JP4580561B2

JP4580561B2 - Superconducting magnet protector

Info

Publication number: JP4580561B2
Application number: JP2001006526A
Authority: JP
Inventors: 基仁五十嵐; 哲郎浅原; 薫根本; 昭彦岸川; 芳直眞田
Original assignee: Railway Technical Research Institute
Current assignee: Railway Technical Research Institute
Priority date: 2001-01-15
Filing date: 2001-01-15
Publication date: 2010-11-17
Anticipated expiration: 2021-01-15
Also published as: JP2002217021A

Description

【０００１】
【発明の属する技術分野】
本発明は、磁場を応用した磁気浮上列車に搭載される超電導コイルを用いた超電導磁石装置に対する超電導磁石保護装置に関する。
【０００２】
【従来の技術】
磁場を応用した磁気浮上列車の車両の概略的な構造は図５に示すようなものである。超電導コイル１及び永久電流スイッチを収納した超電導磁石装置６は、車両３の床下の左右両側に取り付けられ、地上側の左右に設けられた推進コイル４及び浮上案内コイル５それぞれと対向している。このような構造の磁気浮上列車の車両３は、超電導磁石装置６と推進コイル４との電磁力で推進され、それに伴う超電導磁石装置６と浮上案内コイル５との誘導電流で浮上力が発生すると共に、左右の変位に対して常に中央位置になるように案内力が作用する。
【０００３】
このような磁気浮上列車の超電導磁石装置６には、超電導コイル１のクエンチに対する保護装置として、図６〜図８に示すような回路構成のものが採用されている。図６に示す超電導磁石保護装置は、ダイオード７と保護抵抗８との直列回路を左右両側の超電導コイル１毎にそれぞれに並列に接続したものである。図７に示す保護装置は、励消磁電源１０に近い側と遠い側との両端位置の超電導コイル１のみ、特許第２７０８６７８号公報に記載されている構成の放電管９を用いて強制消磁する回路と緊急消磁する回路を兼ねさせた回路構成にし、中央部の超電導コイル１は図６に示した回路構成と同じである。そして図８に示す超電導磁石保護回路は、超電導磁石装置６のすべての超電導コイル１に対して放電開始電圧が異なるループ放電管９ａ，９ｂ，９ｃ，９ｄを用いて緊急消磁する回路と強制消磁する回路とを兼ねた回路構成である。なお、ここで、ループ放電管９，９ａ，９ｂ，…等には、特許第２７０８６７８号の発明の「超電導磁石保護回路用スイッチ」が用いられている。
【０００４】
このような従来の超電導磁石保護装置では、片方の超電導コイル１がクエンチした場合に、対向する反対側の超電導コイル１の永久電流スイッチ２のヒータを投入して緊急消磁する。また、励消磁電源１０がない場合でも、超電導コイル１をクエンチさせずに永久電流スイッチ２のヒータを投入して強制消磁が可能なように、保護抵抗値を選択している。
【０００５】
【発明が解決しようとする課題】
しかしながら、上記のいずれの構成の超電導磁石保護装置にあっても、次のような問題点があった。図６に示した超電導磁石保護装置では、強制消磁でクエンチを起こさない保護抵抗値としているため、緊急消磁時においてクエンチした超電導コイル１の速い電流減衰に比べて、対向側の超電導コイル１の電流減衰が遅く、対向側の超電導コイルのクエンチによる緊急消磁時の異常左右力の低減ができない問題点があった。
【０００６】
また図７に示した超電導磁石保護装置では、超電導コイル１の４コイルの同時クエンチを想定した場合、中央コイルの回路構成のために、クエンチした中央コイルに対する対向側コイルの電流減衰が遅く、対向側コイルのクエンチによる緊急消磁時の異常左右力の低減効果が十分に期待できない問題点があった。
【０００７】
さらに図８に示した超電導磁石保護装置では、超電導コイル１の４コイルの同時クエンチを想定した場合、対向側コイルのクエンチによる緊急消磁時の異常左右力の低減は可能であるが、抵抗値の選択及び超電導コイルのインダクタンス、常電導転移時のコイル抵抗などによっては、発生電圧が機器の許容耐電圧を超える可能性がある問題点があった。また、励消磁時に保護抵抗のある片側の超電導コイルで保護抵抗への電流分流が発生し、コイル電流が定格電流に達するまで定格電流保持時間が必要となり、操作性が悪くなる問題点もあった。さらに、電流リードの熱容量の増加、励消磁ロスの増加を伴い、熱侵入量、熱負荷が大きくなる問題点もあった。
【０００８】
本発明は、このような従来の問題点に鑑みてなされたもので、高電圧の発生を防止できる超電導磁石保護装置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の発明の超電導磁石保護装置は、左右に相対向するように同数の超電導コイルが左右それぞれにおいて直列に接続され、前記左右それぞれにおける直列に接続された超電導コイルの内の始端位置の超電導コイルそれぞれの始端端子間に電源が接続され、前記左右それぞれにおける直列に接続された超電導コイルの内の終端位置の超電導コイルそれぞれの終端端子間が短絡接続されて成る超電導磁石装置と、前記左右に相対向する超電導コイル毎にそれらの端子間に挿入された、ループ放電管と強制消磁保護抵抗との直列回路と、右側又は左側の前記超電導コイル毎にその両端子間毎に接続された緊急消磁保護抵抗と、前記左右の終端位置の超電導コイルそれぞれの終端端子間の接続点と前記電源との間に前記緊急消磁保護抵抗群と並列に接続された、回路保護抵抗と基準設定電圧で放電開始する回路保護放電管との直列回路とから成り、前記回路保護抵抗は、前記緊急消磁保護抵抗群との並列合成抵抗値が基準値以下となる抵抗値であることを特徴とするものである。
【００１０】
請求項１の発明の超電導磁石保護装置では、電源に対して、右側又は左側の超電導コイル毎にその両端子間毎に接続された緊急消磁保護抵抗群と並列に、当該緊急消磁保護抵抗との並列合成抵抗値が基準値以下となる抵抗値の回路保護抵抗と基準設定電圧で放電開始する回路保護放電管との直列回路を接続することにより、異常時の高電圧発生時にも電圧制御が可能な基準値よりも高い電圧を発生させない。これにより、超電導磁石装置の構成機器である超電導コイル及び電流リードの印加電圧を耐電圧の規定値以下に確実に制御でき、耐電圧設計ができると共に不確定要素のための裕度を設定しなくても済むようになる。
【００１１】
請求項２の発明の超電導磁石保護装置は、左右に相対向するように同数の超電導コイルが左右それぞれにおいて直列に接続され、前記左右それぞれにおける直列に接続された超電導コイルの内の始端位置の超電導コイルそれぞれの始端端子間に電源が接続され、前記左右それぞれにおける直列に接続された超電導コイルの内の終端位置の超電導コイルそれぞれの終端端子間が短絡接続されて成る超電導磁石装置と、前記左右に相対向する超電導コイルの両端子の接続中点間毎に挿入された緊急消磁保護抵抗と、前記接続中点と左右いずれか一方の前記超電導コイルの端子との間毎に挿入された、ループ放電管と強制消磁保護抵抗との直列回路と、前記接続中点と左右いずれか他方の前記超電導コイルの端子との間毎に挿入されたループ放電管と、前記左右の終端位置の超電導コイルそれぞれの終端端子間の接続点と前記電源との間に前記緊急消磁保護抵抗群と並列に接続された、回路保護抵抗と回路保護放電管との直列回路から成り、前記回路保護抵抗は、前記緊急消磁保護抵抗群との並列合成抵抗値が基準値以下となる抵抗値を持ち、前記回路保護放電管は、基準設定電圧で放電開始する特性を持つことを特徴とするものである。
