JP2004032859A

JP2004032859A - Distance relay system and distance relay device

Info

Publication number: JP2004032859A
Application number: JP2002183238A
Authority: JP
Inventors: Shigeto Oda; 尾田　重遠
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2002-06-24
Filing date: 2002-06-24
Publication date: 2004-01-29
Anticipated expiration: 2022-06-24
Also published as: JP3798346B2

Abstract

<P>PROBLEM TO BE SOLVED: To accurately perform a positive operation and a non-operation against an external failure, and also to accurately perform the positive operation against an internal failure, in a distance relay for protecting a power system having capacitors in series on a power cable. <P>SOLUTION: A steady-state voltage Vpo1 before the occurrence of the failure in the power system is detected, a voltage Vop at the time of the occurrence of the failure is detected, and the power system is protected corresponding to a phase difference between the steady-state voltage Vpo1 before the occurrence of the failure and the voltage Vop at the time of the occurrence of the failure. A distance relay device 8D is used for the protection of the power system having the capacitors 4, 21, thus accurately performing the positive operation and the non-operation against the external failure, and the positive operation against the internal failure. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
この発明は、送電線上に直列コンデンサを有する電力系統を保護する距離リレ−方式、及び送電線上に直列コンデンサを有する電力系統の保護に適用できる距離リレ−装置に関するものである。
【０００２】
【従来の技術】
図７〜図１１は、例えば特公昭５３−２６２９５号公報に示される従来の距離リレ−方式及び距離リレ−装置を示す図で、図７は誤動作防止対策回路を示す図、図８は距離リレ−装置の背後故障における誤動作説明図、図９は誤動作対策の説明図、図１０は距離リレ−装置の前方故障における誤不動作となる系統構成を示す図、図１１は距離リレ−装置の前方故障における誤不動作の説明図である。
【０００３】
図７〜図１１において、１は電源、２及び３は送電線、４は直列コンデンサ、５は母線、６は計器用変圧器、７は計器用変流器、８は距離リレ−、９は故障点、１０は前記距離リレ−８の動作領域、１１は入力端子、１２は記憶回路、１３は位相比較回路、１４は前記位相比較回路１３の出力信号、１５は入力電圧、１６は前記記憶回路１２の出力電圧、１７はＮＯＴ回路、１８はＡＮＤ回路、１９はリレ−出力、２０は相手端の第２の電源、２１は前記距離リレ−８の前方の直列コンデンサ、２２は前記直列コンデンサ２１直後の故障点である。
【０００４】
なお、前記距離リレ−８は、前記送電線２を保護するためのものであり、その保護領域は、例えばモ−リレ−とすると図８に示すように横軸を抵抗分Ｒ、縦軸をリアクタンス分Ｘとして１０で示す円内となる。ここで、前記送電線２の方向が図８の第１象限である。
【０００５】
次に図７〜図１１によって動作について説明する。図７において、送電線２上の背後（距離リレ−の後方）方向で且つ直列コンデンサ４の母線５と反対側で故障９が発生した場合、故障点９の位置は、図８におけるＸ軸上に見ることになり、距離リレ−８の動作特性内に入る場合があり、誤動作に至る。従来技術におけるこの誤動作防止対策の考え方は図９（ａ）（ｂ）に示されている。
【０００６】
図９（ａ）（ｂ）において、Ｖ１は電源１の電圧、Ｖ５は母線５における電圧とする。電力系統の健全時には、図９（ａ）に示すように、前記電圧Ｖ１，Ｖ５は或る程度の電圧位相差を持っており、この電圧位相差に対応した電力が前記電源１から母線５の方に流れている。即ち、電圧Ｖ１と電圧Ｖ５の各頂点を結ぶ線上に送電線各部の電圧ベクトルがあると見ることができる。
【０００７】
ところが、図７における地点９に故障が発生すると、図９（ｂ）に示すように、直列コンデンサ４の為に母線５の電圧Ｖ５は極性が反転してしまう。前記母線５の電圧Ｖ５の極性が反転したときには距離リレ−８から見て背後故障であるとして出力をロックするという手段で誤動作を防ぐ。即ち、図７において、電圧位相を記憶する記憶回路１２の出力１６と電圧入力（計器用変圧器６の出力）１５とが比較回路１３に入力され、前記記憶回路１２の出力１６に対し前記電圧入力（計器用変圧器６の出力）１５の位相が反転しておれば、前記比較回路１３は出力する。この比較回路１３の出力１４を次段のＮＯＴ回路１７で反転して、次段のＡＮＤ回路１８をロックする。即ち、距離リレ−８の動作出力があっても、比較回路１３の出力１４が出力しておれば、リレ−出力端子１９からリレ−動作信号（通常は遮断器トリップ信号）が出力されないようにロックし、距離リレ−装置は正不動作となる。
【０００８】
【発明が解決しようとする課題】
従来の距離リレ−方式及び距離リレ−装置は、前述のように構成されているので、前述のように背後故障での誤動作を防ぐことはできるが、例えば図１０のように、電源１の相手端に第２の電源２０があり、直列コンデンサ２１が距離リレ−８の前方にもある場合には、直列コンデンサ２１の直後の地点２２で故障が発生した場合には、距離リレ−８の見るインピ−ダンスが図１１に示すように、距離リレ−８の動作領域１０外にくるために、前方故障（内部故障）に対して正動作できないという不具合が生じる。
【０００９】
この発明は前述のような課題を解決するためになされたものであり、外部故障に対する正不動作と内部故障に対する正動作ができる距離リレ−方式及び距離リレ−装置を得ることを目的とするものである。
【００１０】
【課題を解決するための手段】
請求項１に記載の発明に係る距離リレ−方式は、電力送電線上に直列にコンデンサを有する電力系統における故障前の定常電圧を検出するとともに前記電力系統における故障発生時の電圧を検出し、前記故障前の定常電圧と前記故障発生時の電圧との位相差の程度に応動する距離リレ−装置を前記電力系統に設け、前記距離リレ−装置により前記電力系統を保護するものである。
【００１１】
請求項２に記載の発明に係る距離リレ−装置は、電力系統における故障前の定常電圧を検出するとともに前記電力系統における故障発生時の電圧を検出し、前記故障前の定常電圧と前記故障発生時の電圧との位相差の程度に応動して前記電力系統を保護するものである。
【００１２】
請求項３に記載の発明に係る距離リレ−装置は、電力系統における故障を検出する故障検出機能、故障前の定常電圧を記憶し前記故障検出機能の出力に応動して前記故障の数サイクル前の故障前定常電圧をベクトル電圧として出力し続ける記憶機能、及び前記ベクトル電圧と故障発生時の電圧との位相差の程度に応動する距離リレ−動作判定機能を備え、前記距離リレ−動作判定機能の判定結果により前記電力系統を保護するものである。
