JPS608465B2 - Cable insulation resistance monitoring method - Google Patents

Cable insulation resistance monitoring method

Info

Publication number
JPS608465B2
JPS608465B2 JP50110356A JP11035675A JPS608465B2 JP S608465 B2 JPS608465 B2 JP S608465B2 JP 50110356 A JP50110356 A JP 50110356A JP 11035675 A JP11035675 A JP 11035675A JP S608465 B2 JPS608465 B2 JP S608465B2
Authority
JP
Japan
Prior art keywords
cable
insulation resistance
voltage
power supply
line
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
Application number
JP50110356A
Other languages
Japanese (ja)
Other versions
JPS5233772A (en
Inventor
忠晴 中山
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumitomo Electric Industries Ltd
Original Assignee
Sumitomo Electric Industries Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sumitomo Electric Industries Ltd filed Critical Sumitomo Electric Industries Ltd
Priority to JP50110356A priority Critical patent/JPS608465B2/en
Publication of JPS5233772A publication Critical patent/JPS5233772A/en
Publication of JPS608465B2 publication Critical patent/JPS608465B2/en
Expired legal-status Critical Current

Links

Landscapes

  • Electric Cable Installation (AREA)
  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
  • Measurement Of Resistance Or Impedance (AREA)
  • Emergency Protection Circuit Devices (AREA)

Description

【発明の詳細な説明】 本発明は、送電中のケーブルの絶縁抵抗を測定してその
劣化状態を監視するケーブル絶縁抵抗監視方法に関する
ものである。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cable insulation resistance monitoring method for measuring the insulation resistance of a cable during power transmission and monitoring its deterioration state.

布設されたケーブルも経年変化により絶縁抵抗が劣化す
る場合があるが、通常の絶縁抵抗を測定する手段では、
送電を中断した期間に於いてのみ測定が可能であり、こ
のような送電中断は1年に1度あるかどうかと云うよう
に、まれにしか起らないものである。
The insulation resistance of installed cables may deteriorate due to aging, but with normal means of measuring insulation resistance,
Measurements can only be made during the period during which power transmission is interrupted, and such interruptions in power transmission occur rarely, perhaps once a year.

従ってケーブルの絶縁抵抗は1年に1度程度測定される
に過ぎず、時によっては数年に1度しか測定できない場
合もある。更に絶縁抵抗の測定はケーブルの切離し、測
定器具の倭統、警戒要員、測定要員の配置、再送電可能
状態とする為の復旧等、多くの作業員と多くの手数とを
要するものであった。従ってケーブルの絶縁劣化を早期
に発見し、ケーブルの電気的破壊を未然に防止すること
ができないのが現実の状態であった。
Therefore, the insulation resistance of a cable can only be measured about once a year, and sometimes only once every few years. Furthermore, measuring insulation resistance required many workers and a lot of effort, such as disconnecting cables, transferring measuring instruments, arranging security personnel and measuring personnel, and restoring power so that power could be transmitted again. . Therefore, the reality is that it is not possible to detect cable insulation deterioration early and prevent electrical breakdown of the cable.

本発明は、簡単に送電中のケーブルの絶縁抵抗を定期的
に監視し得る方法を提供することを目的とするものであ
る。
An object of the present invention is to provide a method for easily periodically monitoring the insulation resistance of a cable during power transmission.

以下実施例について詳細に説明する。第1図は本発明の
一実施例の説明図であり、Tはケーブル1その他のケー
ブルが接続されている3相送配電線路であって、1次側
Y結線、2次側△結線の変圧器Tyの2次側に接続され
ている。
Examples will be described in detail below. FIG. 1 is an explanatory diagram of an embodiment of the present invention, where T is a three-phase power transmission and distribution line to which cable 1 and other cables are connected, and the transformer has a Y connection on the primary side and a Δ connection on the secondary side. It is connected to the secondary side of the device Ty.

