JPS6380711A - Power cable failure predicting relay - Google Patents
Power cable failure predicting relayInfo
- Publication number
- JPS6380711A JPS6380711A JP22658586A JP22658586A JPS6380711A JP S6380711 A JPS6380711 A JP S6380711A JP 22658586 A JP22658586 A JP 22658586A JP 22658586 A JP22658586 A JP 22658586A JP S6380711 A JPS6380711 A JP S6380711A
- Authority
- JP
- Japan
- Prior art keywords
- cable
- current
- power
- zero
- 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.)
- Pending
Links
- 230000015556 catabolic process Effects 0.000 claims description 14
- 230000006866 deterioration Effects 0.000 claims description 11
- 238000009413 insulation Methods 0.000 claims description 11
- 238000001514 detection method Methods 0.000 claims description 9
- 230000005540 biological transmission Effects 0.000 claims description 6
- 229920003023 plastic Polymers 0.000 claims description 6
- 239000004033 plastic Substances 0.000 claims description 6
- 230000007935 neutral effect Effects 0.000 claims description 2
- 229920003020 cross-linked polyethylene Polymers 0.000 description 11
- 239000004703 cross-linked polyethylene Substances 0.000 description 11
- 239000002184 metal Substances 0.000 description 4
- 230000008033 biological extinction Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000012774 insulation material Substances 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
Landscapes
- Locating Faults (AREA)
- Emergency Protection Circuit Devices (AREA)
- Insulated Conductors (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
本発明は電力ケーブルの自然劣化による完全地絡故障を
あらかじめ予知するための１１電器にかか・わるもので
ある。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to eleven electric appliances for predicting in advance a complete ground fault caused by natural deterioration of a power cable.
現在、電力ケーブルは、従来使用されていた油浸紙ケー
ブルから、架橋ポリエチレン等のプラスチックを絶縁材
料とするケーブルにかわりつつある。Currently, in power cables, the conventionally used oil-impregnated paper cables are being replaced by cables made of plastic such as cross-linked polyethylene as an insulating material.
架橋ポリエチレンケーブルは長年月使用されるとこれま
での電力ケーブル同様に自然劣化し絶縁破壊により、完
全地絡故障を引きおこし送電停止という事態にいたる。When cross-linked polyethylene cables are used for many years, they naturally deteriorate, just like conventional power cables, and insulation breakdown occurs, leading to complete ground faults and power outages.
本発明はこのような地絡故障をあらかじめ予知し、送電
線路の切り替え等により、未然に電気故障を防止するこ
とを目的とするものである。The present invention aims to predict such ground faults in advance and prevent electrical faults by switching power transmission lines or the like.
従来電力ケーブルの自然劣化を予知する方法として、ケ
ーブルの絶縁抵抗測定をはじめとする種々の絶縁劣化試
験が行われてきたが架橋ポリエチレンケーブルの絶縁性
能がすぐれているため、劣化状況を判定することは非常
に困難であった。Conventionally, various insulation deterioration tests such as cable insulation resistance measurements have been conducted as a way to predict the natural deterioration of power cables, but since cross-linked polyethylene cables have excellent insulation performance, it is difficult to judge the deterioration status. was extremely difficult.
本発明はこのような従来の考え方とその原理をまったく
異にするものである。The present invention is completely different from such conventional concept and principle.
本発明の着目するところは、健全なケーブルの状態から
劣化を検出しようとするものではなく、完全地格直前の
前駆現象をつかまえて、故障の直前に故障予知を行おう
とするものである。The focus of the present invention is not to detect deterioration from the condition of a healthy cable, but to predict a failure immediately before it occurs by grasping a precursor phenomenon immediately before a complete failure.
このような着眼点にたって、ケーブルの故障直前の状態
を見ると、架橋ポリエチレンケーブルには自然消弧能力
があり、今仮にケーブルが絶縁破壊しても、急に完全地
絡にいたらず、そのまま消弧する現象がある。From this point of view, if we look at the state of the cable just before it fails, cross-linked polyethylene cables have a natural arc-extinguishing ability, and even if the cable breaks down now, it will not suddenly become a complete ground fault and will remain as it is. There is a phenomenon of arc extinction.
