JPH0510635B2 - - Google Patents
Info
- Publication number
- JPH0510635B2 JPH0510635B2 JP59050769A JP5076984A JPH0510635B2 JP H0510635 B2 JPH0510635 B2 JP H0510635B2 JP 59050769 A JP59050769 A JP 59050769A JP 5076984 A JP5076984 A JP 5076984A JP H0510635 B2 JPH0510635 B2 JP H0510635B2
- Authority
- JP
- Japan
- Prior art keywords
- cable
- tape
- deteriorated
- high voltage
- detected
- 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
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 21
- 229910052802 copper Inorganic materials 0.000 claims description 21
- 239000010949 copper Substances 0.000 claims description 21
- 238000000034 method Methods 0.000 claims description 15
- 238000009413 insulation Methods 0.000 claims description 12
- 238000001514 detection method Methods 0.000 claims description 5
- 238000011835 investigation Methods 0.000 description 16
- 230000002950 deficient Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 3
- 229920002554 vinyl polymer Polymers 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 2
- 240000000491 Corchorus aestuans Species 0.000 description 1
- 235000011777 Corchorus aestuans Nutrition 0.000 description 1
- 235000010862 Corchorus capsularis Nutrition 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 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
- 230000000694 effects Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
Landscapes
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Locating Faults (AREA)
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は高圧、特高圧用CVケーブルの絶縁層
の部分的な劣化部分を芯線を切断することなく検
出する方法に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for detecting a partially degraded portion of an insulating layer of a high-voltage or extra-high-voltage CV cable without cutting the core wire.
（従来技術）
従来、高圧、特高圧用CVケーブル（以後単に
ケーブルという）の短絡事故等の事故点は例えば
電気抵抗を測定するマレーループ法によりケーブ
ル端部から事故点までの距離を推定する方法が確
立されている。しかし、事故に至らない絶縁層の
劣化したケーブルの劣化部分を推定する有効な方
法は確立されていない。(Prior art) Conventionally, the point of an accident such as a short circuit accident in a high-voltage or extra-high-voltage CV cable (hereinafter simply referred to as a cable) has been estimated by estimating the distance from the end of the cable to the accident point using the Murray loop method, which measures electrical resistance. has been established. However, no effective method has been established for estimating the deteriorated portion of a cable whose insulating layer has deteriorated and which does not lead to an accident.
現在一般に行なわれている推定方法は、第１図
に示すようなケーブルを切断する方法である。こ
れはケーブル１の一端の芯線と銅テープ間に、直
流高電圧を印加出来る直流高電圧発生器１０と電
流計（μA計）１１を設け、高電圧（750V以上）
を印加してμA計１１に微少電流（10μA程度）が
流れたとき、ケーブルのどこかに劣化部分があ
り、洩れ電流が流れたと判断し、まず任意位置Ａ
を切断（第１回目）して、切断点より左右どちら
に絶縁不良部分があるか、上記と同様直流高電圧
をかける方法で調査し、微少電流の流れたケーブ
ルを更に任意位置Ｂで切断（第２回目）し、切断
点より左右どちらに絶縁不良部分があるか上述の
方法で調査するというように不良部分のあるケー
ブルを順次切断してゆき、範囲を狭めてゆく追跡
調査方法がとられている。この追跡調査方法では
以下の欠点があつた。 The currently commonly used estimation method is to cut the cable as shown in FIG. This is equipped with a DC high voltage generator 10 that can apply DC high voltage and an ammeter (μA meter) 11 between the core wire at one end of the cable 1 and the copper tape.
When a small current (approximately 10 μA) flows through the μA meter 11 by applying
(first time), investigate whether there is a defective insulation part on the left or right side of the cutting point by applying a high DC voltage in the same way as above, and then cut the cable through which a small current was flowing at any position B ( (Second time) Then, a follow-up investigation method was adopted in which cables with defective parts were successively cut and the area narrowed down, using the method described above to investigate whether there was a defective insulation part on the left or right side of the cutting point. ing. This follow-up survey method had the following drawbacks.
１ 再ジヨイント出来ない場所での調査が出来な
い。1 It is not possible to conduct an investigation in a place where re-joints are not possible.
２ 調査に要する停電時間が長い（再ジヨイント
工事に10〜19時間要する）。2. The power outage required for investigation is long (re-joint work takes 10 to 19 hours).
