JP3545485B2 - Transmission line accident point location device - Google Patents

Description

但し、１は送電線、２Ａは電圧変成器、３Ａは電流変成器、Ｖ_Ａ はＡ端子の対地電圧、Ｖ_Ｆ は事故点の対地電圧、Ｆは事故点、Ｉ_Ａ はＡ端子からの事故電流、Ｉ_Ｆ は事故電流、ｘはＡ端子から事故点までの距離である。
【０００４】
本式のＩ_Ｆ は事故点電流そのもので、各端子電流Ｉ_Ａ ，Ｉ_Ｂ のベクトル和電流として算出される。しかし本式はあくまでも事故点抵抗が実抵抗として扱った場合に成立するもので、これがリアクタンス成分を有するとＩ_Ｆ とＶ_Ｆ とは同位相とはならず、（３） 式が成立しないため、そのまま測距誤差となってしまう。このような状況を解決するには対向端子の電圧を使えば事故点の残り電圧に影響されない。原理は（５） 式，（６） 式の通りである。図１１に原理を説明する系統図を示す。
【数２】

【０００５】
【発明が解決しようとする課題】
しかし電流差動リレーの構成を適用する場合、（６） 式の標定計算を行なうには対向端子の全相電流及び電圧が必要で、電流は電流差動リレーの電流を流用すればよいが、電圧の伝送速度が制限されると全相の電圧を所定の速度で伝送できない。例えば電気学会論文誌Ｂ（１１３巻２号、平成５年）に記載の典型的な各端子対向形ＰＣＭ電流差動リレーの伝送速度は５４ｋｂｐｓである。
【０００６】
実際の伝送例は文献（東芝レビュー４１巻１１号“送電線用ディジタル電流差動継電装置”、’８６年１１月）に記載されているが、図１２にその一部を示す。本図では電流データ３相分を３相＊１２ビット／（１／７２０Ｈｚ＝１．３８８ｍｓ）で伝送し、電圧データとしては４ビット／（１／７２０Ｈｚ＝１．３８８ｍｓ）が割り当てられている。
【０００７】
更に事故相が何れかで標定電気量を変える必要がある。例えば２線短絡・地絡事故の場合は当該相間電圧，電流を使う必要があり、１線地絡事故の場合は地絡相の電気量が使われるのが一般的である。そのためには事故相を選別する機能が必要となるので、全相の電気量を対向端子に送出する必要がある。
【０００８】
本発明は上記事情に鑑みてなされたものであり、伝送速度上の制約があっても対向端子の電圧データの伝送量を必要最小限に抑えて、事故点の残り電圧に影響されず、かつ、事故相を選別する機能を要せずに測距できる多端子のデータを使用した送電線事故点標定装置を提供することを目的としている。
【０００９】
【課題を解決するための手段】
本発明の請求項１に係る送電線事故点標定装置は、２回線送電線を有する電力系統の各端子から電気量を抽出し、事故発生時の送電線の事故点を標定する送電線事故点標定装置において、下記８つの手段を備えた。
【００１０】
（１）２回線送電線の一方の端子Ａの各々の回線の３相電圧Ｖ_Ａ１Ｌ，Ｖ_Ａ２Ｌの差分の正相電圧ΔＶ_Ａ１を得る第１の手段。
【００１１】
（２）他方の端子Ｂの各々の回線３相電圧Ｖ_Ｂ１Ｌ，Ｖ_Ｂ２Ｌの差分の正相電圧Δ_Ｂ１を得る第２の手段。
【００１２】
（３）端子Ｂの各々の回線の３相電流Ｉ_Ｂ１Ｌ，Ｉ_Ｂ２Ｌと前記第２の手段で得られる正相電圧ΔＶ_Ｂ１を夫々端子Ａに伝送する第３の手段。
【００１３】
（４）第３の手段で伝送された端子Ｂの各々の回線の３相電流と予め設定された当該送電線の端子Ａと端子Ｂ間の各々の回線の当該回線の送電線線路長インピーダンスＺ_Ｓ１Ｌ，Ｚ_Ｓ２Ｌ及び隣回線との間の相互線路長インピーダンスＺ_ｍ１Ｌ，Ｚ_ｍ２Ｌとの積の差分の３相電圧値｛（Ｚ_Ｓ１Ｌ・Ｉ_Ｂ１Ｌ＋Ｚ_ｍ１Ｌ・Ｉ_Ｂ２Ｌ）−（Ｚ_Ｓ２Ｌ・Ｉ_Ｂ２Ｌ＋Ｚ_ｍ２Ｌ・Ｉ_Ｂ１Ｌ）・Ｌ_１｝を得る第４の手段。
【００１４】
（５）第４の手段で得られた３相の電圧値から正相電圧｛（Ｚ_Ｓ１Ｌ・Ｉ_Ｂ１Ｌ＋Ｚ_ｍ１Ｌ・Ｉ_Ｂ２Ｌ）−（Ｚ_Ｓ２Ｌ・Ｉ_Ｂ２Ｌ＋Ｚ_ｍ２Ｌ・Ｉ_Ｂ１Ｌ）・Ｌ_１｝_１を得る第５の手段。
【００１５】
（６）端子Ａと端子Ｂの各々の回線の電流のベクトル和Ｉ_ｄ１Ｌ，Ｉ_ｄ２Ｌを各３相分算出し、その３相分の電流と予め設定された前記送電線線路の当該回線の単位長当りの送電線線路インピーダンスｚ_Ｓ１Ｌ，ｚ_Ｓ２Ｌ及び隣回線との間の単位長当りの相互インピーダンスｚ_ｍ１Ｌ，ｚ_ｍ２Ｌとの積の差分の３相電圧値｛（ｚ_Ｓ１Ｌ・Ｉ_ｄ１Ｌ＋ｚ_ｍ１Ｌ・Ｉ_ｄ２Ｌ）−（ｚ_Ｓ２Ｌ・Ｉ_ｄ２Ｌ＋ｚ_ｍ２Ｌ・Ｉ_ｄ１Ｌ）｝_１を得る第６の手段。
【００１６】
（７）第６の手段で得られる３相の電圧値から正相電圧｛（ｚ_Ｓ１Ｌ・Ｉ_ｄ１Ｌ＋ｚ_ｍ１Ｌ・Ｉ_ｄ２Ｌ）−（ｚ_Ｓ２Ｌ・Ｉ_ｄ２Ｌ＋ｚ_ｍ２Ｌ・Ｉ_ｄ１Ｌ）｝_１を得る第７の手段。
【００１７】
（８）第１の手段で得られる正相電圧から第３の手段で伝送された正相電圧を減じ更に第５の手段で得られる正相電圧を加算した値から［ΔＶ_Ａ１−ΔＶ_Ｂ１＋Ｌ・｛（Ｚ_Ｓ１Ｌ・Ｉ_Ｂ１Ｌ＋Ｚ_ｍ１Ｌ・Ｉ_Ｂ２Ｌ）−（Ｚ_Ｓ２Ｌ・Ｉ_Ｂ２Ｌ＋Ｚ_ｍ２Ｌ・Ｉ_Ｂ１Ｌ）｝_１］を求め、更にこれを第７の手段で得られた正相電圧で除して事故点までの距離を算出する第８の手段。
【００１８】
本発明の請求項２に係る送電線事故点標定装置は、請求項１において、第２の手段では、端子Ｂの２回線各々の３相電圧Ｖ_Ｂ１Ｌ，Ｖ_Ｂ２Ｌを検出しこれらを正相変換して正相電圧Ｖ_Ｂ１Ｌ１，Ｖ_Ｂ２Ｌ１を得、各回線の３相電流Ｉ_Ｂ１Ｌ，Ｉ_Ｂ２Ｌと共にＡ端子に伝送し、これを受信したＡ端子では第８の手段にて、３相電圧の差分のΔＶ_Ｂ１に代えて（Ｖ_Ｂ１Ｌ１−Ｖ_Ｂ１Ｌ２）として標定値を算出するようにした。
【００１９】
本発明の請求項３に係る送電線事故点標定装置は、請求項１又は請求項２において、第３の手段において、端子ＢのＡ端への伝送速度は３相電流に対して正相電圧を遅らせるようにした。
【００２０】
本発明の請求項４に係る送電線事故点標定装置は、請求項１において、第８の手段において、片回線停止時、停止回線の正相電圧及び正相電流を零にすることにより、標定値を算出するようにした。
【００２１】
本発明の請求項５に係る送電線事故点標定装置は、２回線送電線を有する電力系統の各端子から電気量を抽出し、事故発生時の送電線の事故点を標定する送電線事故点標定装置において、下記９つの手段を備えた。
【００２２】
（１）２回線送電線の各々の回線の電気量を同一時刻に抽出するために各々の回線を同期制御して制御信号を出力する第９の手段。
【００２３】
（２）各回線毎に第９の手段から同期制御信号に基づいて、一方の端子Ａの一方の回線の３相電圧Ｖ_Ａ（）Ｌの正相電圧Ｖ_{Ａ（）Ｌ１}を得る第１の手段。
【００２４】
（３）他方の端子Ｂの一方の回線の３相電圧Ｖ_Ｂ（）Ｌの正相電圧Ｖ_{Ｂ（）Ｌ１}を得る第２の手段。
【００２５】
（４）端子Ｂの一方の回線の３相電流Ｉ_Ｂ（）Ｌと第２の手段で得られる正相電圧Ｖ_ＢＬ１を端子Ａに伝送する第３の手段。
【００２６】
（５）端子Ｂの各々の回線の３相電流と予め設定された当該送電線の端子Ａと端子Ｂ間の各々の回線の当該回線の送電線線路長インピーダンスＺ_Ｓ（）Ｌ及び隣回線との間の相互線路長インピーダンスＺ_ｍ（）Ｌとの積演算で得られる３相電圧値（Ｚ_Ｓ（）Ｌ・Ｉ_Ｂ（）Ｌ＋Ｚ_ｍ（）Ｌ・Ｉ_{Ｂ（）′Ｌ}）・Ｌ_１を得る第４の手段。
【００２７】
（６）第４の手段で得られた３相の電圧値から正相電圧｛（Ｚ_Ｓ（）Ｌ・Ｉ_Ｂ（）Ｌ＋Ｚ_ｍ（）Ｌ・Ｉ_{Ｂ（）′Ｌ}）_１｝を得る第５の手段。
【００２８】
（７）端子Ａと端子Ｂの各々の回線の電流ベルト和Ｉ_ｄ（）Ｌ，Ｉ_{ｄ（）′Ｌ}を各３相分加算したり、その３相分の電流と予め設定された前記送電線線路の当該回線の単位長当りの送電線線路インピーダンスｚ_Ｓ１Ｌ及び単位長当りの隣回線との間の相互インピーダンスｚ_ｍ（）Ｌとの積演算で得られる３相電圧値（ｚ_Ｓ（）Ｌ・Ｉ_ｄ（）Ｌ＋ｚ_ｍ（）Ｌ・Ｉ_{ｄ（）′Ｌ}）_１を得る第６の手段。
【００２９】
（８）第６の手段で得られる３相の電圧値から正相電圧（ｚ_Ｓ（）Ｌ・Ｉ_ｄ（）Ｌ＋ｚ_ｍ（）Ｌ・Ｉ_{ｄ（）′Ｌ}）_１を得る第７の手段。
【００３０】
（９）第１の手段で得られる正相電圧から第３の手段で伝送された正相電圧を減じ更に第５の手段で得られる正相電圧を加算した値から［Ｖ_{Ａ（）Ｌ１}−Ｖ_{Ｂ（）Ｌ１}＋Ｌ・（Ｚ_Ｓ（）Ｌ・Ｉ_Ｂ（）Ｌ＋Ｚ_ｍ（）Ｌ・Ｉ_{Ｂ（）′Ｌ}）・Ｌ_１］を求め、更にこれを第７の手段で得られた正相電圧で除して事故点までの距離を算出する第８の手段。
【００３１】
【作用】
本発明の請求項１，２，３，４，５に係る送電線事故点標定装置は、標定方式の作用は各請求項に共通であるため、その詳細は実施例の項で述べるが、その基本的な考え方は全端子の電圧，電流を使って事故点迄の距離を測定しようとするもので、その電圧，電流量として正相変換した電気量を使用しようというものである。正相電気量を使用することにより、事故相選別機能を必要とせずに、かつ、相手端子に正相変換した電気量を送出することにより、３相分の電気量を送る必要がなく、伝送容量に制約がある場合にも正確に標定可能となる。
【００３２】
そして、各請求項では各端子の正相電気量を使って、事故点を挟む各端子の正相電圧から各々の線路降下電圧の正相分を差し引いた事故点の正相電圧が等しいことを用いて、事故点迄の距離を正確に算出している。なかんずく請求項１では平行２回線送電線を対象とし、各々の端子電圧の回線間差電圧が略零である性質を利用し、回線の正相電気量の差分量を使って、各端子電圧の大きさによって生じる誤差を軽減して、事故点迄の距離を正確に算出している。
【００３３】
又、請求項２は相手端子の正相電圧を回線毎に送出し、受けた端子で回線間の差分をとるように構成したものである。又、請求項３は電流と電圧の伝送速度を変えて、伝送容量の制約があっても標定計算できる伝送方法を示し、請求項４は請求項１の平行２回線送電線の何れか一方の回線が休止している場合には休止している回線の電気量を強制的に零にして、単一回線の標定方式に切り替える方式を示している。更に、請求項５は回線間の正相電気量を使用せずに回線毎の正相電気量で標定する方式を示している。
【００３４】
【実施例】
以下図面を参照して実施例を説明する。
図１は本発明に係る送電線事故点標定装置を説明する一実施例のハードウェアを示す構成図である。先ずＡ端子のみを説明する。図において、１Ａは対象となる平行２回線送電線、２Ａ，２Ｂは変流器、３Ａ，３Ｂは変成器、４Ａは変流器２Ａの電流出力と電圧変成器３Ａの電圧出力とを入力して各々適当なレベルに変換する入力変換回路、５ＡはＡ端子の電流・電圧をサンプリングするサンプリング保持回路、６Ａは５Ａの電流・電圧出力をアナログ・ディジタル変換する回路、７ＡはＡ端子（自端子）の伝送制御回路でＡ端子とＢ端子のサンプリング同期制御処理を行ない、サンプリング保持回路（Ｓ／Ｈ）５Ａの同時サンプリング制御信号を生成する。
【００３５】
８ＡはＡ端子の電流，電圧データを相手Ｂ端子に送信し、Ｂ端子からの電流，電圧データを受信制御する伝送インターフェース、９Ａは事故前後のデータ（自端子，相手端子のデータ）を収集する記憶回路、１０Ａ は前記電流データを用いて電流差動リレーの動作判定及び図２に示す本発明の対象である事故点標定演算を実施する演算回路（ＣＰＵ）、１１Ａ はその標定結果を表示する表示回路であり、相手端子も同様に構成されシンボルを夫々Ｂとしている。
【００３６】
図２は演算回路１０Ａで行なう標定演算の内容を示す図である。１０Ａでは各端子の電流データ（Ａ端子電流：Ｉ_Ａ（）Ｌ，Ｂ端子電流：Ｉ_Ｂ（）Ｌ）のベクトル和をとり、差動電流を算出して下式に基づく差動リレーの動作判定を行なうのと並行に、差動リレーに適用する電流データを使用して事故点標定計算を行なう（詳細は後述する）。但し、以下の説明では差動リレーの構成を説明することは本発明の骨子から外れるので割愛する。
【数３】