その原因はアークの発弧によりガスが発生したり、また
アーク熱によって溶けたプラスチックの移動等により絶
縁を回復すること、ケーブルの静電容量の作用により再
点弧がしにくい状件があることなどである。The cause of this is that gas is generated by the arc, the insulation is restored due to the movement of plastic melted by the arc heat, and there are conditions that make it difficult to re-ignite due to the action of the cable's capacitance. etc.
しかしながら、この自然消弧は、実験的には一部に知ら
れていたが、実際の電力系統では地絡の電流容量が大き
いために、このような現象はあられれないものと思われ
ていた。However, although this spontaneous arc extinction was known to some people experimentally, it was thought that such a phenomenon would never occur in actual power systems due to the large current capacity of ground faults. .
現在、架橋ポリエチレンケーブルが主として使用、さｔ
＆Ｔ１．Ｎる６、６ＫＶ、３３ＫＶ、７７ＫＶ等の。Currently, cross-linked polyethylene cables are mainly used.
&T1. Nru 6, 6KV, 33KV, 77KV etc.
電圧縁ではその電源変圧器の中性点は抵抗接地ま°たは
非接地で、そのため地絡電流は制限されている。At the voltage edge, the neutral point of the power transformer is resistively grounded or ungrounded, so ground fault currents are limited.
このような電力系統では架橋ポリエチレンケーブルの自
然劣化による地絡故障はいきなり完全地絡となるのでは
なく、その絶縁破壊直後、半波あるいは数サイクルの瞬
間的地絡をともない、そのまま絶縁回復し、また一定時
間後それを繰り返しながら完全地絡故障に移行する。In such power systems, a ground fault due to natural deterioration of a cross-linked polyethylene cable does not suddenly become a complete ground fault, but immediately after the insulation breaks down, there is a momentary ground fault of half a wave or several cycles, and then the insulation recovers. After a certain period of time, this process repeats and the failure progresses to a complete ground fault.
本発明の原理は、この前′駆現象的な瞬間的な絶縁破壊
現象を検出して警報等を行い、数１０分後あるいは数時
間後、に完全地絡故障が発生することを予知するもので
ある。The principle of the present invention is to detect this precursory instantaneous dielectric breakdown phenomenon, issue an alarm, etc., and predict that a complete ground fault will occur several tens of minutes or several hours later. It is.
以下 本発明の原理を具体例でもフて説明する。The principle of the present invention will be explained below using specific examples.
図−１は、架橋ポリエチレンケーブルにおいて自然劣化
による絶縁破壊の進行状況を表したものである。Figure 1 shows the progress of dielectric breakdown due to natural deterioration in a crosslinked polyethylene cable.
図−１の１は、架橋ポリエチレンケーブル等の電力ケー
ブルの心線である。ケーブルの金属シース３と電力ケー
ブルの心線ｌとの間の架橋ポリエチレン等のプラスチッ
ク絶縁材２が自然劣化による絶縁破壊を起こすと初期放
電経路５が形成されるが、放電に伴うアークの熱により
ガスが発生したり、またアーク熱によフて溶けたプラス
チックが初期放電経路５を塞ぐこと等により絶縁を回復
する。1 in Figure 1 is the core wire of a power cable such as a cross-linked polyethylene cable. When the plastic insulation material 2 such as cross-linked polyethylene between the metal sheath 3 of the cable and the core wire 1 of the power cable undergoes dielectric breakdown due to natural deterioration, an initial discharge path 5 is formed, but due to the heat of the arc accompanying the discharge. Insulation is restored by gas generation, plastic melted by arc heat, etc. blocking the initial discharge path 5.
７は電力ケーブルの心線１とケーブルの金属シース３と
の間に印加されている電圧のオシログラフによる波形で
ある。交流半サイクルで絶縁を回復し自然消弧した状態
を表しものである。7 is an oscillographic waveform of the voltage applied between the core wire 1 of the power cable and the metal sheath 3 of the cable. This represents the state in which the insulation is restored and the arc is naturally extinguished in half an AC cycle.
この瞬間的な絶縁破壊現象に伴い瞬間的な電流８が流れ
る。An instantaneous current 8 flows due to this instantaneous dielectric breakdown phenomenon.
この絶縁破壊の段階では電力系統の地絡保護継電器も動
作することなく送電停止には至らない。At this stage of insulation breakdown, the power system's earth fault protection relay does not operate, and power transmission does not stop.