【００１３】
請求項４に記載の発明に係る距離リレ−装置は、第１の動作領域と、この第１の動作領域と異なる動作領域の第２の動作領域とを有し、電力系統における故障前の定常電圧に対して故障発生時の電圧の位相が反転していない場合は前記第１の動作領域が、電力系統における故障前の定常電圧に対して故障発生時の電圧の位相が反転している場合は前記第２の動作領域が、それぞれリレ−出力として出力されることにより前記電力系統を保護するものである。
【００１４】
請求項５に記載の発明に係る距離リレ−装置は、動作領域調整機能を有し、この動作領域調整機能により、電力系統における故障前の定常電圧に対して故障発生時の電圧の位相が反転している場合と反転してない場合とで、異なる動作領域に調整されて前記電力系統を保護するものである。
【００１５】
【発明の実施の形態】
実施の形態１．
以下、この発明の実施の形態１の一例を図１〜図３に基づいて説明する。図１は接続図、図２は記憶機能による電圧記憶時間を示す図、図３は図１の動作説明図である。なお、前述の従来技術を示す図７〜図１１と同一又は相当する部分には図７〜図１１と同一符号を付し、その構成、機能の説明は割愛する。
【００１６】
図１〜図３において、８Ｄは距離リレ−装置で、後述の乗算回路（乗算機能）１０１と後述の動作電圧生成回路（動作電圧生成機能）１０２と後述の故障検出回路（故障検出機能）１０３と後述の記憶回路（記憶機能）１０４と後述の距離リレ−動作判定回路（距離リレ−動作判定機能）１０５とで構成されている。１０１は乗算回路（乗算機能）で、入力電流Ｉ（計器用変流器７の出力電流Ｉ）にモ−特性の動作整定値を乗算する機能を有しており、距離リレ−特性を設定するものである。１０２は動作電圧生成回路（動作電圧生成機能）で、電圧入力（計器用変圧器６の出力Ｖ）と前記乗算回路（乗算機能）１０１の出力とをベクトル除算して動作電圧ベクトルＶｏｐ（Ｖｏｐ＝Ｖ−Ｚ・Ｉ）を生成するものである。１０３は故障検出回路（故障検出機能）で、電圧変化幅検出リレ−要素（図示省略）とタイマ−要素（図示省略）とで構成され、電圧Ｖの変化（故障発生）から、少なくとも故障が解除されるまで、出力１０３ｏを継続するように構成されている。
【００１７】
１０４は記憶回路（記憶機能）で、常時数サイクル分の電圧波形を記憶し、前記故障検出回路（故障検出機能）１０３の出力１０３ｏをトリガ−信号として受けて、例えば図２に示すように、故障発生前複数サイクル前（この実施の形態１では３サイクル前を例示）の１サイクル間の定常電圧の電圧波形１ＣＶＷのデ−タを出力Ｖｐｏｌとするものである。この故障発生前複数サイクル前の１サイクル間の電圧波形デ−タは、後段回路での演算処理において故障終了まで繰り返し使用される。
【００１８】
なお、故障発生の複数サイクル前（この実施の形態１では３サイクル前を例示）の１サイクル間の定常電圧の電圧波形１ＣＶＷのデ−タを出力Ｖｐｏｌとする理由は、例えば故障発生直前の電圧波形は、デ−タの取り方によっては故障時波形を含んでしまう可能性があったり、正確な定常電圧とならない可能性があり、従って、正確な定常電圧を得るためには故障発生の複数サイクル前の定常電圧デ−タをＶｐｏｌとした方が好ましい。
【００１９】
１０５は距離リレ−動作判定回路（距離リレ−動作判定機能）で、前記動作電圧生成回路（動作電圧生成機能）１０２の出力Ｖｏｐ（Ｖｏｐ＝Ｖ−Ｚ・Ｉ）と前記記憶回路（記憶機能）１０４の出力Ｖｐｏｌとから得られるベクトルからモ−特性の動作領域を構成する回路（機能）で、ベクトルＶｏｐとベクトルＶｐｏｌとのなす角が、例えば９０°以上で動作するように構成することでモ−特性を得るものである。つまり、距離リレ−動作判定回路（距離リレ−動作判定機能）１０５の動作判定は、例えば、∠（Ｖｏｐ，Ｖ−ＺＩ）＜９０°⇒　不動作、∠（Ｖｏｐ，Ｖ−ＺＩ）≧９０°⇒　動作、と設定されている。
【００２０】
次に動作について説明する。図１の地点９での故障（距離リレ−８の外部故障）の場合には、図３（ａ）に示すように、前記記憶回路（記憶機能）１０４の出力Ｖｐｏｌは故障前３サイクル前の電圧位相であり、一方、前記動作電圧生成回路（動作電圧生成機能）１０２の出力ＶｏｐはＶ−Ｚ・Ｉ（Ｖは現在の距離リレ−入力電圧（計器用変圧器６の出力電圧）、Ｉは現在の距離リレ−入力電流（計器用変流器７の出力電流））であるので、これら両電圧Ｖｐｏｌ，Ｖｏｐ間のベクトル位相差の程度は９０°未満となり、動作外となる。つまりリレ−出力１９からリレ−動作出力は出ない。
【００２１】
一方、地点２２での故障（距離リレ−８の内部故障）の場合には、図３（ｂ）に示すように、前記記憶回路（記憶機能）１０４の出力Ｖｐｏｌは故障前３サイクル前の電圧位相であり、一方、前記動作電圧生成回路（動作電圧生成機能）１０２の出力ＶｏｐはＶ−Ｚ・Ｉ（Ｖは現在の距離リレ−入力電圧（計器用変圧器６の出力電圧）、Ｉは現在の距離リレ−入力電流（計器用変流器７の出力電流））であるので、これら両電圧Ｖｐｏｌ，Ｖｏｐ間のベクトル位相差の程度は９０°以上となり、動作する。つまりリレ−出力１９からリレ−動作出力が出る。リレ−出力１９からリレ−動作出力が出れば、電力系統における距離リレ−８の保護区間の両端遮断器（図示省略）がトリップして、電力系統から保護区間が切り離され所期の系統保護が行われる。
【００２２】
なお、図３（ａ）と図３（ｂ）とで、前記距離リレ−入力電圧（計器用変圧器６の出力電圧）Ｖが逆位相になるのは、故障地点９（図３（ａ））の場合の距離リレ−入力電流（計器用変流器７の出力電流）Ｉの方向と、故障地点２２（図３（ｂ））の場合の距離リレ−入力電流（計器用変流器７の出力電流）Ｉの方向とが逆位相となるので、図３（ａ）および図３（ｂ）においてリレ−入力電流ＩをＲ軸方向にとると、故障地点９（図３（ａ））は後方故障であるので前記ＶはＲ軸から９０°進みの電圧ベクトルとなり、故障地点９（図３（ａ））は前方故障であるので前記ＶはＲ軸から９０°遅れの電圧ベクトルとなる。
【００２３】
また、図３（ａ）（故障地点９）と図３（ｂ）（故障地点２２）において、前記記憶回路（記憶機能）１０４の出力Ｖｐｏｌは、故障前３サイクル前の１サイクル間の定常時電圧を記憶した電圧であるので電圧ベクトル方向自体は同じであるが、図３（ａ）および図３（ｂ）では電流をＲ軸方向に固定してあり、且つ、故障後の電流Ｉは直列コンデンサ４，２１の影響で故障前と逆極性になるので、図３（ａ）および図３（ｂ）では、Ｖｐｏｌ電圧位相が逆になっているように見える。
【００２４】
また、前記記憶回路（記憶機能）１０４の出力、つまり、前記記憶回路（記憶機能）１０４に記憶されたデ−タを故障中に使用するデ−タは、例えば、故障発生時の時刻をｔ、距離リレ−装置８Ｄの電圧サンプリングが３０度電気角毎、３０度電気角に相当する時間をＴ、デ−タは故障前２−３サイクル前のデ−タとすれば、Ｖ（ｔ−３６Ｔ）、Ｖ（ｔ−３５Ｔ）、Ｖ（ｔ−３４Ｔ）、・・・、Ｖ（ｔ−２５Ｔ）の１２サンプルデ−タとなる。
【００２５】
この１２サンプルデ−タを、
Ｖ（ｔ）　　　　　→　Ｖ（ｔ−３６Ｔ）
Ｖ（ｔ＋１Ｔ）　　→　Ｖ（ｔ−３５Ｔ）
Ｖ（ｔ＋２Ｔ）　　→　Ｖ（ｔ−３４Ｔ）
Ｖ（ｔ＋３Ｔ）　　→　Ｖ（ｔ−３３Ｔ）
・・・・・・・・・・・・・・
Ｖ（ｔ＋１２Ｔ）　→　Ｖ（ｔ−３６Ｔ）
Ｖ（ｔ＋１３Ｔ）　→　Ｖ（ｔ−３５Ｔ）
Ｖ（ｔ＋１４Ｔ）　→　Ｖ（ｔ−３４Ｔ）
Ｖ（ｔ＋１５Ｔ）　→　Ｖ（ｔ−３３Ｔ）
・・・・・・・・・・・・・・
Ｖ（ｔ＋２４Ｔ）　→　Ｖ（ｔ−３６Ｔ）
Ｖ（ｔ＋２５Ｔ）　→　Ｖ（ｔ−３５Ｔ）
Ｖ（ｔ＋２６Ｔ）　→　Ｖ（ｔ−３４Ｔ）
Ｖ（ｔ＋２７Ｔ）　→　Ｖ（ｔ−３３Ｔ）
のように繰り返し、故障が終了するまで、故障発生前電圧Ｖｐｏｌとして前記記憶回路（記憶機能）１０４は出力する。
【００２６】
尚、前記故障検出回路（故障検出機能）１０３は、前述同様に例えば、故障発生時の時刻をｔ、距離リレ−装置８Ｄの電圧サンプリングが３０度電気角毎、３０度電気角に相当する時間をＴ、とすれば、｜Ｖ（ｔ）−Ｖ（ｔ−１２Ｔ）｜＞ｄＶ１の式を演算して当該式を満足することで故障検出し、復帰タイマ−でその出力を継続する。なお、ｄＶ１は電圧変化幅設定値、｜　　｜は演算後実行値処理計算することを意味する。
【００２７】