【００３７】
前述したように事故相選別を要さず、伝送容量の制約からどんな事故であっても測距できる対称分電気量としては正相電気量がある。正相電気量は対称座標法の対称分（正相，逆送，零相）の１つで、どんな事故ケースでも必ず存在するので、事故相を検出せずに所望の機能を達成できる。
【００３８】
しかし、正相に対して零相は地絡事故のみ（短絡では発生しない）、逆送は不平衡事故のみ（３相短絡事故では発生せず）発生するので、事故相を検出せずに事故点を標定するには不適である。だが正相電圧を使うと、言うまでもなく正相電圧は下式（事故点抵抗は零）に示すように事故点電圧が零にならない（電気学会編：安藤文郎他著「保護継電工学」第３章）ので、一端判定方式による標定計算量としては不適である。
【数４】

【００３９】
図３は各々の事故についての対称分回路である。図から分かるように事故点Ｆでの電圧（Ｖ_Ｆ１）は前記したように事故点抵抗の有無に拘らず必ず残る。この対策として、事故点の正相電圧に影響を受けない方式として対向端子の電気量を使う方式がある。
【００４０】
広く運用されている平行２回線送電線の端子Ａと端子Ｂ間に事故が発生した場合、両端子の正相電圧Ｖ_{Ａ（ ）１} ，Ｖ_{Ｂ（ ）１} と正相電流Ｉ_{Ａ（ ）Ｌ１}，Ｉ_{Ｂ（ ）Ｌ１}と事故点正相電圧Ｖ_{Ｆ（ ）１} の関係は次式の通りである（（ ） ＝１，２：回線名を示す）。本原理の次式を説明する系統図を図４に示す。
【００４１】
【数５】

