JP3656824B2

JP3656824B2 - Ground fault direction relay device

Info

Publication number: JP3656824B2
Application number: JP2000284309A
Authority: JP
Inventors: 英明高田
Original assignee: 株式会社戸上電機製作所
Priority date: 2000-09-19
Filing date: 2000-09-19
Publication date: 2005-06-08
Anticipated expiration: 2020-09-19
Also published as: JP2002101549A

Description

【０００１】
【発明の属する技術分野】
本発明は、地絡事故の発生箇所が電源側か負荷側かを検出する地絡方向継電装置に関し、特に地絡事故前に発生する微地絡状態を検出する地絡方向継電装置に関する。
【０００２】
【従来の技術】
従来、この種の地絡方向継電装置として特許第２５５４２１７号の特許公報に開示されるものがあり、これを図９に示す。この図９は従来の地絡方向継電装置のブロック回路構成図を示す。
前記図９において従来の地絡方向継電装置は三相三線式高圧配電線に配設される零相変流器ＺＣＴ（図示を省略）で検出される零相電流Ｉ0が地絡電流レベルに達したか否かを検出する零相電流要素２００と、前記三相三線式高圧配電線に配設される零相変成器ＺＰＤ（図示を省略）で検出される零相電圧Ｖ0が地絡電圧レベルに達したか否かを検出する零相電圧要素３００と、前記地絡電流レベル及び地絡電圧レベルに達した零相電流及び零相電圧の位相を比較して判別する位相判別回路４００と、前記零相電圧が設定値以下でも零相電流が設定値以上となったときに地絡検出信号を出力する零相電流動作回路１００とを備える構成である。
【０００３】
この零相電流要素２００は零相変流器ＺＣＴで検出した零相電流Ｉ0とこのフィルタ２１０の出力を増幅器２２０で増幅し、設定レベルを越えたとき出力信号を出すレベル検出回路２３０と、フィルタ２１０の出力を矩形に整形する波形整形回路２４０と、この波形整形回路２４０の出力とレベル検出回路２３０の出力のアンド条件が成立したときに零相電流分の信号を出力するアンド回路２５０よりなる構成である。
【０００４】
また、前記零相電圧要素３００は、零相電圧検出器で検出した零相電圧Ｖ0の基本成分を取り出すフィルタ３１０と、これを増幅する増幅器３２０、増幅器３２０の出力が設定レベルを越えたときに出力信号を出すレベル検出回路３３０、フィルタ３１０の出力を矩形波又はパルス上に波形整形する波形整形回路３４０と、この波形成形回路３４０とレベル検出回路３３０の出力のアンド条件をとり、アンド条件が成立したときに零相電圧分の信号を出力するアンド回路３５０よりなる構成である。
【０００５】
位相判別回路４００は、零相電流分と零相電圧分の信号を入力し、両信号の位相比較し、地絡事故が零相変流器ＺＣＴの電源側か、あるいは負荷側かを判断し、負荷側のとき出力を時限回路５００に送出する。この出力を時限回路５００に入力したときは所定時間経過後の出力リレーＸの接点を閉じ、遮断器を遮断する等の所定保護動作を行う。
【０００６】
この零相電流動作回路１００は、アンド回路１１０を設け、このアンド回路１１０の一方の入力側に零相電流要素２００側のレベル検出回路２３０の出力を入力し、他方の入力側に零相電圧要素３００側のレベル検出回路３３０からインバータ回路１２０を介して入力する。そしてアンド回路１１０の出力信号は直接又はオア回路ＯＲを介して時限回路５００に入力する。インバータ回路１２０は、零相電圧要素３００のレベル検出回路３３０の出力信号が０のとき、即ち、零相電圧が設定レベル以下のときは、アンド回路１１０に出力信号を出力し、レベル検出回路３３０の出力信号が有るときはアンド回路１１０への出力を停止する。
【０００７】
零相電圧要素３００側の検出信号が動作設定値（感度値）以下のときでも、零相電流要素２００側の検出値が動作設定値以上になると、この両条件でアンド回路１１０は地絡検出信号を出し、時限回路５００を介して所定の時限経過後に出力リレーＸを動作させる。
そして零相電圧要素３００側の検出値が動作設定値以上になると、零相電流動作回路１００は出力信号を出さないようにロックされる。従って、地絡方向継電装置の本来の動作を妨げることはない。
【０００８】
【発明が解決しようとする課題】
従来の地絡方向継電装置は以上のように構成されていたことから、零相電圧が設定値以下でも零相電流が設定値以上発生した場合に地絡方向を特定して動作させることができるが、零相電流が地絡動作電流に至らない高圧設備の絶縁劣化に伴う微地絡状態を予め検出できないという課題を有していた。この高圧設備の絶縁劣化としては、高圧配電線の絶縁劣化、遮断器、トランス、進相コンデンサ、高圧モニタ等の高圧機器の絶縁劣化がある。
【０００９】
また、従来の地絡方向継電装置は、零相電流Ｉ0と零相電圧Ｖ0との位相差に基づいて地絡方向を検出していたが、電源側に接続する他の負荷設備に三相交流の二線のみで電力を供給している等により対地浮遊静電容量のアンバランスに起因して発生する残留零相電圧Ｖ0が大きい場合に、前記位相差では地絡方向がより確実に検出できないという課題を有していた。特に、負荷側地絡では零相電圧Ｖ0が極めて小さく、また実際の配電線には数十［Ｖ］以上の残留零相電圧が存在することから、零相電流Ｉ0と零相電圧Ｖ0との位相差では微地絡状態の地絡方向を判定することが極めて困難であるという課題を有する。
【００１０】
本発明は、前記課題を解消するためになされたもので、地絡方向をより確実に検出できると共に、微地絡状態を検出できる地絡方向継電装置を提供することを目的とする。
【００１１】
【課題を解決するための手段】
本発明に係る地絡方向継電装置は、三相三線式高圧配電線の零相電流を検出する零相電流検出手段と、前記三相三線式高圧配電線の零相電圧を検出する零相電圧検出手段と、前記検出された零相電流を地絡動作電流整定値より小さな値に予め設定された設定微地絡電流と比較し、当該零相電流が大きいと判断された場合に微地絡電流検出信号を出力する微地絡電流検出手段と、前記検出された零相電流及び零相電圧を次式に代入し、