【００１２】
請求項２の発明の超電導磁石保護装置では、左右の相対向する超電導コイルそれぞれの端子と両者間の接続中点との間毎にループ放電管が存在することにより、片側の超電導コイルのみに生じる保護抵抗の励消磁時の電流分流を防止することができ、電源による定格電流での保持やこの間の永久電流スイッチヒータの通電が不要となり、励消磁時の電源操作性が良くなり、また電流リードの熱容量の増加、永久電流スイッチヒータの発熱による励消磁ロスなどの熱負荷増分を低減することができる。
さらに、請求項２の発明の超電導磁石保護装置では、電源に対して、緊急消磁保護抵抗群と並列に接続された、当該緊急消磁保護抵抗との並列合成抵抗値が基準値以下となる抵抗値の回路保護抵抗と、基準設定電圧で放電開始する回路保護放電管との直列回路を備えたことにより、請求項１の発明のように、超電導磁石装置の構成機器である超電導コイル及び電流リードの印加電圧を耐電圧の規定値以下に確実に制御でき、耐電圧設計ができると共に不確定要素のための裕度を設定しなくても済むようになる。
【００１３】
請求項３の発明の超電導磁石保護装置は、左右に相対向するように同数の超電導コイルが左右それぞれにおいて直列に接続され、前記左右それぞれにおける直列に接続された超電導コイルの内の始端位置の超電導コイルそれぞれの始端端子間に電源が接続され、前記左右それぞれにおける直列に接続された超電導コイルの内の終端位置の超電導コイルそれぞれの終端端子間が短絡接続されて成る超電導磁石装置と、前記左右に相対向する超電導コイルの両端子の接続中点間毎に挿入された緊急消磁保護抵抗と、前記接続中点と左右それぞれの前記超電導コイルの端子との間毎に挿入された、ループ放電管と強制消磁保護抵抗との直列回路と、前記左右の終端位置の超電導コイルそれぞれの終端端子間の接続点と前記電源との間に前記緊急消磁保護抵抗群と並列に接続された、回路保護抵抗と回路保護放電管との直列回路から成り、前記回路保護抵抗は、前記緊急消磁保護抵抗群との並列合成抵抗値が基準値以下となる抵抗値を持ち、前記回路保護放電管は、基準設定電圧で放電開始する特性を持つことを特徴とするものである。
【００１４】
請求項３の発明の超電導磁石保護装置では、ループ放電管、強制消磁保護抵抗、緊急消磁保護抵抗が左右の相対向する超電導コイルに対して対称的に接続されているので、請求項２の発明の作用に加えて、左右の超電導コイルにおいて、片側の超電導コイルだけに強制消磁保護抵抗が挿入されている場合にはクエンチ発生時に起こり得る左右コイル間の発生電圧のアンバランスを防止することができ、左右両側の構成機器に電圧仕様が同一のものを採用することできるようになる。
さらに、請求項３の発明の超電導磁石保護装置では、電源に対して、緊急消磁保護抵抗群と並列に接続された、当該緊急消磁保護抵抗との並列合成抵抗値が基準値以下となる抵抗値の回路保護抵抗と、基準設定電圧で放電開始する回路保護放電管との直列回路を備えたことにより、請求項１の発明のように、超電導磁石装置の構成機器である超電導コイル及び電流リードの印加電圧を耐電圧の規定値以下に確実に制御でき、耐電圧設計ができると共に不確定要素のための裕度を設定しなくても済むようになる。
【００１６】
請求項４の発明は、請求項１〜３のいずれかに記載の超電導磁石保護装置において、さらに、その中点電位点をアース抵抗を介して接地したものであり、請求項１〜３の発明の作用に加えて、発生電圧を中点アースから両側に分割発生させることによって両端の電圧を１／２に固定でき、超電導コイル、電流リードの機器の耐電圧に余裕を確保することができ、また保護抵抗の設定値を上げることができて緊急消磁の異常左右力をより低減することができる。
【００１７】
【発明の実施の形態】
以下、本発明の実施の形態を図に基づいて詳説する。図１は本発明の第１の実施の形態の超電導磁石保護装置の回路構成を示している。この実施の形態の超電導磁石保護装置は、左右両側に配置された超電導コイル１と、永久電流スイッチ２と、左右両側の超電導コイル１の端子間毎に挿入されたループ放電管９と強制消磁保護抵抗８ｂとの直列回路と、各超電導コイル１の両端子間毎に並列に接続された緊急消磁保護抵抗８ａから構成されている。そして、この超電導磁石保護装置に対して、端位置の緊急消磁保護抵抗８ａの外側の端子Ｃｎと励消磁電源１０との間に緊急消磁保護抵抗８ａ群と並列に、回路保護抵抗８ｐと回路保護放電管９ｐとの直列回路で成る保護回路１１が接続されている。
【００１８】
この保護回路１１における回路保護抵抗８ｐは、緊急消磁保護抵抗８ａ群との並列回路の合成抵抗が基準値以下となるようにその抵抗値が選択されている。また、回路保護放電管９ｐは、基準設定電圧値で放電を開始する特性のものが選択されている。
【００１９】
ループ放電管９には、全ループ放電管９ａ、３／４ループ放電管９ｂ、１／２ループ放電管９ｃ、１／４ループ放電管９ｄが用いられていて、これらループ放電管９ａ〜９ｄは順次比例的に放電開始電圧が低いものである。
【００２０】
なお、これらのループ放電管９，９ａ，…等にはすべて、従来例でも説明したように、特許第２７０８６７８号の発明にかかる「超電導磁石保護回路用スイッチ」を採用している。そしてその動作の原理は、内部の電極をあらかじめ不活性ガス中に微小距離をおいて配置し、保護時には超電導磁石に蓄えられているエネルギーを利用し、保護の初期には両電極がアーク放電によって回路を構成し、その後はアーク放電中にアーク熱によって電極を溶解し両電極を溶着させることで回路を構成することにより、アーク放電による回路構成から両電極の溶着による回路構成に移行するというものである。
【００２１】
上記の実施の形態の超電導磁石保護装置では、緊急消磁保護抵抗８ａ、強制消磁保護抵抗８ｂ、ループ放電管９ａ〜９ｄで構成される保護装置に対し、これに並列に、回路保護抵抗８ｐと回路保護放電管９ｐとで成る保護回路１１を並列に設け、また回路保護抵抗８ｐの抵抗値を保護抵抗８ａ群との並列合成抵抗値が基準値以下となるように設定し、また回路保護放電管９ｐとして基準電圧値で放電開始するもの選択したので、基準電圧値よりも高い異常な高電圧が発生した時に回路保護放電管９ｐが最初に放電し、電圧分担により電圧を低く制御することが可能である。このため、基準値以上の電圧が発生するのを防止することができる。
【００２２】
次に、本発明の第２の実施の形態を図２に基づいて説明する。第２の実施の形態の超電導磁石保護装置は、左右に相対向する超電導コイル１の両端子の接続中点間毎に緊急消磁保護抵抗８ａを挿入し、また各接続中点と左右いずれか一方（ここでは上側を右、下側を左とすれば、左側）の超電導コイル１の端子との間毎に、ループ放電管９ｌと強制消磁保護抵抗８ｂとの直列回路を挿入し、また各接続中点と左右いずれか他方（ここでは右側）の超電導コイル１の端子との間毎にループ放電管９ｒを挿入した構成である。
