JPH0614086B2 - Single-core cable shield disconnection monitoring device and method - Google Patents
Single-core cable shield disconnection monitoring device and methodInfo
- Publication number
- JPH0614086B2 JPH0614086B2 JP63153104A JP15310488A JPH0614086B2 JP H0614086 B2 JPH0614086 B2 JP H0614086B2 JP 63153104 A JP63153104 A JP 63153104A JP 15310488 A JP15310488 A JP 15310488A JP H0614086 B2 JPH0614086 B2 JP H0614086B2
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- Prior art keywords
- shield
- ground
- line
- grounding
- terminal
- Prior art date
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Description
【発明の詳細な説明】 （イ）産業上の利用分野 この発明は単心ケーブルの遮蔽の断線を監視する装置お
よびその方法に関する。The present invention relates to an apparatus and method for monitoring disconnection of a shield of a single-core cable.
（ロ）従来技術 単心ケーブルはその遮蔽金属体が何等かの理由により断
線すると断線箇所で放電を発生することがあり、電気破
壊事故に直結しやすい。この事故を防止するため従来第
２図および第３図示す監視方法が行われている。(B) Conventional technology When a shielded metal body of a single-core cable is broken for some reason, a discharge may occur at the broken place, which is likely to directly lead to an electrical breakdown accident. In order to prevent this accident, the monitoring method shown in FIGS. 2 and 3 has been conventionally performed.
第２図および第３図において、１Ｒ，１Ｓ，１Ｔは単心
ケーブル３条から成る活線電力ケーブル線路の各条の遮
蔽をＲ相，Ｓ相，Ｔ相毎に示している。通常、単心ケー
ブル１のの遮蔽はその上流側（電源側）の端部、図でＡ
端において３条一括して接地されている。一方、遮蔽の
下流側（負荷側）の端部、図でＢ端の各条の遮蔽端末は
それぞれフロートして使用されている。この理由は大地
から遮蔽への迷走電流の流入や遮蔽間の循環電流の発生
を避けるためである。このような接地方式下で遮蔽断線
を監視するには遮蔽端末がフロートしているＢ端へ携帯
型測定器としての交流電圧計２、抵抗計３′を持参して
遮蔽端末に発生している交流電圧または遮蔽のループ抵
抗を測定し、異常の有無をみるものである。In FIGS. 2 and 3, 1R, 1S, and 1T show the shielding of each line of the live power cable line consisting of three single-core cables for each R phase, S phase, and T phase. Normally, the shield of the single-core cable 1 is the upstream end (power supply side) of the end, A in the figure.
Three lines are grounded together at the end. On the other hand, the end portion on the downstream side (load side) of the shield, that is, each end of the shield end at the B end in the figure, is floated and used. The reason for this is to avoid the inflow of stray current from the ground to the shield and the generation of circulating current between the shields. In order to monitor the shield disconnection under such a grounding system, the AC voltmeter 2 and the resistance meter 3'as portable measuring instruments are brought to the terminal B where the shield terminal is floating, and the shield terminal is generated. The presence or absence of abnormality is measured by measuring the AC voltage or the loop resistance of the shield.
交流電圧計２で測定する場合は第２図に示すようにその
一端は大地に接続し、他端子はフロートしている各条の
遮蔽端末に接続して遮蔽端末に発生している対地交流電
圧を測定し、これを各相ごとに順次接続替えして３回の
測定を行う。また、抵抗計３′で測定を行う場合も第２
図に示すようにその一端子を大地に接続して他端子をフ
ロートしている各条の遮蔽端末に接続して遮蔽端末と大
地間のループ抵抗を測定し、順次接続替えして３回の測
定を行う。この場合は測定値は共通の大地帰路抵抗を含
んだものであるが、通常その値は小さくて無視し得るも
のとして処理している。When measuring with an AC voltmeter 2, as shown in Fig. 2, one end is connected to the ground and the other terminal is connected to the floating shielding terminal of each line, and the AC voltage to the ground generated at the shielding terminal. Is measured, and the connection is sequentially changed for each phase, and measurement is performed three times. In addition, when the measurement is made with the resistance meter 3 ', the second
As shown in the figure, connect one terminal to the ground and connect the other terminal to the floating shield terminal of each line, measure the loop resistance between the shield terminal and the ground, and change the connection three times. Take a measurement. In this case, the measured value includes a common earth return resistance, but it is usually treated as a small value that can be ignored.