Ｃ1；電源側の対地浮遊静電容量
Ｃ2；負荷側の対地浮遊静電容量
ｊ；虚数単位
ω；角周波数
当該代入して得られる特性グラフの分布から求められる方向判別閾値に基づいて地絡方向を判別する地絡方向判別手段とを備えるものである。
【００１２】
このように本発明においては、零相電流検出手段で検出された零相電流が地絡動作電流整定値より小さな値の設定微地絡電流よりも大きいと判断した場合に微地絡電流検出手段から微地絡電流検出信号を出力し、予め求められた方向判別閾値に基づいて地絡方向判別手段が地絡方向を判別するようにしているので、零相電流が地絡動作電流整定値以上の地絡に至らない微地絡状態が零相電流検出手段を基準として負荷側又は電源側で発生しているかを特定できる。
【００１３】
また、本発明に係る地絡方向継電装置は必要に応じて、地絡方向の判別結果に基づいて微地絡電流検出信号を記憶する記憶手段を備えるものである。このように本発明においては、微地絡電流検出手段から出力される微地絡電流検出信号を地絡方向判別手段による地絡方向の判別結果に基づいて記憶手段に記憶するようにしているので、零相電流検出手段が配設される三相三線式高圧配電線の負荷側か電源側かを区別して微地絡状態を判断できることとなり、配電線及び高圧機器の漏電を特定できる。
【００１４】
また、本発明に係る地絡方向継電装置は必要に応じて、記憶手段に格納された微地絡電流検出信号の履歴情報に基づいて負荷側及び／又は電源側の各高圧設備の絶縁劣化を類推する絶縁劣化類推手段を備えるものである。このように本発明においては、絶縁劣化類推手段が微地絡電流検出信号の履歴情報に基づいて負荷側か電源側かの高圧設備の絶縁劣化を類推するようにしているので、零相電流が地絡動作電流整定値以上の地絡に至る前に予め配電線、高圧機器等の高圧設備の交換等の対策を採ることができる。
【００１５】
また、本発明に係る地絡方向継電装置は必要に応じて、検出された零相電流及び零相電圧の位相差を検出し、当該位相差に基づいて地絡方向を検出する地絡方向検出手段を備え、前記地絡方向判別手段で微地絡の地絡方向を判別すると共に、前記地絡方向検出手段で地絡電流が地絡動作電流整定値以上の場合の地絡方向を検出するものである。このように本発明においては、微地絡の地絡方向を地絡方向判別手段で判別し、地絡電流が地絡動作電流整定値以上の地絡方向を地絡方向検出手段で検出するようにしているので、従来の地絡方向継電装置に併せて設けることができることとなり、微地絡から完全地絡までの総ての地絡状態の方向を検出できる。
【００１６】
本発明に係る地絡方向継電装置は、三相三線式高圧配電線の零相電流を検出する零相電流検出手段と、前記三相三線式高圧配電線の零相電圧を検出する零相電圧検出手段と、前記検出された零相電流を地絡動作電流整定値より小さな値に予め設定された設定微地絡電流と比較し、当該零相電流が大きいと判断された場合に微地絡電流検出信号を出力する微地絡電流検出手段と、前記検出された零相電流から次式に基づいて零相電圧閾値を演算し、
負荷側の地絡関係式 │ｖｏ│＝│ｉｏ／（ｊω３Ｃ1）│
電源側の地絡関係式 │ｖｏ│＝│−ｉｏ／（ｊω３Ｃ2）│
Ｃ1；電源側の対地浮遊静電容量
Ｃ2；負荷側の対地浮遊静電容量
当該零相電圧閾値と前記検出された零相電圧とを比較して地絡方向を判別する地絡方向判別手段とを備えるものである。このように本発明においては、地絡方向判別手段が零相電流検出手段で検出された零相電流から零相電圧閾値を演算し、この零相電圧閾値と零相電圧検出手段で検出された零相電圧とを比較して地絡方向を判別するようにしているので、地絡電流が地絡動作電流整定値に至らない微地絡状態が零相電流検出手段を基準として負荷側又は電源側で発生しているかを特定できる。
【００１７】
【発明の実施の形態】
（本発明の第１の実施形態）
以下、本発明の第１の実施形態に係る地絡方向継電装置を図１ないし図５に基づいて説明する。この図１は本実施形態に係る地絡方向継電装置の全体ブロック構成図、図２は図１記載の地絡方向継電装置における地絡方向判別手段の詳細ブロック構成図、図３は図１に記載の地絡方向継電装置における記憶手段及び絶縁劣化判断手段の詳細ブロック図、図４は図１に記載の地絡方向継電装置電源側及び負荷側の各漏電状態説明図、図５は図１に記載の地絡方向継電装置の領域判別動作説明図を示す。
【００１８】
前記各図において本実施形態に係る地絡方向継電装置は、図９に記載の従来の地絡方向継電装置と同様に零相電流要素２（図９では２００に相当）及び零相電圧要素３（図９では３００に相当）を共通して備え、この構成に加え、前記零相電流要素２から出力される零相電流信号ＳI0及び零相電圧要素３から出力される零相電圧信号ＳV0により予め求められた零相電圧閾値ＶSLに基づいて地絡方向（微地絡方向を含む）を判断して負荷側又は電源側の各判断信号ＳLO、ＳSOを出力する地絡方向判別手段１と、前記零相電流信号ＳIOを地絡動作電流（例えば、０．３［Ａ］）より小さな値に予め設定された設定微地絡電流△Ｉoと比較し、この零相電流信号ＳIOが大きいと判断された場合に微地絡電流検出信号ＳTOを出力する微地絡電流検出手段５と、この地絡方向判別手段１及び微地絡電流検出手段５の各出力を出力する出力手段６と、この出力手段６からの各出力データを記憶手段７と、この記憶手段７に記憶された出力データに基づいて高圧設備の絶縁劣化を判断する絶縁劣化判断手段８とを備える構成である。
【００１９】
前記地絡方向判別手段１は、零相電流要素２から出力される零相電流信号ＳIOに基づいて予め求められた零相電流・電圧関係閾値ＰIVのうち対応する零相電圧閾値ＶSLを検出する零相電圧閾値検出部１１と、この検出された零相電圧閾値ＶSLと前記零相電圧要素３から出力される零相電圧信号ＳV0とを比較演算する零相電圧比較演算部１２と、この演算結果に基づいて地絡方向を判断して負荷側判断信号ＳLO又は電源側判断信号ＳSOを出力する地絡方向判別部１３とを備える構成である。この零相電流・電圧関係閾値ＰIVは、零相電流Ｉ0、零相電圧Ｖ0、電源側の対地浮遊静電容量Ｃ1又は負荷側の対地浮遊静電容量Ｃ2とから次式の各地絡関係式により理論上求められる計算値により、図５中に電源側地絡を破線及び負荷側地絡を一点鎖線で各々図示する特性グラフを描画し、この各特性グラフの中間を区分けするような実線で設定される。
【００２０】

