１，２の一端と当該コイルの導電コーティング７，８とを電気的に接続して（図５）各導電コーティング７，８を当該コイルに相応する電位にフロートさせるようにし、以て図４に示す一次側と二次側との円筒状の導電コーティングシングルモールドコイルＡ，Ｂを構成している。なお、図示のものでは一次側（低圧側）の導電コーティングシングルモールドコイルＡにおける内周面の導電コーティングを省略している（図４）。各導電コーティング７，８の内外各コイル１，２への電気的接続は当該コイルの中間タップであってもよい。
【００１２】
このように構成した図４に示す一次側と二次側の両導電コーティングシングルモールドコイルＡ，Ｂは、図２、図３に示すように、所要間隔で内外同心に配して更に難燃性樹脂の絶縁材で一体的にダブルにモールドし、このダブルモールド９にも上述の導電塗料による総合導電コーティング１０を施し、該総合導電コーティング１０には、図１乃至図３に示すように、端面の適所に保護チューブ２４を貫通させて該保護チューブ２４内に一次（低圧側）の前記内コイル１の引出線１２，１３を挿通させ、かつ、外周面の中間部適所に円形の窓孔１１を開けて該窓孔１１の中央部で上記ダブルモールド９から外方へと丸棒１４を一体に突出させるとともに該丸棒１４内に二次（高圧側）の前記外コイル２の引出線１５，１６を貫装させことにより該引出線１５，１６をその窓孔１１の中央部に挿通させており、また、その窓孔１１の孔縁に断面円形乃至ほぼ円形の導電性のコロナリング１７を付設して、総合導電コーティングダブルモールド複合一体化コイルＣを設けている。なお、上記ダブルモールド９は両端の内外縁部２５，２６を角張った状態にしてもよいが、図１、図３に示すように、断面円弧状に形成してもよい。
【００１３】
図１乃至図３に示すように、上記丸棒１４の形成には電気絶縁性の合成樹脂パイプ１８を外郭材として用い、該合成樹脂パイプ１８に上記引出線１５，１６を通して上記ダブルモールド９の形成と同時に同じ難燃性樹脂の絶縁材を充填することによりそのダブルモールド９と一体に形成している。なお、その合成樹脂パイプ１８の中に更に適数の合成樹脂細パイプを内装して各合成樹脂細パイプに引出線１５，１６を通してもよく、こうすることで引出線１５，１６の位置の確保がより容易になる場合がある。
【００１４】
上述の内外のシングルモールド３，４とこれらを一つにするダブルモールド９には、エポキシ樹脂、ポリウレタン樹脂などの難燃性樹脂の固体絶縁材１９を用いればよいが、図示のものでは、図２、図３に示すように、そのダブルモールド９に熱膨張を吸収させるためのシリコン樹脂などの難燃性樹脂の軟体絶縁材２０を部分的に用いている。すなわち、図２、図３に示すように、ダブルモールド９の固体絶縁材１９において、内外のシングルモールド３，４相互の中間部分に周辺部の熱膨張を許容するに足る間隔２１を形成させ、該間隔２１内にゼリー状乃至ゴム状の軟体絶縁材２０をモールドして弾性変形可能に一体化させている。
【００１５】
上述の総合導電コーティングダブルモールド複合一体化コイルＣは、図１乃至図３に示すように、鉄心２２に装着して上記総合導電コーティング１０を該鉄心に電気的に接続している（図５）。この電気的接続はその鉄心２２に前述の導電塗料による導電コーティング２３を施して該導電コーティング２３と上記総合導電コーティング１０とを連続一体化させることにより行っている。勿論、他の接続手段でもよいが、この導電コーティング手段の方が比較的容易に行えるものと考えられる。なお、鉄心２２は図１乃至図３に示す断面四角形のものでよいが、図６に示すように、上記総合導電コーティングダブルモールド複合一体化コイルＣの内周形状に適合させて断面四角形のものの四隅を円弧状に丸めたものや断面円形にしたものなどを用いてもよい。
【００１６】
如上の構造であり、使用に当たっては、本体を適宜に設置して、一次の内コイル１の引出線１２，１３を低電圧系路に、また、二次の外コイル２の引出線１５，１６を高電圧系路に接続するとともに、鉄心２３と総合導電コーティング１０を設置基準に従いアース又はアースと遊離した要所に電気的に接続する。
【００１７】
このようにして使用すると、内コイル１又は外コイル２との電気的接続により当該コイルに相応する電位にフロートされている各導電コーティング７，８は、導電性ゆえに全面においてその電位（等電位）となる。また、内コイル１と外コイル２のシングルモールド３，４は、両端の内外縁部５，６が断面円弧状に形成されているから、結果として各導電コーティング７，８の内外縁部もこれに沿って断面円弧状に丸められるので、各導電コーティング７，８には周辺へ電荷の集中をもたらすエッジは形成されない。更に、内コイル１と外コイル２は、そのようにして当該各コイル相応する電位にフロートされた各導電コーティング７，８に包まれているから、たとえ内コイル１と外コイル２の端部にエッジがあってもこれが各導電コーティング７，８の外側にまで電荷の集中などの悪影響を及ぼすことはなく、内コイル１と当該コイルの導電コーティング７との間、外コイル２と当該コイルの導電コーティング８との間の電位差が格別大きくなるようなことも変動するようなこともない。
【００１８】
