JPS59135377A - Method for evaluating grounding fault point of three- phase power transmission distribution line - Google Patents
Method for evaluating grounding fault point of three- phase power transmission distribution lineInfo
- Publication number
- JPS59135377A JPS59135377A JP976783A JP976783A JPS59135377A JP S59135377 A JPS59135377 A JP S59135377A JP 976783 A JP976783 A JP 976783A JP 976783 A JP976783 A JP 976783A JP S59135377 A JPS59135377 A JP S59135377A
- Authority
- JP
- Japan
- Prior art keywords
- distribution line
- fault
- fault point
- transmission
- ground fault
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Emergency Protection Circuit Devices (AREA)
- Locating Faults (AREA)
Abstract
Description
〔発明の属する技術分舒〕
本発明は三相送配電線路中で地絡故障が生じたとき５地
絡故障点の位置の評定１例えばある測定点からの該地絡
故障を生じた送配電線中の故障点までの距離の推定を行
なう方法に関する。
〔従来技術とその問題点〕
在来のかかる故障位置評定の最も簡単な手段は。
ある測定点から地絡故障点までの送配電線のインピーダ
ンスを測定して、これと該送配電線の特性インピーダン
スとから故障点までの距離を推定するものであるが、装
置が比較的簡易に構成できる反面、地絡故障点における
送配電線と大地とのインピーダンスすなわちいわゆる故
障点インピーダンス□の値によって距離の推定値に誤差
が生じやすいことが一般に知られている。
前記の故障点インピーダンスは主として抵抗性であり、
この点に注目して送配電線のりアクタンス成分を重点に
測定して故障点を評定する手段も公知である。しかし、
非接地送配電系におけるある測定例では架空線の断面が
６０−のとき地絡故障点における故障点インピーダンス
の抵抗弁はＯ〜加キロオームの間の広範囲に変動しうろ
ことが知られている。−万において評定距離の誤差を１
００メートル以内に納めるには、送配電線の地絡故障に
よるインピーダンスの変化を抵抗弁で０．０３オーム、
リアクタンス分でも０．０３０（５０ヘルツに対する値
）以内の精度で測定する必要がある。従って故ｉｌ１点
インピーダンスが高くて１０キロオーム程度ある場合に
は、故障点インピーダンスの１０ 〜１０ すなわち
少なくとも子分の１パ一セント以上の精度の測定が必要
になり、実用的にはかかる測定は不可能に近い。
このため、故障点インピーダンスの影響を余り受けない
で送配電線の故障点までのインピーダンスもしくはこれ
に関連する電気量を精密に測定する手段として、本出願
人は特願昭５６−２２４２３号の発明を出頭した。しか
し、当該発明では測定用電源の周波数を比較的低くとる
必要があり、測定用電源を高圧ないし超高圧の送配線に
結合するための変成器などの結合器を経済的に製作する
には当該測定用電源の周波数を高めるのが望ましいが、
周波数を数百ヘルツ程度にまで上げると送配電線のもつ
分布キャパシタンスの影響が無視できなくなってしまう
。
〔発明の目的〕
本発明は以上に説明した従来技術の欠点ないし問題点の
認識トて立脚して、地絡故障点における故８１ ｈ”４
インピーダンスの変動の影響が少なく、かつ送配電線へ
の評定用交流電圧の注入を簡単にできるよう試験用電源
の周波数を高（とっ[Distribution of the technology to which the invention pertains] When a ground fault occurs in a three-phase power transmission/distribution line, 5. Evaluation of the location of the ground fault point 1. This invention relates to a method for estimating the distance to a fault point in an electric wire. [Prior art and its problems] What is the simplest conventional means of fault location evaluation? This method measures the impedance of a power transmission and distribution line from a certain measurement point to a ground fault point, and estimates the distance to the fault point from this and the characteristic impedance of the power transmission and distribution line, but the device is relatively simple. However, it is generally known that errors are likely to occur in the estimated value of the distance depending on the impedance between the power transmission/distribution line and the ground at the ground fault point, that is, the value of the so-called fault point impedance □. The fault point impedance mentioned above is mainly resistive;
In view of this point, there is also a known method of evaluating the fault point by measuring the actance component of the power transmission/distribution line as a priority. but,
In certain measurements in ungrounded power transmission and distribution systems, it is known that when the cross section of the overhead line is 60 -, the resistance valve of the fault point impedance at the ground fault point will vary over a wide range between 0 and +K ohms. - 1 million errors in evaluation distance
In order to keep the range within 0.00 meters, the change in impedance due to ground faults in power transmission and distribution lines should be reduced to 0.03 ohm using a resistance valve.
Even the reactance component needs to be measured with an accuracy within 0.030 (value for 50 hertz). Therefore, if the impedance at one point is high, about 10 kilohms, it is necessary to measure with an accuracy of 10 to 10 of the impedance at the failure point, that is, at least 1% of the subordinate, and such measurement is not practical. Close to possible. Therefore, the present applicant has proposed the invention of Japanese Patent Application No. 56-22423 as a means to precisely measure the impedance up to the fault point of a power transmission/distribution line or the amount of electricity related thereto without being significantly influenced by the fault point impedance. appeared in court. However, in this invention, it is necessary to keep the frequency of the power supply for measurement relatively low, and in order to economically manufacture a coupler such as a transformer for coupling the power supply for measurement to high-voltage or ultra-high voltage transmission lines, It is desirable to increase the frequency of the measurement power supply, but
When the frequency is increased to several hundred hertz, the influence of the distributed capacitance of power transmission and distribution lines cannot be ignored. [Object of the Invention] The present invention is based on the recognition of the above-described shortcomings or problems of the prior art, and is based on the above-mentioned problem.
