JPH0534397A - Method of forecasting ground fault for high voltage cable - Google Patents
Method of forecasting ground fault for high voltage cableInfo
- Publication number
- JPH0534397A JPH0534397A JP3212661A JP21266191A JPH0534397A JP H0534397 A JPH0534397 A JP H0534397A JP 3212661 A JP3212661 A JP 3212661A JP 21266191 A JP21266191 A JP 21266191A JP H0534397 A JPH0534397 A JP H0534397A
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- JP
- Japan
- Prior art keywords
- ground fault
- ground
- cable
- current
- currents
- 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.)
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、高圧電力ケーブルの
地絡予知方法に関するもので、特に完全地絡を起こす前
に、その可能性のあるケーブル線路（多数あるケーブル
線路の内の一つ）を予知する方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of predicting a ground fault of a high-voltage power cable, and in particular, a cable line (one of many cable lines) which has a possibility of causing a complete ground fault. It is about the method of predicting.
【０００２】[0002]
【従来の技術】地絡事故が発生する前に、その前駆現象
として、ケーブル内で、単発的な地絡（図９のＡのａ）
やあるいは間欠的な地絡（図９のＢのｂ）が発生するこ
とがある。そこで、前記単発地絡や間欠地絡（以下単発
性地絡等という）を検出し、それによって、地絡事故を
予知しようという下記の技術が発表されている（特開平
２−２０１２７４号公報、平成元年電気学会全国大会論
文集、1476参照）。2. Description of the Related Art Before a ground fault occurs, as a precursor to the ground fault, a single ground fault (a in FIG. 9A) occurs in the cable.
Somewhat intermittent ground faults (b in FIG. 9B) may occur. Therefore, the following technology has been announced to detect the single-shot ground fault or the intermittent ground fault (hereinafter referred to as a single-shot ground fault, etc.) and thereby predict a ground fault accident (JP-A-2-201274, 1989 Annual Conference of the Institute of Electrical Engineers of Japan, 1476).
【０００３】図８のように、電力ケーブル１２の接地線
１４に流れる電流を、常時測定する。ケーブル内で単発
性地絡等が発生すると、健全相と逆極性のあるしきい値
以上の電流が接地線１４に流れる。そのとき、地絡の危
険ありとして警報を出す。As shown in FIG. 8, the current flowing through the ground wire 14 of the power cable 12 is constantly measured. When a single ground fault or the like occurs in the cable, a current having a polarity equal to or higher than a threshold value and having a polarity opposite to the normal phase flows in the ground wire 14. At that time, an alarm is issued as there is a risk of a ground fault.
【０００４】[0004]
（１）同一系統に複数の電力ケーブル線路が近接してあ
る場合、一つのケーブル線路の接地線に大きな電流が流
れると、その電流が大地を通して他のケーブル線路の接
地線に流れ込む（このことは、後でより詳しく説明す
る）。そのために、どのケーブル線路が危険であるか
（単発性地絡がどのケーブル線路で起こったか）、分か
らないことがある。 （２）異常に大きい外部ノイズにより、接地線１４電流
が、しきい値以上になる場合もある。そのような場合、
外部ノイズによるものか、あるいは単発性地絡等による
ものか、判然としないことがある。(1) When a plurality of power cable lines are close to the same system and a large current flows through the ground line of one cable line, the current flows through the ground into the ground line of another cable line (this is , More on that later). As a result, it may not be known which cable line is dangerous (on which cable line the single ground fault occurred). (2) The ground line 14 current may exceed the threshold value due to abnormally large external noise. In such cases,
It may be unclear whether it is due to external noise or due to a single-shot ground fault.
【０００５】[0005]
（１）複数の電力ケーブル線路について、各電力ケーブ
ル線路ごとに、接地線に流れる電流を、常時、測定し、
かつ接地線電流のしきい値を予め設定しておくこと（こ
のことは上記の場合と同じ）、 （２）ケーブルのある部分において単発性地絡が発生
し、接地線電流が、しきい値を越えたとき、前記電流の
極性を、ケーブル線路間で比較すること、を、特徴とす
る。(1) For a plurality of power cable lines, the current flowing through the ground line is constantly measured for each power cable line,
In addition, the threshold value of the ground wire current must be set in advance (this is the same as the above case). (2) A single ground fault occurs at a certain part of the cable, and the ground wire current becomes the threshold value. When the voltage exceeds, the polarities of the currents are compared between the cable lines.
