JP3562674B2

JP3562674B2 - Transformer protection relay

Info

Publication number: JP3562674B2
Application number: JP02333496A
Authority: JP
Inventors: 知敬西田; 力生佐藤
Original assignee: ティーエム・ティーアンドディー株式会社
Priority date: 1996-01-17
Filing date: 1996-01-17
Publication date: 2004-09-08
Anticipated expiration: 2016-01-17
Also published as: JPH09200950A

Description

【０００１】
【発明の属する技術分野】
本発明は点検回路を有する変圧器保護継電装置に関する。
【０００２】
【従来の技術】
変圧器保護継電装置は、近年は一般にディジタル形保護継電装置が適用され、主検出継電器ユニットと事故検出継電器ユニットにより構成されている。常時は主検出継電器動作かつ事故検出継電器動作のＡＮＤ条件により遮断器引き外し指令を出力する。また、点検は一方のユニットを点検しその点検終了後残りのユニットの点検を実施する構成としている。
【０００３】
このとき、点検中のユニットは点検入力が印加されており、点検中に事故が発生した場合に動作できない可能性がある。しかしながら、点検中に変圧器内部で事故が発生した場合、点検中止してから遮断器引き外しを実施していたのでは、事故除去が遅れ、変圧器タンクの防爆曲線と協調がとれずにタンク破壊ひいては火災に至る可能性がある。このため、点検中は非点検中の継電器ユニット収納の継電器動作単独条件で遮断器引き外し指令を出力している。この方式の例を図４を用いて具体的に説明する。
【０００４】
図４において、１次母線及び２次母線間に遮断器２を介在させて存在する変圧器１の各端子の電流が、変流器３及び入力変換器５を介して、変圧器保護継電装置の主検出継電器ユニットならびに事故検出継電器ユニットに導入される。主検出継電器ユニット及び事故検出継電器ユニットには各端子電流を用いて差動演算を行う主検出差動継電器６、事故検出差動継電器９がそれぞれ収納されている。
【０００５】
主検出継電器ユニットあるいは事故検出継電器ユニットの点検中は、点検信号がそれぞれＯＲ回路１９を介して補助リレー（ＴＸＭ）１３Ａあるいは補助リレー（ＴＸＦ）１３Ｄに入力されて動作状態に保持する。補助リレー１３Ａ及び補助リレー１３Ｄはそれぞれ常開接点を有する。
【０００６】
主検出継電器ユニットの点検中は強制的に主検出継電器ユニットの補助リレー（ＴＸＭ）１３Ａを動作させ、その開接点を閉にし、事故検出継電器ユニットの事故検出差動継電器９が動作するとの単独条件で遮断器引き外し指令を出力する。また、逆に事故検出ユニットの点検中は強制的に事故検出継電器ユニットの補助リレー（ＴＸＦ）１３Ｄを動作させ、その開接点を閉にし、主検出継電器ユニットの差動継電器６が動作するとの単独条件で遮断器引き外し指令を出力する。
【０００７】
ところで、差動継電器を用いた変圧器保護継電装置においては変圧器励磁突入電流による誤動作防止対策が必要となるが、一般的には差動電流中の第２高調波含有率が一定値以上であることを検出すると励磁突入電流と判断し、主検出差動継電器６及び事故検出差動継電器９の出力をロックするかまたは抑制量を強める処理が採用されている。
【０００８】
変圧器励磁突入電流による誤動作防止対策として、図４の例では、主検出継電器ユニット及び事故検出継電器ユニットに第２高調波含有検出要素７、ＮＯＴ回路１０をそれぞれ設け、変圧器励磁突入電流が存在する場合は入力変換器５の出力中の第２高調波の含有率が一定値以上であることを該第２高調波含有検出要素７で検出し、その出力をＮＯＴ回路１０を介して主検出差動継電器６及び事故検出差動継電器９の出力と共にＡＮＤ回路１１で条件をとるが、ＡＮＤ条件が成立しないので励磁突入電流と判断し、主検出差動継電器６あるいは事故検出差動継電器９の出力をロックして補助リレー１３Ａあるいは１３Ｄを動作させることはない。したがって、遮断器引き外し指令は出力されない。
【０００９】
変圧器励磁突入電流が存在しない場合であって、入力変換器５の出力中の第２高調波の含有率が一定値以下であれば、ＡＮＤ回路１１の一方の条件が成立し、他方の条件である主検出差動継電器６あるいは事故検出差動継電器９の出力が存在すると補助リレー１３Ａあるいは１３Ｄを動作させる。したがって、遮断器引き外し指令が出力される。
【００１０】
【発明が解決しようする課題】
前述のごとく点検中に非点検中のユニットの差動継電器動作単独条件で遮断出力を出す構成の場合は、主検出継電器及び事故検出継電器の両方に励磁突入電流対策を実装する必要が生じる。このため、事故検出継電器の構成も励磁突入電流対策の処理負担が大きくなり、結果的にアナログ入力部とリレー演算部とシーケンス処理部を１ないし２枚の基板に収納することができずに、アナログ入力部とリレー演算部とシーケンス処理部をそれぞれ独立の基板構成とした主検出継電器ユニットと同等のハード構成を採用せざるを得なくなっている。この点が変圧器保護継電装置の縮小化、保守性の向上を阻害している。