したがって、各導電コーティング７，８では全面において平等電界となり、高圧側の外コイル２の導電コーティング８と低圧側の内コイル１の導電コーティング７との間、高圧側の外コイル２の導電コーティング８と総合導電コーティング１０との間における電位差がかなり大きくとも、それらの間の電界の分布を容易に均一乃至ほぼ均一にさせることができ、ダブルモールド９における電荷を適切に分散させることができて、ダブルモールド９の絶縁耐力の設定が容易にかつ的確にしかも無駄なく合理的に行え、同時に、内外各コイル１，２のシングルモールド３，４の絶縁耐力の設定についても容易にかつ的確にしかも無駄なく合理的に行えることとなり、トランス内部での無用なコロナの発生及びコロナによるシングルモールド３，４及びダブルモールド９の絶縁劣化乃至絶縁破壊を適正に防止できる。つまり、各シングルモールド３，４の表面を丸めて導電塗料を塗布し、平等電界を作りだすことにより、短い距離で所要の耐圧を確保することができ、結果として小型、軽量化が実現できるのである。
【００１９】
そして、高圧側の外コイル２の引出線１５，１６は、総合導電コーティング１０に開けた窓孔１１の中央部に挿通されることで、その窓孔１１の孔縁との間の絶縁距離を容易にかつ適正に確保でき、しかも、その窓孔１１の孔縁に付設されたコロナリング１７によりその孔縁にエッジが生じることはなく、その孔縁付近の電荷をそのコロナリング１７により適正に分散させることができて、トランス外部での無用なコロナの発生及びコロナによる当該部分の絶縁劣化乃至絶縁破壊を適正に防止できる。
【００２０】
加えて、固体絶縁材１９のダブルモールド９において、内外のシングルモールド３，４相互の中間部分に設けた間隔２１と、該間隔２１内にモールドして弾性変形可能に一体化させた軟体絶縁材２０により、そのダブルモールド９における熱膨張による損傷を回避でき、熱膨張による損傷からのダブルモールド９における絶縁劣化乃至絶縁破壊を適正に防止できる。
【００２１】
試作では、これまで実現を見ていない２７０ｋＶ、１０分間の耐圧試験にも充分に耐える小型で軽量の乾式高耐圧トランスを容易に製作することができた。
【００２２】
なお、内コイル１と外コイル２において、一次と二次、高圧側と低圧側、を逆にして実質的に同様に構成することも可能である。
【００２３】
【発明の効果】
以上に説明したように、本発明の請求項１の高耐圧トランスによれば、前述の構成により、トランス内部及びトランス外部での無用なコロナの発生及びコロナによるモールドの絶縁劣化乃至絶縁破壊を適正に防止でき、高耐圧で、小型軽量で、容易に製作できかつ廉価に提供できるモールドトランスを実現できる。そして、本発明の請求項２の高耐圧トランス用導電コーティングシングルモールドコイルによれば、トランス内部において、短い距離で所要の耐圧を確保させることが可能となり、結果として小型軽量化の実現が可能となるのである。
【図面の簡単な説明】
【図１】本発明の高耐圧トランスに係る実施の形態を示す斜視図である。
【図２】同截断横断面図である。
【図３】同截断側面図である。
【図４】同要部部材の一部切断分解斜視図である。
【図５】同電気回路図である。
【図６】鉄心の変形例を示す断面図である。
【符号の説明】
Ａ…一次（低圧側）の導電コーティングシングルモールドコイル
Ｂ…二次（高圧側）の導電コーティングシングルモールドコイル
Ｃ…総合導電コーティングダブルモールド複合一体化コイル
１…内コイル
２…外コイル
３，４…シングルモールド
５，６…内外縁部
７，８…導電コーティング
９…ダブルモールド
１０…総合導電コーティング
１１…窓孔
１２，１３…引出線
１４…丸棒
１５，１６…引出線
１７…コロナリング
１８…合成樹脂パイプ
１９…固体絶縁材
２０…軟体絶縁材
２１…間隔
２２…鉄心
２３…導電コーティング
２４…保護チューブ
２５，２６…内外縁部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dry type high voltage transformer and a conductive coating single mold coil for the high voltage transformer.
[0002]
[Prior art]
A wet high-voltage transformer that uses a primary coil and a secondary coil wound together and mounted on a common iron core, with one coil connected to the low-voltage system and the other coil connected to the high-voltage system. Already known.
[0003]
In this case, since the transformer body is housed in a metal case containing insulating oil, even if a corona due to a high potential difference occurs between the coils or between the coil and the surrounding conductor, the convection of the insulating oil Since insulation is restored, there is no particular problem with insulation performance.
[0004]
[Patent Document 1]
JP 2002-367834 A [Patent Document 2]
JP 2000-260634 A [Patent Document 3]
Japanese Patent Application Laid-Open No. 2002-57040