Ｃ1；電源側の対地浮遊静電容量
Ｃ2；負荷側の対地浮遊静電容量
ｊ；虚数単位
ω；角周波数
即ち、図４（Ａ）は三相三線式高圧配電線に開閉器が介装され、この開閉器内に配設される零相変流器ＺＣＴから電源側で漏電（地絡抵抗Ｒ）が生じている場合を示し、また、同図（Ｂ）は零相変流器ＺＣＴから負荷側で漏電（地絡抵抗Ｒ）が生じている場合を示す。これらの場合に零相変成器ＺＰＤの出力は│ｖｏ│＝│Ｖｔ／（ｊω３ＣＲ＋１）│となり、電源側漏電における零相変流器ＺＣＴの出力が│ｉｏ│＝│−ｖｏ×ｊω３Ｃ2│となり、負荷側漏電における零相変流器ＺＣＴの出力が│ｉｏ│＝│ｖｏ×ｊω３Ｃ1│となる。ここでＣは高圧配電線（系統）総ての対地浮遊静電容量であり、電源側の対地浮遊静電容量Ｃ1と負荷側の対地浮遊静電容量Ｃ2との和である。
【００２１】
一般的な配電線においては、前記電源側の対地浮遊静電容量Ｃ1は１μＦ〜１２μＦの範囲内、前記負荷側の対地浮遊静電容量Ｃ2は０．３３μＦ以下である。
前記出力手段６は、負荷側判断信号ＳLO、電源側判断信号ＳSO及び微地絡電流検出信号ＳTOに基づいて負荷側地絡信号を図示を省略する開閉器へ出力し、負荷側地絡信号、電源側地絡信号、負荷側微地絡信号及び電源側微地絡信号を記憶手段７へ出力する構成である。
【００２２】
前記記憶手段７は、負荷側微地絡信号を履歴データとして記憶する負荷側微地絡記憶部７１と、電源側微地絡信号を履歴データとして記憶する電源側微地絡記憶部７２と、負荷側地絡信号を履歴データとして記憶する負荷側地絡記憶部７３と、電源側地絡信号を履歴データとして記憶する電源側地絡記憶部７４とを備える構成である
前記絶縁劣化判断手段８は、前記負荷側微地絡記憶部７１に記憶された履歴データに基づいて負荷側の高圧設備の絶縁劣化を類推する負荷側絶縁劣化判断部８１と、前記電源側微地絡記憶部７２に記憶された履歴データに基づいて電源側の高圧設備の絶縁劣化を類推する電源側絶縁劣化判断部８２とを備える構成である。
【００２３】
次に、前記構成に基づく本実施形態に係る地絡方向継電装置の地絡方向継電動作について説明する。前提として需要家第１柱の開閉器内に配設された零相変流器ＺＣＴ、零相変成器ＺＰＤで三相三線式高圧配電線の零相電流Ｉ0、零相電圧Ｖ0を検出したものであり、この零相変流器ＺＣＴから電源側をみた対地浮遊静電容量Ｃ1、負荷側をみた対地浮遊静電容量Ｃ2とし、さらにこの高圧配電線には各相の対地浮遊静電容量の不平衡等に基づく残留零相電圧の発生がないものと仮定する。このような条件で前記電源側及び負荷側の各地絡関係式より図５に示すような特性グラフを求め、これらの特性グラフを区分する零相電流・電圧関係閾値ＰIVを予め求めて地絡方向判別手段１の零相電圧閾値検出部１１における図示を省略する記憶部に記憶させる。
【００２４】
まず、零相変流器ＺＣＴから零相電流Ｉ0、零相変成器ＺＰＤから零相電圧Ｖ0が各々零相電流要素２及び零相電圧要素３に入力され、この零相電流要素２で零相電流信号ＳIOが生成され、零相電圧要素３で零相電圧信号ＳV0が生成される。この零相電流信号ＳIOが地絡方向判別手段１の零相電圧閾値検出部１１に入力され、この零相電圧閾値検出部１１は記憶部（図示を省略）から零相電流・電圧関係閾値ＰIVを読出し、入力された零相電流信号ＳIOに対応する零相電圧閾値ＶSLを零相電流・電圧関係閾値ＰIVから検出する。この検出された零相電圧閾値ＶSLと前記生成された零相電圧信号ＳV0とを零相電圧比較演算部１２が比較演算し、この演算結果に基づいて地絡方向判別部１３が地絡方向を判断して負荷側判断信号ＳLO、電源側判断信号ＳSOを出力する。
【００２５】
また、前記生成された零相電流信号ＳIOが微地絡電流検出手段５に入力され、この微地絡電流検出手段５は、この零相電流信号ＳIOを地絡動作電流整定値（例えば、０．３［Ａ］）より小さな値に予め設定された設定微地絡電流△Ｉoと比較し、この零相電流信号ＳIOが大きいと判断された場合に微地絡電流検出信号ＳTOを出力する。
【００２６】
この検出された微地絡電流検出信号ＳTOに基づいて出力手段６は、地絡方向判別手段１から入力される負荷側判断信号ＳLO、電源側判断信号ＳSOを開閉器又は記憶手段７へ出力する。この開閉器へ出力される場合としては、負荷側判断信号ＳLOが入力され、且つ地絡動作電流整定値（例えば、０．３［Ａ］）以上の零相電流Ｉ0が検出された場合である。
【００２７】
また、出力手段６から記憶手段７の負荷側微地絡記憶部７１へ出力される場合としては、負荷側判断信号ＳLOが入力され且つ微地絡電流検出信号ＳTOが入力された場合に負荷側微地絡信号が出力されて履歴データとして記憶される。出力手段６から記憶手段７の電源側微地絡記憶部７２へ出力される場合としては、電源側判断信号ＳSOが入力され、且つ微地絡電流検出信号ＳTOが入力された場合に電源側微地絡信号が出力されて記憶データとして記憶される。
【００２８】
さらに、出力手段６から記憶手段７の負荷側地絡記憶部７３へ出力される場合としては、負荷側判断信号ＳLOが入力され、且つ地絡動作電流整定値（例えば、０．３［Ａ］）以上の零相電流Ｉ0が検出された場合に負荷側地絡信号が記憶される。出力手段６から記憶手段７の電源側地絡記憶部７４へ出力される場合としては、電源側判断信号ＳSOが入力され、且つ地絡動作電流整定値整定値（例えば、０．３［Ａ］）以上の零相電流Ｉ0が検出された場合に電源側地絡信号が記憶される。
【００２９】
前記負荷側微地絡記憶部７１（又は電源側微地絡記憶部７２）に各々履歴データとして記憶された負荷側（又は電源側）微地絡信号は、負荷側絶縁劣化判断部８１（又は電源側絶縁劣化判断部８２）において変化の推移が検出され、この変化の推移に基づいて負荷側（又は電源側）の高圧設備における絶縁劣化状態を類推する。この絶縁劣化状態の類推結果及び記憶手段７に記憶された各データは、図示を省略する表示装置、プリンタ、通信回線等で出力されることとなる。
【００３０】
（本発明の第２の実施形態）
本発明の第２の実施形態に係る地絡方向継電装置を図６ないし図８に基づいて前記図４及び図５を参照して説明する。この図６は本実施形態に係る地絡方向継電装置の全体ブロック構成図、図７は図６に記載の地絡方向継電装置における出力手段の詳細構成図、図８は図６に記載の地絡方向継電装置の領域判別動作説明図を示す。
【００３１】
前記各図において本実施形態に係る地絡方向継電装置は、前記図１に記載する第１の実施形態に係る地絡方向継電装置と同様に地絡方向判別手段１、零相電流要素２、零相電圧要素３、出力手段６０（図１では６に相当）及び記憶手段７を共通して備え、この構成に加え、零相電流要素２で増幅・波形整形されたアナログの零相電流ｉ0及び零相電圧ｖ0が入力され、この零相電流ｉ0及び零相電圧ｖ0の位相差を演算して判別する位相判別手段４と、零相電流要素２で生成された零相電流信号ＳIO、零相電圧信号ＳV0の各レベルを予め設定された設定値と比較する比較部９とを備える構成である。また、前記出力手段６０は、第１の実施形態における出力手段６に加え、位相判別手段４及び比較部９からの各出力信号に基づいて演算して出力動作を実行する構成である。
【００３２】
前記比較部９は、零相電流要素２から零相電流信号ＳIOが入力されて零相電流信号ＳIOを予め設定された地絡動作電流整定値ＳIA（例えば、０．３［Ａ］、又は０．２［Ａ］ないし０．８［Ａ］）と比較し、大きい場合にはＯＮ信号を出力する零相電流レベル比較部９１と、零相電圧要素３から零相電圧信号ＳV0が入力されて零相電圧信号ＳV0を予め設定された零相電圧整定値ＳVA（例えば、１９０Ｖ＝３８００Ｖの５％相当、その他７．５％、１０％等）と比較し、大きい場合にはＯＮ信号を出力する零相電圧レベル比較部９２とを備える構成である。
【００３３】
次に、前記構成に基づく本実施形態に係る地絡方向継電装置の地絡方向継電動作について説明する。まず、零相変流器ＺＣＴ、零相変成器ＺＰＤで検出された零相電流Ｉ0、零相電圧Ｖ0が零相電流要素２、零相電圧要素３に入力され、この零相電流要素２、零相電圧要素３は零相電流信号ＳIO、零相電圧信号ＳV0の他にアナログ値の零相電流ｉ0、零相電圧ｖ0を生成して出力する。このアナログ値の零相電流ｉ0、零相電圧ｖ0は、増幅、漏波、波形整形等の処理を加えることにより生成される。
【００３４】
このアナログ値の零相電流ｉ0、零相電圧ｖ0が位相判別手段４に入力され、この位相判別手段４は零相電流ｉ0及び零相電圧ｖ0の位相差を検出してこの位相差より地絡事故が零相変流器ＺＣＴの電源側か、又は負荷側かを判別し、各判別結果に基づいて負荷側または電源側の各判別信号ＳL、ＳSを出力する。また、前記ディジタル値の零相電流信号ＳIO、零相電圧信号ＳV0が比較部９の零相電流レベル比較部９１及び零相電圧レベル比較部９２に入力され、この零相電流レベル比較部９１、零相電圧レベル比較部９２は予め設定された動作電流整定値ＳIA、零相電圧整定値ＳVAと比較し、零相電流信号ＳIO、零相電圧信号ＳV0が大きいと判断された場合にＯＮ信号を出力手段６０に出力する。
【００３５】
この出力手段６０は、零相電流レベル比較部９１、零相電圧レベル比較部９２からのＯＮ信号、位相判別手段４からの各判別信号ＳL、ＳS、地絡方向判別手段１からの電源側判断信号ＳSOまたは負荷側判断信号ＳLO、微地絡電流検出手段５からの微地絡電流検出信号ＳTOに基づいて図７に示すように出力を制御して開閉器（図示を省略）、記憶手段７、表示装置７０へ制御信号、各データを出力する。
この地絡方向判別手段１で生成される電源側判断信号ＳSOと負荷側判断信号ＳLO及び位相判別手段４で生成される各判別信号ＳS及びＳLに基づいて図８（Ａ）、（Ｂ）、（Ｃ）、（Ｄ）に示す領域が地絡方向が検出され地絡動作を実行する。
【００３６】
即ち、図８（Ａ）におけるハッチング部分の領域Ａは、負荷側判別信号ＳLが出力され且つ零相電流レベル比較部９１及び零相電圧レベル比較部９２からの各ＯＮ信号が所定時間（例えば、０．２秒間）継続して出力されることを条件として開閉器へ出力されると共に、負荷側地絡記憶部７３に負荷側地絡信号が記録される。また、前記領域Ａおいては、電源側判別信号ＳSが出力され且つ零相電流レベル比較部９１及び零相電圧レベル比較部９２からの各ＯＮ信号が所定時間（例えば、０．２秒間）継続して出力されることを条件として電源側地絡記憶部７４に電源側地絡信号が記録される。
【００３７】
同図（Ｂ）におけるハッチング部分の領域Ｂは、負荷側判別信号ＳLが出力され且つ零相電圧レベル比較部９２からのＯＮ信号が出力されると共に、微地絡電流検出信号ＳTOが所定時間（例えば、０．２秒間）継続して出力されることを条件として負荷側微地絡記憶部７１に負荷側微地絡信号が記録される。また、前記領域Ｂおいては、電源側判別信号ＳSが出力され且つ零相電圧レベル比較部９２からのＯＮ信号が出力されると共に、微地絡電流検出信号ＳTOが所定時間（例えば、０．２秒間）継続して出力されることを条件として電源側微地絡記憶部７２に電源側微地絡信号が記録される。
【００３８】
同図（Ｃ）におけるハッチング部分の領域Ｃは、地絡方向判別手段１から負荷側判断信号ＳLOが出力されると共に、微地絡電流検出手段５から微地絡電流検出信号ＳTOが所定時間（例えば、０．２秒間）継続して出力されることを条件として負荷側微地絡記憶部７１に負荷側微地絡信号が記録される。
同図（Ｄ）におけるハッチング部分の領域Ｄは、地絡方向判別手段１から電源側判断信号ＳSOが出力されると共に、微地絡電流検出手段５から微地絡電流検出信号ＳTOが所定時間（例えば、０．２秒間）継続して出力されることを条件として電源側微地絡記憶部７２に電源側微地絡地絡信号が記録される。
【００３９】
【発明の効果】
本発明においては、零相電流検出手段で検出された零相電流が地絡動作電流整定値より小さな値の設定微地絡電流よりも大きいと判断した場合に微地絡電流検出手段から微地絡電流検出信号を出力し、予め求められた方向判別閾値に基づいて地絡方向判別手段が地絡方向を判別するようにしているので、地絡電流が地絡動作電流整定値に至らない微地絡状態が零相電流検出手段を基準として負荷側又は電源側で発生しているかを特定できるという効果を奏する。
【００４０】
また、本発明においては、微地絡電流検出手段から出力される微地絡電流検出信号を地絡方向判別手段による地絡方向の判別結果に基づいて記憶手段に記憶するようにしているので、零相電流検出手段が配設される三相三線式高圧配電線の負荷側か電源側かを区別して微地絡状態を判断できることとなり、配電線及び高圧機器の漏電を特定できるという効果を有する。
【００４１】
また、本発明においては、絶縁劣化類推手段が微地絡電流検出信号の履歴情報に基づいて負荷側か電源側かの高圧設備の絶縁劣化を類推するようにしているので、地絡電流が地絡動作電流整定値に至る前に予め配電線、高圧機器等の高圧設備の交換等の対策を採ることができるという効果を有する。
また、本発明においては、微地絡の地絡方向を地絡方向判別手段で判別し、地絡電流が地絡動作電流整定値以上の地絡方向を地絡方向検出手段で検出するようにしているので、従来の地絡方向継電装置に併せて設けることができることとなり、微地絡から完全地絡までの総ての地絡状態の方向を検出できるという効果を有する。
【００４２】
本発明においては、地絡方向判別手段が零相電流検出手段で検出された零相電流から零相電圧閾値を演算し、この零相電圧閾値と零相電圧検出手段で検出された零相電圧とを比較して地絡方向を判別するようにしているので、地絡電流が地絡動作電流整定値に至らない微地絡状態が零相電流検出手段を基準として負荷側又は電源側で発生しているかを特定できるという効果を有する。
【図面の簡単な説明】
【図１】本発明の第１の実施形態に係る地絡方向継電装置の全体ブロック構成図
【図２】図１記載の地絡方向継電装置における地絡方向判別手段の詳細ブロック構成図である。
【図３】図１に記載の地絡方向継電装置における記憶手段及び絶縁劣化判断手段の詳細ブロック図である。
【図４】図１に記載の地絡方向継電装置電源側及び負荷側の各漏電状態説明図である。
【図５】図１に記載の地絡方向継電装置の領域判別動作説明図である。
【図６】本発明の第２の実施形態に係る地絡方向継電装置の全体ブロック構成図である。
【図７】図６に記載の地絡方向継電装置における出力手段の詳細構成図であろ。
【図８】図６に記載の地絡方向継電装置の領域判別動作説明図である。
【図９】従来の地絡方向継電装置のブロック回路構成図である。
【符号の説明】
１地絡方向判別手段
２、２００零相電流要素
３、３００零相電圧要素
４位相判別手段
５微地絡電流検出手段
６、６０出力手段
７記憶手段
８絶縁劣化判断手段
９比較部
１１零相電圧閾値検出部
１２零相電圧比較演算部
１３地絡方向判別部
７０表示装置
７１負荷側微地絡記憶部
７２電源側微地絡記憶部
７３負荷側地絡記憶部
７４電源側地絡記憶部
８１負荷側絶縁劣化判断部
８２電源側絶縁劣化判断部
９１零相電流レベル比較部
９２零相電圧レベル比較部
１００零相電流動作回路
２１０、３１０フィルタ
２２０、３２０増幅器
２３０、３３０レベル検出回路
２４０、３４０波形整形回路
１１０、２５０、３５０アンド回路
４００位相判別回路
５００時限回路[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ground fault direction relay device that detects whether a ground fault accident occurs at a power source side or a load side, and more particularly, to a ground fault direction relay device that detects a micro ground fault state that occurs before a ground fault accident. .
[0002]
[Prior art]
Conventionally, this kind of ground fault direction relay device is disclosed in Japanese Patent No. 2554217, which is shown in FIG. FIG. 9 shows a block circuit configuration diagram of a conventional ground fault direction relay device.
