JPS5836195Y2 - Electric circuit insulation resistance monitoring device - Google Patents
Electric circuit insulation resistance monitoring deviceInfo
- Publication number
- JPS5836195Y2 JPS5836195Y2 JP132877U JP132877U JPS5836195Y2 JP S5836195 Y2 JPS5836195 Y2 JP S5836195Y2 JP 132877 U JP132877 U JP 132877U JP 132877 U JP132877 U JP 132877U JP S5836195 Y2 JPS5836195 Y2 JP S5836195Y2
- Authority
- JP
- Japan
- Prior art keywords
- insulation resistance
- circuit
- detection
- ground
- monitoring device
- 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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Description
【考案の詳細な説明】
この考案は配電線路の絶縁抵抗が予め設定された値以下
になったことを検知する絶縁抵抗監視装置に関するもの
である。[Detailed Description of the Invention] This invention relates to an insulation resistance monitoring device that detects when the insulation resistance of a power distribution line has fallen below a preset value.
この種の装置としては例えば第1図に示すものが考えら
れる。An example of this type of device is shown in FIG. 1, for example.
即ち、第1図において、1,2.3は配電線路(以下電
路という)、4は変圧器、この変圧器4の低圧側中性点
と大地間には、電流制限用抵抗器5とダイオード6と検
出装置7が直列接続されている。That is, in Fig. 1, 1, 2.3 are distribution lines (hereinafter referred to as electric lines), 4 is a transformer, and between the low voltage side neutral point of this transformer 4 and the ground, there is a current limiting resistor 5 and a diode. 6 and a detection device 7 are connected in series.
7Aは検出装置7の検出用抵抗器、7Bは電圧増幅作動
装置である。7A is a detection resistor of the detection device 7, and 7B is a voltage amplification operating device.
8は電圧増幅作動装置7Bと電源となる電源用変圧器、
11.12.13は電路1,2.3に対応して発生する
対地浮遊静電容量(以下浮遊容量という)である。8 is a voltage amplification operating device 7B and a power transformer serving as a power source;
11, 12, and 13 are stray capacitances to the ground (hereinafter referred to as stray capacitances) generated corresponding to the electric lines 1, 2, and 3.
次に上記構成の装置の動作について説明すると、各相の
電路1,2.3が正常なときには電路1,2゜3と大地
間に地絡電流は流れないが、電路1,2.3と大地間に
は通常浮遊容量11,12.13が存在して・いるため
充電電流が流れる場合がある。Next, to explain the operation of the device with the above configuration, when the circuits 1, 2.3 of each phase are normal, no ground fault current flows between the circuits 1, 2.3 and the ground, but when the circuits 1, 2.3 and the ground Since stray capacitances 11, 12, and 13 usually exist between the ground and the ground, a charging current may flow.
この充電電流は各相の浮遊容量11,12.13がバラ
ンスしている場合にはキャンセルしてそれからのベクト
ル和は零となって流れないが、もし浮遊容量11,12
゜13がアンバランスの場合には、B点を経て検出用抵
抗器7A、ダイオード6、電流制限用抵抗器5を通じて
変圧器4の中性点へ充電電流が流れる。If the stray capacitances 11, 12 and 13 of each phase are balanced, this charging current will cancel and the vector sum will be zero and will not flow, but if the stray capacitances 11, 12
When 13 is unbalanced, the charging current flows to the neutral point of the transformer 4 via the detection resistor 7A, the diode 6, and the current limiting resistor 5 via the point B.
このとき流れる電流はダイオード6により整流されて浮
遊容量11,12.13を充電し、−たん充電が完了す
ると放電回路はダイオード6で阻止されているため、浮
遊容量11,12.13は充電状態となりそれ以上に充
電電流は流れなくなる。The current flowing at this time is rectified by the diode 6 and charges the stray capacitances 11, 12.13, and when the charging is completed, the discharge circuit is blocked by the diode 6, so the stray capacitances 11, 12.13 are in a charged state. Therefore, charging current no longer flows.