[Problems to be solved by the invention]
However, the above-described wet high-pressure transformer is considerably increased in size and weight. At present, the use of insulating oil has been avoided due to increased safety awareness such as fire prevention, and dry mold transformers molded with flame-retardant insulating resin are becoming mainstream (for example, JP-A-2002-367834). In a mold transformer, since a solid insulator is used as an insulating material, if a corona is generated inside the transformer, it cannot be repaired like insulating oil, and the corona is generated over time. The deterioration of the insulation in the part proceeds, and finally dielectric breakdown occurs.
[0006]
Furthermore, in the high-voltage mold transformer, if there is an edge at the end of each coil, electric charges are concentrated around the portion and corona easily occurs, and the potential of each coil gradually increases or decreases from one end to the other end. As a result, the entire peripheral surface is not formed in a uniform electric field, so that charges are locally concentrated around the coil and corona is likely to occur. In addition, when the outer periphery of the transformer is covered with a conductive material and grounded, the lead wire from the coil on the high voltage side is inserted into the conductive material coating by opening a window hole at the edge of the window hole. Since an edge is formed, electric charges are concentrated around the portion and corona is easily generated. Therefore, there is a high possibility of causing many deteriorations of corona due to corona generation, and there is a demand for improvement in pressure resistance.
[0007]
In addition, the deterioration of the insulating material is prevented by applying a corona ring (electric field reducing member) to each of the four corners of the square-shaped iron core inserted into the coil and making a round parallel to the iron core (in the direction of magnetic flux flow). Has already been proposed for some transformers (Japanese Patent Laid-Open No. 2002-57040). However, the above-described deterioration of the insulating material and dielectric breakdown cannot be solved by such means.
[0008]
Therefore, the present invention aims to improve the mold transformer to a high withstand voltage to prevent the insulation deterioration or breakdown of the mold and to reduce the size and weight.