【００１１】
そこで、本発明の目的は、前記問題点に鑑み、事故検出継電器に第２高調波含有率判定などの複雑な機能を持たせることなく簡易な事故検出継電器構成であって、かつ点検中に事故検出継電器動作単独条件による遮断器引き外し出力を行う回路となっても励磁突入電流で誤動作せずかつ本来の保護機能を損なわない変圧器保護継電装置を提供することにある。
【００１２】
【課題を解決するための手段】
本発明は前記の目的を達成するため、本発明の請求項１に係る変圧器保護継電装置は、点検機能を有し、事故検出継電器に変圧器各端子電流によって差動保護を構成する差動継電器を用い、主検出継電器に変圧器各端子電流によって差動保護を構成する差動継電器を用いた変圧器保護継電装置において、変圧器３次母線電圧の低下を検出する不足電圧継電器を有し、前記事故検出継電器不動作かつ前記不足電圧継電器動作により信号を出力する信号回路と前記信号の出力の復帰を一定時間遅延させる回路を具備し、前記主検出継電器が点検中であることかつ前記遅延回路の信号出力がないことを条件に、前記事故検出継電器動作により遮断器引き外し指令を出力する回路とから構成した。
【００１３】
本発明の請求項２に係る変圧器保護継電装置は、点検機能を有し、事故検出継電器に励磁巻線電流とタップ巻線電流を使用した電流平衡継電器を用い、主検出継電器に励磁巻線電流とタップ巻線電流を使用した電流平衡継電器を用いた変圧器保護継電装置において、変圧器３次母線電圧の低下を検出する不足電圧継電器を有し、前記事故検出継電器不動作かつ前記不足電圧継電器動作により信号を出力する信号回路と前記信号の出力の復帰を一定時間遅延させる回路を具備し、前記主検出継電器が点検中であることかつ前記遅延回路の信号出力がないことを条件に、前記事故検出継電器動作により遮断器引き外し指令を出力する回路とから構成した。
【００１４】
本発明の請求項３に係る変圧器保護継電装置は、点検機能を有し、事故検出継電器に変圧器各端子電流によって差動保護を構成する差動継電器を用い、主検出継電器に変圧器各端子電流によって差動保護を構成する差動継電器を用いた変圧器保護継電装置において、変圧器３次母線電圧の低下を検出する不足電圧継電器を有し、前記事故検出継電器不動作かつ前記不足電圧継電器動作により信号を出力する信号回路と前記信号の出力を前記主検出継電器点検中を条件に点検中の間保持する回路を具備し、前記主検出継電器が点検中であることかつ前記保持回路の信号出力がないことを条件に、前記事故検出継電器動作により遮断器引き外し指令を出力する回路とから構成した。
【００１５】
本発明の請求項４に係る変圧器保護継電装置は、点検機能を有し、事故検出継電器に励磁巻線電流とタップ巻線電流を使用した電流平衡継電器を用い、主検出継電器に励磁巻線電流とタップ巻線電流を使用した電流平衡継電器を用いた変圧器保護継電装置において、変圧器３次母線電圧の低下を検出する不足電圧継電器を有し、前記事故検出継電器不動作かつ前記不足電圧継電器動作により信号を出力する信号回路と前記信号の出力を前記主検出継電器点検中を条件に点検中の間保持する回路を具備し、前記主検出継電器が点検中であることかつ前記保持回路の信号出力がないことを条件に、前記事故検出継電器動作により遮断器引き外し指令を出力する回路とから構成した。
【００１６】
本発明の請求項５に係る変圧器保護継電装置は、点検機能を有し、事故検出継電器に励磁巻線電流とタップ巻線電流を使用した電流平衡継電器を用い、主検出継電器に励磁巻線電流とタップ巻線電流を使用した電流平衡継電器を用いた変圧器保護継電装置において、変圧器１次母線電圧あるいは変圧器２次母線電圧の低下を検出する不足電圧継電器を有し、前記事故検出継電器不動作かつ前記不足電圧継電器動作により信号を出力する信号回路と前記信号の出力を前記主検出継電器点検中を条件に点検中の間保持する回路を具備し、前記主検出継電器が点検中であることかつ前記保持回路の信号出力がないことを条件に、前記事故検出継電器動作により遮断器引き外し指令を出力する回路とから構成した。
【００１７】
上記のような構成により、本発明の変圧器保護継電装置は、非点検中は主検出継電器の動作と第２高調波含有検出要素などの励磁突入対策機能は実装していない事故検出継電器の動作のＡＮＤ条件により遮断器引き外し指令を出力する。主検出継電器ユニット点検中に変圧器内部事故が発生した場合は、事故検出継電器ユニットの事故検出継電器が動作するため母線電圧の低下を検出する不足電圧継電器の動作でかつ事故検出継電器ユニットの事故検出継電器が不動作である条件で成立する出力を一定時限引き延ばす回路の出力が生じず、高速に遮断器引き外しが可能となる。
【００１８】
また、主検出継電器ユニット点検中に変圧器保護範囲外の事故が発生し、電圧が低下し事故除去時の電圧回復により、励磁突入電流が発生する可能性が考えられるが、不足電圧継電器の動作でかつ事故検出継電器ユニットの事故検出継電器が不動作である条件で成立する出力を一定時限引き延ばす前記回路の出力が生じており、事故検出継電器ユニットの事故検出継電器が誤動作したとしても遮断器引き外し指令は出力されない。
【００１９】