したがって検出用抵抗器7Aの両端には一時的に充電電
流による電圧信号が現われるが、その後は電圧信号が無
くなり電路1,2.3の浮遊容量11゜12.13の影
響を受けないようになっている。Therefore, a voltage signal due to the charging current appears temporarily across the detection resistor 7A, but after that, the voltage signal disappears and is no longer affected by the stray capacitances 11° and 12.13 of the electrical circuits 1 and 2.3. ing.
次に電路3の絶縁が低下してA点で地絡が発生したとす
ると、地絡電流が浮遊容量11,12.13の放電電流
となりA点、C点(浮遊容量11,12.13の接地点
)を経て浮遊容量11,12.13に流れる。Next, if the insulation of the electrical path 3 deteriorates and a ground fault occurs at point A, the ground fault current becomes the discharge current of the stray capacitances 11, 12.13, and points A and C (of the stray capacitances 11, 12.13 It flows through the stray capacitors 11, 12, and 13 through the ground point).
このため電源周波数の各サイクルのある区間で浮遊容量
11,12.13を充電する電流が上記C点、B点、検
出用抵抗器7A、ダイオード6、電流制限用抵抗器5を
流れる。Therefore, a current that charges the stray capacitances 11, 12, and 13 flows through the points C and B, the detection resistor 7A, the diode 6, and the current limiting resistor 5 during a certain section of each cycle of the power supply frequency.
この定常的充電電流により検出用抵抗器7Aの両端には
電圧信号が現われるので、この電圧信号を電圧増幅作動
装置7Bで検出して電路1,2.3の絶縁低下を警告す
る。This steady charging current causes a voltage signal to appear across the detection resistor 7A, and this voltage signal is detected by the voltage amplification actuator 7B to warn of deterioration in the insulation of the electrical circuits 1, 2.3.
上記構成の装置を理解し易くするために等価回路で示せ
は゛第2図のごとくなる。In order to make it easier to understand the device having the above configuration, an equivalent circuit is shown as shown in FIG.
即ち、Cは合成の浮遊容量で下記で表わされる。That is, C is a composite stray capacitance and is expressed as below.
CzCo+Cu+Cu mmmeaemHaHa@@
@ (1)C11・−・浮遊容量Oの静電容量
C1を−・浮遊容量0の静電容量
C13・−・浮遊容量(至)の静電容量
法に、Rは合成の電路の絶縁抵抗で下記で表わされる。CzCo+Cu+Cu mmmeaemHaHa@@
@ (1) C11 - Capacitance C1 of stray capacitance O - Capacitance C13 of stray capacitance 0 - Capacitance method of stray capacitance (to), R is the insulation resistance of the composite circuit is expressed as below.
R1−・電路(1)の絶縁抵抗
R2・−・電路(2)の絶縁抵抗
R3・・・電路(3)の絶縁抵抗
電源15の電圧ENは第1図においてB点で接地線を切
った場合に大地と電路の中性点間に現われる電圧であり
、下記で表わされる。R1-・Insulation resistance of the electric path (1) R2・-・Insulation resistance of the electric path (2) R3・Insulation resistance of the electric path (3) The voltage EN of the power supply 15 is the ground wire cut off at point B in Figure 1. It is the voltage that appears between the earth and the neutral point of the electric circuit when
上記(3)式において、
EU;U相の相電圧
YU;U相(電路(ロ)の相)
の大地に対するアド
ミタンスで、Yv冨jwcH+−
11
Yy:V相(電路■の相)の大地に対す
す
るアドミタンスで、Yy= jw C12+−12
Yw:W相([路(2)の相)の大地に対すす
るアドミタンスで、Yw== jWcts ”=この等
価回路において、電路の絶縁抵抗Rが十分大きいときに
は浮遊容量Cが放電しないので、充電電流■は零である
が、電路の絶縁抵抗Rが低下すると、浮遊容量Cの電荷
が抵抗Rを通じて放電されるため、浮遊容量Cの両端の
電圧■。In the above equation (3), EU: Phase voltage of U phase YU: Admittance of U phase (phase of electric circuit (B)) to the ground, YvFujwcH+- 11 Yy: Phase voltage of phase V (phase of electric circuit (■)) to the ground. The admittance to the ground is Yy = jw C12+-12 Yw: The admittance of the W phase ([path (2) phase) to the ground] Yw = = jWcts ” = In this equivalent circuit, if the insulation resistance R of the electrical circuit is sufficient When it is large, the stray capacitance C does not discharge, so the charging current ■ is zero. However, when the insulation resistance R of the circuit decreases, the charge of the stray capacitance C is discharged through the resistor R, so the voltage across the stray capacitance C increases .