第３図においてはＢ端において抵抗計３′を用い，大地
に対して無定位に測定する。この場合、遮蔽１Ｒ，１
Ｓ，１Ｔの抵抗をそれぞれＲｒ，Ｒｓ，ＲｔとするとＲ
ｒ＋Ｒｓ＝ｒ１、Ｒｓ＋Ｒｔ＝ｒ２、Ｒｔ＋Ｒｒ＝ｒ３
の３通りの直列抵抗の組み合わせを作り、３回のループ
抵抗の測定を行う。測定結果は次ぎの式により分解して
各相ごとの遮蔽抵抗値を得る。In FIG. 3, the resistance meter 3'is used at the end B to measure atactically with respect to the ground. In this case, the shields 1R, 1
If the resistances of S and 1T are Rr, Rs, and Rt, respectively, R
r + Rs = r 1 , Rs + Rt = r 2 , Rt + Rr = r 3
3 combinations of series resistance are made and the loop resistance is measured 3 times. The measurement result is decomposed by the following formula to obtain the shielding resistance value for each phase.
（ハ）この発明が解決しょうとする課題 前述の従来技術には次のような課題がある。 (C) Problems to be Solved by the Invention The above-mentioned conventional technique has the following problems.
（ｉ）測定のための接続が容易でない。Ｂ端の遮蔽端末
では対大地絶縁、対他相絶縁を意図して処理されている
ので、人の接近、測定リード線の接続に障害が多くかつ
手数を必要とする。さらに、各回線のＢ端は相互に離れ
ているのは不便である。(I) Connection for measurement is not easy. Since the shield terminal at the B end is processed for the purpose of insulation against the ground and insulation against the other phase, there are many obstacles and troubles in the approach of a person and the connection of the measurement lead wire. Furthermore, it is inconvenient for the B ends of each line to be separated from each other.
（ii）感電の危険がある。断線がすでに発生していると
すると高電圧が遮蔽端末に誘起している可能性がある。
この際、遮蔽端末からの引出リードが出ていない場合、
またリードがでていてもその先端がテープ等で絶縁処理
されている場合はリード先端を金属的に露出させ測定リ
ード線をこれに接続する作業は難しく、感電の危険性が
ある。(Ii) There is a risk of electric shock. If the disconnection has already occurred, it is possible that high voltage is induced in the shield terminal.
At this time, if the withdrawal lead from the shielding terminal does not come out,
Further, even if the lead is exposed, if the tip is insulated by a tape or the like, it is difficult to expose the tip of the lead metallically and connect the measurement lead wire to this, and there is a risk of electric shock.
（iii）しばしば測定することは実際条不可能である。
上述の煩雑さのために頻度高く測定を繰り返すことは実
際上不可能となり、結局、不時の電気破壊事故を招く可
能性が大きい。(Iii) Often it is impossible to measure.
Due to the complexity described above, it is practically impossible to repeat the measurement frequently, and in the end, there is a high possibility of causing an accidental electric breakdown.
（iv）測定誤差が入りやすい。遮蔽端末に発生する対地
交流電圧は遮蔽断線だけに起因するのではなく、自回線
の導体電流からの電磁誘導電圧、並行他ケーブルからの
電磁誘導電圧、自己静電容量の充電電流による遮蔽長さ
方向の電圧降下等種々の要因による複合電圧である。特
に電磁誘導電圧は起因電流の大きさに比例して変わるの
で一定のものでなく、断線の初期状態があってもその変
動にマスクされて分からないことが多い。(Iv) Measurement error is likely to occur. The AC voltage to the ground generated at the shield terminal is not only caused by the shield disconnection, but the shield length due to the electromagnetic induction voltage from the conductor current of the own line, the electromagnetic induction voltage from other parallel cables, and the charging current of the self-capacitance. It is a composite voltage due to various factors such as the voltage drop in the direction. In particular, since the electromagnetic induction voltage changes in proportion to the magnitude of the induced current, it is not constant, and even if there is an initial state of disconnection, it is often not known because it is masked by the fluctuation.
上述のほか第２図の大地を帰路とするループ抵抗測定で
は、大地帰路抵抗が零でなくしかも変動性で一定で無い
ことから正確な測定ができない本質的欠陥がある。第３
図の２条の遮蔽の直列からなるループ抵抗の測定では抵
抗計に侵入してくる交流電圧が大となるので抵抗計３′
の内部のフィルタ回路が強化されていないと誤指示を得
るおそれがある。In addition to the above, in the loop resistance measurement of FIG. 2 which uses the earth as a return path, there is an essential defect in that the earth return resistance is not zero and variability is not constant, so that accurate measurement cannot be performed. Third
In the measurement of the loop resistance consisting of a series of shields shown in Fig. 2, the AC voltage entering the resistance meter becomes large, so the resistance meter 3 '
If the filter circuit inside is not strengthened, there is a risk of erroneous instructions.
