JP3986809B2

JP3986809B2 - Three-phase electromagnetic equipment

Info

Publication number: JP3986809B2
Application number: JP2001368053A
Authority: JP
Inventors: 博道佐藤; 大日向　　敬; 重昭赤塚; 智之葵木; 峰夫川上
Original assignee: Tohoku Electric Power Co Inc
Current assignee: Tohoku Electric Power Co Inc
Priority date: 2001-12-03
Filing date: 2001-12-03
Publication date: 2007-10-03
Anticipated expiration: 2021-12-03
Also published as: JP2003168612A

Description

【０００１】
【発明の属する技術分野】
この発明は、リアクタンスを可変できる三相形の電磁機器に関する。さらに、主巻線の励磁電流に影響されることなく、高調波歪みの少ない、鉄心の突き合わせ面に絶縁フィルムを必要としない、電力系統に直列に接続可能な三相形の電磁機器に関する。
【０００２】
【従来の技術】
リアクタンスを可変する従来の技術としては、本出願人が先に提案した線形可変リアクトル（特開平０９−３３０８２９号公報）や誘導性素子（特開平０９−１２９４５０号公報）がある。
【０００３】
図８は、線形可変リアクトルの一実施例を示す斜視図で、この線形可変リアクトルは、図８に示すように、主巻線３２が巻回された第１のＵ形カットコア３１と、制御巻線３４が巻回された第２のＵ形カットコア３３から構成され、これら第１及び第２のＵ形カットコア３１、３３は、そのカット面同志を互いに対向させ、且つ、第１のＵ形カットコア３１に対して第２のＵ形カットコア３３を捩じり方向に９０°回転させた状態で接触させている。カット面同志の４面の接触面３６は、主巻線３２、制御巻線３４の各々に電圧ｅ１、ｅ２を印加して発生する磁束φ１、φ２の全てが通る共通磁路となる。そこで、制御巻線３４の電流ｉ２で当該共通磁路を磁気飽和させることにより主巻線３２による磁束の磁路を楔形の間隙３５に移行させることができ、制御巻線３４の励磁電流を変えることにより、主巻線３２のリアクタンスを線形に可変させることができる。
【０００４】
図９は、誘導性素子の一実施例を示す斜視図で、この誘導性素子は、図９に示すように、Ｅ型コア４２とＩ型コア４３とからなるＥＩ型コア４４に主巻線４５と制御用巻線４６を巻回した構成であり、主巻線に交流電源を接続することにより、巻線部４５ａによる磁束φ１及び巻線部４５ｂによる磁束φ２が発生する。ここで、Ｅ型コア４２の中枠４９に巻回された制御用巻線に制御電流を流すと磁束φ３が発生するが、外枠４７と外枠４８を等断面積とすることにより、外枠４７内には磁束φ１に磁束φ３の１／２を加算した磁束が通過し、外枠４８内には磁束φ２に磁束φ３の１／２を差し引いた磁束が通過する。このとき、外枠４７の端部４７ａに前記加算磁束が集中し、先端部が磁気飽和して外枠４７の透磁率が減少しインダクタンスが低下する。
【０００５】
【発明が解決しようとする課題】
しかし、上記線形可変リアクトルは、第１及び第２のＵ形カットコアの共通磁路を制御巻線の励磁電流により磁気飽和させ透磁率を制御することによりリアクタンスを可変しており、また、上記誘導性素子についても、主磁束と制御磁束により外枠先端部を磁気飽和させ透磁率を制御することによりリアクタンスを可変している。このため、共に、主巻線に流れる負荷電流が増加すると、負荷電流により磁気飽和現象が生じてしまい、制御巻線の励磁電流によるリアクタンス制御が困難になるという課題があった。
【０００６】
また、上記線形可変リアクトルは、Ｕ形カットコアの磁心接合面において積層鋼板が互いに直交することから、磁心の接合面において生ずる渦電流発生の対策として、突き合わせ面における積層鋼板間の短絡を防止するため接合面に絶縁フィルムを挿入しているが、十分な耐久性をもつ絶縁フィルム材料を確保することが困難であり、また、絶縁フィルムを介在させると磁気回路の磁気抵抗が増大し、大きなリアクタンスの変化が困難となるという課題があった。
【０００７】
さらに、上記線形可変リアクトル及び誘導性素子は、共に単相型であることから電力系統に使用する場合には３台で三相構成する必要があり、重量や容積の観点から三相一体構成の電磁機器が望まれていた。
【０００８】
そこで、本発明は、上記課題に鑑み、主巻線に流れる負荷電流による影響が少なく、磁気回路構造及び巻線の巻装構造が簡単で、三相一体構造を構成でき、且つ、絶縁フィルムを必要としないで高調波を低減させ、リアクタンスを可変できる電磁機器を提供することを目的とする。
【０００９】
【課題を解決するための手段】