【００２３】
ループ放電管９ｒ，９ｌには、全ループ放電管９ａｒ，９ａｌ、３／４ループ放電管９ｂｒ，９ｂｌ、１／２ループ放電管９ｃｒ，９ｃｌ、１／４ループ放電管９ｄｒ，９ｄｌが用いられ、これらのループ放電管９ａｒ〜９ｄｒ；９ａｌ〜９ｄｌは順次比例的に放電開始電圧が低いものである。
【００２４】
この第２の実施の形態の超電導磁石保護装置では、図１に示した第１の実施の形態の回路構成に対して、ループ放電管９ｒ，９ｌを左右の超電導コイル１各々に対して個別に接続した構成であるので、左右片側の超電導コイル１のみに生じる緊急消磁保護抵抗８ａへの励消磁時の電流分流を防止することができ、コイル電流を励消磁電源１０の電源電流まで持ち上げる定格電流の保持を不要とし、また分流が消滅するまでの時間の永久電流スイッチ２のヒータへの通電を不要とし、励消磁時の超電導磁石コイル１及び励消磁電源１０の操作性を良くすると共に、電流リードの熱容量増加、永久電流スイッチ２のヒータ発熱による励消磁ロスなどの熱負荷増分を低減する。
【００２５】
次に、本発明の第３の実施の形態を図３に基づいて説明する。第３の実施の形態の超電導磁石保護装置は、図２に示した第２の実施の形態の超電導磁石保護装置に対して、さらに左右両側の超電導コイル１の相対向する端子と接続中点との間毎に、左右対称にループ放電管９ｒと強制消磁保護抵抗８ｒとの直列回路、またループ放電管９ｌと強制消磁保護抵抗８ｌとの直列回路を挿入し、左右両側のこれらの直列回路の接続中点間毎に、緊急消磁保護抵抗８ａを接続した構成である。なお、ループ保護放電管９ｒ，９ｌには、第１、第２の実施の形態と同様に、全ループ放電管９ａｒ，９ａｌ、３／４ループ放電管９ｂｒ，９ｂｌ、１／２ループ放電管９ｃｒ，９ｃｌ、１／４ループ放電管９ｄｒ，９ｄｌが用いられている。
【００２６】
この第３の実施の形態の超電導磁石保護装置では、強制消磁保護抵抗とループ放電管とを一対とした直列回路を、左右の超電導コイル１それぞれに対して個別に挿入した構成であるので、図２に示した第２の実施の形態の保護装置と同様に、左右片側の超電導コイル１のみに生じる緊急消磁保護抵抗８ａへの励消磁時の電流分流を防止することができ、コイル電流を励消磁電源１０の電源電流まで持ち上げる定格電流の保持を不要とし、また分流が消滅するまでの時間の永久電流スイッチ２のヒータへの通電を不要とし、励消磁時の超電導磁石コイル１及び励消磁電源１０の操作性を良くすると共に、電流リードの熱容量増加、永久電流スイッチ２のヒータ発熱による励消磁ロスなどの熱負荷増分を低減する。
【００２７】
そして、これに加えて、回路構成が左右対称であることにより、図２に示した第２の実施の形態のように片側の超電導コイル１だけに強制消磁保護抵抗８ｂが挿入されていることに起因するクエンチ発生のコイル側の差違による発生電圧の違いが起きず、したがって、左右の機器に電圧仕様が同一のものを採用することができる。
【００２８】
次に、本発明の第４の実施の形態を図４に基づいて説明する。この第４の実施の形態の超電導磁石保護装置は、図１に示した第１の実施の形態の超電導磁石保護装置に対して、回路中点Ｃｔを数ｋオームのアース抵抗８ｒを介して接地したことを特徴とする。
【００２９】
このように超電導磁石保護装置の回路中点Ｃｔをアース抵抗８ｒを介してアース接地することにより、発生電圧を中点接地点Ｃｔから両側に分割発生させて、両端の発生電圧を２分の１に固定することができ、超電導コイル１、電流リードの機器の耐圧電圧の余裕度を確保することができ、さらに、保護抵抗８ｐの設定値を上げて電流減衰を速めることが可能となり、緊急消磁時の異常左右力のさらなる低減が図れる。
【００３０】
なお、本発明は上記の各実施の形態に限定されることはなく、次のような構成を採用することもできる。図２に示した第２の実施の形態、また図３に示した第３の実施の形態において、超電導コイル１群の外側の端部の端子Ｃｎと励消磁電源１０との間に、第１の実施の形態と同様に、回路保護抵抗８ｐと回路保護放電管９ｐとで成る保護回路１１を並列に接続することができる。これによって、第１の実施の形態と同様に、基準電圧値よりも高い異常な高電圧が発生した時に回路保護放電管９ｐが最初に放電し、電圧分担により電圧を低く制御することが可能である。
【００３１】
また、図１に示した第１の実施の形態、図２に示した第２の実施の形態、図３に示した第３の実施の形態それぞれにおいて、図４に示した第４の実施の形態と同様に、回路中点Ｃｔをアース抵抗８ｒを介して接地することができ、これによって、発生電圧を中点接地点Ｃｔから両側に分割発生させて、両端の発生電圧を２分の１に固定することができ、超電導コイル１、電流リードの機器の耐圧電圧の余裕度を確保することができる。
【００３２】
さらに、図２に示した第２の実施の形態、図３に示した第３の実施の形態において、図４に示した第４の実施の形態と同様に、保護回路１１と共に回路中点Ｃｔの接地を行うことができ、これによって、第４の実施の形態と同様の作用効果を奏する。
【００３３】
【発明の効果】
以上のように請求項１の発明によれば、電源に対して、右側又は左側の超電導コイル毎にその両端子間に並列に接続された緊急消磁保護抵抗群と並列に、当該緊急消磁保護抵抗との並列合成抵抗値が基準値以下となる抵抗値の回路保護抵抗と基準設定電圧で放電開始する回路保護放電管との直列回路を接続することにより、異常時の高電圧発生時にも電圧制御が可能な基準値よりも高い電圧を発生させることがなく、超電導磁石装置の構成機器である超電導コイル及び電流リードの印加電圧を耐電圧の規定値以下に確実に制御でき、耐電圧設計ができると共に不確定要素のための裕度を設定しなくても済む。
【００３４】
請求項２の発明によれば、左右の相対向する超電導コイルそれぞれの端子と両者間の接続中点との間毎にループ放電管が存在することにより、片側の超電導コイルのみに生じる保護抵抗の励消磁時の電流分流を防止することができ、電源による定格電流での保持やこの間の永久電流スイッチヒータの通電が不要となり、励消磁時の電源操作性が良くなり、また電流リードの熱容量の増加、永久電流スイッチヒータの発熱による励消磁ロスなどの熱負荷増分を低減することができ、その上に、請求項１の発明のように、超電導磁石装置の構成機器である超電導コイル及び電流リードの印加電圧を耐電圧の規定値以下に確実に制御でき、耐電圧設計ができると共に不確定要素のための裕度を設定しなくても済む。
【００３５】
請求項３の発明によれば、ループ放電管、強制消磁保護抵抗、緊急消磁保護抵抗が左右の相対向する超電導コイルに対して対称的に接続されているので、請求項２の発明のように、左右の相対向する超電導コイルそれぞれの端子と両者間の接続中点との間毎にループ放電管が存在することにより、片側の超電導コイルのみに生じる保護抵抗の励消磁時の電流分流を防止することができ、電源による定格電流での保持やこの間の永久電流スイッチヒータの通電が不要となり、励消磁時の電源操作性が良くなり、また電流リードの熱容量の増加、永久電流スイッチヒータの発熱による励消磁ロスなどの熱負荷増分を低減することができ、加えて、左右の超電導コイルにおいて、片側の超電導コイルだけに強制消磁保護抵抗が挿入されている場合にはクエンチ発生時に起こり得る左右コイル間の発生電圧のアンバランスを防止することができ、左右両側の構成機器に電圧仕様が同一のものを採用することできる。その上に、請求項３の発明によれば、請求項１の発明のように、超電導磁石装置の構成機器である超電導コイル及び電流リードの印加電圧を耐電圧の規定値以下に確実に制御でき、耐電圧設計ができると共に不確定要素のための裕度を設定しなくても済む。