この発明は遮蔽断線の早期発見を容易にかつ安全に行う
ことができ、たとえ断線が発生しても電気的破壊事故に
直結する可能性を大幅に減少できる、単心ケーブル遮蔽
断線監視装置及びその方法を提供することである。This invention makes it possible to easily and safely detect early breaks in a shield, and can greatly reduce the possibility of being directly connected to an electrical breakdown accident even if a break occurs, and a single-core cable shield breakage monitoring device and the same. Is to provide a method.
（ニ）課題を解決するための手段 この発明の装置は、活線電力ケーブルと一方の端部の各
条の一括した遮蔽端末と大地との間に接続される高イン
ピーダンスの異常電圧検出報知装置と、 前記活線電力
ケーブルの他方の端部の各条の遮蔽端末毎に設けられ、
接地位置と測定位置とを有して常時は該接地装置を介し
て該遮蔽端末は接地されている遮蔽接地切換スイッチ
と、前記各遮蔽接地切換スイッチの一括された測定位置
と大地との間に並列接続された静電容量および抵抗計と
を備えて構成される。(D) Means for Solving the Problems The device of the present invention is a high impedance abnormal voltage detection / informing device connected between a live power cable, a shield terminal for all the strips at one end, and the ground. And provided for each of the shielding terminals of each of the other ends of the live power cable,
Between the grounded ground changeover switch, which has a grounded position and a measured position and whose grounding terminal is always grounded through the grounding device, and the collective measured position of each of the grounded ground changeover switches and the ground. It is configured by including a capacitance and an ohmmeter connected in parallel.
また、この発明の方法は単心ケーブルの一方の端部は各
条の遮蔽端末を一括して高インピーダンスの異常電圧検
出装置を通じて常時接地すると共に、 前記単心ケーブ
ルの他方の端部は各条の遮蔽端末毎に設けた遮蔽接地切
換スイッチを通じて常時接地する段階と、 前記異常電
圧検出装置からの報知を得た時または定期的に、前記遮
蔽接地切換スイッチを１条宛に接地位置から測定位置に
切り替えて静電容量を通じての接地とする段階と、 前
記切り替えの都度、遮蔽端末と大地間のループ抵抗を測
定して３点の測定値を得、この各測定値から計算により
各条ごとの遮蔽抵抗値を得る段階を含んでいる。Further, according to the method of the present invention, one end of the single-core cable is always grounded together with the shielding terminals of each strip through a high-impedance abnormal voltage detection device, and the other end of the single-core cable is each strip. The step of always grounding through the shield grounding changeover switch provided for each of the shielding terminals, and the time when the abnormal ground voltage detection device gives a notification or periodically, the shield grounding changeover switch from the ground position to the measurement position for one article. And grounding through capacitance, and each time the switching is performed, the loop resistance between the shielding terminal and the ground is measured to obtain three measurement values, and from each measurement value, calculation is performed for each article. The step of obtaining the shielding resistance value is included.
（ホ）作用 この発明は、活線電力ケーブル線路の一方の端部の各条
は一括して異常電圧検出手段を介して接地するととも
に、他方の端部の各条も常時は各遮蔽端末スイッチを介
して接地されているから、前記一方の端部に異常が無い
時に発生する電圧は従来より低く押さえられる。また３
相の遮蔽が全部断線しない限り大地から浮か無いから前
記一方の端部に異常電圧は発生し難く、発生しても電気
事故に直結する可能性は少ない。さらに、前記遮蔽接地
端末スイッチを１条宛測定位置に切り替えて静電容量を
介して各条の遮蔽を接地し、抵抗計により遮蔽のループ
抵抗を３回測定しているから、測定中に危険な電圧が発
生すること無く安全にかつ簡単に測定できる。(E) Action In the present invention, each strip at one end of the live power cable line is collectively grounded via the abnormal voltage detecting means, and each strip at the other end is always a shield terminal switch. Since it is grounded via, the voltage generated when there is no abnormality at the one end can be suppressed to a lower level than before. Again 3
Unless all the phase shields are broken, it does not float from the ground, so it is difficult for abnormal voltage to occur at the one end, and even if it does occur, there is little possibility of being directly connected to an electrical accident. Furthermore, the shield ground terminal switch is switched to the measurement position for one line, the line shield is grounded via the capacitance, and the loop resistance of the line is measured three times by the resistance meter. It is possible to measure safely and easily without generating a large voltage.
