JPH0342584A - Deciding system for insulation deterioration of electric power system - Google Patents
Deciding system for insulation deterioration of electric power systemInfo
- Publication number
- JPH0342584A JPH0342584A JP1177828A JP17782889A JPH0342584A JP H0342584 A JPH0342584 A JP H0342584A JP 1177828 A JP1177828 A JP 1177828A JP 17782889 A JP17782889 A JP 17782889A JP H0342584 A JPH0342584 A JP H0342584A
- Authority
- JP
- Japan
- Prior art keywords
- phase
- section
- zero
- power system
- current
- 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.)
- Pending
Links
- 238000009413 insulation Methods 0.000 title claims abstract description 52
- 230000006866 deterioration Effects 0.000 title claims abstract description 43
- 238000004891 communication Methods 0.000 abstract description 10
- 238000000034 method Methods 0.000 abstract description 9
- 230000015654 memory Effects 0.000 abstract description 7
- 230000035945 sensitivity Effects 0.000 abstract description 7
- 238000000819 phase cycle Methods 0.000 abstract 2
- 230000005611 electricity Effects 0.000 abstract 1
- 238000010183 spectrum analysis Methods 0.000 abstract 1
- 230000001131 transforming effect Effects 0.000 abstract 1
- 230000018199 S phase Effects 0.000 description 6
- 239000003990 capacitor Substances 0.000 description 5
- 238000001514 detection method Methods 0.000 description 5
- 238000004804 winding Methods 0.000 description 4
- 210000000988 bone and bone Anatomy 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 229910001219 R-phase Inorganic materials 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Landscapes
- Testing Relating To Insulation (AREA)
- Locating Faults (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は電力系統の絶縁劣化判定システムに係り、特に
、配電系統における絶縁劣化を判定するに好適な電力系
統の絶縁劣化判定システムに関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an insulation deterioration determination system for a power system, and more particularly to an insulation deterioration determination system for a power system suitable for determining insulation deterioration in a power distribution system.
電力系統のうち配電系統には地絡や線間短絡などの故障
を検知して線路を遮断する保護装置が設けられているが
、これらの保護装置が作動すると広範囲にわたって停電
となる。このため、ケーブル、変圧器、避雷器、碍子あ
るいは開閉器などの配電器材に故障が生じる恐れがある
箇所、すなわち絶縁劣化箇所を巡回などによって点検し
、配電器材が故障するのを未然に防止することがおこな
われている。Within the power system, distribution systems are equipped with protection devices that detect failures such as ground faults and short circuits between lines and shut off the lines, but when these protection devices are activated, it can cause widespread power outages. For this reason, it is necessary to patrol and inspect locations where there is a risk of failure in power distribution equipment such as cables, transformers, lightning arresters, insulators, or switches, that is, locations where insulation has deteriorated, in order to prevent failures of power distribution equipment. is being carried out.
しかし、配電器材は多品種かつ多量であるため、すべて
の器材を点検するには多くの人手がかかると共に、各器
材の隠蔽化が進んでいるため、器材の各部を十分に点検
することができない場合がある。そこで、故障の大部分
を占める地絡故障を未然に防止するために、各種の絶縁
劣化検出システムが提案されている。However, since there are many types and quantities of power distribution equipment, it takes a lot of manpower to inspect all the equipment, and each piece of equipment is increasingly hidden, making it impossible to fully inspect each part of the equipment. There are cases. Therefore, various insulation deterioration detection systems have been proposed in order to prevent ground faults, which account for the majority of failures.
例えば、特開昭６０−１３９１１８号公報に記載されて
いるように、機器の接地線に電流センサを取り付け、地
絡故障に至る前の洩れ電流信号などから劣化を検出する
方法が提案されている。しかし、面的な広がりをもって
構成されている配電系統のひとつひとつの機器に電流セ
ンサを取り付けることは相当な費用と労力を必要とする
。また、接地線に流れる電流には多くのノイズが含まれ
るため、場合によっては劣化を十分に検出できない場合
がある。For example, as described in Japanese Unexamined Patent Publication No. 139118/1984, a method has been proposed in which a current sensor is attached to the grounding wire of equipment and deterioration is detected from leakage current signals before a ground fault occurs. . However, attaching current sensors to each device in a power distribution system that spans a wide area requires considerable cost and effort. Furthermore, since the current flowing through the ground wire contains a lot of noise, deterioration may not be detected sufficiently in some cases.