【００４２】
ここにｚ_（）１Ｌ，ｚ_（）２Ｌは＃１，＃２回線の単位長インピーダンスであり、対称であればｚ_（）１Ｌ＝ｚ_（）２Ｌであることは言うまでもない。（７）式から（８）式のように測距できる。
【数６】

【００４３】
ここに添え字１で示す各相電気量から正相電気量に変換する演算子は（９） 式で示され、インピーダンス行列（ｚ_Ｓ１Ｌ ，ｚ_ｍ１Ｌ ，ｚ_Ｓ２Ｌ ，ｚ_ｍ２Ｌ ）と各相電圧，電流の関係は（１０）式で表される。
【数７】

【００４４】
更にｚ_Ｓ１Ｌ ，ｚ_ｍ１Ｌ ，ｚ_Ｓ２Ｌ ，ｚ_ｍ２Ｌ は夫々（１１）式のマトリックスを表わしている。
【数８】

【００４５】
上記をふまえて、図２に示す演算回路１０Ａの演算処理内容を説明する。平行２回線送電線の端子Ａ，Ｂ間で事故が発生した場合、端子Ａから事故点までの距離Ｘを、正相電圧と正相電流で示すと（８）式の通りであり、以下に再度示す。
【数９】

【００４６】
図２は請求項１に係る送電線事故点標定装置の一実施例の構成図である。したがって本実施例では前記（８） 式を演算するようにした具体例として示す。図２において、第１の手段１では２回線送電線の一方の端子Ａの回線の３相電圧Ｖ_Ａ１Ｌ ，Ｖ_Ａ２Ｌ の差分の正相電圧ΔＶ_Ａ１を得る。なお、「Ｐ」は正相変換行列である（以下同じ）。
【００４７】
一点鎖線で囲った部分は他方の端子（Ｂ端）で、ここにおいて第２の手段２では他方の端子Ｂの各回線の３相電圧Ｖ_Ｂ１Ｌ ，Ｖ_Ｂ２Ｌ の差分の正相電圧ΔＶ_Ｂ１を得て正相変換する。
【００４８】
Ｂ端（相手端）にある伝送制御手段３では、端子Ｂの各回線の３相電流Ｉ_Ｂ１Ｌ ，Ｉ_Ｂ２Ｌ と前記第２の手段で得られる正相電圧ΔＶ_Ｂ１を夫々端子Ａに伝送する。
【００４９】
第４の手段４では、第３の手段で伝送された端子Ｂの各回線の３相電流と予め設定された当該送電線の端子Ａと端子Ｂ間の各回線の当該回線の送電線線路長インピーダンスｚ_Ｓ１Ｌ ，Ｚ_Ｓ２Ｌ 及び隣回線の相互線路長インピーダンスＺ_ｍ１Ｌ ，Ｚ_ｍ２Ｌ との積の差分の３相電圧値｛（Ｚ_Ｓ１Ｌ ・Ｉ_Ｂ１Ｌ ＋Ｚ_ｍ１Ｌ ・Ｉ_Ｂ２Ｌ ）−（Ｚ_Ｓ２Ｌ ・Ｉ_Ｂ２Ｌ ＋Ｚ_ｍ２Ｌ ・Ｉ_Ｂ１Ｌ ）｝を得る。
【００５０】
第５の手段では、前記第４の手段で得られた３相の電圧値から正相電圧｛（Ｚ_Ｓ１Ｌ・Ｉ_Ｂ１Ｌ＋Ｚ_ｍ１Ｌ・Ｉ_Ｂ２Ｌ）−（Ｚ_Ｓ２Ｌ・Ｉ_Ｂ２Ｌ＋Ｚ_ｍ２Ｌ・Ｉ_Ｂ１Ｌ）｝_１を得る。
【００５１】
第６の手段６では、端子Ａと端子Ｂの各回線の電流のベクトル和Ｉ_ｄ１Ｌ ，Ｉ_ｄ２Ｌ を各３相分算出し、その３相分の電流と予め設定された前記送電線線路の当該回線の単位長当たりの送電線線路インピーダンスｚ_Ｓ１Ｌ ，ｚ_Ｓ２Ｌ 及び単位長当たりの隣回線との相互インピーダンスｚ_ｍ１Ｌ ，ｚ_ｍ２Ｌ との積の差分の３相電圧値｛（ｚ_Ｓ１Ｌ ，Ｉ_ｄ１Ｌ ＋ｚ_ｍ１Ｌ ・Ｉ_ｄ２Ｌ ）−（ｚ_Ｓ２Ｌ ・Ｉ_ｄ２Ｌ ＋ｚ_ｍ２Ｌ ・Ｉ_ｄ１Ｌ ）｝を得る。
【００５２】
第７の手段では、前記第６の手段で得られる３相の電圧値から正相電圧｛（ｚ_Ｓ１Ｌ・Ｉ_ｄ１Ｌ＋ｚ_ｍ１Ｌ・Ｉ_ｄ２Ｌ）−（ｚ_Ｓ２Ｌ・Ｉ_ｄ２Ｌ＋ｚ_ｍ２Ｌ・Ｉ_ｄ１Ｌ）｝_１を得る。
【００５３】
第８の手段８では、前記第１の手段で得られる正相電圧から第３の手段で伝送された正相電圧を減じ、更に第５の手段で得られる正相電圧を加算した値から［ΔＶ_Ａ１−ΔＶ_Ｂ１＋Ｌ・｛（Ｚ_Ｓ１Ｌ・Ｉ_Ｂ１Ｌ＋Ｚ_ｍ１Ｌ・Ｉ_Ｂ２Ｌ）−（Ｚ_Ｓ２Ｌ・Ｉ_Ｂ２Ｌ＋Ｚ_ｍ２Ｌ・Ｉ_Ｂ１Ｌ）｝_１］を第７の手段で得られた正相電圧で除して事故点までの距離を算出する。
【００５４】
ここに図２の第２の手段２で作成される他方の端子の回線間差分電圧ΔＶ_Ｂ１（＝（Ｖ_Ｂ１−Ｖ_Ｂ２）_１）を一方の端子に送信するのは第３の手段３によって行なわれる。当然このデータはＡ端子のデータと同期がとれており、同一時刻に抽出される。この同期をとる手法については前記した電気学会論文誌Ｂ（１１３巻２号、平成５年）に詳述されている技術であり、ここでの説明は割愛する。
【００５５】
本実施例によれば平行２回線送電線において夫々の端子電圧の回線間差電圧が略零である性質を利用し、回線の正相電気量の差分量をつかって、各端子電圧の大きさによって生じる誤差を軽減して故障点までの距離を正確に算出できる。
【００５６】
図５は本発明の請求項２に係る送電線事故点標定装置の一実施例の構成図である。図５において、図２と同一部分及び同一機能部分については同一符号を付して説明を省略する。本実施例では２回線送電線の電圧を各々正相変換して送信し、受信した端子（Ａ端子）で差分をとって同一式で標定計算するものである。
【００５７】
即ち、第２の手段２−１ において、２回線送電線の電圧Ｖ_Ｂ１Ｌ ，Ｖ_Ｂ２Ｌ を個々に検出すると共に、それらを正相変換することにより、Ｖ_Ｂ１Ｌ１＝［Ｐ］Ｖ_Ｂ１Ｌ ，Ｖ_Ｂ２Ｌ１＝［Ｐ］Ｖ_Ｂ２Ｌ を得、Ｉ_Ｂ１Ｌ ，Ｉ_Ｂ２Ｌ と共に個別にＡ端子へ送信するものである。
【００５８】
なお、これを受信したＡ端子では（８） 式を演算することは前記実施例の場合と同様である。ただし第８の手段ではＶ_Ｂ１Ｌ１とＶ_Ｂ１Ｌ２との差分をとるようにしている。本実施例によれば図の実施例と同様の効果が得られる。
【００５９】
図６は本発明の請求項３に係る送電線事故点標定装置の一実施例の構成図であり、本実施例では３相電流と正相電圧の伝送速度を制御するものである。この種の装置において、３相電流の伝送速度を遅らせることは差動リレーの動作責務に直接影響を与えるために許容されない。
【００６０】
即ち、系統の安定度を確保するため事故検出・事故除去を高速に行ない、かつ、高速に各相再閉路を行なうためには事故相を確実に判別する必要がある。そして、図６（ａ） は両者を同じ伝送速度で送る場合、図６（ｂ） は３相の電流データに対して正相電圧を１／３の速度にして（分割して）送信する例を示している。
【００６１】
伝送フォーマットの具体例の詳細は文献（東芝レビュー４１巻１１号“送電線用ディジタル電流差動継電装置”、’８６年１１月）に説明されている通りで、前述の図５に示す。同図の高速ｏｎ−ｏｆｆ４ビットのところに１２ビット長／１リードの正相電圧データを３フレーム毎４ビット長に分割して割り付けて伝送することができる。本実施例によれば送電容量に制約があったとしても、電圧量を電流量に比して遅れて伝送することにより、充分対応可能である。
【００６２】
図７は本発明の請求項４に係る送電線事故点標定装置の一実施例を説明する系統構成図であり、２回線送電線の片回線停止時の状態を示す。これを＃２回線停止の例で示すと、Ｉ_Ａ２Ｌ＝０，Ｉ_Ｂ２Ｌ＝０，Ｉ_Ａ２Ｌ＋Ｉ_Ｂ２Ｌ＝０であるため、標定値ｘは（１２）式となる。
【数１０】