しかしながらこのまま放置されていると一定時閏後ガス
圧の低下等に伴い再度放電を繰り返しながら放電経路６
を拡大してついにはビニールシース４を破り完全地絡故
障アーク６となる。However, if left as it is, the discharge path 6 will continue to repeat discharge due to the drop in gas pressure after a certain period of time.
expands and finally breaks the vinyl sheath 4, resulting in a complete ground fault arc 6.
この時の、電力ケーブルの心線ｌとケーブルの金属シー
ス３との間に印加されている電圧のオシログラフによる
波形９、及び電流波形ｌＯは図のようになり連続的な完
全地絡となる。At this time, the oscillographic waveform 9 of the voltage applied between the core l of the power cable and the metal sheath 3 of the cable and the current waveform lO are as shown in the figure, resulting in a continuous complete ground fault. .
一定時間継続すると地絡保護継電器が動作し送電停止に
至る。If this continues for a certain period of time, the earth fault protection relay will operate and power transmission will stop.
本発明の原理とするところは、この前駆現象的な瞬間的
な絶縁破壊直後の電流波形８を検出して警報等を行い、
数１０分後あるいは数時間後に完全地絡故障が発生する
ことを予知するものである。The principle of the present invention is to detect the current waveform 8 immediately after this precursory momentary dielectric breakdown and issue an alarm, etc.
This predicts that a complete ground fault will occur in several tens of minutes or hours.
？ぎに本発明を図−２の実施例でもって説明する。? Next, the present invention will be explained with reference to an embodiment shown in FIG.
１１は送電中に自然劣化による絶縁破壊で初期放電経路
５を生じた電力ケーブルである。Reference numeral 11 denotes a power cable in which an initial discharge path 5 was created due to dielectric breakdown due to natural deterioration during power transmission.
自然劣化による絶縁破壊は通常三相ケーブルの一相で生
じるため、零相電圧を電力系統の地絡故隙をＦｉ視する
通常グランドＰＴとよばれる計器用変成器１３で検出す
ることができる。Since dielectric breakdown due to natural deterioration usually occurs in one phase of a three-phase cable, the zero-sequence voltage can be detected by the instrument transformer 13, usually called a ground PT, which views the ground fault gap in the power system as Fi.
しかしながらこの零相電圧４はケーブル区管内での絶縁
破壊であるかどうかを判定できない。However, it is not possible to determine whether this zero-sequence voltage 4 is due to dielectric breakdown within the cable section.
そのた、めケーブルの接地線１９に取り付けた電流検出
コイル１２により地絡故障点の′ｒｆｊ、流を検出して
ケーブル区管内であることを確認する。In addition, the current detection coil 12 attached to the ground wire 19 of the cable detects the current 'rfj at the ground fault point to confirm that it is within the cable area.
電力ケーブル故障子知装置１６の零相電圧検出回路Ｉ５
と零相電流検出回路１４とが共に動作したことをもって
′Ｈ報回路１７により外部の警報器♀を動作、あるいは
有人の変電所等にＮ報内容を送り、電力ケーブル故障子
知を行うものである。Zero-phase voltage detection circuit I5 of power cable fault detection device 16
When the zero-phase current detection circuit 14 and 14 operate together, the H alarm circuit 17 activates an external alarm ♀, or sends the N alarm contents to a manned substation, etc., to detect a power cable failure. be.
本発明の結果シー◆４、微地絡故障が発生しても、その
意味するところがたんに架空送電線での樹木の接触故障
や完全地絡にいたらない鳥獣による接触故障なのかそれ
とも、この後ケーブルが完全地格故障にいたる前駆現象
であるかを区別できその結果、本発明の装置のＷ報にも
とすき系統をただちに切り替えるなどして未然に停電故
障を防止できるものである。As a result of the present invention, see ◆4. Even if a slight ground fault occurs, does it simply mean a contact fault caused by a tree on an overhead power transmission line or a contact fault caused by a bird or animal that does not lead to a complete ground fault? It is possible to distinguish whether the cable is a precursor to a complete ground failure, and as a result, it is possible to prevent a power outage failure by immediately switching the system when the system of the present invention receives a W warning.
