JPH0376430B2 - - Google Patents
Info
- Publication number
- JPH0376430B2 JPH0376430B2 JP58076883A JP7688383A JPH0376430B2 JP H0376430 B2 JPH0376430 B2 JP H0376430B2 JP 58076883 A JP58076883 A JP 58076883A JP 7688383 A JP7688383 A JP 7688383A JP H0376430 B2 JPH0376430 B2 JP H0376430B2
- Authority
- JP
- Japan
- Prior art keywords
- cable
- positive
- negative polarity
- insulation deterioration
- leakage 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.)
- Expired - Lifetime
Links
- 230000006866 deterioration Effects 0.000 claims description 22
- 238000009413 insulation Methods 0.000 claims description 20
- 240000005572 Syzygium cordatum Species 0.000 claims description 8
- 235000006650 Syzygium cordatum Nutrition 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 7
- 239000004020 conductor Substances 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 12
- 238000005259 measurement Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 238000003745 diagnosis Methods 0.000 description 3
- 239000002184 metal Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 229920003020 cross-linked polyethylene Polymers 0.000 description 1
- 239000004703 cross-linked polyethylene Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
Landscapes
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Testing Relating To Insulation (AREA)
Description
【発明の詳細な説明】
本発明は、電力ケーブル主として架橋ポリエチ
レン絶縁電力ケーブル（CVケーブル）の絶縁劣
化診断法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for diagnosing insulation deterioration of power cables, mainly cross-linked polyethylene insulated power cables (CV cables).
従来の電力ケーブルの絶縁劣化診断法の一つと
して直流高圧法による方法があつた。この方法
は、ケーブルの導体側から負極性の直流高電圧を
印加し、ケーブルに流れる漏洩電流を測定し、そ
の大きさ及び時間特性からケーブルの絶縁劣化状
態を判定するものであつた。 One of the conventional methods for diagnosing the insulation deterioration of power cables is the DC high voltage method. In this method, a negative DC high voltage is applied from the conductor side of the cable, the leakage current flowing through the cable is measured, and the state of insulation deterioration of the cable is determined from the magnitude and time characteristics of the leakage current.
一方、CVケーブルの絶縁劣化は、主として水
トリー劣化によるものである。この水トリはー
は、ケーブルの内部半導電層から発生する内導水
トリーと外部半導電層から発生する外導水トリー
に分けられる。 On the other hand, insulation deterioration of CV cables is mainly due to water tree deterioration. This water tree is divided into an inner water tree generated from the inner semiconductive layer of the cable and an outer water tree generated from the outer semiconductive layer.
本発明者らは、水トリー現象について研究をし
ている過程で次のことを発見した。即ち、内導水
トリーの発生した強制劣化ケーブルに導体側から
正極性の直流電圧を印加した場合、当該ケーブル
に発生する直流漏洩電流は大きさ、時間特性共に
正常ケーブルと大差ないが、負極性の直流電圧を
印加すると正常ケーブルの場合と顕著な差異があ
ること、また、外導水トリーの発生した強制劣化
ケーブルの場合、内導水トリーの発生した強制劣
化ケーブルと全く逆の特性があることである。 The present inventors discovered the following in the process of researching the water tree phenomenon. In other words, when a positive polarity DC voltage is applied from the conductor side to a forcibly degraded cable in which an internal water conduction tree has occurred, the DC leakage current generated in the cable is not much different in magnitude or time characteristics from a normal cable, but the negative polarity When a DC voltage is applied, there is a noticeable difference from that of a normal cable, and in the case of a forcedly degraded cable with an external water guide tree, the characteristics are completely opposite to those of a forced deteriorated cable with an internal water guide tree. .
このことは、単一極性の直流電圧印加した直流
漏洩電流測定では、ケーブルの絶縁劣化判定が正
確にできないことを示している。 This indicates that cable insulation deterioration cannot be accurately determined by measuring DC leakage current with a single polarity DC voltage applied.
本発明の目的は、前記した従来技術の欠点を解
消し、電力ケーブルの絶縁劣化状態をより正確に
診断できる方法を提供することにある。 SUMMARY OF THE INVENTION An object of the present invention is to provide a method that eliminates the drawbacks of the prior art described above and allows more accurate diagnosis of the insulation deterioration state of a power cable.