また、特開昭５８−１３０７２３号公報、特開昭５８−
２０７８２０号公報に記載されているように、フィーダ
毎に零相電流を測定し、零相電流の大きさあるいは零相
電圧に対する位相から配電線の劣化を検出する方法が提
案されているが、これらの方法は、いずれもフィーダ単
位で零相電流を検出しているため、フィーダに沿って点
検する必要があり多くの人手が必要である。また零相電
流の大きさや信相の変化分を検出することにより対地静
電容量の不平衡などによって発生する零相電流の残留分
に起因するノイズの影響を低減するようにしているが、
この方法で３１、徐々に進展する配電線の劣化を十分に
検出できない場合がある。Also, JP-A-58-130723, JP-A-58-
As described in Japanese Patent No. 207820, a method has been proposed in which the zero-sequence current is measured for each feeder and deterioration of the distribution line is detected from the magnitude of the zero-sequence current or the phase with respect to the zero-sequence voltage. In both methods, the zero-sequence current is detected for each feeder, so it is necessary to inspect along the feeder, which requires a lot of manpower. In addition, by detecting the magnitude of the zero-sequence current and the amount of change in the signal phase, it is possible to reduce the influence of noise caused by the residual amount of the zero-sequence current caused by unbalanced ground capacitance.
With this method31, it may not be possible to sufficiently detect gradual deterioration of power distribution lines.
また特開昭５９−４６８６７号公報に記載されているよ
うに、フィーダに沿って複数の零相電流センサを設け、
各零相電流センサの検出による零相電流の不連続点から
Ｉｌ！ｌ縁劣化縁間化区間するようにしたものが提案さ
れている。しかし、この方法の場合にも、ノイズの影響
を受け、絶縁劣化を十分に検出できない場合がある。Furthermore, as described in Japanese Patent Application Laid-Open No. 59-46867, a plurality of zero-phase current sensors are provided along the feeder,
Il! from the discontinuity point of the zero-phase current detected by each zero-phase current sensor! A method has been proposed in which the edges are degraded and the edges are separated. However, even with this method, insulation deterioration may not be sufficiently detected due to the influence of noise.
さらに、上記従来技術においては、配電線に変圧器など
が接続されて配電線の対地静電容量が不平衡となり配電
線に零相電流の残留分が生じた場合、その影響を受けて
配電線の絶縁劣化を高感度で検出できない場合がある。Furthermore, in the above conventional technology, when a transformer or the like is connected to the distribution line and the ground capacitance of the distribution line becomes unbalanced, and a residual amount of zero-sequence current occurs in the distribution line, the distribution line Insulation deterioration may not be detected with high sensitivity.
本発明の目的は、電力系統における！！１ｍ劣化を残留
零相電流の影響を減少して高感度で検出することができ
る電力系統の絶縁劣化判定システムを提供することにあ
る。The purpose of the present invention is in the power system! ! An object of the present invention is to provide an insulation deterioration determination system for a power system that can detect 1 m deterioration with high sensitivity by reducing the influence of residual zero-sequence current.
前記目的を達成するために、本発明は、第１の判定シス
テムとして、電力系統の監視対象区間内あるいはこの区
間近傍の各相電圧を検出すると共に、監視対象区間両端
側でそれぞれ零相電流を検出し、両零相電流の差と各相
電圧とから監視対象区間内の各相の対地アドミタンスを
算出し、この算出値を基に監視対象区間における電力系
統の絶縁劣化を判定する電力系統の絶縁劣化判定システ
ムを構成したものである。In order to achieve the above object, the present invention, as a first determination system, detects each phase voltage in or near the monitored section of the power system, and detects zero-sequence current at both ends of the monitored section. The ground admittance of each phase in the monitored section is calculated from the difference between both zero-sequence currents and each phase voltage, and the insulation deterioration of the power system in the monitored section is determined based on this calculated value. This constitutes an insulation deterioration determination system.
第２の判定システムとして、電力系統の監視対象区間内
あるいはこの区間近傍の各相電圧を検出すると共に、監
視対象区間両端側でそれぞれ零相電流を検出し、両零相
電流の差と各相電圧とから監視対象区間内の各相の対地
アドミタンスを算出し、この算出値のうち対地アドミタ
ンスの抵抗弁から監視対象区間における電力系統の絶縁
劣化を判定する電力系統の絶縁劣化判定システムを構成
したものである。The second determination system detects the voltage of each phase within the monitored section of the power system or near this section, and also detects the zero-sequence current at both ends of the monitored section, and calculates the difference between both zero-sequence currents and each phase. We constructed an insulation deterioration determination system for power systems that calculates the ground admittance of each phase in the monitored section from the voltage and determines the insulation deterioration of the power system in the monitored section from the resistance valve of the ground admittance of this calculated value. It is something.
第３の判定システムとして、電力系統の監視対象区間内
あるいはこの区間近傍の各相電圧を検出すると共に、監
視対象区間両端側でそれぞれ零相電流を検出し、両零相
電流の差と各相電圧とから監視対象区間内の各相の対地
アドミタンスを算出し、この算出値のうち対地アドミタ
ンスの抵抗弁から監視区間における電力系統の絶縁劣化
を判定する電力系統の絶縁劣化判定システムを構成した
ものである。The third determination system detects the voltage of each phase within the monitored section of the power system or near this section, and also detects the zero-sequence current at both ends of the monitored section, and calculates the difference between both zero-sequence currents and each phase. A power system insulation deterioration determination system that calculates the ground admittance of each phase in the monitored section from the voltage and determines the insulation deterioration of the power system in the monitored section from the resistance valve of the ground admittance of this calculated value. It is.