なお、図８が本実施例の第８の手段８の処理内容を示す構成図である。
【００６３】
（１２）式の各端子の電圧は線路電圧であり、停止回線側には運用側の電流による誘導電圧分が生じることになる。即ち、その影響は相互インピーダンスｚ_ｍ２Ｌ により生じる。回線が停止しているか否かについては送電線に入っている遮断器の開閉状態を見て判断することができることは言うまでもない。本実施例によれば片回線が休止している場合であっても、休止している回線の電気量を強制的に零にすることにより標定できる。
【００６４】
図９は本発明の請求項５に係る送電線事故点標定装置の一実施例の構成図である。図９において、図１と同一部分及び同一機能部分については同一符号を付す。本実施例では回線毎に同一時刻のデータ（隣回線の電流）を抽出するために、回線間のサンプリングを同期させるものである。
【００６５】
そして本実施では回線単位に収集した両端子の３相電流と正相電圧を使って、自端子（Ａ端子）で（13）式に基づいて標定計算するものである。これは＃１回線側の事故を標定するもので、＃２回線側の事故は(14)式に基づいて標定することは言うまでもない。
【数１１】

【００６６】
上記内容を基に図９に示す実施例を説明する。図９において、新たに付加された第９の手段９では各回線の電気量を同一時刻に抽出するために回線間を同期制御して制御信号を出力する。
【００６７】
第２の手段１では、第９の手段からの同期制御信号に基づいて、各回線毎に、一方の端子Ａの一方の回線の３相電圧Ｖ_{Ａ（ ）Ｌ} の正相電圧Ｖ_{Ａ（ ）Ｌ１}を得る。
【００６８】
第２の手段２では、他方の端子Ｂの一方の回線の３相電圧Ｖ_{Ｂ（ ）Ｌ} の正相電圧Ｖ_{Ｂ（ ）Ｌ１}を得る。
【００６９】
第３の手段３では、端子Ｂの一方の回線の３相電流Ｉ_{Ｂ（ ）Ｌ} と第２の手段で得られる正相電圧Ｖ_{Ｂ（ ）Ｌ１}を端子Ａに伝送する。
【００７０】
第４の手段４では、端子Ｂの各回線の３相電流と予め設定された当該送電線の端子Ａと端子Ｂ間の各々の回線の当該回線の送電線線路長インピーダンスＺ_Ｓ（）Ｌ及び隣回線との間の相互線路長インピーダンスＺ_ｍ（）Ｌとの積演算で得られる３相電圧値（Ｚ_Ｓ（）Ｌ・Ｉ_Ｂ（）Ｌ＋Ｚ_ｍ（）Ｌ・Ｉ_{Ｂ（）′Ｌ}）を得る。
【００７１】
第５の手段５では、前記第４の手段で得られた３相の電圧値から正相電圧（Ｚ_Ｓ（）Ｌ・Ｉ_Ｂ（）Ｌ＋Ｚ_ｍ（）Ｌ・Ｉ_{Ｂ（）′Ｌ}）_１を得る。
【００７２】
第６の手段６では、端子Ａと端子Ｂの各々の回線の電流のベクトル和Ｉ_{ｄ（ ）Ｌ} ，Ｉ_{ｄ（ ） ′ Ｌ} を各３相分算出し、その３相分の電流と予め設定された前記送電線線路の当該回線の単位長当たりの送電線線路インピーダンスｚ_Ｓ１Ｌ 及び単位長当たりの隣回線との相互インピーダンスｚ_{ｍ（ ）Ｌ} との積演算で得られる３相電圧値（ｚ_{Ｓ（ ）Ｌ} ・Ｉ_{ｄ（ ）Ｌ} ＋ｚ_{ｍ（ ）Ｌ} ・Ｉ_{ｄ（ ） ′ Ｌ} ）を得る。
【００７３】
第７の手段７では、前記第６の手段で得られる３相の電圧値から正相電圧（ｚ_Ｓ（）Ｌ・Ｉ_ｄ（）Ｌ＋ｚ_ｍ（）Ｌ・Ｉ_{ｄ（）′Ｌ}）_１を得る。
【００７４】
第８の手段８では、第１の手段で得られる正相電圧から第３の手段で伝送された正相電圧を減じ、更に第５の手段で得られる正相電圧を加算した値［Ｖ_{Ａ（）Ｌ１}−Ｖ_{Ｂ（）Ｌ１}＋（Ｚ_Ｓ（）Ｌ・I_Ｂ（）Ｌ＋Ｚ_ｍ（）Ｌ・Ｉ_{Ｂ（）′Ｌ}）_１］を求め、更にこれを第７の手段で得られた正相電圧で除して事故点までの距離を算出する。
【００７５】
本実施例では回線毎に同一時刻のデータ（隣回線の電流）を抽出するために回線間のサンプリングを同期制御する必要がる。同期をとる手法は種々あるが、これらは本発明の骨子ではないため割愛する。
【００７６】
なお、この方式でも片回線停止時の処置や３相電流と正相電圧の伝送速度の制御方法については各々前記実施例同様に成り立つ。本実施例によれば回線間の正相電気量を使用せずに回線毎の正相電気量で標定できる。
【００７７】
【発明の効果】
以上説明したように、本発明によれば送電線を挟む端子の電気量を集めて事故点を標定する方式において、各端子の電気量から所定の量を作成し、それを正相変換して標定するようにしたので、事故相を選別せずに必要最小限の電気量で精度よく事故点を標定することができる。
【図面の簡単な説明】
【図１】本発明の実施例のハード構成図を説明する図。
【図２】本発明の請求項１に係る送電線事故点標定装置の一実施例の処理内容を示すブロック図。
【図３】各事故種別毎の対称分回路。
【図４】２回線送電線と事故点との関係を示す図。
【図５】本発明の請求項２に係る送電線事故点標定装置の一実施例の構成図。
【図６】本発明の請求項３に係る送電線事故点標定装置の一実施例の構成図。
【図７】本発明の請求項４に係る送電線事故点標定装置の一実施例の構成図。
【図８】図７の場合の第８の手段の処理内容図。
【図９】本発明の請求項５に係る送電線事故点標定装置の一実施例の構成図。
【図１０】従来の一端判定形のインピーダンス測定方式を示す図。
【図１１】従来の対向端子の電圧を使った事故点標定方式を示す図。
【図１２】従来の伝送方式を説明する図。
【符号の説明】
１Ａ 送電線
２Ａ，２Ｂ 変流器
３Ａ，３Ｂ 変成器
４Ａ 入力変換回路
５Ａ Ｓ／Ｈ
６Ａ Ａ／Ｄ
７Ａ 伝送制御回路
８Ａ 伝送インターフェース
９Ａ ＲＡＭ
１０Ａ ＣＰＵ
１１Ａ 表示回路
１ 第１の手段
２ 第２の手段
３ 第３の手段
４ 第４の手段
５ 第５の手段
６ 第６の手段
７ 第７の手段
８ 第８の手段
９ 第９の手段[0001]
[Industrial applications]
The present invention relates to a transmission line fault point locating device that converts a three-phase voltage of an opposite terminal into a positive-phase voltage, transmits the voltage together with each phase current, and locates a fault point with a positive-phase quantity of electricity.
[0002]
[Prior art]
Conventionally, there are a surge receiving method and a pulse radar method as fault point locating methods for transmission lines, and in particular, an impedance measuring method has recently been applied in recent years. The former requires an expensive signal coupling device to the transmission line, while the latter converts the voltage and current obtained by the voltage transformer and current transformer into digital data to obtain impedance and measures the distance to the fault point. To do. This method is based on the method of determining the voltage and current of one terminal (Japanese Patent Publication No. 58-29471) and the method of using the voltage and current of two terminals ("Transmission line fault locator") by Hoki, Kitani, Showa 32 Year Ohmsha).
[0003]
In general, in digital current differential relays, there is a method for realizing an impedance measurement method of a one-end determination type based on the following equation, utilizing that the vector sum current of current data of each terminal obtained is the fault current component itself. . FIG. 10 is a system diagram showing the principle. It is well known that equations (1) and (2) hold in FIG._FIs a real resistance component, the expression (3) is established.
(Equation 1)