このように、この発明の実施の形態１においては、コンデンサを有する電力系統における故障前定常電圧Ｖｐｏｌと故障発生時動作電圧Ｖｏｐ（Ｖ−Ｚ・Ｉ）との位相差の程度に応動（∠（Ｖｏｐ，Ｖ−ＺＩ）＜９０°⇒　不動作、∠（Ｖｏｐ，Ｖ−ＺＩ）≧９０°⇒　動作）する距離リレ−装置を設け、前記距離リレ−装置により前記電力系統を保護する距離リレ−方式としたものであり、また、電力系統における故障前定常電圧Ｖｐｏｌと故障発生時動作電圧Ｖｏｐ（Ｖ−Ｚ・Ｉ）との位相差の程度に応動（∠（Ｖｏｐ，Ｖ−ＺＩ）＜９０°⇒　不動作、∠（Ｖｏｐ，Ｖ−ＺＩ）≧９０°⇒　動作）して前記電力系統を保護する距離リレ−装置としたものであり、更に具体的には、電力系統における故障を検出する故障検出機能１０３、故障前定常電圧を記憶し前記故障検出機能の出力に応動して前記故障の数サイクル前の故障前定常電圧をベクトル電圧Ｖｐｏｌとして出力し続ける記憶機能１０４、及び前記ベクトル電圧Ｖｐｏｌと故障発生時動作電圧Ｖｏｐ（Ｖ−Ｚ・Ｉ）との位相差の程度に応動（∠（Ｖｏｐ，Ｖ−ＺＩ）＜９０°⇒　不動作、∠（Ｖｏｐ，Ｖ−ＺＩ）≧９０°⇒　動作）する距離リレ−動作判定機能１０５を備え、前記距離リレ−動作判定機能１０５の判定結果により前記電力系統を保護する距離リレ−装置としたものであり、前述のように、コンデンサ４，２１を含む電力系統の保護に適用した場合、外部故障（故障点９）に対する正不動作、内部故障（故障点２２）に対する正動作、を確実に行うことができる。
【００２８】
実施の形態２．
この発明の実施の形態２は、前述の実施の形態１における電圧変化幅ｄＶを検出する故障検出回路（機能）１０３に代えて、図４に示すように電流変化幅ｄＩを検出する故障検出回路（機能）１０６を使用した場合の一例を示す。前記故障検出回路（機能）１０３は、前述のように、電力系統の故障を検出して前記記憶回路（機能）に対しその記憶デ−タから故障発生数サイクル前の１サイクル間のデ−タをＶｐｏｌとして出力させるトリガ−機能であり、従って、この機能は、前述の実施の形態１における電圧変化幅ｄＶを検出する故障検出回路（機能）１０３（図１）に限られるものではなく、実施の形態２のように電流変化幅ｄＩを検出する故障検出回路（機能）１０６（図４）としても良く、更には、不足電圧検出要素、過電流検出要素、等であっても、また、それらの組み合わせであっても、前述の実施の形態１の場合と同様な効果が得られる。なお、距離リレ−装置８Ｄは、乗算回路（乗算機能）１０１と動作電圧生成回路（動作電圧生成機能）１０２と記憶回路（記憶機能）１０４と距離リレ−動作判定回路（距離リレ−動作判定機能）１０５と故障検出回路（故障検出機能）１０６とで構成されている。なお、前述の図１〜図３、及び前述の従来技術を示す図７〜図１１と同一又は相当する部分には図１〜図３、及び図７〜図１１と同一符号を付し、その構成、機能の説明は割愛してある。
【００２９】
実施の形態３．
以下にこの発明の実施の形態３の一例を図５に基づいて説明する。図５において、前述の図１〜図４、及び前述の従来技術を示す図７〜図１１と同一又は相当する部分には図１〜図４、及び図７〜図１１と同一符号を付し、その構成、機能の説明は割愛する。
【００３０】
図５において、８１は第１の距離リレ−動作判定回路（距離リレ−動作判定機能）で、直列コンデンサ４，２１による位相反転が生じてない系統故障に応動する第１の動作領域を有する第１の距離リレ−特性を有するものである。８２は第２の距離リレ−動作判定回路（距離リレ−動作判定機能）で、直列コンデンサ４，２１による位相反転が生じる系統故障に的確に応動する第２の動作領域を有する第２の距離リレ−特性、即ち地点２２の故障（内部故障）には応動するが地点９の故障（外部故障）には応動しない距離リレ−特性を有するものである。
【００３１】
１０８は位相反転検出回路（位相反転検出機能）で、記憶回路（記憶機能）１０４の出力Ｖｐｏｌと、計器用変圧器６の出力Ｖとを入力し、両出力Ｖｐｏｌ，Ｖを比較して前記計器用変圧器６の出力Ｖの位相が反転した場合に出力するものである。１０９はＡＮＤ回路、１１０はＯＲ回路である。なお、距離リレ−装置８Ｄは、前記第１の距離リレ−動作判定回路（距離リレ−動作判定機能）８１と前記第２の距離リレ−動作判定回路（距離リレ−動作判定機能）８２と故障検出回路（故障検出機能）１０３と記憶回路（記憶機能）１０４と位相反転検出回路（位相反転検出機能）１０８とＮＯＴ回路１７とＡＮＤ回路１８とＡＮＤ回路１０９とＯＲ回路１１０とで構成されている。
【００３２】
次に動作について説明する。位相反転検出回路（位相反転検出機能）１０８は、前記記憶回路（記憶機能）１０４の出力Ｖｐｏｌと、前記計器用変圧器６の出力Ｖとを比較し、故障発生に伴って前記計器用変圧器６の出力Ｖの電圧位相が反転した場合に動作出力して、ＮＯＴ回路１７を介して、第１の距離リレ−動作判定回路（距離リレ−動作判定機能）８１のリレ−出力をロックし、第２の距離リレ−動作判定回路（距離リレ−動作判定機能）８２のリレ−出力をＡＮＤ回路１０９及びＯＲ回路１１０を介して最終出力としてリレ−出力１９に出力する。即ち、地点２２の故障（内部故障）には応動するが地点９の故障（外部故障）には応動しない前述の実施の形態１及び実施の形態２と同様に正動作、正不動作を確実に行う。
【００３３】
一方、位相反転検出回路（位相反転検出機能）１０８は、前記記憶回路（記憶機能）１０４の出力Ｖｐｏｌと、前記計器用変圧器６の出力Ｖとを比較し、故障発生に伴って前記計器用変圧器６の出力Ｖの電圧位相が反転していない場合には動作出力を出さないので、ＮＯＴ回路１７にはロック信号は入らない。従って、第１の距離リレ−動作判定回路（距離リレ−動作判定機能）８１のリレ−出力をＡＮＤ回路１８及びＯＲ回路１１０を介して最終出力としてリレ−出力１９に出力する。
【００３４】
即ち、前述の実施の形態３では、故障前電圧位相と故障発生後の電圧位相とを比較して、故障発生後の電圧の位相反転の有無によって、第１の動作領域（第１の距離リレ−動作判定回路（距離リレ−動作判定機能）８１）と第２の動作領域（第２の距離リレ−動作判定回路（距離リレ−動作判定機能）８２）の判定出力を自動的に切り替えるリレ−回路構成にすることによって、外部故障、内部故障に対して前述の実施の形態１及び実施の形態２と同様に正不動作、正動作を確実に行うものである。
【００３５】
実施の形態４．
以下にこの発明の実施の形態４の一例を図６に基づいて説明する。図６において、前述の図１〜図５、及び前述の従来技術を示す図７〜図１１と同一又は相当する部分には図１〜図５、及び図７〜図１１と同一符号を付し、その構成、機能の説明は割愛する。
【００３６】
図６において、１１１はＺ設定制御回路（Ｚ設定制御機能）で、例えば前述の実施の形態３における第１の動作領域（第１の距離リレ−動作判定回路（距離リレ−動作判定機能）８１）に設定するベクトルインピ−ダンスＺの整定値として（Ｚ１，θ１）を有するとともに、例えば前述の実施の形態３における第２の動作領域（第２の距離リレ−動作判定回路（距離リレ−動作判定機能）８２）に設定するベクトルインピ−ダンスＺの整定値としてとして（Ｚ２，θ２）を有している。
【００３７】
１１２は選択Ｚ乗算回路で、前記Ｚ設定制御回路（Ｚ設定制御機能）１１１から選択的に出力されたベクトルインピ−ダンスＺ１の整定値（Ｚ１，θ１）またはベクトルインピ−ダンスＺ２の整定値（Ｚ２，θ２）を乗算するものである。１１３は動作領域調整回路（動作領域調整機能）で、動作電圧生成回路（動作電圧生成機能）１０２と、前記Ｚ設定制御回路（Ｚ設定制御機能）１１１と、前記選択Ｚ乗算回路（選択Ｚ乗算機能）１１２とで構成されている。なお、距離リレ−装置８Ｄは、選択Ｚ乗算回路（選択Ｚ乗算機能）１１２と動作電圧生成回路（動作電圧生成機能１０２と距離リレ−動作判定回路（距離リレ−動作判定機能）１０５と故障検出回路（故障検出機能）１０３と記憶回路（記憶機能）１０４と位相反転検出回路（位相反転検出機能）１０８とＺ設定制御回路（Ｚ設定制御機能）１１１とで構成されている。
【００３８】
次に動作について説明する。位相反転検出回路（位相反転検出機能）１０８が、前述の実施の形態３と同様に機能して、系統故障検出に伴い計器用変圧器６の電圧位相が反転していないことによりその動作出力を出さない場合は、Ｚ設定制御回路（Ｚ設定制御機能）１１１はベクトルインピ−ダンスＺ１の整定値（Ｚ１，θ１）を選択して出力する。この出力は前記選択Ｚ乗算回路（乗算機能）１１２の入力となり、動作電圧生成回路（動作電圧生成機能）１０２は、前記Ｚ設定制御回路（Ｚ設定制御機能）１１１からの前記選択的出力に応じて、電圧入力（計器用変圧器６の出力Ｖ）と前記選択Ｚ乗算回路（乗算機能）１１２の出力とをベクトル除算して、動作電圧ベクトルＶｏｐ１（Ｖｏｐ＝Ｖ−Ｚ１・Ｉ）を生成し、その結果、距離リレ−８は、例えば前述の実施の形態３における第１の動作領域（第１の距離リレ−動作判定回路（距離リレ−動作判定機能）８１）に設定される。