図−１は架橋ポリエチレンケーブルの断面図およびオシ
ログラフの波形であり、本発明の原理である絶縁破壊の
進行状況を説明したものである。
図−２は電気回路の概略図であり、架橋ポリエチレンケ
ーブルに本発明の装置を取り付けた実施例である。
１ 環カケープルの心線
２ 環カケープルのプラスチック絶縁材３ 環
カケープルの金属シース
４ 環カケープルのビニールシース５ 初期放
電経路
６ 完全地格故障アーク
７ 絶縁破壊直後の電圧波形
８ 絶縁破壊直後の電流波形
９ 完全地格故障の電圧波形
１０ 完全地格故障の電流波形
１１ 絶縁破壊した環カケープル
１２ 電流検出コイル
１３ 計器用変成器
１４ 零相電流検出回路
１５ 零相電圧検出回路
１６ ？！カケープル故障子知装萱
１７ 警報回路
１８ 警報器
１９ 環カケープルの接地線
図−１FIG. 1 is a cross-sectional view of a cross-linked polyethylene cable and an oscillographic waveform, and illustrates the progress of dielectric breakdown, which is the principle of the present invention. FIG. 2 is a schematic diagram of an electric circuit, and is an embodiment in which the device of the present invention is attached to a cross-linked polyethylene cable. 1 Core wire of the ring capeple 2 Plastic insulation material of the ring capeple 3 Metal sheath of the ring capeple 4 Vinyl sheath of the ring capeple 5 Initial discharge path 6 Complete earth fault arc 7 Voltage waveform immediately after dielectric breakdown 8 Current waveform immediately after dielectric breakdown 9 Voltage waveform of complete earth fault 10 Current waveform of complete earth fault 11 Dielectrically broken ring capeple 12 Current detection coil 13 Instrument transformer 14 Zero-sequence current detection circuit 15 Zero-sequence voltage detection circuit 16 ? ! Capable fault detection system 17 Alarm circuit 18 Alarm 19 Grounding diagram of the ring capeple - 1
Claims (2)
地の電力系統において、プラスチック絶縁電力ケーブル
の自然劣化による絶縁破壊後自然消弧するまでの間、瞬
間的にケーブルシースに流れる電流をケーブルシースの
接地線に取り付けたコイルで検出し、さらにその系統の
零相計器用変成器で、零相電圧も検出されていることを
条件に、警報器を動作させて、ケーブルが短時間後に完
全地絡故障を引きおこし送電停止することを予知せしめ
ることを特徴とする装置。(1) In a power system where the neutral point of a power transformer is resistively grounded or ungrounded, the current momentarily flows through the cable sheath after insulation breakdown due to natural deterioration of the plastic insulated power cable until it naturally extinguishes. is detected by a coil attached to the ground wire of the cable sheath, and if the zero-sequence voltage is also detected by the zero-sequence voltage transformer in that system, an alarm will be activated to ensure that the cable is A device characterized by foretelling that a complete ground fault will later occur and power transmission will be stopped.
流れる電流をケーブル心線の両端に取付けた零相計器用
変流器により検出し、両端の検出信号の比較からケーブ
ル区間内で発生した電流であることを判定することを特
徴とする装置。(2) The above-mentioned device detects the current instantaneously flowing through the cable sheath using zero-phase instrument current transformers attached to both ends of the cable core, and compares the detection signals at both ends to detect the current flowing within the cable section. A device characterized in that it determines that the current is
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22658586A JPS6380711A (en) | 1986-09-25 | 1986-09-25 | Power cable failure predicting relay |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22658586A JPS6380711A (en) | 1986-09-25 | 1986-09-25 | Power cable failure predicting relay |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6380711A true JPS6380711A (en) | 1988-04-11 |
Family
ID=16847480
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22658586A Pending JPS6380711A (en) | 1986-09-25 | 1986-09-25 | Power cable failure predicting relay |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6380711A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH022424U (en) * | 1988-06-17 | 1990-01-09 | ||
| JPH0258521U (en) * | 1988-06-17 | 1990-04-26 |
-
1986
- 1986-09-25 JP JP22658586A patent/JPS6380711A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH022424U (en) * | 1988-06-17 | 1990-01-09 | ||
| JPH0258521U (en) * | 1988-06-17 | 1990-04-26 |
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