本発明の要旨は、正及び負極性の両方の直流電
圧を発生できる電源装置を用いて測定対象ケーブ
ルに正及び負極性の直流電圧を印加し、この時、
測定対象ケーブルの導体と遮蔽層間に流れる正及
び負極性の直流漏洩電流を測定して、この正及び
負極性の直流漏洩電流の絶対値の差異、並びに正
及び負極性の直流漏洩電流の時間に対する変化の
差異からケーブルの絶縁劣化の程度並びに絶縁劣
化が測定対象ケーブルの内・外部半導電層のどち
ら側で発生した水トリーに起因するものであるか
の別を判定する方法にある。 The gist of the present invention is to apply positive and negative polarity DC voltages to a cable to be measured using a power supply device that can generate both positive and negative polarity DC voltages, and at this time,
The positive and negative polarity DC leakage currents flowing between the conductor and the shielding layer of the cable to be measured are measured, and the difference in the absolute value of the positive and negative polarity DC leakage currents, as well as the relationship between the positive and negative polarity DC leakage currents over time, are determined. The present invention is based on a method for determining the degree of insulation deterioration of a cable and whether the insulation deterioration is caused by water trees occurring on either side of the inner or outer semiconducting layer of the cable to be measured, based on the difference in change.
正及び負極性の両方の直流電圧を用いる理由に
ついて実験データをもとに説明する。 The reason for using both positive and negative polarity DC voltages will be explained based on experimental data.
実験に用いたケーブルは、6KV級400mm2CVケ
ーブルで正常ケーブル、内導水トリーの発生した
強制劣化ケーブル及び外導水トリーの発生した強
制劣化ケーブルの三種である。 The cables used in the experiment were 6KV class 400mm 2 CV cables of three types: a normal cable, a forcedly deteriorated cable with an internal water conduction tree, and a forcedly deteriorated cable with an external water conduction tree.
これら三種のケーブルの導体側から正及び負極
性の両方の直流電圧を印加し、正及び負極性の直
流漏洩電流を測定した。印加電圧の大きさは両極
性ともに、100V、500V、1000V、5000V、
10000Vであり、これらの電圧をそれぞれ10分間
ずつ印加し、正及び負極性の直流漏洩電流を測定
した。 Both positive and negative polarity DC voltages were applied from the conductor sides of these three types of cables, and the positive and negative polarity DC leakage currents were measured. The magnitude of the applied voltage is 100V, 500V, 1000V, 5000V, both polarities.
These voltages were applied for 10 minutes each, and the positive and negative polarity DC leakage currents were measured.
第１図は、正常ケーブルの場合の実験結果であ
る。図から明らかなように、正及び負極性の両方
の直流電圧を印加した場合の両漏洩電流は、共に
同様な特性を示した。 FIG. 1 shows the experimental results for a normal cable. As is clear from the figure, both leakage currents exhibited similar characteristics when both positive and negative polarity DC voltages were applied.
第２図は、内導水トリーの発生した強制劣化ケ
ーブルの実験結果である。正極性の直流電圧を印
加した場合は、直流漏洩電流の絶対値の大きさ及
び直流漏洩電流の時間に対する変化の状態が共に
正常ケーブルのそれと同様な特性を示したのに対
し、負極性の直流電圧を印加した場合には、正極
性の直流電圧を印加した場合と全く異なり、直流
漏洩電流の絶対値は約２桁大きく且つ漸増傾向を
示した。 Figure 2 shows the experimental results of a forcedly deteriorated cable in which internal water guiding trees occurred. When a positive polarity DC voltage was applied, both the magnitude of the absolute value of the DC leakage current and the state of change of the DC leakage current over time showed characteristics similar to those of a normal cable, whereas negative polarity DC voltage When a voltage was applied, the absolute value of the DC leakage current was about two orders of magnitude larger and showed a gradual increasing tendency, which was completely different from when a positive DC voltage was applied.
第３図は、外導水トリーの発生した強制劣化ケ
ーブルの実験結果である。この結果は、内導水ト
リーの発生した強制劣化ケーブルの特性と全く異
なる。即ち、負極性の直流電圧を印加した場合
は、直流漏洩電流の絶対値の大きさ及び直流漏洩
電流の時間に対する変化の状態が共に正常ケーブ
ルのそれと同様な特性を示したのに対し、正極性
の直流電圧を印加した場合には、負極性の直流電
圧を印加した場合と全く異なり、直流漏洩電流の
絶対値は約２桁大きく且つ漸増傾向を示した。 Figure 3 shows the experimental results of a forcedly deteriorated cable in which an external water guide tree occurred. This result is completely different from the characteristics of a forcedly degraded cable in which internal water guiding trees have occurred. In other words, when a negative polarity DC voltage was applied, both the magnitude of the absolute value of the DC leakage current and the state of change of the DC leakage current over time showed characteristics similar to those of a normal cable, whereas the positive polarity When a DC voltage of 100% was applied, the absolute value of the DC leakage current was about 2 orders of magnitude larger and showed a gradual increasing tendency, which was completely different from when a negative polarity DC voltage was applied.