【００３７】
請求項４の発明によれば、当該保護装置の中点電位点をアース抵抗を介して接地したので、請求項１〜３それぞれの発明の効果に加えて、発生電圧を中点アースから両側に分割発生させることによって両端の電圧を１／２に固定でき、超電導コイル、電流リードの機器の耐電圧に余裕を確保することができ、また保護抵抗の設定値を上げることができて緊急消磁時の異常左右力をより低減することができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態の回路図。
【図２】本発明の第２の実施の形態の回路図。
【図３】本発明の第３の実施の形態の回路図。
【図４】本発明の第４の実施の形態の回路図。
【図５】一般的な磁気浮上列車の構造を示す断面図。
【図６】従来例の回路図。
【図７】他の従来例の回路図。
【図８】さらに他の従来例の回路図。
【符号の説明】
１超電導コイル
２永久電流スイッチ
６超電導磁石装置
８ａ，８ａｒ，８ａｌ緊急消磁保護抵抗
８ｂ，８ｂｒ，８ｂｌ強制消磁保護抵抗
８ｐ回路保護抵抗
８ｒアース抵抗
９ループ放電管
９ａ，９ａｒ，９ａｌ全ループ放電管
９ｂ，９ｂｒ，９ｂｌ３／４ループ放電管
９ｃ，９ｃｒ，９ｃｌ１／２ループ放電管
９ｄ，９ｄｒ，９ｄｌ１／４ループ放電管
９ｐ回路保護放電管
１０励消磁電源
１１保護回路[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a superconducting magnet protection device for a superconducting magnet device using a superconducting coil mounted on a magnetic levitation train using a magnetic field.
[0002]
[Prior art]
A schematic structure of a magnetic levitation train vehicle using a magnetic field is as shown in FIG. The superconducting magnet device 6 containing the superconducting coil 1 and the permanent current switch is mounted on both the left and right sides under the floor of the vehicle 3 and faces the propulsion coil 4 and the levitation guide coil 5 provided on the left and right sides on the ground side. The vehicle 3 of the magnetic levitation train having such a structure is propelled by the electromagnetic force of the superconducting magnet device 6 and the propulsion coil 4, and a levitation force is generated by the induced current of the superconducting magnet device 6 and the levitation guide coil 5 associated therewith. At the same time, the guide force acts so as to always be in the center position with respect to the left and right displacement.
[0003]
The superconducting magnet device 6 of such a magnetic levitation train employs a circuit configuration as shown in FIGS. 6 to 8 as a protection device against quenching of the superconducting coil 1. The superconducting magnet protection device shown in FIG. 6 has a series circuit of a diode 7 and a protective resistor 8 connected in parallel to each of the superconducting coils 1 on both the left and right sides. The protective device shown in FIG. 7 is a circuit that forcibly demagnetizes only the superconducting coil 1 at both ends of the side closer to and far from the excitation demagnetizing power source 10 using the discharge tube 9 having the configuration described in Japanese Patent No. 2708678. The superconducting coil 1 at the center is the same as the circuit configuration shown in FIG. 6. The superconducting magnet protection circuit shown in FIG. 8 forcibly demagnetizes all the superconducting coils 1 of the superconducting magnet device 6 with a circuit that performs emergency demagnetization using loop discharge tubes 9a, 9b, 9c, and 9d having different discharge starting voltages. The circuit configuration also serves as a circuit. Here, for the loop discharge tubes 9, 9a, 9b,..., Etc., the “switch for superconducting magnet protection circuit” of the invention of Japanese Patent No. 2708678 is used.
