JP3041207B2 - Oil-filled transformer insulation diagnostic device - Google Patents

Oil-filled transformer insulation diagnostic device

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Publication number
JP3041207B2
JP3041207B2 JP6272639A JP27263994A JP3041207B2 JP 3041207 B2 JP3041207 B2 JP 3041207B2 JP 6272639 A JP6272639 A JP 6272639A JP 27263994 A JP27263994 A JP 27263994A JP 3041207 B2 JP3041207 B2 JP 3041207B2
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JP
Japan
Prior art keywords
insulation resistance
oil
value
resistance value
insulation
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
Application number
JP6272639A
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Japanese (ja)
Other versions
JPH08136597A (en
Inventor
直也 山田
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.)
Mitsubishi Electric Building Techno-Service Co Ltd
Original Assignee
Mitsubishi Electric Building Techno-Service Co Ltd
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Priority to JP6272639A priority Critical patent/JP3041207B2/en
Publication of JPH08136597A publication Critical patent/JPH08136597A/en
Application granted granted Critical
Publication of JP3041207B2 publication Critical patent/JP3041207B2/en
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  • Measurement Of Resistance Or Impedance (AREA)
  • Testing Electric Properties And Detecting Electric Faults (AREA)
  • Housings And Mounting Of Transformers (AREA)

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【産業上の利用分野】この発明は、油入変圧器の絶縁診
断を非停電下（活線下）で実施するようにした油入変圧
器の絶縁診断装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulation diagnosis apparatus for an oil-filled transformer in which the insulation diagnosis of the oil-filled transformer is performed without power interruption (under a live line).

【０００２】[0002]

【従来の技術】ビル電気室等に据え付けられている配電
用変圧器の絶縁管理を行うものとして、最近、活線下に
て絶縁診断できる装置が使用されてきている。図６は例
えば特開平４ー２０８８６８号公報に開示された電気機
器の非停電絶縁診断装置を示す構成図である。図６にお
いて、１は母線、２は母線１から課電される受変電設備
機器としての被診断機器、３は母線１により同時に課電
される隣接の受変電機器、４は接地線、５は被診断機器
２の接地線４にクランプされるクランプ型変成器、６は
高周波電源、７は断路器、８は母線１に断路器７を介し
て給電する引込ケーブルの母線、９は引込ケーブル、１
０はケーブルを一括するクランプ型の電流センサ、１１
は計測部である。2. Description of the Related Art Insulation management of a distribution transformer installed in an electric room of a building or the like has recently been performed using a device capable of performing insulation diagnosis under a live line. FIG. 6 is a block diagram showing a non-power failure insulation diagnosis device for electric equipment disclosed in, for example, Japanese Patent Application Laid-Open No. 4-208868. In FIG. 6, 1 is a bus, 2 is a device to be diagnosed as a power receiving / transforming facility device to which power is applied from the bus 1, 3 is an adjacent power receiving / transforming device that is simultaneously powered by the bus 1, 4 is a ground wire, and 5 is a ground wire. A clamp-type transformer clamped to the ground wire 4 of the device under diagnosis 2; 6 a high-frequency power supply; 7 a disconnector; 8 a bus of a drop cable for supplying power to the bus 1 via the disconnector 7; 1
0 is a clamp type current sensor that bundles cables, 11
Is a measuring unit.

【０００３】上記のように構成された電気機器の非停電
絶縁診断装置において、被診断機器２の接地線４に磁気
結合されたクランプ型変成器５を高周波電源６により励
磁すると、接地線４のａ点に高周波電圧ＶS が誘導さ
れ、被診断機器２の絶縁抵抗Ｒｘと静電容量Ｃｘを経由
して漏れ電流Ｉｘが引込ケーブル９を介して電源側に流
出するので、これを引込ケーブル９に一括してクランプ
した電流センサ１０によって検出することができる。こ
れらの高周波電圧ＶS及び漏れ電流ＩXを入力する計測部
１１は、図７に示すベクトル図のように、基準ベクトル
となる高周波電圧ＶS に同相の電流成分ＩRXと、π／２
進みの電流成分ＩCXとに弁別し、最終的に誘電正接ｔａ
ｎδ、絶縁抵抗ＲX及び静電容量ＣXを表示する。In the non-interruptible insulation diagnostic apparatus for electric equipment configured as described above, when the clamp-type transformer 5 magnetically coupled to the ground wire 4 of the equipment under test 2 is excited by the high-frequency power supply 6, A high-frequency voltage V S is induced at the point a, and a leakage current Ix flows to the power supply side via the lead-in cable 9 via the insulation resistance Rx and the capacitance Cx of the device under diagnosis 2. The current can be detected by the current sensor 10 which is collectively clamped. As shown in the vector diagram of FIG. 7, the measuring unit 11 that inputs the high-frequency voltage V S and the leakage current IX outputs a current component I RX in phase with the high-frequency voltage V S serving as a reference vector, and π / 2.
Discriminated from the leading current component I CX and finally the dielectric loss tangent ta
nδ, insulation resistance R X and capacitance C X are displayed.