請求項１の発明は、各端が対をなす磁路を形成する３つのＨ状脚部と、これらＨ状脚部の各端側を連結して閉磁路を形成する２つの枠部とから成る三相電磁路を有し、前記Ｈ状脚部の一方の連結端側において、前記Ｈ状脚部の対をなす磁路の各磁路に三相交流電源の各相に対応する主巻線を巻回して有するとともに、前記Ｈ状脚部の他方の連結端側において、前記Ｈ状脚部の対をなす磁路の各磁路に制御巻線を巻回して有し、前記主巻線は前記一対の磁路に生じる主磁束が同一方向になるように直列又は並列に接続し、前記制御巻線は前記主磁束によって生じる誘起電圧が互いに打消されるように直列に接続してなり、前記制御巻線の開放端子側に制御回路を接続し、直流制御電流を供給することにより、前記主磁束と制御磁束の共通磁路の磁気抵抗を制御し主巻線のリアクタンスを連続的に可変することを特徴としたものである。
【００１０】
請求項２の発明は、請求項１の発明において、前記３つのＨ状脚部は、それぞれ個別の３つのＨ状鉄心から成り、前記枠部はそれぞれ別個の２つのＩ状鉄心から成り、前記Ｈ状鉄心とＩ状鉄心の連結部においてこれら鉄心の積層鋼板を互いに平行になるように突き合わせて形成したことを特徴としたものである。
【００１１】
請求項３の発明は、請求項１又は２の発明において、前記各脚部（各相）の主巻線を巻回した各々の磁路に二次巻線を巻回し、前記主巻線のリアクタンスを連続的に可変することに加え、該主巻線に変圧機能を持たせたことを特徴としたものである。
【００１２】
請求項４の発明は、請求項１又は２の発明において、前記各脚部（各相）に二次巻線を巻回し、前記主巻線のリアクタンスを連続的に可変することに加え、該主巻線に変圧機能を持たせたことを特徴としたものである。
【００１３】
【発明の実施の形態】
図１は、本発明による三相形電磁機器の電磁鉄心及び巻線の基本構成例を示す図、図２は、図１で示した三相形電磁機器を等価的に回路表示した回路構成図である。
本発明による三相形電磁機器を構成する電磁磁心は、各端（両端）に対をなす磁路を有する３つのＨ状脚部（磁心）、すなわち、第１のＨ状磁心４ａと第２のＨ状磁心４ｂと第３のＨ状磁心４ｃと、これらＨ状磁心の各（両）端部を連結して閉磁路を形成する２つのＩ状磁心、すなわち、第１のＩ状磁心５ａと第２のＩ状磁心５ｂとより成り、それぞれのＨ状磁心４ａ，４ｂ，４ｃにおいて、鉄心窓部が２個所形成されるように対称に対向させ、第１のＨ状磁心４ａとＩ状磁心５ａ及び５ｂの連結部、及び第２のＨ状磁心４ｂとＩ状磁心５ａ及び５ｂの連結部、及び第３のＨ状磁心４ｃとＩ状磁心５ａ及び５ｂの連結部は、磁心を構成する各々の積層鋼板を平行になるように突き合わせて構成する。
【００１４】
第１のＨ状磁心４ａを構成する２対の脚のうちの一方の対の各々の脚（磁路）に主巻線１ａａ及び主巻線１ａｂを巻回し、主巻線１ａａ及び１ａｂを、両主巻線から生じる磁束φａ１及びφａ２が同方向になるように直列又は並列に接続する。
第１のＨ状磁心４ａの残る他の対の各々の脚（磁路）には、それぞれ制御巻線２ａａ及び２ａｂを巻回し、主巻線１ａａ及び１ａｂによる磁束で制御巻線２ａａ及び２ａｂに生じる誘起電圧が互いに打消されるように両制御巻線を直列に接続し、その開放端子側に制御回路３を接続する。
同様に第２のＨ状磁心４ｂには、主巻線１ｂａ及び１ｂｂ並びに制御巻線２ｂａ及び２ｂｂを巻回し、第３のＨ状磁心４ｃには、主巻線１ｃａ及び１ｃｂ並びに制御巻線２ｃａ及び２ｃｂを巻回する。
【００１５】
図１において、それぞれのＨ状磁心に巻回して接続した主巻線の開放端子に三相交流電源を接続し、それぞれの主巻線に図示矢印方向の電流ＩＬａ、ＩＬｂ、ＩＬｃが流れていたとする。なお、図示の電流矢印方向を正サイクルとした場合、負サイクルでは逆方向の電流が流れる。
【００１６】
今、主巻線に三相電流ＩＬａ、ＩＬｂ、ＩＬｃが流れると磁心４ａ、４ｂ、４ｃにそれぞれ各相の主磁束φａ１／φａ２、φｂ１／φｂ２、φｃ１／φｃ２が発生し、これら各相の主磁束は、それぞれ各相の制御巻線が巻回された磁心部を経て枠部５ａ、５ｂに至り三相閉磁路を還流する。
各相の制御巻線を巻回した磁心は、それぞれ制御磁束φｃａ、φｃｂ、φｃｃと上記各相の主磁束との共通磁路となる。
【００１７】
以下、第１のＨ状磁心４ａ部について説明すると、制御巻線に直流制御電流を流さない場合には主巻線１ａａ／１ａｂには磁心の磁気抵抗に応じたリアクタンスが生じる。
主巻線電流ＩＬａを流した状態で制御巻線に直流制御電流Ｉｃａを流すと、制御巻線２ａａ及び２ａｂにおいて、制御巻線の巻数と制御電流Ｉｃａの積で表される起磁力が発生することで、制御巻線磁束φｃａと主磁束φａ１及びφａ２が同方向となる共通磁路部分の磁束密度が大となって透磁率が変化し、主磁束が制御されリアクタンスが低下する。
【００１８】
主巻線電流ＩＬａあるいは直流制御電流Ｉｃａを増加させることにより共通磁路が磁気飽和状態になると、主巻線１ａａ及び１ａｂより発生する主磁束は、Ｈ状磁心中央部が連結しているため、増加する主磁束φａ１及びφａ２は磁心連結部で互いに相殺され、磁路は完全な磁気飽和状態に至らず一定の磁束密度に保たれる。
【００１９】
一対の主巻線１ａａ及び１ａｂによる主磁束の増加分が制御巻線を巻回した磁路を通過しないので、互いの主巻線の起磁力を相殺することになる。
更に、主巻線電流ＩＬａが増加しても、磁路が一定の磁束密度に保たれるように、増加する主巻線１ａａによる主磁束と主巻線１ａｂによる主磁束は相殺されるため、直流制御電流Ｉｃａを制御することにより主磁束が制御でき、リアクタンスを可変することができる。
即ち、主巻線電流に拘わらず、制御巻線に直流制御電流Ｉｃａを流すことでリアクタンスを可変することができる。
