JPS63205578A - Method for diagnosing deterioration of crosslinked polyethylene insulated cable - Google Patents
Method for diagnosing deterioration of crosslinked polyethylene insulated cableInfo
- Publication number
- JPS63205578A JPS63205578A JP3867987A JP3867987A JPS63205578A JP S63205578 A JPS63205578 A JP S63205578A JP 3867987 A JP3867987 A JP 3867987A JP 3867987 A JP3867987 A JP 3867987A JP S63205578 A JPS63205578 A JP S63205578A
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- cable
- water tree
- leakage current
- current
- 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
- 230000006866 deterioration Effects 0.000 title claims description 15
- 238000000034 method Methods 0.000 title claims description 8
- 229920003020 cross-linked polyethylene Polymers 0.000 title claims description 3
- 239000004703 cross-linked polyethylene Substances 0.000 title claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 6
- 230000035515 penetration Effects 0.000 claims description 3
- 240000005572 Syzygium cordatum Species 0.000 abstract description 21
- 235000006650 Syzygium cordatum Nutrition 0.000 abstract description 21
- 230000000149 penetrating effect Effects 0.000 abstract description 6
- 238000001514 detection method Methods 0.000 abstract 1
- 238000009413 insulation Methods 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 238000003745 diagnosis Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000005684 electric field Effects 0.000 description 2
- 239000003973 paint Substances 0.000 description 2
- 102000029749 Microtubule Human genes 0.000 description 1
- 108091022875 Microtubule Proteins 0.000 description 1
- 241001325280 Tricardia watsonii Species 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000002405 diagnostic procedure Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 210000004688 microtubule Anatomy 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 210000005239 tubule Anatomy 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Landscapes
- Testing Relating To Insulation (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
Ｃｖケーブルと略称する）の直流漏れ電流による劣化診
断方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for diagnosing deterioration of a Cv cable (abbreviated as Cv cable) due to direct current leakage current.
（従来技術及び解決しようとする問題点）Ｃｖケーブル
は３〜８ｋＶ配電用高圧ケーブルとし、て広（用いられ
ている。(Prior Art and Problems to be Solved) Cv cables are widely used as high voltage cables for 3 to 8 kV power distribution.
Ｃｖケーブルは布設後、外傷等による部分放電劣化や水
の侵入による水トリー、ボウタイトリー（以下水トリー
と称す）によって劣化することが知られており、特に水
トリーはＣＶケーブル特有の劣化であって、水、電界、
微小な欠陥の３要素が重なって引きおこされる。この水
トリーが大きく成長するとケーブルの絶縁破壊事故の可
能性があるため、かかる事故を未然に防止するという目
的から劣化診断は極めて重要な試験である。After installation, CV cables are known to deteriorate due to partial discharge deterioration due to external damage, water intrusion, and bow tree tree (hereinafter referred to as water tree). In particular, water tree is a type of deterioration that is unique to CV cables. , water, electric field,
This is caused by a combination of three tiny defects. If this water tree grows too large, there is a possibility of damage to the insulation of the cable, so deterioration diagnosis is an extremely important test for the purpose of preventing such accidents.
従来行なわれていたＣｖケーブルの劣化診断試験には、
例えば直流漏れ電流（直流漏れ電流値、キック現象、成
極比等）、誘電正接（ｔａｎδ）あるいは部分放電の測
定等あるが、特に水トリー劣化を確実に把持できる単独
の１ｌｔｌｌ定法がな（、現在、通常行なわれているの
は、例えば直流漏れ電流値とｔａｎδの両方の特性から
あるレベルを設定し総合的に判定しているのが多い。The conventional Cv cable deterioration diagnostic test includes:
For example, there are measurements of DC leakage current (DC leakage current value, kick phenomenon, polarization ratio, etc.), dielectric loss tangent (tanδ), or partial discharge, but there is no single standard method that can reliably grasp water tree deterioration. Currently, it is common practice to set a certain level based on the characteristics of both the DC leakage current value and tan δ, for example, and make a comprehensive determination.
のベース材料、配合、絶縁厚さ、ケーブル長さ、端末の
状態等の要因によって大きく変る。従っである電流値が
得られたとしてもそれが水トリー劣化なのか、他の要因
によるものなのか判定が難しい。ｔａｎδ測定の場合も
同様なことがいえる。このように単独では劣化判定が難
しいので、前述のようにいくつかの測定を行ない総合判
定をするが、一つの線路を測定する場合でも測定用設備
を多く必要とし、７Ｉｔｌｌ定時間が長いという問題点
がある。It varies greatly depending on factors such as the base material, composition, insulation thickness, cable length, and terminal condition. Therefore, even if a certain current value is obtained, it is difficult to determine whether it is due to water tree deterioration or other factors. The same can be said for tan δ measurement. As described above, it is difficult to judge the deterioration independently, so several measurements are performed to make a comprehensive judgment as described above, but even when measuring one line, it requires a lot of measurement equipment and the waiting time is long. There is a point.