Sは直流高電圧電源で通常は十側を接地し、一側を送配
電線路Tの任意の線に接続する。Msは直流高電圧電源
Sによる電流を測定する電流計、R3は保護抵抗、C,
,C2,C3は静電容量、Lはチョークコイル、S,は
開閉器、Mxはケーブルの絶縁抵抗Rxを通して流れる
電流を測定する電流計である。静電容量C3はケーブル
1の遠端の遮蔽層を交流的に接地する為のものであり、
又静電容量C,,C2とチョークコイルLは交流分を阻
止して電流計Mxで直流漏洩電流lxを測定し得るよう
にするもので、ケーブル1の近端の遮蔽層に接続されて
いる。
S is a DC high voltage power supply whose tenth side is normally grounded, and whose one side is connected to an arbitrary line of the power transmission/distribution line T. Ms is an ammeter that measures the current from the DC high voltage power supply S, R3 is a protective resistor, C,
, C2, and C3 are capacitances, L is a choke coil, S is a switch, and Mx is an ammeter that measures the current flowing through the insulation resistance Rx of the cable. The capacitance C3 is for AC grounding the shielding layer at the far end of the cable 1,
Furthermore, the capacitances C, C2 and the choke coil L block the AC component so that the DC leakage current lx can be measured with the ammeter Mx, and are connected to the shielding layer at the near end of the cable 1. .

このうちの静電容量C,は開閉器S,を開いたとき、ケ
ーブル1の遮蔽層の電位を交流的に接地電位とする為、
大容量、低インピーダンスのものを用いる。各ケーブル
毎に前述の如き構成を設けるものであるが、×印で示す
K点に切換スイッチ等を設けて、各ケーブルの遮蔽層の
りード線との切換えを行なう構成として測定回路を共通
化することもできる。
Of these, the capacitance C, when the switch S is opened, sets the potential of the shielding layer of the cable 1 to the ground potential in an alternating current manner.
Use one with large capacity and low impedance. The above-mentioned configuration is provided for each cable, but a changeover switch, etc. is provided at the K point indicated by an x mark, and the measurement circuit is shared by a configuration that switches between each cable's shielding layer lead wire. You can also.

直流高圧電源Sは、例えば氷V配電線路に対してはIK
V,舷V配電線路に対しては狐Vの直流電圧に選定する
For example, the DC high voltage power supply S is IK for the ice V distribution line.
For the V and side V distribution lines, select the Fox V DC voltage.

又線路Tと直流高圧電源Sとは保護抵抗Rsを介して直
接接続されているが、ディスコン或はカットアウトスイ
ッチ等を介して接続し、測定時のみ線路Tに直流高電圧
を印加するようにすることもできる。又保護抵抗Rsは
例えば滋V配電線路に対しては20■MQ,靴V配電線
路に対しては40山MQの如く高抵抗を用いるものであ
る。この為、多数のケーブルが接続されて対地静電容量
が大きくなっている線路に対しては、充電に要する時間
を数分程度必要とすることになるが、その代わり急峻な
電圧変化を与えるとがなくなり、又絶縁抵抗の低下して
いるケーブルに対する最終充電電圧も自動的に低くなる
ので、絶縁破壊を生じさせるようになることもなくなる
。なお直流電圧は線路Tの任意の線に印加することによ
り「電源変圧器Tyの2次側巻線を通して各相に同じ直
流電圧が印加されることになる。電流計Msに流れる電
流lsは、線路Tの対地絶縁抵抗が零のとき最大になり
、例えば直流高圧電源Sの電圧と保護抵抗Rsとを前述
の如き値に選定したときIS=群端):衆機器5(ムA
) となる。
In addition, the line T and the DC high voltage power supply S are directly connected via a protective resistor Rs, but they are connected via a disconnector or cut-out switch, so that a DC high voltage is applied to the line T only during measurement. You can also. Further, the protective resistor Rs is a high resistance such as 20 MQ for the Shigeru V distribution line and 40 MQ for the Shoe V distribution line. For this reason, for lines where many cables are connected and the ground capacitance is large, it will take several minutes to charge, but at the cost of applying steep voltage changes. Furthermore, the final charging voltage for cables with reduced insulation resistance is automatically lowered, so that insulation breakdown does not occur. By applying the DC voltage to any line of the line T, the same DC voltage is applied to each phase through the secondary winding of the power transformer Ty.The current ls flowing through the ammeter Ms is When the insulation resistance to ground of the line T is zero, it is maximum.For example, when the voltage of the DC high-voltage power supply S and the protective resistance Rs are selected to the values described above,
) becomes.