【０００６】[0006]
【作 用】接地線電流の極性を比較することにより、間
欠地絡等を起こしたケーブル線路を特定することができ
る。また、しきい値を越えた接地線電流が、間欠地絡等
によるものかあるいは外来ノイズによるものかの判別が
できる（その理由は以下に述べる）。[Operation] By comparing the polarities of the ground line currents, it is possible to identify the cable line that has caused an intermittent ground fault. Further, it is possible to determine whether the ground line current that exceeds the threshold value is due to an intermittent ground fault or the like or due to external noise (the reason is described below).
【０００７】[0007]
【原理】図６は、ケーブル地絡時の地絡電流経路であ
る。ここで、２０１，２０２，２０３，−−−−はこの
系統の電力ケーブル線路（単線結線で示す）、２２はケ
ーブル導体、２４は接地線、２６は接地用変圧器、Ｃ
2，Ｃ3，−−−−は、それぞれのケーブルの静電容量、
Ｃgは母線２８あるいは他のケーブルと大地間の静電容
量を示す。この系統において、ケーブル線路２０１のＰ
点に単発性地絡が生じた場合、ケーブル線路２０１の接
地線２４に地絡電流Ｉ1が流れる。また、その電流（の
一部）は、大地を通って健全ケーブルの接地線２４およ
び接地用変圧器の接地線２７に流入する。また健全ケー
ブルに流入した電流はケーブル静電容量を通じて母線２
８へ帰る。それらの電流Ｉ2，Ｉ3，−−−−およびＩg
の方向は、地絡電流Ｉ1と逆である（極性が反転す
る）。[Principle] FIG. 6 shows a ground fault current path at the time of a cable ground fault. Here, 201, 202, 203, ---- are power cable lines (shown by single wire connection) of this system, 22 is a cable conductor, 24 is a ground wire, 26 is a grounding transformer, C
2, C3, ----- is the capacitance of each cable,
Cg represents the capacitance between the bus 28 or another cable and the ground. In this system, P of the cable line 201
When a single ground fault occurs at a point, a ground fault current I1 flows through the ground wire 24 of the cable line 201. Further, (a part of) the current flows into the ground wire 24 of the sound cable and the ground wire 27 of the grounding transformer through the ground. In addition, the current that flows into the healthy cable is not
Return to 8. Their currents I2, I3, ---- and Ig
Is opposite to the ground fault current I1 (the polarity is reversed).
【０００８】図７に、ＥＭＴＰによる模擬系統のシミュ
レーション結果を示す。（Ａ）は健全ケーブル、（Ｂ）
は地絡ケーブルの電流波形であり、（Ｃ）は地絡ケーブ
ルの時間軸を100倍に拡大したものである。図７から、
地絡ケーブルと健全ケーブルとで、接地線に流れる電流
の極性が反転しており、かつ電流は数μsecで立ち上が
っていることが分かる。FIG. 7 shows the simulation result of the simulated system by EMTP. (A) is a healthy cable, (B)
Is the current waveform of the ground fault cable, and (C) is the time axis of the ground fault cable magnified 100 times. From FIG.
It can be seen that the polarity of the current flowing through the ground wire is reversed between the ground fault cable and the sound cable, and the current rises in several μsec.
【０００９】[0009]
［構成］図１に、単線結線で一例を示す。各ケーブルの
接地線２４にＣＴ３０を、また接地用変圧器２６の接地
線２７にもＣＴ３１を取り付ける（ＣＴ３０とＣＴ３１
は、同じ構造のものであるが、説明の都合上、別の符号
を付けた）。ケーブルの場合は、図２のように、各ケー
ブルＡ，Ｂ，Ｃの共通の接地線２４にＣＴ３０を取り付
ける。ＣＴ３０，３１に貫通型のものを用いれば、既設
の設備を改良することなく、取り付けられる。３２は予
知装置で、その部分のブロックダイアグラムを図３に示
した。バンドパスフィルタ３４には、帯域が100HZ〜50k
Hz程度のものを用いる。100Hz以下は商用周波のノイズ
をカットするため、50kHz以上は放送波ノイズをカット
するためである。[Structure] FIG. 1 shows an example of single wire connection. Attach CT30 to the ground wire 24 of each cable and CT31 to the ground wire 27 of the grounding transformer 26 (CT30 and CT31).
Are of the same structure, but for convenience of explanation, they are given different symbols). In the case of a cable, the CT 30 is attached to the common ground wire 24 of each cable A, B, C as shown in FIG. If CT30s and 31s of the through type are used, they can be attached without improving existing equipment. Reference numeral 32 is a prediction device, and a block diagram of the part is shown in FIG. The band pass filter 34 has a band of 100 Hz to 50 k.