【００３９】
次に、位相反転検出回路（位相反転検出機能）１０８が、前述の実施の形態３と同様に機能して、系統故障検出に伴い計器用変圧器６の電圧位相が反転していることによりその動作出力を出した場合は、Ｚ設定制御回路（Ｚ設定制御機能）１１１はベクトルインピ−ダンスＺ２の整定値（Ｚ２，θ２）を選択して出力する。この出力は前記選択Ｚ乗算回路（乗算機能）１１２の入力となり、動作電圧生成回路（動作電圧生成機能）１０２は、前記Ｚ設定制御回路（Ｚ設定制御機能）１１１からの前記選択的出力に応じて、電圧入力（計器用変圧器６の出力Ｖ）と前記選択Ｚ乗算回路（乗算機能）１１２の出力とをベクトル除算して、動作電圧ベクトルＶｏｐ２（Ｖｏｐ＝Ｖ−Ｚ２・Ｉ）を生成し、その結果、距離リレ−８は、例えば前述の実施の形態３における第２の動作領域（第２の距離リレ−動作判定回路（距離リレ−動作判定機能）８２）に設定される。
【００４０】
即ち、前述の実施の形態４では、故障前電圧位相と故障発生後の電圧位相とを比較して、故障発生後の電圧の位相反転の有無によって、前記Ｚ設定制御回路（Ｚ設定制御機能）１１１がベクトルインピ−ダンスＺの整定値を選択して、後段の動作電圧生成回路（動作電圧生成機能）１０２で生成する動作電圧ベクトルＶｏｐ（Ｖｏｐ＝Ｖ−Ｚ・Ｉ）におけるベクトルインピ−ダンスＺを自動的に制御することよって、外部故障、内部故障に対して前述の実施の形態１〜実施の形態３と同様に正不動作、正動作を確実に行うものである。なお、この実施の形態４においては、動作電圧生成回路（動作電圧生成機能）１０２で生成する動作電圧ベクトルＶｏｐ（Ｖｏｐ＝Ｖ−Ｚ・Ｉ）におけるベクトルインピ−ダンスＺを切替変更するだけであるので、演算処理の負担は軽くなる。
【００４１】
なお、前述の実施の形態１〜実施の形態４において、それらの一例としてＨ／Ｗ回路的に図示（図１、図４〜図６）してあるが、各図における各機能をＳ／Ｗで実行するようにしても前述の実施の形態１〜実施の形態４と同様な機能、効果を奏し、この出願の発明に包含される。
【００４２】
【発明の効果】
請求項１に記載の距離リレ−方式の発明は、電力送電線上に直列にコンデンサを有する電力系統における故障前の定常電圧を検出するとともに前記電力系統における故障発生時の電圧を検出し、前記故障前の定常電圧と前記故障発生時の電圧との位相差の程度に応動する距離リレ−装置を前記電力系統に設け、前記距離リレ−装置により前記電力系統を保護するようにしたので、電力送電線上に直列にコンデンサを有する電力系統であっても、電力系統を保護する距離リレ−装置を、前記故障前の定常電圧と前記故障発生時の電圧との位相差の程度に応動する距離リレ−装置としたことから、外部故障に対する正不動作、内部故障に対する正動作、を確実に行うことができる効果がある。
【００４３】
請求項２に記載の距離リレ−装置の発明は、電力系統における故障前の定常電圧を検出するとともに前記電力系統における故障発生時の電圧を検出し、前記故障前の定常電圧と前記故障発生時の電圧との位相差の程度に応動して前記電力系統を保護するようにしたので、この発明の距離リレ−装置を電力送電線上に直列にコンデンサを有する電力系統の保護に適用した場合や、この発明の距離リレ−装置を使用した電力系統の電力送電線上に直列にコンデンサを設置した場合、外部故障に対する正不動作、内部故障に対する正動作、を確実に行うことができる効果がある。
【００４４】
請求項３に記載の距離リレ−装置の発明は、電力系統における故障を検出する故障検出機能、故障前の定常電圧を記憶し前記故障検出機能の出力に応動して前記故障の数サイクル前の故障前定常電圧をベクトル電圧として出力し続ける記憶機能、及び前記ベクトル電圧と故障発生時の電圧との位相差の程度に応動する距離リレ−動作判定機能を備え、前記距離リレ−動作判定機能の判定結果により前記電力系統を保護するようにしたので、この発明の距離リレ−装置を電力送電線上に直列にコンデンサを有する電力系統の保護に適用した場合や、この発明の距離リレ−装置を使用した電力系統の電力送電線上に直列にコンデンサを設置した場合、前記故障前の定常電圧と前記故障発生時の電圧との位相差の程度に応動して、外部故障に対する正不動作、内部故障に対する正動作、を確実に行うことができる距離リレ−装置を実現する具体的構成の距離リレ−装置を提供できる効果がある。
【００４５】
請求項４に記載の距離リレ−装置の発明は、第１の動作領域と、この第１の動作領域と異なる動作領域の第２の動作領域とを有し、電力系統における故障前の定常電圧に対して故障発生時の電圧の位相が反転していない場合は前記第１の動作領域が、電力系統における故障前の定常電圧に対して故障発生時の電圧の位相が反転している場合は前記第２の動作領域が、それぞれリレ−出力として出力されることにより前記電力系統を保護するようにしたので、この発明の距離リレ−装置を電力送電線上に直列にコンデンサを有する電力系統の保護に適用した場合や、この発明の距離リレ−装置を使用した電力系統の電力送電線上に直列にコンデンサを設置した場合、前記請求項３の発明と具体的構成が異なる構成でありながら、外部故障に対する正不動作、内部故障に対する正動作、を確実に行うことができる距離リレ−装置を実現する具体的構成の距離リレ−装置を提供できる効果がある。
【００４６】
請求項５に記載の距離リレ−装置の発明は、動作領域調整機能を有し、この動作領域調整機能により、電力系統における故障前の定常電圧に対して故障発生時の電圧の位相が反転している場合と反転してない場合とで、異なる動作領域に調整されて前記電力系統を保護するようにしたので、この発明の距離リレ−装置を電力送電線上に直列にコンデンサを有する電力系統の保護に適用した場合や、この発明の距離リレ−装置を使用した電力系統の電力送電線上に直列にコンデンサを設置した場合、前記請求項３及び請求項４の発明と具体的構成が異なる構成でありながら、外部故障に対する正不動作、内部故障に対する正動作、を確実に行うことができる距離リレ−装置を実現する具体的構成の距離リレ−装置を提供できる効果がある。
【図面の簡単な説明】
【図１】この発明の実施の形態１の一例を示す接続図。
【図２】図１における記憶機能による電圧記憶時間を示す図。
【図３】図１の動作説明図。
【図４】この発明の実施の形態２の一例を示す接続図。
【図５】この発明の実施の形態３の一例を示す接続図。
【図６】この発明の実施の形態３の一例を示す接続図。
【図７】従来技術における誤動作防止対策回路を示す図。
【図８】従来技術における距離リレ−装置の背後故障における誤動作説明図。
【図９】従来技術における誤動作対策の説明図。
【図１０】従来技術における距離リレ−装置の前方故障における誤不動作となる系統構成を示す図。
【図１１】従来技術における距離リレ−装置の前方故障における誤不動作の説明図。
【符号の説明】
Ｖｐｏｌ　故障前の定常電圧、　　　Ｖｏｐ　故障発生時の電圧（Ｖ−Ｚ・Ｉ）、４　コンデンサ、　　　　　　　　　　８　距離リレ−、
８Ｄ　距離リレ−装置、　　　　　　　９　故障点（外部故障）、
１９　リレ−出力、　　　　　　　　　２１　コンデンサ、
２２　故障点（内部故障）、
８１　第１の動作領域（第１の距離　リレ−動作判定回路（機能））、
８２　第２の動作領域（第２の距離　リレ−動作判定回路（機能））、
１０３　故障検出機能、　　　　　　　１０４　記憶機能、
１０５　距離リレ−動作判定機能、　　１０８　位相反転検出機能、
１１２　動作領域調整機能。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a distance relay system for protecting a power system having a series capacitor on a transmission line, and a distance relay device applicable to protection of a power system having a series capacitor on a transmission line.