一方、主検出継電器ユニット非点検中の励磁突入電流に対しては、遮断器引き外し指令の出力条件がが主検出継電器の動作と事故検出継電器の動作のＡＮＤ条件となるが、主検出継電器ユニットの主検出継電器に励磁突入電流対策が施してあり主検出継電器が動作出力を出さないためＡＮＤ条件が成立せず、遮断器引き外しの誤出力は生じない。
【００２０】
【発明の実施の形態】
図１を参照して、本発明の変圧器保護継電装置の実施の形態について具体的に説明する。図１において、図４に示すものと同等のものには同一の番号を付す。図１に示すものと図４のものとは、３次母線電圧の低下を検出する不足電圧継電器８を設け、不足電圧継電器の動作でかつ事故検出継電器ユニットの事故検出差動継電器９が不動作であることをＡＮＤ条件とする出力を一定時限引き延ばす復帰遅延回路１２を具備し、主検出継電器ユニット点検中は前記復帰遅延回路１２の出力が存在しないことと事故検出継電器９が動作したことを条件にして遮断器引き外し指令を出力する回路構成とした点で相違し、他は図４のものと同じである。
【００２１】
また、ここで事故検出継電器ユニットの事故検出差動継電器９は第２高調波含有率検出等の励磁突入対策機能は実装していない差動継電器である。そして、補助リレー（ＴＸＭ）１３Ａ、補助リレー（１１ＸＭ）１３Ｂ、補助リレー（ＴＸＦ）１３Ｄ、補助リレー（１１ＸＦ）１３Ｅは常開接点を有するリレーであり、補助リレー（ＴＬＸ）１３Ｃは常閉接点を有するリレーである。
【００２２】
変圧器１の各端子電流が計器用変流器３から変圧器保護継電装置１４に取り込まれ、３次母線電圧が計器用変圧器４から同様に取り込まれ、入力変換器５を介して主検出継電器ユニットと事故検出継電器ユニットに導入される。主検出継電器の主検出差動継電器６の出力は、第２高調波含有検出要素７の出力が存在しないことをＡＮＤ回路１１の条件として補助リレー（ＴＸＭ）１３Ａを駆動する。
【００２３】
一方、事故検出継電器９は第２高調波含有率の検出等の励磁突入電流対策なしで補助リレー（ＴＸＦ）１３Ｄを駆動する。また、不足電圧継電器８が動作し、事故検出継電器９が不動作であるとのＡＮＤ条件により補助リレー（ＴＬＸ）１３Ｃを駆動し、その出力は復帰遅延回路１２により所定時限だけ引き延ばされる。また、１１ＸＭは主検出継電器ユニット点検中の間駆動される補助リレー１３Ｂであり、１１ＸＦは事故検出継電器ユニット点検中の間駆動される補助リレー１３Ｅである。
【００２４】
非点検中の場合は、主検出継電器６の動作出力で駆動される補助リレー（ＴＸＭ）１３Ａと事故検出継電器９の動作出力で駆動される補助リレー（ＴＸＦ）１３Ｄが動作したことにより、補助リレー（ＴＸＭ）１３Ａと補助リレー（ＴＸＦ）１３Ｄの常開接点が閉成して遮断器引き外し指令が出力される。このときは補助リレー（ＴＸＭ）１３Ａの動作条件には励磁突入電流対策の条件が含まれている。
【００２５】
即ち、変圧器励磁突入電流が存在する場合は、入力変換器５の出力中の第２高調波の含有率が一定値以上であることを第２高調波含有検出要素７で検出し、その出力をＮＯＴ回路１０を介して主検出差動継電器６の出力と共にＡＮＤ回路１１で条件をとるが、ＡＮＤ条件が成立しないので励磁突入電流と判断し、主検出差動継電器６の出力をロックして補助リレー（ＴＸＭ）１３Ａを動作させることはない。したがって、補助リレー（ＴＸＭ）１３Ａの常開接点は開放されたままであり遮断器引き外し指令は出力されない。
【００２６】
変圧器励磁突入電流が存在しない場合は、入力変換器５の出力中の第２高調波の含有率が一定値以下であることを第２高調波含有検出要素７が検出すれば、ＡＮＤ回路１１の一方の条件が成立し、他方の条件である主検出差動継電器６の出力が存在するとＡＮＤ条件が成立し、補助リレー（ＴＸＭ）１３Ａを動作させる。したがって、補助リレー（ＴＸＭ）１３Ａの常開接点が閉成されて遮断器引き外し指令が出力される。
【００２７】
事故検出継電器ユニット点検中の場合は、補助リレー（１１ＸＦ）１３Ｅが動作しその常開接点は閉成され、主検出差動継電器６の動作出力で駆動される補助リレー（ＴＸＭ）１３Ａの動作により遮断器引き外し指令が出力される。この場合も補助リレー（ＴＸＭ）１３Ａの動作条件に、上記したような、励磁突入電流対策の条件が含まれている。
【００２８】
一方、主検出継電器ユニット点検中の場合は、補助リレー（１１ＸＭ）１３Ｂが動作しているため、補助リレー（１１ＸＭ）１３Ｂの常開接点は閉成されている。変圧器内部事故で即時に事故検出差動継電器９が動作すると、ＡＮＤ回路１１の条件は成立しないため補助リレー（ＴＬＸ）１３Ｃは動作せず、その接点は閉成されたままであり、補助リレー（ＴＸＦ）１３Ｄの動作により、補助リレー（ＴＸＦ）１３Ｄの常開接点は閉成されて遮断器引き外し指令が出力される。
【００２９】
主検出継電器ユニット点検中で変圧器保護範囲外の事故で電圧低下が生じた場合は、不足電圧継電器８がそれを検出して出力しＡＮＤ回路１１の条件は成立して補助リレー（ＴＬＸ）１３Ｃが動作するため、補助リレー（ＴＬＸ）１３Ｃの常閉接点は開放され、例え、その後の事故除去電圧回復による励磁突入電流によって事故検出差動継電器９が動作したとしても、補助リレー（ＴＬＸ）１３Ｃの常閉接点の開放により引き外し指令が出力ロックされており、遮断器引き外し指令の誤出力は生じない。
【００３０】