【００２０】
上述のように、リアクタンスを制御する共通磁路部が完全な磁気飽和状態に至らないので、高調波電流の抑制された電磁機器を実現することができる。
このことは、同様に他のＨ状磁心部についても成り立つことから、主巻線電流に拘わらず、高調波電流を抑制し、リアクタンスを可変できる三相形の電磁機器として機能することができる。
【００２１】
図３（Ａ）は、本発明によるリアクタンスの制御特性例を示したものであり、縦軸は主巻線のリアクタンス、横軸は直流制御電流で、直流制御電流Ｉｃを増加させることにより、リアクタンスを可変できることがわかる。
図３（Ｂ）は、本発明によるリアクタンスの磁化特性を示したもので、縦軸は主巻線部の磁束密度Ｂ、横軸は主巻線の磁化力Ｈを表している。
直流制御電流Ｉｃが少ない場合には磁化特性の非線形が生じているものの、制御電流を増加させることにより、主磁束が相殺されて磁束の増加を抑制し、磁化特性の非線形性が改善されることが確認でき、これにより高調波歪みが減少することがわかる。
【００２２】
以上のように、本発明によると、直流制御電流を調整することにより主磁束を制御するとともに、主巻線間の主磁束を相殺することにより、主巻線電流の影響を受けずに高調波を低減させてリアクタンスを高速且つ連続的に可変することができる。
また、図４に示すように、３つの個別のＨ状磁心４ａ、４ｂ、４ｃと２つの個別のＩ状磁心５ａ、５ｂの簡単な構成により、部品を用い、これら磁心を構成する積層鋼板を平行になるように突き合せて組合せることにより、容易に本三相形電磁機器を構成することができる。
【００２３】
図５は、図１で示した磁路巻線構成において、電磁機器を構成する主巻線を一次巻線１０とし、一次巻線１０ａａを巻回した脚（磁路）に二次巻線１１ａａ、一次巻線１０ａｂを巻回した脚に二次巻線１１ａｂ、一次巻線１０ｂａを巻回した脚に二次巻線１１ｂａ、一次巻線１０ｂｂを巻回した脚に二次巻線１１ｂｂ、一次巻線１０ｃａを巻回した脚に二次巻線１１ｃａ、一次巻線１０ｃｂを巻回した脚に二次巻線１１ｃｂを巻回して一次巻線と同様に接続して構成した三相形の電磁機器である。
【００２４】
図５において、一次巻線に三相交流電源を接続し二次巻線には三相負荷を接続し、それぞれの二次巻線に図示矢印方向の電流ＩＬａ２、ＩＬｂ２、ＩＬｃ２が流れていたとする。
【００２５】
以下、第１のＨ状磁心部について説明する。
制御電流を流さない場合には、一次巻線１０ａａ及び１０ａｂには、上記二次電流で発生した磁束を打消すように一次電流ＩＬａ１が流れ、全体として変圧器動作を示す。制御巻線に直流制御電流Ｉｃａを流すと、制御巻線の巻数と制御電流Ｉｃａの積で表される起磁力が発生することで透磁率が変化し、主磁束が制御される。このため、一次巻線には制御電流の制御に伴う主磁束の減少に応じて、一次巻線の端子間電圧を維持するために必要な主磁束を発生させるために励磁電流が増加する。
【００２６】
即ち、変圧器としての変圧機能に加えて、制御電流を調整することで主巻線のリアクタンスを連続的に可変して一次側に流入する無効電流の調整が可能となる。このことは、同様に他のＨ状磁心部についても成り立つことから、変圧器としての変圧機能に加えて、リアクタンスを可変できる三相形の電磁機器として機能することができる。
【００２７】
図６は、図１で示した磁路巻線構成において、電磁機器を構成する主巻線を一次巻線１０とし、一次巻線１０ａａと１０ａｂを巻回した脚に二次巻線１１ａ、一次巻線１０ｂａと１０ｂｂを巻回した脚に二次巻線１１ｂ、一次巻線１０ｃａと１０ｃｂを巻回した脚に二次巻線１１ｃを巻回して構成した三相形の電磁機器である。
【００２８】
図５と同様に変圧器としての変圧機能に加えて、制御電流を調整することで主巻線のリアクタンスを連続的に可変して一次側に流入する無効電流の調整が可能となる。さらに、二次巻線の配置位置を変えることにより、制御電流を調整することにより生ずる漏洩磁束の二次巻線への鎖交磁束量を制御することにより、上記に加え二次電圧も連続的に可変できる三相形の電磁機器として機能することができる。
なお、図５及び図６に示した巻線構成を組み合わせた構成としても変圧器として動作することは明らかである。
【００２９】
（適用例）
図７は、本発明の三相形電磁機器の無効電力補償装置への適用例である。図７において、三相形電磁機器１２と電力用コンデンサ１３を並列に接続し、送電線路（交流系統）に並列に挿入し、三相形電磁機器の制御により、系統に生じる遅相から進相の無効電力を連続的に補償するようにしたものである。
【００３０】
【発明の効果】
以上に詳述したように、本発明によれば、タップを設けることなく、負荷電流の有無に拘わらず、高調波電流を抑制し、広範囲にリアクタンスを可変する三相形の電磁機器を実現することができ、近年の電力需要の増大や負荷の多様化により、系統電圧の変動等負荷の多様化に対応できるフレキシブルな電力設備の提供がはかられ、電力系統の電圧の安定化に寄与できる。
なお、この他、発明の要旨を逸脱しない範囲で種々変形して実施することができる。
【図面の簡単な説明】
【図１】請求項１又は２の発明による三相形電磁機器の基本構成例を示す接続図である。
【図２】図１に示した三相形電磁機器の等価回路を示す回路構成図である。
【図３】三相形電磁機器の制御特性例を示す図である。