[0002]
[Prior art]
7 to 11 are diagrams showing a conventional distance relay system and a distance relay device disclosed in Japanese Patent Publication No. 53-26295, for example. FIG. 7 is a diagram showing a malfunction prevention countermeasure circuit, and FIG. FIG. 9 is an explanatory view of a malfunction in the case of a failure behind the apparatus, FIG. 9 is an explanatory view of measures against the malfunction, FIG. 10 is a view showing a system configuration in which a malfunction occurs due to a forward failure of the distance relay apparatus, and FIG. FIG. 9 is an explanatory diagram of a malfunction caused by a failure.
[0003]
7 to 11, 1 is a power supply, 2 and 3 are transmission lines, 4 is a series capacitor, 5 is a bus, 6 is an instrument transformer, 7 is an instrument current transformer, 8 is a distance relay, and 9 is Fault point, 10 is the operating area of the distance relay 8, 11 is an input terminal, 12 is a storage circuit, 13 is a phase comparison circuit, 14 is an output signal of the phase comparison circuit 13, 15 is an input voltage, and 16 is the storage. The output voltage of the circuit 12, 17 is a NOT circuit, 18 is an AND circuit, 19 is a relay output, 20 is a second power supply at the other end, 21 is a series capacitor in front of the distance relay 8, and 22 is the series capacitor. This is the point of failure immediately after 21.
[0004]
Note that the distance relay 8 is for protecting the transmission line 2, and its protection area is, for example, a moly relay, as shown in FIG. The reactance X is within the circle indicated by 10. Here, the direction of the transmission line 2 is the first quadrant in FIG.
[0005]
Next, the operation will be described with reference to FIGS. In FIG. 7, if a failure 9 occurs in the direction behind the transmission line 2 (behind the distance relay) and on the opposite side of the bus 5 of the series capacitor 4, the position of the failure point 9 is indicated on the X-axis in FIG. In some cases, the operation may fall within the operating characteristics of the distance relay 8, which may lead to malfunction. The concept of this malfunction prevention measure in the prior art is shown in FIGS. 9 (a) and 9 (b).
[0006]
9A and 9B, V1 is the voltage of the power supply 1, and V5 is the voltage of the bus 5. When the power system is healthy, as shown in FIG. 9A, the voltages V1 and V5 have a certain voltage phase difference, and power corresponding to this voltage phase difference is supplied from the power source 1 to the bus 5. Is flowing towards you. That is, it can be seen that the voltage vector of each part of the transmission line is on the line connecting the vertices of the voltage V1 and the voltage V5.
[0007]
However, when a failure occurs at the point 9 in FIG. 7, the polarity of the voltage V5 of the bus 5 is inverted due to the series capacitor 4 as shown in FIG. 9B. When the polarity of the voltage V5 of the bus 5 is reversed, a malfunction is prevented by means of locking the output on the assumption that it is a back failure as viewed from the distance relay-8. That is, in FIG. 7, the output 16 of the storage circuit 12 for storing the voltage phase and the voltage input (output of the instrument transformer 6) 15 are input to the comparison circuit 13, and the output 16 of the storage circuit 12 If the phase of the input (output of the instrument transformer 6) 15 is inverted, the comparison circuit 13 outputs. The output 14 of the comparison circuit 13 is inverted by the NOT circuit 17 in the next stage, and the AND circuit 18 in the next stage is locked. That is, even if there is an operation output of the distance relay 8, if the output 14 of the comparison circuit 13 is output, a relay operation signal (normally, a circuit breaker trip signal) is not output from the relay output terminal 19. It locks and the distance relay device is inoperative.
[0008]
[Problems to be solved by the invention]
Since the conventional distance relay system and distance relay device are configured as described above, it is possible to prevent a malfunction due to a back failure as described above. However, for example, as shown in FIG. If there is a second power supply 20 at the end and the series capacitor 21 is also in front of the distance relay 8, and if a failure occurs at the point 22 immediately after the series relay 21, the distance relay 8 is As shown in FIG. 11, since the impedance is out of the operation area 10 of the distance relay 8, there is a problem that a normal operation cannot be performed for a forward failure (internal failure).
[0009]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a distance relay system and a distance relay device that can perform a normal operation and a normal operation with respect to an external failure and an internal failure. It is.
[0010]
[Means for Solving the Problems]
The distance relay system according to the first aspect of the present invention detects a steady-state voltage before a failure in a power system having a capacitor in series on a power transmission line, and detects a voltage when a failure occurs in the power system, A distance relay device that responds to the degree of the phase difference between the steady voltage before the failure and the voltage at the time of the failure is provided in the power system, and the power system is protected by the distance relay device.
[0011]
According to a second aspect of the present invention, there is provided a distance relay device that detects a steady-state voltage of a power system before a failure and detects a voltage of the power system when a failure occurs, and detects a steady-state voltage before the failure and the failure occurrence. The power system is protected in response to the degree of the phase difference from the voltage at the time.
[0012]
A distance relay device according to a third aspect of the present invention includes a failure detection function for detecting a failure in the power system, a steady voltage before the failure is stored, and several cycles before the failure in response to an output of the failure detection function. A storage function for continuously outputting the pre-fault steady voltage as a vector voltage, and a distance relay operation determination function for responding to the degree of the phase difference between the vector voltage and the voltage at the time of occurrence of the failure. Is used to protect the power system.
[0013]
A distance relay device according to a fourth aspect of the present invention has a first operation region and a second operation region that is different from the first operation region, and is used in a steady state before a failure in the power system. In the case where the phase of the voltage at the time of occurrence of the failure is not inverted with respect to the voltage, the case where the first operation region is the case where the phase of the voltage of the occurrence of the failure is inverted with respect to the steady voltage before the failure in the power system. Protects the power system by outputting the second operation areas as relay outputs.
[0014]
The distance relay device according to the fifth aspect of the present invention has an operation area adjustment function, and the operation area adjustment function inverts the phase of the voltage at the time of occurrence of a failure with respect to the steady voltage before the failure in the power system. In this case, the power system is adjusted to different operation regions depending on whether or not the power system is not inverted, thereby protecting the power system.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
Hereinafter, an example of the first embodiment of the present invention will be described with reference to FIGS. 1 is a connection diagram, FIG. 2 is a diagram showing a voltage storage time by a storage function, and FIG. 3 is an operation explanatory diagram of FIG. The same or corresponding parts as those in FIGS. 7 to 11 showing the above-described conventional technology are denoted by the same reference numerals as those in FIGS. 7 to 11, and the description of the configuration and function is omitted.