このことにより、事故検出差動継電器９に第２高調波含有率検出などの複雑な励磁突入電流対策を施さずとも、励磁突入電流で誤動作することなく、かつ点検中の事故に対し高速に遮断器引き外し指令の出力が可能となる。
【００３１】
本発明の変圧器保護継電装置の他の実施の形態を図２に示す。図２のものは、図１に示す本発明の変圧器保護継電装置における主検出差動継電器６と事故検出差動継電器９に替えて、変圧器１の励磁巻線１６の電流とタップ巻線１５の電流の平衡がくずれたことにより巻線の故障を検出する主検出電流平衡継電器１７及び事故検出電流平衡継電器１８を適用した場合である。そして、その他の構成及び回路要素の番号は図１のものと同様である。
【００３２】
この事故検出電流平衡継電器１８も励磁突入電流対策が必要となるが、図１と同様に、不足電圧継電器８の動作と事故検出電流平衡継電器１８の不動作の条件が成立したときの出力を一定時間引き延ばす回路である復帰遅延回路１２の組み合わせにより、事故検出電流平衡継電器１８に励磁突入電流対策を付加せずとも、励磁突入電流で誤動作せず、かつ点検中であっても変圧器内部事故時は高速に遮断器引き外し指令を出力することが可能となる。非点検中及び点検中のそれぞれの事故に対する動作は図１の実施例の場合と同じであるので、ここではその説明は省略する。
【００３３】
本発明の変圧器保護継電装置の他の実施の形態を図３に示す。図３のものは、図１または図２の復帰遅延回路１２の代わりに、不足電圧継電器８が動作でかつ事故検出差動継電器９が不動作のＡＮＤ条件が成立することによりなされる出力を、主検出継電器ユニット点検中の条件により保持する回路とした例である。その他の回路構成は図１または図２のものと同じである。
【００３４】
不足電圧継電器８の動作と事故検出差動継電器９の不動作のＡＮＤ回路１１Ａでの条件成立による出力がＯＲ回路１９を経て、主検出継電器ユニット点検中の条件とＡＮＤ回路１１Ｂでの条件成立により出力されて補助リレー（ＴＬＸ）１３Ｃを駆動すると同時にＯＲ回路１９に入力される。このため、主検出継電器ユニット点検中の条件がなくなるまでは補助リレー（ＴＬＸ）１３Ｃが駆動保持される。それ以外の励磁突入電流に対する動作と変圧器内部事故に対する動作は図１、図２に説明したことと全く同じであるので、ここではその説明は省略する。
【００３５】
また、以上の説明においては、不足電圧継電器８が検出する電圧を３次母線電圧の低下を検出するものとして説明したが、１次母線電圧の低下を検出するようにしても、または２次母線電圧の低下を検出するようにしてもあるいは遮断器２より変圧器端子側に設置された計器用変圧器による各端子電圧の低下を検出するような構成をとってもよく、その作用効果には変わりはない。
【００３６】
【発明の効果】
以上説明したように、本発明を用いれば、事故検出継電器に第２高調波含有率判定などの複雑な励磁突入電流対策要素を設けずに簡易な事故検出継電器構成とすることができ、点検中に事故検出継電器の動作単独条件による遮断器引き外し指令の出力を行う回路となっても励磁突入電流で誤動作せず、かつ点検中であっても変圧器内部事故に対して高速に事故除去可能な、縮小化され保守性の向上した変圧器保護継電装置を提供できる。
【図面の簡単な説明】
【図１】本発明の構成を説明した構成図。
【図２】本発明の他の実施の形態を示した構成図。
【図３】本発明の他の実施の形態を示した構成図。
【図４】従来装置の説明図。
【符号の説明】
１変圧器
２遮断器
３計器用変流器（ＣＴ）
４計器用変圧器（ＰＴ）
５入力変換器
６主検出差動継電器
７第２高調波含有検出要素
８不足電圧継電器
９事故検出差動継電器
１０ＮＯＴ回路
１１ＡＮＤ回路
１２復帰遅延（オフディレイ）回路
１３補助リレー
１４変圧器保護継電装置
１５タップ巻線
１６励磁巻線
１７主検出電流平衡継電器
１８事故検出電流平衡継電器
１９ＯＲ回路[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transformer protection relay having an inspection circuit.
[0002]
[Prior art]
In recent years, a digital protection relay is generally applied to a transformer protection relay, and is composed of a main detection relay unit and an accident detection relay unit. Normally, a breaker trip command is output according to the AND condition of the main detection relay operation and the accident detection relay operation. The inspection is performed such that one unit is inspected, and after the inspection is completed, the remaining units are inspected.