However, 1 is a transmission line, 2A is a voltage transformer, 3A is a current transformer, V_AIs the ground voltage of the A terminal, V_FIs the ground voltage at the fault point, F is the fault point, I_AIs the fault current from the A terminal, I_FIs the fault current, and x is the distance from the A terminal to the fault point.
[0004]
I of this formula_FIs the fault point current itself, and each terminal current I_A, I_BIs calculated as the vector sum current of However, this equation is satisfied only when the accident point resistance is treated as a real resistance, and if this has a reactance component, I_FAnd V_FDoes not have the same phase, and the formula (3) is not satisfied, so that the distance measurement error is directly generated. To solve such a situation, if the voltage of the opposite terminal is used, it is not affected by the remaining voltage at the fault point. The principle is as shown in equations (5) and (6). FIG. 11 is a system diagram illustrating the principle.
(Equation 2)

[0005]
[Problems to be solved by the invention]
However, when the configuration of the current differential relay is applied, the orientation calculation of the equation (6) requires all the phase currents and voltages of the opposite terminals, and the current may be the current of the current differential relay. If the voltage transmission speed is limited, it is not possible to transmit all the phase voltages at a predetermined speed. For example, the transmission speed of a typical PCM current differential relay with opposed terminals described in IEEJ Transactions on Journal B (Vol. 113, No. 2, 1993) is 54 kbps.
[0006]
An actual transmission example is described in the literature (Toshiba Review Vol. 41, No. 11, "Digital Current Differential Relay for Transmission Lines", November 1986). FIG. In this figure, three phases of current data are transmitted at three phases * 12 bits / (1/720 Hz = 1.388 ms), and 4 bits / (1/720 Hz = 1.388 ms) are allocated as voltage data.
[0007]
Further, it is necessary to change the standardized electricity quantity in any of the accident phases. For example, in the case of a two-wire short-circuit and ground fault, it is necessary to use the inter-phase voltage and current. For that purpose, a function for selecting the accident phase is required, so that it is necessary to transmit the electric quantity of all phases to the opposite terminal.
[0008]
The present invention has been made in view of the above circumstances, and even if there is a restriction on the transmission speed, the transmission amount of voltage data at the opposite terminal is minimized, and the voltage is not affected by the remaining voltage at the fault point, and It is another object of the present invention to provide a transmission line fault point locating device using multi-terminal data that can measure a distance without a function of selecting a fault phase.
[0009]
[Means for Solving the Problems]
A transmission line fault point locating device according to claim 1 of the present invention extracts a quantity of electricity from each terminal of a power system having two circuit transmission lines and locates a fault point of the transmission line when an accident occurs. The orientation device was provided with the following eight means.
[0010]
(1) Three-phase voltage V of each line of one terminal A of the two-line transmission line_A1L, V_A2LPositive-phase voltage ΔV of the difference_A1The first means to obtain
[0011]
(2) Three-phase voltage V of each line of the other terminal B_B1L, V_B2LPositive-sequence voltage Δ_B1The second means to obtain.
[0012]
(3) Three-phase current I of each line of terminal B_B1L, I_B2LAnd the positive-phase voltage ΔV obtained by the second means._B1Third means for transmitting to the terminal A respectively.
[0013]
(4) The three-phase current of each line of the terminal B transmitted by the third means and a preset transmission line length impedance Z of each line between the terminals A and B of the transmission line set in advance._S1L, Z_S2LAnd the mutual line length impedance Z between adjacent lines_m1L, Z_m2LAnd the three-phase voltage value ｛(Z_S1L・ I_B1L+ Z_m1L・ I_B2L)-(Z_S2L・ I_B2L+ Z_m2L・ I_B1L) ・ L₁A fourth means of obtaining｝.
[0014]
(5) From the three-phase voltage values obtained by the fourth means, the positive-phase voltage ｛(Z_S1L・ I_B1L+ Z_m1L・ I_B2L)-(Z_S2L・ I_B2L+ Z_m2L・ I_B1L) ・ L₁｝₁A fifth means for obtaining
[0015]
(6) Vector sum I of current of each line of terminal A and terminal B_d1L, I_d2LAre calculated for each of the three phases, and the currents for the three phases and the transmission line impedance z per unit length of the line of the transmission line set in advance are calculated._S1L, Z_S2LAnd the mutual impedance z per unit length between adjacent lines_m1L, Z_m2LAnd the three-phase voltage value ｛(z_S1L・ I_d1L+ Z_m1L・ I_d2L)-(Z_S2L・ I_d2L+ Z_m2L・ I_d1L)｝₁A sixth means for obtaining
[0016]
(7) From the three-phase voltage values obtained by the sixth means, the positive-phase voltage ｛(z_S1L・ I_d1L+ Z_m1L・ I_d2L)-(Z_S2L・ I_d2L+ Z_m2L・ I_d1L)｝₁Seventh means for obtaining
[0017]
(8) From the value obtained by subtracting the positive-phase voltage transmitted by the third means from the positive-phase voltage obtained by the first means and further adding the positive-phase voltage obtained by the fifth means, [ΔV_A1-ΔV_B1+ L ｛(Z_S1L・ I_B1L+ Z_m1L・ I_B2L)-(Z_S2L・ I_B2L+ Z_m2L・ I_B1L)｝₁Eighth means for calculating a distance to an accident point by dividing the same by the positive-sequence voltage obtained by the seventh means.
[0018]
In the transmission line fault point locating device according to claim 2 of the present invention, in the first means, the three-phase voltage V of each of the two lines of the terminal B is used as the second means._B1L, V_B2LAre detected, and these are converted to a positive phase to convert the positive phase voltage V_B1L1, V_B2L1And the three-phase current I of each line_B1L, I_B2LIs transmitted to the A terminal together with the A terminal._B1Instead of (V_B1L1-V_B1L2) To calculate the orientation value.
[0019]
The transmission line fault point locating device according to claim 3 of the present invention is the transmission line fault point locating device according to claim 1 or 2, wherein the transmission speed of the terminal B to the terminal A is a positive-phase voltage with respect to the three-phase current. Was delayed.
[0020]
In the transmission line fault point locating device according to claim 4 of the present invention, in the eighth means, when one line is stopped, the positive-phase voltage and the positive-phase current of the stopped line are set to zero. The value was calculated.
[0021]
A transmission line fault point locating device according to claim 5 of the present invention extracts a quantity of electricity from each terminal of a power system having two circuit transmission lines and locates the fault point of the transmission line when an accident occurs. The orientation apparatus was provided with the following nine means.
[0022]
(1) Ninth means for synchronously controlling each line and outputting a control signal in order to extract the amount of electricity of each line of the two-line transmission line at the same time.
[0023]
(2) For each line, based on the synchronization control signal from the ninth means, the three-phase voltage V of one line of one terminal A_{A () L}Positive-phase voltage V_{A () L1}The first means to obtain
[0024]
(3) Three-phase voltage V of one line of the other terminal B_{B () L}Positive-phase voltage V_{B () L1}The second means to obtain.
[0025]
(4) Three-phase current I of one line of terminal B_{B () L}And the positive-phase voltage V obtained by the second means_BL1A third means for transmitting to the terminal A.
[0026]
(5) The three-phase current of each line of the terminal B and a preset transmission line length impedance Z of each line between the terminals A and B of the transmission line set in advance._{S () L}And the mutual line length impedance Z between adjacent lines_{m () L}And the three-phase voltage value (Z_{S () L}・ I_{B () L}+ Z_{m () L}・ I_{B () 'L}) ・ L₁A fourth means of obtaining
[0027]
(6) From the three-phase voltage values obtained by the fourth means, the positive-phase voltage ｛(Z_{S () L}・ I_{B () L}+ Z_{m () L}・ I_{B () 'L})₁A fifth means of obtaining｝.
[0028]
(7) Current belt sum I of each line of terminal A and terminal B_{d () L}, I_{d () 'L}For each of the three phases, and the current for the three phases and the transmission line impedance z per unit length of the line of the transmission line set in advance._S1LAnd the mutual impedance z between adjacent lines per unit length_{m () L}And the three-phase voltage value (z_{S () L}・ I_{d () L}+ Z_{m () L}・ I_{d () 'L})₁A sixth means for obtaining
[0029]
(8) From the three-phase voltage values obtained by the sixth means, the positive-phase voltage (z_{S () L}・ I_{d () L}+ Z_{m () L}・ I_{d () 'L})₁Seventh means for obtaining
[0030]
(9) The positive phase voltage transmitted by the third means is subtracted from the positive phase voltage obtained by the first means, and the positive phase voltage obtained by the fifth means is added._{A () L1}-V_{B () L1}+ L ・ (Z_{S () L}・ I_{B () L}+ Z_{m () L}・ I_{B () 'L}) ・ L₁Eighth means for calculating a distance to an accident point by dividing the same by the positive-sequence voltage obtained by the seventh means.
[0031]
[Action]
In the transmission line fault point locating device according to claims 1, 2, 3, 4, and 5 of the present invention, the operation of the locating method is common to each claim. The basic idea is to measure the distance to the fault point using the voltages and currents of all terminals, and to use the positive-phase converted electricity quantity as the voltage and current quantity. By using the positive phase electricity quantity, there is no need for the accident phase selection function, and by sending the positive phase transformed electricity quantity to the partner terminal, there is no need to send the three phase electricity quantity, so transmission Even when the capacity is restricted, accurate orientation can be performed.
[0032]
Then, in each claim, the positive-phase voltage at each fault point obtained by subtracting the positive-phase component of each line drop voltage from the positive-phase voltage at each terminal sandwiching the fault point using the positive-phase electric quantity at each terminal is equal. The distance to the accident point is accurately calculated. In particular, claim 1 is directed to a parallel two-line transmission line, utilizing the property that the line-to-line difference voltage of each terminal voltage is substantially zero, and using the difference amount of the positive-phase electricity quantity of each line to determine the voltage of each terminal voltage. The error caused by the size is reduced, and the distance to the accident point is calculated accurately.
[0033]
According to a second aspect of the present invention, the positive-phase voltage of the partner terminal is transmitted for each line, and the difference between the lines is obtained at the received terminal. Further, claim 3 shows a transmission method in which the transmission speed of current and voltage is changed so that orientation calculation can be performed even when the transmission capacity is restricted. Claim 4 shows one of the parallel two-line transmission lines of claim 1. In the case where the line is suspended, the amount of electricity of the suspended line is forcibly reduced to zero, and the system is switched to the single line orientation system. Further, claim 5 shows a method of locating the normal phase electric quantity for each line without using the positive phase electric quantity between the lines.
[0034]
【Example】
Embodiments will be described below with reference to the drawings.
FIG. 1 is a configuration diagram showing hardware of one embodiment for explaining a transmission line fault point locating apparatus according to the present invention. First, only the A terminal will be described. In the figure, 1A is a target parallel two-line transmission line, 2A and 2B are current transformers, 3A and 3B are transformers, and 4A is a current output of the current transformer 2A and a voltage output of the voltage transformer 3A. 5A is a sampling and holding circuit for sampling the current and voltage of the A terminal, 6A is a circuit for converting the 5A current / voltage output from analog to digital, and 7A is the A terminal (own terminal). ) Performs the sampling synchronization control processing of the A terminal and the B terminal in the transmission control circuit to generate a simultaneous sampling control signal for the sampling and holding circuit (S / H) 5A.
[0035]
8A is a transmission interface for transmitting the current and voltage data of the A terminal to the partner B terminal and receiving and controlling the current and voltage data from the B terminal, and 9A is collecting data before and after the accident (data of the own terminal and the partner terminal). The storage circuit 10A is a calculation circuit (CPU) for performing the operation determination of the current differential relay and the fault point locating operation shown in FIG. 2, which is the object of the present invention shown in FIG. This is a display circuit, and a partner terminal is similarly configured, and each symbol is B.
[0036]
FIG. 2 is a diagram showing the contents of the orientation calculation performed by the arithmetic circuit 10A. At 10A, the current data of each terminal (A terminal current: I_{A () L}, B terminal current: I_{B () L}), The differential current is calculated, and the operation of the differential relay is determined based on the following equation. At the same time, the fault point locating calculation is performed using the current data applied to the differential relay ( Details will be described later). However, in the following description, description of the configuration of the differential relay will be omitted since it is outside the gist of the present invention.
(Equation 3)