The frequency of the test power supply was set to a high frequency to reduce the influence of impedance fluctuations and to easily inject the evaluation AC voltage into the transmission and distribution lines.
本発明によれば上述の目的を達成するために、故障点評
定なすべき送配電線路区間の両端に地絡故障が生じた送
配電線に評定用の交流電流を注入する電流源回路をそれ
ぞれ設けておき、地絡故障が生じたとき両端の電流源回
路から同一周波数。
同一振幅でかつ互いに逆位相の評定電流をそれぞれ当該
地絡事故送配線に注入する。地絡事故発生点における故
障点インピーダンスにはこれら画定流源回路から注入さ
れた評定用電流が１資して流れることになるが、前述の
ように両測定用電流は逆位相なので両者は実質的に相殺
され、当該故障点インピーダンスには全（測定用電流が
流れないかあるいは流れても従来手段に比して極めて小
さな電流が流れるに過ぎなくなる。このことが本発明方
法が故障インピーダンスの影響を受けることが本質的に
少ない大きな理由になっている。
さて、地絡故障が生じると、評定用電流に対する送配電
線のインピーダンスが正規状態から当然）
て変化するので、本発明による評定にあたフてはかかる
特性電気値を測定して第１の測定値とする。
この第１の測定値は地絡故障点の位置の関数であるが、
同時に故障点インピーダンスの関数でもあるので、故障
インピーダンスの値が決まらな（・と地絡故障点の位置
を決めることができない。
このため本発明においては第２の測定値として地絡故障
時の三相送配電線の零相電圧を測定する。
この零相電圧は故障点インピーダンスの関数ではあるが
、地絡故障点の位置とは関係しな（・。従ってとの零相
電圧の測定値から故障点インピーダンスの値を一錠的に
決めることができ、次にこの故障点インピーダンスの値
を用いて第１の測定値から容易に地絡故障点の位置を評
定することかで館る。
〔発明の実施例〕
次に図面を参照しながら本発明の詳細な説明する。第１
図は本発明の原理説明図であって、Ｌが１本の送配電線
を模式的に示し、その長さｌが本発明方−法によって地
絡故障を評定すべき区間を示している。該区間の両端に
は電流源回路１．２がそれぞれ設けられて適当な結合手
段を介して高電圧の送配電線りに評定用電流を注入する
のであるが、この図では簡単化のため評定用電流１１．
Ｉ２が電流源回路１．２から逆配置！線ＬＫ直接注入さ
れるよう描かれている。これら測定電流は同一の周波数
ｆと同一の振幅工、をもっように制御されるが、その位
相は互いに逆位相に選ばれる。この逆位相であることを
示すため、第１図では電流源回路２の測定用電流Ｉ２は
送配電線りから注出される方向に矢印が付されている。
地絡故障点はＦで示され、この点と大地との間の故障点
インピーダンスすなワチ地絡抵抗ハｎ・ｇであり、送配
電線区間りの左端から地絡故障ＡＰまでの距離がＸであ
るとする。
いま地絡故障点Ｆが送配電線区間りの中央点にあり、従
って、Ｚ’ ＝ ｌ／２であったとすると、故障点イン
ピーダンスＲｇには電流源回路１からの測定用電流ＩＩ
Ｋ比例する電流ＩＩ’ と電流源回路２がらの測定用
電流工２に比例する電流Ｉ２’ とが互いに逆方向に
流れ、容易に諒解されるようにＩｆ’ とＩ２’の大
きさは等しいので、面電流ＩＩ’とＩ２’とは相殺し合
って故障点インピーダンスＲ，ｇに流れる電流は零にな
る。しかし、地絡故障点Ｆが中央点以外にあるときには
、送配電線りの左端から故障点Ｆまでのインピーダンス
ｚ１と右端から故障点ＦまでのインピーダンスＺ２はそ
れらの間の送配電線の長さＸおよび７３−ｘに比例する
から、インピーダンスＺ１．Ｚ２の値は相異なり、故障
点Ｆにおける２電流１１’、Ｉ２’ の大きさも異な
って来て面電流は完全には相殺しない。かがる一般的な
場合には次の方程式が成立する。
上式中のすべての符号はベクトル舒であり、Ｖｌ。
ｖ２は第１図に示すように送配電線りの左端および右端
の電圧であるが、これらは周波数ｆの測定用電流回踏め
電圧であって送配電線の商用周波電圧とは異なることに
留意されたい。
まりだその他の符号の内容は次のとおりである。
Ｒａ ＝ｖ’ｙｚ （伝播定数）。
】二等価インピーダンス／単位長
Ｚ＃−、／フ「（４＋性インピーダンス）２：等価対地
アドミッタンス／単位長
ＡＩ ＝ ｃａｓｈ （Ｒｏｒ＊ｘ ）ＣＩ ＝（１／
Ｚａ＋ ） ５ｉｎｈ （Ｒａｘ ）Ｂｌ −Ｚｍ ５
ｉｎｈ （ＲａＩｘ ）ＤＩ ＝ｃｏｓｈ （Ｒａ１ｘ
）
Ａ２＝ｃｏｓｈ（Ｒａ＋（Ｊ−ｘ））
Ｃ２＝ （１／Ｚω） ５ｉｎｈ ｉ Ｒａ（ｌ！−ｒ
））Ｂ２＝Ｚω５ｉｎｈ（Ｒｓ（ｌ！−ｚ））Ｄ２＝ｃ
ｏｓｈ （Ｒａ（ｌ −２’ ） ）さて、前述のよ
５にＩｘ＝Ｉｚ＝Ｉｇであるから、この条件を（１１式
に入れて開式左辺の■１の値を故障点インピータンスＲ
，をパラメークとしＸを変数として求めることができる
。この結果により送配電線の左端側における特性電気値
たとえば無効電力Ｑ爾ＶＩ ＩＩ、 ｓｉｎθ （ただ
しθは■１と１３との間の位相角）を求めると第２図の
とおりＫなる。
第２図の横軸は送配電線の左端から地絡故障点Ｆまでの
距離ｘ、縦軸は前述の無効電力Ｑであって、図の曲線勤
は故障虞インピーダンスＲｇが零すなわち完全接地の場
合１曲線１（，５，Ｒ１０は故障点インピーダンスがそ
れぞれ５．１０キロオームの場合。
曲線Ｒは故障点インピーダンスが無限大すなわち地絡故
障がない場合に対応する。ただしこの数値計算は送配電
線が６０−＠面の架空銅線の分布インダクタンス０．０
０１ ｍＨ／ｍ 、分布キャパシタンス０．０１ｎＦ、
漏、測定用電流の周波数ｆ＝３００Ｈｚ、注入電流値Ｉ
、＝ＩＡ、送配電線長ｚ−ｓｔｂとして無効電力Ｑを求
めたもので、６．６ｋＶ級の配電線の代表的な値である
。
第２図に表わされた結果から次のことがわかる。
送配電線の中央点で接地故障が生じた場合は該線区端に
おける無効電力Ｑは故障点インピーダンスＲｇＱいかん
に拘らず地絡故障が全くない場合の無効電力Ｑ。に等し
い。これは前述のように故障が中央点にあるとき故障点
インピーダンスＲＩｌに測定電流が全（流れないことか
らも容易に予測されたところで−ある。つぎに地絡故障