[0016]
1 to 3, reference numeral 8D denotes a distance relay device, which is a multiplication circuit (multiplication function) 101 described later, an operation voltage generation circuit (operation voltage generation function) 102 described later, and a failure detection circuit (failure detection function) 103 described later. And a storage circuit (storage function) 104 to be described later and a distance relay operation determination circuit (distance relay operation determination function) 105 to be described later. A multiplication circuit (multiplication function) 101 has a function of multiplying an input current I (an output current I of the current transformer for instrument 7) by an operation set value of a mo-characteristic to set a distance relay characteristic. Things. An operating voltage generating circuit (operating voltage generating function) 102 divides a voltage input (output V of the instrument transformer 6) and an output of the multiplying circuit (multiplying function) 101 by vector division to obtain an operating voltage vector Vop (Vop = VZ · I). Reference numeral 103 denotes a failure detection circuit (failure detection function) which includes a voltage change width detection relay element (not shown) and a timer element (not shown), and at least a failure is released from a change in the voltage V (failure occurrence). Until this is done, the output 103o is configured to continue.
[0017]
Reference numeral 104 denotes a storage circuit (storage function) which constantly stores voltage waveforms for several cycles, receives an output 103o of the failure detection circuit (failure detection function) 103 as a trigger signal, and for example, as shown in FIG. Data of a voltage waveform 1CVW of a steady voltage during one cycle before a failure occurs a plurality of cycles before (three cycles before in the first embodiment) is used as an output Vpol. The voltage waveform data during one cycle before a plurality of cycles before the occurrence of the fault is repeatedly used until the end of the fault in the arithmetic processing in the subsequent circuit.
[0018]
The reason why the data of the voltage waveform 1CVW of the steady voltage during one cycle a plurality of cycles before the occurrence of the failure (in this embodiment, three cycles before the example) is used as the output Vpol is, for example, the voltage immediately before the occurrence of the failure. The waveform may include a waveform at the time of failure depending on how data is taken, or may not be an accurate steady voltage. It is preferable that the steady voltage data before the cycle be Vpol.
[0019]
Reference numeral 105 denotes a distance relay operation determination circuit (distance relay operation determination function), which is an output Vop (Vop = VZ−I) of the operation voltage generation circuit (operation voltage generation function) 102 and the storage circuit (storage function). A circuit (function) that configures an operation region of the M-characteristics from a vector obtained from the output Vpol of the output 104 and operates so that the angle between the vector Vop and the vector Vpol is, for example, 90 ° or more. -To obtain properties; In other words, the operation determination of the distance relay operation determination circuit (distance relay operation determination function) 105 is, for example, ∠ (Vop, V-ZI) <90 ° → non-operation, ∠ (Vop, V-ZI) ≧ 90 ° ⇒ Operation is set.
[0020]
Next, the operation will be described. In the case of a failure at the point 9 in FIG. 1 (external failure of the distance relay-8), as shown in FIG. 3A, the output Vpol of the storage circuit (storage function) 104 is three cycles before the failure. On the other hand, the output Vop of the operating voltage generating circuit (operating voltage generating function) 102 is VZ ・ I (V is the current distance relay input voltage (output voltage of the instrument transformer 6), I Is the current distance relay input current (the output current of the current transformer 7 for the instrument), the degree of the vector phase difference between these two voltages Vpol and Vop is less than 90 °, and the operation is not performed. That is, no relay operation output is output from the relay output 19.
[0021]
On the other hand, in the case of a failure at the point 22 (internal failure of the distance relay-8), as shown in FIG. 3B, the output Vpol of the storage circuit (storage function) 104 is the voltage three cycles before the failure. On the other hand, the output Vop of the operating voltage generating circuit (operating voltage generating function) 102 is VZ · I (V is the current distance relay input voltage (output voltage of the instrument transformer 6), and I is Since this is the current distance relay input current (output current of the current transformer for instrument 7), the degree of the vector phase difference between these two voltages Vpol and Vop becomes 90 ° or more, and the device operates. That is, a relay operation output is output from the relay output 19. When a relay operation output is output from the relay output 19, a circuit breaker (not shown) at both ends of the protection section of the distance relay 8 in the power system trips, the protection section is separated from the power system, and the intended system protection is performed. Done.
[0022]
3 (a) and 3 (b), the distance relay input voltage (output voltage of the instrument transformer 6) V has the opposite phase because of the failure point 9 (FIG. 3 (a)). )), The direction of the distance relay input current (output current of the current transformer 7 for the instrument 7) I and the distance relay input current (the current transformer 7 for the instrument 7) at the failure point 22 (FIG. 3B). 3A and FIG. 3B, when the relay input current I is taken in the R-axis direction in FIG. 3A and FIG. 3B, the failure point 9 (FIG. 3A) Is a rearward failure, the V is a voltage vector advanced by 90 ° from the R axis, and the failure point 9 (FIG. 3A) is a forward failure, and the V is a voltage vector delayed by 90 ° from the R axis. .
[0023]
3 (a) (failure point 9) and FIG. 3 (b) (failure point 22), the output Vpol of the storage circuit (storage function) 104 is in a steady state for one cycle three cycles before the failure. Since the voltage is a stored voltage, the voltage vector direction itself is the same. However, in FIGS. 3A and 3B, the current is fixed in the R-axis direction, and the current I after the failure is connected in series. The polarity of the Vpol voltage appears to be reversed in FIGS. 3A and 3B because the polarity is reversed from that before the failure due to the influence of the capacitors 4 and 21.
[0024]
The output of the storage circuit (storage function) 104, that is, the data stored in the storage circuit (storage function) 104 that is used during a fault, is, for example, a time t when the fault occurs. If the time during which the voltage sampling of the distance relay device 8D corresponds to the 30-degree electrical angle at every 30-degree electrical angle is T, and the data is the data 2-3 cycles before the failure, V (t- 36T), V (t-35T), V (t-34T),..., V (t-25T).
[0025]
This 12 sample data is
V (t) → V (t-36T)
V (t + 1T) → V (t-35T)
V (t + 2T) → V (t-34T)
V (t + 3T) → V (t-33T)
...
V (t + 12T) → V (t-36T)
V (t + 13T) → V (t-35T)
V (t + 14T) → V (t-34T)
V (t + 15T) → V (t-33T)
...
V (t + 24T) → V (t-36T)
V (t + 25T) → V (t-35T)
V (t + 26T) → V (t-34T)
V (t + 27T) → V (t-33T)
The storage circuit (storage function) 104 outputs the pre-failure voltage Vpol until the failure ends.
[0026]
As described above, the failure detection circuit (failure detection function) 103 determines, for example, that the time at which a failure occurs is t, and that the voltage sampling of the distance relay device 8D is performed at every 30-degree electrical angle, and the time corresponding to 30-degree electrical angle. Is T, a formula of | V (t) −V (t−12T) |> dV1 is calculated and a fault is detected by satisfying the formula, and the output is continued by the recovery timer. Here, dV1 is the voltage change width set value, and || means that the execution value processing is calculated after the operation.
[0027]
As described above, in the first embodiment of the present invention, the power system having a capacitor responds to the degree of the phase difference between the pre-fault steady-state voltage Vpol and the fault occurrence operating voltage Vop (VZI) (・ ( Vop, V-ZI) <90 ° ⇒ non-operating, ∠ (Vop, V-ZI) ≧ 90 ° ⇒ operating) distance relay device is provided, and the distance relay device protects the power system by the distance relay device. In addition, it responds to the degree of the phase difference between the pre-fault steady-state voltage Vpol and the fault-occurring operating voltage Vop (VZI) in the power system (∠ (Vop, V-ZI) <90). ° ⇒ non-operation, ∠ (Vop, V-ZI) ≧ 90 ° ⇒ operation) to protect the power system as a distance relay device, and more specifically, to detect a failure in the power system. Failure detection function 103, pre-failure determination A storage function 104 for storing a voltage and continuously outputting a pre-failure steady voltage several cycles before the failure as a vector voltage Vpol in response to the output of the failure detection function, and the vector voltage Vpol and the failure operating voltage Vop ( Distance relay operation judgment (応 (Vop, V-ZI) <90 ° ⇒ non-operation, ∠ (Vop, V-ZI) ≧ 90 ° ⇒ operation) responding to the degree of phase difference from VZ−I) The distance relay device includes a function 105 and protects the power system based on the determination result of the distance relay operation determination function 105. As described above, the distance relay device is applied to protection of the power system including the capacitors 4 and 21. In this case, correct operation of an external failure (fault point 9) and correct operation of an internal failure (fault point 22) can be reliably performed.