第１、第２または第３の判定システムを含む第４の判定
システムとして、各相電圧の検出値から各相電圧の周波
数成分のうち相数に対応した周波数成分の絶対値と位相
を求め、各周波数成分の絶対値と位相及び各周波数成分
に対する両零相電流の差を基に監視対象区間内の各相の
対地アドミタンスを算出する電力系統の絶縁劣化判定シ
ステムを構成したものである。A fourth determination system including the first, second, or third determination system determines the absolute value and phase of the frequency component corresponding to the number of phases among the frequency components of each phase voltage from the detected value of each phase voltage, This system constitutes an insulation deterioration determination system for a power system that calculates the ground admittance of each phase within a monitored section based on the absolute value and phase of each frequency component and the difference between both zero-sequence currents for each frequency component.
第５の判定システムとして、電力系統の監視対象区間内
あるいはこの区間近傍の各相電圧を検出すると共に、監
視対象区間両端側の各相電流をそれぞれ検出し、この検
出値から各相電流の差をそれぞれ求め、各相電流の差と
各相電圧とを基に監視対象区間内の各相の対地アドミタ
ンスを算出し、この算出値から監視対象区間における電
力系統の絶縁劣化を判定する電力系統の絶縁劣化判定シ
ステムを構成したものである。As a fifth judgment system, each phase voltage in or near the monitored section of the power system is detected, and each phase current at both ends of the monitored section is detected, and the difference between each phase current is determined based on the detected value. The ground admittance of each phase in the monitored section is calculated based on the difference in each phase current and each phase voltage, and from this calculated value, the power system's insulation deterioration in the power system in the monitored section is determined. This constitutes an insulation deterioration determination system.
電力系統の地絡故障は対地絶縁抵抗の低下によって発生
するため、対地静電容量の不平衡によって零相電流の残
留分が発生しても、各相の対地アドミタンスを算出すれ
ば、対地アドミタンスのうち容量分は残留分に関係する
が、抵抗弁は残留分に関係しないため、電力系統の絶縁
劣化を高感度で検出することができる。Ground faults in power systems occur due to a drop in insulation resistance to ground, so even if a residual zero-sequence current occurs due to unbalanced ground capacitance, calculating the ground admittance of each phase will reduce the ground admittance. The capacitance part is related to the residual part, but the resistance valve is not related to the residual part, so insulation deterioration in the power system can be detected with high sensitivity.
また対地アドミタンスのうち抵抗弁あるいは抵抗弁を流
れる電流を求めれば、電力系統の絶縁劣化をさらに高感
度で検出することができる。In addition, by determining the resistance valve or the current flowing through the resistance valve in the ground admittance, insulation deterioration in the power system can be detected with even higher sensitivity.
以下、本発明の一実施例を図面に基づいて説明する。 Hereinafter, one embodiment of the present invention will be described based on the drawings.
第を図において、配電変電所１に設置された変圧器２に
は他の電力系統からの電力が供給されており、この電力
が変圧器２を介して三相の給電線３に供給されている。In the figure, a transformer 2 installed in a distribution substation 1 is supplied with power from another power system, and this power is supplied to a three-phase feeder line 3 via the transformer 2. There is.
この給電線３には接地変圧器４が接続されていると共に
三相のフィーダ（配電線）１２，１３．１４が接続され
ている。接地変圧器４は中性線が接地されたＹ結線の一
次巻線５とＹ結線の二次巻線６と開放Δ結線の三次巻線
７より構成されており、二次巻線６の出力がプリアンプ
８に接続されている。このプリアンプ８は低域フィルタ
９．Ａ／Ｄ変換器１０を介してコンピュータ１１に接続
されている。すなわち二次巻線６の相電圧がプリアンプ
８によって検出され、検出された相電圧がディジタルデ
ータとしてコンピュータ１１に入力されるようになって
いる。A grounding transformer 4 is connected to this power supply line 3, and three-phase feeders (distribution lines) 12, 13, and 14 are also connected thereto. The grounding transformer 4 is composed of a Y-connected primary winding 5 whose neutral wire is grounded, a Y-connected secondary winding 6, and an open delta-connected tertiary winding 7. is connected to preamplifier 8. This preamplifier 8 has a low-pass filter 9. It is connected to a computer 11 via an A/D converter 10. That is, the phase voltage of the secondary winding 6 is detected by the preamplifier 8, and the detected phase voltage is input to the computer 11 as digital data.
またフィーダ１２，１３．１４の配電変電所１出口側に
は零相電流センサ１５ａ、１６ａ。Further, zero-phase current sensors 15a, 16a are provided on the distribution substation 1 exit side of the feeders 12, 13, 14.