Use the one of about Hz. 100 Hz or less is for cutting commercial frequency noise, and 50 kHz or more is for cutting broadcast wave noise.
【００１０】図４に、ケーブル線路10回線の場合の基本
構成を示す。Ａ／Ｄは、図３のバンドパスフィルタ３
４，増幅回路３６，Ａ／Ｄ変換３８，比較回路付Ａ／Ｄ
変換３９を含むユニットで、数字はケーブル線路の番号
である。最上段の比較回路付Ａ／Ｄは、接地用変圧器２
６に取り付けたＣＴ３１の出力電流を、しきい値と比較
するためのもの。またＣＰＵは、図３のメモリ装置４
０，判定回路４４，波形記録装置４６を含む。ウオッチ
ユニットは、記録に日時を与える。FIG. 4 shows a basic configuration in the case of 10 cable lines. A / D is the bandpass filter 3 of FIG.
4, amplifier circuit 36, A / D conversion 38, A / D with comparison circuit
In the unit including the conversion 39, the numbers are the numbers of the cable lines. The A / D with comparison circuit at the top is the grounding transformer 2
For comparing the output current of CT31 attached to 6 with a threshold value. Further, the CPU is the memory device 4 of FIG.
0, determination circuit 44, and waveform recording device 46. The watch unit gives the date and time to the record.
【００１１】［動作］ （１）各ＣＴ３０およびＣＴ３１からの電流波形データ
をＡ／Ｄ変換ユニット（比較回路付きを含む）を介し
て、常時ＣＰＵのメモリ装置４０に取り込む（図３，
４）。図５にフローチャートを示した。 （２）比較回路の入力が、しきい値より大きいと、トリ
ガがかかってある一定期間のデータを、ＣＰＵ内のメモ
リ装置４０にホールドする。 （３）そのデータをＣＰＵで読み出し、判定回路４４
で、接地線電流の極性および大きさを、各ケーブル線路
間で比較する。そして、上記のように、逆極性のもので
一番大きな電流値のものがあれば、その線路で、間欠地
絡等が発生したことが分かる。そこで、各波形、発生の
日時を記録し、データを表示し、警報を出す[Operation] (1) The current waveform data from each CT 30 and CT 31 is constantly taken into the memory device 40 of the CPU via the A / D conversion unit (including the one with the comparison circuit) (FIG. 3, FIG.
4). A flowchart is shown in FIG. (2) When the input of the comparison circuit is larger than the threshold value, the data for a certain period in which the trigger is applied is held in the memory device 40 in the CPU. (3) The CPU reads the data, and the determination circuit 44
Then, the polarity and magnitude of the ground wire current are compared between the cable lines. Then, as described above, if there is a reverse polarity one having the largest current value, it is understood that an intermittent ground fault or the like has occurred in the line. Therefore, record each waveform and the date and time of occurrence, display the data, and issue an alarm.
【００１２】なお電流極性の比較は、各接地線電流の第
１波について行う。間欠地絡等が起きると、地絡電流
は、ＣＴの設置してある側に流れると同時に反対側にも
流れる。その電流が、終端で反射して、第２波以降にオ
ーバーラップする形で、ＣＴで検出される場合がある。
そうなると、波形がたいへん複雑になり、正確な比較が
できなくなる。そこで、第１波を比較するようにする。
また、各ＣＴの接地電流を検出する時間にズレがあると
各接地線電流の第一波が正確に測定できないので、デー
タのサンプリングにあたっては、時間を揃えて（同期さ
せて）その結果を比較する。The current polarities are compared for the first wave of each ground line current. When an intermittent ground fault or the like occurs, the ground fault current flows to the side where the CT is installed and simultaneously to the opposite side. The current may be detected by CT in the form of being reflected at the end and overlapping after the second wave.
In that case, the waveform becomes very complicated and an accurate comparison cannot be performed. Therefore, the first wave is compared.
Also, if there is a gap in the detection time of the ground current of each CT, the first wave of each ground line current cannot be measured accurately, so when sampling the data, align the times (synchronize) and compare the results. To do.
【００１３】（４）上記の（３）において、接地線電流
の極性を比較したとき、全部同じであれば、間欠地絡等
でなかった、と判断する（異常に大きい外部ノイズが侵
入したとき起きる現象）。そこで、判定不能を表示し、
上記の（１）に戻る（図５）。(4) In (3) above, when the polarities of the ground wire currents are compared, if they are all the same, it is judged that there is no intermittent ground fault (when an abnormally large external noise enters. Phenomenon that occurs). Therefore, display the judgment impossible,
Return to (1) above (FIG. 5).