（ニ）実施例 第１図はこの発明の一実施例を示すもので、単心ケーブ
ル３条から成る活線電力ケーブル線路の各条の遮蔽１
Ｒ，１Ｓ，１Ｔの下流側（負荷側）端部、即ちＢ端は各
条の遮蔽端末を一括し、高インピーダンスの異常電圧検
出報知装置４を通じて接地されている。また、遮蔽の上
流側（電源側）端部、即ちＡ端には各条の遮蔽１Ｒ，１
Ｓ、１Ｔごとに遮蔽接地切換スイッチ５Ｒ，５Ｓ，５Ｔ
が接続されその各ｂ（常閉）接点を経由して接地されて
いる。各条の遮蔽接地切換スイッチのａ（常開）接点は
一括して静電容量６、抵抗計３およびアレスタ７が並列
接続された一端に接続され、他端の並列接続点は接地さ
れている。(D) Embodiment FIG. 1 shows an embodiment of the present invention, in which each line of a live power cable line consisting of three single-core cables is shielded 1
The downstream side (load side) end of R, 1S, 1T, that is, the B end is collectively grounded by the shielding terminals of the respective strips and is grounded through a high impedance abnormal voltage detection / informing device 4. In addition, at the upstream side (power supply side) end of the shield, that is, at the A end, the shields 1R and 1
Shielded ground changeover switch 5R, 5S, 5T for each S and 1T
Are connected and grounded via their b (normally closed) contacts. The a (normally open) contact of each shield grounding changeover switch is collectively connected to one end where the capacitance 6, the resistance meter 3 and the arrester 7 are connected in parallel, and the parallel connection point at the other end is grounded. .
前記異常電圧検出装置の高インピーダンス値は少なくと
も１ＭΩ以上必要である。この高インピーダンスは大地
から遮蔽へを迷走電流の流入を遮断する目的もあるが、
異常電圧検出装置４自身の交流電圧検出感度を最高にす
る意味が強い。従って、直流抵抗が高いことのほか交流
インピーダンスも高いことが必要で大容量のコンデンサ
を異常電圧検出装置４と並列に挿入することは不可であ
る。ところで異常電圧検出報知装置４に要求される性能
は異常な交流電圧の検出と、この検出を容易に認知させ
る報知機能を併せもつことである。しかも異常電圧検出
装置４は多数の各回数のＢ端ごとに常時設置するためそ
の価格に制限があり、複雑、精巧で高価な装置は実用性
に欠けて使用し難い。そこで、第１図に例示されている
異常電圧検出装置４は安定抵抗が直列に接続されたネオ
ンランプという簡単で安価な装置である。このネオンラ
ンプの点灯開始電圧はＢ端に通常生じる誘起電圧より高
ければ良い。普通の１００Ｖネオンランプの点灯開始電
圧数十Ｖはこの条件を満足し、その点灯光により容易に
異常の発生を報知できる。The high impedance value of the abnormal voltage detector is required to be at least 1 MΩ or more. This high impedance also has the purpose of blocking the inflow of stray current from the ground to the shield,
The significance of maximizing the AC voltage detection sensitivity of the abnormal voltage detection device 4 itself is strong. Therefore, it is necessary to have a high DC resistance as well as a high AC impedance, and it is impossible to insert a large-capacity capacitor in parallel with the abnormal voltage detection device 4. By the way, the performance required for the abnormal voltage detection / informing device 4 is to have both the detection of an abnormal AC voltage and the informing function for making this detection easy to recognize. Moreover, since the abnormal voltage detection device 4 is always installed at each B end of a large number of times, its price is limited, and a complicated, delicate and expensive device is impractical and difficult to use. Therefore, the abnormal voltage detection device 4 illustrated in FIG. 1 is a simple and inexpensive device called a neon lamp in which stable resistors are connected in series. The lighting start voltage of the neon lamp may be higher than the induced voltage normally generated at the B end. A lighting start voltage of several tens of volts of a normal 100V neon lamp satisfies this condition, and the occurrence of abnormality can be easily notified by the lighting light.