【０００４】[0004]

【発明が解決しようとする課題】上述した従来装置は活
線の状態で電気機器の絶縁状態が計測可能であり、この
ため多くのメリットを与えるものの、この装置により得
られる絶縁抵抗ＲX は交流に対するものであり、この装
置が出現するまでに慣用されていたメガー等による直流
絶縁抵抗とは相異なるものゆえ、両者を突き合わせたト
レンド的な絶縁管理を困難なものとしているという問題
点があった。SUMMARY OF THE INVENTION The above-mentioned conventional apparatus is not active.
Insulated electrical equipment in the form of a line are possible measure, although this order provides many benefits, the insulation resistance R X obtained by this apparatus is for AC, is conventionally up to this device appears There is a problem that it is difficult to perform a trendy insulation management that matches the two because it is different from a DC insulation resistance by a megger or the like.

【０００５】この発明は上述した従来例にかかる問題点
を解消するためになされたもので、非停電下での絶縁診
断によって得られた交流絶縁抵抗を直流絶縁抵抗に換算
して、非停電下で直流絶縁抵抗をも得ることができ、停
電の制約なしに絶縁抵抗の傾向管理が行い得る油入変圧
器の絶縁診断装置を得ることを目的とする。SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the prior art, and converts an AC insulation resistance obtained by an insulation diagnosis under a non-power failure into a DC insulation resistance to obtain a DC insulation resistance. An object of the present invention is to obtain an insulation diagnosis device for an oil-filled transformer, which can also obtain a DC insulation resistance and can manage the insulation resistance tendency without restriction of a power failure.

【０００６】[0006]

【課題を解決するための手段】この発明に係る油入変圧
器の絶縁診断装置は、被診断機器としての油入変圧器の
接地線に磁気結合された変成器を高周波電源により励磁
することにより、上記接地線に誘導される高周波電圧と
該油入変圧器を経由して電源側に流出する漏れ電流とを
検出し、それら検出値に基づいて油入変圧器の絶縁診断
を行う計測部を備えた油入変圧器の絶縁診断装置におい
て、上記油入変圧器の油温を検出する油温検出器を備え
ると共に、上記計測部として、上記油入変圧器の油温に
対する直流絶縁抵抗値と交流絶縁抵抗値の比の値を予め
記憶してなるメモリと、上記高周波電圧と漏れ電流との
検出値に基づいて油入変圧器の交流絶縁抵抗値及び静電
容量を求める第１の演算部と、上記油温検出器による油
温検出値及び上記第１の演算部により求められた静電容
量の値に応じた直流絶縁抵抗値と交流絶縁抵抗値の比の
値を上記メモリから読み出し、その比の値から上記第１
の演算部により求められた交流絶縁抵抗値を直流絶縁抵
抗値に換算して直流絶縁抵抗値を求める第２の演算部と
を備えたことを特徴とするものである。An oil-immersed transformer insulation diagnostic apparatus according to the present invention is provided by exciting a transformer magnetically coupled to a ground wire of an oil-immersed transformer as a device to be diagnosed with a high-frequency power supply. A measuring unit that detects a high-frequency voltage induced in the ground line and a leakage current flowing out to the power supply side via the oil-immersed transformer and performs insulation diagnosis of the oil-immersed transformer based on the detected values. The oil-immersed transformer insulation diagnostic device provided with an oil temperature detector that detects the oil temperature of the oil-immersed transformer, and as the measurement unit, a DC insulation resistance value with respect to the oil temperature of the oil-immersed transformer. A memory in which a value of the ratio of the AC insulation resistance is stored in advance, and a first arithmetic unit for obtaining the AC insulation resistance and the capacitance of the oil-immersed transformer based on the detected values of the high-frequency voltage and the leakage current And the oil temperature detected value by the oil temperature detector and the above The value of the ratio of the DC insulation resistance and AC insulation resistance value corresponding to the value of the capacitance obtained by the first arithmetic unit read out from the memory, the first from the value of the ratio
And a second calculating unit for converting the AC insulation resistance value obtained by the calculation unit into a DC insulation resistance value to obtain a DC insulation resistance value.