従ってこの場合は電流計Msは5仏Aのフルフケールの
ものを用いれば良いことになる。前述の如く直流高圧電
源Sから直流電圧を印加して1増数分後に開閉器S,を
開く、それによってケーブル1の絶縁層の絶縁抵抗Rx
を通して開閉器S,経由で大地へ流れていた直流漏洩電
流lxがチョークコイルLを介して電流計Mxに流れる
ことになる。この場合、静電容量C,,C2とチョーク
コイルLとからなる交流分阻止回路により交流分が電流
計Mkに流れることを阻止する。例えば靴V配電線路に
対して前述の如くIKVの直流電圧を印加し「電流計M
sでは電流lsが1.0仏A、電流計Mxでは電流lx
が0.05仏Aとして測定されたとすると、ケーブル1
の絶縁抵抗RxはRX:E三王き李ご1X1ぴ−左さま
蔓手斧羊。
Therefore, in this case, it is sufficient to use a full scale ammeter of 5 A as the ammeter Ms. As mentioned above, the DC voltage is applied from the DC high-voltage power supply S, and after one increment, the switch S is opened, thereby increasing the insulation resistance Rx of the insulation layer of the cable 1.
The DC leakage current lx, which was flowing to the ground via the switch S and the choke coil L, flows to the ammeter Mx via the choke coil L. In this case, an alternating current blocking circuit including capacitances C, , C2 and a choke coil L prevents alternating current from flowing to the ammeter Mk. For example, if a DC voltage of IKV is applied to the shoe V distribution line as described above,
At s, the current ls is 1.0 French A, and at the ammeter Mx, the current lx
is measured as 0.05 French A, then cable 1
The insulation resistance Rx is RX:

〇×1び=16000×1ぴ即ち160仰け○であるこ
とが判る。
It can be seen that 〇×1bi=16000×1, that is, 160 times ○.

測定終了により開閉器S,を閉じてケーブル1の遮蔽層
を接地電位とし、他のケーブルに対する測定を行なう。
When the measurement is completed, the switch S is closed to set the shielding layer of the cable 1 to the ground potential, and measurements on other cables are performed.

その他のケーブルの絶縁抵抗も前述の如く直流高圧電源
Sを流れる直流電錠asとケーブルの絶縁層を通して流
れ電流lxとを測定することにより絶縁抵抗を送電状態
のまま測定することができる。そして全ケーブルの絶縁
抵抗の測定が完了すれば直流高圧電源Sの動作の停止又
は線路Tからの切離しを行なうことにより全裸作が終了
する。第2図は線路Tに接地用変圧器CPTが接続され
ている場合の実施例の説明図であり、直流高圧電源Sは
保護抵抗沢sを介して接地用変圧器GPTの1次巻線の
中性点に接続される。
The insulation resistance of other cables can be measured while the power is being transmitted by measuring the DC electric current AS flowing through the DC high-voltage power supply S and the current lx flowing through the insulating layer of the cable as described above. When the measurement of the insulation resistance of all the cables is completed, the operation of the DC high-voltage power supply S is stopped or the cable is disconnected from the line T, thereby completing the complete stripping. FIG. 2 is an explanatory diagram of an embodiment in which a grounding transformer CPT is connected to a line T, and a DC high-voltage power supply S is connected to the primary winding of the grounding transformer GPT via a protective resistor s. Connected to neutral point.

なお通常はこの中性点0は直接大地に接続されているも
のであるから、測定時にのみ第2図に示す接続状態とな
るような自動挿入回路を構成することが望ましい。又中
性点○と大地との間に静電容量Coを接続し、測定中に
於ける地絡電流の低インピーダンス通路を形成しておく
ことが必要である。更にこの地絡電流が増大する罵れが
ある場合には、接地用変圧器GPTの2次側で地絡電流
を検出して静電容量C。を短絡する構成とするか、又は
図示の如く静電容量Coに並列にアレスタAyを接続す
ることが、安全対策上望ましい。この第2図に示す実施
例は線路Tの中性点が接地されている場合であるから、
電源変圧器Tyの・2次巻線がY結線の場合にも適用で
きることを示している。
Note that since this neutral point 0 is normally connected directly to the ground, it is desirable to construct an automatic insertion circuit that is in the connection state shown in FIG. 2 only during measurement. It is also necessary to connect a capacitance Co between the neutral point ○ and the ground to form a low impedance path for the ground fault current during measurement. If this ground fault current increases further, the ground fault current is detected on the secondary side of the grounding transformer GPT and the capacitance C is increased. For safety reasons, it is desirable to short-circuit the capacitance Co or to connect the arrester Ay in parallel to the capacitance Co as shown in the figure. Since the embodiment shown in FIG. 2 is a case where the neutral point of the line T is grounded,
This shows that it can also be applied to the case where the secondary winding of the power transformer Ty is Y-connected.