[0028]
Embodiment 2 FIG.
In the second embodiment of the present invention, a failure detecting circuit (function) 103 for detecting voltage variation dV in the first embodiment described above is replaced with a failure detection circuit for detecting current variation dI as shown in FIG. An example when (function) 106 is used is shown. As described above, the failure detection circuit (function) 103 detects a failure in the power system and supplies data to the storage circuit (function) for one cycle several cycles before the occurrence of the failure from the stored data. Is output as Vpol. Therefore, this function is not limited to the failure detection circuit (function) 103 (FIG. 1) for detecting the voltage change width dV in the first embodiment described above. As in the second embodiment, a failure detection circuit (function) 106 (FIG. 4) for detecting the current change width dI may be used, and further, an undervoltage detection element, an overcurrent detection element, or the like. In this case, the same effect as in the first embodiment can be obtained. The distance relay device 8D includes a multiplication circuit (multiplication function) 101, an operation voltage generation circuit (operation voltage generation function) 102, a storage circuit (storage function) 104, and a distance relay operation determination circuit (distance relay operation determination function). ) 105 and a failure detection circuit (failure detection function) 106. In addition, the same reference numerals as those in FIGS. 1 to 3 and FIGS. 7 to 11 denote the same or corresponding parts as those in FIGS. The description of the configuration and functions is omitted.
[0029]
Embodiment 3 FIG.
Hereinafter, an example of the third embodiment of the present invention will be described with reference to FIG. In FIG. 5, the same reference numerals as those in FIGS. 1 to 4 and FIGS. 7 to 11 denote the same or corresponding parts as those in FIGS. The description of the configuration and function is omitted.
[0030]
In FIG. 5, reference numeral 81 denotes a first distance relay operation judging circuit (distance relay operation judging function) which has a first operation region which responds to a system failure in which phase inversion by the series capacitors 4 and 21 does not occur. It has a distance relay characteristic of 1. A second distance relay operation determining circuit (distance relay operation determining function) 82 has a second distance relay having a second operation region that accurately responds to a system failure in which phase inversion occurs due to the series capacitors 4 and 21. A characteristic, that is, a distance relay characteristic that responds to a failure at the point 22 (internal failure) but does not respond to a failure at the point 9 (external failure).
[0031]
Reference numeral 108 denotes a phase inversion detection circuit (phase inversion detection function), which inputs the output Vpol of the storage circuit (storage function) 104 and the output V of the instrument transformer 6 and compares both outputs Vpol and V to obtain the meter. It is output when the phase of the output V of the power transformer 6 is inverted. 109 is an AND circuit, and 110 is an OR circuit. The distance relay device 8D includes a first distance relay operation determination circuit (distance relay operation determination function) 81, a second distance relay operation determination circuit (distance relay operation determination function) 82, and a failure relay device. It comprises a detection circuit (failure detection function) 103, a storage circuit (storage function) 104, a phase inversion detection circuit (phase inversion detection function) 108, a NOT circuit 17, an AND circuit 18, an AND circuit 109, and an OR circuit 110. .
[0032]
Next, the operation will be described. A phase inversion detection circuit (phase inversion detection function) 108 compares the output Vpol of the storage circuit (storage function) 104 with the output V of the instrument transformer 6 and, when a failure occurs, the instrument transformer 6 outputs an operation when the voltage phase of the output V is inverted, locks the relay output of the first distance relay operation determination circuit (distance relay operation determination function) 81 via the NOT circuit 17, The relay output of the second distance relay operation judging circuit (distance relay operation judging function) 82 is outputted to the relay output 19 as the final output via the AND circuit 109 and the OR circuit 110. That is, the normal operation and the non-operation are reliably performed in the same manner as in the first and second embodiments described above, which responds to the failure at the point 22 (internal failure) but does not respond to the failure at the point 9 (external failure). Do.
[0033]
On the other hand, the phase inversion detection circuit (phase inversion detection function) 108 compares the output Vpol of the storage circuit (storage function) 104 with the output V of the instrument transformer 6, When the voltage phase of the output V of the transformer 6 is not inverted, no operation output is output, so that the lock signal is not input to the NOT circuit 17. Accordingly, the relay output of the first distance relay operation judging circuit (distance relay operation judging function) 81 is output to the relay output 19 as the final output via the AND circuit 18 and the OR circuit 110.
[0034]
That is, in the above-described third embodiment, the voltage phase before the failure is compared with the voltage phase after the occurrence of the failure, and the first operation area (the first distance relay) is determined depending on whether or not the phase of the voltage after the occurrence of the failure is inverted. A relay for automatically switching the judgment output of the operation judgment circuit (distance relay-operation judgment function) 81) and the second operation area (second distance relay-operation judgment circuit (distance relay-operation judgment function) 82); By adopting the circuit configuration, correct / non-operation and correct operation are reliably performed against an external failure and an internal failure in the same manner as in the first and second embodiments.
[0035]
Embodiment 4 FIG.
Hereinafter, an example of the fourth embodiment of the present invention will be described with reference to FIG. In FIG. 6, the same or corresponding parts as those in FIGS. 1 to 5 and FIGS. 7 to 11 showing the above-described prior art are denoted by the same reference numerals as those in FIGS. 1 to 5 and FIGS. The description of the configuration and function is omitted.
[0036]
In FIG. 6, reference numeral 111 denotes a Z setting control circuit (Z setting control function), for example, the first operation area (first distance relay operation determining circuit (distance relay operation determining function)) 81 in the third embodiment. ) Is set as (Z1, θ1) as the set value of the vector impedance Z and, for example, the second operation area (the second distance relay operation determination circuit (distance relay operation) in the third embodiment described above. (Z2, θ2) as a set value of the vector impedance Z to be set in the judgment function 82).
[0037]
A selection Z multiplying circuit 112 is a set value (Z1, θ1) of the vector impedance Z1 or a set value of the vector impedance Z2 (Z1) selectively output from the Z setting control circuit (Z setting control function) 111. Z2, θ2). An operation area adjustment circuit (operation area adjustment function) 113 includes an operation voltage generation circuit (operation voltage generation function) 102, the Z setting control circuit (Z setting control function) 111, and the selected Z multiplication circuit (selection Z multiplication). Function) 112. The distance relay device 8D includes a selection Z multiplication circuit (selection Z multiplication function) 112, an operation voltage generation circuit (operation voltage generation function 102, a distance relay operation determination circuit (distance relay operation determination function) 105, and a fault detection. The circuit includes a circuit (failure detection function) 103, a storage circuit (storage function) 104, a phase inversion detection circuit (phase inversion detection function) 108, and a Z setting control circuit (Z setting control function) 111.
[0038]
Next, the operation will be described. The phase inversion detection circuit (phase inversion detection function) 108 functions in the same manner as in the above-described third embodiment, and outputs its operation output because the voltage phase of the instrument transformer 6 has not been inverted with the detection of a system failure. If not, the Z setting control circuit (Z setting control function) 111 selects and outputs the set value (Z1, θ1) of the vector impedance Z1. This output is input to the selection Z multiplication circuit (multiplication function) 112, and the operation voltage generation circuit (operation voltage generation function) 102 responds to the selective output from the Z setting control circuit (Z setting control function) 111. Then, the voltage input (the output V of the instrument transformer 6) and the output of the selected Z multiplication circuit (multiplication function) 112 are vector-divided to generate an operating voltage vector Vop1 (Vop = V−Z1 · I). As a result, the distance relay 8 is set, for example, in the first operation area (first distance relay operation determination circuit (distance relay operation determination function) 81) in the third embodiment.