【図４】請求項２の発明による三相形電磁機器の基本構成例を示す接続図である。
【図５】請求項３の発明による三相形電磁機器の基本構成例を示す接続図である。
【図６】請求項４の発明による三相形電磁機器の基本構成例を示す接続図である。
【図７】本発明の無効電力補償装置への適用例を示す回路構成図である。
【図８】本出願人が先に提案した従来の線形可変リアクトルの一例を示す斜視図である。
【図９】従来の誘導性素子の一例を示す斜視図である。
【符号の説明】
１（１ａａ〜１ｃｂ）…主巻線、２（２ａａ〜２ｃｂ）…制御巻線、３…制御回路、４（４ａ〜４ｃ）…Ｈ状磁心、５（５ａ，５ｂ）…Ｉ状磁心、６…磁心、１０（１０ａａ〜１０ｃｂ）…一次巻線、１１（１１ａａ〜１１ｃｂ）…二次巻線、１２…三相形電磁機器、１３…電力用コンデンサ、３１…第１のＵ形カットコア、３２…主巻線、３３…第２のＵ形カットコア、３４…制御巻線、３５…楔形間隙、３６…カット面同士の接触面、４２…Ｅ型コア、４３…Ｉ型コア、４４…ＥＩ型コア、４５…主巻線、４６…制御用巻線、４７…外枠、４８…外枠、４９…中枠。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a three-phase electromagnetic device whose reactance can be varied. Furthermore, the present invention relates to a three-phase electromagnetic device that can be connected in series to a power system without being affected by the excitation current of the main winding, with less harmonic distortion, and without requiring an insulating film on the butt surface of the iron core.
[0002]
[Prior art]
As conventional techniques for changing reactance, there are a linear variable reactor (Japanese Patent Laid-Open No. 09-330829) and an inductive element (Japanese Patent Laid-Open No. 09-129450) previously proposed by the present applicant.
[0003]
FIG. 8 is a perspective view showing an embodiment of the linear variable reactor. As shown in FIG. 8, the linear variable reactor includes a first U-shaped cut core 31 around which a main winding 32 is wound, and a control. The first and second U-shaped cut cores 31 and 33 are formed of a second U-shaped cut core 33 around which a winding 34 is wound. The second U-shaped cut core 33 is brought into contact with the U-shaped cut core 31 in a state where the second U-shaped cut core 33 is rotated by 90 ° in the twisting direction. The four contact surfaces 36 between the cut surfaces serve as a common magnetic path through which all of the magnetic fluxes φ1 and φ2 generated by applying voltages e1 and e2 to the main winding 32 and the control winding 34, respectively. Therefore, by magnetically saturating the common magnetic path with the current i2 of the control winding 34, the magnetic path of the magnetic flux by the main winding 32 can be shifted to the wedge-shaped gap 35, and the excitation current of the control winding 34 is changed. As a result, the reactance of the main winding 32 can be varied linearly.