これらの結果より、次のことが言える。即ち、
CVケーブルの絶縁劣化診断を行う際、
(1) 片極性の直流電圧を印加し、漏洩電流を測定
することにより、偶然に或る種の絶縁劣化状態
を知ることができる場合があるが正確な絶縁劣
化診断を行なうことができない。 From these results, the following can be said. That is,
When diagnosing insulation deterioration of CV cables, (1) By applying a unipolar DC voltage and measuring the leakage current, it may be possible to discover a certain type of insulation deterioration by chance, but Insulation deterioration diagnosis cannot be performed.
(2) 正及び負極性の両方の直流電圧を印加して正
及び負極性の直前漏洩電流を測定し、この正及
び負極性の直流漏洩電流の絶対値の差異、並び
に正及び負極性の直流漏洩電流の時間に対する
変化の差異を解析することにより正確にケーブ
ルの絶縁劣化状態を診断することができる。(2) Apply both positive and negative polarity DC voltages, measure the positive and negative polarity immediate leakage currents, and measure the difference in the absolute value of the positive and negative polarity DC leakage currents, as well as the positive and negative polarity DC voltages. By analyzing the difference in change in leakage current over time, it is possible to accurately diagnose the state of cable insulation deterioration.
(3) さらに、第２図及び第３図で述べたように内
導水トリー及び外導水トリーのどちらに起因す
る絶縁劣化であるかという判別も可能である。(3) Furthermore, as described in FIGS. 2 and 3, it is also possible to determine whether the insulation deterioration is caused by the inner water guide tree or the outer water guide tree.
次に、第４図及び第５図により本発明の実施例
を説明する。第４図はケーブルの金属遮蔽層が接
地されている時の漏洩電流測定回路、第５図はケ
ーブルの金属遮蔽層が接地されていない時の漏洩
電流測定回路である。 Next, an embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. 4 shows a leakage current measuring circuit when the metal shielding layer of the cable is grounded, and FIG. 5 shows a leakage current measuring circuit when the metal shielding layer of the cable is not grounded.
第４図及び第５図は一般的な漏洩電流測定回路
である。１は正及び負極性の両方の直流電圧を発
生させる直流電源装置、７は直流漏洩電流測定解
析装置にして、これにより被測定ケーブル３に流
れる正及び負極性の直流漏洩電流の絶対値の差
異、並びに正及び負極性の直流漏洩電流の時間に
対する変化の差異を測定し、もつて当該ケーブル
３の絶縁劣化を診断する。なお、７は単に測定値
を記録計及びCTRに出力できる直流電流計であ
つてもよい。２は充電抵抗、４はケーブル端末、
５はガード部、６は接地線、８は測定値及び解析
データの出力端である。 FIGS. 4 and 5 show general leakage current measuring circuits. 1 is a DC power supply device that generates both positive and negative polarity DC voltages, 7 is a DC leakage current measurement and analysis device, and the difference in the absolute value of the positive and negative polarity DC leakage currents flowing through the cable to be measured 3 is determined. , and the difference in change over time of positive and negative DC leakage currents, thereby diagnosing insulation deterioration of the cable 3. Note that 7 may simply be a DC ammeter that can output measured values to a recorder and CTR. 2 is the charging resistor, 4 is the cable terminal,
5 is a guard part, 6 is a grounding wire, and 8 is an output end for measured values and analysis data.
更に、本発明においては、前述の漏洩電流の定
期的な測定結果を大型コンピユータにフアイリン
グし、解析していくことにより測定対象ケーブル
毎の絶縁劣化状態の経時変化を知ることができ、
ケーブルの保守管理に大きく寄与することができ
る。 Furthermore, in the present invention, by filing the above-mentioned periodic leakage current measurement results in a large computer and analyzing them, it is possible to know the change over time in the insulation deterioration state of each cable to be measured.
This can greatly contribute to cable maintenance management.