[0004]
In such a conventional superconducting magnet protection device, when one of the superconducting coils 1 is quenched, the heater of the permanent current switch 2 of the opposite superconducting coil 1 is turned on for emergency demagnetization. In addition, even when there is no excitation demagnetizing power source 10, the protective resistance value is selected so that forced demagnetization can be performed by turning on the heater of the permanent current switch 2 without quenching the superconducting coil 1.
[0005]
[Problems to be solved by the invention]
However, the superconducting magnet protection device having any of the above-described configurations has the following problems. In the superconducting magnet protection device shown in FIG. 6, since the protective resistance value is set so as not to cause quenching due to forced demagnetization, the current of the superconducting coil 1 on the opposite side is compared with the rapid current decay of the superconducting coil 1 quenched during emergency demagnetization. Attenuation was slow, and there was a problem that the abnormal left-right force could not be reduced during emergency demagnetization due to quenching of the opposing superconducting coil.
[0006]
Further, in the superconducting magnet protection device shown in FIG. 7, when simultaneous quenching of the four coils of the superconducting coil 1 is assumed, the current decay of the opposing coil with respect to the quenched central coil is slow due to the circuit configuration of the central coil. There was a problem that the effect of reducing the abnormal left-right force during emergency demagnetization due to quenching of the side coil could not be fully expected.
[0007]
Further, in the superconducting magnet protection device shown in FIG. 8, when the simultaneous quenching of the four coils of the superconducting coil 1 is assumed, it is possible to reduce the abnormal left-right force at the time of emergency demagnetization by quenching the opposing coil, but the resistance value Depending on the selection and inductance of the superconducting coil, coil resistance at the time of transition to normal conduction, etc., there is a problem that the generated voltage may exceed the allowable withstand voltage of the device. In addition, there is a problem that current shunting to the protective resistor occurs in the superconducting coil on one side with protective resistance during excitation and demagnetization, and the rated current holding time is required until the coil current reaches the rated current, resulting in poor operability. . Furthermore, there is a problem that the heat penetration amount and the heat load increase with an increase in the heat capacity of the current leads and an increase in the excitation and demagnetization loss.
[0008]
The present invention has been made in view of such conventional problems, and an object thereof is to provide a superconducting magnet protection device that can the occurrence of high voltage prevention.
[0009]
[Means for Solving the Problems]
In the superconducting magnet protection device according to the first aspect of the present invention , the same number of superconducting coils are connected in series on the left and right so as to face each other on the left and right, and the superconductivity at the start position of the superconducting coils connected in series on each of the left and right A superconducting magnet device in which a power source is connected between the start terminals of each of the coils, and the terminal terminals of the superconducting coils at the terminal positions of the superconducting coils connected in series in each of the left and right are short-circuited; A series circuit of a loop discharge tube and a forced demagnetization protection resistor inserted between the terminals of each opposing superconducting coil, and an emergency demagnetization connected between both terminals of the right or left superconducting coil. a protective resistor, and the emergency demagnetizing protective resistor group between the connection point between the superconducting coils each end terminal end positions of the left and right and the power supply parallel Connected to, consists of a series circuit of the circuit protection discharge tube to start discharging the circuit protection resistor and the reference setting voltage, the circuit protection resistor, the following reference value parallel combined resistance value of the emergency demagnetizing protective resistor group is to shall and characterized in that the resistance becomes.
[0010]
In the superconducting magnet protection device according to the first aspect of the present invention, the emergency demagnetization protection resistor is connected to the power supply in parallel with the emergency demagnetization protection resistance group connected between both terminals for each of the right and left superconducting coils. By connecting a series circuit of a circuit protection resistor whose resistance value is equal to or less than the reference value and a circuit protection discharge tube that starts discharging at the reference set voltage, voltage control is possible even when a high voltage is generated in the event of an abnormality. Do not generate a voltage higher than the normal reference value. As a result, it is possible to reliably control the applied voltage of the superconducting coil and the current lead, which are the components of the superconducting magnet device, to the specified value or less of the withstand voltage, and withstand voltage design can be performed, and the margin for uncertain elements is not set You can do it.
[0011]
In the superconducting magnet protection device according to the second aspect of the present invention , the same number of superconducting coils are connected in series on the left and right so as to oppose each other on the left and right, and the superconductivity at the start position of the superconducting coils connected in series on each of the left and right A superconducting magnet device in which a power source is connected between the start terminals of each of the coils, and the terminal terminals of the superconducting coils at the terminal positions of the superconducting coils connected in series in each of the left and right are short-circuited; Loop discharge inserted between each of the terminals of the superconducting coil facing each other and the emergency demagnetization protection resistor inserted between the terminals of the superconducting coils facing each other and the terminal of the superconducting coil on either the left or right side. A loop discharge tube inserted between a series circuit of a tube and a forced demagnetization protection resistor and between the connection midpoint and the terminal of the left or right superconducting coil The connected in parallel to the emergency demagnetizing protective resistor group between the right and left and the connection point between the superconducting coils each end terminal end position and the power supply, a series circuit of the circuit protection resistor and the circuit protection discharge tube The circuit protection resistor has a resistance value in which a parallel combined resistance value with the emergency demagnetization protection resistance group is a reference value or less, and the circuit protection discharge tube has a characteristic of starting discharge at a reference set voltage. is to shall and features.
[0012]
In the superconducting magnet protection device according to the second aspect of the present invention, a loop discharge tube exists between each terminal of the left and right superconducting coils opposed to each other and a connection midpoint between them, so that the superconducting magnet protection device is generated only in one superconducting coil. Current shunting at the time of excitation and demagnetization of the protective resistor can be prevented, and it is not necessary to maintain the rated current by the power source and to energize the permanent current switch heater during this time, improving the operability of the power source at the time of excitation and demagnetization. Increment of heat load such as an increase in the heat capacity and loss of excitation and demagnetization due to heat generated by the permanent current switch heater can be reduced.