が第6図のようにENのピース値よりも下り、電源周波
数の各サイクル毎に充電電流■。falls below the piece value of EN as shown in Figure 6, and the charging current ■ for each cycle of the power supply frequency.
が流れる。この充電電流■。flows. This charging current■.
と放電電流■。の間には次の関係がある。and discharge current■. There is the following relationship between them.
即ち、 Icの1サイクルの積分値(充電電荷量)二■。That is, The integral value of Ic for one cycle (amount of charge) 2■.
の1サイクルの積分値(放電電荷量) これはまた次の関係でもある。Integral value of 1 cycle (discharged charge amount) This is also the following relationship.
Icの平均値”IDの平均値 また、放電電流■。Average value of Ic” Average value of ID Also, the discharge current ■.
は11.)平均値= 7°の平均値 であり、さらに電圧V。is 11. ) Average value = Average value of 7° In addition, the voltage V.
と電圧ENの関係は回路の特定器CXRにより一意的に
定まる。The relationship between the voltage EN and the voltage EN is uniquely determined by the circuit specifyer CXR.
■・の実効値 =、(。■・Effective value =, (.
R)ENの実効値
以上の関係より、検出装置7を流れる充電電流Icと、
電路と大地間の絶縁抵抗Rには下記の関係があり、電圧
ENと浮遊容量Cに時間的変化が無ければ、充電電流I
Cの大きさを検出することで絶縁抵抗Rの低下を知るこ
とができた。R) From the relationship above the effective value of EN, the charging current Ic flowing through the detection device 7,
The insulation resistance R between the electric circuit and the ground has the following relationship, and if there is no temporal change in the voltage EN and stray capacitance C, the charging current I
By detecting the magnitude of C, it was possible to know the decrease in insulation resistance R.
即ち、
■・の平均値=8・0実効値 ・/(CR)しかし、上
記の説明中にもある様に、電圧EN、関数関数1共方共
遊容量Cの関数となっており、浮遊容量Cに影響される
ため、検出装置7の感度を電路毎に設定したり、また、
浮遊容量Cの変動の有るところで゛は使用で゛きず、こ
れらのことから検出の精度を上げることも難しかった。That is, the average value of ■・=8・0 effective value ・/(CR) However, as mentioned in the above explanation, the voltage EN and the function 1 are both functions of the mutual stray capacitance C, and the stray Since it is affected by the capacitance C, the sensitivity of the detection device 7 may be set for each circuit, or
It cannot be used where there are fluctuations in the stray capacitance C, and for these reasons, it has been difficult to improve the detection accuracy.
この考案は上記のような欠点を除去するためになされた
もので、電路の浮遊容量と並列に、浮遊容量の約10倍
位の静電容量を持つコンテ゛ンサを挿入することにより
、各相の電路の浮遊容量が時間的に多少変動しても、そ
の浮遊容量の影響を小さくして電路の絶縁抵抗を正確に
検出できる装置を提供することを目的とする。This idea was made to eliminate the above-mentioned drawbacks, and by inserting a capacitor with a capacitance approximately 10 times the stray capacitance in parallel with the stray capacitance of the circuit, the circuit of each phase can be improved. It is an object of the present invention to provide a device that can accurately detect the insulation resistance of an electric circuit by reducing the influence of the stray capacitance even if the stray capacitance changes somewhat over time.
以下この考案の一実施例を第3図、第4図に基いて説明
する。An embodiment of this invention will be described below with reference to FIGS. 3 and 4.