１７ａが設けられており、各センサの検出出力がプリア
ンプ２０、低域フィルタ２１、Ａ／Ｄ変換器２２を介し
てコンピュータ１１へ供給されるようになっている。す
なわちフィーダ１２，１３゜１４の配電変電所１出口側
における零相電流に関するデータがプリアンプ２０、低
域フィルタ２１、Ａ／Ｄ変換器２２を介してディジタル
データとしてコンピュータ１１へ供給されるようになっ
ている。なお、プリアンプ２０、低域フィルタ２１、Ａ
／Ｄ変換器２２についてはフィーダ１４についてのみ図
示されている。17a is provided, and the detection output of each sensor is supplied to the computer 11 via a preamplifier 20, a low-pass filter 21, and an A/D converter 22. That is, data regarding the zero-sequence current at the outlet side of the distribution substation 1 of the feeders 12, 13, 14 is supplied to the computer 11 as digital data via the preamplifier 20, the low-pass filter 21, and the A/D converter 22. ing. In addition, the preamplifier 20, the low-pass filter 21, and the A
The /D converter 22 is shown only for the feeder 14.
またフィーダ１２，１３．１４は複数の監視対象区間に
分割されており、各区間の端部には零相電流センサ１５
ａ、１５ｂ、１５ｃ、１６ａ。In addition, the feeders 12, 13, and 14 are divided into a plurality of monitoring target sections, and a zero-phase current sensor 15 is installed at the end of each section.
a, 15b, 15c, 16a.
１６ｂ、１６ｃ、１７ａ、１７ｂ、１７ｃが設けられて
いる。そして零相電流センサのうち１５ｂ。16b, 16c, 17a, 17b, and 17c are provided. And 15b of the zero-phase current sensors.
１５ｃ、１６ｂ、１６ｃ、１７ｂ、１７ｃは多入力アン
プ２３、低域フィルタ２４、Ａ／Ｄ変換器２５、メモリ
２６を介して通信端末２７に接続されるようになってい
る。またフィーダ１２，１３゜１４の各監視対象区間に
はコンデンサ分圧器１８が設けられており、コンデンサ
分圧器１８の出力が多入力アンプ２３に供給されている
。コンデンサ分圧器１８の出力信号は各フィーダ１２，
１３゜１４の相電圧の信号として多入力アンプ２３に入
力されている。そして各フィーダ１２，１３゜１４の各
相電圧及び零相電流に関する情報がディジタル情報とし
てメモリ２６に格納され、これらのデータが通信端末２
７、通信回線２８を介してコンピュータ１１へ転送され
るようになっている。15c, 16b, 16c, 17b, and 17c are connected to a communication terminal 27 via a multi-input amplifier 23, a low-pass filter 24, an A/D converter 25, and a memory 26. Further, a capacitor voltage divider 18 is provided in each monitoring target section of the feeders 12, 13 and 14, and the output of the capacitor voltage divider 18 is supplied to a multi-input amplifier 23. The output signal of the capacitor voltage divider 18 is transmitted to each feeder 12,
The signal is input to the multi-input amplifier 23 as a signal with a phase voltage of 13°14. Information regarding each phase voltage and zero-sequence current of each feeder 12, 13, 14 is stored as digital information in the memory 26, and these data are transmitted to the communication terminal 2.
7. The data is transferred to the computer 11 via the communication line 28.
なお、コンデンサ分圧器１８を各監視対象区間内に設け
なくても、フィーダ１２，１３．１４の各相電圧を検出
することは可能である。Note that it is possible to detect each phase voltage of the feeders 12, 13, and 14 without providing the capacitor voltage divider 18 in each monitoring target section.
フィーダ１２，１３．１４を複数の監視対象区間に分割
すると、各区間における対地間の等倍回路が第２図のよ
うに表わされる。すなわち、各相の対地間定数が対地絶
縁抵抗３０と対地静電容量３１の並列回路から構成され
、例えばＲ相の対地アドミタンス、対地絶縁抵抗及び対
地静電容量をそれぞれＹｒ、Ｒｒ、Ｃｒとすると、次式
が成立する。When the feeders 12, 13, and 14 are divided into a plurality of sections to be monitored, the equal-magnification circuit between the ground and the ground in each section is represented as shown in FIG. That is, the ground constant of each phase is composed of a parallel circuit of a ground insulation resistance 30 and a ground capacitance 31, and for example, if the ground admittance, ground insulation resistance, and ground capacitance of the R phase are Yr, Rr, and Cr, respectively. , the following equation holds.