[0037]
As described above, there is a positive-sequence electric quantity as the symmetrical electric quantity that can be measured for any accident due to the restriction of the transmission capacity without requiring the fault phase selection. The positive phase electric quantity is one of the symmetric components (positive phase, reverse transmission, and zero phase) of the symmetric coordinate method, and always exists in any accident case. Therefore, the desired function can be achieved without detecting the accident phase.
[0038]
However, for the positive phase, the zero phase occurs only with a ground fault (does not occur with a short-circuit), and the reverse feed occurs only with an unbalanced fault (not with a three-phase short-circuit). It is not suitable for locating points. However, when the positive-sequence voltage is used, it goes without saying that the positive-sequence voltage does not become zero as shown in the following equation (the fault point resistance is zero) (IEEJ: Fumio Ando et al., "Protective Relay Engineering" (Chapter 3), it is not suitable as the orientation calculation amount by the one-end determination method.
(Equation 4)

[0039]
FIG. 3 is a symmetrical circuit for each fault. As can be seen from the figure, the voltage (V_F1) Always remains regardless of the presence or absence of the accident point resistance as described above. As a countermeasure, there is a method using the electric quantity of the opposite terminal as a method not affected by the positive-phase voltage at the fault point.
[0040]
When an accident occurs between terminals A and B of a widely used parallel two-circuit transmission line, the positive-phase voltage V_{A () 1}, V_{B () 1}And positive-sequence current I_{A () L1}, I_{B () L1}And the fault point positive phase voltage V_{F () 1}Is as follows (() = 1, 2: indicates a line name). FIG. 4 is a system diagram illustrating the following equation of the present principle.
[0041]
(Equation 5)

[0042]
Where z_{() 1L}, Z_{() 2L}Is the unit length impedance of the # 1 and # 2 lines, and if symmetric, z_{() 1L}= Z_{() 2L}Needless to say, Distance measurement can be performed as in equations (7) to (8).
(Equation 6)

[0043]
The operator for converting each phase electric quantity indicated by the suffix 1 into a positive-phase electric quantity is expressed by Expression (9), and the impedance matrix (z_S1L, Z_m1L, Z_S2L, Z_m2L) And the relationship between each phase voltage and current are expressed by equation (10).
(Equation 7)

[0044]
And z_S1L, Z_m1L, Z_S2L, Z_m2LRespectively represent the matrices of equation (11).
(Equation 8)

[0045]
Based on the above, the content of the arithmetic processing of the arithmetic circuit 10A shown in FIG. 2 will be described. When an accident occurs between the terminals A and B of the parallel two-circuit transmission line, the distance X from the terminal A to the accident point is expressed by a positive-sequence voltage and a positive-sequence current as shown in Expression (8). I will show you again.
(Equation 9)