Furthermore, in the superconducting magnet protection device according to the second aspect of the present invention, a resistance value in which the parallel combined resistance value with the emergency demagnetization protection resistor connected in parallel with the emergency demagnetization protection resistance group is equal to or less than a reference value with respect to the power source. By providing the series circuit of the circuit protection resistor and the circuit protection discharge tube that starts discharging at the reference set voltage, the superconducting coil and the current lead of the superconducting magnet device as in the invention of claim 1 are provided. The applied voltage can be reliably controlled to be equal to or less than the specified value of the withstand voltage, the withstand voltage can be designed, and a margin for an uncertain element need not be set.
[0013]
In the superconducting magnet protection device according to the third aspect of the present invention , the same number of superconducting coils are connected in series on the left and right so as to face each other on the left and right, and the superconductivity at the starting end position of the superconducting coils connected in series on each of the left and right A superconducting magnet device in which a power source is connected between the start terminals of each of the coils, and the terminal terminals of the superconducting coils at the terminal positions of the superconducting coils connected in series in each of the left and right are short-circuited; An emergency demagnetization protection resistor inserted between the connection midpoints of both terminals of the opposing superconducting coils, and a loop discharge tube inserted between the connection midpoint and the terminals of the left and right superconducting coils, the emergency demagnetizing between a series circuit of a forced demagnetization protection resistor, a connection point between the superconducting coils each end terminal end positions of the left and right and the power supply A series circuit of a circuit protection resistor and a circuit protection discharge tube connected in parallel with the protection resistor group, and the circuit protection resistance is a resistance whose parallel combined resistance value with the emergency demagnetization protection resistance group is a reference value or less has a value, the circuit protection discharge tube is to shall and characterized by having the ability of discharge start in the reference setting voltage.
[0014]
In the superconducting magnet protection device according to the third aspect of the invention, the loop discharge tube, the forced demagnetization protection resistance, and the emergency demagnetization protection resistance are symmetrically connected to the left and right opposing superconducting coils. In addition to the above action, in the left and right superconducting coils, when a forced demagnetization protection resistor is inserted only in one superconducting coil, it is possible to prevent the voltage imbalance between the left and right coils that may occur when a quench occurs. The same voltage specifications can be adopted for the left and right components.
Furthermore, in the superconducting magnet protection device according to the third aspect of the present invention, a resistance value in which a parallel combined resistance value with the emergency demagnetization protection resistor connected in parallel with the emergency demagnetization protection resistance group is equal to or less than a reference value with respect to the power source. By providing the series circuit of the circuit protection resistor and the circuit protection discharge tube that starts discharging at the reference set voltage, the superconducting coil and the current lead of the superconducting magnet device as in the invention of claim 1 are provided. The applied voltage can be reliably controlled to be equal to or less than the specified value of the withstand voltage, the withstand voltage can be designed, and a margin for an uncertain element need not be set.
[0016]
A fourth aspect of the present invention, the superconducting magnet protection device according to any one of claims 1 to 3, more is obtained by grounded through a ground resistor and the midpoint potential point, the invention of claim 1-3 In addition to the above action, by dividing the generated voltage from the midpoint ground to both sides, the voltage at both ends can be fixed to 1/2, and a margin can be secured for the withstand voltage of the superconducting coil and current lead device, Further, the set value of the protective resistance can be increased, and the abnormal left / right force of emergency demagnetization can be further reduced.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a circuit configuration of a superconducting magnet protection device according to a first embodiment of the present invention. The superconducting magnet protection device according to this embodiment includes a superconducting coil 1 disposed on both the left and right sides, a permanent current switch 2, a loop discharge tube 9 inserted between terminals of the left and right superconducting coils 1 and forced demagnetization protection. It is composed of a series circuit with a resistor 8b and an emergency demagnetization protection resistor 8a connected in parallel between both terminals of each superconducting coil 1. Then, with respect to this superconducting magnet protection device, the circuit protection resistor 8p and the circuit protection are provided in parallel with the emergency demagnetization protection resistor 8a group between the terminal Cn outside the emergency demagnetization protection resistor 8a at the end position and the excitation demagnetization power source 10. A protection circuit 11 comprising a series circuit with the discharge tube 9p is connected.
[0018]
The resistance value of the circuit protection resistor 8p in the protection circuit 11 is selected such that the combined resistance of the parallel circuit with the emergency demagnetization protection resistor 8a group is equal to or less than a reference value. The circuit protection discharge tube 9p is selected to have a characteristic of starting discharge at the reference set voltage value.
[0019]
As the loop discharge tube 9, an all-loop discharge tube 9a, a 3/4 loop discharge tube 9b, a 1/2 loop discharge tube 9c, and a 1/4 loop discharge tube 9d are used, and these loop discharge tubes 9a to 9d are The discharge start voltage is gradually lower in proportion.
[0020]
Note that all of these loop discharge tubes 9, 9a,... Employ the “superconducting magnet protection circuit switch” according to the invention of Japanese Patent No. 2708678 as described in the prior art. The principle of the operation is that the internal electrodes are arranged in advance in a small distance in an inert gas, and the energy stored in the superconducting magnet is used during protection. The circuit is constructed, and then the circuit is constructed by melting the electrodes by arc heat during arc discharge and welding both electrodes, thereby shifting from the circuit configuration by arc discharge to the circuit configuration by welding of both electrodes. It is.
[0021]
In the superconducting magnet protection device of the above embodiment, the circuit protection resistor 8p and the circuit are connected in parallel to the protection device constituted by the emergency demagnetization protection resistor 8a, the forced demagnetization protection resistor 8b, and the loop discharge tubes 9a to 9d. A protection circuit 11 including a protection discharge tube 9p is provided in parallel, and the resistance value of the circuit protection resistor 8p is set so that the parallel combined resistance value with the protection resistor 8a group is equal to or less than a reference value. Since 9p is selected to start discharge at the reference voltage value, when an abnormal high voltage higher than the reference voltage value is generated, the circuit protection discharge tube 9p is discharged first, and the voltage can be controlled to be low by voltage sharing. It is. For this reason, it is possible to prevent a voltage exceeding the reference value from being generated.
[0022]
Next, a second embodiment of the present invention will be described with reference to FIG. In the superconducting magnet protection device according to the second embodiment, an emergency demagnetization protection resistor 8a is inserted between the connection midpoints of both terminals of the superconducting coil 1 facing each other on the left and right sides, and each connection midpoint and either the left or right side are connected. A series circuit of a loop discharge tube 9l and a forced demagnetization protection resistor 8b is inserted between the terminals of the superconducting coil 1 (the left side if the upper side is right and the lower side is left). The loop discharge tube 9r is inserted between the middle point and the terminal of the superconducting coil 1 on either the left or right side (right side here).