Ｙ ｒ ＝ ＋ ｊωＣｒ ・・
・・・・ （１）Ｒｒ
ここで、ω：角周波数
（１）式において、実数部が定常値よりも僅かに大きく
なった状態、すなわちＲｒが小さくなった状態がフィー
ダの劣化状態である。そこで１本実施例においては、各
相の対地アドミタンスＹｒのうち対地絶縁抵抗Ｒｒを直
接求めてフィーダー２，１３．１４の劣化を判定するよ
うにしたものである。以下、この判定処理、を第３図の
フローチャートに基づいて説明する。Y r = + jωCr ・・
(1) Rr Here, ω: angular frequency In equation (1), a state in which the real part becomes slightly larger than the steady value, that is, a state in which Rr becomes small, is a deteriorated state of the feeder. Therefore, in this embodiment, the deterioration of the feeders 2, 13, and 14 is determined by directly determining the ground insulation resistance Rr of the ground admittance Yr of each phase. This determination process will be explained below based on the flowchart of FIG.
まず第３図において、零相電流センサー５ａ。First, in FIG. 3, the zero-phase current sensor 5a.
１６ａ、１７ａの出力を取り込み、配電変電所１出口側
の零相電流Ｉｏに関する時系列データをコンピューター
１に取り込み、各フィーダー２゜１３．１４の零相電流
■０の大きさ及び方向を比較し、零相電流工０の方向が
平常値と異なりかつその大きさが設定レベルを越えたか
否かの判定をおこなう（ステップＳｌ、Ｓ２．Ｓ３）、
零相電流ＩＯの検出値が設定値を越えてないときには、
前述した処理を継続しておこない、検出値が設定値を越
えたときには各通信端末２７を通してホールド信号を出
力し、各区間のメモリ２６の内容をホールドさせる（ス
テップＳ４）。この後各区間のメモリ２６にホールドさ
れたメモリ２６の内容を通信端末２７、通信回線２８を
介してコンピュータ１１へ伝送する（ステップＳ５）。16a and 17a, time-series data regarding the zero-sequence current Io on the outlet side of the distribution substation 1 is imported into the computer 1, and the magnitude and direction of the zero-sequence current Io of each feeder 2゜13.14 is compared. , determine whether the direction of the zero-sequence current generator 0 differs from the normal value and its magnitude exceeds the set level (steps Sl, S2, S3);
When the detected value of zero-sequence current IO does not exceed the set value,
The above-described processing is continued, and when the detected value exceeds the set value, a hold signal is output through each communication terminal 27 to hold the contents of the memory 26 in each section (step S4). Thereafter, the contents of the memory 26 held in the memory 26 of each section are transmitted to the computer 11 via the communication terminal 27 and the communication line 28 (step S5).
コンピュータ１１は各通信端末２７から伝送されてきた
時系列データを周波数スペクトル分析し。The computer 11 analyzes the frequency spectrum of time series data transmitted from each communication terminal 27.
周波数ごとに總対値と位相を求める処理をおこなう。そ
してこれらの処理結果を基に、ステップＳ７．Ｓ８，８
９において、対地絶縁抵抗及び対地静電容量を求める処
理をおこなう。Processing is performed to obtain the pairwise value and phase for each frequency. Based on these processing results, step S7. S8,8
In step 9, processing for determining the ground insulation resistance and ground capacitance is performed.
ここで、本実施例においては、フィーダ１２゜１３．１
４の各相の電流を検出する代りに、零相電流を求めてい
るため、スペクトル分析された周波数成分のうち相数に
対応した３点の周波数ｆ ｔ？ｆ、、ｆ、を選択し、さ
らに各監視対象区間両端側における零相電流の差及び各
相電圧を各周波数に対応づけて求めることとしている。Here, in this embodiment, the feeder 12°13.1
Since the zero-sequence current is obtained instead of detecting the current of each phase of 4, the frequency f t? of three points corresponding to the number of phases among the spectrum-analyzed frequency components is calculated. f,, f, are selected, and the difference in zero-sequence current and each phase voltage on both ends of each monitored section are determined in association with each frequency.
なお、零相電流や各相電圧には電源周波数の基本周波数
及びその整数倍の高調波が含まれているため、これらの
周波数から任意の周波数を３点選択することは可能であ
る。Note that since the zero-phase current and each phase voltage include the fundamental frequency of the power supply frequency and harmonics that are integral multiples thereof, it is possible to select three arbitrary frequencies from these frequencies.
ここで選択した３つの角周波数をω１．ω２゜ω、とす
ると、これらの周波数に応じた零相電流の差電流は次の
（２）式によって表わされる。The three angular frequencies selected here are ω1. Assuming ω2°ω, the difference current of the zero-sequence current according to these frequencies is expressed by the following equation (2).
Ｉ ｄ （ｎ）−Ｌｔ （ｎ） Ｉ。２ （ｎ）
・＝ （２）ここで、ｎ＝１．２．３
Ｉ、８．Ｉ。２：それぞれ区間両端の零相電流センサの
添字（ｎ）は選択された周波数に対応する。I d (n)-Lt (n) I. 2 (n)
・= (2) Here, n=1.2.3 I, 8. I. 2: The subscripts (n) of the zero-phase current sensors at both ends of each section correspond to the selected frequency.