第3図は本発明による監視方法の絶縁抵抗測定時の等価
回路を示すもので、Rpは測定対象以外の全線路の対地
絶縁合成抵抗であり、これに電流lpが流れるが、この
電流lpは本発明に於いては直接には測定する必要のな
いものである。
Figure 3 shows an equivalent circuit when measuring insulation resistance using the monitoring method according to the present invention. In the present invention, there is no need to directly measure it.

そして直流高圧電源Sの電圧E、それに流れる電流ls
、保護抵抗Rs、絶縁層を通して流れる電流lxにより
絶縁層の絶縁抵抗RxはRX:竺器ミ で求まることになる。
Then, the voltage E of the DC high voltage power supply S, and the current ls flowing through it
, the protective resistance Rs, and the current lx flowing through the insulating layer, the insulation resistance Rx of the insulating layer can be found as RX:Rx.

第4図は滋V配電線路に対する直流漏洩電流lx〔山A
〕と絶縁抵抗Rx〔MQ〕との関係を示すもので、直流
高圧電源Sの電圧EをIKV、保護抵抗Rsを200M
Qとした場合のものであり、ls=lxの曲線はRp=
功の場合を示す。
Figure 4 shows the DC leakage current lx [mountain A
] and insulation resistance Rx [MQ], where the voltage E of the DC high-voltage power supply S is IKV and the protective resistance Rs is 200M.
Q, and the curve of ls=lx is Rp=
The case of gong is shown.

そして絶縁抵抗Rxは10MQ〜20000MQ程度の
範囲の測定が可能であり、通常の高圧電力ケーブルでは
この程度の絶縁抵抗の測定ができれば実用上充分である
。例えば雛VCVケ−ブルに於いては、10皿MQ−K
mを限界とし、これより絶縁抵抗が低下すれば、近い中
に電気的破壊する虞れが多分にあり、このようなケーブ
ルは早急に取替える必要があるとするのを絶縁抵抗劣化
の診断基準とすると、この様な診断を行うには上記の性
能で充分である。以上説明したように、本発明はケーブ
ルの送電状態に於いても、そのケーブルの絶縁抵抗を測
定することができるから、例えば1週間程度の比較的短
期間毎の定期的測定も容易となり、ケーブルの絶縁抵抗
の変化を把握して、ケーブルの絶縁劣化を早期に発見し
、大事故を禾然に防止することができる。
The insulation resistance Rx can be measured in a range of about 10MQ to 20,000MQ, and it is practically sufficient to measure insulation resistance of this level with a normal high-voltage power cable. For example, in the Hina VCV cable, 10 plates MQ-K
The standard for diagnosing insulation resistance deterioration is that if the insulation resistance falls below this limit, there is a high risk of electrical breakdown in the near future, and such cables must be replaced immediately. Then, the above performance is sufficient for performing such a diagnosis. As explained above, the present invention can measure the insulation resistance of a cable even when the cable is in a power transmission state, making it easy to perform periodic measurements over a relatively short period of time, for example, about one week. By understanding changes in cable insulation resistance, it is possible to detect cable insulation deterioration early and prevent major accidents.

又測定時に印加する直流電圧は、交流使用電圧に比較し
て低くすることができ、又高抵抗の保護抵抗を介してケ
ーブルに印加するものであるから、時間的には徐々に印
加電圧が上昇する状態となって、ケーブル及びそれに接
続される変圧器等の劣化を促進する簾れがない。
In addition, the DC voltage applied during measurement can be lower than the AC working voltage, and since it is applied to the cable via a high-resistance protective resistor, the applied voltage gradually increases over time. In this situation, there is no screen that can accelerate the deterioration of the cable and the transformer connected to it.

なお本発明は送電中のみでなく送電中断時に於いても、
絶縁抵抗の測定を行なうことができることは勿論である
The present invention is applicable not only during power transmission but also during power transmission interruption.
Of course, insulation resistance can also be measured.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図及び第2図は本発明のそれぞれ異なる実施例の説
明図、第3図は測定時の等価回路、第4図は漏洩電流l
xと絶縁抵抗Rxとの関係曲線図である。 Sは直流高圧電源、Rsは保護抵抗、C。 ,C,,C2,C3は静電容量、Tは送配電線路、Ms
,Mxは電流計、いまチョークコイル、S,は開閉器、
1【まケーブルである。オ1図 オ2蟹 オ3図 .汁4斑
Figures 1 and 2 are explanatory diagrams of different embodiments of the present invention, Figure 3 is an equivalent circuit during measurement, and Figure 4 is a leakage current l.
It is a relationship curve diagram between x and insulation resistance Rx. S is a DC high voltage power supply, Rs is a protection resistor, and C. , C,, C2, C3 are capacitances, T is transmission and distribution line, Ms
, Mx is an ammeter, now a choke coil, S is a switch,
1 [Well, it's a cable. O1 figure O2 crab O3 figure. 4 spots of juice