[0003]
At this time, the unit under inspection receives the inspection input, and may not be able to operate if an accident occurs during the inspection. However, if an accident occurs inside the transformer during the inspection, if the inspection was stopped and the circuit breaker was tripped, the removal of the accident would be delayed, and the tank could not be coordinated with the explosion-proof curve of the transformer tank. There is a risk of destruction and eventually a fire. For this reason, during inspection, a circuit breaker trip command is output under the sole condition of the relay operation of the relay unit housed during non-inspection. An example of this method will be specifically described with reference to FIG.
[0004]
In FIG. 4, the current at each terminal of the transformer 1 that is present with the circuit breaker 2 interposed between the primary bus and the secondary bus is transmitted through the current transformer 3 and the input converter 5 to protect the transformer. Introduced into the main detection relay unit and accident detection relay unit of the device. The main detection relay unit and the accident detection relay unit house a main detection differential relay 6 and an accident detection differential relay 9 for performing a differential operation using each terminal current.
[0005]
During inspection of the main detection relay unit or the accident detection relay unit, an inspection signal is input to the auxiliary relay (TXM) 13A or the auxiliary relay (TXF) 13D via the OR circuit 19, and is maintained in the operating state. Each of the auxiliary relay 13A and the auxiliary relay 13D has a normally open contact.
[0006]
During the inspection of the main detection relay unit, the independent condition that the auxiliary relay (TXM) 13A of the main detection relay unit is forcibly operated, its open contact is closed, and the accident detection differential relay 9 of the accident detection relay unit is operated. To output the breaker trip command. Conversely, during inspection of the accident detection unit, the auxiliary relay (TXF) 13D of the accident detection relay unit is forcibly operated, its open contact is closed, and the differential relay 6 of the main detection relay unit is operated independently. Outputs a breaker trip command according to conditions.
[0007]
By the way, in a transformer protection relay using a differential relay, it is necessary to take measures to prevent malfunction due to transformer inrush current, but in general, the second harmonic content in the differential current is more than a certain value. Is detected, it is determined that the current is an inrush current, and the output of the main detection differential relay 6 and the fault detection differential relay 9 is locked or the suppression amount is increased.
[0008]
As a countermeasure for preventing malfunction due to transformer inrush current, in the example of FIG. 4, the main detection relay unit and the accident detection relay unit are provided with the second harmonic content detection element 7 and the NOT circuit 10, respectively, and the transformer excitation inrush current is present. In this case, the second harmonic content detection element 7 detects that the content rate of the second harmonic in the output of the input converter 5 is equal to or more than a predetermined value, and the output is mainly detected via the NOT circuit 10. The AND circuit 11 takes a condition together with the outputs of the differential relay 6 and the fault detecting differential relay 9. However, since the AND condition is not satisfied, it is determined that the excitation is an inrush current, and the main detecting differential relay 6 or the fault detecting differential relay 9 is operated. The output is not locked to operate the auxiliary relay 13A or 13D. Therefore, no circuit breaker trip command is output.
[0009]
If the transformer inrush current does not exist and the content of the second harmonic in the output of the input converter 5 is equal to or less than a certain value, one condition of the AND circuit 11 is satisfied and the other condition is satisfied. When the output of the main detection differential relay 6 or the fault detection differential relay 9 is present, the auxiliary relay 13A or 13D is operated. Therefore, a circuit breaker trip command is output.
[0010]
[Problems to be solved by the invention]
As described above, in the case of a configuration in which a cut-off output is generated under the sole condition of the differential relay operation of the unit that is not being inspected during the inspection, it is necessary to implement a measure against the inrush current in both the main detection relay and the fault detection relay. For this reason, the configuration of the fault detection relay also increases the processing load for countermeasures against inrush current, and as a result, the analog input unit, the relay operation unit, and the sequence processing unit cannot be accommodated on one or two boards. A hardware configuration equivalent to a main detection relay unit having an analog input unit, a relay operation unit, and a sequence processing unit that are independent from each other has to be adopted. This impedes downsizing of the transformer protection relay and improvement in maintainability.
[0011]
In view of the above problems, an object of the present invention is to provide a simple accident detection relay configuration without providing a complicated function such as a second harmonic content determination to the accident detection relay, It is an object of the present invention to provide a transformer protection relay device which does not malfunction due to an inrush current of an exciting circuit and does not impair the original protection function even if a circuit for performing a circuit breaker trip output based on a single condition of a detection relay operation is provided.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a transformer protection relay device according to claim 1 of the present invention, which has an inspection function, and provides a fault protection relay with differential protection by a terminal current of each transformer. In the transformer protection relay device using the differential relay which constitutes the differential protection by the terminal current of the transformer as the main detection relay using the moving relay, the undervoltage relay which detects the drop of the transformer tertiary bus voltage is used. A signal circuit that outputs a signal due to the operation of the accident detection relay and the operation of the undervoltage relay, and a circuit that delays the return of the output of the signal for a predetermined time, wherein the main detection relay is under inspection; and A circuit for outputting a circuit breaker trip command by the operation of the fault detection relay on condition that there is no signal output from the delay circuit.