In FIG. 9, in the conventional ground fault direction relay device, the zero phase current I0 detected by the zero phase current transformer ZCT (not shown) disposed in the three-phase three-wire high-voltage distribution line becomes the ground fault current level. The zero-phase voltage V0 detected by the zero-phase current element 200 for detecting whether or not it has been reached and the zero-phase transformer ZPD (not shown) disposed in the three-phase three-wire high-voltage distribution line is the ground fault voltage. A zero-phase voltage element 300 that detects whether or not a level has been reached, and a phase determination circuit 400 that compares the ground-fault current level and the phase of the zero-phase current and zero-phase voltage that have reached the ground-fault voltage level to determine The zero-phase current operation circuit 100 outputs a ground fault detection signal when the zero-phase voltage becomes equal to or higher than the set value even when the zero-phase voltage is equal to or lower than the set value.
[0003]
The zero-phase current element 200 amplifies the zero-phase current I0 detected by the zero-phase current transformer ZCT and the output of the filter 210 by an amplifier 220, and outputs a level detection circuit 230 that outputs an output signal when a set level is exceeded. A waveform shaping circuit 240 that shapes the output of 210 into a rectangle, and an AND circuit 250 that outputs a signal corresponding to a zero-phase current when an AND condition between the output of the waveform shaping circuit 240 and the output of the level detection circuit 230 is satisfied. It is a configuration.
[0004]
The zero-phase voltage element 300 includes a filter 310 that extracts a basic component of the zero-phase voltage V0 detected by the zero-phase voltage detector, an amplifier 320 that amplifies the filter 310, and an output of the amplifier 320 that exceeds a set level. A level detection circuit 330 that outputs an output signal, a waveform shaping circuit 340 that shapes the output of the filter 310 into a rectangular wave or a pulse, and an AND condition of the outputs of the waveform shaping circuit 340 and the level detection circuit 330 are obtained. It is configured by an AND circuit 350 that outputs a signal corresponding to the zero-phase voltage when it is established.
[0005]
The phase discriminating circuit 400 inputs the signals for the zero-phase current and the zero-phase voltage, compares the phases of both signals, and determines whether the ground fault is the power source side or the load side of the zero-phase current transformer ZCT. The output is sent to the time limit circuit 500 when it is on the load side. When this output is input to the time limit circuit 500, a predetermined protection operation such as closing the contact of the output relay X after a predetermined time has elapsed and breaking the circuit breaker is performed.
[0006]
This zero-phase current operation circuit 100 is provided with an AND circuit 110. The output of the level detection circuit 230 on the zero-phase current element 200 side is input to one input side of the AND circuit 110, and the zero-phase voltage is input to the other input side. Level detection circuit on element 300 side 330 From the inverter circuit 120. The output signal of the AND circuit 110 is input to the time limit circuit 500 directly or through the OR circuit OR. The inverter circuit 120 outputs an output signal to the AND circuit 110 when the output signal of the level detection circuit 330 of the zero-phase voltage element 300 is 0, that is, when the zero-phase voltage is lower than the set level, and the level detection circuit 330 Output to the AND circuit 110 is stopped.
[0007]
Even when the detection signal on the zero-phase voltage element 300 side is equal to or lower than the operation set value (sensitivity value), if the detection value on the zero-phase current element 200 side becomes equal to or higher than the operation set value, the AND circuit 110 detects the ground fault under both conditions. A signal is output, and the output relay X is operated after a predetermined time has passed through the time circuit 500.
When the detected value on the zero-phase voltage element 300 side becomes equal to or higher than the operation set value, the zero-phase current operation circuit 100 is locked so as not to output an output signal. Therefore, the original operation of the ground fault direction relay device is not hindered.
[0008]
[Problems to be solved by the invention]
Since the conventional ground fault direction relay device is configured as described above, even when the zero phase voltage is lower than the set value, the zero fault current can be specified and operated when the zero phase current exceeds the set value. However, there was a problem that a fine ground fault state due to insulation deterioration of the high voltage equipment in which the zero phase current does not reach the ground fault operating current cannot be detected in advance. As the insulation deterioration of the high-voltage equipment, there are insulation deterioration of the high-voltage distribution line, insulation deterioration of high-voltage equipment such as a circuit breaker, a transformer, a phase advance capacitor, and a high-voltage monitor.
[0009]
Further, the conventional ground fault direction relay device detects the ground fault direction based on the phase difference between the zero phase current I0 and the zero phase voltage V0, but the three-phase is connected to other load equipment connected to the power source side. When the residual zero-phase voltage V0 generated due to the imbalance of the floating capacitance to the ground due to supplying power with only two AC wires, the ground fault direction is more reliably detected with the phase difference. I had a problem that I couldn't. In particular, the zero-phase voltage V0 is extremely small in the load-side ground fault, and the residual zero-phase voltage of several tens [V] or more exists in an actual distribution line. Therefore, the zero-phase current I0 and the zero-phase voltage V0 The phase difference has a problem that it is extremely difficult to determine the ground fault direction in the fine ground fault state.
[0010]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a ground fault direction relay device that can detect a ground fault direction more reliably and can detect a fine ground fault state.
[0011]
[Means for Solving the Problems]
A ground fault direction relay device according to the present invention includes a zero-phase current detection means for detecting a zero-phase current of a three-phase three-wire high-voltage distribution line, and a zero-phase voltage for detecting a zero-phase voltage of the three-phase three-wire high-voltage distribution line. A voltage detection means compares the detected zero-phase current with a set fine ground fault current preset to a value smaller than the ground fault operating current set value, and if it is determined that the zero phase current is large, A fine ground fault current detection means for outputting a fault current detection signal, and the detected zero phase current and zero phase voltage are substituted into the following equation:

C1: Ground capacitance on the power supply side
C2: Ground-side electrostatic capacitance on the load side
j: Imaginary unit
ω: angular frequency
A ground fault direction discriminating means for discriminating the ground fault direction based on a direction discriminating threshold obtained from the distribution of the characteristic graph obtained by the substitution.
[0012]
Thus, in the present invention, when it is determined that the zero-phase current detected by the zero-phase current detection means is larger than the set fine ground-fault current having a value smaller than the ground fault operating current set value, the fine ground-fault current detection means Since the ground fault direction detection means determines the ground fault direction based on the predetermined direction determination threshold value, the zero-phase current exceeds the ground fault operating current set value. It is possible to specify whether a fine ground fault state that does not lead to a ground fault occurs on the load side or the power source side with reference to the zero-phase current detection means.
[0013]
In addition, the ground fault direction relay device according to the present invention includes storage means for storing a fine ground fault current detection signal based on the determination result of the ground fault direction, if necessary. Thus, in the present invention, the fine ground fault current detection signal output from the fine ground fault current detection means is stored in the storage means based on the ground fault direction discrimination result by the ground fault direction discrimination means. Thus, the ground fault state can be determined by distinguishing between the load side and the power source side of the three-phase three-wire high-voltage distribution line provided with the zero-phase current detection means, and the leakage of the distribution line and the high-voltage equipment can be specified.
[0014]
In addition, the ground fault direction relay device according to the present invention, as necessary, is insulation deterioration of each high-voltage equipment on the load side and / or the power source side based on the history information of the fine ground fault current detection signal stored in the storage means. Insulation deterioration analogy means for analogizing is provided. Thus, in the present invention, the insulation deterioration analogy means analogizes the insulation deterioration of the high-voltage equipment on the load side or the power supply side based on the history information of the fine ground fault current detection signal. Measures such as replacement of high-voltage equipment such as distribution lines and high-voltage equipment can be taken in advance before a ground fault exceeding the ground fault operating current set value is reached.
[0015]
Further, the ground fault direction relay device according to the present invention detects a phase difference between the detected zero phase current and zero phase voltage as necessary, and detects a ground fault direction based on the phase difference. A ground fault direction is detected by the ground fault direction determining means, and a ground fault direction is detected by the ground fault direction detecting means when the ground fault current is equal to or greater than a ground fault operating current set value. To do. As described above, in the present invention, the ground fault direction of the ground fault is determined by the ground fault direction determining means, and the ground fault direction in which the ground fault current is equal to or higher than the ground fault operating current set value is detected by the ground fault direction detecting means. Therefore, it can be provided together with the conventional ground fault direction relay device, and the direction of all ground fault states from the fine ground fault to the complete ground fault can be detected.
[0016]
A ground fault direction relay device according to the present invention includes a zero-phase current detection means for detecting a zero-phase current of a three-phase three-wire high-voltage distribution line, and a zero-phase voltage for detecting a zero-phase voltage of the three-phase three-wire high-voltage distribution line. Voltage detection means; The detected zero-phase current is compared with a set fine ground fault current set in advance to a value smaller than the ground fault operating current set value, and if it is determined that the zero phase current is large, the fine ground fault current detection signal is A fine ground fault current detecting means for outputting; A zero-phase voltage threshold is calculated based on the following equation from the detected zero-phase current,
Load-side ground fault relation | vo | = | io / (jω3C1) |
Ground fault relation on power supply side │vo│ = │-io / (jω3C2) │
C1: Ground capacitance on the power supply side
C2: Ground-side electrostatic capacitance on the load side
The zero-phase voltage threshold is compared with the detected zero-phase voltage to determine the ground fault direction. Land And an entanglement direction discriminating means. Thus, in the present invention The ground The winding direction discriminating means calculates a zero-phase voltage threshold value from the zero-phase current detected by the zero-phase current detection means, and compares the zero-phase voltage threshold value with the zero-phase voltage detected by the zero-phase voltage detection means. Since the fault direction is discriminated, it is possible to specify whether a fine ground fault state in which the ground fault current does not reach the ground fault operating current set value occurs on the load side or the power source side with reference to the zero-phase current detection means. .
[0017]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment of the present invention)
Hereinafter, a ground fault direction relay device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5. 1 is an overall block configuration diagram of a ground fault direction relay device according to the present embodiment, FIG. 2 is a detailed block configuration diagram of a ground fault direction determining means in the ground fault direction relay device shown in FIG. 1, and FIG. FIG. 4 is a detailed block diagram of the storage means and the insulation deterioration determining means in the ground fault direction relay device described in FIG. 1, FIG. 4 is an explanatory diagram of each leakage state on the power source side and load side of the ground fault direction relay device shown in FIG. 5 is a diagram for explaining the region discrimination operation of the ground fault direction relay device shown in FIG.
[0018]
In each of the drawings, the ground fault direction relay device according to the present embodiment is the same as the conventional ground fault direction relay device shown in FIG. 9 and the zero phase current element 2 (corresponding to 200 in FIG. 9) and the zero phase voltage. Element 3 (corresponding to 300 in FIG. 9) is provided in common, and in addition to this configuration, the zero-phase current signal SI0 output from the zero-phase current element 2 and the zero-phase voltage signal output from the zero-phase voltage element 3 Ground fault direction discriminating means 1 for judging the ground fault direction (including the fine ground fault direction) based on the zero-phase voltage threshold VSL obtained in advance by SV0 and outputting the judgment signals SLO, SSO on the load side or the power source side. The zero-phase current signal SIO is compared with a set fine ground-fault current ΔIo preset to a value smaller than the ground fault operating current (for example, 0.3 [A]). A fine ground fault current detection means 5 for outputting a fine ground fault current detection signal STO when it is determined that The output means 6 for outputting the outputs of the ground fault direction determination means 1 and the fine ground fault current detection means 5, the output data from the output means 6, the storage means 7, and the output stored in the storage means 7 It is a structure provided with the insulation degradation judgment means 8 which judges the insulation degradation of a high voltage | pressure installation based on data.
[0019]
The ground fault direction discriminating means 1 detects a corresponding zero phase voltage threshold value VSL among the zero phase current / voltage related threshold values PIV obtained in advance based on the zero phase current signal SIO output from the zero phase current element 2. The zero-phase voltage threshold detection unit 11, the zero-phase voltage comparison calculation unit 12 that compares the detected zero-phase voltage threshold VSL and the zero-phase voltage signal SV 0 output from the zero-phase voltage element 3, and this calculation It is a structure provided with the ground fault direction discrimination | determination part 13 which judges a ground fault direction based on a result, and outputs the load side judgment signal SLO or the power supply side judgment signal SSO. The zero-phase current / voltage relation threshold PIV is calculated by the following equation for each phase from the zero-phase current I0, the zero-phase voltage V0, the ground-side floating capacitance C1 on the power source side, or the ground-side floating capacitance C2 on the load side. In accordance with the theoretically calculated values, a power supply side ground fault is drawn in FIG. 5 by a broken line and a load side ground fault is shown by a one-dot chain line, and a solid line is set to separate the middle of each characteristic graph. Is done.
[0020]