【００１４】（５）接地用変圧器２６のない系統では、
任意の１つのケーブル線路の接地線電流からトリトガを
とるようにする。そうすれば、上記同様にして、地絡予
知ができる。 （６）上記の間欠地絡等の情報を公衆回線利用で１箇所
に集中させれば、広範囲のケーブル劣化状態のモニタが
できる。(5) In a system without the grounding transformer 26,
Tritga is taken from the ground wire current of any one cable line. Then, the ground fault can be predicted in the same manner as above. (6) If the information such as the intermittent ground fault is concentrated in one place by using the public line, it is possible to monitor the deterioration state of the cable in a wide range.
【００１５】[0015]
【発明の効果】複数の電力ケーブル線路について、前記
各電力ケーブル線路ごとに、接地線に流れる電流を、常
時測定し、ケーブルに単発性地絡が生じたとき、前記電
流の極性およびその大きさを前記ケーブル線路間で比較
するので、 （１）地絡予知が可能であり、かつ地絡の恐れのあるケ
ーブル線路を、多くの中から特定できる。 （２）たまたま、異常に大きい外来ノイズにより、しき
い値より大きい接地線電流が流れても、間欠地絡等によ
るものと区別できる。 （３）電力ケーブルの接地線にＣＴを取り付けるだけで
済み、既設設備を改造する必要がない。 （４）接地用変圧器のない系統においても適用可能であ
る。 （５）常時監視であるから、電力ケーブル故障予知の可
能性が上がる。With respect to a plurality of power cable lines, the current flowing through the ground line is constantly measured for each of the power cable lines, and when a single ground fault occurs in the cable, the polarity of the current and its magnitude. Since the cable lines are compared with each other, (1) it is possible to identify from among many cable lines that are capable of ground fault prediction and that are at risk of ground fault. (2) Even if a ground line current larger than the threshold value happens to flow due to an abnormally large external noise, it can be distinguished from an intermittent ground fault or the like. (3) It is only necessary to attach the CT to the ground wire of the power cable, and there is no need to modify the existing equipment. (4) It can be applied to a system without a grounding transformer. (5) Since it is always monitored, the possibility of power cable failure prediction increases.
【図１】本発明の実施例を単線結線で示した説明図。FIG. 1 is an explanatory view showing an embodiment of the present invention with a single wire connection.
【図２】本発明における三相ケーブルにおけるＣＴの取
付け方の説明図。FIG. 2 is an explanatory diagram of how to attach a CT in the three-phase cable according to the present invention.
【図３】本発明における予知装置のブロックダイアグラ
ム。FIG. 3 is a block diagram of a prediction device according to the present invention.
【図４】本発明を10回線に適用した例の基本構成図。FIG. 4 is a basic configuration diagram of an example in which the present invention is applied to 10 lines.
【図５】本発明の動作のフローチャート。FIG. 5 is a flowchart of the operation of the present invention.
【図６】地絡が起きたときの、接地線電流の方向を示す
説明図。FIG. 6 is an explanatory diagram showing a direction of a ground line current when a ground fault occurs.
【図７】模擬系統の地絡シミュレーション結果の電流波
形図。FIG. 7 is a current waveform diagram of a ground fault simulation result of the simulated system.
【図８】従来技術の説明図。FIG. 8 is an explanatory diagram of a conventional technique.
【図９】単発地絡および間欠地絡の波形図。FIG. 9 is a waveform diagram of a single-shot ground fault and an intermittent ground fault.
１２ 電力ケーブル １４ 接地線 ２０１，２０２等 電力ケーブル線路 ２２ ケーブル導体 ２４ 接地線 ２６ 接地用変圧器 ２７ 接地線 ２８ 母線 ３０ ＣＴ ３１ ＣＴ ３２ 予知装置 ３４ バンドパスフィルタ ３８ Ａ／Ｄ変換 ４０ メモリ装置 ４４ 判定回路 12 power cable 14 ground wire 201, 202 etc. power cable line 22 cable conductor 24 ground wire 26 grounding transformer 27 ground wire 28 busbar 30 CT 31 CT 32 predictor 34 bandpass filter 38 A / D conversion 40 memory device 44 judgment circuit
───────────────────────────────────────────────────── フロントページの続き (72)発明者 荒金 昌克 三重県桑名市野田二丁目７番15号 (72)発明者 永田 達也 愛知県名古屋市東区砂田橋三丁目２番大幸 東団地101−1205 (72)発明者 丸山 孝 東京都江東区木場一丁目５番１号 藤倉電 線株式会社内 (72)発明者 山本 憲 東京都江東区木場一丁目５番１号 藤倉電 線株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masakatsu Arakane 2-7-15 Noda, Kuwana-shi, Mie (72) Inventor Tatsuya Nagata 3-2, Sunadabashi, Higashi-ku, Nagoya, Aichi 101-1205 (72) ) Inventor Takashi Maruyama 1-5-1, Kiba, Koto-ku, Tokyo Within Fujikura Electric Line Co., Ltd. (72) Inventor Ken Yamamoto 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Electric Line Co., Ltd.