【０００７】[0007]

【作用】この発明に係る油入変圧器の絶縁診断装置にお
いては、計測部内のメモリに、油入変圧器の油温に対す
る直流絶縁抵抗値と交流絶縁抵抗値の比の値を予め記憶
させ、油温検出器により、油入変圧器の油温を検出し、
計測部内の第１の演算部により、高周波電圧と漏れ電流
との検出値に基づいて油入変圧器の交流絶縁抵抗値及び
静電容量を求め、第２の演算部により、上記油温検出器
による油温検出値及び上記第１の演算部により求められ
た静電容量の値に応じた直流絶縁抵抗値と交流絶縁抵抗
値の比の値を上記メモリから読み出し、その比の値から
上記第１の演算部により求められた交流絶縁抵抗値を直
流絶縁抵抗値に換算して直流絶縁抵抗値を求めることに
より、非停電下での絶縁診断によって得られた交流絶縁
抵抗を直流絶縁抵抗に換算して、非停電下で直流絶縁抵
抗をも得ることができ、停電の制約なしに絶縁抵抗の傾
向管理を行うことを可能にする。In the insulation diagnostic apparatus for an oil-immersed transformer according to the present invention, the ratio of the DC insulation resistance value to the AC insulation resistance value with respect to the oil temperature of the oil-immersed transformer is previously stored in a memory in the measuring unit. The oil temperature detector detects the oil temperature of the oil-immersed transformer,
The first arithmetic unit in the measuring unit obtains the AC insulation resistance value and the capacitance of the oil-immersed transformer based on the detected values of the high-frequency voltage and the leakage current, and the second arithmetic unit calculates the oil temperature detector. The value of the ratio between the DC insulation resistance value and the AC insulation resistance value according to the oil temperature detection value and the capacitance value obtained by the first arithmetic unit is read out from the memory, and the value of the ratio is read from the memory. The AC insulation resistance obtained by the insulation diagnosis under no power failure is converted to the DC insulation resistance by calculating the DC insulation resistance by converting the AC insulation resistance obtained by the operation unit 1 into the DC insulation resistance. As a result, a DC insulation resistance can be obtained even without a power failure, and the trend of the insulation resistance can be managed without restriction of the power failure.

【０００８】[0008]

【実施例】以下、この発明を図示実施例に基づいて説明
する。図１はこの発明の一実施例に係る油入変圧器の絶
縁診断装置を示す構成図である。図１において、図６に
示す従来例と同一部分は同一符号を示し、１は母線、２
Ａは母線１から課電される受変電設備機器としての被診
断機器である油入変圧器、３は母線１により同時に課電
される隣接の受変電機器、４は接地線、５は油入変圧器
２Ａの接地線４にクランプされるクランプ型変成器、６
は高周波電源、７は断路器、８は母線１に断路器７を介
して給電する引込ケーブルの母線、９は引込ケーブル、
１０はケーブルを一括するクランプ型の電流センサであ
る。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a configuration diagram showing an insulation diagnosis device for an oil-filled transformer according to one embodiment of the present invention. In FIG. 1, the same parts as those in the conventional example shown in FIG.
A is an oil-immersed transformer that is a device to be diagnosed as a substation equipment to be charged from the bus 1, 3 is an adjacent substation that is simultaneously charged by the bus 1, 4 is a ground line, 5 is an oil-filled A clamp type transformer clamped to the ground wire 4 of the transformer 2A, 6
Is a high-frequency power supply, 7 is a disconnector, 8 is a bus of a drop cable that supplies power to the bus 1 via the disconnector 7, 9 is a drop cable,
Reference numeral 10 denotes a clamp-type current sensor that bundles cables.

【０００９】また、新たな構成としての符号１２は上記
油入変圧器２Ａ内の油温を検出する油温検出器、１３は
上記高周波電源６による油入変圧器２Ａの接地線４に磁
気結合されたクランプ型変成器５の励磁により該接地線
４のａ点に誘導される高周波電圧ＶS と電流センサ１０
による漏れ電流Ｉｘの検出値及び上記油温検出器１２に
よる油温検出値に基づいて交流絶縁抵抗値ＲACを求める
と共にその交流絶縁抵抗値ＲACを直流絶縁抵抗値ＲDCに
換算して直流絶縁抵抗値ＲDC求め交流絶縁抵抗値ＲACと
直流絶縁抵抗値ＲDCとを対比させた評価を可能にする計
測部である。Reference numeral 12 as a new configuration is an oil temperature detector for detecting the oil temperature in the oil-immersed transformer 2A, and 13 is magnetically coupled to the ground line 4 of the oil-immersed transformer 2A by the high-frequency power source 6. Of the high frequency voltage V S induced at the point a of the ground line 4 by the excitation of the clamped transformer 5 and the current sensor 10
DC in terms of its AC insulation resistance R AC with obtaining an AC insulation resistance R AC on the basis of the detected value and the detected value the oil temperature by the oil temperature detector 12 of the leakage current Ix to the DC insulation resistance R DC by This is a measuring unit that enables the evaluation in which the insulation resistance value R DC is obtained and the AC insulation resistance value R AC is compared with the DC insulation resistance value R DC .