点までの距Ｋｌ 、１Ｍが中央点からはずれると、故障
点インピーダンスＲｇＯ値に応じて無効電力値Ｑの値は
距離Ｘのほぼ直線的な関数に従って変化する。従って故
障点インピータンスＩｊｇＯ値さえわかれば第２図に示
すような関係を用いて、前述の第１の測定値である無効
電力Ｑの測定値から極めて簡単に距離Ｘを求めることが
できる。
この故障点インピーダンスＲｇＯ値を求めるために、本
発明においては第２の測定値として地絡故障時の三相送
配電Ｉ？ｌｉ！路の商用周波に対する零相電圧を測定す
る。この零相電圧■。は次式で表わされる。
ただしく２）式において。
Ｅ ： 三相送配電線の相電圧
Ｒｎ＝ 中性点接地抵抗
Ｃｂ二 対地静電容量（三相分）
ω−２πｆ、ｆ：周波数（髄用周波）
である。（２）式においてＥ ＝ ６．６／Ｊ３ ｋＶ
、 Ｒ，ｎ ＝ １０キロオーム、（シｂ＝３μＦ、ｆ
＝５０Ｈｚとし、たときのｖ。とＲｇとの間の関係を第
３図に示す。なお、上の（２）式の対地静電容量Ｃｂけ
三相送ｌ記這線路全体の値であり、故障点から見たこの
イ［αは故障点の位置に関せず一定であり、従って琴相
′這圧Ｖ。は故障点の位置に関係せず線路がきまれば故
障点インピーダンスの１直にのみ関係することがわかる
。
以上のように第１測定値である前述の特性電気値たとえ
ば無効電力Ｑと第２の測定値である零相電圧■。とが測
定されると、該零相電圧Ｖ。の値から第３図のような関
係によって故障点インピーダンス几ｇの値が知られ、こ
の故障点インピーダンスＲｇの値と無効電力Ｑの値とか
ら第２図に示すような関係によって地絡故障点までの距
離ｘを求めることができる。
つぎに上述の原理を用いた送配電線路、の地絡故障点評
定の方法を第４区により説明する。第４図では送配電線
路りは三相の高圧架空線Ｌｌ 、 Ｌ２ およびＬ３か
らなり、このうら架空＠Ｌ２の故障点Ｆに故障点インピ
ーダンスＲｇの地絡故障が生じた場合が示されている。
電流源回路］、２は当該送配電線路区間りの両端にそれ
ぞれ配設され、定電に、発生装置１１．２１で発生した
同一周波数、同−損１＠の評定用電流を変漆器１２．２
２を介して高圧の送配電線の内の１本に測定用電流を注
入する。もちろん区間の左右端からは互いに逆位相の評
定用電流が注入される。地絡判別装置１２ 、２３は公
知の装置であってよいので簡略化１〜て描かれており、
地絡故障を生じた送配電線を見付けてその線に対応する
開閉器１４ 、２４ ＋７’）接点を選択的に閉じて各
３個の変流器１２゜２２０うちの対応する変流器のみに
定電流装置１１ 。
２１からの電流を流して故障線に測定用電流を注入する
。なお、変流器１５ 、２５は所定の送配電線路区間外
に評定用電流が流出するのを防ぐためのものであって、
前述の地絡相判８１＋装置１３ 、２３からの指令圧よ
って開閉器１６の接点を選択的に閉じて、各３個のｆ流
器１．５ 、２５の５ちの対応する変流器の回路のみを
事故＃に接続する。またフィルタ１７ 、２７は変流器
１２ 、２２を介して電流源回路１．２内に侵入してく
る商用周波イ８号を除去するためのものである。
測定回路３０は電流源回路１．２の特性電気値だ１、止
えは無効電力、電圧、力率などを測定するものである。
図示の電流源回路１．２の構、成において、定電流装置
ｉｉ ｔたは２１がらの定電流はそれぞれ３個の変流器
１２または２２の５ちの一つを流れ、さらにそれぞれ３
個の変流器１５または２５の５ちの〜つぉよび開閉器１
４または脚を通うて測定器３ｏに入り、そこからそれぞ
れ定′Ｐｔ流装置１１または２１ Ｋ帰る。
なお、測定器３０は線路区間りの測定端たとえば図の左
方の電流源回路１＠にのみ設げるだけでよい。
いま電流源回路１の万を測定端として故障点評定の方法
を説明する。図示のよ５に送配電線Ｌ２の故障点Ｆで地
絡故障が生じると、図示しない地絡検出装置が地絡が生
じたことを検出し、これによってｊｔｌ！絡相判別装ｆ
ｉ １３ 、２３が動作して送配を線Ｌ２が故障線であ
ることを判別し、開閉器１４．２／ｊおよび開閉器肌２
６の接点を選択的に閉じて事故線に対応する変流器ル、
２２および変流器１５．２５を電流源回路１．２にそれ
ぞれ接続する。この状態において測定器３０は電流諒回
路工内の特性電気値例えば無効電力Ｑを６１１定する。
これが第１の測定値となる。
同時に公知の図示しない手段により三相送配電線路の零
相電圧Ｖ。を測定する。例えは送配電線Ｌ１〜Ｌ３の各
線に接続された電圧変成器の出力を相加して平均値をと
るだけで地絡故障時の零相電圧■。
を第２の測定値として簡単に読取りないしは記録するこ
とができる。なお、この零相電圧Ｖ。は区間り内で測定
する必要はなく、三相送配電線路のどこで測定してもよ
（・。
前述のように第１の測定値と第２の測定値がわかれば容
易に故障点までの距離Ｘを推定することができる。すな
わち、まず第２の測定値である零相電圧■。の値から（
２１式によりあるいは第３図の図式により故障点インピ
ーダンスＲｇを求め、ついでこのＲＫの値に対応する距
離Ｘの値を第２図の図式から簡単に求めることができる
。
上記のような故障点評定にあたりては、測定電流の周波
数は数百ないし数千ヘルツの範囲に選ぶことができる。
また上述の説明においては測定すべき特性電気値として
主に無効電力について説明したが、必ずしもこれに限定
されるものではなく、無効力率でも、インピーダンス値
でも、あるいは有効電力であっても差し支えない。
〔発明の効果〕
釣上説明したとおり、本発明においては地絡故障評定を
すべき送配電線路区間の両端に該区間の送配電線に評定
用交流電流を注入する電流源回路をそれぞれ設けて、両
筒流源回路がら同一周波数。
同一振幅かつ互いに逆位相の評定用電流を送配電線に注
入した状態において、測定端となる電流源回路において
無効電力などの特性電気値を第１の測定値として測定し
、−万三和送配電線路の地絡故障時の零相電圧を第２の
測定値として測定して、該第１および第２の測定値から
地絡故障点の測定端からの距離を推定するようにしたの
で、地絡故障点の故障インピーダンスに流れる評定用電
流が本質的に少なく、従って該故障インピーダンスが高
い場合においても地絡故障点の位置ないし距離の評定誤
差が従来技術に比して少ない利点がある。
また第２図から読み取れるように本発明の場合には評定
電流の周波数が数百ヘルツ（第２図は３００ヘルツに対
するもの）になっても、故障点までの距Ｍｒとｉｉｌの