尚、上述の通常の誘起電圧は第２図に示す交流電圧計２
により遮蔽に異常のない時に測定される自回線の導体電
流からの電磁誘導電圧では無く、それよりはるかに小さ
い。第１図の遮蔽接地回路では自回線の導体電流からの
電磁誘導電圧は消滅しているので、通常の誘起電圧は各
条の電力ケーブルの配列が純三角形で無いことから発生
する残留零相電圧と、並行他ケーブルからの電磁誘導電
圧とが複合したもので、その値が５０Ｖ以上に達するこ
とはまず有り得ない。そこで、ネオンランプが点灯すれ
ば遮蔽断線に間違いないと判定できる。さらに、Ｂ端で
各条の遮蔽端末を一括しているから例え遮蔽断線が発生
しても電気破壊事故に直結する可能性が従来の接地方式
よりはるかに減少している。The above-mentioned normal induced voltage is the AC voltmeter 2 shown in FIG.
Therefore, it is not the electromagnetic induction voltage from the conductor current of its own line that is measured when there is no abnormality in the shield, and is much smaller than that. In the shielded ground circuit of Fig. 1, the electromagnetically induced voltage from the conductor current of its own line has disappeared, so the normal induced voltage is the residual zero-phase voltage generated because the arrangement of the power cables in each section is not a pure triangle. And the electromagnetic induction voltage from the parallel cable are combined, and the value is unlikely to reach 50 V or more. Therefore, if the neon lamp is turned on, it can be determined that there is no doubt that the shielding wire is broken. Furthermore, since the shielding terminals of each strip are bundled together at the B end, the possibility of being directly connected to an electric breakdown accident even if a shielding disconnection occurs is much reduced compared to the conventional grounding method.
次の表は遮蔽断線の種々な発生様相に対するＢ端におけ
る異常交流電圧発生の有無の予測について従来の接地方
式と本発明の接地方式とで対比したものである。The following table is a comparison of the conventional grounding method and the grounding method of the present invention with respect to the prediction of the presence or absence of abnormal AC voltage generation at the B end for various appearances of shielding breakage.
上記表は、３相の遮蔽が全部断線しない限り大地から完
全に浮くことが無い本発明一部を構成している接地方式
は、従来の遮蔽接地方式よりはるかに少ない割合でしか
Ｂ端における異常電圧交流の発生は起こらないことを示
している。即ち、遮蔽断線が発生しても断線箇所を挟ん
での発生交流電圧が低いため、断線箇所での放電が発生
し難く、電気破壊事故に直結する可能性は激減する。最
も危険な３相遮蔽１Ｒ，１Ｓ，１Ｔが全部断線する事態
では異常電圧の発生があり検出報告される。しかし、３
相遮蔽の全部断線がたまたま線路中の同一箇所で起こっ
た場合はＢ端で電圧発生は無く、従って検出報告しない
が、断線箇所における異常電圧の発生も無く安全であ
る。 The above table shows that the grounding method forming part of the present invention, which does not completely float from the ground unless all three-phase shields are broken, is abnormal at the B-end only at a much lower rate than the conventional shielded grounding method. It shows that the generation of voltage alternating current does not occur. That is, even if a shield disconnection occurs, the AC voltage generated across the disconnection point is low, so it is difficult for discharge to occur at the disconnection point, and the possibility of being directly connected to an electrical breakdown accident is drastically reduced. When all the most dangerous three-phase shields 1R, 1S, 1T are disconnected, abnormal voltage is generated and it is detected and reported. But 3
If all the breaks in the phase shield happen to occur at the same point in the line, no voltage is generated at the B end, so no detection is reported, but no abnormal voltage is generated at the break point, which is safe.
第１図の遮蔽接地方式では例え断線が発生しても直ちに
電気破壊事故に結び着く可能性は随分押さえられるが、
皆無ではなく、特に同一相内での複数箇所の遮蔽断線の
場合は危険である。本接地方式は遮蔽断線の発生を押さ
えるのでは無く、遮断断線の発生の確率は従来の方式と
変わらない。With the shielded grounding method of Fig. 1, even if a wire breakage occurs, the possibility of an electric breakdown accident can be immediately suppressed, but
Not all, especially if there are multiple shielding breaks in the same phase, it is dangerous. This grounding method does not suppress the occurrence of shield disconnection, and the probability of occurrence of shield disconnection is the same as the conventional method.