【００１０】ここで、上記計測部１３には、図２に示す
ように、油入変圧器２Ａの油温Ｔに対する直流絶縁抵抗
値ＲDCと交流絶縁抵抗値ＲACの比αの値を予め記憶して
なるメモリ１３ａと、上記接地線４のａ点に誘導される
高周波電圧ＶS と電流センサ１０による漏れ電流Ｉｘの
検出値に基づいて油入変圧器２Ａの交流絶縁抵抗値ＲAC
及び静電容量ＣX を求める第１の演算部１３ｂと、上記
油温検出器１２による油温検出値Ｔ及び上記第１の演算
部１３ｂにより求められた静電容量ＣX の値に応じた直
流絶縁抵抗値ＲDCと交流絶縁抵抗値ＲACの比αの値を上
記メモリ１３ａから読み出し、その比αの値から上記第
１の演算部１３ｂにより求められた交流絶縁抵抗値ＲAC
を直流絶縁抵抗値ＲDCに換算して直流絶縁抵抗値ＲDCを
求める第２の演算部１３ｃとを備えている。なお、図２
において、第２の演算部１３ｃからメモリ１３ａに向け
た点線で示す矢印は第２の演算部１３ｃによるメモリ１
３ａに対する読み出し制御信号を示し、また、第１の演
算部１３ｂとしては、上記交流絶縁抵抗値ＲAC及び静電
容量ＣX の他に誘電正接ｔａｎδが求められるようにな
され、計測部１３の出力としては、交流絶縁抵抗値ＲAC
と直流絶縁抵抗値ＲDCの他に、静電容量ＣX 及び誘電正
接ｔａｎδも出力でき、絶縁診断の総合的な評価に供さ
れる。Here, as shown in FIG. 2, the measuring unit 13 previously stores the value of the ratio α between the DC insulation resistance value R DC and the AC insulation resistance value R AC with respect to the oil temperature T of the oil-immersed transformer 2A. The AC insulation resistance value R AC of the oil-filled transformer 2A is determined based on the stored memory 13a, the high-frequency voltage V S induced at the point a of the ground line 4, and the leakage current Ix detected by the current sensor 10.
And a first calculating unit 13b for calculating the capacitance C X and an oil temperature detected value T by the oil temperature detector 12 and a value of the capacitance C X obtained by the first calculating unit 13b. The value of the ratio α between the DC insulation resistance value R DC and the AC insulation resistance value R AC is read from the memory 13a, and the AC insulation resistance value R AC obtained by the first arithmetic unit 13b from the value of the ratio α is read.
To a DC insulation resistance value R DC , and obtains a DC insulation resistance value R DC . Note that FIG.
, The arrow indicated by a dotted line from the second operation unit 13c to the memory 13a indicates the memory 1 by the second operation unit 13c.
3a, and the first arithmetic unit 13b calculates the dielectric loss tangent tan δ in addition to the AC insulation resistance value R AC and the capacitance C X. Is the AC insulation resistance value R AC
The capacitance C X and the dielectric loss tangent tan δ can also be output in addition to the DC insulation resistance value R DC and the DC insulation resistance value R DC , and are used for comprehensive evaluation of insulation diagnosis.

【００１１】また、図３は例えば定格電圧６．６ＫＶ〜
２２ＫＶ未満の油入変圧器２Ａの油温に対する直流絶縁
抵抗値ＲDCと交流絶縁抵抗値ＲACの比αの値を予め記憶
してなるメモリ１３ａ内の記憶内容を説明するもので、
静電容量Ｃｘをパラメータとして、油入変圧器２Ａの油
温Ｔを横軸としたとき、油入変圧器２Ａの直流絶縁抵抗
値ＲDCと交流絶縁抵抗値ＲACの比αを縦軸として示した
絶縁抵抗の交流値と直流値の交直換算を可能とするもの
である。例えば油温Ｔが４０℃下で油入変圧器２Ａによ
り得られた交流絶縁抵抗ＲACが１００ＭΩのとき、同時
に得られた静電容量ＣXが２ｎＦであれば、α＝１５を
採用することにより直流絶縁抵抗ＲDCを１５００ＭΩと
推定することができる。FIG. 3 shows, for example, a rated voltage of 6.6 KV-
It describes the contents stored in the memory 13a in which the value of the ratio α of the DC insulation resistance value R DC and the AC insulation resistance value R AC to the oil temperature of the oil-immersed transformer 2A of less than 22 KV is stored in advance.
With the capacitance Cx as a parameter and the oil temperature T of the oil-immersed transformer 2A on the horizontal axis, the ratio α between the DC insulation resistance R DC and the AC insulation resistance R AC of the oil-immersed transformer 2A is expressed on the vertical axis. This enables AC-DC conversion of the indicated AC value and DC value of the insulation resistance. For example, if the AC insulation resistance R AC obtained by the oil-immersed transformer 2A at an oil temperature T of 40 ° C. is 100 MΩ and the simultaneously obtained capacitance C X is 2 nF, α = 15 should be adopted. Thus, the DC insulation resistance R DC can be estimated to be 1500 MΩ.