C1: Ground capacitance on the power supply side
C2: Ground-side electrostatic capacitance on the load side
j: Imaginary unit
ω: angular frequency
That is, in FIG. 4A, a switch is interposed in a three-phase three-wire high-voltage distribution line, and a leakage (ground fault resistance R) is caused on the power source side from the zero-phase current transformer ZCT disposed in the switch. FIG. 4B shows a case where a leakage (ground fault resistance R) is generated on the load side from the zero-phase current transformer ZCT. In these cases, the output of the zero-phase transformer ZPD is | vo | = | Vt / (jω3CR + 1) |, and the output of the zero-phase current transformer ZCT in the power supply side leakage is | io | = | −vo × jω3C2 | The output of the zero-phase current transformer ZCT in the load-side leakage is | io | = | vo × jω3C1 |. Here, C is the ground floating capacitance of all the high-voltage distribution lines (systems), and is the sum of the ground floating capacitance C1 on the power source side and the ground floating capacitance C2 on the load side.
[0021]
In a general distribution line, the ground-side electrostatic capacitance C1 on the power source side is in the range of 1 μF to 12 μF, and the ground-side electrostatic capacitance C2 on the load side is 0.33 μF or less.
The output means 6 outputs a load side ground fault signal to a switch (not shown) based on the load side judgment signal SLO, the power source side judgment signal SSO and the fine ground fault current detection signal STO. The power supply side ground fault signal, the load side fine ground fault signal, and the power source side fine ground fault signal are output to the storage means 7.
[0022]
The storage means 7 includes a load-side fine ground fault storage unit 71 that stores a load-side fine ground fault signal as history data, a power source side fine ground fault storage unit 72 that stores a power-side fine ground fault signal as history data, The load-side ground fault storage unit 73 stores the load-side ground fault signal as history data, and the power-side ground fault storage unit 74 stores the power-side ground fault signal as history data.
The insulation deterioration determination means 8 includes a load side insulation deterioration determination unit 81 that analogizes insulation deterioration of a high voltage equipment on the load side based on history data stored in the load side fine ground fault storage unit 71, and The power supply-side insulation deterioration determining unit 82 estimates the insulation deterioration of the high-voltage equipment on the power supply side based on the history data stored in the ground fault storage unit 72.
[0023]
Next, the ground fault direction relay operation of the ground fault direction relay device according to the present embodiment based on the above configuration will be described. As a premise, the zero-phase current Z0 and zero-phase voltage V0 of the three-phase three-wire high-voltage distribution line are detected by the zero-phase current transformer ZCT and zero-phase transformer ZPD installed in the switch of the customer's first pillar. The ground-floating capacitance C1 seen from the power source side to the zero-phase current transformer ZCT, the ground-floating capacitance C2 seen from the load side, and this high-voltage distribution line have the ground-floating capacitance of each phase. Assume that no residual zero-phase voltage is generated due to unbalance. Under such conditions, a characteristic graph as shown in FIG. 5 is obtained from the local fault relational expression on the power source side and the load side, and a zero-phase current / voltage relation threshold value PIV that divides these characteristic graphs is obtained in advance to determine the ground fault direction. The data is stored in a storage unit (not shown) in the zero-phase voltage threshold value detection unit 11 of the determination unit 1.
[0024]
First, the zero-phase current I0 from the zero-phase current transformer ZCT and the zero-phase voltage V0 from the zero-phase transformer ZPD are input to the zero-phase current element 2 and the zero-phase voltage element 3, respectively. A current signal SIO is generated, and a zero-phase voltage signal SV0 is generated by the zero-phase voltage element 3. This zero-phase current signal SIO is input to the zero-phase voltage threshold value detecting unit 11 of the ground fault direction discriminating means 1, and this zero-phase voltage threshold value detecting unit 11 receives the zero-phase current / voltage related threshold value PIV from the storage unit (not shown). , And the zero phase voltage threshold VSL corresponding to the inputted zero phase current signal SIO is detected from the zero phase current / voltage related threshold PIV. The detected zero-phase voltage threshold VSL and the generated zero-phase voltage signal SV0 are compared by the zero-phase voltage comparison calculation unit 12, and the ground fault direction determination unit 13 determines the ground fault direction based on the calculation result. The load side determination signal SLO and the power supply side determination signal SSO are output after determination.
[0025]
Further, the generated zero-phase current signal SIO is input to the fine ground fault current detecting means 5, and the fine ground fault current detecting means 5 uses the zero phase current signal SIO as a ground fault operating current set value (for example, 0). .3 [A]) is compared with a set fine ground fault current ΔIo preset to a smaller value, and when it is determined that the zero-phase current signal SIO is large, a fine ground fault current detection signal STO is output.
[0026]
Based on the detected minute ground fault current detection signal STO, the output means 6 outputs the load side judgment signal SLO and the power source side judgment signal SSO inputted from the ground fault direction judgment means 1 to the switch or storage means 7. . The output to this switch is a case where the load-side determination signal SLO is input and a zero-phase current I0 greater than or equal to a ground fault operating current set value (for example, 0.3 [A]) is detected. .
[0027]
Further, the output from the output means 6 to the load side fine ground fault storage unit 71 of the storage means 7 is performed when the load side judgment signal SLO is inputted and the fine ground fault current detection signal STO is inputted. A fine ground fault signal is output and stored as history data. The output from the output means 6 to the power supply side fine ground fault storage unit 72 of the storage means 7 is performed when the power supply side judgment signal SSO is inputted and the fine ground fault current detection signal STO is inputted. A ground fault signal is output and stored as stored data.
[0028]
Furthermore, as a case where the output means 6 outputs to the load-side ground fault storage unit 73 of the storage means 7, the load-side determination signal SLO is input and the ground fault operating current set value (for example, 0.3 [A]) ) When the above zero-phase current I0 is detected, the load side ground fault signal is stored. As an output from the output means 6 to the power supply side ground fault storage unit 74 of the storage means 7, the power supply side judgment signal SSO is inputted, and the ground fault operating current set value set value (for example, 0.3 [A]) ) When the above zero-phase current I0 is detected, the power-supply side ground fault signal is stored.
[0029]
The load side (or power supply side) micro ground fault signal stored as history data in the load side micro ground fault storage unit 71 (or the power source side micro ground fault storage unit 72) is the load side insulation deterioration determination unit 81 (or The change of the change is detected in the power supply side insulation deterioration judgment unit 82), and the insulation deterioration state in the high voltage equipment on the load side (or the power supply side) is inferred based on the change change. The analogy result of the insulation deterioration state and each data stored in the storage means 7 are output by a display device, a printer, a communication line, etc. (not shown).
[0030]
(Second embodiment of the present invention)
A ground fault direction relay device according to a second embodiment of the present invention will be described with reference to FIGS. 4 and 5 based on FIGS. 6 is an overall block configuration diagram of the ground fault direction relay device according to the present embodiment, FIG. 7 is a detailed configuration diagram of output means in the ground fault direction relay device described in FIG. 6, and FIG. 8 is described in FIG. The area | region discrimination | determination operation | movement explanatory drawing of this earth fault direction relay apparatus is shown.
[0031]
In each figure, the ground fault direction relay device according to the present embodiment is the same as the ground fault direction relay device according to the first embodiment described in FIG. 2, zero-phase voltage element 3, output means 60 (corresponding to 6 in FIG. 1) as well as Storage means 7 In addition to this configuration, analog zero-phase current i0 and zero-phase voltage v0 amplified and waveform-shaped by zero-phase current element 2 are input, and the phase difference between zero-phase current i0 and zero-phase voltage v0 is input. And a comparator 9 for comparing the levels of the zero-phase current signal SIO and the zero-phase voltage signal SV0 generated by the zero-phase current element 2 with preset values. And It is the composition provided. Further, the output means 60 is configured to execute an output operation by calculating based on the output signals from the phase discriminating means 4 and the comparison unit 9 in addition to the output means 6 in the first embodiment.
[0032]
The comparator 9 receives the zero-phase current signal SIO from the zero-phase current element 2 and sets the zero-phase current signal SIO to a preset ground fault operating current set value SIA (for example, 0.3 [A] or 0 .2 [A] to 0.8 [A]), the zero-phase voltage signal SV0 is inputted from the zero-phase voltage element 3 and the zero-phase voltage element 3 that outputs an ON signal when it is larger. The zero-phase voltage signal SV0 is compared with a preset zero-phase voltage setting value SVA (for example, equivalent to 5% of 190V = 3800V, other 7.5%, 10%, etc.), and if it is larger, an ON signal is output. The zero-phase voltage level comparison unit 92 is provided.
[0033]