（２）式により各監視対象区間の対地アドミタンスを通
してグランド側に流れ込む各相電流の総和が求められ、
他の区間の影響を取り除くことができる。これは、各区
間でその両端側の零相電流を基に、差電流を求めている
ためである。さらにＲ相、Ｓ相、Ｔ相の対地電流Ｉｒ、
Ｉｓ、Ｉｔは＋Ｉｔとなる。ここで、Ｙｒ、÷ｓ、Ｙｔ
はそれぞれＲ相、Ｓ相及びＴ相の区間内対地アドミタン
スである。従って、Ｉｄは次の式によって表わされる。Using equation (2), the sum of each phase current flowing into the ground side through the ground admittance of each monitored section is calculated,
The influence of other sections can be removed. This is because the difference current is calculated based on the zero-sequence currents at both ends of each section. Furthermore, the ground current Ir of the R phase, S phase, and T phase,
Is and It become +It. Here, Yr, ÷s, Yt
are the in-section ground admittances of the R phase, S phase, and T phase, respectively. Therefore, Id is expressed by the following formula.
Ｉｄ＝ＹｒＶｒ＋ＹｓＶｓ＋ＹｔＶｔ−（３）土ｄ：ｉ
。、とｉ、、２の差電流
（３）式は、周波数分析された結果についても成立する
ため、選択された３つの周波数について次式が成立する
。Id=YrVr+YsVs+YtVt-(3) Sat d:i
. , and i, , 2, the equation (3) holds true for the results of frequency analysis, so the following equation holds true for the three selected frequencies.
Ｖｒ、Ｖｓ、Ｖｔ ：それぞれの区間または区間近傍の
Ｒ相、Ｓ相及びＴ相の電圧
一般に、対地絶縁抵抗や対地静電容量は周波数に対して
一定であるため、例えば（４）式のＹｒ（１）、 Ｙ
ｒ（２）、 Ｙ ｒ（３）等は次式で表わされる。Vr, Vs, Vt: R-phase, S-phase, and T-phase voltages in each section or in the vicinity of the section Generally, ground insulation resistance and ground capacitance are constant with respect to frequency, so for example, Yr in equation (4) (1), Y
r(2), Y r(3), etc. are expressed by the following formula.
Ｒｒ ここで、ｊは虚数単信を表わす。Rr Here, j represents a simple imaginary number.
Ｒｒ、Ｒｓ、Ｒｔ ：それぞれＲ相、Ｓ相及びＴ相の区
間内対地絶縁抵抗
Ｃｒ、Ｃｓ、Ｃｔ ：それぞれＲ相、Ｓ相及びＴ相の区
間内対地静電容量
（５）式と同様な式が、Ｓ相及びＴ相についても成立し
、これらの式を（４）式に代入して、実数部と虚数部に
分けると次式が成立する。Rr, Rs, Rt: Insulation resistance to ground within the section of R phase, S phase and T phase, respectively Cr, Cs, Ct: Capacitance to ground within the section of R phase, S phase and T phase, respectively Same as formula (5) The equations also hold true for the S phase and the T phase, and when these equations are substituted into equation (4) and divided into a real part and an imaginary part, the following equation holds true.
・・・ （６）
ここで、実数部と虚数部をそれぞれの記号右上につけた
ダッシュの本数で区別する。例えばＩｄ（１）の実数部
と虚数部はそれぞれＩｄ’（１）。... (6) Here, the real part and the imaginary part are distinguished by the number of dashes added to the upper right of each symbol. For example, the real part and imaginary part of Id(1) are each Id'(1).
Ｉｄ”（１）のように表わされる。（６）式を簡単のた
めに次のように表わす。Id” (1).Equation (6) is expressed as follows for simplicity.
１”Ｉｏｌ ＝ ［Ｖ］［Ｙ］ ・・・（
７）（７）式で［Ｖ］の逆マトリクスを左から乗するこ
とによって［Ｙ］、すなわち各相の対地絶縁抵抗の逆数
及び対地静電容量が次式で求められる。1” Iol = [V] [Y] ... (
7) By multiplying the inverse matrix of [V] from the left in equation (7), [Y], that is, the reciprocal of the ground insulation resistance and the ground capacitance of each phase, can be obtained by the following equation.
［Ｙ］ ＝ ［■］ ［ＩＤ］ ・・
・ （８）ステップＳ９までの処理によって対地絶縁抵
抗が求められた後は、各区間の対地絶縁抵抗に関するデ
ータベースを呼び出し、以前に算出された抵抗値と現時
点の抵抗値を第４図に示されるようなトレンドカーブで
表示する。このトレンドカーブで示された絶縁抵抗値の
推移、傾きなどから総合的に絶縁劣化の危険度や区間の
判定をおこなう。[Y] = [■] [ID] ・・
- (8) After the ground insulation resistance has been determined through the processing up to step S9, the database regarding the ground insulation resistance of each section is called up, and the previously calculated resistance value and the current resistance value are shown in Figure 4. It is displayed as a trend curve like this. The risk of insulation deterioration and the area are determined comprehensively based on the transition and slope of the insulation resistance value shown in this trend curve.