【００１２】図３において、パラメータとする静電容量
Ｃｘの５本の実線（Ｃｘ＝１、２、３、５、１０ｎＦに
対応）は、図４に示す従来から慣用されて来た直流絶縁
抵抗ＲDCの許容値カーブ及び図５に示す誘電正接ｔａｎ
δの判定基準に基づいて以下の手順により導出されたも
のである。今、油入変圧器の絶縁状態を静電容量Ｃｘと
絶縁抵抗Ｒｘの並列等価回路で表せば、交流誘電正接ｔ
ａｎδは下式となる。 ｔａｎδ＝１／（２πｆＣｘＲｘ） ・・・（１） ここで、ｆは交流課電の周波数である。（１）式の絶縁
抵抗Ｒｘを交流絶縁抵抗ＲACと置き換えれば ＲAC＝１／（２πｆＣｘｔａｎδ） ・・・（２） となるので、図５に示す判定カーブの不良域下限のｔａ
ｎδ値から各種の静電容量Ｃｘに対応した交流絶縁抵抗
ＲACの許容値を（２）式から演算できることになる。一
方、図４により直流絶縁抵抗ＲDCの許容値が与えられて
いるので、例えば定格電圧６．６ＫＶ〜２２ＫＶ未満の
油入変圧器では、図３に示すようなα＝ＲDC／ＲAC対油
温の換算カーブが導出されることとなる。In FIG. 3, five solid lines (corresponding to Cx = 1, 2, 3, 5, 10 nF) of the capacitance Cx as a parameter are the DC insulation resistance conventionally used and shown in FIG. The allowable value curve of R DC and the dielectric loss tangent tan shown in FIG.
It is derived by the following procedure based on the criterion of δ. Now, if the insulation state of the oil-immersed transformer is represented by a parallel equivalent circuit of the capacitance Cx and the insulation resistance Rx, the AC dielectric loss tangent t
anδ is given by the following equation. tan δ = 1 / (2πfCxRx) (1) where f is the frequency of AC power application. If the insulation resistance Rx in the equation (1) is replaced by the AC insulation resistance R AC , R AC = 1 / (2πfCxtan δ) (2)
From the nδ value, the allowable value of the AC insulation resistance R AC corresponding to various capacitances Cx can be calculated from the equation (2). On the other hand, since the allowable value of the DC insulation resistance R DC is given in FIG. 4, for example, in an oil-filled transformer having a rated voltage of 6.6 KV to less than 22 KV, α = R DC / R AC as shown in FIG. An oil temperature conversion curve is derived.

【００１３】図３に示す換算図中、Ａ〜Ｄのマーキング
は、数種類の稼動中の高圧変圧器について実際に測定し
た直流絶縁抵抗ＲDCと交流絶縁抵抗ＲACの比αを静電容
量Ｃｘと共にプロットした（３φ２００ＫＶＡとは、三
相変圧器で定格容量２００ＫＶＡを示す）結果で、これ
らの結果から、本発明によって導出された交流絶縁抵抗
ＲACと直流絶縁抵抗ＲDCの換算図から、非停電絶縁診断
装置としての油入変圧器によって得られた交流絶縁抵抗
ＲACを良い精度にて直流絶縁抵抗ＲDCに換算できるとい
う効果が得られることが検証された。In the conversion diagram shown in FIG. 3, markings A to D indicate the ratio α of the DC insulation resistance R DC and the AC insulation resistance R AC actually measured for several types of operating high-voltage transformers to the capacitance Cx. (3φ200 KVA indicates a rated capacity of 200 KVA in a three-phase transformer). From these results, the conversion diagram of the AC insulation resistance R AC and the DC insulation resistance R DC derived by the present invention shows that It has been verified that the effect that the AC insulation resistance R AC obtained by the oil-immersed transformer as the power failure insulation diagnosis device can be converted to the DC insulation resistance R DC with good accuracy can be obtained.

【００１４】すなわち、図１に示す油入変圧器の絶縁診
断装置において、被診断機器としての油入変圧器２Ａの
接地線４に磁気結合されたクランプ型変成器５を高周波
電源６により励磁すると、接地線４のａ点に高周波電圧
ＶS が誘導され、油入変圧器２Ａの絶縁抵抗Ｒｘと静電
容量Ｃｘを経由して漏れ電流Ｉｘが引込ケーブル９を介
して電源側に流出するので、これを引込ケーブル９に一
括してクランプした電流センサ１０によって検出するこ
とができる。That is, in the insulation diagnosis apparatus for an oil-immersed transformer shown in FIG. 1, when a clamp-type transformer 5 magnetically coupled to the ground wire 4 of the oil-immersed transformer 2A as a device to be diagnosed is excited by a high-frequency power supply 6, , A high-frequency voltage V S is induced at the point a of the ground line 4, and the leakage current Ix flows to the power supply side via the drop cable 9 via the insulation resistance Rx and the capacitance Cx of the oil-immersed transformer 2A. This can be detected by the current sensor 10 which is collectively clamped to the lead-in cable 9.