[0009]
[Means for Solving the Problems]
From this point of view, the high voltage transformer according to claim 1 of the present invention is obtained by molding either the primary or secondary small-diameter inner coil and the other large-diameter outer coil into a single with an insulating material over the entire circumferential surface. Each single mold has inner and outer edges formed in an arc shape in cross section, and a conductive coating is applied with a conductive paint, and an appropriate connection between the inner and outer coils and the conductive coating of the coil are electrically connected to each conductive mold. The coating is configured to float to an electric potential corresponding to the coil, and both conductive coating single mold coils thus formed are arranged concentrically at the required intervals inside and outside, and are further integrally molded with an insulating material in a double shape. Also apply a conductive coating with conductive paint and open a window hole at the appropriate position of the conductive coating to either the inside or outside of the high voltage side. The lead wire of the wire is inserted into the center of the window hole, and a corona ring is attached to the hole edge of the window hole to provide a comprehensive conductive coating double mold composite integrated coil. A conductive-coating single mold coil for a high voltage transformer according to claim 2 is characterized in that the coil is attached to an iron core and the core is electrically connected to the total conductive coating. A single mold is formed with an insulating material over the entire peripheral surface, the inner and outer edges of both ends are formed in an arc shape in cross section, and a conductive coating is applied with a conductive paint, and the conductive coating is electrically connected to the coil. It is characterized in that it is connected and floated to a potential corresponding to the coil.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on illustrated embodiments.
[0011]
1 to 5, reference numeral 1 denotes a primary (low-pressure side) small-diameter cylindrical inner coil, 2 denotes a secondary (high-pressure side) large-diameter cylindrical outer coil, and both coils are shown in FIGS. As shown in Fig. 1, each of the single molds 3 and 4 is molded in a single piece with an insulative material of a flame retardant resin, and inner and outer edge portions 5 and 6 are formed in a circular arc shape at both ends. Conductive coatings 7 and 8 made of a conductive paint mixed with powder of a conductive material such as aluminum are applied, and one end of each of the inner and outer coils 1 and 2 is electrically connected to the conductive coatings 7 and 8 of the coil (FIG. 5). Each of the conductive coatings 7 and 8 is floated to a potential corresponding to the coil, thereby forming cylindrical conductive coating single mold coils A and B having primary and secondary sides shown in FIG. In the illustrated example, the conductive coating on the inner peripheral surface of the primary-side (low-pressure side) conductive coating single mold coil A is omitted (FIG. 4). The electrical connection of the conductive coatings 7 and 8 to the inner and outer coils 1 and 2 may be an intermediate tap of the coil.
[0012]
As shown in FIGS. 2 and 3, the primary and secondary conductive coating single mold coils A and B shown in FIG. 4 configured as described above are arranged concentrically inside and outside as shown in FIGS. The double conductive mold 10 is integrally molded with a resin insulating material, and the double conductive mold 10 is also provided with the above-mentioned conductive coating 10 with the above-mentioned conductive paint. As shown in FIGS. The protective tube 24 is passed through the appropriate position of the lead wire 12 and 13 of the primary (low-pressure side) inner coil 1 through the protective tube 24, and the circular window hole 11 is provided at a suitable position in the middle of the outer peripheral surface. And the round bar 14 is integrally protruded outward from the double mold 9 at the center of the window hole 11 and the lead wire 15 of the secondary (high-voltage side) outer coil 2 extends into the round bar 14. , 16 through The lead wires 15 and 16 are inserted through the central portion of the window hole 11, and a conductive corona ring 17 having a circular or substantially circular cross section is attached to the hole edge of the window hole 11, thereby providing a total conductive coating. A double mold composite integrated coil C is provided. The double mold 9 may be formed in a state where the inner and outer edge portions 25 and 26 at both ends are squared, but may be formed in a circular arc shape as shown in FIGS.
[0013]
As shown in FIGS. 1 to 3, the round bar 14 is formed using an electrically insulating synthetic resin pipe 18 as an outer shell, and the double mold 9 is formed through the lead wires 15 and 16 into the synthetic resin pipe 18. Simultaneously with the formation, it is formed integrally with the double mold 9 by filling an insulating material of the same flame retardant resin. In addition, an appropriate number of synthetic resin thin pipes may be further provided in the synthetic resin pipe 18 and the lead wires 15 and 16 may be passed through the respective synthetic resin thin pipes, thereby securing the positions of the lead wires 15 and 16. May be easier.