第3図において、1,2,3は配電線路(以下電路とい
う)、4は変圧器、5は電流制限用抵抗器、6はダイオ
ード、7は検出装置、7Aは検出用抵抗器、7Bは平均
値検出形電圧増幅作動装置、8は電源用変圧器、11,
12.13は対地浮遊静電容量(以下浮遊容量という)
であり、これらは接続関係も含めて総べて第1図に示し
たものと同じである。In Fig. 3, 1, 2, and 3 are distribution lines (hereinafter referred to as electric lines), 4 is a transformer, 5 is a current limiting resistor, 6 is a diode, 7 is a detection device, 7A is a detection resistor, and 7B is a average value detection type voltage amplification operating device; 8 is a power supply transformer; 11;
12.13 is floating capacitance to ground (hereinafter referred to as stray capacitance)
These are all the same as shown in FIG. 1, including connection relationships.
14はこの考案の要旨となるコンデンサで、電路3と大
地間にのみあって、上記浮遊容量11,12.13と並
列に挿入されている。A capacitor 14 is the gist of this invention, and is located only between the electric line 3 and the ground, and is inserted in parallel with the stray capacitances 11, 12, and 13.
なお、第4図は等価回路を示し、コンテ゛ンサ14を挿
入している以外は第2図に示す等価回路と同じである。Note that FIG. 4 shows an equivalent circuit, which is the same as the equivalent circuit shown in FIG. 2 except that a capacitor 14 is inserted.
つぎにこの考案の装置の作用について説明すると、第4
図の等価回路において、電路の絶縁が良好なとき、即ち
絶縁抵抗Rが非常に大きい場合には、浮遊容量Cはダイ
オード6により整流された直流で充電される。Next, to explain the operation of the device of this invention, the fourth
In the equivalent circuit shown in the figure, when the insulation of the electric path is good, that is, when the insulation resistance R is very large, the stray capacitance C is charged with direct current rectified by the diode 6.
コンテ゛ンサ14も同様に充電される。このとき充電電
流が流れるので検出用抵抗器7Aの両端には電圧信号が
短時間現われる。Container 14 is also charged in the same way. At this time, since a charging current flows, a voltage signal appears for a short time at both ends of the detection resistor 7A.
しかし、絶縁抵抗Rの値が大きいことから放電時定数が
太きくなるので、浮遊容量Cおよびコンデンサ14は放
電せず充電された状態を維持し、その後は充電電流は流
れない。However, since the value of the insulation resistance R is large, the discharge time constant becomes thick, so the stray capacitance C and the capacitor 14 are not discharged but remain charged, and no charging current flows thereafter.
つぎに電路の絶縁状態が悪化し、絶縁抵抗Rの値が大地
に対して数10OKΩ程度に低下すると、放電時定数R
XCの値が小さくなって充放電が繰返されることになる
。Next, when the insulation condition of the electrical circuit deteriorates and the value of the insulation resistance R decreases to about several tens of ohms with respect to the ground, the discharge time constant R
The value of XC becomes small and charging and discharging are repeated.
これは第4図に示す等価回路で説明すると、コンテ゛ン
サ14が1相にのみ接続されているため、電路は大地に
対し不平衡になり、電圧ENの値は前記(1)式と、C
工s + C12+ C13<C14の関係より、IE
、N”:”EUとなって電源電圧と相電圧とがほぼ等し
くなる。This can be explained using the equivalent circuit shown in FIG. 4. Since the capacitor 14 is connected to only one phase, the electric path becomes unbalanced with respect to the ground, and the value of the voltage EN is determined by the above equation (1) and C
From the relationship of engineering + C12 + C13<C14, IE
, N":"EU, and the power supply voltage and the phase voltage are approximately equal.
また、電圧■。Also, the voltage ■.