[0013]
The transformer protection relay according to claim 2 of the present invention has an inspection function, uses a current balancing relay using an exciting winding current and a tap winding current as an accident detection relay, and uses an excitation winding as a main detection relay. In a transformer protection relay using a current balancing relay using a line current and a tap winding current, an undervoltage relay for detecting a drop in a transformer tertiary bus voltage is provided, and the accident detection relay is inoperable and the A signal circuit that outputs a signal due to the operation of the undervoltage relay and a circuit that delays the return of the output of the signal for a certain period of time, provided that the main detection relay is under inspection and there is no signal output from the delay circuit. And a circuit for outputting a circuit breaker trip command by the operation of the fault detection relay.
[0014]
A transformer protection relay device according to claim 3 of the present invention has an inspection function, uses a differential relay that configures differential protection with each terminal current of the transformer as an accident detection relay, and uses a transformer as a main detection relay. In a transformer protection relay using a differential relay constituting differential protection by each terminal current, an undervoltage relay for detecting a drop in a transformer tertiary bus voltage is provided, and the accident detection relay is inoperable and the A signal circuit for outputting a signal due to undervoltage relay operation and a circuit for holding the output of the signal during inspection under the condition that the main detection relay is being inspected, wherein the main detection relay is being inspected and the holding circuit And a circuit for outputting a circuit breaker trip command by the operation of the fault detection relay on condition that there is no signal output.
[0015]
The transformer protection relay according to claim 4 of the present invention has an inspection function, uses a current balance relay using an exciting winding current and a tap winding current as an accident detection relay, and uses an excitation winding as a main detection relay. In a transformer protection relay using a current balancing relay using a line current and a tap winding current, an undervoltage relay for detecting a drop in a transformer tertiary bus voltage is provided, and the accident detection relay is inoperable and the A signal circuit for outputting a signal due to undervoltage relay operation and a circuit for holding the output of the signal during inspection under the condition that the main detection relay is being inspected, wherein the main detection relay is being inspected and the holding circuit And a circuit for outputting a circuit breaker trip command by the operation of the fault detection relay on condition that there is no signal output.
[0016]
The transformer protection relay according to claim 5 of the present invention has an inspection function, uses a current balancing relay using an exciting winding current and a tap winding current as an accident detection relay, and uses an excitation winding as a main detection relay. A transformer protection relay using a current balance relay using a line current and a tap winding current, comprising an undervoltage relay for detecting a decrease in a transformer primary bus voltage or a transformer secondary bus voltage, A signal circuit for outputting a signal due to the operation of the accident detection relay and the operation of the undervoltage relay, and a circuit for holding the output of the signal during the inspection under the condition that the main detection relay is being inspected, wherein the main detection relay is being inspected. And a circuit for outputting a circuit breaker trip command by the operation of the fault detection relay on condition that there is a signal output from the holding circuit.
[0017]
With the above-described configuration, the transformer protection relay of the present invention provides an operation of the main detection relay and an accident detection relay that does not have a function for preventing inrush of the second harmonic content detection element or the like during non-inspection. The circuit breaker trip command is output according to the AND condition of the operation. If an accident inside the transformer occurs during inspection of the main detection relay unit, the fault detection relay of the fault detection relay unit operates and the undervoltage relay that detects a drop in bus voltage is detected.The fault detection of the fault detection relay unit is detected. The output of the circuit for extending the output that is satisfied under the condition that the relay is inoperative for a certain period of time does not occur, and the circuit breaker can be quickly removed.
[0018]
In addition, during the inspection of the main detection relay unit, an accident outside the transformer protection range may occur, the voltage may drop, and the voltage may recover when the accident is eliminated. In addition, the output of the circuit that extends the output that is established under the condition that the fault detection relay of the fault detection relay unit is inoperative for a certain period of time occurs, and even if the fault detection relay of the fault detection relay unit malfunctions, the breaker is tripped. No command is output.
[0019]
On the other hand, for the inrush current during the main detection relay unit not being inspected, the output condition of the breaker trip command is the AND condition of the operation of the main detection relay and the operation of the accident detection relay. The main detection relay of (1) has a countermeasure against the inrush current, and the main detection relay does not output any operation output. Therefore, the AND condition is not satisfied, and no erroneous output of tripping the circuit breaker does not occur.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
With reference to FIG. 1, an embodiment of a transformer protection relay device of the present invention will be specifically described. In FIG. 1, the same components as those shown in FIG. 4 are denoted by the same reference numerals. 1 and 4 are provided with an undervoltage relay 8 for detecting a drop in the tertiary bus voltage, and the operation of the undervoltage relay and the operation of the fault detection differential relay 9 of the fault detection relay unit are inoperative. And a return delay circuit 12 for extending the output for a certain period of time under the AND condition that the output of the return delay circuit 12 does not exist during the inspection of the main detection relay unit and that the accident detection relay 9 operates. And a circuit configuration for outputting a circuit breaker trip command, and the other configuration is the same as that of FIG.
[0021]
Here, the fault detecting differential relay 9 of the fault detecting relay unit is a differential relay that does not have a function for preventing inrush of the second harmonic content or the like. The auxiliary relay (TXM) 13A, the auxiliary relay (11XM) 13B, the auxiliary relay (TXF) 13D, and the auxiliary relay (11XF) 13E are relays having normally open contacts, and the auxiliary relay (TLX) 13C is a normally closed contact. It has a relay.
[0022]
Each terminal current of the transformer 1 is taken into the transformer protection relay 14 from the current transformer 3 for the instrument, and the tertiary bus voltage is likewise taken from the transformer 4 for the instrument. Installed in the detection relay unit and the accident detection relay unit. The output of the main detection differential relay 6 of the main detection relay drives the auxiliary relay (TXM) 13A under the condition of the AND circuit 11 that the output of the second harmonic content detection element 7 does not exist.