（問題点を解決するための手段）
本発明は上述の問題点を解消した直流漏れ電流によるＣ
Ｖケーブルの劣化診断方法を提供するもので、その特徴
は、印加する直流電圧を複数ステップで昇圧し、それぞ
れの電圧における直流漏れ電流を測定して直流電圧電流
特性の急増現象を把握することにより貫通水トリーを検
知することにある。(Means for Solving the Problems) The present invention solves the above-mentioned problems and provides a
This provides a method for diagnosing deterioration of V cables.The feature is that the applied DC voltage is boosted in multiple steps, and the DC leakage current at each voltage is measured to understand the rapid increase in DC voltage-current characteristics. The purpose is to detect penetrating water trees.
Ｊ１図はＣｖケーブルの貫通水トリーの測定法の概略説
明図で、（１）は測定しようとするＣｖケーブルでＯＤ
はその導体、■はＣＶケーブル絶縁層の外表面の一部に
設けた半導電塗料層、（３）は電極である。Figure J1 is a schematic explanatory diagram of the method for measuring the penetration water tree of a Cv cable, and (1) shows the OD of the Cv cable to be measured.
(3) is the conductor, (3) is the semiconductive paint layer provided on a part of the outer surface of the CV cable insulation layer, and (3) is the electrode.
Ｃｖケーブルに発生する水トリーは、例えば６ｋＶケー
ブル（絶縁厚さ３．５〜４．０龍）の場合、長さ１００
μｍ程度の水トリーが数多くあってもこれらが部分的に
存在し、架橋ポリエチレンの健全な部分がいくらかでも
残っていると絶縁破壊電圧が高く直流漏れ電流も小さい
。従ってケーブルの寿命に実際に影響するのは、絶縁体
を貫通するような長い水トリーの発生である。従って、
劣化診断ではこのような絶縁体を貫通するような長い水
トリーが１ケ所でも発生した時に、これを確実に検知す
る方法が望まれている。For example, in the case of a 6 kV cable (insulation thickness 3.5 to 4.0 mm), the water tree that occurs in a Cv cable has a length of 100 mm.
Even if there are many water trees on the order of micrometers, if these are partially present and some healthy portion of crosslinked polyethylene remains, the dielectric breakdown voltage will be high and the DC leakage current will be small. Therefore, what actually affects the life of the cable is the occurrence of long water trees that penetrate the insulation. Therefore,
In deterioration diagnosis, a method is desired that can reliably detect when a long water tree that penetrates an insulator occurs at even one location.
て、種々検討の結果、直流電圧を複数ステップで昇圧し
て行き、貫通した水トリー１ケの直流漏れ３丸
電径の電圧電流特性をとると第２図に示すように通常の
オーム則（比例）と異なり電流が急増するという特異な
現象のあることを見出した。この現象はボイドと微細管
の集合体である水トリーに電界がかかるとマックスウェ
ル応力によって水が細管に流れ、充滴することによって
電流が急増するものと考えられる。As a result of various studies, we found that when we step up the DC voltage in multiple steps and take the voltage-current characteristics of the DC leakage of 3 round diameters of 1 water tree that has penetrated, we obtain the usual Ohm's law ( It was discovered that there is a unique phenomenon in which the current increases rapidly, unlike when the current is proportional (proportional). This phenomenon is thought to be due to the fact that when an electric field is applied to a water tree, which is a collection of voids and microtubules, water flows into the tubules due to Maxwell stress and becomes filled with water, causing a sudden increase in current.
通常の場合、直流漏れ電流の測定は、例えば６ｋＶ Ｃ
Ｖケーブルノ場合、８ｋＶ 又ｉｔ ｌ０ｋＶ 印加ｔ
、、５〜ＩＯ分後の漏れ電流値を読みとっていた。しか
るに本願発明では、例えば８ｋＶ ＣＶケーブルの場合
、直流課電電圧の上限は６ｋＶ又はｌ０ｋＶとするが、
昇圧は例えば１ｋＶ／分のステップで昇圧し、それぞれ
の電圧における直流漏れ電流値を測定する。Normally, DC leakage current measurements are carried out using e.g. 6kV C
In case of V cable, 8kV or it l0kV applied t
,, The leakage current value was read after 5 to 10 minutes. However, in the present invention, for example, in the case of an 8kV CV cable, the upper limit of the DC applied voltage is 6kV or 10kV,
The voltage is increased in steps of, for example, 1 kV/minute, and the DC leakage current value at each voltage is measured.
この結果から電圧電流特性曲線を画き、値が小さく、オ
ーム則に従う場合は健全、急増現象がある場合は貫通水
トリーによる劣化と判定する。なお、このような電圧電
流特性を自動的に検出してもよい。A voltage-current characteristic curve is drawn from this result, and if the value is small and follows Ohm's law, it is determined to be healthy, and if there is a rapid phenomenon, it is determined to be deterioration due to water tree penetration. Note that such voltage-current characteristics may be automatically detected.