と電圧ENの関係も、コンデンサ14が固定されている
ため、絶縁抵抗Rの値によってのみ定まり、
7°0平均値 −4=f(C・4・R)
ENの実効値
とな 上記の関係から充電電流Icは、
亀
Icの平均値=
電源の相電圧EUの実効値 、、(。Since the capacitor 14 is fixed, the relationship between the voltage EN and the voltage EN is determined only by the value of the insulation resistance R, and the 7°0 average value -4=f(C・4・R) is the effective value of EN. The charging current Ic is calculated from: Average value of Ic = Effective value of power supply phase voltage EU , (.
、4.R)となって、電路の絶縁抵抗Rのみによって一
意的に定まる。,4. R), which is uniquely determined only by the insulation resistance R of the electric circuit.
この充電電流■。は検出用抵抗器7Aを流れ、その両端
に電圧信号を発生させる。This charging current■. flows through the detection resistor 7A and generates a voltage signal across it.
従って、この電圧信号を平均値検出形電圧増幅作動装置
7Bで検出することにより、電路1,2.3の絶縁低下
の状態を正確に把握できる。Therefore, by detecting this voltage signal with the average value detection type voltage amplification operating device 7B, it is possible to accurately grasp the state of insulation deterioration of the electric circuits 1, 2.3.
なお、上記実施例では電路3と大地間にのみコンデンサ
ー4を挿入したが、電路1または2と大地間の何れか一
方にのみ挿入しても同様の効果を奏することは明らかで
ある。In the above embodiment, the capacitor 4 is inserted only between the electric line 3 and the ground, but it is clear that the same effect can be obtained even if the capacitor 4 is inserted only between the electric line 1 or 2 and the ground.
また、変圧器4の低圧側中性点と大地間に電流制限用抵
抗器5、ダイオード6、検出装置7を挿入したが、第5
図に示すごとく、各相に電流制限用抵抗器5a、5b、
5Cを接続し、その中性点と大地間にダイオード6、検
出装置7を挿入しても差支えない。In addition, a current limiting resistor 5, a diode 6, and a detection device 7 were inserted between the low voltage side neutral point of the transformer 4 and the ground.
As shown in the figure, each phase has current limiting resistors 5a, 5b,
5C and inserting a diode 6 and a detection device 7 between the neutral point and the ground.
更に検出装置7は単に高感度の直流電流計であっても、
それが平均値指示をするため絶縁抵抗Rを流れる電流は
確認できる。Furthermore, even if the detection device 7 is simply a highly sensitive DC ammeter,
Since it indicates the average value, the current flowing through the insulation resistance R can be checked.
また、上記第3図の実施例における電圧増幅作動装置7
Bの代用として直流電圧計を用いても、それが平均値指
示をするため絶縁抵抗Rを流れる電流を確認できる。Further, the voltage amplification operating device 7 in the embodiment shown in FIG.
Even if a DC voltmeter is used as a substitute for B, the current flowing through the insulation resistance R can be checked because it indicates the average value.
以上のようにこの考案によれば、電路の中性点と大地間
に、電流制限用抵抗器、ダイオード、平均値検出形検出
装置を直列に接続し、更に電路の浮遊容量と並列に電路
の1線にのみコンデンサを挿入したので、電路の絶縁抵
抗が低下して地絡を生じたとしても、浮遊容量に基く影
響を生ぜず、従って電路の絶縁抵抗が低下した状態を正
確に検出できる装置となる。As described above, according to this invention, a current limiting resistor, a diode, and an average value detection type detector are connected in series between the neutral point of the electric circuit and the earth, and the electric current limiting resistor, a diode, and an average value detection type detector are connected in series, and the electric current limiting resistor, a diode, and an average value detection type detector are connected in series with each other. Since a capacitor is inserted only in one wire, even if the insulation resistance of the electrical circuit decreases and a ground fault occurs, there will be no effect due to stray capacitance, and therefore the device can accurately detect the state in which the insulation resistance of the electrical circuit has decreased. becomes.