[0004]
FIG. 9 is a perspective view showing an embodiment of the inductive element. As shown in FIG. 9, the inductive element has an EI type core 44 composed of an E type core 42 and an I type core 43 and a main winding. 45 and the control winding 46 are wound, and by connecting an AC power source to the main winding, a magnetic flux φ1 by the winding portion 45a and a magnetic flux φ2 by the winding portion 45b are generated. Here, when a control current is passed through the control winding wound around the inner frame 49 of the E-type core 42, a magnetic flux φ3 is generated. By making the outer frame 47 and the outer frame 48 have an equal cross-sectional area, A magnetic flux obtained by adding 1/2 of the magnetic flux φ3 to the magnetic flux φ1 passes through the frame 47, and a magnetic flux obtained by subtracting 1/2 of the magnetic flux φ3 from the magnetic flux φ2 passes through the outer frame 48. At this time, the added magnetic flux is concentrated on the end 47a of the outer frame 47, the tip is magnetically saturated, the magnetic permeability of the outer frame 47 is reduced, and the inductance is reduced.
[0005]
[Problems to be solved by the invention]
However, the linear variable reactor varies the reactance by magnetically saturating the common magnetic path of the first and second U-shaped cut cores with the excitation current of the control winding and controlling the permeability. The reactance of the inductive element is also varied by magnetically saturating the outer frame tip with the main magnetic flux and the control magnetic flux to control the magnetic permeability. For this reason, when the load current flowing through the main winding increases, a magnetic saturation phenomenon occurs due to the load current, and there is a problem that reactance control by the excitation current of the control winding becomes difficult.
[0006]
Further, the linear variable reactor prevents the short circuit between the laminated steel sheets on the butt surface as a countermeasure against the generation of eddy currents generated on the magnetic core joining surface because the laminated steel sheets are orthogonal to each other on the magnetic core joining surface of the U-shaped cut core. For this reason, an insulating film is inserted on the joint surface, but it is difficult to secure an insulating film material having sufficient durability. In addition, if an insulating film is interposed, the magnetic resistance of the magnetic circuit increases and a large reactance is obtained. There was a problem that it would be difficult to change.
[0007]
Furthermore, since the linear variable reactor and the inductive element are both single-phase type, it is necessary to form a three-phase structure with three units when used in a power system. Electromagnetic equipment was desired.
[0008]
Therefore, in view of the above problems, the present invention is less affected by the load current flowing in the main winding, the magnetic circuit structure and the winding structure of the winding are simple, can form a three-phase integrated structure, and an insulating film is provided. An object of the present invention is to provide an electromagnetic device that can reduce harmonics and change reactance without being required.
[0009]
[Means for Solving the Problems]
The invention of claim 1 includes three H-shaped leg portions that form a magnetic path in which each end forms a pair, and two frame portions that connect the respective end sides of the H-shaped leg portions to form a closed magnetic path. A main winding corresponding to each phase of the three-phase AC power source in each magnetic path of the magnetic path forming a pair of the H-shaped leg portions on one coupling end side of the H-shaped leg portions. The main winding is provided with a winding wound around each magnetic path of a magnetic path forming a pair of the H-shaped legs on the other connecting end side of the H-shaped legs. The wires are connected in series or in parallel so that the main magnetic flux generated in the pair of magnetic paths is in the same direction, and the control winding is connected in series so that the induced voltages generated by the main magnetic flux cancel each other. By connecting a control circuit to the open terminal side of the control winding and supplying a DC control current, the common magnetic path of the main magnetic flux and the control magnetic flux It is obtained characterized by continuously varying the reactance of controlled main winding care resistance.
[0010]
According to a second aspect of the present invention, in the first aspect of the invention, the three H-shaped leg portions are each composed of three individual H-shaped iron cores, and the frame portion is composed of two separate I-shaped iron cores, The laminated steel plates of these iron cores are formed so as to be parallel to each other at the connecting portion between the H-shaped iron core and the I-shaped iron core.
[0011]
According to a third aspect of the present invention, in the first or second aspect of the present invention, a secondary winding is wound around each magnetic path around which the main winding of each leg (each phase) is wound. In addition to continuously changing the reactance, the main winding is provided with a transforming function.
[0012]
The invention of claim 4 is the invention of claim 1 or 2, wherein a secondary winding is wound around each leg (each phase) and the reactance of the main winding is continuously varied. The main winding is characterized by having a transformation function.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing a basic configuration example of an electromagnetic core and windings of a three-phase electromagnetic device according to the present invention, and FIG. 2 is a circuit configuration diagram equivalently displaying a circuit of the three-phase electromagnetic device shown in FIG. .