【００１５】これらの高周波電圧ＶS及び漏れ電流ＩXを
入力する計測部１３は次のようにして油入変圧器２Ａの
交流絶縁抵抗ＲACを良い精度にて直流絶縁抵抗ＲDCに換
算する。まず、第１の演算部１３ｂにより、高周波電圧
ＶS 及び漏れ電流Ｉｘの検出値に基づいて油入変圧器２
Ａの交流絶縁抵抗値ＲAC及び静電容量Ｃｘが求められ、
この交流絶縁抵抗値ＲAC及び静電容量Ｃｘと共に油温検
出器１２による油温検出値を入力する第２の演算部１３
ｃにより、油温検出値及び静電容量ＣX の値に応じた直
流絶縁抵抗値ＲDCと交流絶縁抵抗値ＲACの比αの値をメ
モリ１３ａから読み出し、その比αの値から上記第１の
演算部１３ｂにより求められた交流絶縁抵抗値ＲACを直
流絶縁抵抗値ＲDCに換算して直流絶縁抵抗値ＲDCを求め
る。このようにして、計測部１３の出力としては、交流
絶縁抵抗値ＲACと直流絶縁抵抗値ＲDCの他に、このと
き、同時に第１の演算部１３ｂにより求められる静電容
量ＣX 及び誘電正接ｔａｎδも出力でき、絶縁診断の総
合的な評価に供される。The measuring unit 13 which inputs the high-frequency voltage V S and the leakage current IX converts the AC insulation resistance R AC of the oil-immersed transformer 2A into the DC insulation resistance R DC with good accuracy as follows. . First, the first calculation unit 13b performs an operation on the oil-filled transformer 2 based on the detection values of the high-frequency voltage V S and the leakage current Ix.
A AC insulation resistance value R AC and capacitance Cx of A are obtained,
A second calculating unit 13 for inputting the oil temperature detection value by the oil temperature detector 12 together with the AC insulation resistance value R AC and the capacitance Cx.
c, the value of the ratio α between the DC insulation resistance value R DC and the AC insulation resistance value R AC corresponding to the oil temperature detection value and the value of the capacitance C X is read from the memory 13a, and The DC insulation resistance value R DC is obtained by converting the AC insulation resistance value R AC obtained by the first calculation unit 13b into a DC insulation resistance value R DC . In this manner, the outputs of the measuring unit 13 include, besides the AC insulation resistance value R AC and the DC insulation resistance value R DC , the capacitance C X and the dielectric constant C X simultaneously obtained by the first calculation unit 13b. The tangent tan δ can also be output and used for comprehensive evaluation of insulation diagnosis.

【００１６】上述したように、上記実施例１によれば、
油入変圧器２Ａの接地線４に磁気結合されたクランプ型
変成器５を高周波電源６により励磁することにより、上
記接地線４に誘導される高周波電圧と該油入変圧器２Ａ
を経由して電源側に流出する漏れ電流とを検出し、それ
ら検出値に基づいて油入変圧器２Ａの絶縁診断を行う計
測部１３を備えた油入変圧器の絶縁診断装置において、
上記油入変圧器２Ａの油温を検出する油温検出器１２を
備えると共に、上記計測部１３として、上記油入変圧器
２Ａの油温に対する直流絶縁抵抗値と交流絶縁抵抗値の
比の値を予め記憶してなるメモリ１３ａと、上記高周波
電圧と漏れ電流との検出値に基づいて油入変圧器２Ａの
交流絶縁抵抗値及び静電容量を求める第１の演算部１３
ｂと、上記油温検出器１２による油温検出値及び上記第
１の演算部１３ｂにより求められた静電容量の値に応じ
た直流絶縁抵抗値と交流絶縁抵抗値の比の値を上記メモ
リ１３ａから読み出し、その比の値から上記第１の演算
部１３ｂにより求められた交流絶縁抵抗値を直流絶縁抵
抗値に換算して直流絶縁抵抗値を求める第２の演算部１
３ｃとを備えたので、非停電下での絶縁診断によって得
られた交流絶縁抵抗を直流絶縁抵抗に換算して、非停電
下で直流絶縁抵抗をも得ることができ、停電の制約なし
に絶縁抵抗の傾向管理が行い得る。As described above, according to the first embodiment,
By energizing a clamp-type transformer 5 magnetically coupled to the ground line 4 of the oil-immersed transformer 2A with a high-frequency power source 6, the high-frequency voltage induced on the ground line 4 and the oil-immersed transformer 2A are excited.
In the insulation diagnosis device for an oil-filled transformer provided with a measuring unit 13 which detects a leakage current flowing out to the power supply side via the measuring unit 13 and performs an insulation diagnosis of the oil-filled transformer 2A based on the detected values,
An oil temperature detector 12 for detecting the oil temperature of the oil-immersed transformer 2A is provided, and the measuring unit 13 is a ratio of a DC insulation resistance value to an AC insulation resistance value with respect to the oil temperature of the oil-immersed transformer 2A. And a first calculating unit 13 for obtaining the AC insulation resistance value and the capacitance of the oil-filled transformer 2A based on the detected values of the high-frequency voltage and the leakage current.
b, and the value of the ratio between the DC insulation resistance value and the AC insulation resistance value according to the oil temperature detection value obtained by the oil temperature detector 12 and the capacitance value obtained by the first calculation unit 13b. 13a, and converts the AC insulation resistance value obtained by the first calculation unit 13b into a DC insulation resistance value from the ratio value to obtain a DC insulation resistance value.
3c, the AC insulation resistance obtained by the insulation diagnosis under non-power failure can be converted to DC insulation resistance, and DC insulation resistance under non-power failure can also be obtained. Resistance trend management can be performed.