[0023]
For the loop discharge tubes 9r and 9l, all-loop discharge tubes 9ar and 9al, 3/4 loop discharge tubes 9br and 9bl, 1/2 loop discharge tubes 9cr and 9cl, and 1/4 loop discharge tubes 9dr and 9dl are used. These loop discharge tubes 9ar to 9dr; 9al to 9dl have discharge start voltages that are proportionally lower in order.
[0024]
In the superconducting magnet protection device of the second embodiment, the loop discharge tubes 9r and 9l are individually provided for the left and right superconducting coils 1 with respect to the circuit configuration of the first embodiment shown in FIG. Because of the connected configuration, it is possible to prevent current shunting at the time of excitation demagnetization to the emergency demagnetization protection resistor 8a that occurs only in the superconducting coil 1 on the left and right sides, and the rated current that raises the coil current to the power supply current of the excitation demagnetization power source Is not necessary, and it is not necessary to energize the heater of the permanent current switch 2 for the time until the shunting disappears, improving the operability of the superconducting magnet coil 1 and the excitation demagnetizing power source 10 during excitation and demagnetization, and the current. The thermal load increments such as increase in the heat capacity of the leads and loss of excitation and demagnetization due to the heat generated by the heater of the permanent current switch 2 are reduced.
[0025]
Next, a third embodiment of the present invention will be described with reference to FIG. The superconducting magnet protection device according to the third embodiment is further compared with the superconducting magnet protection device according to the second embodiment shown in FIG. Between the left and right sides, a series circuit of the loop discharge tube 9r and the forced demagnetization protection resistor 8r and a series circuit of the loop discharge tube 9l and the forced demagnetization protection resistor 8l are inserted symmetrically. In this configuration, an emergency demagnetization protection resistor 8a is connected between connection midpoints. The loop protection discharge tubes 9r, 9l include all loop discharge tubes 9ar, 9al, 3/4 loop discharge tubes 9br, 9bl, 1/2 loop discharge tube 9cr, as in the first and second embodiments. 9cl and 1/4 loop discharge tubes 9dr and 9dl are used.
[0026]
In the superconducting magnet protection device according to the third embodiment, a series circuit in which a forced demagnetization protection resistor and a loop discharge tube are paired is inserted into each of the left and right superconducting coils 1 individually. Similarly to the protection device of the second embodiment shown in FIG. 2, it is possible to prevent current shunting at the time of excitation / demagnetization to the emergency demagnetization protection resistor 8a that occurs only in the superconducting coil 1 on the left and right sides, thereby exciting the coil current. It is not necessary to maintain the rated current that is raised to the power supply current of the demagnetizing power source 10, and it is not necessary to energize the heater of the permanent current switch 2 until the shunt current disappears, and the superconducting magnet coil 1 and the excited demagnetizing power source during excitation demagnetization are eliminated. 10 is improved, and the thermal load increment such as the increase in the heat capacity of the current lead and the loss of excitation and demagnetization due to the heat generation of the heater of the permanent current switch 2 is reduced.
[0027]
In addition to this, since the circuit configuration is symmetrical, the forced demagnetization protection resistor 8b is inserted only in the superconducting coil 1 on one side as in the second embodiment shown in FIG. The difference in the generated voltage due to the difference in the coil occurrence due to quenching does not occur, and therefore, the right and left devices having the same voltage specifications can be adopted.
[0028]
Next, a fourth embodiment of the present invention will be described with reference to FIG. The superconducting magnet protection device according to the fourth embodiment is connected to the circuit middle point Ct via a ground resistance 8r of several k ohms with respect to the superconducting magnet protection device according to the first embodiment shown in FIG. It is characterized by that.
[0029]
In this way, the circuit midpoint Ct of the superconducting magnet protection device is grounded via the grounding resistor 8r, so that the generated voltage is divided and generated on both sides from the midpoint grounding point Ct, and the generated voltage at both ends is reduced by half. It is possible to secure the margin of the withstand voltage of the superconducting coil 1 and the current lead device, and it is possible to increase the set value of the protective resistance 8p to speed up the current attenuation, and thus emergency demagnetization. It is possible to further reduce the abnormal lateral force at the time.
[0030]
The present invention is not limited to the above-described embodiments, and the following configuration can also be adopted. In the second embodiment shown in FIG. 2 and the third embodiment shown in FIG. 3, the first terminal Cn between the outer ends of the superconducting coils 1 group and the excitation demagnetizing power source 10 are As in the embodiment, the protection circuit 11 including the circuit protection resistor 8p and the circuit protection discharge tube 9p can be connected in parallel. Thus, as in the first embodiment, when an abnormal high voltage higher than the reference voltage value is generated, the circuit protection discharge tube 9p is discharged first, and the voltage can be controlled to be low by voltage sharing. is there.
[0031]
Further, in each of the first embodiment shown in FIG. 1, the second embodiment shown in FIG. 2, and the third embodiment shown in FIG. 3, the fourth embodiment shown in FIG. Similarly to the embodiment, the circuit middle point Ct can be grounded via the grounding resistor 8r, whereby the generated voltage is divided and generated on both sides from the middle point ground point Ct, and the generated voltage at both ends is reduced by half. It is possible to secure the margin of withstand voltage of the superconducting coil 1 and the current lead device.
[0032]
Further, in the second embodiment shown in FIG. 2 and the third embodiment shown in FIG. 3, the circuit midpoint Ct together with the protection circuit 11 is provided in the same manner as the fourth embodiment shown in FIG. Thus, the same effects as those of the fourth embodiment can be obtained.
[0033]
【The invention's effect】
As described above, according to the first aspect of the present invention, the emergency demagnetization protection resistor is connected in parallel to the emergency demagnetization protection resistance group connected in parallel between both terminals of the right or left superconducting coil with respect to the power source. By connecting a series circuit of a circuit protection resistor whose resistance value is equal to or less than the reference value and a circuit protection discharge tube that starts discharging at the reference set voltage, voltage control is possible even when a high voltage is generated in the event of an abnormality. The voltage applied to the superconducting coil and the current lead, which are the components of the superconducting magnet device, can be reliably controlled below the specified value of the withstand voltage, and the withstand voltage can be designed. At the same time, it is not necessary to set a margin for uncertainties.
[0034]
According to the invention of claim 2, since there is a loop discharge tube between each of the terminals of the left and right superconducting coils opposed to each other and the connection midpoint between them, the protective resistance generated only in the superconducting coil on one side is reduced. Current shunting at the time of excitation demagnetization can be prevented, and it is not necessary to maintain the rated current by the power source and to energize the permanent current switch heater during this time, improving the operability of the power source at the time of excitation demagnetization, and the heat capacity of the current lead It is possible to reduce the increase in thermal load, such as an increase or a loss of excitation and demagnetization due to the heat generated by the permanent current switch heater. Furthermore , as in the invention of claim 1, a superconducting coil and a current lead that are components of the superconducting magnet device The applied voltage can be reliably controlled to be equal to or less than the specified value of the withstand voltage, the withstand voltage can be designed, and the tolerance for the uncertain element need not be set.