The electromagnetic core constituting the three-phase electromagnetic device according to the present invention has three H-shaped leg portions (magnetic cores) having a magnetic path paired at each end (both ends), that is, the first H-shaped magnetic core 4a and the second H-shaped magnetic core 4a. An H-shaped magnetic core 4b, a third H-shaped magnetic core 4c, and two I-shaped magnetic cores that connect each (both) ends of the H-shaped magnetic core to form a closed magnetic path, that is, a first I-shaped magnetic core 5a The first I-shaped magnetic core 4a and the I-shaped magnetic core 4a, 4b, 4c are symmetrically opposed to each other so that two iron core window portions are formed. The connecting portion between 5a and 5b, the connecting portion between the second H-shaped magnetic core 4b and the I-shaped magnetic cores 5a and 5b, and the connecting portion between the third H-shaped magnetic core 4c and the I-shaped magnetic cores 5a and 5b constitute a magnetic core. Each laminated steel plate is abutted and configured to be parallel.
[0014]
The main winding 1aa and the main winding 1ab are wound around each leg (magnetic path) of one of the two pairs of legs constituting the first H-shaped magnetic core 4a, and the main windings 1aa and 1ab are The magnetic fluxes φa1 and φa2 generated from both main windings are connected in series or in parallel so that they are in the same direction.
The control windings 2aa and 2ab are wound around the legs (magnetic paths) of the remaining pairs of the first H-shaped magnetic core 4a, respectively. The magnetic fluxes of the main windings 1aa and 1ab are applied to the control windings 2aa and 2ab. Both control windings are connected in series so that the induced voltages generated cancel each other, and the control circuit 3 is connected to the open terminal side.
Similarly, main windings 1ba and 1bb and control windings 2ba and 2bb are wound around the second H-shaped magnetic core 4b, and main windings 1ca and 1cb and control winding 2ca are wound around the third H-shaped magnetic core 4c. And 2cb.
[0015]
In FIG. 1, a three-phase AC power source is connected to the open terminals of the main windings wound and connected to the respective H-shaped magnetic cores, and currents ILa, ILb, and ILc in the directions indicated by the arrows flow through the respective main windings. To do. When the current arrow direction shown in the figure is a positive cycle, a current in the reverse direction flows in the negative cycle.
[0016]
Now, the main winding to a three-phase current ILa, ILb, ILc flows the core 4a, 4b, of each phase to 4c main magnetic flux φa1 / φa2, φb1 / φb2, φc1 / φ c 2 occurs, these phases The main magnetic flux passes through the magnetic core portion around which the control winding of each phase is wound, reaches the frame portions 5a and 5b, and circulates through the three-phase closed magnetic circuit.
The magnetic core wound with the control winding of each phase serves as a common magnetic path for the control magnetic fluxes φca, φcb, φcc and the main magnetic flux of each phase.
[0017]
Explaining the first H-shaped core 4a portion, if not shed DC control currents to the control winding reactance in response to magnetic resistance of the magnetic core is generated in the main winding 1aa / 1 a b.
When a DC control current Ica is supplied to the control winding while the main winding current ILa is supplied, a magnetomotive force represented by the product of the number of turns of the control winding and the control current Ica is generated in the control windings 2aa and 2ab. As a result, the magnetic flux density of the common magnetic path portion in which the control winding magnetic flux φca and the main magnetic fluxes φa1 and φa2 are in the same direction is increased, the magnetic permeability is changed, the main magnetic flux is controlled, and the reactance is lowered.
[0018]
When the common magnetic path is in a magnetic saturation state by increasing the main winding current ILa or the direct current control current Ica, the main magnetic flux generated from the main windings 1aa and 1ab is connected to the central portion of the H-shaped magnetic core. The increasing main magnetic fluxes φa1 and φa2 cancel each other at the magnetic core connecting portion, and the magnetic path does not reach a complete magnetic saturation state but is maintained at a constant magnetic flux density.
[0019]
Since the increase in the main magnetic flux due to the pair of main windings 1aa and 1ab does not pass through the magnetic path wound around the control winding, the magnetomotive forces of the main windings cancel each other.
Further, even if the main winding current ILa increases, the main magnetic flux due to the increasing main winding 1aa and the main magnetic flux due to the main winding 1ab cancel each other so that the magnetic path is maintained at a constant magnetic flux density. By controlling the DC control current Ica, the main magnetic flux can be controlled and the reactance can be varied.
That is, regardless of the main winding current, the reactance can be varied by passing the DC control current Ica through the control winding.
[0020]
As described above, since the common magnetic path portion for controlling the reactance does not reach a complete magnetic saturation state, an electromagnetic device in which harmonic current is suppressed can be realized.
Since this also holds true for other H-shaped magnetic cores, it can function as a three-phase electromagnetic device that can suppress harmonic current and vary reactance regardless of the main winding current.
[0021]
FIG. 3A shows an example of reactance control characteristics according to the present invention. The vertical axis represents the reactance of the main winding, the horizontal axis represents the direct current control current, and the direct current control current Ic is increased to increase the reactance. It can be seen that can be varied.
FIG. 3B shows the reactance magnetization characteristic according to the present invention. The vertical axis represents the magnetic flux density B of the main winding portion, and the horizontal axis represents the magnetization force H of the main winding.