測定値例えば無効電力値Ｑとの関係は明確な相関関係が
あり、従って第１の測定値に対応して求める距離ｘを正
硼に決めることができる。さらに前述のＱとＸとの相関
はほとんど直線的であり、Ｘの推定に便利な点はもちろ
ん評定周波数がさらに高（なっても本発明の方法が利用
できることを示している。具体的には数千ヘルツまで適
用が可能なことがわかっており、従って本発明の方法は
従来技術て較べて評定電流の周波数を高（選定して送配
電線への評定電流の注入のための装置を経済化できる利
Ａ￥有する。この利点はとくに配電線網中の地絡故障点
を評定するため、多数の個所に評定区間を設定しなげれ
ばならない時に大きな意味をもつものである。According to the present invention, in order to achieve the above-mentioned object, current source circuits for injecting alternating current for evaluation into the transmission and distribution line in which the ground fault has occurred are provided at both ends of the transmission and distribution line section where the fault point evaluation is to be performed. Keep the same frequency from the current source circuits at both ends when a ground fault occurs. Rating currents with the same amplitude and mutually opposite phases are injected into the ground fault transmission wiring. The evaluation current injected from these defined current source circuits will contribute to the fault point impedance at the point where the ground fault occurs, but as mentioned above, since the two measurement currents are in opposite phases, they are substantially equal to each other. This cancels out the current at the fault point, and either no measurement current flows through the impedance at the fault point, or even if it does, only a very small current flows compared to the conventional means.This means that the method of the present invention eliminates the influence of the fault impedance. This is a major reason why there are essentially fewer ground faults.Now, when a ground fault occurs, the impedance of the transmission and distribution line relative to the rating current changes from its normal state (of course), so this Then, this characteristic electrical value is measured and used as the first measurement value. This first measurement is a function of the location of the ground fault point;
At the same time, it is also a function of the fault point impedance, so the fault impedance value cannot be determined (and the position of the ground fault fault point cannot be determined. Therefore, in the present invention, the second measured value is Measure the zero-sequence voltage of the phase transmission and distribution line. This zero-sequence voltage is a function of the fault point impedance, but is not related to the position of the ground fault fault point (... Therefore, from the measured value of the zero-sequence voltage The value of the fault point impedance can be determined in one step, and then this fault point impedance value can be used to easily evaluate the position of the ground fault fault point from the first measurement value. Embodiments of the Invention] Next, the present invention will be described in detail with reference to the drawings.