[0035]
According to the invention of claim 3, loop discharge tube, forced demagnetization protection resistor, since emergency demagnetization protection resistor are symmetrically connected to the left and right opposing superconducting coil, as in the invention of claim 2 In addition, the existence of a loop discharge tube between each terminal of the left and right superconducting coils and the midpoint of connection between them prevents current shunting when the protective resistance is excited and demagnetized only in one superconducting coil. This eliminates the need to maintain the rated current from the power source and energize the permanent current switch heater during this time, improve the operability of the power supply during excitation and demagnetization, increase the heat capacity of the current leads, and generate heat from the permanent current switch heater. by it is possible to reduce the heat load increment, such as magnetization and demagnetization loss, in addition, in the right and left of the superconducting coil, if only the forced demagnetization protection resistor one side of the superconducting coil is inserted It is possible to prevent unbalance of the voltage generated between the left and right coils that can occur when the quench occurs, the voltage specification construction equipment on the left and right sides can be adopted the same. In addition, according to the invention of claim 3, as in the invention of claim 1, the applied voltage of the superconducting coil and the current lead, which are components of the superconducting magnet device, can be reliably controlled to be equal to or less than the specified value of the withstand voltage. In addition, it is possible to design a withstand voltage and not to set a margin for an uncertain factor.
[0037]
According to the invention of claim 4 , since the midpoint potential point of the protection device is grounded via the ground resistor, in addition to the effects of the inventions of claims 1 to 3 , the generated voltage is transferred from the midpoint ground to both sides. By dividing it, the voltage at both ends can be fixed to ½, a margin can be secured for the withstand voltage of the superconducting coil and current lead device, and the set value of the protective resistance can be increased, so that emergency demagnetization The abnormal left / right force can be further reduced.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a first embodiment of the present invention.
FIG. 2 is a circuit diagram of a second embodiment of the present invention.
FIG. 3 is a circuit diagram of a third embodiment of the present invention.
FIG. 4 is a circuit diagram of a fourth embodiment of the present invention.
FIG. 5 is a cross-sectional view showing the structure of a general magnetic levitation train.
FIG. 6 is a circuit diagram of a conventional example.
FIG. 7 is a circuit diagram of another conventional example.
FIG. 8 is a circuit diagram of still another conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Superconducting coil 2 Permanent current switch 6 Superconducting magnet apparatus 8a, 8ar, 8al Emergency demagnetization protection resistance 8b, 8br, 8bl Forced demagnetization protection resistance 8p Circuit protection resistance 8r Earth resistance 9 Loop discharge tube 9a, 9ar, 9al All loop discharge tube 9b , 9br, 9bl 3/4 loop discharge tube 9c, 9cr, 9cl 1/2 loop discharge tube 9d, 9dr, 9dl 1/4 loop discharge tube 9p circuit protection discharge tube 10 excitation demagnetizing power source 11 protection circuit

Claims

The same number of superconducting coils are connected in series on the left and right so as to oppose each other on the left and right, and a power source is connected between the starting end terminals of each of the superconducting coils at the starting end position of the superconducting coils connected in series on the left and right, A superconducting magnet device in which the terminal terminals of the superconducting coils at the terminal positions of the superconducting coils connected in series in each of the left and right are short-circuited;
A series circuit of a loop discharge tube and a forced demagnetization protection resistor inserted between the terminals of each of the superconducting coils opposed to the left and right ,
An emergency demagnetization protection resistor connected between each of the terminals for each of the right or left superconducting coils;
Series times of the connected in parallel to the emergency demagnetization protection resistor group, circuitry protection resistors and circuitry protection discharge tube between the power source and the connection point between the superconducting coils each end terminal end position of the right and left road or RaNaru is,
The circuit protection resistor has a resistance value at which a parallel combined resistance value with the emergency demagnetization protection resistor group is a reference value or less,
The circuit protection discharge tube, a superconducting magnet protector you characterized by having the ability of discharge start in the reference setting voltage.

The same number of superconducting coils are connected in series on the left and right so as to oppose each other on the left and right, and a power source is connected between the starting end terminals of each of the superconducting coils at the starting end position of the superconducting coils connected in series on the left and right, A superconducting magnet device in which the terminal terminals of the superconducting coils at the terminal positions of the superconducting coils connected in series in each of the left and right are short-circuited;
Emergency demagnetization protection resistance inserted between the connection midpoints of both terminals of the superconducting coil opposite to the left and right ,
A series circuit of a loop discharge tube and a forced demagnetization protection resistor inserted between the connection midpoint and the terminal of either the left or right superconducting coil,
A loop discharge tube inserted between the midpoint of connection and the terminal of the left or right superconducting coil ;
A series circuit of a circuit protection resistor and a circuit protection discharge tube connected in parallel with the emergency demagnetization protection resistor group between a connection point between the terminal terminals of the superconducting coils at the left and right end positions and the power source. ,
The circuit protection resistor has a resistance value at which a parallel combined resistance value with the emergency demagnetization protection resistor group is a reference value or less,
The circuit protection discharge tube, a superconducting magnet protector you characterized by having the ability of discharge start in the reference setting voltage.

The same number of superconducting coils are connected in series on the left and right so as to oppose each other on the left and right, and a power source is connected between the starting end terminals of each of the superconducting coils at the starting end position of the superconducting coils connected in series on the left and right, A superconducting magnet device in which the terminal terminals of the superconducting coils at the terminal positions of the superconducting coils connected in series in each of the left and right are short-circuited;
Emergency demagnetization protection resistance inserted between the connection midpoints of both terminals of the superconducting coil opposite to the left and right ,
A series circuit of a loop discharge tube and a forced demagnetization protection resistor inserted between the connection midpoint and the terminals of the superconducting coils on the left and right sides ,
A series circuit of a circuit protection resistor and a circuit protection discharge tube connected in parallel with the emergency demagnetization protection resistor group between a connection point between the terminal terminals of the superconducting coils at the left and right end positions and the power source. ,
The circuit protection resistor has a resistance value at which a parallel combined resistance value with the emergency demagnetization protection resistor group is a reference value or less,
The circuit protection discharge tube, a superconducting magnet protector you characterized by having the ability of discharge start in the reference setting voltage.

The superconducting magnet protection device according to any one of claims 1 to 3 , wherein the midpoint potential point is grounded via an earth resistance.