３ 再ジヨイント工事後に耐圧試験が必要であ
る。3 A pressure test is required after re-jointing work.
４ 調査に要する費用が大きい、等。4. The cost required for the investigation is large, etc.
（発明の目的）
本発明は従つて、上記問題点を解決するために
なされたもので、ケーブルの芯線及び絶縁層を切
断せず、絶縁不良箇所を流れる微少電流を簡単な
手段で測定して劣化部分を検出する方法を提供す
ることを目的とするものである。(Object of the Invention) The present invention was made to solve the above-mentioned problems, and it is possible to measure the minute current flowing through the defective insulation part by a simple means without cutting the core wire or insulation layer of the cable. The object of this invention is to provide a method for detecting deteriorated parts.
（発明の概要）
上記目的を達成するための本発明方法は、ケー
ブルの長さ方向任意位置で電流が流れなように銅
テープ、半導電テープを切離し、切離した該銅テ
ープ又は半導電テープ間に電流計を接続し、さら
に、該ケーブル一端の芯線と銅テープ又は半導電
テープ間を直流高電圧発生装置と電流計を介して
接続し、前記ケーブル一端の芯線と銅テープ又は
半導電テープ間に直流高電圧を印加して、絶縁層
に劣化部分がある場合に流れる微少電流を前記各
電流計で検出し、微少電流の流れた電流計とその
電流値により、片方だけの電流計で微少電流が検
出される場合、両方の電流計で等しい微少電流が
検出される場合、両方の電流計で異なつた微少電
流が検出される場合の３つのパターンにより、ケ
ーブルの絶縁層の劣化部分有無及びその範囲を判
断し、該劣化部分のある範囲について前記の検出
作業をくり返し行つて劣化部分位置を検出するこ
とを特徴とする高圧、特高圧用ケーブルの絶縁層
劣化位置検出方法にある。(Summary of the Invention) The method of the present invention to achieve the above object involves separating a copper tape or a semiconductive tape so that no current flows at any position in the length direction of a cable, and separating the separated copper tape or semiconductive tape. An ammeter is connected to the core wire at one end of the cable and the copper tape or semiconductive tape is further connected via a DC high voltage generator and an ammeter, and the core wire at one end of the cable and the copper tape or semiconductive tape are connected to each other. A high DC voltage is applied to the insulating layer, and each of the ammeters detects the minute current that flows when there is a deteriorated part of the insulating layer. When current is detected, there are three patterns: when both ammeters detect the same minute current, and when both ammeters detect different minute currents, it is possible to determine whether or not there is a deteriorated part of the insulation layer of the cable. The present invention provides a method for detecting a position of insulation layer deterioration in a high voltage or extra-high voltage cable, characterized in that the range is determined, and the position of the deteriorated part is detected by repeatedly performing the above-mentioned detection operation for a certain range of the deteriorated part.
（発明の構成） 以下、本発明を図面により詳細に説明する。(Structure of the invention) Hereinafter, the present invention will be explained in detail with reference to the drawings.
第２図イ，ロは３芯及び１芯CVケーブルの構
成を示す断面図で、１はケーブル、９はビニール
シース、２は銅テープ、３は外部半導電テープ、
４は架橋ポリエチレン層、５は内部半導電テー
プ、６は導体（芯線）、７は介在ジユートである。 Figure 2 A and B are cross-sectional views showing the configurations of 3-core and 1-core CV cables, where 1 is the cable, 9 is the vinyl sheath, 2 is the copper tape, 3 is the external semiconductive tape,
4 is a crosslinked polyethylene layer, 5 is an internal semiconductive tape, 6 is a conductor (core wire), and 7 is an intervening jute.