【００１７】実施例２．上述した実施例１では、定格電
圧６．６ＫＶ〜２２ＫＶ未満の油入変圧器についてのα
＝ＲAC／ＲDCの換算の導出について説明したが、図４に
示されたように他の三ケースの定格電圧の油入変圧器に
ついても同様に導出でき、同じ効果をもたらすことがで
きる。Embodiment 2 FIG. In the first embodiment described above, α for the oil-filled transformer having a rated voltage of 6.6 KV to less than 22 KV
Although the derivation of the conversion of = R AC / R DC has been described, as shown in FIG. 4, the oil-immersed transformer having the other three rated voltages can be similarly derived, and the same effect can be obtained.

【００１８】[0018]

【発明の効果】以上のように、この発明によれば、計測
部内のメモリに、油入変圧器の油温に対する直流絶縁抵
抗値と交流絶縁抵抗値の比の値を予め記憶させ、油温検
出器により、油入変圧器の油温を検出し、計測部内の第
１の演算部により、高周波電圧と漏れ電流との検出値に
基づいて油入変圧器の交流絶縁抵抗値及び静電容量を求
め、第２の演算部により、上記油温検出器による油温検
出値及び上記第１の演算部により求められた静電容量の
値に応じた直流絶縁抵抗値と交流絶縁抵抗値の比の値を
上記メモリから読み出し、その比の値から上記第１の演
算部により求められた交流絶縁抵抗値を直流絶縁抵抗値
に換算して直流絶縁抵抗値を求めるようにしたので、非
停電下での絶縁診断によって得られた交流絶縁抵抗を直
流絶縁抵抗に換算して、非停電下で直流絶縁抵抗をも得
ることができ、停電の制約なしに絶縁抵抗の傾向管理を
行い得るという効果がある。As described above, according to the present invention, the ratio of the DC insulation resistance value to the AC insulation resistance value with respect to the oil temperature of the oil-immersed transformer is previously stored in the memory in the measuring unit, The oil temperature of the oil-immersed transformer is detected by the detector, and the AC insulation resistance and the capacitance of the oil-immersed transformer are detected by the first arithmetic unit in the measuring unit based on the detected values of the high-frequency voltage and the leakage current. And a ratio of a DC insulation resistance value to an AC insulation resistance value corresponding to the oil temperature detection value obtained by the oil temperature detector and the capacitance value obtained by the first calculation unit is calculated by the second calculation unit. Is read out from the memory, and the DC insulation resistance value obtained by converting the AC insulation resistance value obtained by the first arithmetic unit into the DC insulation resistance value from the value of the ratio is obtained. Conversion of AC insulation resistance obtained by insulation diagnosis to DC insulation resistance Te, can be obtained a direct current insulation resistance under non power failure, there is an effect that, without the outage constraint may perform trend management of the insulation resistance.

【図面の簡単な説明】[Brief description of the drawings]

【図１】 この発明の実施例１に係る油入変圧器の絶縁
診断装置の全体構成図である。FIG. 1 is an overall configuration diagram of an insulation diagnosis device for an oil-immersed transformer according to a first embodiment of the present invention.

【図２】 図１の計測部内の構成図である。FIG. 2 is a configuration diagram of a measurement unit of FIG. 1;

【図３】 図１のメモリ内の記憶内容の説明図である。FIG. 3 is an explanatory diagram of contents stored in a memory of FIG. 1;

【図４】 図３に示す油温対直流絶縁抵抗と交流絶縁抵
抗との比を導出するためのもので、従来から慣用されて
きた直流絶縁抵抗の許容値カーブの説明図である。FIG. 4 is a diagram for deriving a ratio of oil temperature to DC insulation resistance and AC insulation resistance shown in FIG. 3, and is an explanatory diagram of a conventionally used allowable value curve of DC insulation resistance.

【図５】 図３に示す油温対直流絶縁抵抗と交流絶縁抵
抗との比を導出するためのもので、誘電正接の判定基準
の説明図である。5 is a diagram for deriving a ratio of oil temperature to DC insulation resistance and AC insulation resistance shown in FIG. 3, and is an explanatory diagram of a criterion for determining a dielectric loss tangent.

【図６】 従来の電気機器の非停電絶縁診断装置を示す
構成図である。FIG. 6 is a configuration diagram illustrating a conventional non-power failure insulation diagnosis device for electric equipment.