そこで本発明の方法はＢ端における異常電圧発生の検出
報知を受けた時速やかに、または検出報知を受けなくて
も定期的に予めＡ端に設置された前記遮蔽接地切換スイ
ッチを１条宛、常時の接地位置から測定位置に切り替え
る。例えば第１図に示すように遮蔽接地切換スイッチ５
Ｒをｂ接点からａ接点に切り替えると、遮蔽１Ｒの端末
電位はａ接点から通じて静電容量６に導かれ、静電容量
６を通じての接地状態になる。この切替時には測定者の
安全確保のためにａ，ｂ接点間の一時点ラップ機構が必
要である。例え、遮蔽１Ｒが断線していても操作中に遮
蔽１Ｒの端末に危険な電圧が誘起することは無く、数十
Ｖないし十数Ｖ程度に押さえ込まれるように静電容量６
の値が用いられる。Therefore, in the method of the present invention, the shield grounding changeover switch previously installed at the end A is promptly sent when the detection notification of the abnormal voltage occurrence at the end B is received, or periodically even if the detection notification is not received. Switch from the normal ground position to the measurement position. For example, as shown in FIG.
When R is switched from the b-contact to the a-contact, the terminal potential of the shield 1R is led from the a-contact to the electrostatic capacitance 6 and is brought into a grounded state through the electrostatic capacitance 6. At the time of this switching, a temporary point wrap mechanism between the a and b contacts is required to ensure the safety of the measurer. For example, even if the shield 1R is broken, no dangerous voltage is induced at the terminal of the shield 1R during operation, and the electrostatic capacitance 6 is set so as to be suppressed to about several tens V to several tens of V.
The value of is used.
さらに、抵抗計３により遮蔽のループ抵抗を測定する。
まず、遮蔽接地切換スイッチ５Ｒをａ接点に切り替えた
場合はＲｒ＋（ＲｓとＲｔの並列）＝Ｒ1となるループ
抵抗を測定する。次に遮断接地切換スイッチ５Ｒをｂ接
点に戻し、遮断接地切換スイッチ５Ｓをａ接点に切り替
えて、Ｒｓ＋（ＲｔとＲｒの並列）＝Ｒ2となるループ
抵抗Ｒ2を測定する。次に、遮蔽接地切換スイッチ５Ｓ
をｂ接点に戻し、遮蔽接地切換スイッチ５Ｔをａ接点に
切り替えて、Ｒｓ＋（ＲｔとＲｒの並列）＝Ｒ3とまる
ループ抵抗Ｒ3を測定する。遮蔽接地切換スイッチ５Ｔ
をｂ接点に戻して測定を終了し、他回線で同様な測定を
行う。この測定において、静電容量６とアレスタ７との
組み合わせは測定対象の単心ケーブル線路が何回線あっ
ても１組で良い。尚、上述の測定において抵抗計３はそ
の一端を大地に落として測定しているが、ループ抵抗測
定回路中に大地が入っているのでは無く、大地の電位を
一方の電位として使用しているためである。Furthermore, the resistance loop 3 measures the loop resistance of the shield.
First, when the shield grounding changeover switch 5R is switched to the a-contact, the loop resistance at which Rr + (parallel to Rs and Rt) = R 1 is measured. Then, the breaking grounding changeover switch 5R is returned to the b contact, the breaking grounding changeover switch 5S is changed to the a contact, and the loop resistance R 2 at which Rs + (parallel to Rt and Rr) = R 2 is measured. Next, the shield grounding changeover switch 5S
Back to the contact b, to switch the shield ground selector switch 5T to a contact (parallel Rt and Rr) Rs + = measuring the R 3 loop resistance R 3 that stops. Shield grounding switch 5T
Is returned to the b contact and the measurement is completed, and the same measurement is performed on the other line. In this measurement, the combination of the capacitance 6 and the arrester 7 may be one set regardless of the number of single-core cable lines to be measured. In the above measurement, the resistance meter 3 is measured by dropping one end thereof to the ground, but the ground is not included in the loop resistance measuring circuit, and the ground potential is used as one potential. This is because.
上記測定から得たループ抵抗値Ｒ1、Ｒ２、Ｒ３は次の
ように計算により分解して遮蔽抵抗値Ｒｒ，Ｒｓ，Ｒｔ
を得る。即ち、 尚、上述のループ抵抗の組み合わせにより測定する代わ
りに、例えば遮蔽接地切換スイッチ５Ｒと５Ｓを同時に
測定位置のａ接点に切り替え、遮蔽１Ｒと１Ｓの直列ル
ープの抵抗を測定することは、スイッチ操作が２倍要す
ること、安全確保のためには静電容量６とアレスタ７と
の組み合わせが各条毎に必要で少なくとも３倍、さらに
単心ケーブル線路がｎ回線あれば３ｎ倍必要であるこ
と、抵抗計３を無定位で使用せねばならず侵入してくる
交流電圧も高くなること等から得策ではなく採用しな
い。The loop resistance values R 1 , R 2 and R 3 obtained from the above measurement are decomposed by calculation as follows and the shielding resistance values Rr, Rs and Rt are calculated.