第３図は絶縁層劣化部分を検出する本発明方法
の１芯ケーブルの場合の実施例で、ロはイのＡ部
分の拡大図である。本発明ではケーブルの長さ方
向任意の位置Ａ点でビニールシース９、銅テープ
２、外部半導電テープ３を高圧電気的に洩れ電流
が流れないように切離す。次いで、切離した銅テ
ープ２間にマイクロアンペア計（μA計）１２を
接続する。更に、ケーブル端の芯線６を直流高圧
発生装置１０に接続し、そしてケーブル端の銅テ
ープ２をマイクロアンペア計（μA計）１１を介
して直流高圧発生装置１０に接続し、ケーブル芯
線６と銅テープ２間に直流高電圧を印加出来る構
成とする。 FIG. 3 shows an embodiment of the method of the present invention for detecting a deteriorated portion of the insulation layer in the case of a one-core cable, and FIG. 3 is an enlarged view of part A in FIG. In the present invention, the vinyl sheath 9, the copper tape 2, and the external semiconductive tape 3 are cut off at an arbitrary position A in the length direction of the cable so that high voltage electrical leakage current does not flow. Next, a microampere meter (μA meter) 12 is connected between the separated copper tapes 2. Furthermore, the core wire 6 at the cable end is connected to the DC high voltage generator 10, and the copper tape 2 at the cable end is connected to the DC high voltage generator 10 via a microampere meter (μA meter) 11, and the cable core wire 6 and the copper The structure is such that a high DC voltage can be applied between the tapes 2.
（発明の作用）
第４図により作用の構成をする。直流高圧発生
装置１０で高電圧（750V以上）を発生させ、芯
線６と銅テープ２間に直流高電圧を印加する。ケ
ーブルの絶縁層に劣化部分がなく、健全であれば
芯線６と銅テープ２間に洩れ電流は流れずμA計
１１，１２の指示は０であるが、絶縁層に劣化部
分があると電流が流れる。イのようにＡ点より左
側に劣化部分８が存在し、右側は健全である場
合、劣化部分を洩れる微少電流ｉがμA計１１に
流れるが、μA計１２には流れない。又、ロのよ
うにＡ点より右側の絶縁層に劣化部分８が存在
し、左側は健全な場合はμA計１１，１２共に等
しい電流ｉが流れる。さらにハのようにＡ点のの
左右両側の絶縁層に劣化部分８，８が存在する場
合はμA計１１には電流i1＋i2が流れ、μA計１２
には電流i2が流れる。従つて、μA計に流れる電
流ｉにより絶縁層の劣化部分が切離したＡ点の左
右どちらにあるか判断可能となる。すなわち、
μA計１１だけに電流ｉが流れればＡ点から左側
に、μA計１１，１２共に等しい電流ｉが流れれ
ばＡ点から右側に、μA計１１，１２共に電流が
流れるが、μA計１１に多く流れる場合はＡ点の
両側に絶縁層の劣化部分があることが判明する。(Operation of the invention) The operation is constructed according to FIG. A high voltage (750V or more) is generated by a DC high voltage generator 10, and the DC high voltage is applied between the core wire 6 and the copper tape 2. If there is no deteriorated part in the insulation layer of the cable and it is healthy, no leakage current will flow between the core wire 6 and the copper tape 2, and the indications of μA meters 11 and 12 will be 0. However, if there is a deteriorated part in the insulation layer, the current will not flow. flows. If there is a deteriorated part 8 on the left side of point A as shown in A, and the right side is healthy, a small current i leaking through the deteriorated part flows to the μA meter 11, but does not flow to the μA meter 12. Further, as shown in (b), if there is a deteriorated portion 8 in the insulating layer on the right side of point A and the left side is healthy, an equal current i of μA totals 11 and 12 flows. Furthermore, if there are deteriorated parts 8, 8 in the insulating layer on both the left and right sides of point A as shown in c, current i 1 + i 2 flows through the μA total 11, and the μA total 12
A current i2 flows through. Therefore, it is possible to determine whether the degraded portion of the insulating layer is on the left or right side of the separated point A by the current i flowing through the μA meter. That is,
If the current i flows only in μA total 11, then the current i flows from point A to the left side, and if the same current i flows in both μA totals 11 and 12, the current flows from point A to the right side in both μA totals 11 and 12, but the μA total 11 If there is a large amount of flow at the point A, it becomes clear that there are deteriorated portions of the insulating layer on both sides of point A.