[0023]
On the other hand, the fault detection relay 9 drives the auxiliary relay (TXF) 13D without taking measures against the inrush current such as the detection of the second harmonic content. Further, the auxiliary relay (TLX) 13C is driven by an AND condition that the undervoltage relay 8 operates and the fault detection relay 9 does not operate, and the output thereof is extended by the return delay circuit 12 for a predetermined time period. 11XM is an auxiliary relay 13B driven during inspection of the main detection relay unit, and 11XF is an auxiliary relay 13E driven during inspection of the accident detection relay unit.
[0024]
When the inspection is not being performed, the auxiliary relay (TXM) 13A driven by the operation output of the main detection relay 6 and the auxiliary relay (TXF) 13D driven by the operation output of the accident detection relay 9 are operated. The normally open contacts of the (TXM) 13A and the auxiliary relay (TXF) 13D are closed, and a circuit breaker trip command is output. At this time, the operating conditions of the auxiliary relay (TXM) 13A include conditions for countermeasures against inrush current.
[0025]
That is, when there is a transformer inrush current, the second harmonic content detection element 7 detects that the content of the second harmonic in the output of the input converter 5 is equal to or more than a certain value, and outputs the same. The condition is taken by the AND circuit 11 together with the output of the main detection differential relay 6 via the NOT circuit 10. However, since the AND condition is not satisfied, it is determined that the excitation is an inrush current, and the output of the main detection differential relay 6 is locked. The auxiliary relay (TXM) 13A is not operated. Therefore, the normally open contact of the auxiliary relay (TXM) 13A remains open, and no breaker trip command is output.
[0026]
When the transformer inrush current does not exist, if the second harmonic content detection element 7 detects that the content rate of the second harmonic in the output of the input converter 5 is equal to or less than a predetermined value, the AND circuit 11 When one of the conditions is satisfied and the other condition, that is, the output of the main detection differential relay 6 is present, the AND condition is satisfied and the auxiliary relay (TXM) 13A is operated. Therefore, the normally open contact of the auxiliary relay (TXM) 13A is closed, and a circuit breaker trip command is output.
[0027]
When the accident detection relay unit is under inspection, the auxiliary relay (11XF) 13E operates, the normally open contact is closed, and the auxiliary relay (TXM) 13A driven by the operation output of the main detection differential relay 6 operates. A breaker trip command is output. Also in this case, the operating conditions of the auxiliary relay (TXM) 13A include the above-described conditions for the countermeasure for the inrush current.
[0028]
On the other hand, when the main detection relay unit is being inspected, the normally open contact of the auxiliary relay (11XM) 13B is closed because the auxiliary relay (11XM) 13B is operating. If the fault detection differential relay 9 immediately operates due to a fault inside the transformer, the condition of the AND circuit 11 is not satisfied, so that the auxiliary relay (TLX) 13C does not operate, and its contact remains closed, and the auxiliary relay (TLX) is closed. By the operation of the (TXF) 13D, the normally open contact of the auxiliary relay (TXF) 13D is closed, and a circuit breaker trip command is output.
[0029]
If a voltage drop occurs due to an accident outside the transformer protection range during inspection of the main detection relay unit, the undervoltage relay 8 detects and outputs the same, the condition of the AND circuit 11 is satisfied, and the auxiliary relay (TLX) 13C Operates, the normally closed contact of the auxiliary relay (TLX) 13C is opened. Even if the fault detection differential relay 9 is operated by the inrush current caused by the recovery of the fault elimination voltage after that, the auxiliary relay (TLX) 13C The output of the tripping command is locked by opening the normally closed contact, and no erroneous output of the circuit breaker tripping command occurs.
[0030]
As a result, even if a complicated countermeasure against inrush current such as detection of the second harmonic content is not applied to the fault detection differential relay 9, it does not malfunction due to the inrush current and shuts off the fault under inspection at high speed. It is possible to output a device trip command.
[0031]
FIG. 2 shows another embodiment of the transformer protection relay device of the present invention. In FIG. 2, the current and the tap winding of the exciting winding 16 of the transformer 1 are replaced with the main detection differential relay 6 and the fault detection differential relay 9 in the transformer protection relay device of the present invention shown in FIG. This is a case where a main detection current balance relay 17 and an accident detection current balance relay 18 that detect a failure of a winding due to an imbalance in the current of the line 15 are applied. Other configurations and circuit element numbers are the same as those in FIG.
[0032]
This fault detection current balance relay 18 also requires measures against the magnetizing inrush current. However, as in FIG. 1, the output when the condition of the operation of the undervoltage relay 8 and the condition of the non-operation of the fault detection current balance relay 18 are satisfied is kept constant. Due to the combination of the return delay circuit 12, which is a circuit for extending the time, the malfunction detection current balancing relay 18 does not malfunction due to the magnetizing inrush current without taking measures against the magnetizing inrush current. Can output a circuit breaker trip command at high speed. The operations for the accidents during the non-inspection and during the inspection are the same as those in the embodiment of FIG.
[0033]
FIG. 3 shows another embodiment of the transformer protection relay device of the present invention. The output of FIG. 3 is obtained by satisfying an AND condition that the undervoltage relay 8 operates and the fault detection differential relay 9 does not operate, instead of the return delay circuit 12 of FIG. 1 or FIG. This is an example in which a circuit is held according to conditions during inspection of the main detection relay unit. Other circuit configurations are the same as those in FIG. 1 or FIG.