To get That is, Instead of measuring with the combination of the loop resistances described above, for example, the shield grounding changeover switches 5R and 5S are simultaneously switched to the contact a at the measurement position and the resistance of the series loop of the shields 1R and 1S is measured by a switch operation. It is necessary to double, to ensure safety, it is necessary to combine the capacitance 6 and the arrester 7 for each article, at least 3 times, and if there are n single-core cable lines, 3n times are required. This is not a good idea and should not be adopted because the total of 3 must be used in a non-stationary manner and the AC voltage that comes in will be high.
また、本発明の実線路で実施する頻度は毎日１回の測定
が望ましい。このため、前述の測定操作、測定値の計算
による分解、その結果から遮蔽抵抗の異常の有無を判断
して警報を発する動作は全部自動化し、人手を要さずに
進行することが望ましく、本発明はこのような自動測定
に適している。Moreover, it is desirable that the actual line of the present invention be measured once a day. For this reason, it is desirable to automate all of the above-mentioned measurement operations, disassembly by calculation of measured values, and judge the presence or absence of abnormalities in the shielding resistance from the results and issue an alarm, and proceed without human intervention. The invention is suitable for such automatic measurement.
（ト）効果 本発明は、活線電力ケーブルの一方の端部における各条
の遮蔽端末を一括して異常電圧検出報知装置を介して接
地しているので、遮蔽断線が発生しても大部分は電気破
壊事故へ直結する可能性が大幅に押さえられて線路運転
上の安全度が大きい。また、３相遮蔽の全部断線という
事態発生の場合は異常電圧報知装置が報知機能を発揮す
るがこれは簡単な装置で経済的に設置できるので実用的
である。さらに、異常電圧検出報知装置からの報知を受
け、または報知がなくても定期的に遮断のループ抵抗を
測定してどの相の遮蔽がどの程度異常抵抗値であるか容
易に判断できる。さらに測定操作は簡単かつ安全であ
り、自動化も容易であり、単心ケーブル遮蔽断線を早期
に発見できる。(G) Effect In the present invention, since the shielding terminals of the respective strips at one end of the live power cable are collectively grounded via the abnormal voltage detection / informing device, even if a shielding wire breakage occurs, most of them are grounded. Has a high degree of safety in track operation because the possibility of being directly connected to an electric breakdown accident is greatly suppressed. Further, in the event of a situation where all three-phase shielding is broken, the abnormal voltage notification device exerts a notification function, but this is practical because it can be economically installed with a simple device. Furthermore, it is possible to easily determine which phase the shielding is and how much the abnormal resistance value is, by receiving the notification from the abnormal voltage detection / informing device, or periodically measuring the interruption loop resistance even without the notification. Furthermore, the measurement operation is simple and safe, and it is easy to automate, so that the disconnection of the single core cable can be detected early.
第１図はこの発明の一実施例を示す回路構成図、第２図
は従来の単心ケーブル遮蔽断線監視方法を説明する回路
構成図、第３図は従来の他の監視方法を説明する回路構
成図である。 １Ｒ，１Ｓ，１Ｔ……単心電力ケーブルの遮蔽、３……
抵抗計、４……異常電圧検出報知装置、５Ｒ，５Ｓ，５
Ｔ……遮蔽接地切換スイッチ、６……静電容量、７……
アレスタ。FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention, FIG. 2 is a circuit configuration diagram for explaining a conventional single-core cable shield disconnection monitoring method, and FIG. 3 is a circuit for explaining another conventional monitoring method. It is a block diagram. 1R, 1S, 1T ... Single-core power cable shielding, 3 ...
Resistance meter, 4 ... Abnormal voltage detection notification device, 5R, 5S, 5
T: Shield grounding switch, 6 ... Capacitance, 7 ...
Arrester.