Next, the ground fault direction relay operation of the ground fault direction relay device according to the present embodiment based on the above configuration will be described. First, the zero-phase current I 0 and the zero-phase voltage V 0 detected by the zero-phase current transformer ZCT and the zero-phase transformer ZPD are input to the zero-phase current element 2 and the zero-phase voltage element 3. The zero-phase voltage element 3 generates and outputs an analog zero-phase current i0 and zero-phase voltage v0 in addition to the zero-phase current signal SIO and the zero-phase voltage signal SV0. The analog zero-phase current i0 and zero-phase voltage v0 are generated by applying processing such as amplification, leakage wave, and waveform shaping.
[0034]
The analog zero-phase current i0 and zero-phase voltage v0 are input to the phase discriminating means 4. The phase discriminating means 4 detects the phase difference between the zero-phase current i0 and the zero-phase voltage v0 and detects the ground fault from the phase difference. It is determined whether the accident is the power source side or the load side of the zero-phase current transformer ZCT, and the determination signals SL, SS on the load side or the power source side are output based on the determination results. The digital phase zero-phase current signal SIO and zero-phase voltage signal SV0 are input to the zero-phase current level comparison unit 91 and the zero-phase voltage level comparison unit 92 of the comparison unit 9, and the zero-phase current level comparison unit 91, The zero-phase voltage level comparison unit 92 compares the preset operating current set value SIA and the zero-phase voltage set value SVA, and outputs an ON signal when it is determined that the zero-phase current signal SIO and the zero-phase voltage signal SV0 are large. Output to the output means 60.
[0035]
This output means 60 includes an ON signal from the zero-phase current level comparison section 91 and the zero-phase voltage level comparison section 92, each determination signal SL and SS from the phase determination section 4, and a power source side determination from the ground fault direction determination section 1. Based on the signal SSO or the load side determination signal SLO and the fine ground fault current detection signal STO from the fine ground fault current detection means 5, the output is controlled as shown in FIG. The control signal and each data are output to the display device 70.
8A, 8B, and 8B based on the power-side determination signal SSO and the load-side determination signal SLO generated by the ground fault direction determination unit 1 and the determination signals SS and SL generated by the phase determination unit 4, respectively. In the areas shown in (C) and (D), the ground fault direction is detected and the ground fault operation is executed.
[0036]
That is, in the hatched area A in FIG. 8A, the load-side discrimination signal SL is output, and each ON signal from the zero-phase current level comparison unit 91 and the zero-phase voltage level comparison unit 92 is set for a predetermined time (for example, 0.2 seconds) is output to the switch on the condition that it is continuously output, and the load-side ground fault signal is recorded in the load-side ground fault storage unit 73. In the region A, the power source side determination signal SS is output, and each ON signal from the zero phase current level comparison unit 91 and the zero phase voltage level comparison unit 92 continues for a predetermined time (for example, 0.2 seconds). The power supply side ground fault signal is recorded in the power source side ground fault storage unit 74 on the condition that the power source side ground fault signal is output.
[0037]
In the hatched area B in FIG. 5B, the load side discrimination signal SL is output, the ON signal from the zero phase voltage level comparison unit 92 is output, and the fine ground fault current detection signal STO is output for a predetermined time ( For example, the load-side fine ground fault signal is recorded in the load-side fine ground fault storage unit 71 on the condition that it is continuously output. In the region B, the power-side discrimination signal SS is output, the ON signal from the zero-phase voltage level comparison unit 92 is output, and the fine ground fault current detection signal STO is output for a predetermined time (for example, 0. 0). The power-side fine ground fault signal is recorded in the power-side fine ground fault storage unit 72 on the condition that the output is continued for 2 seconds.
[0038]
In the hatched area C in FIG. 5C, the load side determination signal SLO is output from the ground fault direction determination means 1 and the micro ground fault current detection signal STO is output from the micro ground fault current detection means 5 for a predetermined time ( For example, the load-side fine ground fault signal is recorded in the load-side fine ground fault storage unit 71 on the condition that it is continuously output.
In a hatched area D in FIG. 4D, the ground fault direction determination means 1 outputs the power source side determination signal SSO and the fine ground fault current detection means 5 outputs the fine ground fault current detection signal STO for a predetermined time ( For example, the power-side fine ground fault signal is recorded in the power-side fine ground fault storage unit 72 on the condition that it is continuously output.
[0039]
【The invention's effect】
In the present invention, when it is determined that the zero-phase current detected by the zero-phase current detection means is larger than the set fine ground fault current having a value smaller than the ground fault operating current set value, the fine ground fault current detection means detects the fine ground current. Since the ground fault current detection signal is output and the ground fault direction discriminating means discriminates the ground fault direction based on the direction discrimination threshold determined in advance, the ground fault current does not reach the ground fault operating current set value. There is an effect that it is possible to specify whether the ground fault state occurs on the load side or the power source side with reference to the zero-phase current detection means.
[0040]
Further, in the present invention, since the fine ground fault current detection signal output from the fine ground fault current detection means is stored in the storage means based on the determination result of the ground fault direction by the ground fault direction determination means. It is possible to determine the micro ground fault state by distinguishing between the load side and the power source side of the three-phase three-wire high-voltage distribution line in which the zero-phase current detection means is arranged, and it has the effect that the leakage of the distribution line and the high-voltage equipment can be specified .
[0041]
In the present invention, since the insulation deterioration analogy means analogizes the insulation deterioration of the high voltage equipment on the load side or the power supply side based on the history information of the fine ground fault current detection signal, the ground fault current It has an effect that measures such as replacement of high-voltage equipment such as distribution lines and high-voltage equipment can be taken in advance before reaching the tangled operating current set value.
Further, in the present invention, the ground fault direction of the micro ground fault is determined by the ground fault direction determining means, and the ground fault direction in which the ground fault current is equal to or higher than the ground fault operating current set value is detected by the ground fault direction detecting means. Therefore, it can be provided together with the conventional ground fault direction relay device, and it has an effect that the direction of all the ground fault states from the fine ground fault to the complete ground fault can be detected.
[0042]
In the present invention The ground The direction determining means calculates a zero-phase voltage threshold from the zero-phase current detected by the zero-phase current detecting means, compares the zero-phase voltage threshold with the zero-phase voltage detected by the zero-phase voltage detecting means, Since the fault direction is discriminated, it is possible to specify whether a micro ground fault state in which the ground fault current does not reach the ground fault operating current settling value occurs on the load side or the power source side with reference to the zero-phase current detection means. It has the effect.
[Brief description of the drawings]
FIG. 1 is an overall block configuration diagram of a ground fault direction relay device according to a first embodiment of the present invention;
FIG. 2 is a detailed block diagram of a ground fault direction discriminating means in the ground fault direction relay device shown in FIG. 1;
FIG. 3 is a detailed block diagram of storage means and insulation deterioration judgment means in the ground fault direction relay device shown in FIG. 1;
FIG. 4 is an explanatory diagram of each earth leakage state on the power supply side and load side of the ground fault direction relay device shown in FIG. 1;
FIG. 5 is an explanatory diagram of a region discrimination operation of the ground fault direction relay device shown in FIG. 1;
FIG. 6 is an overall block configuration diagram of a ground fault direction relay device according to a second embodiment of the present invention.
7 is a detailed configuration diagram of output means in the ground fault direction relay device shown in FIG. 6;
FIG. 8 is an explanatory diagram of an area determination operation of the ground fault direction relay device shown in FIG. 6;
FIG. 9 is a block circuit configuration diagram of a conventional ground fault direction relay device.
[Explanation of symbols]
1 Ground fault direction discriminating means
2,200 Zero-phase current element
3,300 Zero phase voltage element
4 Phase discrimination means
5 Micro ground fault current detection means
6, 60 Output means
7 Memory means
8 Insulation deterioration judgment means
9 Comparison part
11 Zero-phase voltage threshold detector
12 Zero-phase voltage comparison calculator
13 Ground fault direction discriminator
70 Display device
71 Load-side fine ground fault storage
72 Power-side fine ground fault memory
73 Load-side ground fault storage
74 Power-supply side ground fault storage
81 Load-side insulation deterioration judgment unit
82 Power-supply side insulation deterioration judgment unit
91 Zero phase current level comparator
92 Zero phase voltage level comparator
100 Zero-phase current operation circuit
210, 310 filters
220, 320 amplifier
230, 330 Level detection circuit
240, 340 Waveform shaping circuit
110, 250, 350 AND circuit
400 Phase discrimination circuit
500 timed circuit