[0034]
The output of the operation of the undervoltage relay 8 and the failure of the fault detection differential relay 9 due to the establishment of the condition in the AND circuit 11A passes through the OR circuit 19, and the output during the inspection of the main detection relay unit and the satisfaction of the condition in the AND circuit 11B. The signal is output to drive the auxiliary relay (TLX) 13C and is input to the OR circuit 19 at the same time. Therefore, the auxiliary relay (TLX) 13C is driven and held until the condition during the inspection of the main detection relay unit disappears. The operation for the other inrush current and the operation for the fault inside the transformer are exactly the same as those described with reference to FIGS. 1 and 2, and therefore the description thereof is omitted here.
[0035]
Further, in the above description, the voltage detected by the undervoltage relay 8 is described as detecting a drop in the tertiary bus voltage. However, the voltage detected by the undervoltage relay 8 may be detected as a drop in the primary bus voltage. A configuration may be adopted in which a drop in voltage is detected or a drop in each terminal voltage is detected by an instrument transformer installed on the transformer terminal side from the circuit breaker 2. Absent.
[0036]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a simple accident detection relay configuration without providing a complicated excitation inrush current countermeasure element such as a second harmonic content determination in the accident detection relay. Even if a circuit that outputs a breaker trip command based on the independent condition of the operation of the fault detection relay does not malfunction due to the inrush current of the magnet, and even during the inspection, the fault inside the transformer can be eliminated at high speed even during inspection Further, it is possible to provide a transformer protection relay device that is reduced in size and has improved maintainability.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating a configuration of the present invention.
FIG. 2 is a configuration diagram showing another embodiment of the present invention.
FIG. 3 is a configuration diagram showing another embodiment of the present invention.
FIG. 4 is an explanatory view of a conventional device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transformer 2 Circuit breaker 3 Instrument current transformer (CT)
4 Instrument transformer (PT)
Reference Signs List 5 Input converter 6 Main detection differential relay 7 Second harmonic content detection element 8 Undervoltage relay 9 Fault detection differential relay 10 NOT circuit 11 AND circuit 12 Return delay (off delay) circuit 13 Auxiliary relay 14 Transformer protection relay Electrical device 15 Tap winding 16 Excitation winding 17 Main detection current balance relay 18 Fault detection current balance relay 19 OR circuit

Claims

It has a check function and uses a differential relay that configures differential protection with each terminal current of the transformer as the fault detection relay, and a differential relay that configures differential protection with each terminal current of the transformer as the main detection relay. In the transformer protection relay device, there is an undervoltage relay for detecting a drop in a tertiary bus voltage of a transformer, a signal circuit for outputting a signal by the operation of the accident detection relay and the operation of the undervoltage relay, and an output of the signal. A circuit for delaying the return of the circuit for a predetermined time, and on the condition that the main detection relay is under inspection and there is no signal output from the delay circuit, a circuit breaker trip command is output by the operation of the accident detection relay. A transformer protection relay having a circuit.

It has a check function, and uses a current balancing relay that uses the exciting winding current and tap winding current as the accident detection relay, and uses a current balancing relay that uses the exciting winding current and tap winding current as the main detection relay. In the transformer protection relay device, there is an undervoltage relay for detecting a drop in a tertiary bus voltage of a transformer, a signal circuit for outputting a signal by the operation of the accident detection relay and the operation of the undervoltage relay, and an output of the signal. A circuit for delaying the return of the circuit for a predetermined time, and on the condition that the main detection relay is under inspection and there is no signal output from the delay circuit, a circuit breaker trip command is output by the operation of the accident detection relay. A transformer protection relay device having a circuit.

It has a check function and uses a differential relay that configures differential protection with each terminal current of the transformer as the fault detection relay, and a differential relay that configures differential protection with each terminal current of the transformer as the main detection relay. In the transformer protection relay device, there is an undervoltage relay for detecting a drop in a tertiary bus voltage of a transformer, a signal circuit for outputting a signal by the operation of the accident detection relay and the operation of the undervoltage relay, and an output of the signal. A circuit for holding the main detection relay during the inspection under the condition that the main detection relay is being inspected, and interrupted by the operation of the accident detection relay on condition that the main detection relay is being inspected and there is no signal output from the holding circuit. A transformer protection relay having a circuit for outputting a device tripping command.

It has a check function, and uses a current balancing relay that uses the exciting winding current and tap winding current as the accident detection relay, and uses a current balancing relay that uses the exciting winding current and tap winding current as the main detection relay. In the transformer protection relay device, there is an undervoltage relay for detecting a drop in a tertiary bus voltage of a transformer, a signal circuit for outputting a signal by the operation of the accident detection relay and the operation of the undervoltage relay, and an output of the signal. A circuit for holding the main detection relay during the inspection under the condition that the main detection relay is being inspected, and interrupted by the operation of the accident detection relay on condition that the main detection relay is being inspected and there is no signal output from the holding circuit. A transformer protection relay having a circuit for outputting a device tripping command.

2. An undervoltage relay for detecting a drop in a primary bus voltage of a transformer or a secondary bus voltage in place of an undervoltage relay for detecting a drop in a third bus voltage of a transformer. The transformer protection relay device according to claim 2, 3, or 4.