The figure is an explanatory diagram of the principle of the present invention, where L schematically represents one power transmission/distribution line, and its length l represents the section in which a ground fault should be evaluated by the method of the present invention. Current source circuits 1 and 2 are provided at both ends of the section, respectively, and inject current for evaluation into the high-voltage power transmission and distribution line via appropriate coupling means. Current 11.
I2 is reversely placed from current source circuit 1.2! Line LK is drawn to be directly injected. These measuring currents are controlled to have the same frequency f and the same amplitude, but their phases are chosen to be opposite to each other. In order to indicate this opposite phase, in FIG. 1, an arrow is attached in the direction in which the measuring current I2 of the current source circuit 2 is drawn out from the power transmission/distribution line. The ground fault fault point is indicated by F, and the fault point impedance between this point and the ground is the ground fault resistance han g, and the distance from the left end of the transmission/distribution line section to the ground fault AP is Suppose that it is X. Now, if the ground fault fault point F is located at the center point of the transmission and distribution line section, and therefore Z' = l/2, then the fault point impedance Rg has the measurement current II from the current source circuit 1.
Since the current II' proportional to K and the current I2' proportional to the measuring current 2 of the current source circuit 2 flow in opposite directions, and as is easily understood, the magnitudes of If' and I2' are equal. , the plane currents II' and I2' cancel each other out, and the current flowing through the fault point impedances R and g becomes zero. However, when the ground fault fault point F is located other than the center point, the impedance z1 from the left end of the power transmission/distribution line to the fault point F and the impedance Z2 from the right end to the fault point F are the lengths of the power transmission/distribution line between them. Since it is proportional to X and 73-x, the impedance Z1. The values of Z2 are different, the magnitudes of the two currents 11' and I2' at the fault point F are also different, and the plane currents do not cancel out completely. In the general case, the following equation holds. All symbols in the above formula are vectors, Vl. As shown in Figure 1, v2 is the voltage at the left and right ends of the power transmission and distribution lines, but note that these are current stepping voltages for measuring frequency f and are different from the commercial frequency voltage of the power transmission and distribution lines. I want to be The contents of Marida and other codes are as follows. Ra = v'yz (propagation constant). ]2 equivalent impedance/unit length Z#-,/F'(4+sexual impedance)2: equivalent ground admittance/unit length AI = cash (Ror*x) CI = (1/
Za+) 5inh (Rax)Bl-Zm 5
inh (RaIx) DI = cosh (Ra1x
) A2=cosh(Ra+(J-x)) C2= (1/Zω) 5inh i Ra(l!-r
)) B2=Zω5inh(Rs(l!-z))D2=c
osh (Ra(l -2')) Now, as mentioned in 5 above, since Ix = Iz = Ig, put this condition into equation (11) and calculate the value of ■1 on the left side of the opening equation as the fault point impedance R.