（実施例）
願発明の方法で劣化診断を行なった。得られた結果を直
流電圧電流特性曲線で表わすと第３図のようになった。(Example) Deterioration diagnosis was performed using the method of the claimed invention. The obtained results were expressed as a DC voltage-current characteristic curve as shown in FIG. 3.
３心のうち、青相はほぼオーム則に従った直線が得られ
たが、赤相及び白和には急増現象があられれた。又３心
一括で測定するとほぼ３心合計した電流値が得られた。Among the three hearts, a straight line almost following Ohm's law was obtained for the blue phase, but a rapid phenomenon was observed for the red phase and the white phase. Moreover, when the three cores were measured at once, the current value that was approximately the sum of the three cores was obtained.
ケーブルを解体調査した結果、青相には微小な水トリー
やボウタイトリーが多数あったが、貫通水トリーはなか
った。これに対して赤相及び白和には１１通水トリーが
発見された。As a result of dismantling and inspecting the cable, there were many small water trees and bow-tied trees in the blue phase, but no penetrating water trees. On the other hand, 11 water trees were found in Akase and Shirawa.
（発明の効果）
上述した本発明の劣化診断方法によれば、電圧可変な直
流漏れ電流測定装置（メガ−でもよい）のみを用いるこ
とにより、確実に有害な貫通水トリーを検出することが
可能となる。(Effects of the Invention) According to the deterioration diagnosis method of the present invention described above, it is possible to reliably detect harmful penetrating water trees by using only a voltage variable DC leakage current measuring device (megger may also be used). becomes.
又他の装置や測定法と併用しなくてもよいので１心づつ
測定したとしても大幅な時間短縮となるが、特に３心一
括して測定すればより確実で、ざらに時間短縮が実現出
来る。Also, since it does not need to be used in conjunction with other devices or measurement methods, even if you measure each core one at a time, it will significantly reduce the time, but if you measure all three cores at once, it will be more reliable and will significantly reduce the time. .
説明図である。It is an explanatory diagram.
第２図は貫通水トリー１ケの直流漏れ電流の電圧電流特
性図、第３図は劣化した６ｋＶ ＣＶケーブルの直流湿
れ電流の電圧電流特性図である。Fig. 2 is a voltage-current characteristic diagram of DC leakage current of one through-water tree, and Fig. 3 is a voltage-current characteristic diagram of DC wetting current of a deteriorated 6kV CV cable.
１・・・Ｃｖケーブル、２・・・半導電塗料層、３・・
・電極。1...Cv cable, 2...semiconductive paint layer, 3...
·electrode.
Claims (1)
ぞれの電圧における直流漏れ電流を測定して直流電圧電
流特性の急増現象を把握することにより貫通水トリーを
検知することを特徴とする架橋ポリエチレン絶縁ケーブ
ルの劣化診断方法。(1) Cross-linked polyethylene characterized by increasing the applied DC voltage in multiple steps, measuring the DC leakage current at each voltage, and detecting the rapid increase in DC voltage-current characteristics to detect water penetration trees. Method for diagnosing deterioration of insulated cables.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3867987A JPS63205578A (en) | 1987-02-20 | 1987-02-20 | Method for diagnosing deterioration of crosslinked polyethylene insulated cable |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3867987A JPS63205578A (en) | 1987-02-20 | 1987-02-20 | Method for diagnosing deterioration of crosslinked polyethylene insulated cable |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63205578A true JPS63205578A (en) | 1988-08-25 |
Family
ID=12531964
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3867987A Pending JPS63205578A (en) | 1987-02-20 | 1987-02-20 | Method for diagnosing deterioration of crosslinked polyethylene insulated cable |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63205578A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111025090A (en) * | 2019-11-19 | 2020-04-17 | 云南电网有限责任公司临沧供电局 | Cable life prediction method based on leakage current difference coefficient |
| CN111025092A (en) * | 2019-11-19 | 2020-04-17 | 云南电网有限责任公司临沧供电局 | XLPE cable terminal air gap defect safety intelligent and rapid assessment method |
| CN111025095A (en) * | 2019-11-19 | 2020-04-17 | 云南电网有限责任公司临沧供电局 | XLPE cable terminal insulation reliability intelligent and rapid assessment method |
-
1987
- 1987-02-20 JP JP3867987A patent/JPS63205578A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111025090A (en) * | 2019-11-19 | 2020-04-17 | 云南电网有限责任公司临沧供电局 | Cable life prediction method based on leakage current difference coefficient |
| CN111025092A (en) * | 2019-11-19 | 2020-04-17 | 云南电网有限责任公司临沧供电局 | XLPE cable terminal air gap defect safety intelligent and rapid assessment method |
| CN111025095A (en) * | 2019-11-19 | 2020-04-17 | 云南电网有限责任公司临沧供电局 | XLPE cable terminal insulation reliability intelligent and rapid assessment method |
| CN111025090B (en) * | 2019-11-19 | 2022-04-26 | 云南电网有限责任公司临沧供电局 | Cable life prediction method based on leakage current difference coefficient |
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