そして絶縁劣化の疑いがあるときには該当区間に対する
点検指令の表示をおこない、ステップＳ１の処理に戻る
。If insulation deterioration is suspected, an inspection command for the corresponding section is displayed, and the process returns to step S1.
一方、絶縁劣化の疑いがないときには、算出された絶縁
抵抗値に関するデータをデータベースに格納しステップ
Ｓ１の処理に戻る。On the other hand, if there is no suspicion of insulation deterioration, data regarding the calculated insulation resistance value is stored in the database and the process returns to step S1.
このように本実施例においては、各区間の各相の対地ア
ドミタンスの抵抗値を直接求めるようにしたため、零相
電流の残留分によるノイズの影響を受けることなくフィ
ーダの絶縁劣化を高感度で検出することが可能となる。In this way, in this example, the resistance value of the ground admittance of each phase in each section is directly determined, so feeder insulation deterioration can be detected with high sensitivity without being affected by noise due to residual zero-sequence current. It becomes possible to do so.
また、対地アドミタンスの抵抗骨を直接求める代りに、
対地アドミタンスの容量分と各相電圧とから各区間の容
量分を流れる電流を求め、この電流と零相電流の差を示
す電流との偏差から各区間の抵抗骨を流れる電流を求め
、この電流仏からフィーダの絶縁劣化を判定することも
可能である。Also, instead of directly finding the resistance bone of ground admittance,
Find the current flowing through the capacitance of each section from the capacitance of the ground admittance and each phase voltage, find the current flowing through the resistor bones of each section from the deviation between this current and the current that indicates the difference between the zero-sequence current, and calculate the current flowing through the resistor bones of each section. It is also possible to determine the insulation deterioration of the feeder from the sensor.
また、各フィーダの相毎に相電流を検出する相電流検出
センサを設け、各センサの検出値から各相電流の差を求
め、各相電流の差と各相電圧とから、各区間の各相にお
ける対地アドミタンスを算出することも可能である。In addition, a phase current detection sensor is provided to detect the phase current for each phase of each feeder, and the difference in each phase current is determined from the detection value of each sensor. From the difference in each phase current and each phase voltage, each It is also possible to calculate the ground admittance at the phase.
以上説明したように１本発明によれば、監視対象区間内
の各相の対地アドミタンスを求め、この算出値を基に監
視対象区間における電力系統の絶縁劣化を判定するよう
にしたため、電力系統に対地静電容量の不平衡に伴う零
相電流の残留分が生じても、零相電流の残留分による影
響を受けることなく電力系統の絶縁劣化を高感度で検出
することができ、検出精度の向上に寄与することができ
る。As explained above, according to the present invention, the ground admittance of each phase within the monitored section is determined, and insulation deterioration of the power system in the monitored section is determined based on this calculated value. Even if residual zero-sequence current occurs due to unbalanced ground capacitance, insulation deterioration in power systems can be detected with high sensitivity without being affected by the residual zero-sequence current, and detection accuracy can be improved. can contribute to improvement.
第１図は本発明の一実施例を示す構成図、第２図は監視
対象区間の等価回路図、第３図は第１図に示すシステム
の作用を説明するためのフローチャート、第４図は時間
と絶縁抵抗値との関係を示す線図である。
１・・・配電変電所、２・・・変圧器、３・・・給電線
、８．２０．２３・・・プリアンプ、
９．２１．２４・・・低域フィルタ、
１０．２２，２５・・・Ａ／Ｄ変換器、１１・・・コン
ピュータ、
１２．１３．１４・・・フィーダ、
１５ａ、１５ｂ、１５ｃ、１６ａ、１６ｂ。
１６ ｃ 、 １７ ａ 、 １７ ｂ 、 ｌ ７
ｃ −零相電流センサ、１８・・・コンデンサ分圧器、
２６・・・メモリ、２７・・・通信端末。Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is an equivalent circuit diagram of the monitored section, Fig. 3 is a flowchart for explaining the operation of the system shown in Fig. 1, and Fig. 4 is FIG. 3 is a diagram showing the relationship between time and insulation resistance value. 1... Distribution substation, 2... Transformer, 3... Feeder line, 8.20.23... Preamplifier, 9.21.24... Low pass filter, 10.22, 25. ... A/D converter, 11... Computer, 12.13.14... Feeder, 15a, 15b, 15c, 16a, 16b. 16 c, 17 a, 17 b, l 7
c - Zero-phase current sensor, 18... capacitor voltage divider,
26...Memory, 27...Communication terminal.