Claims

三相三線式高圧配電線の零相電流を検出する零相電流検出手段と、
前記三相三線式高圧配電線の零相電圧を検出する零相電圧検出手段と、
前記検出された零相電流を地絡動作電流整定値より小さな値に予め設定された設定微地絡電流と比較し、当該零相電流が大きいと判断された場合に微地絡電流検出信号を出力する微地絡電流検出手段と、
前記検出された零相電流及び零相電圧を次式に代入し、

Ｃ1；電源側の対地浮遊静電容量
Ｃ2；負荷側の対地浮遊静電容量
当該代入して得られる特性グラフの分布から求められる方向判別閾値に基づいて地絡方向を判別する地絡方向判別手段とを備えることを
特徴とする地絡方向継電装置。Zero-phase current detection means for detecting the zero-phase current of a three-phase three-wire high-voltage distribution line;
Zero-phase voltage detection means for detecting the zero-phase voltage of the three-phase three-wire high-voltage distribution line;
The detected zero-phase current is compared with a set fine ground fault current set in advance to a value smaller than the ground fault operating current set value, and if it is determined that the zero phase current is large, the fine ground fault current detection signal is A fine ground fault current detecting means for outputting;
Substituting the detected zero-phase current and zero-phase voltage into the following equation:

C1; Ground-side electrostatic capacitance on the power source side C2; Ground-side electrostatic capacitance on the load side Ground fault direction discriminating means for discriminating the ground fault direction based on the direction discrimination threshold obtained from the distribution of the characteristic graph obtained by the substitution. A ground fault direction relay device comprising:

前記請求項１に記載の地絡方向継電装置において、
前記地絡方向の判別結果に基づいて微地絡電流検出信号を記憶する記憶手段を備えることを
特徴とする地絡方向継電装置。In the ground fault direction relay device according to claim 1,
A ground fault direction relay device, comprising storage means for storing a fine ground fault current detection signal based on the determination result of the ground fault direction.

前記請求項２に記載の地絡方向継電装置において、
前記記憶手段に格納された微地絡電流検出信号の履歴情報に基づいて負荷側及び／又は電源側の各高圧設備の絶縁劣化を類推する絶縁劣化類推手段を備えることを
特徴とする地絡方向継電装置。In the ground fault direction relay device according to claim 2,
A ground fault direction characterized by comprising an insulation deterioration analogy means for analogizing an insulation deterioration of each high-voltage facility on the load side and / or the power source side based on history information of a micro ground fault current detection signal stored in the storage means Relay device.

前記請求項１ないし３のいずれかに記載の地絡方向継電装置において、
前記検出された零相電流及び零相電圧の位相差を検出し、当該位相差に基づいて地絡方向を検出する地絡方向検出手段を備え、
前記地絡方向判別手段で微地絡の地絡方向を判別すると共に、前記地絡方向検出手段で零相電流が地絡動作電流整定値以上の地絡の地絡方向を検出することを
特徴とする地絡方向継電装置。In the ground fault direction relay device according to any one of claims 1 to 3,
A ground fault direction detection means for detecting a phase difference between the detected zero phase current and zero phase voltage and detecting a ground fault direction based on the phase difference;
The ground fault direction determining means determines the ground fault direction of the fine ground fault, and the ground fault direction detecting means detects the ground fault direction of the ground fault whose zero phase current is equal to or higher than the ground fault operating current set value. A ground fault direction relay device.

三相三線式高圧配電線の零相電流を検出する零相電流検出手段と、
前記三相三線式高圧配電線の零相電圧を検出する零相電圧検出手段と、
前記検出された零相電流を地絡動作電流整定値より小さな値に予め設定された設定微地絡電流と比較し、当該零相電流が大きいと判断された場合に微地絡電流検出信号を出力する微地絡電流検出手段と、
前記検出された零相電流から次式に基づいて零相電圧閾値を演算し、
負荷側の地絡関係式 │ｖｏ│＝│ｉｏ／（ｊω３Ｃ1）│
電源側の地絡関係式 │ｖｏ│＝│−ｉｏ／（ｊω３Ｃ2）│
Ｃ1；電源側の対地浮遊静電容量
Ｃ2；負荷側の対地浮遊静電容量
当該零相電圧閾値と前記検出された零相電圧とを比較して地絡方向を判別する地絡方向判別手段とを備えることを
特徴とする地絡方向継電装置。Zero-phase current detection means for detecting the zero-phase current of a three-phase three-wire high-voltage distribution line;
Zero-phase voltage detection means for detecting the zero-phase voltage of the three-phase three-wire high-voltage distribution line;
The detected zero-phase current is compared with a set fine ground fault current set in advance to a value smaller than the ground fault operating current set value, and if it is determined that the zero phase current is large, the fine ground fault current detection signal is A fine ground fault current detecting means for outputting;
A zero-phase voltage threshold is calculated based on the following equation from the detected zero-phase current,
Load-side ground fault relation | vo | = | io / (jω3C1) |
Ground fault relation on power supply side │vo│ = │-io / (jω3C2) │
C1; the power supply side of the ground stray capacitance C2; load side of the earth stray capacitance the zero-phase voltage threshold and the detected zero-phase voltage and the earth fault direction discrimination means you determine ground fault direction by comparing the And a ground fault direction relay device.

前記請求項５に記載の地絡方向継電装置において、
前記地絡方向の判別結果に基づいて微地絡電流検出信号を記憶する記憶手段を備えることを
特徴とする地絡方向継電装置。In the ground fault direction relay device according to claim 5,
A ground fault direction relay device, comprising storage means for storing a fine ground fault current detection signal based on the determination result of the ground fault direction.

前記請求項６に記載の地絡方向継電装置において、
前記記憶手段に格納された微地絡電流検出信号の履歴情報に基づいて負荷側及び／又は電源側の各高圧設備の絶縁劣化を類推する絶縁劣化類推手段を備えることを
特徴とする地絡方向継電装置。In the ground fault direction relay device according to claim 6,
A ground fault direction characterized by comprising an insulation deterioration analogy means for analogizing an insulation deterioration of each high-voltage facility on the load side and / or the power source side based on history information of a micro ground fault current detection signal stored in the storage means Relay device.

前記請求項５ないし７のいずれかに記載の地絡方向継電装置において、
前記検出された零相電流及び零相電圧の位相差を検出し、当該位相差に基づいて地絡方向を検出する地絡方向検出手段を備え、
前記地絡方向判別手段で微地絡の地絡方向を判別すると共に、前記地絡方向検出手段で零相電流が地絡動作電流整定値以上の地絡の地絡方向を検出することを
特徴とする地絡方向継電装置。In the ground fault direction relay device according to any one of claims 5 to 7,
A ground fault direction detection means for detecting a phase difference between the detected zero phase current and zero phase voltage and detecting a ground fault direction based on the phase difference;
The ground fault direction determining means determines the ground fault direction of the fine ground fault, and the ground fault direction detecting means detects the ground fault direction of the ground fault whose zero phase current is equal to or higher than the ground fault operating current set value. A ground fault direction relay device.