[0046]
FIG. 2 is a configuration diagram of one embodiment of the transmission line fault point locating device according to claim 1. Therefore, in the present embodiment, a specific example in which the equation (8) is calculated will be described. In FIG. 2, in the first means 1, the three-phase voltage V of the line at one terminal A of the two-line transmission line is shown._A1L, V_A2LPositive-phase voltage ΔV of the difference_A1Get. Note that “P” is a normal phase transformation matrix (the same applies hereinafter).
[0047]
The portion surrounded by the dashed line is the other terminal (end B). In the second means 2, the three-phase voltage V of each line of the other terminal B is used._B1L, V_B2LPositive-phase voltage ΔV of the difference_B1And perform normal phase conversion.
[0048]
In the transmission control means 3 at the B end (the other end), the three-phase current I_B1L, I_B2LAnd the positive-phase voltage ΔV obtained by the second means._B1Are transmitted to the terminal A, respectively.
[0049]
In the fourth means 4, the three-phase current of each line of the terminal B transmitted by the third means and the preset transmission line length of each line between the terminals A and B of the transmission line are set in advance. Impedance z_S1L, Z_S2LAnd the mutual line length impedance Z of the adjacent line_m1L, Z_m2LAnd the three-phase voltage value ｛(Z_S1L・ I_B1L+ Z_m1L・ I_B2L)-(Z_S2L・ I_B2L+ Z_m2L・ I_B1L) Get｝.
[0050]
In the fifth means, the positive-phase voltage ｛(Z) is obtained from the three-phase voltage values obtained in the fourth means._S1L・ I_B1L+ Z_m1L・ I_B2L)-(Z_S2L・ I_B2L+ Z_m2L・ I_B1L)｝₁Get.
[0051]
In the sixth means 6, the vector sum I of the current of each line of the terminal A and the terminal B is I_d1L, I_d2LIs calculated for each of the three phases, and the currents for the three phases and the transmission line impedance z per unit length of the line of the transmission line set in advance are calculated._S1L, Z_S2LAnd the mutual impedance z with the adjacent line per unit length_m1L, Z_m2LAnd the three-phase voltage value ｛(z_S1L, I_d1L+ Z_m1L・ I_d2L)-(Z_S2L・ I_d2L+ Z_m2L・ I_d1L) Get｝.
[0052]
In the seventh means, the positive-phase voltage ｛(z) is obtained from the three-phase voltage values obtained in the sixth means._S1L・ I_d1L+ Z_m1L・ I_d2L)-(Z_S2L・ I_d2L+ Z_m2L・ I_d1L)｝₁Get.
[0053]
In the eighth means 8, the positive-phase voltage transmitted by the third means is subtracted from the positive-phase voltage obtained by the first means, and a value obtained by adding the positive-phase voltage obtained by the fifth means to [ ΔV_A1-ΔV_B1+ L ｛(Z_S1L・ I_B1L+ Z_m1L・ I_B2L)-(Z_S2L・ I_B2L+ Z_m2L・ I_B1L)｝₁] Is divided by the positive-sequence voltage obtained by the seventh means to calculate the distance to the fault point.
[0054]
Here, the line-to-line differential voltage ΔV of the other terminal created by the second means 2 in FIG._B1(= (V_B1-V_B2)₁) Is transmitted to one terminal by the third means 3. Naturally, this data is synchronized with the data of the terminal A and is extracted at the same time. The technique for achieving this synchronization is a technique that is described in detail in the above-mentioned IEEJ Transactions on Papers B (113, 2, 1993), and a description thereof will be omitted.
[0055]
According to the present embodiment, the magnitude of each terminal voltage is determined by using the difference between the positive-phase electricity amounts of the lines by utilizing the property that the line-to-line difference voltage of each terminal voltage is substantially zero in a parallel two-line transmission line. Therefore, the distance to the failure point can be accurately calculated by reducing the error caused by the error.
[0056]
FIG. 5 is a configuration diagram of one embodiment of the transmission line fault point locating apparatus according to claim 2 of the present invention. In FIG. 5, the same portions and the same functional portions as those in FIG. In this embodiment, the voltages of the two transmission lines are converted to positive phases and transmitted, and the difference is calculated at the received terminal (A terminal) to perform the orientation calculation using the same formula.
[0057]
That is, in the second means 2-1, the voltage V of the two-line transmission line is_B1L, V_B2LAre detected individually, and they are subjected to normal-phase conversion, so that V_B1L1= [P] V_B1L, V_B2L1= [P] V_B2LAnd I_B1L, I_B2L, And individually transmitted to the A terminal.
[0058]
At the terminal A receiving this, the operation of the equation (8) is performed in the same manner as in the above embodiment. However, in the eighth means, V_B1L1And V_B1L2And take the difference. According to this embodiment, the same effects as those of the embodiment shown in the figure can be obtained.
[0059]
FIG. 6 is a block diagram of an embodiment of a transmission line fault point locating device according to claim 3 of the present invention. In this embodiment, the transmission speed of a three-phase current and a positive-phase voltage is controlled. In this type of device, slowing down the transmission speed of the three-phase current is not allowed because it directly affects the operational duty of the differential relay.
[0060]
That is, in order to ensure the stability of the system and to perform accident detection and accident elimination at high speed, and to perform high-speed reclosing of each phase, it is necessary to reliably identify the accident phase. FIG. 6A shows an example in which both are transmitted at the same transmission rate, and FIG. 6B shows an example in which the positive-phase voltage is reduced (divided) to three-phase current data and transmitted. Is shown.
[0061]
The details of a specific example of the transmission format are as described in the literature (Toshiba Review Vol. 41, No. 11, "Digital Current Differential Relay for Transmission Lines", November 1986), and are shown in FIG. It is possible to transmit the 12-bit length / 1-read positive-phase voltage data by dividing it into 4-bit lengths for every three frames at the high-speed on-off 4 bits in FIG. According to the present embodiment, even if the power transmission capacity is restricted, it is possible to sufficiently cope with the problem by transmitting the voltage amount later than the current amount.
[0062]
FIG. 7 is a system configuration diagram illustrating an embodiment of a transmission line fault point locating apparatus according to claim 4 of the present invention, and shows a state in which one line of a two-line transmission line is stopped. If this is shown in the example of # 2 line suspension, I_A2L= 0, I_B2L= 0, I_A2L+ I_B2LSince = 0, the orientation value x is given by equation (12).
(Equation 10)

FIG. 8 is a configuration diagram showing the processing contents of the eighth means 8 of this embodiment.
[0063]
The voltage at each terminal in the equation (12) is a line voltage, and a voltage induced by the current on the operation side is generated on the stopped line side. That is, the effect is the mutual impedance z_m2LCaused by It goes without saying that whether or not the line is stopped can be determined by checking the open / closed state of the circuit breaker in the transmission line. According to the present embodiment, even when one of the lines is inactive, the orientation can be determined by forcibly setting the electric quantity of the inactive line to zero.
[0064]
FIG. 9 is a block diagram of one embodiment of the transmission line fault point locating device according to claim 5 of the present invention. 9, the same reference numerals are given to the same portions and the same function portions as those in FIG. In this embodiment, sampling between lines is synchronized in order to extract data at the same time (current of an adjacent line) for each line.
[0065]
In this embodiment, the orientation calculation is performed at the terminal (A terminal) based on the equation (13) using the three-phase current and the positive-phase voltage of both terminals collected for each line. This locates the accident on the # 1 line side, and it goes without saying that the accident on the # 2 line side is located based on the equation (14).
(Equation 11)

[0066]
An embodiment shown in FIG. 9 will be described based on the above contents. In FIG. 9, a newly added ninth means 9 outputs a control signal by synchronously controlling the lines in order to extract the electric quantity of each line at the same time.
[0067]
In the second means 1, on the basis of the synchronization control signal from the ninth means, for each line, the three-phase voltage V of one line of one terminal A is applied._{A () L}Positive-phase voltage V_{A () L1}Get.
[0068]
In the second means 2, the three-phase voltage V of one line of the other terminal B is_{B () L}Positive-phase voltage V_{B () L1}Get.
[0069]
In the third means 3, the three-phase current I_{B () L}And the positive-phase voltage V obtained by the second means_{B () L1}To the terminal A.
[0070]
In the fourth means 4, the three-phase current of each line of the terminal B and a preset transmission line length impedance Z of each line between the terminals A and B of the transmission line are preset._{S () L}And the mutual line length impedance Z between adjacent lines_{m () L}And the three-phase voltage value (Z_{S () L}・ I_{B () L}+ Z_{m () L}・ I_{B () 'L}Get)
[0071]
The fifth means 5 converts the three-phase voltage values obtained by the fourth means into a positive-phase voltage (Z_{S () L}・ I_{B () L}+ Z_{m () L}・ I_{B () 'L})₁Get.
[0072]
In the sixth means 6, the vector sum I of the current of each line of the terminal A and the terminal B_{d () L}, I_{d () ′ L}Is calculated for each of the three phases, and the currents for the three phases and the transmission line impedance z per unit length of the line of the transmission line set in advance are calculated._S1LAnd the mutual impedance z with the adjacent line per unit length_{m () L}And the three-phase voltage value (z_{S () L}・ I_{d () L}+ Z_{m () L}・ I_{d () ′ L}Get)
[0073]
The seventh means 7 converts the three-phase voltage values obtained by the sixth means into positive-phase voltages (z_{S () L}・ I_{d () L}+ Z_{m () L}・ I_{d () 'L})₁Get.
[0074]
The eighth means 8 subtracts the positive-phase voltage transmitted by the third means from the positive-phase voltage obtained by the first means, and further adds a value [V] obtained by adding the positive-phase voltage obtained by the fifth means._{A () L1}-V_{B () L1}+ (Z_{S () L}・ I_{B () L}+ Z_{m () L}・ I_{B () 'L})₁], And dividing this by the positive-sequence voltage obtained by the seventh means to calculate the distance to the fault point.
[0075]
In this embodiment, it is necessary to perform synchronous control of sampling between lines in order to extract data at the same time (current of an adjacent line) for each line. There are various methods for achieving synchronization, but these are not the gist of the present invention and will not be described.
[0076]
In this method, the measures for stopping one line and the method of controlling the transmission speed of the three-phase current and the positive-sequence voltage are the same as in the above-described embodiment. According to the present embodiment, it is possible to specify the normal phase electric quantity for each line without using the positive phase electric quantity between the lines.
[0077]
【The invention's effect】
As described above, according to the present invention, in the method of locating the fault point by collecting the electric quantity of the terminals sandwiching the transmission line, a predetermined quantity is created from the electric quantity of each terminal, and the phase is converted to the positive phase. Since the orientation is performed, the accident point can be accurately located with the minimum necessary amount of electricity without selecting the accident phase.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a hardware configuration diagram according to an embodiment of the present invention.
FIG. 2 is a block diagram showing processing contents of an embodiment of the transmission line fault point locating apparatus according to claim 1 of the present invention.
FIG. 3 is a symmetrical circuit for each accident type.
FIG. 4 is a diagram showing a relationship between a two-circuit transmission line and an accident point.
FIG. 5 is a configuration diagram of an embodiment of a transmission line fault point locating apparatus according to claim 2 of the present invention.
FIG. 6 is a configuration diagram of an embodiment of a transmission line fault point locating device according to claim 3 of the present invention.
FIG. 7 is a configuration diagram of an embodiment of a transmission line fault point locating apparatus according to claim 4 of the present invention.
FIG. 8 is a processing content diagram of an eighth means in the case of FIG. 7;
FIG. 9 is a configuration diagram of an embodiment of a transmission line accident point locating apparatus according to claim 5 of the present invention.
FIG. 10 is a diagram showing a conventional one-end determination type impedance measurement method.
FIG. 11 is a diagram showing a conventional fault point locating method using the voltage of the opposite terminal.
FIG. 12 is a diagram illustrating a conventional transmission system.
[Explanation of symbols]
1A transmission line
2A, 2B current transformer
3A, 3B transformer
4A input conversion circuit
5A S / H
6A A / D
7A transmission control circuit
8A transmission interface
9A RAM
10A CPU
11A Display circuit
1 First means
2 Second means
3 Third means
4 Fourth means
5 Fifth means
6 Sixth means
7 Seventh means
8 Eighth Means
9 ninth means