以上の原理を応用して、絶縁層の劣化部分８の
ある側をさらに任意箇所でビニールシース９、銅
テープ２、外部半導電テープ３を切離す作業をく
り返し、上述の回路構成により流れる電流ｉを測
定することにより順次絶縁層の劣化部分８の範囲
を狭めて行き、劣化部分を検出するものである。
調査の終つた切離した箇所は銅テープ２、外部半
導電テープ３をつなぎ、補修用防食テープ（商品
名バルコテープ）を巻いて修復するだけで良い。
つきとめた劣化部分８は、ある長さ分だけ芯線６
を切断し、ケーブルにたるみ、余裕があればその
まま再ジヨイントとすればよく、ケーブルにたる
み、余裕のない場合は、切断長さにみあつた新し
いケーブルを用意して再ジヨイントを行う。実際
の作業では調査のくり返し数、劣化部分の切断長
さは調査費用、調査時間、ケーブルの敷設状態等
を勘案して決め、作業することがのぞましい。 Applying the above principle, repeat the operation of cutting off the vinyl sheath 9, copper tape 2, and external semiconducting tape 3 at arbitrary points on the side where the deteriorated part 8 of the insulating layer is, and the current i flowing due to the above circuit configuration is By measuring this, the range of the degraded portion 8 of the insulating layer is successively narrowed down and the degraded portion is detected.
Once the investigation has been completed, all that is needed is to connect the copper tape 2 and the external semiconductive tape 3 to the separated area and wrap it with a repair anticorrosive tape (trade name: Balco Tape) to repair it.
The identified deteriorated part 8 is a certain length of the core wire 6.
If there is slack in the cable and there is room, you can simply rejoin it. If there is slack in the cable and there is no room, prepare a new cable that matches the cut length and rejoin it. In actual work, it is recommended that the number of repetitions of the investigation and the cutting length of the degraded portion be determined by taking into account the investigation cost, investigation time, cable installation condition, etc.
今まで、１芯ケーブルの例で説明して来たが、
３芯ケーブルでも１芯ケーブルと同様実施出来
る。又、μA計１１，１２を銅テープに接続する
例で説明したが、外部半導電テープ３に接続して
も電流ｉの流れが小さくなるが調査は可能であ
る。従つて、本発明の調査方法はCVケーブルの
銅テープと同じ構造、機能を備えたケーブルであ
れば応用可能であり、さりに従来の事故ケーブル
の事故点検出方法にも応用出来ることは言うまで
もない。 Until now, we have explained using the example of a single-core cable, but
This can be done with a 3-core cable in the same way as with a 1-core cable. Further, although the example in which the μA meters 11 and 12 are connected to the copper tape has been described, the flow of the current i will be reduced even if the μA meters 11 and 12 are connected to the external semiconducting tape 3, but the investigation can still be carried out. Therefore, the investigation method of the present invention can be applied to any cable that has the same structure and function as the copper tape of a CV cable, and it goes without saying that it can also be applied to conventional fault point detection methods for fault cables. .
（実施例）
725ｍの３芯ケーブルに5000Vの直流高電圧を
印加したところ150μAの洩れ電流が流れ、劣化部
分の追跡調査を行つた結果、２回目のテープ切離
しで管路内敷設部の劣化部分を検出出来た。劣化
部分のある管路130ｍを切断し、新品と交換した。
従来の切断による追跡調査方法に比べ調査時間は
１／３に、費用も1/6であつた。(Example) When a high DC voltage of 5000V was applied to a 725m long 3-core cable, a leakage current of 150μA flowed.As a result of a follow-up investigation of the deteriorated part, the second time the tape was cut, the deteriorated part of the laid part inside the conduit was detected. was detected. A 130m section of pipeline with deteriorated parts was cut and replaced with a new one.
Compared to the conventional follow-up method using cutting, the investigation time was 1/3 and the cost was 1/6.
（発明の効果）
本発明方法は従来の芯線を切断して劣化部分の
範囲を狭めていく方法に比べ
１ 再ジヨイント出来ない場所であつても調査が
可能になつた、
２ 調査に要する時間も４時間程度でよく、停電
調査作業が簡単、
３ 追跡調査中の再ジヨイント工事が不要であ
り、調査費用が少ない、又、耐圧試験も不要で
ある、
等すぐれた利点を有するもので、効果大なるもの
がある。(Effects of the invention) Compared to the conventional method of cutting the core wire and narrowing the area of deteriorated parts, the method of the present invention: 1. It is now possible to investigate even in places where re-jointing is not possible; 2. The time required for investigation is also reduced. It only takes about 4 hours, the power outage investigation work is easy, 3. There is no need for re-joint work during the follow-up investigation, the investigation cost is low, and there is no need for a pressure test.It is highly effective. There is something.