Claims (1)
記各電力ケーブル線路ごとに、接地線に流れる電流を、
常時測定し、ケーブルが完全地絡に至る以前に生じるパ
ルス状地絡電流を捕え、前記電流の極性およびその大き
さを前記ケーブル線路間で比較する、高圧ケーブルの地
絡予知方法。Claim: What is claimed is: 1. With respect to a power cable line having a plurality of lines, a current flowing through a ground line is calculated for each of the power cable lines.
A method for predicting a ground fault of a high-voltage cable, which is constantly measured, and a pulsed ground fault current generated before the cable reaches a complete ground fault is captured, and the polarity and magnitude of the current are compared between the cable lines.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03212661A JP3137684B2 (en) | 1991-07-30 | 1991-07-30 | Ground fault prediction method for high voltage cables |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03212661A JP3137684B2 (en) | 1991-07-30 | 1991-07-30 | Ground fault prediction method for high voltage cables |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0534397A true JPH0534397A (en) | 1993-02-09 |
| JP3137684B2 JP3137684B2 (en) | 2001-02-26 |
Family
ID=16626313
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03212661A Expired - Lifetime JP3137684B2 (en) | 1991-07-30 | 1991-07-30 | Ground fault prediction method for high voltage cables |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3137684B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000009786A (en) * | 1998-06-19 | 2000-01-14 | Miwa Electric Co Ltd | Ground fault detection method for secondary power cable of main transformer |
| JP2020148579A (en) * | 2019-03-13 | 2020-09-17 | 日油技研工業株式会社 | Single-shot earth fault detector |
| JP2021081400A (en) * | 2019-11-23 | 2021-05-27 | 清華大学Ｔｓｉｎｇｈｕａ Ｕｎｉｖｅｒｓｉｔｙ | Line selection method of one-phase ground fault of distribution line and storage medium capable of performing computer-reading |
| CN113933748A (en) * | 2021-10-15 | 2022-01-14 | 劲逐软件技术(深圳)有限公司 | Grounding monitoring method and device, computer equipment and storage medium |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63209412A (en) * | 1987-02-26 | 1988-08-31 | 株式会社東芝 | Preventive maintenance system of gas insulated switchgear |
| JPH01297566A (en) * | 1988-05-26 | 1989-11-30 | Sumitomo Electric Ind Ltd | Discriminating method for light ground-fault generation cable |
| JPH02201274A (en) * | 1989-01-31 | 1990-08-09 | Chubu Electric Power Co Inc | Method of foreseeing ground fault of power cable |
-
1991
- 1991-07-30 JP JP03212661A patent/JP3137684B2/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63209412A (en) * | 1987-02-26 | 1988-08-31 | 株式会社東芝 | Preventive maintenance system of gas insulated switchgear |
| JPH01297566A (en) * | 1988-05-26 | 1989-11-30 | Sumitomo Electric Ind Ltd | Discriminating method for light ground-fault generation cable |
| JPH02201274A (en) * | 1989-01-31 | 1990-08-09 | Chubu Electric Power Co Inc | Method of foreseeing ground fault of power cable |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000009786A (en) * | 1998-06-19 | 2000-01-14 | Miwa Electric Co Ltd | Ground fault detection method for secondary power cable of main transformer |
| JP2020148579A (en) * | 2019-03-13 | 2020-09-17 | 日油技研工業株式会社 | Single-shot earth fault detector |
| JP2021081400A (en) * | 2019-11-23 | 2021-05-27 | 清華大学Ｔｓｉｎｇｈｕａ Ｕｎｉｖｅｒｓｉｔｙ | Line selection method of one-phase ground fault of distribution line and storage medium capable of performing computer-reading |
| US11543462B2 (en) | 2019-11-23 | 2023-01-03 | Tsinghua University | Single-phase-to-ground fault line selection method for distribution lines and computer readable storage medium |
| CN113933748A (en) * | 2021-10-15 | 2022-01-14 | 劲逐软件技术(深圳)有限公司 | Grounding monitoring method and device, computer equipment and storage medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3137684B2 (en) | 2001-02-26 |
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