[0039]
Next, the phase inversion detection circuit (phase inversion detection function) 108 functions in the same manner as in the above-described third embodiment, and the voltage phase of the instrument transformer 6 is inverted due to the detection of the system failure. When the operation output is issued, the Z setting control circuit (Z setting control function) 111 selects and outputs the set value (Z2, θ2) of the vector impedance Z2. This output is input to the selection Z multiplication circuit (multiplication function) 112, and the operation voltage generation circuit (operation voltage generation function) 102 responds to the selective output from the Z setting control circuit (Z setting control function) 111. Then, the voltage input (output V of the instrument transformer 6) and the output of the selected Z multiplication circuit (multiplication function) 112 are vector-divided to generate an operating voltage vector Vop2 (Vop = V−Z2 · I). As a result, the distance relay 8 is set in, for example, the second operation area (the second distance relay operation determination circuit (distance relay operation determination function) 82) in the third embodiment.
[0040]
That is, in the fourth embodiment, the Z-setting control circuit (Z-setting control function) compares the pre-fault voltage phase with the post-fault voltage phase and determines whether the phase of the voltage after the fault has been inverted. 111 selects a set value of the vector impedance Z, and sets a vector impedance Z in an operating voltage vector Vop (Vop = V−Z · I) generated by an operating voltage generating circuit (operating voltage generating function) 102 in a subsequent stage. Is automatically controlled, positive and non-operations and normal operations are reliably performed against external failures and internal failures in the same manner as in the first to third embodiments. In the fourth embodiment, the vector impedance Z in the operating voltage vector Vop (Vop = V−Z · I) generated by the operating voltage generating circuit (operating voltage generating function) 102 is simply changed. Therefore, the load of the arithmetic processing is reduced.
[0041]
In the above-described first to fourth embodiments, H / W circuits are shown as examples (FIGS. 1, 4 to 6) as examples, but each function in each figure is performed by S / W. In this case, the functions and effects similar to those of the above-described first to fourth embodiments are achieved, and are included in the invention of this application.
[0042]
【The invention's effect】
The distance relay system according to the first aspect of the present invention detects a steady-state voltage before a failure in a power system having a capacitor in series on a power transmission line, detects a voltage at the time of occurrence of a failure in the power system, and detects the failure. A distance relay device that responds to the degree of the phase difference between the previous steady voltage and the voltage at the time of occurrence of the failure is provided in the power system, and the power system is protected by the distance relay device. Even in a power system having a capacitor in series on a line, a distance relay device for protecting the power system is provided with a distance relay that responds to a degree of a phase difference between a steady voltage before the failure and a voltage at the time of the failure. Since the device is used, there is an effect that positive / non-operation for an external failure and normal operation for an internal failure can be reliably performed.
[0043]
The distance relay device according to claim 2 detects a steady-state voltage in a power system before a fault and detects a voltage at the time of occurrence of a fault in the power system. The power system is protected in response to the degree of the phase difference with the voltage of the voltage, so when the distance relay device of the present invention is applied to the protection of a power system having a capacitor in series on a power transmission line, When a capacitor is installed in series on a power transmission line of a power system using the distance relay device of the present invention, there is an effect that positive / non-operation for an external failure and normal operation for an internal failure can be reliably performed.
[0044]
According to a third aspect of the present invention, there is provided a distance relay device for detecting a failure in a power system, storing a steady state voltage before the failure, and responding to an output of the failure detection function, a few cycles before the failure. A storage function for continuously outputting the pre-failure steady-state voltage as a vector voltage, and a distance relay operation determining function responding to the degree of the phase difference between the vector voltage and the voltage at the time of the failure. Since the power system is protected based on the determination result, the distance relay device of the present invention is applied to protection of a power system having a capacitor in series on a power transmission line, or the distance relay device of the present invention is used. When a capacitor is installed in series on the power transmission line of the power system, the external failure is prevented in response to the degree of the phase difference between the steady state voltage before the failure and the voltage at the time of the failure. Inactive, direct action against internal faults, the distance can be reliably performed relay - distance of a specific structure for realizing the device relay - there is an effect capable of providing a device.
[0045]
According to a fourth aspect of the present invention, there is provided a distance relay device having a first operation region and a second operation region different from the first operation region, and a steady voltage before a failure in the power system. In the case where the phase of the voltage at the time of occurrence of the failure is not inverted, the first operation region is the case where the phase of the voltage at the time of occurrence of the failure is inverted with respect to the steady voltage before the failure in the power system. Since the second operation area is output as a relay output to protect the power system, the distance relay device according to the present invention can protect the power system having a capacitor in series on a power transmission line. When the capacitor is installed in series on a power transmission line of a power system using the distance relay device of the present invention, an external failure may occur even though the specific configuration is different from that of the third embodiment. Against Positive inoperative, direct action against internal faults, the distance can be reliably performed relay - distance of a specific structure for realizing the device relay - there is an effect capable of providing a device.
[0046]
The distance relay device according to the present invention has an operation area adjustment function, and the operation area adjustment function inverts the phase of the voltage at the time of occurrence of a failure with respect to the steady voltage before the failure in the power system. The distance relay device of the present invention is adjusted to a different operation area to protect the power system when the power system is not inverted. When applied to protection, or when a capacitor is installed in series on a power transmission line of a power system using the distance relay device of the present invention, the concrete configuration differs from that of the third and fourth inventions. In spite of this, there is an effect that a distance relay device having a specific configuration for realizing a distance relay device capable of reliably performing correct operation and non-operation for an external failure and correct operation for an internal failure can be provided.
[Brief description of the drawings]
FIG. 1 is a connection diagram showing an example of Embodiment 1 of the present invention.
FIG. 2 is a diagram showing a voltage storage time by a storage function in FIG. 1;
FIG. 3 is an operation explanatory diagram of FIG. 1;
FIG. 4 is a connection diagram showing an example of Embodiment 2 of the present invention.
FIG. 5 is a connection diagram showing an example of Embodiment 3 of the present invention.
FIG. 6 is a connection diagram showing an example of Embodiment 3 of the present invention.
FIG. 7 is a diagram illustrating a malfunction prevention circuit according to the related art.
FIG. 8 is an explanatory diagram of a malfunction in the case of a fault behind the distance relay device in the related art.
FIG. 9 is an explanatory diagram of a countermeasure against malfunction in the related art.
FIG. 10 is a diagram showing a system configuration that causes a malfunction in a forward failure of a distance relay device in the related art.
FIG. 11 is an explanatory diagram of a malfunction caused by a forward failure of the distance relay device according to the related art.
[Explanation of symbols]
Vpol Steady-state voltage before failure, Vop Voltage when failure occurs (VZI), 4 capacitors, 8 distance relay,
8D distance relay device, 9 failure points (external failure),
19 relay outputs, 21 capacitors,
22 failure points (internal failure),
81 first operation area (first distance relay operation determination circuit (function));
82 second operation area (second distance relay operation determination circuit (function));
103 failure detection function, 104 storage function,
105 distance relay operation judgment function, 108 phase inversion detection function,
112 Operation area adjustment function.

Claims

Detecting a pre-failure steady-state voltage in a power system having a capacitor in series on a power transmission line and detecting a voltage at the time of occurrence of a failure in the power system, and determining a position of the steady-state voltage before the failure and the voltage at the time of the failure. A distance relay system in which a distance relay device responsive to the degree of the phase difference is provided in the power system, and the power system is protected by the distance relay device.

Detects a steady-state voltage in the power system before the fault and detects a voltage at the time of the fault in the power system, and responds to the degree of a phase difference between the steady-state voltage before the fault and the voltage at the time of the fault to generate the power. Distance relay device to protect the system.

A failure detection function for detecting a failure in the power system, a storage function for storing a steady-state voltage before the failure and continuously outputting a steady-state voltage before the failure several cycles before the failure as a vector voltage in response to the output of the failure detection function, And a distance relay device that has a distance relay operation determining function that responds to a degree of a phase difference between the vector voltage and the voltage at the time of occurrence of a failure, and protects the power system based on a determination result of the distance relay operation determining function.

It has a first operation region and a second operation region in an operation region different from the first operation region, and the voltage phase at the time of occurrence of the failure is inverted with respect to the steady voltage before the failure in the power system. If not, the first operation area is output as a relay output when the phase of the voltage at the time of occurrence of the failure is inverted with respect to the steady voltage before the failure in the power system. A distance relay device for protecting the power system by being operated.

It has an operation area adjustment function, and this operation area adjustment function causes different operation depending on whether the phase of the voltage at the time of occurrence of the failure is inverted with respect to the steady voltage before the failure in the power system and when it is not inverted. A distance relay device adjusted to an area to protect the power system.