第１図は従来のケーブル絶縁劣化位置検出法の
説明図、第２図は検出対象であるケーブルの構造
を示す断面図、第３図は本発明の検出法の要部を
説明する図、第４図は本発明の実施例を示す説明
図である。
図面で１はケーブル、Ａは任意の位置、２は銅
テープ、３は半導電テープ、１２は電流計、６は
芯線、１０は直流高電圧発生装置、１１は電流計
である。
Fig. 1 is an explanatory diagram of the conventional cable insulation deterioration position detection method, Fig. 2 is a sectional view showing the structure of the cable to be detected, and Fig. 3 is a diagram illustrating the main part of the detection method of the present invention. FIG. 4 is an explanatory diagram showing an embodiment of the present invention. In the drawings, 1 is a cable, A is an arbitrary position, 2 is a copper tape, 3 is a semiconducting tape, 12 is an ammeter, 6 is a core wire, 10 is a DC high voltage generator, and 11 is an ammeter.
Claims (1)
いように銅テープ、半導電テープを切離し、切離
した該銅テープ又は半導電テープ間に電流計を接
続し、さらに、該ケーブル一端の芯線と銅テープ
又は半導電テープ間を直流高電圧発生装置と電流
計を介して接続し、前記ケーブル一端の芯線と銅
テープ又は半導電テープ間に直流高電圧を印加し
て、絶縁層に劣化部分がある場合に流れる微小電
流を前記各電流計で検出し、微小電流の流れた電
流計とその電流値により、片方だけの電流計で微
少電流が検出される場合、両方の電流計で等しい
微少電流が検出される場合、両方の電流計で異な
つた微少電流が検出される場合の３つのパターン
により、ケーブルの絶縁層の劣化部分有無及びそ
の範囲を判断し、該劣化部分のある範囲について
前記の検出作業をくり返し行つて劣化部分位置を
検出することを特徴とする高圧、特高圧用ケーブ
ルの絶縁層劣化位置検出方法。1. Separate the copper tape or semiconductive tape so that no current flows at any position along the length of the cable, connect an ammeter between the separated copper tape or semiconductive tape, and connect the core wire at one end of the cable to the copper tape. Connect the tapes or semiconducting tapes via a DC high voltage generator and an ammeter, and apply a DC high voltage between the core wire at one end of the cable and the copper tape or semiconducting tape to detect deteriorated parts of the insulating layer. If a minute current is detected by only one ammeter, the same minute current is detected by both ammeters. If detected, the presence or absence of a deteriorated part of the insulation layer of the cable and its range are determined based on three patterns in which different minute currents are detected by both ammeters, and the above-mentioned detection is performed for the range where the deteriorated part exists. A method for detecting the position of a deteriorated insulation layer of a cable for high voltage or extra-high voltage, characterized in that the position of the deteriorated part is detected by repeating the work.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59050769A JPS60195462A (en) | 1984-03-16 | 1984-03-16 | Insulating layer deteriorated position detecting method of cable for high voltage and extra-high voltage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59050769A JPS60195462A (en) | 1984-03-16 | 1984-03-16 | Insulating layer deteriorated position detecting method of cable for high voltage and extra-high voltage |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60195462A JPS60195462A (en) | 1985-10-03 |
| JPH0510635B2 true JPH0510635B2 (en) | 1993-02-10 |
Family
ID=12868035
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59050769A Granted JPS60195462A (en) | 1984-03-16 | 1984-03-16 | Insulating layer deteriorated position detecting method of cable for high voltage and extra-high voltage |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60195462A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5077526A (en) * | 1988-03-30 | 1991-12-31 | Automated Light Technologies, Inc. | Cable failure detection system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5284479A (en) * | 1975-12-31 | 1977-07-14 | Showa Electric Wire & Cable Co | Searching method of breakdown point for rubber * plastic insulated cable |
| JPS5482692A (en) * | 1977-12-15 | 1979-07-02 | Sumitomo Electric Ind Ltd | Searching for insulation deffcts point in cable |
-
1984
- 1984-03-16 JP JP59050769A patent/JPS60195462A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5284479A (en) * | 1975-12-31 | 1977-07-14 | Showa Electric Wire & Cable Co | Searching method of breakdown point for rubber * plastic insulated cable |
| JPS5482692A (en) * | 1977-12-15 | 1979-07-02 | Sumitomo Electric Ind Ltd | Searching for insulation deffcts point in cable |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60195462A (en) | 1985-10-03 |
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