When the DC control current Ic is small, non-linearity of the magnetization characteristic occurs, but by increasing the control current, the main magnetic flux is canceled and the increase of the magnetic flux is suppressed, and the non-linearity of the magnetization characteristic is improved. It can be seen that this reduces the harmonic distortion.
[0022]
As described above, according to the present invention, the main magnetic flux is controlled by adjusting the direct current control current, and the main magnetic flux between the main windings is canceled, so that the harmonics are not affected by the main winding current. The reactance can be varied at high speed continuously.
Moreover, as shown in FIG. 4, the laminated steel plate which comprises these magnetic cores by using components with a simple configuration of three individual H-shaped magnetic cores 4a, 4b, 4c and two individual I-shaped magnetic cores 5a, 5b. The three-phase electromagnetic device can be easily configured by combining them so that they are parallel to each other.
[0023]
FIG. 5 shows the configuration of the magnetic path winding shown in FIG. 1, in which the main winding constituting the electromagnetic device is the primary winding 10 and the secondary winding 11aa on the leg (magnetic path) around which the primary winding 10aa is wound. The secondary winding 11ab is wound around the leg wound with the primary winding 10ab, the secondary winding 11ba is wound around the leg wound with the primary winding 10ba, the secondary winding 11bb is wound around the leg wound with the primary winding 10bb, A three-phase electromagnetic device constructed by connecting the secondary winding 11ca to the leg wound with the winding 10ca and connecting the secondary winding 11cb to the leg wound with the primary winding 10cb in the same manner as the primary winding. It is.
[0024]
In FIG. 5, it is assumed that a three-phase AC power source is connected to the primary winding and a three-phase load is connected to the secondary winding, and currents ILa2, ILb2, and ILc2 in the directions indicated by the arrows flow through the respective secondary windings. .
[0025]
Hereinafter, the first H-shaped magnetic core will be described.
When the control current is not passed, the primary current ILa1 flows through the primary windings 10aa and 10ab so as to cancel the magnetic flux generated by the secondary current, and the transformer operation is shown as a whole. When the DC control current Ica is passed through the control winding, the magnetic permeability is changed by the generation of magnetomotive force represented by the product of the number of turns of the control winding and the control current Ica, and the main magnetic flux is controlled. For this reason, in accordance with the decrease in the main magnetic flux accompanying the control of the control current, the exciting current increases in order to generate the main magnetic flux necessary for maintaining the voltage between the terminals of the primary winding.
[0026]
That is, in addition to the transformation function as a transformer, the reactive current flowing into the primary side can be adjusted by continuously adjusting the reactance of the main winding by adjusting the control current. Since this holds true for other H-shaped magnetic cores as well, in addition to the transformer function as a transformer, it can function as a three-phase electromagnetic device with variable reactance.
[0027]
FIG. 6 shows that the main winding constituting the electromagnetic device is the primary winding 10 in the magnetic path winding configuration shown in FIG. 1, and the secondary winding 11a and the primary winding are wound around the legs wound with the primary windings 10aa and 10ab. This is a three-phase electromagnetic device configured by winding a secondary winding 11b around a leg around which the windings 10ba and 10bb are wound and a secondary winding 11c around the leg around which the primary windings 10ca and 10cb are wound.
[0028]
Similar to FIG. 5, in addition to the transformer function as a transformer, the reactive current flowing into the primary side can be adjusted by continuously changing the reactance of the main winding by adjusting the control current. In addition to the above, the secondary voltage is continuously increased by changing the position of the secondary winding to control the amount of flux linkage to the secondary winding caused by adjusting the control current. It can function as a three-phase electromagnetic device that can be varied.
It should be noted that a configuration combining the winding configurations shown in FIGS. 5 and 6 operates as a transformer.
[0029]
(Application example)
FIG. 7 shows an application example of the three-phase electromagnetic device of the present invention to a reactive power compensator. In FIG. 7, a three-phase electromagnetic device 12 and a power capacitor 13 are connected in parallel, inserted in parallel in a transmission line (AC system), and the phase is invalidated from the slow phase generated in the system by the control of the three-phase electromagnetic device. The power is continuously compensated.
[0030]
【The invention's effect】
As described in detail above, according to the present invention, it is possible to realize a three-phase electromagnetic device capable of suppressing a harmonic current and varying a reactance over a wide range regardless of the presence or absence of a load current without providing a tap. With the recent increase in power demand and diversification of loads, it is possible to provide flexible power equipment that can cope with the diversification of loads such as fluctuations in the system voltage, thereby contributing to the stabilization of the voltage of the power system.
In addition, various modifications can be made without departing from the scope of the invention.
[Brief description of the drawings]
FIG. 1 is a connection diagram showing a basic configuration example of a three-phase electromagnetic device according to the invention of claim 1 or 2;
2 is a circuit configuration diagram showing an equivalent circuit of the three-phase electromagnetic device shown in FIG. 1. FIG.
FIG. 3 is a diagram showing an example of control characteristics of a three-phase electromagnetic device.