[0014]
The inner and outer single molds 3 and 4 and the double mold 9 that combines them may be made of a solid insulating material 19 of a flame-retardant resin such as an epoxy resin or a polyurethane resin. 2. As shown in FIG. 3, the double mold 9 partially uses a soft insulating material 20 of a flame retardant resin such as a silicon resin for absorbing thermal expansion. That is, as shown in FIGS. 2 and 3, in the solid insulating material 19 of the double mold 9, an interval 21 sufficient to allow thermal expansion of the peripheral portion is formed in the middle part between the inner and outer single molds 3 and 4, A jelly-like or rubber-like soft insulating material 20 is molded in the gap 21 and integrated so as to be elastically deformable.
[0015]
As shown in FIGS. 1 to 3, the above-mentioned total conductive coating double mold composite integrated coil C is mounted on an iron core 22 to electrically connect the total conductive coating 10 to the core (FIG. 5). . This electrical connection is performed by applying the conductive coating 23 with the above-mentioned conductive paint to the iron core 22 and continuously integrating the conductive coating 23 and the total conductive coating 10. Of course, other connecting means may be used, but it is considered that this conductive coating means can be performed relatively easily. The iron core 22 may have a rectangular cross section shown in FIGS. 1 to 3, but as shown in FIG. 6, the iron core 22 has a square cross section adapted to the inner peripheral shape of the integrated conductive coating double mold composite integrated coil C. You may use what rounded the four corners in circular arc shape, and made circular cross section.
[0016]
With the above structure, in use, the main body is appropriately installed so that the lead wires 12 and 13 of the primary inner coil 1 are connected to the low voltage system and the lead wires 15 and 16 of the secondary outer coil 2 are used. Is connected to the high voltage system path, and the iron core 23 and the total conductive coating 10 are electrically connected to the ground or to a point separated from the ground according to the installation standard.
[0017]
When used in this manner, the conductive coatings 7 and 8 that are floated to a potential corresponding to the coil by electrical connection with the inner coil 1 or the outer coil 2 are electrically conductive and therefore have the same potential (equal potential). It becomes. Further, since the inner and outer edge portions 5 and 6 at both ends of the single molds 3 and 4 of the inner coil 1 and the outer coil 2 are formed in an arc shape in cross section, the inner and outer edge portions of the conductive coatings 7 and 8 are also formed as a result. , The conductive coatings 7 and 8 are not formed with edges that cause charge concentration to the periphery. Further, since the inner coil 1 and the outer coil 2 are encased in the respective conductive coatings 7 and 8 that are floated to potentials corresponding to the respective coils in this way, even at the ends of the inner coil 1 and the outer coil 2, respectively. Even if there is an edge, this does not have an adverse effect such as concentration of charges to the outside of each conductive coating 7, 8, and between the inner coil 1 and the conductive coating 7 of the coil, and between the outer coil 2 and the coil. The potential difference between the coating 8 and the coating 8 does not increase or fluctuate.
[0018]
Accordingly, the respective conductive coatings 7 and 8 have an equal electric field across the entire surface, and between the conductive coating 8 of the high voltage side outer coil 2 and the conductive coating 7 of the low voltage side inner coil 1, the conductive coating 8 of the high voltage side outer coil 2. Even if the potential difference between the conductive coating 10 and the total conductive coating 10 is quite large, the electric field distribution between them can be easily made uniform or almost uniform, and the charge in the double mold 9 can be appropriately dispersed, The dielectric strength of the double mold 9 can be set easily, accurately and rationally without waste. At the same time, the dielectric strength of the single molds 3 and 4 of the inner and outer coils 1 and 2 can be set easily and accurately and wastefully. It is possible to do it reasonably without generating unnecessary corona inside the transformer and single molds 3, 4 by corona. The insulation deterioration or breakdown of the fine double mold 9 can be properly prevented. In other words, by rolling the surface of each single mold 3, 4 and applying a conductive paint to create an equal electric field, the required breakdown voltage can be secured over a short distance, resulting in a reduction in size and weight. .