フロントページの続き (56)参考文献 特開 昭54−43544（ＪＰ，Ａ) 特開 昭54−38584（ＪＰ，Ａ) 特開 昭53−121184（ＪＰ，Ａ) 特開 昭53−88979（ＪＰ，Ａ) 特開 昭58−106473（ＪＰ，Ａ)Continuation of front page (56) Reference JP 54-43544 (JP, A) JP 54-38584 (JP, A) JP 53-121184 (JP, A) JP 53-88979 (JP , A) JP-A-58-106473 (JP, A)
Claims (2)
ル線路において、 前記活線電力ケーブルの一方の端部の各条の一括した遮
蔽端末と大地との間に接続される高インピーダンスの異
常電圧検出報知装置と、 前記活線電力ケーブルの他方の端部の各条の遮蔽端末毎
に設けられ、接地位置と測定位置とを有して常時は該接
地位置を介して該遮蔽端末は接地されている遮蔽接地切
換スイッチと、 前記各遮蔽接地切換スイッチの一括された測定位置と大
地との間に並列接続された静電容量および抵抗計と、を
備えて成る単心ケーブルの遮蔽断線監視装置。1. In a live-line power cable line comprising three single-core cables, a high-impedance anomaly connected between the ground and a shield terminal of each line at one end of the live-line power cable. A voltage detection / informing device, and a shield terminal provided at each end of each line of the live power cable, each having a ground position and a measurement position, and the shield terminal is normally grounded through the ground position. A shield breakage monitor for a single-core cable, which comprises a shield grounding changeover switch that is installed, and a capacitance and resistance meter connected in parallel between the collective measurement position of each of the shield grounding changeover switches and the ground. apparatus.
ル遮蔽の断線を監視する方法であつて、 前記単心ケーブルの一方の端部は各条の遮蔽端末を一括
して高インピーダンスの異常電圧検出装置を通じて常時
接地すると共に、 前記単心ケーブルの他方の端部は各
条の遮蔽端末毎に設けた遮蔽接地切換スイッチを通じて
常時接地する段階と、 前記異常電圧検出装置からの報知を得た時または定期的
に、前記遮蔽接地切換スイッチを１条宛接地位置から測
定位置に切り替えて静電容量を通じての接地とする段階
と、 前記切り替えの都度、遮蔽端末と大地間のループ抵抗を
測定して３点の測定値を得、この各測定値から計算によ
り各条ごとの遮蔽抵抗値を得る段階と、を備えて成る単
心ケーブル遮蔽断線監視方法。2. A method for monitoring breakage of a shield of a live power cable consisting of three single-core cables, wherein one end of the single-core cable has a high-impedance abnormality in which shield terminals of each line are collectively attached. While constantly grounding through the voltage detecting device, the other end of the single-core cable is always grounded through the shield grounding changeover switch provided for each shielding terminal of each strip, and the notification from the abnormal voltage detecting device was obtained. When or periodically, the shield grounding changeover switch is switched from the grounding position addressed to one line to the measurement position to ground via the electrostatic capacitance, and the loop resistance between the shield terminal and the ground is measured each time the switching is performed. And a step of obtaining a shield resistance value for each strip by calculating from these respective measured values, and a shield breakage monitoring method for a single-core cable.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63153104A JPH0614086B2 (en) | 1988-06-21 | 1988-06-21 | Single-core cable shield disconnection monitoring device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63153104A JPH0614086B2 (en) | 1988-06-21 | 1988-06-21 | Single-core cable shield disconnection monitoring device and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01320480A JPH01320480A (en) | 1989-12-26 |
| JPH0614086B2 true JPH0614086B2 (en) | 1994-02-23 |
Family
ID=15555061
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63153104A Expired - Lifetime JPH0614086B2 (en) | 1988-06-21 | 1988-06-21 | Single-core cable shield disconnection monitoring device and method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0614086B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100447823C (en) * | 2006-12-07 | 2008-12-31 | 时均泉 | Caution device of monitoring low voltage distribution line |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002214273A (en) * | 2001-01-22 | 2002-07-31 | Yazaki Corp | Breaking inspection circuit for high voltage cable shielding copper tape |
| DE102019107399A1 (en) * | 2019-03-22 | 2020-09-24 | Vega Grieshaber Kg | Field device with monitoring device and method for operating a field device |
| CN117471175B (en) * | 2023-10-30 | 2024-06-11 | 国网四川省电力公司超高压分公司 | Method and device for reducing induced voltage |
-
1988
- 1988-06-21 JP JP63153104A patent/JPH0614086B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100447823C (en) * | 2006-12-07 | 2008-12-31 | 时均泉 | Caution device of monitoring low voltage distribution line |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01320480A (en) | 1989-12-26 |
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