以上の通りであるから、本発明によれば電力ケ
ーブルの絶縁劣化の程度並びに絶縁劣化が電力ケ
ーブルの内・外部半導電層のどちら側で発生した
水トリーに起因するものであるかの別を正確に診
断でき、従つて電力ケーブルの破壊事故を未然に
防ぐことができ、延いては停止事故を未然に防ぐ
ことができ、電力需要家への損害の大幅な低減を
図ることができる。 As described above, according to the present invention, it is possible to determine the degree of insulation deterioration of a power cable and whether the insulation deterioration is caused by water trees occurring on the inner or outer semiconductive layer of the power cable. Accurate diagnosis can be made, and power cable breakage accidents can therefore be prevented, and power outage accidents can be prevented, and damage to power consumers can be significantly reduced.
第１図は正及び負極性の直流電圧を印加した時
の正常ケーブルの正及び負極性の直流漏洩電流の
実測図、第２図は正及び負極性の直流電圧を印加
した時の内導水トリーの発生した強制劣化ケーブ
ルの正及び負極性の直流漏洩電流の実測図、第３
図は正及び負極性の直流電圧を印加した時の外導
水トリーの発生した強制劣化ケーブルの正及び負
極性の直流漏洩電流の実測図、第４図及び第５図
は本発明の実施例説明図である。
１：直流電源装置、２：充電抵抗、３：ケーブ
ル本体、４：ケーブル端末、５：ガード部、６：
接地線、７：直流漏洩電流測定解析装置、８：出
力端。
Figure 1 is an actual measurement diagram of the positive and negative DC leakage current of a normal cable when positive and negative DC voltages are applied, and Figure 2 is the inner water conduction tree when positive and negative DC voltages are applied. Actual measurement diagram of the positive and negative polarity DC leakage current of the forced deterioration cable that occurred, Part 3
The figure is an actual measurement diagram of the positive and negative polarity DC leakage current of a forcedly degraded cable in which an external water conduction tree has occurred when positive and negative polarity DC voltages are applied, and Figures 4 and 5 are illustrations of embodiments of the present invention. It is a diagram. 1: DC power supply, 2: Charging resistor, 3: Cable body, 4: Cable terminal, 5: Guard part, 6:
Grounding wire, 7: DC leakage current measurement and analysis device, 8: Output end.
Claims (1)
及び負極性の直流電圧を印加して、当該ケーブル
に流れる正及び負極性の直流漏洩電流を測定し、
この正及び負極性の直流漏洩電流の差異により絶
縁劣化の程度並びに絶縁劣化が電力ケーブルの
内・外部半導電層のどちら側で発生した水トリー
に起因するものであるかの別を判定することを特
徴とする電力ケーブルの絶縁劣化診断法。1. Apply positive and negative DC voltages from the conductor side to the power cable to be measured, measure the positive and negative DC leakage currents flowing through the cable,
Based on the difference between the positive and negative polarity DC leakage currents, it is possible to determine the degree of insulation deterioration and whether the insulation deterioration is caused by water trees occurring on either side of the inner or outer semiconducting layer of the power cable. A method for diagnosing insulation deterioration of power cables.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58076883A JPS59202074A (en) | 1983-04-30 | 1983-04-30 | Diagnosis of insulation deterioration of power cable |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58076883A JPS59202074A (en) | 1983-04-30 | 1983-04-30 | Diagnosis of insulation deterioration of power cable |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59202074A JPS59202074A (en) | 1984-11-15 |
| JPH0376430B2 true JPH0376430B2 (en) | 1991-12-05 |
Family
ID=13618030
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58076883A Granted JPS59202074A (en) | 1983-04-30 | 1983-04-30 | Diagnosis of insulation deterioration of power cable |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59202074A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111025097B (en) * | 2019-11-19 | 2022-04-15 | 云南电网有限责任公司临沧供电局 | Intelligent method for evaluating leakage current difference factor of XLPE cable after aging |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS564066A (en) * | 1979-06-26 | 1981-01-16 | Furukawa Electric Co Ltd:The | Water-tree detection method of rubber/plastic insulated power cable |
-
1983
- 1983-04-30 JP JP58076883A patent/JPS59202074A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS564066A (en) * | 1979-06-26 | 1981-01-16 | Furukawa Electric Co Ltd:The | Water-tree detection method of rubber/plastic insulated power cable |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59202074A (en) | 1984-11-15 |
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