Claims (1)

【特許請求の範囲】[Claims] 1 ケーブルが接続されている送電中の送配電線路の任
意の線又は中性点と大地との間に保護抵抗を介して直流
高電圧電源を接続し、前記ケーブルの遮蔽層と大地との
間に直流通過ろ波回路を接続し、前記保護抵抗に流れる
直流電流と前記ケーブルからその絶縁層及び直流通過ろ
波回路を通して大地に流れる直流漏洩電流とを測定して
、前記直流高電圧電源の直流電圧と前記保護抵抗との関
係によりケーブルの絶縁抵抗を求めることを特徴とする
ケーブル絶縁抵抗監視方法。
1. A DC high voltage power source is connected between any line or neutral point of the power transmission/distribution line to which the cable is connected and the earth via a protective resistor, and between the shielding layer of the cable and the earth. A DC pass filter circuit is connected to the DC high voltage power supply, and the DC current flowing through the protective resistor and the DC leakage current flowing from the cable to the ground through its insulating layer and the DC pass filter circuit are measured. A method for monitoring cable insulation resistance, characterized in that the insulation resistance of the cable is determined based on the relationship between voltage and the protective resistance.
JP50110356A 1975-09-10 1975-09-10 Cable insulation resistance monitoring method Expired JPS608465B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP50110356A JPS608465B2 (en) 1975-09-10 1975-09-10 Cable insulation resistance monitoring method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP50110356A JPS608465B2 (en) 1975-09-10 1975-09-10 Cable insulation resistance monitoring method

Publications (2)

Publication Number Publication Date
JPS5233772A JPS5233772A (en) 1977-03-15
JPS608465B2 true JPS608465B2 (en) 1985-03-02

Family

ID=14533686

Family Applications (1)

Application Number Title Priority Date Filing Date
JP50110356A Expired JPS608465B2 (en) 1975-09-10 1975-09-10 Cable insulation resistance monitoring method

Country Status (1)

Country Link
JP (1) JPS608465B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54124766A (en) * 1978-03-20 1979-09-27 Sumitomo Electric Ind Ltd Searching method of insulation defective points of corrosion preventing layer
JPS5855870A (en) * 1981-09-30 1983-04-02 Sumitomo Metal Ind Ltd Measurement of insulation resistance for winding of ac equipment

Also Published As

Publication number Publication date
JPS5233772A (en) 1977-03-15

Similar Documents

Publication Publication Date Title
US11435409B2 (en) Temporary overvoltage and ground fault overvoltage protection based on arrester current measurement and analysis
Bridger High-resistance grounding
JP5349036B2 (en) Insulation diagnostic system
US8487635B1 (en) System and method for determining system charging current
JPS61243375A (en) Deterioration diagnosis for insulator of power cable
CN108646125A (en) A kind of test method of capacitance current, apparatus and system
RU2550751C2 (en) Method and device for detection of ground short-circuit
US4634981A (en) Method for testing a circuit breaker using a three terminal current transformer
JP2006200898A (en) Interrupt insulation measuring device
EP2196812A1 (en) Monitoring device for detecting earth faults
JPH03206976A (en) Diagnosis of insulation
JPS608465B2 (en) Cable insulation resistance monitoring method
CN108548982A (en) A kind of test method of capacitance current, apparatus and system
CN207798991U (en) A kind of voltage transformer multipoint earthing detection device
JP2578766B2 (en) Live tan δ measuring device
JP2876322B2 (en) Diagnosis method for insulation deterioration of CV cable
JPS6029074B2 (en) Lightning arrester deterioration detection method
Killen et al. Protection of pilot wires from induced potentials
Opsahl et al. Lightning protection for distribution transformers
JPS5934977B2 (en) Power cable insulation resistance measuring device
Al-Hajri Neutral ground resistor monitoring schemes
JPS59202073A (en) Diagnosis of insulation deterioration of power cable
DE911867C (en) Peak voltmeter with capacitor reloading for the measurement of one-off processes
JPH0442779Y2 (en)
CN110456158A (en) A kind of method for preventing induced electricity from hurting sb.'s feelings when measurement circuit power frequency parameter