, can be obtained as a parameter and X as a variable. Based on this result, the characteristic electrical value at the left end of the power transmission and distribution line, such as the reactive power QVI II, sin θ (where θ is the phase angle between 1 and 13), is determined to be K as shown in FIG. The horizontal axis in Figure 2 is the distance x from the left end of the power transmission/distribution line to the ground fault point F, and the vertical axis is the aforementioned reactive power Q. Case 1 Curve 1 (, 5, R10 is when the fault point impedance is 5.10 kilohms. Curve R corresponds to the case where the fault point impedance is infinite, that is, there is no ground fault. However, this numerical calculation is based on the transmission and distribution line. The distributed inductance of the overhead copper wire on the 60-@ plane is 0.0
01 mH/m, distributed capacitance 0.01 nF,
Leakage, measurement current frequency f = 300Hz, injection current value I
, = IA, the reactive power Q was determined as the power transmission/distribution line length z-stb, and is a typical value for a 6.6 kV class power distribution line. The following can be seen from the results shown in FIG. When a ground fault occurs at the center point of a power transmission/distribution line, the reactive power Q at the end of the line is the reactive power Q when there is no ground fault at all, regardless of the fault point impedance RgQ. be equivalent to. This is easily predicted from the fact that when the fault is at the center point, the entire measured current does not flow through the fault point impedance RIl, as described above.Next, the distance Kl, 1M, to the ground fault fault point is When it deviates from the center point, the value of the reactive power Q changes according to the fault point impedance RgO value according to a nearly linear function of the distance Using the relationship, the distance X can be found extremely easily from the measured value of the reactive power Q, which is the first measured value. As a measurement value, the zero-sequence voltage with respect to the commercial frequency of the three-phase power transmission/distribution I?li! line at the time of a ground fault is measured. This zero-sequence voltage (■) is expressed by the following equation. However, in equation 2). E: Phase voltage of three-phase power transmission and distribution line Rn = Neutral point grounding resistance Cb2 Ground capacitance (for three phases) ω-2πf, f: Frequency (medullary frequency). In equation (2), E = 6.6/J3 kV
, R,n = 10 kilohms, (shib = 3μF, f
= 50Hz, v. The relationship between Rg and Rg is shown in FIG. In addition, the ground capacitance Cb in equation (2) above is the value of the entire three-phase transmission line, and this α [α is constant regardless of the location of the fault point, Therefore, the pressure is V. It can be seen that, regardless of the location of the fault point, once the line is determined, it is related only to one line of the fault point impedance. As described above, the characteristic electric value, for example, the reactive power Q, which is the first measurement value, and the zero-sequence voltage (2), which is the second measurement value. When V is measured, the zero-sequence voltage V. From the value of , the value of the fault point impedance g is known from the relationship shown in Figure 3, and from the value of this fault point impedance Rg and the value of the reactive power Q, the ground fault fault point can be determined from the relationship shown in Figure 2. The distance x can be found. Next, a method for evaluating the ground fault point of power transmission and distribution lines using the above-mentioned principle will be explained in Section 4. In Figure 4, the power transmission and distribution line consists of three-phase high-voltage overhead lines Ll, L2, and L3, and a ground fault with a fault point impedance Rg occurs at the fault point F of the overhead @L2. . Current source circuits], 2 are respectively arranged at both ends of the transmission and distribution line section, and transformer 12. 2
A measuring current is injected into one of the high voltage transmission and distribution lines via 2. Of course, evaluation currents with mutually opposite phases are injected from the left and right ends of the section. Since the ground fault determination devices 12 and 23 may be known devices, they are depicted as simplified 1 to 1.
Find the transmission/distribution line where the ground fault has occurred and selectively close the contacts of the switch (14, 24 +7') corresponding to that line, and disconnect only the corresponding current transformer out of each of the three current transformers (12, 220). Constant current device 11. 21 to inject a measuring current into the fault line. Note that the current transformers 15 and 25 are for preventing the evaluation current from flowing outside the predetermined transmission/distribution line section.
The contacts of the switch 16 are selectively closed by the command pressure from the above-mentioned ground fault detector 81 + devices 13 and 23, and the circuits of the five corresponding current transformers of the three F current transformers 1.5 and 25 are closed. Only connect to Accident #. Further, the filters 17 and 27 are for removing the commercial frequency No. 8 that enters the current source circuit 1.2 via the current transformers 12 and 22. The measuring circuit 30 measures the characteristic electrical values of the current source circuit 1.2, and the measuring circuit 30 measures reactive power, voltage, power factor, etc. In the configuration of the illustrated current source circuit 1.2, the constant current from the constant current device II or 21 flows through one of the three current transformers 12 or 22, respectively, and
5 current transformers 15 or 25 and switch 1
4 or leg into the meter 3o and from there return to the constant Pt flow device 11 or 21K, respectively. Note that the measuring device 30 only needs to be provided at the measuring end of the line section, for example, at the current source circuit 1@ on the left side of the figure. Now, the method of fault point evaluation will be explained using the current source circuit 1 as the measuring terminal. When a ground fault occurs at the fault point F of the power transmission/distribution line L2 as shown in FIG. Entanglement discriminator f
i 13 and 23 operate to determine that the transmission/distribution line L2 is a faulty line, and switch 14.2/j and switch skin 2
A current transformer corresponding to the fault line by selectively closing the contacts of 6;
22 and current transformer 15.25 are respectively connected to the current source circuit 1.2. In this state, the measuring device 30 determines 611 a characteristic electrical value, for example, a reactive power Q in the current duct. This becomes the first measurement value. At the same time, the zero-sequence voltage V of the three-phase power transmission and distribution line is determined by known means (not shown). Measure. For example, by simply adding up the outputs of the voltage transformers connected to each line of power transmission and distribution lines L1 to L3 and taking the average value, the zero-sequence voltage (■) at the time of a ground fault can be determined. can be simply read or recorded as a second measurement value. Note that this zero-phase voltage V. It is not necessary to measure within the section, it can be measured anywhere on the three-phase transmission and distribution line (... As mentioned above, if the first and second measured values are known, it is easy to trace to the failure point. It is possible to estimate the distance
The fault point impedance Rg can be determined using Equation 21 or the diagram shown in FIG. 3, and then the value of the distance X corresponding to the value of RK can be easily determined from the diagram shown in FIG. For fault point evaluation as described above, the frequency of the measured current can be selected in the range of several hundred to several thousand hertz. Also, in the above explanation, reactive power was mainly explained as the characteristic electrical value to be measured, but it is not necessarily limited to this, and it may be reactive power factor, impedance value, or active power. . [Effects of the Invention] As explained above, in the present invention, current source circuits are provided at both ends of a transmission/distribution line section in which ground fault fault evaluation is to be performed for injecting alternating current for evaluation into the transmission/distribution line in the section. , the same frequency from both cylinder flow source circuits. With evaluation currents of the same amplitude and mutually opposite phases injected into the transmission and distribution line, characteristic electrical values such as reactive power are measured as the first measurement value in the current source circuit serving as the measurement end, and the The zero-sequence voltage at the time of a ground fault in the distribution line is measured as the second measurement value, and the distance from the measurement end to the ground fault point is estimated from the first and second measurement values. The evaluation current flowing through the fault impedance of the ground fault point is essentially small, so even when the fault impedance is high, there is an advantage that the error in evaluating the position or distance of the ground fault point is smaller than in the prior art. Furthermore, as can be read from Fig. 2, in the case of the present invention, even if the frequency of the rating current is several hundred hertz (Fig. 2 is for 300 hertz), the measured distances Mr and iil to the failure point are invalid, for example. There is a clear correlation with the power value Q, and therefore the distance x to be found corresponding to the first measurement value can be accurately determined. Furthermore, the correlation between Q and It has been found that the method of the present invention can be applied up to several thousand hertz, and therefore the method of the present invention makes it possible to select a high frequency of the rated current (as compared to the prior art) and to make the equipment for the injection of rated current into the transmission and distribution lines economical. This advantage is particularly significant when evaluation sections must be set at a large number of locations in order to evaluate ground fault fault points in a power distribution network.