第1図は従来考えられていた装置の回路構成図、第2図
はその等価回路図、第3図はこの考案の一実施例を示す
装置の回路構成図、第4図はその等価回路図、第5図は
他の実施例の回路構成図、第6図は動作説明用の電圧電
流波形図である。
図中、1,2,3は電路、5は電流制限用抵抗器、6は
ダイオード、7は平均値検出形検出装置、7Aは検出用
抵抗圧、7Bは平均値検出形電圧増幅作動装置、11,
12.13は浮遊静電容量、14はコンデンサである。
なお、図中同一符号は夫々同一または相当部分を示す。Figure 1 is a circuit configuration diagram of a conventional device, Figure 2 is its equivalent circuit diagram, Figure 3 is a circuit diagram of a device showing an embodiment of this invention, and Figure 4 is its equivalent circuit diagram. , FIG. 5 is a circuit configuration diagram of another embodiment, and FIG. 6 is a voltage and current waveform diagram for explaining the operation. In the figure, 1, 2, 3 are electric circuits, 5 is a current limiting resistor, 6 is a diode, 7 is an average value detection type detection device, 7A is a detection resistance voltage, 7B is an average value detection type voltage amplification operating device, 11,
12 and 13 are floating capacitances, and 14 is a capacitor. Note that the same reference numerals in the figures indicate the same or corresponding parts.
Claims (5)
用抵抗器、整流器、および上記電路と大地間の絶縁抵抗
に対応する地絡電流の平均値を検出する検出装置と、上
記電路の1線のみと大地間に接続されたコンデンサとを
備え、上記コンデンサにより上記電路を大地に対し不平
衡にし、上記電路と大地間に生じる浮遊静電容量を上記
コンテ゛ンサにより無視しうるようにしたことを特徴と
する電路絶縁抵抗監視装置。(1) A current-limiting resistor and a rectifier connected in series between the neutral point of the electric path and the ground, and a detection device that detects the average value of the ground fault current corresponding to the insulation resistance between the electric path and the earth; A capacitor is connected between only one wire of the electric circuit and the ground, and the electric circuit is made unbalanced with respect to the earth by the capacitor, so that the stray capacitance generated between the electric circuit and the earth can be ignored by the capacitor. A circuit insulation resistance monitoring device characterized by:
接続して形成したことを特徴とす、る実用新案登録請求
の範囲第1項記載の電路絶縁抵抗監視装置。(2) A circuit insulation resistance monitoring device according to claim 1, wherein the neutral point of the circuit is formed by connecting a current limiting resistor to each phase of the circuit.
用新案登録請求の範囲第1項または第2項記載の電路絶
縁抵抗監視装置。(3) The circuit insulation resistance monitoring device according to claim 1 or 2, wherein the detection device is a DC ammeter.
並列接続された直流電圧計とにより構成されていること
を特徴とする実用新案登録請求の範囲第1項または第2
項記載の電路絶縁抵抗監視装置。(4) Claims 1 or 2 for registration of a utility model, characterized in that the detection device is composed of a detection resistor and a DC voltmeter connected in parallel to the detection resistor.
The circuit insulation resistance monitoring device described in Section 1.
並列接続された平均値検出形電圧増幅作動装置とにより
構成されていることを特徴とする実用新案登録請求の範
囲第1項または第2項記載の電路絶縁抵抗監視装置。(5) Utility model registration claim 1, characterized in that the detection device is constituted by a detection resistor and an average value detection type voltage amplification operating device connected in parallel to the detection resistor. Or the circuit insulation resistance monitoring device according to item 2.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP132877U JPS5836195Y2 (en) | 1977-01-10 | 1977-01-10 | Electric circuit insulation resistance monitoring device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP132877U JPS5836195Y2 (en) | 1977-01-10 | 1977-01-10 | Electric circuit insulation resistance monitoring device |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5396636U JPS5396636U (en) | 1978-08-05 |
JPS5836195Y2 true JPS5836195Y2 (en) | 1983-08-15 |
Family
ID=28688359
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP132877U Expired JPS5836195Y2 (en) | 1977-01-10 | 1977-01-10 | Electric circuit insulation resistance monitoring device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5836195Y2 (en) |
-
1977
- 1977-01-10 JP JP132877U patent/JPS5836195Y2/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
JPS5396636U (en) | 1978-08-05 |
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