4 is a connection diagram showing a basic configuration example of a three-phase electromagnetic device according to the invention of claim 2. FIG.
5 is a connection diagram showing a basic configuration example of a three-phase electromagnetic device according to the invention of claim 3. FIG.
6 is a connection diagram showing a basic configuration example of a three-phase electromagnetic device according to the invention of claim 4. FIG.
FIG. 7 is a circuit configuration diagram showing an application example of the present invention to a reactive power compensator.
FIG. 8 is a perspective view showing an example of a conventional linear variable reactor previously proposed by the present applicant.
FIG. 9 is a perspective view showing an example of a conventional inductive element.
[Explanation of symbols]
1 (1aa to 1cb) ... main winding, 2 (2aa to 2cb) ... control winding, 3 ... control circuit, 4 (4a to 4c) ... H-shaped magnetic core, 5 (5a, 5b) ... I-shaped magnetic core, 6 ... Magnetic core, 10 (10aa to 10cb) ... Primary winding, 11 (11aa to 11cb) ... Secondary winding, 12 ... Three-phase electromagnetic device, 13 ... Power capacitor, 31 ... First U-shaped cut core, 32 ... Main winding, 33 ... Second U-shaped cut core, 34 ... Control winding, 35 ... Wedge-shaped gap, 36 ... Contact surface between cut surfaces, 42 ... E-type core, 43 ... I-type core, 44 ... EI Mold core, 45 ... main winding, 46 ... control winding, 47 ... outer frame, 48 ... outer frame, 49 ... middle frame.

Claims

各端が対をなす磁路を形成する３つのＨ状脚部と、これらＨ状脚部の各端側を連結して閉磁路を形成する２つの枠部とから成る三相電磁路を有し、前記Ｈ状脚部の一方の連結端側において、前記Ｈ状脚部の対をなす磁路の各磁路に三相交流電源の各相に対応する主巻線を巻回して有するとともに、前記Ｈ状脚部の他方の連結端側において、前記Ｈ状脚部の対をなす磁路の各磁路に制御巻線を巻回して有し、前記主巻線は前記一対の磁路に生じる主磁束が同一方向になるように直列又は並列に接続し、前記制御巻線は前記主磁束によって生じる誘起電圧が互いに打消されるように直列に接続してなり、前記制御巻線の開放端子側に制御回路を接続し、直流制御電流を供給することにより、前記主磁束と制御磁束の共通磁路の磁気抵抗を制御し主巻線のリアクタンスを連続的に可変することを特徴とする三相形電磁機器。It has a three-phase electromagnetic path consisting of three H-shaped legs that form a magnetic path with a pair of ends, and two frames that connect the ends of these H-shaped legs to form a closed magnetic path. In addition, on one connecting end side of the H-shaped leg portion, a main winding corresponding to each phase of the three-phase AC power source is wound around each magnetic path of the magnetic path forming the pair of the H-shaped leg portions. A control winding is wound around each magnetic path of the magnetic path forming a pair of the H-shaped leg portions on the other connecting end side of the H-shaped leg portions, and the main winding is the pair of magnetic paths. The control windings are connected in series so that the main magnetic fluxes generated in the same direction are in the same direction, and the control windings are connected in series so that the induced voltages generated by the main magnetic fluxes cancel each other. By connecting a control circuit to the terminal side and supplying a DC control current, the magnetic resistance of the common magnetic path of the main magnetic flux and the control magnetic flux is controlled. Three-phase form electromagnetic devices, which comprises varying the reactance of the line continuously.

前記３つのＨ状脚部は、それぞれ個別の３つのＨ状鉄心から成り、前記枠部はそれぞれ別個の２つのＩ状鉄心から成り、前記Ｈ状鉄心とＩ状鉄心の連結部においてこれら鉄心の積層鋼板を互いに平行になるように突き合わせて形成したことを特徴とする請求項１に記載の三相形電磁機器。Each of the three H-shaped leg portions is composed of three individual H-shaped iron cores, and each of the frame portions is composed of two separate I-shaped iron cores, and at the connecting portion between the H-shaped iron core and the I-shaped iron core, The three-phase electromagnetic device according to claim 1, wherein the laminated steel plates are abutted so as to be parallel to each other.

前記各脚部（各相）の主巻線を巻回した各々の磁路に二次巻線を巻回し、前記主巻線のリアクタンスを連続的に可変することに加え、該主巻線に変圧機能を持たせたことを特徴とする請求項１又は２に記載の三相形電磁機器。In addition to continuously changing the reactance of the main winding by winding a secondary winding around each magnetic path around which the main winding of each leg (each phase) is wound, The three-phase electromagnetic device according to claim 1 or 2, characterized by having a transforming function.

前記各脚部（各相）に二次巻線を巻回し、前記主巻線のリアクタンスを連続的に可変することに加え、該主巻線に変圧機能を持たせたことを特徴とする請求項１又は２に記載の三相形電磁機器。A secondary winding is wound around each leg (each phase), and in addition to continuously changing the reactance of the main winding, the main winding has a transforming function. Item 3. The three-phase electromagnetic device according to item 1 or 2.