Claims (5)

A transmission line fault point locating apparatus for extracting an amount of electricity from each terminal of a power system having a two-line transmission line and locating a fault point of the transmission line at the time of occurrence of an accident, comprising: Transmission line accident point locator.
Serial (1) 2-line 3-phase voltage _V A1L of each line of one terminal A of the transmission _line, a first means for obtaining a positive sequence voltage [Delta] V _A1 of the difference between _{V A2L.}
(2) the other 3-phase voltages _V B1L of each of the line terminal _B, second means for obtaining a positive phase voltage delta _B1 of the difference of _{V B2L.}
(3) three-phase current of each of the line terminal B _{I B1L,} third means for transmitting a positive phase voltage [Delta] V _B1 obtained by the second means and _{I B2L} respectively terminal A.
(4) transmission lines line length of the line of each of the line between the terminals A and B of the 3-phase currents with a preset the transmission line of each line of the transmitted terminal B by the third means impedance _{Z S1L,} cross line length impedance _{Z M1L,} 3-phase voltage value of the difference of the product of the _{Z M2L} between _{Z S2L} and next line _{{(Z S1L · I B1L +} Z m1L · I B2L) - (Z S2L · Fourth means for obtaining I _B2L + Z _m2L · I _B1L )｝.
(5) Fourth positive-phase voltage from the voltage values of the obtained three-phase with means _- obtain _{{(Z S1L · I B1L +} Z m1L · I B2L) (Z S2L · I B2L + Z m2L · I B1L)} 1 Fifth means.
(6) of each of the lines of current terminals A and B vector sum I _d1L, the I _d2L calculates the three phases, of the line of pre-set the transmission line path and the current of the three phases The three-phase voltage value of the difference between the product of the transmission line impedance z _S1L , z _S2L per unit length and the mutual impedance z _m1L , z _m2L per unit length between the adjacent line and ｛(z _S1L · _Id1L + z _{m1L) · I d2L) - (z S2L} · I d2L + z m2L · I d1L) sixth means for obtaining a}.
(7) positive-phase voltage from the voltage value of three phases obtained by the sixth means _{{(z S1L · I d1L +} z m1L · I d2L) - (z S2L · I d2L + z m2L · I d1L)} first get ₁ 7 means.
_{(8) [ΔV A1 -ΔV B1} + L from the value obtained by adding the positive-phase voltage obtained by further subtracting the transmitted positive phase voltage from the positive phase voltage obtained by the first means in the third means fifth means _{· {(Z S1L · I B1L} + Z m1L · I B2L) - (Z S2L · I B2L + Z m2L · I B1L)} 1] a determined, divided by the further positive phase voltage obtained this in seventh means Eighth means for calculating the distance to the accident point by using the following method. The suffix 1 is a sign indicating that the parentheses have been subjected to normal phase conversion by the symmetric coordinate method. same as below. 2. The transmission line _fault point locating device according to claim 1, wherein the second means detects the three-phase voltages V _B1L and V _B2L of each of the two lines of the terminal B, and converts the three-phase voltages into positive-phase voltages V _B1L1 and V _B1L1 . give a V _B2L1, 3-phase current _I B1L for each _{line, I} transmitted to the a terminal with _B2L, at eighth means is the a terminal that has received this, instead of the difference [Delta] V _B1 of the three-phase voltage (V _B1L1 −V _B1L2 ), wherein a location value is calculated as a transmission line accident point location apparatus. In power transmission line fault point locating system according to claim 1 or claim 2 wherein the transmission rate of the A end of the terminal B by the third means feed characterized by delaying the positive-phase voltage to three-phase current Electric wire accident point location device. 8. The transmission line fault point locating apparatus according to claim 1, wherein in the eighth means, when one line is stopped, the normal value and the positive current of the stopped line are set to zero to calculate the position value. Transmission line accident point locating equipment. A transmission line fault point locating device for extracting an amount of electricity from each terminal of a power system having a two-line transmission line and locating a fault point of the transmission line at the time of occurrence of an accident, comprising: Transmission line accident point locator.
(1) A ninth means for synchronously controlling each line and outputting a control signal in order to extract the electric quantity of each line of the two-line transmission line at the same time.
(2) _A first method for obtaining a positive-phase voltage _{VA () L1} of the three-phase voltage _{VA () L} of one line of one terminal A based on a synchronization control signal from ninth means for each line. Means.
(3) Second means for obtaining the positive-phase voltage VB _{() L1} of the three-phase voltage VB _{() L} of one line of the other terminal B.
(4) Third means for transmitting the three-phase current IB _{() L} of one line of the terminal B and the positive-phase voltage V _{B () L1} obtained by the second means to the terminal A.
(5) The three-phase current of each line of the terminal B and a predetermined length of the transmission line length impedance ZS _{() L} of each line between the terminal A and the terminal B of the transmission line and the adjacent line. A three-phase voltage value (ZS _{() L ） IB () L} + Zm _{() L}・ IB _{() 'L} ) obtained by a product operation with the mutual line length impedance Zm _{() L} between 4 means.
(6) Fourth positive-phase voltage from the voltage values of the obtained three-phase with means _{{(Z S () L ·} I B () L + Z m () L · I B () 'L)} to obtain a ₁ Fifth means.
(7) terminal A and the vector sum of each line of the current terminal _{B I d () L, I} d () ' to _L is calculated each three phases, preset the current of the three phases A three-phase voltage value obtained by a product operation of the transmission line impedance z _{S () L} per unit length of the transmission line and the mutual impedance z _{m () L} between the transmission line and the adjacent line per unit length ( _{z S () L · I d} () L + z m () L · I d () 'L) sixth means for obtaining.
(8) A seventh method for obtaining a positive-phase voltage (zS _{() L.Id () L} + zm _{() L.Id () 'L} ) ₁ from the three-phase voltage values obtained by the sixth means. means.
(9) _A value obtained by subtracting the positive-phase voltage transmitted by the third means from the positive-phase voltage obtained by the first means, and further adding the positive-phase voltage obtained by the fifth means [ _{VA () L1− V B () L1 + (Z} S () L · I B () L + Z m () L · I B () 'L) 1] the determined positive-phase voltage obtained further this in seventh means Eighth means for calculating the distance to the accident point by dividing by. The suffix 1 is a symbol indicating that the inside of the parentheses has been subjected to normal phase conversion by the symmetric coordinate method. (): The relevant line, () ′ is the other line. The same shall apply hereinafter .

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