【図７】 高周波電圧ＶS と漏れ電流ＩX のベクトル図
である。7 is a vector diagram of a high frequency voltage V S and the leakage current I X.

【符号の説明】[Explanation of symbols]

２Ａ 油入変圧器、４ 接地線、５ クランプ型変成
器、６ 高周波電源、１０ 電流センサ、１２ 油温検
出器、１３ 計測部、１３ａ メモリ、１３ｂ第１の演
算部、１３ｃ 第２の演算部。2A oil-filled transformer, 4 ground wire, 5 clamp type transformer, 6 high frequency power supply, 10 current sensor, 12 oil temperature detector, 13 measuring unit, 13a memory, 13b first calculating unit, 13c second calculating unit .

Claims (1)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】 被診断機器としての油入変圧器の接地線
に磁気結合された変成器を高周波電源により励磁するこ
とにより、上記接地線に誘導される高周波電圧と該油入
変圧器を経由して電源側に流出する漏れ電流とを検出
し、それら検出値に基づいて油入変圧器の絶縁診断を行
う計測部を備えた油入変圧器の絶縁診断装置において、
上記油入変圧器の油温を検出する油温検出器を備えると
共に、上記計測部として、上記油入変圧器の油温に対す
る直流絶縁抵抗値と交流絶縁抵抗値の比の値を予め記憶
してなるメモリと、上記高周波電圧と漏れ電流との検出
値に基づいて油入変圧器の交流絶縁抵抗値及び静電容量
を求める第１の演算部と、上記油温検出器による油温検
出値及び上記第１の演算部により求められた静電容量の
値に応じた直流絶縁抵抗値と交流絶縁抵抗値の比の値を
上記メモリから読み出し、その比の値から上記第１の演
算部により求められた交流絶縁抵抗値を直流絶縁抵抗値
に換算して直流絶縁抵抗値を求める第２の演算部とを備
えたことを特徴とする油入変圧器の絶縁診断装置。1. A transformer magnetically coupled to a ground line of an oil-immersed transformer as a device to be diagnosed is excited by a high-frequency power supply to pass a high-frequency voltage induced on the ground line and the oil-immersed transformer. In the insulation diagnosis device of the oil-filled transformer having a measuring unit that detects the leakage current flowing out to the power supply side and performs an insulation diagnosis of the oil-filled transformer based on the detected values,
An oil temperature detector for detecting the oil temperature of the oil-immersed transformer is provided, and as the measuring unit, a value of a ratio of a DC insulation resistance value and an AC insulation resistance value to the oil temperature of the oil-immersed transformer is stored in advance. A first calculating unit for obtaining an AC insulation resistance value and a capacitance of an oil-immersed transformer based on the detected values of the high-frequency voltage and the leakage current; and a detected oil temperature value by the oil temperature detector. And reading a value of a ratio between a DC insulation resistance value and an AC insulation resistance value according to the value of the capacitance obtained by the first calculation unit from the memory, and from the ratio value by the first calculation unit. A second calculating unit for converting the obtained AC insulation resistance value into a DC insulation resistance value to obtain a DC insulation resistance value.
JP6272639A 1994-11-07 1994-11-07 Oil-filled transformer insulation diagnostic device Expired - Lifetime JP3041207B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6272639A JP3041207B2 (en) 1994-11-07 1994-11-07 Oil-filled transformer insulation diagnostic device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6272639A JP3041207B2 (en) 1994-11-07 1994-11-07 Oil-filled transformer insulation diagnostic device

Publications (2)

Publication Number Publication Date
JPH08136597A JPH08136597A (en) 1996-05-31
JP3041207B2 true JP3041207B2 (en) 2000-05-15

Family

ID=17516732

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6272639A Expired - Lifetime JP3041207B2 (en) 1994-11-07 1994-11-07 Oil-filled transformer insulation diagnostic device

Country Status (1)

Country Link
JP (1) JP3041207B2 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4270636B2 (en) * 1999-03-29 2009-06-03 株式会社日立国際電気 Resistivity meter
JP4515940B2 (en) * 2005-03-08 2010-08-04 日置電機株式会社 Insulation resistance tester
CN104714161B (en) * 2015-04-02 2017-11-10 兖州煤业股份有限公司 A kind of cable insulation data processing method
CN105305716B (en) * 2015-11-23 2018-01-12 国网山东济南市历城区供电公司 Main transformer annex integration temperature measuring equipment
JP6595355B2 (en) * 2016-01-26 2019-10-23 株式会社東芝 Magnetic core member deterioration diagnosis device, magnetic core member deterioration diagnosis method
CA3048995C (en) * 2016-12-31 2023-12-12 Abb Schweiz Ag Systems and methods for monitoring components in a power transformer or the like
CN110174137B (en) 2019-05-07 2020-06-19 西安交通大学 Monitoring method of transformer monitoring device based on non-electric quantity comprehensive characteristic information

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