図面はすべて本発明の詳細な説明するものであり、第１
図は本発明の原理説明のための回路図、第２図は測定端
から地絡故障点までの距離Ｘを変数とする本発明による
評定時に測定すべき特性電気値の一例としての無効電力
の変化を示すダイヤグラム、第３図は本発明による評定
時に測定される零相電圧と故障点インピーダンスとの相
関を示すダイヤグラム、第４図は本発明による評定時の
特性電気値の測定の具体的賽施例を説明する回路図であ
る。図において、１，２：電流源回路、１１．２１定電
流装置 、 １２，２２．１５．２５ ：評定用電流を
送配電線に注入する手段としての変流器、Ｆ：地絡故障
点、Ｌ：地絡故障点を評定すべき送配電線路。
Ｌ２：地絡故障を生じた送配電線、ｌ：送配電線路長、
Ｑ：測定すべき電流源回路の特性電気値の例としての無
効電力、Ｖｏ：零相電圧、 Ｘ：測定端から地府故障点
までの距離、である。All drawings are for detailed explanation of the invention, and the first
The figure is a circuit diagram for explaining the principle of the present invention, and Figure 2 shows reactive power as an example of the characteristic electrical value to be measured during evaluation according to the present invention, where the distance X from the measuring end to the ground fault point is a variable. FIG. 3 is a diagram showing the correlation between the zero-sequence voltage measured during evaluation according to the present invention and fault point impedance, and FIG. 4 is a diagram showing the specific method of measuring characteristic electrical values during evaluation according to the present invention. It is a circuit diagram explaining an example. In the figure, 1, 2: current source circuit, 11.21 constant current device, 12, 22. 15.25: current transformer as a means for injecting current for evaluation into the transmission and distribution line, F: ground fault point, L: Transmission and distribution line where the ground fault point should be assessed. L2: Transmission and distribution line where the ground fault occurred, l: Transmission and distribution line length,
Q: reactive power as an example of the characteristic electrical value of the current source circuit to be measured, Vo: zero-sequence voltage, X: distance from the measuring end to the local fault point.
Claims (1)
設けて該画定流源回路から同一周波数、同一振幅かつ互
いに逆位相の評定用電流を前言己区間内で地絡故障を生
じた送配電線に注入した４犬態で測定した前記電流源回
路の特性電久値と、地絡故障時における三相送配電線の
零相電圧とを演１ｊ定Ｌ、該零相電圧から推定される地
絡故障点の故障点インピーダンスと前記電流源回路の特
性電慄値とカ・ら地絡故障点の前記区間内の位置を評定
することを特徴とする三相送配電線路・の地絡故障点評
定方法０ ２、特許請求の範囲第１項記載の方法におし・℃、評定
用電流の周波数が数百から数千ヘルツの範囲内に選ばれ
たことを特徴とする三相送配電線路の地絡故障点評定方
法。 ３）ｌ！！ｊ許請求の範囲第１項記載の方法にお〜・て
。 零相電圧が商用周波で測定されることを特徴とする三相
送配電線路の地絡故障点評定方法。 る三相送配電線路の地絡故障点評定方法。 ５）特許請求の範囲第１項記載の方法において、特性電
ヌ値が無効電力値であることを特徴とする三相送配電線
路の地絡故障点評定方法。[Scope of Claims] 1) Current source circuits are provided at both ends of a three-phase transmission and distribution line section, and evaluation currents of the same frequency, same amplitude, and mutually opposite phases are applied to the ground within the aforementioned section from the defined current source circuit. The characteristic voltage value of the current source circuit measured in four states injected into the transmission and distribution line where the fault occurred and the zero-sequence voltage of the three-phase transmission and distribution line at the time of the ground fault are calculated as follows: A three-phase transmission characterized in that the position of the ground fault fault point within the section is evaluated from the fault point impedance of the ground fault fault point estimated from the zero-sequence voltage and the characteristic voltage value of the current source circuit. A method for evaluating the ground fault point of a power distribution line 0 2. The method described in claim 1 is used to determine that the frequency of the evaluation current is selected within the range of several hundred to several thousand hertz Features: Earth fault fault evaluation method for three-phase power transmission and distribution lines. 3)l! ! j. The method according to claim 1. A method for evaluating the ground fault point of a three-phase power transmission and distribution line, characterized in that zero-sequence voltage is measured at a commercial frequency. Ground fault fault evaluation method for three-phase power transmission and distribution lines. 5) A method for evaluating a ground fault fault point of a three-phase power transmission/distribution line in the method according to claim 1, wherein the characteristic power value is a reactive power value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP976783A JPS59135377A (en) | 1983-01-24 | 1983-01-24 | Method for evaluating grounding fault point of three- phase power transmission distribution line |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP976783A JPS59135377A (en) | 1983-01-24 | 1983-01-24 | Method for evaluating grounding fault point of three- phase power transmission distribution line |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59135377A true JPS59135377A (en) | 1984-08-03 |