[0019]
The lead wires 15 and 16 of the outer coil 2 on the high voltage side are inserted into the central portion of the window hole 11 opened in the total conductive coating 10, so that the insulation distance from the hole edge of the window hole 11 is increased. The corona ring 17 attached to the hole edge of the window hole 11 does not cause an edge at the hole edge, and charges near the hole edge can be appropriately adjusted by the corona ring 17. It can be dispersed, and generation of useless corona outside the transformer and insulation deterioration or dielectric breakdown of the portion due to the corona can be prevented appropriately.
[0020]
In addition, in the double mold 9 of the solid insulating material 19, the space 21 provided in the middle part between the inner and outer single molds 3, 4 and the soft insulating material molded into the space 21 and integrated so as to be elastically deformable. 20, damage due to thermal expansion in the double mold 9 can be avoided, and insulation deterioration or breakdown in the double mold 9 from damage due to thermal expansion can be appropriately prevented.
[0021]
In the trial production, it was possible to easily produce a small and lightweight dry high-voltage transformer that can sufficiently withstand a pressure test of 270 kV and 10 minutes that has not been realized so far.
[0022]
Note that the inner coil 1 and the outer coil 2 can be configured in substantially the same manner by reversing the primary and secondary, the high voltage side and the low voltage side.
[0023]
【The invention's effect】
As described above, according to the high voltage transformer according to the first aspect of the present invention, the above-described configuration makes it possible to properly generate unnecessary corona inside and outside the transformer and to prevent deterioration of the mold due to corona and dielectric breakdown or breakdown of the mold. Therefore, it is possible to realize a mold transformer that can be prevented at a high voltage, is compact and lightweight, can be easily manufactured, and can be provided at low cost. According to the conductive coating single mold coil for a high voltage transformer according to claim 2 of the present invention, it becomes possible to secure a required breakdown voltage within a short distance inside the transformer, and as a result, a reduction in size and weight can be realized. It becomes.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment according to a high voltage transformer of the present invention.
FIG. 2 is a transverse cross-sectional view of the same.
FIG. 3 is a side view of the same cutting.
FIG. 4 is a partially cut exploded perspective view of the main part member.
FIG. 5 is an electric circuit diagram of the same.
FIG. 6 is a cross-sectional view showing a modified example of the iron core.
[Explanation of symbols]
A ... primary (low voltage side) conductive coating single mold coil B ... secondary (high voltage side) conductive coating single mold coil C ... general conductive coating double mold composite integrated coil 1 ... inner coil 2 ... outer coils 3, 4 ... Single molds 5, 6 ... Inner and outer edges 7, 8 ... Conductive coating 9 ... Double mold 10 ... Total conductive coating 11 ... Window holes 12, 13 ... Lead wire 14 ... Round bar 15, 16 ... Lead wire 17 ... Corona ring 18 ... Synthetic resin pipe 19 ... Solid insulating material 20 ... Soft insulating material 21 ... Spacing 22 ... Iron core 23 ... Conductive coating 24 ... Protective tubes 25 and 26 ... Inner and outer edges

Claims

Either the primary or secondary inner coil with a small diameter and the other outer coil with a large diameter are molded in a single piece with an insulating material over the entire circumference, and the inner and outer edges of both ends are arc-shaped in each single mold. Forming a conductive coating with a conductive paint and electrically connecting the appropriate position of each coil inside and outside and the conductive coating of the coil to float each conductive coating to a potential corresponding to the coil, thus The resulting both conductive coating single mold coils are arranged concentrically inside and outside at the required intervals, and are further double-molded integrally with an insulating material. Open the window hole and insert the lead wire of either the inside or outside high voltage side coil into the center part of the window hole, A corona ring is attached to the hole edge of the window hole to provide a comprehensive conductive coating double mold composite integrated coil. The composite conductive coating double mold composite integrated coil is attached to the iron core, and the core and the above comprehensive conductive coating are attached. A high voltage transformer characterized by electrical connection.

A single coil is single-molded with an insulating material over the entire peripheral surface, the inner and outer edges of both ends are formed in a circular arc shape on the single mold, and a conductive coating is applied with a conductive paint. A conductive coating single mold coil for a high voltage transformer characterized in that it is electrically connected and floated to a potential corresponding to the coil.