Claims (1)
各相電圧を検出すると共に、監視対象区間両端側でそれ
ぞれ零相電流を検出し、両零相電流の差と各相電圧とか
ら監視対象区間内の各相の対地アドミタンスを算出し、
この算出値を基に監視対象区間における電力系統の絶縁
劣化を判定する電力系統の絶縁劣化判定システム。 ２、電力系統の監視対象区間内あるいはこの区間近傍の
各相電圧を検出すると共に、監視対象区間両端側でそれ
ぞれ零相電流を検出し、両零相電流の差と各相電圧とか
ら監視対象区間内の各相の対地アドミタンスを算出し、
この算出値のうち対地アドミタンスの抵抗分から監視対
象区間における電力系統の絶縁劣化を判定する電力系統
の絶縁劣化判定システム。 ３、電力系統の監視対象区間内あるいはこの区間近傍の
各相電圧を検出すると共に、監視対象区間両端側でそれ
ぞれ零相電流を検出し、両零相電流の差と各相電圧とか
ら監視対象区間内の各相の対地アドミタンスを算出し、
この算出値のうち対地アドミタンスの容量分と各相電圧
から監視対象区間の容量分を流れる電流を求め、この電
流と前記両零相電流の差を示す電流との偏差から監視対
象区間内の抵抗分を流れる電流を求め、この電流値から
監視対象区間における電力系統の絶縁劣化を判定する電
力系統の絶縁劣化判定システム。４、各相電圧の検出値
から各相電圧の周波数成分のうち相数に対応した周波数
成分の絶対値と位相とを求め、各周波数成分の絶対値と
位相及び各周波数成分に対する両零相電流の差を基に監
視対象区間内の各相の対地アドミタンスを算出する請求
項１、２又は３記載の電力系統の絶縁劣化判定システム
。 ５、電力系統の監視対象区間内あるいはこの区間近傍の
各相電圧を検出すると共に、監視対象区間両端側の各相
電流をそれぞれ検出し、この検出値から各相電流の差を
それぞれ求め、各相電流の差と各相電圧とを基に監視対
象区間内の各相の対地アドミタンスを算出し、この算出
値から監視対象区間における電力系統の絶縁劣化を判定
する電力系統の絶縁劣化判定システム。[Claims] 1. Detect each phase voltage in or near the monitored section of the power system, and also detect the zero-sequence current at both ends of the monitored section, and calculate the difference between both zero-sequence currents and each phase voltage. Calculate the ground admittance of each phase within the monitored section from the phase voltage,
A power system insulation deterioration determination system that determines the power system insulation deterioration in the monitored section based on this calculated value. 2. Detect each phase voltage within the monitored section of the power system or near this section, and also detect the zero-sequence current at both ends of the monitored section, and determine the monitored target from the difference between both zero-sequence currents and each phase voltage. Calculate the ground admittance of each phase in the section,
A power system insulation deterioration determination system that determines the power system insulation deterioration in the monitored section based on the ground admittance resistance of this calculated value. 3. Detect each phase voltage within the monitored section of the power system or near this section, and also detect the zero-sequence current at both ends of the monitored section, and determine the monitored target from the difference between both zero-sequence currents and each phase voltage. Calculate the ground admittance of each phase in the section,
From this calculated value, calculate the current flowing through the capacitance of the monitored section from the ground admittance capacitance and each phase voltage, and calculate the resistance within the monitored section from the deviation between this current and the current indicating the difference between the two zero-sequence currents. A power system insulation deterioration determination system that calculates the current flowing through the area and determines the insulation deterioration of the power system in the monitored section from this current value. 4. Find the absolute value and phase of the frequency component corresponding to the number of phases among the frequency components of each phase voltage from the detected value of each phase voltage, and calculate the absolute value and phase of each frequency component and both zero-sequence currents for each frequency component. 4. The power system insulation deterioration determination system according to claim 1, 2 or 3, wherein the ground admittance of each phase within the monitored section is calculated based on the difference between the two. 5. Detect the voltage of each phase in or near the monitored section of the power system, and also detect the current of each phase at both ends of the monitored section, calculate the difference between the currents of each phase from the detected values, and A power system insulation deterioration determination system that calculates the ground admittance of each phase in a monitored section based on the difference in phase current and each phase voltage, and determines the insulation deterioration of the power system in the monitored section from this calculated value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1177828A JPH0342584A (en) | 1989-07-10 | 1989-07-10 | Deciding system for insulation deterioration of electric power system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1177828A JPH0342584A (en) | 1989-07-10 | 1989-07-10 | Deciding system for insulation deterioration of electric power system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0342584A true JPH0342584A (en) | 1991-02-22 |
Family
ID=16037819
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1177828A Pending JPH0342584A (en) | 1989-07-10 | 1989-07-10 | Deciding system for insulation deterioration of electric power system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0342584A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114924162A (en) * | 2022-04-18 | 2022-08-19 | 云南电网有限责任公司电力科学研究院 | Insulation state detection method and system for distribution line |
-
1989
- 1989-07-10 JP JP1177828A patent/JPH0342584A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114924162A (en) * | 2022-04-18 | 2022-08-19 | 云南电网有限责任公司电力科学研究院 | Insulation state detection method and system for distribution line |
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