| JPH0515990B2 JPH0515990B2 (en) | 1993-03-03 |
Family
ID=11729417
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP976783A Granted JPS59135377A (en) | 1983-01-24 | 1983-01-24 | Method for evaluating grounding fault point of three- phase power transmission distribution line |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59135377A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6145977A (en) * | 1984-08-09 | 1986-03-06 | Takamatsu Electric Works Ltd | Detecting and displaying method of earth point of distribution line |
| JPS6183974A (en) * | 1984-09-29 | 1986-04-28 | Takamatsu Electric Works Ltd | Method for detecting ground fault point of distribution line |
| WO2011016213A1 (en) * | 2009-08-05 | 2011-02-10 | 株式会社 東芝 | Fault location method and system |
| CN102621451A (en) * | 2012-03-28 | 2012-08-01 | 北京水木源华电气有限公司 | Distribution line single-phase grounding fault detecting method and system based on instantaneous signal method |
| CN103336220A (en) * | 2013-05-29 | 2013-10-02 | 河南省电力公司鹤壁供电公司 | Method and apparatus for monitoring and positioning fault in power distribution network |
| CN103852688A (en) * | 2012-11-30 | 2014-06-11 | 施耐德电器工业公司 | Method for confirming position of a ground fault and device thereof |
| CN106501678A (en) * | 2016-11-02 | 2017-03-15 | 李晓明 | A kind of earth fault line selection method and system |
| CN106526413A (en) * | 2016-10-13 | 2017-03-22 | 国家电网公司 | Off-line ground fault detection system and method |
| CN106526429A (en) * | 2016-12-06 | 2017-03-22 | 李晓明 | Earth fault line selection method having error correction function |
| CN107064728A (en) * | 2016-09-26 | 2017-08-18 | 国网甘肃省电力公司电力科学研究院 | The single-ended holographic frequency domain Fault Locating Method of ultra-high-tension power transmission line |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57136172A (en) * | 1981-02-18 | 1982-08-23 | Fuji Electric Co Ltd | Orientating system for trouble point |
-
1983
- 1983-01-24 JP JP976783A patent/JPS59135377A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57136172A (en) * | 1981-02-18 | 1982-08-23 | Fuji Electric Co Ltd | Orientating system for trouble point |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6145977A (en) * | 1984-08-09 | 1986-03-06 | Takamatsu Electric Works Ltd | Detecting and displaying method of earth point of distribution line |
| JPH0580629B2 (en) * | 1984-08-09 | 1993-11-09 | Energy Support Corp | |
| JPS6183974A (en) * | 1984-09-29 | 1986-04-28 | Takamatsu Electric Works Ltd | Method for detecting ground fault point of distribution line |
| WO2011016213A1 (en) * | 2009-08-05 | 2011-02-10 | 株式会社 東芝 | Fault location method and system |
| CN102621451A (en) * | 2012-03-28 | 2012-08-01 | 北京水木源华电气有限公司 | Distribution line single-phase grounding fault detecting method and system based on instantaneous signal method |
| CN102621451B (en) * | 2012-03-28 | 2016-01-06 | 北京水木源华电气股份有限公司 | Based on the distribution circuit single-phase earth fault detection method of momentary signal method |
| CN103852688A (en) * | 2012-11-30 | 2014-06-11 | 施耐德电器工业公司 | Method for confirming position of a ground fault and device thereof |
| CN103336220A (en) * | 2013-05-29 | 2013-10-02 | 河南省电力公司鹤壁供电公司 | Method and apparatus for monitoring and positioning fault in power distribution network |
| CN107064728A (en) * | 2016-09-26 | 2017-08-18 | 国网甘肃省电力公司电力科学研究院 | The single-ended holographic frequency domain Fault Locating Method of ultra-high-tension power transmission line |
| CN107064728B (en) * | 2016-09-26 | 2019-10-25 | 国网甘肃省电力公司电力科学研究院 | The single-ended holographic frequency domain Fault Locating Method of ultra-high-tension power transmission line |
| CN106526413A (en) * | 2016-10-13 | 2017-03-22 | 国家电网公司 | Off-line ground fault detection system and method |
| CN106501678A (en) * | 2016-11-02 | 2017-03-15 | 李晓明 | A kind of earth fault line selection method and system |
| CN106526429A (en) * | 2016-12-06 | 2017-03-22 | 李晓明 | Earth fault line selection method having error correction function |
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| Publication number | Publication date |
|---|---|
| JPH0515990B2 (en) | 1993-03-03 |
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